JPH03162896A - Balance ring for washing machine - Google Patents

Abstract

PURPOSE:To obtain the balance ring of a small deformation amount even when hot water is used by providing a metallic reinforcing member in an internal part so as to hold the air-tightness of fluid and to be abutted to one of the inner periphery or outer periphery, at least, of the almost hollow ring-shaped balance ring composed of a synthetic resin. CONSTITUTION:A balance ring 6 composed of the synthetic resin with low rigidity cancels imbalanced load to be generated by the eccentricity of laundry in a bucket 5 at the time of centrifugal dehydration and the concentration of internal fluid (water with salt 14) on the opposite side. The force caused by the fluid is operated in a direction opposite to force to be generated by the imbalance of cloth and therefore, the force becomes canceling force as resultant force. However, in respect to the balance ring, the force becomes force to pull in the opposite direction and deformation is promoted. In order to cancel this deformation, a metallic ring 16 is arranged so as to be abutted to one of the outer periphery and inner periphery, at least, of the balance ring 6 and the rigidity is increased so as to prevent the deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improving the strength of a washing/drying tub and a balance ring of a fully automatic washing machine. [Conventional technology] The operating principle and effects of the balance ring are explained in the machine and
Design September! (1950) pp. 119-12
4 pages (MACI{INE DESIGN SeP., (
1950) ppll9-124), and an example of its application to a fully automatic washing machine is described in JP-A-63-2.
Discussed in No. 06284. However, these do not discuss the strength and deformation of the centrifugal force generated by the uneven distribution of fluid within the balance ring. However, in actual use, unbalanced loads caused by uneven distribution of fabric and centrifugal force caused by uneven distribution of fluid occur, deforming the balance ring. Particularly in recent years, hot water has been used to wash laundry, and the flexural modulus of composite II resin has a strong temperature dependence, and there is growing interest in the deformation of balance rings. [Problems to be Solved by the Invention] As described above, the above-mentioned conventional technology does not take into consideration the prevention of deformation of the balance ring when hot water is used, and when dehydrating using hot water, the balance ring deforms. There were problems such as contact with the outer tank. The purpose of the present invention is to provide a balance ring that has a small amount of deformation even when using hot water. [Means for solving the problem] In order to achieve the above object, a metal ring is arranged so as to contact at least one of the outer periphery and inner periphery of the balance ring to increase rigidity and prevent deformation. This is what I did. [Function] The backup ring of the present invention is used in the same way as a hoop around a bucket, for example.It works to prevent deformation of the balance ring made of synthetic resin, which has low rigidity, so deformation is prevented. can.

〔Example〕

An embodiment of the present invention will be explained below with reference to FIGS. 1 to 6. In Fig. 1, a box-shaped outer frame 1 made of steel plate includes an outer tank 4 made of synthetic resin, which is supported by hanging rods 2 and anti-vibration springs 3.
is supported with anti-vibration support. A rib 4a is formed on the side wall of the outer tank 4 to which a hanging rod 2 and a vibration isolating spring 3 are attached.
Inside the outer tank 4, a washing/drying tank 5 made of synthetic resin and having a substantially circular cross-sectional shape is provided. A balance ring 6 made of synthetic resin is attached to the upper end of the washing and dehydrating tank 5 by means such as ultrasonic welding. The detailed configuration of the balance ring 6 will be described later. A large number of vertical grooves 5a are provided at equal intervals on the side wall of the washing and dewatering tank 5. A large number of dehydration holes 5b are provided in the vertical groove 5a. A rotary blade 7 is arranged at the center of the inner bottom of the washing and dewatering tank 5. A tub cover 8 made of synthetic resin is fixed to the upper end of the outer tub 4 to prevent laundry from falling between the outer tub 4 and the washing and dehydrating tub 5. At the outer bottom of the outer tank 4, a drainage device 9,
A drive device 10 for rotating the rotary blade 7 and the washing/dehydration tank 5 is attached via a support made of steel plate. Next, the details of the balance ring 6 will be explained with reference to Fig. 2. The balance ring force bar 11 and the balance ring case l2 are airtightly joined at welds 15a and 15b.
Salt water 14 is sealed inside. The backup ring 16 is made of metal and has a shape that roughly follows the inner circumference of the balance ring 6. A top force bar 21 is arranged at the top of the outer frame 1, and a control device for controlling a series of washing processes, a water supply device, etc. are installed inside. Further, the power of the drive motor 15 is transmitted to the drive device 10 via a belt 17.
It is transmitted to A drainage system M9 is provided at the bottom of the outer tank 4, and drains the water in the tank to the outside of the machine via a drainage hose 13.
Next, we will explain the operation. Water is supplied into the basket up to a predetermined water level according to a command from a control device (not shown) located inside the top cover 13. When a predetermined water level is reached, the motor 5 is energized and the rotor blades 7 are rotated to start the washing process.6 The rotation speed of the rotor blades 7 is approximately 150 to 250 revolutions per minute, for example, clockwise rotation (manuseconds). Pause (0.5 seconds), turn left (
It rotates in a short period such as 1 second). When the washing process is carried out for a predetermined period of time (for example, 10 minutes), the drain valve opens and the washing liquid is discharged from the drain hose 13 to the outside of the machine.
When a predetermined amount of water is discharged, the dewatering process is started by the drive unit 110. After spin-drying the laundry for a predetermined time and centrifugally dehydrating the washing liquid contained in the laundry, the rotation of the basket 5 is stopped by a brake mechanism (not shown) and water supply is started. When the water reaches a predetermined level, the water supply is stopped and the rinsing process begins. After rinsing for a specified period of time, drainage and dehydration will occur. Next, enter the second rinsing process, and after supplying water, rinsing, and draining water in the same manner, perform the final dehydration. Next, the balance ring 6, which is the main point of the present invention, will be explained. The operating principle of the balance ring 6 is detailed in the above-mentioned literature, so it will be omitted here, but the main point is that in centrifugal dehydration, the internal fluid (in the case of the present invention) In this case, the salt water 14) collects and tries to cancel out the unbalanced load caused by the unevenness of the laundry.6 It should be noted here that the force due to the fluid is in the opposite direction to the force generated by the unbalanced fabric. The resultant force is a counteracting force, but the balance ring 6 becomes a pulling force in the opposite direction, promoting deformation. Now, in recent years, the use of enzyme-containing detergents that contain enzymes in laundry detergents has rapidly become widespread. These enzymes are said to be most effective when used with warm water of approximately 40°C to 60°C. In addition, in Europe and the United States, due to water quality issues, it is also customary to wash clothes using warm water of approximately 80°C.
When using high-temperature water in this way, problems arise with the strength and deformation of the synthetic resin parts often used in washing machines. Figure 3 shows an example of the temperature dependence of the flexural modulus of polypropylene resin, which is often used for the basket 5 and balance ring 6. On the other hand, as described above, the basket 5 and the balance ring 6 are subjected to an unbalanced load due to uneven distribution of cloth and an unbalanced load due to uneven distribution of fluid, respectively. This is shown in Figure 4(a) in the L model. However, it is assumed that the above two loads are equal. When such a load is applied, the basket 5 and balance ring 6 deform into an ellipse as shown in FIG. 4(b). If this deformation is large, the basket 5 or balance ring 6 will come into contact with the outer tank 4 during centrifugation, and in the worst case, a hole will be formed in the outer tank 4. Therefore, it is important to minimize this deformation as much as possible. This amount of deformation is represented by ΔX in Fig. 4(b) and is expressed by the formula shown below. Here, W: load, R: radius of balance ring, E: elastic modulus of material, A: cross-sectional area of balance ring, K: coefficient related to cross-sectional shape. As can be seen from this equation, the amount of deformation is inversely proportional to the elastic modulus of the material. I understand that. In other words, as seen from Figure 3, the amount of deformation is approximately 1.7 times greater at 40°C than at 20°C, 6
At 0°C, the amount of deformation is approximately 3.2 times greater, and at 80°C, the amount of deformation is approximately 5.2 times greater. On the other hand, strengthening polypropylene resin by means such as mixing glass fibers has a limit to the strength reduction mentioned above. However, polypropylene resin has excellent properties such as versatility and ease of welding, and currently there is no resin that can replace it. Accordingly, as in the present invention, by forming the liquid sealing portion in the form of an abutment or using a back-up ring 6 for strength compensation, a balance ring 6 with sufficient strength can be provided at low cost. As an example, if the amounts of deformation in the synthetic resin balance ring and the steel plate backup ring shown in Figures 5 and 6 are respectively ΔA and ΔB, then ΔA ΔB, and the strength can be improved by about 28 times with a simple structure. Recognize. In other words, it can be seen that even when used at 80°C, it has greater strength than a balance ring made of only synthetic resin at 20°C. 7-8 show other embodiments.

In addition, other effects can be expected from the embodiment of the structure shown in Figure 2. That is, since the balance ring 6 is sealed, as the temperature rises, the internal pressure rises. This increase in internal pressure is the sum of the increase in air temperature and the increase in vapor pressure of salt water. Assuming that the vapor pressure of salt water is equal to the vapor pressure of water, O
℃ and used at 80℃, the air pressure increase ΔP. is 27 3 -0.29 (kg/aJ) The vapor pressure increase ΔPv is ΔPv = 0.4 8 - 0.0 1-0.47
(kg/J) However, the above values are based on the water vapor table. From the above, the total pressure increase ΔP is ΔP=ΔP&+ΔPv =0.76 (kg/J). This pressure will be applied to the entire inner surface of the balance ring 6. As mentioned above, the balance ring cover 11 and the balance ring case 12 are generally welded together, but the tensile strength of this welded part is lower than the tensile strength of the base material. Furthermore, the tensile strength of the base material itself decreases as the temperature increases. Therefore, when used at high temperatures, there is a risk of the welded part being destroyed, but with the structure shown in Figure 2, the backup ring 16 will receive the vertical force, ensuring the reliability of this part. It also has effects. FIG. 9 shows an embodiment in which the washing and dehydrating tub 5 is made of metal. In this embodiment, the backup ring 16 constitutes a part of the washing and dehydrating tank 5, and is an example in which the backup ring 16 is integrated. [Effects of the Invention] Since the present invention is configured as explained above, it produces the effects as described below. In other words, since the salt water sealing part of the balance ring is made of synthetic resin, it is easy to weld and has excellent airtightness. In addition, by using a metal backup ring, the strength of the balance ring as a ring can be ensured, and deformation of the balance ring due to unbalanced forces caused by uneven distribution of cloth can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a fully automatic washing machine according to an embodiment of the present invention, Fig. 2 is a detailed view of the main parts of the present invention, Fig. 3 is a diagram showing the relationship between the bending elastic modulus of polypropylene resin and temperature, and Fig. Figure 4(a) is a load state diagram, Figure 4(b) is a diagram showing deformation, Figure 5 is a dimensional diagram of a balance ring, Figure 6 is a dimensional diagram of an embodiment of a backup ring, Figure 7, FIGS. 8 and 9 are diagrams showing other embodiments. 1...Outer frame, 5...Washing/water tank, 6...Balance ring, 11...Balance ring force bar 12...Balance ring case, 14...Salt water, 15a, 15b...・Figure 1 Figure 2 Figure 3 Groove degree

Claims (1)

[Claims] 1. In a washing machine having a substantially hollow annular balance ring made of a synthetic resin that keeps fluid airtight therein, and a substantially bottomed cylindrical dewatering tank having the balance ring at least on the open end side, the interior of the balance ring is A balance ring for a washing machine, characterized in that a metal reinforcing member is provided in contact with at least one of the periphery or the outer periphery.