JP3336427B2 - Parking brake mechanism for vehicle disk brake and method of assembling bearings used for the parking brake mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a parking mechanism by pressing a bearing into a bearing hole without slanting easily, preventing the wear of the bearing and the bearing hole and the generation of a burr and turning a cam shaft smoothly. SOLUTION: A bearing 15 is formed by rounding an elastic sheet material in a cylindrical shape with a larger diameter than that of a bearing hole 9. A guide hole 9c with such bigness that the bearing 15 in a free state can be stored is formed between the bearing hole 9 and the boot groove 9a. The bearing 15 in the free state is stored to the through hole 22b of a guide table 22 while projecting its tip 15c. A stopper pin 21 is inserted in the insertion hole 22c of the guide table 22 and the tip of the bearing projected from the through hole 22b is inserted into the guide hole 9c while making the stopper pin 21 to a fulcrum and the other end 15d of the bearing 15 is push-pressed by a press-in tool 23 and the bearing 15 is pressed into the bearing hole 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parkin brake mechanism for a disc brake used for a rear wheel brake or the like of a four-wheeled motor vehicle, and more particularly, to a cam hole of a parking brake mechanism in which a cam shaft is inserted. The present invention relates to a parking brake mechanism of a vehicle disk brake capable of accurately mounting a movably supported bearing, and a method of assembling a bearing used for the parking brake mechanism.

[0002]

2. Description of the Related Art A disk with a parking brake mechanism, in which a hydraulic operating mechanism is disposed on a disk rotor side of a caliper body and a mechanical operating mechanism is disposed on a side opposite to a disk rotor, for a rear wheel disk brake of a four-wheeled vehicle or the like. A brake is used, as an example of which is disclosed in Japanese Utility Model Laid-Open No. 60-4083.
There is one disclosed in Japanese Unexamined Patent Publication No. 3 (KOKAI).

In this parking brake mechanism, a cam shaft integral with a cam lever which is rotated by pulling a brake cable is inserted into a bearing hole, and a power transmission mechanism such as a sleeve piston or a push rod is inserted into a bottom of a cylinder hole or a communication hole following the same. And the rotational force of the camshaft is converted into thrust by the power transmission mechanism to operate the piston of the hydraulic operating mechanism disposed on the cylinder hole opening side. A bearing such as a needle bearing is interposed in the bearing hole of the caliper body in which the camshaft is accommodated to reduce the rotational resistance of the camshaft. In order to reduce the size, weight, and cost of the body, it has been proposed to use a cylindrical bearing having an inner surface subjected to a low friction treatment.

FIGS. 6 and 7 show a cylindrical bearing 32 formed of a pipe material having a diameter larger than that of a bearing hole 31 of a caliper body 30 and a plate-shaped guide table 33 and a rod-shaped press fitting 3.
4 shows a state of press-fitting into the bearing hole 31 using
Guide table 3 containing bearing 32 in through hole 33a
3, a stopper pin 35 protruding from the vicinity of the bearing hole 31 is inserted into the through hole 33b, the guide table 33 is rotated around the stopper pin 35, and the through hole 33a is inserted into the bearing hole 3b.
1 and the bearing 32 in the through hole 33a is
At 4, it was press-fitted into the bearing hole 31.

The opening of the bearing hole 31 has a large-diameter boot groove 31a into which one end of the boot is fitted.
1a and the bearing hole 31 are connected by a tapered hole 31b, and the bearing 32 pressed by the press-fitting tool 34 is brought into contact with the outer periphery of the tip against the tapered hole 31b. While being pressed into the bearing hole 31.

[0006]

In the press-fitting of the bearing 32, the bearing 32 of the through hole 33a is guided to the bearing hole 31 by rotating the guide table 33 with the stopper pin 35 as a reference. However, since the bearing hole 31 is covered with the guide table 33 and cannot be seen, the bearing 32
It is difficult and time-consuming to align the shaft with the bearing hole 31. Before the bearing 32 is pressed into the bearing hole 31, the tip of the bearing 32 has a tapered hole 31 b.
Since it is set in an unstable state in which only line contact is made, when the tapered hole 31b is squeezed into the bearing hole 31, an unbalanced load acts on the bearing 32, causing a misalignment as shown in FIG. Since the camshaft is press-fitted into the bearing hole 31 while being inclined, the bearing hole 31 and the bearing 32 are damaged or burrs are generated. There is a possibility that smooth rotation may be impaired or durability may be impaired.

Accordingly, the present invention provides a parking mechanism for a disk brake for a vehicle which can press-fit a bearing for supporting a camshaft into a bearing hole in a short time without tilting, thereby ensuring smooth rotation of the camshaft. And a method of assembling a bearing used in the parking brake mechanism.

[0008]

In order to achieve the above object, according to a first aspect of the present invention, a working portion of a caliper body disposed on one side of a disk rotor has a cylinder hole opening toward the disk rotor, A bearing hole which is orthogonal to a rear portion of the cylinder hole and is opened to one side wall of the action portion, and the bearing hole and the cylinder hole are connected by a communication hole in a cylinder axial direction, and the opening of the cylinder hole is formed. A piston is housed in the part side, and a cam shaft is rotatably inserted into the bearing hole via a bearing,
Power transmission means for transmitting rotation of the camshaft to the piston as thrust is interposed between the camshaft and the piston, and an outer end of the camshaft protruding from the bearing hole to one side of the action portion. A cam lever to be pulled by a brake cable, and a large-diameter boot groove for fitting one end of a boot to the opening side of the bearing hole, and press-fitting the bearing into the bearing hole. In the parking brake mechanism for a vehicle disk brake to be attached, the bearing is formed by rolling a pipe or elastic plate having a diameter larger than the bearing hole into a cylindrical shape having a diameter larger than the bearing hole. A guide hole having a diameter larger than that of the bearing hole and capable of accommodating the bearing in a free state is formed between the boot groove and the boot groove.

According to a second aspect of the present invention, a working portion of a caliper body disposed on one side of a disk rotor has a cylinder hole opening toward the disk rotor and the working portion orthogonal to a rear portion of the cylinder hole. A bearing hole opening to one side wall is provided, the bearing hole and the cylinder hole are connected by a communication hole in the cylinder axial direction, and a piston is accommodated in the opening side of the cylinder hole, and the bearing hole is formed in the bearing hole. A camshaft is rotatably inserted through a bearing, and a power transmission means for transmitting the rotation of the camshaft to the piston as a thrust is interposed between the camshaft and the piston. A cam lever pulled by a brake cable is journaled to the outer end of a cam shaft protruding to one side of the portion, and the retraction limit of the cam lever is regulated by a stopper pin protruding from one side wall of the working portion. And the bearing hole A bearing mounting method for use in a parking brake mechanism of a disk brake for a vehicle, comprising a large-diameter boot groove in which one end of a boot is fitted on the mouth side and press-fitting the bearing into the bearing hole. To
A pipe or elastic plate having a diameter larger than that of the bearing hole is formed into a cylindrical shape having a diameter larger than that of the bearing hole, and is formed between the bearing hole and the boot groove with a diameter larger than that of the bearing hole and freely. A guide hole capable of accommodating the bearing in the state is provided in series, the bearing in the free state is housed by projecting a tip into a through hole of the guide table, and the stopper pin is inserted into an insertion hole formed in the guide table. While using the stopper pin as a fulcrum,
A tip of the bearing projecting from the through hole is inserted into the guide hole, and the other end of the bearing is pressed by a press fitting to press-fit the bearing into the bearing hole.

According to the parking brake mechanism of the first invention, when the tip of the bearing is pressed into the bearing hole while being squeezed, the guide hole holds the bearing without tilting, so that the bearing is pressed into the bearing hole without tilting. Will be able to do it. First
According to the bearing assembling method of the second invention using the configuration of the present invention, since the tip of the bearing protrudes from the through hole of the guide table, the stopper pin is inserted into the insertion hole of the guide table while the stopper pin is used as a fulcrum. By rotating the guide table, even when the operator cannot visually recognize the guide hole, the bearing can be easily positioned in the guide hole and can be easily inserted into the guide hole. The bearing inserted into the guide hole is guided without inclination on the center axis of the guide hole as a stage before being pressed into the bearing hole, and the bearing is pressed by the press-in tool while being held in the guide hole in this way. Pressed into the bearing hole without tilt.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The disc brake 1 has a parking brake in which a caliper body 2 is provided with a hydraulic operating mechanism 3 operated by a brake pedal and a mechanical operating mechanism 4 for a parking brake operated by a hand lever or a foot pedal. The caliper body 2 is supported by the caliper bracket 5 via a pair of sliding pins (not shown) so as to be movable in the disk axial direction.

The caliper body 2 includes an operating portion 2a and a reaction portion 2b which are disposed on both sides of the disk rotor 6, and
A bridge portion 2c for connecting the two over the outside of the disk rotor 6;
b, a pair of friction pads 7 are suspended so as to be movable in the disk axial direction with the disk rotor 6 interposed therebetween. The action portion 2a has a large-diameter cylinder hole 8 in the disk axis direction that opens on the disk rotor 6 side, and a bearing hole 9 that opens to one side wall of the action portion 2a at the rear of the cylinder hole 8 and is orthogonal to the disk axis. And a communication hole 10 having a small diameter in the disk axial direction connecting the cylinder hole 8 and the bearing hole 9.

A cylindrical piston 11 having a bottom is accommodated at the tip opening side of the cylinder hole 8, and a hydraulic chamber 12 is defined between the piston 11 and the bottom of the cylinder hole 8. In the hydraulic chamber 12, an automatic braking gap adjusting device 13 for automatically compensating the wear amount of the friction pads 7, 7 is provided. The automatic adjusting device 13 is provided with an adjusting nut 13.
a, the adjustment bolt 13b, and the sleeve piston 1
3c, the operation of which is the same as that of the well-known one, and a description thereof will be omitted.

The sleeve piston 13c has a cylinder hole 8
The camshaft 14 is rotatably accommodated in the bearing hole 9 via a cylindrical bearing 15 in the bearing hole 9. A cam groove 14a is formed in the camshaft 14, and a push rod 16 is suspended between the cam groove 14a and the engagement recess 13d of the sleeve piston 13c. The rod 16 corresponds to the power transmission mechanism of the present invention.

On the opening side of the bearing hole 9, a large-diameter boot groove 9a is provided continuously to the inlet hole 9b.
A guide hole 9c is formed between the bearing hole 9 and
A tapered hole 9d is provided between the guide hole 9c and the bearing hole 9. The guide hole 9c located between the bearing hole 9 and the boot groove 9a has a diameter larger than that of the bearing hole 9 and has a diameter capable of accommodating the bearing 15 in a free state in which no load is applied inward and outward. The bearing 15 is formed with a length capable of holding the bearing 15 inserted through the boot groove 9a without falling off. Further, one end of a boot 17 is fitted into the boot groove 9a, and the other end of the boot 17 is fitted to the camshaft 14, so that dust and water in the bearing hole 9 are prevented.

A cam shaft 14 protruding to one side of the action portion 2a
The cam lever 18 has a fixing nut 19
A coil-shaped return spring 20 is wound around the outer periphery of the fixed nut 19, and the cam shaft 14 and the cam lever 18 are constantly urged in the non-operation direction by the torsion force of the return spring 20. ing. A brake wire (not shown) connected to a hand lever or a foot pedal in the driver's seat is connected to the outer end of the cam lever 18, and the cam lever 18 is retracted to a position near the bearing hole 9 on one side wall of the action portion 2 a. A stopper pin 21 for restricting the limit is protruded. In addition, the cam lever 18 pulled by the brake wire, the cam shaft 14, the push rod 17, and the brake clearance automatic adjusting device 13 constitute the mechanical operating mechanism 4 described above.

The bearing 15 is a wound bushing obtained by rolling an elastic plate material such as a spring plate into a cylindrical shape having a diameter slightly larger than that of the bearing hole 9 and coating the inner peripheral surface thereof with a low friction processing layer such as a low friction resin. The elastic force of the elastic plate material used for the bearing 15 is set to such a strength that when the cam plate 14 is pressed into the bearing hole 9 using the guide table 22 and the press fitting 23, the cam shaft 14 does not rotate together. A slit 15a for allowing the elastic plate to expand and contract is provided between both ends of the bearing 15 at the start and end of winding.
In the cylindrical portion of the bearing 15, a window 15b through which the push rod 16 is inserted is formed. The window portion 15 b is provided with the communication hole 1 in the circumferential direction of the bearing 15.
0, and is formed in an oval shape having a width in the width direction of the bearing 15 and an intermediate width between the thickness of the push rod 16 and the diameter of the communication hole 10. Tip 15c of bearing 15
An outer peripheral edge of the rear end 15d is chamfered in the same shape as the tapered hole 9d so that the guide hole 9c and the bearing hole 9 can be easily inserted.

The guide table 22 has a table main body 22a large enough to cover the opening side of the bearing hole 9 and the protruding portion of the stopper pin 21. Hole 22b and stopper pin 2
1 and a bottomed insertion hole 22c into which the insertion hole 22b can be inserted. A free end bearing 15 is housed at one end of the through hole 22b where the insertion hole 22b is opened, with the tip 15c protruding. (FIG. 4).

A press fitting 23 is inserted into the other end of the through hole 22b. The guide table 22 rotates the guide table 22 about the stopper pin 21 while inserting the stopper pin 21 into the insertion hole 22c. The bearing 15
Is positioned in the guide hole 9c, and is inserted into the guide hole 9c by pushing the press-in tool 23. The amount of the bearing 15 pressed by the press-fitting tool 23 into the guide hole 9c is regulated by the contact between the tip 15c and the tapered hole 9d, and the bearing 15 is held on the central axis of the guide hole 9c without inclination (FIG. 5). ). When the pressing of the press fitting 23 is further applied, the bearing 15 is gradually pressed down from the tip 15c abutting on the tapered hole 9d and pressed into the bearing hole 9 while being held in the guide hole 9c. Is mounted at a predetermined position in the bearing hole 9 (FIGS. 1 and 2).

In this embodiment, the bearing 15 in the free state which is not subjected to an external force is connected to the through-hole 22 of the guide table 22 as described above.
b, the tip 15c is protruded and housed, and the guide table 2
While inserting the stopper pin 21 into the second insertion hole 22c,
By rotating the guide table 22 with the stopper pin 21 as a fulcrum, even when the operator cannot see the guide hole 9c, the tip 15c of the bearing 15 protruding from the through hole 22b can be easily inserted into the guide hole 9c. , And can be easily inserted, so that the assembling workability can be improved.

The guide hole 9c is formed between the bearing hole 9 and the boot groove 9a in such a size that the free bearing 15 can be accommodated. 15 can be set on the center axis of the guide hole 9c without any inclination by surface contact with the guide hole 9c. When the bearing 15 is pressed into the bearing hole 9 while being squeezed, the holding by the guide hole 9c is continued. Without giving an eccentric load to
Pressing into the center axis of the bearing hole 9 with a small pressing force can be performed in a short time. Therefore, the conventional bearing 1
The camshaft 15 can be smoothly rotated, and the durability of the parking mechanism can be improved.

Incidentally, it is conceivable to set the guide hole of the present invention outside the boot groove, but in this case, when the press-fitting tool presses the bearing and enters the guide hole or the boot groove, The press-fitting tool may undesirably pry the guide hole or the boot groove to give wear or generate burrs. Further, the bearing of the present invention is not limited to the wound bush obtained by rolling the elastic plate material as in the above-described embodiment, but may be a cylindrical bearing formed of a pipe material having a diameter larger than the bearing hole.

[0023]

As described above, according to the parking brake mechanism for a vehicle disk brake of the first invention,
Since a guide hole large enough to accommodate a free-form bearing is formed between the bearing hole and the boot groove, the bearing before pressing into the bearing hole is brought into contact with the guide hole on its central axis by surface contact. It can be set without inclination, and when press-fitting into the bearing hole while squeezing the bearing, the holding by the guide hole will continue, so there is no uneven load on the bearing and a small pressing force on the center axis of the bearing hole Press-fitting can be performed in a short time. Therefore, unlike the related art, there are no problems such as damage to bearings and bearing holes and occurrence of burrs, so that the cam shaft can be smoothly rotated, and the durability of the parking mechanism can be improved.

According to the method of assembling a bearing for use in a parking brake mechanism of a vehicle disk brake according to the second invention, the guide table is supported by the stopper pin while the stopper pin is inserted into the insertion hole of the guide table. By rotating, even when the operator cannot visually recognize the guide hole, the bearing housed by projecting the tip into the through hole of the guide table can be easily aligned with the guide hole and easily inserted. It is possible to improve the assembling workability.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG. 2;

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a partial cross-sectional view of a vehicle disk brake showing one embodiment of the present invention.

FIG. 4 is an explanatory view when assembling a bearing.

FIG. 5 is an explanatory view when a bearing is pressed into a bearing hole.

FIG. 6 is an explanatory view when a conventional bearing is assembled.

FIG. 7 is an explanatory view when press-fitting a conventional bearing into a bearing hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc brake 2 ... Caliper body 2a ... Working part 8 ... Cylinder hole 9 ... Bearing hole 9a ... Boot groove 9c ... Guide hole 9d ... Taper hole 10 ... Communication hole 11 ... Piston 13 ... Automatic braking gap adjusting device 13c ... Sleeve piston (Power transmission means of the present invention) 14 camshaft 15 bearing 15 c tip 15 d rear end 16 push rod (power transmission means of the present invention) 17 boot 18 cam lever 20 return spring 21 stopper pin 22 Guide table 22a Table main body 22b Through hole 22c Insertion hole 23 Press-in tool

Continuation of the front page (56) References Japanese Utility Model Showa 60-40833 (JP, U) Japanese Utility Model Showa 57-25229 (JP, U) Japanese Utility Model Showa 53-87378 (JP, U) Japanese Utility Model Utility Model No. 3-98340 (JP) , U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16D 65/18

Claims (2)

(57) [Claims] An operating portion of a caliper body disposed on one side of a disk rotor has a cylinder hole opening toward the disk rotor, and an opening on one side wall of the operating portion orthogonal to a rear portion of the cylinder hole. A bearing hole to be provided, the bearing hole and the cylinder hole are connected by a communication hole in the cylinder axial direction,
A piston is accommodated in the opening side of the cylinder hole, and a camshaft is rotatably inserted into the bearing hole via a bearing, and between the camshaft and the piston, the rotation of the camshaft is thrust by the piston. A cam lever pulled by a brake cable is axially attached to an outer end of a cam shaft protruding from the bearing hole to one side of the working portion, and an opening of the bearing hole is provided. A parking brake mechanism for a disk brake for a vehicle in which a large-diameter boot groove for fitting one end of a boot is fitted to the part side and the bearing is assembled into the bearing hole by press fitting. A large diameter pipe or elastic plate is formed into a cylindrical shape larger in diameter than the bearing hole, and between the bearing hole and the boot groove, a bearing having a diameter larger than the bearing hole and in a free state. Form a guide hole that can be stored Parking brake mechanism of the vehicle disc brake, characterized in that. 2. An operation portion of a caliper body disposed on one side of a disk rotor, a cylinder hole opening toward the disk rotor, and an opening on one side wall of the operation portion orthogonal to a rear portion of the cylinder hole. A bearing hole to be provided, the bearing hole and the cylinder hole are connected by a communication hole in the cylinder axial direction,
A piston is accommodated in the opening side of the cylinder hole, and a camshaft is rotatably inserted into the bearing hole via a bearing, and between the camshaft and the piston, the rotation of the camshaft is thrust by the piston. A cam lever, which is pulled by a brake cable, is axially attached to an outer end of a cam shaft protruding from the bearing hole to one side of the working portion, and the cam lever is retracted. Is regulated by a stopper pin protruding from one side wall of the acting portion, and a large-diameter boot groove for fitting one end of a boot is provided on the opening side of the bearing hole, and the bearing is provided in the bearing hole. In a bearing assembling method used for a parking brake mechanism of a vehicle disk brake to be assembled by press fitting, the bearing is formed by forming a pipe or elastic plate having a diameter larger than the bearing hole into a cylindrical shape having a diameter larger than the bearing hole. Roll and form, A guide hole having a diameter larger than that of the bearing hole and capable of accommodating the bearing in a free state is continuously provided between the bearing hole and the boot groove. While inserting the stopper pin into the insertion hole formed in the guide table while inserting the stopper pin into the insertion hole, the tip of the bearing projecting from the through hole is inserted into the guide hole with the stopper pin as a fulcrum. A method of assembling a bearing used for a parking brake mechanism of a vehicle disk brake, wherein the other end is pressed by a press-fitting tool to press-fit the bearing into the bearing hole.