SU862259A1 - Thermal relay - Google Patents

Description

(54) THERMORARELLE

one

The invention relates to electrical engineering, namely, thermal relays, based on the use of thermal or volumetric linear expansion of various materials, and is intended for operation in thermal protection and signaling devices, as well as in automatic temperature control devices.

Thermal relays are known in which microcrystalline wax is used as a sensitive element, which at a certain temperature passes into the liquid phase, increasing in volume. The increase in volume is accompanied by an increase in pressure, which is transmitted to the contact system flj.

The disadvantage of this device is a significant response time, as well as the impossibility of controlling the response temperatures.

The closest to the technical essence of the invention is a thermal relay, containing a metal sensor, a sealed body and movable and fixed contacts, placed inside a sealed G23 case.

The disadvantage of this device is the low response time.

 The purpose of the invention is to improve the response speed.

For this purpose, the thermal relay is equipped with a lever, one shoulder of which is located outside the sealed enclosure, and the other inside it, one of the walls of the geometrically designed body is made in the form of a spring diagram rigidly connected to the lever, the metal sensing element is made in the form of a thread fixed

15 on the outer surface of the sealed housing, with the lever arm, located outside the sealed housing, connected to the sensing element, and the lever shoulder, located inside the sealed housing, is connected to a movable contact.

The drawing shows a thermal switch.

The thermostat consists of body 1

25 in which a threaded sleeve 2 is installed with a bushing insulator 3, to the pin of which a fixed contact 4 is attached. In the case 1 a spring diaphragm 5 of the coder is also installed, sealed to the case. A lever is rigidly connected with the diaphragm, one shoulder 6 of which is located on the outer side of the diaphragm, and the other shoulder 1 is the inner one. On the arm 7 of the lever, a contact spring 8 is fixed with a sliding contact 9. A thread 10 is attached to the outer shoulder of the lever b, which, after creating pre-tensioning with the second end, is attached to the rack 11 of the housing.

The adjustment of the gap (pressure) between the contacts 9, 4 and thus the adjustment, the relay to different operation temperatures is carried out by screwing in the bushing insulator 3, after which the threaded connection is sealed. The relay can also be adjusted by adding tension or loosening the thread by moving the rack 11, bending it, or setting an adjusting screw on it.

To increase the transfer ratio: elongation of the thread - moving the contact 4 can be ibpolovano, for example, the contact device in the form of a crank mechanism with a spring hinge.

The relay works as follows.

In the initial state of the relay, the IP filament through the levers 6, 7 is exerted by the tensile force created by the elastic strains in the diaphragm 5 caused earlier by the filament tension. When the ambient temperature rises (decreases), thermal expansion (compression) of the thread 10 occurs, as a result of which the two shoulders rotate relative to the place of its fixation in the diaphragm, leading to re-evaluation of the moving contact 9 to the closing 4 of the scan) with its moving contact 4.

In order for the relay to operate in the thermostatic control mode, the material of the filament 10 must have a large coefficient of thermal linear expansion compared with the material of the body. However, it is often required that the thermal relay reacts to the rate of temperature change. In this case, the thread 10 and the body 1 can be made of materials having identical or similar thermal expansion coefficients. Then the relay contacts 9.4 will be activated only due to the difference in thermal constant heating (cooling) time of the thread 10 and the housing 1, and when a certain steady-state temperature is reached, the contacts 9, 4 will return to their original position.

Due to the fact that the thread 10 has a very small heat capacity and is in direct contact with the environment, the terrellum has a higher response speed. As shown by the result. Investigations of a test sample made in accordance with the proposal, the response time of the relay was reduced to 0, 5 sec, i.e. about 10 times.

Claims (2)

1. The UK patent W 1312399 cl. HI N, 1971. 2.Sotskov B.C. Basics of calculation and design of electromechanical elements of automatic and telemechanical devices, Energie, 1965, p. 277. P