Patent Publication Number: US-9905348-B2

Title: Electromagnetic operating device

Description:
TECHNICAL FIELD 
     The present invention relates to an electromagnetic operating device used as an operating mechanism of a switch device such as a circuit breaker. Furthermore, the present invention relates to an electromagnet device utilized for an operating mechanism of a switch device such as a circuit breaker and a switch device using the electromagnet device. 
     BACKGROUND ART 
     Generally, driving of an electromagnetic operating device is configured such that a capacitor that stores electric power which is for exciting an electromagnetic coil of an electromagnet and a control board that controls the energization direction of a current to be supplied from the capacitor to the electromagnetic coil in response to a closing command or a command of opening contacts (hereinafter, referred to as an “open-contact command”) to a switch device are provided, a movable core is driven by exciting the electromagnetic coil by the electric power stored in the capacitor to open or close contacts of the switch device by the driving force of the movable core. 
     As the conventional electromagnetic operating device equipped with a circuit that operates the switch device by the control board, there is disclosed a configuration which is equipped with, for example, an alternating current (AC)/direct current (DC) converter, a charging circuit, a control logic portion, and a discharging circuit; the discharging circuit has a field effect transistor (FET), a relay contact, and the like as a main control means; and the capacitor is connected to the electromagnetic coil. Opening/closing operation of the switch device is performed by energization to the electromagnetic coil; and opening/closing is controlled by an energization direction to the electromagnetic coil. Electric power charged to the capacitor through the charging circuit is energized to the electromagnetic coil; the energization direction is controlled by the relay contact; and ON/OFF of the energization to the electromagnetic coil is controlled by ON/OFF of the FET (for example, see Patent Document 1). 
     Furthermore, in an electromagnet device for use in the conventional switch device, a movable portion of the electromagnet device is composed of: a non-magnetic driving shaft that passes through the center of an opening of flat plates provided on both ends in a movable direction; a columnar movable core serving as a magnetic substance of bulk (mass) fixed by being fitted onto the driving shaft; and a disk movable core serving as a magnetic substance, which is arranged on the upper side of the magnetic substance via a thin sheet serving as a magnetic member and is fixed to the driving shaft. The columnar movable core and the disk movable core are fixed to the driving shaft by screwing or a stopper. A fixing process is applied to the driving shaft and an outer diameter dimension is different according to a position. A fixed core is configured by a steel pipe, a flat plate, and a cylinder (for example, see Patent Document 2). 
     Moreover, in order to protect facilities by instantaneously interrupting a short-circuit fault current and/or an abnormal current, the switch device is used for electric facilities and electric power facilities. 
     There are disclosed an electromagnet device and a switch device using the electromagnet device in order to prolong the life thereof and to save spaces, the electromagnet device including: an electromagnet which is excited during closing contacts (hereinafter, referred to as “during close-contact”) to operate a movable core; a driving shaft which is fixed by passing through the movable core and whose lower end is coupled to the other end of a spindle lever; an open-contact spring which is provided on the upper end of the driving shaft and biases the driving shaft in an interruption direction; and a cushioning device which is provided on an upper part of the driving shaft and with which the upper end of the driving shaft during close-contact comes in contact (for example, see Patent Document 3). 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: JP-A-2004-152628 (Pages 11 and 12, FIG. 10) 
     Patent Document 2: JP-A-2006-222438 
     Patent Document 3: JP-A-H8-64057 (Paragraphs [0009] to [0015], FIG. 1) 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In the electromagnetic control device (electromagnetic operating device) operated by the control board and the electromagnetic coil as shown in Patent Document 1, a large number of components such as a semiconductor element and a switching relay are used in the control board portion and the number of components is increased; and accordingly, failure probabilities of the semiconductor element and the respective components are accumulated to become higher in failure probability of the entire electromagnetic operating device. As a result, a problem exists in that reliability of the switch device which is opening/closing-driven by the electromagnetic operating device is deteriorated. 
     In the switch device using the electromagnet device as shown in the aforementioned conventional Patent Document 2, the electromagnet device is manufactured by designing: the columnar movable core; the disk movable core; the driving shaft; and the steel pipe, the flat plate, and the cylinder of the fixed core according to operating force necessary for the switch device of each rating with respect to a plurality of ratings. Accordingly, a problem exists in that standardization of the components of the electromagnet device cannot be achieved. 
     In the disclosed invention of Patent Document 3, the cushioning device which is for reducing impacts on the close-contact side is provided on the upper side of the driving shaft; and accordingly, a problem exists in that the entire device cannot be reduced in size. 
     The present invention has been made to solve the above described problem, and an object of the present invention is to provide an electromagnetic operating device that enhances reliability by a simple configuration. 
     Another object of the present invention is to reduce costs in an electromagnet device by standardizing the shape of a movable core and a fixed core with respect to a plurality of ratings and to reduce in size of the whole of a switch device using the electromagnet device. 
     A further object of the present invention is to provide an electromagnet device which is equipped with a cushioning device that reduces impacts during the completion of close-contact and open-contact operation and to achieve a reduction in size of the entire device. 
     Means for Solving the Problems 
     According to the present invention, there is provided an electromagnetic operating device including: a fixed core; a movable core movably configured with respect to the fixed core; an electromagnetic coil which moves the movable core by excitation to open or close a switch device coupled to the movable core; and a driving power supply that supplies electric power to the electromagnetic coil. The driving power supply is composed of: a capacitor power supply which performs opening/closing operation of the switch device in a normal time, and has a capacitor that stores electric power to be supplied to the electromagnetic coil and a control board that controls a current to be supplied from the capacitor to the electromagnetic coil in response to an open-contact or close-contact command to the switch device; and a DC power supply which performs opening/closing operation of the switch device in an emergency at which the capacitor power supply does not operate and directly supplies DC electric power to the electromagnetic coil. The electromagnetic operating device includes switching means which switches between a circuit to be connected from the capacitor power supply to the electromagnetic coil and a circuit to be connected from the DC power supply to the electromagnetic coil. Then, the switching means is attachably and detachably connected by the connecting means inserted in the middle of the circuit to be connected from the capacitor power supply to the electromagnetic coil, and switches from the circuit on the capacitor power supply side to the circuit on the DC power supply side in the emergency at which the capacitor power supply does not operate. 
     According to the present invention, there is provided an electromagnet device including: a fixed core configured by laminating a plurality of magnetic substance sheets; a movable core which is configured by laminating a plurality of magnetic substance sheets and moves backward and forward in the fixed core; an electromagnetic coil provided on the fixed core; and a driving shaft arranged in a central portion of the movable core. The driving shaft passes through a central portion of the movable core and is configured as one shaft body coupled to the movable core by a coupling member on a connection portion of the movable core; and the shaft diameter of the connection portion of the driving shaft has a shaft diameter different from the shaft diameter of other portion of the driving shaft. 
     Furthermore, in a switch device including: a switch main body portion having a fixed contact and a movable contact capable of being connected to and separated from the fixed contact; and an electromagnet device which is coupled to the movable contact of the switch main body portion via a coupling device and makes the movable contact connect to and separate from the fixed contact, the electromagnet device uses the electromagnet device as set forth in the above-mentioned means. 
     Moreover, according to the present invention, there is provided an electromagnet device including: a fixed core; a movable core arranged in face-to-face relation to the fixed core; a driving shaft fixed by passing through the movable core; an electromagnetic coil that displaces the movable core along the center axis of the driving shaft by flowing a current; an isolating spring to be biased to displace the movable core in a direction to be separated from the fixed core along the center axis of the driving shaft; and a cushioning device that reduces impacts during the completion of the displacement of the movable core. The cushioning device is of a structure in which a cushioning body portion is provided on the driving shaft and a cushioning chamber to be fitted to the cushioning body portion is provided. 
     In addition, according to the present invention, there is provided an electromagnet device including: a fixed core; a movable core arranged in face-to-face relation to the fixed core; a driving shaft fixed by passing through the movable core; an electromagnetic coil that displaces the movable core along the center axis of the driving shaft by flowing a current; an isolating spring to be biased to displace the movable core in a direction to be separated from the fixed core along the center axis of the driving shaft; and a plurality of cushioning devices that reduce impacts during the completion of the displacement of the movable core. The cushioning device is of a structure in which a cushioning body portion is provided on a cushioning device shaft; a cushioning chamber to be fitted to the cushioning body portion is provided; and the cushioning device shaft is coupled to the movable core. 
     Advantageous Effect of the Invention 
     According to the electromagnetic operating device according to the present invention, the driving power supply that supplies electric power to the electromagnetic coil is composed of two types of power supplies: a power supply which is for performing opening/closing operation in the normal time with respect to the switch device; and a power supply which is for performing opening/closing operation in the emergency, whereby even when the power supply which is for performing opening/closing operation in the normal time has an operational defect for some causes, opening/closing operation of the switch device can be performed by the power supply which is for performing opening/closing operation in the emergency and therefore reliability of the electromagnetic operating device is considerably improved. 
     Furthermore, according to the electromagnet device according to the present invention, a reduction in cost can be achieved by standardizing the shape of the movable core and the fixed core with respect to a plurality of ratings and the entire switch device using the electromagnet device can be reduced in size. 
     Moreover, the electromagnet device according to the present invention is of the above-mentioned structure, whereby the cushioning device which reduces impacts during the completion of close-contact and open-contact operation can be provided and there has an effect that the entire device can be reduced in size. 
     In addition, the electromagnet device according to the present invention is of the above-mentioned structure, whereby the cushioning device which reduces impacts during the completion of close-contact and open-contact operation can be provided and there has an effect that the entire device can be reduced in size. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an entire configuration view showing an electromagnetic operating device and a switch device to be operated by the electromagnetic operating device, according to Embodiment 1 of the present invention; 
         FIG. 2  is a circuit diagram showing a switching means portion of an electromagnetic operating device according to Embodiment 2 of the present invention; 
         FIG. 3  is an entire configuration view showing an electromagnetic operating device and a switch device to be operated by the electromagnetic operating device, according to Embodiment 3 of the present invention; 
         FIG. 4  is an entire configuration view showing an electromagnetic operating device and a switch device to be operated by the electromagnetic operating device, according to Embodiment 4 of the present invention; 
         FIG. 5  is an entire configuration view showing other example of an electromagnetic operating device according to Embodiment 4; 
         FIG. 6  is a sectional view showing an electromagnet device and a switch device using the electromagnet device, according to Embodiment 5 of the present invention; 
         FIG. 7  is a sectional view showing an electromagnet device according to Embodiment 5 of the present invention; 
         FIG. 8  is a sectional view taken along the line VIII-VIII of  FIG. 7  showing the electromagnet device according to Embodiment 5 of the present invention; 
         FIG. 9  is an entire configuration view of an electromagnet device and a switch device using the electromagnet device, according to Embodiment 6 of the present invention; 
         FIG. 10  is a configuration view according to the electromagnet device of Embodiment 6 of the present invention; 
         FIG. 11  is a configuration view according to the electromagnet device of Embodiment 6 of the present invention; 
         FIG. 12  is a perspective view of a movable core according to the electromagnet device of Embodiment 6 of the present invention; 
         FIGS. 13( a ), 13( b ), 13( c )  are sectional views and a related part view of a fixed core portion according to the electromagnet device of Embodiment 6 of the present invention; 
         FIG. 14  is other configuration view according to an electromagnet device of Embodiment 6 of the present invention; 
         FIG. 15  is other configuration view according to an electromagnet device of Embodiment 6 of the present invention; 
         FIG. 16  is a configuration view according to an electromagnet device of Embodiment 7 of the present invention; 
         FIG. 17  is a configuration view according to an electromagnet device of Embodiment 8 of the present invention; 
         FIG. 18  is a configuration view according to an electromagnet device of Embodiment 9 of the present invention; 
         FIG. 19  is a configuration view according to an electromagnet device of Embodiment 10 of the present invention; and 
         FIG. 20  is a configuration view according to an electromagnet device of Embodiment 11 of the present invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Embodiment 1 
       FIG. 1  is an entire configuration view showing an electromagnetic operating device and a switch device to be operated by the electromagnetic operating device, according to Embodiment 1; and an electromagnetic operating portion and the switch device are each shown in cross section. 
     The electromagnetic operating device is connected to the movable side of the switch device to opening/closing-drive the switch device. The electromagnetic operating device is composed of an electromagnetic operating portion and a driving power supply portion that supplies electric power to the electromagnetic operating portion. 
     First, a description will be made from the switch device to be driven by the electromagnetic operating device. Hereinafter, an example of the switch device will be described by exemplifying a vacuum valve. 
     A vacuum valve  1  is configured such that a fixed contact  3  and a movable contact  4  are incorporated in the inside of an insulation container  2  and one end of a movable electrode rod  4   a  fixed to the movable contact  4  is led out from the insulation container  2  to the outside via a bellows. The inside of the insulation container  2  is maintained in vacuum in order to improve arc extinguishing performance between both contacts  3 ,  4 . 
     Next, the electromagnetic operating portion of the electromagnetic operating device will be described. 
     An electromagnetic operating portion  5  includes: a fixed core  6 ; a movable core  7  arranged in face-to-face relation to the fixed core  6 ; a driving shaft  8  which passes through a central portion of the movable core  7  and is fixed to the movable core  7 ; an electromagnetic coil  9  which is provided on the fixed core  6  and generates a magnetic field by energization; a permanent magnet  10  provided on the fixed core  6  side; braces  11  that fix the fixed core  6 ; and an open-contact side plate  12  and a close-contact side plate  13 , which are arranged on both ends of the braces  11 . The electromagnetic coil  9  has an open-contact coil  9   a  and a close-contact coil  9   b . The fixed core  6  is sandwiched and fixed by the braces  11 ; whereas the movable core  7  is separated from the fixed core  6  and is capable of being displaced by being driven together with the driving shaft  8  between a backward movement position (position of  FIG. 1 ) coming in contact with the open-contact side plate  12  and a forward movement position coming in contact with the fixed core  6 . 
     The electromagnetic operating portion  5  is supported to a supporting plate  14  via a mounting member  15 . The supporting plate  14  is, for example, a frame that supports the vacuum valve  1 , a case provided on the frame, and the like. The mounting member  15  is arranged in a standing condition on the supporting plate  14 ; the close-contact side plate  13  is fixed to the mounting member  15  by bolt fastening or the like; and the braces  11  are fixed to the close-contact side plate  13 . 
     Furthermore, a spring receiver  16  is fixed on the leading end side of the driving shaft  8  protruded from the open-contact side plate  12  to the outside; and an open-contact spring  17  is inserted between the open-contact side plate  12  and the spring receiver  16 . The open-contact spring  17  is, for example, a compressed coil spring and generates elastic repulsive force in an axial direction between the open-contact side plate  12  and the spring receiver  16 . 
     Next, a description will be made on a coupling portion between the driving shaft  8  of the electromagnetic operating portion  5  and the movable electrode rod  4   a  of the vacuum valve  1 . The coupling portion includes: an insulation rod  18  coupled to the movable electrode rod  4   a ; and a contact pressure device  19  interposed between the insulation rod  18  and the driving shaft  8 . The drawing shows one in which a bellows is provided at a portion in which the insulation rod  18  passes through the supporting plate  14 ; however, there are also cases where the bellows is unnecessary according to the configuration of the supporting plate  14 . 
     Furthermore, the drawing shows one in which an axis line of a driving shaft  8  and an axis line of the vacuum valve  1  are arranged in a straight line; however, a configuration may also be such that the directions of both axis lines are converted by interposing a lever or the like in the coupling portion. 
     Incidentally, the configuration of the vacuum valve  1  serving as the switch device, the electromagnetic operating portion  5  of the electromagnetic operating device, the contact pressure device  19 , and the fixing portion of the electromagnetic operating portion  5 , shown in  FIG. 1  show one example; and the present invention is not limited to the shape of the drawing. 
     Next, the operation of the electromagnetic operating portion  5  and the opening/closing operation of the vacuum valve  1  will be briefly described. When the movable contact  4  is in an open-contact state being separated from the fixed contact  3 , the movable core  7  is at the backward movement position as shown in  FIG. 1  by the biasing force of the open-contact spring  17 . When energization is performed to the close-contact coil  9   b  of the electromagnetic coil  9  by a driving power supply (to be described later), the movable core  7  is suctioned to the fixed core  6  and is displaced from the backward movement position toward the forward movement position against a load of the open-contact spring  17 . This moves the movable contact  4  of the vacuum valve  1  coupled to the driving shaft  8  toward the fixed contact  3 . 
     After that, when the movable contact  4  comes in contact with the fixed contact  3 , the movable contact  4  stops its movement. However, the movable core  7  is further displaced until coming in contact with the fixed core  6  to reach the forward movement position. This shortens a contact pressure spring  19   a  of the contact pressure device  19 ; and the movable contact  4  is pressed to the fixed contact  3  by a predetermined pressing force to complete close-contact operation. 
     When the movable core  7  reaches the forward movement position, the movable core  7  is sucked and held by a holding magnetic flux of the permanent magnet  10  to be held at the forward movement position. 
     In the case of releasing the forward movement position of the movable core  7  from being held to perform open-contact, energization is performed from the driving power supply to the open-contact coil  9   a ; and thus, the suction force between the movable core  7  and the fixed core  6  is lowered and the movable core  7  moves to the backward movement position by each force of the open-contact spring  17  and the contact pressure spring  19   a.    
     Next, a description will be made on a driving power supply portion  21  of the electromagnetic operating device, which is a characterizing portion of the present invention. As described before, the electromagnetic coil  9  of the electromagnetic operating portion  5  of the electromagnetic operating device has the open-contact coil  9   a  and the close-contact coil  9   b.    
     The driving power supply portion  21  includes: capacitors  22   a ,  22   b  which store electric power to be supplied to the open-contact coil  9   a  and the close-contact coil  9   b  of the electromagnetic coil  9 ; and a control board  23  which controls a current to be supplied from the capacitors  22   a ,  22   b  to the open-contact coil  9   a  or the close-contact coil  9   b  in response to an open-contact or close-contact command to the vacuum valve  1  serving as the switch device. In a normal time, the electromagnetic operating portion  5  is driven by the power supply; and thus, the vacuum valve  1  is opened or closed. In the following description, the power supply equipped with the capacitors  22   a ,  22   b  and the control board  23  will be referred to as a “capacitor power supply  24 .” 
     Further, in the driving power supply portion  21 , a DC power supply  26  is connected via switching means  25  to a circuit in which the capacitor power supply  24  and the open-contact coil  9   a  are connected. The switching means  25  is composed of switching switches  25   a ,  25   b  each configured by, for example, a manual push button switch. The DC power supply  26  drives the electromagnetic operating portion  5  to operate the vacuum valve  1  in an emergency. Normally, the DC power supply  26  may utilize a DC power supply equipped for controlling the switch device. 
     The switching means  25  is incorporated in the circuit by being connected by connecting means  27  inserted in the middle of the circuit in which the control board  23  and the open-contact coil  9   a  are connected. The connecting means  27  is, for example, a generally known connector composed of a plug and a receptacle. 
     Actually, normally, the control board  23  is connected to the electromagnetic coil  9  via the connecting means  27 ; and therefore, the connecting means  27  are opened and the switching means  25  having the connector means  27  having the same connecting shape may be inserted therebetween. This permits to connect the DC power supply  26  by subsequently and easily inserting the switching means  25  even to an existing electromagnetic operating device that does not have the DC power supply  26 . 
     As described above, the driving power supply portion  21  of the present invention is composed of two types of power supplies including: the capacitor power supply  24 ; and the DC power supply  26 , as the driving power supply. 
     Next, the operation of the driving power supply portion  21  will be described. 
     The capacitors  22   a ,  22   b  are charged by a charging circuit not previously shown in the drawing. The switching means  25  is normally switched to the control board  23  side. A description will be made on the case of performing close-contact from the open-contact state like  FIG. 1 . When a command of closing contacts (hereinafter, referred to as a “close-contact command”) is inputted to the control board  23 , electric power stored in the capacitor  22   b  is discharged to the close-contact coil  9   b  by a signal from the control board  23  to energize the close-contact coil  9   b ; and thus, the movable core  7  is suctioned to the fixed core  6  side and both contacts  3 ,  4  of the vacuum valve  1  are closed and becomes a closing state by the close-contact operation as described before. 
     In the case of performing open-contact, when the open-contact command is inputted to the control board  23 , electric power stored in the capacitor  22   a  is discharged to the open-contact coil  9   a  by a signal from the control board  23  to energize the open-contact coil  9   a , the suction force between the movable core  7  and the fixed core  6  is lowered, the movable core  7  moves in a direction to be separated from the fixed core  6  by each load of the open-contact spring  17  and the contact pressure spring  19   a , and both contacts  3 ,  4  of the vacuum valve  1  are open-contacted. 
     The above-mentioned opening/closing operation is the opening/closing operation of the vacuum valve  1  in the normal time. 
     Here, if, in the case where some failure occurs in the control board  23  of the capacitor power supply  24  and open-contact control cannot be performed from the capacitor power supply  24  side, a circuit flowing from the DC power supply  26  to the open-contact coil  9   a  can be secured by switching the switching switches  25   a ,  25   b  of the switching means  25  to the DC power supply  26  side; and the open-contact operation of the electromagnetic operating portion  5  can be performed by energizing to the open-contact coil  9   a  by the DC power supply  26 . 
     As described above, two types of power supplies to be connected to the electromagnetic coil  9  of the electromagnetic operating portion  5 , that is, the capacitor power supply  24  and the DC power supply  26  are provided; and thus, even when either the power supply is shut down, the other power supply can be operated. Therefore, reliability of the electromagnetic operating device is improved and reliability of the switch device to be operated by the electromagnetic operating device is improved. 
     Furthermore, by such a configuration, even when one power supply needs to be replaced, replacement can be easily performed. 
     Moreover, the circuit on the DC power supply  26  side is considerably small in the number of components constituting an electric circuit as compared to that on the control board  23  side; and therefore, failure probability due to accumulation of the number of components can be considerably reduced and operational reliability of the switch device is considerably improved. 
     Further, as shown in  FIG. 1 , there is provided the switching means  25  which is for switching to any of the connections between the electromagnetic operating portion  5  and the power supplies  24  and between the electromagnetic operating portion  5  and the power supply  26 ; and thus, an interference between the power supplies  24 ,  26  is blocked and an influence on other power supply circuit can be prevented. The switching means  25  is the manual switching switch; and thus, the switching means can be reduced in cost. 
     Incidentally, the description has been made on the case where the DC power supply  26  is connected on the open-contact coil  9   a  side of the electromagnetic coil  9  in  FIG. 1 . In this case, the configuration is such that priority is given to interrupting a current by the switch device by performing open-contact. In this regard, however, the present invention is not limited to this, but the configuration may be such that the DC power supply  26  is connected on the close-contact coil  9   b  side, and priority is given to conducting the current by the switch device. Furthermore, if the operation of both open-contact and close-contact is duplex by connecting the DC power supply via the switching means to the connection portions with the control board  23  with respect to both of the open-contact side and the close-contact side, reliability can be further improved. 
     Further, the connecting means  27  by which the switching means  25  is inserted between the electromagnetic operating portion  5  and the control board  23  are provided; and thus, a change to the configuration of the present invention can be easily made by connecting the circuit shown in a dashed-dotted line of  FIG. 1  to, for example, the electromagnetic operating device having the existing electromagnetic operating portion and the power supply including the capacitors and the control board. A modification period and a power failure time can be shortened; and therefore, a rate of operation time of an apparatus connected on the lower stream side of the switch device can be improved. 
     Incidentally, the description has been made on the case where the electromagnetic coil is composed of the open-contact coil and the close-contact coil in  FIG. 1 ; however, the present invention can also be applied to an electromagnetic operating device which uses one electromagnetic coil and performs opening/closing control by switching an energization direction to the electromagnetic coil. 
     As described above, according to the electromagnetic operating device of Embodiment 1, the electromagnetic operating device includes: the fixed core; the movable core movably configured with respect to the fixed core; the electromagnetic coil which moves the movable core by excitation to open or close the switch device coupled to the movable core; and the driving power supply that supplies electric power to the electromagnetic coil. The driving power supply is composed of two types of power supplies: the power supply which is for performing opening/closing operation in the normal time with respect to the switch device; and the power supply which is for performing opening/closing operation in an emergency. Thus, even when the power supply which is for performing opening/closing operation in the normal time has an operational defect for some causes, the opening/closing operation of the switch device can be performed by the power supply which is for performing opening/closing operation in the emergency; and therefore, reliability of the electromagnetic operating device is improved. 
     Furthermore, in the driving power supply, the power supply which is for performing opening/closing operation in the normal time is the capacitor power supply which includes: the capacitor that stores electric power to be supplied to the electromagnetic coil; and the control board that controls the current to be supplied from the capacitor to the electromagnetic coil in response to the open-contact or close-contact command to the switch device. Then, the power supply which is for performing opening/closing operation in the emergency is the DC power supply that directly supplies DC electric power to the electromagnetic coil. Thus, the circuit of the DC power supply can be considerably reduced in the number of constituting components as compared to the capacitor power supply; and therefore, failure probability due to accumulation of the number of components can be considerably reduced and the electromagnetic operating device with high reliability can be provided. 
     Moreover, the switching means which switches between the circuit to be connected from the capacitor power supply to the electromagnetic coil and the circuit to be connected from the DC power supply to the electromagnetic coil is provided; and therefore, the interference between the capacitor power supply and the DC power supply is prevented and the influence on other power supply circuit can be prevented. 
     In addition, the switching means is attachably and detachably connected by the connecting means inserted in the middle of the circuit connected from the capacitor power supply to the electromagnetic coil. Thus, modification to the electromagnetic operating device in which the switching means and the DC power supply are easily added with respect to the existing electromagnetic operating device having only the capacitor power supply. Furthermore, replacement can be easily dealt with even when replacement of another power supply is needed. 
     Embodiment 2 
       FIG. 2  is a circuit diagram showing the configuration of a switching means portion of an electromagnetic operating device according to Embodiment 2. The entire configuration of the electromagnetic operating device including a capacitor power supply  24 , a DC power supply  26 , and an electromagnetic operating portion  5  is equivalent to that of  FIG. 1  of Embodiment 1; and the portion of the switching means  25  shown by the dashed line of  FIG. 1  is configured by switching means  28  shown by a dashed line in  FIG. 2 . Portions equivalent to those in  FIG. 1  are shown by the same reference numerals and their detailed description will be omitted. The switching means  25  of  FIG. 1  of Embodiment 1 uses the manual switching switch; however, switching means  28  of this embodiment is electrically-driven. 
     As shown in  FIG. 2 , the switching means  28  has a first relay  29  and a second relay  30 . A normally closed contact  29   b  of the first relay  29  is connected between the open-contact coil  9   a  of the electromagnetic coil  9  of the electromagnetic operating portion  5  that opens or closes the switch device and the control board  23 ; and open-contact operation of the vacuum valve  1  serving as the switch device can be performed by energizing from the control board  23  to the open-contact coil  9   a . Furthermore, the DC power supply  26  is connected to the open-contact coil  9   a  via a normally open contact  30   a  of the second relay  30 . 
     Further, the switching means  28  has input terminals in which an external command  31  is inputted; a circuit from the external command  31  is connected to an operation coil  29   c  of the first relay  29 ; and a normally open contact  29   a  of the first relay  29  and an operation coil  30   c  of the second relay  30  are connected in series. 
     By such a configuration, when the switching means  28  receives the external command  31  and energization is started, first, the operation coil  29   c  of the first relay  29  is energized to operate the first relay  29 , the normally closed contact  29   b  is opened to separate the circuit between the control board  23  and the open-contact coil  9   a ; the normally open contact  29   a  of the first relay  29  is closed; a current from the external command  31  is energized to the operation coil  30   c  of the second relay  30 ; the normally open contact  30   a  of the second relay  30  is closed; a circuit between the DC power supply  26  and the open-contact coil  9   a  is connected; energization is performed from the DC power supply  26  to the open-contact coil  9   a  to drive the movable core  7  in an open-contact direction; and the vacuum valve  1  is open-contacted. 
     Opening/closing operation of the switch device in a normal time is performed from the capacitor power supply  24  side equipped with the capacitors  22   a ,  22   b  and the control board  23 . The normally closed contact  29   b  of the first relay  29  is in a connection state during power supply OFF of the first relay  29 ; and therefore, the first relay  29  does not consume electric power for opening/closing in the normal time and electric power of the electromagnetic operating device can be saved. 
     When the switch device is operated by the DC power supply  26  in an emergency, the circuit on the side of the control board  23  and the electromagnetic coil  9  is automatically interrupted by inputting the external command  31  and, after that, the DC power supply  26  can be connected to the electromagnetic coil  9  side. As described above, a controlling device does not need to be provided in addition to the switching means  28 ; and therefore, there is no possibility to erroneously operate a connection destination and an erroneous operation can be prevented. Furthermore, switching can be carried out by an operation time of each relay  29 ,  30 ; and therefore, the circuit can be switched in a short time. 
       FIG. 2  shows the configuration in which the switching means  28  comprised of the relays is connected to the circuit of the open-contact coil  9   a  of the electromagnetic coil  9 ; however, a configuration may be such that priority is given to conducting a current to the switch device by connecting the DC power supply  26  by providing the switching means  28  on the close-contact coil  9   b  side. Furthermore, the operation of both open-contact and close-contact may be duplex by connecting the DC power supply by providing the switching means  28  on both of the open-contact side and the close-contact side. 
     Furthermore, as in Embodiment 1, it may be attachably and detachably configured by connecting the portion of the switching means  28  in the middle of the circuit connected between the control board  23  and the electromagnetic coil  9  by using the connecting means  27 . 
     As described above, according to the electromagnetic operating device of Embodiment 2, the switching means has: the first relay which is provided in the middle of the circuit to be connected from the capacitor power supply to the electromagnetic coil and is operated by the external command; and the second relay which is provided in the circuit to be connected from the DC power supply to the electromagnetic coil and is operated by the external command. Thus, opening/closing operation of the switch device can be performed from afar by giving the external command in an emergency; and therefore, reliability of the operation of the electromagnetic operating device is improved. 
     Furthermore, the first relay has the normally closed contact in which the first relay is ON during energization of the operation coil and is OFF during non-energization thereof, and the capacitor power supply and the electromagnetic coil are connected via the normally closed contact of the first relay. Thus, electric power of the first relay side is not consumed in the electrical connection between the capacitor power supply which is for performing opening/closing operation in the normal time and the electromagnetic coil; and therefore, electric power of the electromagnetic operating device can be saved even in the case of having two types of power supplies. 
     In addition, the first relay has the normally open contact in addition to the normally closed contact; the second relay has the normally open contact; and the normally open contact of the first relay is connected to the operation coil of the second relay. Then, when the operation coil of the first relay is energized by the external command, the normally closed contact of the first relay is opened; the normally open contact of the first relay is closed; and the normally open contact of the second relay is further closed, whereby supply of electric power to the electromagnetic coil is switched from the capacitor power supply to the DC power supply. Thus, the DC power supply can be connected to the electromagnetic coil after the capacitor power supply is automatically cut off by giving the external command; and therefore, there can be prevented an erroneous operation which erroneously operates a connection destination. Furthermore, switching can be carried out by the operation time of the relays; and therefore, the power supply circuit can be switched in a short time. 
     Embodiment 3 
       FIG. 3  is an entire configuration view showing an electromagnetic operating device and a switch device operated by the electromagnetic operating device, according to Embodiment 3. Portions equivalent to those in  FIG. 1  of Embodiment 1 are shown by the same reference numerals and their description will be omitted and a description will be made centering on different points. 
     In Embodiment 1, for example, when the DC power supply is connected to the open-contact coil side, the capacitor power supply and the DC power supply are switched by using the switching means with respect to one open-contact coil. 
     On the other hand, in this embodiment, for example, when a power supply of an open-contact coil is a duplex power supply of a capacitor power supply and a DC power supply, an open-contact coil  32   b  to be connected to a capacitor power supply  24  and an open-contact coil  32   a  to be connected to a DC power supply  26  are individually provided as shown in  FIG. 3 . More specifically, an electromagnetic coil  32  is composed of two open-contact coils  32   a ,  32   b  and a close-contact coil  32   c.    
     By such a configuration, in addition to the effect like Embodiment 1 by the duplex power supply, switching means does not need to be provided and probability of failure of the switching circuit can be reduced; and therefore, an improvement in reliability and a reduction in cost can be achieved by a simple configuration. 
     Furthermore, it is possible to prevent mutual influence between the power supplies of the capacitor power supply  24  and the DC power supply  26 . Therefore, means that prevents an influence on other power supply circuit does not need to be provided and a reduction in cost can be achieved. 
     In addition, each winding of the electromagnetic coil  32  can be appropriately designed in correspondence to each power supply and therefore an electric element that adjusts a circuit constant does not need to be added. 
     An electromagnetic operating portion  5  can generate electromagnetic force by the product of current and the number of winding turns even in the case of small current energization by increasing the number of winding turns of the electromagnetic coil  32 . Therefore, in this configuration, the electromagnet can also be operated by energization with a small current by increasing the number of winding turns of the DC power supply. 
     Further, in the electromagnetic coil  32  that reciprocates the movable core  7 , as winding means that moves in one direction, there can be connected a small-capacity capacitor for a winding with a large number of winding turns and a large-capacity capacitor for a winding with a small number of winding turns. If operation is made by the large-capacity capacitor side in the case of responding at high speed and if operation is made by the small-capacity capacitor side when the circuit on the large capacity capacitor side is not operated, a reduction in size of the capacitor can be achieved. In addition, a current value is small on the small-capacity side; and therefore, an element of the control board may also be small in capacity and the control board can also be reduced in size and in cost. 
     Incidentally, in  FIG. 3 , the configuration is such that two open-contact coils are provided and are each connected to a different type power supply, and priority is given to interrupting a current by performing open-contact. The present invention is not limited to this configuration, but a configuration may be such that two close-contact coils are provided and are each connected to a different type power supply, and priority is given to conducting a current by prioritizing close-contact. Furthermore, reliability of both operations of open-contact and close-contact can also be improved by providing two electromagnetic coils on each of both of the open-contact side and the close-contact side. 
     As described above, according to the electromagnetic operating device according to the Embodiment 3, the electromagnetic coil is individually provided with coils, each of which is connected to each of two types of the power supplies; and therefore, it is possible to prevent an influence on other power supply circuit without the need for means that prevents the influence on other power supply circuit. 
     Furthermore, switching means can be eliminated as compared to Embodiment 1 or 2 and thus probability of failure can be reduced by just that much; and therefore, reliability can be improved and a reduction in cost can be achieved by a simple configuration. 
     Embodiment 4 
       FIG. 4  is an entire configuration view showing an electromagnetic operating device and a switch device operated by the electromagnetic operating device according to Embodiment 4. Portions equivalent to those in  FIG. 1  of Embodiment 1 are shown by the same reference numerals, their description will be omitted, and a description will be made centering on a different point. 
     The different point from  FIG. 1  is that a resistor  33  is inserted in the middle of a circuit connected between a DC power supply  26  and an open-contact coil  9   a  of an electromagnetic coil  9 , more specifically, in the front of a switching switch  25   a.    
     The following effects are generated by inserting the resistor  33  on the DC power supply  26  side. 
     When a plurality of types of power supplies are connected to one electromagnetic coil, the characteristics of the electromagnetic coil are designed to be optimized to the characteristics of any one of the power supplies; and accordingly, there is a case where the characteristics are not matched to that of other power supplies. More particularly, when a DC power supply is added to an electromagnetic operating device equipped with a capacitor power supply at a later time, the characteristics of the electromagnetic coil is optimized to the characteristics of the capacitor power supply and the characteristics of the DC power supply need to be matched with the characteristics of the electromagnetic coil. 
     So, as shown in  FIG. 4 , the resistor  33  is inserted in the middle of the circuit in which the DC power supply  26  is connected to the electromagnetic coil  9 ; and thus, an electric circuit constant can be adjusted and appropriate characteristics can be achieved. For example, a current continuously flows in the DC power supply  26 ; and accordingly, if no measure is taken, the electromagnetic coil  9  is likely to be burned out due to heat generation caused by a large current. However, the current can be suppressed by inserting the resistor  33 , thereby permitting continuous energization. 
       FIG. 5  is a view showing other example of a configuration in which a resistor is inserted on the DC power supply side and a resistor  33  is inserted in a circuit equivalent to  FIG. 3  of Embodiment 3. 
     Like  FIG. 5 , even when individual coils  32   a  to  32   c , each of which is connected to each power supply, are provided as an electromagnetic coil  32  and each coil  32   a  to  32   c  is optimized to the corresponding power supply, the following effect exists by the connection of the resistor  33 . 
     The effect is that stable operation without depending on an ambient temperature can be achieved. Resistance of copper wire varies with temperature by 0.00393/K. A flowing current value varies depending on the ambient temperature; and accordingly, design is made at a minimum temperature of operation specification at which capacity of the DC power supply  26  becomes a maximum energization current and it becomes excessive specification. So, a substantially constant resistor is mounted irrespective of the temperature and a resistance value of the electromagnetic coil  32  is designed to be small; and thus, the entire change of the resistance value due to the temperature becomes small and an advantage exists in that a current capacity of the DC power supply  26  can be reduced. Furthermore, an energization current value becomes substantially constant; and therefore, the operation of the electromagnetic operating device is stabilized. 
     Here, if a current flowing in the electromagnetic coil connected to the DC power supply  26  is further adjusted to be equal to or lower than 5 A at a voltage of the DC power supply  26  by the resistor  33 , the following effect can be expected. 
     When a user uses the switch device, a current value to be used is required to be suppressed to 5 A at maximum. When facility update in which the DC power supply is added to the existing electromagnetic operating device is performed, a current value flowing in the DC power supply circuit is set to be equal to or lower than 5 A by adjusting a resistance value of the resistor  33 ; and thus, the updated facility can be used with compatibility with the conventional switch device and therefore there can be achieved a reduction in cost of facility change without largely changing the facilities in updating. 
     As described above, according to the electromagnetic operating device of Embodiment 4, the resistor is inserted in the middle of the circuit connected from the DC power supply to the electromagnetic coil. Thus, even in the case of the electromagnetic coil optimized to any one of power supplies, adjustment of the characteristics with other power supplies can be performed by the resistor. Furthermore, the resistor which does not depend on the temperature is arranged; and thus, the operation of the electromagnetic operating device can be suppressed from being influenced by the temperature and stable operation can be achieved. 
     Furthermore, the resistor is adjusted to be the resistance value at which the current flowing in the circuit to be connected from the DC power supply to the electromagnetic coil is set to be equal to or lower than 5 A. Thus, the current value becomes equal to or lower than a current value of a generally frequently used electromagnetic operating device; and therefore, in the case of updating by adding the DC power supply to the existing facilities, the update can be carried out without a large change of the facilities. 
     Embodiment 5 
     Hereinafter, Embodiment 5 of the present invention will be described with reference to  FIG. 6  to  FIG. 8 ; and in each of the drawings, identical or equivalent members and portions will be described with the same reference numerals assigned thereto.  FIG. 6  is a sectional view showing an electromagnet device and a switch device using the electromagnet device, according to Embodiment 5 of the present invention.  FIG. 7  is a sectional view showing the electromagnet device according to Embodiment 5 of the present invention.  FIG. 8  is a sectional view taken along the line VIII-VIII of  FIG. 7  showing the electromagnet device according to Embodiment 5 of the present invention. 
     In these respective drawings, the switch device includes: a vacuum valve  103  serving as a switch device body having a fixed contact  101  and a movable contact  102 ; an electromagnet device  104  that displaces the movable contact  102  of the vacuum valve  103  in a direction connected to and separated from the fixed contact  101 ; a coupling device  105  that couples the vacuum valve  103  to the electromagnet device  104 ; and an open-contact spring  106  serving as a biasing body which biases the movable contact  102  in a direction to be separated from the fixed contact  101 . 
     The vacuum valve  103  serving as the switch device body incorporates the fixed contact  101  and the movable contact  102  in an insulation container  103   a ; and one end of the movable electrode rod  103   b  fixed to the movable contact  102  is led out to the outside from the insulation container  103   a  and is coupled to the movable side of the electromagnet device  104  via the coupling device  105 . This moves and displaces the movable contact  102  in the axial direction of the vacuum valve  103 . The movable contact  102  is brought in contact with the fixed contact  101  to perform close-contact; and the movable contact  102  is separated from the fixed contact  101  to perform open-contact. The inside of the vacuum valve  103  is maintained in vacuum in order to improve arc extinguishing performance between the fixed contact  101  and the movable contact  102 . Incidentally, a fixed electrode rod  103   c  is fixed to the fixed contact  101 . 
     The electromagnet device  104  includes: a fixed core  107  configured by laminating a plurality of magnetic substance sheets; a movable core  108  which is configured by laminating a plurality of magnetic substance sheets and is arranged so as to move backward and forward in the fixed core  107 ; a driving shaft  109  which is provided by passing through a central portion of the movable core  108  and is fixed to the movable core  108 ; an electromagnetic coil  110  which is provided on the fixed core  107  and generates a magnetic field by energization; a permanent magnet  111  provided on the fixed core  107  side; braces  112  that fix the fixed core  107 ; and an open-contact side plate  113  and a close-contact side plate  114 , which are arranged on both ends of the braces  112 . The movable core  108  is capable of being displaced by being driven to the axial direction of the driving shaft  109  (hereinafter, merely referred to as the “axial direction”) G with respect to the fixed core  107 . 
     Further, bearings  115   a ,  115   b  of the driving shaft  109  are fixed to portions at which the driving shaft  109  passes through the open-contact side plate  113  and the close-contact side plate  114 , respectively. 
     In addition, an open-contact spring receiver  116  is fixed to the other side  109   b  of the driving shaft  109  protruded to the outside from the open-contact side plate  113 ; and an open-contact spring  106  serving as a biasing body is inserted onto the driving shaft  109  between the open-contact side plate  113  and the open-contact spring receiver  116 . The open-contact spring  106  is, for example, a compressed coil spring and generates elastic repulsive force in the axial direction G between the open-contact side plate  113  and the open-contact spring receiver  116 . 
     Next, the configuration of the electromagnet device  104  will be further described in detail. The fixed core  107  and the movable core  108  are each configured by laminating the plurality of magnetic substance thin sheets. The shape of the fixed core  107  is such that the fixed core  107  has: a lateral core portion  107   a  extending in a direction perpendicular to the axial direction; a longitudinal core portion  107   b  extending in the axial direction from both end portions of the lateral core portion  107   a ; and a permanent magnet fixing portion  107   c  extending toward the axis line from the longitudinal core portion  107   b . The longitudinal core portion  107   b  of the fixed core  107  is fastened and fixed to the braces  112  by being sandwiched by the braces  112  from both sides of the sheet surfaces of the longitudinal core portion  107   b , that is, from both surfaces of the lamination direction. 
     On the other hand, the movable core  108  has: a major portion  108   a  arranged along the axial direction; and a pair of branch portions  108   b  which protrude from the sides of the major portion  108   a  in the opposite directions from each other toward directions perpendicular to the axial direction. The fixed core  107  and the movable core  108  are integrated by being fastened by a plurality of bolts  118  passing in the lamination direction and nuts (not shown in the drawing) screwed to the respective bolts  118 . Then, the movable core  108  is capable of being displaced between a backward movement position at which the movable core  108  is separated from the fixed core  107  and comes in contact with the open-contact side plate  113  and a forward movement position at which the movable core  108  comes in contact with the fixed core  107 . 
     Incidentally, a magnetic material with high permeability may be permissible as a material of the fixed core  107  and the movable core  108 ; and, for example, steel member, electromagnetic soft iron, silicon steel, ferrite, permalloy, and the like can be used. 
     Furthermore, a material with low permeability (low magnetic material), for example, stainless steel and the like can be used as a material of the driving shaft  109 . 
     The permanent magnet  111  is arranged on the permanent magnet fixing portion  107   c  of the fixed core  107  in face-to-face relation to the surface of the close-contact side of the branch portion  108   b  of the movable core  108 . Then, the permanent magnet  111  has an N-pole and an S-pole (a pair of magnetic poles); one magnetic pole is in face-to-face relation to the permanent magnet fixing portion  107   c  and the other magnetic pole is in face-to-face relation to the close-contact side of the branch portion  108   b  of the movable core  108 . The permanent magnet  111  generates a holding magnetic flux that holds the movable core  108  at the forward movement position. Incidentally, the permanent magnet  111  may be fixed such that, for example, a mounting member formed by bending in a channel shape (not shown in the drawing) is placed from the upper side of the permanent magnet  111  and the mounting member is fastened by bolts in the lamination direction of the permanent magnet fixing portion  107   c.    
     Furthermore, the electromagnetic coil  110  is arranged so as to pass between the major portion  108   a  of the movable core  108  and the longitudinal core portion  107   b  of the fixed core  107 . In an example of this embodiment, the electromagnetic coil  110  surrounds the major portion  108   a  of the movable core  108  in a projection plane toward the axial direction. With this configuration, when the electromagnetic coil  110  is energized, the electromagnetic coil  110  generates a magnetic flux that passes through the fixed core  107  and the movable core  108 . Furthermore, the direction of the magnetic flux generated by the electromagnetic coil  110  can be reversed by switching an energization direction to the electromagnetic coil  110 . 
     Next, a coupling portion between the electromagnet device  104  and the vacuum valve  103  serving as the switch device body will be described. The electromagnet device  104  is supported to a plate-like supporting member  119  via mounting braces  120 . Normally, the vacuum valve  103  is incorporated in a container (not shown in the drawing) sealed with insulating gas (for example, sulfur hexafluoride (SF6) gas, dry air, or the like) which is for securing dielectric strength voltage of a peripheral portion. Therefore, the above-mentioned supporting member  119  is, for example, a lid body of the container; the mounting braces  120  are arranged in a standing condition on the supporting member  119  made by the lid body; and the close-contact side plate  114  of the electromagnet device  104  is fixed to the mounting braces  120  by bolt fastening or the like. In this regard, however, the supporting member  119  is not limited to this; and, for example, a supporting plate of a switchboard may be permissible. 
     The coupling device  105  that couples the movable electrode rod  103   b  fixed to the movable contact  102  of the vacuum valve  103  to one side  109   a  of the driving shaft  109  of the electromagnet device  104  has: an insulation rod  121  coupled to the movable electrode rod  103   b ; a contact pressure device  122  interposed between the insulation rod  121  and one side  109   a  of the driving shaft  109 ; and a bellows  124  which is provided by connecting the coupling rod  123  portion and the supporting member  119  so that the coupling rod  123  portion is movable while maintaining hermetic seal with respect to the supporting member  119  serving as a part of the gas container in a portion in which the coupling rod  123  portion of the insulation rod  121  passes through the supporting member  119 . Incidentally, there is also a case where the bellows  124  is not needed according to the configuration of the supporting member  119 . 
     The contact pressure device  122  has: a spring frame  125  fixed to an end portion of the coupling rod  123  portion; a latch plate  126  which is fixed to one side  109   a  of the driving shaft  109  and is arranged in the spring frame  125 ; and a contact pressure spring  127  inserted in a compressed state between the spring frame  125  and the latch plate  126 . The contact pressure spring  127  biases the driving shaft  109  in a direction to be separated from the insulation rod  121 . The driving shaft  109  is capable of being displaced in the axial direction together with the latch plate  126 ; and its displacement is regulated by engagement of the latch plate  126  with the spring frame  125 . 
       FIG. 6  shows that an axis line of the electromagnet device  104  and an axis line of the vacuum valve  103  are arranged in a straight line; however, a configuration may also be such that the directions of both axis lines are converted by interposing a lever or the like in the coupling device  105  portion. 
     Next, the operation of the switch device will be described. When the movable contact  102  is in an open-contact state being separated from the fixed contact  101 , the movable core  108  is at the backward movement position by the biasing force of the open-contact spring  106 . When energization is performed to the electromagnetic coil  110 , the movable core  108  is suctioned to the fixed core  107  and is displaced from the backward movement position toward the forward movement position against a load of the open-contact spring  106 . This moves the movable contact  102  toward the fixed contact  101 . 
     After that, when the movable contact  102  comes in contact with the fixed contact  101 , the movable contact  102  stops its movement. However, the movable core  108  is further displaced; and the major portion  108   a  comes in contact with the lateral core portion  107   a  of the fixed core  107  to reach the forward movement position. This shortens the contact pressure spring  127 ; and the movable contact  102  is pressed to the fixed contact  101  by a predetermined pressing force to complete close-contact operation. 
     When the movable core  108  reaches the forward movement position, the movable core  108  is sucked and held by the holding magnetic flux of the permanent magnet  111  to be held at the forward movement position. 
     In the case of releasing the forward movement position of the movable core  108  from being held, energization to the electromagnetic coil  110  is performed in a direction opposite to that during the close-contact operation. This lowers the suction force between the movable core  108  and the fixed core  107 ; and thus, the movable core  108  moves to the backward movement position by each load of the open-contact spring  106  and the contact pressure spring  127 . In the early stages of the displacement, the movable contact  102  remains pressed to the fixed contact  101 . 
     After that, when the displacement of the movable core  108  toward the backward movement position proceeds, the latch plate  126  is engaged with the spring frame  125 . This displaces the movable contact  102  in a direction to be separated from the fixed contact  101 . When the movable core  108  is further displaced and fixed by coming in contact with the open-contact side plate  113  to reach the backward movement position (the state of  FIG. 6 ), open-contact operation is completed. 
       FIG. 7  shows a driving shaft portion of the electromagnet device in the switch device of Embodiment 5 of the present invention. The movable core  108  and the fixed core  107  are each configured by laminating the plurality of magnetic substance thin iron sheets. The driving shaft  109  passes through a central portion of the movable core  108  and is configured as one shaft body coupled to the movable core  108  by, for example, rod bodies  128  serving as coupling members at a connection portion  109   c  with the movable core  108 . The shaft diameter of the connection portion  109   c  of the driving shaft  109  is configured as a shaft diameter that is different from the shaft diameter of other portion of the driving shaft  109 . The driving shaft  109  is coupled to the movable core  108  by the rod bodies  128 ; and therefore, the connection portion  109   c  of the driving shaft  109  has a predetermined shaft diameter in order to improve strength. 
     On the other hand, a coupling portion of the open-contact spring receiver  116  of the open-contact spring  106  positioned at the other side  109   b  of the driving shaft  109  and a coupling portion of the latch plate  126  of the contact pressure device  122  have shaft diameters each having a predetermined strength necessary for a load generated at each coupling portion during operation of the switch device. 
     Therefore, the driving shaft  109  is different in each shaft diameter: a shaft diameter b of the connection portion  109   c  serving as the coupling portion by the rod body  128  with the movable core  108 ; a shaft diameter a 2  of the other side  109   b  serving as the coupling portion on the open-contact spring receiver  116  side; and a shaft diameter a 1  of one side  109   a  serving as the coupling portion with the latch plate  126 . The shaft diameter a 1  of one side  109   a  of the driving shaft  109  and the shaft diameter a 2  of the other side  109   b  thereof are configured to be smaller than the shaft diameter b of the connection portion  109   c  of the driving shaft  109 . More specifically, the shaft diameter a 1  of one side  109   a  of the driving shaft  109  at the movable core  108  portion to be suctioned to the fixed core  107  is configured to be smaller than the shaft diameter b of the connection portion  109   c  of the driving shaft  109  coupled to the movable core  108  by the rod bodies  128 . Incidentally, in  FIG. 7 , the open-contact spring receiver  116  and the latch plate  126  are fixed by being fastened from both sides by nuts  129  that are general fastening parts. 
     These nuts  129  are different in outer diameter according to the shaft diameter of the driving shaft  109 . The nut  129  to be used for the shaft with a large shaft diameter is also large in dimension of the axial direction. The nut  129  to be used for the shaft with a small shaft diameter is also small in dimension of the axial direction. Thus, as compared to the case of one driving shaft  109  that keeps the shaft diameter of the connection portion  109   c  of the driving shaft  109  with the movable core  108 , the nuts  129  of the coupling portions with the open-contact spring receiver  116  and the latch plate  26  can be reduced in size; and therefore, axial dimension can be shortened and the entire dimensions of the switch device can be reduced. 
     The electromagnet device of Embodiment 5 of the present invention can increase or decrease suction holding force generated by the electromagnet device in response to opening/closing operating force required for each rating in the switch device by an increase or decrease in the number of laminated sheets of the movable core and the fixed core. The shapes of the thin sheets constituting the respective cores can be the same; and therefore, the suction holding force can be easily adjusted. 
       FIG. 8  is a sectional view taken along the line VIII-VIII of  FIG. 7  with regard to the movable core  108 . In the driving shaft portion, the connection portion  109   c  of the driving shaft  109  with the movable core  108  is fixed by coupling with the rod bodies  128  serving as the coupling members; and therefore, as shown in  FIG. 8 , the driving shaft  109  can be fixed to the movable core  108  if the number of laminated sheets of a driving shaft pass-through portion  108   c  of the movable core  108  is adjusted according to the shaft diameter of the connection portion  109   c  of the driving shaft  109 , the connection portion  109   c  being the coupling portion with the movable core  108 . 
     Furthermore, the bearing  115   a  of the driving shaft  109  is fixed to a through hole of the open-contact side plate  113  and the bearing  115   b  of the driving shaft  109  is fixed to a through hole of the close-contact side plate  114 , the open-contact side plate  113  and the close-contact side plate  114  being provided differently from the fixed core  107 , thereby allowing to easily deal with a change in shaft diameter of the driving shaft  109  by only changing hole dimensions and thereby allowing to easily deal with a plurality of ratings. 
     Therefore, the shape of the thin sheets constituting the fixed core  107  and the movable core  108  can be constant regardless of the rating of the switch device by adopting the configuration of the present invention. Further, optimization of the dimensions of the switch device by virtue of optimizing each coupling portion of the driving shaft  109  by reducing the size of the nuts can be easily performed by only changing the dimensions of the bearing holes of the open-contact side plate  113  and the close-contact side plate  114  of the electromagnet device  104 . 
     As described above, it can be easily dealt with each rating; and therefore, in manufacturing the electromagnet device  104 , pressing metal dies of the fixed core  107  and the movable core  108  do not need to be prepared for each rating and can be standardized. The amount of initial investment of the pressing metal dies can be reduced and it further becomes possible to reduce costs by the effect of mass production. 
     In Embodiment 5 of the present invention, the suction holding force of the electromagnet device  104  is increased or reduced according to the area of a contact portion S between the movable core  108  and the fixed core  107 , the suction holding force being for maintaining a close-contact state of the switch device with respect to the loads of the open-contact spring  106  and the contact pressure spring  127 . In order to secure the area, if the movable core  108  becomes large and the weight of a movable portion is increased, a problem arises in that switching speed necessary for the function of the switch device cannot be satisfied. In Embodiment 5 of the present invention, the shaft diameter a 1  of one side  109   a  of the driving shaft  109  at the contact portion S between the movable core  108  and the fixed core  107  is made smaller with respect to the shaft diameter b of the connection portion  109   c  of the driving shaft  109 , the connection portion  109   c  being the coupling portion with the movable core  108 ; and thus, the area of the contact portion S between the movable core  108  and the fixed core  107  can be larger as compared to the case when the shaft diameter of the driving shaft  109  is set to be constant. More specifically, the movable core  108  can be reduced while securing the area of the contact portion S; and therefore, the electromagnet device  104  can reduce the movable core  108  which is for satisfying the suction holding force which is for maintaining the close-contact state of the switch device and the entire dimensions of the electromagnet device  104  can be reduced in size. 
     Furthermore, the amount of expensive permanent magnet  111  to be mounted in order to satisfy the suction holding force of the electromagnet device  104  can also be reduced; and therefore, the electromagnet device  104  can be reduced in cost. 
     Moreover, in the configuration of Embodiment 5 of the present invention, the driving shaft  109  is one shaft body. In the driving shaft  109  coupled to the movable core  108 , the driving shaft  109  has highly accurate coaxiality as compared to the case where the driving shaft  109  is composed of a plurality of parts being coupled, the driving shaft  109  being supported by the bearing  115   a  portion of the open-contact side plate  113  and the bearing  115   b  portion of the close-contact side plate  114 . Therefore, friction of the bearing  115   a ,  115   b  portions can be reduced, operational failure due to operational loss and shaft center deviation of the electromagnet device  104  can be reduced. 
     Embodiment 6 
     Embodiment 6 relates to an electromagnet device and a switch device using the electromagnet device, the electromagnet device having a structure in which a fixed core, a movable core, a driving shaft fixed by passing through the movable core, an electromagnetic coil that displaces the movable core to the fixed core along the driving shaft, an open-contact spring that displaces the movable core in a direction to be separated from the fixed core, and a cushioning device that reduces impacts during the completion of the displacement of the movable core are integrated with the driving shaft. 
     Hereinafter, the configuration and the operation of the electromagnet device and the switch device of Embodiment 6 of the present invention will be described with reference to  FIG. 9  that is an entire configuration view,  FIG. 10  and  FIG. 11  that are configuration views of the electromagnet device,  FIG. 12  that is a perspective view of the movable core of the electromagnet device,  FIG. 13( a ), 13( b ), 13( c )  that is a sectional view of a fixed core portion, and  FIG. 14  and  FIG. 15  that are other configuration views of the electromagnet device. 
     In the following description, first, the entire configuration of the electromagnet device and the switch device using the electromagnet device will be described. Next, the configuration and the operation of the electromagnet device will be described. Further, the configuration and the operation of the switch device will be described. 
     Incidentally, other embodiments of the present invention with regard to the electromagnet device of Embodiment 6 will be described by turns in Embodiment 7 to Embodiment 11. 
     First, a description will be made on the basic configuration of the electromagnet device and the entire configuration of the switch device using the electromagnet device with reference to  FIG. 9 . 
     In  FIG. 9 , as a whole, a switch device  400  is composed of an electromagnet device  201  and an opening and closing operation portion  300 . 
     The electromagnet device  201  has: an electromagnet portion  202 ; a driving shaft  203 ; a cushioning device  204 ; and an open-contact spring  205 , as major constituent elements. The cushioning device  204  will be described later in a description of the electromagnet device  201  with reference to  FIG. 10  and  FIG. 11 . 
     The electromagnet portion  202  has: a fixed core  209 ; a movable core  210 ; an electromagnetic coil  211 ; and a permanent magnet  212 , as major constituent elements. 
     The opening and closing operation portion  300  includes a vacuum valve  303  and a coupling device  304 . 
     First, the configuration and the operation of the electromagnet device  201  will be described with reference to  FIG. 9  to  FIG. 13 . Incidentally,  FIG. 10  and  FIG. 11  are views each describing details of the cushioning device  204  of  FIG. 9 . FIG.  10  represents a state where the movable core  210 , the driving shaft  203 , and the vacuum valve  303  are in an open-contact side position.  FIG. 11  represents a state where the movable core  210 , the driving shaft  203 , and the vacuum valve  303  are in a close-contact side position. 
     Incidentally, the open-contact side position and the close-contact side position will be described later. Furthermore, in  FIG. 10  and  FIG. 11 , detailed reference numerals such as  209   a  to  209   c  of the electromagnet portion  202  are omitted. 
     The electromagnet portion  202  has: the fixed core  209 , the movable core  210  arranged in face-to-face relation to the fixed core  209 , and the driving shaft  203  which is provided by passing through a central portion of the movable core  210  and is fixed to the movable core  210 . Furthermore, the electromagnet portion  202  has: the electromagnetic coil  211  which is provided on the fixed core  209  and generates a magnetic field by energization; and the permanent magnet  212  provided on the fixed core  209  side. Further, the electromagnet portion  202  has: braces  213  that fix the fixed core  209 ; and an upper plate  206  serving as an open-contact side plate and a lower plate  207  serving as a close-contact side plate, which are arranged on both ends of the braces  213 . 
     Here, the movable core  210  is capable of being displaced by being driven to the axial direction of the driving shaft  203  (hereinafter, described as the “axial direction”) with respect to the fixed core  209 . 
     Further, a bearing  214   a  of the driving shaft  203  is fixed to a portion in which the driving shaft  203  passes through the upper plate  206 ; and a bearing  214   b  of the driving shaft  203  is fixed to a portion in which the driving shaft  203  passes through the lower plate  207 . 
     Furthermore, a spring receiver  208  is fixed on the leading end side of the driving shaft  203  protruded to the outside from the upper plate  206 . An open-contact spring  205  (biasing body) is inserted onto a shaft portion of the driving shaft  203  between the upper plate  206  and the spring receiver  208 . The open-contact spring  205  is, for example, a compressed coil spring and generates elastic repulsive force in the axial direction between the upper plate  206  and the spring receiver  208 . The biased open-contact spring displaces the movable core  210  in a direction to be separated from the fixed core  209  along the center axis of the driving shaft  203 . 
     Incidentally, the open-contact spring  205  is an isolating spring of the present invention. 
     Next, details of the cushioning device  204  will be described with reference to  FIG. 10 . 
     The cushioning device  204  is arranged in the open-contact spring  205  and is fixed to the upper plate  206 . 
     The cushioning device  204  is sealed with, for example, a liquid viscous body  204   c  in the inside thereof. The driving shaft  203  passing through the inside of the cushioning device  204  is provided with, for example, a disk-shaped cushioning body portion  204   b . For example, a cylindrical upper cushioning chamber  204   d  and a cylindrical lower cushioning chamber  204   e  are provided on both end portions in the axial direction of the cushioning device  204 . A structure is such that the upper and lower cushioning chambers  204   d ,  204   e  become small in inner diameter in the inside of the cushioning device  204 ; and the cushioning body portion  204   b  integrated with the driving shaft  203  is fitted thereinto. 
     When the cushioning body portion  204   b  is fitted (enters) into the upper cushioning chamber  204   d , the viscous body  204   c  passes between the cushioning body portion  204   b  and the lower cushioning chamber  204   e ; and when the cushioning body portion  204   b  is fitted (enters) into the lower cushioning chamber  204   e , the viscous body  204   c  passes between the cushioning body portion  204   b  and the upper cushioning chamber  204   d . A movable portion is decelerated to reduce impacts by resistance of the viscous body  204   c  when the viscous body  204   c  passes between the cushioning body portion  204   b  and the upper cushioning chamber  204   d  and between the cushioning body portion  204   b  and the lower cushioning chamber  204   e . The cushioning device  204  is sealed by connecting with an upper bellows  204   f  and a lower bellows  204   g  between the driving shaft  203  and a case of the cushioning device  204 . 
     Incidentally, the upper cushioning chamber  204   d  and the lower cushioning chamber  204   e  are a cushioning chamber of the present invention. 
     Connection of the bellows is performed by a method such as welding or soldering. The upper bellows  204   f  and the lower bellows  204   g  are each provided with corrugations on a metal-made cylindrical one to have flexibility, airtightness, and spring property. In such a manner, the movable portion of the cushioning device  204  is sealed by the upper bellows  204   f  and the lower bellows  204   g ; and thus, the viscous body  204   c  is prevented from leaking to the outside of the cushioning device  204 . A cushioning structure in the cushioning device  204  may be a general orifice structure. 
       FIG. 10  represents a state where the cushioning body portion  204   b  is fitted into the lower cushioning chamber  204   e ; whereas  FIG. 11  represents a state where the cushioning body portion  204   b  is fitted into the upper cushioning chamber  204   d.    
     The fixed core  209  and the movable core  210  of the electromagnet portion  202  will be further described in detail with reference to  FIG. 9 . 
     The fixed core  209  and the movable core  210  are each configured by laminating thin sheets. The fixed core  209  has: a lateral core portion  209   a  that extends in a direction perpendicular to the axial direction; a longitudinal core portion  209   b  that extends in the axial direction from both end portions of the lateral core portion  209   a ; and a permanent magnet fixing portion  209   c  that extends from the longitudinal core portion  209   b  toward the axis line. 
     The longitudinal core portion  209   b  of the fixed core  209  is fastened and fixed to the braces  213  by being sandwiched by the braces  213  from both sides of the sheet surfaces, that is, from both surfaces of the lamination direction. 
     Next, the movable core  210  will be described.  FIG. 12  shows a perspective view of the movable core  210  having a T-shape. 
     The movable core  210  has: a major portion  210   a  arranged along the axial direction; and a pair of branch portions  210   b  which protrude from the sides of the major portion  210   a  in the opposite directions from each other toward directions perpendicular to the axial direction. The fixed core  209  and the movable core  210  are integrated by being fastened by a plurality of bolts  215  passing in the lamination direction and nuts (not shown in the drawing) screwed to the respective bolts  215 . Then, the movable core  210  is capable of being displaced between a backward movement position at which the movable core  210  is separated from the fixed core  209  and comes in contact with the upper plate  206  and a forward movement position at which the movable core  210  comes in contact with the fixed core  209 . 
       FIGS. 13( a ), 13( b ), 13( c )  show sectional views and a related component view of the fixed core  209  portion seen from the line XIII-XIII of  FIG. 9 . 
       FIG. 13( a )  is a sectional plan view in which a state where the fixed core  209 , the braces  213 , and the lower plate  207  are combined is seen from the line XIII-XIII of  FIG. 9 . 
       FIG. 13( b )  is a plan view in which the fixed core  209  and the braces  213  are seen from the line XIII-XIII of  FIG. 9 . In  FIG. 13( b ) , screw holes  213   a  for mounting the upper plate  206  and the lower plate  207  are processed on both end portions in the longitudinal direction of the braces  213 . Furthermore, an opening hole  209   d  in which the driving shaft  203  movably passes is formed in the fixed core  209 . 
       FIG. 13( c )  is a plan view of the lower plate  207 . In  FIG. 13( c ) , the lower plate  207  is formed with a bearing mounting hole  207   a  in which the bearing  214   b  of the driving shaft  203  is mounted at a central portion and a plurality of brace mounting holes  207   b  which are for mounting the braces  213  at peripheral portions. 
     Incidentally, none of  FIG. 13( a )  to  FIG. 13( c )  show bolts. 
     Materials of the fixed core  209 , the movable core  210 , and the driving shaft  203  will be described. 
     A magnetic material with high permeability may be permissible as the material of the fixed core  209  and the movable core  210 ; and, for example, steel member, electromagnetic soft iron, silicon steel, ferrite, permalloy, and the like can be used. 
     Furthermore, a material with low permeability (low magnetic material), for example, stainless steel and the like can be used as the material of the driving shaft  203 . 
     Next, the permanent magnet  212  will be described. 
     The permanent magnet  212  is arranged on the permanent magnet fixing portion  209   c  of the fixed core  209  in face-to-face relation to the surface of the lower side of the branch portion  210   b  of the movable core  210 . Then, the permanent magnet  212  has an N-pole and an S-pole (a pair of magnetic poles). One magnetic pole of the permanent magnet  212  is in face-to-face relation to the permanent magnet fixing portion  209   c  and the other magnetic pole is in face-to-face relation to the lower side of the branch portion  210   b  of the movable core  210 . The permanent magnet  212  generates a holding magnetic flux that holds the movable core  210  at the close-contact side position (forward movement position). 
     Incidentally, the permanent magnet  212  is fixed such that, for example, a mounting member formed by bending in a channel shape (not shown in the drawing) is placed from the upper side of the permanent magnet  212  and the mounting member is fastened by bolts in the lamination direction of the permanent magnet fixing portion  209   c.    
     Next, the electromagnetic coil  211  will be described with reference to  FIG. 9 . 
     The electromagnetic coil  211  is arranged so as to pass between a major portion  210   a  of the movable core  210  and the longitudinal core portion  209   b  of the fixed core  209 . In an example of this Embodiment 6, the electromagnetic coil  211  surrounds the major portion  210   a  of the movable core  210  in a projection plane toward the axial direction. When the electromagnetic coil  211  is energized, the electromagnetic coil  211  generates a magnetic flux that passes through the fixed core  209  and the movable core  210 . Furthermore, the direction of the magnetic flux generated by the electromagnetic coil  211  can be reversed by switching an energization direction to the electromagnetic coil  211 . The switching of the energization direction is performed by a control board (not shown in the drawing) connected to a capacitor. 
     Next, the vacuum valve  303  and the coupling device  304  will be described with reference to  FIG. 9 . 
     The vacuum valve  303  incorporates a fixed contact  301  and a movable contact  302  in an insulation container  303   a . One end of a movable electrode rod  303   b  fixed to the movable contact  302  is led out to the outside from the insulation container  303   a  and is coupled to the driving shaft  203  of the electromagnet device  201  via the coupling device  304 . This moves and displaces the movable contact  302  in the axial direction of the vacuum valve  303 . The movable contact  302  is brought in contact with the fixed contact  301  to perform close-contact and is separated from the fixed contact  301  to perform open-contact. The inside of the vacuum valve  303  is maintained in vacuum in order to improve arc extinguishing performance between the fixed contact  301  and the movable contact  302 . 
     The coupling device  304  includes: as major constituent elements; an insulation rod  307 ; a contact pressure device  308 ; a coupling bellows  309 ; and a coupling rod  313 . The coupling device  304  includes a plate-like supporting member  305  and supporting braces  306 , which are for coupling to the electromagnet portion  202  of the electromagnet device  201 . 
     The contact pressure device  308  has: a spring frame  310  fixed to an end portion of the coupling rod  313 ; a latch plate  311  which is fixed to a tip end portion of the driving shaft  203  and is arranged in the spring frame  310 ; and a contact pressure spring  312  inserted in a compressed state between the spring frame  310  and the latch plate  311 . The contact pressure spring  312  biases the driving shaft  203  in a direction to be separated from the insulation rod  307 . The driving shaft  203  is capable of being displaced in the axial direction together with the latch plate  311 ; and its displacement is regulated by engagement with respect to the spring frame  310  of the latch plate  311 . 
     The bellows  309  is provided to connect the coupling rod  313  portion and the supporting member  305  so that the coupling rod  313  portion is movable while maintaining hermetic seal with respect to the supporting member  305  serving as a part of the gas container in a portion in which the coupling rod  313  portion of the insulation rod  307  passes through the supporting member  305 . Incidentally, there is also a case where the bellows  309  is not needed according to the configuration of the supporting member  305 . 
     The electromagnet portion  202  is supported to the plate-like supporting member  305  via the supporting braces  306 . Normally, the vacuum valve  303  is incorporated in a container (not shown in the drawing) sealed with insulating gas (for example, SF6 gas, dry air, or the like) which is for securing dielectric strength voltage of a peripheral portion. Therefore, the supporting member  305  is, for example, a lid body of the container; the supporting braces  306  are arranged in a standing condition on the supporting member  305  made by the lid body; and the lower plate  207  of the electromagnet portion  202  is fixed to the supporting braces  306  by bolt fastening or the like. In this regard, however, the supporting member  305  is not limited to this; and, for example, a supporting plate of a switchboard may be permissible. 
     Next, the open-contact and close-contact operation of the vacuum valve  303  of the switch device  400  will be described. 
     When the movable contact  302  is in an open-contact state being separated from the fixed contact  301 , the movable core  210  is at the open-contact side position (backward movement position) by the biasing force of the open-contact spring  205 . When energization is performed from the control board to the electromagnetic coil  211 , the movable core  210  is suctioned to the fixed core  209  and is displaced from the open-contact side position (backward movement position) toward the close-contact side position (forward movement position) against a load of the open-contact spring  205 . This moves the movable contact  302  toward the fixed contact  301 . 
     After that, when the movable contact  302  comes in contact with the fixed contact  301 , the movable contact  302  stops its movement. However, the movable core  210  is further displaced; and the major portion  210   a  comes in contact with the lateral core portion  209   a  of the fixed core  209  to reach the close-contact side position (forward movement position). This shortens the contact pressure spring  312 ; and the movable contact  302  is pressed to the fixed contact  301  by a predetermined pressing force to complete the close-contact operation. 
     When the close-contact operation is completed, the cushioning body portion  204   b  in the cushioning device  204  is fitted into the lower cushioning chamber  204   e  on the lower side (the close-contact side); and thus, speed is reduced by resistance of the viscous body  204   c  and impacts during the completion of the close-contact operation can be reduced. 
     When the movable core  210  reaches the close-contact side position (forward movement position), the movable core  210  is sucked and held by the holding magnetic flux of the permanent magnet  212  to be held at the close-contact side position (forward movement position). 
     In the case of releasing the close-contact side position (forward movement position) of the movable core  210  from being held, energization from the control board to the electromagnetic coil  211  is performed in a direction opposite to that during the close-contact operation. This lowers the suction force between the movable core  210  and the fixed core  209 ; and the movable core  210  moves to the open-contact side position (backward movement position) by each load of the open-contact spring  205  and the contact pressure spring  312 . In the early stages of the displacement, the movable contact  302  remains pressed to the fixed contact  301 . 
     After that, when the displacement of the movable core  210  toward the open-contact side position (backward movement position) proceeds, the latch plate  311  is engaged with the spring frame  310 . This displaces the movable core  302  in a direction to be separated from the fixed contact  301 . When the movable core  210  is further displaced and fixed by coming in contact with the upper plate  206  to reach the open-contact side position (backward movement position) (the state of  FIG. 9 ), open-contact operation is completed. 
     When the open-contact operation is completed, the cushioning body portion  204   b  in the cushioning device  204  is fitted into the upper cushioning chamber  204   d  on the upper side (the open-contact side); and thus, speed is reduced by resistance of the viscous body  204   c  and impacts during the completion of the open-contact operation can be reduced. 
     In the electromagnet device  201  of Embodiment 6, the cushioning device  204  that reduces impacts during the completion of the close-contact operation and the open-contact operation is arranged in the open-contact spring  205 ; and therefore, there can be shortened the entire length of the electromagnet device  201  in which the cushioning device  204  and the electromagnet portion  202  are combined. 
     As shown in  FIG. 9 , in the switch device  400 , the driving shaft  203  of the electromagnet device  201  is coupled to the movable electrode rod  303   b  fixed to the movable contact  302  of the vacuum valve  303 . More specifically, in the switch device  400 , an axis line of the electromagnet device  201  and an axis line of the vacuum valve  303  are arranged in a straight line; and therefore, the entire length of the device can be shortened. 
     For example, in an electromagnetic operation type vacuum circuit breaker disclosed in JP-A-2012-238505 (Patent Document 4), a damper (corresponding to the cushioning device  204  of this Embodiment 6) is arranged; and accordingly, the entire length is elongated. In the electromagnet device  201  of Embodiment 6 of the present invention, the driving shaft  203  and the cushioning device  204  are integrated; and thus, a space for only the cushioning device  204  can be reduced and the switch device  400  can be reduced in size. 
     When the switch device  400  is installed in an outdoor location, the switch device  400  is influenced by a fluctuation of an external temperature. In the cushioning device  204 , when a rubber gasket is used as a material which is for sealing the viscous body  204   c  between the driving shaft  203  and the case of the cushioning device  204 , the cushioning device  204  is influenced by the external temperature of installation environment. More particularly, in the case of a low temperature, there are cases where a standard rubber gasket hardens, sealing property deteriorates, and oil leakage occurs. There are cases where a rubber gasket made of a special material, which takes into consideration the affinity with the viscous body  204   c ; and accordingly, a problem exists in that standardization cannot be achieved. 
     In the electromagnet device  201  of Embodiment 6, the upper bellows  204   f  and the lower bellows  204   g  are connected to seal between the driving shaft  203  and the case of the cushioning device  204 ; and therefore, the viscous body  204   c  is not influenced by ambient temperature. Therefore, standardization can be achieved in a unified manner at all environmental temperatures of the cushioning device  204 . 
     In  FIG. 10  and  FIG. 11 , both of the upper cushioning chamber  204   d  and the lower cushioning chamber  204   e  are provided in the cushioning device  204 ; however, the cushioning chamber can be provided only on one side.  FIG. 14  shows an electromagnet device  221  having a configuration in which only an upper cushioning chamber  224   d  is provided in a cushioning device  224 . The electromagnet device  221  can reduce impacts during open-contact. 
       FIG. 15  shows an electromagnet device  231  having a configuration in which only a lower cushioning chamber  234   e  is provided in a cushioning device  234 . The electromagnet device  231  can reduce impacts during close-contact. 
       FIG. 9  shows that the axis line of the driving shaft  203  of the electromagnet device  201  and the axis line of the vacuum valve  303  are arranged in a straight line. However, a configuration can also be such that the directions of both axis lines are converted by interposing a lever or the like in the coupling device  304  portion. 
     As described above, in the electromagnet device according to Embodiment 6, the fixed core, the movable core, the driving shaft fixed by passing through the movable core, the electromagnetic coil that displaces the movable core to the fixed core along the driving shaft, the open-contact spring that displaces the movable core in the direction to be separated from the fixed core, and the cushioning device that reduces impacts during the completion of the displacement of the movable core are integrated with the driving shaft. Therefore, the electromagnet device can be provided with the cushioning device which reduces impacts during the completion of the close-contact and the open-contact operation and there has an effect that the entire device can be reduced in size. 
     Furthermore, the switch device using the electromagnet device according to Embodiment 6 is configured such that the driving shaft of the electromagnet device is coupled to the movable electrode rod fixed to the movable contact of the vacuum valve and the axis line of the electromagnet device and the axis line of the vacuum valve arranged in a straight line. Therefore, the switch device has a function which reduces impacts during the completion of the close-contact and open-contact operation and has an effect that the entire switch device can be reduced in size. 
     Embodiment 7 
     In Embodiment 6, the cushioning device is placed on the upper plate of the electromagnet portion in the electromagnet device. However, in this Embodiment 7, a configuration is made such that a connection portion is provided between a cushioning device and an electromagnet portion. 
     Hereinafter, with regard to the configuration and the operation of Embodiment 7 of the present invention, a description will be made centering on differences from Embodiment 6 with reference to  FIG. 16  serving as a configuration view of an electromagnet device  241 . 
     In  FIG. 16 , the same reference numerals are given to those identical or equivalent to portions in  FIG. 10  and  FIG. 11 , each serving as the configuration view of the electromagnet device  201  of Embodiment 6. 
     An electromagnet portion  202  has: a fixed core  209 , a movable core  210  arranged in face-to-face relation to the fixed core  209 , and a driving shaft  243  which is provided by passing through a central portion of the movable core  210  and is fixed to the movable core  210 . Furthermore, the electromagnet portion  202  has: an electromagnetic coil  211  which is provided on the fixed core  209  and generates a magnetic field by energization; and a permanent magnet  212  provided on the fixed core  209  side. Further, the electromagnet portion  202  has: braces  213  that fix the fixed core  209 ; and an upper plate  206  serving as an open-contact side plate and a lower plate  207  serving as a close-contact side plate, which are arranged on both ends of the braces  213 . 
     A spring receiver  208  is fixed on the leading end side of the driving shaft  243  protruded to the outside from the upper plate  206 . An open-contact spring  245  (biasing body) is inserted onto a shaft portion of the driving shaft  243  between the upper plate  206  and the spring receiver  208 . The open-contact spring  245  is a compressed coil spring and generates elastic repulsive force in the axial direction between the upper plate  206  and the spring receiver  208 . 
     A cushioning device  204  is fixed to the upper plate  206  via a connection portion  242 . The cushioning device  204  and the connection portion  242  are arranged in the open-contact spring  245 . In the driving shaft  243  of the electromagnet device  241 , a driving shaft  243   a  of the electromagnet portion  202  and a driving shaft  243   b  of a cushioning device  204  portion are coupled at a coupling portion  243   c.    
     The connection portion  242  is provided between the cushioning device  204  and the electromagnet portion  202 ; and thus, even when breakage of the cushioning device  204  occurs by any chance, replacement can be made by removing only the cushioning device  204  portion at the coupling portion  243   c . Therefore, during the breakage of the cushioning device  204 , it can be dealt with by the replacement of only the cushioning device  204  portion, the replacement of the electromagnet portion  202  is not needed and maintainability can be improved. 
     As described above, the electromagnet device according to Embodiment 7 is configured such that the connection portion is placed between the cushioning device and the electromagnet portion. Therefore, effects are exhibited as in the electromagnet device of Embodiment 6 and there has an effect that it can be dealt with by only the replacement of the cushioning device portion during the breakage of the cushioning device. 
     Embodiment 8 
     Embodiment 8 relates to an electromagnet device which is structured such that a cushioning device is placed on the lower surface of an upper plate and is incorporated in a concave portion provided on a movable core. 
     Hereinafter, the configuration and the operation of Embodiment 8 of the present invention will be described centering on differences from Embodiment 6 with reference to  FIG. 17  serving as a configuration view of an electromagnet device  251 . 
     An electromagnet portion  252  has: a fixed core  259 ; a movable core  260  arranged in face-to-face relation to the fixed core  259 ; and a driving shaft  253  which is provided by passing through a central portion of the movable core  260  and is fixed to the movable core  260 . Furthermore, the electromagnet portion  252  has: an electromagnetic coil  261  which is provided on the fixed core  259  and generates a magnetic field by energization; and a permanent magnet  262  provided on the fixed core  259  side. Further, the electromagnet portion  252  has: braces  263  that fix the fixed core  259 ; and an upper plate  256  serving as an open-contact side plate and a lower plate  257  serving as a close-contact side plate, which are arranged on both ends of the braces  263 . 
     A spring receiver  258  is fixed on the leading end side of the driving shaft  253  protruded to the outside from the upper plate  256 . An open-contact spring  255  (biasing body) is inserted onto a shaft portion of the driving shaft  253  between the upper plate  256  and the spring receiver  258 . The open-contact spring  255  is a compressed coil spring and generates elastic repulsive force in the axial direction between the upper plate  256  and the spring receiver  258 . 
     Next, the placing position of a cushioning device  254  will be described. 
     A concave portion  266  surrounding the driving shaft  253  is provided on an upper portion of the movable core  260 . The cushioning device  254  is fixed to the lower surface of the upper plate  256  serving as the open-contact side plate. When the movable core  260  is displaced from an open-contact side position (backward movement position) to a close-contact side position (forward movement position) or is displaced from the close-contact side position (forward movement position) to the open-contact side position (backward movement position), the cushioning device  254  is displaced inside the concave portion  266  of the movable core  260 . 
     As described above, the electromagnet device according to Embodiment 8 is structured such that the cushioning device is fixed to the lower surface of the upper plate and is incorporated in the concave portion provided on the movable core. Therefore, the electromagnet device can be provided with the cushioning device which reduces impacts during the completion of the close-contact and the open-contact operation and there has an effect that the entire device can be reduced in size. 
     Embodiment 9 
     The open-contact spring is provided on the upper portion of the upper plate in Embodiment 8; whereas, Embodiment 9 relates to an electromagnet device which is structured such that an open-contact spring is provided between a branch portion of a movable core and a lower plate. 
     Hereinafter, the configuration and the operation of Embodiment 9 of the present invention will be described centering on differences from Embodiment 6 with reference to  FIG. 18  serving as a configuration view of an electromagnet device  271 . 
     In  FIG. 18 , the same reference numerals are given to those identical or equivalent to portions in  FIG. 17 . 
     An electromagnet portion  272  has: a fixed core  259 ; a movable core  280  arranged in face-to-face relation to the fixed core  259 ; and a driving shaft  273  which is provided by passing through a central portion of the movable core  280  and is fixed to the movable core  280 . Furthermore, the electromagnet portion  272  has: an electromagnetic coil  261  which is provided on the fixed core  259  and generates a magnetic field by energization; and a permanent magnet  262  provided on the fixed core  259  side. Further, the electromagnet portion  272  has: braces  283  that fix the fixed core  259 ; and an upper plate  256  serving as an open-contact side plate and a lower plate  257  serving as a close-contact side plate, which are arranged on both ends of the braces  283 . 
     Open-contact springs  275   a ,  275   b  (biasing body) are provided between the lower surface of a branch portion  280   b  of the movable core  280  and the lower plate  277 . The open-contact springs  275   a ,  275   b  are each a compressed coil spring and generate elastic repulsive force in the axial direction between the branch portion  280   b  of the movable core  280  and the lower plate  277 . 
     The placing position of a cushioning device  254  is similar to that of Embodiment 8. 
     A concave portion  286  surrounding the driving shaft  273  is provided on an upper portion of the movable core  280 . The cushioning device  254  is fixed to the lower surface of the upper plate  256  serving as the open-contact side plate. When the movable core  280  is displaced from an open-contact side position (backward movement position) to a close-contact side position (forward movement position) or is displaced from the close-contact side position (forward movement position) to the open-contact side position (backward movement position), the cushioning device  254  is displaced inside the concave portion  286  of the movable core  280 . 
     As compared to Embodiment 8, the open-contact spring moves from the upper portion of the upper plate to between the branch portion of the movable core and the lower plate; and therefore, the length of the driving shaft is shortened in the upper portion of the upper plate. As described above, the length of the driving shaft portion can be shortened; and therefore, the entire length of the electromagnet device can be further shortened (an effect exists). 
     As described above, the electromagnet device according to Embodiment 9 is structured such that the open-contact spring is provided between the branch portion of the movable core and the lower plate. Therefore, effects similar to that of the electromagnet device of Embodiment 8 are exhibited and there has an effect that the entire length of the electromagnet device can be further shortened. 
     Embodiment 10 
     Embodiment 10 relates to an electromagnet device which is configured such that a cushioning device is provided in a fixed core. 
     Hereinafter, the configuration and the operation of Embodiment 10 of the present invention will be described centering on differences from Embodiment 6 with reference to  FIG. 19  serving as a configuration view of an electromagnet device  501 . 
     An electromagnet portion  502  has: a fixed core  509 ; a movable core  510  arranged in face-to-face relation to the fixed core  509 ; and a driving shaft  503  which is provided by passing through a central portion of the movable core  510  and is fixed to the movable core  510 . Furthermore, the electromagnet portion  502  has: an electromagnetic coil  511  which is provided on the fixed core  509  and generates a magnetic field by energization; and a permanent magnet  512  provided on the fixed core  509  side. Further, the electromagnet portion  502  has: braces  513  that fix the fixed core  509 ; and an upper plate  506  serving as an open-contact side plate and a lower plate  507  serving as a close-contact side plate, which are arranged on both ends of the braces  513 . 
     A spring receiver  508  is fixed on the leading end side of the driving shaft  503  protruded to the outside from the upper plate  506 . An open-contact spring  505  (biasing body) is inserted onto a shaft portion of the driving shaft  503  between the upper plate  506  and the spring receiver  508 . The open-contact spring  505  is a compressed coil spring and generates elastic repulsive force in the axial direction between the upper plate  506  and the spring receiver  508 . 
     A cushioning device  504  is provided in the inside of the fixed core  509  and is fixed on the lower plate  507 . Incidentally, the structure of the cushioning device  504  is the same as that of the cushioning device  204  of Embodiment 6. 
     In the case of having a margin in the fixed core portion, for example, in the case of increasing the suction force of the permanent magnet at the close-contact side position (forward movement position) by increasing the amount of the magnetic substance of the fixed core, the entire length of the electromagnet device can be shortened by arranging the cushioning device as shown in  FIG. 19 . 
     As described above, the electromagnet device according to Embodiment 10 is configured such that the cushioning device is provided in the fixed core. Therefore, the electromagnet device can be provided with the cushioning device which reduces impacts during the completion of the close-contact and the open-contact operation and there has an effect that the entire device can be reduced in size. 
     Embodiment 11 
     Embodiment 11 relates to an electromagnet device which is configured such that a cushioning device is separated from a driving shaft of an electromagnet portion, a plurality of cushioning devices are placed on the upper surface of an upper plate, and driving shafts of the cushioning devices are coupled to a movable core. 
     Hereinafter, the configuration and the operation of Embodiment 11 of the present invention will be described centering on differences from Embodiment 6 with reference to  FIG. 20  serving as a configuration view of an electromagnet device  611 . 
     An electromagnet portion  612  has: a fixed core  619 ; a movable core  620  arranged in face-to-face relation to the fixed core  619 ; and a driving shaft  613  which is provided by passing through a central portion of the movable core  620  and is fixed to the movable core  620 . Furthermore, the electromagnet portion  612  has: an electromagnetic coil  621  which is provided on the fixed core  619  and generates a magnetic field by energization; and a permanent magnet  622  provided on the fixed core  619  side. Further, the electromagnet portion  612  has: braces  623  that fix the fixed core  619 ; and an upper plate  616  serving as an open-contact side plate and a lower plate  617  serving as a close-contact side plate, which are arranged on both ends of the braces  623 . 
     A spring receiver  618  is fixed on the leading end side of the driving shaft  613  protruded to the outside from the upper plate  616 . An open-contact spring  615  (biasing body) is inserted onto a shaft portion of the driving shaft  613  between the upper plate  616  and the spring receiver  618 . The open-contact spring  615  is a compressed coil spring and generates elastic repulsive force in the axial direction between the upper plate  616  and the spring receiver  618 . 
     A plurality of cushioning devices  631 ,  632  are fixed to the upper surface of the upper plate  616 . Driving shafts of the cushioning devices (hereinafter, described as “cushioning device driving shafts”) of the cushioning devices  631 ,  632  are coupled to branch portions of the movable core  620  of the electromagnet portion  612 . 
     The operation of the cushioning devices  631 ,  632  will be described. The structure and the operation of the cushioning devices  631 ,  632  are basically similar to that of the cushioning device  204  of Embodiment 6. However, a different point is that the cushioning device driving shaft  633  of the cushioning device  631  and the cushioning device driving shaft  634  of the cushioning device  632  are each coupled to each of the branch portions of the movable core  620 . 
     First, the movable core  620  is at an open-contact side position (backward movement position). At this time, a cushioning body portion  631   b  of the cushioning device  631  is fitted into an upper cushioning chamber  631   d ; and a cushioning body portion  632   b  of the cushioning device  632  is fitted into an upper cushioning chamber  632   d.    
     When energization is performed from a control board to the electromagnetic coil  621 , the movable core  620  is suctioned to the fixed core  619  and is displaced from the open-contact side position (backward movement position) toward a close-contact side position (forward movement position) against a load of the open-contact spring  615 . At this time, the cushioning device driving shaft  633  of the cushioning device  631  is displaced toward a lower cushioning chambers  631   e ; and the cushioning device driving shaft  634  of the cushioning device  632  is displaced toward a lower cushioning chamber  632   e.    
     When the movable core  620  reaches the close-contact side position (forward movement position), the cushioning body portion  631   b  of the cushioning device  631  is fitted into the lower cushioning chamber  631   e  and the cushioning body portion  632   b  of the cushioning device  632  is fitted into the lower cushioning chamber  632   e.    
       FIG. 20  represents a state where the movable core  620  is at the close-contact side position (forward movement position), the cushioning body portion  631   b  of the cushioning device  631  coupled to the movable core  620  is fitted into the lower cushioning chamber  631   e , and the cushioning body portion  632   b  of the cushioning device  632  coupled to the movable core  620  is fitted into the lower cushioning chamber  632   e.    
     In  FIG. 20 , two cushioning devices are placed; however, three or more cushioning devices can be provided. In the case where a plurality of cushioning devices are arranged in axial symmetry; for example, three cushioning devices are provided, the cushioning devices are preferable to be placed at 120 degree intervals. 
     A plurality of the cushioning devices  631 ,  632  are fixed to the upper surface of the upper plate  616 ; and thus, the plurality of the cushioning devices  631 ,  632  can be arranged in a range smaller than the height of the open-contact spring  615  and therefore the entire length of the electromagnet device can be shortened as in Embodiment 6. 
     Furthermore, in the case of exchanging the cushioning devices  631 ,  632 , the open-contact spring  615  does not need to be removed and maintainability is improved. 
     As described above, the electromagnet device according to Embodiment 11 is configured such that the cushioning device is separated from the driving shaft of the electromagnet portion, the plurality of the cushioning devices are placed on the upper surface of the upper plate, and the cushioning device driving shafts are coupled to the movable core. Therefore, the electromagnet device can be provided with the cushioning devices which reduce impacts during the completion of the close-contact and the open-contact operation and there has an effect that the entire device can be reduced in size. Further, maintainability during replacement of the cushioning devices can be improved. 
     Incidentally, the present invention can freely combine the respective embodiments and appropriately change and/or omit the respective embodiments, within the scope of the present invention.