JPH01185299A - Vibration preventing foot of washing machine - Google Patents

Abstract

PURPOSE:To surely prevent vibration without mat plate even under any floor conditions by monolithically providing relatively solid foot plate and soft rubber intermediate foot inside a foot main body, and specifying resonance frequency of a washing machine supported by the foot. CONSTITUTION:A foot bar 16 is fitted in the upper part of a foot main body 14 to fix the body 14 to a main body 1, and to pressure-fix an intermediate foot 17 to the body 14. The foot 17 has hardness 30-50 deg. and made of butyl rubber having repelling resiliency rate 20% or less, and also at the lower part, a relatively hard rubber made foot plate 15 is formed monolithically. The plate 15 and the foot 17 has a clearance in the lateral direction in the body 14, and the lower part of the plate 15 protrudes downwards by 2-6mm. The foot 17 is set to have a spring constant (k) such that the resonance frequency of a washing machine is 0.9 or less of frequency of dehydrant vibration. This constant (k) is determined according to the diameter, height and hardness parameter of the foot 17.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vibration isolating leg for a washing machine that dampens vibrations generated during spin-drying operation.

BACKGROUND OF THE INVENTION Conventionally, washing machines have been provided with vibration isolating legs as shown in FIG. 4 in order to dampen vibrations during spin-drying operation. That is, a leg body 14 made of resin is provided at the bottom of the main body 1, and a leg plate 15 made of rubber is provided at the bottom for the purpose of preventing slipping, and this leg structure allows it to be supported on a hard floor such as concrete. As shown in Figure 5A, the primary resonance frequency of the entire washing machine is set higher than its spin-drying frequency port (generally equal to the spin-drying rotation speed), and the spin-drying frequency port and the entire washing machine during steady spin-driving operation. The resonant frequencies A and B were made to not match.

(Generally, when the dehydration vibration frequency and the washing machine's resonant frequency match, the vibration increases.) However, if it can be installed on a wooden floor in a general household, the installation location will be soft, so as shown in Figure 6B, There is a problem in that the resonant frequency of the whole washing machine is lowered and is located at or near the dehydration frequency opening, which increases vibrations during the dehydration operation.

Therefore, in order to solve this problem, we have included a floor plate 9 exclusively for wooden floor boards, and when installing it on a soft floor such as a wooden floor board,
The instruction manual etc. instructed to install it by laying it on the bottom of the leg plate 15. This floor plate 9 is a flat plate made of rubber, and is placed between the soft floor plate and the leg plate 16 as shown in Fig. 6C.
As shown in the figure, vibration damping was achieved by lowering the resonant frequency of the entire washing machine compared to the dehydration frequency.

3. Problems to be Solved by the Invention However, in the conventional configuration, the user of the washing machine had to select whether or not a floor plate was necessary depending on the installation location.

If you make a mistake in selecting whether or not to use a bed plate at that time, for example, if you lay a bed board on a hard floor, or if you do not lay a bed board on a soft floor such as a wooden floor, the dehydration vibration frequency and the resonance frequency of the washing machine will change. As a result, vibrations during dehydration could become large.

Also, these days, more than half of households place their washing machines on soft floors, so the above-mentioned mistakes tend to increase. Furthermore, it is extremely costly to bundle the bottom plate, which is a separate part, with the washing machine.

In view of the above-mentioned problems, it is an object of the present invention to provide reliable vibration isolation without a floor plate, regardless of the floor conditions.

Means for Solving the Problems In order to achieve the above object, the present invention provides a soft rubber intermediate leg and a relatively hard leg plate integrally inside the leg body, and eliminates the resonance of the washing machine supported by the legs. The frequency is set to 0.9 or less of the dehydration frequency on a hard floor.

Effects According to the above configuration, the resonant frequency of the washing machine on a hard floor is smaller than the dehydration vibration frequency, which is less than 0.9, so the dehydration vibration does not become large on a hard floor as in the conventional case. In addition, if the washing machine is installed on a soft floor such as a wooden floorboard, the resonance frequency of the washing machine will be lower than that on a hard floor, so the dehydration frequency will be further apart and will not match, and the vibration isolation effect will be reduced. It gets expensive. Further, since the soft intermediate leg and the relatively hard leg plate are integrally provided, and the hard leg plate is in contact with the floor, local permanent deformation of the leg plate and scratches caused by pulling and the like are less likely to occur.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to FIGS. 1 to 3.

The configuration of the washing machine in this embodiment is as shown in Fig. 2.
An outer tank 11 is suspended and supported from the main body 1 via a support rod 2 and a compression spring 3. The washing/dehydration tank 10 is rotatably arranged inside the outer tank 11 (51\-/), and has a stirring blade 12 rotatably arranged at its inner bottom. The stirring blades 12 and the washing/dehydration tank 10 are selectively switched by a mechanical case 13, and the rotational force of the motor 4 is transmitted thereto. Reference numeral 14 denotes a leg main body, which is fixed to the lower part of the main body 1.

Next, the legs will be explained in detail with reference to FIG. Reference numeral 16 denotes a leg rod which is fitted onto the upper part of the leg main body 14 to fix the leg main body 14 to the main body 1, and also inserts and fixes the intermediate leg 17 into the leg main body 14. The intermediate leg 17 is made of butyl rubber with a hardness of 30° to 60° and a rebound modulus of 20% or less (according to JIS K5301), and a relatively hard rubber leg plate 16 is formed at the bottom thereof. There is. The leg plate 16 and the intermediate leg 17 are provided in the leg main body (4) 14 with a gap in the lateral direction, and the lower part of the leg plate 16 protrudes 2 to 6 mm below the leg main body 14. The intermediate leg 17 is set to a spring constant k such that the resonance frequency of the washing machine is 0.9 or less of the dehydration frequency, and this spring constant is determined by the parameters of the diameter, height, and hardness of the intermediate leg 17. The resonance frequency f of the washing machine is expressed by the following equation using the spring constant k of the intermediate leg 17.

l - Distance between legs J = Moment of inertia of washing Since the dehydration frequency is generally 14 to 15 Hz, co/
Resonance frequency f of a washing machine on hard floor soil such as IJ-to
The diameter of the intermediate leg 1a is set so that the frequency is about 12 to 13 Hz.
The height and hardness may be adjusted to set the nokune constant k.

The vibration characteristics of a washing machine supported by the legs configured as described above are approximately as shown in Figure 3. They are placed on soft floors such as floorboards, and their resonant frequency is
Since it is further away than the dehydration frequency opening, it has a high vibration-proofing effect during dehydration.

Also, as is clear from Figure 3, wash/W Kasukande 7t
,−,.

When the water (water tank 10) starts to start up and reaches the dewatering frequency port of steady rotation, it will always pass through the resonance frequency A.

Therefore, since the vibration temporarily increases at this time, the material of the intermediate leg 17 is made of a material with a thick damping characteristic so that the characteristic is set to the characteristic a in the figure and the vibration is made as small as possible. .

In this embodiment, as described above, butyl rubber having a rebound modulus of 20% or less is used.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the resonant frequency of the washing machine on hard floor soil is set to 0.9 or less of the dehydration frequency. Even under such floor conditions, a high vibration isolation effect can be achieved without using a floor plate, and installation errors can also be prevented. In addition, since the leg plate is relatively hard in contact with the floor, local deformation or damage to the leg plate is less likely to occur, resulting in high reliability.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the vibration isolating legs of a fully automatic washing machine according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of the same washing machine, and FIG.
The figure is a graph showing the frequency characteristics of the vibration amplitude of the same body.
The figure is a longitudinal sectional view of the vibration isolating legs of a conventional fully automatic washing machine, and FIG. 6 is a graph showing the frequency characteristics of the vibration amplitude of the main body. 1 - Main body, 14... Leg main body, 16... Leg plate, 1
6... Leg stick, 17... Intermediate leg. Name of agent: Patent attorney Toshio Nakao and 1 other person -+
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Claims (1)

[Claims] Legs fixed to the lower part of the main body The washing machine main body is equipped with an intermediate leg made of a soft material inside the main body and a leg plate integrally formed below the intermediate leg, and the washing machine main body supported by these legs is provided with an intermediate leg made of a soft material. A vibration isolating leg for a washing machine, characterized in that the primary resonance frequency is set to be 0.9 or less of the dehydration frequency.