JPH0714668Y2 - Mounting structure of pad retraction spring in disc brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a structure for mounting a pad retraction spring in a disc brake that separates the brake pad from the rotor surface when the brake is not applied to prevent so-called brake drag. is there.

<Prior Art> In general, a disc brake has a pair of brake pads on both sides of a disc-shaped rotor and an actuator behind the brake pad, and both sides of the rotor that rotate the brake pad by the operation of the actuator. Braking is performed by pressing it against the surface.

By the way, in the non-braking state, unless the brake pad is separated from the rotor surface, a sliding noise is generated or the brake pad is worn early. In particular, when the rotor entry side of the brake pad is dragged, the harmful effect is increased due to the entrainment phenomenon. As a measure to eliminate such harmful effects,
It has been proposed to use the pad retraction spring shown in Japanese Patent Publication No. 61-39857. This pad retraction spring consists of a single wire that is approximately V-shaped or W-shaped.
The main body portion is bent in a V shape, and the hooking portions are formed at both end portions thereof so as to be bent substantially at right angles. Then, each hooking portion of the pad retraction spring is press-fitted into a hole formed in the brake pad, and its main body portion is elastically attached to the inner surface of the movable caliper.

<Problems to be Solved by the Present Invention> The prior art using the pad retraction spring described above has the following problems.

(A) Since the main body of the pad retraction spring is arranged inside the caliper, the work of attaching and detaching the brake pad is very troublesome.

That is, in the assembling work, an assembly in which a pair of brake pads and pad retraction springs are integrated is placed on the torque member. At this time, the dimension between the outsides of both brake pads is the reaction portion of the caliper. The caliper must be installed while supporting both brake pads against the spring force so that the size is smaller than the dimension between the piston and the piston, which is troublesome. Also, when disassembling work is performed in the reverse order of the assembling work, but when the caliper is removed, both pads may expand due to the spring force and may drop from the hooking part of the torque member, so handle it with caution. I won't.

(B) Each time the brake is operated, the piston and one brake pad that comes into contact with the piston and the other brake pad that comes into contact with the caliper and its reaction portion move in opposite directions. Therefore, the main body of the pad retraction spring that elastically contacts the caliper slides with the caliper, and the main body is easily damaged.

(C) Each time each brake pad moves in the opposite direction, the bending stress repeatedly acts on the hooking portion of the pad retraction spring inserted in the brake pad.

Therefore, the pad retraction spring may be deformed or the press-fitting holding force of the hooking portion may be reduced, and the pad retraction spring may come off during use.

(D) If the pad retraction spring deforms and its posture collapses for the above reason, the push-back force acting on both brake pads will not work evenly.

(E) When replacing the brake pad with a new one, not only is the work of attaching and removing the pad retraction spring cumbersome, but it is also difficult to push and pull the latching part straight against the hole drilled in the brake pad. The pad retraction spring may be deformed.

(F) Most of the main body of the pad retraction spring is hidden by the caliper, so it is difficult to visually check for missing items.

(G) Since the entire pad retraction spring is directly subjected to radiant heat generated during braking, deterioration of the elastically deformed portion causing internal stress due to heat is particularly likely to occur.

<Purpose of the Invention> The present invention has been made in view of the above problems, and an object thereof is to provide a mounting structure for a pad retraction spring in the following disc brake.

(A) A pad retraction spring mounting structure for disc brakes that allows the brake pads to be easily attached and removed without disturbing the work of attaching and removing the brake pads.

(B) A pad retraction spring mounting structure for disc brakes that is less likely to be damaged or deformed during use.

(C) A pad retraction spring mounting structure for a disc brake, in which the pushing back force acts evenly on both brake pads.

(D) A pad retraction spring mounting structure for a disc brake that allows easy attachment / detachment of the spring when replacing the brake pad.

(E) Pad retraction spring mounting structure for disc brakes that allows easy visual inspection of missing items.

(F) Pad retraction spring mounting structure for disc brakes that is not easily affected by radiant heat during braking.

(G) Pad retraction spring mounting structure for disc brakes that improves the stability of the pad retraction spring mounting posture.

<Structure of the Invention> An embodiment of the invention will be described below with reference to the drawings.

(A) Structure of assembly FIGS. 1 to 3 show an assembly of a disc brake.

Reference numeral 1 is a disk-shaped rotor that rotates integrally with wheels, 10 is a torque member fixed to a stationary portion such as a vehicle body, and 13 and 14 are guide pins standing on one side of the torque member 10. 1 in the circumferential direction.

Reference numeral 20 is a caliper that is slidably fitted to the guide pins 13 and 14.

As shown in FIG. 3, the caliper 20 includes an actuator portion 21, a reaction portion 23 that faces the actuator portion 21 across the rotor 1, and a parking brake device portion 24 provided on the opposite side of the actuator portion 21. .

A piston 30 is slidably fitted in the central hole 22 of the actuator portion 21.

40 and 50 are a pair of brake pads, which are composed of back plates 41 and 51 and linings 45 and 55, respectively. Then, as shown in FIGS. 1 and 2, guide grooves formed on both end sides of the back plates 41 and 51.
42 and 52 are connected to the torque member 10 via the pad clips 60 and 61.
The guide projections 11 and 12 are slidably mounted. The pad clips 60, 61 have a substantially U-shaped cross section and have a folding piece 62 at the center of an upper surface 62 thereof, which improves the corrosion resistance and wear resistance of the sliding surfaces of the brake pads 40, 50 and the brake pad 40, This is a member for the purpose of preventing vibration of 50. Further, hooking grooves 43, 53 are provided in parallel with the axial direction of the rotor 1 on the upper surfaces of the guide grooves 42, 52 of the back plates 41, 51.

(B) Pad retraction spring (first, second, fourth
(Fig.) In Fig. 1, 70 is a pad retraction spring, which is arranged at least on the inlet side of the rotor 1.

As shown in the enlarged view of FIG. 4, the pad retraction spring 70 is formed by bending one wire into a substantially W-shape, and a main body 71 having a substantially W-shape, and a hook formed at both ends of the main body 71. It is composed of stop portions 75 and 76. The main body portion 71 includes three folding portions, that is, a central folding portion 72 and outer folding portions 73 and 74 located on both sides of the central folding portion 72. It has a spring function to urge to. The hook portions 75 and 76 formed at both end portions of the main body portion 71 are intermediate positions in the height direction between the central folding portion 72 and the respective outer folding portions 73 and 74, and are substantially perpendicular to the outside. It is formed by bending. The main body 71 and the hooks 75 and 76 are formed on the same plane.

(C) Spring attachment / detachment method (Figs. 2 and 4) To attach the pad retraction spring 70, grasp the vicinity of the catches 75, 76 with your fingers to compress and deform them, and then attach each catch 75, 76 to the back. The plates 41 and 51 are inserted into the hooking grooves 43 and 53.

Then, the outer folded portions 73 and 74 are lightly elastically contacted with the upper surface of the torque member 10, and the other central folded portion 72 is lightly elastically contacted with the upper surface of the pad clip 60 while attaching both brake pads 40 and 50 in the expanding direction. Energize. When the pad retraction spring 70 is mounted as described above, as shown in FIG. 4, the outer folding portions 73, 74 and the central folding portion 72 are the torque member 10 which is a non-movable member having an open outer space. The hooks 75 and 76 are elastically contacted with the upper surface of the folding piece 62 of the pad clip 60 respectively, and the hooking portions 75 and 76 are located between the outer contacting portions 73 and 74 and the center folding portion 72, respectively. The rotation of the pad retraction spring 70 centering around the contact holes 76 and 76 is restricted.

Further, when removing the pad retraction spring 70, the vicinity of the hook portions 75, 76 is compressed and deformed by pinching with fingers, and the hook portions 75, 76 are hook grooves 43, 53 of the back plates 41, 51. All you have to do is remove it from the box.

<Operation of the Invention> Next, the operation of the disc brake will be described.

(B) During braking When pressure fluid is supplied to the actuator section 21, the piston 30
Moves forward to press the brake pad 40 against the rotor 1 first, and the reaction force moves the caliper 20 to the right in FIG. 3, pressing the brake pad 50 against the rotor 1 for braking. At this time, as shown by the alternate long and short dash line in FIG. 4, the main body 71 is deformed in the contracting direction in response to the movement of both brake pads 40, 50. Even if the body portion 71 is deformed, the outer folding portions 73, 74 and the central folding portion 72 are lightly elastically contacted with the torque member 10 and the folding piece 62, respectively, and the rotation around the hook portions 75, 76 is restricted. As a result, the posture of the pad retraction spring 70 is maintained in a good condition.

(B) When braking is released When the braking is released, the piston 30 and the caliper 20 are returned to their original positions by a known means. At the same time, the return force of the retraction spring 70 acts evenly on the brake pads 40, 50, whereby the surfaces of the linings 45, 55 of the brake pads 40, 50 are quickly separated from the side surface of the rotor 1. Even when the braking is released and the body portion 71 of the pad retraction spring 70 is restored, the posture of the pad retraction spring 70 is still maintained in a good state, as in the case of the braking described above.

<Other Embodiment 1> The shape of the hooking portions of the brake pads 40, 50 is not limited to the hooking grooves 43, 53 described above, but the upper portion of the guide groove 52 may be formed as shown in the brake pad 50 of FIG. The hook holes 54 may be provided.

<Other Embodiment 2> Further, as shown in FIG. 6, a grooved portion formed between the bottom portions 73 and 74 and the hook portions 75 and 76 by bending in a direction away from the torque member 10.
Providing 77 and 78 makes the attachment / detachment work easier even if the main body 71 is close to the torque member 10.

In FIGS. 5 and 6, the same parts as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

<Other Embodiment 3> A small gap may be provided between the central folded portion 72 and the outer folded portions 73 and 74 without elastically contacting the torque member 10 and the pad clip 60, which are non-movable members. Even if this has a slight gap, since the central folded portion 72 or the outer folded portions 73, 74 abut the pad clip 60 and the torque member 10 which are non-movable members, the hook portions 75, 76 are provided. The rotation of the pad retraction spring 70 that serves as a fulcrum can be restricted.

<Effects of the Invention> The invention has the following effects.

(A) Since the hooking portion is located in the middle of each elastic contact position of the main body portion, rotation about the hooking portion as a fulcrum can be restricted, and the mounting posture of the pad retraction spring is stabilized.

(B) Since the main body of the pad retraction spring is arranged on the non-movable member, deformation or damage of the pad retraction spring due to sliding can be avoided.

(C) The spring force of the body of the pad retraction spring that makes elastic contact with the top surface of the non-movable member or pad clip can absorb the vibration of the brake pad, pad clip, etc., resulting in abnormal noise such as squeal and rattling noise. Can be prevented.

(D) Since the entire body of the pad retraction spring is exposed to the outside, not only is it easy to assemble and remove the pad retraction spring, but it is also easy to visually inspect it.

(E) Since it is not necessary to directly receive radiant heat during braking, thermal deterioration of the pad retraction spring can be avoided.

(F) Overall, the pushing back force of the brake pad can be stably applied over a long period of time.

[Brief description of drawings]

Fig. 1: Plan view with a part of the disc brake broken Fig. 2: Left side view with a part of Fig. 1 broken Fig. 3: III-III cross section of Fig. 4 Fig. 4: Between brake pads 5: Enlarged view of pad retraction spring arranged in FIG. 5: Perspective view showing assembled state of pad retraction spring and brake pad FIG. 6: Perspective view showing other pad retraction spring

Claims (1)

[Scope of utility model registration request] 1. A disc brake in which a pair of brake pads are arranged on both sides of a disc-shaped rotor and the pair of brake pads are pressed against both sides of a rotating rotor to brake the disc. The main body portion is formed into a substantially W shape and has a spring function of urging the pair of brake pads in the expanding direction, and both end portions of the main body portion are bent outward at substantially right angles, Using a pad retraction spring consisting of a hooking portion hooked to a pair of brake pads, the main body portion is a central folded portion formed by bending the center of the wire rod,
A pair of outer folds formed on both sides of the central fold, and the one fold of the main body is elastically contacted with the open non-movable member of the outer space, and the main fold of the main body is The other folding part makes elastic contact with the upper surface of the pad clip inserted in the guide part between the torque member and the pad back plate, and each of the engaging parts that engages with the pair of brake pads is in the middle of each elastic contact position of the main body part. The structure for mounting the pad retraction spring in the disc brake, which is characterized by being located at.