JPS589295B2 - Emban brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc brake for an automobile, and in particular, a caliper that straddles the outer periphery of a disc is slidably guided in the axial direction of the disc with respect to a fixed support by a pair of guide pins. The invention relates to a type of disc brake.

Generally speaking, in this type of disc brake, the caliper gradually moves relative to the fixed support in the axial direction of the disc as the lining wears, and the sliding part of the caliper is affected by the effective wear of a pair of friction pads. It is necessary to take the amount of wear into account and make it large, and the structure for protecting this sliding part (for example, dustproof boots, etc.) must naturally take into account the large amount of effective wear.

In contrast, in the present invention, the caliper is guided by reciprocating motion in a fixed position, and the sliding part is limited to a small part where there is no need to particularly consider wear of the lining, so that the outside of the sliding part is It has a structure that allows for easy protection.

Accordingly, an increase in the gap between the friction pad and the disc due to wear of the lining of the friction pad is compensated for by an adjustment screw that extends forward from the caliper in the direction of the disc.

To explain this more specifically, if we assume that the caliper makes a small reciprocating motion in a substantially fixed position, then the friction pad (hereinafter referred to as the inner friction pad) on the side that is pressed against the disk by the piston of the caliper's hydraulic cylinder device ) and the friction pad (hereinafter referred to as the outer friction pad) on the side that is pressed against the disc by the reaction part of the caliper, the linings of which are worn out by repeated braking, increasing the gap between them and the disc.

In this case, with respect to the inner friction pad, the increasing gap can be filled without moving the position of the caliper by gradually protruding the piston that presses it from the cylinder, but with respect to the outer friction pad, There is no particular means to fill the growing gap.

Therefore, it has been considered to provide a means of filling such an increasing gap by assembling an adjustment screw that automatically screws out gradually in the direction of the disk in the reaction part, and by this,
Basically, pressing the inner and outer friction pads against the disk can be achieved by means of calipers reciprocating in a substantially fixed position.

However, it is necessary for the friction pad not to contact (do not drag) the disc when not braking, and this problem cannot be solved by the above-mentioned configuration alone.

Of course, for the inner friction pad, the known solution of using the restoration of the elastic deformation of the piston seal can be applied as is, but there is no such known solution for the outer friction pad.Therefore, the present invention By providing a means to solve this problem, we have completed a disc brake that can generate braking by reciprocating the caliper at a substantially fixed position.

The characteristic feature of the present invention is that the caliper, which is supported by the fixed support via the caliper guide pin, is provided so that it returns to the initial position by the force of a return spring when the brake is released, and that the caliper is provided in the reaction part of the caliper. A middle plate made of sheet metal is interposed between the automatic adjustment device and the outer friction pad, and a pair of middle plate pins extending in the axial direction of the disc are fixed to this middle plate, and the ends of the middle plate pins are fixed. In addition to fitting into corresponding pin holes formed in the support, a rubber bush is provided between the middle plate pin and the pin hole, and the sliding resistance between the rubber bush and the middle plate pin is controlled by an automatic adjustment device. By making the spring force greater than the spring force of the adjustment spring that unscrews the adjustment screw (that is, moves the outer friction pad forward in the disk direction), the restoring force of the elastic deformation of the rubber bush is used to prevent over-adjustment during automatic adjustment. It's what I chose to do.

The present invention will be explained below with reference to the embodiments shown in the drawings. In FIGS.
A fixed support in the form of a disk, located on one side of the disk.

2 is a caliper that straddles a disc and includes a part of the cylinder and a reaction part; 3 is a disc; 4 is a plurality of bolts that fasten the part of the cylinder of the caliper and the reaction part; 5 is a part of the cylinder of the caliper; 6 is the reaction part of the caliper, 7 is the oil inlet,
Reference numeral 8 designates a bleeder hole, and reference numeral 9 designates a pair of pad guide pins that are spaced apart in the circumferential direction of the disc, extending between a part of the cylinder of the caliper and the reaction part, and extending on both sides of the disc. A pair of friction pads is provided so as to be slidably guided in the axial direction of the disk.

10 is a pair of intermediate plate pins which are fixed to the intermediate plate and are spaced apart in the circumferential direction of the disc and extend in the axial direction of the disc, 11 is a pair of arm parts of the fixed support 1, and 12 is a periphery of the disc. A pair of caliper guide pins are arranged spaced apart in the direction, and are fixed to a fixed support so as to slidably guide the caliper in the axial direction of the disc.

The structural relationship among the caliper guide pin 12, the caliper 2, and the fixed support 1 is shown in detail in FIG.

13 is a boot that is installed between the caliper and the caliper guide pin to protect the sliding part of the caliper; 14 is a plurality of mounting holes formed in the fixed support 1 to the vehicle body fixed part;
Reference numeral 15 designates an intermediate plate interposed between an adjustment screw of an automatic adjustment device to be described later and an outer friction pad, and is provided so as to transmit the pressing force from the caliper transmitted through the adjustment screw to the outer friction pad. There is.

16 is an inner friction pad, 17 is the same back plate, 18 is an outer friction pad, 19 is the same back plate, and 20 is a middle plate pin hole formed in the fixed support 1, which are spaced apart in the circumferential direction of the disk. They form a pair and are assembled so as to form a fitting relationship with a pair of middle plate pins 10 fixed to the middle plate 20.

Reference numeral 21 denotes a rubber bush installed between the fitting surface of the middle plate pin hole 20 and the middle plate pin 10, and a boot integrally extends from the end thereof.

In Fig. 3, 3 is a disk, 5 is a part of the cylinder of the caliper, 6 is a reaction part, 7 is an oil inlet, 14 is a mounting hole of a fixed support, 15 is a middle plate, 16 is an inner friction pad, 17 18 is the same back plate, 18 is an outer friction pad, 19 is the same back plate, 22 is a piston in the cylinder, 23 is an oil chamber, and 24 is a seal that snaps onto the circumference of the piston. When the piston moves forward, it is slightly deformed, and when the hydraulic pressure is released, the deformation is restored to cause the piston to move slightly backward.

25 is a boot that protects the open end of a part of the cylinder; 26 is an adjustment screw for transmitting pressing force screwed into the reaction part 6 of the caliper; 27 is the same head; 28 is a cylinder with a bottom; The part is fitted into the hole 37 formed in the caliper reaction part,
It is a sleeve whose bottom part is located between the adjustment screw 26 and the middle plate 15, and is used to attach a boot 30, which will be described later.

Reference numeral 29 denotes an adjustment spring which is provided between the caliper reaction part and the adjustment screw and has a spring force stored in advance in the direction of screwing out the adjustment screw. configuring the device.

30 and 31 are boots that protect the automatic adjustment device.

In FIG. 4, 1 is a fixed support, 2 is a caliper, 1
2 is a caliper guide pin; 13 is a boot; 32 is a head with an enlarged diameter formed at the tip of the guide pin; 33 is a return spring for the caliper provided between the caliper and the head; 34 and 35 are A rubber ring 36 provided between the caliper guide pin and the caliper is a seal.

Next, the operation of the brake will be explained.

When pressure oil is introduced into the oil chamber 23 in FIG. 3 from the oil inlet 7,
The piston 22 is pushed towards the disc 3, bringing the inner friction pad 16 into frictional engagement with one side of the disc 3.

Due to the reaction force at this time, the entire caliper 2 moves in the opposite direction to the piston 22 (to the right in the figure), and the reaction part 6 moves the outer friction pad 18 to the other surface of the disc 3 via the adjustment screw 26 and the middle plate 15. Frictional engagement and braking.

The movement of the caliper 2 at this time is provided by a sliding mechanism including a caliper guide pin 12 provided so as to have a relative sliding relationship with the fixed support 1 (see FIG. 4).

The function of the intermediate plate pin 10 will be explained with reference to FIG.

When the brake is activated, when the middle plate 15 moves in the direction of the disc 3 by being pushed by the adjustment screw 26, the middle plate pin 10, which is integrated with the middle plate 15, also moves in the same direction, slightly elastically deforming the rubber bushing and closing the rubber bushing. It will be pushed strongly into 21.

At that time, if the amount of wear on the friction pad exceeds the allowable amount of deformation of the rubber bush, the middle plate pin 10 will enter the rubber bush 21 by an amount equivalent to the amount of wear on the outer friction pad 18. .

On the other hand, since the caliper 2 is supported by the fixed support 1 in the structure shown in FIG. 4, the caliper 2, which had been moving in the direction of compressing the spring 33 due to the reaction, is released from braking. It is returned to its original state by the restoring force of the spring 33 (returns to the left in the figure).

In the automatic adjustment device, as shown in FIG. 3, an adjustment screw 26 is screwed into a screw hole formed in the reaction part 6 of the caliper, and its head 27 is in contact with the middle plate 15 through a sleeve 28.

Then, the head 27 of the adjustment screw is adjusted so that the adjustment spring 29 applies a rotational force in the forward direction of screwing out (the direction in which the screw approaches the disk by screwing out).
and the reaction section 6.

Therefore, if the friction pad is worn to a specified value or more during braking, the middle plate pin 10 elastically deforms the rubber bush 21 and slides, and then when the braking is released, the caliper returns to its original position due to the restoring force of the spring 33. However, the outer friction pad 18 returns only a certain amount due to the restoring force caused by the elastic deformation of the rubber bush 21, so it is screwed into the reaction part 6. There will be play between the head 27 of the adjusting screw 26 and the middle plate 15.

Then, the adjustment spring 2, which is provided with energy stored in advance,
9 compensates for this play by rotating the adjusting screw 26 in the threading direction.

The sliding resistance between the middle plate pin 10 and the rubber bush 21 is
Since the adjustment screw is set to overcome the spring force of the adjustment spring 29 which attempts to move the intermediate plate 15 forward in the disc direction by the rotating operation of the adjustment screw, automatic adjustment of the gap between the friction pad and the disc is possible without any problem. It will be done.

Torque during braking is directly received by the fixed support 1 at the inner friction pad, and is received by the fixed support 1 from the caliper 2 via the guide pin 12 at the outer friction pad.

Also, when the brake is released, the middle plate pin 10 is moved to the rubber bush 21.
As a result, the middle plate 15 is returned together with the outer friction pad 18, so that it is possible to prevent the so-called dragging of the friction pad and the disk after the brake is released.

As mentioned above, the disc brake according to the present invention has
The caliper, which is supported movably in the axial direction of the disk by a fixed support via a caliper guide pin, always repeats its movement within a substantially constant range, while a friction pad is pressed against the disk for this purpose. The gap between and the disk is
The problem that increases with lining wear, in other words, the amount of movement of the caliper must increase, is absorbed by the relative advancement of the piston from a part of the cylinder on the inside, and by the forward rotation of the adjustment screw on the outside. an intermediate plate having an intermediate plate pin attached to the fixed support with a predetermined frictional resistance so as to prevent an excessive amount of rotational forward movement of the outer adjusting screw;
An automatic adjustment device is constructed by combining an adjustment screw that is screwed into the caliper and is applied with rotational force, and the effect is that the length of the sliding part of the caliper can be extremely short. It is something that has.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the disc brake of the present invention, Fig. 2 is a front view of the same as above, Fig. 3 is a sectional view taken along line A-A in Fig. 2,
FIG. 4 is a sectional view taken along line BB in FIG. 1... Fixed support body, 2... Caliper, 3... Disc, 4... Bolt, 5...
... Part of the caliper cylinder, 6... Caliper reaction part, 7... Oil inlet, 8...
...Bleeder hole, 9...Pad guide pin,
10... Middle plate pin, 11... Arm portion of fixed support body, 12... Caliper guide pin, 13
...Boots, 14...Mounting holes, 15.
... Middle plate, 16, 18 ... Friction pad,
17, 19... Back plate, 20... Middle plate pin hole.

Claims (1)

[Claims] 1 A fixed support fixed close to the disk, supported by this fixed support so as to slide back and forth in the disk axial direction via a caliper guide pin, and a hydraulically operated type on the inside of the disk. A disc brake comprising: a cylinder part with a built-in piston; a caliper having a reaction part on the outside of the disc; and inner and outer friction pads that are frictionally engaged with the disc by the piston and reaction part of the caliper. A spring for returning the caliper when the brake is released is attached to the caliper guide pin, and an adjusting screw for transmitting a pressing force that can be moved in and out in the axial direction of the disc is screwed into the reaction part of the caliper. An adjustment spring is attached to the adjustment screw to provide a rotational force for screwing forward in the direction of the disk, and further, between the adjustment screw and the outer friction pad, a rubber bush is inserted into a pair of pin holes of the fixed support. A middle plate is provided that has a pair of middle plate pins extending in the axial direction of the disks that fit together with a predetermined sliding resistance, and this sliding resistance is greater than the screw-out rotation forward force applied to the adjusting screw by the adjusting spring. A disc brake characterized by being set to be large.