JP7543618B2 - Push Switch - Google Patents

Description

The present invention relates to a push switch.

Conventionally, there is a push switch in which a pressing protrusion formed of an elastic body of a push button is abutted against the top of a conductive disc spring, and a support part formed of an elastic body of a push button is abutted against part of the periphery of the conductive disc spring, thereby depressing the pressing protrusion and reversing the conductive disc spring. The elastic body (pressing protrusion, support part) abutting against the top and part of the periphery of the conductive disc spring absorbs vibrations and suppresses operating noise caused by vibrations. The conductive disc spring comes into contact with the selection contact in the middle of reversing (see, for example, Patent Document 1).

JP 2001-084866 A

However, in conventional push switches, the conductive disc spring comes into contact with the selection contact while it is in the middle of reversing, so the feel when pressed is not good.

Therefore, the objective is to provide a push switch that provides a good feel when pressed and reduces the impact noise when the movable contact and fixed contact come into contact.

The push switch according to an embodiment of the present invention includes a housing having a storage section, a movable contact member having a dome section that is stored in the storage section, a first fixed contact member that is stored in the storage section and has a first fixed contact that contacts the movable contact member when the dome section is reversed, a second fixed contact member that contacts the movable contact member, and an operating member that abuts against the center of the dome section, and the first fixed contact is located outside the center of the dome section in a plan view, and the dome section and the first fixed contact come into contact when the dome section has been reversed by pressing down the operating member, or when the center of the dome section is pressed down further than when the reverse operation is completed.

It is possible to provide a push switch that provides a good feel when pressed and reduces the impact noise when the movable contact and fixed contact come into contact.

FIG. 1 is a perspective view showing a push switch according to an embodiment. FIG. FIG. 2 is a diagram showing a metal contact. FIG. FIG. 4 is a diagram showing the FS characteristic of a push switch. 1 is a diagram showing the operation of a push switch in stages. FIG. 2 is a plan view of a push switch; 7A is a cross-sectional view taken along the line CC of FIG. 7A, illustrating the operation of the push switch. 11A and 11B are diagrams illustrating the reversal speed of a dome portion of a push switch.

The following describes an embodiment in which the push switch of the present invention is applied.

<Embodiment>
Fig. 1 is a perspective view showing a push switch 100 according to an embodiment. Fig. 2 is an exploded view of the push switch 100. In the following, an XYZ coordinate system is defined and described. For convenience of explanation, the -Z direction side will be referred to as the lower side or bottom, and the +Z direction side will be referred to as the upper side or top, but this does not represent a universal up-down relationship. In the following, a plan view refers to an XY plane view.

The push switch 100 includes a housing 110, metal plates 120A, 120B, a metal contact 130A, leaf springs 130B, 130C, an insulating sheet 135, a metal spring 140, an operating member 150, and a frame 160. Below, the metal contact 130A will be described with reference to FIG. 3, which shows the metal contact 130A alone. FIG. 3 shows the metal contact 130A. FIG. 3(A) is a perspective view, and FIG. 3(B) is a cross-sectional view taken along the line A-A in FIG. 3(A). Furthermore, the leaf springs 130B, 130C are structurally similar to the metal contact 130A, since they are configured without the silver plating applied to the underside of the metal contact 130A.

The following description will be given using FIG. 4 in addition to FIG. 1 to FIG. 3. FIG. 4 is a diagram showing the push switch 100. FIG. 4(A) shows a plan view of the push switch 100 with the metal contact 130A, leaf springs 130B, 130C, insulating sheet 135, metal spring 140, operating member 150, and frame 160 removed, and FIG. 4(B) shows a cross section taken along the line B-B in FIG. 4(A).

The push switch 100 switches between on (conductive state) and off (non-conductive state) by changing the electrical conductivity state between the metal plates 120A and 120B via the metal contact 130A.

When the push switch 100 is off (non-conductive), the metal contact 130A is in contact with the peripheral fixed contact 121B of the metal plate 120B, but is not in contact with the plate portion 121A of the metal plate 120A. In other words, the metal plates 120A and 120B are not electrically connected, and the push switch 100 is off (non-conductive).

When the operating member 150 of the push switch 100 begins to be pressed downward from its initial position (see Figure 1) where it is not being pressed downward, first only the metal spring 140 elastically deforms, and the leaf springs 130B, 130C and metal contact 130A enter an operating region where they do not elastically deform. The downward stroke (displacement) of the operating member 150 in this operating region is called the prestroke. In the prestroke state, the metal contact 130A does not reverse and is not in contact with the metal plate 120A, so the push switch 100 is off (non-conductive).

In addition, when the center of the metal spring 140 begins to contact the leaf spring 130C, the push switch 100 transitions from the prestroke operating range to the main stroke operating range.

When the operating member 150 is pressed downward in the main stroke operating range, the center of the metal spring 140 presses the center of the leaf springs 130C and 130B downward, and the center of the leaf springs 130C and 130B presses the center of the metal contact 130A downward. When the leaf springs 130C and 130B and the metal contact 130A perform a reversal operation, the metal contact 130A comes into contact with the metal plate 120A, and the metal plates 120A and 120B are electrically connected via the metal contact 130A, and the push switch 100 turns on (conductive state).

Next, we will explain each component when the operating member 150 is in the initial position where it is not pressed downward (see Figure 1).

The housing 110 is made of resin and holds the metal plates 120A and 120B. The housing 110 and the metal plates 120A and 120B are manufactured integrally by insert molding. The housing 110 has an opening 111, a storage section 112 that communicates with the opening 111, and an engagement section 113. The opening 111 is formed on the surface on the +Z direction side. The storage section 112 is formed downward from the opening 111, and has four recesses 112A, a step section 112B, and a bottom surface 112C.

The opening 111 and the storage section 112 are circular in plan view, and the four recesses 112A are recessed from the circular shape toward the four corners of the housing 110. The four recesses 112A are provided to store the four legs 141 of the metal spring 140 and to position the legs 141. Note that the opening 111 and the storage section 112 are not limited to being circular in plan view, and may be of other shapes.

The step portion 112B is provided to surround the periphery of the bottom surface 112C located at the center of the storage section 112 in a plan view, and is at the same height as the bottom surface of the recessed portion 112A, and is one step higher than the bottom surface 112C. The outline of the step portion 112B surrounding the bottom surface 112C is recessed outward at the four corners in a plan view of the housing 110, similar to the four recessed portions 112A. The step portion 112B has a recessed portion 112B1 (see FIG. 4A) that is recessed in a plan view to avoid two abutment portions 112C1 of the bottom surface 112C described below and two contact portions 121B2 of the peripheral fixed contacts 121B of the metal plate 120B.

On the bottom surface 112C, the plate portion 121A and the stopper 124A of the metal plate 120A and the peripheral fixed contacts 121B of the metal plate 120B are arranged and exposed inside the storage section 112. The bottom surface 112C is located at the bottom of the storage section 112, and the plate portion 121A, the stopper 124A, and the peripheral fixed contacts 121B are provided in a manner that they are exposed from the bottom surface 112C. The bottom surface 112C is one step lower than the step portion 112B, but the height of the bottom surface 112C may vary depending on the position.

The bottom surface 112C has two abutment portions 112C1 at positions corresponding to the two recesses 112A located on the -X direction side in a plan view. The lower surfaces of two of the four legs 131A of the metal contact 130A located on the -X direction side abut against the two abutment portions 112C1. Therefore, the two legs 131A located on the -X direction side of the metal contact 130A do not contact the metal plate 120A.

In the storage section 112, metal contact 130A, leaf springs 130B, 130C are arranged in this order on top of plate portion 121A, stopper 124A, and peripheral fixed contact 121B (see FIG. 2), and insulating sheet 135, metal spring 140, and operating member 150 are further stacked on top of them. Metal spring 140 is stored in storage section 112, and operating portion 152 of operating member 150 protrudes upward from opening 111.

The engagement portion 113 protrudes in the Y direction from the upper portion of the outer wall portion extending in the X direction on the ±Y direction side. The engagement portion 113 is provided to fix the frame 160 to the housing 110.

The metal plate 120A is an example of a first fixed contact member, and has a plate portion 121A, a terminal 122A, a fixed portion 123A, and a stopper 124A. The stopper 124A is an example of a metal plate material, and is an extension of the metal plate 120A toward the center of the dome portion 132A in a plan view. The metal plate 120A is made of copper, for example. The plate portion 121A, the terminal 122A, the fixed portion 123A, and the stopper 124A are manufactured integrally.

The plate portion 121A is provided to surround the stopper 124A protruding from the center of the bottom surface 112C of the storage portion 112, within approximately half of the area on the -X direction side of the center of the bottom surface 112C. The plate portion 121A has two first fixed contacts 121A1. The two first fixed contacts 121A1 are located outside the center portion 132A1 of the dome portion 132A in a plan view. The two first fixed contacts 121A1 are provided between the two abutment portions 112C1 and the stopper 124A. The distances of the two abutment portions 112C1 from the center 124A1 of the stopper 124A in a plan view are equal. The two first fixed contacts 121A1 are portions that protrude upward from the upper surface of the plate portion 121A. The two first fixed contacts 121A1 are equal in height to the top surface of the plate portion 121A.

When the operating member 150 is in the initial position where it is not pressed downward (see FIG. 1), the metal contact 130A is not in contact with the first fixed contact 121A1. When the operating member 150 is pressed downward and the metal contact 130A performs a reversing operation, the metal contact 130A comes into contact with the first fixed contact 121A1.

The terminal 122A and the fixing portion 123A protrude in the -X direction of the housing 110. The terminal 122A is connected to a device or the like outside the push switch 100. The fixing portion 123A is a portion that is connected to and held by the hoop material when the housing 110 and the metal plate 120A are integrally manufactured by insert molding, and is a portion that is cut from the hoop material after insert molding. The cut location between the fixing portion 123A and the hoop material may be anywhere on the outside of the housing 110, but by leaving the fixing portion 123A inside the housing 110, the metal plate 120A and the housing 110 are fixed more stably. The metal plate 120A may be configured not to have the fixing portion 123A.

The stopper 124A is provided to receive the dome portion 132A located in the center of the metal contact 130A and stop the pressing operation when the metal contact 130A is reversed and pressed further downward by the operating member 150. For this reason, the stopper 124A is provided in the center of the bottom of the storage section 112 in a plan view.

As an example, a form in which the stopper 124A is integrally formed as part of the metal plate 120A will be described here, but the metal plate 120A does not have to have the stopper 124A. In this case, for example, the bottom wall having the bottom surface 112C of the housing 110 can be used as the stopper. However, since using the stopper 124A, which is part of the metal plate 120A, provides greater strength than the bottom wall of the plastic housing 110, the use of the stopper 124A can improve the stability of the operation of the push switch 100.

The metal plate 120B is an example of a second fixed contact member, and has a peripheral fixed contact 121B, a terminal 122B, and a fixed portion 123B. The metal plate 120B is made of copper, for example. The peripheral fixed contact 121B is exposed from the bottom surface 112C at the peripheral portion of the bottom of the storage portion 112, and has a second fixed contact 121B1 and two contact portions 121B2.

The second fixed contact 121B1 is a portion that protrudes upward from the upper surface of the peripheral fixed contact 121B, and is located between the stopper 124A and the terminal 122B. As an example, the second fixed contact 121B1 is divided into a portion on the +Y direction side and a portion on the -Y direction side, but it does not have to be divided. The distance between the second fixed contact 121B1 and the center 124A1 of the stopper 124A is equal to the distance between the first fixed contact 121A1 and the center 124A1 of the stopper 124A. In addition, since the positions of the metal plates 120A and 120B in the Z direction are equal, the height of the surface of the peripheral fixed contact 121B and the surface of the plate portion 121A are equal. The height of the second fixed contact 121B1 relative to the peripheral fixed contact 121B may be equal to the height of the first fixed contact 121A1 relative to the plate portion 121A, but as an example here, the height of the second fixed contact 121B1 relative to the peripheral fixed contact 121B is set lower than the height of the first fixed contact 121A1 relative to the plate portion 121A. In other words, the height of the first fixed contact 121A1 is higher than the height of the second fixed contact 121B1. The reason for this height relationship will be described later.

The two contact portions 121B2 are provided on the +Y and -Y sides of the second fixed contact 121B1. The two contact portions 121B2 are located between the stopper 124A and the two recesses 112A on the +X side of the four recesses 112A of the housing 110.

When the operating member 150 is in the initial position where it is not pressed downward (see FIG. 1), the lower surfaces of the two of the four legs 131A of the metal contact 130A located on the +X direction side are in contact with the two contact portions 121B2, but the metal contact 130A is not in contact with the second fixed contact 121B1.

The terminal 122B and the fixing portion 123B protrude in the +X direction of the housing 110. The terminal 122B is connected to an external device of the push switch 100. The fixing portion 123B is a portion that is connected to and held by the hoop material when the housing 110 and the metal plate 120B are integrally manufactured by insert molding, and is a portion that is cut from the hoop material after insert molding. The cut location between the fixing portion 123B and the hoop material may be anywhere on the outside of the housing 110, but by leaving the fixing portion 123B inside the housing 110, the metal plate 120B and the housing 110 are fixed more stably. The metal plate 120B may be configured not to have the fixing portion 123B.

The metal contact 130A is a metal spring made of a metal member, and has four legs 131A and a dome portion 132A that protrudes upward in a dome shape and can be inverted (see FIG. 2). The metal contact 130A is an example of a movable contact member. The four legs 131A are an example of an end portion of a movable contact member. The metal contact 130A is made of stainless steel, for example.

The metal contact 130A is placed at the bottom surrounded by the step portion 112B of the storage section 112 with the leaf springs 130B and 130C stacked on top of each other. The bottom surrounded by the step portion 112B is the part that is lower than the step portion 112B and where the bottom surface 112C, the plate portion 121A and the stopper 124A of the metal plate 120A, and the peripheral fixed contact 121B of the metal plate 120B are located, and is the bottom of the storage section 112.

The four legs 131A extend outward from the dome portion 132A at equal intervals (90 degree intervals) in a plan view, and extend diagonally downward from the dome portion 132A in a side view. Such a metal contact 130A is produced by forming the legs 131A by punching a metal sheet.

Each leg 131A has a bent portion 131A1. The leg 131A extends diagonally downward from the dome portion 132A toward the bent portion 131A1, is bent at the bent portion 131A1, and extends diagonally upward toward the tip.

Two of the four legs 131A on the +X direction side are in contact with two contact portions 121B2 of the peripheral fixed contact 121B of the metal plate 120B. The two legs 131A on the -X direction side are in contact with two contact portions 112C1 on the bottom surface 112C of the housing 110. The step portion 112B of the housing 110 has a recess 112B1 for avoiding the two contact portions 121B2 and the two contact portions 112C1 in a plan view, so the four legs 131A are positioned by the four recesses 112B1 of the step portion 112B. The four legs 131A have a shape that matches the shape and size of the step portion 112B surrounding the bottom surface 112C in a plan view, and are located at the four corners of the dome portion 132A.

Dome portion 132A is located at the center of the four legs 131A, and can be inverted from an upwardly convex state to a downwardly convex state relative to legs 131A. In other words, the inverting direction of dome portion 132A is the direction in which the orientation of dome portion 132A changes to be convex, and is the direction in which it changes from an upwardly convex state to a downwardly convex state.

Dome portion 132A has a central portion 132A1 and a peripheral portion 132A2. Central portion 132A1 is a portion located in the center of dome portion 132A, and peripheral portion 132A2 is a ring-shaped portion surrounding central portion 132A1. The amount of displacement caused by the inversion operation of dome portion 132A is greater for central portion 132A1 than for peripheral portion 132A2.

The top of the dome portion 132A (the central portion in a plan view) is located above the stopper 124A. The leg portion 131A is positioned by the recess 112B1 of the step portion 112B and abuts against two contact portions 121B2 of the peripheral fixed contact 121B of the metal plate 120B and two abutment portions 112C1 of the bottom surface 112C of the housing 110.

When the dome portion 132A is pressed from above and inverts to become convex downward, the inverted dome portion 132A comes into contact with the first fixed contact 121A1 and the second fixed contact 121B1, and the metal contact 130A establishes electrical convexity between the metal plates 120A and 120B. The underside of the metal contact 130A is silver plated because the underside comes into contact with the metal plates 120A and 120B through which current flows. In addition, the inversion of the dome portion 132A provides the operator with a tactile sensation. The operation of the push switch 100 accompanying the inversion will be described in detail later.

Such a metal contact 130A is produced by forming a dome portion 132A by punching a metal sheet molded into a roughly rectangular shape in plan view.

The leaf spring 130B has a structure in which the silver plating has been removed from the metal contact 130A. Therefore, the leaf spring 130B has a leg portion 131B and a dome portion 132B. The leaf spring 130B is placed on top of the metal contact 130A.

Leaf spring 130C has the same configuration as leaf spring 130B, and therefore has leg portion 131C and dome portion 132C. Leaf spring 130C is placed on top of leaf spring 130B.

The insulating sheet 135 is a circular sheet member made of an insulating material in a plan view, and is provided to insulate the leaf spring 130C from the metal spring 140. The size of the insulating sheet 135 in a plan view is larger than the metal contact 130A and the leaf springs 130B and 130C. The outer periphery of the insulating sheet 135 is located on the step portion 112B inside the storage section 112, and the center of the insulating sheet 135 is in contact with the top of the leaf spring 130C.

The metal spring 140 is a metal leaf spring having four legs 141 and a central portion 142. The central portion 142 is located in the center of the four legs 141 and is a circular, flat portion in a plan view.

The four legs 141 extend outward at equal intervals (90 degree intervals) from the center 142 in a plan view, and extend diagonally downward from the center 142 in a side view. Such a metal spring 140 is made by forming the legs 141 by punching a metal sheet cut into a roughly cross shape. In addition, since each leg 141 extends toward the four corners of the storage section 112, the legs 141 can be made long.

Each leg 141 has a bent portion 141A. The leg 141 extends diagonally downward from the center portion 142 toward the bent portion 141A, is bent at the bent portion 141A, and has a shape that extends diagonally upward toward the tip.

The height of the legs 141 (the length in the Z-axis direction from the bent portion 141A to the base where it connects to the central portion 142) is set to be higher than the height of the dome portion 132C of the leaf spring 130C (the height of the top of the dome portion 132C relative to the legs 131C). In addition, the positions of the four bent portions 141A are located outside the dome portion 132C of the leaf spring 130C in a plan view.

The metal spring 140 is placed in the storage section 112 with the four legs 141 stored in the recess 112A of the housing 110 in a plan view. In this state, a gap is created between the center section 142 and the dome section 132C.

When the central portion 142 of the metal spring 140 is pressed downward by the operating member 150, the legs 141 are elastically deformed so as to be pushed outward from the central portion 142, so that the central portion approaches the dome portion 132C of the leaf spring 130C.

The prestroke operating range is the range in which the metal spring 140 elastically deforms until either the part of the leg 141 closer to the central portion 142 than the bent portion 141A or the central portion 142 comes into contact with the dome portion 132C of the leaf spring 130C.

When the metal spring 140 is pressed further downward by the operating member 150, it transitions to the operating range of the main stroke, which presses the dome portion 132C of the leaf spring 130C downward.

The operating member 150 has a base 151, an operating portion 152, and a convex portion 153, and the base 151 and the convex portion 153 are stored in the storage portion 112. The base 151 is a disk-shaped portion provided around the lower end of the truncated cone-shaped operating portion 152, and the operating portion 152 protrudes upward from the upper surface of the center of the base 151. The convex portion 153 is a portion that protrudes downward from the lower side of the operating portion 152, as shown in FIG. 4(B). The convex portion 153 protrudes downward below the lower surface of the base 151. The operating member 150 is what is called a stem.

The operating member 150 is made of a hard material, such as synthetic resin, metal, or ceramic, which hardly undergoes elastic deformation. In other words, a hard material is a synthetic resin, metal, or ceramic, which hardly undergoes elastic deformation, and ideally is a material that has no elasticity. In the operating range of the main stroke, the push switch 100 makes the operating member 150 out of a hard material that hardly undergoes elastic deformation in order to suppress an increase in stroke due to elastic deformation of the operating member 150.

The frame 160 has a base 161 and a leaf spring portion 162. The base 161 is rectangular in plan view and has an opening 161A. The base 161 is arranged on top of the upper surface of the housing 110, and the opening 161A has an opening diameter that allows the operating portion 152 of the operating member 150 to be inserted therethrough.

The leaf springs 162 are provided on each of the ±Y direction sides of the base 161, and are rectangular loop-shaped leaf springs that can engage with the engagement parts 113 of the housing 110. The leaf springs 162 are bent downward relative to the base 161, and engage with the engagement parts 113 on the side of the housing 110.

The metal contact 130A, leaf springs 130B and 130C, insulating sheet 135, and metal spring 140 shown in FIG. 2 are stored in storage section 112 of housing 110, and with operating member 150 placed on top of metal spring 140, frame 160 is placed over housing 110 and fixed in place, completing push switch 100 as shown in FIG. 1.

In this state, the metal contact 130A, leaf springs 130B, 130C, insulating sheet 135, metal spring 140, and operating member 150 are held in place so as not to rattle.

In addition, leaf springs 162 may be provided on both sides of the base 161 in the X direction and engaged with engagement portions 113 provided on both side surfaces of the housing 110 in the X direction.

The push switch 100 having the above-described configuration can be used, for example, as a switch for various operating systems in the interior of a vehicle. In such a case, the operating portion 152 of the operating member 150 may be covered with a thin resin sheet or the like.

In order to prevent the metal contact 130A, leaf springs 130B, 130C, metal spring 140, and operating member 150 of the push switch 100 from rattling due to vibrations caused by the vehicle being driven, the operating member 150 may be installed in a state where it is pressed slightly downward from the initial position shown in FIG. 1. In such a case, the operating member 150 can be installed in a state where it is pressed downward within the prestroke range. Note that by installing the operating member 150 in this state where it is pressed downward, individual differences in the push switch 100 may be absorbed.

Figure 5 is a diagram showing the FS (Force-Stroke) characteristics of the push switch 100. The horizontal axis is the stroke (S) of pushing the operating member 150 downward, and the vertical axis is the force (F) required to push the operating member 150 downward. The force (F) is the operating load. The FS characteristics shown in Figure 5 are the FS characteristics of the entire push switch 100.

As shown in Figure 5, the prestroke ends and the main stroke begins at approximately 0.2 mm, the operating load reaches its maximum value (approximately 4.6 N) at a stroke of approximately 0.35 mm, and reaches its minimum value (approximately 2.0 N) at a stroke of approximately 0.48 mm. If pressure is applied further from the position where the operating load is at its minimum value, the operating load increases, and at a stroke of approximately 0.58 mm the operating member 150 is fully depressed.

Here, in order to explain the relationship between the FS characteristic and the operation of the push switch 100, the operation of the push switch 100 will be explained using FIG. 6. FIG. 6 is a diagram showing the operation of the push switch 100 step by step. Note that in FIG. 6(A) to FIG. 6(D), the push switch 100 is shown in a simplified cross-sectional shape, and only the abutment portion 112C1, metal plate 120A, plate portion 121A, first fixed contact 121A1, stopper 124A, metal plate 120B, peripheral fixed contact 121B, second fixed contact 121B1, and metal contact 130A are shown.

Figure 6 (A) shows the state in which the operating member 150 (see Figure 1) is in the initial position where it is not pressed downward, and as shown by the dashed oval, the leg 131A on the +X side of the metal contact 130A is in contact with the peripheral fixed contact 121B of the metal plate 120B. At this time, the leg 131A on the -X side is in contact with the abutment portion 112C1. Therefore, the metal contact 130A is in contact with the metal plate 120B but not with the metal plate 120A, and the push switch 100 is in the off state. In the FS curve of Figure 5, this corresponds to the prestroke region where the stroke is from 0.0 mm to approximately 0.2 mm.

Figure 6 (B) shows a state in which the operating member 150 (see Figure 1) is pressed downward, causing the dome portion 132A to perform an inversion operation, with the peripheral portion 132A2 in contact with the first fixed contact 121A1. In Figure 6 (B), the inversion operation of the dome portion 132A is completed. The first fixed contact 121A1 and the second fixed contact 121B1 are at the same distance from the center 124A1 (see Figure 4 (A)) of the stopper 124A, and the height of the first fixed contact 121A1 is higher than the height of the second fixed contact 121B1, so the peripheral portion 132A2 of the dome portion 132A comes into contact with the first fixed contact 121A1 before the second fixed contact 121B1.

In this state, as shown by the two dashed ellipses, the leg 131A on the +X direction side of the metal contact 130A is in contact with the peripheral fixed contact 121B of the metal plate 120B, and the peripheral portion 132A2 is in contact with the first fixed contact 121A1. Therefore, the metal contact 130A is in contact with both the metal plates 120A and 120B, and the push switch 100 is in the ON state. This corresponds to the region where the operating load is minimal in the FS curve of FIG. 5. The change in the operating load from a maximum value to a minimum value provides a clicking sensation to the operator's hand, etc.

Figure 6(C) shows a state where the stroke is slightly increased compared to Figure 6(B). That is, in Figure 6(C), the central portion 132A1 of the dome portion 132A is further pressed down from the state where the reversal operation of the dome portion 132A is completed (the state of Figure 6(B)). In Figure 6(C), the peripheral portion 132A2 is in contact with the first fixed contact 121A1 and the second fixed contact 121B1. The first fixed contact 121A1 and the second fixed contact 121B1 are at the same distance from the center 124A1 of the stopper 124A (see Figure 4(A)), and the height of the second fixed contact 121B1 is lower than the height of the first fixed contact 121A1. Therefore, by performing a further pressing operation from the state of Figure 6(B), the peripheral portion 132A2 is in contact with the first fixed contact 121A1 and the second fixed contact 121B1 as shown in Figure 6(C).

In this state, as shown by the three dashed ellipses, the leg 131A on the +X direction side of the metal contact 130A contacts the peripheral fixed contact 121B of the metal plate 120B, and the peripheral portion 132A2 contacts the first fixed contact 121A1 and the second fixed contact 121B1. Therefore, the metal contact 130A is held in a state in which it is in contact with both the metal plates 120A and 120B, and the push switch 100 is held in an on state. In the FS curve of FIG. 5, this is a region that is approximately equal to the state shown in FIG. 6(B), and corresponds to the region where the operating load is minimized. When the state of FIG. 6(A) transitions to the state shown in FIG. 6(B) and FIG. 6(C), and the operating load changes from a maximum value to a minimum value and a clicking sensation is provided to the operator's hand, the push switch 100 switches from off to on, so the feeling when pressing the switch from off to on is good.

Here, the height of the first fixed contact 121A1 is made higher than the height of the second fixed contact 121B1 so that the peripheral portion 132A2 contacts the first fixed contact 121A1 before the second fixed contact 121B1 for the following reason. If the heights of the first fixed contact 121A1 and the second fixed contact 121B1 are made equal, the height of the second fixed contact 121B1 may be higher than the height of the first fixed contact 121A1 due to manufacturing errors, etc. If the height relationship is reversed in this way, even if a pressing operation is performed and the dome portion 132A performs an inversion operation to provide a click feeling, a state may occur in which the peripheral portion 132A2 does not contact the first fixed contact 121A1 but only contacts the second fixed contact 121B1. If no further pressing operation is performed in this state, a situation may occur in which the push switch 100 is maintained in the OFF state even if a click feeling is provided and the operator recognizes that it is turned on through the tactile sensation. To prevent this situation from occurring and ensure that the push switch 100 is switched on when a clicking sensation is provided, the height of the first fixed contact 121A1 is made higher than the height of the second fixed contact 121B1.

In addition, if there are no problems due to manufacturing errors, etc., the height of the first fixed contact 121A1 and the height of the second fixed contact 121B1 may be made equal so that the peripheral portion 132A2 contacts the first fixed contact 121A1 and the second fixed contact 121B1 simultaneously when a pressing operation is performed.

In FIG. 6(D), the central portion 132A1 of the dome portion 132A is pressed further down than in the state of FIG. 6(C), and the bottom surface of the central portion 132A1 is in contact with the top surface of the stopper 124A. In other words, the operating member 150 (see FIG. 1) is pressed down completely, and the pressing operation has been performed to the point where the operating member 150 cannot be pressed down any further.

In the FS curve of FIG. 5, this corresponds to a state where the stroke is about 0.58 mm and the operating load is about 7.0 N. Because the lower surface of the central portion 132A1 abuts against the upper surface of the stopper 124A, the operator is provided with a reaction force due to the operation member 150 being fully depressed.

At this time, as shown by the three dashed ellipses, the peripheral portion 132A2 contacts the first fixed contact 121A1 and the second fixed contact 121B1, and the central portion 132A1 abuts against the stopper 124A, so that the metal contact 130A is conductive with the metal plate 120A even at the stopper 124A. Also, since the upper side of the leg portion 131A of the metal contact 130A is free and is not particularly pressed down, in the state shown in Figure 6 (D), the leg portion 131A on the +X direction side is separated from the peripheral fixed contact 121B. This is because the leg portion 131A is warped upward in reaction to the central portion 132A1 of the dome portion 132A being pressed down further than in the state of Figure 6 (C). However, because the metal contact 130A is in contact with the second fixed contact 121B1 of the metal plate 120B, the electrical connection between the metal contact 130A and the metal plate 120B is maintained in a stable state.

In addition, at this time, the leg 131A on the -X direction side may separate from the abutment portion 112C1, but since the abutment portion 112C1 is part of the housing 110 and is not electrically connected to the metal contact 130A, this does not affect the electrical connection between the metal contact 130A and the metal plate 120A.

Next, the operation state of the push switch 100 in a more specific cross-sectional structure will be described with reference to FIG. 7 and FIG. 8. FIG. 7 is a plan view of the push switch 100. FIG. 8 is a view showing the operation of the push switch 100 in the cross section along arrows C-C in FIG. 7(A). FIG. 7(B) is a view showing the position of the cross section along arrows C-C in FIG. 7(A) with the metal contact 130A, leaf springs 130B and 130C, insulating sheet 135, metal spring 140, operating member 150, and frame 160 removed in order to explain the position of the cross section along arrows C-C. As shown in FIG. 7(B), the cross section along arrows C-C is a cross section passing through the first fixed contact 121A1 on the +Y direction side, the center 124A1 of the stopper 124A, and the center of the two divided parts of the second fixed contact 121B1.

Figure 8 (A) shows a cross section taken along the line CC in the initial position (see Figure 1) where the operating member 150 is not pressed downward. As shown in Figure 8 (A), the leg 131A on the +X side of the metal contact 130A is in contact with the peripheral fixed contact 121B of the metal plate 120B. At this time, the leg 131A on the -X side is in contact with the abutment portion 112C1. Because the metal contact 130A is in contact with the metal plate 120B but not with the metal plate 120A, the push switch 100 is in the OFF state.

Also, FIG. 8(B) shows a state in which the peripheral portion 132A2 of the metal contact 130A is in contact with both the first fixed contact 121A1 and the second fixed contact 121B1, and the central portion 132A1 is not in contact with the stopper 124A. The state shown in FIG. 8(B) corresponds to the state shown in FIG. 6(C). As shown in FIG. 8(B), the leg portion 131A on the +X direction side of the metal contact 130A is in contact with the peripheral fixed contact 121B of the metal plate 120B, and the peripheral portion 132A2 is in contact with the first fixed contact 121A1 and the second fixed contact 121B1, so that the metal contact 130A is held in contact with both the metal plates 120A and 120B, and the push switch 100 is held in the on state.

Figure 9 is a diagram explaining the reversal speed of the dome portion 132A in the push switch 100. Figures 9(A) and 9(B) show the reversal movement of the dome portion in a comparative push switch. Figure 9(C) shows the reversal movement of the dome portion 132A in the push switch 100.

Figure 9 (A) shows two first fixed contacts 11, a second fixed contact 12, a metal contact 13A, and an operating member 15A. Metal contact 13A has a dome portion located in the center, similar to metal contact 130A, and the initial position before the reversal operation is indicated by a dashed line, and the state after the reversal operation is performed is indicated by a solid line. Metal contact 13A has its ends in contact with two first fixed contacts 11, and when it is pressed by operating member 15A to perform the reversal operation, the dome portion comes into contact with second fixed contact 12. The reversal speed of the center of the dome portion of metal contact 13A at this time is V.

9B shows two first fixed contacts 11, two second fixed contacts 12A, a metal contact 13B, and an operating member 15B. The metal contact 13B has a shape in which an opening is provided in the center of the dome portion 132A of the metal contact 130A. The initial position of the metal contact 13B before the reversal operation is shown by a dashed line, and the state after the reversal operation is shown by a solid line. The end of the metal contact 13B is in contact with the two first fixed contacts 11, and when the metal contact 13B is pressed by the two convex portions of the operating member 15B to perform the reversal operation, the edge portion of the opening of the dome portion comes into contact with the two second fixed contacts 12A. The reversal speed of the edge portion of the opening of the dome portion of the metal contact 13B at this time is V. Since the edge portion of the opening of the dome portion 132A of the metal contact 130A is directly pressed by the two convex portions of the operating member 15B, the reversal speed is approximately the same as that shown in FIG. 9A.

In the case of the push switch 100 of the embodiment shown in FIG. 9(C), the following is true. The distance displaced by the center of the dome portion 132A of the metal contact 130A during reversal is defined as d1. The distance displaced by the peripheral portion 132A2 of the metal contact 130A when it comes into contact with the first fixed contact 121A1 during reversal is defined as d2. The distance d2 is shorter than the distance d1. This is because the metal contact 130A displaces more toward the center and less toward the center. The distance from one end of the dome portion 132A to the other is defined as D1, and the distance between the first fixed contact 121A1 and the second fixed contact 121B1 is defined as D2. The distance D1 is equal to the diameter of the dome portion 132A.

The speed at which the center of the metal contact 130A is displaced by the reversing action is V, the same as the comparative push switches shown in Figures 9(A) and 9(B). Here, using the distances d1, d2, D1, and D2, the reversing speed V1 of the peripheral portion 132A2 in the push switch 100 shown in Figure 9(C) can be expressed by the following formula (1).

Equation (1) indicates that the speed V1 is reduced in proportion to the ratio of the distances d1 and d2 relative to the speed V, and also indicates that the speed V1 is reduced approximately in proportion to the ratio of the distances D1 and D2. Since the distances d1 and d2 are the moving distances due to the reversal operation, the speed V1 is obtained by multiplying the speed V by the ratio of the distances d1 and d2. Furthermore, the distances D1 and D2 are the radial dimensions of the metal contact 130A, and since the dome portion 132A of the metal contact 130A is curved in a spherical shape, the speed V1 can be considered to be approximately equal to the value obtained by multiplying the speed V by the ratio of the distances D1 and D2.

As expressed by formula (1), the speed V1 at which the peripheral portion 132A2 of the push switch 100 of the embodiment abuts against the second fixed contact 121B1 is reduced from the speed V at which the metal contacts 13A and 13B abut against the second fixed contacts 12 and 12A, respectively, in the comparative push switch shown in Figures 9(A) and 9(B).

As a result, compared to the comparative push switch shown in Figures 9(A) and 9(B), it is possible to reduce the impact sound when the metal contact 130A abuts against the first fixed contact 121A1 and the second fixed contact 121B1. Note that while only the metal contact 130A has been described here, the same applies to the leaf springs 130B and 130C, which are arranged on top of the metal contact 130A and have a similar configuration.

As described above, when the metal contact 130A performs a reversing operation, the peripheral portion 132A2 of the metal contact 130A comes into contact with the first fixed contact 121A1 and the second fixed contact 121B1, and the push switch 100 is switched on. When the metal contact 130A performs a reversing operation, a clicking sensation is provided to the operator. This provides a good tactile sensation when switching the push switch 100 on.

In addition, the speed at which the peripheral portion 132A2 comes into contact with the first fixed contact 121A1 and the second fixed contact 121B1, which are located outside the center of the metal contact 130A in a plan view, is reduced as described above. This reduces the impact noise when the metal contact 130A comes into contact with the first fixed contact 121A1 and the second fixed contact 121B1.

Therefore, it is possible to provide a push switch 100 that provides a good feel when the push operation is performed and reduces the impact sound when the movable contact (metal contact 130A) and the fixed contact (first fixed contact 121A1 and second fixed contact 121B1) come into contact. Note that although the impact sound when the movable contact (metal contact 130A) and the fixed contact (first fixed contact 121A1 and second fixed contact 121B1) come into contact is described here, when the metal contact 130A comes into contact with the first fixed contact 121A1 after coming into contact with the second fixed contact 121B1, the impact sound when the metal contact 130A comes into contact with the first fixed contact 121A1 may become dominant. Even in this case, the distance displaced when the peripheral portion 132A2 comes into contact with the first fixed contact 121A1 is d2 shown in FIG. 9(C), which is shorter than the distance displaced d1 of the center of the metal contact 130A, and therefore the impact sound can be reduced.

The ratio of the distances D1 and D2 is ideally in the range of 10:4 to 10:7. If the distance d2 is too short, it becomes difficult to ensure the withstand voltage between the metal contact 130A and the first fixed contact 121A1 when the operating member 150 is in the initial position where it is not pressed downward, and if the distance d2 is too long, the effect of reducing the impact sound when the metal contact 130A comes into contact with the first fixed contact 121A1 and the second fixed contact 121B1 is reduced. If the distance D1 is 10, the minimum value of the distance D2 when considering the withstand voltage is 4, and the maximum value of the distance D2 when considering the effect of reducing the impact sound is 7. Therefore, the ratio of the distances D1 and D2 is ideally in the range of 10:4 to 10:7.

In addition, since the first fixed contact 121A1 is provided above the bottom surface 112C of the storage section 112 of the housing 110 in the direction of depression of the operating member 150, the timing at which the peripheral portion 132A2 of the metal contact 130A comes into contact with the first fixed contact 121A1 can be determined by setting the height of the first fixed contact 121A1. In other words, the timing at which the push switch 100 turns on can be determined by setting the height of the first fixed contact 121A1.

The push switch 100 includes a stopper 124A that is provided on the bottom surface 112C of the storage section 112 and contacts the central portion 132A1 of the dome section 132A. When the dome section 132A of the metal contact 130A is fully depressed by inverting, the impact of the central portion 132A1 can be received by the metal stopper 124A. The metal stopper 124A has high rigidity, so it is difficult to break even if it is repeatedly impacted, and it is possible to provide a push switch 100 that enables stable operation for a long period of time. Due to the recent trend toward smaller and thinner push switches, the push switch 100 may also be required to be smaller and thinner. Instead of the metal stopper 124A, the bottom wall of the storage section 112 of the housing 110 may receive the impact, but in particular when a thinner bottom wall is required, using the metal stopper 124A is useful for ensuring stability of operation.

In addition, the metallic stopper 124A is an extension of the metal plate 120A toward the center of the dome portion 132A in a plan view, so it can be manufactured as an integral part of the metal plate 120A. Furthermore, when manufacturing the stopper 124A integrally with the housing 110 by insert molding, the stopper 124A can be manufactured at the same time. This allows the number of parts to be reduced, leading to reduced manufacturing costs.

The metal plate 120B has a contact portion 121B2 that contacts the leg portion 131A on the +X direction side of the metal contact 130A when the dome portion 132A is not performing the inversion operation, and a second fixed contact 121B1 located outside the center of the dome portion 132A in a plan view. When the inversion operation of the metal contact 130A is completed, or when the center portion 132A1 of the dome portion 132A is pressed down further than when the inversion operation is completed, the peripheral portion 132A2 outside the center portion 132A1 of the dome portion 132A contacts the first fixed contact 121A1 and the second fixed contact 121B1. Therefore, the speed at which the peripheral portion 132A2 contacts the first fixed contact 121A1 and the second fixed contact 121B1 can be reduced, and the impact sound at the time of contact can be reduced. Therefore, it is possible to provide a push switch 100 that reduces the impact sound generated during operation.

The two legs 131A on the +X direction side of the metal contact 130A move away from the contact portion 121B2 of the metal plate 120B when the central portion 132A1 of the dome portion 132A is pressed down further than when the reversal operation is completed. This allows the peripheral portion 132A2 to move more easily, and a configuration can be realized in which the peripheral portion 132A2 and the second fixed contact 121B1 are more likely to come into contact when the central portion 132A1 of the dome portion 132A is pressed down further than when the reversal operation is completed. Therefore, when the central portion 132A1 of the dome portion 132A is pressed down further than when the reversal operation is completed, a stable electrical connection state between the metal contact 130A and the metal plate 120B can be ensured, and a highly reliable push switch 100 can be provided.

In addition, the height of the first fixed contact 121A1 is higher than the height of the second fixed contact 121B1, or the height of the first fixed contact 121A1 is equal to the height of the second fixed contact 121B1, so that when a reversal operation is performed, the first fixed contact 121A1 and the peripheral portion 132A2 can be reliably brought into contact with each other, and a push switch 100 can be provided that turns on when a clicking sensation is provided.

In the above, the metal contact 130A has the legs 131A, but as long as the same operation as described above can be achieved, the metal contact 130A does not have to have the legs 131A. The same applies to the leaf springs 130B and 130C.

In addition, the above describes a configuration in which the metal spring 140 has legs 141, but as long as the same operation as described above can be achieved, the metal spring 140 does not need to have legs 141.

The above describes a push switch according to an exemplary embodiment of the present invention, but the present invention is not limited to the specifically disclosed embodiment, and various modifications and variations are possible without departing from the scope of the claims.

REFERENCE SIGNS LIST 100 Push switch 110 Housing 111 Opening 112 Storage section 112B Step section 112C Bottom surface 120A Metal plate 121A1 First fixed contact 124A Stopper 120B Metal plate 121B1 Second fixed contact 130A Metal contact 131A Leg section 132A Dome section 132A1 Central section 132A2 Peripheral section 150 Operation member

Claims (6)

A housing having a storage section;
a movable contact member housed in the housing portion and having a dome portion;
a first fixed contact member that is accommodated in the accommodation portion and has a first fixed contact that comes into contact with the movable contact member by an inverted movement of the dome portion;
a second fixed contact member in contact with the movable contact member;
an operating member that abuts against a central portion of the dome portion;
a metal plate provided on a bottom surface of the storage section and against which a center portion of the dome section abuts ;
the first fixed contact is located outside a center of the dome portion in a plan view,
A push switch in which the dome portion and the first fixed contact come into contact when the inversion movement of the dome portion due to the pressing operation of the operating member is completed, or when the center of the dome portion is pressed further down than when the inversion movement is completed. 2. The push switch according to claim 1 , wherein the metal plate is an extension of the first fixed contact member toward a center of the dome portion in a plan view. A housing having a storage section;
a movable contact member housed in the housing portion and having a dome portion;
a first fixed contact member that is accommodated in the accommodation portion and has a first fixed contact that comes into contact with the movable contact member by an inverted movement of the dome portion;
a second fixed contact member in contact with the movable contact member;
an operating member that abuts against a central portion of the dome portion,
the first fixed contact is located outside a center of the dome portion in a plan view,
When the inverting operation of the dome portion due to the pressing down operation of the operating member is completed, or when the center of the dome portion is pressed down further than when the inverting operation is completed, the dome portion and the first fixed contact are in contact with each other,
the second fixed contact member has a contact portion that comes into contact with an end portion of the movable contact member when the dome portion is not performing an inverting motion, and a second fixed contact that is located outside a center portion of the dome portion in a plan view,
A push switch in which, when the reversal operation is completed, or when the central portion of the dome portion is pressed further down than when the reversal operation is completed, a peripheral portion of the dome portion outer than the central portion contacts the first fixed contact and the second fixed contact . 4. The push switch according to claim 3, wherein the end of the movable contact member is separated from the contact portion of the second fixed contact member when the center of the dome portion is pressed further downward than when the reversal operation is completed. 5. The push switch according to claim 4 , wherein a height of the first fixed contact is higher than a height of the second fixed contact, or the height of the first fixed contact is equal to a height of the second fixed contact. 6. The push switch according to claim 1 , wherein the first fixed contact is provided above a bottom surface of the storage portion of the housing in a pressing direction of the pressing operation.

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