JPS631831A - Disk brake with automatic regulator - 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] 3. Detailed explanation of Ming It concerns disc brakes.

The invention particularly relates to disc brakes of the type with a sliding caliper incorporating a brake actuator that can be actuated separately. 1 by directly pressing the friction member and i4 of the li5'1 rotation disk.
] The second friction member is frictionally engaged with the surface, and the reaction force through the sliding caliper pushes the second friction member opposite to the first member 114.
The second disc of No. 11 is brought into frictional engagement. The caliper slides against a fixed support, which directly or indirectly supports all of the torque generated by the friction member. In this type of disc brake, the initial thickness of the friction member is not considered, and the automatic adjustment device is designed to prevent the stroke of the mechanical control device from increasing as the friction member wears out. It is necessary to provide this mechanical control device with a control device. Various methods have been proposed to solve this problem. The disadvantage is that this type of automatic adjustment device not only compensates for the normal wear of the friction elements, but also compensates for the elastic deformation of the caliper when the control pressure is high. Therefore, it is necessary to make the reactive stroke considerably large without interfering with the automatic adjustment device and to allow for the deformation of the caliper that occurs during operation. Applicant, No. 2,075,
In French Patent Application No. 7 1-00748, published as No. 4 2 5, a fully-filled compressed material which deforms elastically under the action of fluid pressure when the control pressure reaches a predetermined value is described. The self-adjusting device is disabled by the enclosure, i.e., the enclosing body elastically deforms above a predetermined pressure, thereby increasing the dead travel and preventing interference with the self-adjusting device, and the side Will the elastic deformation of the caliper be compensated for when the crushing force is high? A disc brake configured to be anti-I is proposed.

Although this method solves the above-mentioned problems, it has the following drawbacks. In other words, the material of the elastic envelope, which is constantly deformed by pressure, becomes fatigued within a period of time, and as a result, the material breaks and not only does the desired effect not be obtained, but also due to the breakage of the envelope, A large amount of gas is introduced into the fluid circuit, resulting in a loss of braking ability of the brake, and the manufacturing of such an enclosure is quite difficult and results in variations, resulting in the braking torque acting on the two lower wheels on the same axle. Furthermore, the value of the fluid pressure, which should completely prevent the operation of the automatic adjustment device, cannot be easily changed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a disc brake of the above-mentioned type which eliminates the above-mentioned drawbacks and is constructed to be easy to manufacture and cost-effective.

To achieve this object, according to the present invention, the caliper and the first friction member are provided with a
acts on the second friction member by the reaction force exerted on C, and
eye! Fluid through pJJ regulator? A mechanical control device acting on the piston includes a brake actuator, the automatic adjustment device comprising a screw and nut device for controlling a reversible pitch, and the screw and nut device is connected to the annular member and the screw and nut device. actuated by the fluid control piston above a predetermined paddle of the fluid control piston defined by a clearance between the acting thrust bearing and the clearance being able to vary in response to the pressure acting on said fluid control piston; In this case, when the control force reaches a predetermined pressure, it slides into the flow printing piston.
A disc brake with an automatic adjustment device is proposed, which is characterized in that a monitoring piston that is freely and tightly fitted can move the annular member against the fluid control piston in the axial direction against a pressing blade of an elastic member. has been done.

According to this configuration, the dead stroke is controlled by the beginning of the annular part (O), and the movement of this annular member is monitored by the monitoring piston. Since the movement of the rod can be easily changed and does not change over time, high operational reliability can be ensured.

These and other features and advantages of the invention will become apparent from the following description of a penitential example made with reference to the accompanying drawings.

The disc brake shown in FIG. 1 is equipped with a sliding caliper generally designated by the reference numeral 10, and the caliper is a fixed part of the vehicle (
It is mounted on a fixing member or support (not shown) that is fixed to a support (not shown).

The caliper 10 includes a brake actuator, generally designated 12, which acts directly on the first friction member 14 and indirectly acts on the second friction member 16 through the sliding caliper 10ft. , both friction members are brought into frictional engagement with the rotating disk 18. Brake actuator 12? 'i
-Equipped with a fluid control device and a mechanical control device, details of which will be described later.

Conventionally, the fluid control device is connected to the brake actuator 1
2 is formed by a fluid control piston 20 slidably fitted within a bore 22 formed in the fluid control piston 20 . A seal between the piston 20 and the bore 22 is obtained by a knoll 24, and the piston is protected by a piston cap 26. A chamber 30 in which the piston 20 and the bottom wall 28 of the bore 22 are connected to a pressure source (not shown), such as a master cylinder of the vehicle.
Fully formed.

A mechanical control device, generally designated 32, is connected to a cable or similar device (not shown) and is connected to shaft 36.
A groove 38 is provided in the field 36 to accommodate a link 40. axis 36
is housed within two holes formed in the brake actuator 12 and is secured longitudinally thereto by a shoulder formed in the lever 34 and a retaining ring or similar device. The shaft 36 and link 40 are housed in a blind hole 12 formed in the brake actuator, and the opening of the blind hole is completely submerged in the plug, and these assemblies are protected by a cap 44. . blind hole 4
2 houses the screw 16 of the self-adjusting device and is provided with a groove 50 that cooperates with the enlarged part 48 of the screw/beam 40. A return spring 52 is disposed between the bottom of blind hole 42 and enlarged portion 48 . The screw 46 includes a grooved cylindrical portion with a seal 54 provided therein. This seal 54 and the cylindrical portion of the screw 46 can slide against a hole 56 formed in the body of the brake actuator. The screw 46 extends into the chamber 30 via a reversible threaded portion 58 into which a nut 60 is fitted. The fluid control piston 20 has a first bore 62 within which a monitoring piston 64 has a seal 66.
It is slidably and sealingly fitted through the . The fluid control piston 20 has a second diameter larger than the diameter of the bore 62.
holes 68, the step of which forms a wall 70 directed towards the chamber 30.

A washer 72 is held against this wall 70 to limit movement of a seal 74 disposed between the outer surface 76 of the extension 78 of the monitor piston 64 and the bore 68 to the left in FIG.
This extension 78 is a collar 80 formed on the nut 60.
You can freely pass around; The end of the extension 78 of the monitoring piston 64 axially abuts an annular member 82 mounted within the third bore 84 of the fluid control piston 20 . On the same side as chamber 30, an annular member 82 is urged to the left in FIG. .

The annular member 82 can be slid within the bore 8.1 by means of a spring 86. In particular, in the rest position shown in FIG. 1, the spring 86 pushes the annular member 82 to the left in FIG. Let it touch the bottom of the. A chamber 88 is formed between the bore 62, the monitoring piston 64 and/or the luer 4 and is communicated with the atmosphere by a passageway 90. Nando 60
A ball thrust bearing 92 is disposed between the collar 80 and the m pillow member 82, and the ball thrust bearing 92 is arranged between the collar 80 and the annular member 82.
2, an axial gap J is formed to limit the operating gap at the rest position. This gap J is small at the rim, and this gap,
■It is shown only in Figure 2, which is considerably enlarged to make it visible. Collar 80 and annular member 82I-i form a rolling track for ball thrust bearing 92. The nut 60 is connected to the fluid control piston 20 via a one-way clutch, generally designated 94, which, in the illustrated example, is wrapped around the cylindrical surface of the nut 60 and has one end. Part of the fluid system bacterium piston 2
It is formed by a clutch spring inserted into the OjDW. The monitoring piston 64 is a differential piston that slides through the seal 66 into the fluid control piston entry hole 62 and cooperates with the seal 74 on the outer surface 76 of its extension 78.

The disc brake described above with respect to FIG. 1 operates in the following manner.

A number of components of the disc brake are shown in rest positions. When the brake is actuated by mechanical control 32, lever 34 and shaft 36 push link 40 in the direction indicated by arrow A. The link 40 is connected to the screw 4 through the groove 50.
The enlarged portion 48i of No. 6 is pushed against the return spring 52. Since the cylindrical portion of the screw 46 can slide against the hole 56 formed in the brake actuator, the screw 46 also moves in the direction of arrow A. This movement of the screw 46 is transmitted to the nut 60 via the threaded portion 58, and the -direction clutch 9
4 prevents the nut from rotating 600 times, so the nut 60 comes into contact with the fluid control piston 20. Therefore, the sword of the link 40 is transmitted to the friction member 14,
Then, due to the reaction force of this friction member against the disk 18, another reaction force acts on the shaft 36, driving the caliper lO to slide in the direction opposite to the arrow A, and engaging the friction member 16 with the disk 18. urge When the mechanical control device 32 is released, the numerous components of the brake return to the positions shown.

When the brake is actuated by the fluid control system, fluid pressure is supplied to chamber 30 to force fluid control piston 20 to the left in FIG. If the movement of the fluid control piston 20 relative to the nut 60 does not exceed the working clearance Ji defined between the pole thrust bearing 92, the annular member 82, and the collar 80, no self-adjustment will occur due to movement of the piston 20. When the movement of the fluid control piston 20 is larger than the predetermined working gap J, the spring 86, the annular member 82, and the ball thrust bearing 92 are driven by a retaining ring fixed to the piston.
The piston 20 protrudes leftward through the piston 20. Because the screw 46 is fixed axially by the return ring 52, the nut 60 can rotate relative to the screw 46 to follow the movement of the fluid control piston 20 due to its reversible pitch; Allowed by directional clutch 94. During this phase of operation, the monitoring piston 64 is always held against the bottom of the bore 62 and does not interfere with the annular member 82. Then, when the fluid pressure is released,
Seal 24 controls fluid in a normal manner, IJ piston 20
is slightly returned, and the - direction clutch 94 completely prevents the rotation of the Nara 60. As the nut 60 rotates and moves to the left during brake application, the automatic adjustment device assumes a new position offset to the left with respect to the initial position, completely preventing the fluid control piston 20 from returning to its initial position. .

However, if the brake application is not released immediately, chamber 3
The pressure in the caliper 10 continues to rise and the action of this pressure and the force generated by the fluid control piston 20 causes the caliper 10 to
is deformed. It is therefore necessary to prevent the automatic adjustment device from operating before mechanical deformation of the caliper begins.

When the pressure in the chamber 30 reaches a value limited by the effective area jet of the differential or monitoring piston and the force of the spring 86, the monitoring piston 64 is moved to the right in FIG. 1 under the influence of this pressure. The annular member 82 is moved against the spring 86 to increase the gap between the ball thrust bearing 92 between the collar 80 of the nut 60 and the annular member 82, and the increased gap causes the V annular member 82 to tighten against the nut 60. operation is prevented, the automatic adjustment device is disabled,
The nut 60 no longer follows the movement of the fluid control piston 20. If the pressure continues to rise, the monitoring piston 64 will move further to the right in FIG. 1 against the spring 86, completely freeing the nut 60.

In FIG. 2, which shows the automatic regulator # in the position when the pressure in the chamber 30 exceeds a predetermined pressure value, the monitoring piston 6
4 is moved to the right in FIG. 2 by pushing the annular member 82. Therefore, the operating gap J is set so that the annular member 82 does not act at all on the ball thrust bearing 92 and the nut 60 of the automatic adjustment device. Existing.

When the fluid pressure in the chamber 30 is released, in a first step the fluid control piston 20 is moved to the right in FIGS. 1 and 2 due to the elastic deformation of the caliper 10, and in a second step this The piston continues to move to the right, but the spring 86 simultaneously moves to the left relative to the piston 20, and the monitoring piston 64 gradually returns toward the position shown in FIG. Finally, in the third step, the seal 24 moves the fluid control piston 20 slightly to the right in the normal manner, and the ball thrust bearing 92 and the two There is an initial operating gap between the collar 80 and the annular member 82 of the rolling track (Nar) 60.

As can be seen from the above description, in the automatic adjustment device according to the present invention, the working gap is controlled by a simple and reliable differential piston, and the pressure in the chamber exceeds a predetermined value. As a result of the differential piston moving in response to this pressure, the working gap increases, the fluid consumption l accompanying the movement of the differential piston gradually increases as it is exposed to the above pressure, and conversely, the initial position and spring 86
The directing piston is connected to the fluid via the annular member 82 and the annular member 82.
At intermediate pressures between the position of contact with the control piston 20 and the position of contact with the control piston 20, the pedal travel can be reduced.

This configuration also allows the fluid control piston to be mounted with a nut and differential piston without changing the machining of the brake actuator, thus
It is advantageous that brakes which are not equipped with the assistance device according to the invention can incorporate a fluid-controlled piston according to the invention without requiring any modifications. In fact, the assembly of fluid control piston 20, differential or monitoring piston 64, nut 60, annular member 82 and spring 86 forms a subassembly that can be removed as a unit and is easily installed in existing brakes. be able to. This configuration also allows the predetermined pressure value kff to be increased by simply replacing the fluid control piston 20 by changing the characteristics of the spring 86 or the diameter of the monitoring piston 6402.

The present invention is not limited to the embodiments described above; for example, the spring 86 may be formed in the shape of a saucer-shaped seat, and the spring 86 may be formed in the shape of a dish-shaped seat. 114iIO piston 21- to the annular member 82
Furthermore, the differential piston, in particular its seal, may be constructed in any manner within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a disc brake according to the present invention, and FIG.
The figure is an enlarged cross-sectional view of the essential parts of the brake of FIG. 1, shown in a state where the pressure exceeds a predetermined value. 1011.Sliding caliper, 12..Brake actuator, 14.a first friction member, 16..second friction member,
18...Rotating disk, 20...Fluid control piston, 3
2. Mechanical starvation device, 46ee screw, 60.. Nut, 62, 68, 84-. Hole, 64.. Monitoring piston, 72.. Washer, 74.. Seal, 82.. Annular member,
86...Spring, 92--Ball thrust bearing, 94...-Direction clutch, J...Gap. (other) names)

Claims (1)

[Scope of Claims] 1. Acts directly on the caliper (10) and the first friction member (14) and acts on the second friction member (16) by a reaction force via the caliper (10), and , a brake actuator (1) with a mechanical control device (32) acting on the fluid control piston (20) via an automatic adjustment device.
2), wherein the automatic adjusting device comprises a screw/nut device (46, 60) having a reversible pitch, and the screw/nut device (46, 60) connects the annular member (82) with the screw/nut device (46, 60).
The fluid control piston (
The gap (J) is actuated by the fluid control piston over a predetermined stroke of the fluid control piston (20).
a monitoring piston slidably and sealingly fitted into the fluid control piston (20) when the control pressure reaches a predetermined pressure; A disc brake with an automatic adjustment device, characterized in that (64) is capable of moving the annular member (82) in the axial direction with respect to the fluid control piston (20) against the pressing force of the elastic member (86). 2. At a control pressure equal to or lower than the predetermined pressure, a predetermined stroke of the fluid control piston causes the annular member (
82), said monitoring piston (64) being adapted to abut axially against the bottom of a bore (62) formed in the fluid control piston (20) and housing the monitoring piston; A disc brake according to claim 1, characterized in that: 3. Claim characterized in that the fluid control piston (20), the monitoring piston (64), the annular member (82) and the nut (60) of the screw-and-nut device form an assembly that can be removed as a unit. A disc brake according to item 1 or 2 of the range.