SU1518576A1 - Locking device - Google Patents

Abstract

The invention relates to mechanical engineering, in particular to the connection of machine parts. The purpose of the invention is to increase the reliability of the locking device. In the tangential opening of the housing 1, a locking mechanism is arranged, consisting of a rod 2, pressure screws 3 and pins 4 of a material with a shape memory effect. The rod is made with a cylindrical recess and thread on it. After assembly, when the device heats up to the operating temperature, the pins lengthen and deform the rod, ensuring constant contact with the male part. This allows to ensure reliable operation of the device both at high (up to 250 ° C) and at low temperatures up to (-196 ° C). 2 hp f-ly, 2 ill.

Description

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; The invention relates to machine building (construction and it can be used with 1 joint of machine parts and an ijiHSMOB mechanism as a friction locking joint operating both at elevated and at lower temperatures.

The aim of the invention is to increase the reliability of the locking during operation in a given temperature range.

Figure 1 shows the proposed locking device; Fig. 2 -:; the locking mechanism idler before settling.

The locking device contains a corolic 1, which can be made with a threaded axial bore and a last tangential cross-cutting bore that has a locking mechanism in the form of a rod 2 with deaf axial nests at the ends placed in the middle part of the aperture and installed | at the outlet of the hole of the pressure wines- .JTOB 3, in which the response 1 deaf axial sockets. Pins 4 of a material with a shape memory effect are installed between the interconnected ends of the rod 2 and the clamp screws 3. The rod 2 is made in the middle part with a notch whose radius is equal to the radius of the axial bore. If the axial bore of the housing is threaded, then a thread is made at the recess, which is a continuation of the thread of the axial hole in the housing 1, the rod is made with two annular necks in the radius of the notch area and with cuts on the cylindrical part. The modulus of elasticity of the material of the pins is greater than the modulus of elasticity of the material of the rod, but less than the modulus of elasticity of the material of the pressure screws.

In the housing 1, additional tangential holes can be made, each of which has a locking mechanism similar to that described.

The device works as follows. .

The assembly on the shaft or the threaded stubble of the housing 1 in the assembly with parts 2-4 is carried out, for example, at a temperature of 20 ° C.

The pins 4, before assembling, move deformations to the memory, i.e. training on the calculated value

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linear deformation at working temperature. For example, the initial billet under the pins is subjected to stretching by 20% at 60 ° C, then the billet is deposited by 20% at 20 ° C (i.e., returned to the initial position). After several cycles of training, the material nitinol remembers the form and is able to perform over a million cycles, developing a specific pressure of up to 70 kN / cm.

The device is locked by heating the case 1 to 60 ° C, while the pins 4 do work against external forces, move relative to the ends of the screws 3 and plastically deform - the middle part of the rod 2. Both pins work towards each other. Due to the movement of the ends of the rod 2 and under the action of its plastic deformation, the shaft is locked against the housing 1. The friction forces between the stopper and the locking parts are supported by axial force from the side of the pins when a residual deformation, vibration, and pulsation of the joint appear.

In order to ensure an increased force in the locking zone, the body is cooled to 20 ° C. The pins 4 return to their original condition (take a length equal to the original workpiece), after which they turn back the screws 3 until they stop at the end of the pin and heat up again. The pins re-run and, if the joint is operated at a given temperature, it is resiliently maintained at a constant pressure.

The locking device can work under any conditions in the temperature range of nitinol operation from +250 to -196 C, while the pins can work once or twice, followed by tightening the screws (sampling the gap between the screw and the pin). However, better results are achieved if the device operates at a constant temperature equal to the temperature under operating conditions, thus achieving greater reliability of the device. .

Tangential holes in the housing can be located in mutually parallel planes, contain three holes at an angle of 120 ° in different planes, etc. In addition, the middle part of the rod can be made of a material with

friction properties, such as metal ceramics.

The proposed design solution allows to increase the reliability of the locking device when it is operated under conditions of both high (up to 250 ° C) and low (up to -196 ° C) temperatures, ensuring the stability of frictional contact with the male part.

Claims (3)

1. A locking device comprising a housing with an axial bore and a tangential bore intersecting the latter, in which a locking mechanism is installed in the form of a rod located in the middle part of the tangential bore, and a pressure screw installed at its outlet with a blind axial socket on the side of the rod,. so that, in order to increase the reliability of locking during operation in a given temperature range, the locking mechanism is equipped with an additional pressure screw with a deaf axial nest and two pin mi of a material with memory effect 0 five 0 five 0 the tangential hole is made through, the additional screw is placed on the side of the second exit of the tangential hole, the rod in the middle part is made with a notch with a radius equal to the radius of the axial hole, two annular necks in the area of the notch and blind axial sockets on the ends, each pin installed between the interacting ends of the rod and pressure screws with the location of the end sections in the axial nests of the latter, and the elastic modulus of the pin material is greater than the elastic modulus of the rod material But less than the elastic modulus of the pressure screw material. 2, the device according to claim 1, about tl, which is due to the fact that in the case additional tangential holes are made, in each of which there is a locking mechanism identical to the similar mechanism placed in the first hole. 3. The device according to claim 1, characterized in that the middle part of the rod is made of a material. la with frictional properties, such as metal ceramics.