JPH0824789B2 - Anti-vibration leg of washing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolating leg of a washing machine for isolating vibration generated during a dehydration operation.

2. Description of the Related Art Conventionally, a vibration-proof leg shown in FIG. 4 is provided to prevent vibration during a spin-drying operation of a washing machine. 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 for the purpose of preventing slippage is provided at the bottom of the body 1, and the leg structure of the entire washing machine supported on a solid floor such as concrete. As shown in FIG. 5A, the primary resonance frequency (b) is set higher than the dehydration frequency (b) (generally equal to the dehydration rotation speed), and during the steady dehydration operation, the dehydration frequency (b) and the resonance frequency (b) of the entire washing machine are set. Were trying not to match. (Generally, the vibration increases when the dehydration frequency and the resonance frequency of the washing machine match.) However, when installed on a wooden floor in a general household, the installation place becomes soft, as shown in FIG. 5B. In addition, the resonance frequency (i) of the entire washing machine is lowered and may be located at or near the dehydration frequency (b), which causes a problem that the vibration during the dehydration operation becomes large. Therefore, in order to solve it, conventionally, when a floorboard 9 dedicated to a wooden floorboard is bundled and installed on a soft floor such as a wooden floorboard, a footboard is required.
It was instructed by the instruction manual etc. to lay it on the bottom of 15. This floor plate 9 is a rubber flat plate, which is laid between a soft floor plate and the leg plate 15 to reduce the vibration by lowering the resonance frequency a of the entire washing machine below the dehydration frequency b as shown in FIG. 5C. It was something to do.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional configuration, the user of the washing machine needs to select the necessity of the floor board depending on the installation location. If you make a mistake in selecting the floorboard at that time, for example, if you lay the floorboard on a hard floor, or if you do not lay the floorboard on a soft floor such as a wooden floorboard, the dehydration frequency and the resonance frequency of the washing machine are Consistently, the vibration during dehydration sometimes increased.

Recently, more than half of households place their washing machines on a soft floor, and the above-mentioned mistakes tend to increase. Further, bundling a floorboard, which is a separate component, in a washing machine is extremely expensive in terms of cost.

The present invention has been made in view of the above problems, and an object of the present invention is to reliably perform vibration isolation without a floor plate under any floor condition.

Means for Solving the Problems In order to achieve the above object, the present invention provides a downwardly open hollow leg body fixed to a lower portion of the body, and a hollow inner surface which is internally provided in the leg body with a gap therebetween. The intermediate leg is made of a soft material and is integrally provided below the intermediate leg. The leg is positioned so as to project from the lower side of the leg main body and has a hardness higher than that of the intermediate leg. And a leg plate made of a high material, and the primary resonance frequency of the washing machine main body supported by the legs is set to be lower than the dehydration frequency.

Action According to the above configuration, since the resonance frequency of the washing machine is set to be lower than the dehydration frequency on the hard floor, the dehydration vibration does not increase on the hard floor as in the conventional case. Also,
When installed on a soft floor such as a wooden floor board, the resonance frequency of the washing machine can be smaller than that on a hard floor, so that the resonance frequency is farther than the dehydration frequency and does not match, resulting in a high vibration damping effect. Further, since the soft intermediate leg and the relatively stiff leg plate are integrally provided and the stiff leg plate is in contact with the floor, local permanent deformation of the leg plate and scratches due to pulling or the like are unlikely to occur.

Embodiments Embodiments of the present invention will be described below with reference to FIGS.

As shown in FIG. 2, the structure of the washing machine in this embodiment is such that an outer tub 11 is suspended and supported by a main body 1 via a support rod 2 and a compression spring 3. The washing / dehydrating tub 10 rotatably arranged in the outer tub 11 has a stirring blade 12 rotatably arranged at the inner bottom thereof. The mechanical vane 13 selectively switches between the stirring blade 12 and the selection / dehydration tank 10, and the rotational force of the motor 4 is transmitted. A leg body 14 is fixed to the lower portion of the body 1.

Next, the leg portion will be described in detail with reference to FIG. Reference numeral 16 denotes a leg bar, which is fitted to the upper portion of the leg body 14 to fix the leg body 14 to the body 1 and to press and fix the intermediate leg 17 to the leg body 14. The intermediate leg 17 is made of butyl rubber having a hardness of 30 ° to 50 ° and a repulsion elastic modulus of 20% or less (according to JIS K6301), and a relatively hard rubber leg plate 15 is integrally formed under the lower leg. The leg plate 15 and the intermediate leg 17 are laterally provided in the leg body 14 with a gap therebetween.
It projects 6mm downward. The intermediate leg 17 is set to have a spring constant k such that the resonance frequency of the washing machine becomes 0.9 or less, and the spring constant k is determined by parameters of the diameter, height and hardness of the intermediate leg 17. The resonance frequency 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 machine Since the dehydration frequency is generally 14 to 15 Hz, the resonance frequency of the washing machine on a hard floor such as concrete is 12
The spring constant k may be set by adjusting the diameter, height and hardness of the intermediate leg 17 so as to be about 13 Hz.

The vibration characteristics of the washing machine supported by the legs configured as described above are roughly as shown in FIG. 3, FIG. 3A being on a hard floor such as concrete, and FIG. 3B being a wooden floorboard. Since it is on a soft floor, and its resonance frequency (i) is farther than the dehydration frequency (b), it has a high vibration isolation effect during dehydration.

In addition, as is apparent from FIG.
Will start to start and will always pass through the resonance frequency B until the dehydration frequency b of steady rotation is reached. Therefore, at this time, the vibration temporarily becomes large, so that the characteristics are changed from the characteristics b to a in the figure and the material of the intermediate leg 17 has a large damping characteristic so as to minimize the vibration. In this embodiment, butyl rubber having a rebound resilience of 20% or less is used as described above.

EFFECTS OF THE INVENTION As is apparent from the above examples, according to the present invention, the resonance frequency of the washing machine on the hard floor is set to be lower than the dehydration frequency, so that from the soft floor to the hard floor, It is possible to obtain a high vibration-proof effect without using a floor plate under any floor condition, and prevent an error in installation. Also, because the contact part with the floor is a relatively rigid leg plate,
The leg plate is unlikely to be locally deformed or damaged, and the leg plate can be made highly reliable.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a vibration-proof leg of a fully automatic washing machine according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view of the washing machine.
Fig. 4 is a graph showing the frequency characteristics of the vibration amplitude of the main body.
FIG. 5 is a vertical sectional view of a vibration-proof leg of a conventional fully automatic washing machine, and FIG. 5 is a graph showing frequency characteristics of vibration amplitude of the main body. 1 …… Main body, 14 …… Leg body, 15 …… Leg plate, 16 …… Leg bar, 17 …… Intermediate leg.

Claims (1)

[Claims] 1. A hollow leg body which is fixed to the lower part of the body and which is open downward, and a leg portion which is provided inside the leg body with a gap from the hollow inner surface. An intermediate leg made of a material, and a leg plate integrally provided below the intermediate leg, positioned so as to project from the lower side of the leg body, and made of a material having a hardness higher than that of the intermediate leg, The anti-vibration leg of the washing machine, wherein the primary resonance frequency of the washing machine body supported by the legs is set to be lower than the dehydration frequency.