JPS6348029Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact mechanism for electrical contacts such as relays or switches.

Conventional contacts for switchgears such as relays and switches generally have a movable contact in a hemispherical shape and a fixed contact in a flat plate shape, which causes a large amount of welding, transfer, and consumption due to arcing, and also has a poor insulation coating. This tends to occur, increasing contact resistance and adversely affecting the performance of the device. The center of a conventional fixed contact and the center of a movable contact are arranged on the same center line. When a hemispherical movable contact is subjected to a sliding wipe action on a hemispherical fixed contact, the movable contact is likely to get caught on the fixed contact and not be released.

The electrical contact contact mechanism according to the present invention was devised to solve the above-mentioned problems.
Moreover, it is an object of the present invention to solve the above-mentioned problems by forcibly bringing the movable contact point into incomplete alignment with the fixed portion side of the leaf spring.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a relay will be described in detail as an example of a contact mechanism of an electrical contact according to the present invention based on the accompanying drawings.

In the attached drawings, 1 is a normally closed fixed contact;
A contact portion that contacts the movable contact 5a is formed into a hemispherical shape, and is fixed to the contact terminal 2 by welding or crimping. A normally open fixed contact 3 has a hemispherical contact portion that contacts the movable contact 5b, and is welded or crimped to the contact terminal 4. Movable contact 5
a, 5b have contact portions formed in a hemispherical shape, and the centers of the movable contacts 5a, 5b are located at positions higher than the center lines of the normally closed fixed contact 1 and the normally open fixed contact 3, that is, the movable contacts 5a, 5b swing. 5b so as to be forced to be imperfectly aligned with the fulcrum O side. Alternatively, the normally closed fixed contact 1 and the normally open fixed contact 3 may be replaced by the movable contact 5a,
Insert molding is performed by forcing incomplete alignment to the base side below 5b. The distance for the imperfect matching is set longer than the distance for wiping and sliding of the movable contacts 5a and 5b. The leaf spring 6 has movable contacts 5a and 5b fixed to one end, is bent into an L-shape at the other end, and is fixed to the armature 8 via a spacer 7 by crimping with rivets or the like. A leaf spring 6, a spacer 7, which are fixed together with rivets etc.
and armature 8 are formed on the spacer 7,
A notch 10 serving as a fulcrum O of the swinging movable contacts 5a and 5b is brought into contact with a yoke 9, and the spacer 7 is supported by the elasticity of a spring 11. The spring 11 has one end hooked to the upper end of the armature 8 and the other end hooked to the upper end of the yoke 9.
The upper end of the yoke is pulled toward the yoke 9 side. Reference numeral 12 denotes a coil, and by passing a current through the coil 12, a magnetic field is generated in the iron core 13, and the armature 8 is attracted. The coil 12 is connected to the yoke 9 by the iron core 13.
It is swaged and fixed.

The contact mechanism of the electrical contact according to the present invention has the above-mentioned structure, and its operation will be described in detail below.

When no current flows through the coil 12, the armature 8 that moves together with the leaf spring 6 is pulled by the spring 11, so the movable contacts 5a and 5b are located at opposing positions from the fulcrum O.
swings clockwise and is in contact with the normally closed fixed contact 1. The leaf spring 6 is pulled by a spring 11 and has a rotational force around a fulcrum O near the contact part of the yoke 9 and the notch 10 of the spacer 7 which is integrated with the leaf spring 6 by a rivet. Movable contact 5
Since a is in pressure contact with the normally closed fixed contact 1, it is curved. Therefore, the movable contact 5a initially contacts the normally closed fixed contact 1, and the length l ₁ is increased by bending the leaf spring 6 from the position of the movable contact 5a in FIG. 2 where the leaf spring 6 is not curved. After wiping, it remains stationary at the position of the movable contact 5a'.

When current flows through the coil 12, the armature 8 is attracted to the iron core 13. The movable contact 5a is separated from the normally closed fixed contact 1 by sliding wiping from the position of the movable contact 5a' shown in FIG. 2 to the position of the movable contact 5a. Normally closed fixed contact 1,
The movable contacts 5a and 5b are hemispherical in order to improve the durability of the contact portion and to enhance the wiping effect. The center of the movable contact 5a to be wiped is set from the center of the normally closed fixed contact 1,
The movable contact 5a performs a sliding wipe action and is fixed in an imperfectly aligned position upwardly for a longer distance than the sliding distance. When the movable contact 5a wipes the normally closed fixed contact 1, the contact point of the hemispherical movable contact 5a always contacts above the center of the contact portion of the hemispherical normally closed fixed contact 1. Become. When wiping, the movable contact 5a does not slide to a position where the contact point exceeds the apex, which is the center of the contact surface of the normally closed fixed contact 1, so that it is prevented from getting caught on the normally closed fixed contact 1. Smoothly separates from normally closed fixed contact 1. The movable contact 5b swings in an arc having a radius r around the fulcrum O, and comes into contact with the normally closed fixed contact 3 at the position of the movable contact 5b in FIG. The movable contact 5b in contact with the normally open fixed contact 3 is
Coil 12 from the position of movable contact 5b shown in FIG.
When the armature 8 is attracted, the leaf spring 6 curves and slides downward by a length l ₂ and comes to rest at the position of the movable contact 5b'.

When the current to the coil 12 is cut off, the iron core 13
The suction force is removed, and the movable contact 5b is separated from the normally open fixed contact 3 by the spring 11. At this time, the shape of the leaf spring 6 which was curved is restored. Then, the movable contact 5b slides and wipes from the position of the movable contact 5b' in FIG. 2 to the position of the movable contact 5b. The movable contact 5b is
The sliding distance by which the movable contact 5b slides and wipes the apex of the contact surface from the apex of the normally open fixed contact 3.
It is longer than l ₂ and is shifted toward the fulcrum O side above the movable contact 5b. In other words, the movable point contact 5b has a length l ₂
By shifting the movable contact 5b further upward, the movable contact 5b gets over the top of the normally open fixed contact 3, and the movable contact 5b
It is possible to prevent the contact from being caught on the normally open fixed contact 3 and not being released. And the movable contact 5a
The movable contact 5a comes into contact with the normally closed fixed contact 1 as the movable contact 5a swings around the fulcrum O near the abutting portion of the spacer 7 and the iron core 9 in a circular arc with a radius. Imagine that the movable contact 5a in contact with the normally closed fixed contact 1 slides in the direction of length l ₁ from the position of the movable contact 5a shown in FIG. 2 by bending the leaf spring 6 with the elasticity of the spring 11. It comes to rest at the position of the movable contact 5a' indicated by the line.

Although the relay has been described in detail as an example of the contact mechanism of the electrical contact according to the present invention, the same applies to switches having a slide wipe function.

The contact mechanism of the electrical contact according to the present invention has the above-mentioned configuration and operation, and has the following effects.

That is, the center of the contact portion of the movable contacts 5a and 5b is arranged on the leaf spring 6 so as to be imperfectly aligned with the fulcrum O side from the center of the contact portion of the normally closed fixed contact 1 and the normally open fixed contact 3 that are in contact with each other. This makes wiping of the normally closed fixed contact 1 and the normally open fixed contact 3 more effective, and improves the slidability of the movable contacts 5a and 5b. Therefore, the vertices of the movable contacts 5a and 5b climb over the vertices of the normally closed fixed contact 1 and the normally open fixed contact 3, and the movable contacts 5a and 5b catch or weld to the normally closed fixed contact 1 and the normally open fixed contact 3. It is possible to prevent this from happening.

[Brief explanation of drawings]

1 and 2 are drawings showing a contact mechanism of an electrical contact according to the present invention, in which FIG. 1 is a side view of the relay, and FIG. 2 is an enlarged view of section A in FIG. 1. 1... Normally closed fixed contact, 2, 4... Contact terminal, 3... Normally open fixed contact, 5a, 5a', 5b, 5
b'...Movable contact, 6...Leaf spring.

Claims (1)

[Scope of utility model registration request] A leaf spring whose one end is fixed to a swingable armature, a movable contact which is fixed to the other end of the leaf spring and has a hemispherical wiping contact part, and a contact part which comes into contact with the movable contact. A hemispherical fixed contact,
A switchgear having a fixed contact and a contact terminal fixed to a pole plate, characterized in that the movable contact is shifted from the apex of the contact surface of the fixed contact to the fulcrum side of the movable contact. Contact mechanism of electrical contacts.