JPH0710713Y2 - Washing machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic washing machine for washing clothes and the like.

2. Description of the Related Art A washing machine for washing household clothes is one in which laundry is automatically washed by agitating clothes and washing liquid in a washing tub by rotation of a pulsator. Conventionally, to drive this pulsator, there has been a method in which the rotation of the motor is transmitted by deceleration by a V-belt or the like. In this case, the pulsator rotated at a relatively high speed, the ridge of the pulsator was low, and the time required for left-right reversal was long. Therefore,
The noise at the time of washing is small because it is only the slip noise of the belt, and a sufficiently effective washing rate can be obtained for washing only ordinary clothes. However, for delicate clothes such as wool and lace, this belt system causes the water to be too strong and damages the clothes, and washing with a washing machine is impossible.

Therefore, it was devised to make it possible to wash ordinary clothes as well as delicate clothes with a washing machine. A gear speed reduction system in which the rotation of the motor is decelerated by a one-stage V-belt and further decelerated by a gear. Is. With this method,
A wide variety of clothes can be washed. In other words, the deceleration mechanism using the V-belt and gear can lower the rotation of the pulsator, generate a weak water flow that makes it possible to wash delicate clothes, and wash normal clothes and delicate clothes with a single washing machine. It was made possible.

However, in this gear reduction system, the gear noise of the gear reduction device is high, and this gear noise is further amplified by vibrating the bottom surface of the washing tub, and there has been a problem of reducing noise during driving.

A conventional gear reduction type washing machine is shown in FIG. In FIG. 4, 1 is an outer box, 2 is a washing tub, 3 is a pulsator, 4
Is a gear reduction device, and the output shaft 4a is engaged with the pulsator 3 to transmit power. A pulley 5 is fitted to the input shaft of the gear reduction device 4. The pulley 5 transmits the rotation of the motor 8 to the gear reduction device 4 via the motor pulley 7 of the motor 8 by the V belt 6. Reference numeral 9 is an underframe, and 10 is a frame fixed to the underframe 9. 11 is an operation box that houses switches and the like.

The gear reduction device 4 is a boss provided at the bottom of the washing tub 2.
2a and the screw receiver 4b of the flange portion 4c of the gear reduction device 4 are fixed to the lower part of the washing tub 2 by screwing. Reference numeral 12 is a seal packing for waterproofing the gear reduction device 4 and the washing tub 2.

However, in such a conventional configuration, the pulley 5 is rotated by the rotation of the motor 8 during washing, and the gear sound of the gear reduction device 4 is generated by the boss 2a on the bottom of the washing tub 2 and the seal packing 12.
Is transmitted to the bottom surface of the washing tub 2. Here, washing tub 2
As with the speakers of radios, etc., the gear sound was amplified by vibration, and noise was generated when the washing machine was driven.

In order to reduce this noise, there is also a method of isolating the gear reduction device 4 itself. In this case, however, since the gear reduction device 4 supports the load of the pulsator 3, it is necessary to use an anti-vibration material for vibration isolation support. The anti-vibration structure becomes complicated and also requires strength.

An object of the present invention is to reduce the noise generated when the gear sound of the gear reduction device 4 causes the washing tub 2 to resonate and to maintain the strength of the drive mechanism of the pulsator of the washing machine.

Means for Solving the Problems In order to solve the above-mentioned problems, the washing machine of the present invention is provided with circular ribs on the bottom of the washing tub at positions corresponding to the radial ribs and the flange portion of the gear reducer. A plurality of bosses formed on the above-mentioned structure have a structure in which the vibration damping material disposed between the circular rib and the flange portion is sandwiched. In this case, when the radius of the circular rib is r, the radius of the bottom of the washing tub is R, the pulsator rotation angular velocity is ω, and the constant of proportionality is K, r = KRω allows more effective vibration isolation, Reverberation can be reduced.

The above-mentioned noise of the washing machine is caused by the vibration of the gear meshing rotation noise of the gear reduction gears according to the rotation speed of the pulsator during washing, causing the bottom of the washing tub to vibrate and resonate in the washing tub. The present invention achieves the object by reducing the resonance vibration and increasing the strength of the bottom portion of the washing tub to make it difficult to vibrate. r = KRω
From the formula, the diameter r of the circular rib that reinforces the point where the amplitude of the vibration of the bottom of the washing tub that reduces the resonance vibration is effectively obtained, and further, in order to absorb the vibration, this rib and the flange portion of the gear reducer are The vibration resonance at the bottom of the washing tub is reduced by sandwiching the vibration-proof material between them. In addition, the radial ribs increase the strength of the bottom of the washing tub to make it less likely to vibrate.

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

In FIG. 1, radial ribs 2b and circular ribs 2c are formed on the bottom of the washing tub 2. The gear reduction device 4 has a screw 14 attached to the boss 2a provided on the circular rib 2c via a vibration isolator 13.
Fixed by. A hole 13a is formed in the vibration isolator 13 as a relief for the boss 2a. The vibration isolator 13 is sandwiched and pressed by the circular rib 2c on the bottom of the washing tub 2 and the rib 4c on the flange of the gear reduction device 4.

The gear reduction device 4 includes the bottom of the washing tub 2 and the waterproof packing 12
Also, they are abutted against each other by the vibration isolator 13 and fixed by the screw 14 by the boss 2a. The load from the pulsator 3 is supported by the boss 2a of the washing tub 2 via the flange of the gear reduction device 4.

Now, the position of the circular rib 2c at the bottom of the washing tub 2 must be set to a position where vibration resonance at the bottom of the washing tub 2 is most reduced. Vibration can be prevented by increasing the strength of the bottom of the washing tub 2 at the position where vibration resonance occurs.

In order to obtain this position, the mass of the gear reduction device 4 is m,
If the rotation speed of the pulsator is v and the displacement of vibration is x,
The energy equation of vibration is expressed as (1/2) mv ^2- (1/2) Bx ² = C (B: proportional constant) (1), and it is good to consider the case where C = 0. In this equation, 1/2 mv ² represents the kinetic energy of the oscillation source (gear speed reducer), and 1/2 Kx ² represents the absorbed energy of the vibration isolator that absorbs vibration. Therefore, the ideal state in which there is no vibration is a state in which the vibration is absorbed by the vibration isolator, that is, a state in which the kinetic energy of the oscillation source and the absorbed energy of the vibration isolator are equal.

Assuming that the radius of the circular rib is r, the radius of the bottom of the washing tub 2 is R, and the rotational angular velocity of the pulsator of the gear reduction device 4 is ω, v = Rω and r = x. Substituting this into the ideal state in which vibration is absorbed by the anti-vibration material and completely disappearing, C = 0, and when the equation (1) is solved, (1/2) m (Rω) ² = (1/2) Br ² ω = (r / R) · (B / m) ^1/2 (2) r = ωR · (B / m) ^1/2 (3)

Here, the spring constant of the vibration isolator is k ₁ , and the elastic modulus of the washing tub is k ₂
Then, it can be shown that B = f (k ₁ , k ₂ ). Therefore, B can be obtained experimentally, and if K = (B / m) ^1/2 , it can be expressed as r = KRω (4).

When the washing tub is made of polypropylene resin and the vibration damping material has a hardness of 50 °, K is experimentally required to be about 0.024 when the pulsator rotation speed ω = 200 rpm and the washing tub radius R = 200 mm. The radius r of the circular rib is about 50 mm.

Furthermore, the vibration resonance can be further reduced by increasing the strength of the bottom of the washing tub 2 at the position where the vibration resonance occurs and absorbing the vibration at this position. Therefore, the vibration isolator 13 is sandwiched between the circular rib 2c and the rib 4a formed on the flange portion of the gear reduction device 4 to absorb the vibration. FIG. 3 shows the details of the gear reduction device. 17 is an internal gear, 18 is a planet gear, 19 is a gear shaft, and a sun gear 19a
And meshes with the planet gear 18. Numeral 17 is an output shaft to which a pulsator 3 is fixed at the tip. Anti-vibration material 13
Is generally EPT rubber or butyl rubber, and is pressed and sandwiched between the circular rib 2c at the bottom of the washing tub 2 and the flange of the gear reduction device 4.

Further, in order to prevent the vibration itself of the bottom of the washing tub 2 which causes resonance vibration and to further prevent the vibration of the washing tub 2, the bottom of the washing tub 2 is provided with a radial rib 2b to reinforce the bottom of the washing tub 2. To make it difficult to vibrate.

The noise level of the washing machine having the above structure is about 45 to 46 decibels. This measurement condition is the rated voltage, rated load (dry cloth amount 3kg: JIS test cloth used), using a washing machine, JIS
It is measured by a noise measuring method. The noise level of a conventional washing machine is 48 to 49 decibels in the same way.
By using the conventional washing machine, the present invention can reduce the amount of noise that the user cannot withstand to the noise to a level acceptable as the sound of the living environment.

As described above, according to the present invention, it is possible to effectively prevent the vibration resonance of the bottom of the washing tub due to the gear meshing rotation noise of the gear reduction gear according to the rotation of the pulsator during washing, and The noise can be reduced. In other words, when the radius r of the circular rib at the bottom of the washing tub is R, the radius of the bottom of the washing tub is R, the pulsator rotation angular velocity is ω, and the proportionality constant is K, r = KRω. It is possible to increase the strength of the position of the bottom of the tank and prevent resonance vibration. Further, a vibration damping material is sandwiched between the rib and the flange portion of the gear reduction gear to absorb the vibration, thereby improving the vibration prevention effect.

Further, by providing radial ribs, the strength of the bottom of the washing tub itself is increased and vibration is prevented, so that amplification of gear sound can be suppressed and noise can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a washing drive unit according to an embodiment of the present invention, FIG. 2 is a view for explaining the position of the reinforcing ribs at the bottom of the washing tub, and FIG. 3 is a cross-sectional view of the gear reducer, and FIG. The figure shows the structure of a conventional washing machine. 2 ... washing tub, 2b ... radial ribs, 2c ... circular ribs, 3
...... Pulsator 4 ...... Gear speed reducer

Claims (1)

[Scope of utility model registration request] 1. A pulsator is arranged at the bottom of a bottomed tubular washing tub, and a gear reduction device for reducing the rotation of the pulsator is provided, and a circular rib is provided at a position corresponding to a flange portion of the gear reduction device. A radial rib is formed on the bottom of the washing tub between the outer periphery of the bottom and the circular rib, the radius of the circular rib is r, the radius of the bottom of the washing tub is R, the pulsator rotation angular velocity is ω, and the proportional constant is K. Then, r = KRω, and the vibration-proof material is sandwiched between the circular rib and the flange portion of the gear reduction gear, and fixed to the multiple bosses formed on the circular rib with screws through the flange receiver of the gear reduction gear. A washing machine.