JPH04144594A - Vibration isolator of washing machine - Google Patents

Abstract

PURPOSE:To eliminate collision sound and the shift of a main body due to unbalance at the time of the passage through a resonance point by making suspension with a compression coil spring with irregular pitch and enlarging a load when the suspension goes into an adhesion state without changing the free length, the spring constant, and the damping force of the suspension. CONSTITUTION:A compression coil spring 14 is a compression coil spring with irregular pitch, having long pitch between a 2nd and a 4th turns located almost in the center and comparatively short pitch, in comparson with the pitch in the center, in remaining both ends. In the case of a compression coil spring B with irregular pitch, the spring constant is the same as that of a compression coil spring with equal pitch if the load is small and the part with short pitch is not adhering. However, when the load becomes large and the part with short pitch adheres, the remaining part with long pitch acts as a spring with a small number of active coils on a point Y, and thus the spring constant increases rapidly. Therefore, at the resonance point at which the load becomes large, the spring constant becomes large and adhesion becomes unlikely to occur, because of passage beyond the point Y. Thus, the shift of a product due to collsion sound or its impact can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a vibration isolating device for washing machines used in general households.

2. Description of the Related Art As shown in Fig. 3, a conventional washing and dehydrating machine is equipped with a washing and dehydrating tank 2 inside a water tank 1 that stores water during washing, and a washing and dehydrating tank 2 at the bottom of the central part for stirring clothes. A large number of small holes 10 for draining water are provided on the side wall of the pulsator 3.

The bearing 5 is a box, and the motor 6 rotates only the pulsator 3 during washing, and the washing tub and dehydration tub 2 during dehydration.
It has a mechanism that transmits the driving force. Also, motor 6
The bearing transmits driving force to the box 6 by means of a belt 14 and a pulley 16. 4 is a reinforcing plate, and aquarium 1. motor 6,
The bearing is provided with a box 6, etc., and is supported by a support rod 9 to hang down from the corner of the main body 13 via a suspension 12 and a slider 8. 1" 1 is a balancer installed at the top of the washing and dehydrating tank. Also, it is rare for clothes to be evenly distributed inside the washing and dehydrating tank 2, and the dehydration effect is not achieved while the clothes are unevenly distributed. This non-uniformity in the clothing causes an unbalance of the rotating object and causes vibrations.

The structure supported by the vibration isolation system such as the support rod 9 and the suspension 12 is called a vibration system, and what is necessarily constituted by this vibration system and vibration isolation system is a natural frequency. If the frequency of vibration generated in the vibration system matches the natural frequency during dehydration, the amplitude of the vibration system will become extremely large, and for example, the vibration system will bounce up and down, collide with the main body 13, or the rotation axis A state called a resonance point occurs, which can lead to damage at critical speeds. In order to prevent this vibration, the amplitude must be suppressed by a vibration isolating mechanism.

A conventional vibration isolator is shown in FIG. As shown in the figure, a rubber cap 7 is disposed at the lower end of the support rod 9 and has a seal portion on the outer periphery, and the support rod 9 is penetrated at the center and comes into contact with the rubber camp 7 at the inner periphery. It is formed by a slider 8 having a cylindrical portion like this, and a suspension disposed between the slider 8 and the cap 7 and passing through a support rod 9.

A damper that obtains a damping force by the contact friction force between the cap 7 and the slider 8, and a suspension formed by the coil springs 12 with equal pitches dampen vibrations caused by unbalanced clothing.

Problems to be Solved by the Invention However, as washing machines have recently become larger and the weight of laundry has increased, the vibration isolating device configured as described above has problems when the spin speed reaches the resonance point of the vibration system. There was a problem in that when the water tank 1 vibrates greatly up and down and reaches the bottom dead center, the coil spring 12 of the suspension tends to come into close contact.

In such a case, when the coil spring 12 of Susvensilane comes into close contact with the product, a large impact sound is generated, and furthermore, the entire product moves due to the impact force, which is an extremely bad phenomenon.

There were three ways to solve this problem:

(1) Increase the free length of the suspension. Increase the load when the body coil springs are in close contact.

(2) Increase the repelling constant of Susbensilane to increase the load when making close contact.

(3) Increase the contact friction force between the cap 7 and the slider 8 to increase the damping force.

However, each of these solution methods had the following problems and was impossible to implement.

In the above solution (1), since the nutroke for the coil spring to come into close contact becomes longer, the difference in the height of the water tank between the no-load state and the washing state with water increases ( When water is added, the weight increases and the coil springs of the suspension are in a tight state), making the user feel uncomfortable.

In the solution of (2)l (3) above, the vibration of the main body during steady dehydration becomes large.

In view of the above problems, the present invention provides a free length of the suspension,
The purpose is to increase the load when the suspension is in a close contact state without changing the spring constant and damping force, and to eliminate collision noise and movement of the main body due to imbalance when passing the resonance point.

Means for Solving the Problems In order to achieve the above object, the present invention employs compression coil springs with unequal pitches for the suspension, and increases the load when the suspension is in a close contact state, so that when the suspension passes the resonance point during dehydration, the suspension This is intended to prevent them from becoming in close contact.

Effect With the above configuration, if the suspension is made of a coil spring with unequal pitches, when a load is applied, the short pitched parts will come into close contact first, and the long pitched parts will act as a spring with a reduced number of effective turns. .

At this time, since the effective number of turns of this coil spring has decreased, the spring constant increases rapidly compared to the initial value, and the load required until the entire coil spring is brought into close contact with each other increases accordingly.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2. Note that the same parts as in the conventional example are given the same numbers, and their explanations are omitted.

In FIG. 1, reference numeral 9 denotes a support rod that suspends and supports the vibration system.A cap 7 is attached to the lower end of this support rod 9, and a cap 7 is inserted through the support rod 9 at the center. A slider 8 that makes frictional contact is provided. Reference numeral 12 denotes a compression coil spring disposed between the top surface of the camp 7 and the slider 8. This compression coil spring 14 is a compression coil spring with unequal pinch. The pitch at both ends of the cylinder is shorter than that at the center.
The free length is set to such a length that the cap 7 slightly enters the slider 8 in order to obtain an appropriate damping force in an unloaded state.

And the support rod 9. Slider 8. The cap 7 and the compression coil spring 14 constitute a suspension. FIG. 2 shows a load-deformation diagram of the unequal pitch compression coil spring 14.

Line A in the figure shows the relationship between the load and deformation amount of a conventional uniform-pitch compression coil spring, and line B shows the unequal-pitch compression coil spring of the present invention. In the case of compression coil springs with uneven pitches, when the load is small and the short pitch parts are not in close contact, the spring constant (the slope of the line in the diagram) is exactly the same as that of a compression coil spring with equal pitches. , when the load increases and the short pitch parts come into close contact (Y point in the figure), the remaining long pitch part acts as a spring with a small number of effective turns, and the spring constant suddenly increases (spring constant is inversely proportional to the effective number of turns). Therefore, during steady dehydration operation with a small load, the spring constant is the same as before, so the vibration of the main body is the same as before, and when the load is at the resonance point, the Y point is exceeded, so the spring constant is The height makes it difficult for them to stick tightly together, which prevents the product from moving due to collision noise and impact.

Effects of the Invention As described above, according to the present invention, by using a compression coil spring with unequal pinch for the suspension, the spring constant is normally small, and when the load increases at the resonance point, the spring constant is reduced. Because of the large size, it is possible to prevent unpleasant m=sound and movement of the product.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a vibration isolator showing an embodiment of the present invention;
FIG. 2 is a load-deformation diagram of the same compression coil spring, FIG. 3 is a longitudinal sectional view of a conventional washing machine, and Section 4 is a longitudinal sectional view of a conventional vibration isolator. 7...Cap, 8...--Slider, 9
...Support rod, 14...Compression coil spring,
.

Claims (1)

[Claims] A vibration isolating device for a washing machine, in which a water tank is suspended from the upper part of a main body by a support rod via a suspension, and the suspension is composed of a compression coil spring having both a short pitch part and a long pitch part.