JPS635139Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in plunger switches, particularly small-sized plunger switches.

Plunger switches are used in automobile transmissions to detect the position of a shift lever. This plunger switch is
The operation of the transmission member driven by the shift lever is transmitted to a plunger built into the switch, and the detection circuit is closed by the operation of the plunger.

By the way, a plunger switch has a roughly cylindrical metal body with a dustproof diaphragm interposed therein to divide the inside of the body into one opening side and the other opening side, and the drive member including the plunger is housed in one opening side. On the other hand, the other opening side accommodates a fixed contact holding board and a movable contact member driven by the driving section with respect to the board, and a shoulder part formed on the inner wall of the body with the peripheral edge of the diaphragm. and the lower periphery of the peripheral wall of the fixed contact holding board, bend the upper periphery of the body inward against the upper periphery of the peripheral wall of the fixed contact holding board and caulk it; After the cord wiring is performed, a cover resin is filled into the peripheral wall of the fixed contact holding board to prevent oil and mud from entering.

Incidentally, the clamping pressure at the peripheral edge of the diaphragm needs to be set to an appropriate pressure from the viewpoint of stability and reliability of sealing performance. In order to set this clamping pressure to an appropriate pressure, large plunger switches have a positioning shoulder formed on the inner peripheral surface of the metal body, and a positioning shoulder formed on the outer peripheral surface of the peripheral wall of the fixed contact holding board. It has a structure in which the parts are engaged. Because of this engagement structure, the relative positional relationship of the fixed contact holding board to the body is regulated, so even if there is variation in the caulking pressure on the upper periphery of the metal body, the clamping pressure on the periphery of the diaphragm is held constant.

However, in a small plunger switch, as described above, since the body and the fixed contact holding board are positioned inside the body, this structure of engaging the two is difficult to adopt due to space constraints.

Therefore, conventionally, for small-sized plunger switches, the structure for engaging the fixed contact holding board with the body, which is used for large-sized plunger switches, has not been adopted. Therefore, a small plunger switch has a simple structure in which the peripheral edge of the diaphragm is sandwiched between the shoulder for supporting the diaphragm formed on the inner peripheral surface of the body and the lower peripheral edge of the peripheral wall of the fixed contact holding board. Because it is familiar,
When the upper peripheral edge of the body is caulked against the upper peripheral edge of the peripheral wall of the fixed contact holding substrate, the caulking force is directly applied to the peripheral edge of the diaphragm. Therefore, if the caulking force varies, the clamping force at the peripheral edge of the diaphragm will not be constant, causing a serious problem in terms of sealing performance.

The above matters relate to a diaphragm whose purpose is to prevent dust, oil, mud, etc. from entering the body from the plunger side, but similarly, dust, oil, mud, etc. from the fixed contact holding board Conventionally, there have been problems with the cover resin used to prevent intrusion.

In conventional small plunger switches,
The cord is guided from the outside along the axial direction of the switch onto the fixed contact holding board and connected to the terminal rivet of the board, and then a cover resin is filled into the peripheral wall of the fixed contact holding board.

However, in the above configuration, the cord may be pulled strongly during the installation work of the switch, so there is a problem that a gap may occur between the cord and the cover resin, or the cover resin may peel off. It was hot. Furthermore, in general, in order to route the cord in a transmission, it is preferable to introduce the cord from the side of the switch, that is, from a direction perpendicular to the axial direction of the switch, and connect it to the fixed contact of the fixed contact holding board. Problems arose from this perspective as well.

The present invention was developed in view of the above-mentioned conventional circumstances, and it improves the stability and reliability of the sealing performance of the diaphragm and the cover resin, and also has a structure that allows the cord to be introduced into the switch from the side of the switch. The purpose is to provide a plunger switch.

In the plunger switch according to the present invention, a part of the circumferential wall of the metal body on the side where the fixed contact holding board is housed is cut out in a letter shape, and the bottom of the letter shaped notch of the circumferential wall of the body is cut out in the circumferential wall of the fixed contact holding board. Further, a cord introduction hole is formed in the peripheral wall of the fixed contact holding board at a portion corresponding to the letter-shaped notch in the peripheral wall of the body, and the cord is inserted from the outside. The cord is introduced into the peripheral wall of the fixed contact holding board through the introduction hole, and a grommet tightly fitted around the outer periphery of the cord is tightly fitted into the cord introduction hole to close the hole.

The present invention will be described in detail below with reference to the illustrated embodiments.

The illustrated embodiment is a plunger switch for detecting the position of a shift lever applied to an automobile transmission.

As shown in the figure, this plunger switch has a disk-shaped dustproof diaphragm 2 interposed in a roughly cylindrical metal body 1 to divide the inside of the body into an upper opening side and a lower opening side. A drive member including a plunger 7 is housed on the opening side, while a fixed contact holding board 3 and a movable contact member 4 driven by the drive unit with respect to the board 3 are housed on the upper opening side. A shoulder portion 1 in which the peripheral edge portion 2a of the diaphragm 2 is formed on the inner peripheral surface of the body 1.
a and the lower peripheral edge 3b of the peripheral wall 3a of the fixed contact holding board 3, the upper peripheral edge 1 of the body 1
d is bent inward against the upper peripheral edge 3c of the peripheral wall 3a of the fixed contact holding board 3 and caulked, and after wiring the cord 5 to the fixed contact holding board 3, It has a general structure filled with cover resin 6, such as polyurethane rubber.

The driving member includes the plunger 7 which is driven by a member interlocked with a shift lever in the transmission and slides within the body 1, and as the plunger 7 slides, the plunger 7 moves through the coil spring 8. It is composed of a cap 9 and the like that interlock with each other and drive the movable member 4 via the diaphragm.

The fixed contact holding board 3 has a bottom wall 3d between the peripheral walls 3a, and a pair of terminal rivets 10a and 10b are vertically penetrated and fixed to the bottom wall 3d. Each terminal rivet 10a,
The lower end of 10b is connected to each movable contact 4 of the movable contact member 4.
It is facing a.

The movable contact member 4 has a protrusion 4b for preventing rotation.
The protrusion 4b is inserted into a hole 3e formed in the bottom wall 3d of the fixed contact holding board 3 so as to be movable in the axis o direction but not rotatable. The movable contact member 4 also has a coil spring 1 interposed between its recess 4c and the hole 3f of the fixed contact holding board 3.
1, the fixed contact holding board 3 is constantly biased downward in the figure. As shown in the right half cross-section of FIG. 2, when the plunger 7 is pushed into the body 1, the movable contact member 4 is pushed up by the cap 9 through the diaphragm 2, and each movable contact 4a is connected to each terminal rivet. 10a,1
0b, both terminal rivets 10a, 1
0b is electrically connected.

By the way, the upper peripheral wall 1e of the metal body 1
has letter-shaped notches 1b at two opposing locations.

On the other hand, as clearly shown in FIGS. 4 and 5, the fixed contact holding board 3 has, at opposing positions on its peripheral wall 3a,
Engagement protrusions 3h corresponding to each letter-shaped notch 1b of the body 1 are provided protrudingly, and a shoulder 3g is formed at the lower part of the engagement protrusions 3h.

Thus, when the fixed contact holding board 3 is assembled into the body 1, each of its shoulders 3g comes into contact with the bottom part 1c of each character-shaped notch 1b of the body 1. Therefore, this positions the fixed contact holding board 3 with respect to the body 1, and the peripheral edge 2 of the diaphragm 2 on the lower peripheral edge 3b of the peripheral wall 3a.
The amount of pressure applied to a is regulated.

The peripheral wall 3a of the fixed contact holding board 3 further includes:
One through hole 3i is formed. This hole 3i is an introduction hole for the cord 5, and has one protrusion 3h.
It is formed on the top of the part with However,
The cord 5 is introduced into the interior from the outside through the cord introduction hole 3i, and as clearly shown in FIG. The lead terminals 13 are connected to each lead terminal 13. Furthermore, code 5
A grommet 12 is tightly fitted to the outer periphery of the cord, and when the cord is attached to the switch, the cord 5 is introduced into the cord introduction hole 3i, and the grommet 12 is tightly fitted into the hole 3i. is completely occluded.

The cover resin 6 is filled into the peripheral wall 3a of the fixed contact holding board 3 after the cord 6 has been attached, but at this time, the cord introduction hole 3i is completely closed by the grommet 12, so I have never experienced anything leaking outside from this hole 3i.

As detailed above, the plunger switch according to the present invention does not have a conventional structure in which a positioning shoulder is formed on the inner peripheral wall of the body in order to position the fixed contact holding board with respect to the body.
A portion of the peripheral wall of the body itself is cut out in a letter shape, and the bottom of the letter-shaped cutout is used as an engaging means, and an engaging portion formed on a part of the fixed contact holding board is engaged with the bottom of the letter-shaped cutout. Since it is configured to
It can be suitably applied to small plunger switches with limited space. Therefore, even in a small plunger switch, the clamping force of the periphery of the diaphragm as a sealing member can be controlled, and good sealing performance can be guaranteed for the diaphragm.

Furthermore, the plunger switch according to the present invention is
A cord introduction hole is formed in the peripheral wall of the fixed contact holding board, and the cord is introduced into the switch through this hole, so the cord can be introduced into the switch from the outside side. In addition, since the cord introduction hole is tightly fitted with a grommet that tightly fits around the outer periphery of the cord, if the resin for the cover leaks outside when filling the peripheral wall of the fixed contact holding board, It also prevents
Very good workability. Furthermore, since the cord is passed through the cord introduction hole in the body, even if the cord is handled roughly when the switch is installed,
Since the cord is securely fixed through the introduction hole, there is an advantage that problems such as the generation of a gap between the resin and the cord and the peeling of the resin, which were conventionally seen, do not occur.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of the switch, and FIG. 2 is a sectional view taken along the - line of FIG. 1, with the left half section showing the switch off state and the right half section showing the switch on state. Figure 3 is a left side view of Figure 1, Figure 4 is a plan view of the fixed contact holding board, and Figure 5 is a left side view of Figure 1.
The figure is a sectional view taken along the line -- in FIG. 4. 1... Body, 1a... Shoulder, 1b... Letter-shaped notch, 1c... Bottom, 2... Diaphragm, 2a
...Peripheral portion, 3...Fixed contact holding board, 3a...
Peripheral wall, 3b...lower periphery, 3c...upper periphery, 3h...
...Engaging protrusion, 3i...Shoulder, 4...Movable contact member, 5...Cord, 6...Cover resin, 7...
Plunge, 12... Grommet.

Claims (1)

[Claims for Utility Model Registration] A dustproof diaphragm is interposed in a roughly cylindrical metal body to divide the inside of the body into one opening side and the other opening side, and a driving member including a plunger is attached to one opening side. On the other hand, a fixed contact holding substrate and a movable contact member driven by the drive unit with respect to the substrate are housed on the other opening side, and the peripheral edge of the diaphragm is formed on the inner peripheral surface of the body. The upper periphery of the body is sandwiched between the shoulder and the lower periphery of the peripheral wall of the fixed contact holding board, and the upper periphery of the body is bent inward against the upper periphery of the peripheral wall of the fixed contact holding board and caulked to fix the above. In a plunger switch in which the peripheral wall of the fixed contact holding board is filled with a cover resin after the cord wiring is performed on the contact holding board, a part of the surrounding wall of the metal body on the side where the fixed contact holding board is stored is The peripheral wall of the fixed contact holding substrate is formed with an engaging portion that engages with the bottom of the notch in the peripheral wall of the body. A hole for cord introduction is formed in a portion of the peripheral wall corresponding to the letter-shaped notch, and the cord is introduced from the outside through the hole for cord introduction into the peripheral wall of the fixed contact holding board, and a grommet tightly fitted around the outer periphery of the cord is formed. A plunger switch characterized in that it is tightly fitted into the cord introduction hole to close the hole.