JP2908860B2 - Case for small switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a case for a small switch that houses a mechanism such as a so-called microswitch.

[Prior art]

2. Description of the Related Art Conventionally, there has been provided a small switch case that can be used in a bad environment by preventing dust and water droplets from entering the case. This type of conventional small switch case has a rectangular parallelepiped body with one side open.
A cover for closing the opening of the body is inserted into the opening of the body. The periphery of the opening of the body and the periphery of the cover are sealed by a resin mold or the like, so that terminals and lead wires are drawn through the cover. Further, the cover presses and positions the mechanism of the switch mounted in the body.

[Problems to be solved by the invention]

In the above-described conventional configuration, the cover is not fixed to the body until the cover is sealed to the body, so the cover is likely to be displaced, and when the cover is displaced, the mechanism of the switch pressed by the cover rattles. Problems arise. In order to solve such a problem, an engagement protrusion is protruded at a point on the outer surface of the peripheral wall surrounding the opening of the body, and a connecting cylinder overlapping the outer surface of the peripheral wall surrounding the opening of the body is provided on the cover. It is conceivable to engage an engagement hole formed in the connecting cylinder with an engagement projection of the body. According to the above configuration, by temporarily engaging the body with the cover by engaging the engagement protrusion with the engagement hole, the body and the cover can be temporarily fixed. However, there is a dimensional error between the engagement protrusion and the engagement hole. Then, there is a problem that the cover rattles to the body and cannot be positioned with sufficiently high accuracy. Therefore, as shown in FIG. 5, a recess 10 having a shape in which the side surface on the cover side (right side in FIG. 5) and one surface on the tip side of the engagement protrusion 9 are formed so as to surround the engagement protrusion 9. Then, it is conceivable to position the connecting tube by bringing the leading edge of the connecting tube into contact with the inner surface of the recess 10. The engagement protrusion 9 needs to be formed on a pair of peripheral walls facing each other among the peripheral walls surrounding the opening of the body 1. In this case, if the recesses 10 are formed at two places in the same manner as the engagement projections, the following problem occurs. That is, the deeper the recess 10 is, the better for positioning, and the shorter the distance d from the bottom surface of the recess 10 to the engagement projection 9 is, for the purpose of miniaturization (see FIG. 5).
In order to form the recess 10 and the engaging projection 9 having such a shape, it is necessary to arrange the mold as shown in FIG. That is, for a cross section orthogonal to the opening of the body and including both engagement projections 9, three slide cores 25 to 27 are required, and each engagement projection 9 and the corresponding recess 10 are respectively provided with the first The first slide core 25 and the second slide core 26 are formed by a slide core 25 and a second slide core 26.
A parting line P3 with the third slide core 27 is set on the same plane as the opening of the body 1. As described above, when three slide cores 25 to 27 are used, the mold opening directions become three directions as indicated by arrows in FIG. slide core
Since other members cannot be arranged in the mold opening direction of 25 to 27, as shown in FIG. 16, the number of bodies 1 that can be molded by one mold is up to two. Here, the arrow in FIG. 16 indicates the mold opening direction. As described above, in a configuration in which the slide cores 25 to 27 necessary to form one body 1 are opened in three directions, only two pieces can be formed at a time, and there is a problem that the production efficiency is poor. The present invention is aimed at solving the above problems,
An object of the present invention is to provide a case for a small switch in which the shape of a body can be formed up to four at a time and productivity can be improved.

[Means for Solving the Problems]

In the present invention, in order to achieve the above object, a body formed in a rectangular parallelepiped shape with one surface opened and in which a switch mechanism is housed, and a cover fitted to the body so as to close the opening of the body are provided. In the small switch case provided, the body has projections formed on the outer surfaces of a pair of peripheral walls facing each other among the peripheral walls surrounding the opening, and the cover overlaps with the outer surface of the peripheral wall surrounding the opening of the body. And a connection cylinder having an engagement hole for engaging with the engagement protrusion is provided at a key point, and the cover is attached to the body in such a manner that the leading edge of the connection cylinder abuts a step formed on the body. The stepped portion of the surface on which one of the engagement protrusions is fitted is formed with a recess in which the opening side of the body is opened and a part of the connecting cylinder is engaged with respect to a cross section parallel to the surface, and the other is formed. The step on the surface on which the engagement protrusion is projected is flat with the opening. The opening across the engaging projection comprising at is what is formed on a straight line on the opposite side.

[Action]

According to the above configuration, the cover is provided with the connecting cylinder having the engaging hole overlapping the outer surface of the peripheral wall surrounding the opening of the body and having the engaging hole engaging with the engaging protrusion formed at a key point. The cover is fitted to the body such that the edge abuts on the step formed on the body, and the step on the surface on which one of the engagement projections is protruded has the opening side of the body in a cross section parallel to that surface. Since the opening is formed to form a recess in which a part of the connecting cylinder is engaged, the body and the cover are coupled by engaging the engaging projection with the engaging hole, and the edge of the connecting cylinder is concave. Engaging in place prevents the cover from rattling against the body. The recess is formed only on the surface on which one of the engagement protrusions is provided, and the step on the surface on which the other engagement protrusion is provided is formed on a straight line parallel to the opening. Therefore, if the parting line of the mold is set on the same plane as the side surface of the engagement protrusion, a section including both the engagement protrusions and orthogonal to the opening uses a fixed mold and two slide cores. Thus, the body can be formed, and in this cross section, the mold opening directions are two directions. As a result, conventionally, the mold opening direction is three directions, and the body can be arranged only in the remaining one direction at the time of molding, whereas in the shape of the present invention, the bodies are arranged in two directions and molded. In the present invention, only two pieces can be formed at one time, whereas in the present invention, four pieces can be formed.
It is possible to mold up to individual pieces. In this way, twice as many bodies as the conventional body can be formed at one time, so that the production efficiency is improved.

【Example】

As shown in FIG. 1, the small switch case is formed by combining a body 1 made of a synthetic resin and a cover 2, and as shown in FIG.
Through the lead, a lead 3 as a terminal is drawn out. As shown in FIGS. 3 to 6, the body 1 is formed in a rectangular parallelepiped shape having an opening 4 on one surface, and a switch mechanism is housed therein. An opening 4 is formed on one surface surrounded by two sides excluding the longest side among the three types of lengths of the body 1, and a peripheral wall surrounded by the shortest side and the longest side has a switch mechanism. Is disposed at one end opposite to the opening 4 (see FIG. 2). The actuator 5 is provided so as to be able to advance and retreat with respect to the body 1, and a seal member 6 made of an elastic material such as rubber is provided around the actuator 5 for waterproofing or dustproofing. At a position corresponding to the actuator 5, a through hole 5a through which the actuator 5 is inserted is formed in the body 1,
Further, a pair of mounting holes 7 penetrating in a direction perpendicular to the plane of the paper in FIG. Here, the dimensions of the body 1 and the positions of the actuator 5 and the mounting hole 7 are set to dimensions that have been standardized conventionally. The outer surface of the peripheral wall surrounding the opening 4 is formed thinner via the step 8 with respect to the outer surface of the other portion. In the thin portion, engaging projections 9 are provided on outer surfaces of a peripheral wall on which the actuator 5 is provided and a peripheral wall facing the peripheral wall.
Is protruding. The two engaging projections 9 are formed at the same position in the left-right direction in FIG. 3 and have a projection amount equal to the step of the step portion 8. The side of the engaging projection 9 on the side of the opening 4 becomes an inclined surface 9a which is inclined in a direction away from the opening 4 toward the front end, and the side opposite to the opening 4 is substantially perpendicular to the outer surface of the peripheral wall. Surface 9b. In the portion surrounding one of the engagement projections 9, as in the related art,
A recess 10 is formed in which the opening 4 side and the distal end side of the engaging projection 9 are open. In short, the step 8 is formed substantially U-shaped around the engagement projection 9. On the surface provided with the other engagement projection 9, the step 8 is formed on a straight line parallel to the opening 4, and the position of the step 8 is substantially the same as the left end of the recess 10 in the left-right direction in FIG. They are set at the same position. Therefore, the step portions 8 formed on both of the peripheral walls surrounding the opening 4 and adjacent to the peripheral wall provided with the engagement projections 9 are formed on a fold line as shown in FIG. On the other hand, the cover 2 is formed in a shape as shown in FIG. 7 to FIG. That is, the connecting cylinder 13 is formed so as to project from the entire periphery of the main wall 12 where the insertion hole 11 through which the lead 3 is inserted is formed so as to overlap the outer surface of the thin portion of the body 1. I have. The distal end edge of the connecting cylinder 13 is formed in a shape that matches the step 8 formed in the body 1. A connecting piece 15 surrounded by a substantially U-shaped cutout groove 14 is formed on the peripheral wall of the connecting cylinder 13 that overlaps the surface on which the engagement protrusion 9 is formed. That is, the connecting piece 15 is formed such that only the edge on the opening 4 side of the body 1 is continuous with the connecting cylinder 13 when the cover 2 is mounted on the body 1. The connecting piece 15 is provided with an engaging hole 16. When the cover 2 is attached to the body 1, the connecting piece 15 is bent along the inclined surface 9 a of the engaging projection 9, and the connecting piece 15 is engaged with the engaging hole 16. When the mating projection 9 is inserted, the periphery of the engagement hole 16 becomes the locking surface 9b.
Is locked. Thus, the cover 2 is connected to the body 1. A plurality of positioning projections 17 are protruded at key points on the inner surface of the main wall 12 of the cover 2, and the peripheral wall of the body 1 is sandwiched between the peripheral wall of the connecting cylinder 13 and the positioning projections 17. The positioning between the cover and the cover 2 is ensured. In order to form the body 1 having the above configuration, a mold is provided as shown in FIG. That is, in the cross section shown in FIG. 12, the mold mainly includes a fixed mold 20 that mainly determines the shape of the lower surface side of the body 1, a first slide core 21 that mainly determines the internal shape of the body 1, and a 1 and a second slide core 22 that determines the shape of the upper surface side. Here, the arrows shown in FIG. 12 indicate the mold opening directions of the first slide core 21 and the second slide core 22, respectively. The parting line P1 between the fixed mold 20 and the first slide core 21 is formed on the same plane as the locking surface 9b of the engagement protrusion 9 on the lower surface side of the body 1. Also, the first slide core 21
A parting line P2 between the first slide core 22 and the second slide core 22 is formed on the same plane as the opening 4 of the body 1. In short, the upper surface side of the body 1 is formed with the recess 10 around the engaging projection 9 so as to prevent the cover 2 from rattling. Therefore, the second slide core 22 is required. Since the recess 10 is not formed on the lower surface side of 1, the parting line
P2 can be set as described above. As a result, the lower surface side of the body 1 can be formed by the fixed mold 20 and the mold opening direction can be set to two directions. By configuring the mold as described above, by setting the layout at the time of molding as shown in FIG. 13, four bodies 1 can be molded at one time. Here, the arrow in FIG.
And the mold opening direction of the second slide core 22. According to the above, the number of molded articles per one time is doubled as compared with the conventional case, and the production efficiency is improved. As shown in FIG. 14, the side surface of the body 1 is formed by a pair of slide cores 23, 24, and the mounting holes 7 are formed by these slide cores 23, 24. Here, the arrow in FIG. 14 is the mold opening direction, and the arrow is the knockout direction.

【The invention's effect】

As described above, according to the present invention, the connection cylinder is provided on the cover, the coupling cylinder having an engagement hole that overlaps the outer side surface of the peripheral wall surrounding the opening of the body and is formed at a key point to engage with the engagement protrusion. The cover is fitted to the body so that the leading edge of the body abuts on the step formed on the body, and the step on the surface on which one of the engaging projections is protruded has a cross section parallel to that surface. Since the opening side is opened to form a recess in which a part of the connecting cylinder is engaged, the body and the cover are coupled by engaging the engaging projection with the engaging hole, and the edge of the coupling cylinder is connected. There is an advantage that engagement of the cover with the recess prevents rattling of the cover with respect to the body. The recess is formed only on the surface on which one of the engagement protrusions is provided, and the step on the surface on which the other engagement protrusion is provided is formed on a straight line parallel to the opening. If you set the parting line of the mold on the same plane as the side of the engagement projection,
In a cross section including both the engagement projections and orthogonal to the opening, the body can be formed using the fixed mold and the two slide cores. In this cross section, the mold opening directions are two directions. It works. As a result, conventionally, the mold opening direction is three directions, and the body can be arranged only in the remaining one direction at the time of molding, whereas in the shape of the present invention, the bodies are arranged in two directions and molded. Can be formed. Conventionally, only two pieces can be formed at one time, but in the present invention, up to four pieces can be formed. In this way, twice as many bodies as the conventional body can be formed at one time, so that the production efficiency is improved.

[Brief description of the drawings]

FIG. 1 is an exploded side view showing an embodiment of the present invention with a part cut away, FIG. 2 is a side view of the same, FIG. 3 to FIG. 6 are side views, a horizontal sectional view, and a plan view of a body used in the same. Figures, longitudinal sectional views, FIGS. 7 to 11 are sectional views, plan views, bottom views, left side views, right side views, and FIG. 12, respectively, of the covers used in the above. FIG. 13 is an explanatory diagram showing a layout when molding a body used in the above embodiment. FIG. 14 is an explanatory diagram showing an array of a mold for molding a side portion of the body used in the embodiment.
FIG. 15 is an explanatory diagram showing an arrangement of a mold for molding a body used in the conventional example, and FIG. 16 is an explanatory diagram showing a layout when molding the body used in the above. 1 ... body, 2 ... cover, 3 ... lead, 4 ... opening, 8 ...
Step part, 9 ... engagement projection, 10 ... recess, 13 ... connection cylinder, 16 ... connection hole.

Claims (1)

(57) [Claims] 1. A small switch case comprising: a body formed in a rectangular parallelepiped shape with one surface opened, in which a switch mechanism is housed, and a cover fitted to the body so as to close the opening of the body. The body has projections formed on the outer surfaces of a pair of peripheral walls facing each other out of the peripheral walls surrounding the opening, and the cover overlaps with the outer surfaces of the peripheral walls surrounding the opening of the body and engages with the engagement projections. A connecting cylinder having a mating engagement hole formed at a key point is provided, and a cover is fitted to the body such that a leading edge of the connecting cylinder abuts a step formed on the body. The stepped portion of the surface on which the mating projection is projected forms a recess in which the opening side of the body is opened and a part of the connecting cylinder is engaged with respect to a cross section parallel to the surface, and the other engaging projection is projected. The step of the surface is parallel to the opening and sandwiches the engagement protrusion Case for a small switch, characterized by comprising formed on a straight line on the opposite side of the mouth.