JP2009129260A - Switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switching device capable of precisely detecting an operation angle of an operation part. <P>SOLUTION: The switching device includes a case 1, an operation part 2 installed to the case 1 freely rotationally, a return spring 13 returning the operation part 2 to a prescribed position for the case 1, and a detection block BK housed inside the case 1 for detecting displacement of the operation part 2 from the prescribed position for the case 1. The detection block BK includes a detection part 4 having a detection coil L, an operation element 3, which has a gear 3a meshing with a gear 2b formed on the operation part 2 side and a magnetic material core variably positioned for the detection coil L according to the displacement of the operation part 2, and a signal processing part 5 outputting electric current with a predetermined frequency and predetermined amplitude to the detection coil L to convert a voltage signal decided based on the electric current and impedance of the detection coil L into an electric signal showing the displacement of the operation part 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a switch device that detects displacement of an operation unit.

2. Description of the Related Art Conventionally, there has been known a switch device including a detection coil, an operation unit, an actuator including a magnetic core that contacts the operation unit, and an actuator spring that returns the actuator to a specified position (Patent Document 1). reference). The switch device detects a displacement of the operation unit from a specified position by detecting a change in impedance of the detection coil caused by a displacement of the actuator relative to the detection coil in accordance with an operation of the operation unit.
JP 2007-5208 A

  In the conventional switch device, since the structure for returning the operating element to the specified position by the operating spring is unstable, the position of the operating element with respect to the operation unit is not stable, which causes a decrease in detection accuracy. Further, in the conventional switch device, the detected value is not proportional to the angle of the operation unit but is proportional to the amount of vertical pressing, and thus the operation angle of the operation unit cannot be detected.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a switch device that can detect the operation angle of the operation unit with high accuracy.

  The switch device according to the present invention includes a case, an operation unit rotatably attached to the case, a return spring for returning the operation unit to a specified position with respect to the case, and housed in the case. A detection block that detects a displacement from a specified position, and the detection block includes a detection unit having a detection coil and a gear that meshes with a gear formed on the operation unit side, and detects according to the displacement of the operation unit. An actuator having a magnetic core whose position relative to the coil changes, and a current having a predetermined frequency and amplitude is output to the detection coil, and a voltage signal determined by the current and the impedance of the detection coil is converted into an electrical signal indicating the displacement of the operation unit. A signal processing unit.

  According to the switch device of the present invention, the position of the operating element with respect to the operating unit is stabilized and the linear movement amount of the operating unit with respect to the rotation angle of the operating unit is proportional, so that the operating angle of the operating unit can be detected with high accuracy. it can.

  Hereinafter, the configuration of the switch device according to the embodiment of the present invention will be described.

[Configuration of switch device]
As shown in FIG. 1, the switch device SW according to the embodiment of the present invention includes a case 1, an operation unit 2 movably attached to the case 1, and a case 1 of the operation unit 2 housed in the case 1. The detection block BK has a gear 3a that meshes with a gear 2b formed in the operation unit 2, and detects the displacement from the specified position according to the displacement of the operation unit 2 by a rack and pinion structure. The actuator 3 whose position with respect to the detection coil L is relatively changed, the detection unit 4 having the detection coil L, and a current having a predetermined frequency and amplitude are output to the detection coil L so that the current and the impedance of the detection coil L A signal processing unit 5 that converts the determined voltage signal into an electrical signal indicating the displacement of the operation unit 2 and a plurality of (three in the illustrated example) terminal units that are formed of a metal plate and connected to the signal processing unit 5 Provided with a door.

  The case 1 is formed of a body member 8 and a cover member 9 which are resin molded products made of an insulating resin material. The body member 8 is formed in a rectangular box shape, and is opened on one side in the thickness direction (upper surface side in FIG. 1) and the other side in the thickness direction (lower surface side in FIG. 1). On both side surfaces in the width direction of the body member 8 (in the direction perpendicular to the paper surface in FIG. 1), bearing holes (not shown) for the shaft portion 10 serving as the swing shaft (handle shaft) of the operation portion 2 are thick. It is formed in a shape that is located in the central part on one side in the direction. On one side in the thickness direction of the outer peripheral surface of the body member 8, a flange portion 8 b protruding sideways is formed so as to go around the outer peripheral surface of the body member 8. On both side surfaces of the body member 8 in the length direction, mounting pieces 8c for mounting the body member 8 to the gripping portion of the operating device are integrally projected. A rib 8d that abuts against one surface in the thickness direction of the printed circuit board 5a is provided around the inner peripheral surface of the body member 8, and the printed circuit board 6a is stored with the one surface in the thickness direction abutted against the rib 8d.

  The cover member 9 is a so-called back cover that is attached to the body member 8 so as to close the opening on the other side in the thickness direction of the body member 8 (the lower surface side in FIG. 1). The cover member 9 is formed in a rectangular plate shape having a size capable of closing the opening on the other side in the thickness direction of the body member 8 (the lower surface side in FIG. 1). A plurality of through-holes (not shown) are provided in the thickness direction.

  The operation unit 2 is an operation handle for manually operating the switch device SW, and is formed in a box shape from an insulating resin material. The operation portion 2 has an outer diameter shape in a plane orthogonal to the width direction, with both sides on one side in the thickness direction protruding from the center to one side in the thickness direction, and the center on the other side in the thickness direction on the other side in the thickness direction from both sides. It is formed in a generally U-shape projecting to the side. One surface in the thickness direction (upper surface in FIG. 1) of the operation unit 2 is used as an operation surface with which a person contacts, and the other surface side in the thickness direction (lower surface side in FIG. 1) is opened. The thickness dimension of the operation unit 2 is set so that the operation surface protrudes outside the case 1 when attached to the case 1. An insertion hole (not shown) through which the shaft portion 10 is inserted is formed in the center portion in the length direction on each side surface in the width direction of the operation portion 2.

  A return spring 13 for returning the operation unit 2 to a specified position with respect to the case 1 is provided at the center of the inner bottom surface of the operation unit 2 (the surface opposite to the operation surface of the wall portion on the one side in the thickness direction of the operation unit 2). A pair of holding portions 2 a having a gear 2 b that is fixed and meshed with a gear 3 a formed on the actuator 3 on the outer peripheral surface are formed so as to be separated from each other in the length direction of the operation portion 2. The return spring 13 is a so-called torsion coil spring that integrally includes a coil portion 13a and a pair of arm portions 13b extending from both ends of the coil portion 13a in a direction orthogonal to the winding axis direction of the coil portion 13a. Torsion spring) is used. A pair of positioning ribs (not shown) in which the pair of arm portions 13b of the return spring 3 are elastically contacted to one surface in the thickness direction are integrally provided on each inner side surface of the operation portion 2 in the width direction. .

  The return spring 13 is disposed between the pair of holding pieces in such a manner that the coil part 13a is aligned with the winding axis direction in the width direction of the operation part 2, and the pair of arm parts 13b is provided on each of the pair of positioning ribs. It is attached to the operation unit 2 in a state of being elastically contacted. In a state where the return spring 13 is attached to the operation portion 2, the inside of the coil portion 13a of the return spring 13 communicates with each through hole, and the shaft portion 10 inserted into the operation portion 2 from one through hole has a coil 13a. Projecting from the other through hole 2a to the outside of the operation portion 2.

  The actuator 3 is formed in a cylindrical shape from an insulating resin material, and has a cylindrical core formed in a magnetic material such as ferrite or a metal material. The detection unit 4 includes a cylindrical coil bobbin 4a and a detection coil L wound around the coil bobbin 4a. The coil bobbin 4a is a resin molded product made of an insulating resin material, and is provided on the winding drum portion 4b around which the detection coil L is wound, and on one axial end side (upper end side in FIG. 1) of the winding drum portion 4b. The formed first flange portion 4c and the second flange portion 4d formed on the other axial end side (the lower end side in FIG. 1) of the winding drum portion 4b are integrally provided. The inner diameter of the coil bobbin 4 a is set to be greater than or equal to the outer diameter of the actuator 3. The second flange portion 4d is formed on the winding drum portion 4b in such a manner that the end portion on the other axial end side of the winding drum portion 4b protrudes toward the other axial end side.

  The signal processing unit 5 includes a rectangular printed board 5a on which electronic components (not shown) are mounted, and includes a drive circuit A and a signal processing circuit B as shown in FIG. The printed board 5a has a fitting hole (not shown) for fitting the end portion on the other end side in the axial direction of the winding drum portion 4b and an insertion hole (not shown) for each terminal portion 7 in thickness. It is penetrated in the direction. The drive circuit A is a current circuit that outputs a current having a predetermined frequency and amplitude (that is, a constant current that does not depend on the impedance of the detection coil L) to the detection coil L. The drive circuit A generates a DC voltage having a predetermined frequency and amplitude. The circuit is composed of an oscillation circuit A1 that generates a voltage on which an alternating voltage is superimposed, and a VI circuit (voltage-current conversion circuit) A2 that converts a voltage output from the oscillation circuit A1 into a current. The signal processing circuit B includes positional information on the actuator 3 and the detection coil L according to the peak value V1 of the voltage across the detection coil L (detection signal) determined by the current output from the drive circuit A and the impedance of the detection coil L. That is, an output signal Vout indicating the displacement of the operation unit 2 is output.

  The signal processing circuit B includes a peak hold circuit B1, an AD conversion circuit B2, and a digital operation block B3 having a level shift unit B3a, a temperature compensation unit B3b, and an amplification unit B3c. The peak hold circuit B1 extracts the peak value V1 of the voltage across the detection coil L, and the AD conversion circuit B2 converts the peak value V1 into a digital signal DV1. Then, in the digital operation block B3, as the digital signal operation, a digital signal DV2 that has been level-shifted by adding a predetermined digital amount in the level shift unit B3a is output, and in the temperature compensation unit B3b, an operation for performing temperature compensation is performed. The amplifying unit B3c amplifies the digital signal output from the temperature compensation negative B3b and outputs a digital signal output signal Vout.

[Operation of switch device]
From the initial state where the operation unit 2 is located at the specified position, one end side (left side in FIG. 1) in the length direction of the operation surface of the operation unit 2 is pressed to move from the specified position to the first rotation direction (C1 in FIG. 1). 1 is moved in the direction indicated by M1 and M2 in FIG. 1 according to the amount of displacement, and as a result, the left side in FIG. And the amount of insertion of the right actuator 3 into the detection coil L increases and decreases, respectively. Thereafter, when the pressing operation of the operation unit 2 is released, the operation unit 2 is rotated in the second rotation direction (clockwise direction indicated by C2 in FIG. 1) by the spring force of the return spring 13 to return to the specified position. To do. On the other hand, the left and right actuators 3 in FIG. 1 move in the directions indicated by M2 and M1 in FIG. 1, respectively. Accordingly, the amount of insertion of the left and right actuators 3 in the detection coil L in FIG. 1 is decreased and increased by the amount increased and decreased by the pressing operation of the operation unit 2, respectively.

  On the other hand, from the initial state where the operation unit 2 is located at the specified position, the other end side in the length direction of the operation surface of the operation unit 2 (the right side in FIG. 1) is pressed to move from the specified position to the second rotation direction (FIG. 1). 1 is moved in the directions indicated by M2 and M1 in FIG. 1 according to the amount of displacement, respectively. As a result, the left and right actuators 3 in FIG. The amount of insertion of the right actuator 3 into the detection coil L decreases and increases, respectively. Thereafter, when the pressing operation of the operation unit 2 is released, the operation unit 2 is rotated in the first rotation direction (counterclockwise direction indicated by C1 in FIG. 1) by the spring force of the return spring 13 and returns to the specified position. . With this return operation, the left and right actuators 3 in FIG. 1 move in the directions indicated by M1 and M2 in FIG. 1, respectively. Accordingly, the amount of insertion of the left and right actuators 3 into the detection coil L in FIG. 1 increases and decreases by the amount that is decreased and increased by the pressing operation of the operation unit 2, respectively.

  As described above, when the operation unit 2 is operated, the amount of insertion of the actuator 3 into the detection coil L changes according to the amount of displacement. Since the impedance of the detection coil L changes linearly with respect to the amount of insertion of the actuator 3 into the detection coil L, the output signal Vout output from the signal processing circuit B of the signal processing unit 6 indicates the displacement of the operation unit 2. .

  As is apparent from the above description, according to the switch device SW according to the embodiment of the present invention, the actuator 3 has the gear 3a that meshes with the gear 2b formed on the operation unit 2 side, and the rack and pinion Because the structure is displaced according to the displacement of the operation unit 2, the position of the operator 3 with respect to the operation unit 2 is stabilized, and the linear movement amount of the operator 3 with respect to the rotation angle of the operation unit 2 is proportional, so The angle can be detected with high accuracy.

  As mentioned above, although embodiment which applied the invention made | formed by this inventor was demonstrated, this invention is not limited with the description and drawing which make a part of indication of this invention by this embodiment. That is, all other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

It is sectional drawing which shows the structure of the switch apparatus used as embodiment of this invention. It is a circuit block diagram which shows the structure of the control system of the switch apparatus shown in FIG.

Explanation of symbols

1: Case 2: Operation unit 3: Actuator 4: Detection unit 5: Signal processing unit 13: Return spring SW: Switch device

Claims (1)

Case and
An operation unit rotatably attached to the case;
A return spring for returning the operating portion to a specified position with respect to the case;
A detection block that is housed in the case and detects a displacement of the operation unit from a specified position with respect to the case;
The detection block is:
A detection unit having a detection coil;
An actuator including a gear meshing with a gear formed on the operation unit side, and including a magnetic core whose position with respect to the detection coil changes according to the displacement of the operation unit;
And a signal processing unit that outputs a current having a predetermined frequency and amplitude to the detection coil and converts a voltage signal determined by the current and the impedance of the detection coil into an electric signal indicating the displacement of the operation unit. Switch device.

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