JPH08148054A - Waterproof structure for switch - Google Patents

Abstract

PURPOSE: To prevent infiltrating water in a surface of a printed board through a drilled part in the case of the drilled part being equipped in a coating sheet. CONSTITUTION: A cylindrically shaped protrusive wall 30 is formed around a mouth edge in a reverse side of an opening part 8 for a switch button 24. A cylindrically shaped waterproof wall 31 is formed around a mouth edge in a surface side of a fitting hole 27 in a boss part 10 formed in a coating sheet 3, also to form a waterproof wall 32 also around a mouth edge in a surface side of a positioning hole 28. In the case of splashing water in an operating panel 7 to infiltrate into the inside from the opening part 8, infiltrated water, after it is transmitted along an internal peripheral surface of the protrusive wall 30, is dropped onto the coating sheet 3 without turning around a reverse side of the operating panel 7. Even when the water, dropped onto the coating sheet 3, is transmitted along its surface to tend to infiltrate into the fitting hole 27 of the boss part 10 and the positioning hole 28, infiltrating this water is regulated by the waterproof walls 31, 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for switches used in remote control switches and the like.

[0002]

2. Description of the Related Art A remote control switch or the like for operating an electric mirror on the interior side of a vehicle door may be mounted. In a switch used in a place where rainwater may splash when the door is opened like this, it is necessary to provide a waterproof structure so that the contacts and the like do not get wet with water. Conventionally, as an example of a switch having a waterproof function of this type, one shown in FIG. 5 is known. This switch has a pair of upper and lower cases 41 and 42 made of synthetic resin that are fitted to each other. An operation panel 43 having an opening 44 formed at a predetermined position is provided on the top surface of the upper case 41, and the operation is performed. A printed circuit board 45 is arranged on the lower surface side of the panel 43. The printed circuit board 45 is positioned by fitting a positioning pin 46 protruding from the back surface of the operation panel 43 into a positioning hole 47, and a screw hole 4 of a boss portion 48 also protruding from the back surface of the operation panel 43.
It is fixed by tightening a screw 50 on the shaft 9. Fixed contacts 51 are provided on the printed circuit board 45 at positions corresponding to below the opening 44 of the operation panel 43.

A cover sheet 52 called a rubber contact is arranged on the upper surface of the printed circuit board 45.
The cover sheet 52 is made of a rubber material having elasticity, and the printed circuit board 45 is provided with a peripheral wall 53 projecting over the entire circumference of the peripheral edge thereof in close contact with the back surface of the operation panel 43.
Is arranged so as to cover the entire upper surface of the. The cover sheet 52 is formed with a recess 54 for opening the portion where the fixed contact 51 is disposed, and a switch button 55 fitted in the opening 44 of the operation panel 43 so as to be able to move forward and backward is elastically deformable thereabove. It is integrally formed through a dome-shaped connecting portion 56 having a narrow upper end, and a movable contact 57 that is capable of contacting and separating from the fixed contact 51 is provided on the lower surface of the switch button 55. . That is, the covering sheet 52 prevents water that has entered from the opening 44 for the switch button 55 from splashing on the upper surface of the printed circuit board 45 including the fixed contact 51,
The switch can be turned on and off by pressing the switch button 55.

[0004]

On the cover sheet 52 described above, the printed circuit board 45 is provided with the operation panel 43.
Hole 59 for inserting the positioning pin 46 required for attaching to the boss 48 and the hole 60 for fitting the boss 48 cut from the screw hole 49.
However, conventionally, these holes 59,
No preventive measures were taken for the inundation from 60. Therefore, the water that has entered through the opening 44 for the switch button 55 drips onto the covering sheet 52 and then travels thereover to enter the holes 59 and 60, or the positioning pin 46 and the boss from the rear surface of the operation panel 43. Part 48
To penetrate into the holes 59 and 60, pass through between the covering sheet 52 and the printed circuit board 45, and wet the fixed contacts 51 and the like,
There was a risk of electrical connection failure.

The present invention has been completed based on the above circumstances, and it is possible to effectively prevent water from entering the surface of a printed circuit board by a simple structure when the surface of the board is relatively small. It is intended to provide a waterproof structure for a switch.

[0006]

As means for achieving the above object, the present invention provides an operation panel having an opening formed on the top surface of a casing, and a printed circuit board is provided on the lower surface side of the operation panel. Are provided at intervals and fixed contacts are provided on the printed circuit board so as to correspond to the openings, and the upper surface of the printed circuit board is made of an elastic material and part of which is provided with perforations. A switch covered with a covering sheet, a switch button formed in the covering sheet so as to be fitted in the opening so as to be able to move forward and backward, and provided with a movable contact corresponding to the fixed contact in the switch button. In the above, the back surface of the operation panel is provided with an uneven portion for restricting the water that has entered from the opening from dripping down the perforated portion of the covering sheet along the back surface of the operation panel. Together, wherein the rotation of the drilling locations, characterized in was configured to waterproof wall for water along the upper the cover sheet to restrict from entering the drilling portion is circumferentially provided.

[0007]

The operation of the present invention is as follows. Even if water that has entered through the opening of the operation panel travels on the cover sheet and enters the perforated portion of the cover sheet, the water is regulated by the waterproof wall provided around the perforated portion. Similarly, water that has entered the opening of the operation panel and turned to the back surface side of the operation panel is prevented from being transmitted to the upper side of the perforation portion by the concave portion or the convex portion provided on the back surface of the operation panel. Dropping is regulated.

[0008]

[Effects of the Invention] That is, according to the present invention, even if a perforated portion is provided in the covering sheet for fixing or positioning the printed circuit board, the permeation of water from the perforated portion is restricted so that the surface of the printed circuit board is exposed. There is an effect that it is possible to prevent water from being infiltrated and ensure good electrical connection.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a remote control switch for operating an electric mirror of an automobile will be described below with reference to the accompanying drawings. <First Embodiment> FIG. 1 shows a first embodiment of the present invention. The switch of the present embodiment roughly includes a casing 1 made of synthetic resin, a printed circuit board 2, and a cover sheet 3 made of rubber called a rubber contact. Casing 1
Comprises an upper case 5 and a lower case 6 which are butted against each other and coupled to each other. An operation panel 7 is formed on the top surface of the upper case 5, and a switch button 24 to be described later is provided at a predetermined position.
The two openings 8 shown in the figure for fitting the two are formed.

The printed circuit board 2 is arranged and fixed on the lower surface side of the operation panel 7 with a constant space. Therefore, in the central part of the back surface of the operation panel 7,
A boss portion 10 that cuts the screw hole 11 is provided in a protruding manner, and a positioning pin 12 is provided in a protruding manner on one end side. On one printed circuit board 2, an insertion hole 15 for a screw 14 to be screwed into the screw hole 11 and a positioning hole 16 for inserting the tip of the positioning pin 12 are formed at corresponding positions. Fixed contacts 18 incorporated in a drive circuit for an electric mirror (not shown) are provided at positions corresponding to the respective openings 8 of the operation panel 7 on the printed circuit board 2.

The cover sheet 3 is arranged on the surface of the printed circuit board 2, and a peripheral wall 21 projects over the entire periphery of the periphery of the sheet portion 20 which can cover the entire surface of the printed circuit board 2. It is set up. The cover sheet 3 is formed with recesses 22 that open the portion where the fixed contacts 18 are arranged, and the rim of each recess 22 is elastically deformable in a dome shape with the upper end side gradually tapered. A connecting portion 23 is formed, and a switch button 24 fitted to the opening 8 of the operation panel 7 by the connecting portion 23 so as to be able to move forward and backward by the connecting portion 23.
Are integrally formed. A movable contact 25 is provided on the lower surface of each switch button 24 so as to be capable of coming into contact with and separating from the fixed contact 18. In addition, the cover sheet 3 is formed with a fitting hole 27 into which the lower end of the boss portion 10 of the operation panel 7 is fitted and a positioning hole 28 into which the positioning pin 12 is fitted.

In the present embodiment, a cylindrical projecting wall 30 is formed around the back edge of both openings 8 formed in the operation panel 7. The projecting wall 30 has a slight gap with the switch button 24. Also, the protruding wall 3
The protrusion height of 0 from the operation panel 7 is set so as not to come into contact with the connecting portion 23, and to the extent that the water passage can be reliably cut off.

Further, the boss portion 1 formed on the cover sheet 3
A cylindrical waterproof wall 31 is formed around the front edge of the fitting hole 27 of 0, and a cylindrical waterproof wall 31 is formed around the front edge of the positioning hole 28. Wall 3
2 is formed. These waterproof walls 31 and 32 are provided with a slight gap between them and the boss portion 10 or the positioning pin 12, and have a protruding height enough to reliably cut off the water passage.

The first embodiment has the above structure,
Next, the operation will be described. At the time of assembly, the positioning holes 16 and 28 of the printed board 2 and the covering sheet 3 are aligned with each other, the insertion hole 15 of the screw 14 and the fitting hole 27 of the boss portion 10 are aligned, and the covering sheet 3 is placed on the surface of the printed board 2. Pile up. Then, the printed circuit board 2 on which the covering sheet 3 is superposed is passed through the positioning pins 12 through both the positioning holes 16 and 28, and the boss portion 10 is fitted into the fitting hole 27 so that the rear surface side of the operation panel 7 of the upper case 5 is covered. Apply to. Subsequently, the screw 14 passed through the insertion hole 15 of the printed board 2 is screwed into the screw hole 1
When screwed into 1 and tightened, the printed circuit board 2 is fixed to the operation panel 7, and at that time, with the peripheral wall 21 of the covering sheet 3 adhered to the back surface of the operation panel 7, the sheet portion 20 is placed on the front surface of the printed circuit board 2. Then, both switch buttons 24 are fitted into the corresponding openings 8 of the operation panel 7 with part of the projections protruding upward. Finally, the upper case 5 and the lower case 6 are joined together to complete the assembly.

In the switch assembled in this manner, when the switch button 24 is pushed in while elastically deforming the connecting portion 23, the movable contact 25 is pressed against the fixed contact 18 so that the switch is turned on and an electric mirror (not shown) is driven. It On the other hand, when the pressing force on the switch button 24 is removed, the switch button 24 moves upward as the connecting portion 23 is restored and deformed, and the movable contact 25 separates from the fixed contact 18 so that the switch is cut off. To do.

During this time, if water is splashed on the operation panel 7,
The water may enter the inside through the opening 8 for the switch button 24. In that case, since the projecting wall 30 is formed at the edge of the opening 8 on the back surface side, the water that has entered through the opening 8 travels along the inner peripheral surface of the projecting wall 30 and then the back surface side of the operation panel 7. It is dripped on the sheet portion 20 of the covering sheet 3 without turning around. Even if the water dropped on the sheet portion 20 travels along the surface and enters the fitting hole 27 and the positioning hole 28 of the boss portion 10, the waterproof walls 31 and 32 are provided at the edges of the holes 27 and 28. Since it is formed, water is restricted from entering the holes 27 and 28.

As described above, according to the first embodiment, water is restricted from entering through the fitting hole 27 and the positioning hole 28 opened in the cover sheet 3, whereby the water is covered by the cover sheet 3 and the printed circuit board 2. A situation in which the fixed contact 18 on the printed circuit board 2 is wetted through the gap can be avoided, and a good electrical connection between the contacts 18 and 25 is ensured. In addition, since the projecting wall 30 is added to the operation panel 7 and the waterproof walls 31 and 32 are added to the cover sheet 3, the structure can be manufactured without increasing the cost. It is suitable as a structure.

<Second Embodiment> FIG. 2 shows a second embodiment of the present invention. In this embodiment, similar to the first embodiment described above,
A waterproof wall 31 is formed around the rim of the fitting hole 27 with respect to the boss portion 10 of the covering sheet 3, and a projecting wall 34 is provided on the back surface of the operation panel 7 so as to surround the upper end of the waterproof wall 31. Has been formed.

Therefore, when the water that has entered through the opening 8 of the operation panel 7 travels along the back surface of the operation panel 7 and moves above the fitting hole 27 of the boss portion 10, the protruding wall 34
Is regulated by and is dropped onto the sheet portion 20 outside the waterproof wall 31 along the outer peripheral surface thereof. The water dripping on the seat 20 is restricted by the waterproof wall 31 from entering the fitting hole 27.

Although not shown, a waterproof wall is formed around the rim of the positioning hole 28 of the cover sheet 3 as in the first embodiment, and the waterproof wall is formed on the back surface of the operation panel 7. When the projecting wall is formed so as to surround the upper end, water from the positioning hole 28 is similarly restricted.

<Third Embodiment> FIG. 3 shows a third embodiment of the present invention. In this embodiment, instead of the protruding wall 34 of the second embodiment, a circumferential groove 36 is formed around the base portion of the boss portion 10. The outer peripheral surface of the circumferential groove 36 is covered with the covering sheet 3
It is located outside the waterproof wall 31 provided in the.

That is, when the water that has entered from the opening 8 of the operation panel 7 travels along the back surface of the operation panel 7 and moves above the fitting hole 27 of the boss portion 10, the circumferential groove 3
It is regulated by the recess of 6 and propagates along the outer peripheral surface thereof to be dropped on the sheet portion 20 outside the waterproof wall 31. Seat part 2
The water that has dripped on the surface 0 is prevented from entering the fitting hole 27 by the waterproof wall 31.

<Fourth Embodiment> FIG. 4 shows a fourth embodiment of the present invention. This embodiment is a modification of the first embodiment. That is, the fitting hole 27 of the cover sheet 3
At the upper end of the waterproof wall 31 formed around the mouth edge, a flange 38 protruding outward is further provided. As a result, water is transmitted through the sheet portion 20 of the covering sheet 3 and the fitting hole 2
Entry into 7 is more effectively regulated.

Of course, a brim may be similarly provided on the waterproof wall 32 provided around the positioning hole 28. Since the covering sheet 3 is made of soft rubber, it is possible to perform die cutting at the time of molding even if the brim 38 is provided.

Further, the present invention is not limited to the remote control switch for the electric mirror shown in the above-described embodiment, but can be widely applied to the switches for other purposes in general for simple waterproofing.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a partial sectional view of a second embodiment.

FIG. 3 is a partial sectional view of a third embodiment.

FIG. 4 is a partial sectional view of a fourth embodiment.

FIG. 5 is a cross-sectional view of a conventional example.

[Explanation of symbols]

 1 ... Casing 2 ... Printed circuit board 3 ... Covering sheet 7 ... Operation panel 8 ... Opening 18 ... Fixed contact 24 ... Switch button 25 ... Movable contact 27 ... Fitting hole 28 ... Positioning hole 30 ... Projection wall 31, 32 ... Waterproof wall 34 ... Projection wall 36 ... Circumferential groove

Claims (1)

[Claims] 1. An operation panel having an opening is provided on a top surface of a casing, and a printed circuit board is arranged on the lower surface side of the operation panel with a space therebetween to correspond to the opening on the printed circuit board. And a fixed contact is provided, and the upper surface of the printed circuit board is covered with a cover sheet made of an elastic material and provided with a perforated portion in a part thereof,
A switch in which a switch button fitted in the opening so as to be able to move forward and backward is formed in the cover sheet, and a movable contact corresponding to the fixed contact is provided in the switch button is provided in the switch. On the back surface, an uneven portion for restricting water that has entered the opening from dripping on the back surface of the operation panel to the perforated portion of the cover sheet is provided, and around the perforated portion, the A waterproof structure for a switch, characterized in that a waterproof wall is provided around the cover sheet so as to prevent water that has traveled on the cover sheet from entering the perforated portion.