JP2559874Y2 - Back plate structure of vehicle drum brake - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum brake for a vehicle which performs a braking action by expanding a brake shoe.
More specifically, the present invention relates to a back plate structure for supporting a brake shoe.

[0002]

2. Description of the Related Art Conventionally, a drum brake of an inward expansion type in which a pair of brake shoes arranged opposite to a back plate is expanded by an actuator such as a wheel cylinder or a cam to perform a braking action, a ledge is provided on an inner surface of the back plate. There is a surface, and the brake shoe expands and contracts while guiding the shoe rim to this ledge surface ,
In such a configuration, the performance and shape of the drum brake
The brake system depends on the conditions such as
The screen vibrates partially and hits the ledge surface,
This may cause a click sound. So, the ledge side
Made of elastic material to prevent vibration and chatter noise
( JP-A- 55-30535 , JP-A- 2-3035)
See JP-A-203028 and JP-A-2-107837.
See) .

[0003]

[Problem to be Solved by the Invention] However, in such a configuration, the ledge surface also serves as a vibration damping material.
As the brake shoe rubs the ledge surface,
The ledge surface is dragged and bent, and the guide function of the ledge surface
Is not maintained, and smooth expansion and contraction of the brake shoe is impeded.
May be In addition, the brake shoe
Vibration is likely to occur on the brake drum recirculation side.
Japanese Patent Publication No. 55-30535 discloses a vehicle driver.
In the case of a brake, a damping material that is
Bar connecting the center of the plate to the center of the actuator
Back plate perpendicular to the back plate diametric line
Sufficient damping effect because it is provided on the orthogonal line passing through the heart
No result, generated between brake shoe and ledge surface
Vibration noise and chattering noise can be effectively prevented?
Was.

Therefore, the present invention provides a guide function for a ledge surface.
While maintaining the brake,
The brake shoe absorbs the vibration of the rake drum inflow side and
It is an object of the present invention to provide a back plate structure of a vehicle drum brake that can effectively prevent a vibration sound and a chatter sound generated between the vehicle and a ledge surface .

[0005]

In order to achieve the above object, a back plate structure of a vehicle drum brake according to the present invention has a pair of brake shoes opposed to each other on the back plate, and the brake shoes are mounted on the back plate. No
-Support the rim and guide the expansion and contraction operation of the brake shoe
Press the ledge surface and the shoe rim of the brake shoe
-It is made of an elastic material that absorbs vibrations
And at least one brake
The end of the shoe where the brake drum enters and the other brake shoe
Between the brake drum and the brake drum exit side.
In a vehicle drum brake provided with an opening actuator, a center of the back plate and the actuator are provided.
Perpendicular to the diameter line of the back plate connecting to the center of the motor
Perpendicular to the center of the back plate and
Between the brake drum entry side end of the
At least one of the ledge surfaces is provided separately .

[0006]

[Function] In this way, the vibration of the brake shoe is generated.
Provided separately from the ledge surface on the side of the pan brake drum
The vibration damping material absorbs the vibration of the brake shoes,
Axial and radial directions of the back plate generated on the rake shoe
Direction amplitude to a very small
-Minimize fine rubbing caused by vibration between rim and ledge surface
And a ledge surface separate from the damping material
The guide on the brake drum retraction side of the brake shoe
Function can be maintained.

[0007]

EXAMPLES Hereinafter, that describes the present invention based on the drawings an embodiment which is applied to the leading-trailing type drum brake.

The drum brake 1 includes a pair of bow-shaped brake shoes 3 and 4 inside a back plate 2.
Are opposed to each other, and the shoe
The brake drum reciprocating side end 3d of the bush 3a and the brake shoe
No. 4 shoe web 4a and the brake drum outlet side end 4e.
Between, is an actuator for opening the brake shoe
A wheel cylinder 5 is provided, and a brake shoe 3
Brake drum outlet side end 3e of the web 3a and the brake
The brake drum retraction side of the shoe web 4a of the shoe 4
Between the end 4d and the supporting fulcrum of the shoes 3, 4
A car 6 is provided.

[0009] The brake drum rotation of the shoe web 3a
Entry side end 3d and brake drum exit side of shoe web 4a
The end 4e is connected to the pistons 5a and 5b of the wheel cylinder 5.
Each is supported and the brake drum of the shoe web 3a
Bending of the brake drum between the outlet side end 3e and the shoe web 4a
The side ends 4d are respectively supported by the anchors 6, and
Approximately the center of the webs 3a and 4a
And over field down pin 7及 beauty shoe-hold spring 8
To hold the back plate 2 and brake shoes
3 as the leading brake shoe,
-4 as a trailing brake shoe,
-The shoes 3 and 4 are always
It is urged in the radially decreasing direction.

[0010] The wheel cylinder 5, at the rear of the back plate 2 is connected brake hose, not shown, the piston 5 by hydraulic pressure supplied to the wheel cylinders 5
a and 5b advance, the brake shoe 3 which comes into contact with the pistons 5a and 5b is in contact with the brake drum reciprocating side end 3d.
And the brake drum outlet side end 4e of the shoe 4
Brake drum of brake shoe 3 supported on car 6
Retracting end 3e and retraction of brake shoe 4 into brake drum
With the side end 4d as a fulcrum, the linings 3c , 4c fixed respectively on the outer circumferences of the shoe rims 3b , 4b are slid on the inner peripheral surface of a brake drum (not shown) rotating in the direction of arrow A. It intends line the braking action in contact with each other.

The brake shoe on the outer peripheral side of the back plate 2
The shoe rim 3b is supported on the part facing
Surface 2 that guides the expansion and contraction operation of brake shoe 3
a, 2b, 2c and shoe rim 4b
Ledge surfaces 2d, 2e, 2 for guiding the expansion and contraction operation of the shoe 4
f are provided respectively. And the ledge surface
2b and 2e are the center of the back plate 2 and the wheel
Back plate diametrical line L connecting to the center of the cylinder 5
Orthogonal line L passing through the center O of the back plate 2 at right angles to 1
2, the ledge surfaces 2a, 2d are each
The end 3d of the brake shoes 3, 4 on the brake drum reciprocating side,
4d, the ledge surfaces 2c and 2f are perpendicular to the orthogonal line.
L2 and each brake shoe, brake drum circulation of 3 and 4
It is provided between the side ends 3e and 4e, respectively. This
These ledge surfaces 2a to 2f extend the brake shoes 3 and 4.
The back plate 2 has a width sufficient to guide the shoe rims 3b and 4b during the contraction operation in the radial direction of the back plate 2.

Prerequisites for drum brake braking and
The brake shoe slides on the brake drum during braking
The braking torque generated by the brake shoe
Strength across the orthogonal line L2 passing through the substantially intermediate portion of rk in shoe
The brake drum rotation with small braking torque
A lot of vibration occurs on the entry side. Therefore, in this embodiment,
And trailing drum brake 1
In this case, at the time of this braking, the leading side brake
In the shoe 3, the orthogonal line L2 and the brake drum outlet side end 3
e, the braking torque is large, and the trailing side
-In the shoe 4, the orthogonal line L2 and the brake drum exit side
Since the braking torque works greatly with the end 4e,
In the rate 2, the braking torque acting on the brake shoe 3 is small.
Between the orthogonal line L2 and the end 3d of the brake drum
And an orthogonal line with a small braking torque acting on the brake shoe 4
L2 and the brake drum recirculation side end 4d, the vibration damping material 1
0 and 10 are provided respectively.

[0013] Each damping material 10 has been formed of an elastic material such as rubber or soft synthetic resin, the back plate 2 Les
Mounting holes 2g formed near the edge surfaces 2a and 2d, respectively.
And stoppers 10a to be fitted in, consists with the abutment portion 10b which is pressed against the back plate within 2 shoe rim 3b, to 4b. The thickness of the contact portion 10b is the shoe rim 3b , 4b
Is slightly thicker than the gap formed between the contact portion 10b and the shoe rims 3b , 4b of the contact portion 10b.
A concave portion 10c serving as a grease pool is formed on the contact surface with the grease G, and the inside thereof is filled with grease G. When the brake shoe 3, 4 is attached to the back plate 2, Zhu
-Rim 3b, 4b on ledge surface 2a-2c, 2d-2f
Supported and ledge surface of shoe rim 3b, 4b
The portions near 2a and 2d are pressed against the contact portion 10b of the damping material 10.
Touched. The contact portion 10b is formed by expanding the brake shoes 3 and 4.
When opened, it is deformed outward with the shoe rims 3b, 4b,
When the diameter of the brake shoes 3 and 4 is reduced, the shoe rims 3b and 4
It moves inward with b and returns to its original shape.

[0014] In the drum brake 1 of the present embodiment, Bradenton
The pressing force against the drum is weak, and the generated braking torque is small.
Line L2 of brake shoes 3 and 4 and brake drum
Between the reciprocating side ends 3d and 4d (the leading side brake shoe 3 is closer to the wheel cylinder 5 than the orthogonal line L2 , and the trailing side brake shoe 4 is orthogonal line L
2 is closer to the anchor 6 than to the back rim 2), but the vibration of the back plate 2 in the radial direction is
b, 4b are pressed against the contact portion 10b of the damping member 10 suppresses the amplitude of the brake <br/> Kishu 3, 4 negligible ones, fine with the shoe rim 3b, 4b and ledge surface 2a, 2d Rubbing is the pole
As a result , the abutment portion 10b of the vibration damping material 10 is connected to the shoe rims 3b , 4b.
The shoe rims 3b , 4b absorb the vibration by expanding or following the compression to the original position , and buffer the collision between the shoe rims 3b , 4b and the ledge surfaces 2a , 2d . As described above, the damping material 10 is moved by the elastic force of the brake shoes 3 and 4 having a small braking torque.
Since vibration between the orthogonal line L2 and the brake drum reciprocating side ends 3d, 4d is absorbed, vibration noise and chattering sound generated when the shoe rims 3b , 4d hit the ledge surfaces 2a , 2d are reduced. It can be effectively prevented.

Further , the damping material 10 includes brake shoes 3,
4 and the rotation of the brake drum
By providing between the entrance side ends 3d and 4d, the minimum number of
Vibration can be effectively absorbed by the vibration material. Further, the vibration damping material 10
Can be easily attached and detached, so that if the damping material 10 is removed , the degree of wear of the linings 3c and 4c can be easily checked through the mounting hole 2g . Moreover, the vibration damper 10 and the ledge
Since it is provided separately from the surfaces 2a and 2d,
Guide of ledge surfaces 2a and 2d for guiding expansion and contraction of -3 and 4
The function can be reliably maintained.

It should be noted that the present invention provides, in addition to the leading and trailing, for example, two actions for expanding the brake shoes.
2 reading and 2 reading using a tutor
The present invention is also applicable to a printing format or the like.

The shape and number of the damping material and the ledge surface of the present invention are not limited to the above-mentioned embodiment, but can be changed as appropriate according to the degree of vibration of the brake shoe.
Further, the vibration damping material of the present invention is not limited to one fitted with a mounting hole particularly in the back plate, but may be mounted inside the back plate with an adhesive or the like.

[0018]

[Effects of the invention] As described above, the invention provides a back plate
Attach the damping material and at least one ledge surface
Actuator for opening the center of the brake plate and opening the brake shoe
To the back plate diameter line connecting the center of the eta
An orthogonal line passing through the center of the back plate and each brake
Separately located between the shoe and the brake drum retraction-side end
Therefore, conventional vehicle doors provided with damping material on the orthogonal line
Since the braking torque is smaller than that of the ram brake,
Bars that often occur on the side of the rake shoe that enters the brake drum
Vibration in the axial and radial directions of the
Can be absorbed by the damping material provided separately.
Brake shoes no longer hit the ledge surface
Vibration and chattering noise can be effectively prevented.
Wear. Also, the orthogonal lines and the brakes of each brake shoe
Insert a ledge surface between the drum recirculation end and the damping material separately.
Guides the expansion and contraction of the brake shoe
The guide function of the ledge surface can be reliably maintained.

[Brief description of the drawings]

FIG. 1 is a front view of a drum brake showing an embodiment of the present invention.

FIG. 2 is a front view of the back plate.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

[Explanation of symbols]

1. Drum brake, 2. Back plate, 2a to 2f
... Ledge surface , 3 , 4 ... Brake shoe, 3a , 4a ... Shoe web, 3b , 4b ... Shoe rim, 3c , 4c ... Lining, 3d, 4d ... Brake drum reciprocating end, 3
e, 4e: Brake drum circulation side end, 5 : Wheel cylinder, 6 : Anchor, 10 : Damping material, 10a : Plug body, 1
0b : contact portion, O: center of back plate 2, L1: bar
Center O of the lock plate 2 and the center of the wheel cylinder 5
Back plate diametrical line connecting L2, back plate
The center of the back plate 2 perpendicular to the diametrical line L1
Orthogonal line passing through O

Claims (1)

(57) [Scope of request for utility model registration] A pair of brake shoes are disposed on a back plate to face each other, and the brake shoes are mounted on the back plate.
Support the shoe rim of
Guide the ledge surface and the shoe rim of the brake shoe
Pressing to absorb vibration during braking action of the brake shoe
And a vibration damping material made of an elastic material.
And the other end of the brake shoe
Brake between the brake shoe and the end of the brake drum
In the case of a vehicle drum brake provided with an actuator for expanding a shoe, the center of the back plate and the front
Back plate diameter connecting to the center of the actuator
A perpendicular line passing through the center of the back plate perpendicular to the direction line
Between each brake shoe and the end of the brake drum
The damping material and at least one of the ledge surfaces are separately provided.
A back plate structure of a vehicle drum brake characterized by being radiated .