JPH06154480A - Vibration isolating device of automatic washing machine - Google Patents

Abstract

PURPOSE:To provide a vibration isolating device for automatic washing machine which accomplishes a great reduction of vibration at starting and also vibrations of the body of washing machine during steady rotation for spin drying. CONSTITUTION:A vibration isolating device for an automatic washing machine is equipped with an outer trough 13, which receives water at the time of spin drying from a washing drying basket 16, and suspensions 18a-18d which resiliently supports the outer trough from the four corners of the body 19 of washing machine, wherein the outer trough is fitted with a vibration absorber 21 whose natural frequency is approx. identical to the frequency of at least in one direction vibration of the machine body and the outer trough.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device used in a household automatic washing machine.

[0002]

2. Description of the Related Art Conventionally, this type of automatic washing machine is shown in FIGS.
The structure is as shown in. That is, an outer tub 3 for receiving water at the time of dehydration is provided outside the washing / dehydrating tub 1, and a stirring blade 6 and a drive motor 4 for the washing / dehydrating tub 1 are attached to the outer tub 3. . The outer tub 3 is suspended from the washing machine main body 2 via a suspension 5 to prevent the washing and dehydrating tub 1 from vibrating.
A fluid balancer 1a containing a liquid is fixed to the upper portion of the washing / dehydrating tank 1. Furthermore, on the outer periphery of the outer tank 3,
A lateral attenuator 7 is provided around which two friction bands are wound. Both ends of each of the friction bands forming the attenuator 7 are attached to the washing machine main body 2 via elastic bodies 8 formed by bending a wire rod. Further, the friction band is provided with a coil spring 9 near the middle thereof so that it can be expanded and contracted. In FIG. 7, reference numeral 10 denotes a round bar spring made of metal, which is an elastic body, and is attached in a suspended state near the point where the attenuator 7 and the elastic body 8 are connected. A vibration absorber 12 which is a vibrating body composed of the round bar spring 10 and the mass body 11 is attached to a point connecting the elastic body 8 and the attenuator 7. The resonance frequency f of the vibration absorber 12 is set to be substantially equal to the number of revolutions per second when the washing / dehydrating tub 1 is stationary. With the above configuration, water supply, washing, drainage, and centrifugal dehydration were automatically performed.

[0003]

In the conventional automatic washing machine having the above-mentioned structure, the unbalanced vibration during the dehydration process is not so much transmitted to the washing machine body 2 by the action of the suspension 5. However, during dehydration start-up, the outer tub 3 swings largely when passing through the resonance frequency of the anti-vibration support system, and in the worst case, the outer tub 3 may hit the washing machine body 2. In order to minimize the whirling at the time of this resonance,
The attenuator 7 is installed in the outer tub 3. That is,
When the outer tub 3 swings largely, the friction band forming the attenuator 7 and the outer tub 3 rub, and the whirling of the outer tub 3 is suppressed by the friction loss generated at this time. In the steady state, a part of the force swinging around the outer tub 3 is transmitted to the elastic body 8 via the attenuator 7 of the friction band and vibrates the elastic body 8. At this time, since the elastic body 8 is attached with the vibration absorber 12 having a resonance frequency equal to the steady-state rotational speed per second, in the steady state, the vibration absorber 12 vibrates largely and the vibration of the elastic body 8 is small. It will be.

However, this structure has a problem in that the number of parts is large and the structure is complicated because measures against vibration at the time of starting and at the time of steady rotation of dehydration are separately taken.

Therefore, the present invention solves the problems of the above-mentioned conventional structure, and significantly reduces both the vibration at the time of start-up and the vibration of the washing machine body at the time of steady rotation of the dehydration, and at a low cost. The purpose of the present invention is to obtain an anti-vibration device for a low-weight automatic washing machine.

[0006]

Means for achieving this object are: an outer tub located outside the washing / dehydrating tub for receiving water during dehydration, and the outer tub being elastic from four corners of the washing machine body. A vibration absorber having a mass body and a spring element is attached to the bottom portion or wall surface portion of the outer tub with supporting suspension, and the resonance frequency of the vibration absorber is at least the frequency of vibration at startup and during steady rotation of dehydration. This is an anti-vibration device for an automatic washing machine configured so as to be substantially the same in one direction.

[0007]

The present invention operates as follows. When centrifugally dehydrating, a large vibration is generated due to an imbalance caused by uneven displacement of clothes. At start-up, the vibration amplitude becomes maximum when passing through resonance, but by setting the resonance frequency of the mass body mounted in the outer tub and the vibration absorber with the spring element to be approximately equal to this vibration direction and frequency, the vibration absorber operates. The vibration of the outer tank can be greatly reduced. During steady operation of the dehydration tank, the vibration absorber acts to significantly reduce the vibration of the outer tank by setting the resonance frequency of the vibration absorber to be approximately equal to the direction and frequency of vibration of the outer tank. is there.

As a result, the transmission of vibration to the main body of the washing machine can be greatly reduced, and the vibration of the main body of the washing machine can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. An outer tub 13 for receiving water at the time of dehydration is provided outside the washing / dehydrating tub 16. This outer tank 13
At the bottom of the, is a speed reducer 14 connected to the motor 15 by a belt.
Is stuck. The drive shaft of the speed reducer 14 has a double structure, and the washing and dehydrating tub 16 is fixed to the outer shaft. A stirring blade 17 positioned inside the washing / dehydrating tank 16 is fixed to the inner shaft. The outer tub 13 is a washing machine body 19
The vibration-proofing is supported from the four corners of the suspension via suspensions 18a to 18d. Further, a vibration absorber 21 configured so that the vibration frequency of the vibration of the washing machine main body 16 and the outer tub 13 in at least one direction and the natural vibration frequency are substantially equal to each other is attached to the bottom surface portion or the outer wall portion of the outer tub 13. The vibration absorber 21 is
It is composed of a mass body 22, a rubber spring 23, and a fixing bracket 24, and is attached to the outer tub 13 by a mounting bolt 25.

At this time, the rubber spring 23 which is a spring element
May be a spring system such as a coil spring, a leaf spring, or an air spring. However, in this case a suitable damping element must be provided. In addition, in FIG. 1, W has shown the cloth imbalance.

The situation of the vibration amplitude of the outer tub 13 having the above structure will be described with reference to FIGS. In FIG. 3, the vertical axis is the outer tank 13
The amplitude Dx in the front-back direction is shown, and the horizontal axis shows the frequency f of the vibration. In FIG. 4, the vertical axis shows the vertical amplitude Dz of the outer tub 13, and the horizontal axis shows the vibration frequency f. In FIG. 5, the vertical axis shows the amplitude Dy of the outer tub 13 in the left-right direction, and the horizontal axis shows the vibration frequency f. The frequency f of vibration gradually increases from the origin 0 with the start of the dehydration operation, and reaches the frequency ft at the time of steady dehydration rotation. The frequency f on the horizontal axis does not necessarily have to be the frequency but may be the angular frequency w. The frequency f is the unbalance of the washing / dehydrating tub 16 and the forced frequency generated from the vibrating portion of the motor 15 and the like. Also, the outer tank 1
3, the components such as the main body 19 have respective natural frequencies Fn as a vibration system.

A case where the vibration absorber 21 is not attached will be described. When the frequency f matches or approaches the natural frequency Fn in the process from 0 to ft, the vibration is greatly amplified and becomes large. This situation is shown in Figure 3 and Figure 4.
-The solid line is shown in FIG. In FIGS. 3 and 5, at the point where the frequency f coincides with the horizontal natural vibration frequency F ₁ of the outer tub 13, the amplitudes P ₁ and P ₃ are large. Further, as shown in FIG. 4, the frequency f rises and the outer tank 13
At the point P ₂ that coincides with the natural frequency F _{2 in} the vertical direction of, the frequency f vibrates violently, and the amplitude P ₂ is also large. Further, the frequency f rises to reach the frequency ft at the time of steady rotation of dehydration. This frequency ft may not match the natural frequency F of the outer tub 13, but the vibration amplitude of the outer tub 13 is large and the vibration is transmitted to the washing machine body 19, which causes a problem.

Next, the case where the vibration absorber 11 is mounted will be described. The natural frequency fs of the vibration absorber 21 is defined as m (k
g) and the spring constant of the spring element is k (N / m), it is expressed by fs = 1 / 2π · √ (k / m).

In the present embodiment, the natural frequency of the vibration absorber 21 is the natural frequency F in the horizontal direction of the outer tub 13 in the front-rear direction.
It is set to be almost equal to _1, and the outer tank 13 in the vertical direction.
Is set to be substantially equal to the natural frequency F _{2 in} the up and down direction, and is set to be substantially equal to the frequency f _t in the steady dehydration rotation in the left and right direction. In this way, the vibration absorber 21 of the present embodiment can be set up to 6 directions including the rotation component. The characteristics when the vibration absorber 21 is attached are shown by broken lines in FIGS. 3, 4, and 5. As for the characteristics in the front-back direction in FIG. 3, some resonance phenomena occur at points F ₁₁ and F ₁₂ lower than the natural frequency F _{1 in} the horizontal direction of the outer tub 13, but almost no resonance phenomena occur at F _1. It is a thing. The points F ₁₁ and F ₁₂ are determined by the mass of the outer tub 18 and the mass of the mass body 22 of the vibration absorber 21. Also, F ₁₁
Amplitude peaks P ₁₂ of the amplitude peaks P ₁₁ and F ₁₂ of at the point is lower than the peak P ₁ of the amplitude at any horizontal natural frequency F _1. This is due to the damping effect of the rubber spring 23 supporting the vibration absorber 21, and if this damping effect is optimally selected according to the mass ratio of the outer tank 13 and the mass ratio of the vibration absorber 21, P ₁₁ and P ₁₂ should be extremely low. You can

[0015] The same is true for the vertical direction in FIG. 4, P ₂₁ · P ₂₂ When optimally choose according to their mass ratio of the mass and the vibration absorber 21 of the outer tub 13 can be very low.

As for the characteristics in the left-right direction, as shown in FIG. 5, a point f lower than the frequency f _t at the time of steady spin rotation is used.
₁₁ and a high point f ₁₂ causes a slight resonance phenomenon, but f ₁₂
Is higher than the normal rotation speed and there is no problem. The oscillation amplitude at the f _t is significantly reduced, resulting points of the f _{1 1} · f ₁₂ are those determined by the mass of the mass body 22 of the mass and vibration absorber 21 of the outer tub 13.

[0017]

The present invention comprises an outer tub located outside the washing / dehydrating tub for receiving water during dehydration, and a suspension for elastically supporting the outer tub from the four corners of the washing machine body. By installing a vibration absorber having a mass body and a spring element configured so that the vibration frequency of the vibration of the main body and the outer tank in at least one direction matches the natural vibration frequency, on the bottom surface or outer wall of the tank, With a compact and lightweight structure, it can be used as an anti-vibration device for an automatic washing machine that can suppress vibration in at least one direction from startup to steady state of the outer tub, and can also significantly reduce vibration of the washing machine body. is there.

[Brief description of drawings]

FIG. 1A is a plan view of an automatic washing machine showing an embodiment of the present invention, and FIG.

FIG. 2 is a sectional view of a vibration absorber mounted on the automatic washing machine.

FIG. 3 is an amplitude characteristic diagram in the front-rear direction before and after the vibration absorber is attached to the automatic washing machine.

FIG. 4 is an amplitude characteristic diagram in the vertical direction before and after the vibration absorber of the automatic washing machine is attached.

FIG. 5: Amplitude characteristic diagram in the left-right direction before and after the vibration absorber is attached to the automatic washing machine

FIG. 6 is a vertical sectional view showing a conventional automatic washing machine.

FIG. 7 is a perspective view showing a vibration absorber provided in the automatic washing machine.

[Explanation of symbols]

 13 Outer tub 16 Washing / dehydrating tub 18a, 18b, 18c, 19d Suspension 19 Washing machine body 20 Hanging rod 21 Vibration absorber 22 Mass body 23 Rubber spring

Claims (1)

[Claims] 1. An outer tub located outside the washing / dehydrating tub for receiving water at the time of dehydration, and a suspension elastically supporting the outer tub from four corners of the main body of the washing machine. Alternatively, a vibration proof of an automatic washing machine in which a vibration absorber having a mass body and a spring element configured so that a vibration frequency of a vibration of at least one direction of a washing machine body and an outer tub and a natural vibration frequency are substantially matched to each other on an outer wall portion apparatus.