Abstract:
An electromagnetic force driving device having reduced size and weight, and easily changeable electromagnetic characteristics and holding force, is provided. The device includes: a first housing; a second housing installed under the first housing; a partitioning wall partitioning the first and second housings; a first mover installed on a top of the first housing; a coil unit installed at a lower portion of the second housing to be movable according to a direction of current supplied; a second mover including one end combined with the coil unit, and another end passing through the partitioning wall and connected to the first mover to operate the first mover according to a movement of the coil unit; an upper magnet installed in the first housing to maintain a predetermined position of the first mover; and a lower magnet arranged in the second housing to form a magnetic field at the coil unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 USC §119(a) of Korean Application No. 10-2013-00165734 filed on Dec. 27, 2013 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an electromagnetic force driving device, and more specifically, to an electromagnetic force driving device, in which the size and weight can be reduced by combining a magnetic substance and a coil unit through a connection pin inside thereof, and electromagnetic characteristics and a holding force can be easily changed by forming independent motion paths. 
         [0004]    2. Background of the Related Art 
         [0005]    Generally, a circuit breaker is installed at a sending end or a receiving end of a power transmission line to open and close a normal current when there is no failure in a power system and, in addition, to protect the power system and various power devices (loads) by blocking a fault current when a failure such as a short circuit or the like occurs. 
         [0006]    Such a circuit breaker is classified into a Vacuum Circuit Breaker (VCB), an Oil Circuit Breaker (OCB), a Gas Circuit Breaker (GCB) and the like according to an extinguishing/insulating material. 
         [0007]    When the circuit breaker blocks the fault current, arcs generated between two contacting points should be extinguished, and the gas circuit breaker is classified again into a Puffer type, a Rotating arc type, a Thermal expansion type, a Hybrid extinction type and the like according to a method of extinguishing the arcs. 
         [0008]    In such a circuit breaker, an opening operation should be accomplished at a high speed in order to block the failure current and promptly recover insulation between electrodes, and, for example, a high voltage/extra high voltage (generally, 365 kv or higher) circuit breaker for power transmission has a stroke length (SL) of about 250 mm and requires a force and a speed as large as to complete the operation within an extremely short time of 45 ms (milliseconds). 
         [0009]    Although a hydraulic or pneumatic actuator is chiefly used as a high voltage/extra high voltage circuit breaker at present, there is a problem in that such an actuator is very expensive as much as one third of a total price of the circuit breaker, and, in Korean, most of actuators are imported. 
         [0010]    Furthermore, in such a hydraulic or pneumatic actuator, working fluid may be leaked according to changes in the temperature of surrounding areas, and since the actuator is configured of a lot of parts, it is worried that the actuator may not operate if any one of the parts is out of order. 
         [0011]    Accordingly, studies on development of actuators for substituting hydraulic or pneumatic actuators are under progress, and a spring actuator (a spiral spring), a motor drive (a system for converting a rotation motion into a linear motion using a motor), and a permanent magnetic actuator (PMA) are representatively used as results of the studies. 
         [0012]    However, since the spring actuator is a system for obtaining power by releasing a compressed force when needed while a spring is compressed, its manufacturing cost is low. However, it is disadvantageous in that reliability of an operation state is low since elastic force of the spring is inconsistent. Therefore, it is difficult to apply the spring actuator to a high voltage/extra high voltage in which extinction gas should be sprayed, and, in addition, probability of failing the cutoff will be very high. 
         [0013]    In addition, although manufacturing cost of the motor drive is low compared with that of the hydraulic or pneumatic actuator, since it is still expensive and difficult to generate a high power, the motor drive can be used for a low voltage, but may not exhibit sufficient performance at a high or extra high voltage. 
         [0014]    In addition, the PMA actuator is formed to operate a mover using an electromagnetic force caused by a magnetic force generated by a permanent magnet and a magnetic field generated by flowing current through a coil, and since the PMA actuator is advantageous in that it has a simple structure and a good actuating efficiency and a consistent and uniform operation can be expected, it is frequently used as an actuator for a low voltage circuit breaker recently. 
         [0015]    However, since the PMA actuator is a system which should be driven by a magnetic force generated by a permanent magnet and a magnetic force generated by flowing current through a coil, a path for flowing the magnetic field should be prepared using a magnetic substance (an iron core), and, in addition, the driven mover also should be formed of a magnetic substance. 
         [0016]    Accordingly, when the breaking capacity is increased and thus the actuator needs a more powerful force, more magnetic fields should be generated, and the magnetic substance also should be increased as much as to flow the magnetic fields without being saturated, and thus the burden on the size of the actuator is increased, and since magnetic flux densities excited at the permanent magnet and the coil are inverse proportional to the square of an air gap length, there is a limit in applying the PMA actuator to a high voltage or extra high voltage circuit breaker having a large contact gap of a breaking unit, and thus there is a problem in that when the PMA actuator is used for an extra high voltage, its size should be much bigger, and its weight is much heavier than that of a hydraulic or pneumatic actuator, and, in addition, manufacturing cost is also increased. 
         [0017]    Recently, an actuator such as an electromagnetic circuit breaker or an Electro-Magnetic Force Driving Actuator (EMFA) have been proposed in Korea Patent Registration No. 10-0718927 (title of the invention: Actuator using electromagnetic force and circuit breaker using thereof) to maximize the actuating speed and force while having a small size and weight to solve the problems of the circuit breakers. 
         [0018]    Such an electromagnetic circuit breaker is a kind of circuit breaker having a structure of providing inner and outer hollow containers formed of a magnetic substance, arranging inner and outer permanent magnets on the facing surfaces of the inner and outer containers, and arranging a coil and a mover of a non-magnetic substance operating together with the coil as one piece between the inner permanent magnet and the outer permanent magnet, and thus when a current is supplied to the coil, the coil and the mover linearly move in the axis direction between the inner permanent magnet and the outer permanent magnet by an electromagnetic repulsion force generated by the magnetic field of the inner and outer permanent magnets and the current density of the coil. 
         [0019]    However, in such an electromagnetic circuit breaker (EMFA), since the coil is arranged inside the enclosed outer container, it is difficult to connect an electric wire inside the outer container to supply current to the coil. 
         [0020]    In addition, although the wire is connected, since the connected wire moves in the axis direction according to the linear motion of the coil, there is a problem of open circuit since the moving speed of the coil is too high and thus the electric wire is fatigued by compression and tension. 
         [0021]    In addition, since a conventional electromagnetic circuit breaker has a mover arranged inside the enclosed hollow inner and outer containers, a moving axis or a connection axis should be extended long from the mover in the axis direction in order to connect the mover to an external movement element, and, in addition, the length of the extension should be long enough to sufficiently secure a stroke distance of the mover. 
         [0022]    In addition, since increase of the length leads to increase of the overall height occupied by the circuit breaker, and the number of the connection axis or the moving axis should be increased or a connection axis or a moving axis of a large diameter should be used considering strength of the connection axis or the moving axis, there is a problem in that the overall weight of the circuit breaker is increased. 
         [0023]    In addition, since the conventional circuit breaker has a coil unit and a magnetic substance formed in one piece, there is a problem in that electromagnetic characteristics and a holding force for maintaining a top or bottom dead point state cannot be changed according to an installation environment. 
       SUMMARY OF THE INVENTION 
       [0024]    Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an electromagnetic force driving device, in which the size and weight can be reduced by combining a magnetic substance and a coil unit through a connection pin inside thereof, and electromagnetic characteristics and a holding force can be easily changed by forming independent motion paths. 
         [0025]    To accomplish the above object, according to one aspect of the present invention, there is provided an electromagnetic force driving device comprising: a housing  210  or  210 ′ including a first housing  210   a  in which a first mover  220  is installed, a second housing  210   b  in which a coil unit  230  is installed, a third housing  210   c  installed on a bottom surface of the second housing  210   b , and a fourth housing  210   d  for partitioning the first housing  210   a  and the second housings  210   b ; a first mover  220  installed on a top of the first housing  210   a  to be movable in a vertical direction; a coil unit  230  installed in parallel to the second housing  210   b  to move either upwards or downwards by a repulsive force according to a direction of current supplied in a forward direction or a reverse direction; a second mover  240 , one end of which is combined with the coil unit  230 , and the other end of which passes through the fourth housing  210   d  to be connected to the first mover  220 , to operate the first mover  220  according to a movement of the coil unit  230 ; an upper magnet  250  installed in the first housing  210   a  to be tightly attached to the first mover  220  to provide a magnetic force for the first mover  220  to maintain either a top dead point or a bottom dead point; and a lower magnet  260  installed in the second housing  210   b  to form a magnetic field using the coil unit  230 . 
         [0026]    In addition, the second housing  210   b  according to the present invention includes: a first non-magnetic substance  270  installed between the fourth housing  210   d  and the lower magnet  260 ; and a second non-magnetic substance  271  installed between the lower magnet  260  and the third housing  210   c.    
         [0027]    In addition, the first mover  220  according to the present invention includes: a first mover lower body  221  connected to a bottom surface of a body of the first mover  220  through a first mover link  221   a ; a first attaching unit  220   a  protruded from the body of the first mover  220  by a certain thickness to be tightly attached to the upper magnet  250  through a magnetic field; and a second attaching unit  221   b  protruded from the first mover lower body  221  by a certain thickness to be tightly attached to the upper magnet  250  through a magnetic field. 
         [0028]    In addition, the upper magnet  250  according to the present invention further includes: a first magnetic substance  251  installed at both sides of a body of the upper magnet  250  to form a path of a magnetic field; and a first non-magnetic substance  252  having a first mover link penetration hole  252   a  formed for the first mover link  220   a  to pass through and preventing a magnetic field formed by the upper magnet  250  and the first magnetic substance  251  from being formed at the first housing  210   a.    
         [0029]    In addition, the electromagnetic force driving device according to the present invention further comprises: a supporting housing  210   e  installed under the third housing  210   c  of the housing  210 ′; a first supporting mover  220 ′ installed under the supporting housing  210   e  to be movable in a vertical direction; a second supporting mover  240 ′, one end of which is combined with the coil unit  230 , and the other end of which passes through the third housing  210   c  to be connected to the first supporting mover  220 ′, to operate the first supporting mover  220 ′ according to a movement of the coil unit  230 ; and a supporting magnet  250 ′ installed in the supporting housing  210   e  to be tightly attached to the first supporting mover  220 ′ to provide a magnetic field for the first supporting mover  220 ′ to maintain either the top dead point or the bottom dead point. 
         [0030]    In addition, the first supporting mover  220 ′ according to the present invention includes: a first supporting mover lower body  221 ′ connected to a bottom surface of a body of the first supporting mover  220 ′ through a first supporting mover link  221   a ′; a first supporting attaching unit  220   a ′ protruded from the body of the first supporting mover  220 ′ by a certain thickness to be tightly attached to the supporting magnet  250 ′ through a magnetic field; and a second supporting attaching unit  221   b ′ protruded from the first supporting mover lower body  221 ′ by a certain thickness to be tightly attached to the supporting magnet  250 ′ through a magnetic field. 
         [0031]    In addition, the supporting magnet  250 ′ according to the present invention further includes: a first supporting magnetic substance  251 ′ installed at both sides of a body of the supporting magnet  250 ′ to form a path of a magnetic field; and a first supporting non-magnetic substance  252 ′ having a first supporting mover link penetration hole  252   a ′ formed for the first supporting mover link  220   a ′ to pass through and preventing a magnetic field formed by the supporting magnet  250 ′ and the first supporting magnetic substance  251 ′ from being formed at the supporting housing  210   e.    
         [0032]    In addition, the first housing  210   a  and the supporting housing  210   e  according to the present invention are arranged to be parallel or perpendicular to a length direction of the coil unit  230  of the second housing  210   b.    
         [0033]    The present invention is advantageous in that when an error occurs in a power distribution and transmission line, it can be promptly cut off, and the overall weight and size can be reduced by simplifying the structure of the electromagnetic force driving device by combining a magnetic substance and a coil unit through a connection pin inside thereof. 
         [0034]    In addition, the present invention is advantageous in that electromagnetic characteristics and a holding force can be easily changed by forming independent motion paths for moving the mover and the coil unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0035]      FIG. 1  is a perspective view showing a first embodiment of an electromagnetic force driving device according to the present invention. 
           [0036]      FIG. 2  is an exploded perspective view showing the configuration of the electromagnetic force driving device according to  FIG. 1 . 
           [0037]      FIG. 3  is a cross-sectional view showing the structure and operation of the electromagnetic force driving device according to  FIG. 1 . 
           [0038]      FIG. 4  is a perspective view showing a second embodiment of an electromagnetic force driving device according to the present invention. 
           [0039]      FIG. 5  is a cross-sectional view showing the structure of the electromagnetic force driving device according to  FIG. 4 . 
           [0040]      FIG. 6  is a perspective view showing a third embodiment of an electromagnetic force driving device according to the present invention. 
           [0041]      FIG. 7  is an exploded perspective view showing the configuration of the electromagnetic force driving device according to  FIG. 6 . 
           [0042]      FIG. 8  is a cross-sectional view showing the structure of the electromagnetic force driving device according to  FIG. 6 . 
           [0043]      FIG. 9  is a perspective view showing a fourth embodiment of an electromagnetic force driving device according to the present invention. 
           [0044]      FIG. 10  is a cross-sectional view showing the structure of the electromagnetic force driving device according to  FIG. 9 . 
       
    
    
     DESCRIPTION OF SYMBOLS 
       [0000]    
       
           200 ,  200 ′,  400 ,  400 ′: Electromagnetic force driving device 
           210 ,  210 ′,  410 ,  410 ′: Housing 
           220 ,  420 : First mover 
           220 ′,  420 ′: First supporting mover 
           230 ,  430 : Coil unit 
           240 ,  440 : Second mover 
           240 ′,  440 ′: Second supporting mover 
           250 ′,  450 : Upper magnet 
           260 ,  460 : Lower magnet 
           270 ,  470 : First non-magnetic substance 
           271 ,  471 : Second non-magnetic substance 
       
     
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0056]    Hereafter, preferred embodiments of an electromagnetic force driving device according to the present invention will be described in detail with reference to the accompanying drawings. 
       First Embodiment 
       [0057]      FIG. 1  is a perspective view showing a first embodiment of an electromagnetic force driving device according to the present invention,  FIG. 2  is an exploded perspective view showing the configuration of the electromagnetic force driving device according to  FIG. 1 , and  FIG. 3  is a cross-sectional view showing the structure and operation of the electromagnetic force driving device according to  FIG. 1 . 
         [0058]    As shown in  FIGS. 1 to 3 , an electromagnetic force driving device  200  according to a first embodiment is configured to include a housing  210 , a first mover  220 , a coil unit  230 , a second mover  240 , an upper magnet  250  and a lower magnet  260 . 
         [0059]    The housing  210  is a magnetic substance configured to include a first housing  210   a , a second housing  210   b , a third housing  210   c  and a fourth housing  210   d . The first housing  210   a  forms a structure in which side walls are installed at both sides, and both sides of the first housing  210   a , as well as the top side thereof, are open in the length direction. 
         [0060]    In addition, a first mover  220  and an upper magnet  250  are installed in the first housing  210   a , and a first motion path  211  along which the first mover  220  moves is formed inside the first housing  210   a.    
         [0061]    The second housing  210   b  is installed under the first housing  210   a  to be separated by the fourth housing  210   d , and a second motion path  212  for moving the coil unit  230  is formed inside thereof. 
         [0062]    The third housing  210   c  is installed under the second housing  210   b  to support the lower magnet  260 , a first non-magnetic substance  270  and a second non-magnetic substance  271  installed in the second housing  210   b , and the second and third housings  210   b  and  210   c  are preferably formed of a magnetic substance. 
         [0063]    The fourth housing  210   d  is installed between the first housing  210   a  and the second housing  210   b  to partition the first and second housings  210   a  and  210   b , and a non-magnetic substance  214  may be installed between the first housing  210   a  and the fourth housing  210   d.    
         [0064]    The first mover  220  is installed on the top of the first housing  210   a  to be movable in the vertical direction and fixed to the first housing  210   a  to be selectively positioned at the top dead point or the bottom dead point, and a first mover lower body  221  of a plate shape moving along the first motion path  211  of the first housing  210   a  is spaced apart from the first mover  220  by a certain distance under the first mover  220  of a plate shape and connected to the first mover  220  through a first mover link  221   a.    
         [0065]    In addition, the first mover  220  is protruded from the bottom surface of the body of the first mover  220  by a certain thickness to form a first attaching unit  220   a , and if the first mover  220  moves downwards, the first mover  220  forms a magnetic field together with the upper magnet  250  so that the first mover  220  may maintain a state of being tightly attached to the first housing  210   a.    
         [0066]    In addition, the first mover lower body  221  is protruded from the top surface of the first mover lower body  221  by a certain thickness to form a second attaching unit  221   b , and if the first mover lower body  221  moves upwards, the first mover lower body  221  forms a magnetic field together with the upper magnet  250  so that the first mover lower body  221  may maintain a state of being tightly attached to the first housing  210   a.    
         [0067]    In addition, the first mover  220  and the first mover lower body  221  are configured of a magnetic substance to form a magnetic force together with the upper magnet  250  to be fixed at a predetermined position. 
         [0068]    The coil unit  230  is a configuration installed inside the second housing  210   b  to be movable in the vertical direction and providing a driving force so as to move in a direction perpendicular to the magnetic field of the lower magnet  260  (either upwards or downwards in the figure) by a magnetic flux density generated by the lower magnet  260 , a density of current supplied to the coil unit  230  and an electromagnetic repulsive force according to a direction of current supplied in a forward or reverse direction, and it is configured to be wound (wrapped) with a conductive wire in an approximate oval shape so that, for example, current may flow in a forward direction of flowing clockwise from the left to the right or in a reverse direction of flowing counterclockwise from the right to the left in the figure. 
         [0069]    The coil unit  230  is installed to penetrate the second housing  210   b  in the lateral direction, and the second mover  240  is installed on the coil unit  230  so that operation of the coil unit  230  can be performed together with the first mover  220 . 
         [0070]    The second mover  240  is a pipe shaped member, in which one end is combined with the top of the coil unit  230 , and the other end passes through the second mover penetration hole  213  of the fourth housing  210   d  to be connected to the first mover  220 , to operate the first mover  220  to move in the vertical direction according to the vertical movement of the coil unit  230 . 
         [0071]    The upper magnet  250  is a bar shaped permanent magnet tightly attached to either the first mover  220  or the first mover lower body  221  to form a magnetic field for moving the first mover  220  upwards and maintaining a top dead point or to form a magnetic field for moving the first mover  220  downwards and maintaining a bottom dead point where the first mover  220  is tightly attached to the top surface of the first housing  210   a  and thus provides a holding force (magnetic force) so that the first mover  220  may maintain either the top dead point or the bottom dead point. 
         [0072]    In addition, a first magnetic substance  251  is installed at both sides of the upper magnet  250  to provide a large holding force with a small size (area or volume) and may provide an appropriate holding force to the first mover  220  or the first mover lower body  221  according to the usage of installation by freely changing the size of the upper magnet  250 . 
         [0073]    The first magnetic substance  251  is installed at both sides of the upper magnet  250  so that the upper magnet  250  may be fixed to the first housing  210   a , has a magnet installation groove  251   a  formed in the length direction to insert the upper magnet  250 , and forms a magnetic circuit together with the first mover  220  or the first mover lower body  221  through the magnetic field formed by the upper magnet  250 . 
         [0074]    Meanwhile, a non-magnetic substance  252  is installed between the first magnetic substance  251  and the first housing  210   a  to prevent the magnetic field formed by the upper magnet  250  and the first magnetic substance  251  from being formed at the first housing  210   a  which is a magnetic substance, and a first mover link penetration hole  252   a  is formed so that the first mover link  221   a  which connects the first mover  220  and the first mover lower body  221  may pass through. 
         [0075]    The lower magnet  260  is a configuration installed inside the second housing  210   b  to form a magnetic field around the coil unit  230 , in which a first lower magnet  260   a , a second lower magnet  260   b , a third lower magnet  260   c  and a fourth lower magnet  260   d  are sequentially arranged around the coil unit  230  and form a magnetic field to generate a repulsive force for moving the coil unit  230  upwards or downwards according to a direction of current supplied to the coil unit  230 . 
         [0076]    In addition, the first non-magnetic substance  270  and the second non-magnetic substance  271  are installed above and below the first to fourth lower magnets, respectively, between the first to fourth lower magnets  260   a ,  260   b ,  260   c  and  260   d  and the fourth housing  210   d  and between the first to fourth lower magnets  260   a ,  260   b ,  260   c  and  260   d  and the third housing  210   c  to form a magnetic path by maintaining a distance, and N poles and S poles of the first to fourth lower magnets  260   a ,  260   b ,  260   c  and  260   d  are sequentially arranged inside the second housing  210   b  centering on the coil unit  230  so that a magnetic field may be formed in a predetermined direction. 
         [0077]    If the first to fourth lower magnets  260   a ,  260   b ,  260   c  and  260   d  are arranged as described above and a forward or reverse current flows through the coil unit  230 , the coil unit  230  is moved in a direction perpendicular to the magnetic field, i.e., upwards or downwards, by a force generated by the Fleming&#39;s left hand rule based on the magnetic density generated by the first to fourth magnets  260   a ,  260   b ,  260   c  and  260   d , current density of the coil unit  230  and the repulsive force according to the direction of the current. 
         [0078]    The first non-magnetic substance  270  is installed between the fourth housing  210   d  and the lower magnet  260 , and the second non-magnetic substance  271  is installed between the lower magnet  260  and the third housing  210   c  so that a magnetic path may be formed around the coil unit  230 . 
         [0079]    Next, the operation procedure of the electromagnetic force driving device  200  according to a first embodiment of the present invention will be described. 
         [0080]    (Supply of Forward Current) 
         [0081]    When the first mover  220  is positioned at the top dead point protruded above the first housing  210   a , a magnetic field is formed between the upper magnet  250  and the first mover lower body  221 , and the first mover  220  maintains a state of being positioned at the top dead point. 
         [0082]    Then, if a forward current is supplied to the coil unit  230 , the coil unit  230  moves downwards due to the electromagnetic force caused by the electric field generated by the coil unit  230  and the magnetic field generated by the lower magnet  260 , and the first mover  220  also moves downwards by the second mover  240  combined with the coil unit  230 . 
         [0083]    If the forward current supplied to the coil unit  230  is cut off, a magnetic field is generated between the first mover  220  and the upper magnet  250 , and thus the first mover  220  is held at the bottom dead point where the first mover  220  is tightly attached to the first housing  210   a , through a magnetic force generated by the magnetic field. 
         [0084]    (Supply of Reverse Current) 
         [0085]    When the first mover  220  is positioned at the bottom dead point where the first mover  220  is tightly attached to the top surface of the first housing  210   a , the first mover  220  maintains the bottom dead point through a holding force generated by the magnetic field between the upper magnet  250  and the first mover  220 . 
         [0086]    Then, if a reverse current is supplied to the coil unit  230 , the coil unit  230  moves upwards due to the electromagnetic force caused by the electric field generated by the coil unit  230  and the magnetic field generated by the lower magnet  260 , and the first mover  220  also moves upwards by the second mover  240  combined with the coil unit  230 . 
         [0087]    If the reverse current supplied to the coil unit  230  is cut off, a magnetic field is generated between the first mover lower body  221  and the upper magnet  250 , and thus the first mover  220  moves to the top dead point above the first housing  210   a  and is held through a magnetic force generated by the magnetic field and. 
       Second Embodiment 
       [0088]      FIG. 4  is a perspective view showing a second embodiment of an electromagnetic force driving device according to the present invention, and  FIG. 5  is a cross-sectional view showing the structure of the electromagnetic force driving device according to  FIG. 4 . 
         [0089]    Repeated descriptions of the elements the same as those of the first embodiment are omitted, and like numerals are used for like elements of the first embodiment, and characteristic elements of a second embodiment will be described. 
         [0090]    As shown in  FIGS. 4 and 5 , the electromagnetic force driving device  200 ′ according to a second embodiment of the present invention is configured to include a housing  210 , a first mover  220 , a first supporting mover  220 ′, a coil unit  230 , a second mover  240 , a second supporting mover  240 ′, an upper magnet  250 , a supporting magnet  250 ′, a lower magnet  260 , a first non-magnetic substance  270  and a second non-magnetic substance  271 . 
         [0091]    The housing  210 ′ is a magnetic substance configured to include a first housing  210   a , a second housing  210   b , a third housing  210   c , a fourth housing  210   d , and a supporting housing  210   e.    
         [0092]    The supporting housing  210   e  is installed in a direction opposite to the first housing  210   a  from the second housing  210   b , separated from the second housing  210   b  through the third housing  210   c , and configured in a shape the same as the first housing  210   a  of the third embodiment, and a non-magnetic substance  214 ′ may be installed between the third housing  210   c  and the supporting housing  210   e.    
         [0093]    In addition, a first supporting mover  220 ′ and a supporting magnet  250 ′ are installed in the supporting housing  210   e , and a motion path for moving the first supporting mover  220 ′ is formed inside the supporting housing  210   e.    
         [0094]    The first supporting mover  220 ′ is a magnetic substance installed on the bottom of the supporting housing  210   e  to be movable in the vertical direction and fixed to the supporting housing  210   e  to be selectively positioned at the top dead point or the bottom dead point, and a first supporting mover lower body  221 ′ of a plate shape moving along the motion path of the supporting housing  210   e  is spaced apart from the first supporting mover  220 ′ by a certain distance under the plate shaped first supporting mover  220 ′ and connected to the first supporting mover  220 ′ through a first supporting mover link  221   a′.    
         [0095]    In addition, the first supporting mover  220 ′ is protruded from the body of the first supporting mover  220 ′ by a certain thickness to form a first supporting attaching unit  220   a ′, and if the first supporting mover  220 ′ moves upwards, the first supporting mover  220 ′ forms a magnetic field together with the supporting magnet  250 ′ and maintains a state of being tightly attached to the supporting housing  210   e.    
         [0096]    In addition, the first supporting mover lower body  221 ′ is protruded from the bottom surface of the first supporting mover lower body  221 ′ by a certain thickness to form a second supporting attaching unit  221   b ′, and if the first supporting mover lower body  221 ′ moves downwards, the first supporting mover lower body  221 ′ forms a magnetic field together with the supporting magnet  250 ′ so that the first supporting mover lower body  221 ′ may maintain a state of being tightly attached to the supporting housing  210   e.    
         [0097]    In addition, the first supporting mover  220 ′ and the first supporting mover lower body  221 ′ are configured of a magnetic substance to form a magnetic field together with the supporting magnet  250 ′ to be fixed at the top dead point or the bottom dead point. 
         [0098]    The second supporting mover  240 ′ is a pipe shaped member, in which one end is combined with the bottom of the coil unit  230 , and the other end passes through the third housing  210   c  to be connected to the first supporting mover  220 ′, to operate the first supporting mover  220 ′ to move in the vertical direction according to the vertical movement of the coil unit  230 . 
         [0099]    The supporting magnet  250 ′ is a bar shaped permanent magnet tightly attached to either the first supporting mover  220 ′ or the first supporting mover lower body  221 ′ to form a magnetic field for moving the first supporting mover  220 ′ upwards and maintaining the top dead point or to form a magnetic field for moving the first supporting mover  220 ′ downwards and maintaining the bottom dead point where the first supporting mover  220 ′ is tightly attached to the supporting housing  210   e  and thus provides a holding force (magnetic force) so that the first supporting mover  220 ′ may maintain either the top dead point or the bottom dead point. 
         [0100]    In addition, a first supporting magnetic substance  251 ′ is installed at both sides of the supporting magnet  250 ′ to provide a large holding force with a small size (area or volume) and may provide an appropriate holding force to the first supporting mover  220 ′ or the first supporting mover lower body  221 ′ according to the usage of installation by freely changing the size of the supporting magnet  250 ′. 
         [0101]    The first supporting magnetic substance  251 ′ is installed at both sides of the supporting magnet  250 ′ so that the supporting magnet  250 ′ may be fixed to the supporting housing  210   e , has a magnet installation groove formed in the length direction to insert the supporting magnet  250 ′, and forms a magnetic circuit together with the first supporting mover  220 ′ or the first supporting mover lower body  221 ′ through the magnetic field formed by the supporting magnet  250 ′. 
         [0102]    Meanwhile, a supporting non-magnetic substance  252 ′ is installed between the first supporting magnetic substance  251 ′ and the supporting housing  210   e  to prevent the magnetic field formed by the supporting magnet  250 ′ and the first supporting magnetic substance  251 ′ from being formed at the supporting housing  210   e  which is a magnetic substance, and a first supporting mover link penetration hole is formed so that the first supporting mover link  221   a ′ which connects the first supporting mover  220 ′ and the first supporting mover lower body  221 ′ may pass through. 
         [0103]    Accordingly, if a forward current is supplied to the coil unit  230 , the coil unit  230  moves downwards due to the electromagnetic force caused by the electric field generated by the coil unit  230  and the magnetic field generated by the lower magnet  260 , and the first mover  220  and the first supporting mover  220 ′ also move downwards by the second mover  240  and the second supporting mover  240 ′ combined with the coil unit  230 . If the forward current supplied to the coil unit  230  is cut off, a magnetic field is generated between the first mover  220  and the upper magnet  250 , and thus the first mover  220  is held at the bottom dead point where the first mover  220  is tightly attached to the first housing  210   a , through a magnetic force generated by the magnetic field, and held at the top dead point where the first supporting mover  220 ′ is tightly attached to the supporting housing  210   e  by the magnetic field generated between the first supporting mover lower body  221 ′ and the supporting magnet  250 ′, through a magnetic force generated by the magnetic field. 
         [0104]    Then, if a reverse current is supplied to the coil unit  230 , the first mover  220  and the first supporting mover  220 ′ move upwards by a repulsive force generated by the electromagnetic force and held at the top dead point and the bottom dead point respectively through a magnetic force generated by the upper magnet  250  and the supporting magnet  250 ′. 
       Third Embodiment 
       [0105]      FIG. 6  is a perspective view showing a third embodiment of an electromagnetic force driving device according to the present invention,  FIG. 7  is an exploded perspective view showing the configuration of the electromagnetic force driving device according to  FIG. 6 , and  FIG. 8  is a cross-sectional view showing the structure of the electromagnetic force driving device according to  FIG. 6 . 
         [0106]    As shown in  FIGS. 6 to 8 , an electromagnetic force driving device  400  according to a third embodiment is configured to include a housing  410 , a first mover  420 , a coil unit  430 , a second mover  440 , an upper magnet  450  and a lower magnet  460 . 
         [0107]    The housing  410  is a magnetic substance configured to include a first housing  410   a , a second housing  410   b , a third housing  410   c , and a fourth housing  410   d . The first housing  410   a  forms a structure in which side walls are installed at both sides, and both sides of the first housing  410   a , as well as the top side thereof, are open in the length direction. 
         [0108]    In addition, a first mover  420  and an upper magnet  450  are installed in the first housing  410   a , and a first motion path  411  along which the first mover  420  moves is formed inside the first housing  410   a.    
         [0109]    The second housing  410   b  is installed under the first housing  410   a  to be separated by the fourth housing  410   d , and a second motion path  412  for moving the coil unit  430  is formed inside thereof. 
         [0110]    The third housing  410   c  is installed under the second housing  410   b  to support the lower magnet  460 , a first non-magnetic substance  470  and a second non-magnetic substance  471  installed in the second housing  410   b , and the second and third housings  410   b  and  410   c  are preferably formed of a magnetic substance. 
         [0111]    The fourth housing  410   d  is installed between the first housing  410   a  and the second housing  410   b  to partition the first and second housings  410   a  and  410   b , and a non-magnetic substance  414  may be installed between the first housing  410   a  and the fourth housing  410   d.    
         [0112]    The difference between the electromagnetic force driving device  400  according to the third embodiment and the electromagnetic force driving device  200  according to the first embodiment is installation directions of the first and second housings  410   a  and  410   b , and the first housing  410   a  according to the third embodiment is arranged such that the groove unit formed in the length direction is parallel to the length direction of the coil unit  430  of the second housing  410   b.    
         [0113]    The first mover  420  is installed on the top of the first housing  410   a  to be movable in the vertical direction and fixed to the first housing  410   a  to be selectively positioned at the top dead point or the bottom dead point, and a first mover lower body  421  of a plate shape moving along the first motion path  411  of the first housing  410   a  is spaced apart from the first mover  420  by a certain distance under the first mover  420  of a plate shape and connected to the first mover  420  through a first mover link  421   a.    
         [0114]    In addition, the first mover  420  is protruded from the bottom surface of the body of the first mover  420  by a certain thickness to form a first attaching unit  420   a , and if the first mover  420  moves downwards, the first mover  420  forms a magnetic field together with the upper magnet  450  so that the first mover  420  may maintain a state of being tightly attached to the first housing  410   a.    
         [0115]    In addition, the first mover lower body  421  is protruded from the top surface of the first mover lower body  421  by a certain thickness to form a second attaching unit  421   b , and if the first mover lower body  421  moves upwards, the first mover lower body  421  forms a magnetic field together with the upper magnet  450  so that the first mover lower body  421  may maintain a state of being tightly attached to the first housing  410   a , and the first mover  420  and the first mover lower body  421  are configured of a magnetic substance. 
         [0116]    The coil unit  430  is a configuration installed inside the second housing  410   b  to be movable in the vertical direction and providing a driving force so as to move in a direction perpendicular to the magnetic field of the lower magnet  460  (either upwards or downwards in the figure) by a magnetic flux density generated by the lower magnet  460 , a density of current supplied to the coil unit  430  and an electromagnetic repulsive force according to the direction of current supplied in a forward or reverse direction, and since a conductive wire is wound (wrapped) in an approximate oval shape, the current may flow in a forward or reverse direction. 
         [0117]    The coil unit  430  is installed to penetrate the second housing  410   b  in the lateral direction, and the second mover  440  is installed on the coil unit  430  so that operation of the coil unit  430  can be performed together with the first mover  420 . 
         [0118]    The second mover  440  is a pipe shaped member, in which one end is combined with the top of the coil unit  430 , and the other end passes through the second mover penetration hole  413  of the fourth housing  410   d  to be connected to the first mover  420 , to operate the first mover  420  to move in the vertical direction according to the vertical movement of the coil unit  430 . 
         [0119]    The upper magnet  450  is a bar shaped permanent magnet tightly attached to either the first mover  420  or the first mover lower body  421  to form a magnetic field for moving the first mover  420  upwards and maintaining the top dead point or to form a magnetic field for moving the first mover  420  downwards and maintaining the bottom dead point where the first mover  420  is tightly attached to the top surface of the first housing  410   a  and thus provides a holding force (magnetic force) so that the first mover  420  may maintain either the top dead point or the bottom dead point. 
         [0120]    In addition, a first magnetic substance  451  is installed at both sides of the upper magnet  450  and may provide an appropriate holding force to the first mover  420  or the first mover lower body  421  according to the usage of installation by freely changing the size of the upper magnet  450 . 
         [0121]    The first magnetic substance  451  is installed at both sides of the upper magnet  450  so that the upper magnet  450  may be fixed to the first housing  410   a , has a magnet installation groove  451   a  formed in the length direction to insert the upper magnet  450 , and forms a magnetic circuit together with the first mover  420  or the first mover lower body  421  through the magnetic field formed by the upper magnet  450 . 
         [0122]    In addition, a non-magnetic substance  452  is installed between the first magnetic substance  451  and the first housing  410   a  to prevent the magnetic field formed by the upper magnet  450  and the first magnetic substance  451  from being formed at the first housing  410   a  which is a magnetic substance, and a first mover link penetration hole  452   a  is formed so that the first mover link  421   a  which connects the first mover  420  and the first mover lower body  421  may pass through. 
         [0123]    The lower magnet  460  is a configuration installed inside the second housing  410   b  to form a magnetic field around the coil unit  430 , in which a first lower magnet  460   a , a second lower magnet  460   b , a third lower magnet  460   c  and a fourth lower magnet  460   d  are sequentially arranged around the coil unit  430  and form a magnetic field to generate a repulsive force for moving the coil unit  430  upwards or downwards according to a direction of current supplied to the coil unit  430 . 
         [0124]    In addition, the first non-magnetic substance  470  and the second non-magnetic substance  471  are installed above and below the first to fourth lower magnets, respectively, between the first to fourth lower magnets  460   a ,  460   b ,  460   c  and  460   d  and the fourth housing  410   d  and between the first to fourth lower magnets  460   a ,  460   b ,  460   c  and  460   d  and the third housing  410   c  to form a magnetic path by maintaining a distance, and N poles and S poles of the first to fourth lower magnets  460   a ,  460   b ,  460   c  and  460   d  are sequentially arranged inside the second housing  410   b  centering on the coil unit  430  so that a magnetic field may be formed in a predetermined direction. 
       Fourth Embodiment 
       [0125]      FIG. 9  is a perspective view showing a fourth embodiment of an electromagnetic force driving device according to the present invention, and  FIG. 10  is a cross-sectional view showing the structure of the electromagnetic force driving device according to  FIG. 9 . 
         [0126]    As shown in  FIGS. 9 and 10 , the electromagnetic force driving device  400 ′ according to a fourth embodiment of the present invention is configured to include a housing  410 , a first mover  420 , a first supporting mover  420 ′, a coil unit  430 , a second mover  440 , a second supporting mover  440 ′, an upper magnet  450 , a supporting magnet  450 ′, a lower magnet  460 , a first non-magnetic substance  470  and a second non-magnetic substance  471 . 
         [0127]    The housing  410 ′ is a magnetic substance configured to include a first housing  410   a , a second housing  410   b , a third housing  410   c , a fourth housing  410   d , and a supporting housing  410   e.    
         [0128]    The supporting housing  410   e  is installed in a direction opposite to the first housing  410   a  from the second housing  410   b , separated from the second housing  410   b  through the third housing  410   c , and configured in a shape the same as the first housing  410   a  of the third embodiment, and a non-magnetic substance  414 ′ may be installed between the third housing  410   c  and the supporting housing  410   e.    
         [0129]    In addition, a first supporting mover  420 ′ and a supporting magnet  450 ′ are installed in the supporting housing  410   e , and a motion path for moving the first supporting mover  420 ′ is formed inside the supporting housing  410   e.    
         [0130]    The difference between the electromagnetic force driving device  400 ′ according to the fourth embodiment and the electromagnetic force driving device  100 ′ according to the second embodiment is installation directions of the first and supporting housings  410   a  and  410   e  and the second housing  410   b , and the first housing  410   a  and the supporting housing  410   e  according to the fourth embodiment are arranged such that the groove units formed in the length direction are parallel to the length direction of the coil unit  430  of the second housing  410   b.    
         [0131]    The first supporting mover  420 ′ is a magnetic substance installed on the bottom of the supporting housing  410   e  to be movable in the vertical direction and fixed to the supporting housing  410   e  to be selectively positioned at the top dead point or the bottom dead point, and a first supporting mover lower body  421 ′ of a plate shape moving along the motion path of the supporting housing  410   e  is spaced apart from the first supporting mover  420 ′ by a certain distance under the plate shaped first supporting mover  420 ′ and connected to the first supporting mover  420 ′ through a first supporting mover link  421   a′.    
         [0132]    In addition, the first supporting mover  420 ′ is protruded from the body of the first supporting mover  420 ′ by a certain thickness to form a first supporting attaching unit  420   a ′, and if the first supporting mover  420 ′ moves upwards, the first supporting mover  420 ′ forms a magnetic field together with the supporting magnet  450 ′ and maintains a state of being tightly attached to the supporting housing  410   e.    
         [0133]    In addition, the first supporting mover lower body  421 ′ is protruded from the bottom surface of the first supporting mover lower body  421 ′ by a certain thickness to form a second supporting attaching unit  421   b ′, and if the first supporting mover lower body  421 ′ moves downwards, the first supporting mover lower body  421 ′ forms a magnetic field together with the supporting magnet  450 ′ so that the first supporting mover lower body  421 ′ may maintain a state of being tightly attached to the supporting housing  410   e , and the first supporting mover  420 ′ and the first supporting mover lower body  421 ′ are configured of a magnetic substance. 
         [0134]    The second supporting mover  440 ′ is a pipe shaped member, in which one end is combined with the bottom of the coil unit  430 , and the other end passes through the third housing  410   c  to be connected to the first supporting mover  420 ′, to operate the first supporting mover  420 ′ to move in the vertical direction according to the vertical movement of the coil unit  430 . 
         [0135]    The supporting magnet  450 ′ is a bar shaped permanent magnet tightly attached to either the first supporting mover  420 ′ or the first supporting mover lower body  421 ′ to form a magnetic field for moving the first supporting mover  420 ′ upwards and maintaining the top dead point or to form a magnetic field for moving the first supporting mover  420 ′ downwards and maintaining the bottom dead point where the first supporting mover  420 ′ is tightly attached to the supporting housing  410   e  and thus provides a holding force (magnetic force) so that the first supporting mover  420 ′ may maintain either the top dead point or the bottom dead point. 
         [0136]    In addition, a first supporting magnetic substance  451 ′ is installed at both sides of the supporting magnet  450 ′ and may provide an appropriate holding force to the first supporting mover  420 ′ or the first supporting mover lower body  421 ′ according to the usage of installation by freely changing the size of the supporting magnet  450 ′. 
         [0137]    The first supporting magnetic substance  451 ′ is installed at both sides of the supporting magnet  450 ′ so that the supporting magnet  450 ′ may be fixed to the supporting housing  410   e , has a magnet installation groove formed in the length direction to insert the supporting magnet  450 ′, and forms a magnetic circuit together with the first supporting mover  420 ′ or the first supporting mover lower body  421 ′ through the magnetic field formed by the supporting magnet  450 ′. 
         [0138]    Meanwhile, a supporting non-magnetic substance  452 ′ is installed between the first supporting magnetic substance  451 ′ and the supporting housing  410   e  to prevent the magnetic field formed by the supporting magnet  450 ′ and the first supporting magnetic substance  451 ′ from being formed at the supporting housing  410   e  which is a magnetic substance, and a first supporting mover link penetration hole is formed so that the first supporting mover link  421   a ′ which connects the first supporting mover  420 ′ and the first supporting mover lower body  421 ′ may pass through. 
         [0139]    Accordingly, when an error occurs in a power distribution and transmission line, it can be promptly cut off, and the overall weight and size can be reduced by simplifying the structure of the electromagnetic force driving device by combining a magnetic substance and a coil unit through a connection pin inside thereof, and, in addition, electromagnetic characteristics and a holding force can be easily changed by forming independent motion paths for moving the mover and the coil unit. 
         [0140]    While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. 
         [0141]    In addition, in the process of describing embodiments of the present invention, thickness of the lines and sizes of the elements shown in the figures may be exaggerated for clarity and convenience of the descriptions, and the terms described above are terminologies defined considering the functions of the present invention, and since meanings thereof may vary depending on the intention of an operator or common practices, definitions of the terms should be made based on the overall contents of this specification.