JPH11148523A - Automatic pad clearance regulating device of disk brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the machinability and durability by recessing an engagement groove parallel to the axis in a peripheral surface of a screw member slidably fitted to a cylinder hole, and engaging the engagement groove with a peripheral surface of the tip part of a pin fixed in a pin hole to communicate with a side of the cylinder hole in a non-rotational and slidable manner. SOLUTION: A pin 19 is press-fitted and fixed to the pin hole 2g of a caliper 2, and the engagement groove 15b of a part of a head 15 of an adjustment nut 14 is engaged with a tip part of the pin 19 in a non-rotational and axially slidable manner. Though the rotational force is applied to the head 15 when the pad clearance is automatically regulated, the pin 19 is allowed to abut on the engagement groove 15b to prevent the rotation of the head 15. In the head 15, the engagement groove 15b is of the arc shape of the radius of curvature same as the radius of the pin 19, a base material capable of withstanding he stress concentration is left behind, and the engagement groove 15b and the pin 19 are neither deformed or broken by the rotational force because the tip of the pin 19 is of circular section free from any shipping in the circumferential surface. When a parking brake is applied, the pin 19 does not prevent the head from sliding because the engagement groove 15b is parallel to the pin 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake having a mechanical operating mechanism and an automatic pad gap adjusting mechanism, and more particularly to an automatic pad gap adjusting apparatus for a disc brake.

[0002]

2. Description of the Related Art Disc brake devices with an automatic pad gap adjusting mechanism are known from Japanese Patent Publication No. 2628325 and Japanese Patent Publication No. 63-35857. In these disc brake devices, a piston is fitted on the large-diameter side of a different-diameter cylinder of a caliper, and a pad gap automatic adjustment mechanism including an adjustment bolt and an adjustment nut is disposed in a liquid chamber. In addition to the automatic gap adjusting function, the piston is pushed through the automatic gap adjusting mechanism by a mechanical operation to perform a braking action. This type of automatic gap adjusting mechanism has a small diameter of a sleeve piston in which an adjusting nut screwed to an adjusting bolt is clutch-engaged with a bottom surface of a bottomed hole of the piston and the other adjusting bolt is directly or coaxially arranged with the adjusting bolt. The part is non-rotatably fitted to the small diameter side of the different diameter cylinder and is slidably fitted in the axial direction. Then, at the time of service braking when the friction material of the pad is worn, the adjust nut is screwed out of the adjustment bolt to supplement the wear amount of the friction material, and the gap between the pad and the rotor is automatically adjusted.

[0003] In the above-mentioned structure, as means for attaching an adjustment bolt or a sleeve piston so as to be non-rotatable and slidable in the axial direction, the former is disclosed in Japanese Patent Application Publication No.
No. 28325) has a structure in which an adjust bolt is inserted through a key plate so as to be non-rotatable and slidable in the axial direction, and an engaging projection provided on the outer periphery of the key plate is provided on a large diameter bottom side peripheral wall of a different diameter cylinder. It is engaged with the mating groove and is retained in a retaining state by a retaining ring. The latter (Japanese Patent Publication No. 63-3585)
No. 7), a pin implanted in the sleeve piston is inserted into an engagement hole formed in the bottom of the large-diameter portion of the different-diameter cylinder, thereby controlling the rotation of the sleeve piston.
It is slidably mounted in the axial direction. The adjusting bolt is substantially integrated with the sleeve piston by clutch engagement.

[0004]

The means for attaching the above-described adjusting bolt or sleeve piston so as to be non-rotatable and slidable in the axial direction has the following common problems. <A> It is necessary to provide a groove or a hole in the inner part of the different diameter cylinder, and the processing of providing the groove or the hole is troublesome and difficult to perform. <B> Since the grooves and holes provided in the inner part of the different diameter cylinder face the liquid chamber, the burrs must be completely removed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a disk brake pad gap automatic adjusting apparatus which is excellent in manufacturability. It is still another object of the present invention to provide an automatic pad gap adjusting device for a disc brake having excellent durability.

[0006]

The invention according to claim 1 is
A piston that slides into a large-diameter cylinder formed on the caliper to press the pad, and a first screw member that is built in a fluid chamber that operates the piston and that automatically adjusts the gap between the disk rotor and the pad And a pad gap automatic adjusting mechanism including a second screw member, and a mechanical operating mechanism that applies a thrust to the pad gap automatic adjusting mechanism and presses a pad, and the first screw member or the second screw is provided. One of the members is clutch-engaged with the bottom surface of the bottomed hole of the piston, and the other member of the second screw member or the first screw member is smoothly fitted into the small-diameter cylinder hole. In the pad gap automatic adjustment device, a pin hole communicating with the side of the small-diameter cylinder hole is formed in the caliper, and a second screw member or a first screw member that is smoothly fitted into the small-diameter cylinder hole is provided. An engaging groove parallel to the axis is recessed in the peripheral surface of one of the members, and a pin having a circular tip at the distal end is fixed to the pin hole, and the other screw member is disposed on the peripheral surface of the distal end of the pin. Characterized in that the engagement groove of the disc brake is slidably and non-rotatably engaged. The invention according to claim 2 is claim 1
Wherein the engagement groove of the other screw member is an R groove or a tapered groove. According to a third aspect of the present invention, there is provided a piston which slides into a large-diameter cylinder formed on a caliper and presses a pad, and is built in a fluid chamber for operating the piston to automatically form a gap between the disk rotor and the pad. A pad gap automatic adjusting mechanism comprising a first screw member and a second screw member for adjusting the position, and a mechanical operating mechanism for pressing the pad by applying a thrust to the pad gap automatic adjusting mechanism are arranged in order, One of the first screw member or the second screw member is clutch-engaged with the bottom surface of the bottomed hole of the piston, and the other member of the second screw member or the first screw member is smoothly fitted in the small-diameter cylinder hole. In the automatic pad gap adjusting device for a disc brake, a pin hole communicating with a side of the small-diameter cylinder hole is formed in the caliper, and a second screw is smoothly fitted into the small-diameter cylinder hole. A flat surface is formed on the peripheral surface of the other member of the material or the first screw member, and a pin having a flat surface formed on the peripheral surface of the distal end portion is inserted and fixed into the pin hole, and the flat surface of the distal end portion of the pin is formed. An automatic pad gap adjusting device for a disc brake, characterized in that the other screw members face each other so as to face each other so as to be non-rotatably and slidably engaged. The invention according to claim 4 is claim 1
4. The automatic pad gap adjusting device according to claim 3, wherein the first screw member is an adjusting bolt and the second screw member is an adjusting nut. It is an adjustment device. According to a fifth aspect of the present invention, in the apparatus for automatically adjusting a pad gap of a disc brake according to any one of the first to third aspects, the first screw member is an adjust nut and the second screw member is an adjust bolt. An automatic pad gap adjusting device for a disc brake.

[0007]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<A> Overall Structure of Disc Brake FIG. 1 is a central sectional view of a disc brake incorporating a mechanical operating mechanism and an automatic pad gap adjusting mechanism according to the present invention. A caliper 2 is fixed to a non-rotating portion (not shown). Carrier 1
The rotor 3 is movably supported in the axial direction of the rotor 3 by two guide mechanisms spaced apart in the circumferential direction of the rotor 3. Caliper 2
Is an actuator portion 2a, a reaction portion 2b having a bifurcated claw portion separated in the circumferential direction of the rotor, and a rotor 3a.
2c connecting between the two 2a and 2b across the bridge
Consisting of

In the actuator section 2a, a large-diameter cylinder 2d for slidably housing the piston assembly 7 and a rear side of an adjust nut 14 as a second screw member constituting the adjust nut assembly 13 are slidable. And a small-diameter cylinder 2e to be accommodated therein are formed coaxially. The actuator section 2a is provided with a pin hole 2g communicating with the rear side of the small-diameter cylinder 2e and parallel to the axis of the cylinder 2e.

A camshaft hole 2f is formed at the innermost portion of the actuator portion 2a and communicates with the small-diameter cylinder 2e and extends in a direction perpendicular to the small-diameter cylinder 2e. 22 is a bearing 23
Are rotatably accommodated via the Camshaft 22
The push rod 24 is inserted between the eccentric groove 22a and an engagement hole 15c of the head 15 described later. A brake lever (not shown) to which a parking brake operation force is transmitted is fixed to an end of the camshaft 22 protruding from the actuator 2a.

An inner pad 4 and an outer pad 5 are provided on both sides of the rotor 3, and both ends of the pads 4, 5 in the rotor circumferential direction are slidably mounted on rails of the carrier 1. Shims 6a and 6b for suppressing squeal during braking are provided on the back plate side of each of the pads 4 and 5, respectively.

<B> Piston Assembly FIG. 2 is a sectional view of the piston assembly 7. The piston assembly 7 includes a piston 8, an adjust bolt 9 as a first screw member, two low friction members 10a and 10b, a first spring means 11, and a seal member 12. In this example, the adjustment bolt 9 excluding the piston 8
Two low friction members 10a, 10b, first spring means 11,
The seal member 12 forms a sub-assembly adjustment bolt assembly as a first screw member assembly, and this adjustment bolt assembly is assembled to the piston 8 to form the assembly-assembled piston assembly 7.

[Piston] The piston 8 is substantially cup-shaped, and a plurality of axial grooves 8b are formed in the inner peripheral surface of the large-diameter hole 8a in the right half of the drawing in the axial direction. This shaft groove 8b
Has reached the conical surface 8c at the back of the large-diameter hole 8a to facilitate air release. A small-diameter blind hole 8d is formed at the bottom of the large-diameter hole 8a of the piston 8. In order to smoothly slide the adjustment bolt 9 in the small diameter blind hole 8d, a through hole 8e communicating from the small diameter blind hole 8d to the outside is provided.
An annular groove 8f for engaging a part of the first spring means 11 is formed at the axially intermediate portion of the large diameter hole 8a.

[Adjustment bolt] Adjustment bolt 9
A shaft portion 9a which fits the seal member 12 on the peripheral surface and slides into the small-diameter blind hole 8d of the piston 8, and a conical surface 8 of the piston 8;
c, a conical portion 9b that is engaged with the clutch, and a multi-threaded male screw portion 9c that is screwed to the adjust nut 14. Disc-shaped low friction members 10a and 10b are fitted in the shaft portion of the adjusting bolt 9 on the side of the multiple threaded portion 9c, and the annular groove 8f is formed.
The first spring means 11 fitted to the low friction member 10a,
10b is urged so as to be in contact with the back surface of the conical portion 9b.

[Low friction members] Low friction members 10a, 10b
Is a member in which a low-friction coating layer is formed on the surface of a flat washer to reduce the friction coefficient of the friction surface, and the number of layers is not limited to the two shown in the figure. The point is that the adjusting bolt 9 only needs to have a function of rotating slightly when the engagement of the conical clutch is released. Therefore, a conventional thrust bearing may be used instead of the low friction members 10a and 10b.

[First Spring Means] As shown in FIGS. 2 and 3, the first spring means 11 obtains a reaction force from the piston 8 and causes the conical portion 9b of the adjusting bolt 9 to engage with the conical surface 8c of the piston 8 by clutching. A part of the ring body is cut out by a spring means constantly biasing in the direction, and an annular groove 9d of the adjustment bolt 9 is formed.
, A plurality of extending pieces 11b radially extending from a side edge of the fitting section 11a, and each of the extending pieces 11b.
Is formed by folding a radial end portion of the piston toward the fitting portion 11a, and is engaged with the annular groove 8f of the piston 8.
And a preload portion 11d formed by bending the distal end portion of the hook portion 11c to urge the low friction members 10a and 10b against the back surface of the conical portion 9b of the adjusting bolt 9.

<C> Adjust Nut Assembly FIG. 4 is a sectional view of an adjust nut assembly 13 as a second screw member assembly. Adjust nut assembly 13
Comprises an adjusting nut 14 as a second screw member, a holding member 16a as a second spring means 16 and a coil spring 17.

The adjusting nut 14 of the present embodiment is composed of a nut body 14a and a head 15, which are easy to process the header of the outer shape. The two nuts 14a and 15 cannot rotate and cannot slide or slide in the axial direction. It is connected as possible. It is desirable that the two members 14a and 15 be connected non-slidably in the axial direction from the viewpoint of handleability. In addition, both 14a, 15
May be integrally formed.

A coil spring 17 is contracted between a holding member 16a hooked on the annular groove 14d of the nut body 14a and a flange 14e of the nut body 14a.

[Nut Body] The nut body 14a has a multi-threaded female thread 14b formed on the left side of the axis, and a hexagonal hole 1 on the right side.
4c is formed. An annular groove 14d for fitting the fitting portion 16b of the holding member 16a is formed on the left side of the outer periphery of the nut body 14a, and an outwardly protruding flange portion 14e is formed on the right side.

[Head] The head 15 has a hexagonal shaft portion 15a formed on the left side thereof.
c. A seal member 18 for sealing the small-diameter cylinder 2e is mounted on the outer periphery of the intermediate portion of the head 15. An engagement hole 15c that engages with the left end of the push rod 24 is formed in the axis of the head 15. A plurality of engagement grooves 15b are formed on the right outer periphery of the head 15 according to the present invention by header processing along the axial direction thereof.
The engagement groove 15b is a groove for making it impossible to rotate with the tip of the pin 19 and to be slidable in the axial direction, and the sectional shape is not limited to the R groove shown in FIG.

[Holding Member Constituting Second Spring Means] As shown in FIGS. 4 and 5, the holding member 16a is formed by cutting out a part of a ring body and fitted in an annular groove 14d of a nut body 14a. 16b, a plurality of extension pieces 16c radially extending from the extension piece 16c, and the tip end of each extension piece 16c is formed by turning the tip of the extension piece outward, and is hooked on the annular groove 2h at the back of the large-diameter cylinder 2d of the caliper 2. A hook 16d for stopping the coil spring 17
A plurality of holding portions 16e for holding one side end winding portion are formed. The urging force of the coil spring 17 contracted between the holding portion 16e of the holding member 16a and the flange portion 14e of the nut body 14a is set larger than that of the first spring means 11. The holding portion 16e is omitted, and the extension piece 16
You may make it hold the one side end winding part of the coil spring 17 in the rising part of c.

The holding member 16a constituting the second spring means 16 is operated by pushing and pulling the adjusting nut 14.
By adopting a locking structure that allows the hooking portion 16d to be hooked and detached from the annular groove 2h of the large-diameter cylinder 2d, which is a member to be attached, the attaching and detaching work of the adjust nut assembly 13 is simplified.

<D> Seal Member As shown in FIG. 1, a seal member 20 having both a sealing function and a returning function of the piston 8 is disposed at the mouth of the large-diameter cylinder 2d of the caliper 2.

<E> Dust Cover Reference numeral 21 in FIG. 1 denotes a dust cover, which is a large-diameter cylinder 2d.
It prevents foreign substances from entering the inside.

<F> Pin As shown in FIG. 7, the pin 19 forms a shaft portion 19b having a circular cross section integrally with the head portion 19a, and has a hemispherical or tapered surface 19d and a serration portion 19c below its neck. Are formed respectively. As shown in FIG. 8, the pin 19 is pressed into a pin hole 2g formed in the actuator portion 2a of the caliper 2, and is fixed by the serration portion 19c biting into the hole wall. Hemisphere or tapered surface 1 under the neck of pin 19
9d is brought into close contact with the entrance surface of the pin hole 2g, so that the pin 19
And a high sealing property is secured between the pin hole 2g. FIG. 6 is a cross-sectional view showing the engagement state between the engagement groove 15b of the head 15 and the tip of the pin 19.
5 with a slight gap.

<G> Push rod As shown in FIG.
A push rod 24 is interposed between the engaging hole 15c of the head 15 and converts the rotational force of the camshaft 22 into a propulsive force.
4. It can be transmitted to the piston 8 via the adjustment bolt 9.

[0028]

Next, the operation of the disc brake will be described.

<A> Service Brake Operation When the fluid chamber 25 defined by the seal members 12, 18 and 20 is pressurized, the inner pad 4 presses one surface of the rotor 3 as the piston 8 advances. Caliper 2 by the reaction force
Retreats, and the reaction portion 2 b presses the outer pad 5 against the opposite surface of the rotor 3. As described above, the pads 4 and 5 pinch the rotor 3 to brake the rotating rotor 3.

<B> Parking brake operation When the camshaft 22 is rotated clockwise in FIG. 1 by a brake lever (not shown), the acting force is transmitted in the order of the push rod 24, the adjust nut assembly 13, the adjust bolt 9, and the piston 8. Then, the piston 8 moves forward. The subsequent brake operation is the same as the above-described service brake operation, and a description thereof will be omitted.

As means for mounting the adjustment nut 14 so as to be non-rotatable and slidable in the axial direction, a large number of teeth such as splines and serrations are formed on both circumferential surfaces of the adjustment nut 14 and the pin 19, respectively. A method of meshing these teeth is considered, but cannot be adopted for the following reasons.

Since the disc brake device does not have a self-servo property, in order to secure a predetermined braking force when the parking brake is operated, the disc brake device acts on the adjust nut 14 as the second screw member and the adjust bolt 9 as the first screw member. And the pressing force on the rotor must be increased. Since this thrust acts as a rotational force on the threaded portion of the adjusting nut 14 and the adjusting bolt 9, there is a risk that the teeth of the meshing portion between the adjusting nut 14 and the pin 19 may be deformed or broken. If the meshing both teeth are designed to be large, the load on the meshing portion can be reduced, but the shape of the teeth cannot be designed so large due to the restriction of the layout surface, and it is technically difficult to secure the strength of the roots of the teeth. Further, it is necessary to form a large number of teeth on the peripheral surfaces of both the pin 19 and the adjust nut 14, and there is also a disadvantage that the processing requires attention.

According to the present invention, the engaging groove 15b is provided only on the peripheral surface side of the head 15 constituting the adjusting nut 14, and the front end of the pin 19 which has not been processed is fitted into the engaging groove 15b. Thus, the load (rotational force) applied to the fitting portion when the parking brake is operated can be reduced.

<C> Pad gap automatic adjustment operation When the service brake is operated, the adjustment bolt 9 moves forward together with the piston 8. On the other hand, the adjustment nut 14 retreats together with the caliper 2. Now, the wear amount of the friction material of the pads 4 and 5 is adjusted by the adjusting bolt 9 and the adjusting nut 1.
When the backlash of the threaded portion with the screw 4 is exceeded, the conical clutch surface of the adjusting bolt 9 (the contact surface between the conical surface 8c of the piston 8 and the conical portion 9b of the adjusting bolt 9 in FIG. 2) slips and rotates. Then, it is screwed out of the adjustment nut 14.

The seal member 12 of the adjustment bolt 9
When a predetermined pressure is applied to the adjusting bolt 9, the frictional force of the conical clutch surface of the adjusting bolt 9 rapidly increases and the rotation becomes impossible, so that the coil spring 17 bends, and the adjusting nut 14 cooperates with the adjusting bolt 9 integrally. The automatic adjustment stops without any adverse effect. Thereby, elastic deformation of the caliper 2 and the pads 4 and 5 is not picked up.

Then, when the brake is released, the piston 8 and the adjustment bolt 9 are returned by the backlash of the bolt 9 by the rollback force of the seal member 20 of the piston 8, and the pad gap is always kept constant.

During the automatic operation of adjusting the pad gap, the head 15,
That is, the rotational force acting on the adjust nut 14 is supported by the pin 19, and the adjust nut 14 is kept in a non-rotatable state.

<D> Function of the engagement portion between the adjust nut and the pin The pin 19 is pressed into the pin hole 2g of the caliper 2 and fixed. The adjustment nut 14, that is, a part of the engagement groove 15 b of the head 15 is engaged with the tip end of the pin 19 so as to be non-rotatable and slidable in the axial direction.

At the time of the above-described automatic adjustment of the pad gap, a rotational force acts on the head 15, but the pin 19 is
b, and stops the rotation of the head 15. Head 15
Has an engaging groove 15b formed in an arc shape having substantially the same curvature as the radius of the pin 19, and has a base material capable of withstanding stress concentration. The tip of the pin 19 has a circular cross section with no defect on the peripheral surface. Therefore, even if a rotational force acts on the engaging portion between the engaging groove 15b and the pin 19, there is no possibility that the engaging groove 15b and the pin 19 are deformed or broken.

When the parking brake is activated, the engagement groove 15b of the head 15 and the pin 19 are located in parallel.
The pin 19 does not hinder the sliding of the head 15, that is, the adjustment nut assembly 13.

[0041]

[Embodiment 2] Other embodiments will be described below. In the description, the same parts as those in the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted. FIG. 9 shows the engagement groove 15b of the head 15 formed into a tapered cross section by header processing.
The fitting of the leading end portion so as to be non-rotatable and slidable in the axial direction is the same as in the above embodiment. Also in this example, since the contact position of the engagement groove 15b with which the pin 19 contacts can be shifted in the axial direction of the head 15, there is an advantage that the variation in the weight of the reaction portion 2b can be reduced.

[0042]

Third Embodiment FIG. 10 shows an outer peripheral surface of an end portion of a head 15 having a polygonal cross section formed by a plurality of flat surfaces 15d, and a flat surface 19e formed only at the distal end portion of a pin 19 or near a press-fit portion of a shaft portion. The head 15 cannot be rotated with the flat surfaces 15d and 19e of these two members 15 and 19 facing each other.
Further, the engagement may be slidable in the axial direction. In this example, the flat surfaces 15d and 19e of the two members 15 and 19 facing each other.
Are in surface contact with each other, so that there is an advantage that the resistance to deformation and breakage of the head 15 and the pin 19 is further improved.

[0043]

Embodiment 4 FIG. 11 shows another fixing means of the pin 19. In the first embodiment, the pin 19 is press-fitted and fixed, but the male screw 19f is formed in the lower shaft portion of the neck of the pin 19, and the female screw 2i is provided in the pin hole 2g. Is also good.

[0044]

Fifth Embodiment The right and left arrangement of the adjustment bolt 9 and the adjustment nut 14 can be easily reversed. In this case, the adjustment bolt 9 is a second screw member, and the adjustment nut 14 is a first screw member.

That is, the adjust nut 14 is clutch-engaged with the bottom side of the bottomed hole of the piston 8, and the adjust bolt 9 is non-rotatably and liquid-tightly fitted into the small-diameter cylinder 2e. In this case, the adjustment nut 14 (first screw member) is held by the first spring means 11 hooked in the piston 8, and the second spring means 16a,
At 17, the adjustment bolt 9 (second screw member) is held.

[0046]

Embodiment 6 The present invention can be applied to any disc brake having a mechanical operating mechanism and a pad gap automatic adjusting mechanism, and is limited to the disc brake of the type shown in the drawings. is not.

[0047]

According to the present invention, the following effects can be obtained.

<A> There is no need to provide a groove or a hole in the inner part of the different diameter cylinder, and no special processing is required for the cylinder.

<B> It is only necessary to perform a simple header processing on the peripheral surface of the first screw member or the second screw member, and it is possible to obtain a disk brake pad gap automatic adjusting device excellent in manufacturability.

<C> Since the circular peripheral surface of the pin is engaged with the engaging groove provided on the peripheral surface of the first screw member or the second screw member, rotational force is applied to the engaging portion between the engaging groove and the pin. It is excellent in proof stress when acted, and can effectively avoid deformation and breakage of the engagement groove and the pin.

<D> Even when the flat surface formed on the peripheral surface of the first screw member or the second screw member and the flat surface formed on the peripheral surface of the pin are faced and engaged with each other, the engagement between the engagement groove and the pin is also possible. It is excellent in proof stress when a rotational force acts on the joint portion, and can effectively avoid deformation and breakage of the engagement groove and the pin.

<E> Since no special additional processing is required in the fluid chamber, it is not necessary to pay more attention to removing burrs than ever.

[Brief description of the drawings]

FIG. 1 is a central sectional view of a disc brake device according to the present invention.

FIG. 2 is a cross-sectional view of a piston assembly.

FIG. 3 is a perspective view of a first spring means.

FIG. 4 is a cross-sectional view of an adjustment nut assembly.

FIG. 5 is a perspective view of a second spring means.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 1;

FIG. 7 is a perspective view of an adjustment nut and a pin.

FIG. 8 is a partial sectional view of a pin fixing portion.

FIG. 9 is a partial cross-sectional view of an engagement portion showing another head-pin engagement structure.

FIG. 10 is a partial cross-sectional view of an engaging portion between another head and a pin having a flat surface facing each other.

FIG. 11 is a partial cross-sectional view of an actuator portion showing another pin fixing means.

[Explanation of symbols]

1 Carrier 2 Caliper 2a Actuator 2b Reaction 2c Bridge 2d Large Diameter Cylinder 2e Small Diameter Cylinder 2f Camshaft Hole 2g Pin Hole 2h Annular Groove of Large Diameter Cylinder 2i Pin Hole Female Screw 3 Rotor 4 Inner Pad 5 Outer Pad 6a, 6b Shim 7 Piston assembly 8 Piston 8a Piston large diameter hole 8b Piston axial groove 8c Piston conical surface 8d Piston small blind hole 8e Piston through hole 8f Piston annular groove 9 Adjust bolt (first screw member or second screw member) 9a Adjusting bolt shaft 9b Adjusting bolt conical 9c Multi-threaded male screw 9d Adjusting bolt annular groove 10a, 10b Low friction member 11 First spring means 11a Fitting part of first spring means 11b Extension of the first spring means Piece 11c Latch portion of first spring means 11d Preload portion of first spring means 12 Seal member 13 Adjust nut assembly 14 Adjust nut (second screw member or first screw member) 14a Nut body 14b Nut body multi-section Female thread 14c hexagonal hole in the nut body 14d annular groove in the nut body 14e flange part of the nut body 15 head 15a hexagonal shaft part of the head 15b engaging groove of the head 15c engaging hole of the head 15d flat surface of the head 16 16a Holding member 16b Fitting portion of holding member 16c Extension piece of holding member 16d Holding portion of holding member 16e Holding portion of holding member 17 Coil spring 18 Sealing member 19 Pin 19a Pin Head 19b Pin shaft 19c Pin serration 19d Pin hemisphere Or taper surface 19e Pin flat surface 19f Pin male screw 20 Seal member 21 Dust cover 22 Camshaft 22a Eccentric groove of camshaft 23 Bearing 24 Push rod 25 Fluid chamber

Claims (5)

[Claims] 1. A piston, which is fitted into a large-diameter cylinder formed on a caliper and presses a pad, and is built in a fluid chamber for operating the piston, and automatically adjusts a gap between the disk rotor and the pad. An automatic pad gap adjusting mechanism including a first screw member and a second screw member to be provided, and a mechanical operating mechanism for pressing a pad by applying a thrust to the pad gap automatic adjusting mechanism, and the first screw While one member of the member or the second screw member is clutch-engaged with the bottom surface of the bottomed hole of the piston, the other member of the second screw member or the first screw member is smoothly fitted into the small-diameter cylinder hole. In the apparatus for automatically adjusting a pad gap of a disc brake, a pin hole communicating with a side of the small-diameter cylinder hole is formed in the caliper, and a second screw member or a second screw member that is smoothly fitted into the small-diameter cylinder hole is provided. An engaging groove parallel to the axis is recessed in the peripheral surface of the other member of the one screw member, and a pin having a circular cross section is fixed to the pin hole. An automatic pad gap adjusting device for a disc brake, wherein an engaging groove of the other screw member is non-rotatably and slidably engaged. 2. The automatic pad gap adjustment of a disk brake according to claim 1, wherein the engagement groove of the other screw member is an R groove or a tapered groove. apparatus. 3. A piston which is slidably fitted in a large-diameter cylinder formed in a caliper and presses a pad, and is built in a fluid chamber for operating the piston, and automatically adjusts a gap between the disk rotor and the pad. An automatic pad gap adjusting mechanism including a first screw member and a second screw member to be provided, and a mechanical operating mechanism for pressing a pad by applying a thrust to the pad gap automatic adjusting mechanism, and the first screw While one member of the member or the second screw member is clutch-engaged with the bottom surface of the bottomed hole of the piston, the other member of the second screw member or the first screw member is smoothly fitted into the small-diameter cylinder hole. In the apparatus for automatically adjusting a pad gap of a disc brake, a pin hole communicating with a side of the small-diameter cylinder hole is formed in the caliper, and a second screw member or a second screw member that is smoothly fitted into the small-diameter cylinder hole is provided. A flat surface is formed on the peripheral surface of the other member of the one screw member, and a pin having a flat surface formed on the peripheral surface of the distal end portion is inserted and fixed in the pin hole, and the flat surface of the distal end portion of the pin and the other end are fixed. An automatic pad gap adjusting device for a disc brake, wherein a screw member is engaged so as to be non-rotatable and slidable with a flat surface of a screw member facing the screw member. 4. The pad gap automatic adjusting device according to claim 1, wherein the first screw member is an adjusting bolt and the second screw member is an adjusting nut. Automatic adjustment of the pad gap of the disc brake. 5. The apparatus for automatically adjusting a pad gap of a disc brake according to claim 1, wherein the first screw member is an adjust nut, and the second screw member is an adjust bolt. Automatic adjustment of the pad gap of the disc brake.