JPH0453586A - Band brake device for washing machine - Google Patents

Abstract

PURPOSE:To obtain an optimum brake torque value even if curvature or assembling precision is slightly disordered by forming a lining fixed to the inside of a tie plate band and making contact with a drum surface in the inside layer out of a material having a high wear rate and from the inside layer toward the outside layer out of materials getting lower in wear rates. CONSTITUTION:A lining 43 is formed in the inside layer 43a of a friction material having a high wear rate, in the outside layer 43c of a friction material having a low wear rate, and in the middle layer 43b of a friction material having a wear rate nearly middle between the inside layer 43a and the outside layer 43c. When the curvature or assembling precision of a band 41 is slightly disordered, and an unevenness of the contact pressure of the lining 43 to a drum surface 17a appears at the time of initial movement of operation of a brake band 39, the lining 43 is highly worn in the strong contact state position and slightly worn in the light contact state position, and consequently, the contact pressure is automatically corrected over the whole range to ensure a nearly equal contact pressure in the whole area of the lining 43, and a normal brake torque can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) This invention relates to a band brake device for a washing machine that is excellent in braking performance.

(Prior Art) In general, in a double type washing machine in which a dehydration tank is installed inside the washing tub, the rotation of the dehydration tank is forcibly stopped at the end of the dehydration process or in an emergency, or A brake device is provided that restrains the movement of the dehydration tank in the washing mode and prevents co-rotation caused by the water flow.

The band brake device consists of a brake drum installed at the bottom of the washing tub and a brake band that can be moved into and out of contact with the drum surface of the brake drum using a brake lever, and the brake band is in strong contact with the drum surface. By matching, a braking condition is ensured and the movement of the dehydration tank is restrained.

(Problem to be Solved by the Invention) As mentioned above, in a dehydration tank, a braking state and a braking release state can be obtained by the brake band coming into contact with or separating from the drum surface, but the normal brake torque value This is achieved through correct contact of the brake band lining with the drum surface over its entire area.

Brake bands have a relatively high bending rigidity because they are made of a metal band with a lining fixed to the inside. For this reason, if processing control is neglected, the curvature and attachment of the band tend to be inaccurate, making the contact between the lining and the drum surface unstable, and making it difficult to obtain a regular brake torque value.

As a way to solve this problem, for example, by making the brake band thinner and having a shape that suppresses bending rigidity, it can adapt to the drum surface and conform to the shape even if there is a slight deviation in curvature etc. However, since the band becomes thinner, the surface rigidity is insufficient, causing a new problem of resonance and squealing noise during braking.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a band brake device for a washing machine in which an optimum brake torque value can be obtained even if there is a slight deviation in the precision of curvature and assembly.

[Configuration of the Invention (Means for Solving the Problem) In order to achieve the above object, the present invention includes a brake drum provided at the bottom of the washing tub, and a brake lever that controls the drum surface of the brake drum. In a band brake device for a washing machine, the brake band is comprised of a brake band that can be moved into and out of contact with the brake. It is formed of a strip-shaped band connected to a lever, and a lining that is fixed to the inside of the band and comes into contact with the drum surface of the brake drum,
The inner layer of the lining is made of a material with a high wear rate, and the wear rate gradually decreases from the inner layer to the outer layer.

(Function) According to such a band brake device for a washing machine, at the initial stage of operation, if the curvature or assembly becomes slightly inaccurate and the contact pressure between the lining and the drum surface varies, the contact pressure becomes strong. The lining wears out quickly in certain areas, and the wear in areas where the contact pressure is weak is kept to a minimum, so that the entire area of the lining is in almost equal contact with the drum surface.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings of FIGS. 1 to 5.

In the figure, reference numeral 1 indicates a washing machine main body, in which a washing tub 5 is suspended and supported by four suspensions 3 made of wires and springs.

A drain hose 7 is connected to the bottom of the washing tub 5.

A dehydration tank 9 is arranged inside the washing tub 5, a balancer 11 is provided at the top, and a pulsator 13 is provided at the bottom, and the pulsator 13 is spline-fitted to the first transmission shaft 15. A mounting flange 21 for a second transmission shaft 19 equipped with a brake drum 17 is coupled and supported at the bottom of the dewatering tank 9 .

The second transmission shaft 19 is attached to the base plate 23 at the bottom of the washing tub 5.
is attached and rotatably supported by a bearing 27 of a brake drum cover 25 that covers the brake drum 17.

A pulley 29 is attached to the first transmission shaft 15, and this pulley 2
Reference numeral 9 is electrically coupled to a pulley 33 of a drive motor 31 via a V-belt 35, and the driving force from the drive motor 31 input via the V-belt 35 is transferred to the first transmission shaft by switching the clutch 37. 15 or the second transmission shaft 19, respectively.

Therefore, by transmitting the driving force to the first transmission shaft 15, the pulsator 13 can be rotated, and the second transmission shaft 1
The rotation of the dehydration tank 9 is made possible by transmitting the driving force to the dehydration tank 9.

As shown in FIG. 1, the drum surface 17a of the brake drum 17 is provided with a brake that is in a braking state (solid line) in which it comes into contact with the drum surface 17a and restricts its movement, and in a braking release state (dashed line) in which it is separated from the drum surface 17a. A band 39 is provided.

The brake band 39 consists of a metal band 41 and a lining 43 fixed to the inside of the band 41. The band 41 has a band-like shape that follows the curvature of the drum surface 17a, and one end is fixed to the outer peripheral surface of the brake drum cover 25 by bolts 45. The other end is bent along the drum surface 17a, then extended straight along the tangential direction, and pivoted to the brake lever 47.

The lining 43 of the brake band 39 is made of a friction material such as cast iron, bronze, vapor, organic material, or sintered alloy, and the wear rate is determined by changing the proportion of the friction material. It has a 3-layer laminated structure. The inner layer 43a is made of a friction material with a high wear rate.
3c is made of a friction material with a low wear rate. The intermediate layer 43b is formed of a friction material that has a wear rate approximately between that of the inner layer 43a and the outer layer 43c. It is set to be smaller.

The brake lever 47 can be switched around a lever shaft 53 by power from a drive motor (not shown), and is constantly biased clockwise (arrow A) in FIG. 1 by a biasing spring 55.

According to the band brake device configured in this way, during the initial operation of the brake band 39, the band 4
1. The curvature and installation of No. 1 may cause a slight deviation in accuracy, and the contact pressure of the lining 43 against the drum surface 17a will be strong in some places and weak in some places, as shown in Figs. 4 and 5. As a result, the contact pressure is automatically corrected over the entire area, ensuring almost equal contact pressure over the entire area of the lining 43, and a regular brake torque value can be obtained. .

In this embodiment, automatic correction of the lining 43 in the longitudinal direction has been described, but the same applies to automatic correction of the lining 43 in the width direction.

Furthermore, the lining 43 has a structure in which three layers of friction materials with different wear rates are stacked one on top of the other, but it does not necessarily have to be a laminate structure, and the mixing ratio of the friction materials changes from the inside of the lining 43 to the outside. It is also possible to obtain it by changing .

[Effects of the Invention] As explained above, according to the band brake device for a washing machine of the present invention, even if there is a slight deviation in the accuracy of the curvature and attachment of the band, the inside of the lining is made of friction material with a high wear rate. As a result, areas with strong contact pressure wear out faster than areas with weaker contact pressure, and the contact pressure is automatically corrected, ensuring almost uniform contact pressure over the entire lining area and allowing the normal brake torque value to be obtained. .

[Brief explanation of the drawing]

Fig. 1 is a cutaway plan view showing the band brake device of the present invention, Fig. 2 is a cutaway side view of the whole washing machine, Fig. 3 is an exploded perspective view of the brake band, and Fig. 4 is an exploded perspective view of the brake band. The plan view and FIG. 5 are explanatory diagrams showing the state of wear of the lining. 9... Dehydration tank 17... Brake drum 17a... Drum surface 25... Brake drum cover (body case) 39.
... Brake band 41 ... Band 43 ... Lining 47 ... Brake lever

Claims (1)

[Claims] A band brake device for a washing machine comprising a brake drum provided at the bottom of a washing tub, and a brake band that can be moved into and out of contact with the drum surface of the brake drum by a brake lever, wherein one end of the brake band is connected to the main body. A strip-like band that is coupled to the case and bent along the drum surface of the brake drum, and whose other end is coupled to the brake lever; and a lining that is fixed to the inside of the band and comes into contact with the drum surface of the brake drum. A band brake device for a washing machine, characterized in that the inner layer of the lining is made of a material with a high wear rate, and the parts from the inner layer to the outer layer are made of materials with a gradually lower wear rate.