Push switch

Abstract

This push switch comprises: a housing having a storage section; a movable contact member provided inside the storage section; a fixed contact member having a fixed contact and provided on an inner bottom surface of the storage section so as to face the movable contact member; and an operation member that presses the movable contact member. The fixed contact has a peripheral edge which is embedded in the housing, and the peripheral edge has a multi-level shape.

Description

Push switch

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

[0002] The following Patent Document 1 discloses a technology for a push switch in which a central fixed contact portion is supported by a pin during insert molding, thereby forming a through hole in a resin material on the back side of the central fixed contact portion, in which a bent portion is provided at the end of the central fixed contact portion, making it difficult for flux that has entered through the through hole during soldering to spread to the front side of the central fixed contact portion.

[0003] International Publication No. 2018 / 142752

[0004] However, the technology of Patent Document 1 still has the risk of the flux wrapping around the end of the central fixed contact portion and spreading to the front side of the central fixed contact portion, and there is room for improvement in the shape of the bent portion at the end of the central fixed contact portion.

[0005] A push switch according to one embodiment comprises a housing having a storage section, a movable contact member provided inside the storage section, a fixed contact member having a fixed contact provided opposite the movable contact member on the inner bottom surface of the storage section, and an operating member that presses the movable contact member, wherein the fixed contact has a peripheral portion embedded in the housing, and the peripheral portion has a multi-step shape.

[0006] According to the push switch of one embodiment, it is possible to prevent flux from entering the front surface side of the fixed contact by going around the periphery of the fixed contact from the rear surface side of the fixed contact.

[0007] 1 is an external perspective view of a push switch according to an embodiment; 2 is an exploded perspective view of a push switch according to an embodiment; 3 is a cross-sectional view of a push switch according to an embodiment; 4 is an external perspective view of a housing included in the push switch according to an embodiment; 5 is an external perspective view of a first fixed contact member and a second fixed contact member included in the housing according to an embodiment;

[0008] An embodiment will be described below with reference to the drawings. For convenience, in the following description, the Z-axis direction in the drawings is the up-down direction, the Y-axis direction in the drawings is the left-right direction, and the X-axis direction in the drawings 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.

[0009] (Overview of Push Switch 100) Fig. 1 is an external perspective view of a push switch 100 according to one embodiment. As shown in Fig. 1, the push switch 100 is configured such that an upper surface 110A of a housing 110 is covered with a metal cover 120. A cylindrical protrusion 121 is formed in the center of the metal cover 120, and a circular opening 122 is further formed in the center of the protrusion 121.

[0010] The cylindrical operating portion 141 of the stem 140 passes through the opening 122 of the metal cover 120 and protrudes upward (in the positive direction of the Z axis) beyond the metal cover 120. This allows the push switch 100 to be pressed downward (in the negative direction of the Z axis) using the operating portion 141 of the stem 140, and this pressing operation can switch the switch 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 Figs. 2 and 3, the push switch 100 includes, in order from the bottom (negative side of the Z axis) in the drawing, a housing 110, a movable contact member 130, a stem 140, and a metal cover 120.

[0012] The housing 110 is a container-like member having a thin rectangular parallelepiped shape in the vertical direction (Z-axis direction). The housing 110 has a roughly square shape when viewed from above. The housing 110 has a storage section 110B that is recessed downward from the top surface 110A. The movable contact member 130 is housed inside the storage section 110B. For example, the housing 110 is formed by insert molding using a relatively hard insulating material (e.g., hard resin, etc.).

[0013] A first fixed contact 114 and two second fixed contacts 115 are provided and exposed on the inner bottom surface of the storage section 110B of the housing 110.

[0014] The first fixed contact 114 is an example of a "fixed contact." The first fixed contact 114 is provided in the center of the inner bottom surface of the storage section 110B, facing the back surface of the top of the dome section 131 of the movable contact member 130. The first fixed contact 114 is provided integrally with the first fixed contact member 112, which is made of metal and has a plate shape.

[0015] The two second fixed contacts 115 are arranged on the inner bottom surface of the storage section 110B, facing each other with the first fixed contact 114 sandwiched therebetween. The two second fixed contacts 115 are provided integrally with a metal, plate-shaped second fixed contact member 113. A peripheral portion 132 of a movable contact member 130 is placed on each of the two second fixed contacts 115.

[0016] The first fixed contact member 112 and the second fixed contact member 113 are both formed using a conductive plate material (for example, a metal plate) and are embedded in the housing 110 by insert molding.

[0017] The movable contact member 130 is a member made of a thin metal plate and disposed in the storage portion 110B of the housing 110. The movable contact member 130 is circular in top view and has a dome portion 131 that is convex upward (in the positive direction of the Z axis). The movable contact member 130 also has a horizontal, flat peripheral portion 132 that surrounds the dome portion 131. The peripheral portion 132 has a square outer shape in top view. The peripheral portion 132 is placed on each of the two second fixed contacts 115 provided on the inner bottom surface of the storage portion 110B. As a result, the movable contact member 130 is stably supported at two points by the two second fixed contacts 115 and is electrically connected to the two second fixed contacts 115.

[0018] The dome portion 131 of the movable contact member 130 is a so-called "reversal spring." When the operating portion 141 of the stem 140 is pressed, the top (center portion) is pressed downward by the central protrusion 143 of the stem 140. When a predetermined operating load is exceeded, the top elastically deforms (reverses) into a concave shape. As a result, the dome portion 131 of the movable contact member 130 contacts the first fixed contact 114 at the back side of the top and is electrically connected to the first fixed contact 114. As a result, the movable contact member 130 can electrically connect the first fixed contact member 112 and the second fixed contact member 113 to each other via the movable contact member 130. When the pressing operation by the operating portion 141 of the stem 140 is released, the dome portion 131 of the movable contact member 130 returns to its original convex shape due to its elastic force.

[0019] The stem 140 is an example of an "operating member" and is a member that is pressed downward by an operator. The stem 140 is disposed inside the protrusion 121 of the metal cover 120. The stem 140 is formed using a hard material (e.g., hard resin, metal, etc.) or an elastic material (e.g., rubber, silicone, etc.). The stem 140 has an operating portion 141, a base portion 142, and a central protrusion portion 143.

[0020] The operating portion 141 is provided in the center of the stem 140 and has a cylindrical shape that protrudes upward from the base portion 142. The operating portion 141 passes through the opening 122 of the metal cover 120 and is pressed by the operator.

[0021] The base portion 142 is a flat, annular portion provided around the operating portion 141. The base portion 142 moves up and down together with the operating portion 141 inside the storage portion 110B of the housing 110.

[0022] Central protrusion 143 is a downward dome-shaped portion that protrudes downward from the bottom surface of operating portion 141. When operating portion 141 is pressed, central protrusion 143 moves downward together with operating portion 141 and base portion 142, thereby pressing the top of dome portion 131 of movable contact member 130.

[0023] The metal cover 120 is a flat metal member. A cylindrical protrusion 121 that protrudes upward is formed in the center of the metal cover 120. The stem 140 is disposed inside the protrusion 121. A circular opening 122 is formed in the center of the protrusion 121 of the metal cover 120 in a top view, allowing the operating portion 141 of the stem 140 to protrude upward. The metal cover 120 is fixedly attached to the upper surface 110A of the housing 110, thereby fixing the stem 140 to the upper surface 110A of the housing 110. As a result, the metal cover 120 confines the stem 140 inside the protrusion 121 and confines the movable contact member 130 in the storage portion 110B of the housing 110. For example, the metal cover 120 is formed by processing a metal plate using a processing method such as press working.

[0024] Further, downwardly hanging hooks 123 are provided on each of the four sides of the outer periphery of metal cover 120. Metal cover 120 is positioned and fixed to housing 110 by each of four hooks 123 engaging with the side surfaces of housing 110.

[0025] (Operation of Push Switch 100) When the operating portion 141 of the stem 140 is not being pressed, the push switch 100 according to one embodiment is in an initial state in which the operating portion 141 is in the highest position and the movable contact member 130 is in an upwardly convex shape. At this time, the movable contact member 130 is in contact with the second fixed contact 115 but not with the first fixed contact 114. In other words, the second fixed contact 115 and the first fixed contact 114 are not electrically connected to each other. Therefore, the push switch 100 according to one embodiment is in a switch-off state when the operating portion 141 of the stem 140 is not being pressed.

[0026] In push switch 100 according to one embodiment, when operating portion 141 of stem 140 is pressed, central protrusion 143 of stem 140 presses down on the top of dome portion 131 of movable contact member 130. This causes dome portion 131 of movable contact member 130 to elastically deform into a concave shape (reverse motion), and the back side of the top of dome portion 131 of movable contact member 130 comes into contact with first fixed contact 114. As a result, push switch 100 according to one embodiment is switched on by establishing electrical conduction between first fixed contact 114 and two second fixed contacts 115 via movable contact member 130.

[0027] (Configuration of first fixed contact member 112 and second fixed contact member 113) Fig. 4 is an external perspective view of housing 110 included in push switch 100 according to one embodiment. Fig. 5 is an external perspective view of first fixed contact member 112 and second fixed contact member 113 included in housing 110 according to one embodiment. Fig. 6 is an A-A cross-sectional view of housing 110 included in push switch 100 according to one embodiment.

[0028] 4 and 5 , a first fixed contact member 112 and a second fixed contact member 113 are integrally provided in the housing 110 by insert molding. The first fixed contact member 112 and the second fixed contact member 113 are formed by processing a metal plate. A portion of the first fixed contact member 112 and the second fixed contact member 113 is embedded in the housing 110, and the remaining portion is exposed from the housing 110.

[0029] The first fixed contact member 112 is a metal, plate-shaped member located on the rear side (negative side of the X-axis) of the bottom of the housing 110. The first fixed contact member 112 has a first portion 112P1 that extends linearly in the left-right direction (Y-axis direction) and a second portion 112P2 that extends forward (positive direction of the X-axis) from the center of the first portion 112P1. External connection terminals 112B are provided at both ends of the first portion 112P1. A first fixed contact 114 is provided at the tip of the second portion 112P2.

[0030] 4, first fixed contact 114 is provided at the center of the inner bottom surface of storage section 110B of housing 110 and exposed from the resin section of housing 110. First fixed contact 114 faces the back side of the apex of dome section 131 of movable contact member 130. As a result, when dome section 131 of movable contact member 130 is reversed, first fixed contact 114 comes into contact with the back side of the apex of dome section 131 of movable contact member 130, thereby electrically connecting first fixed contact 114 to movable contact member 130.

[0031] Here, a pedestal-like contact portion 114A that has a circular shape in top view and protrudes upward is provided on the surface of first fixed contact 114. Therefore, first fixed contact 114 is configured so that the back side of the top of dome portion 131 of movable contact member 130 can locally come into contact with contact portion 114A.

[0032] The second fixed contact member 113 is a metal, plate-shaped member provided on the front side (positive side of the X-axis) of the bottom of the housing 110. The second fixed contact member 113 has a first portion 113P1 extending linearly in the left-right direction (Y-axis direction) and a pair of second portions 113P2 extending obliquely rearward (negative direction of the X-axis) from the center of the first portion 113P1. External connection terminals 113B are provided at both ends of the first portion 113P1. A second fixed contact 115 is provided at the tip of each of the pair of second portions 113P2.

[0033] 4 , the pair of left and right second fixed contacts 115 are arranged on the inner bottom surface of the storage section 110B of the housing 110, facing each other in the left-right direction (Y-axis direction) with the first fixed contact 114 sandwiched therebetween, and are provided exposed from the resin portion of the housing 110. When the movable contact member 130 is arranged in the storage section 110B of the housing 110, the peripheral portions 132 of the movable contact member 130 are placed on the pair of left and right second fixed contacts 115. As a result, the pair of left and right second fixed contacts 115 are electrically connected to the movable contact member 130.

[0034] Here, a pedestal-shaped contact portion 115A that has a rectangular shape when viewed from above and that protrudes upward is provided on the surface of the second fixed contact 115. Therefore, the second fixed contact 115 is configured so that the back surface of the peripheral portion 132 of the movable contact member 130 can locally contact the contact portion 115A.

[0035] 5 and 6, the first fixed contact 114 has a multi-step peripheral edge 116 that slopes downward toward the outside. As shown in FIGS. 4 and 6, the peripheral edge 116 is embedded in the resin portion of the housing 110.

[0036] As a result, in one embodiment of the push switch 100, even if flux penetrates through the hole portion 117 of the housing 110 (see Figure 7) to the back side of the first fixed contact 114, the flux can be prevented from passing around the peripheral portion 116 from the back side of the first fixed contact 114 and penetrating to the front side of the first fixed contact 114.

[0037] Specifically, as shown in FIG. 6, the back surface of the peripheral portion 116 has multiple steps that descend toward the outside, that is, it has a plurality of perpendicular step portions 116A (three step portions 116A in the example shown in FIG. 6) continuously extending outward.

[0038] Therefore, the flux that penetrates the back surface of the first fixed contact 114 through the hole 117 in the housing 110 and flows outward along the back surface of the first fixed contact 114 hits the vertical surface of the first step portion 116A at the highest position of the peripheral portion 116, thereby being restricted from further outward flow.

[0039] Even if the flux should overflow the first step portion 116A and flow further outward, it will collide with the vertical surface of the second step portion 116A provided further outward, thereby restricting further outward flow.

[0040] Furthermore, even if the flux should overflow the second step portion 116A and flow further outward, it will collide with the vertical surface of the third step portion 116A provided further outward, thereby restricting further outward flow.

[0041] In this way, the back surface of the peripheral portion 116 has a plurality of continuous right-angled step portions 116A facing outward, and the outflow of flux can be restricted on the vertical surfaces of each step portion 116A, making it difficult for the flux to overcome all of the step portions 116A.

[0042] Therefore, the push switch 100 according to the embodiment is able to prevent the flux from going around the side end surface 116B of the peripheral portion 116 and invading the surface side of the first fixed contact 114.

[0043] Similarly to the back surface, the front surface of the peripheral portion 116 has a plurality of perpendicular steps 116A extending outward. Therefore, in the unlikely event that flux flows around the side end surface 116B of the peripheral portion 116 and invades the front surface of the peripheral portion 116, the plurality of steps 116A on the surface of the peripheral portion 116 can prevent the flux from invading the exposed portion of the surface of the first fixed contact 114 (the portion inside the peripheral portion 116).

[0044] In this embodiment, the peripheral edge portion 116 has a multi-step shape with three steps, for example, but is not limited to this, and may have a multi-step shape with two steps or four or more steps.

[0045] In this embodiment, the peripheral edge 116 is formed in multiple steps using a half punch press. This allows the push switch 100 according to one embodiment to simultaneously form multiple step portions 116A on both the front and back surfaces of the peripheral edge 116, and to form the multiple step portions 116A with high precision. For example, in this embodiment, compared to bending, the squareness of the corners (edges) of the step portions 116A can be increased, and the perpendicularity of the vertical surfaces of the step portions 116A can be improved. Therefore, the push switch 100 according to one embodiment can further enhance the effect of the multiple step portions 116A in suppressing flux outflow. However, this is not a limitation, and the peripheral edge 116 may be formed in multiple steps using other methods (e.g., cutting).

[0046] 5, the first fixed contact 114 has multiple steps over the entire peripheral edge 116. This allows the push switch 100 according to the embodiment to achieve the effect of suppressing flux outflow over the entire peripheral edge 116.

[0047] In this embodiment, because the inner corners of each step portion 116A have high squareness and sharp edges, gaps may be formed in the inner corners during insert molding where the resin material is not filled in. In this case, the push switch 100 according to the embodiment can further suppress the outflow of flux by allowing the flux to accumulate in the gaps.

[0048] (Configuration of the Bottom Side of the Housing 110) FIG. 7 is a perspective view of the exterior of the housing 110 included in the push switch 100 according to one embodiment, as viewed from the bottom side.

[0049] As shown in Figure 6, two holes 117 are formed in the portion of the bottom surface 110C of the housing 110 that overlaps with the back surface of the first fixed contact 114, which are the marks of fixing pins used to fix the first fixed contact 114 during insert molding.

[0050] Similarly, two holes 118 are formed in the bottom surface 110C of the housing 110 at the portion that overlaps with the back surface of the second fixed contact 115, which are the marks of fixing pins used to fix the second fixed contact 115 during insert molding.

[0051] Here, the hole 117 penetrates the bottom surface 110C of the housing 110 in the vertical direction. Therefore, when the housing 110 of this embodiment is soldered to a substrate, there is a risk that flux may enter the back surface of the first fixed contact 114 through the hole 117.

[0052] However, as described above, in the housing 110 of this embodiment, the back surface of the peripheral portion 116 of the first fixed contact 114 has multiple continuous step portions 116A facing outward, so that even if flux penetrates through the hole portion 117 to the back surface side of the first fixed contact 114, the flux can be prevented from flowing around the side end surface 116B of the peripheral portion 116 of the first fixed contact 114 and penetrating to the front surface side of the first fixed contact 114.

[0053] 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.

[0054] This international application claims priority based on Japanese Patent Application No. 2024-003972, filed on January 15, 2024, the entire contents of which are incorporated herein by reference.

[0055] DESCRIPTION OF SYMBOLS 100 Push switch 110 Housing 110A Top surface 110B Storage section 112 First fixed contact member 112B External connection terminal 112P1 First portion 112P2 Second portion 113 Second fixed contact member 113B External connection terminal 113P1 First portion 113P2 Second portion 114 First fixed contact 114A Contact portion 115 Second fixed contact 115A Contact portion 116 Peripheral edge portion 117 Hole portion 120 Metal cover 121 Convex portion 122 Opening 123 Hook 130 Movable contact member 131 Dome portion 132 Peripheral portion 140 Stem 141 Operation portion 142 Base portion 143 Central protrusion portion

Claims

1. A push switch comprising: a housing having a storage portion; a movable contact member provided inside the storage portion; a fixed contact member having a fixed contact provided to face the movable contact member on the inner bottom surface of the storage portion; and an operation member for pressing the movable contact member, wherein the fixed contact has a peripheral portion embedded in the housing, and the peripheral portion has a multi-step shape.

2. The push switch according to claim 1, wherein the peripheral portion has the multi-step shape having a plurality of right-angled stepped portions continuously toward the outside.

3. The push switch according to claim 1, wherein the peripheral portion is formed in the multi-step shape by a half punch for press working.

4. The push switch according to claim 1, wherein the fixed contact has the multi-step shape over the entire area of the peripheral portion.

5. The push switch according to claim 1, wherein a hole portion, which is a trace of a fixing pin for fixing the fixed contact at the time of insert molding, is formed in a portion of the bottom surface of the housing that overlaps the back surface of the fixed contact.

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