Push switch

Abstract

To enable a suppression of a collision noise of a movable contact member while presenting a good operation feeling to an operator.SOLUTION: A push switch comprises: a case that includes a concave part where an upper part is opened, and includes a fixing contact point into an internal part of the concave part; a dome-like movable contact member that is housed into the concave part of the case, and is formed by a metal plate; and an operation member that presses the movable contact member to make the movable contact member to be reversed and operated. The movable contact member includes a side cut shape of which both sides is cut in a liner shape against a circular shape in an upper surface view, and a side cut ratio calculated by (B / A)×100 is within 40% to 70% in the case where a diameter of the circular shape is A, and an interval of a pair of liner parts formed by the cut is B.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a push switch. [Background technology]

[0002] Patent Document 1 listed below discloses a dome-shaped movable contact member used in a switch device, the dome-shaped movable contact member having a pair of opposing notches in a skirt portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-64401 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional technology has a problem in reducing the impact sound when the movable contact member collides with the fixed member due to the reversing motion. In the conventional technology, it is possible to reduce the impact sound by suppressing the reversing speed of the movable contact member, but on the other hand, there is a risk that the operator will not be able to experience a good operating feel. [Means for solving the problem]

[0005] A push switch according to one embodiment comprises a case having a recess that is open at the top and has a fixed contact inside the recess, a dome-shaped movable contact member made of a metal plate that is housed in the recess of the case, and an operating member that presses the movable contact member to cause it to perform an inverted operation. When viewed from above, the movable contact member has a side cut shape in which both sides are cut linearly into a circular shape, and when the diameter of the circle is A and the distance between a pair of linear portions formed by the cuts is B, the side cut ratio calculated by (B / A) x 100 is within the range of 40% to 70%. Effect of the Invention

[0006] According to the push switch of one embodiment, it is possible to provide an operator with a good operational feel and to suppress the collision noise of the movable contact member. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an external perspective view of a push switch according to an embodiment; [Diagram 2] FIG. 1 is an exploded perspective view of a push switch according to an embodiment; [Diagram 3] 1 is a cross-sectional view of a push switch according to an embodiment; [Figure 4] A perspective view of the metal inversion dome placed in the recess of the case. [Diagram 5] A top view of the metal inversion dome as it sits in the recess of the case. [Figure 6] Graph showing operation load characteristics of a push switch according to an embodiment and a conventional push switch. [Figure 7] Graph showing the relationship between side cut ratio and inversion speed of a metal inversion dome according to one embodiment [Figure 8A] A graph showing the reversal speed of the metal reversal dome in a conventional push switch [Figure 8B] Graph showing the reversal speed of a metallic reversal dome in a push switch according to one embodiment [Figure 9] Graph showing the relationship between side cut ratio and sound pressure of a metallic inverted dome according to one embodiment [Figure 10] Graph showing the relationship between side cut ratio and dome height of a metallic inverted dome according to one embodiment [Figure 11] FIG. 11 is a plan view showing a modified example of the case and the metal inverted dome. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings. For the sake of convenience, in the following description, the Z-axis direction in the drawing is the up-down direction, the Y-axis direction in the drawing is the left-right direction, and the X-axis direction in the drawing is the front-rear direction. However, the positive Z-axis direction is the up direction, the positive Y-axis direction is the right direction, and the positive X-axis direction is the front direction.

[0009] (Outline of Push Switch 100) Fig. 1 is an external perspective view of a push switch 100 according to an embodiment. As shown in Fig. 1, the push switch 100 has a thin rectangular parallelepiped shape in the up-down direction (Z-axis direction) as a whole, and has a roughly square shape when viewed from above. In addition, the push switch 100 has a case 110 whose upper surface 110A is covered by a frame 120. The case 110 contains a stem 130 and the like. The stem 130 has an operating portion 131 at its center that protrudes upward (in the positive direction of the Z-axis) in a convex shape.

[0010] The operating portion 131 of the stem 130 passes through a circular opening 120A formed in the frame 120 and protrudes upward (in the positive direction of the Z axis) beyond the frame 120. This allows the push switch 100 to be pressed downward (in the negative direction of the Z axis) by the operating portion 131 of the stem 130, and the push operation can switch the push switch 100 from an off state to an on state.

[0011] (Configuration of push switch 100) Fig. 2 is an exploded perspective view of the push switch 100 according to one embodiment. Fig. 3 is a cross-sectional view of the push switch 100 according to one embodiment. As shown in Fig. 2 and Fig. 3, the push switch 100 includes, in order from the bottom in the figure (the negative side of the Z axis), a case 110, a metal inversion dome 140, an insulator 150, an elastic member 160, a stem 130, and a frame 120.

[0012] The case 110 is a container-like member that is thin in the up-down direction (Z-axis direction). The case 110 has a roughly square shape when viewed from above. The case 110 has a recess 110B that is recessed downward from an upper surface 110A and has an open top. A metallic inverted dome 140 is housed inside the recess 110B. For example, the case 110 is formed by insert molding using a relatively hard insulating material (for example, hard resin, etc.).

[0013] A central fixed contact 112 and a pair of left and right peripheral fixed contacts 113 are provided on the inner bottom surface of recess 110B of case 110. Central fixed contact 112 is provided in the center of the inner bottom surface of recess 110B. The pair of left and right peripheral fixed contacts 113 are provided at both left and right ends of the inner bottom surface of recess 110B. Both central fixed contact 112 and peripheral fixed contacts 113 are formed using a conductive material (e.g., a metal material).

[0014] 4, the inner wall 110Ba of the recess 110B of the case 110 is provided generally along the outer edge of the metallic inverted dome 140. However, in the inner wall 110Ba of the recess 110B of the case 110, the portions facing each of the pair of straight line portions 142 of the metallic inverted dome 140 are provided at positions farther away in the X-axis direction than the straight line portions 142. As a result, in the recess 110B of the case 110, gaps 110Bb are formed between each of the pair of straight line portions 142 of the metallic inverted dome 140 and the inner wall 110Ba.

[0015] As a result, in the push switch 100 according to one embodiment, each of the pair of straight portions 142 of the metallic inversion dome 140 is not in close proximity to the inner wall portion 110Ba of the recess 110B of the case 110. Therefore, the push switch 100 according to one embodiment can suppress the occurrence of restrictions on the movable range of the insulator 150, and therefore can suppress the influence on the operational feel.

[0016] The metallic inversion dome 140 is an example of a "movable contact member." The metallic inversion dome 140 is a thin plate-like member made of a metal plate, having a dome shape that is convex upward (in the positive direction of the Z axis) with an apex 140A at the center. For example, the metallic inversion dome 140 is formed into a dome shape by pressing a metal plate.

[0017] The metal inverted dome 140 is accommodated in the recess 110B of the case 110 and is placed on the inner bottom surface of the recess 110B. The metal inverted dome 140 is placed on the inner bottom surface of the recess 110B of the case 110, so that its outer peripheral edge contacts each of a pair of peripheral fixed contacts 113.

[0018] The metallic inversion dome 140 is a so-called "inversion spring", and when a pressing operation is performed by the operating part 131 of the stem 130, the top 140A is pressed downward by the pressing part 133 of the stem 130, and when a predetermined operating load is exceeded, the top 140A suddenly elastically deforms (inverts) into a concave shape. As a result, the metallic inversion dome 140 contacts the central fixed contact 112 at the back side of the top 140A and is electrically connected to the central fixed contact 112. As a result, the metallic inversion dome 140 can make the central fixed contact 112 and the peripheral fixed contact 113 conductive to each other via the metallic inversion dome 140. Note that when the pressing operation by the operating part 131 of the stem 130 is released, the metallic inversion dome 140 returns to its original convex shape by elastic force.

[0019] The insulator 150 is an example of a "protective sheet" and is a thin sheet-like member arranged on the upper surface 110A of the case 110. The insulator 150 is made of a resin material such as PET. The insulator 150 has a generally square shape in a top view, similar to the case 110. The insulator 150 is attached to the upper surface 110A of the case 110 by any bonding means (e.g., thermal welding, laser welding, adhesive, etc.) while covering the upper surface 110A of the case 110. The insulator 150 closes the upper opening of the recess 110B of the case 110, thereby sealing the recess 110B.

[0020] The stem 130 is an example of an "operation member" and is pressed downward by an operator. For example, the stem 130 is made of a relatively hard insulating material (for example, hard resin, etc.). The stem 130 has an operation portion 131, a support portion 132, and a pressing portion 133.

[0021] The operating portion 131 is provided in the center of the stem 130, has a cylindrical shape protruding upward from the support portion 132, and is the portion that is pressed by the operator.

[0022] The support portion 132 is a horizontal, flat plate-like portion provided around the operation portion 131. The support portion 132 is provided integrally with the operation portion 131, and supports the operation portion 131. The outer shape of the support portion 132 is approximately square when viewed from above.

[0023] The pressing portion 133 is a dome-shaped portion that protrudes downward from the center of the bottom surface of the stem 130. The pressing portion 133 moves downward to press the top portion 140A of the metallic inverted dome 140 when a pressing operation is performed by the operating portion 131 of the stem 130.

[0024] The stem 130 is positioned between the frame 120 and the insulator 150 with the operating portion 131 passing through the opening 120A of the frame 120 and the top of the pressing portion 133 abutting the top 140A of the metal inverted dome 140 via the insulator 150.

[0025] The frame 120 is a flat metal member. The frame 120 supports the stem 130 disposed above the insulator 150 by being fixedly attached to the upper surface 110A of the case 110 while pressing down the support portion 132 of the stem 130 from above.

[0026] For example, frame 120 is formed by processing a metal plate by a processing method such as press working. In top view, a circular opening 120A is formed in the center of frame 120 for allowing operating portion 131 of stem 130 to protrude upward. Also, a pair of left and right sides at the outer periphery of frame 120 is provided with hooks 120B hanging down downward. Frame 120 is fixed to case 110 by engaging each of the pair of hooks 120B with the side and bottom surfaces of case 110.

[0027] (Operation of push switch 100) In the push switch 100 according to one embodiment, when no pressing operation is performed by the operating portion 131 of the stem 130, the metallic inversion dome 140 is in an initial state in which it is convex upward. Therefore, the metallic inversion dome 140 is in contact with the peripheral fixed contact 113 but is not in contact with the central fixed contact 112. In other words, the peripheral fixed contact 113 and the central fixed contact 112 are not electrically connected to each other. Therefore, the push switch 100 according to one embodiment is in a switched-off state when no pressing operation is performed by the operating portion 131 of the stem 130.

[0028] In one embodiment of the push switch 100, when a pressing operation is performed using the operating portion 131 of the stem 130, the pressing portion 133 of the stem 130 presses the top 140A of the metal inversion dome 140, causing the metal inversion dome 140 to elastically deform.

[0029] Furthermore, in the push switch 100 according to one embodiment, when the operating load of the pressing operation by the operating part 131 of the stem 130 exceeds a predetermined threshold (i.e., when the stroke amount of the stem 130 exceeds the top stroke amount), the top 140A of the metal inversion dome 140 elastically deforms into a concave shape (inverts). As a result, the stroke amount of the stem 130 becomes the bottom stroke amount, and the back side part of the top 140A of the metal inversion dome 140 comes into contact with the central fixed contact 112, thereby electrically connecting with the central fixed contact 112.

[0030] As a result, the push switch 100 according to one embodiment is switched on by the central fixed contact 112 and the peripheral fixed contact 113 being electrically connected to each other via the metallic inversion dome 140. At this time, the push switch 100 according to one embodiment can provide a clicking sensation in response to the pressing operation by the pressing portion 133 of the stem 130 due to the inversion action of the metallic inversion dome 140. Therefore, the push switch 100 according to one embodiment allows the operator to tactilely know that the switch has been switched on.

[0031] In the push switch 100 according to one embodiment, when the pressing operation by the pressing portion 133 of the stem 130 is released, the metallic inversion dome 140 returns to its original convex shape by its own elasticity. As a result, the push switch 100 according to one embodiment returns to the switch-off state.

[0032] (Metal inverted dome 140 shape) Fig. 4 is a perspective view showing the metallic inversion dome 140 in a state where it is placed in the recess 110B of the case 110. Fig. 5 is a plan view showing the metallic inversion dome 140 in a state where it is placed in the recess 110B of the case 110.

[0033] The metallic inverted dome 140 has a side cut shape in which both sides of a circular shape C are cut in a straight line when viewed from above. Specifically, the metallic inverted dome 140 has a pair of curved portions 141 along the circumference of the circular shape C, and a pair of straight portions 142 parallel to each other. The circular shape C is a circle having a common center with the metallic inverted dome 140, and has a predetermined radius r.

[0034] In the metallic inverted dome 140, a pair of curved portions 141 are provided at both ends in the left-right direction (Y-axis direction). The curved portion 141 on the left side (negative side of the Y-axis) is a curved portion with a radius of curvature r, and connects the left ends of the pair of straight portions 142. The curved portion 141 on the right side (positive side of the Y-axis) is a curved portion with a radius of curvature r, and connects the right ends of the pair of straight portions 142.

[0035] The pair of straight portions 142 are provided at both ends in the front-rear direction (X-axis direction) of the metallic inverted dome 140. Each of the pair of straight portions 142 extends linearly in the left-right direction (Y-axis direction).

[0036] For example, the metallic inverted dome 140 is formed by cutting both sides (the portions that become the pair of straight portions 142) of a metallic dome-shaped member having a circular shape of radius r when viewed from above in a straight line shape, so that the metallic inverted dome 140 has a shape having a pair of curved portions 141 and a pair of straight portions 142.

[0037] 5, when the diameter of the circular shape C (i.e., the distance between a pair of curved portions 141) is A and the interval between a pair of straight portions 142 is B, the diameter A and interval B of the metallic inverted dome 140 are set so that the side cut ratio calculated by (B / A)×100 is within the range of 40% to 70%. Note that the above-mentioned range of the side cut ratio is a suitable one determined by the applicants through simulations or the like.

[0038] As a result, the push switch 100 of one embodiment can provide the operator with an equivalent operating feel (i.e., a good operating feel) compared to a conventional push switch that uses a metal inversion dome that is circular when viewed from above (i.e., a metal inversion dome without side cuts), and in addition, the inversion speed of the metal inversion dome 140 can be slowed down to suppress the collision sound (i.e., the operating sound) between the metal inversion dome 140 and the central fixed contact 112.

[0039] Furthermore, it is more preferable that the side cut ratio of the metallic inverted dome 140 is within a range of 60% to 70%. This is because the higher the side cut ratio, the closer the shape becomes to a dome shape, and the easier it becomes to present to the operator an operational feel equivalent to that of a metallic inverted dome without side cuts.

[0040] (Example of comparison of operation load characteristics) Fig. 6 is a graph showing the operation load characteristics of the push switch 100 according to one embodiment and a conventional push switch. In the graph shown in Fig. 6, the solid line shows the operation load characteristics of the push switch 100 according to one embodiment using the metallic inversion dome 140 having a side cut shape, and the dotted line shows the operation load characteristics of the conventional push switch using a circular metallic inversion dome.

[0041] As shown in FIG. 6, in the push switch 100 according to one embodiment, the amount of movement from the top load to the bottom load during the reversal operation of the metallic reversal dome 140 is smaller than that of a conventional push switch.

[0042] Furthermore, as shown in FIG. 6, in the push switch 100 according to one embodiment, the amount of change in load from the top load to the bottom load during the reversing operation of the metallic reversal dome 140 is smaller than in the conventional push switch.

[0043] Therefore, compared to conventional push switches, the push switch 100 of one embodiment is able to reduce the reversal speed of the metal reversal dome 140, thereby suppressing the collision sound (i.e., operation sound) between the metal reversal dome 140 and the central fixed contact 112.

[0044] The triangular areas S1 and S2 shown in Fig. 6 contribute to the operational feel. The areas of areas S1 and S2 represent the amount of inversion movement of the metallic inversion dome 140. The areas of areas S1 and S2 are calculated by C x D x 1 / 2, where C is the amount of change in the operating load during the inversion movement of the metallic inversion dome, and D is the amount of change in the apex during the inversion movement of the metallic inversion dome.

[0045] 6, the area of ​​region S2 of the push switch 100 according to one embodiment is equal to the area of ​​region S1 of the conventional push switch. This means that the push switch 100 according to one embodiment can provide an operator with an equivalent operational feel (i.e., a good operational feel) compared to the conventional push switch.

[0046] In other words, in the push switch 100 of one embodiment, the amount of reversal movement of the metal inversion dome 140 is equal when the metal inversion dome 140 has a side cut shape and when the metal inversion dome 140 does not have a side cut shape.

[0047] (Relationship between side cut ratio and inversion speed of metal inversion dome 140) 7 is a graph showing the relationship between the side cut ratio and the inversion speed of the metallic inversion dome 140 according to one embodiment. The graph shown in FIG. 7 shows the measurement results of the inversion speed of the metallic inversion dome 140 when the side cut ratio of the metallic inversion dome 140 is set to 40%, 50%, 60%, 70%, and 100%.

[0048] As shown in Fig. 7, it was found that the larger the side cut ratio of the metallic inverted dome 140, the higher the inversion speed of the metallic inverted dome 140. In particular, as shown in Fig. 7, it was found that by setting the side cut ratio of the metallic inverted dome 140 within the range of 40% to 70%, the inversion speed of the metallic inverted dome 140 can be significantly reduced compared to when the side cut ratio of the metallic inverted dome 140 is 100% (i.e., when there is no side cut shape).

[0049] (Example of reverse speed comparison) Fig. 8A is a graph showing the reversal speed of the metallic inversion dome in a conventional push switch. Fig. 8B is a graph showing the reversal speed of the metallic inversion dome 140 in the push switch 100 according to one embodiment. In the graphs shown in Fig. 8A and Fig. 8B, the horizontal axis indicates time [s], and the vertical axis indicates the movement amount [mm] of the top of the metallic inversion dome.

[0050] 8A and 8B, in the push switch 100 according to one embodiment, the metallic inversion dome 140 has a side cut shape, so that the amount of movement of the top of the metallic inversion dome 140 during the inversion operation of the metallic inversion dome 140 is smaller and the time required for the inversion operation is longer than in the conventional push switch. That is, in the push switch 100 according to one embodiment, the inversion speed of the metallic inversion dome 140 is smaller than that of the conventional push switch.

[0051] Therefore, the push switch 100 according to one embodiment is able to suppress the impact sound (that is, the operation sound) between the metallic inversion dome 140 and the central fixed contact 112, as compared to conventional push switches.

[0052] (Relationship between side cut ratio and sound pressure of metal inverted dome 140) Fig. 9 is a graph showing the relationship between the side cut ratio and sound pressure of the metallic inverted dome 140 according to one embodiment. The graph shown in Fig. 9 shows the measurement results of the sound pressure of the collision sound between the metallic inverted dome 140 and the central fixed contact 112 for each of the cases where the side cut ratio of the metallic inverted dome 140 is set to 40%, 50%, 60%, 70%, and 100%.

[0053] As shown in Fig. 9, it was found that the larger the side cut ratio of the metallic inverted dome 140, the higher the sound pressure of the collision sound of the metallic inverted dome 140 with the central fixed contact 112. In particular, as shown in Fig. 9, it was found that by setting the side cut ratio of the metallic inverted dome 140 within the range of 40% to 70%, the sound pressure of the collision sound of the metallic inverted dome 140 with the central fixed contact 112 can be significantly reduced compared to when the side cut ratio of the metallic inverted dome 140 is 100% (i.e., when there is no side cut shape).

[0054] (Relationship between side cut ratio and dome height of metal inverted dome 140) 10 is a graph showing the relationship between the side cut ratio and the dome height of the metallic inverted dome 140 according to one embodiment. The graph shown in FIG. 10 shows the measurement results of the dome height required to obtain a certain operating force of the metallic inverted dome 140 for each of the cases where the side cut ratio of the metallic inverted dome 140 is 40%, 50%, 60%, 70%, and 100%.

[0055] As shown in Fig. 10, it was found that the smaller the side cut ratio of the metallic inverted dome 140, the higher the dome height must be in order to obtain a certain operating force. In other words, it was found that the metallic inverted dome 140 according to one embodiment can obtain an operating force equivalent to that of a metallic inverted dome without a side cut shape by setting the dome height to an appropriate height, even when the impact sound is suppressed by using a side cut shape.

[0056] In the push switch 100 according to one embodiment, the diameter of the metallic inversion dome 140 is preferably within a range of 3 mm to 8 mm. This allows the push switch 100 according to one embodiment to be miniaturized, and the metallic inversion dome 140 in the miniaturized push switch 100 can provide the operator with a good operational feel.

[0057] In the push switch 100 according to one embodiment, the thickness of the metal plate of the metallic inversion dome 140 is preferably within a range of 25 μm to 80 μm. This allows the metallic inversion dome 140 in the push switch 100 according to one embodiment to have good spring characteristics, and as a result, the metallic inversion dome 140 can provide the operator with a good operational feel.

[0058] In the push switch 100 according to one embodiment, the material of the metal plate of the metallic inversion dome 140 is preferably SUS 301 or SUS 304. This allows the metallic inversion dome 140 of the push switch 100 according to one embodiment to have good spring characteristics, and as a result, the metallic inversion dome 140 can provide the operator with a good operating feel.

[0059] (One Modification of Case 110 and Metallic Inverted Dome 140) Fig. 11 is a plan view showing a modified example of the case 110 and the metallic inverted dome 140. The case 110-2 shown in Fig. 11 is a modified example of the case 110. The metallic inverted dome 140-2 shown in Fig. 11 is a modified example of the metallic inverted dome 140.

[0060] The case 110-2 has a generally rectangular outer shape with its longitudinal direction extending in the left-right direction (Y-axis direction) when viewed from above. The case 110-2 also has a generally rectangular recess 110B with its longitudinal direction extending in the left-right direction (Y-axis direction) when viewed from above. A metallic inverted dome 140-2 is housed inside the recess 110B of the case 110-2.

[0061] The metallic inverted dome 140-2 has a side cut shape in which both sides in the front-rear direction (X-axis direction) of the circular shape C are cut in a straight line in top view. Specifically, the metallic inverted dome 140-2 has a pair of left and right curved portions 141 along the circumference of the circular shape C, and a pair of front and rear straight portions 142 that are parallel to each other. The circular shape C is a circle that has a common center with the center (top portion 140A) of the metallic inverted dome 140, and has a predetermined radius r.

[0062] Here, the metallic inverted dome 140-2 has cutout portions 143 cut inwardly formed on both the front and rear straight portions 142. As a result, the metallic inverted dome 140-2 has a narrow width portion 140B in the middle in the left-right direction (Y-axis direction) where the width in the front-back direction (X-axis direction), which is the direction perpendicular to the direction in which the pair of straight portions 142 extend, is narrowed.

[0063] Here, similarly to the metallic inverted dome 140, the diameter A and the interval B of the metallic inverted dome 140-2 are set so that the side cut ratio calculated by (B / A)×100 falls within the range of 40% to 70%.

[0064] However, when a metal inverted dome 140 is used, the distance between a pair of straight portions 142 is used as the distance B to calculate the above-mentioned side cut ratio, but since the metal inverted dome 140-2 has a narrow portion 140B, the side cut ratio is calculated by using the width of the narrow portion 140B as the distance B, as shown in FIG. 11.

[0065] When the push switch 100 includes a metallic inversion dome 140-2 having a narrow portion 140B, it is not the interval between the pair of straight portions 142 of the metallic inversion dome 140-2 but the width of the narrow portion 140B of the metallic inversion dome 140-2 that determines the operation load characteristics of the push switch 100. For this reason, when the push switch 100 includes a metallic inversion dome 140-2, the width of the narrow portion 140B is set as the interval B to calculate the above side cut ratio.

[0066] As a result, even when the push switch 100 of one embodiment is provided with the metal inversion dome 140-2 shown in FIG. 11, it is possible to provide the operator with an equivalent operating feel (i.e., a good operating feel) compared to a conventional push switch that uses a metal inversion dome that is circular when viewed from above (i.e., a metal inversion dome without side cuts), and in addition, the inversion speed of the metal inversion dome 140 can be slowed down to suppress the collision sound (i.e., the operating sound) between the metal inversion dome 140 and the central fixed contact 112.

[0067] Furthermore, it is more preferable that the side cut ratio of the metallic inverted dome 140-2 is within a range of 60% to 70%, similar to the metallic inverted dome 140. This is because the higher the side cut ratio, the closer the shape becomes to a dome shape, and the easier it becomes to present to the operator an operational feel equivalent to that of a metallic inverted dome without side cuts.

[0068] The metallic inversion dome 140-2 is positioned in the front-rear direction (X-axis direction) and the rotation direction by abutting the pair of front and rear straight portions 142 against the inner wall portion 110Ba of the recess 110B of the case 110-2. Meanwhile, the metallic inversion dome 140-2 determines the operation load characteristics of the push switch 100 by the width of the narrow portion 140B. Therefore, when the metallic inversion dome 140-2 is used in the push switch 100, the operation load characteristics of the push switch 100 can be adjusted by changing the shape of the cutout portion 143 of the metallic inversion dome 140-2 to adjust the width of the narrow portion 140B without changing the size of the metallic inversion dome 140-2 and the recess 110B of the case 110-2.

[0069] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0070] 100 Push Switch 110,110-2 Case 110A top 110B Recess 110Ba inner wall 110Bb void 112 Central fixed contact 113 Peripheral fixed contact 120 frames 120A opening 120B Hook 130 Stem (operating member) 131 Operation section 132 Support part 133 Pressing part 140, 140-2 Metallic inverted dome (movable contact part) 140A top 140B Narrow part 141 Curved section 142 Straight section 143 Cutout 150 Insulator (protective sheet)

Claims

1. a case having a recess with an open top and a fixed contact inside the recess; a dome-shaped movable contact member made of a metal plate and housed in the recess of the case; an operating member that presses the movable contact member to cause the movable contact member to perform a reversing operation; Equipped with The movable contact member is When viewed from above, the side cut shape is a circle with both sides cut in a straight line, and when the diameter of the circle is A and the distance between a pair of straight lines formed by the cut is B, the side cut ratio calculated by (B / A) x 100 is within the range of 40% to 70%. A push switch characterized by the above.

2. The movable contact member is The smaller the side cut ratio, the higher the height of the dome shape is, thereby obtaining a constant operating force for the reversal motion.

2. The push switch according to claim 1 .

3. When the amount of change in the operating load during the reversing operation of the movable contact member is C and the amount of change in the top of the movable contact member during the reversing operation is D, the amount of reversing operation of the movable contact member calculated by C x D x 1 / 2 is equal when the movable contact member has the side cut shape and when the movable contact member does not have the side cut shape.

2. The push switch according to claim 1 .

4. The diameter of the movable contact member is within a range of 3 mm to 8 mm.

2. The push switch according to claim 1 .

5. The thickness of the metal plate of the movable contact member is within a range of 25 μm to 80 μm.

2. The push switch according to claim 1 .

6. The material of the metal plate of the movable contact member is SUS301 or SUS304.

2. The push switch according to claim 1 .

7. The side cut ratio is within the range of 60% to 70%.

2. The push switch according to claim 1 .

8. The recess of the case has gaps at positions facing the pair of straight portions of the movable contact member.

2. The push switch according to claim 1 .

9. a protective sheet covering the top surface of the case and attached to the top surface of the case; 9. The push switch according to claim 8.

10. The movable contact member is a narrow width portion having a width in a direction perpendicular to a direction in which the pair of straight portions extend, the narrow width portion being narrowed by having a notch portion in each of the pair of straight portions; The side cut ratio is calculated by using the width of the narrow portion as B instead of the interval between the pair of straight portions.

2. The push switch according to claim 1 .

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