JPH0439609Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a sliding contact switch that is operated by the reciprocating movement of a plunger, and in particular, a sliding contact switch that is suitable for reducing wear and improving durability. The present invention relates to a plunger switch device having a plunger switch device.

[Conventional technology]

Conventionally, a plunger switch device has been provided which has both an opposed contact switch operated by depression of a brake pedal and a sliding contact type autodrive release switch. Sliding contact type is No. 3a
As shown in the figure, it is formed of a cylindrical contact 13 having an outer diameter r ₂ and a flat leaf spring contact 12, and these contacts are point-shaped contacts a.
Since the on/off switching is severe, the amount of wear e of the leaf spring contact 12 is large, as shown in FIG. 3b. As shown in Fig. 3c, the initial contact a is changed to the leaf spring contact 1 after the durability test.
2 retreats to contact point b due to wear. the result,
The switching point C at which the leaf spring contact 12 approaches and separates from the cylindrical contact 13 shown in FIG. 3d becomes D as shown in FIG. 3e, and the switching stroke becomes longer by l. That is, when the brake pedal is depressed to break the contact between the cylindrical contact 13 and the leaf spring contact 12, the amount of depression of the brake pedal increases corresponding to the amount of movement l at the contact portion.

[Problem that the invention attempts to solve]

Since the contact between the cylindrical contact and the leaf spring contact forming the sliding contact switch is a point contact, the leaf spring contact wears out quickly and becomes a surface contact, resulting in a problem of large fluctuations in the switching stroke.

An object of the present invention is to provide a plunger switch device that reduces wear on the leaf spring contacts of a sliding contact switch, reduces fluctuations in switching stroke, and improves electrical and mechanical durability.

[Means for solving problems]

In order to achieve the above object, the plunger switch device according to the present invention includes a plunger whose one end is supported in a reciprocating manner by a cylindrical shaft fixed to a case, and a movable contact and a cylinder attached to the tip of the plunger. A fixed contact that is fixed via an insulator on the inner periphery of the case and cooperates with a movable contact to form a counter contact switch, and a cylindrical contact that can be brought into contact and separated by sliding relative to the outer peripheral surface of the contact. In a plunger switch device comprising a leaf spring contact forming a sliding contact switch, the sliding contact portion of the leaf spring contact is formed to have the same curvature as the curved surface of the cylindrical contact.

[Effect]

According to the present invention, since the contact portion of the leaf spring contact forming the sliding contact switch has a curvature that matches the curved surface of the cylindrical contact, the leaf spring contact makes line contact with the cylindrical contact, increasing the contact area. This reduces local wear.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1a to 2.

As shown in FIGS. 1a to 1c, a metallic cylindrical container-shaped case 3 is caulked and fixed to one end of a metallic cylindrical shaft 2 to form a case complete 1. A cylindrical plunger 4 made of an insulating material is supported on the inner periphery so as to be movable back and forth. Insulators 5 and 6 formed of an insulating material are provided on the inner periphery of the case 3, and the insulators 5 and 6 are caulked and fixed inside the case 3 with their end surfaces abutted to form a switch case 7. The fixed contact 8 is a contact for a pair of opposing contact switches 10 that are arranged oppositely in the case 3 with the plunger 4 in between.The outer periphery of these contacts is held between the insulators 5 and 6, and the terminal portion is connected to the terminal h~ k.
The movable contact 9 is a contact that cooperates with the fixed contact 8 to form a counter contact switch 10, and is movably disposed within the case 3.
It is always biased in the direction of arrow A by the compression coil spring 11. The tip of the plunger 4 is inserted into a through hole provided in the center of the movable contact 9. The leaf spring contacts 12 shown in FIG. 1c form a pair of sliding contact switches 15 which are arranged oppositely in the case 3 with the plunger 4 in between, and which are located opposite the fixed contacts 8.
It has a contact portion (sliding contact portion) 12a at its tip, and a terminal portion at its base passes through the end plate of the insulator 6. The cylindrical contact 13 is a cylindrical contact attached to the outer periphery of the large-diameter stepped portion of the plunger 4, and this is a plate that comes into contact with and separates from the cylindrical contact 13 by sliding relative to the outer periphery of the cylindrical contact 13. A spring contact 12 and a sliding contact switch 15 are formed. The bush 16 adjacent to the cylindrical contact 13 is an insulating member, and is inserted and fixed from the tip side of the plunger 4, and the outer diameter of the bush 16 is set to be approximately the same diameter as the cylindrical contact 13. The compression coil spring 18 is disposed in the inner cylindrical portion of the plunger 4, so that the plunger 4 is always biased in the direction of arrow B. terminal h
-k are caulked and connected to the terminal portions of the respective contacts on the outer side of the end of the insulator 6 by soldering. Note that one opposing contact switch 10 is used as a stop switch, and the other sliding contact switch 15 is used as an autodrive release switch, and at the same time lights a stop lamp.

Next, the effect will be explained.

When the brake pedal (not shown) is depressed, the plunger 4 slides in the direction of arrow B due to the elastic force of the compression coil spring 18 and assumes the state shown in FIG. is moved in the direction of arrow A by the elastic force of
0 exhibits an on state, and at the same time the cylindrical contact 13
is moved in the direction of arrow B, the leaf spring contact 12 is slid relative to the outer circumferential surfaces of the cylindrical contact 13 and the bush 16, and comes into contact with the outer circumference of the bush 16. The contact switch 15 is in an off state. In normal conditions, when the brake pedal is not depressed, the plunger 4 is pushed in against the compression coil spring 18, and the movable contact 9 is pressed by the end surface of the bush 16 against the elastic force of the compression coil spring 11. When separated from the fixed contact 8, the opposing contact switch is in the OFF state, and when the leaf spring contact 12 comes into contact with the cylindrical contact 13, the sliding contact switch 15 is in the ON state. Here, as shown in FIG. 2, the curvature r ₁ of the contact portion 12a of the leaf spring contact 12 with the cylindrical contact 13 is the same curvature as the curved surface r ₂ of the cylindrical contact 13 (r ₁ = r ₂ ). Since they are in line contact, the contact area increases and electrical resistance, that is, heat generation decreases, so that the contact portion 12a of the leaf spring contact 12 will not wear out even if it is repeatedly turned on and off. Therefore, since the switching stroke does not vary, the autodrive release position when the brake pedal is depressed does not vary, so the amount of depression of the brake pedal can be kept constant even after long-term use.

[Effect of idea]

According to the present invention, since the sliding contact portion of the leaf spring contact forming the sliding contact switch of the plunger switch 4 device has the same curvature as the cylindrical contact, the leaf spring and the cylindrical contact are in line contact and the leaf spring contact The wear of the brake pedal is eliminated, the switching stroke of the contact point is kept constant, and the amount of depression of the brake pedal does not increase.

[Brief explanation of drawings]

Figure 1a is a side sectional view showing an embodiment of the present invention, Figure 1b is a front view of Figure 1a, Figure 1c is an enlarged view of section F in Figure 1a, and Figure 2 shows the effects of the present invention. The partially omitted diagrams shown in FIGS. 3a to 3e are partially omitted diagrams showing the prior art. 2... Cylindrical shaft, 3... Case, 4... Plunger, 5, 6... Insulator, 7... Fixed contact, 9... Movable contact, 12...
Leaf spring contact, 13...cylindrical contact.

Claims (1)

[Scope of utility model registration request] a plunger whose one end is reciprocatably supported by a cylindrical shaft fixed to the case; a movable contact and a cylindrical contact attached to the tip of the plunger; A fixed contact that cooperates with a movable contact to form an opposed contact switch, and a leaf spring contact that slides relative to the outer peripheral surface of the cylindrical contact to come into contact with and separate from it to form a sliding contact switch. A plunger switch device comprising: a sliding contact portion of the leaf spring contact; and a sliding contact portion of the leaf spring contact having the same curvature as a curved surface of the cylindrical contact.