RU121541U1 - COMBINED HYDRAULIC DAMPER - Google Patents

Abstract

A hydraulic damper containing a housing filled with a working fluid and a rod with two pistons located in the housing, characterized in that springs are installed in the housing above and below the pistons, and the upper piston has symmetrical holes, and the lower one is equipped with a central hole and protrusions in the shape of a truncated cone and located under the holes of the upper piston, and a rubber bushing is installed between the pistons.

Description

The proposed damper relates to vibration protection and vibration isolation and can be used in any industry.

Known devices for vibration protection in the form of shock absorbers, for example, a combined spring - rubber shock absorber (see. In the book. "Labor Protection in Construction". Study Guide. Koptev D.V. et al. Edited by D.V. Koptev. M. ICFER. 2007.512 s. Fig. 11.12. P. 171). In such a device, a combination of the elastic properties of the spring and the rubber rod is used, each of which has its own linear characteristic of elasticity: Δ = K * P, where Δ is the strain value, P is the external load, K is the elastic coefficient, different respectively for the spring and for rubber . The disadvantages of such devices are that they have a limited damping range and their inherent disadvantage - they tend to enter the resonance region when the natural frequencies of vibration (spring and rubber, respectively) coincide with the frequency of the external load. This is due to the fact that the elastic properties of the spring and rubber are constant.

Similar disadvantages are combined elastic element (AS No. 1184987, bull. No. 38. 10/15/85) in which a combination of a spring and a bellows.

Known hydraulic damper (AS No. 538173, bull. No. 45. 16.10.78), in which to damp the vibrations used a hydraulic cylinder filled with a working fluid and having several cavities. This device is taken by us as a prototype. The disadvantages of the prototype are as follows. In this device, to change the frequency and amplitude characteristics of the damper, a readjustment is necessary, associated with a change in the distance between the internal partitions. With each readjustment of the damper, its frequency and amplitude characteristics will be different, but also constant.

The readjustment is associated with technological difficulties and involves a preliminary frequency analysis of external disturbing forces.

The purpose of the proposed device is to simplify the design and expand the damping range in a wide range of vibrations.

This goal is achieved in that a hydraulic damper comprising a housing filled with a working fluid and a rod with two pistons located in the housing, characterized in that springs are installed above and below the pistons, moreover, the upper piston has symmetrical holes and the lower one is provided with a central hole and truncated cone protrusions located under the openings of the upper piston, and a rubber sleeve is installed between the pistons.

Figure 1 presents a diagram of a combined hydraulic damper, figure 2 is a diagram of the combined damper.

Here:

1. The housing of the hydraulic cylinder,

2. The bottom spring,

3. The bottom piston,

4. Rubber sleeve,

5. The upper piston,

6. Stock

7. The upper spring,

8. The fluid.

The proposed utility model is a hydraulic cylinder consisting of a housing 1, inside of which there is a liquid 8 and a movable piston 5 with a rod 6. The piston 5 has symmetrical holes B and an upper spring 7 is installed above it. Inside the housing 1, under the upper piston 5 there is a lower piston 3, which has a central hole and protrusions having the shape of a truncated cone and located under the holes of the upper piston 5. A rubber sleeve 4 is installed between the pistons 3 and 5.

The device operates as follows.

When external force acts on the rod 6, the upper piston 5 begins to move in the direction of the lower piston 3, which also moves in the direction of the spring 2, overcoming its elasticity. Liquid 8 from the cavity located under the lower piston 3, through the hole B begins to flow between the piston 5 and the lower piston 3. When a certain pressure of the liquid in the cavity under the lower piston 3 is reached, the piston 3 begins to move up to the piston 5, deforming the rubber sleeve 4 The conical protrusions on the lower piston 3 begin to enter the holes B, blocking the passage sections and increasing the hydraulic resistance. When a certain pressure is reached in the cavity between the upper 5 and lower 3 pistons, the piston 5 begins to move, overcoming the force of the upper spring 7 and the external force acting on the rod 6. When the external force on the rod ceases, the interaction of the forces of the springs 2 and 7, the elastic action additional piston 3 and hydrostatic forces of the fluid in the cavities of the hydraulic cylinder is repeated in reverse order.

The presence in a single device of a combination of several elastic elements: springs, rubber and hydrostatic forces of a fluid with variable characteristics allows damping of vibrations in a wide range of parameters, because springs dampen vibrations with a low frequency, a rubber washer is effective for high frequencies, and the presence of a hydraulic cylinder with variable amplitude-frequency characteristics allows you to effectively perceive vibrations with different forces.

Thus, the proposed device allows, without any readjustment, to damping in a wide range of oscillations.

Figure 2. The operation diagram of the combined hydraulic damper.

The diagram of the damper in figure 2. explains the nature of the interaction of external forces P and the deformation of the elements of the damper. There are 3 characteristic areas of work:

1 zone: P = f (Soot. Piston.)

2 zone: P = f (F rubber + S hole washers)

3 zone: Р = f (Sper. Washers + F springs)

Claims (1)

A hydraulic damper comprising a housing filled with a working fluid and a rod with two pistons located in the housing, characterized in that springs are installed in the housing above and below the pistons, the upper piston having symmetrical holes, and the lower one having a central hole and truncated protrusions cone and located under the holes of the upper piston, and between the pistons a rubber sleeve is installed.