Variable resistor operation structure and electric device

Abstract

To inhibit a cam-out phenomenon in a variable resistor operation structure.SOLUTION: A variable resistor operation structure 21 includes a variable resistor 22, a switching dial 13, a spacer 23, a guide 24, and a spring 25. The variable resistor 22 is mounted on a substrate 26. The switching dial 13 rotates according to an operation of an operator. In the spacer 23, a tip 41 is fitted in the variable resistor 22 and a tip 37 of the switching dial 13 is fitted in a base end. The guide 24 is fixed to the substrate 26 and rotatably holds the spacer 23. The spring 25 biases the spacer 23 toward the variable resistor 22.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a variable resistor operation structure and an electrical device.

Background Art

[0002] Patent Document 1 describes a switch structure for switching an operation mode, a time scale, and a time unit in a timer that outputs a signal at a predetermined timing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The switch structure is configured to operate the top surface of a variable resistor surface-mounted on a substrate by a switching dial. The variable resistor is a delicate component, and if there is a height change in the depth direction including dimensional tolerances, the fitting of the switching dial will not be sufficient, and a cam-out phenomenon may occur. An object of the present invention is to suppress the cam-out phenomenon in a variable resistor operation structure.

Means for Solving the Problems

[0005] A variable resistor operation structure according to an aspect of the present invention includes a variable resistor, a switching dial, a spacer, a guide, and a spring. The variable resistor is mounted on a substrate. The switching dial rotates in response to a user operation. The spacer has a tip that fits into the variable resistor and a base end that fits into the tip of the switching dial. The guide is fixed to the substrate and rotatably holds the spacer. The spring biases the spacer toward the variable resistor. An electrical device according to another aspect of the present invention includes a variable resistor operation structure.

Advantages of the Invention

[0006] According to the present invention, since a spacer is interposed between the variable resistor and the switching dial and the spacer is biased toward the variable resistor, even if there is a height change in the depth direction including dimensional tolerances, the cam-out phenomenon can be suppressed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that each drawing is schematic and may be different from the actual one. Further, the following embodiments illustrate devices and methods for embodying the technical idea of the present invention and do not specify the configuration to the following. That is, the technical idea of the present invention can be variously modified within the technical scope described in the claims.

[0009] "Embodiment" "Configuration" In the following description, for convenience, three mutually orthogonal directions are defined as the vertical direction, the width direction, and the depth direction. The vertical direction is the up-down direction. FIG. 1 is a diagram showing the electric device 11. In the figure, (a) shows the state of the electric device 11 as viewed from the front in the depth direction. (b) in the figure shows the state of the electric device 11 as viewed from one side in the width direction. The electric device 11 is an electronic timer, which is a control device that outputs an output signal at a predetermined time after an input signal is received. The electric device 11 is formed in a substantially rectangular parallelepiped shape and is fixed by fitting the back side in the depth direction into the socket of the terminal block.

[0010] The electric device 11 includes a resin front frame 12 (frame) at the front in the depth direction. The front frame 12 is provided with a switching dial 13, a switching dial 14, and a switching dial 15 at three of the four corners as viewed from the front in the depth direction. The switching dials 13 to 15 are made of resin, and cross grooves are formed on the top surface facing the front in the depth direction, and they are operated by a plus driver or a minus driver. The switching dials 13 to 15 can be rotated either clockwise or counterclockwise, and the operator can obtain a feeling of operation with a sense of moderation at predetermined angles.

[0011] The switching dial 13 is provided at the corner that is one in the vertical direction and one in the width direction as viewed from the front in the depth direction. Every time the switching dial 13 is rotated by 45 degrees, the operation mode of the electronic timer is switched among "PO" of on-delay, "FL" of flicker, "OS" of one-shot, and "SF" of signal off-delay. The switching dial 14 is provided at the corner that is the other in the vertical direction and one in the width direction as viewed from the front in the depth direction. Every time the switching dial 14 is rotated by 45 degrees, the maximum scale of the electronic timer is switched among "6", "12", "30", and "60". The switching dial 15 is provided at a corner that is on the other side in the longitudinal direction and on the other side in the width direction when viewed from the front in the depth direction. Each time the switching dial 15 is rotated by 45 degrees, the unit time of the electronic timer is switched among "0.1s" of 0.1 second, "sec" of 1 second, "min" of 1 minute, and "hrs" of 1 hour.

[0012] Figure 2 is a diagram showing the front frame 12. (a) in the figure shows the state of the front frame 12 when viewed from one side in the longitudinal direction, one side in the width direction, and the front in the depth direction. (b) in the figure shows the state of a cross section along the longitudinal direction and the depth direction passing through the center of the switching dial 13 in the front frame 12 when viewed from one side in the width direction. The front frame 12 is provided with a variable resistor operation structure 21 for each of the switching dials 13 to 15. In the following description, the switching dial 13 will be described. Since the switching dials 14 and 15 have the same configuration as the switching dial 13, detailed descriptions thereof will be omitted.

[0013] The variable resistor operation structure 21 includes a variable resistor 22, the aforementioned switching dial 13, a spacer 23, a guide 24, and a spring 25. The variable resistor 22 is mounted on a substrate 26. The substrate 26 is a flat printed circuit board along the longitudinal direction and the width direction, and the variable resistor 22 is surface-mounted on one side facing the front in the depth direction. Here, the substrate 26 is drawn by being integrally formed with the front frame 12 for convenience, but actually it is integrally formed with other electronic circuit components housed inside the electric device 11. The spacer 23 has a tip that fits into the variable resistor 22 and a base end that fits into the tip of the switching dial 13. The guide 24 is fixed to the substrate 26 and rotatably holds the spacer 23. The spring 25 is a compression coil spring that biases the spacer 23 toward the variable resistor 22.

[0014] Figure 3 is a diagram showing the variable resistor 22. In the figure, (a) shows the variable resistor 22 as seen from one side in the longitudinal direction, one side in the width direction, and the front in the depth direction. (b) in the figure shows the variable resistor 22 as seen from the front in the depth direction. The upper layer of the variable resistor 22 is rotatable, and a cross groove is formed on the top surface of the upper layer facing the front in the depth direction. The variable resistor 22 has a longitudinal dimension and a width dimension of about 3 mm, and a depth dimension of about 1 to 2 mm. On the substrate 26, engaging ports 31 (through holes) and engaging ports 32 (notches) that can pass from the front surface side to the back surface side are formed on both sides sandwiching the variable resistor 22 along the longitudinal direction.

[0015] The engaging port 31 is arranged inside the substrate 26 in the plane direction, here inside in the longitudinal direction, and is formed by a through hole penetrating the substrate 26. The engaging port 31 is a rectangle with rounded inner corners when viewed from the depth direction. Let the inner dimension in the width direction, which is the longitudinal direction, be Wp, and the inner dimension in the longitudinal direction, which is the short direction, be Dp. The engaging port 32 is arranged inside the substrate 26 in the plane direction, here outside in the longitudinal direction, and is formed by a notch in which the edge of the substrate 26 is recessed inward in the longitudinal direction. The engaging port 32 is U-shaped with rounded inner corners when viewed from the depth direction, and the inner dimension Wp in the width direction, which is the longitudinal direction, is the same as that of the engaging port 31.

[0016] Figure 4 is a diagram showing the switching dial 13. In the figure, (a) shows the switching dial 13 held by the front frame 12 as seen from one side in the longitudinal direction, the other side in the width direction, and the back in the depth direction. (b) in the figure shows the switching dial 13 held by the front frame 12 as seen from the back in the depth direction. A cylindrical boss 36 is formed on the front frame 12, and the switching dial 13 has a cylindrical body portion that fits inside the boss 36 and is rotatably held. The tip 37 of the switching dial 13 protruding toward the back in the depth direction is formed in a cross shape like the tip shape of a plus driver.

[0017] Figure 5 is a diagram showing the spacer 23. In the figure, (a) shows the spacer 23 as viewed obliquely from the front in the depth direction. (b) in the figure shows the spacer 23 as viewed obliquely from the back in the depth direction. The spacer 23 is made of resin, formed in a substantially cylindrical shape, and the rear end 41 in the depth direction is formed in a cross shape like the tip shape of a plus driver. The spacer 23 is divided into four by a slit 42 extending from the front base end in the depth direction toward the tip side, so that a deep cross groove is formed on the base end side. The spacer 23 is formed with a flange 43 protruding in a direction perpendicular to the axis on the tip side.

[0018] Figure 6 is a view showing the guide 24. In the figure, (a) shows the guide 24 as viewed from one side in the longitudinal direction, one side in the width direction, and the front in the depth direction. (b) in the figure shows the guide 24 as viewed from one side in the longitudinal direction, one side in the width direction, and the back in the depth direction. Figure 7 is a view showing the guide 24. In the figure, (a) shows the guide 24 as viewed from one side in the width direction. (b) in the figure shows the guide 24 as viewed from one side in the longitudinal direction. (c) in the figure shows the guide 24 as viewed from the back in the depth direction.

[0019] The guide 24 is made of resin and includes a pair of side plates 46 and a connecting plate 47. The pair of side plates 46 are plate-shaped along the width direction and the depth direction, one end of which is fixed to the substrate 26 and they face each other. On the pair of side plates 46, protruding pieces 54 protruding toward the substrate 26 are formed. The protruding piece 54 is a narrow plate-shaped along the width direction and the depth direction, and the tip side is formed in a hook shape convex toward the inner side of the pair, and fits into either the engaging opening 31 or the engaging opening 32. When fitting the engaging opening 31 and the protruding piece 54 together, the hook-shaped tip side is pushed by the engaging opening 31 and the protruding piece 54 bends, and when the hook-shaped tip side gets over the engaging opening 31, the protruding piece 54 restores to form a snap-fit structure. The same applies to the engaging opening 32 and the protruding piece 54. On the protruding piece 54, a rib 55 extending along the protruding direction in the depth direction and convex toward the outer side of the pair is formed. The rib 55 is formed to extend to the side plate 46. On the tip side of the protruding piece 54, convex portions 56 convex on one side and the other side are formed.

[0020] The connecting plate 47 is plate-shaped along the longitudinal direction and the width direction, is connected between the other ends of the side plates 46, and a round hole 51 through which the spacer 23 fits is formed to penetrate in the axial direction in the depth direction. The round hole 51 protrudes toward the substrate 26 and is formed by a cylindrical portion 52 into which the spacer 23 fits inside. The outer diameter of the cylindrical portion 52 is slightly larger than the inner diameter of the spring 25, and the inner diameter of the cylindrical portion 52 is larger than the outer diameter of the spacer 23. On the cylindrical portion 52, a groove 53 into which the spring 25 fits is formed at the base of the outer peripheral surface. On the connecting plate 47, four ribs 57 extending in the radial direction around the round hole 51 and convex toward the switching dial 13 or the boss 36 are formed. The four ribs 57 are formed at equal intervals every 90 degrees along the circumferential direction, and when viewed from the depth direction, they extend radially with a 45-degree shift with respect to the longitudinal direction and the width direction. The rib 57 is inclined so that the height from the connecting plate 47 becomes higher toward the outside in the radial direction.

[0021] Figure 8 is a view showing the cylindrical portion 52. In the figure, (a) shows a cross-section of the guide 24 along the line A-A in (c) of FIG. 7, that is, a cross-section passing through the center of the cylindrical portion 52 and along the width direction and the depth direction, as viewed from the other side in the vertical direction. (b) in the figure shows a cross-section of the cylindrical portion 52 along the line B-B in (a) of FIG. 8, that is, a cross-section passing through the groove 53 and along the vertical direction and the width direction, as viewed from in front in the depth direction. The groove 53 is formed one by one on both sides in the width direction, that is, at positions on the outer peripheral surface of the cylindrical portion 52 that face away from each other. The pair of grooves 53 are parallel to each other and linearly extend along the vertical direction when viewed from the axial direction of the cylindrical portion 52, and the depth from the outer peripheral surface of the cylindrical portion 52 is the same. The groove 53 has a substantially semi-circular cross-sectional shape when viewed from the vertical direction. The both sides in the vertical direction of the outer peripheral surface of the cylindrical portion 52 are planed by a plane orthogonal to the groove 53 (H cut). When the spring 25 is fitted to the cylindrical portion 52, the spring 25 is caught and held at the portion shaded in (b) in the figure.

[0022] FIG. 9 is a view showing the protruding piece 54. In the figure, (a) shows the protruding piece 54 as viewed from one side in the width direction. (b) in the figure shows the protruding piece 54 as viewed from the inner side opposite in the vertical direction. When viewed from the protruding direction of the protruding piece 54, the dimension Di from the tip of the convex strip 55 to the hooked tip is set to be larger than the inner dimension Dp in the vertical direction in the engaging port 31 (through hole) (Di > Dp). When viewed from the protruding direction of the protruding piece 54, the dimension Wi from the tip of one convex portion 56 to the tip of the other convex portion 56 is set to be larger than the inner dimension Wp in the width direction in the engaging port 31 and the inner dimension Wp in the width direction in the engaging port 32 (Wi > Wp).

[0023] FIG. 10 is a view for explaining the assembly. Here, the variable resistor 22, spacer 23, guide 24, and spring 25 are shown as viewed from one side in the width direction. First, the spring 25 is fitted into the cylindrical portion 52 of the guide 24. At this time, the spring 25 is caught by the groove 53 in the cylindrical portion 52, and the spring 25 is held by the guide 24. Then, the spacer 23 is inserted inside the spring 25, the tip 41 of the spacer 23 is fitted to the variable resistor 22, and the pair of protruding pieces 54 are inserted into the engaging ports 31 and 32. When the tip side of the protruding piece 54 passes through the engaging port 31, the ridge 55 and the pair of convex portions 56 are compressed, and the hook-shaped tip side is pushed by the engaging port 31 and the protruding piece 54 bends. When the tip side of the protruding piece 54 gets over the engaging port 31, the protruding piece 54 restores. Similarly, when the tip side of the protruding piece 54 passes through the engaging port 32, the pair of convex portions 56 are compressed, and the hook-shaped tip side is pushed by the engaging port 32 and the protruding piece 54 bends. When the tip side of the protruding piece 54 gets over the engaging port 32, the protruding piece 54 restores. Thus, the variable resistor operation structure 21 excluding the switching dial 13 is fixed to the substrate 26.

[0024] FIG. 11 is a diagram showing the variable resistor operation structure 21. In the figure, (a) shows the variable resistor operation structure 21 excluding the switching dial 13 as viewed from one side in the width direction. (b) in the figure shows the variable resistor operation structure 21 excluding the switching dial 13 as viewed from one side in the longitudinal direction, one side in the width direction, and the front in the depth direction. The spacer 23 has its base end side fitted into the round hole 51 of the guide 24 and its tip fitted to the variable resistor 22. The cross groove at the base end of the spacer 23 is exposed by the round hole 51, and the tip 37 of the switching dial 13 is fitted here (see (b) of FIG. 2). FIG. 12 is a diagram showing three variable resistor operation structures 21. Here, the variable resistor operation structure 21 attached to the substrate 26 excluding the switching dial 13 is shown as viewed from one side in the longitudinal direction, one side in the width direction, and the front in the depth direction. By attaching the front frame 12 to the electric device 11, the switching dials 13 to 15 are respectively fitted into the variable resistor operation structure 21.

[0025] "Function and Effect" Next, the main function and effect of the embodiment will be described. The variable resistor operation structure 21 includes a variable resistor 22, a switching dial 13, a spacer 23, a guide 24, and a spring 25. The variable resistor 22 is mounted on a substrate 26. The switching dial 13 rotates in response to an operation by an operator. The spacer 23 has a tip 41 that fits into the variable resistor 22 and a proximal end that fits into the tip 37 of the switching dial 13. The guide 24 is fixed to the substrate 26 and rotatably holds the spacer 23. The spring 25 biases the spacer 23 toward the variable resistor 22. In this way, since the spacer 23 is interposed between the variable resistor 22 and the switching dial 13 and the spacer 23 is biased toward the variable resistor 22, even if there is a height change in the depth direction including dimensional tolerances, the cam-out phenomenon can be suppressed. By adopting an operation structure using the switching dial 13 via the spacer 23, a dedicated precision tool is not required.

[0026] The spacer 23 is cylindrical. The guide 24 includes a pair of side plates 46 and a connecting plate 47. One end of each of the pair of side plates 46 is fixed to the substrate 26 and they face each other. The connecting plate 47 is connected between the other ends of the side plates 46 and has a round hole 51 that axially penetrates and into which the spacer 23 fits. Thereby, the spacer 23 can be easily held in a state where it is displaceable and rotatable in the axial direction. The round hole 51 protrudes toward the substrate 26 and is formed by a cylindrical portion 52 into which the spacer 23 fits on the inside. Thereby, the spacer 23 can be stably held in a state where it is displaceable and rotatable in the axial direction.

[0027] The spacer 23 has a flange 43 formed on the tip side. The spring 25 is a compression coil spring disposed outside the cylindrical portion 52 and interposed between the flange 43 and the connecting plate 47. Thereby, the spacer 23 can be easily biased toward the variable resistor 22. In the cylindrical portion 52, at the base of the outer peripheral surface, a groove 53 into which a compression coil spring fits is formed. As a result, since the spring 25 is held by the guide 24, the assemblability is improved. The variable resistor operation structure 21 is composed of fine parts and is particularly effective when handling small parts having a repulsive force such as the spring 25.

[0028] The grooves 53 are formed one by one at positions on the outer peripheral surface of the cylindrical portion 52 that face away from each other. Thereby, the spring 25 can be stably held. The pair of grooves 53 extend linearly and parallel to each other when the cylindrical portion 52 is viewed in the axial direction. Thereby, the pair of grooves 53 are easy to form. On the substrate 26, an engagement port 31 and an engagement port 32 that can pass from the front surface side to the back surface side are formed. On the side plate 46, a protruding piece 54 that protrudes toward the substrate 26 and is formed in a hook shape with the tip side convex toward the inner side facing each other is formed and fits into the engagement port 31 and the engagement port 32. When fitting the engagement port 31 (or the engagement port 32) and the protruding piece 54 together, the hook-shaped tip side is pushed into the engagement port 31 (or the engagement port 32) and the protruding piece 54 bends. Then, when the hook-shaped tip side gets over the engagement port 31 (or the engagement port 32), the protruding piece 54 restores, forming a snap fit structure. Thereby, the assemblability is improved.

[0029] The engagement port 31 disposed inside the substrate 26 in the plane direction is formed by a through hole penetrating the substrate 26. Thereby, the engagement port 31 can be easily formed. If a through hole is formed at a position near the edge of the substrate 26, the substrate 26 may crack or split. Therefore, the engagement port 32 disposed outside the substrate 26 in the plane direction is formed by a notch that recesses the edge of the substrate 26 inward in the plane direction. Thereby, it is possible to suppress the substrate 26 from cracking or splitting. The protruding piece 54 is formed with a rib 55 that extends along the protruding direction and is convex toward the opposite outer side. When viewed from the protruding direction of the protruding piece 54, the dimension Di from the tip of the rib 55 to the hook-shaped tip of the protruding piece 54 is set to be larger than the inner dimension Dp of the engaging port 31 (through hole). Thereby, when the protruding piece 54 is inserted into the engaging port 31, it is in a press-fitting state, and the operator can obtain an appropriate feeling of insertion.

[0030] The rib 55 is formed to extend to the side plate 46. Thereby, the strength of the side plate 46 can be enhanced. On the tip side of the protruding piece 54, convex portions 56 that are convex on one side and the other side are formed. When viewed from the protruding direction of the protruding piece 54, the dimension Wi from the tip of one convex portion 56 to the tip of the other convex portion 56 is set to be larger than the inner dimension Wp of the engaging port 31 (through hole) and the inner dimension Wp of the engaging port 32 (notch). Thereby, when the protruding piece 54 is inserted into the engaging port 31 and the engaging port 32, it is in a press-fitting state, and the operator can obtain an appropriate feeling of insertion.

[0031] The switching dial 13 is held by a cylindrical boss 36 formed on the front frame 12. On the connecting plate 47, a plurality of ribs 57 are formed that extend radially around the round hole 51 and are convex toward the switching dial 13 or the boss 36. Thereby, when the ribs 57 approach the switching dial 13 or the boss 36, the lifting of the guide 24 can be suppressed. That is, the guide 24 is biased in the lifting direction by the spring 25, and when the protruding piece 54 comes off from the engaging port 31 or the engaging port 32, the guide 24 will fall off from the substrate 26, but such a situation can be avoided.

[0032] The plurality of ribs 57 are formed at equal intervals along the circumferential direction. Thereby, the lifting of the guide 24 can be suppressed evenly along the circumferential direction. The rib 57 is inclined such that the height from the connecting plate 47 increases toward the radially outer side. Thereby, it is possible to suppress the lifting of the guide 24 even for the switching dial 13 or the boss 36 having different diameters, and it is possible to align and center the axis of the guide 24 with respect to the switching dial 13 or the boss 36. The spacer 23 is columnar, and the base end side is divided into a plurality by a slit 42 extending from the base end toward the tip end side. Thereby, it is possible to easily form a deep groove and also to cope with displacement in the axial direction.

[0033] The electric device 11 includes a variable resistor operation structure 21. Therefore, it can be widely applied to any electric device 11 that requires the operation of the variable resistor 22. The electric device 11 is an electronic timer. Since the electronic timer requires the operation of a plurality of variable resistors 22, it is suitable. The switching dial 13 switches any one of the operation mode, the time scale, and the time unit. Generally, since an electronic timer has a function of switching the operation mode, the time scale, and the time unit, it can be applied thereto.

[0034] Next, a comparative example will be described. In the comparative example, a structure in which a variable resistor is operated by a switching dial will be described. The variable resistor is a delicate part, and if there is a height change in the depth direction including dimensional tolerances, the fitting of the switching dial becomes insufficient, and a cam-out phenomenon may occur. Therefore, depending on the variable resistor, it was necessary to increase the height, interpose another part between the variable resistor and the switching dial, or make the variable resistor itself a custom-made product, resulting in an increase in cost. Also, if it is to be operated without using a switching dial, a dedicated precision tool is required.

[0035] <<Modification Example>> In the embodiment, the configuration in which the base end of the spacer 23 is formed in a cross groove has been described, but it is not limited thereto. Any other shape may be used as long as it can fit into the tip of the switching dial 13 and transmit rotation. In the embodiment, the configuration in which the engaging port 32 is formed by a notch has been described, but the present invention is not limited thereto. If it is possible to suppress the substrate 26 from cracking or being chipped, the engaging port 32 may be formed by a through hole. In the embodiment, the electronic timer has been described as the electric device 11, but the present invention is not limited thereto. That is, any electric device 11 may be used as long as it has a structure for operating the variable resistor 22 whose upper layer is rotatable. For example, it may be applied to a control relay, an external unit of a magnetic switch, a leakage circuit breaker, an annunciator, or the like.

[0036] Although the present invention has been described with reference to a limited number of embodiments, the scope of rights is not limited thereto, and modifications of the embodiments based on the above disclosure are obvious to those skilled in the art.

Explanation of Reference Numerals

[0037] 11... Electric device, 12... Front frame, 13... Switching dial, 14... Switching dial, 15... Switching dial, 21... Variable resistor operating structure, 22... Variable resistor, 23... Spacer, 24... Guide, 25... Spring, 26... Substrate, 31... Engaging port, 32... Engaging port, 36... Boss, 37... Tip, 41... Tip, 42... Slit, 43... Flange, 46... Side plate, 47... Connecting plate, 51... Round hole, 52... Cylindrical portion, 53... Groove, 54... Protruding piece, 55... Ridge, 56... Protrusion, 57... Rib

Claims

1. A variable resistor mounted on a substrate, A switching dial that rotates in response to an operator's operation, A spacer whose tip fits into the variable resistor and whose base end fits into the tip of the switching dial, A guide fixed to the substrate and rotatably holding the spacer, A variable resistor operation structure comprising a spring that biases the spacer toward the variable resistor.

2. The spacer is cylindrical, The guide is A pair of side plates with one end fixed to the substrate and facing each other, A connecting plate connected between the other ends of the side plates and having a round hole formed axially therethrough for the spacer to fit into, characterized in that the variable resistor operation structure according to claim 1 is provided.

3. The round hole is convex toward the substrate and is formed by a cylindrical portion into which the spacer fits on the inside, characterized in that the variable resistor operation structure according to claim 2 is provided.

4. The spacer has a flange formed on the tip side, The spring is a compression coil spring disposed outside the cylindrical portion and interposed between the flange and the connecting plate, characterized in that the variable resistor operation structure according to claim 3 is provided.

5. The cylindrical portion is formed with a groove at the base of the outer peripheral surface for the compression coil spring to fit into, characterized in that the variable resistor operation structure according to claim 4 is provided.

6. The grooves are formed one by one at positions on the outer peripheral surface of the cylindrical portion facing away from each other, characterized in that the variable resistor operation structure according to claim 5 is provided.

7. The pair of grooves are parallel to each other and linearly extend when the cylindrical portion is viewed axially, characterized in that the variable resistor operation structure according to claim 6 is provided.

8. The substrate is formed with an engaging opening that can pass from the front surface side to the back surface side, The side plate is formed with a protruding piece that protrudes toward the substrate and has a hook shape with the tip side convex toward the inner side of the opposite side, and the protruding piece fits into the engaging opening, The engaging opening and the protruding piece have a snap-fit structure in which when the two are fitted together, the tip side of the hook is pushed into the engaging opening and the protruding piece bends, and when the tip side of the hook crosses over the engaging opening, the protruding piece restores, characterized in that the variable resistor operation structure according to claim 2 is provided.

9. The engaging opening disposed inside the substrate in the plane direction is formed by a through hole penetrating the substrate, The engagement opening disposed on the outer side in the plane direction of the substrate is formed by a notch that recesses the edge of the substrate inward in the plane direction, and the variable resistor operation structure according to claim 8 is characterized in that.

10. On the protruding piece, a convex strip is formed that extends along the protruding direction and is convex toward the outer side of the opposite side. When viewed from the protruding direction of the protruding piece, the dimension from the tip of the convex strip to the hooked tip of the protruding piece is set to be larger than the inner dimension of the through hole, and the variable resistor operation structure according to claim 9 is characterized in that.

11. The variable resistor operation structure according to claim 10, wherein the convex strip is formed to extend to the side plate.

12. On the tip side of the protruding piece, convex portions that are convex on one side and the other side are formed. When viewed from the protruding direction of the protruding piece, the dimension from the tip of one convex portion to the tip of the other convex portion is set to be larger than the inner dimension of the through hole and the inner dimension of the notch, and the variable resistor operation structure according to claim 9 is characterized in that.

13. The switching dial is held by a cylindrical boss formed on the frame. On the connecting plate, a plurality of ribs are formed that extend in the radial direction around the round hole and are convex toward the switching dial or the boss, and the variable resistor operation structure according to claim 2 is characterized in that.

14. The variable resistor operation structure according to claim 13, wherein the plurality of ribs are formed at equal intervals along the circumferential direction.

15. The variable resistor operation structure according to claim 13, wherein the rib is inclined so that the height from the connecting plate becomes higher toward the outer side in the radial direction.

16. The spacer is cylindrical, and the base end side is divided into a plurality by a slit extending from the base end toward the tip end side, and the variable resistor operation structure according to claim 1 is characterized in that.

17. An electric device provided with the variable resistor operation structure according to claim 1.

18. The electric device according to claim 17, characterized in that it is an electronic timer.

19. The electric device according to claim 18, wherein the switching dial switches any one of an operation mode, a time scale, and a time unit.

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