Patent Publication Number: US-7902468-B2

Title: Detent changeover switch apparatus

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a detent changeover switch apparatus capable of changing over click feeling generated by an operating portion of an operating switch. 
     Conventionally, as an input operation system for performing operation setting of various vehicle-loaded equipment such as an air conditioning device and an audio device, various kinds of operating switches are mounted on a vehicle corresponding to respective functions. As one example, with respect to the operating switches of the air conditioning device, for example, a temperature setting switch for setting a supply-air temperature, an air volume setting switch for setting an air volume, an air blow direction setting switch for setting an air blow and the like are used. As such a group of switches, a rotary operating switch, that is, a rotary switch which performs setting of various functions by rotatably operating a dial knob of a rotational operation type as an operating portion has been popularly used. 
     Further, this kind of rotary switch is provided with a detent mechanism capable of imparting a desired operation force or click feeling to the dial knob as a click for ensuring an operation of the dial knob by enhancing operation feeling of the dial knob. As one example of such a detent mechanism, there has been known a motor-driven click generating mechanism shown in JP-A-2006-178861 which imparts click feeling to a dial knob of a rotary switch using a motor, for example. In the disclosed technique, the motor is connected to the dial knob of the rotary switch, and upon a rotational operation of the dial knob, the motor is driven in the direction opposite to the knob operating direction thus imparting a reaction force to the dial knob and hence, an operating force is imparted to an operator as click feeling. 
     Recently, to realize the reduction of the number of parts of the operating switch, there has been an attempt to use one rotary switch in common among a plurality of selection functions. In this kind of operating switch having the common use structure, a switch controller which constitutes a control unit of the input operation system brings a switch determination mode into a function selection setting mode in a switch determination initial state. At this point of time, when the dial knob is operated, in response to a switch signal acquired from the rotary switch, a vehicle-loaded equipment which the operator requires setting a function thereof is selected and designated. The switch controller, after the selection and the designation of the vehicle-loaded equipment, changes over the switch determination mode to a detail setting mode. When the dial knob is operated at this point of time, in response to a switch signal acquired from the rotary switch, the detail of the selected and designated vehicle-loaded equipment is set to a state corresponding to the switch operation. 
     In case of the operating switch having the common-use structure, it is desirable that the click feeling generated in the rotary switch by the detent mechanism differs for every selection function. Here, when a motor-driven click generating mechanism described in JP-A-2006-178861 is used as a detent mechanism, in changing over click feeling of the dial knob based on respective selection functions, the changeover of click feeling is performed by controlling a reaction force imparted to the dial knob by a motor based on the respective selection functions. That is, when the strong click is necessary, the reaction force of the motor is increased so as to allow the dial knob to generate the strong click, while when the weak click is necessary, the reaction force of the motor is decreased so as to allow the dial knob to generate the weak click. 
     Further, the rotary switch of the air conditioner is, in view of setting of temperature or selection functions, often a switch which limits a rotational operation range in which the dial knob is operated within a predetermined rotational operation range. Accordingly, this type of rotary switch is configured to be rotary operated within a range of 120 degrees, 180 degrees, 270 degrees or the like, for example, corresponding to a usage of the rotary switch. Here, when the motor-driven click generating mechanism described in JP-A-2006-178861 is used as the detent mechanism, to bring the dial knob into a fixed state at a preset stop position, a reaction force larger than a reaction force generated at the time of generating click by the motor is generated thus restricting the further rotational operation of the dial knob. 
     However, when the motor-driven click generating mechanism is used as the detent mechanism, it is necessary to perform processing for a control of the reaction force generated by the motor for changing over the click feeling generated in the dial knob by the detent mechanism or bringing the dial knob into a fixed state. Accordingly, this type of motor control requires complicate processing and hence, when the motor-driven click generating mechanism is used as the detent mechanism, a control unit of a switch system requires a complete motor control. Accordingly, also for reducing a burden on processing of the control unit, there has been a demand for changeover and fixing of click of the rotary switch which can be performed with processing as simple as possible. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a detent changeover switch apparatus which can perform changeover or fixing of click feeling generated by an operating switch with simple processing. 
     In order to solve the problem, the present invention provides the following arrangements.
     (1) A detent changeover switch apparatus performing a selection function operation, comprising:   

     a housing; 
     an operating portion to be operated by an operator to rotate with respect to the housing; 
     an operating shaft extending integrally from the operating portion; 
     a plurality of detent mechanisms, each including a detent member and a piece member rotatable relatively to the detent crest member to generate a click feeling; 
     an electromagnet that is provided at the housing and selectively fixes the crest members of the detent mechanisms to the housing by a magnetic attracting action; 
     an auxiliary magnetic filed generating member capable of imparting an auxiliary electric field to a magnetic circuit generated by the electromagnet; 
     a magnetic attracting member that fixes the operating shaft to the housing by the magnetic attracting action of the electromagnet when a large magnetic field is imparted to the magnetic attracting member; 
     a detector that detects an operation state when the operator operates the operating portion; and 
     a controller that performs a drive control of the electromagnet based on a detection quantity of the detector for changing over a circuit state of a magnetic circuit generated in the housing by the electromagnet and the auxiliary magnetic field generating member, thereby changing over the click feeling and a fixed state of the operating portion.
     (2) The detent changeover switch apparatus according to (1), wherein   

     one of the detent mechanisms includes an interlocking member movable together with the operating shaft, a mounting member mounted on the operating shaft in a relatively movable manner, and a part group for large click positioned between the interlocking member and the mounting member, 
     the other detent mechanism includes the mounting member, a support member fixed to the housing and a part group for small click positioned between the mounting member and the support member, 
     a magnetic body magnetically attractable to the electromagnet is integrally mounted on the mounting member, and 
     the controller changes over a drive state of the electromagnet among a non-electricity-supply state, a backward connection electricity supply state and a forward connection electricity supply state to bring a magnetic attracting state between the electromagnet and the magnetic body and a magnetic attracting state between the magnet attracting member and the housing into different states, respectively, for changing over the click feeling and the fixed state.
     (3) The detent changeover switch apparatus according to (2), wherein   

     the auxiliary magnetic field generating member generates the auxiliary magnetic field by forming a magnetic path using the housing and the operating shaft made of a magnetic material, 
     the electromagnet has an electromagnetic magnetic field directed along the magnetic path of the auxiliary magnetic field, and 
     when the operating portion is changed over into the fixed state, the controller performs the drive control of the electromagnet for changing over the magnetic field of the magnetic circuit generated by the housing and the operating shaft. 
     According to the above arrangement, the controller changes over the magnetic field which the electromagnet generates due to a changeover control of an electricity-supply state of the electromagnet based on a detection quantity of the detector. Here, a magnetic circuit generated in the inside of the operating switch is changed over due to the cooperative operation of the drive magnetic field generated by the electromagnet and the auxiliary magnetic field generated by the auxiliary magnetic field generating member in an auxiliary manner. When the magnetic circuit in the inside of the operating switch is changed over, for example, a magnetic field balance between the drive magnetic field generated by the electromagnet and the auxiliary magnetic field generated by the auxiliary magnetic field generating member is changed and hence, the detent mechanism driven by the magnetic field change is selected from the plurality of detent mechanisms or the strong magnetic field is generated in the housing so as to fix the operating portion to the housing thus bringing the operating portion into a non-operable fixed state. 
     Here, as explained in the description of the Background Art, when the structure which uses the motor is adopted as the detent mechanism, to change over the click feeling or the fixed state of the operating portion, it is necessary to perform the complicate control processing such as sequential changeover of a quantity of electric current of the motor. To the contrary, according to the arrangement of the present invention, the changeover of the click feeling of the operating portion or the changeover of the fixed state of the operating portion is performed by controlling the supply of electricity to the electromagnet. In this manner, it is sufficient for this type of electromagnet control to perform the simple control processing which merely changes ON-OFF of electric current flowing in the electromagnet and hence, it is possible to perform the changeover of click feeling or the changeover of fixing of the operating portion with the simple control processing. 
     According the above arrangement, when the electromagnet is brought into a non-electricity-supply state, for example, the operating switch assumes a state in which the magnetic circuit is generated due to the auxiliary magnetic field of the auxiliary magnetic field generating member. However, the auxiliary magnetic field generating member is provided for generating the auxiliary magnetic field and hence, the magnetic attracting member mounted on the operating portion is not brought into a state in which the magnetic attracting member is magnetically attracted to the housing whereby the operating portion can be smoothly operated. Here, since the electromagnet is in a non-electricity-supply state, the mounting portion is not fixed to the housing side. Accordingly, when the operating portion is operated in such a state, the slide resistance of the large detent part group is set larger than the slide resistance of the small detent part group and hence, the mounting member is moved along with the movement of the operating portion together with the interlocking member due to this slide resistance relationship, and the mounting member assumes a state in which the mounting member is movable relative to the support member on the housing side. Accordingly, the large detent mechanism between the interlocking member and the mounting member does not function, while the small detent mechanism between the mounting member and the support member functions thus allowing the operating portion to generate the small click. 
     Further, when the electromagnet is brought into a backward connection electricity supply state, the electromagnetic magnetic field generated by the electromagnet and the auxiliary magnetic field generated by the auxiliary magnetic field generating member assumes directions opposite from each other and hence, no large magnetic field is applied to the magnetic attracting member mounted on the operating portion whereby the operating portion is not magnetically attracted to the housing thus allowing the operation of the operating portion. Here, the electromagnet is in an electricity supply state, and the electromagnet and the magnetic body are magnetically attracted to each other and hence, the mounting portion integrally formed with the magnetic body is fixed to the housing side. When the operating portion is operated in such a state, the mounting member is fixed to the support portion side at this point of time and hence, the interlocking member assumes a state in which the interlocking member is movable relative to the mounting portion. Accordingly, the small detent mechanism between the mounting member and the support member does not function, while the large detent mechanism between the interlocking member and the mounting member functions thus allowing the operating portion to generate the large click. 
     Further, when the electromagnet is brought into a forward connection electricity supply state, the electromagnetic magnetic field generated by the electromagnet and the auxiliary magnetic field generated by the auxiliary magnetic field generating member assumes the same direction. Here, a resultant magnetic field of the electromagnetic magnetic field and the auxiliary magnetic field is generated in the operating switch and hence, the magnetic attracting member assumes a state in which the magnetic attracting member is magnetically attracted to the housing due to such a magnetic field whereby the operating portion assumes a fixed state which prevents the further operation of the operating portion. Accordingly, with respect to the detent changeover switch apparatus having the above-mentioned operational state, from a viewpoint of arrangement of parts, the mounting parts can be used as common-use parts between the large detent mechanism and the small detent mechanism and hence, the number of operating switch parts can be highly effectively reduced. 
     According to the above arrangement, the electromagnetic magnetic field which the electromagnet generates takes the direction along the auxiliary magnetic field generated by the auxiliary magnetic field generating member and hence, in overlapping the drive magnetic field and the auxiliary magnetic field to change over the generated click of the operating portion, the drive magnetic field can easily applied to the auxiliary magnetic field. Accordingly, the circuit condition of the magnetic circuit generated in the click generator and the magnetic attracting member can be more reliably changed over thus leading to the more reliable changeover of click feeling. 
     According to the present invention, the changeover and fixing of click feeling generated in the operating switch can be performed with simple processing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the interior of a vehicle according to one embodiment. 
         FIG. 2  is a schematic structure view showing the device arrangement of an operating switch apparatus. 
         FIG. 3  is a longitudinal cross-sectional view showing the inner arrangement of an operating switch having a detent changeover mechanism. 
         FIG. 4  is a decomposed perspective view showing a part group of the operating switch having the detent changeover mechanism. 
         FIG. 5  is a screen view of a menu screen displayed on a display. 
         FIG. 6  is a screen view of an air conditioner function setting screen displayed on the display. 
         FIGS. 7A and 7B  being explanatory views of an operation in generating small click in the operating switch. 
         FIGS. 8A and 8B  being explanatory views of an operation in generating large click in the operating switch. 
         FIGS. 9A and 9B  being explanatory views of an operation in fixing the operating switch. 
         FIG. 10  is an explanatory view of an operation in stopping a rotational operation of a dial knob. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     One embodiment of a detent changeover switch apparatus which embodies the present invention is explained in conjunction with  FIG. 1  to  FIG. 10  hereinafter. 
     As shown in  FIG. 1 , on a center cluster  2  of a vehicle  1 , an operating switch apparatus  3  is mounted as an operation system of various vehicle loaded equipment such as an air conditioning device, an audio device and a car navigation device. The operating switch  3  of this embodiment uses a graphical user interface (GUI) for enhancing visibility and operability at the time of performing a button selection operation. The graphical-user-interface-type operating switch apparatus  3  performs a graphic display of item buttons  5 , icons  6  and the like on a display  4  mounted on the center cluster  2  and, while selectively designating the item buttons  5 , the icons  6  or the like on the display  4  using an operating switch  7  mounted on the same center cluster  2 , performs an input operation using a decision switch  7   a  and a return switch  7   b  arranged close to the operating switch  7 . 
     As shown in  FIG. 3 , on an inner side of a cluster panel  8  of the center cluster  2 , a yoke  9  constituting a switch casing for housing various kinds of switching parts such as the operating switch  7  is fixedly mounted. The yoke  9  is formed in a cylindrical shape with an upper portion thereof opened, for example, and is made of a magnetic material as a material thereof in this embodiment. When the operating switch  7  is of a dial operation type, a dial knob  10  which forms an operating portion at the time of operating the operating switch  7  is mounted on the yoke  9  in a rotatably operable state. The dial knob  10  is constituted of an approximately cylindrical knob portion  10   a  forming a grip portion at the time of operating the operating switch  7  and a shaft  10   b  extending integrally from a bottom surface of the knob portion  10   a  in the vertical direction at a coaxial position. The shaft  10   b  extends outwardly through a through hole  9   a  formed in a bottom wall of the yoke  9  in a penetrating manner in a state that the shaft  10   b  is rotatably operable. Here, the yoke  9  corresponds to a housing and the dial knob  10  corresponds to an operating portion. 
     As shown in  FIG. 3  and  FIG. 4 , in the inside of the yoke  9 , a multi-stage detent mechanism  11  capable of generating click feelings in multiple stages in the dial knob  10  when the dial knob  10  is rotatably operated is arranged. The multi-stage detent mechanism  11  of this embodiment is a mechanism capable of changing the click feeling of the dial knob  10  among three states consisting of a small click generating state which generates small click (many click feelings) of the dial knob  10 , a large click generating state which generates large click (few click feelings) of the dial knob  10 , and a dial knob fixed state which stops the rotational operation of the dial knob  10 , that is, fixes the dial knob  10 . 
     To explain the multi-stage detent mechanism  11  hereinafter, in the inside of the yoke  9 , a small click generating member  12  operable for allowing the dial knob  10  to generate a small click is fixedly mounted on an inner peripheral surface of the yoke  9 . The small click generating member  12  is made of resin, for example, formed in a cylindrical shape with an upper end thereof opened, and is always fixed to the yoke  9 . On an inner peripheral surface of an opening portion of the small click generating member  12 , a small click uneven pattern  13  formed of a plurality of valleys and crests is formed. The small click uneven pattern  13  assumes a shape pattern in which a plurality of detent crests  14  and a plurality of detent valleys  15  are alternately arranged along the rotary operating direction of the dial knob  10 , and a projecting quantity of detent crests  14  is set to a small value. A planar circular through hole  12   a  is formed in the small click generating member  12  at a center position of the small click generating member  12 , and the shaft  10   b  is rotatably inserted into the through hole  12   a . The small click generating member  12  corresponds to a support member and the small click uneven pattern  13  constitutes to a detent crest member. 
     On the other hand, at a knob-portion-side position of the shaft  10   b , a large click generating member  16  operable for allowing the dial knob  10  to generate a large click is fixedly mounted on the shaft  10   b  in a state that the large click generating member  16  is integrally rotatable with the shaft  10   b . The large click generating member  16  is made of resin, for example, formed in a bottomless cylindrical shape with a bottom surface side thereof opened, and is arranged coaxially with the shaft  10   b . On an inner peripheral surface of the large click generating member  16 , in the same manner as the small click generating member  12 , a large click uneven pattern  17  formed of a plurality of valleys and crests is formed. The large click uneven pattern  17  sets a height of the detent crests  18  thereof relative to detent valleys  19  thereof higher than a height of the detent crests  14  of the small click uneven pattern relative to the detent valleys  15  and, at the same time, sets an interval of the detent crests  18  larger than an interval of the detent crests  14  of the small click uneven pattern  13 . Here, the large click generating member  16  corresponds to an interlocking member and the large click uneven pattern  17  constitutes the detent crest member. 
     To the shaft  10   b , a plunger case  20  made of a resin, for example, and formed in an approximately cylindrical shape is connected in a relatively rotatable manner. The plunger case  20  assumes a mounting state in which the plunger case  20  is arranged in an accommodating space  21  (see  FIG. 3 ) defined between an opening portion of the small click generating member  12  and a recessed portion of the large click generating member  16 . A planar circular-cross-sectional through hole  20   a  is formed in a central portion of the plunger case  20  in a penetrating manner, and the shaft  10   b  is inserted into the through hole  20   a  in a relatively rotatable manner. 
     A small click piece  22  which functions as a small click generating part and a large click piece  23  which functions as a large click generating part are mounted on the plunger case  20 . A first accommodating portion  24  opening toward the small click uneven pattern  13  is formed in a side portion of the plunger case  20  at a position opposite to the knob portion. The small click piece  22  which functions as the small click generating part is accommodated in the first accommodating portion  24  in a state that the small click piece  22  is relatively movable in the biasing direction (the shaft orthogonal direction in this embodiment: direction indicated by an arrow Ra in  FIG. 4 ) due to a biasing force of a first biasing member  25  and is brought into resilient contact with the small click uneven pattern  13 . Here, the plunger case  20  corresponds to a mounting member and the small click piece  22  and the large click piece  23  constitute piece parts. 
     On the other side, a second accommodating portion  26  opening toward the large click uneven pattern  17  is formed in a side portion of the plunger case  20  at a position close to the knob portion. The large click piece  23  which functions as the large click generating part is accommodated in the second accommodating portion  26  in a state that the large click piece  23  is relatively movable in the biasing direction (the shaft orthogonal direction in this embodiment: direction indicated by an arrow Ra in  FIG. 4 ) due to a biasing force of a second biasing member  27  and is brought into resilient contact with the large click uneven pattern  17 . Here, in this embodiment, the detent mechanism constituted of the small click uneven pattern  13  and the small detent part group such as small click piece  22  form the first-stage detent mechanism  11   a , and the detent mechanism constituted of the large click uneven pattern  17  and the large detent part group such as large click piece form the second-stage detent mechanism  11   b.    
     In the inside of the small click generating member  12 , a coil member  28  capable of generating a coil magnetic field in the surrounding thereof is fixedly mounted in a state that the coil member  28  is accommodated in the inside of the small click generating member  12 . The coil member  28  is constituted of a coil  29  formed by winding a copper spring or the like, for example, a large number of times and a coil magnetic body  30  made of a magnetic material such as iron or nickel and forming a portion around which the coil  29  is wound. Further, the coil member  28  is always fixed to the small click generating member  12 , that is, to the yoke  9 . A planar circular cross-sectional through hole  28   a  is formed in the coil member  28  at a center position of the coil member  28 , and the shaft  10   b  is inserted into the through hole  28   a  in a relatively rotatable manner. The coil  29  has the winding direction of winding thereof arranged about an axis of the shaft  10   b  and, at the same time, generates a coil magnetic field Hb (see  FIG. 7A  to  FIG. 9 ) in the inside of the operating switch  7  when an electric current is supplied thereto. 
     On a bottom surface of the plunger case  20 , a plunger magnetic body  31  made of a magnetic material such as iron or nickel, for example, is fixedly mounted in a state that the plunger magnetic body  31  is integrally rotatable with the plunger case  20 . The plunger magnetic body  31  is arranged at a position where the plunger magnetic body  31  is in contact with the coil member  28 . When electricity is supplied to the coil member  28  and a magnetic field is generated, the plunger magnetic body  31  is attracted to the coil member  28  by this magnetic field thus restricting the rotational operation of the plunger case  20 . A planar circular cross-sectional through hole  31   a  is formed in the plunger magnetic body  31  at a center position of the plunger magnetic body  31 , and the shaft  10   b  is inserted into the through hole  31   a  in a relatively rotatable manner. On a side portion of the plunger magnetic body  31 , a removal preventing member  32  is mounted in a projecting manner over a whole rotational operation direction area of the dial knob  10 . By engaging the removal preventing member  32  with a groove portion  33  (see  FIG. 3 ) defined between the small click generating member  12  and the coil member  28  in a relatively rotatable manner, the removal of the plunger case  20  can be prevented. Here, the coil  29  corresponds to an electromagnet and the plunger magnetic body  31  corresponds to a magnetic body. 
     On an end portion of the shaft  10   b  on a side opposite to the dial knob  10 , a shaft magnetic body  34  made of a magnetic material such as iron or nickel, for example, is fixedly mounted in a state that the shaft magnetic body  34  is integrally rotatable with the shaft  10   b . The shaft magnetic body  34  is mounted coaxially with the shaft  10   b  and assumes a mounting state where the shaft magnetic body  34  is in contact with an inner-wall bottom surface of the yoke  9 . The shaft magnetic body  34  is a member which is attracted to the yoke  9  when a strong magnetic force is generated in the yoke  9  so as to restrict the rotational operation of the shaft  10   b . Accordingly, the shaft magnetic body  34  is configured to have stepped portions consisting of a large-diameter portion  34   a  and a small-diameter portion  34   b . By forming the shaft magnetic body  34  in such a shape, a contact surface S between the shaft magnetic body  34  and the inner-wall bottom surface of the yoke  9  (see  FIG. 3 ) can ensure a sufficient contact area. Here, the shaft magnetic body  34  corresponds to a magnetic attracting member. 
     Further, at an opening-end-portion position of the yoke  9 , an approximately planar permanent magnet  35  is fixedly mounted so as to close the opening end portion of the yoke  9 . The permanent magnet  35  is a magnet having a N pole on a radially outer side and an S pole on a center side and is formed using a magnetic material such as iron, nickel or cobalt as a material thereof, for example. A planar circular cross-sectional through hole  35   a  is formed in the permanent magnet  35  at a center position of the permanent magnet  35 , and the shaft  10   b  is inserted into the through hole  35   a  in a relatively rotatable manner. With respect to a magnet magnetic field Ha of the permanent magnet  35  (see  FIG. 7A  to  FIG. 9 ), the yoke  9 , the shaft  10   b  and the shaft magnetic body  34  are made of the magnetic material and hence, these parts form a magnetic path when a magnetic field is generated. Here, the permanent magnet  35  corresponds to an auxiliary magnetic field generating member. 
     Here, the changeover of the click generated in the dial knob  10  of this embodiment includes the change of click feeling generated in the dial knob  10  when the dial knob  10  is rotatably operated and the change of click strength corresponding to an operation load when the dial knob  10  is rotatably operated in broad meaning. That is, the description “the click is increased” implies the increase of the click feeling or the click strength, while the description “the click is decreased” implies the decrease of the click feeling or the click strength. Further, a distance between the detent crests  14 ( 18 ) positioned close to each other is mainly relevant to the change of click feeling, while a height of the detent crests  14 ( 18 ), a size of the click piece  22 ( 23 ), and a biasing force of the biasing member  25 ( 27 ) are relevant to the change of click strength. 
     As shown in  FIG. 2  and  FIG. 3 , on a lower end of the operation shaft  10   b  of the dial knob  10 , an encoder  36  for detecting a rotary quantity (rotational speed) of the dial knob  10  is mounted. The encoder  36  is constituted of a pulse encoder which outputs a rotation detection output value as pulse signals, for example. In detecting the rotation of the dial knob  10 , the encoder  36  is capable of outputting a detection signal consisting of the number of pulses corresponding to the rotational quantity of the dial knob  10  at the point of time. Here, the decision switch  7   a , the return switch  7   b  and the encoder  36  constitutes a detector. 
     As shown in  FIG. 2 , the operating switch apparatus  3  includes a switch controller  37  as a control unit for the operating switch apparatus  3 . The switch controller  37  includes a CPU  38  for systematically controlling the switch controller  37 , a ROM  39  for storing various programs and data groups, a RAM  40  used as an operational region at the time of performing a program operation and the like, and is operated in accordance with a control program in the inside of the ROM  39 . The switch controller  37  is connected to the encoder  36  through electric wiring. The switch controller  37  calculates a rotational operation quantity of the dial knob  10  using the detection signal acquired from the encoder  36 , and supplies the operation quantity information to other control units which require such a rotational operation quantity or performs a display control of a display screen of the display  4 . 
     The switch controller  37  performs a changeover control of click feeling generated in the dial knob  10  such that an electricity supply state of the coil  29  is controlled based on various operations performed by an operator at the time of operating the dial knob  10  so as to change over the generation direction of a magnetic field generated by the coil  29  or the presence or non-presence of the generation of the magnetic field. That is, the switch controller  37  can bring the coil  29  into any one of the electricity supply states consisting of a non-electricity-supply state, a backward connection electricity supply state and a forward connection electricity supply state. Here, by making a coil magnetic field Hb generated by the coil  29  and a magnet magnetic field Ha generated by the permanent magnet  35  cooperatively function, the click feeling generated in the dial knob  10  is changed over among three states consisting of a small click generating state, a large click generating state and a fixed state. Here, the switch controller  37  corresponds to a controller. 
     Next, the manner of operation of the operating switch apparatus  3  of this embodiment is explained. 
     When an ignition switch (not shown in the drawing) of the vehicle I is operated to assume an ACC position or an IG position, the switch controller  37  assumes a start state and sets an operation mode thereof to an item button selection mode, displays a menu screen  41  shown in  FIG. 6  as an initial operation screen on the display  4 , and recognizes the operating switch  7  as an item button selection switch. On the menu screen  41 , a plurality of item buttons  5 ,  5  . . . which is selectively designated at the time of setting functions of various vehicle equipment mounted on the vehicle  1  is displayed in an allocated manner As the item buttons  5 ,  5  . . . displayed on the menu screen  41 , for example, an air conditioner function setting button  5   a  selected for setting the various functions of the air conditioner, a car navigation button  5   b  selected for setting various functions of the car navigation device, an audio button  5   c  selected for setting various functions of the audio device and the like are provided. 
     Here, in selecting and designating the item button  5  on the menu screen  41 , a selection coordinate position Px on the display  4  is moved by the dial knob  10  so as to position the button focus  42  on the desired item button  5  and, after such positioning, the decision switch  7   a  (see FIG. I and  FIG. 2 ) mounted on the center cluster  2  is operated by pushing. When the switch controller  37  recognizes the selection operation of the decision switch  7   a , the switch controller  37  recognizes the item button  5  positioned at the selection coordinate position Px immediately before the decision switch  7   a  is operated as an operation demand button, and various processing corresponding to functions which the operation demand button possesses are performed with respect to the vehicle  1 . 
     Here, in the operating switch apparatus  3  of this embodiment which uses one operating switch  7  in common among a plurality of selection functions, objects to be selected or items to be selected differ depending on the respective selection functions (including the display screen and the knob rotational operating position) and hence, it is preferable to cope with such a situation by changing the click strength generated in the dial knob  10  corresponding to the respective selection functions. Accordingly, the operating switch  7  of this embodiment includes the detent mechanism  11  capable of generating click feelings in multiple stages in the dial knob  10 . In this type of detent mechanism  11 , the generated click differs for every detent mechanism  11   a ,  11   b  and hence, this embodiment copes with the above-mentioned situation by bringing the desired detent mechanism  11   a ,  11   b  into a drive state at the time of operating the switch. 
     For example, when the menu screen  41  is displayed on the display  4  and the dial knob  10  is set to generate the small click, the switch controller  37 , in displaying the menu screen  41  on the display  4 , brings the coil  29  into a non-electricity-supply state together with the image display. Here, the operating switch  7  assumes a state shown in  FIG. 7A  where a magnetic circuit to which only the magnet magnetic field Ha generated by the permanent magnet  35  is applied is generated, and a magnetic path in which the magnet magnetic field Ha reaches the yoke  9 , the shaft magnetic body  34  and the shaft  10   b  and returns to the permanent magnet  35  is established. 
     Here, when the electricity is not supplied to the coil  29 , an attracting force attributed to the coil magnetic field Hb is generated on a contact surface S between the yoke  9  and the shaft magnetic body  34 . However, the permanent magnet  35  is formed using a magnet which generates a weak magnetic field when used alone. Accordingly, in this case, although an attracting force attributed to the magnet magnetic field Ha is applied to the contact surface S, this attracting force is extremely weak and hence, the smooth rotational operation of the shaft  10   b  is allowed. Further, when the electricity is not supplied to the coil  29 , the plunger magnetic body  31  is not attracted to the coil member  28  due to a magnetic force and hence, the rotational operation of the plunger case  20  relative to the yoke  9  is allowed. Accordingly, in this case, as shown in  FIG. 7B , the part group consisting of the dial knob  10 , the large click generating member  16 , the plunger case  20  and the plunger magnetic body  31  forms a part group whose rotational operation is allowed and other parts form a part group (part group indicated by dots in  FIGS. 7A and 7B ) fixed to the yoke  9  side. 
     Further, the meshing resistance between the large click piece  23  and the large click uneven pattern  17  is set larger than the meshing resistance between the small click piece  22  and the small click uneven pattern  13  and hence, when the dial knob  10  is rotatably operated when the electricity is not supplied to the coil  29 , the plunger case  20  (including the plunger magnetic body  31 ) is integrally rotated with the dial knob  10  (shaft  10   b ). Accordingly, along with the rotational operation of the dial knob  10 , the small click piece  22  takes an action to sequentially get over the detent crests  14  of the small click uneven pattern  13  and hence, the first-stage detent mechanism  11   a  is brought into a drive state whereby the click feeling with small click which the first-stage detent mechanism  11   a  possesses is generated in the dial knob  10 . 
     On the other hand, when the menu screen  41  is displayed on the display  4  and the dial knob  10  is set to generate the large click, the switch controller  37 , in displaying the menu screen  41  on the display  4 , brings the coil  29  into a backward connection electricity supply state together with the image display. The “backward connection electricity supply” described here implies a phenomenon in which the electricity is supplied to the coil  29  such that the coil magnetic field Hb generated in the coil  29  when the electricity is supplied to the coil  29  is directed opposite to the direction of the magnet magnetic field Ha of the permanent magnet  35 . In this case, as shown in  FIG. 8A , the coil magnetic field Hb having the magnetic field direction opposite to the magnetic field direction of the magnet magnetic field Ha is generated in the coil  29 . Accordingly, at this point of time, in the operating switch  7 , a magnetic circuit which generates a subtracted magnetic filed H 1  obtained by subtracting the coil magnetic field Hb from the magnet magnetic field Ha of the permanent magnet  35  is generated, and this subtracted magnetic filed H 1  is applied to the contact surface S. 
     Here, also at this point of time, an attracting force attributed to the magnetic field generation is applied to the contact surface S. However, at this point of time, the generated magnetic field on the contact surface S is the subtracted magnetic filed H 1  of low magnetic field strength obtained by subtracting the coil magnetic field Hb of the coil  29  from the magnet magnetic field Ha of the permanent magnet  35 . Accordingly, although the attracting force attributed to the magnetic field generation is generated on the contact surface S also at this point of time, the attracting force is extremely weak and hence, the smooth rotational operation of the shaft  10   b  is allowed. Further, when the coil  29  assumes an electricity-supply state (here, backward connection electricity supply state), the plunger magnetic body  31  is attracted to the coil member  28  due to the magnetic force of the plunger magnetic body  31  and hence, the plunger case  20  is fixed to the yoke  9  side. Accordingly, in this case, as shown in  FIG. 8B , the part group consisting of the dial knob  10  and the large click generating member  16  forms a part group whose rotational operation is allowed and other parts form a part group (part group indicated by dots in  FIG. 8B ) constitute a part group fixed to the yoke  9  side. 
     Accordingly, when the dial knob  10  is rotatably operated due to the supply of electricity by the backward connection electricity supply, along with such a rotational operation, the large click generating member  16  performs a rotation relative to the plunger case  20 . Accordingly, along with the rotational operation of the dial knob  10 , the large click piece  23  takes an action to sequentially get over the detent crests  18  of the large click uneven pattern  17  and hence, the second-stage detent mechanism  11   b  is brought into a drive state whereby the click feeling with large click which the second-stage detent mechanism  11   b  possesses is generated in the dial knob  10 . 
     When the selection and decision operations of the air conditioner function setting button  5   a  is performed on the menu screen  41 , the switch controller  37  sets an operation mode thereof to an air conditioner function setting mode, and displays an air conditioner function setting screen  43  shown in  FIG. 6  as a detailed function setting screen of the air conditioner on the display  4  and, at the same time, recognizes the operating switch  7  as an air conditioner function switch. On this air conditioner function setting screen  43 , a blower button  44  selected at the time of changing over an air blow-off port, an air volume setting button  45  selected at the time of setting an air volume, and a supply-air temperature setting button  46  selected at the time of setting a supply-air temperature of air are allocated. Here, the selection and decision operation of these buttons  44  to  46  is performed in the same manner at the time of selecting and deciding the item buttons  5  on the menu screen  41 , and the click generated by the dial knob  10  is set to either one of large and small clicks. 
     When the blower button  44  is selected and designated on the air conditioner function setting screen  43 , the switch controller  37  which detects the button selection and decision operation sets the operation mode thereof to a blower function setting mode, and displays the blower setting screen  47  shown in  FIG. 6  on the display  4  and, at the same time, recognizes the operating switch  7  as a blower function setting switch. On the blower setting screen  47 , blower function images  47   a ,  47   a  . . . corresponding to the respective blower functions are displayed as images. Here, the blower function in a selected state is notified to a user by a designation display which designates the blower function image  47   a  on the screen with an arrow  47   b . Here, when the selection state of the blower function is changed over due to the rotational operation of the dial knob  10 , the display position of the arrow  47   b  on the blower setting screen  47  is also changed over and displayed corresponding to the blower function position after the selection and the designation. 
     When the air volume setting button  45  is selected and designated on the air conditioner function setting screen  43 , the switch controller  37  which detects the button selection and decision operation sets the operation mode thereof to an air volume setting mode, and displays an air volume setting screen  48  shown in  FIG. 6  on the display  4  and, at the same time, recognizes the operating switch  7  as an air volume setting switch. On the air volume setting screen  48 , an air volume image  48   a  imaging an air volume is displayed as an image. Here, the air volume in a selected state is notified to a user by a designation display which designates the air volume image  48   a  on the screen with an arrow  48   b  at a set air volume position. Here, when the selection state of the air volume is changed over due to the rotational operation of the dial knob  10 , the display position of the arrow  48   b  on the air volume setting screen  48  is also changed over and displayed corresponding to the air volume after the selection and the designation. 
     When the supply-air temperature setting button  46  is selected and designated on the air conditioner function setting screen  43 , the switch controller  37  which detects the button selection and decision operation sets the operation mode thereof to a supply-air temperature setting mode, and displays an supply-air temperature setting screen  49  shown in  FIG. 6  on the display  4  and, at the same time, recognizes the operating switch  7  as a supply-air temperature setting switch. On the supply-air temperature setting screen  49 , a supply-air temperature image  49   a  imaging a supply-air temperature is displayed as an image. Here, the supply-air temperature in a selected state is notified to a user by a designation display which designates the supply-air temperature image  49   a  on the screen with an arrow  49   b  at the supply-air temperature setting position. Here, when the selection state of the supply-air temperature is changed over due to the rotational operation of the dial knob  10 , the display position of the arrow  49   b  on the supply-air temperature setting screen  49  is also changed over and displayed corresponding to the supply-air temperature after the selection and the designation. 
     The switch controller  37 , in displaying the various screens  47  to  49  on the display  4 , sets the click feeling generated in the dial knob  10  to click strengths corresponding to these screens  47  to  49 . Further, for example, the number of selection items is relatively small with respect to such kinds of blower functions and hence, in displaying the blower setting screen  47  on the display  4 , the small click is generated in the dial knob  10  by bringing the first-stage detent mechanism  11   a  into a drive state. In this case, each time the blower function is changed over from one function to the neighboring function, the dial knob  10  is brought into a state in which the dial knob  10  generates operation feeling of one click so that the number of the blower selection function stages corresponds to the number of clicks of the dial knob  10 . Further, the number of selections items of the air volume setting function and the number of selections items of the supply-air temperature setting function are larger than the number of selection items of the blower functions. Accordingly, in such a situation, the second-stage detent mechanism  11   b  is brought into a drive state to cope with the situation. 
     Further, when the display screen of the display  4  becomes a screen which prohibits the rotational operation of the dial knob  10 , the switch controller  37 , in displaying this kind of display screen on the display  4 , brings the coil  29  into a forward connection electricity supply state along with this image display. Here, the “forward connection electricity supply” described here implies a phenomenon in which the electricity is supplied to the coil  29  such that the coil magnetic field Hb generated in the coil  29  when the electricity is supplied to the coil  29  is directed in the same direction as the magnet magnetic field Ha of the permanent magnet  35 . The forward connection electricity supply is executed by supplying the same quantity of electric current having the direction opposite to the direction of the electric current in the backward connection electricity supply. Accordingly, at this point of time, in the operating switch  7 , as shown in  FIG. 9A , a magnetic circuit which generates a resultant magnetic filed H 2  obtained by combining the frontward-connection coil magnetic field Hb which the coil  29  generates and the magnet magnetic field Ha of the permanent magnet  35  is generated, and this resultant magnetic filed H 2  is applied to the contact surface S. 
     Accordingly, when electricity is supplied to the coil  29  in a forward connection electricity supply state, an extremely strong magnetic field which is the resultant magnetic filed H 2  acquired by superposing the frontward-connection coil magnetic field Hb which the coil  29  generates and the magnet magnetic field Ha of the permanent magnet  35  is generated on the contact surface S and hence, the shaft magnetic body  34  is strongly attracted to the yoke  9  with an extremely strong force generated by the resultant magnetic filed H 2  whereby the dial knob  10  is fixed to the yoke  9 . Accordingly, as shown in  FIG. 9B , almost all parts including the dial knob  10  constitute a part group fixed to the yoke  9  side (part group indicated by dots in  FIG. 9B ). Due to such a arrangement, even in an attempt to rotatably operate the dial knob  10  when the electricity is supplied to the coil  29  in the forward connection, since the dial knob  10  is fixed to the yoke  9  at this point of time, the dial knob  10  cannot be rotatably operated whereby the operation of the operating switch  7  is inhibited. 
     Further, the general-type blower function setting switch is often a rotational-operation-range limited switch with a dial knob portion rotatable only within a predetermined range. When the operating switch  7  of this embodiment is used for setting the blower function, in view of a use mode in general, it is preferable to impose a rotational operation limit to the operating switch  7 . Accordingly, the switch controller  37  recognizes the blower function arranged at one-end position in the rotary operating direction of the dial knob  10  (front-surface blow-off port) and the blower function arranged at another-end position in the rotary operating direction of the dial knob  10  (dehumidifying function direction) as a dial knob stop position, and stops the further rotational operation of the dial knob  10  when the dial knob  10  is positioned at these dial knob stop positions. 
     That is, the switch controller  37 , when the dial knob  10  is positioned at these dial knob stop positions, supplies electricity to the coil  29  in forward connection at this timing and hence, the dial knob  10  is fixed thus inhibiting the rotational operation of the dial knob  10 . Accordingly, the further rotational operation of the dial knob  10  is prevented and hence, the operating switch  7  also functions as a rotational operation range limiting switch. Further, the same goes for the operation of the air volume setting system or the supply-air temperature setting system. 
     Here, the actual dial knob stop position is set, as shown in  FIG. 10 , to a middle position Xa where the click peace  22 ( 23 ) climbs a slope of the detent crest  14 ( 18 ). This is because when the click peace  22 ( 23 ) falls down the slope of the detent crest  14 ( 18 ) due to a biasing force of a biasing member  25 ( 27 ) after the dial knob  10  is fixed, the dial knob  10  is made to return with rotation by a slight quantity and hence, the position of the dial knob  10  is displaced from the middle position Xa which is the dial knob stop position thus returning the dial knob  10  to a non-fixed state. Due to such an operation, even after the dial knob  10  arrives at the dial knob stop position and is fixed, the fixed state can be released with no problem thus enabling the subsequent rotational operation of the dial knob  10 . 
     Accordingly, in this embodiment, by making use of the magnet magnetic field Ha of the permanent magnet  35  forming a portion of the case part of the operating switch  7 , this magnet magnetic field Ha and the coil magnetic field Hb generated by the coil  29  for changing over click feeling are cooperatively used to change over the click feeling generated by the dial knob  10  and fixing of the dial knob  10 . Accordingly, the click generated in the dial knob  10  can be freely changed over among three stages consisting of large click feeling, small click feeling and a fixed state. Even when one dial knob  10  is used in common among a plurality of selection functions as in the case of this embodiment, by generating the click which differs for every function, the operating switch  7  constitutes operating switches corresponding to respective selection functions thus highly effectively enhancing the switch operating feeling. 
     Further, the multi-stage detent mechanism  11  of this embodiment is a mechanism for changing over the click by making use of a magnetic field generated by the permanent magnet  35  as an assist magnetic field (auxiliary magnetic field) in changing over the click generated by the dial knob  10  in three stages consisting of large click, small click and the fixed state. Accordingly, it is unnecessary to apply the control of the switch controller  37  to this type of permanent magnet  37 . Further, in changing over the click feeling of the dial knob  10 , it is sufficient to perform the control processing which only changes the electricity supply direction of the coil  29  or prevents the flow of an electric current thus realizing the changeover of the click of the dial knob  10  with the simple control processing. 
     According to the arrangement of the present invention, the following advantageous effects can be realized. 
     (1) The multi-stage detent mechanism  11  of this embodiment is a mechanism which changes over, by making use of the magnetic field generated by the permanent magnet  35  as the assist magnetic field, the click generated by the dial knob  10  in three stages consisting of large click, small click and the fixed state. Accordingly, in changing over the click feeling of the dial knob  10 , it is sufficient to perform the control processing which only changes the electricity supply direction of the coil  29  or prevents the flow of an electric current thus realizing the changeover of the click of the dial knob  10  with the simple control processing. 
     (2) The multi-stage detent mechanism  11  of this embodiment adopts the mechanism which allows the first-stage detent mechanism  11   a  for generating small click and the second-stage detent mechanism  11   b  for generating large click to use the plunger case  20  in common and hence, the number of parts necessary for such case parts can be decreased thus realizing the miniaturization of device size and the reduction of part cost. 
     (3) The yoke  9  or the shaft  10   b  of the operating switch  7  are used as the magnetic path through which the magnet magnetic field Ha of the magnet  35  passes, and the coil  29  is arranged such that the coil magnetic field Hb generated by the coil  29  take the direction along the magnetic path of the magnet magnetic field Ha. Due to such a arrangement, in superposing the magnet magnetic field Ha of the magnet  35  and the coil magnetic field Hb of the coil  29  to each other, the coil magnetic field Hb can be easily applied to the magnet magnetic field Ha thus surely allowing or inhibiting the rotational operation of the dial knob  10 . 
     (4) In rotatably operating the dial knob  10 , when the rotary operating position of the dial knob  10  arrives at the knob rotation stop position where the rotational operation of the dial knob  10  is restricted, by performing the detent changeover which brings the dial knob  10  whose rotational operation has been allowed into a fixed state thus imparting feeling of wall to the dial knob  10  at the knob rotation stop position. Due to such a arrangement, this kind of rotational-operation-range-non-limited operating switch  7  can also be used as a rotational-operation-range-limited operating switch with a limited rotational operation range. 
     (5) The operating switch apparatus  3  of this embodiment uses the GUI in which various item buttons  5  are displayed on the display  4 , and button selection decision operation is performed by selectively operating various item buttons  5  using the dial knob  10 . Accordingly, even when the structure which uses one dial knob  10  in common among a plurality of switch selection functions, in this case, it is possible to inform an operator of a possible operation quantity range and items selectable among the selection items at this point of time using the selection function in an operative state. Accordingly, the operator can recognize the operating position to be operated at the time of operating the operating switch  7  thus ensuring the high operability of the operating switch  7 . 
     Here, this embodiment is not limited to the above-mentioned arrangements and may be modified in following modes. 
     The multi-stage detent mechanism is not always limited to the structure which allows the plurality of click feeling to use one plunger case  20  in common. For example, this embodiment may adopt the structure in which the respective detent mechanisms  11  . . . are formed as independent units having respective cases, and a drive state is changed over by changing over the presence or non-presence of attraction using the respective dedicated coils. Further, in using such structure, the number of steps of detent mechanism may not be always two and may be three or more. 
     This embodiment is not limited to the case in which the uneven pattern  13 ( 17 ) is formed on the dial-knob- 10  side and the click piece  22 ( 23 ) is formed on the yoke- 9  side and this combination may be reversed. 
     The positional relationship between the uneven pattern  13 ( 17 ) and the click piece  22 ( 23 ) is not limited to the case in which the click piece  22 ( 23 ) is positioned at the radially inner side of the dial knob  10  and the uneven pattern  13 ( 17 ) is positioned at the radially outer side of the dial knob  10 . This arrangement relationship may be reversed. 
     The operating switch  7  is not limited to the rotational-operation-type switch which operates the dial knob  10  which constitutes the operating portion in the rotational direction and may be a slide-operation-type switch which operates the operating portion in the lateral direction, for example. 
     The changeover of click feeling of the operating switch  7 , when the display  4  is of a touch-panel-type display, for example, may be performed based on a panel touch operation or based on a rotation operation quantity of the encoder  36  since the rotation operation quantity of the dial knob  10  is detected by the encoder  36 . 
     Item values on click feeling such as the shape and the interval of the detent crest  14 ( 18 ) of each detent mechanism  11   a ,  11   b , the size of the click piece  22 ( 23 ), a biasing force of the biasing member  25 ( 27 ) and the like can be suitably and freely set and changed. 
     The auxiliary magnetic field generating member is not always limited to the permanent magnet  35  and may be an electromagnet, for example. 
     The click piece  22 ( 23 ) may not be always limited to the spherical shape and may be formed in a shape having a removal preventing portion for preventing the removal of the click piece  22 ( 23 ) from the plunger case  20 , for example. 
     The operating switch apparatus  3  of this embodiment is not always limited to the vehicle-loaded switch apparatus, and an object on which the switch apparatus is mounted is not particularly limited provided that the operating switch apparatus  3  is a switch apparatus having an operating system such as an electric appliance, for example. 
     Next, technical concepts which can be grasped based on the above-mentioned embodiment and other embodiments are explained hereinafter together with advantageous effects acquired by these embodiments. 
     (1) According to the present invention, the detent changeover switch apparatus includes 
     a function changeover element which changes over the selection functions of the operating portion based on the detection quantity of the detector, and a display controller which performs an image display of the display screen corresponding to the selected function on the display element when the controller controls whether or not the operating portion is allowed to be operated based on the selected function set by the function changeover element. In this case, since the image screen corresponding to the selected function selected and designated time to time is displayed on the display element and hence, even when one operating portion is used in common among the plurality of selection functions as in the case of this embodiment, it is possible to a possible to display an operation quantity range of the operating portion and items selectable among the selection items at this point of time using the selection function on the display in such an operative state. Further, it is also possible to inform an operator of the detail of operations operable by the operating portion for every selected function. Accordingly, it is possible to avoid the case in which the operator cannot recognize the operating position to be operated at the time of operating the operating portion thus ensuring the high operability of the operating portion. 
     According to the above-mentioned technical concept (1) of the present invention, the auxiliary magnetic field generating member is a permanent magnet. In this case, when an electromagnet is used as the auxiliary magnetic field generating member, for example, it is necessary to perform an electricity supply control of the electromagnet. By adopting the electromagnet having the above-mentioned arrangement, this type of electricity supply control is unnecessary thus highly effectively simplifying the control processing in changing over the click feeling and the fixed state of the operating portion.