JPH0139798B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention eliminates the so-called seat jumping phenomenon that occurs when abnormal vibrations occur in the water receiving tank in a double-tank type or the rotating tank in a single-tank type, without requiring the addition of a weight to adjust the center of gravity position. This invention relates to a washing machine that can also be used as a dehydrator and a washing machine that can prevent such problems.

The basic structure of a conventional dual-tub type washing machine that combines dewatering and dewatering is generally shown in FIGS. 1 to 3.
In these figures, 1 is a water tank corresponding to a tab, and 2 is a water tank 1 with a pulsator 3 on the inner bottom.
The rotary tank 4 arranged inside is four hanging rods that are swingably suspended inside the outer box 5, to which the water receiving tank 1 is supported via a supporting member 6 that is integral with the rotating tank 4. .
Reference numeral 7 denotes a motor installed at a position eccentric from the center of the outer bottom of the water receiving tank 1 (which is also the center of rotation of the rotating tank 2), and transmits its rotational force through a belt transmission mechanism 8 and a power transmission control mechanism 9. The power is selectively transmitted to the pulsator 3 and the rotating tank 2.
Now, 10 is the damper mechanism, which is the hanging rod 4.
A sliding member 11 connected to the lower end of the slide member 11, a friction cylinder 12 inserted into the hanging rod 4 so as to surround the lower part thereof so that the sliding member 11 slides by friction, and a friction cylinder 12 that is constantly connected to It consists of a compression coil spring 13 that biases upward movement. The support member 6 has a concave support point 6a, and the hanging rod 4 is inserted through a through hole 6b formed in the center of the concave support point 6a so as to be able to move up and down. 1
It is placed on the receiving part (upper surface part of the friction cylinder) 10a of No. 0. According to this configuration, when the water receiving tank 1 is vertically displaced with lateral vibration due to abnormal vibration during dewatering,
A friction tube 12 is attached to the support member 6 that moves up and down together with this.
As a result of the following vertical movement (vertical vibration), the friction between the friction tube 12 and the sliding member 11 provides a vibration damping effect to the water receiving tank 1. Such abnormal vibrations reach a maximum at the resonance point before transition to steady rotation. By the way, in order to prevent the water receiving tank 1 from colliding with the outer box 5 due to an increase in abnormal vibration, the damper effect should be strengthened, that is, the friction between the friction tube 12 and the sliding member 11 should be set high. However, in that case, the friction tube 11 will no longer be able to follow the tilting vibration of the support member 6, and its support point portion 6a will rise away from the receiving portion 10a of the damper mechanism 10, as shown by the two-dot chain line in FIG. At the moment of , a so-called seat jumping phenomenon occurs when the water falls and collides with the receiving part 10a, and the sound of the collision and the sound of the water receiving tank 1 colliding with the outer box 5 due to the seat jumping become abnormal noise. As described above, the seat jumping phenomenon occurs when the damper mechanism 10 is unable to follow the movement of the support point portion 6a.

By the way, conventional tabs were made of enamel, so seat jumping was not a problem. Recently, I've been switching from enamel to plastic tabs, but it wasn't until this stage that I started having problems with the tabs jumping. The causes of seat jumping when the tab is made of plastic are as follows.

First, seat jumping is more likely to occur if the center of gravity of the entire tab is eccentric from the center of the tab.

Now, in the dehydrating/washing machine, the rotation of the motor is transmitted by the belt transmission mechanism to the power transmission control mechanism in the center of the tub, so if the motor is placed too close to the center of the tub, the belt pulley will The contact angle against the belt becomes small and the belt slips. Therefore, in order to prevent this slippage, it is necessary to move the motor away from the center of the tab to a certain extent.

The effect of the eccentric arrangement of the motor on the eccentricity of the center of gravity of the entire tab is not so great if the tab is made of enamel and has a considerable weight. However, if the tab is made of plastic, it will be lightweight, so the motor will have a greater influence on the eccentricity of the center of gravity of the tab as a whole, and the center of gravity will shift further toward the motor. The degree to which the center of gravity shifts toward the motor side tends to be larger as the washing machine becomes smaller, since it is necessary to ensure a contact angle between the belt and the pulley.

On the other hand, in addition to the motor, the tub is equipped with a capacitor, a drain valve, an electromagnet for driving the drain valve, etc., but the total weight of these is approximately 4 kg, whereas the motor weighs approximately 4 kg.
Less than 1Kg. However, in the case of enamel tabs, the center of gravity of the entire tab does not shift to the motor side due to the large weight of the tab, so by placing these other parts on the opposite side of the motor, the center of gravity of the entire tab can be adjusted. It was possible to move the position closer to the center to prevent seat jumps. but,
In the case of plastic tabs, it has become difficult to correct the eccentricity of the center of gravity of the tab as a whole to the extent that it does not cause the tab to jump by simply considering the arrangement of the other components and the motor. Since the weight of the motor does not change much depending on the size of the washing machine, the eccentricity of the center of gravity can hardly be improved, especially in small washing machines.

For this reason, if the tab is made of plastic, the center of gravity will be significantly offset from the center of the tab, making it more likely to jump.

In order to eliminate this bounce, it is possible to move all the support points of the tab's hanging rods far away from the outer circumferential surface of the tab, but this would increase the length of the support members that make up the support points, causing the tab to The supporting member is likely to hit the outer box due to the swinging, and if this is avoided, the outer box will have to be large, which is not practical.

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a damper to prevent the tab from colliding with the outer cylinder during abnormal vibrations in tabs made of plastic, regardless of the capacity. To provide a dehydrating and washing machine capable of preventing the phenomenon of seat jumping caused by abnormal vibrations without having to separate all the support points of hanging rods from the outer circumferential surface of the tub. .

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 7, along with the background to the invention including investigation of the cause of the seat jump phenomenon.

The present inventor believes that in order to prevent the seat jumping phenomenon, the center of gravity of the water tank 1 should be at the center of rotation of the rotating tank 2, but the rotation of the motor 7 is transmitted to the power transmission control mechanism 9 via the belt transmission mechanism 8. While accepting that the motor 7 must be placed at an eccentric position for reasons such as transmission, it was clarified within what range the support point 6a should be positioned with respect to its center of gravity. This will be explained below with reference to FIGS. 1 to 5. First, considering steady rotation, in a standard model washing machine, during steady rotation when the rotation speed of the rotating tub 2 is approximately 900 rpm, the damper mechanism 10 rotates at 15 Hz in the direction of the arrow 14 with respect to the support point 6a.
It vibrates at a fairly high frequency. Now, as shown in FIG.
The distance between the support point 6aR on the side is XR, and the distance between the center of gravity G and the support point _6aL on the motor 7 side is
X _L , the spring constant of the compression coil spring 13 located at each support point 6aR, _6aL is k, the total mass of the vibration system is M, the damping coefficient of each damper mechanism 10 is c,
Each support point portion 6a _L and 6aR of the compression coil spring 13
The mutual distance between them is h (h = X _L + XR), the gravitational acceleration is g, the vibration period is T, and XR is X _L
Let the ratio divided by XR/X _L be e. On the other hand, the fourth
α shown in the figure is the angle at which the support member 6 and the water receiving tank 1 are tilted together with the horizontal line 16 passing through the center of gravity G (the tilt angle in the direction of the seat jump) due to vibration. As a result of analysis by the inventor, it was found that the value of α that does not cause the seat jump phenomenon is expressed by the following equation (i).

α = Mg / 2kh (4C / TK - 1) · 1 / e [rad] ... (i) And, considering the standard washing machine currently used with a plastic tab, M x g = 15 ~30Kg, T = 1/15 (second), k = 1.3~2 (Kg/cm), h = 25~35cm, so substitute this into formula (i) and find that it belongs to the lowest value in the above numerical range. The value of α that does not cause the jumping phenomenon in a small capacity washing machine is determined by the following equation (ii).

α=1/200c−4.3・1/e …(ii) In addition, the following equation (iii) is obtained when determining the value of α that does not cause the jumping phenomenon in a large-capacity washing machine that belongs to the maximum value in the above numerical range. .

α=1/140c−4.7・1/e ...(iii) According to equations (ii) and (iii) above, the larger the value of c, that is, the higher the damper effect, the smaller α becomes. It can be seen that the jumping phenomenon is more likely to occur. In addition, in a washing machine, the friction tube 12 shown in FIG.
Once moved downward, the damper mechanism 10 may be used up to the maximum critical damping, which is the limit of the range that can be increased by the repulsive force of the compression coil spring 13, so this value It is necessary to take measures to prevent this phenomenon from occurring. Therefore, the value of α at critical damping is determined.
At this time, the damping value c in one of the four damper mechanisms 10 is expressed by the following equation (iv). Nao co
is the damping value at critical damping.

In the above case, c=0.141 to 0.247 is generally determined, so the value of α that does not cause the jumping phenomenon in a small-capacity washing machine shown in equations (ii) to (v) can be found, In addition, the value of α that does not cause the jumping phenomenon in a large-capacity washing machine as shown in equation (vi) can be found from equation (iii).

α=0.042×1/e[rad] =2.41×1/e[deg] ……(v) α=0.034×1/e[rad] =1.95×1/e[deg] ……(vi) In addition, α in equations (v) and (vi) is expressed by converting the movement speed of the damper mechanism 10 alone when it is under critical damping into the inclination angle of the vibration system (particularly the support member 6). Therefore, a large value of α means that the speed of the damper mechanism 10 when expressed in terms of angle is high and the ability to follow the support point portion 6a is high.

On the other hand, the amplitude of the inclination of the water receiving tank 1 that occurs during steady rotation is generally found to be approximately the maximum practical amplitude when an unbalance of 1.5 kg occurs at the bottom of the rotating tank experimentally. Currently, quality is determined based on this value on the production line. It is also well known that the tilt angle (tilt amplitude) α in steady state from this point of view is expressed by the following equation (vii).

α=mu・rl/I...(vii) where mu is the unbalanced mass, l is the unbalance occurrence position (vertical distance from the center of gravity to the unbalanced mass point), r is the radius of the unbalanced load, I
is the moment of inertia. For standard washing machines with plastic tubs, mu =
1.5/980, r is 12 for small capacity, 15 for large capacity, l is 8 for small capacity, and 8 for large capacity.
10, I is for small capacity and 5 is for large capacity.
Since it is generally about 10, these are (vii)
Substituting into the formula, the value of α (α1) for small capacity
is as shown in equation (viii), and in the case of large capacity, the value of α (α2) becomes as shown in equation (ix).

α1 = 0.029 [rad] = 1.7 [deg] ... (viii) α2 = 0.023 [rad] = 1.3 [deg] ... (ix) It goes without saying that this value was confirmed to be approximately the same as the experimental value. be. Now, in FIG. 5, where α is plotted on the vertical axis and e is plotted on the horizontal axis, the characteristic curve 17 is
The characteristic curve 18 is obtained by the formula (v), and the characteristic curve 18 is obtained by the formula (vi). Therefore, the characteristic curves 17 and 18
This means that the larger the value of α, the higher the movement speed of the damper mechanism 10 in the small-capacity and large-capacity standard washing machines, respectively. By the way, as shown in equations (viii) and (ix), in an actual washing machine, the maximum tilt amplitude during steady rotation, that is, the maximum tilt angle α, is α1 for a small capacity one.
(1.7deg), and α2 (1.3deg) for large capacity ones, which are shown in Figure 5. Then, as is clear from FIG. 5, if a range e is set between the two intersections A1 and A2 of the straight line α1 and the curve 17, the damper mechanism 10 can move faster than the support member 6 in this range. Therefore, the seat jumping phenomenon will not occur. The range of e that satisfies this is expressed by equation (x) as shown in FIG.

0.7≦e≦1.4 ...(x) Here, e is X _R / _XL as mentioned above, and in the embodiment of the present invention, the same parts as in FIG. 3 are shown with the same reference numerals. It is configured as follows. That is, in FIG. 6, among the four support point portions 6a of the support member 6, one diagonal line 15 on which the motor 7 is disposed
The supporting point portion located above is conventionally indicated by two-dot chain lines 6a _L , 6
As shown by a _R , the distance from the conventional water tank 1 was the same for both (the remaining two supporting points 6a,
6b is also the same). On the other hand, in this embodiment, the distance from the water receiving tank 1 to the support point on the motor 7 side is longer than that of the conventional one, as shown by the solid line _6bL .
Regarding the support point on the side opposite to the motor 7, as shown by the solid line _6bR , the distance from the water receiving tank 1 is shorter than that of the conventional case, and it is configured to satisfy 0.7≦e≦1.4. As a result, the damper mechanism 10 can reliably follow the movement of the support point portions (portions shown as 6b _R , 6b _L , and 6a) of the support member 6 of the water receiving tank 1 even during abnormal vibrations, and has critical damping. Even in the state of use, it is possible to reliably prevent the phenomenon of the support point part from jumping.

Therefore, if the hanging position of the water tank 1 in the outer box 5 is slightly shifted toward the shortened support point _6bR side, the vibration system, for example, the support member 6 or the damper mechanism 10,
Alternatively, since it is possible to prevent only one side of the water tank from vibrating strongly and colliding with the outer box, it is possible to avoid increasing the size of the outer box and, of course, to reduce vibration noise.

By the way, in setting X _R and _XL that satisfy the above equation (x), the position of the center of gravity G becomes a problem, but in the present invention, the tub (water tank 1) and the mechanical parts provided therein (mainly the motor 7, Since the position of the center of gravity G determined by the belt transmission mechanism 8 and the power transmission control mechanism 9) satisfies equation (x), the support point 6
It is possible to prevent the seat jump phenomenon by simply setting the positions of b _R and 6b _L , and the configuration is simpler than one in which the position of the center of gravity G is adjusted by providing a new weight.

In the above description, as shown in FIG. 3, the case where one motor 7 is disposed on one diagonal line among the four support points 6a of the support member 6 is used as an example. As shown in Figure 7, two diagonals 2
The present invention can also be applied to a configuration in which one motor 7 is disposed at an intermediate position between 0 and 21, and the position of the support point in that case is shown in FIG. , the conventional one is shown by two-dot chain lines 6a and 6a, the one according to the present invention is shown by 6b _R and 6b _L , and X _R and _XL are also shown. It goes without saying that the present invention can also be applied to a single-tub type dehydrating/dehydrating washing machine having only a non-porous rotary tub as a tub.

As described above, the present invention improves the damping effect when the tab is made of plastic and the tab is elastically suspended by the suspension rod via the damper mechanism and collides with the outer box during abnormal vibration. To provide a dehydrating and washing machine capable of reliably preventing a seat jumping phenomenon caused by abnormal vibration without requiring adjustment of the center of gravity position using a weight and without increasing the size of an outer box. Can be done.

[Brief explanation of drawings]

Figures 1 to 5 are for explaining the vibration phenomenon. Figure 1 is a schematic vertical cross-sectional view of a washing machine with dehydrating function, Figure 2 is an enlarged vertical cross-sectional side view of the damper groove, and Figure 3 is a vertical cross-sectional view of the damper groove. 4 is a bottom view of the motor support portion, FIG. 4 is an explanatory diagram of the tilting phenomenon of the support member, and FIG. 5 is a characteristic curve diagram. FIG. 6 shows a third embodiment of the present invention.
FIG. 7 is a diagram equivalent to FIG. 3 showing another example to which the present invention is applied. In the figure, 1 is a water tank (tab), 4 is a hanging rod, 6a,
6a _R , 6a _L , 6b _R , and 6b _L are support point portions, 7 is a motor, and 10 is a damper mechanism.

Claims (1)

[Claims] 1 A power transmission control mechanism is arranged in the center of the lower part of the plastic tab, and one motor is arranged in an eccentric position, and both are connected by a belt transmission mechanism, and this tab is connected to the lower part of the tab. A plurality of swingable suspension rods each having a damper mechanism are provided, and support points of a plurality of support members provided on the tabs so as to protrude outward are moved up and down along the suspension rods. In a damper mechanism that is supported by being placed on a receiving part of the damper mechanism, the center of gravity of the tab and the power transmission control mechanism, motor, and belt transmission mechanism provided thereon passes through the center of the tab. Regarding the direction, the ratio of the distance X _R from the center of gravity to the support point on the side opposite to the motor divided by the distance X _L from the center of gravity to the support point on the motor side is in the range of 0.7 or more and 1.4 or less. The dehydrating/washing machine is characterized in that the distance from the tab of the support point portion on the side opposite to the motor is shortened, and the distance on the support point portion on the motor side is lengthened.