JPH0343920B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a single-tub washing machine that performs washing, rinsing, and dehydration in the same tank, and in particular, in the rinsing process, the inner tank is intermittently driven with water stored in the inner tank. The purpose is to prevent the water level setting pressure switch from malfunctioning during the rinsing process.

Single-tank washing machines in which the inner tank is driven intermittently by setting the water volume lower than the rated water volume during the rinsing process (e.g., Japanese Patent Application No. 105309/1983, Utility Application No. 1983-1986)
52320), the inner tank 1 as shown in Figure 1.
A flange 3 having a plurality of water holes 2 in the circumferential direction is attached to the bottom of the flange 3, a water pipe 5 is connected to the flange 3 via a water reservoir case 4, and a pressure switch is installed at the end of the water pipe 5. The water pressure inside the inner tank 1 is detected by In addition, 6 is a rotating blade, and 7 is a washing shaft.

In this way, the cross-sectional shape of the conventional water inlet 2 is
As shown in the figure, most of them were approximately vertical or tapered to the extent of a draft angle. However, when the inner tank 1 is driven intermittently, the clothes 8 adhere to the inner wall of the inner tank 1 due to the centrifugal force, the water surface becomes almost parabolic, and the water passage hole 2 formed in the flange 3 also becomes attached to the inner wall of the inner tank 1. Since it rotates at the same time as tank 1, the center of the water surface drops to point A in Figure 1, and at this time, the water pressure acting on the pressure switch is equal to the distance l1mm between point A and the lowest point of the water pipe. Water pressure obtained by
It becomes l1mmH ₂ O.

On the other hand, the contacts of a pressure switch (diaphragm mechanism) need to have a quick-break, quick-on mechanism due to the inrush current, and for this reason, they generally use a toggle mechanism that uses the reaction force of a spring. be. According to this mechanism, there is a trip operating point where the water pressure in the inner tank 1 increases and the contact of the pressure switch switches from the OFF state to the ON state, and conversely, the water pressure decreases and the contact point of the pressure switch switches from the ON state to the OFF state. A reset trip point exists.

During the rinsing process, it is necessary to prevent the pressure switch contacts from resetting, and to do this, reduce the reset operating pressure of the pressure switch.

Suppresses changes in the water level while the washing machine is operating.

There is a method that can be considered, but in this case, it is technically difficult to extremely reduce the reset operating pressure due to mechanical problems and considering operating variations (product variations, temperature variations, etc.). , so it is more effective to proceed in the direction of .

The present invention provides a one-tub type dehydrating washing machine that reduces the degree of water level change seen in the prior art.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 2, 10 is a housing of a washing machine;
is an inner tank having a non-porous peripheral wall except for at least the upper end, and is configured to perform washing, rinsing, and dehydration inside the tank, and a balance ring 12 is provided at the upper opening, and a flange 13 is provided at the bottom. Equipped. One end of a dewatering shaft 14 is fixed to the flange 13, and a plurality of water holes 15 having approximately the same diameter are formed in a downwardly expanding shape. Reference numeral 116 denotes a water reservoir case, which is watertightly provided to the flange 13 and dewatering shaft 14 via oil seals 17 and 18;
Further, a water passage hole 19 is bored in a part of the bottom, and this water passage hole 19 communicates with a plurality of pressure switches 21 and 22 via a water passage pipe 20. 2
Reference numeral 3 denotes a ring body made of a flexible rubber material or the like, with one end being a water reservoir case 16 and the other end being an outer tank 24.
are fixed watertightly to each other. 25 is the inner tank 11
It is a rotary blade provided at the center of the bottom of the washing machine, and is fixed to one end of the washing shaft 26. The washing shaft 26 and the dewatering shaft 14 are arranged coaxially, and a bearing box 27
Washing/dehydration switching clutch built in (not shown)
It is connected to the pulley 26 via. A motor 29 is interlocked with the washing shaft 14 or the dewatering shaft 26 via a motor pulley 30, a V-belt 31, and a pulley 28. Reference numeral 31 denotes a vibration isolator which suspends and holds an outer tank 24 in which the inner tank 11 is rotatably housed, a vibration system including a motor 29, etc. from the upper four corners of the housing 10. 33 is a drain provided at the bottom of the outer tank 24;
4 is a drain port provided at the bottom of the housing 10, and a drain pipe 35
It communicates with the drain port 33 via.

Next, the detailed structure and function of the water passage hole 15 will be explained with reference to FIG. A plurality of water holes 15 arranged in an annular manner are bored in the center of the flange 13, as shown in FIG. Dimension φD between the outer walls 15a at the upper end of the water inlet 15 facing each other
and the dimension φd between the outer wall 15a at the lower end, there is a relationship of φD<φd. 36 is clothing.

Now, when considering the rinsing process, when the inner tank 11 is intermittently rotated with water stored in the inner tank 11,
The water level in the inner tank 11 forms a substantially parabolic shape due to the centrifugal force, and as the rotational speed further increases, the water level in the center further decreases and finally reaches the inside of the water inlet 15. This is because the flange 13 forming the water inlet 15 also rotates in the same manner as the inner tank 11 (forming the water surface shown by the broken line in FIG. 3).

However, as mentioned above, the outer wall 1 of the water inlet 15
If the water inlet 5a is tapered to open downward, when the water located in the water inlet 15 receives a force Fa due to centrifugal force, a force Fb will flow downward along the tapered surface. Therefore, the water in the water inlet 15 will not flow upward. That is, the pressure acting on the water pressure switches 21 and 22 is
The water pressure obtained by the distance l ₂ mm between the lowest point of the water pipe 20 and the upper end of the water port 15 is l ₂ mmH ₂ O
And, as mentioned above, the component force directed downward due to centrifugal force:
Fb becomes a composite form, and the conventional example (see Figure 1)
The difference is large compared to the working pressure l ₁ mmH ₂ O in the case of .

Note that the water passage port 15 can also be formed so that the outer walls 15a are inclined in the radial direction so as to expand downward relative to each other as shown in FIG. 4, and in this case, the same effect can be obtained.

As described in detail in the embodiments above, in the present invention, since there is no protrusion inside the water inlet, it is possible to suppress a decrease in the water pressure acting on the pressure switch, and
Since the component force Fb is applied, the pressure decrease is further reduced, and the reset point operating pressure of the pressure switch can be increased. Therefore, the reliability of the pressure switch is improved, and it is also advantageous in terms of cost.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the main parts of a conventional single-tub dehydrating washing machine, Fig. 2 is a longitudinal cross-sectional view of a washing machine showing an embodiment of the present invention, and Fig. 3 is a detailed view of the main parts of the washing machine. , FIG. 4 is a detailed view of main parts showing another embodiment. 11 is an inner tank, 13 is a flange, 14 is a dewatering shaft,
15 is a water inlet, 15a is an outer wall, 16 is a water reservoir case, 20 is a water pipe, and 21 and 22 are pressure switches.

Claims (1)

[Scope of Claims] 1. The peripheral wall excluding at least the upper end is a non-porous wall, and a plurality of water holes are provided at the center of the lower part of the inner tank where dehydration and washing are performed, and the water inside the inner tank is provided through the water holes. In a single-tank dehydrating washing machine that is equipped with a pressure switch that detects water pressure and that drives the inner tub intermittently during the rinsing process, the dimension between the outer walls of the upper end of the water openings that face each other is determined for each passage. A single-tank dehydrating washing machine characterized by having a dimension smaller than that between the outer walls at the lower end of the water spout. 2. The one-tub dehydrating washing machine according to claim 1, wherein each of the water passage ports has approximately the same diameter and is inclined to spread downward relative to each other. 3. A single-tank dehydrating washing machine according to claim 1, characterized in that each water passage port is formed such that the outer wall surface in the radial direction of the inner tank is inclined so as to expand downward.