JPH051702Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a disc brake, and particularly to a technique for reducing brake drag.

2. Description of the Related Art In a disc brake, a pair of friction pads are placed on both sides of a disc rotor that rotates together with a wheel, and are pressed against the disc rotor by a pressing mechanism provided behind the pads. It is desirable that the brake pads be separated from the disc rotor when the pressing mechanism is not in operation. This is because if the separation is sufficient, so-called dragging occurs, which adds unnecessary rotational load to the disc rotor and accelerates wear of the friction pad and the disc rotor.

In order to prevent this dragging, various mechanisms collectively referred to as retract mechanisms are employed.
For example, in a disc brake disclosed in Japanese Utility Model Application Publication No. 58-60032, a retraction spring is provided that includes an elastic portion that urges a pair of friction pads away from each other. This retraction spring is attached between a pair of friction pads with its mounting leg extending almost completely through the friction pads in the radial direction of the disc rotor. Therefore, the friction pads can be regulated to be parallel to the friction surface of the disc rotor, and when the brake is released, the pair of friction pads can be separated while remaining substantially parallel to each other, reducing brake drag. can.

Problems that the invention aims to solve: As the friction material of the friction pads wears out as they are used, the brake gap adjustment device moves them closer to the disc rotor by the amount of wear of the friction material, reducing the distance between a pair of friction pads. becomes smaller. Therefore, the effectiveness of the retraction spring, that is, the pad returning force, becomes relatively stronger.
There was a problem in that the friction pad could not always be returned with a constant force.

In addition, in a caliper floating type disc brake, when the pair of friction pads are separated from each other by the retraction spring, both friction pads are not necessarily spaced apart from each other at equal intervals with respect to the disc rotor; There was also a problem in that only one of the inner pads was separated from the disc rotor, and the other friction pad remained in contact with the disc rotor and was not returned.

Means for Solving the Problems The present invention has been made to solve the above problems, and is a disc brake in which one end of the disc rotor or the relative position of the disc rotor in the axial direction remains unchanged due to frictional force. A spring member is provided which engages one of the member and the friction pad, and whose other end engages with the other of the members to bias the friction pad in a direction away from the disc rotor. A regulating means is provided to regulate the amount of elastic deformation to a size corresponding to an appropriate gap between the disc rotor and the friction pad when not braking, and the frictional force is regulated by the regulating means so that the elastic deformation of the spring member is not affected. The reason is that the size is set such that movement of the one end relative to the other end is not permitted in the uncontrolled state, and is permitted in the restricted state.

Function In the disc brake configured as described above, the spring member is installed between the friction pad and a member whose relative position in the axial direction with respect to the disc rotor remains unchanged, such as the disc rotor or the torque receiving member. The friction pad and the disc rotor are separated by the biasing force, and the gap between the two is maintained at an appropriate size when braking is not applied. During braking, the spring member elastically degenerates to allow the friction material to approach the disc rotor. The spring member is provided with a regulating means for regulating the amount of elastic deformation of the spring member.
As long as the gap between the friction pad and the disc rotor is maintained properly, the spring member is not restricted by the restriction means.

On the other hand, when the gap between the friction pad and the disc rotor becomes larger than the appropriate gap due to wear of the friction material, the amount of elastic deformation of the spring member is regulated by the regulating means. From this state, as the friction material approaches the disk rotor, the end of the spring member on the friction engagement side is moved against the friction force. In other words, as the friction pad approaches the disc rotor due to wear of the friction material, the position of one end of the spring member is moved in accordance with the amount of wear of the friction material, and a constant return force is always applied to the friction pad. I can do it.

In addition, the friction engagement end of the spring member is not actually necessarily moved when the friction pad wears even a minute amount, but rather when the brake is depressed relatively strongly, the friction pad is brought into tight contact with the disc rotor. It can be moved in stages.

Effects of the invention As described above, according to the invention, the friction pad can always be biased with a constant force regardless of the wear of the friction material, so an appropriate pad return force can be obtained throughout the entire life of the friction pad. brake clearance can be accurately maintained at the desired value.

In addition, the spring member is not provided between a pair of friction pads to separate them, but is provided between the disc rotor or a member whose relative position in the axial direction with the disc rotor remains unchanged, to move the friction pads between the disc rotor and the disc rotor. Therefore, if this invention is applied to both the inner and outer pads of a caliper floating type disc brake, it is possible to reliably separate both pads by the same amount from the disc rotor, thereby reducing brake drag. can be reduced.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In Fig. 2, reference numeral 10 denotes a disk rotor which rotates integrally with the wheel. A mounting bracket 12 is fixedly disposed near the disk rotor (hereinafter simply referred to as the rotor) 10 as a torque receiving member. The mounting bracket 12 has a shape in which pad support parts 14, 16 located on both sides of the rotor 10 are connected by a connecting part which extends beyond the outer periphery of the rotor 10, and is disposed so as to straddle the outer periphery of the rotor 10.
The rotor 10 has friction surfaces 18, 20 on both sides of the outer periphery, and a pair of friction pads, i.e., an inner pad 22 and an outer pad 24, are disposed opposite these friction surfaces.
The friction members 4 are made up of friction materials 26, 28 and steel backing metals 30, 32 fixed to the rear surfaces thereof.
These pads 22, 24 are supported by the mounting bracket 12 so as to be slidable in a direction parallel to the axis of the rotor 10, and are pressed against the rotor 10 by a caliper 34 serving as a pressing mechanism. The caliper 34 is equipped with a hydraulic cylinder 36 provided opposite the back surface of the inner pad 22, a reaction portion 38 provided opposite the back surface of the outer pad 24, and a connecting portion 40 which connects these beyond the outer periphery of the rotor 10, and is supported by two slide pins (not shown) erected on the mounting bracket 12 so as to be movable in a direction parallel to the axis of the rotor 10. Therefore, when braking hydraulic pressure is supplied to the cylinder bore 42 of the hydraulic cylinder 36, the piston 44 presses the inner pad 22 against the friction surface 18 of the rotor 10, and the reaction force of this presses the reaction portion 38 against the other friction surface 20.

Spring members 50 are provided between the inner pad 22 and the rotor 10 and between the outer pad 24 and the rotor 10, respectively. Spring member 50
is formed from a single spring wire, and as shown in an enlarged view in FIG. It is said that The abutting and engaging portion 52 has a rod shape and is capable of abutting against the friction surface 18 of the rotor 10 . The frictional engagement portion 56 is bent into a U-shape, and is inserted into the through hole 58 formed in the backing metal 30 of the inner pad 22 while being elastically deformed by a certain amount in the direction in which the width of the U shape decreases. and is engaged with the back metal 30 by frictional force. The spring member 50, as shown in FIG.
It is attached to a notch 60 formed in the center of the outer peripheral end of the friction material 26 of the inner pad 22 and to a pair of ears 62 formed on the back metal 30, and the abutting and engaging portions 52 of the inner pad 22 are attached to the rotor 10. , the frictional engagement portion 56 is engaged with the back metal 30. A spring member 50 is similarly arranged on the outer pad 24 side, but since both spring members 50 have the same function, only the spring member 50 on the inner pad 22 side will be described below.

The spring member 50 is connected to the pulling member 5 when not braking.
The biasing force of 4 biases the rotor 10 and the inner pad 22 so that they maintain an appropriate gap (for example, 2 mm). During braking, the inner pad 22 is pushed by the piston 44 of the caliper 34, and the friction material 26 is brought into close contact with the friction surface 18 of the rotor 10, but the abutment engagement portion 52 is also pressed against the friction surface 18 of the rotor 10, and the spring The portion 54 is elastically deformed. Since the elastically deformable amount a of the spring portion 54 is approximately equal to the appropriate gap b between the rotor 10 and the inner pad 22, the spring member 50 is elastically deformable while the gap between the inner pad 22 and the rotor 10 is the appropriate gap. to allow the two to come close to each other. This elastically deformable amount a is
This is regulated by the close contact of the spring portion 54.
In this embodiment, the regulating means is that the shape and dimensions of the spring portion 54 are determined so that they come into close contact when compressed by an amount equal to the appropriate gap.

If the gap between the inner pad 22 and the rotor 10 becomes larger than the appropriate gap due to wear of the friction material 26, the inner pad 22 will close to the friction material 26 during braking.
is moved further forward than before it wears out. However, since the elastically deformable amount a of the spring portion 54 is approximately equal to the appropriate gap b, the reaction force from the rotor 10 is transmitted from the abutting engagement portion 52 to the frictional engagement portion 56 via the spring portion 54 that is in close contact. The frictional engagement portion 56 is moved back toward the hydraulic cylinder 36 within the through hole 58 against the frictional force. Frictional engagement part 5
6 is fixed to the back metal 30 when the spring portion 54 is elastically deformable;
The frictional force is set so that the parts 4 move after they are in close contact. Since the amount of retraction is approximately the same as the amount of wear of the friction material 26, the spring member 50 is retracted relative to the inner pad 22 as the inner pad 22 moves forward due to the wear of the friction material 26. Therefore, the gap between the rotor 10 and the inner pad 22 when the brake is released is a proper gap despite the wear of the friction material 26.

If the friction material 26 further wears out, the friction engagement portion 56 is similarly retracted, and the spring member 50 always maintains an appropriate gap between the rotor 10 and the inner pad 22. Furthermore, as shown in Figure 3,
Spring members 5 are installed at three locations on the outer periphery of the inner pad 22.
0 is installed, the inner pad 22
The rotor 10 receives the biasing force at a portion as far away as possible in both the radial direction and the circumferential direction, so that it can be easily moved backward without any strain occurring between the rotor 10 and the mounting bracket 12. Further, even if the friction material 26 wears unevenly, the friction engagement portion 56 of the spring member 50 in the vicinity thereof moves, so that an appropriate distance between the rotor 10 and the inner pad 22 is always maintained. Furthermore, since the spring member 50 of this embodiment is composed of one spring wire, it can be manufactured easily and inexpensively.
Drag can be reduced at low cost.

The present invention can also be implemented in the embodiments shown in FIGS. 4 to 7, respectively. In these embodiments, members similar to those in the previous embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 4, the biasing device 70 includes a shaft member 72,
A spring 74 and an engaging member 76 are provided. The shaft member 72 is a rod-shaped member, and one end thereof is an abutting engagement portion 78 that abuts against the friction surface 18 of the rotor 10 . An engagement member 76 is attached to the other end of the shaft member 72. The engagement member 76 consists of a bottomed cylindrical member 79 and a friction material 80,
It is press-fitted into a through hole 82 formed in the back metal 30 of the inner pad 22, and frictionally engaged with the inner peripheral surface of the through hole 82 by a friction material 80 fixed to a side wall 84. Also, a stopper 8 fixed to the bottom 86 of the bottomed cylindrical member 79 and the center of the shaft member 72
8, a spring 74 is disposed between the spring 74 and the spring 74.

When not braking, the rotor 10 and the inner pad 22 are separated by the urging force of the spring 74 to maintain an appropriate gap between them, and when braking, the spring 74 is elastically deformed and the friction material 26 is pressed against the rotor 1.
0 friction surface 18 is allowed. When the friction material 26 wears out and the gap between the rotor 10 and the inner pad 22 becomes larger than the appropriate gap b, the engagement member 76 slides within the through hole 82 and is moved back. That is, the friction surface 1 of the rotor 10
Before the friction material 26 comes into close contact with the engagement member 8 , the stopper 88 comes into contact with the end surface 90 of the engagement member 76 and the spring 7
4 is restricted, the force transmitted from the shaft member 72 causes the engaging member 76 to retreat against the frictional force of the friction material 80. In this embodiment, a spring 74 as a spring member is used.
One end is indirectly engaged with the disc rotor 10 via the shaft member 72, and the other end is indirectly frictionally engaged with the inner pad 22 via the engagement member 76, and the stopper 88 and The engagement member 76 constitutes a regulating means for regulating the amount of elastic deformation of the spring 74 that is greater than the amount a that can be elastically deformed.

A biasing device 92 in FIG. 5 has substantially the same configuration as the biasing device 70 described above, but the engagement member 94 includes a helical friction ring 96 in place of the friction material 80 of the engagement member 76. There is. The helical friction ring 96 is compressed radially inward and press-fitted into the through hole 82 , is frictionally engaged with the inner peripheral surface of the through hole 82 , and is in contact with a flange portion 98 of a bottomed cylindrical member 97 . engaged. The rest of the structure is similar to the urging device 70.

In these biasing devices 70 and 92, a spring 74 as a spring member is attached to the disk rotor 10.
and pad 22, and the regulating means is also configured separately from the spring member.
This has the advantage that it is easy to obtain a biasing device that is highly durable and operates accurately.

The biasing device 99 shown in FIG. 6 is designed to reduce as much as possible the movement of the abutting and engaging portion 52 of the spring member 50 in the circumferential direction as the disk rotor 10 rotates. Spring member 100
is a member having the same configuration as the spring member 50, and is attached to a container-shaped member 102 made of stainless steel or resin. An opening 104 is provided in the first end wall of the container-like member 102, from which an abutting engagement portion 106 projects. Contact engagement part 1
A roller 108 is rotatably attached to the tip of the roller 06 to reduce frictional resistance with the friction surface 18 of the rotor 10. The end of the spring member 100 on the opposite side from the abutting engagement portion 106 is connected to the container-shaped member 102.
The container member 102 is fixed to the second end wall of the container member 102 so as to move together with the container member 102 . A sleeve 110 made of resin or stainless steel that can tightly fit into the container-like member 102 is press-fitted into the backing metal 30, and its tip portion protrudes rearward from the backing metal 30.

Spring portion 1 of spring member 100 when not braking
The rotor 10 and the inner pad 2 are
2 are separated from each other, and when braking, the spring part 1
12 is elastically deformed within the cylindrical member 102 and the rotor 1
0 friction surface 18 and friction material 26 are allowed to come into close contact. At this time, the abutting and engaging portion 106 is retracted into the container-like member 102 from the opening 104, but the length of the abutting-engaging portion 106 is determined so that the container-like member 102 and the roller 108 do not interfere with each other. There is. Friction material 2
6 wears out, the elastic deformation of the spring portion 112 is restricted by its close contact, so that the spring member 100 is moved rearward within the sleeve 110 together with the container-shaped member 102.

In the biasing device 118 shown in FIG. 7, the spring member 120 is made of a single plate spring material, and the
The mounting bracket 12 and each lug 62 of the back metal 30 are members whose relative position in the axial direction remains unchanged.
is installed between. One end of the spring member 120 has a friction engagement portion 12 to which a friction material 122 is fixed.
4, and the other end is a fixed engagement part 126 fixed to the ear part 62. Fixed engagement part 126
is fixed such that the end portion 128 and the tongue piece 130 sandwich the ear portion 62, but the center portion 132 is elastically deformed in a direction approaching the ear portion 62,
The frictional engagement portion 124 is attached to the mounting bracket 1
2 for frictional engagement.

When not braking, the biasing force of the spring portion 134 maintains an appropriate gap between the rotor 10 and the inner pad 22, and when braking, the spring portion 13
4 is elastically deformed. When the friction material 26 wears out, the protrusion 136 and flat plate portion 138 of the spring member 120
contact, the elastic deformation of the spring portion 134 is restricted, and the frictional engagement portion 124 is moved forward against the frictional force of the friction material 122. In this embodiment, the protrusion 136 and the flat plate portion 138 constitute a regulating means.

As the inner pad 22 moves forward, the spring member 1
20 is also moved forward, and an appropriate gap between the rotor 10 and the inner pad 22 can always be maintained regardless of wear of the friction material 26.

Although several embodiments of the present invention have been described above with reference to the drawings, the present invention can be implemented in other forms with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged front sectional view of a disc brake that is an embodiment of the present invention. FIG. 2 is a front sectional view of the disc brake. FIG. 3 is a front view showing the inner pad of the disc brake. 4 to 6 are partially enlarged front sectional views showing different embodiments of the present invention,
FIG. 7 is a partially enlarged plan sectional view showing another embodiment of the present invention. 10... Disc rotor, 12... Mounting bracket, 18, 20... Friction surface, 22...
...Inner pad, 24...Outer pad, 26,
28...Friction material, 30, 32... Back metal, 34...
Caliper, 50...Spring member, 52...Abutting engagement part, 54...Spring part, 56...Frictional engagement part, 70...Biasing device, 72...Shaft member, 74...
... Spring, 76 ... Engagement member, 80 ... Friction material, 86 ... Bottom, 88 ... Stopper, 92 ...
Biasing device, 96... Helical friction ring, 99...
Biasing device, 100...Spring member, 102...Container-shaped member, 106...Abutting and engaging portion, 108...Roller, 110...Sleeve, 112...Spring portion, 118...Biasing device, 120 ...spring member,
122...Friction material, 124...Friction engagement portion, 12
6...Fixed engagement part, 132...Central part, 134...
...Spring part, 136... Protrusion, 138... Flat plate part.

Claims (1)

[Claim for Utility Model Registration] A disc brake in which a pair of friction pads disposed on both sides of a disc rotor are pressed against the disc rotor by a pressing mechanism to suppress the rotation of the disc rotor, one end of which is pressed against the disc rotor by the friction force. The disc rotor or a member whose relative position in the axial direction with the disc rotor remains unchanged engages one of the friction pads, and the other end engages with the other of them to separate the friction pad from the disc rotor. A spring member is provided that biases the spring member in the direction, and a regulating means is provided that regulates the amount of elastic deformation of the spring member to a size corresponding to the appropriate gap between the disc rotor and the friction pad when braking is not performed. A disc brake characterized in that the force is set to a magnitude that does not allow movement of the one end relative to the other end when the elastic deformation of the spring member is not regulated by the regulating means, but allows it when the elastic deformation of the spring member is regulated.