JPH11287267A - Disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the drag of a brake pad, and also prevent abnormal wear in a disc rotor by applying a return force on a caliper. SOLUTION: A capacity variable space S is formed in a pin hole 60 of a pin sliding mechanism 21, floatably supporting a caliper 23 on a carrier 21 to be locked to an irrotational part of a vehicle in cooperation with a pin 58, and this capacity variable space S is interconnected to a supply chamber in a dust boot 62 covering this pin 58 through a slight clearance C between a pin hole inner surface and the pin, and high viscous grease is sealed in the whole empty area including the capacity variable space S and the supply chamber, and then negative pressure is produced in the capacity variable space S by means of a sudden movement of the caliper 23 in time of braking. Then, this negative pressure is utilized for a return of the caliper 23 in time of the brake release, therefore a portion of enlargement in the capacity variable space S to be expanded by wear of a brake pad is compensated with an inflows of grease from the supply chamber, so that even if the brake pad is worn out, the caliper 23 is made so as to be returned as far as the fixed quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake used for braking a vehicle, and more particularly to a caliper floating type disc brake in which a caliper is supported on a carrier fixed to a non-rotating portion of the vehicle via a pin slide mechanism. Related.

[0002]

2. Description of the Related Art Caliper floating type disc brakes
Conventionally, it generally had a structure as shown in FIGS.
In these figures, 1 is a carrier fixed to a non-rotating portion of the vehicle, 2 is a caliper supported on the left and right support portions 1a of the carrier 1 via a pin slide mechanism 3, and 4 and 5 are calipers. The brake pads 4 and 5 are slidably supported by the support portion 1a of the carrier 1 with brake pads arranged on both sides (inner and outer sides) of the disk rotor D. In addition, each brake pad 4,
Numeral 5 comprises backing plates 4a, 5a and lining members 4b, 5b joined to the backing plates 4a, 5a.
5b is opposed to the disk rotor D.

Here, the caliper 2 has a main body 2a disposed on the vehicle inner side (inner side) of the disk rotor D.
A disk path portion 2b extending from the main body portion 2a to the outside of the vehicle (outer side) across the disk rotor D, and a claw portion 2c extending from the disk path portion 2b in the radial direction of the disk rotor D. The piston 7 is slidably housed in a bore 6 formed in the main body 2a. On the other hand, the pin slide mechanism 3 is attached using bolts 10 to a pin hole 8 formed in the left and right support portion 1a of the carrier 1 and to a pair of arms 9 extending from the main body 2a of the caliper 2 in the left and right direction. The pin 11 is slidably inserted into the pin hole 8. The area around the pin 11 is the dust boot 1
2 is covered.

In the thus constructed disk brake, when hydraulic pressure is supplied into the bore 6, the piston 7 extends to press the inner brake pad 4 against one surface of the disk rotor D, and the caliper is generated by the pressing reaction force. 2 moves to the inner side via the pin slide mechanism 3, and its claw portion 2c presses the outer brake pad 5 against the opposite side of the disk rotor D. As a result, the disk rotor D is sandwiched by the two brake pads 4, 5. And the desired braking force is generated.

A rubber seal (retract seal) 1 having a rectangular cross section is provided on the inner surface of the bore 6 of the caliper 2.
The retract seal 13 is adapted to elastically deform following the piston 7 during the braking. Therefore, when the braking is released, the piston 7 is automatically returned to the original position by the elastic restoring force of the retract seal 13, and the inner and outer brake pads 4, 5 are moved from the disk rotor D by the runout of the disk rotor D. When the outer side brake pad 5 separates from the disk rotor D, the outer side brake pad 5 pushes the claw portion 2c of the caliper 2 in the disk axial direction. Return from the position to the neutral position during non-braking.

[0006]

However, the piston 7 that presses the inner brake pad 4 can be forcibly separated from the disk rotor D and returned by the return mechanism including the retract seal 13 described above, for example. However, there is no return mechanism that directly acts on the claw portion 2c of the caliper 2 that presses the outer-side brake pad 5, and the outer-side brake pad 5 separates from the disk rotor D due to the runout of the disk rotor D, and Since the claw portion 2c is configured to be returned, the caliper 2 becomes large and its weight is increased, so that the return of the caliper 2 is deteriorated. When the brake is not applied, the brake is dragged, and the fuel efficiency is deteriorated. However, there is a problem that abnormal wear is caused to cause deterioration of judder performance.

As this type of disc brake, there is a so-called electric disc brake in which an electric device is provided in the main body 2a of the caliper 2 in place of the piston 7 (for example, International Publication No. 96). In such an electric disc brake, the above-described problem becomes conspicuous because the electric device is installed and the caliper body is significantly heavy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to make it possible to apply a returning force to a caliper, thereby greatly improving fuel efficiency and maintaining stable brake characteristics. The purpose is to provide a contributing disc brake.

[0009]

To achieve the above object, the present invention relates to a caliper floating type disc brake in which a caliper is supported on a carrier fixed to a non-rotating portion of a vehicle via a pin slide mechanism. In the pin hole constituting the pin slide mechanism, a gap with the pin is widened according to the movement of the caliper at the time of braking, and a variable volume chamber for increasing the volume is provided.The variable volume chamber and the orifice passage inside or outside the pin hole And a supply chamber communicating with the supply chamber, and a lubricant is sealed in the variable volume chamber and the supply chamber.

In the disk brake constructed as described above, the volume of the variable volume chamber rapidly increases due to the movement of the caliper during braking, so that a negative pressure is generated in the variable volume chamber. The caliper returns to the neutral position during non-braking. However, in a state where the amount of movement of the caliper is increased due to wear of the brake pad and the volume of the variable volume chamber is expanded, lubricant is supplied from the supply chamber to the variable volume chamber via the orifice passage. It always returns by a fixed amount upon release.

In the present invention, the supply chamber may be set inside a dust boot that covers around the pin, and the orifice passage may be provided by a clearance between the inner peripheral surface of the pin hole and the outer peripheral surface of the pin. In a good configuration, with this configuration, the intended purpose can be achieved with a slight improvement of the existing pin slide mechanism. In the present invention, the kind of the lubricant is not particularly limited, but it is preferable to use grease having a relatively high viscosity. By using such grease, the flow of the lubricant into the variable volume chamber is further restricted, and a negative pressure is reliably generated in the variable volume chamber during braking.

Further, the type of the disc brake to which the present invention is applied is not particularly limited as long as it is a caliper floating type, and may be an electric type disc brake as well as the above-mentioned hydraulic type disc brake.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the present invention. The first embodiment is directed to a hydraulic disc brake, and its structure is the same as that shown in FIGS. 7 and 8 described above. Only the slide mechanism 3 is shown, and the same portions are denoted by the same reference numerals, and the entire description will be omitted. In the first embodiment, the pin 11 attached to the arm 9 of the caliper 2 is inserted into the pin hole 8 provided in the support portion 1a on both sides of the carrier 1 with a slight clearance C, and furthermore, A variable volume chamber S formed at the inner bottom of the pin hole 8, a clearance C between the inner peripheral surface of the pin hole 8 and the outer peripheral surface of the pin 11, and a chamber (supply chamber) S 'inside the dust boot 12. A relatively high-viscosity grease is sealed in the entire airspace.

In the disk brake configured as described above, the pin 11 moves rapidly inside the vehicle (inner side) together with the caliper 2 at the time of braking, so that the volume variable chamber S at the bottom of the pin hole 8 expands. At this time, in addition to the clearance C between the inner peripheral surface of the pin hole 8 and the outer peripheral surface of the pin 11 imparting flow resistance to the lubricant as an orifice passage,
Since grease having a relatively high viscosity is used, the flow of grease from the supply chamber S 'inside the dust boot 12 into the variable volume chamber S is suppressed, and the movement of the caliper 2 causes the variable volume chamber to move. A negative pressure is generated in S. And
The pin 11 is pulled into the pin hole 8 simultaneously with the release of braking due to the generation of the negative pressure, and the caliper 2 moves to the outside of the vehicle (outer side) and returns to the neutral position during non-braking.

The variable volume chamber S in the pin hole 8
As described above, the pin 1 is integrated with the caliper 2 during braking.
1 expands as it moves toward the inner side, but the amount of the expansion increases as the lining material 5b (FIG. 8) of the outer brake pad 5 wears, and becomes maximum at the maximum wear limit of the lining material 5b. . However, in the present embodiment, grease is sealed not only in the variable capacity chamber S but also in the supply chamber S ′ inside the dust boot 12.
The sealed volume is an amount sufficiently larger than the volume in which the variable volume chamber S is maximized. As a result, during repeated braking, grease corresponding to the expansion of the variable volume chamber S is gradually supplied from the supply chamber S ′ via the clearance C around the pin 11, and therefore, depending on the degree of wear of the brake pad 5. The return amount of the caliper 2 is constant.

FIG. 2 shows a second embodiment of the present invention. The feature of the second embodiment is that the annular groove 11a is formed at the tip of the pin 11 in the first embodiment, and the sealing member 20 made of an elastic material is provided in the annular groove 11a. That is, the sealing member 20 is slightly fitted to the inner peripheral surface of the pin hole 8. The sealing member 20 exerts a complete sealing effect when the pin 11 is suddenly moved in the pull-out direction integrally with the caliper 2 during braking, but usually causes a slight grease leakage. That is, the gap between the seal member 20 and the inner peripheral surface of the pin hole 8 functions as a variable orifice, so that the grease does not need to be selected to have a very high viscosity. A sufficient negative pressure is generated. In addition, since the clearance C between the inner peripheral surface of the pin hole 8 and the outer peripheral surface of the pin 11 can be made sufficiently large, assembly of the caliper 2 to the carrier 1 is simplified. That is, the return position of the caliper 2 is adjusted in accordance with the degree of wear of the brake pad 5, and an appropriate return interval is always maintained between the disk rotor D and the outer brake pad 5, and as a result, The brake timing will not be delayed.

In the above two embodiments, the supply chamber S 'is provided inside the dust boot 12, but the location where the supply chamber S' is provided is optional. For example, the inner surface of the pin hole 8 is provided. Alternatively, an annular groove may be formed on the outer periphery of the pin 11 and the inside of this groove may be used as a supply chamber, or a separate independent supply chamber may be provided outside the support 1a of the carrier 1.

FIG. 3 to FIG. 5 show a third embodiment of the present invention. The third embodiment is directed to an electric disc brake, and a carrier 21 fixed to a non-rotating portion of a vehicle is provided with a caliper 23 having a later-described electric device 22 built in left and right. Brake pads 25, which are supported so as to be able to float via a pin slide mechanism 24 and are arranged on both sides of the disc rotor D,
26 are supported. In addition, each brake pad 25,
Reference numeral 26 denotes back metal members 25a, 26a and lining members 25b, 26b joined thereto, and the lining members 25b, 26b are opposed to the disk rotor D (FIG. 4).

As shown in FIG. 5, the carrier 21 has a fixed portion 27 for the non-rotating portion of the vehicle and a bridge portion 28 extending to the outer side over the disk rotor D.
And a hanging portion 29 extending from the tip of the bridge portion 28 in the radial direction of the disk rotor D. The fixed portion 27 and the hanging portion 29 have an inner brake pad 25 and an outer side, respectively. Concave portions 27a and 29a for suspending and supporting the brake pad 26 are formed. On the other hand, as shown in FIG. 4, the caliper 23 includes a main body 30 containing the electric device 22 and a disk path 31 extending from the main body 30 to the outer side across the disk rotor D. And a claw portion 32 extending from the tip of the disk path portion 31 to the inside of the radius of the disk rotor D.

The electric device 22 is schematically constituted by a motor 33, a movable member 34, and a motion conversion mechanism 35 for converting the rotation of the motor 33 into a linear motion of the movable member 34 (FIG. 4). The motor 33 includes a stator (coil) 36 fitted and fixed to the main body 30 of the caliper 23, and a hollow rotor 3 rotatably supported by the main body 30 via a bearing 37.
It consists of eight. A magnet 39 is externally fitted to the rotor 38, and rotates leftward or rightward according to the energization of the stator 36. The stator 36 is provided with the caliper 2
3 is pressed and fixed to a step in the main body 30 by a lid 41 fixed to the open end of the main body 30 using bolts 40.

The movable member 34 is inserted into the hollow interior of the rotor 38, and both are fitted to each other via the motion conversion mechanism 35 described above. Motion conversion mechanism 35
Is a so-called ball screw mechanism in which a ball is interposed between a screw groove provided on the inner surface of the rotor 38 and a screw groove provided on the outer peripheral surface of the movable member 34. The member 34 is commonly used as a nut and a screw shaft constituting the ball screw mechanism. A disc-shaped detent member 43 is fixed to the base end of the movable member 34 using a bolt 42, while a longitudinal groove for receiving the projection of the detent member 43 is provided on the lid 41 fixed to the caliper 23. Cylindrical part 45 having 44
Is protruding. That is, the movable member (screw shaft) 34
Is provided so that it can move in the axial direction but cannot rotate by the engagement between the rotation preventing member 43 and the vertical groove 44, whereby the rotor (nut) 3 of the motor 33 is
When 8 rotates left or right, the motion conversion mechanism (ball screw mechanism) 35 operates and the movable member 34 moves forward and backward in the rotor 38.

On the other hand, the front end of the movable member 34 abuts against the back surface of the inner brake pad 24, whereby the movable member 34 moves toward the disk rotor D in accordance with the rotation of the rotor 38 of the motor 33. When the disk brake is moved forward, the inner brake pad 24 is pressed against one surface of the disk rotor D, and the caliper 23 moves toward the inner side via the pin slide mechanism 24 due to the pressing reaction force.
As a result, the outer brake pad 26 is pressed against the opposite side surface of the disk rotor D, and as a result, the disk rotor D is held between the brake pads 25 and 26, and a desired braking force is generated. The movable member 34
A ring-shaped dust sheet 46 is stretched between the outer periphery of the tip of the caliper 23 and the inner surface of the caliper 23. The dust sheet 46 prevents dust and the like from entering the electric device 22 in the caliper 23. I have.

The rotation of the rotor 38 is monitored by a rotary encoder 47 disposed at a boundary between the main body 30 and the disk path 31 constituting the caliper 23. The rotary encoder 47 includes a plate-like ring 48 with a slit fixed to the front end of the rotor 38 and a detection unit 49 fixed to the front end of the main body 30 of the caliper 23. Is a movable member 34
Is passed through a radial hole 50 and an axial hole 51 which are formed through a lead wire 52 which is taken out of the caliper 23 and is sent to a control device (not shown). The control device has a function of performing feedback control of the amount of power supplied to the stator 36 based on a signal from the rotary encoder 47, and thereby, the amount of rotation (rotation angle) of the rotor 38, that is, the amount of movement of the movable member 34 Is adjusted so that a desired braking force is generated. In this case, since the length of the cylindrical portion 45 of the lid 41, that is, the length of engagement between the rotation preventing member 43 and the vertical groove 44, is sufficient, reliable movement of the movable member 34 is guaranteed. After braking, the rotor 38 rotates in the reverse direction, and the movable member 34 returns to the original position.

As shown in FIGS. 3 and 5, the pin slide mechanism 24 for supporting the caliper 23 on the carrier 21 in a floating manner is provided with a pair of support portions 55 and 56 provided on the carrier 21. A bolted pin 57 bridged between a pair of support portions 55 and 56 and a pin hole 60 provided integrally on both sides of the caliper 23 and through which a pin portion 58 at one end of the bolted pin 57 is inserted. And a pair of front and rear dust boots 62 that cover the exposed portions of the pin portions 58. The bolted pin 57 is
The other end is configured as a bolt 59.

A pair of support portions 5 provided on the carrier 21
One of the supporting portions 55 is provided above the fixing portion 27 of the carrier 21, and the other supporting portion 56 is provided on the fixing portion 27.
The pair of support portions 55 and 56 are disposed in a state of being opposed to each other in the axial direction of the disk rotor D. And
A screw hole 55a is provided in one support portion 55 located on the disk rotor D side, and a concave hole 56a is provided in the other support portion 56. A bolt 57 with a bolt is provided in the screw hole 55a from outside the vehicle. The distal end of the inserted pin portion 58 is fitted into the concave hole 56a, and the screw portion 59 on the head side is screwed into the screw hole 55a to be fixed to the carrier 21.

The pin portion 58 of the bolted pin 57 connects the large-diameter shaft portion 58a on the bolt portion 59 side and the small-diameter shaft portion 58b on the distal end side, while the cylindrical portion 6 of the caliper 23 is connected.
1 has a large diameter shaft portion 58a of the pin portion 58.
The small-diameter hole portion 60b through which the small-diameter shaft portion 58b is inserted through the large-diameter hole portion 60a and the small-diameter shaft portion 58b is connected to each other. An annular variable volume chamber S defined by the step surface 60 is formed. And this variable volume chamber S,
The inner peripheral surface of the small diameter hole portion 60b of the pin hole 60 and the pin portion 58
C between the small diameter shaft portion 58b and the dust boot 6
A relatively high-viscosity grease is sealed in the entire air space including the chamber (supplying chamber) S 'inside 2.

In the disc brake according to the third embodiment, the cylindrical portion 61 of the caliper 23 moves abruptly to the inside of the vehicle (inner side) during braking, so that the pin hole 60 is formed.
The variable volume chamber S at the bottom of the is enlarged. At this time, the pin hole 60
The clearance C between the inner peripheral surface of the pin portion 58 and the outer peripheral surface of the pin portion 58 not only gives a flow resistance to the lubricant as an orifice passage, but also uses a relatively high-viscosity grease. The flow of grease from the replenishing chamber S 'inside the inside of the variable volume chamber S is suppressed, and a negative pressure is generated in the variable volume chamber S by the movement of the caliper 23 described above. Then, at the same time as braking release due to the generation of this negative pressure,
The cylindrical portion 61 of the caliper 23 is drawn toward the bolt portion 59 of the bolted pin 57, and the caliper 23 moves to the outside of the vehicle (outer side) and returns to the neutral position during non-braking.

The variable volume chamber S in the pin hole 60 is provided with the cylindrical portion 6 of the caliper 23 during braking as described above.
1 moves to the inner side, and the amount of the expansion is the same as the lining material 25b of the outer side brake pad 25.
Increases as it wears and reaches its maximum at the maximum wear limit of the lining material 25b. However, in the third embodiment, the dust boot 6 as well as the variable volume chamber S is used.
Since the grease is also sealed in the supply chamber S 'inside 2, the amount of the grease is sufficiently larger than the volume in which the variable volume chamber S is maximized. As a result, during repeated braking, grease corresponding to the expansion of the variable volume chamber S is supplied from the supply chamber S 'via the clearance C. Therefore, the return of the caliper 23 regardless of the degree of wear of the brake pad 25. The amount will be constant. That is,
The return position of the caliper 23 is adjusted according to the degree of wear of the brake pad 25, and an appropriate return interval is always maintained between the disk rotor D and the outer brake pad 25. As a result, the brake There is no delay in timing.

In the third embodiment,
Since the caliper 23 including the electric device 22 is supported in a doubly supported manner between the pair of support portions 55 and 56 constituting the pin slide mechanism 24, the main body 30 of the heavy caliper 23 is stable, The caliper 23 is no longer inclined with respect to the braking surface of the disk rotor D. As a result, the drag torque is reduced and the judder performance is improved. Further, since the bolted pin 57 is screwed into the support portion 55 located on the disk rotor D side from the outside of the vehicle, the bolted pin 57 is removed from the outside of the vehicle to easily attach the brake pads 25 and 26. Can be exchanged. In addition, the pair of support portions 55 and 56 form the bridge portion 2 of the carrier 21 when viewed in the axial direction of the disk rotor D.
8 (FIG. 5), the interference with the bridge portion 28 is prevented when the bolted pin 57 is assembled, so that the bridge portion 28 of the carrier 21 is processed with an extra groove. Alternatively, it is not necessary to take measures such as providing the cylindrical portion 61 of the caliper 23 at a position expanded to the side, which is advantageous in terms of cost or size.

Further, since the lead wire 52 of the rotary encoder 47 is taken out of the caliper 23 by passing through the radial hole 50 and the axial hole 51 formed in the movable member 34, the lead wire passes through the outer surface of the caliper 23. Compared with the case where the wire 52 is taken out, the area around the caliper is simplified, the mountability on the vehicle is improved, and the risk of disconnection of the lead wire 52 is reduced, so that the safety is also improved.

FIG. 6 shows a fourth embodiment of the present invention. The feature of the fourth embodiment is that annular grooves are formed in each of the large-diameter shaft portion 58a and the small-diameter shaft portion 58b of the pin portion 58 of the bolted pin 57 in the third embodiment. Thus, seal members 65 and 66 made of an elastic material are fitted into the annular groove, and the seal member 60 is slightly brought into contact with the inner peripheral surface of the pin hole 60. The sealing member 60 exerts a complete sealing effect when the cylindrical portion 61 of the caliper 23 moves abruptly to the inner side during braking, but usually causes a slight grease leakage. That is, the sealing member 60 and the pin hole 60
Functions as a variable orifice between the inner peripheral surface and the inner peripheral surface, so that a sufficient negative pressure is generated in the variable volume chamber S at the time of braking without selecting a grease having a very high viscosity. . In addition, since the clearance C between the small diameter hole portion 60b of the pin hole 60 and the small diameter shaft portion 58b of the pin portion 58 can be made sufficiently large, the assembly of the caliper 2 to the carrier 1 is simplified.

In the third and fourth embodiments, the supply chamber S 'is provided inside the dust boot 62. However, the location of the supply chamber S' is arbitrary.
For example, an annular groove is formed on the inner surface of the pin hole 60 or the outer periphery of the pin portion 58, and the inside of this groove is used as a replenishing chamber, or a separate independent replenishing chamber is provided outside the cylindrical portion 61 of the caliper 23. Is also good.

[0034]

As described above, according to the disc brake of the present invention, since the return force acts directly on the caliper, the return of the outer brake pad is improved, and the drag of the brake is eliminated, thereby improving the fuel efficiency. In addition, abnormal wear of the disk rotor is eliminated to prevent the occurrence of judder, and these effects become remarkable particularly when the weight of the caliper increases due to electrification or the like. Further, since the return amount of the caliper becomes constant in accordance with the wear of the brake pad, a stable return function is exhibited. Further, since the variable volume chamber is provided in the pin hole of the pin slide mechanism and the lubricant is merely sealed therein, it can be dealt with with a slight improvement of the conventional pin slide mechanism, which is advantageous in manufacturing cost.
In particular, when the supply chamber is set inside the dust boot that covers around the pin, and the orifice passage leading from the supply chamber to the variable volume chamber is provided by the clearance between the inner peripheral surface of the pin hole and the outer peripheral surface of the pin. Can use the conventional pin slide mechanism almost as it is, which is extremely advantageous in terms of manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main structure of a hydraulic disc brake according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a main structure of a hydraulic disc brake according to a second embodiment of the present invention.

FIG. 3 is a plan view showing the entire structure of an electric disc brake according to a third embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 3;

FIG. 6 is a cross-sectional view illustrating a main structure of a hydraulic disc brake according to a fourth embodiment of the present invention.

FIG. 7 is a plan view showing the entire structure of a conventional hydraulic disc brake.

FIG. 8 is a sectional view taken along the line MM of FIG. 7;

FIG. 9 is a sectional view taken along the line NN of FIG. 7;

[Explanation of symbols]

 1, 21 carrier 2, 23 caliper 3, 24 pin slide mechanism 8, 60 pin hole 11 pin 12, 62 dust boot 20 seal member 22 electric device 33 motor 34 movable member 35 motion conversion mechanism 57 pin with bolt 58 pin part S volume Variable chamber S 'Supply chamber C Clearance

Claims (3)

[Claims] 1. A caliper floating type disc brake having a caliper supported on a carrier fixed to a non-rotating portion of a vehicle via a pin slide mechanism, wherein the caliper movement during braking is moved into a pin hole constituting the pin slide mechanism. In accordance with the above, a gap with the pin is widened, a variable volume chamber for increasing the volume is provided, and a supply chamber communicating with the variable volume chamber and the orifice passage inside or outside the pin hole is further provided. A disc brake, wherein a lubricant is sealed in the supply chamber. 2. The supply chamber is set inside a dust boot covering the periphery of the pin, and the orifice passage is provided by a clearance between an inner peripheral surface of the pin hole and an outer peripheral surface of the pin. The disc brake according to claim 1, wherein 3. The disk brake according to claim 1, wherein the lubricant comprises grease.