JPH0544775A - Vibration control device for equipment - Google Patents

Abstract

PURPOSE:To provide a vibration control device for equipment that can reduce a vibration at the time of starting without lowering a vibration control effect at steady driving. CONSTITUTION:Two rubber vibration isolators 4A, 4B installed in space between a vibration source apparatus 1 and its installing part 3 are made so as to be heated over operation of the apparatus. With the heating, at the starting by a cold state, a vibration of low frequency is reduced, and at steady driving becoming a hot state, a vibration of high frequency is reduced, thus a vibration control device made up of ameliorating the extent of vibration control over both cases of starting and during operation is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for equipment,
In particular, the present invention relates to a vibration damping device in which a vibration damping rubber is interposed between a device that constitutes a vibration source and its installation portion.

[0002]

2. Description of the Related Art In a device having an eccentric rotating body such as a compressor used in a refrigerator of a showcase, an anti-vibration rubber is interposed between the device and its installation portion. Vibration is reduced. In setting the characteristics of the anti-vibration rubber, in general, the spring constant K of the anti-vibration system including the anti-vibration rubber is set to be small, and the natural frequency (resonance ) The number ω _n is made sufficiently small to increase the vibration reduction effect. On the other hand, the smaller the damping rate C due to the viscosity of the rubber is, the more the vibration at low speed operation close to ω _n is increased, but the vibration at steady operation becomes small.

Therefore, in general, in order to reduce the vibration during the steady operation, the spring constant K is relatively small with respect to the vibration generated at a low speed at the start-up, at the expense of the vibration damping effect. A soft rubber with a small damping factor C is used.

[0004]

However, in the case of using the anti-vibration rubber as described above, the anti-vibration at the time of steady operation is sufficiently effective, but since the vibration is large at the time of starting, the vibration is great at the time of starting. There was a problem that the vibration was temporarily increased and the pipe connection was damaged, and noise was generated. This vibration is significantly larger than the vibration during steady operation.

An object of the present invention is to provide an antivibration device for equipment which is capable of reducing vibration at startup without degrading the antivibration effect during steady operation.

[0006]

In order to solve the above-mentioned problems, the present invention reduces the vibration of a device by interposing a vibration-proof rubber between the device forming a forced vibration source and its installation part. In a vibration isolator of a device, a heating part that is heated during the operation of the device is attached to a vibration isolating rubber so as to be able to conduct heat.

[0007]

According to the present invention, the spring constant and the damping rate are set so that when the vibration damping rubber reaches a high temperature due to the steady operation, a predetermined reduction is performed against the forced vibration due to the steady operation. Then, according to these set values, there is a natural frequency having a relatively high amplitude corresponding to a relatively low predetermined forced frequency. When the device stops, returns to room temperature, and then starts up again, the spring constant becomes large and the natural frequency becomes large. Then, the attenuation rate becomes large and the above amplitude becomes small. Therefore, the amplitude does not increase so much even if the forced vibration acts at the time of startup. Immediately after this startup, the spring constant and damping rate are higher than at high temperatures,
Although the vibration due to the steady operation becomes large, when the temperature becomes high due to the heating during the operation, a predetermined reduction by the previously set constant is performed thereafter.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a vibration isolator for equipment showing a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a rotary type compressor used in a showcase refrigerator, which has an eccentric rotating body (not shown) and constitutes a forced vibration source having a rotational frequency ω. 2A and 2B are legs of the compressor 1, and 3 is an underframe on which the compressor 1 is installed.

Reference numerals 4A and 4B denote anti-vibration rubbers made of heat-resistant synthetic rubber, which are attached between the leg portions 2A or 2B and the underframe 3. Generally, the rubber has a property that the synthetic spring constant K and the damping rate C decrease as the temperature rises, but in this case, the rubber having such a tendency is used. Then, in the vibration system including these when the anti-vibration rubbers 4A and 4B reach a predetermined high temperature, the forced vibration of the frequency ω is effectively damped particularly at the frequency ω _a of the steady operation. , Its shape and respective values K and C are set. FIG. 2 is a characteristic diagram showing the vibration damping effect of the vibration damping rubber. In the figure, the horizontal axis represents the frequency ω, and the vertical axis represents the static deflection P _o / K of the vibration-proof rubbers 4A and 4B when the compressor 1 is stopped.
The ratio α between (P _o is the amplitude of the forcing force) and the amplitude A of the dynamic deflection
= A / (P _o / K). When the spring constant K is determined, the natural frequency ω _{n of the} vibration system is calculated according to the theory of forced vibration.
Is determined in proportion to K ^1/2 . Natural frequency ω at this high temperature
For example, _nH is set to be about ½ of the frequency ω _a . When the damping rate C is determined, the amplitude at the frequency ω _n is C
Increases and decreases in inverse proportion to. FIG. 2 shows the characteristic α _H at high temperature and the characteristic α _L at low temperature. In the figure, α _Ha is the expected magnification during steady operation, and ω _nL is the natural frequency at low temperature. The maximum amplitude appears near the frequency ω _n , and the increasing / decreasing tendency of this maximum amplitude with respect to C is significantly steeper than the previous increasing / decreasing tendency at the frequency ω _n . As shown in the figure, when the temperature drops, the frequency ω _n increases and the characteristic of the magnification α becomes gentle.

Reference numeral 5 is a suction pipe in which the compressor 1 receives a low temperature refrigerant, and 6 is a discharge pipe in which a high temperature refrigerant is discharged from the compressor. The discharge pipe 6 is a heating unit 7A, 7B in which the vibration proof rubber is wrapped around the rubber 4A, 4B several times in its path.
To form the vibration-proof rubbers 4A, 4B from the heating portions 7A, 7B.
The heat-damping rubbers 4A, 4B are heated during the operation of the compressor 1 so that heat can be effectively conducted.

With the above structure, the vibration-proof rubbers 4A, 4B
Is at room temperature and the characteristic is indicated by the characteristic at low temperature α _L. At this time, when the compressor 1 is started, the rotating body is accelerated due to the relationship between the starting torque and the inertia of the rotating body. The frequency ω shifts from 0 to ω _a . At the beginning of the heating process, the characteristic α _L rises more slowly than the characteristic α _H at high temperature, so that there are relatively few low-frequency vibrations, and the characteristic frequency ω _nL is relatively high due to acceleration in a short time. To pass in a short time. Then, for the frequency ω _a immediately after the start-up, the magnification α is larger than the expected magnification α _{Ha and} the amplitude of the vibration is larger than the expected value. The anti-vibration rubbers 4A and 4B are heated by the heating unit 7 as the compressor 1 is continuously operated.
When heated by A and 7B, the temperature rises, for example, by about 50 ° C.
This characteristic is represented by the characteristic α _H at high temperature. Therefore, the amplitude becomes the expected value after the magnification shifts to α _Ha .

After that, when the operation of the compressor 1 is stopped,
The temperature of the anti-vibration rubber 4A, 4B drops. Since the compressor 1 generally has a rest period of several tens of minutes or more in the operation cycle, the compressor 1 is returned to the normal temperature by the next start-up and the same start-up and operation as before are performed.

FIG. 3 is a perspective view of a vibration isolator for equipment showing a second embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals, and different parts will be described below.

Numerals 8A and 8B are heating portions composed of heaters, which are arranged so as to wrap around the antivibration rubbers 4A and 4B, and are separately energized during the operation of the compressor 1, and the current is cut off when the operation is stopped. It The anti-vibration rubber 4 is applied by the energization.
For example, A and 4B are raised by about 50 ° C.

In this embodiment, the heaters 8A, 8B
Is energized during the operation of the compressor 1, and the vibration isolating operation is performed as in FIG.

[0017]

As described above, according to the present invention, the anti-vibration rubber provided between the equipment of the vibration source and the installation portion thereof is heated during the operation of the equipment. Occasionally, low-frequency vibrations are reduced, and during high-temperature steady-state operation, steady high-frequency vibrations are reduced, resulting in an anti-vibration device that improves both start-up and running vibrations. Be done.

[Brief description of drawings]

FIG. 1 is a perspective view of a vibration isolator for equipment showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the vibration-proof performance of the vibration-proof rubber.

FIG. 3 is a perspective view of a vibration isolator for equipment showing a second embodiment of the present invention.

[Explanation of symbols]

1 ... Compressor, 3 ... Underframe, 4A, 4B ... Anti-vibration rubber, 6 ... Discharge pipe, 7A, 7B, 8A, 8B ... Heating part.

Claims (1)

[Claims] 1. A vibration isolator for a device, wherein a vibration proof rubber is interposed between a device forming a forced vibration source and its installation part to reduce vibration of the device, and heating is performed during operation of the device. A vibration isolator for equipment, characterized in that the part is attached to the anti-vibration rubber so as to be able to conduct heat.