SU547575A1 - Dry friction damper - Google Patents

Description

one

The invention relates to devices for damping oscillations of heavy equipment and can be used in any branch of mechanical engineering.

Known dampers dry friction, containing plates pressed against one another by a pressure device made in the form of a spring ij.

In known dampers, it is impossible to limit the resonant amplitudes if the amplitude of the disturbing force in TC / 4 times the dry friction force in the damper, the depreciation in the resonance region is unsatisfactory with the same amount of dry friction force as in the resonance region, besides, as in the region the resonance and in the resonance region all high-frequency oscillations and disturbances are transmitted to the depreciable object, the amplitude of which is less than the strength of the dry friction force.

Closest to the invention is a dry friction damper, which contains plates pressed against one another, a pressure device for compressing the plates and a control unit that changes the force of dry friction depending on the oscillation frequency of the object and measures it with a recorder.

In this damper, the pressure device is made in the form of an electromagnet and it is impractical to use it to absorb objects with large masses, when the frequency of the disturbing force changes quickly enough. Firstly, a large electromagnet is needed to create the necessary damping force, and secondly, the high TOKai force and alternating voltage cause the coil to become strongly heated so that the service life of this damper is reduced, which makes it difficult to operate.

The purpose of the invention is to expand the scope.

This is achieved by the fact that in the proposed damper the pressure device is made in the form of a power cylinder with two pistons and a spring between them; the control unit is equipped with an electromagnetic valve, and with the help of the latter and the recorder, it is connected to the cavity between the two pistons of the cylinder

Claims (2)

FIG. 1 shows the described damper, general view; in fig. 2 - the pressure device, top view. The damping mass 1 is connected to the base 2 by an elastic element 3 and dry friction dampers containing plates 4, which are mounted in guides 5 fixed in stacks 6. The pressing device is made in the form of a hydraulic or pneumatic cylinder 7 having two spring-connected 8 pistons 9, 10 with rods 11 and a working cavity 12, which through pipe 13 and an electromagnetic valve 14 communicates with a pressure source. The electromagnetic valve is controlled by the structure changing unit 15, using information about the magnitude of the disturbing force frequency, which is measured by the recorder 16, set by HbiM on the base 2. The dry friction force value is changed by the return spring 8 and the hydraulic or pneumatic cylinder 7, the pressure in the working cavity of which is supplied in accordance with the commands of the unit for changing the line. In the resonance region, when the frequency of natural oscillations coincides with the frequency of the disturbing force, the frequency is measured by the recorder 16 and enters the structure changing unit. The structure changing unit 15, after processing the signal, sends a command to open the solenoid valve, and gas or liquid is pushed into the working cavity 12 of the hydraulic or pneumatic cylinder 7 and the pistons 9, 1O are pulled apart. In this case, the plates 4 connected to it are pressed against the plates 17, the damping force exceeds the resonant disturbing force and the object and the base move without relative displacements, and, consequently, the dynamic loads in the resonance region decrease. Thus, the first structure of the system is realized. When oscillations of a depreciable object with an amplitude smaller than that of the base, the device, based on information received from the recorder 16, closes the electromagnetic valve 14, the working cavity 12 of the hydraulic or pneumatic cylinder 7 communicates with the tank or the atmosphere (respectively), the return spring 8 It bends the plates 4 from the plates 17. Thus, the damping force of the dry friction is completely eliminated, since in the resonance region there is no need for damping vibrations. The damper becomes an ordinary shock absorber. This is how the second system structure is implemented. When the frequency of the disturbing one changes in the direction of decreasing, the switching of the electromagnetic valve occurs in the reverse order. The use of a hydraulic or pneumatic expansion cylinder as a pressure device instead of an electromagnet makes it possible to use it in vibro-shielding systems for cushioning large mass objects. The control of forced oscillations of a depreciable object according to the principle of systems with a variable structure makes it possible to simplify the control unit, which ensures efficiency, ease of maintenance, and reliability during operation of the proposed damper. DETAILED DESCRIPTION A dry friction damper comprising pressing one against another plate, a pressure device for compressing the plates and a control unit that changes the strength of the dry friction depending on the oscillation frequency of the object and is measured by the recorder, which is application areas, the pressure device is made in the form of a power cylinder with two pistons and a spring between them, and the control unit is equipped with a solenoid valve and is connected to the cavity with this valve and recorder located between two pistons of the cylinder. Sources of information taken into account in the examination: 1. USSR author's certificate number 311068, M. T 7/08, 1970 2. USSR author's certificate number 329338, M.Kl. F 16 T 15/03, 1970 (prototype). f. Compressor .2.