JPH0732837B2 - Automatic washing machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic washing machine for home use.

2. Description of the Related Art A conventional automatic washing machine of this type has a structure as shown in FIG. That is, a speed reducer 2 having a drive shaft is fixed to the lower part of the outer tub 1 for receiving water at the time of dehydration, and the speed reducer 2 also includes a motor 3 and a belt fixed to the lower part of the outer tub 1. Are connected by. The drive shaft of the speed reducer 2 has a biaxial structure, and a dehydration tub 4 located inside the outer tub 1 and serving as a washing tub is fixed to the outer shaft. A stirring blade 5 located inside the washing tub 4 is fixed to the inner shaft. The outer tank 1 is supported by the main body 5 via a suspension 6 so as to be vibration-proof.

A conventional general automatic washing machine has the above-described configuration and automatically performs water supply, washing, drainage, and centrifugal dehydration.

Problems to be Solved by the Invention However, in the case of such a structure, when the spin-drying tub 4 is rotated and centrifugally dehydrated, a large vibration is generated due to the imbalance caused by the uneven displacement of the clothes, which causes noise. It is the cause. Therefore, reduction of noise and vibration has become a major issue in automatic washing machines.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above conventional problems and provide an automatic washing machine with reduced noise.

Means for Solving the Problems The present invention is to solve the above problems and includes a main body of a washing machine and a washing tub for washing and dewatering, and vibration-supported in the main body via a suspension. An outer tub, a stirring blade that stirs the inside of the washing tub, a motor that drives the washing tub and the stirring wing, and a porous triangular sound absorbing material, and two of the side surfaces of the sound absorbing material are the main body. It has a structure fixed to the inner surface of the corner portion.

Operation The effects of this technical means are as follows.

That is, among the noise caused by the vibration generated during the dehydration process due to the imbalance caused by the uneven displacement of the cloth in the washing tub, the noise of about 300 Hz related to the air column resonance inside the main body is large due to the action of the sound absorbing material. The width is reduced.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, 10 is an outer tank for receiving water during centrifugal dehydration. Reference numeral 11 denotes a speed reducer having a drive shaft 12 having a biaxial structure, which is fixed near the center of the outer bottom of the outer tub 10.
Reference numeral 13 denotes a drive motor, which is also fixed to the bottom of the outer tub and drives the reduction gear 11 with a belt 14. Reference numeral 15 is a washing tub that also serves as a dehydration tub, and the outer tub 10 is located outside thereof. The washing tub 15 is fixed to the outer shaft of the drive shaft 12. Reference numeral 16 denotes a stirring blade, which is located at the central bottom portion inside the washing tub 15 and is fixed to the inner shaft of the drive shaft 12. The outer tub 10 is elastically supported by being suspended from a main body 18 by a suspension 17 having four elastic bodies. 19 is 4 inside the body 18
It is a sound-absorbing material that is provided by vertically attaching to the corners of the locations.In this example, urethane with porous air permeability is used, and it is provided over a length that almost covers the height of the outer tub 10. ing.

The operation of this example in the above configuration is as follows. First, put the clothes you want to wash and the detergent into the washing tub 15 and turn on the electricity to supply a certain amount of water.When the water supply is complete, the stirring blades 16 automatically start rotating to stir the clothes in the washing tub 15. Wash while doing. After washing for a certain period of time, drainage and rinsing are repeated several times, and after drainage is completed, the washing tub 15 rotates and the clothes are centrifugally dehydrated. During this spin-drying process, imbalance occurs due to deviation of clothes and the like, and the washing tub 15 and the outer tub 10 vibrate violently. This vibration causes the outer tank 10 to be suspended.
Since it is elastically supported by the main body 18 by 17, the vibration transmitted to the main body 18 and the floor is considerably reduced.

However, noise is generated by the vibration of the outer tub 10, but cannot be reduced only by reducing the vibration by elastically supporting the outer tub 10 with the suspension 17 or the like. Although this noise has various frequency components, it has a long wavelength and a large amount of noise is generated at around 300 Hz which generates low frequencies.
(See the dotted line in FIG. 2) does not easily disappear, which is a major obstacle to making a low-noise washing machine.

As a result of various studies on this noise, the inside of the main body 18 and the outer tank
It is possible to envision a resonator that is composed of the horizontal side and the vertical side of the outer tank and the length of the distance between the outer tank 10 and the main body 18 in the space between the resonator. It was found that the frequency of the standing wave confined in is around 300Hz.
In other words, the standing wave as shown in FIG.
It occurs in the above space between and. The half-wavelength of this standing wave corresponds to the length of the horizontal side of the main body, and the standing wave shown in FIG. 3 is not attenuated in the form as shown in the figure. It was found that the noise reduction effect by mounting the bottom plate 20 was not so effective because the space between the main body 18 and the outer tub 10 was moved back and forth.

In order to eliminate this standing wave, a porous sound absorbing material 19 is put on the inner surface of the main body 18 to absorb the sound wave, and at the same time, the frequency is changed so that the balance is disturbed and attenuated. You can

The sound absorbing effect of a porous sound absorbing material is determined by how many air particles that are involved in noise are taken in, and the kinetic energy thereof is absorbed and converted into other energy. The kinetic energy of the air particles is
The magnitude of the sound pressure of the standing wave shown in FIG. 3 and the 1/4 wavelength phase have a different relationship, and the kinetic energy of air particles is minimized on the wall surface of the main body 18. The kinetic energy of air particles is very small near the inner wall surface of the main body 18, but increases sharply from a little distance, as estimated from the change in sound pressure of the standing wave. In order to capture air particles where this kinetic energy rapidly increases, a sound absorbing material having a certain thickness is required.

In order to have a thickness of the sound absorbing material in the space where the standing wave exists, in the positional relationship between the main body 18 and the outer tub 10, as in the present invention,
It must be provided at the inner corner of the body 18. That is, by providing a sound absorbing material 19 in a substantially triangular prism shape along the corner shape in the corner portion inside the main body 18, at least the outer tank 10 at the corner portion inside the main body where the sound pressure of the standing wave becomes the largest.
It is possible to secure the thickness of the closest distance between the main body 18 and the main body 18 (the distance that is ensured so that the outer tub 10 does not collide with the main body 18 due to the vibration caused by the normal driving of the washing machine). Furthermore, there are two standing waves of almost the same wavelength from one corner that differ from each other by 90 degrees. Sound absorbing material can be provided.

Moreover, since the standing wave is attenuated by the triangular prismatic sound absorbing material attached to the corner portion of the main body 18, the sound absorbing material has an inclination with respect to the standing wave, and the timing of entering the standing wave depends on this inclination. It is not the same, but it is captured at the position where the phase is shifted.
Therefore, due to this shift, reflected waves of standing waves with different attenuation factors are generated, and these cancel each other,
The attenuation of the standing wave can be promoted more effectively.

As described above, according to the present invention, a standing wave of about 300 Hz can be effectively and surely attenuated, and noise can be reduced and quiet dehydration can be performed by eliminating the standing wave due to the attenuation. Further, it goes without saying that a further noise reduction effect can be obtained by combining the bottom plate 20.

EFFECTS OF THE INVENTION The present invention has an excellent effect that standing waves near about 300 Hz are eliminated by providing a sound absorbing material on the inside of the main body, and as a result, noise near 300 Hz can be greatly reduced. It is a thing.

[Brief description of drawings]

1 is a transverse sectional view of an automatic washing machine according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA 'of FIG. 1, FIG. 3 is a sound pressure distribution diagram of the automatic washing machine, and FIG. FIG. 4 is a sectional view of a conventional automatic washing machine. 10 …… Outer tank, 13 …… Motor, 15 …… Washing tank, 16 …… Stirring blade, 18 …… Main body, 19 …… Sound absorbing material.

Claims (1)

[Claims] 1. A main body of a washing machine, an outer tub which contains a washing tub for washing and dehydrating and is vibration-isolated and supported through a suspension in the main body, a stirring blade for stirring the inside of the washing tub, a washing tub, and An automatic washing machine comprising a motor that drives a stirring blade and a porous triangular sound absorbing material, and two of the side surfaces of the sound absorbing material are fixed to the inner surface of the corner portion of the main body.