JPH0210829Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a disc brake, and particularly to a disc brake with an improved anti-rattle spring that prevents rattling of friction pads.

Prior Art A disc brake consists of (a) a friction pad disposed opposite to a disc rotor, and (b) a cylindrical shape with a bottom, the opening of which faces the friction pad and connects to the cylinder part of the caliper. It is equipped with a fitted piston and (c) a torque plate that supports the friction pad from the inner circumferential side, and is configured to suppress rotation of the rotor by pressing the friction pad against the disc rotor by the piston. There is.

In this type of disc brake, an anti-rattle spring is arranged between the friction pad and the piston, and its center is fixed to the back surface of the friction pad, while the anti-rattle spring is connected to the outer and inner circumferences of the disc rotor from the center. The distal end portions of the single or plural first elastic arm portions and second elastic arm portions that extend respectively are brought into contact with the inner circumferential surface of the piston under their own elastic force, thereby preventing rattling of the friction pad. There is something I tried to do. FIGS. 4 and 5 show a specific example thereof. In the disc brake shown in FIG. 4, the anti-rattle spring 100 has a first elastic arm part 102 and a second elastic arm part 104, each extending from the center along the radial direction of the disc rotor. , and each tip has a friction pad 106.
The friction pads 10 are brought into contact with the inner circumferential surface of the piston 108 at positions relatively far from the back surfaces of the friction pads 10.
The free movement of 6 people is restricted. On the other hand, in the disc brake shown in FIG. 5, each of the first elastic arm portion 112 and the second elastic arm portion 114 of the anti-rattle spring 110 is bent back toward the friction pad 106 at the intermediate portion, respectively. The tip of the friction pad 106 is brought into contact with the inner peripheral surface of the piston at a position relatively close to the back surface of the friction pad 106.

In any of these cases, the friction pad 1
06 is in a state in which the inner circumferential end surface (lower end surface in the figure) is pressed against the support surface 118 of the torque plate 116 based on the elastic force of the first elastic arm portions 102 and 112, thereby eliminating rattling. Prevented. In this state, the friction pad 106 has the first elastic arm portions 102, 1
Reaction force of the elastic force acting on the piston 108 from 12
F ₄ and the reaction force (supporting force) acting on the lower end surface of the friction pad 106 from the torque plate support surface 118
F ₁ , F ₂ and the reaction force F ₃ of the elastic force acting on the piston 108 from the second elastic arm portions 104, 114 act, and are in a balanced state.

Problems to be solved by the invention By the way, the center of action of the resultant force of the forces F ₁ , F ₂ , F ₃ acting upward on the friction pad 106 and the anti-rattle springs 100, 110 and the force F ₄ acting downward There is a fourth
As is clear from FIG.
A rotational moment indicated by arrow M acts on.
That is, the friction pad 106 is subjected to rotational movement in the direction of arrow M, and as a result, the friction pad 106 is rotated in the direction of arrow M.
The lower end of the friction pad 106 tends to protrude toward the disc rotor, causing a so-called pad dragging phenomenon in which the friction pad 106 continues to be in sliding contact with the disc rotor even when the brake is not applied.

Means for Solving the Problems The present invention was made to solve the above problems, and its gist is that the friction pads are arranged opposite to the disc rotor and A torque plate that supports the friction pad from the inner circumferential side of the disc rotor, a piston that has a bottomed cylindrical shape and is fitted into the cylinder part of the caliper with its opening facing the friction pad, and The tip portions of one or more first elastic arm portions and second elastic arm portions are fixed to the piston side surface of the friction pad and extend from the center thereof to the outer circumferential side and the inner circumferential side of the disk rotor, respectively. The friction pad is brought into contact with the inner circumferential surface of the piston based on its own elastic force, and is pressed against the support surface of the torque plate based on the elastic force of the first elastic arm, thereby eliminating the backlash of the friction pad. In a disk brake equipped with an anti-rattle spring that prevents sticking, the center of action of the reaction force of the elastic force acting from the tip of the first elastic arm portion to the inner circumferential surface of the piston is caused by the torque plate. A straight line parallel to the radial direction of the disc rotor, passing through the center of action of the resultant force of the supporting force of the friction pad and the reaction force of the elastic force acting from the tip of the second elastic arm section to the inner peripheral surface of the piston. The abutting position of the tip of the first elastic arm against the inner circumferential surface of the piston is determined so as to be located above or near the straight line thereof.

Function and Effects of the Invention In other words, the present invention provides a force that acts radially inward on the friction pad and the anti-rattle spring fixed thereto (a single force when the first elastic arm is singular, a plurality of forces). In some cases, the line of action of the resultant force of the forces acting on each first elastic arm from the piston and the line of action of the resultant force of the outward forces are approximately on the same straight line parallel to the radial direction of the disc rotor. I made it. If you do this,
No rotational moment acts on the friction pad, and therefore the dragging phenomenon caused by the rotation of the friction pad can be eliminated.

Embodiment Next, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, a caliper 10 is disposed so as to be movable in a direction along the axis of the disc rotor 12, straddling the disc rotor 12, an inner pad 14, and an outer pad 16. The caliper 10 includes a cylinder portion 18 facing the inner pad 14, and a piston 22 having a bottomed cylindrical shape in the cylinder portion 18 has its opening connected to the inner pad 1.
It is fitted so that it can slide toward the 4 side. The piston 22 is a disc rotor 1 that is pushed out from the cylinder part 18 and rotates the inner pad 14 when brake fluid pressure is supplied into the cylinder part 18.
Press it to 2. At this time, the claw portion 20 of the caliper 10 facing the outer pad 16 is pressed against the piston 2.
The outer pad 16 is moved in the opposite direction to the piston 22 due to the reaction at the time of extrusion 2, and the outer pad 16 is pressed against the disc rotor 12, thereby suppressing the rotation of the disc rotor 12. This outer pad 16 is moved integrally with the claw portion 20 by a leaf spring 24. The leaf spring 24 has a longitudinal shape in the rotation direction of the disk rotor 12 (direction perpendicular to the plane of the paper),
The center portion thereof is fixed in a state where it is fitted into the protrusion 26 of the outer pad 16, while both end portions are pressed against each branch portion of the bifurcated claw portion 20 based on its own elastic force.

On the other hand, the inner pad 14 is connected to the torque plate 3.
8, and the lower surfaces of both ends (both ends in the disk rotor rotation direction, that is, both ends in the direction perpendicular to the plane of the drawing) are the support surfaces 40 of the torque plate 38.
It is supported from the inner circumferential side. Further, a protrusion 42 is provided on the back side of the anti-rattle spring 28, and the anti-rattle spring 28 is fixed to the protrusion 42 in a press-fitted state at the center thereof. The anti-rattle spring 28 includes a first elastic arm portion 30 extending outward (upward in the figure) along the radial direction of the disc rotor 12 from the center thereof;
A second elastic arm portion 32 extends inward (downward in the figure) along the same radial direction, and each tip portion is brought into contact with the inner circumferential surface of the piston 22 based on its own elastic force. It is being Second elastic arm portion 32
is extended in a direction away from the back surface of the inner pad 14, and its tip is positioned relatively far from the back surface, while the first elastic arm portion 30
is made to extend away from the back surface of the inner pad 14, and then the inner pad 1 is extended in the middle part.
It is bent back to the side of 4, and its tip is attached to the same pad 14.
It is located near the back surface of. As clearly shown in FIG. 2, a protrusion 34 with a triangular cross section is formed at the tip end of the piston 22. It is engaged with an annular groove 36.

The inner pad 14 is connected to this first elastic arm portion 3.
Its lower end surface is pressed against the support surface 40 of the torque plate 38 by an elastic force of 0, thereby preventing it from rattling when the vehicle is running or when braking is applied.

By the way, in this disc brake, the reaction forces (supporting forces) F ₁ and F ₂ from the torque plate 38 are applied to the lower end surface of the inner pad 14, and the reaction force from the piston 22 is applied to the tip of the second elastic arm part 32.
F ₃ respectively act upward. In addition, the first elastic arm portion 30 receives a reaction force F ₄ from the piston 22.
acts downward, but in this example, the reaction force F ₄
The piston ₂ of the first elastic arm portion ₃₀ is moved such that _the line of action of
The abutting position on 2 has been selected. That is, as shown in FIG. 3, the annular groove 36 of the piston 22 and the protrusion 34 of the first elastic arm portion ₃₀
Since it is located at a point P ₄ on a straight line that passes through the center of action P ₄ ' of the reaction forces F ₁ , F ₂ , F ₃ acting on P 2 _and P ₃ and is parallel to the radial direction of the disc rotor 12. be.

As a result, the reaction force F ₄ and the resultant force of the reaction forces F ₁ , F ₂ , and F ₃ are on the same straight line and cancel each other out,
No rotational moment acts on the inner pad 14. This avoids dragging caused by the rotation of the inner pad 14.

In this example, the anti-rattle spring is formed with one first elastic arm section and one second elastic arm section, but in the present invention, a plurality of first elastic arm sections and second elastic arm sections are formed respectively. It is also possible to apply the present invention to those equipped with a caliper, and it is also possible to apply not only to a disc brake with a floating caliper as in this example, but also to a disc brake with a fixed caliper.

In addition, the present invention can be implemented with various modifications based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a disc brake that is an embodiment of the present invention. Fig. 2 is an enlarged sectional view of a main part of the anti-rattle spring in Fig. 1 that engages with the piston, and Fig. 3 is a plan view showing the anti-rattle spring in Fig. 1 together with an inner pad and a torque plate. It is. FIGS. 4 to 6 are explanatory diagrams for explaining problems with conventional disc brakes, respectively. 10... Caliper, 12... Disc rotor,
14...Inner pad, 16...Outer pad,
18...Cylinder part, 22...Piston, 28...
...Anti-rattle spring, 30...First elastic arm portion, 32...Second elastic arm portion, 38...Torque plate, 40...Support surface.

Claims (1)

[Claims for Utility Model Registration] A friction pad disposed opposite to the disc rotor, a torque plate supporting the friction pad from the inner circumferential side of the disc rotor, and a cylindrical shape with a bottom and an opening thereof. A piston is fitted into the cylinder portion of the caliper with the piston facing toward the friction pad, and the center portion is fixed to the surface of the friction pad on the piston side, and the piston is connected from the center portion to the outer peripheral side and inner side of the disc rotor. The tips of the single or plural first elastic arm portions and second elastic arm portions each extending toward the circumferential side are brought into contact with the inner circumferential surface of the piston based on their own elastic force, and the first elastic arm and an anti-rattle spring that prevents rattling of the friction pad by pressing the friction pad against the support surface of the torque plate based on the elastic force of the first elastic arm part, The center of action of the reaction force of the elastic force acting on the inner circumferential surface of the piston from the tip of the second elastic arm is between the supporting force of the friction pad by the torque plate and the inner circumferential surface of the piston from the tip of the second elastic arm. The tip of the first elastic arm is positioned on or near a straight line parallel to the radial direction of the disc rotor, passing through the center of action of the resultant force of the reaction force of the elastic force acting on the disk rotor. A disc brake characterized by a fixed contact position on the inner peripheral surface of the piston.