JPH047047B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a small push button switch that can be easily attached to a printed circuit board or the like.

<Prior Art and its Problems> The present applicant has previously proposed a small push button switch that can be easily attached to a printed circuit board or the like.

FIG. 1 is a perspective view showing the appearance of this pushbutton switch 1, and FIG. 2 is an exploded perspective view of the same pushbutton switch.

In these figures, a switch case 2 made of synthetic resin has an opening 3 on its top surface, and a metal piece integrally having a contact terminal pin 4 and a fixed contact portion 5 is housed in the bottom part by insert molding.

The return spring 6 is formed into a dome shape using a thin metal plate, and is placed on the fixed contact part 5 in the switch case 2, thereby functioning as a movable contact part. The fixed contact portion 5 and the return spring 6 in the switch case 2 constitute a contact mechanism.

The push button member 7 includes a cylindrical operating shaft portion 8 and a disk portion (hereinafter referred to as the push button portion) 9 formed at the lower end of the operating portion 8, and is placed on the contact mechanism. It is mounted in the switch case 2 in the form of a switch, and opens and closes the contact mechanism according to its vertical movement.

The cover plate 10 is connected to the switch case 2.
It is provided with an insertion hole 11 which closes the upper surface opening 3 and from which the operating shaft portion 8 of the push button member 7 projects, and through which projections 12 formed at the four corners of the upper surface of the switch case 2 penetrate. Through-holes 13 are formed, and by inserting the protrusions 12 into these through-holes 13 and thermally caulking the insertion ends, the cover plate 10 is fixed to the upper surface of the switch case 2, and the upper surface opening is closed. It will block 3.

By the way, in the conventional assembly process of this type of push button switch 1, as shown in FIG. 15 respectively, while push button members 7
The case cover 10 and the case cover 10 are each manufactured as separate independent parts, and these directional parts are fed in alignment with a parts feeder and sequentially assembled into the switch case 2 from above.

However, the alignment and feeding speed of the parts feeder is not always satisfactory, and parts jamming tends to occur easily, resulting in a lack of reliability, which results in a decrease in the operating rate of the entire assembly line. .

In addition, since the push button member 7 in particular is made of synthetic resin, it is likely that they will come into contact with each other in the parts feeder and generate electrostatic charge, and dust in the atmosphere or molding burrs of the push button will be attracted. . and,
This deposit may fall off during assembly and cause the switch case 2
The particles re-adhered to the inner contact surface, causing poor conduction of the contacts.

[Objective of the Invention] The object of the present invention is to prevent electrostatic charging of parts that occurs during assembly and the adhesion of foreign matter and poor contact of contacts due to this, and at the same time to improve the transportability of parts and assembly efficiency. be.

<Structure and Effects of the Invention> The present invention has a first through hole corresponding to a fixing location for fixing the cover plate to the switch case, and a second through hole corresponding to the insertion position of the operating shaft portion of the push button member. a first step of preparing a metal carrier plate having a through hole and an engaging portion formed on the outer periphery of the second through hole; integrally molding the operating shaft portion and the flange-shaped push button portion in a positioned state in which the operating shaft portion of the push button member is stacked on top of each other and protrudes upward from the second through hole of the carrier plate; A cantilever shape having a fixed end on the operating shaft side and a free end on the engaging part side is provided between a predetermined location on the outer circumferential surface of the operating shaft portion at the height of the upper surface of the carrier plate and the engaging portion on the carrier plate. A resin protrusion is simultaneously molded, and a laminate in which a carrier plate is superimposed on the cover plate is sandwiched between the resin protrusion and the flange-shaped push button part, whereby the push button member and the cover plate are connected via the carrier plate. a second step of holding the carrier plate together, and placing the carrier plate on top of the switch case in which the contact mechanism is built in in advance;
a third step of mounting the push button member held by the carrier plate in the switch case and simultaneously closing the top opening of the switch case with a cover plate; a fourth step of fixing the cover plate to the switch case by applying a predetermined fixing treatment to the fixing portion; and fixing the base of the resin protrusion by pressing down the operating shaft portion of the push button member with a predetermined force; A fifth step of pressing the carrier plate against the inner periphery of the second through hole to remove any breakage; and a sixth step of separating the carrier plate from the finished push button switch. That is.

According to this invention, the cover plate and the push button member are held together through the carrier plate by sandwiching the laminate of the carrier plate and the cover plate between the resin protrusion and the push button part. This eliminates the need to use a parts feeder to align and feed the cover plate and push button members, which each have their own directionality, as in the conventional method. This eliminates delays in work due to parts clogging, and facilitates assembly. In addition, since there is no electrostatic charge on the push button member generated in the parts feeder, there is no adhesion of dust, etc., and it is possible to improve the quality of the final product and the yield.

Furthermore, since the carrier plate is made of metal, as long as the operating shaft of the push button member is pushed down, the base of the resin protrusion will come into contact with the inner periphery of the insertion hole of the carrier plate and be easily broken and removed. By appropriately setting the thickness of the carrier plate, this broken part can be positioned above the operating stroke of the operating shaft, so that this broken part does not interfere with the operating stroke of the operating shaft in the final product. I won't come.

In addition, since the outer diameter of the operating shaft and the inner diameter of the insertion hole of the carrier plate are in relatively close contact, there is no possibility that cut pieces or dust will fall into the switch case during the breakage process, and the switch There is also no risk of poor insulation.

Furthermore, the downward load on the operating shaft when the resin protrusion breaks is applied mainly to the carrier plate and not to the switch case or the reversing spring in the switch case, so that it does not affect the characteristics of the switch.

<<Description of Example>> An example of the method of the present invention will be described with reference to FIGS. 4 to 10.

First, as shown in FIG. 4, a carrier plate strip 16 consisting of a large number of carrier plate sections 23 connected in one row is prepared, and as shown in FIG.
A cover plate strip 18 formed by connecting a large number of cover plate parts 17 in one row is prepared.

Each cover plate section 1 of the cover plate strip 18
At 7, there is a protrusion 1 for heat caulking of the switch case 2.
A through hole 19 through which the push button 2 protrudes and an insertion hole 20 through which the operating shaft portion 8 of the push button member 7 is inserted are formed.

On the other hand, the corresponding carrier plate strip 16
Each carrier plate portion 23 has a through hole 21 (first hole) corresponding to each through hole 19 of the cover plate portion 17.
) and the insertion hole 20 of the cover plate portion 17
An insertion hole 22 (second through hole) corresponding to the insertion hole 22 is opened, and two rectangular small recesses 25 are formed on the outer periphery of the insertion hole 22 diametrically opposed to each other across the insertion hole 22.
(engaging portion) is formed.

Next, as shown in FIGS. 6 and 7, the carrier plate section 23 is overlapped on the cover plate section 17, and the carrier plate strip 16 is superimposed on the cover plate strip 18, and this laminate is formed. The operating shaft portion 8 is positioned in the mold so that it completely protrudes from the insertion hole 22, and in this state, the operating shaft portion 8 and the flange-shaped push button portion 9 formed at its lower end are integrated. Along with molding,
Between a predetermined location 24 on the outer peripheral surface of the upper surface height of the carrier plate 23 of the operating shaft portion 8 and a small recess 25 on the carrier plate 23, there is provided a fixed end on the operating shaft portion 8 side;
A cantilevered resin protrusion 26 having a free end on the side of the small recess 25 is integrally molded horizontally along the upper surface of the carrier plate 23.

Further, the inner circumferential surface of the insertion hole 20 of the cover plate portion 17 is formed with a tapered surface that widens at the bottom, thereby facilitating vertical movement of the operating shaft 8.

In addition, in this integral molding, each insertion hole 2 of the carrier plate part 23 and the cover plate part 17 is
2 and 20 each function as a mold for shaping the outer peripheral surface of the operating shaft portion 8 of the push button member 7,
During molding, the outer circumferential surface of the operating shaft section 8 and the inner circumferential surface of each insertion hole 20, 22 are in close contact with each other, and as the resin solidifies, the resin contracts and eventually prevents the operating shaft section 8 from sliding. A suitably acceptable optimum clearance is created between the two.

Furthermore, a convex portion 27 that engages with the small concave portion 25 is formed on the lower surface side of the tip of the resin protrusion 26, so that when the above molding process is completed, the carrier plate portion 23 and the cover plate portion 17 are separated. The laminate is sandwiched between the resin protrusion 26 of the push button member 7 and the push button 9, whereby the push button member 7 and the cover plate 17 are held together via the carrier plate 23, and at the same time the resin protrusion 2
By engaging the convex portion 27 of 6 with the small concave portion 25 of the carrier plate portion 23, the push button member 7 is held in a predetermined position relative to the cover plate portion 17 and is fixed to prevent rotation. Become.

On the other hand, in FIG.
The switch case 2 has a contact terminal pin portion 4 and a fixed contact portion 5 built-in by insert molding.
A large number of switch case strips 28 are connected in one row via the terminal pin portions 4, and the switch case strips 28 are conveyed in the extending direction and intersect with the reversal spring strips 29 at predetermined positions. Then, at this intersection, with the through holes 30 formed at each of the four corners of the reversing spring 6 fitted into the protrusions 12 protruding from the four corners of the switch case 2, the reversing spring is activated by a force from above. 6 is punched out downwards, and at the same time, the punched reversing spring 6 is precisely mounted on the fixed contact part 5 inside the switch case 2.

Next, the switch case strip 28 to which the reversing spring 6 is attached is further attached to the carrier plate strip 16 and the cover plate strip 18 at a predetermined position.
The push button member 7 held by the carrier plate part 23 is intersected with the laminated belt 31 of the switch case 2, and at this intersection, the cover plate part 17 is placed on the reversing spring 6 in the switch case 2 from above. It is installed in the switch case 2, and at the same time, the connection part 33 of the cover plate strip 18 facing from the window 32 is cut, and the upper opening of the switch case 2 is closed with the cut cover plate part 17.

At this time, the cover plate part 17 and the push button member 7 are positioned in a predetermined direction via the carrier plate part 23, so that by lowering the stacked body 31 shown in FIG. The members are accurately mounted at predetermined positions within the switch case 2, and at the same time protrude from the switch case 2 into through holes 19 and 21 formed at each of the four corners of the carrier plate portion 23 and the cover plate portion 17. The protrusion 12 is inserted.

Next, in this inserted state, when the protrusion 12 facing through the through hole 21 of the carrier plate 23 is heat caulked, the cover plate part 17 is fixed to the upper opening of the switch case 2 and closes it.

Next, as shown in FIG. 9, when the operating shaft 8 of the push button member 7 is pushed down, the base of the resin protrusion 26 comes into contact with the inner peripheral edge of the insertion hole of the carrier plate part 23, and as a result, the resin protrusion 26 is pushed down. It is easily broken off at its base and removed.

At this time, as described above, each insertion hole 20, 22
The gap between the outer periphery of the operating shaft portion 8 and the outer periphery of the operating shaft portion 8 is extremely tight, so there is no risk of cut pieces, dust, etc. falling into the switch case 2 when the switch breaks.

Next, as a final step, as shown in FIG. 10, from the insertion hole 22 of the carrier plate part 23,
When the operating shaft portion 8 of the push button member 7 is pulled out, the completed push button switch 34 is separated and removed from the carrier plate portion 23.

Push button switch 34 manufactured by the above method
In this case, the gap between the outer diameter of the operating shaft and the inner diameter of the cover plate insertion hole is extremely tight, so the occurrence of tilted sliding of the operating shaft is extremely rare. There is little risk of insulating materials such as dust getting mixed in, and stable quality can be maintained over a long period of time.

In addition, in the method of this invention, by making the carrier plate into a band shape, the push button member and the cover plate can be conveyed integrally via the carrier plate, and the conventional parts feeder can be easily transported. The transport speed can be significantly improved compared to the transport of cover plates and pushbutton members using conventional methods, and there is no risk of clogging of the parts feeder, which causes a decrease in the operating rate of the entire assembly line. There is no risk of electrostatic charging occurring when transporting the product.
Therefore, it is possible to prevent the possibility of insulating dust adhering to the contact portion due to electrostatic charging.

[Brief explanation of drawings]

Fig. 1 is an external perspective view showing the basic structure of a push button switch according to the present invention, Fig. 2 is an exploded perspective view of the push button switch, Fig. 3 is an exploded perspective view showing the conventional manufacturing process, and Fig. 4 5 is an external perspective view of the carrier plate strip, FIG. 5 is an external perspective view of the cover plate strip, FIG. 6 is a sectional view showing the molding process of the push button member, FIG. 7 is a plan view of the molded state, and FIG. 8 9 is an exploded perspective view for explaining the method of the present invention, FIG. 9 is a sectional view showing the step of breaking the resin protrusion, and FIG. 10 is an external perspective view showing the step of pulling out the carrier plate. 1...Push button switch, 2...Switch case,
3... Top opening, 4... Terminal pin, 5... Fixed contact part,
6...Return spring, 7...Push button member, 8...Operation shaft part, 9...Push button part, 10...Cover plate, 1
1...insertion hole, 12...caulking protrusion, 13...through hole,
16...Carrier plate strip, 17...Cover plate section, 18...Cover plate strip, 19...Through hole, 2
0...Through hole, 21...Through hole, 22...Through hole, 23...
Carrier plate portion, 24...Predetermined position on outer periphery, 25
...Small recess, 26...Resin protrusion, 27...Protrusion, 28...
Switch case strip, 29...Return spring strip, 30...Through hole, 31...Laminated body, 32...Window, 33...Connection part, 3
4...Finished product.

Claims (1)

[Scope of Claims] 1. A switch case having an open top surface and a built-in contact mechanism in the bottom; the switch case being disposed within the switch case on the contact mechanism, and the contact mechanism being arranged in the switch case in accordance with the vertical movement of the switch case; Manufacture of a push button switch comprising: a push button member for opening and closing the mechanism; and a cover plate fixed to and blocking the upper opening of the switch case and having an insertion hole through which the operating shaft of the push button member projects. A first through hole corresponding to a fixing point for fixing the cover plate to a switch case, a second through hole corresponding to an insertion position of an operating shaft portion of the push button member, and a first step of preparing a metal carrier plate having an engaging portion formed on the outer periphery of the second through hole; overlapping the carrier plate on the cover plate in a molding die; and In the positioning state in which the operating shaft portion of the push button member is projected upward from the second through hole of the carrier plate, the operating shaft portion and the flange-shaped push button portion are integrally molded, and the carrier plate of the operating shaft portion is Simultaneously mold a cantilever-shaped resin protrusion with a fixed end on the operating shaft side and a free end on the engagement part side between a predetermined location on the outer peripheral surface at the height of the top surface of the plate and the engagement part on the carrier plate. Then, a laminate in which a carrier plate is superimposed on the cover plate is sandwiched between a resin protrusion and a flange-shaped push button part, thereby holding the push button member and the cover plate together through the carrier plate. and placing the carrier plate on top of a switch case in which a contact mechanism is built in in advance.
a third step of mounting the push button member held by the carrier plate in the switch case and simultaneously closing the top opening of the switch case with a cover plate; a fourth step of fixing the cover plate to the switch case by applying a predetermined fixing treatment to the fixing portion; and fixing the base of the resin protrusion by pressing down the operating shaft portion of the push button member with a predetermined force; A fifth step of pressing the carrier plate against the inner peripheral edge of the second through hole to remove any breakage; and a sixth step of separating the carrier plate from the finished push button switch. A method for manufacturing a push button switch.