JPS5856443B2 - Contact drive device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a contact 1 drive device using a magnet.

Conventionally, as shown in FIG. 1, a contact drive device for this type of switch that opens and closes contacts has a coil spring 3 mounted around a drive rod 2 that is slidable in the axial direction and is provided in a housing 1 made of a molded product. When the force f is applied from the outside against the spring force of the coil spring 3 and the drive rate 2 is pushed downward, the movable contact 4 contacts the fixed contact 5, and when the force f is released, the spring force of the coil spring 3 is applied. The drive rod 2 is returned upward and the contacts are opened.

However, in this structure, the component coil spring 3
Due to variations in the dimensions of the door, there was a drawback that the driving force when driving the contacts varied depending on the individual contacts and door drive devices.

When assembling the rod, the coil spring 3 is arranged on the drive rod 2 and then inserted into the housing 1, which makes it difficult to automate the assembly work.

The present invention improves the above-mentioned drawbacks and uses magnetic energy to
The object of the present invention is to provide a contact point and a drive device using a magnet, which allows the drive rod to return automatically and is easy to assemble.

Hereinafter, the present invention will be explained along with the drawings.

FIG. 2 shows an embodiment of the present invention, in which 1
Reference numeral 1 denotes a housing made of a molded article made of an insulating material such as synthetic resin, and has a longitudinal hole 12 formed from the top to the bottom, and a cavity 13 communicating with the hole 12 at the bottom. Fixed terminals 14 are provided in this empty space 13, the ends of which are exposed to the outside from both sides of the lower part of the housing 11,
A fixed contact 15 is fixedly provided at the opposite end of the fixed terminal 140, respectively.

Reference numeral 16 denotes a long, approximately cylindrical long drive rod that is slidably disposed within the hole 12 of the housing 11, and an N pole is magnetized on one side approximately in the center of the drive rod 16. , and a permanent magnet 17 magnetized with an S pole is provided on the other side, and a push button 16a having a smaller diameter than the body projecting outward from the top surface of the housing 11 is integrally provided at the upper end, and A movable terminal 18 is provided at the lower end and extends horizontally from both sides with respect to the length direction of one drive rod 16.
A movable contact 19 that faces the fixed contact 15 and can be moved toward and away from the fixed contact 15 is fixedly provided at each end of the movable contact 19 .

Therefore, substantially in the center of the hole 12 formed in the housing 11, magnetic bodies 20 are provided on the left and right sides to face the magnetic poles of the permanent magnet 17 provided on the drive rod 16 and constitute a magnetic circuit. They are arranged on the inner wall of the hole 12 so as to face each other via the rod 16.

This magnetic body 20 has an extension piece 20a at the fixed contact 151.
is hanging down.

Of course, the left and right magnetic bodies 20 may be formed by bending a single magnetic plate into a U-shape.

Next, the present invention will be explained in detail.

FIG. 4 shows the operating principle of the present invention, and shows the permanent magnet 17.
When the permanent magnet 17 is shifted downward from the magnetic body 20 as shown in Figure A, the magnetic flux flowing from the N pole to the S pole is uniform as shown by the arrow. Parts are leaking into the air and are in an unstable condition.

However, the magnetic flux emitted into the air is caused by the magnetic material 20 placed nearby.
Since the permanent magnet 17 moves in the A direction due to the so-called attractive force, the permanent magnet 17 faces the magnetic body 20 in alignment with the magnetic body 20, and the magnetic energy is minimized. It will be in a stable state.

Therefore, 1. When no external force f is applied to the drive rod 16, the permanent magnet 17 moves upward so as to align with and face the magnetic body 20, as shown in FIG.
In this case, the shoulders that act as stoppers at the base of the pushbutton 16a come into contact with the inner wall surface of the upper part of the housing 11, so the upward movement of the drive rod 16 is inhibited, and the relationship between the permanent magnet 17 and the magnetic body 20 is not as shown in the figure. The permanent magnet 17 is held in a slightly downwardly shifted state.

Therefore, the push button 16a protruding from the top surface of the housing 11
When an external force f that overcomes the magnetic force is applied to push down the drive rod 16, the drive rod 16 moves downward and the movable contact 19 comes into contact with the fixed contact 15, closing the contact, as shown in the opening of the figure.

When the external force f is released, the first drive rod 16 returns to itself due to magnetic energy, as shown in FIG.

In this case, when looking at the arcs of both the movable and fixed contacts 15 and 19, the arc, the extension piece 20a, and the magnetic flux are perpendicular to each other, as shown in FIG. 6A.

Therefore, the arc expands as shown at the mouth, and is cooled and extinguished.

As described above, according to the present invention, a permanent magnet is disposed on the drive rod that opens and closes the contact, and the magnetic energy is used to self-return, so the contact and driving force are stabilized. .

In addition, there is no need to install a coil spring on the drive rod before assembling the drive rod into the housing as in the conventional case.
Not only can assembly be automated, but the arc is extended by the extension piece 20a of the magnetic body 20, and arc extinguishing performance is improved by cooling.

In addition, in the above explanation, the contact is a contact (normally open contact).
Although the case has been described, it is also possible to apply the present invention to the case of a b contact and a transfer contact.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional contact 1 drive device, Fig. 2 is a sectional view showing an embodiment of the present invention, Fig. 3 is a perspective view of a magnetic material used in the present invention, and Fig. 4 Detailed explanatory diagrams of the present invention, Figures 5A to 5C are operation explanatory diagrams of the present invention, Figure 6A2
The opening is an explanatory diagram of arc extinguishing. 11... Housing, 12... Hole, 13... Vacant room, 14
... Fixed terminal, 15... Fixed contact, 16... Drive rod, 17... Permanent magnet, 18... Movable terminal, 19...
...Movable contact, 20...Magnetic material, 20a...Extension piece.

Claims (1)

[Claims] 1. A push button is provided at the upper end in the hole formed in the housing,
and a drive rod having a movable contact that can come into contact with and separate from a fixed contact provided in the housing is slidably provided at the lower end,
A contact 1 drive device, characterized in that a permanent magnet is provided approximately at the center of the drive rod, and a magnetic body is provided on the inner wall of the hole, facing the permanent magnet and extending through a fixed contact arm.