JP3507973B2 - Divided caliper body for vehicle disc brake - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle disc brake used in a traveling vehicle such as an automobile or a motorcycle. More specifically, the caliper body used in the disc brake is of a split type, and the caliper body is constructed. The present invention relates to a combined structure of divided pieces.

[0002]

2. Description of the Related Art As a conventional example using a split type caliper body for a vehicle disc brake, for example, Japanese Patent Publication No.
There is one disclosed in Japanese Patent No. 5164. In this disc brake, the caliper body is divided from the central portion of the bridge portion to form a pair of divided pieces, and the three joining surfaces divided into the disc entry side, the disc entry side, and the center of each of the divided pieces are respectively separated. A connecting bolt is inserted in the disc axial direction to integrally connect both divided pieces as a caliper body.

Four cylinder holes are provided in opposition to the action parts of both divided pieces arranged on both sides of the disk rotor, and pistons are liquid-tightly and movable inside the cylinder holes, respectively. The hydraulic chamber is defined between each piston and the bottom wall of the cylinder hole. At the center of the bridge part, two ceiling openings are juxtaposed in the disk circumferential direction, and the joining surfaces of the two divided pieces have a disk entrance side and a disk exit side and an intermediate part sandwiching the ceiling opening. It is divided into three.

A fluid passage is provided on one of the joining surfaces of the disc inlet side and the disc outlet side so as to communicate with a pair of hydraulic chambers facing each other with the disc rotor in between, and a joint surface at an intermediate portion. Is provided with another fluid passage in communication with another pair of fluid pressure chambers that are also opposed to each other with the disc rotor in between, and two systems in which two four pistons are operated by separate brake operating elements are provided. It is used as a caliper body for.

[0005]

In such a structure, the braking reaction force in the anti-disc direction from the piston during braking acts on both action portions of the caliper body, and the caliper body acts on the bridge portion. It is well known that the fulcrum opens and deforms in a V shape, but when you want to form a pair of pistons facing each other on the disc feed-in side and a pair of pistons facing each other on the disc feed-out side with different diameters. A large braking reaction force acts on the joint surface on the large-diameter piston side where the pad pressing force is large, causing a larger flexural deformation than the joint surface on the small-diameter piston side.

Therefore, in the hydraulic chamber on the large diameter piston side,
Since the volume increases excessively due to the large amount of flexural deformation, the large-diameter piston makes a large stroke, which causes an extra hydraulic pressure loss until the braking force is generated, which causes a delay in initial braking and also a large diameter. The brake operator on the piston side has a large play stroke and a fluffy operation feeling without rigidity. Further, since the large-diameter piston at the time of releasing the brake is pulled back toward the bottom of the cylinder hole with the same stroke as that at the time of braking, so-called knockback occurs in which the large-diameter piston is pushed into the inner part of the cylinder hole by a predetermined amount or more.

Therefore, the present invention provides a split type caliper body in which four pots are opposed to a caliper body, and two split opposed caliper bodies of a vehicle disc brake can be formed with different diameters. It is intended to be provided.

[0008]

According to the present invention, according to the above-mentioned object, a caliper body is divided into a pair of divided pieces from a bridge portion straddling the outer side of a disk rotor, and a disc entry side and a disc entry side of both the divided pieces. It is a split type in which connecting bolts are respectively inserted in the disc axial direction into three joint surfaces divided into a side portion and an intermediate portion to integrally connect the pair of split pieces, and both side portions of the disc rotor are provided. Disc of the working part of both split pieces that are arranged facing each other
Pistons are inserted liquid-tightly and movably into each of four cylinder holes provided so as to face the turn-in side and the disc turn-out side, so that each piston and the bottom wall of the cylinder hole are connected. In a split type caliper body of a vehicle disc brake in which fluid pressure chambers are defined respectively, a pair of caliper bodies facing each other on the disc entry side are provided.
And a pair of pistons facing each other on the disk feeding side
System with two separate hydraulic systems for the piston and
Corresponding to one friction pad on the front of each piston
And it is provided, the bonding surface area <br/> of the disk rotation entrance side and the area and the intermediate portion of one of the bonding surfaces of the disk rotation exit side, is set larger respectively than the area of the other joint surfaces ,
A pair of opposing pistons in the one joining surface side of, is characterized in that it has a larger diameter than the other pair of opposing pistons in the <br/> other bonding surface side.

According to such a construction, one of the joint surfaces extends over the other.
By abutting the joining surfaces of the intermediate portion and the intermediate portion over a wide area, the rigidity against the braking reaction force increases, so even if the piston on one joining surface side is formed with a larger diameter than the other joining surface side piston, Like the other joint surface, the C-shaped deformation can be suppressed as much as possible.

The present invention also provides a surface of the joint surface of the intermediate portion.
The product is set to be larger than the area of the one joint surface.
It is characterized by having done .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. Disc brake 1
Is a disc rotor 2 that rotates in the direction of arrow A, a caliper body 3 that is attached to the vehicle body at one side of the disc rotor 2, and a caliper body 3 is disposed inside the caliper body 3 so as to face each other with the disc rotor 2 interposed therebetween. Friction pads 4, 4,
5 and 5, two hydraulic chambers 11a and 11b on the disc turn-in side and two 12a and 12b on the disc turn-out side in the caliper body 3 are respectively provided with separate brake operators (not shown). It is a two-system type that operates hydraulically.

The caliper body 3 has a pair of divided pieces 3 formed by cutting the central portion of the bridge portion 3e in the disc circumferential direction.
a, 3b, and three connecting bolts 6a, 6b, 6 on the joining surfaces 3f, 3g, 3h at the three places of the disc turning-in side, the disc turning-out side, and the intermediate part of both split pieces 3a, 3b.
Insert c into the disc axial direction,
It is a split type caliper body that connects a and 3b together.
It is bolted to the vehicle body using a vehicle body mounting bracket 3i integrally formed with one of the divided pieces 3a.

The divided pieces 3a and 3b are composed of half of the bridge portion 3e and action portions 3c and 3d arranged on both sides of the disc rotor 2, and the action sandwiching the disc rotor 2 acting as a leading action is performed. Four cylinder holes 7 are provided on the disk entry side and the disk entry side of the portions 3c and 3d.
7, 8 and 8 are provided facing each other. Of these, the cylinder holes 7, 7 on the disk entry side where the friction pads 4, 4 are pulled into the disk rotor 2 by the leading effect during braking have a small diameter, and the cylinder holes 8, 7 on the disk exit side that are not subject to the leading effect. 8 are formed to have large diameters, respectively. A small diameter piston 9 having a small pad pressing force is provided in each of the disk inlet side cylinder holes 7 and 7, and a large pad pressing force is provided in each of the disk outlet side cylinder holes 8 and 8. The large-diameter pistons 10 are respectively inserted.

Hydraulic chambers 11a and 11b are provided between the piston 9 on the disk advancing side and the bottom wall of the cylinder hole 7, and between the piston 10 on the disk advancing side and the bottom wall of the cylinder hole 8. The hydraulic chambers 12a and 12b are respectively defined, and the hydraulic chambers 11a and 11b on the disk entry side are the liquid passages 1 respectively.
3a and 13a communicate with each other, and the fluid pressure chambers 12a and 12b on the disk feeding side communicate with fluid passages 14a and 14a.

An angular seal 15 is fitted into each of the cylinder holes 7 and 8 with an interference fit with the pistons 9 and 10.
And a dust seal 16 are provided, and the corner seal 15
, The pistons 9 and 10 are held so as to be movable in the cylinder axis direction, and the hydraulic chambers 11a, 11b, 12a, and 12b.
The inside is liquid-tightly sealed, and the dust seal 16 prevents dust and water from entering the cylinder holes 7 and 8.

The pistons 9 and 10 are arranged such that their tips are slightly projected from the openings of the cylinder holes 7 and 8, and the friction pads 4, 4 and 4 are provided on the front surfaces of these four pistons 9, 9, 10, and 10. 5 and 5 are provided corresponding to each one.
Each of the friction pads 4 and 5 includes a lining 17 and a metal back plate 18, and the back plates 18 and 18 facing each other with the disc rotor 2 in between are arranged with the respective linings 17 facing the disc rotor 2. Hanger pin 19 on top
And is movably suspended in the disc axial direction, and is urged toward the disc inward by a pad spring 20 that is contracted between the back plate 18 and the hanger pin 19.

Two ceiling openings 21 and 21 are provided at the center of the bridge portion 3e divided into the divided pieces 3a and 3b.
However, the friction pads 4, 4, 5, 5 are arranged side by side in the circumferential direction of the disc in such a size that the friction pads 4, 4, 5, 5 can be inserted into and removed from the front surfaces of the pistons 9, 10, and the ceiling openings 21, 21 are formed by forming the ceiling openings 21, 21. The joining surfaces 3f, 3g, and 3h are divided at three positions on the disk entry side, the exit side, and the intermediate portion, which sandwich 21.

One divided piece 3a on the vehicle body mounting side
In addition to the bracket 3i and the liquid passages 13a and 14a, there are provided union holes 22a and 22b for introducing the hydraulic fluid and bolt holes 23a, 23b and 23c for connecting the divided pieces. Further, in the other divided piece 3b, in addition to the liquid passages 13b, 14b, bleeder holes 24a, 24b for discharging mixed air in the working fluid, and bolt holes 23a, 23b, 23c for connecting divided pieces. Is provided. The bleeder holes 24a and 24b are opened in the upper surfaces of the bleeder boss portions 3j and 3k protruding from the joining surfaces 3h and 3g on the intermediate portion and the disc feeding side, and the bleeder screw 25 is screwed into each of these opening portions. There is.

The union hole 22a on the disc turn-in side of the divided piece 3a is opened to the joint surface 3h at the intermediate portion together with the liquid passage 13a communicating with the hydraulic chamber 11a on the disc turn-on side, and the union hole on the disc turn-out side is formed. 22b is opened to the joint surface 3g on the disc feed-out side together with the liquid passage 14a communicating with the hydraulic chamber 12a on the disc feed-out side, and is further joined to the disc feed-in side, feed-out side and intermediate portion at three points. Surface 3f, 3g, 3h
Bolt holes 23a, 23b, and 23c are formed by female screw holes.

Further, in the divided piece 3b, the liquid passage 13b communicating with the hydraulic chamber 11b on the disc advancing side is opened to the joint surface 3h at the intermediate portion together with one bleeder hole 24a, and the hydraulic chamber 12b on the disc advancing side is formed. The liquid passage 14b communicating with the other bleeder hole 24b and the joint surface 3g on the disc feeding side.
The connecting bolt 6a is formed on the joining surface 3f, 3g, 3h at the three places of the disk entry side, the entry side, and the center.
Bolt holes 23a, 23b, and 23c having a diameter larger than 6c are bored.

The joint surfaces 3g, 3g on the disc feed-out side have an area approximately twice as large as the joint surfaces 3f, 3f on the disc feed-in side to the disc feed-out side. The joining surfaces 3h and 3h in the middle portion are formed to be larger than 3f, and the areas of the joining surfaces 3h and 3h in the middle portion are extended to the disc entry side and the entry side from the joining surfaces 3f and 3f on the disc entry side. The joint surfaces 3g, 3g are formed larger than the joint surfaces 3g, 3g, 3h, 3h having a large area, and the rigidity of the bridge portion 3e between the disc extension side and the intermediate portion is increased by abutting the joint surfaces 3g, 3g, 3h, 3h. .

Liquid passages 13a and 13b and union hole 22a
The bleeder hole 24a is formed in the middle of the joint surfaces 3h, 3h near the disc advancing side, and the liquid passages 14a, 14b, the union hole 22b, and the bleeder hole 24b are the disc advancing side joint surfaces 3g, 3g of the disc. It is formed in a roundabout way. On the joining surface 3h at the middle portion of the divided piece 3b, a packing 27 is provided in a seal groove 26a recessed in the outer periphery of the opening of the liquid passage 13b and the bleeder hole 24a, and a joining surface 3g of the divided piece 3b on the disk spill-out side. And the seal groove 2 recessed on the outer periphery of the opening of the liquid passage 14b and the bleeder hole 24b.
A packing 27 is fitted to each of 6b, and a joint surface 3 between the disc spill-out side and the intermediate portion of both split pieces 3a and 3b.
When joining g, 3g, 3h, and 3h, liquid passage 13a,
The packings 27 allow the 13b, 14a, and 14b to be connected without liquid leakage.

Bolt holes 23b and 23b are formed in the joint surfaces 3g and 3g on the disc spill-out side near the disc spill-in side.
In addition, the bolt hole 23 is formed at the center of the joint surfaces 3h and 3h in the middle portion.
c, 23c are formed, and the distance between the bolt holes 23a, 23a on the disc turn-in side and the bolt holes 23c, 23c on the middle part, that is, the connecting bolt 6a on the disc turn-in side and the connecting bolt 6c on the middle part The inter-bolt pitch P1 between them is the distance between the bolt holes 23c, 23c in the middle portion and the bolt holes 23b, 23b in the disk feeding side, that is, the connecting bolt 6 in the middle portion.
The length is set to be the same as the bolt pitch P2 between the disc c and the connecting bolt 6b on the disc feeding side.

By setting the above-mentioned bolt pitch P1 = P2, the three connecting bolts 6a to 6 are provided on the joining surfaces 3f, 3f on the disk entry side and the joining surfaces 3g, 3g on the disk exit side.
Although the coupling strength due to the tightening torque of c works evenly, the large-diameter piston 1 is used at the joint surfaces 3g, 3g on the disc shunting side.
0, 10 receives a larger braking reaction force than the joining surfaces 3f, 3f on the disc turn-in side. Therefore, the rigidity that can withstand this braking reaction force and the liquid passages 14a, 14b and the union holes 22b,
The large area is formed as described above in consideration of the decrease in rigidity due to the opening of the bleeder hole 24b and the seal groove 26b.

Next, the operation of the present embodiment configured as described above will be described. The two union holes 22a and 22b are supplied with the hydraulic fluid that is boosted by the hydraulic master cylinder for each brake system by the braking operation of the driver. The hydraulic fluid introduced into the union hole 22a on the disc entry side is
The liquid passages 13a, 13b are branched to enter the hydraulic chambers 11a, 11b on the disc entry side, the pistons 9, 9 are pushed toward the opening of the cylinder hole 7, and the lining 17 of the front friction pad 4 is removed. It is pressed against the side surface of the disc rotor 2. Further, the hydraulic fluid introduced into the union hole 22b on the disc delivery side branches through the fluid passages 14a and 14b, and the hydraulic chamber 12
a, 12b, and the piston 10, 10 into the cylinder hole 8
The lining 17 of the front friction pad 5 is pressed against the side surface of the disc rotor 2 by pushing the lining 17 of the friction pad 5 on the front side.

Braking reaction forces in the anti-disc direction from the pistons 9, 9, 10 and 10 act on the action portions 3c and 3d during braking, respectively, and the caliper body 3 is formed into a V-shape with the bridge portion 3e as a fulcrum. Trying to open and transform. Among them, on the disc entry side of the bridge portion 3e using the small diameter pistons 9, 9, a small braking reaction force acts on the joining faces 3f, 3f on the disc entry side due to the small pad pressing force. And the bridge part 3 using the large-diameter pistons 10, 10.
On the disc feeding side of e, the braking reaction force applied to the joint surfaces 3g, 3g on the disc feeding side is increased due to the larger pad pressing force. However, in the present embodiment, the liquid passages 14a, 14b, the union holes 22b, the bleeder are provided. In consideration of the opening of the hole 24b and the seal groove 26b, the joining surfaces 3g and 3 on the disk feeding side are considered.
Approximately 2 of the joint surfaces 3f, 3f on the disk entry side within the area of g
By taking a doubled area and abutting the joint surfaces 3g, 3g having a larger area than the disc entry side, the rigidity of the disc extension side against the braking reaction force from the pistons 10, 10 is increased. As with the turning-in side, the C-shaped deformation can be suppressed as much as possible.

As a result, in the disc feed-out side brake system, the hydraulic pressure loss becomes as small as possible like the disc feed-in side brake system, and the hydraulic fluid supplied to both fluid pressure chambers 12a and 12b is effectively utilized. As a result, highly efficient braking can be performed. Also, with knockback of the piston 10,
It is possible to effectively prevent the delay of the initial braking due to the increase of the piston stroke, and also the brake operator of the brake system on the disc feed-out side has a good sense of rigidity as with the brake system on the disc feed-in side. It can have a feeling. Further, since it is not necessary to change the size of the hydraulic master cylinder and the operating ratio of the brake lever and the brake pedal, which are the brake operators, by changing the rigidity of the bridge portion 3e, it is possible to manufacture the two-system disc brake device at a low cost. it can.

In the second embodiment of the present invention shown in FIG. 5, two connecting bolts 6 are provided on the joint surface 3h at the intermediate portion of the bridge portion 3e.
c, 6c are inserted, the divided pieces 3a, 3b are connected by four connecting bolts 6a, 6b, 6c, 6c, and the liquid passage 13 is formed in the center of the joint surface 3h at the intermediate portion of the divided piece 3b.
b, the bleeder hole 24a, and the seal groove 26a are coaxially formed, and the bolt holes 23c, 23c are formed on both sides thereof, and the liquid passage is also formed on the joint surface of the intermediate portion of the divided piece on the vehicle body mounting side (not shown). The structure is the same as that of the first embodiment except that two bolt holes are formed with the union hole and the union hole interposed therebetween.

The pitch P3 between bolts between the two connecting bolts 6a and 6c on the disc turning-in side, which sandwiches the friction pad 4 on the disc turning-in side, and the disc feeding-out side, which holds the friction pad 5 on the disc feeding-out side, The inter-bolt pitch P4 between the two connecting bolts 6b and 6c is set to the same length, and the four connecting bolts 6a to 6c are provided on the joining surfaces 3f and 3g on the disk entry side and the disk exit side. The connection strength by the tightening torque of is worked evenly.

The liquid passage 14b and the bleeder hole 24 are formed in the joint surface 3g on the disc feeding side where the large-diameter piston 10 is arranged.
b, taking into account the opening of the seal groove 26b, by taking an area approximately twice as large as the joining surface 3f on the disc turning-in side on which the small-diameter piston 9 is arranged, the disc turning force against the braking reaction force from the piston 10 is taken. The rigidity of the outlet side is increased,
Also in this embodiment, the same effect as that of the second embodiment can be achieved.

[0031] Incidentally, when it is desired to dispose the piston of larger diameter than the exit side disk rotation in disk rotation entrance side, a bonding surface of the disk rotation entrance side may be set large area of the disk rotation exit side.

[0032]

According to the present invention, the area of the joining surface of either one of the disk entry side and the disk entry side of the split type caliper body and the area of the joining surface of the intermediate portion are calculated from the area of the other joining surface. Also, each is set to be large, and the pair of pistons facing each other on the joint surface side is formed to have a larger diameter than the other pair of pistons facing each other on the joint surface side.
Since one of the joint surfaces, which is larger than the other joint surface, is abutted in a wider area from the middle part of the bridge portion, the rigidity against the braking reaction force is increased, and it is the same as the other joint surface side. It is possible to suppress the C-shaped deformation as much as possible.

As a result, the hydraulic pressure loss due to the expansion of the hydraulic chamber becomes as small as possible on the joint surface side of one of the bridge portions, as on the other joint surface side, and the hydraulic fluid supplied to the hydraulic chamber is reduced. Can be effectively utilized to perform highly efficient braking, and the knockback of the piston and the delay of the initial braking due to the increase of the piston stroke can be effectively prevented, and the extra brake operator is used. There is no play stroke, and it is possible to give a good feeling of operation with rigidity.

[0034] Further, the dual type odor which operates the other pair of opposing pistons in a pair of piston and the other bonding surface which faces in the junction surface of the hand in two separate hydraulic system
Thus , the brake operator used for the brake system on the large-diameter piston side and the brake operator used for the brake system on the small-diameter piston side can have substantially the same operation feeling without discomfort. Further, since it is not necessary to change the size of the hydraulic master cylinder and the operation ratio of the brake lever or the brake pedal, which are the brake operators, by changing the rigidity of the bridge portion, the entire two-system disc brake device can be manufactured at low cost. .

[Brief description of drawings]

FIG. 1 is a sectional view taken along the line II of FIG. 2 showing a first embodiment of the present invention.

FIG. 2 is a partially cutaway plan view of a disc brake showing a first embodiment of the present invention.

FIG. 3 is a sectional view taken along line IV-IV of FIG. 1 showing a first embodiment of the present invention.

FIG. 4 is a sectional view taken along line VV of FIG. 1 showing a first embodiment of the present invention.

FIG. 5 is a sectional side view of a disc brake showing a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hydraulic type disc brake 2 ... Disc rotor 3 ... Caliper body 3a, 3b ... Divided pieces 3c, 3d ... Action part 3e ... Bridge part 3f ... Disc insertion side joint surface 3g ... Disc ejection side joint surface 3h ... Joining surfaces 4, 5 in the middle portion ... Friction pads 6a, 6b, 6c ... Connecting bolts 7, 8 ... Cylinder hole 9 ... Small diameter piston 10 ... Large diameter pistons 11a, 11b, 12a, 12b ... Hydraulic chambers 13a, 13b, 14a, 14b ... Liquid passage 17 ... Lining 18 of friction pads 4, 5 ... Back plate 21 of friction pads 4, 5 ... Ceiling openings 23a, 23b, 23c ... Bolt holes A ... Rotation directions P1, P3 of disk rotor 2 ... Connecting bolt 6 for disc entry side and middle part
a, 6c pitches P2, P4 ... Connecting bolts 6 between the disc feeding side and the intermediate portion
b, 6c pitch

Claims (2)

(57) [Claims] 1. A caliper body is divided into a pair of divided pieces from a bridge portion straddling the outer side of a disc rotor,
A division in which connecting bolts are respectively inserted in the disc axial direction into three joint surfaces divided into a disc entry side, a disc ejection side, and an intermediate portion of both divided pieces to integrally connect the pair of divided pieces. Of the working parts of the two divided pieces that are arranged opposite to each other on both sides of the disk rotor .
It is provided to face the disc entry side and the disc entry side.
A split type caliper body for a vehicle disc brake, in which a piston is inserted into each of the four cylinder holes so as to be liquid-tight and movable, and a hydraulic chamber is defined between each piston and the bottom wall of the cylinder hole. The pair of pistons facing each other on the disc entry side and the
A pair of pistons facing each other on the disc feeding side are separated into two
It is a two-system type that operates with various hydraulic systems, and one friction pad is installed on the front of each piston.
Only the area of the disk rotation entrance side and the joint surface area and the intermediate portion of one of the bonding surfaces of the disk rotation exit side, is set larger respectively than the area of the other joint surface, the one bonding surface of the A split type caliper body for a vehicle disc brake, wherein a pair of pistons facing each other is formed to have a larger diameter than another pair of pistons facing each other on the other joint surface side. 2. The area of the joint surface of the intermediate portion is equal to that of the one side.
The disc brake for a vehicle according to claim 1 , wherein the area is larger than the area of the joint surface of the disc brake.