SU388311A1 - TERMINAL - Google Patents

Description

The invention relates to the control and management elements and can be used in various electrical installations to control the movement of objects.

Limit switches on magnetically controlled contact with a moving permanent magnet with pole pieces made of magnetically soft material are known.

A disadvantage of the known limit switches is that the closing and opening of the contact is determined not only by the location of the magnet and the contact relative to each other, but also by a number of parameters of the magnet and the contact, which can vary within wide limits.

The proposed limit switch does not have this disadvantage. This is achieved by the fact that the pole pieces encompass a glass contact cylinder.

Pa figs. 1 shows the proposed switch; in fig. 2 is a graph of the magnitude of the magnetic flux in the contact plates when the magnetic contact moves with respect to the permanent magnet; on fng. 3 - the path of the magnetic flux in the proposed device prn closed contact; in fig. 4 - the same, with the contact open; in fig. 5-diagram of the contact operation in the proposed switch when the magnet moves relative to the magnetically controlled contact.

The proposed limit switch consists of a rod permanent magnet /, a magnetically controlled contact 2 and pole pieces of magnetically soft steel 3, covering the contact cylinder and fixedly connected to the magnet.

The parameters of a permanent magnet are determined by the fact that the magnetic flux created by it, which closes through the pole tips and contact plates, must be 2 to 3 times greater than the value of the flow of response that is sufficient to close the contact with the nominal value of the pickups.

In order to reduce the flow of dissipated magnet closing through the contact plates of the magnetically controlled contact, the distance h between the magnet and the contact plates must be much larger than the radius r of the hole in the pole pole;

 О / Reduction to a certain limit of the thickness of the pole tips improves the accuracy of the limit switch. The limit of reduction of the tip thickness is determined by an increase in the magnetic flux buckling at the point of its transition from the pole to the contact plate.

The limit switch works as follows.

A permanent magnet / with pole lugs 3 is mounted on a controlled object and is displaced relative to a fixedly installed magnetically controlled contact 2. Suppose, in the initial position, the magnet 1 is so located relative to pin 2 that the magnetic note is closed through the pole pieces 3 and both contact plates (Fig 3) and contact 2 is closed. When the permanent magnet / with pole tips 3 is displaced along the magnetically adjustable contact 2, the state of the latter does not change until one of the poles has located the contact point (Fig. 4).

After that, the magnetic flux closes the pole tips 3 and one contact; 0 plate, and the contact opens. The further movement of the magnet / in the same direction does not change the state of the magnetically controlled contact 2 - its state is uniquely determined by the position of the magnet 1. When the magnet moves / in the opposite direction, the contact will open until one pole again reaches the contact point and will then be closed until the point of contact is reached by the second zero. The contact closure diagram is shown in FIG. five.

Subject invention

A limit switch on a magnetically controlled contact consisting of a magnetically controlled contact and a movable permanent magnet equipped with pole pieces of a magnet of a soft material, which differs ----- - p T, n..o -. a permanent magnet and a magnetically controlled contact for the accuracy of the limit switch, pole lugs cover the cylinder of a magnetically adjustable contact.

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