JPH0544751A - Disc brake - Google Patents

Abstract

PURPOSE:To keep off any drag motion of a pad as maintaining a disk brake outer diameter compact in size by setting up the central part of a retractive spring in a recess installed in the inner part of a disk caliper part. CONSTITUTION:A cylinder 27 is installed in a position at the backside of a pad 23 of a caliper 25, while an opposed piston 26 is inserted into a back face of the pact 23 free of slide motion, and a claw part 29 being opposed to the back of a pad 24 is formed in a tip of the caliper 25. A retractive spring 31 is made up of bending a wire material, and a central part 33 is made up into a V-shaped form and set up in a recess 28a formed in an inner surface of a disk caliper part 28 of the caliper 25 in a state of having a restoring force in both directions. An end of the spring 31 is inserted into a hole 34 at each back plate upper end of these pads 23, 24 and engaged with these pads 23, 24. Therefore an outer diameter of the whole disk brake can be miniaturized just as in the case where the retractive spring 31 is not installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake used in, for example, a four-wheel vehicle.

[0002]

2. Description of the Related Art Generally, as a disc brake, FIG.
As shown in FIG. 3, each of the pads is provided on both sides of the disc and is supported so as to be movable in the axial direction of the disc, and the piston and the claw portion at the tip that are provided inside to straddle these pads and the disc It is known to have a caliper that presses each pad toward the disc.

This is because when pressure oil acts on a cylinder formed on the caliper from a master cylinder, one piston is brought into pressure contact with one surface of the disk by the piston of this cylinder, and the other pad is pressed by the claw of the caliper by its reaction. The disc is pressed against the other side of the disc to brake the rotating disc, but what is called a retract spring is provided to urge each pad in a direction in which the pads are separated from each other to prevent the pad from being dragged by the disc. It is normal.

FIG. 5 is a view of the conventional disc brake as seen from the axial direction of the disc. In the figure, reference numeral 1
Is a disk, reference numeral 2 is a torque receiving member for supporting the caliper 5, reference numeral 4 is a pad on the side of the caliper 5 which is pressed by the claw portion 9, and reference numeral 8 is a disk path portion of the caliper. As shown in FIG. 5, conventionally, the retract spring 11 is arranged in the space 10 between the processed surface 8b formed on the inner surface of the disk path portion 8 and the disk 1.

[0005]

In the conventional disc brake described above, when the size of the space 10 (indicated by symbol A in FIG. 5) is secured in order to avoid interference between the retract spring 11 and the disc 1. In order to keep the outer diameter of the disc brake small, it is necessary to reduce the thickness B of the disc path portion 8 of the caliper 5 or to reduce the outer diameter of the disc 1.

However, such a dimensional change causes a problem such as a decrease in rigidity of the caliper 5 or a decrease in heat capacity of the disk 1. Therefore, it is difficult to provide the retract spring 11 and keep the disk brake small. Met.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a disc brake which is provided with a retract spring and is kept small in size.

[0008]

According to a first aspect of the present invention, there is provided a disc brake, which is arranged on both sides of the disc and is supported movably in an axial direction of the disc, and an inner side which is arranged so as to straddle the pad and the disc. A caliper that presses each pad toward the disk with a piston and a claw at the tip, and both ends are engaged with each pad and the central portion urges them in a direction to separate them from each other. And a retract spring that functions as a spring, and a central portion of the retract spring is arranged in a recess provided inside the disc path portion of the caliper.

According to a second aspect of the present invention, in the disc brake according to the first aspect, the central portion of the retract spring is formed by bending a linear material into a V shape, and the inner surface of the concave portion is formed by bending the linear material. V along the center
It is characterized by being formed in a letter shape.

[0010]

According to the disc brake of the first aspect, the central portion of the retract spring located between the disc path portion of the caliper and the disc is arranged in the recess formed on the inner surface of the caliper. Therefore, the retract spring can be provided without reducing the thickness of the disc path portion and the outer diameter of the disc, while maintaining the outer diameter of the entire disc brake.

Further, in the disc brake according to the second aspect of the invention, since the recess is formed so as to follow the shape of the retract spring, the posture of the retract spring can be stably maintained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 and 2, the disc brake of the present embodiment extends from the torque receiving member 22 fixed to the non-rotating portion of the vehicle on one side of the disc 21 that rotates with the wheels. Pads 23 and 24 disposed on both sides of the disk 21 in a state of being supported between the two leg portions 22a and 22a and being movable in the axial direction of the disk 21, and straddling these pads 23 and 24 and the disk 21. Placed on the pins 25a, 25a
The caliper 25 movably supported by the leg portions 22a, 22a via the pads 23, 2 at both ends 34, 34
4 and the central portion 33 is engaged with each pad 2
The retract spring 31 functions as a spring for urging the members 3 and 24 away from each other.

A cylinder 27 is provided at a position on the back side of the pad 23 of the caliper 25.
A piston 26 facing the back surface of the pad 23 is slidably inserted. The tip of the caliper 25 is the pad 2
4 extending to the back side of the pad 4 and facing the back surface of the pad 24
Are formed.

The retract spring 31 is formed by bending a linear material, and its central portion 33 has a V-shape and is elastically bent more than the natural state (spreads to the left and right). In a state having a restoring force in the direction), the caliper 25 is disposed in the recess 28a formed in the inner surface (processing surface 28b) of the disk path portion 28. Here, as shown in FIG. 4, the concave portion 28a of the caliper 25 has an inner side surface 28c whose central portion 33 is the retract spring 31.
It is formed in a V shape so as to extend along.

Further, the end portion 3 of the retract spring 31
As shown in FIG. 3, 4 extends at right angles to the plane along the central portion 33, and by being inserted into the holes 38, 38 formed at the upper ends of the backing metals of the pads 23, 24,
It is engaged with the pads 23, 24.

In the disc brake constructed as described above, when pressure oil acts on the cylinder 7 from a master cylinder (not shown), the pad 6 is pressed against one surface of the disc 21 by the piston 6, and this reaction causes the caliper 25 to move. The claw portion 29 presses the pad 24 against the other surface of the disc 21 to brake the rotating disc 21 (that is, the vehicle).

When the brake is not applied, the restoring force of the central portion 33 of the retract spring 31 causes the pads 23, 2 to move.
4 are pushed in the directions away from each other, so that each pad 23,
The contact between the disk 24 and the disk 24 does not occur, and the drag phenomenon is prevented.

And, with the above disc brake,
The central portion 33 of the retract spring 31 is the caliper 2
The concave portion 28a formed on the inner surface of the disk path portion 28 of FIG.
Therefore, the thickness A of the disc path portion 28 and the outer diameter of the disc 21 are reduced by maintaining the distance A between the disc path portion 28 and the disc 21 sufficiently small. In addition, the outer diameter of the entire disc brake can be made small as in the case where the retract spring 31 is not provided.

Further, in the above disc brake,
Since the recess 28a is formed so as to follow the shape of the central portion 33 of the retract spring 31, there is also an effect that the posture of the retract spring 31 can be stably maintained.

[0020]

As is apparent from the above description, according to the disc brake of the first aspect, the outer diameter of the entire disc brake can be obtained without reducing the thickness of the disc path portion and the outer diameter of the disc. Has the effect of preventing the drag phenomenon of the pad while maintaining a small size.

Further, the disc brake according to the second aspect of the invention has an effect that the posture of the retract spring can be stably maintained.

[Brief description of drawings]

FIG. 1 is a view of the entire disc brake as seen from the axial direction of the disc, in which a part is shown in section.

FIG. 2 is a view of the entire disc brake as seen from the circumferential direction of the disc, and is a diagram showing a part of the disc in cross section.

3 is a cross-sectional view taken along the line I-I of FIG.

FIG. 4 is a horizontal sectional view of a caliper.

FIG. 5 is a view of the entire conventional disc brake as viewed from the axial direction of the disc, in which a part is shown as a cross section.

[Explanation of symbols]

 21 disc 23, 24 pad 25 caliper 26 piston 28 caliper recess 28a caliper disc path part 29 claw part 31 retract spring 33 retract spring end 34 central part of retract spring

Claims (2)

[Claims] 1. A pad disposed on both sides of a disc and movably supported in an axial direction of the disc, a piston disposed inside the disc and straddling the pad and the disc, and a claw portion at a tip end thereof. The retractor includes a caliper that presses the pads toward the disc, and a retract spring that has both ends engaged with the pads and urges the pads in a direction to separate the pads from each other. The disc brake, wherein a central portion of the spring is arranged in a recess provided inside the disc path portion of the caliper. 2. The central portion of the retract spring is formed by bending a linear material in a V shape, and the inner side surface of the recess is formed in a V shape along the central portion. The disc brake according to claim 1.