JP2003281963A - Push-button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a push-button switch, which can force foreign matter such as dust intruding into a storage part of a housing to remain, and makes reliable contact between a movable contact and a fixed contact, by forcing resin powder to remain. <P>SOLUTION: A housing 1 of the push-button switch has a bottom wall 1a, a cylindrical side wall 1b extending from the bottom wall 1a, at least a pair of control parts 1e formed on an inner surface of the bottom wall 1a, and a recess part 1j, which is formed on the inner surface of the bottom wall 1a, by staying between the pair of the control parts 1e near the side wall 1b, and used for storing the foreign matter. Therefore, even if the foreign matter intrudes into the storage part from a place between a stem 6 and the housing 1, the recess part 1j can store the foreign matter, and can keep the foreign matter from moving to the contact parts, so that the reliable contact between the movable contact 4 and the fixed contact 2 can be obtained. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push button switch in which a movable contact is brought into contact with and separated from a fixed contact by being pressed, and in particular, a push button used in an on-vehicle electronic device or the like and requiring dustproof measures. Regarding the structure of the switch.

[0002]

2. Description of the Related Art A drawing of a conventional push button switch will be described. FIG. 15 relates to a conventional push button switch and is a plan view of a housing showing a state of fixed contacts, and FIG. 16 is an enlarged plan view of a movable contact of a conventional push button switch. FIG. 17 is a cross-sectional view showing a state in which a foreign matter is sandwiched between contacts according to a conventional push button switch.

The structure of a conventional push button switch is shown in FIGS.
7, the box-shaped housing 51 made of a synthetic resin molded product includes a bottom wall 51a and a bottom wall 51a.
A cylindrical side wall 51b extending upward from a, a storage part 51c surrounded by a bottom wall 51a and a side wall 51b and having an open top surface, and a stepped portion provided at the center of the inner surface of the bottom wall 51a. A recessed part 51d, two pairs of restricting parts 51e and 51f protruding upward with a space from the inner surface of the bottom wall 51a, and a locking part 51g provided on a pair of opposing side walls 51b.
Another pair of side walls 5 facing each other between the restricting portions 51e and 51f.
1b has an escape portion 51h formed of a vertical recess.

A pair of fixed contacts 5 made of a conductive metal material
2 and 53 are contact portions 52a and 53 and a terminal portion 5, respectively.
2b and 53b, the fixed contacts 52 and 53 are embedded and attached to the housing 51, and the contact portions 52a and
53a is exposed on the recessed portion 51d in the bottom wall 51a, and the terminal portions 52b and 53b project outward from the housing 51.

A movable contact 54 formed by punching out a flat plate-shaped leaf spring is provided with a base portion 54a and a hollow portion 54b, a support portion 51c extending annularly from the base portion 54a, and a cantilevered hollow portion from the base portion 54a. It has a tongue piece 54d formed of an elastically deformable contact portion extended to the portion 54b, and a protruding piece 54e extending outward from the base portion 54a in the direction opposite to the tongue piece 54d.

The movable contact 54 has a bottom wall 51a.
Placed on the inner surface of the protrusion 54e and the protrusion 54e
It is placed in between and is locked. In addition, the movable contact 5
When 4 is stored in the storage portion 51c, the tongue piece 54d faces the contact portions 52a and 53a in a separated state and is in a non-contact state, and the tip end portion of the protruding piece 54e has one escape. It is in a state of facing the portion 51h in a state of being close thereto.

The pressing member 55 is formed in a dome shape with silicone rubber or a flexible elastomer resin, and has a dome-shaped portion 55a, a convex portion 55b provided on the top of the dome-shaped portion 55a, and a dome. The pressing member 55c is provided in the shape portion 55a, and the pressing member 55 has a click feeling when the dome shape portion 55a is inverted.

The pressing member 55 is provided in the storage portion 51.
The lower end surface of the dome-shaped portion 55a is stored in the base 54c.
The movable contact 54 is supported by pressing a and the support portion 54c against the bottom wall 51a.

The stem 56, which is a molded product of synthetic resin,
It has a flat plate-shaped operating portion 56a and a pair of locking arm portions extending downward from the operating portion 56a (not shown here). Then, the stem 56 is attached by locking the locking arm portion inserted into the storage portion 51c to the locking portion 51g of the housing 51, so that the stem 56 can be moved up and down and the pressing member 55. The convex portion 55b is pressed.

When the stem 56 is molded,
The side surface of the operation portion 56a located between the pair of locking arm portions is the gate opening G2. Therefore, when the gate opening G2 is cut, a burr is generated, and the gate opening G2 is formed.
The second burr portion is located in the escape portion 51h so that the burr portion does not rub against the side wall 51b.

In the housing 51, melted resin is injected into the cavity formed by the molding die, and after the resin is hardened, the push pin is pressed against the inner bottom surface of the housing 51 to form the housing 51. However, at this time, the tip portion of the push-out pin rubs against the inner bottom surface to generate resin powder.

In such a conventional push button switch, when the stem 56 is pushed, the pushing member 55 is pushed down and inverted, and the tongue piece 54d of the movable contact 54 is lowered via the pushing portion 55c of the pushing member 55. Pressed by the fixed contact 5
The contact portions 52a and 53 of the contacts 2,3 are contacted. The fixed contacts 52 and 53 are connected via the movable contact 54,
The pair of terminal portions 52b and 53b are electrically connected.

When the pressing of the stem 56 is released, the pressing member 55 returns to its original state by its elasticity, so that the stem 56 is pushed back to its original state by the pressing member 55 and the tongue piece 54d of the movable contact 54 is also returned. Is returned by its own spring property and separated from the contact portions 52a and 53a, and the fixed contacts 52 and 53 are brought out of conduction.

[0014]

However, in the structure of the conventional push button switch described above, the relief portion 51h is provided.
There is a problem that foreign matter such as dust enters the storage portion 51c through the gap between the movable contact 54 and the fixed contacts 52 and 53, and the foreign matter migrates onto the contact portions 52a and 53a. is there. In addition, there is a problem in that the resin powder generated by the push-out pin during the manufacture of the housing 51 migrates onto the contact portions 52a and 53a, which deteriorates the contact between the movable contact 54 and the fixed contacts 52 and 53.

Therefore, the present invention provides a push button switch which can retain foreign matter such as dust that has entered the housing portion of the housing, and retain resin powder to ensure contact between the movable contact and the fixed contact. With the goal.

[0016]

In order to solve the above-mentioned problems, the first means of the present invention is a box-shaped housing having an accommodating portion, and fixed contacts provided on the inner bottom surface of the accommodating portion. A movable contact formed of an elastic piece that is elastically deformable and disposed so as to face the fixed contact so as to be separable from the fixed contact, and a pressing provided on the movable contact that presses the movable contact in the direction of contacting the fixed contact. A housing and a stem movably attached to the housing, the housing comprising:
A bottom wall and a cylindrical side wall formed by extending from the bottom wall,
At least a pair of regulating portions provided on the inner surface of the bottom wall, and a concave portion for retaining foreign matter provided on the inner surface of the bottom wall in a state of being located between the pair of regulating portions in the vicinity of the side wall. Then, the projecting piece for locking the movable contact is hooked on the regulating portion, and the projecting piece is located on the recess.

As a second means for solving the problems, the inner wall surface of the side wall at a position facing the recess is provided with a relief portion formed of a vertical recess. As a third means for solving the problems, a locking portion for locking the locking arm portion of the stem and a locking portion for locking the locking arm portion of the stem are disposed between the escape portion and the locking portion. And the regulation section.

As a fourth solving means, the upper surface of the recess is closed by the projecting piece. Further, as a fifth solving means, the recess is configured such that an extrusion pin for pushing out the housing can come into contact with the recess during molding.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Explaining the drawings of the push button switch of the present invention, FIG. 1 is a longitudinal sectional view of a push button switch according to a first embodiment of the present invention, and FIG. 2 is a first embodiment of the push button switch of the present invention. FIG. 3 is a plan view showing a state in which a stem is removed, FIG. 3 is a plan view of a housing according to a first embodiment of the push button switch of the present invention, and FIG. 4 is related to a first embodiment of the push button switch of the present invention.
It is a top view of a state where a stem and a pressing member are removed.

FIG. 5 shows the first push button switch of the present invention.
FIG. 7 is an enlarged plan view of a movable contact according to a first embodiment of the push button switch of the present invention, and FIG. 7 is a push button switch of the present invention. FIG. 3 is an enlarged perspective view of a main part showing a relationship between a housing and a movable contact according to the first embodiment of the present invention.

FIG. 8 shows the first push button switch of the present invention.
FIG. 9 is an operation explanatory view according to an embodiment, and FIG. 9 is an enlarged explanatory view of a main part at the time of operation according to the first embodiment of the push button switch of the present invention.
10 is an enlarged plan view of the movable contact according to the second embodiment of the push button switch of the present invention, FIG. 11 is an enlarged plan view of the movable contact of the third embodiment of the push button switch of the present invention, and FIG. 12 is FIG.
12 is a sectional view taken along line 12-12 of FIG.

FIG. 13 is an explanatory view showing a first step for explaining a method of manufacturing a housing according to the push button switch of the present invention, and FIG. 14 is a view of explaining a method of manufacturing the housing according to the push button switch of the present invention. It is explanatory drawing which shows the 2nd process for doing.

Next, the structure of the first embodiment of the push-button switch of the present invention will be described with reference to FIGS. 1 to 9. A box-shaped housing 1 made of a synthetic resin molded product includes a bottom wall 1a and a bottom wall 1a. A cylindrical side wall 1b extending upward from the bottom wall 1a, and a bottom wall 1
The storage portion 1c, which is surrounded by a and the side wall 1b and whose top surface is in an open state, the recessed portion 1d provided with a step at the center of the inner surface of the bottom wall 1a, and the space from the inner surface of the bottom wall 1a. And a pair of restricting portions 1e and 1f projecting upward, a locking portion 1g provided on a pair of opposing side walls 1b, and restricting portions 1e and 1f.
Between the f, a clearance portion 1h formed of a vertical recess provided on the inner surface of the other pair of side walls 1b facing each other, and a pair of restriction portions 1e, 1f, and a bottom wall located near the clearance portion 1h. 1a has a concave portion 1j provided on the inner surface thereof.

A pair of fixed contacts 2 and 3 made of a conductive metal material includes contact portions 2a and 3 and terminal portions 2b and 3 respectively.
b and the concave groove 2c provided on the surface of the contact portions 2a, 3a,
3c and. Further, the recessed grooves 2c, 3c are formed by recesses, notches, cut-and-raised parts, etc., and a plurality of the recessed grooves 2c, 3c may be provided in parallel. The fixed contacts 2 and 3 are embedded in the housing 1 and attached, the contact portions 2a and 3a are exposed on the recessed portion 1d in the bottom wall 1a, and the terminal portions 2b and 3b are outward from the housing 1. Overhangs.

Next, a method of manufacturing the housing 1 in which the fixed contacts 2 and 3 are embedded will be described with reference to FIGS. 13 and 14, and as shown in the first step of FIG. 13, the first molding die 2 is used.
1 is provided with a concave portion 21 and a second molding die 2
2 is provided with a convex portion 22a protruding into the concave portion 21a, and a cavity 23 into which a resin can be injected is formed between the convex portion 22a and the concave portion 21a.

Two push-out pins 24 are movably attached to the second molding die 22, and the tips of the push-out pins 24 form the recesses 1j of the second molding die 22. It is flush with the bottom surface of the protrusion 22b. In such a state of FIG. 13, the resin melted from the gate port 25 is injected into the cavity 23.

When the resin hardens, as shown in the second step of FIG. 14, first, the first molding die 21 is removed, and then the push pin 24 is used to move the second molding die 22 to the housing. 1 is pushed out and the housing 1 is taken out from the second molding die 22, as shown in FIG.
3 is buried, and a projection 22 is formed on the inner bottom surface of the bottom wall 1a.
The housing 1 is manufactured with the recess 1j existing by b.

When the housing 1 is extruded from the second molding die 22, the tip of the extrusion pin 24 rubs against the guide hole of the second molding die 22, and the extrusion pin 2
Even if a burr is generated in the gap between the guide hole 4 and the guide hole due to wear, the burr is located at the bottom of the recess 1j, and even if the burr is peeled off due to impact or vibration to become a powder of synthetic resin, this powder is , Staying in the concave portion 1j, the fixed contact 2,
3 does not move to the contact portions 2a, 3a side.

The movable contact 4 formed by punching out a flat plate-shaped leaf spring is provided with a base portion 4a and a hollow portion 4b, a support portion 1c extending annularly from the base portion 4a, and a cantilevered hollow portion from the base portion 4a. The tongue piece 4d, which is an elastically deformable contact portion extended to the portion 4b, and the tongue piece 4d are symmetrically arranged with the center of the tongue piece 4d sandwiched in a direction intersecting the extending direction of the tongue piece 4d. Two V-shaped notches 4e partially cut out, a narrow portion 4f formed by the notches 4e and located at the center of the tongue 4d, and this narrow portion 4f
4g provided at the center of the tongue piece 4 from the base 4a
a protrusion 4h extending outward in the direction opposite to d, a protrusion 4j protruding outward from the support portion 4c in the direction opposite to the protrusion 4h with the tongue 4d interposed, and a connection connecting the base 4a and the tongue 4d. And a hole 4m provided in the portion 4k.

The movable contact 4 is placed on the inner surface of the bottom wall 1a, and the projecting pieces 4h and 4j are a pair of restricting portions 1e,
The outer circumference of the annular support portion 4c is positioned and guided by the inner circumferences of the restricting portions 1e and 1f while being disposed between 1f to prevent rotation. When the movable contact 4 is accommodated in the accommodating portion 1c, the tongue piece 4d faces the contact portions 2a and 3a in a separated state and is in a non-contact state, and the protruding piece 4d.
The tip portions of h and 4j are in a state of facing each other in the state of being close to the escape portion 1h. At this time, the movable contact 4 is arranged so that the cutting burr direction of the movable contact 4 caused by punching is toward the fixed contacts 2 and 3.

In the movable contact 4 mounted on the inner surface of the bottom wall 1a, the projecting piece 4h is located on the recess 1j provided on the bottom wall 1a and covers part or all of the recess 1j. It is like this. Further, when the movable contact 4 is stored in the storage portion 1c, the cutout portion 4e of the tongue piece 4d has the fixed contacts 2, 3
Are arranged so as to cross the concave grooves 2c, 3c. That is, the concave grooves 2c and 3c provided in the contact portions 2a and 3a of the fixed contacts 2 and 3 are arranged so as to cross the cutout portion 4e in a direction intersecting the extending direction of the cutout portion 4e. .

The movable contact 4 is operated by pressing the tongue piece 4d, which is a contact portion, toward the fixed contacts 2 and 3 side. At this time, the connecting portion 4k is elastic toward the fixed contacts 2 and 3 side. There is a first deformation permitting portion 4n for permitting deformation, and
In order to allow the pressing operation after the tongue piece 4d contacts the fixed contacts 2 and 3, the narrow portion 4f in the extending direction of the cutout portion 4e.
There is a second deformation permitting portion 4p which is located at the position of 1 and elastically deforms in the contact region of the fixed contacts 2 and 3 to enable contact with the fixed contacts 2 and 3.

The pressing member 5 is formed in a dome shape with silicone rubber or a flexible elastomer resin, and has a dome-shaped portion 5a, a convex portion 5b provided on the top of the dome-shaped portion 5a, and a dome. The pressing member 5 has a pressing portion 5c provided in the shape portion 5a, and the pressing member 5 has a click feeling when the dome-shaped portion 5a is inverted.

The pressing member 5 is accommodated in the accommodating portion 1c, and the lower end surface of the dome-shaped portion 5a presses the base portion 4a and the supporting portion 4c against the bottom wall 1a to support the movable contact 4. At this time, the outer circumference of the hem portion of the dome-shaped portion 5a is guided and positioned by the inner circumferences of the restriction portions 1e and 1f, and the pressing portion 5c is provided with the convex portion 4g on the side where the cutting burr of the movable contact 4 does not exist. Can be pressed.

The stem 6 made of a molded product of synthetic resin has a flat plate-shaped operating portion 6a and an operating portion 6 (not shown here).
It has a pair of locking arms extending downward from a. And
The stem 6 is attached by locking the locking arm portion inserted in the storage portion 1c to the locking portion 1g of the housing 1, so that the stem 6 can be moved up and down and the pressing member 5 is projected. The portion 5b is pressed.

When the stem 6 is molded, the side surface of the operating portion 6a located between the pair of locking arms serves as the gate opening G1. Therefore, when the gate opening G1 is cut off. The burr portion of the gate opening G1 is located in the escape portion 1h, and the burr portion is the side wall 1b.
I try not to rub against it.

Next, the operation of the push button switch of the present invention having such a structure will be described. As shown in FIG. 1, when the stem 6 is in the non-pressing operation state, the tongue piece 4d of the movable contact 4 is in the first position. It is bent upward by the deformation permitting portion 4n, separated from the fixed contacts 2 and 3, and the switch is off.

In this state, when the stem 6 is pressed by a finger or the like, the pressing member 5 is pressed by the operating portion 6a of the stem 6.
Of the tongue 4d of the movable contact 4 is reversed by bending the thin dome-shaped portion 5a as the convex portion 5b is pressed and the convex portion 5b is pressed downward. Abutting on the convex portion 4g. At this time, since the dome-shaped portion 5a is inverted, there is a click feeling during operation.

The pressing portion 5c is the tongue piece 4 of the movable contact 4.
By pressing d downward, the first deformation allowing portion 4n is elastically deformed, and the tongue piece 4d is pushed down.
At this time, since the tongue piece 4d is pressed downward, the lower surface of the tongue piece 4d of the movable contact 4 has the contact portions 2a of the fixed contacts 2 and 3,
3a is brought into contact with the fixed contacts 2 and 3 via the movable contact 4, and the switch is turned on.

When the pressing force applied to the stem 6 is released from this state, the dome-shaped portion 5a of the pressing member 5 is reversed by its own elasticity to return to the initial state, and at the same time, the stem 6 is urged by the urging force. It is pushed upward and returns to the initial position. At this time, the tongue 4d of the movable contact 4 also returns upward due to the elasticity of the first deformation permitting portion 4n, the lower surface of the tongue 4d is separated from the fixed contacts 2 and 3, and the switch is turned off.

Next, the case where foreign matter such as dust is caught between the contacts will be described with reference to FIGS. 8 and 9. FIG. 9 shows a state in which a foreign matter Z such as dust is sandwiched between the movable contacts 4 and the contact portions 2a of the fixed contacts 2 and 3. In this case, the fixed contacts 2 and 3 where the foreign matter Z is sandwiched and the tongue 4d of the movable contact 4 are separated from each other, but the tongue 4d is projected by the pressing force of the pressing portion 5c of the pressing member 5. 4g is pressed.

The movable contact 4 is the protrusion 4 of the tongue piece 4d.
The second deformation permitting portion 4p which is the narrow portion 4f in which g is formed.
Is elastically deformed by the pressing force of the pressing portion 5c, and the free end side of the tongue piece 4d is urged downward to be in contact with the contact portions 2a and 3a of the fixed contacts 2 and 3,
The switch is turned on.

In this way, the foreign matter Z such as dust enters the housing portion 1a of the housing 1 and the contact portions 2a and 3a are formed.
Even when a foreign substance Z such as dust is caught between the movable contact 4 and the movable contact 4, the first tongue piece 4d is elastically deformed toward the contact portions 2a, 3a when pressed by the pressing member 5. In addition to the deformation permitting portion 4n, a second that elastically deforms in the contact area with the fixed contacts 2 and 3 to enable contact with the fixed contacts 2 and 3
Since the deformation permitting portion 4p is formed, the contacts can be surely conducted.

Further, in this case, even if the foreign matter Z such as dust is sandwiched immediately below the second deformation permitting portion 4p of the tongue piece 4d, the contact portions 2a and 3a contacting the tongue piece 4d come into contact with each other. The V-shaped groove 2 provided in the surface in a direction intersecting the extending direction of the second deformation permitting portion 4p and the cutout portion 4e.
Since the foreign matter Z falls into the concave grooves 2c and 3c, the second deformation permitting portion 4p is formed.
It is possible to prevent defective conduction without hindering elastic deformation of.

Further, since the notch 4e of the tongue piece 4d and the concave grooves 2c, 3c of the contact portions 2a, 3a intersect each other, the tongue piece 4d is pressed against the contact portions 2a, 3a and elastically deformed. At this time, the position of the notch 4e with respect to the recessed grooves 2c, 3c sequentially shifts, that is, the sliding operation is performed between the two, and during that time, the foreign matter Z can surely fall into the recessed grooves 2c, 3. .

Since the second deformation permitting portion 4p is formed on the tongue piece 4d of the movable contact 4 so as to be elastically deformable within the contact area with the fixed contacts 2 and 3, the contact portions 2a and 3a are formed. Since the contact surface does not need to be formed of a flat metal plate with stable contact and the shape of the fixed contacts 2 and 3 can be simplified, a round metal wire (round wire) may be used. It is possible.

Since the housing 1 of the push button switch is closed by the locking arm of the stem 6 on the side of the locking portion 1g, foreign matter such as dust may enter the storage portion 1c during that time. Also, since the restriction portions 1e and 1f are present between the escape portion 1h and the locking portion 1g, the foreign matter that has entered the storage portion 1c from between the restriction portions 1e and 1f.
Due to the f, transfer to the contact portions 2a, 3a is prevented, and further, due to the presence of the recessed portion 1j provided in the vicinity of the escape portion 1h, foreign matter that has entered from the escape portion 1j into the storage portion 1c is transferred to the recessed portion 1j. It is accumulated and is prevented from moving to the contact points 2a, 3a.

Next, a second embodiment of the push button switch of the present invention will be described with reference to FIG.
The notch 4e provided in the above is formed in a strip shape having the same width. The other structure is the same as that of the first embodiment, and therefore, the same parts are designated by the same reference numerals and the description thereof is omitted here.

Next, a third embodiment of the push button switch of the present invention will be described with reference to FIG.
The notch 4e formed in the same shape is formed in a strip shape having the same width, and the arcuate recess 4q is provided so as to widen the width of the notch 4e. The tongue piece located in the arcuate recess 4p. 4d contacts the fixed contacts 2 and 3 while crossing the concave grooves 2c and 3c.

Further, in the movable contact 4, instead of providing the hole 4m, the root portion of the connecting portion 4k is protruded downward by the protrusion processing, and this protrusion portion is formed in the first deformation permitting portion 4
n, and the tongue piece 4d is lifted upward with reference to the first deformation permitting portion 4n. The other parts of the configuration are the same as those of the second embodiment, so the same parts are designated by the same reference numerals and the description thereof is omitted here.

[0051]

The push-button switch of the present invention is provided with a box-shaped housing having a storage portion, a fixed contact provided on the inner bottom surface of the storage portion, and a fixed contact facing the fixed contact. A movable contact formed of an elastically deformable elastic piece, a pressing member that is provided on the movable contact and presses the movable contact in a direction of contacting the fixed contact, and a stem movably attached to the housing, The housing is located between the bottom wall, a cylindrical side wall extending from the bottom wall, at least a pair of restricting portions provided on the inner surface of the bottom wall, and between the pair of restricting portions near the side walls. In this state, there is a concave portion provided on the inner surface of the bottom wall for retaining foreign matter, and the protrusion for locking the movable contact is retained by the regulating portion, and the protrusion is located on the recess. . With this configuration, even if foreign matter enters the housing from between the stem and the housing, this foreign matter can be retained in the recess, preventing foreign matter from migrating to the contact portion, and fixing it to the movable contact. A reliable contact can be obtained.

Since the inner wall surface of the side wall at the position facing the concave portion is provided with a relief portion formed of a vertical concave portion, the foreign matter can be retained in the concave portion even if the foreign matter enters the storage portion from the concave portion. As a result, it is possible to prevent the transfer of foreign matter to the contact portion, and to obtain a reliable contact between the movable contact and the fixed contact. Further, by fitting the gate opening of the stem to the escape portion, it is possible to obtain the one without friction between the stem and the housing.

Further, since the housing has the locking portion for locking the locking arm portion of the stem, and the restricting portion arranged between the escape portion and the locking portion, Even if foreign matter enters through the gap between the housing and the stem, excluding the escape area, the locking arm and the restriction section prevent the foreign matter from moving to the contact point, ensuring reliable contact between the movable contact and the fixed contact. Things are obtained.

Further, since the upper surface of the recess is closed by the protrusion,
Even if burrs are generated due to abrasion of the push pin and the burrs are peeled off due to shock or vibration and become synthetic resin powder, this powder can be blocked by the protrusions and prevents the transfer of resin powder to the contact part. As a result, a reliable contact between the movable contact and the fixed contact can be obtained.

In addition, since the push pin that pushes out the housing can come into contact with the concave portion during molding, burrs are generated between the push pin 24 and the guide hole due to wear.
Even if the burr is peeled off due to impact or vibration to become a powder of synthetic resin, the powder does not stay in the recess 1j and move to the contact portions 2a, 3a side of the fixed contacts 2, 3 and the molding is performed. The mold can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view according to a first embodiment of a push button switch of the present invention.

FIG. 2 is a plan view of the push button switch according to the first embodiment of the present invention with the stem removed.

FIG. 3 is a plan view of the housing according to the first embodiment of the push button switch of the present invention.

FIG. 4 is a plan view of the push button switch according to the first embodiment of the present invention with the stem and the pressing member removed.

FIG. 5 is an enlarged plan view of an essential part showing a state of a movable contact and a fixed contact according to the first embodiment of the push button switch of the present invention.

FIG. 6 is an enlarged plan view of a movable contact according to the first embodiment of the push button switch of the present invention.

FIG. 7 is an enlarged perspective view of essential parts showing the relationship between the housing and the movable contact according to the first embodiment of the push button switch of the present invention.

FIG. 8 is an operation explanatory diagram according to the first embodiment of the push button switch of the present invention.

FIG. 9 is an enlarged explanatory view of a main part during operation according to the first embodiment of the push button switch of the present invention.

FIG. 10 is an enlarged plan view of a movable contact according to a second embodiment of the push button switch of the present invention.

FIG. 11 is an enlarged plan view of a movable contact according to a third embodiment of the push button switch of the present invention.

12 is a sectional view taken along line 12-12 of FIG.

FIG. 13 is an explanatory view showing a first step for explaining the method of manufacturing the housing according to the push button switch of the present invention.

FIG. 14 is an explanatory view showing a second step for explaining the method of manufacturing the housing according to the push button switch of the present invention.

FIG. 15 is a plan view of the housing according to the conventional push button switch, showing the state of the fixed contacts.

FIG. 16 is an enlarged plan view of a movable contact of a conventional push button switch.

FIG. 17 is a cross-sectional view of a conventional push button switch, showing a state in which foreign matter is caught between contacts.

[Explanation of symbols]

1 housing 1a bottom wall 1b Side wall 1c storage 1d recess 1e Regulation Department 1f Regulation Department 1g locking part 1h escape area 1j recess 2 fixed contacts 2a contact part 2b terminal 2c groove 3 fixed contacts 3a Contact part 3b terminal part 3c groove 4 movable contacts 4a base 4b hollow part 4c support piece 4d tongue 4e Notch 4f narrow part 4g convex part 4h protrusion 4j protrusion 4k connection 4m hole 4n First deformation allowance section 4p Second deformation allowance section 4q arcuate recess 5 concave pressure member 5a Dome part 5b convex part 5c pressing part 6 stems 6a Operation part G1 gate opening Z foreign material 21 First Mold 21a recess 22 Second mold 22a convex part 22b protrusion 23 cavities 24 Extruded pin 25 gate

Claims (5)

[Claims] 1. A box-shaped housing having an accommodating portion, a fixed contact disposed on an inner bottom surface of the accommodating portion, and an elastically deformable elastic member which is disposed so as to be contactable with and separable from the fixed contact. A movable contact formed of a piece; a pressing member provided on the movable contact for pressing the movable contact in a direction of contacting the fixed contact; and a stem movably attached to the housing, wherein the housing is A bottom wall, a tubular side wall extending from the bottom wall, at least a pair of restricting portions provided on the inner surface of the bottom wall, and a position between the pair of restricting portions in the vicinity of the side walls. In this state, there is a recess provided on the inner surface of the bottom wall for retaining foreign matter, and a protrusion for retaining the movable contact is retained by the restriction portion, and the protrusion is the recess. Pushbutton switch characterized by being located above Touch. 2. The push button switch according to claim 1, wherein an inner wall surface of the side wall at a position facing the concave portion is provided with a relief portion formed of a vertical concave portion. 3. The locking portion for locking the locking arm portion of the stem and the restricting portion arranged in a state between the escape portion and the locking portion in the housing. The push-button switch according to claim 2, further comprising: 4. The push button switch according to claim 2, wherein the upper surface of the recess is covered with the projecting piece. 5. The push button switch according to claim 1, wherein a push pin that pushes out the housing can come into contact with the recess during molding.