KR100559872B1 - A shoe hole down spring in drum type brake system - Google Patents

Abstract

The present invention relates to a shoe hold down spring of a drum type brake, comprising: a pin member extending downward from a head portion located at an upper portion of a web of a shoe, penetrating a back plate, and having a lower end fixed to a lower surface of the back plate; A fluid spring part interposed between the upper surface of the web of the shoe to generate elastic force by hydraulic pressure, and supplying a working fluid to the fluid spring part when the fluid spring part is compressed, and when the fluid spring part is extended, the fluid spring And an operating means for recovering excess working fluid from the portion. According to the present invention, by generating the buffer force against the behavior of the shoe by the action of the fluid during the brake operation, the rim of the shoe is seated on the back plate after the brake operation, the impact noise is not generated.

Description

Shoe hold down spring in drum type brake system

1 is a partially exploded perspective view of a general drum type brake;

2 is a side view of FIG. 1;

3 is a cross-sectional view of the "AA" portion of FIG.

(A) to (c) a view for explaining the structure and operation of the conventional shoe hold down spring,

5 is a schematic view for explaining the structure of the shoe hold down spring of the drum brake according to the present invention;

6 is a schematic view for explaining the action of the shoe hold down spring shown in FIG.

<Description of Symbols for Main Parts of Drawings>

12: back plate 13: shoe

13a: Web 13b: Rim

100: shoe hold down spring 101: head

102: pin member 103: fixing member

110: fluid spring portion 120: operating means

121: cylinder 122: piston member

123, 124: working rod 125: Euro

F: working fluid

The present invention relates to a shoe hold down spring of a drum type brake, and more particularly, to a shoe hold down spring of a drum type brake capable of preventing the occurrence of an impact sound when the shoe is returned from being lifted from the back plate when the brake is operated.

In general, a brake system is classified into a main brake mainly used for driving and a parking brake used for parking a car, and the main brake includes hydraulic or pneumatic pressure transmitted by the operation of the brake pedal. It is common to generate a braking force by means of a brake. The main brake presses both a drum brake that brakes by pushing a shoe attached with friction material to a drum that is rotated with the wheel, and a brake pad that presses both disks rotated with the wheel. There is a disc brake adapted to brake.

Here, the drum-type brake, as shown in Figure 1, the brake drum 11 is installed on the wheel hub via the bolt to rotate with the wheel, the back plate 12 is fixed to the axle, and the back A pair of shoes 13 and 14 installed on the front of the plate 12 and the outer side surfaces of the shoes 13 and 14 are attached to the brake drum 11 while being in direct contact with the brake drum 11. The shoe (13,14) to the brake drum (11) via the lining (15), which is a friction material to stop the rotation of the rotation and convert the kinetic energy into heat energy and the air pressure supplied from the hydraulic cylinder or reservoir tank generated in the master cylinder It consists of a wheel cylinder 16 or the like to be compressed.

Here, the shoes 13 and 14 are composed of webs 13a and 14a connected to the wheel cylinder 16 and rims 13b and 14b to which the lining 15 is attached.

3, the shoe hold down spring 20 is installed on the webs 13a and 14a of the shoes 13 and 14 to restrain the axial flow of the shoes 13 and 14. .

As shown in FIG. 4A, the shoe hold down spring 20 has a pin member penetrating from the web 13a of the shoe 13 to the lower surface of the back plate 12. 21, the head portion 22 positioned above the web 13a of the shoe 13, and the head portion 22 upwards between the head portion 22 and the upper surface of the web 13a. It is configured to include an elastic member 23 for supporting the elasticity, and a fixing member 24 for fixing the lower end of the pin member 21 to the lower surface of the back plate 12.

Such, the shoe hold down spring 20, when the brake operation, as shown in Figure 4 (b), restrains it when the shoe 13 is lifted up, and when the brake operation is stopped, by the elastic force As shown in FIG. 4C, the shoe 13 is returned to its original position.

However, according to the conventional shoe hold down spring as described above, when the shoe is lifted and then returned to its original position, the elastic force acts rapidly, so that the lower end of the rim 13b of the shoe collides with the back plate 12 so as to "stiff". There was a problem that the impact sound occurs.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to provide a shoe hold down spring of the drum-type brake that can prevent the generation of impact noise due to the behavior of the shoe during brake operation. have.

The shoe hold down spring of the drum-type braking device according to the present invention for achieving the above object is a shoe hold down spring of the drum type brake that firmly fixes the web of the shoe to the back plate, the lower part of the head from the head portion located above the web of the shoe. A pin member extending through the back plate and having a lower end fixed to the lower surface of the back plate; A fluid spring unit disposed between the head portion and the upper surface of the web of the shoe so as to penetrate the center thereof and generating elastic force by hydraulic pressure; The pin member is installed between the web bottom surface of the shoe and the back plate so as to penetrate the center. When the fluid spring part is compressed, a working fluid is supplied to the fluid spring part. And an operating means for recovering excess working fluid from the portion.

In addition, the present invention is characterized in that the fluid spring portion is configured to include a bellows of a form stretchable in the vertical direction, and the working fluid filled in the bellows.

In addition, the present invention, the operating means, the cylinder is provided in the lower portion of the web of the shoe and the working fluid is filled, the piston member is installed to be movable in the vertical direction inside the cylinder, the lower portion of the web of the shoe Another aspect of the present invention includes an operation rod connecting a surface to an upper surface of the piston member, and a flow path connecting a fluid flow between the cylinder and the fluid spring part.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a schematic view for explaining the structure of the shoe hold down spring of the drum brake according to the present invention, as can be seen with reference to the same figure, the shoe hold down spring 100 according to the present invention, the web of the drum brake ( It is installed between the shoe 13 and the back plate 12 formed of the 13a and the rim 13b, and the head portion 101, the pin member 102, the fluid spring portion 110 and the operating means 120 It is configured to include.

The head portion 101 is located above the web 13a of the shoe 13, and the pin member 102 has an upper end coupled to the head portion 101, and the fluid spring portion 110 and the shoe 13 are separated from each other. It is installed through the web 13a, the actuating means 120 and the back plate 12, and its lower end is fixed to the lower surface of the back plate 12 by the fixing member 103.

The fluid spring portion 110 is interposed between the head portion 101 and the upper surface of the web 13a of the shoe 13 and is made of a bellows that is stretchable in the vertical direction, but the working fluid F is filled therein.

The actuating means 120 is installed below the web 13a of the shoe 13 and filled with a working fluid F, and is movable up and down in the interior of the cylinder 121. Piston member 122 to be installed, the operating rod (123, 124) connecting the upper surface of the piston member 122 and the lower surface of the web (13a) of the shoe 13, the cylinder 121 and the fluid spring portion ( It consists of a flow path 125 connecting the fluid flow between the 110.

Now, the effects of the present invention configured as described above will be described with reference to the accompanying drawings.

First, in a state where the brake is not operated, as shown in FIG. 5, the shoe 13 maintains a state where the lower end of the rim 13b is in contact with the back plate 12.

At this time, when the brake is actuated, as shown in FIG. 6, the piston 13 of the operating means 120 moves upward while the shoe 13 is lifted upward, so that the working fluid F in the cylinder 121 is moved. Will be pressed.

The working fluid F of the cylinder 121 is pushed into the fluid spring part 110 through the flow path 125 by the pressing action according to the movement of the piston member 122, and the working fluid to the fluid spring part 110. As (F) is filled, elastic force is generated, and the upward movement of the shoe 12 is restrained.

When the brake is stopped, the shoe 13 moves downward by the elastic force generated by the fluid spring 110 to return to the original position. In this case, the piston member 122 moves downward according to the movement of the shoe 13. As it moves, negative pressure is generated in the cylinder 121 of the operating means 12 to suck the working fluid F from the fluid spring 110.

Here, the buffer force for the downward movement of the shoe 13 is generated by the negative pressure generated in the cylinder 121 of the operating means 12, and the working fluid F is discharged from the fluid spring part 110 by the negative pressure. As it is sucked into the cylinder 121, the elastic force of the fluid spring portion 110 is gently reduced while the buffer force is generated.

That is, as the shoe 13 returns to a gentle speed due to the buffer force generated by the action of the cylinder 121 and the fluid spring 110 of the operating means 12, the rim 13b of the shoe 13 The lower end is gently seated on the back plate 12, the impact sound is not generated.

The present invention is described above by illustrating specific embodiments, but the present invention is not limited to the above embodiments. Those skilled in the art can easily make various changes and modifications to the present invention, and it should be noted that such variations or modifications are included within the scope of the present invention as long as the features of the present invention are used.

As described above, the present invention generates a buffering force against the behavior of the shoe by the action of the fluid during the brake operation, the rim of the shoe is seated on the back plate after the brake operation, there is an effect that the impact sound does not occur.

Claims (3)

In the shoe hold down spring of the drum type brake which firmly fixes the shoe web to the back plate, A pin member extending downward from the head portion located above the web of the shoe, penetrating the back plate, and having a lower end fixed to the lower surface of the back plate; A fluid spring unit disposed between the head portion and the upper surface of the web of the shoe so as to penetrate the center thereof and generating elastic force by hydraulic pressure; The pin member is installed between the web bottom surface of the shoe and the back plate so as to penetrate the center. When the fluid spring part is compressed, a working fluid is supplied to the fluid spring part. Shoe hold down spring of the drum-type brake, characterized in that it comprises an operating means for recovering the excess working fluid from the portion. The method of claim 1, wherein the fluid spring portion, bellows of the type stretchable in the vertical direction, Shoe hold down spring of the drum-type brake, characterized in that comprising a working fluid filled in the bellows. The method according to claim 1 or 2, wherein the operating means, A cylinder installed under the web of the shoe and filled with a working fluid; A piston member installed to be movable up and down in the cylinder; An actuating rod connecting the web lower surface of the shoe and the upper surface of the piston member; And a flow path connecting the fluid flow between the cylinder and the fluid spring portion.

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