JPH0741083U - Return spring device for disc brake - Google Patents

Abstract

(57) [Abstract] [Purpose] In a disc brake, an attempt is made to obtain a return spring device that releases the pad on the outer side satisfactorily when the brake is released to eliminate drag. [Structure] An arm piece 16b is made of a leaf spring and extends laterally from a base part 16a fixed to a disc brake support. The tip of the arm piece 16b is formed at a right angle to the side surface of the caliper at an intermediate portion of the arm piece 16b. The curved portion 16 for elastically contacting
form c.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a return spring device for preventing so-called dragging in a disc brake when the pad lining is not sufficiently separated from the rotor when the brake is released.

[0002]

[Prior art]

 In order to avoid the drag phenomenon in the disc brake, a return spring device has been devised to positively move the pad away from the rotor by the spring force. An example of this return spring device is described in Japanese Utility Model Laid-Open No. 4-107530. 7 and 8 show this known example, FIG. 7 is a plan view with a part cut away, and FIG. 8 is a sectional view taken along line AA of FIG. Next, the disc brake and the return spring device will be described with reference to FIGS.

In FIGS. 7 and 8, reference numeral 1 is a support fixed to a vehicle body, 2 is a pin 5 connected to the support, which is swingably fitted to a leg portion 4 of the support, and a rotor 5 that works together with wheels. This is a caliper that can slide in the axial direction. Pads 9 and 9 are interposed between a rotor 5 and a piston 7 which is hydraulically pushed out from a cylinder 6 provided on one side of the caliper 2 and between a pawl 8 and a rotor 5 formed on the other side of the caliper. When the piston 7 is hydraulically pushed out, the two pads 9, 9 are pressed against both side surfaces of the rotor 5, and the friction between the linings 10, 10 and the rotor 5 brakes the wheels via the rotor. Be done.

In order to release the braking, the hydraulic pressure is removed from the cylinder 6, but the pad lining 10 is not sufficiently separated from the rotor 5 as it is, and dragging occurs. Therefore, both ends of V-shaped springs 12, 12 formed by bending the spring wire rods by making holes in the backing plates 11, 11 of both pads are inserted into these holes, and the pads 9, 9 are positively rotated when the brake is released. I try to keep it away from me.

[0005]

[Problems to be solved by the device]

 The return spring device that separates the pad from the rotor by the V-shaped spring 12 as described above has the following problems. That is, the circular seal material 13 attached to the inner surface of the cylinder 6 is elastically contacted with the piston 7, and when the piston is pushed toward the rotor during braking, the inner peripheral portion of the seal material moves toward the rotor due to frictional action. And is elastically deformed. When the braking is released, the elastic deformation of the inner circumference of the seal material tries to recover, and the piston is pulled back slightly due to the frictional force. Therefore, the movement of the pad on the piston side (inner side) is facilitated, and the lining can be quickly separated from the side surface of the rotor. On the other hand, in the pad on the outer side (claw side), the heavy caliper 2 moves slowly, so that the returning to the original position when releasing the braking is not performed quickly. Therefore, the returning elastic force of the V-shaped spring 12 is first used to return the inner side pad, and the elastic deformation amount is reduced and the elastic force is remarkably reduced to return the outer side pad. Therefore, it was difficult to move the caliper 2 to the outer side sufficiently, and the outer pad was easily dragged.

[0006]

[Means for Solving the Problems]

 This device is a caliper repositioning device when releasing the braking force by using a return spring device that fixes the base to a support and elastically abuts the tip of the arm piece extended from the base to the caliper at a substantially right angle. Is something that is done.

[0007]

[Action]

 The arm that extends from the base fixed to the support and makes the tip contact the caliper at a substantially right angle is bent and deformed to the inner side due to frictional force during braking, and stores elastic force. Push it back to the outer side. As a result, the pads on the outer side can be sufficiently separated from the rotor, and the pads on both sides of the rotor can be quickly separated from the rotor.

[0008]

【Example】

 1 to 6 show the structure and operation of an embodiment of the present invention, FIG. 1 is a plan view of a disc brake, FIG. 2 is a partially cutaway front view, FIG. 3 is a perspective view of a spring piece, and FIGS. FIG. 6 is a schematic diagram showing the relationship between the spring piece and the caliper. FIG. 4 is an exaggerated view of the relationship during non-braking, FIG. 5 during braking, and FIG. 6 during lining wear. The same parts as those of the conventional example shown in FIGS.

The disc brakes shown in FIGS. 1 and 2 are of the same type as those shown in FIGS. 7 and 8, and the caliper 2 has pins 3 attached to both ends (in FIG. 1, covered with the dustproof boot 14). Is slidably inserted into the cylindrical portions at both ends of the support 1 and is movable in the axial direction of the rotor 5. Reference numeral 15 is a pad clip that suppresses shaking of the pad 9.

As shown in FIG. 3, a base portion 16a of a spring piece 16 formed of a leaf spring is fitted to the thin shoulder portion 1a of the support 1 to fix the position by elastic force, and the base portion 16a is directed toward the caliper. The tip of the extended arm piece 16b elastically abuts the side surface of the caliper 2 at a substantially right angle. A loop-shaped bent portion 16c for elastically and squarely pressing the tip of the arm piece against the caliper is formed in the middle of the arm piece 16b. Numerals 16d and 16e are bent edges which are bent in conformity with the shape of the shoulder portion so that the base portion 16a does not come off the shoulder portion 1a.

The return spring device using the spring piece 16 formed as described above operates as follows.

(1) At the time of non-braking, as shown in FIG. 4, the tip end of the arm piece 16b abuts the side surface of the caliper 2 at a substantially right angle, and the elastic force for moving the caliper is not generated.

(2) When the caliper 2 moves toward the inner side as shown by the arrow in FIG. 5 during braking, the tip of the arm piece 16b elastically abutted against this is dragged toward the inner side due to frictional force. It leans toward the inner side and elastically deforms to store elasticity. Since the casting surface remains on the side surface of the caliper, it is difficult for the tip of the arm piece 16b and the side surface of the caliper to slip.

(3) When the piston 7 for moving the caliper to the inner side disappears at the time of releasing the braking, the arm piece 16b tries to return to the state of FIG. 4 due to the stored elastic force, and the caliper 2 due to the frictional force. To the outer side (the side opposite to the arrow in FIG. 5). After that, the outer pad is pushed back by the swell of the rotor, and the outer pad is not dragged as well as the inner pad.

(4) When the pad lining is worn, the amount of movement of the caliper to the inner side during braking is large, so slippage occurs between the tip of the arm piece 16b and the side surface of the caliper, resulting in a non-braking state. When returning to, the caliper is located closer to the inner side than that in the case of FIG. 4, as shown by the movement of the points in FIGS.

In this way, the spring piece 16 allows the outer side pad to fully return when releasing the brake, and automatically adjusts that the gap between the lining and the rotor side surface becomes wider as the lining wears, This gap can be maintained properly.

In this embodiment, the type in which the caliper is guided by the pins 3 and 3 is shown. However, in other types of disc brakes as well, the base of the spring piece is elastic as in this embodiment. The return device can be used by attaching to the support by fitting or when the shape of the support is not appropriate, such as fixing with a small screw.

[0018]

[Effect of device]

 (1) The leaf spring is used to return the caliper when the brake is released by the elastic force stored during braking, so the structure is simple and the manufacture is easy, and there is no need for machining such as piercing the back metal of the pad. .

(2) When the brake is released, the caliper itself is driven to return to the non-braking state, so that both the inner and outer pads can be released well.

(3) As the lining wears, the clearance between the pad lining and the rotor side surface can be automatically adjusted.

[Brief description of drawings]

FIG. 1 is a plan view of a disc brake showing an embodiment of the present invention.

FIG. 2 is a front view in which a part of the disc brake is cut.

FIG. 3 is a perspective view of a spring piece.

FIG. 4 is a schematic view showing a positional relationship between a spring piece and a caliper when not braking.

FIG. 5 is a schematic view showing a positional relationship between a spring piece and a caliper during braking.

FIG. 6 is a schematic view showing a positional relationship between a spring piece and a caliper when the lining is worn and not braking.

FIG. 7 is a plan view of a partially cut disc brake showing a conventional example of a return spring device.

8 is a cross-sectional view taken along the line AA of FIG.

[Explanation of Codes] 1 Support 1a Shoulder 2 Caliper 3 Pin 4 Leg 5 Rotor 6 Cylinder 7 Piston 8 Claw 9 Pad 10 Lining 11 Back metal 12 V-shaped spring 13 Sealing material 14 Dustproof boot 15 Pad clip 16 Spring piece 16a Base 16b Arm piece 16c Curved part 16d, 16e Bend edge

Claims (1)

[Scope of utility model registration request] 1. A base plate (16a) fixed to a support (1) of a disc brake, which is made of a leaf spring, and extends from an arm piece (16).
b) extend and bend the arm (16b) at the middle part (16b).
A return spring device for a disc brake, wherein c) is formed, and the tip of the arm piece (16b) is brought into contact with the side surface of the caliper (2) at a substantially right angle.