JPH04277333A - disc brake - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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, four-wheeled vehicles.

0002

[Prior Art] Generally, as a disc brake, Fig. 4
Disc 1 is placed on both sides of Disc 1 as shown in
Pads 2 and 3 are supported movably in the axial direction of It is known to include a caliper 7 which presses the pad 3 toward the disk 1 with claw portions 6, 6 formed so as to extend on the back side of the other pad 3.

This is because when pressure oil acts on the cylinder 4 of the caliper 7 from the master cylinder, the piston 5 of the cylinder 4 presses one of the pads 2 against one surface of the disk, and the reaction forces the claws 6 of the caliper 7. , 6 press the other pad 3 against the other surface of the disk 1 to brake the rotating disk, but in order to prevent the pads 2 and 3 from dragging due to the disk 1 when not braking, the pad 3 shown in FIG. Retract springs 8 and 9 were provided as shown in FIG.

The retract springs 8 and 9 are shown in FIG.
, as shown in Figure 5, both ends are holes 2 at the top of each pad 2, 3.
a, 3a (only the pad 2 side is shown in FIG. 5), and after braking, the pads 2, 3 are pushed by the retract springs 8, 9 and separated from the disc 1, respectively. This is provided in the hope that it will prevent the dragging phenomenon.

In FIG. 4, reference numeral 10 indicates a torque receiving member that is fixed to the vehicle body and supports the caliper 7, and reference numeral 11 indicates a slide for movably supporting the caliper 7 on the torque receiving member 10. It's a pin. The torque receiving member 10 supports the caliper 7 and also supports the pads 2 and 3 so as to be movable in the axial direction of the disk 1.

[0006]

However, in the above-mentioned conventional disc brake, the retract spring 8,
Since the position where the retract spring 9 engages with the pad 3 is shifted outward from the center of the claws 6, 6 of the caliper 1 in the circumferential direction of the disc 1, there is a difference in the restoring force of the retract springs 8, 9. If there is, a moment is generated that tends to rotate the pad 3.

Furthermore, the two legs 10a, 10a of the torque receiving member 10 supporting both ends of the pad 3 and the pad 3
Since a slight gap is provided between both ends of the disc 1 for the pad 3 to slide, when the pad 3 is pushed in the direction away from the disc 1 by the retract springs 8 and 9 during non-braking. , pad 3 is disk 1
Due to the slight inclination with respect to the circumferential direction of the pad 3, the entire surface of the pad 3 may not be separated from the disk 1, causing partial drag. This dragging phenomenon increases the loss of torque in the vehicle, and thus has been a major hindrance to improving the fuel efficiency of the vehicle.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a disc brake in which the pad is less likely to tilt with respect to the disc during non-braking, and the dragging phenomenon is less likely to occur.

[0009]

[Means for Solving the Problems] The disc brake of the present invention has pads disposed on both sides of the disc and supported movably in the axial direction of the disc, and pads disposed so as to straddle these pads and the disc, and a pad on one side. a caliper that presses one of the pads toward the disk with a piston provided on the other side, and the other of the pads with a claw portion formed on the other side; a retract spring biased in a direction to separate them from each other, and a position where an end of the retract spring engages with the other pad is aligned with the center of the claw in the circumferential direction of the disk. It is characterized by

0010

[Operation] According to the disc brake of the present invention, the position where the force of the retract spring is applied to the pad and the position where the reaction force of the caliper's claw part is applied to the pad coincide in the circumferential direction of the disc, so the retraction occurs when the brake is not applied. When the pad is pressed by the spring, no moment is generated to rotate the pad in the circumferential direction of the disk. Therefore, when the pad is pushed by the retract spring after braking, the pad is unlikely to tilt with respect to the circumferential direction of the disk, and a dragging phenomenon is unlikely to occur.

[0011]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. As shown in the figure, the disc brake of this embodiment has a torque receiving member 22 fixed to a non-rotating part of the vehicle on one side of a disc 21 that rotates together with the wheels.
and two legs 22 extending from this torque receiving member 22.
pads 23 and 24 disposed on both sides of the disk 21 while being supported between the pads 23 and 22a and movable in the axial direction of the disk 21; The caliper 25 is movably supported by the legs 22a, 22a via pins 25a, 25a, and both ends 34a, 35a or 34b, 35b are engaged with the pads 23, 24, respectively, so that the central portion 33
a and 33b are retract springs 3 that function as springs that bias the pads 23 and 24 in a direction that separates them from each other;
1a and 31b.

A cylinder 27 is provided at a position on the back side of the pad 23 of the caliper 25, and this cylinder 27 includes:
A piston 26 facing the back surface of the pad 23 is slidably inserted. Also, in the caliper 25, the pad 2
At positions on the back side of the pad 24, claw portions 29a and 29b are formed to face the back side of the pad 24.

The retract springs 31a and 31b are formed by bending a wire material, and the center portion 33
a and 33b are V-shaped and are arranged inside the disc path portion 28 of the caliper 25 in a state that is more elastically bent than in the natural state (a state that has a restoring force in the direction of spreading from side to side). ing.

[0015] Also, retract springs 31a, 31
As shown in FIG.
Holes 38a, 38b, 39 formed at the upper end of a, 24a
By being inserted into pads 23 and 24 a and 39b,
are engaged with each other.

Note that these holes 38a, 38b, 39a,
39b has a depth that extends to the effective radius position (the position of the central axis of the piston 26) in the radial direction of the disk 21, and the opening side thereof is the retract spring 31.
The diameter is sufficiently larger than each end of the retract springs 31a and 31b, and the bottom side (the part corresponding to the position of the effective radius) is made smaller in diameter. The configuration is such that they fit together.

As shown in FIG. 1, the ends 39a, 3 of the retract springs 31a, 31b are attached to the pad 24
The position where 9b engages is aligned with the center of claw portions 29a, 29b in the circumferential direction of disk 21. In addition, in the pad 23, the vicinity of the piston end in the circumferential direction at the effective radius position of the disc brake (the center of the piston 26) tends to serve as a fulcrum when the pad 23 is tilted. The position where 38a and 38b engage corresponds to the outer peripheral portion of the piston 26 in the circumferential direction of the disk 21.

That is, the point of application of the force applied from the end of each retract spring to each pad is a position on the effective radius of the disk 21, and the center of each claw of the caliper 27 or the piston 26 that receives these forces is a position on the effective radius of the disk 21. The position is opposite to the cylindrical part forming the tip of the cylindrical part.

In the disc brake configured as described above, when pressure oil acts on the cylinder 27 from a master cylinder (not shown), the piston 26 causes the pad 2 to
3 is pressed against one surface of the disc 21, and as a reaction, the pawl portion 29 of the caliper 25 presses the pad 24 against the other surface of the disc 21, thereby braking the rotating disc 21 (that is, the vehicle).

When braking is not applied, the restoring forces of the central portions 33a, 33b of the retract springs 31a, 31b push the pads 23, 24 away from each other. Since the position where the force is applied to each pad and the position where the reaction force of each claw of the caliper 27 or the piston 26 is applied to each pad coincide in the circumferential direction of the disc 21, let's rotate each pad in this direction. There is no moment that occurs. Therefore, when each pad is pushed by each retract spring after braking, it is difficult for each pad to tilt with respect to the circumferential direction of the disk 21.

Furthermore, in the above embodiment, the positions (points of action) where the force of each retract spring is applied to each pad are as follows:
Since it coincides with the position of the effective radius of the disk 21 (the center position of the piston 26 in the radial direction of the disk 21), no moment is generated that tends to tilt each pad with respect to the radial direction of the disk 21. Since tilting in this direction is also less likely to occur, the dragging phenomenon is even more difficult to occur.

In the above embodiment, the retract spring is extended to the inner side of the pad (the effective radius position of the disc brake) and engaged with the pad, but the present invention is not limited to this. That is, as long as the engagement position of the retract spring in the circumferential direction of the disk is maintained as shown in FIG. 1, the depth of the hole in each pad may be set as shown in FIG. 5, for example.

Further, in the above embodiment, the caliper has two pawls, and these are arranged symmetrically with respect to the axis of the disc, but the invention is not limited thereto. The claws may be arranged offset, and even in this case, the same effect can be obtained by aligning the point of action of the retract spring with the center line of each claw.

Furthermore, as schematically shown in FIG. 3, more claws or pistons may be provided than in the above embodiment. In FIG. 3, the claw portion of the caliper is indicated by the symbol 49a,
The case is shown in which three caliper pistons are provided as shown by 49b and 49C, and two caliper pistons are provided as shown by numerals 46 and 46. In this case, the retract spring 51a
.
4, at the center position of the outer claw parts 49a, 49C,
It is sufficient if they are engaged with each other. In addition, this figure 3 shows the effective radius position of the disc brake (center position of the piston)
The engagement position of the retract spring is shown in FIG.

[0025]

As is clear from the above description, according to the disc brake of the present invention, the position where the force of the retract spring is applied to the pad and the position where the reaction force of the caliper claw is applied to the pad are Since the pads coincide in the circumferential direction of the disc, when the pad is pushed by the retract spring during non-braking, no moment is generated that tries to rotate the pad with respect to the circumferential direction of the disc. Therefore, when pressed by the retract spring after braking,
This has the effect that the pad is less likely to be inclined in the circumferential direction of the disk, and a dragging phenomenon is less likely to occur.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a disc brake of the present invention,
FIG. 3 is a view of the caliper and pad cut away at the center of the piston in the radial direction of the disk.

FIG. 2 is a view taken along the line II-II in FIG. 1;

FIG. 3 is a diagram for explaining another embodiment of the present invention.

FIG. 4 is a plan view of a conventional disc brake, with the caliper and pads cut away at the center of the piston in the radial direction of the disc.

FIG. 5 is a cross-sectional view (viewed from the circumferential direction of the disc) of a pad of a conventional disc brake.

[Explanation of symbols]

21 Disc 23 One side of the pad 24 The other side of the pad 25 Caliper 26 Pistons 29a, 29b Claws 31a, 31b Retract springs 34a, 34
b, 35a, 35b Retract spring end

Claims (1)

[Claims] 1. Pads arranged on both sides of a disk and supported so as to be movable in the axial direction of the disk, and a piston provided on one side arranged to straddle these pads and the disk, which controls one of the pads. , a caliper that presses the other pad toward the disk with claws formed on the other side, and a retract spring that has both ends engaged with each pad and biases the pads in a direction to separate them from each other. A disc brake, characterized in that a position where the end of the retract spring engages with the other pad is aligned with the center of the claw in the circumferential direction of the disc.