JPS624745Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to a disc brake.
A pair of pads, which are pressed against both sides of a brake disk that rotates integrally with the axle, are supported in a floating state on a part of the caliper via back metals fixed to their outer surfaces, and the inner surfaces of these pads are Both pads are pressed through their back metals by the operation of pistons which are placed opposite to each other on both sides of the brake disc and are slidably inserted into cylinders provided in the caliper via piston seals, thereby pressing the pads through their backing metals to open the brake disc. This invention relates to a disc brake that is pressed against both sides to generate braking force.

Generally, in this type of disc brake,
Both ends of the padded return spring are locked, for example, to each of a pair of backing metals. Therefore, as the wear of both pads progresses and the distance between the two backing metals gradually decreases, the return force of the pad return spring against both backing metals gradually becomes stronger, increasing the clearance between the two pads and the brake disc. . As a result, the stroke of the brake pedal increases during braking, which is undesirable in terms of braking feeling.

The present invention was developed in light of this situation, and its main purpose is to maintain the return force of the pad return spring approximately constant regardless of the degree of wear on both pads, thereby adjusting the stroke of the brake pedal. The objective is to prevent a decrease in braking feeling caused by an increase in braking feeling.

Hereinafter, the present invention will be explained based on the drawings. FIGS. 1 and 2 show an example of a disc brake according to the present invention. This disc brake is a fixed caliper type disc brake, and includes a brake disc 11 that is fixed to an axle (not shown) and rotates integrally with the axle, a caliper 12 that is fixed to a part of the vehicle body (not shown), and a pair of brake discs provided on the caliper 12. The main components are a pair of pistons 13, 14 fitted into a cylinder 12a, and a pair of pads 17, 18 fixed to both back plates 15, 16.

Both cylinders 12a are provided at mutually opposing parts of the caliper 12 and open inward, and each piston 13, 14 is slidable via a piston seal 12b fixed to the inner peripheral wall of both cylinders 12a. It is inserted. Both pistons 13, 14
is pushed inward by the braking hydraulic pressure applied within the cylinder 12a, and is pulled back outward by a predetermined amount corresponding to the amount of elastic deformation of the piston seal 12b by the elastic return action of the piston seal 12b. Further, one back metal 15 and pad 17 are interposed between the brake disc 11 and one piston 13, and the other back metal 16 and pad 18 are interposed between the brake disc 11 and the other piston 14. Both back metals 15 and 16 are supported in a floating state in the upper opening of the caliper 12 by a pair of support pins 21 inserted through mounting holes 15a and 16a provided on both sides of the upper portion of the metal backings 15 and 16, respectively. As a result, the outer surface of each back plate 15, 16 is
The inner ends of the pads 17 and 14 are opposed to each other, and the inner surfaces of the pads 17 and 18 are opposed to both sides of the brake disc 11, respectively.

Fitting holes 15b and 16b are provided approximately at the center of the upper portions of both backing metals 15 and 16 in the figure, and the outer end of the cylinder 31 is loosely fitted into the fitting hole 15b of one of the backing metals 15. is supported, and the other backing money 1
The outer end of the rod 32 is loosely fitted and supported in the fitting hole 16b of No.6.

As shown in FIG. 3, the cylindrical body 31 includes a cylinder portion 31a that opens inward, and a rod-shaped attachment portion 31b that extends outward from the cylinder portion 31a. Further, the rod body 32 includes a piston portion 32a extending inward, and a rod-shaped attachment portion 32b extending outward from the piston portion 32a.
A friction ring 33 that generates a predetermined sliding resistance is provided on the inner outer circumference of the piston portion 32a of the rod 32.
The piston portion 32a is slidably fitted into the cylinder portion 31a of the cylindrical body 31 via the friction ring 33. Cylindrical body 31 and rod body 3
2 connects the mounting portions 31b and 31b to each back plate 1 through coil springs 34 and 35, which are pad return springs having a predetermined spring constant.
It is loosely fitted into the respective fitting holes 15b, 16b of No. 5, 16, and supported by the respective back metals 15, 16. In this state, the sliding movement of the rod 32 is restricted by the sliding resistance of the friction ring 33, and a predetermined clearance l is secured between the inner surface of each pad 17, 18 and both surfaces of the brake disc 11, and The outer surface of each back plate 15, 16 is the piston 13, 1
It is approximately in contact with the inner end of 4. Each coil spring 34, 35 biases the cylinder 31 and the rod 32 with a force smaller than the sliding resistance of the friction ring 33 within the range of the amount of compression corresponding to the clearance l, and the amount of compression is within the range of the amount of compression corresponding to the clearance l. A spring constant is used that biases the cylinder 31 and the rod 32 with a force greater than the sliding resistance when the clearance l exceeds the corresponding amount.

On the other hand, one contact 36 of an alarm lamp (not shown) is provided at the bottom of the cylinder 31 via an insulating member, and when the rod 32 slides a predetermined amount, the inner end 32c of the piston portion 32a becomes the contact. 36 and the body is grounded through the back plate 16 and caliper 12, an alarm lamp is turned on. Therefore, this warning lamp is connected to each pad 17,1.
It functions to notify when the wear amount of 8 reaches a predetermined value, and the contact point 36 and the piston part 32a
The contact timing with the inner end 32c of each pad 1
It is determined based on the exchange standards of 7.18.

In the disc brake configured in this way, when the brake pedal is depressed, braking oil pressure is applied to each cylinder 12a and each piston 13, 1
Push 4 inward. As a result, each back money 15,1
The pads 6 are pushed inward while compressing the coil springs 34 and 35 to press the inner surfaces of the pads 17 and 18 against both surfaces of the brake disc 11, thereby producing a braking force. Further, when the brake pedal is released, each piston 13, 14 is pulled back outward by a predetermined amount by the elastic return action of the piston seal. As a result, each of the back metals 15 and 16 is pushed outward by an amount corresponding to the clearance l by the return force of each coil spring 34 and 35, and between both surfaces of the brake disc 11 and the inner surface of each pad 17 and 18. A predetermined clearance l is ensured.

By the way, as the inner surfaces of the pads 17 and 18 gradually wear out and the clearance l gradually increases,
When the backing pads 15, 16 are pushed inward, a biasing force greater than the sliding resistance by the friction ring 33 is generated in the coil springs 34, 35, and the pads 17, 1
The rod 32 is always slid inward by an amount corresponding to the sum of the wear amount of the brake disc 11 and the wear amount of the brake disc 11, and the clearance between both surfaces of the brake disc 11 and the inner surface of each pad 17, 18 is maintained by a predetermined amount. maintained at l. In addition, since the increase in the reaction force of each coil spring 34, 35 caused by the wear of each pad 17, 18 is consumed as an inward sliding force of rod 32, each back pad of each coil spring 34, 35 is The return force for each pad 15 and 16 is
Regardless of the degree of wear of parts 7 and 18, it is always approximately constant. Therefore, in the disc brake, the stroke of the brake pedal does not become large, and a decrease in braking feeling is prevented.

In addition, in the disc brake, when the wear of both pads 17 and 18 progresses and the rod 32 slides inward and its inner end 32c contacts the contact 36,
The warning lamp will light up to notify you that it is time to replace both pads 17 and 18.

By the way, each pad 1 is attached to the disc brake.
When incorporating wear alarm devices 7 and 18, both contacts for activating the alarm are connected to the cylinder body 31 and the rod body 32.
There is no need to perform any special processing on the pads as in the past. Also,
Conventional wear warning devices were attached to one of the pads, so if there is a difference in the wear of both pads and the wear of the other pad reaches a limit, it may not be possible to issue an alarm. In this case, since the rod 32 always slides inward by an amount corresponding to the sum of the amount of wear on both pads 17 and 18 and the amount of wear on brake disc 11, the alarm device is activated beyond the wear limit of both pads 17 and 18. Generates a warning slightly earlier and more reliably.

In this embodiment, an example is shown in which the friction ring 33 is fitted to the outer peripheral surface of the piston portion 32a of the rod body 32, but it is also possible to fit the friction ring 33 to the inner peripheral surface of the cylinder portion 31a of the cylinder body 31. Good too. In addition, although this embodiment shows an example of a fixed caliper type disc brake incorporating a warning device, the present invention can be implemented without the warning device, and can also be implemented in a movable caliper type disc brake. You can also. In short, the present invention consists of a pair of pads that are pressed against both sides of a brake disk that rotates integrally with the axle, and are supported in a floating state on a part of the caliper via a back metal fixed to the outer surface of the pads. The inner surfaces of the pads are opposed to both sides of the brake disc, and both pads are pressed through their back metals by the operation of a piston that is slidably inserted into a cylinder provided in the caliper via a piston seal. The present invention can be applied to various types of disc brakes in which braking force is generated by press-contacting both surfaces of the brake disc.

As explained above, the present invention provides brake discs of various types described above, in which the outer end of the cylindrical body is loosely fitted into the fitting hole provided in one of the two backing metals via a pad return spring and supported. At the same time, a pad return spring is inserted into the fitting hole provided in the other of the two backing metals by inserting the outer end of the rod that is slidably fitted into the cylinder through a friction ring that generates a predetermined sliding resistance. Its structural feature lies in the fact that it is loosely fitted and supported. Therefore, according to the present invention, the rod body slides inward in accordance with the wear of both pads, and the return force of both pad return springs is always maintained approximately constant regardless of the degree of wear of both pads. can do. Therefore, it is possible to prevent a decrease in braking feeling caused by an increase in the stroke of the brake pedal. Furthermore, according to the disc brake according to the present invention, when incorporating an alarm device as necessary, there is no need to perform special processing for mounting on each pad, and the alarm device can be activated appropriately depending on the wear of both pads. It also has the additional effect of being able to

[Brief description of the drawings]

Fig. 1 is a front view showing an example of a disc brake according to the present invention, Fig. 2 is a plan view of the same, and Fig. 3 is a front view showing an example of the disc brake according to the present invention.
It is an enlarged cross-sectional plan view along the - line of a figure. Explanation of symbols, 11...Brake disc, 12
...Caliper, 12a...Cylinder, 13, 14
... Piston, 15, 16 ... Secret money, 17, 18
... Pad, 31 ... Cylindrical body, 31a ... Cylinder part, 31c ... Mounting part, 32 ... Rod body, 32a ...
...Piston part, 32b...Mounting part, 33...Friction ring, 34, 35...Coil spring (pad return spring).

Claims (1)

[Scope of utility model registration request] A pair of pads, which are pressed against both sides of a brake disk that rotates integrally with the axle, are supported in a floating state on a part of the caliper via back metals fixed to their outer surfaces, and the inner surfaces of these pads are facing each side of the brake disc,
By the operation of a piston that is slidably inserted into a cylinder provided in the caliper via a piston seal, both pads are pressed through their backing metals and brought into pressure contact with both surfaces of the brake disc, thereby applying braking force. In the disc brake, the outer end of the cylindrical body is loosely fitted and supported in the fitting hole provided in one of the two backing metals via a pad return spring, and a predetermined sliding resistance is generated. The outer end of the rod is slidably fitted into the cylindrical body through a friction ring, and the outer end of the rod is loosely fitted and supported through a pad return spring into a fitting hole provided in the other of the two backing metals. A disc brake featuring