JPH0538254Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a disc brake for vehicles in which braking is performed by a mechanical actuation mechanism, and more specifically, to a disc brake for a vehicle that performs a braking action using a mechanical actuation mechanism. and the structure that regulates the amount of rotation.

[Conventional technology]

The disc brake installed as a brake for the rear wheels of a vehicle is, for example, a hydraulic type that is operated by hydraulic pressure generated in a hydraulic master cylinder when the brake pedal is depressed, as disclosed in Japanese Utility Model Application Publication No. 1-37240. A so-called parking brake system is used, which combines an actuation mechanism and a mechanical actuation mechanism that is actuated by pulling a handbrake lever.

Among these, the mechanical operating mechanism has a bearing hole perpendicular to the disk shaft in the action part of the caliper disposed on the side of the disk rotor, and a friction pad is pressed into the bearing hole against the disk rotor. A camshaft for operation is rotatably inserted through the shaft.

A cam lever is fixed to the protruding shaft portion of the camshaft that protrudes from the bearing hole, and a return spring that urges the camshaft in a non-operating direction is engaged with the cam lever.

The bearing hole is formed as a through hole so that the camshaft can be removed by moving it in the insertion direction, and a circlip for preventing the camshaft from being removed is inserted into the annular first engagement groove formed on the other end opening side of the bearing hole. is installed, and the tip of the insertion shaft of the camshaft disposed inside the bearing hole has a tapered surface that engages with the inner peripheral edge of the circlip to expand the diameter of the circlip when the camshaft is inserted, and a tapered surface that expands the diameter of the circlip when the camshaft is inserted. A second annular engagement groove that engages with the circlip that extends over the tapered surface is provided, and an inner surface of the second annular engagement groove located on the rear side in the camshaft insertion direction is connected to the camshaft. The tapered surface is formed so as to engage with the inner circumferential edge of the circlip and expand the diameter of the circlip when the circlip is removed.

As a result, by simply inserting the camshaft into the bearing hole after installing the circlip in the first annular engagement groove, the circlip can be engaged with the second annular engagement groove of the camshaft, making it easy to create a structure to prevent the camshaft from slipping out. This structure prevents the camshaft from falling out of the bearing hole even if the return spring breaks.

[The problem that the idea aims to solve]

In such a configuration, since the camshaft is removed from the opening at the other end of the bearing hole, a space for removing the camshaft that is at least the full length of the camshaft must be provided at the opening at the other end of the bearing hole. This restricts the arrangement of other members arranged around the wheel.

In addition, in this type of mechanical operating mechanism used as a parking brake, among the rotation of the cam lever in both the operating and non-operating directions, the retraction limit in the non-operating direction is generally restricted by a stopper, but the rotation in the operating direction is restricted by a stopper. Since there is no mechanism, if the handbrake lever is pulled too much, the camshaft will rotate excessively, and the pushrod pushed by the camshaft will tilt with respect to the disk shaft, which may impede smooth operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mechanical disc brake for a vehicle that eliminates the need for a space for extracting the camshaft, and also limits the amount of rotation of the camshaft in the operating direction to ensure smooth operation.

[Means for solving the problem] In order to achieve the above-mentioned object, the first idea is to provide a bearing hole perpendicular to the disk axis on one side wall of the acting part of the caliper disposed on the side of the disk rotor. In a mechanical disc brake for a vehicle, a camshaft for pressing a friction pad against the disc rotor is rotatably inserted into the bearing hole, and a flange is provided on the outside of the opening of the bearing hole, A lever removal prevention member having an engaging arm is fixed to the protruding shaft of the camshaft protruding from the hole, and the distal end of the engaging arm is folded over the outer circumference of the flange to the opposite side, and the engaged The flange is provided with a stopper that comes into contact with the tip of the arm to restrict the amount of rotation of the camshaft. This flange is attached integrally to the operating portion of the caliper by casting or the like, or separately attached by retrofitting.

In addition, in the second invention, a bearing hole that is orthogonal to the disk axis is opened in one side wall and is provided in the action part of the caliper disposed on the side of the disk rotor, and the friction pad is inserted into the bearing hole. In a mechanical disc brake for a vehicle in which a camshaft that presses a rotor is rotatably inserted through the brake, an arc-shaped guide groove centered on the axis of the bearing hole is formed outside the opening of the bearing hole, and A lever removal prevention member having an engaging arm is fixed to the protruding bearing hole of the camshaft protruding from the hole, and the distal end of the engaging arm is inserted into the guide groove and folded into the inner surface,
The distal end of the engagement arm is brought into contact with the end of the guide groove to restrict the amount of rotation of the camshaft.

In addition to exclusive products, the lever removal prevention members of both designs include
The cam lever may be provided with an engagement arm by utilizing a cam lever that is pivoted to the protruding bearing hole of the camshaft.

[Effect]

With this configuration, the camshaft inserted into the bearing hole is prevented from coming off by engagement between the lever retaining member and the flange or guide groove. Furthermore, when the camshaft is rotated in the braking direction, the tip of the engaging arm of the lever retaining member comes into contact with the stopper of the flange or the end of the guide groove, restricting the amount of rotation of the camshaft. As a result, the pushing amount of the friction pad that is pushed is set to be constant.

[Example] Hereinafter, each example of the present invention will be described based on the drawings.

A rear wheel disc brake 1 shown in the first embodiment shown in FIGS. 1 and 2 has a parking brake equipped with a hydraulic actuation mechanism 2 and a mechanical actuation mechanism 3. A caliper 6 is supported by a bracket 5 fixedly attached to the disc 5 so as to be movable in the axial direction of the disc via a pair of sliding pins 7, 7.

Linings 8a are provided on both sides of the disc rotor 4.
A pair of friction pads 8, 8 consisting of and a back plate 8b are arranged facing each other, and an action part 6a and a reaction part 6b of the caliper 6 are arranged with both friction pads 8, 8 in between.
are connected at a bridge portion 6c that straddles the disc rotor 4 and the friction pads 8, 8.

The action part 6a has a large diameter hole 9a and a small diameter communication hole 9.
A cylinder hole 9 is formed in the disk axial direction, and a small-tip piston 10 is fluid-tightly and movably inserted into the large-diameter hole 9a that opens toward the disk rotor 4. An inlet port 12 is formed in communication with a hydraulic pressure chamber 11 defined between the bottom of the large diameter hole 9a and the piston 10, into which hydraulic pressure generated by a known hydraulic master cylinder (not shown) is introduced. There is.

The above-mentioned hydraulic actuation mechanism 2 includes a piston 10,
The hydraulic master cylinder is composed of a hydraulic pressure chamber 11 formed in the large diameter hole 9a and an inlet port 12, and the hydraulic pressure of the hydraulic master cylinder supplied to the hydraulic pressure chamber 11 from the inlet port 12 is transferred to the piston of the large diameter hole 9a. 10, an adjuster 13 and a sleeve piston 14 of the mechanical actuation mechanism 3, which will be described later, are integrally pushed toward the disc rotor 4 side.

The piston 10, which moves forward through the large diameter hole 9a with this supply fluid pressure, moves one friction pad 8 to the disk rotor 4.
Then, due to this reaction, the caliper 6 moves toward the acting part 6a, and the reaction part 6b
The other friction pad 8 is pressed against the other side of the disc rotor 4, and the disc rotor 4 is pressed against both friction pads 8,
8 to perform a braking action.

On the other hand, the mechanical actuation mechanism 3 is for a parking brake that performs a braking operation by the driver's handbrake operation, and this mechanical actuation mechanism 3 includes an adjuster 13 that combines an adjuster bolt 15 and an adjuster nut 16; It has a sleeve piston 14 disposed on the bottom side of the large diameter hole 9a, a camshaft 17 disposed perpendicular to the cylinder axis, and a bushing rod 18 interposed between the camshaft 17 and the sleeve piston 14. ing.

The sleeve piston 14 has a large diameter shaft portion 14a disposed at the bottom of the large diameter hole 9a prevented from rotating by a pin 19, and a rear small diameter shaft portion 14b inserted into the communication hole 9b to move in the disk axial direction. A tapered clutch surface 14c and a small diameter shaft hole 14d are continuously formed in the large diameter shaft portion 14a.

Further, the adjustment bolt 15 has a threaded portion 15a at the tip thereof screwed into a female threaded hole 16a of an adjustment nut 16 which is prevented from rotating around the piston 10 by a pin 20, and a rear end shaft 15b is connected to the shaft of the sleeve piston 14. The sleeve piston 14 is inserted into the hole 14d, and the clutch surface 15d on the outer periphery of the intermediate flange 15c is pushed by the elastic force of the spring 21.
It is attached in frictional engagement with the clutch surface 14c of.

At the rear of the communication hole 9b, a bearing hole 22 that is perpendicular to the disk shaft is provided and opens in one side wall of the operating portion 6a.
is inserted.

The camshaft 17 is composed of an insertion shaft portion 17a disposed in the bearing hole 22 and a protrusion shaft portion 17b protruding from an opening to which the boot 23 is attached. The outer periphery is rotatably supported by a bearing 24. A cam lever 25 for rotation is provided on the protruding shaft portion 17b.
It is fixed by a washer 26 and a nut 27, and a coil-shaped return spring 28 is disposed around the outer periphery of the nut 27. A brake wire 29 is connected to the connecting arm 25a of the cam lever 25.

The cam lever 25 is provided with a stopper piece 25b and an engagement arm 25c with a tip 25d folded into a U-shape in addition to the connecting arm 25a. A flange 6d formed in an arc shape is integrally formed outside the opening of the bearing hole 22. The flange 6d has a notch 6e at the bottom and an opposite side 6f on the side opposite to the cam lever.
A protruding stopper 6g is provided at a distance, and the engagement arm 25c has a distal end 25d cut out 6e.
It is inserted into the opposite side surface 6f and is provided so as to straddle the outer periphery of the flange 6d.

The return spring 28 has one end 28a connected to a stopper pin 30 protruding from the action portion 6a, and the other end 28a
b are respectively engaged with connecting arms 25a of the camshaft 25, urging the camshaft 17 and the cam lever 25 in the non-braking direction (direction of arrow B in FIG. 2). When the camshaft 17 and the cam lever 25 are not braking, due to the elastic force of the return spring 28, as shown by the solid line in FIG. When the brake wire 29 is pulled by the handbrake lever inside the vehicle, it is rotated integrally in the braking direction (direction of arrow A in Fig. 2), and when this pull is released, the return spring 2
It returns to the backward limit position with the restoring force of 8.

The mechanical actuation mechanism 3 of this embodiment is configured as described above, and when the brake wire 29 is pulled by the driver's handbrake operation, the camshaft 17 also serves as the retaining member of the present invention. Rotating together with the cam lever 25, the rotational force of the camshaft 17 is converted into thrust by the push rod 18, which pushes the sleeve piston 14. When the sleeve piston 14 advances toward the disc rotor 4 side, the adjustment bolt 15 and adjustment nut 1
6, the piston 10 advances integrally toward the disc rotor 4, and presses both friction pads 8, 8 against the disc rotor 4 in the same way as in the hydraulic operation described above, thereby performing a braking action.

The engaging arm 25c provided on the cam lever 25 is
When the camshaft 17 and the cam lever 25 rotate in the braking direction as described above, the tip portion 25d
From the position removed from the insertion notch 6e, it rotates so as to embrace the outer circumference of the flange 6d and comes into contact with the stopper 6g of the flange 6d, regulating the amount of rotation of both (as shown by the two-dot chain line in Fig. 2). reference). Further, when a force is applied to the camshaft 17 in the withdrawal direction (in the direction of the cam lever 25), the tip 25d of the engaging arm 25c
This is prevented by coming into contact with the opposite side surface 6f of the flange 6d.

As described above, since the camshaft 17 and the cam lever 25 of this embodiment have a rotation regulating means in the braking direction, the amount of rotation is kept constant, and even if the handbrake lever is pulled excessively, the camshaft 17 is The push rod 1 cannot be over-rotated and is therefore pushed by the camshaft 17.
8 is prevented from tilting and the amount of pushing into the friction pad 8 is kept constant, so smooth and stable operation can be achieved.

Also, the camshaft 17 can be removed from the bearing hole 2.
Since it is performed on the opening side of 2, as in the conventional case,
A camshaft 17 is located on the other end opening side of the bearing hole 22.
There is no need to set up a space for extraction that is longer than the full length of the wheel, and there is no restriction on the arrangement of other members arranged around the wheel.

3 and 4 show a second embodiment of the present invention. In the first embodiment, the flange 6d is integrally formed with the action part 6a of the caliper 6, whereas in this embodiment, a separate flange 40 formed by punching out a plate is provided outside the opening of the bearing hole 22. The flange 40, which has an arcuate outer edge, has a notch 40a at the bottom, and a stopper 4 at the opposite side 40b, which is the side opposite to the cam lever.
0c is provided by folding a tongue piece, and other members including a cam lever 25 are arranged in the same manner as in the first embodiment.

5 and 6 show a third embodiment of the present invention, in which a guide plate 50 is attached to a flange 6h extending from an operating portion 6a outside the opening of a bearing hole 22, and a guide plate 50 is attached to a screw 5.
It is fixed at 1. The flange 6h and the guide plate 50 have arc-shaped concave grooves 52, 52 and guide grooves 53, 53 centered on the axis of the bearing hole 22.
They are provided so as to face each other with the bearing hole 22 in between, and the groove 52 and the guide groove 53 are formed on the guide plate 50.
When attached as described above, both outer edges are overlapped.

The cam lever 54, which is fixed to the protruding shaft portion 17b of the camshaft 17, includes a connecting arm 54a, a stopper piece 54b, and a pair of engaging arms 54c, 54c, which have distal ends 54d folded into a U-shape, and are protruded from each other. has been done. The distal end portion 54d of each engaging arm 54c is inserted into the groove 52, straddling the outer side of the inner edge of the guide groove 53, and is further folded into the inner diameter side of the groove 52, that is, the inner surface 53a of the guide groove 53. It is established by

In this embodiment, the circumferential length of the concave groove 52 and the guide groove 53 is the same as that of the camshaft 17 and the cam lever 5.
4, and the tip portion 54 of the engaging arm 54c
d comes into contact with the circumferential ends of the groove 52 and the guide groove 53, thereby regulating the amount of rotation.

Further, when a force in the withdrawal direction is applied to the camshaft 17, the distal end portion 54d of the engaging arm 54c moves into the guide groove 5.
3 to prevent this. Further, even if an unbalanced load is generated on the camshaft 17, the two opposing engaging arms 54c prevent the camshaft 17 from tilting, so that the thrust after the push rod 18 is not adversely affected.

In each of the above embodiments, the engaging arm is integrally provided with the cam lever so that the cam lever also serves as the lever retaining member of the present invention. However, in the present invention, the lever retaining member having the engaging arm is attached to the cam lever. Apart from this, it may be separately fixed to the protruding shaft portion of the camshaft.

[Effect of idea]

The mechanical disc brake for a vehicle of the present invention has a flange on the outside of the opening of a bearing hole into which the camshaft is rotatably inserted, and a lever having an engagement arm on the protruding shaft of the camshaft that protrudes from the bearing hole. A retaining member is fixedly installed, and the tip of the engaging arm is folded over the outer circumference of the flange to the opposite side,
Either a stopper is provided on the flange to abut against the tip of the engagement arm to restrict the amount of rotation of the camshaft, or a guide groove in the shape of an arc centered on the axis of the bearing hole is provided on the outside of the opening of the bearing hole. A lever retaining member having an engaging arm is fixed to the protruding shaft of the camshaft protruding from the bearing hole, and the distal end of the engaging arm is inserted into the guide groove and folded into the inner surface. At the same time, the distal end of the engagement arm is brought into contact with the end of the guide groove to restrict the amount of rotation of the camshaft, so the camshaft and cam lever are rotated by the rotation restriction means in the braking direction. The amount of movement is kept constant, and even if the handbrake lever is pulled excessively, the camshaft will not rotate excessively. Therefore, the pushing amount of the friction pad pushed by the rotation of the camshaft is kept constant, and smooth and stable operation can be performed.

In addition, since the camshaft is removed on the opening side of the bearing hole, there is no need to provide a removal space longer than the entire length of the camshaft on the other end opening side of the bearing hole, unlike in the conventional case. There is no restriction on the arrangement of other surrounding members.

Further, when the camshaft tries to come out of the bearing hole, the distal end of the engagement arm comes into contact with the opposite side of the flange, thereby reliably preventing the camshaft from coming out.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a partially sectional plan view of a disc brake, FIG. 2 is a front view of the main part of FIG. 1, and FIGS. Figure 4 shows the second embodiment, Figure 3 is a plan view of the main part,
FIG. 4 is a front view of the main part, FIGS. 5 and 6 show the third embodiment, FIG. 5 is a plan view of the main part, and FIG. 6 is a front view of the main part. DESCRIPTION OF SYMBOLS 1... Disc brake, 3... Mechanical operating mechanism, 4... Disc rotor for rear wheels, 6... Caliper, 6a... Acting part, 6d... Flange, 6e
...notch, 6f...opposite side, 6g...stopper, 6h...flange, 8...friction pad, 9...
...Cylinder hole, 9a...Large diameter hole, 9b...Communication hole, 10...Piston, 14...Sleeve piston, 17...Camshaft, 17b...Protruding shaft portion, 18...Push rod, 22...Bearing hole ,
25...Cam lever, 25a...Connection arm, 25b
...Stopper piece, 25c...Engagement arm, 25d...
Tip, 28...Return spring, 29...
Brake wire, 50...Guide plate, 52...Concave groove, 53...Guide groove, 54...Cam lever, 5
4c...engaging arm, 54d...tip part.

Claims (1)

[Claims for Utility Model Registration] 1. A bearing hole perpendicular to the disk axis is provided in one side wall of the acting part of the caliper disposed on the side of the disk rotor, and a friction pad is inserted into the bearing hole to attach the friction pad to the disk rotor. In a mechanical disc brake for a vehicle in which a camshaft that presses a rotor is rotatably inserted through the brake, a flange is provided on the outside of the opening of the bearing hole, and an engaging arm is attached to the protruding shaft portion of the camshaft that protrudes from the bearing hole. A lever retaining member having a locking mechanism is fixedly installed, and the distal end of the engaging arm is folded into the opposite side across the outer circumference of the flange, and the distal end of the engaging arm is brought into contact with the distal end of the flange to restrict the amount of rotation of the camshaft. A mechanical disc brake for a vehicle, characterized in that a stopper is provided on the flange. 2. A bearing hole perpendicular to the disk axis is provided in the action part of the caliper disposed on the side of the disk rotor, and a camshaft for pressing the friction pad against the disk rotor is rotated in the bearing hole. In a mechanical disc brake for a vehicle that is arranged to be movably inserted, an arc-shaped guide groove centered on the axis of the bearing hole is formed outside the opening of the bearing hole, and a camshaft protrudes from the bearing hole. A lever removal prevention member having an engaging arm is fixed to the shaft portion, and the distal end of the engaging arm is inserted into the guide groove and folded into the inner surface, and the distal end of the engaging arm is guided. Contact the end of the groove,
A mechanical disc brake for vehicles characterized by regulating the amount of rotation of a camshaft.