JPH0524368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc brake, and more particularly, to a disc brake, in which two disc brakes are housed in one cylinder and are biased in opposite directions.
This relates to a device that applies a brake by pressing friction pads located on both sides of a disk using two pistons.

[Conventional technology]

Special Publication Showa 48-21031 as the above disc brake
The number is publicly known. This disc brake is the first
As shown in Fig. 2, two pistons 2 and 3 are housed inside a cylinder 1 that is attached to a non-rotating part of the vehicle body, and hydraulic pressure is supplied between both pistons 2 and 3 to move them together. One piston 2 presses the friction pad 4 to bring it into pressure contact with the disk 5 that is integrated with the wheel, and the other piston 3 presses the friction pad 7 via the yoke 6, causing this friction pad to move in the opposite direction. 7 is brought into pressure contact with the other surface of the disk 5 to apply the brake.

The yoke 6 bridges a receiving frame 8 pressed by the piston 3, side frames 9, 9 extending from both ends of the receiving frame 8 in opposite directions beyond the top of the disk 5, and friction pads 7. Pressing frame 9a that presses
For example, it is formed by press molding a flat plate material and has a flat shape. Grooves 10, 10 extending in the direction of the disk 5 are formed on both sides of the cylinder 1, and the inner sides of the side frames 9, 9 fit into these grooves 10, 10, so that the yoke 6 is moved in a direction perpendicular to the disk 5. It can be moved freely.

However, conventional disc brakes require a yoke formed by press-forming a flat plate, which makes processing cumbersome, and the yoke has a large area, resulting in a large overall shape.

Also, grooves 10 and 1 for guiding the yoke 6 are provided.
As a result, the sliding properties of the yoke deteriorate and the force of the piston 3 is not properly transmitted to the pad 7, and even if the hydraulic pressure acting on the piston 3 is released, the yoke does not move properly. This has the drawback that a so-called dragging phenomenon occurs in which the friction pad 7 is constantly in contact with the disk 5 and the friction pad 7 is not restored to its original state.

[Summary of the invention]

The present invention includes a cylinder which is fixed to a non-rotating part of a vehicle with first and second friction pads located on both sides of a disk, and which is opened on both sides and has one opening side facing the first friction pad, and an interior of the cylinder. first and second pistons housed in the disk and urged in opposite directions by hydraulic pressure; an arm facing the second piston on the opposite side of the disk and pressed by the second piston; It consists of a tie rod fixed to both ends and extending in the direction of the second friction pad via a rod cylinder that is parallel to and integral with the cylinder, and a pressing member attached to the tip of the tie rod to press the second friction pad. One piston presses the first friction pad against one surface of the disk, and the second piston presses the second friction pad against the other surface of the disk via the arm, tie rod, and pressing member, and A bridge member having a main body disposed parallel to the tie rod and both legs extending from both sides of the main body and corresponding to the center of the cylinder is provided, and the arm and the pressing member are connected via the bridge member. The disc brake of the present invention will be explained in detail below using Examples.

〔Example〕

3 to 6 are simplified configuration diagrams showing one embodiment of the disc brake according to the present invention, and in each figure, 20 is a disc fixed to the wheel,
First and second friction pads 21 and 22 are located on both sides thereof. 24 is a cylinder having a hollow portion 24x, and one opening side 23 of the hollow portion 24x corresponds to the first friction pad 21. Hollow part 24
pistons 25 moving in opposite directions in x;
26 is stored. The pistons 25 and 26 are attached to the bottom wall 2
5a and 26a, and is arranged so that its open ends 25b and 26b face outside of the hollow portion 24x. Open end 2 of piston 26
Arm 27 is arranged to face 6b.
As shown in FIG. 3, this arm 27 has a central portion 27a that extends across the central axis L of the cylinder.
and protrusions 27b extending from both sides of the central portion 27a in the outer circumferential direction of the disk 20 (radial direction of the cylinder 24).
Holes 27c, 27c are provided at the tips of 7b, 27b. Note that there is a connecting portion 2 on the outer periphery of the cylinder 24.
Two rot cylinders 24a, 24 via 4b
a is provided, and this cylinder 24a is the cylinder 2
4 and extending toward the outer circumferential direction of the disk 20 from the holes 27c, 27c side of the arm 27.
8 is stored. Both ends of each tie rod 28 are threaded, and one threaded portion 28a fits into the hole 27c of the arm 27 and is screwed into the nut 27d.
are screwed on, whereby the protrusions 27b, 27b at both ends of the arm 27 are fixed to the tie rod 28. In addition, the other threaded portion 28 of each tie rod 28
b is a hole 2 provided in a holding plate 29 constituting a pressing member that holds and presses the friction pad 22 shown in FIG.
9a is inserted, and the nut 29b is screwed, thereby fixing the retaining plate 29 to the tie rod 28.

In this case, the ends of the tie rods 28, 28 are connected by the holding plate 29 constituting the pressing member, and the opposite sides of the tie rods 28, 28 are also connected by the arm 27, so that the seventh
A closed loop shown in Figure S will be formed. The first friction pad 21 is held by a retaining plate 21a having a similar shape to the retaining plate 29, and this retaining plate 21
The tie rods 28, 28 pass through the holes 21b, 21b provided in the retaining plate 21a.
can be freely slid in the direction of the disk 20. Grooves 30, 31, 3 are formed on the inner wall of the cylinder 24a.
2, 33 are formed, and seal members 30a, 31a for sealing between the pistons 25, 26 and the cylinder 24 are installed in the grooves 30, 31, and grooves 32, 33 are formed.
Dust seals 32a and 33a are attached to 33. Note that the seal members 30a and 31a seal the piston 2 with respect to the cylinder 24 after the brake is applied.
It also has a return action of 5,26. Further, dust seals 34a and 35a are attached to the inner wall of the rod cylinder 24a.
Grooves 34 and 35 are formed for attaching. Note that the cylinder 24 has a hydraulic inlet 24M and an inflow hole 2.
4L and a cylinder mounting portion 24F.

In this case, the arm 27 and the holding plate 29 are connected by a bridge member 40. The bridge member 40 includes a main body 40a located between the tie rods 28, 28 and extending in a direction parallel to the tie rods 28, 28;
Leg portions 40b and 40c extend from both ends of the main body 40a and have tips corresponding to the central axis L of the cylinder 24.
Consists of. The tip of the leg portion 40b is connected to the center portion 27a of the arm 27, and the tip of the leg portion 40c is connected to a push rod 40d provided on the back side of the holding plate 29.

In addition, tie rod 28 having flange 28h
As shown in FIG. 8, the holding plate 29 may be made movable along the axis L by passing through the hole 29a of the holding plate 29.

In the above configuration, by supplying hydraulic pressure from a master cylinder (not shown) between the pistons 25 and 26 from the inlet 24M through the inflow hole 24L, the pistons 25 and 26 move in opposite directions to each other, and the ends of the piston 25 As a result, the retaining plate 21a is pressed, causing the friction pad 21 to come into pressure contact with one side of the disk 20, and on the other hand, the end of the piston 26 presses the center portion 27a of the arm 27 in the opposite direction, so that the tie rod 28 also The holding plate 29 is pressed against the opposite surface of the disk 20 and the friction pad 22 is pressed against the opposite surface of the disk 20, thereby applying the brake. When the above hydraulic pressure is released, piston 2
By moving the friction pads 5 and 26 toward each other due to the returning action of the sealing materials 30a and 31a, the friction pads 21 and 22 can be separated from the disk 20, and the brake can be released.

〔Effect of the invention〕

According to the present invention, the arm 27 is used as a member for transmitting the force of the piston 26 to the friction pad 22.
Since it is constructed by assembling the tie rod 28 and the pressing member, unlike the conventional yoke formed from a single yoke, assembly processing can be simplified, and it is not as wide as the conventional yoke. It does not take up space and can be made smaller. In particular, unlike the conventional model in which the yoke slides in the body side groove, the tie rod 28 is guided by the rod cylinder 24a, so the tie rod 28 does not become immovable due to adhesion of dust, etc., thereby increasing reliability. be able to.

Since the arm 27 and the pressing member 29 are connected by the bridge member 40, a reinforcing effect is obtained.
It is possible to reduce the stress P acting on the tie rod 28 in the outward warping direction when the brake is applied, to further increase the rigidity, and to protect the connecting member between the tie rod 28, the arm 27, and the pressing member.

[Brief explanation of the drawing]

1 and 2 are simplified configuration diagrams showing an example of a conventional disc brake, FIG. 3 is a front view showing an embodiment of the disc brake according to the present invention, and FIG. Figure 5 is a sectional view taken along line A-A.
6 is a sectional view taken along the line CC in FIG. 5, FIG. 7 is a plan view of FIG. 3, and FIG. 8 is a sectional view of another embodiment. 20... Disc, 21, 22... Friction pad, 24... Cylinder, 24a... Rod cylinder, 25, 26... Piston, 27... Arm,
28... Tie rod, 29, 21a... Holding plate,
40... Bridge member.

Claims (1)

[Claims] 1 first and second friction pads located on both sides of the disc, a cylinder fixed to a non-rotating part of the vehicle and open on both sides with one opening side facing the first friction pad, and a cylinder housed inside the cylinder. a first, hydraulically biased in opposite directions;
A second piston, an arm facing the second piston on the opposite side of the disk and pressed by the second piston, and a rod cylinder fixed to both sides of the arm, parallel to the cylinder, and integral with the cylinder. It consists of a tie rod that extends in the direction of the second friction pad, and a pressing member that is attached to the tip of the tie rod and presses the second friction pad, and the first piston presses the first friction pad against one surface of the disk. , a second piston is configured to press a second friction pad against the other surface of the disk via an arm, a tie-rod, and a pressing member, and a main body disposed parallel to the tie-rod and extending from both sides of the main body. and a bridge member having both legs corresponding to the center of the cylinder, and the arm and the pressing member are connected via the bridge member.