RU2777503C1 - Hydraulic closing sensor - Google Patents

Abstract

FIELD: instrumentation.

SUBSTANCE: invention relates to the field of instrumentation, namely to inertial sensors of threshold action, and is designed to close the actuating contacts after the effective acceleration that occurred when encountering an obstacle falls to a value below the threshold. The hydraulic closing sensor contains a sealed housing, an inertial body, a return spring, a check valve, bellows, movable and fixed contacts. The closure occurs due to the linear expansion of the bellows after the termination of the effect of linear acceleration along the sensitivity axis of the sensor under the action of the return spring of the inertial body.

EFFECT: providing a hydraulic safety device with a thermal compensation function.

1 cl, 2 dwg

Description

The invention relates to the field of instrumentation, namely to inertial sensors of threshold action, and is intended for closing the actuating contacts after the drop in the current acceleration that occurred when encountering an obstacle to a value below the threshold.

Known inertial switch designed to break and switch electrical circuits. The inertial switch contains contact pairs placed in the housing and an inertial mass in the form of a cylindrical piston. The housing is made with a central partition located between the inertial mass and the contact pairs. In the cylindrical groove of the partition there is a latch that is in contact with the inertial body and keeps the contact pairs from turning. A choke is installed in the through channel. Patent No. 2221302, IPC H01H 35/14, 01/10/2004.

The disadvantages of this inertial switch, in particular, is that the inertial switch is triggered after unlocking the latch, which occurs due to the movement of the inertial mass on the working stroke after a certain acceleration integral has been set, and can operate until the acceleration action stops, as well as the requirement in the maintenance process to reduce contact system to its original position using external devices.

The objective of the invention is to create a hydraulic closing sensor that is cocked during the action of linear acceleration and is in the cocked state until the acceleration value drops below the threshold value and closes the electrical circuit when triggered due to the linear expansion of the bellows due to excess pressure arising under the action of the return spring when the value drops acceleration below the threshold.

The technical result is the expansion of the arsenal of measuring tools.

The technical result is achieved by the fact that the hydraulic closing sensor contains an inertial body placed in a sealed housing and pressed against a stop by a spring, a check valve that temporarily locks the liquid in the cavity above the inertial body, a movable contact fixed on a bellows - a temperature compensator for changing the volume of liquid, and electrically isolated fixed contact.

The essence of the invention is illustrated by drawings.

In FIG. 1 shows a hydraulic closing sensor in section, where:

1 - sealed housing;

2 - inertial body;

3 - return spring;

4 - check valve;

5 - bellows;

6 - moving contact;

7 - fixed contact;

8 - casing.

In FIG. 2 shows the stages of operation of the hydraulic closing sensor.

The hydraulic closing sensor contains an inertial body 2 located in a sealed housing 1 and spring-loaded by a return spring 3.

A bellows 5 is hermetically mounted on the housing, hydraulically connected to the internal cavity of the sealed housing by a throttling hole. In the inertial body 2, a check valve 4 is installed, which divides the internal cavity of the housing 1 into two, between which the fluid flows.

At the end of the bellows there is a movable contact 6 electrically connected to the body. At a distance A from the movable contact 6, a fixed contact 7 is installed, mounted on the casing 8 and electrically isolated from the housing.

Hydraulic locking device works as follows.

When accelerating, the inertial body 2 is affected by the inertial force F _in (Fig. 2a), equal to

,

,

where m is the mass of the inertial body; a - the value of the current acceleration.

Under the action of force F _in greater force of the return spring F _CR , the inertial body 2 compresses the return spring 3 and displaces the hydraulic fluid from the area under the inertial body. The hydraulic locking device rises to the cocked position (Fig. 2b).

When the acceleration decreases to the acceleration value at which F _pr > F _in , the inertial body 2 under the action of the force F _pr of the return spring 3 begins to return to its original position of the inertial body, while the check valve 4 prevents the free flow of hydraulic fluid, as a result of which the excess hydraulic fluid enters the cavity of bellows 5. Excessive fluid pressure in bellows 5 leads to its linear expansion, and the movable contact 6 moves together with the bellows 5 towards the fixed contact 7. When the contacts are closed, an electrical circuit occurs through the sealed housing 1, the movable contact 6 and the fixed contact 7 mounted on casing 8 and electrically isolated from the casing (Fig. 2c).

The opening and resetting of the hydraulic closing sensor occurs after the excess pressure in the bellows 5 drops and the fluid flows back into the cavity under the inertial body 2 through the open check valve 4 (Fig. 2d).

This sensor arrangement has the following features. Firstly, the closure occurs due to the linear expansion of the bellows due to the fluid flow carried along by the inertial body with the closed check valve under the action of the return spring after the termination of the linear acceleration. Secondly, the bellows is both an actuating and thermal compensating device. Thirdly, the use of special external devices for returning to the initial position during control checks and settings is not required. Fourthly, the setting of the response delay time can be carried out both by changing the gap between the contacts and by changing the throttling hole.

Claims (1)

Hydraulic closing sensor, including a sealed housing filled with hydraulic fluid, a return spring, an inertial body, a check valve, a temperature-compensating element, a contact system; return spring, inertial body and check valve are placed in the inner cavity of the body; the inertial body has a channel for fluid throttling; the check valve is mounted on the inertial body; thermocompensating element is made in the form of a bellows, hydraulically connected with the internal cavity of the housing; the contact system is made in the form of movable and fixed contacts, and the movable contact is fixed on the bellows and is electrically connected to the body, the fixed contact is not electrically connected to the body.

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