JPH08128467A - Floating caliper type disc brake - Google Patents

Abstract

PURPOSE: To prevent the drag torque by installing an elastic member whose engagement position changes according to the abrasion quantity of an outer pad between a support and a caliper, shifting the caliper through the deformation of the elastic member in brake application, while shifting the caliper by a prescribed length through the elastic return in brake release, CONSTITUTION: In brake application, an inner pad 10 is pressed to a disc 1, and an outer pad 14 is pressed to the disc 1 by the reaction force. At this time, an elastic member 18 is elastically deformed by the length L2 , and when the outer pad 14 is worn out over a prescribed quantity, the engagement position with a support 4 of the elastic member 18 changes according to the abrasion quantity. In the brake release, a seal ring 12 return-shifts by the length L1 (L1 >L2 ), and the gap Δ is formed between the inner pad 10 and the disc 1, and at the same time, the elastic member 18 elastically return-deforms, and a caliper 5 return-shifts by the length L2 , and the gap δ is formed between the outer pad 14 and the disc 1. The gap δ accords with the length L2 . Accordingly, each drag between the disc 1 and the pads 10 and 14 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating caliper type disc brake.

[0002]

2. Description of the Related Art A floating caliper type disc brake includes a support fixed to a non-rotating portion of a vehicle and a caliper slidably supported by the support, and slides on a cylinder portion of a rear arm of the caliper. An inner pad that abuts a freely-fitting piston and an outer pad that is supported on the forearm of the caliper pinch a disk that rotates together with the wheel to generate a braking torque. In this type of disc brake, the clearance between the disc and each pad when the brake is released is secured as follows. That is, a seal ring made of a rubber elastic material is interposed between the cylinder part and the piston, and the protruding movement of the piston in one direction during braking is allowed by elastic deformation of the seal ring, and when releasing the braking. , The piston is moved back by elastic return deformation of the seal ring. When both pads wear, the engagement position of the seal ring with the piston gradually changes according to the amount of wear, and the piston gradually moves in one direction. As a result, the amount of depression of the brake pedal, and thus the amount of brake hydraulic fluid, is kept constant, and a predetermined gap is formed between the disc and the inner pad.
The gap between the disc and the outer pad when the braking is released is formed by moving the outer pad together with the caliper so that the outer pad is moved away by being kicked by the rotating disc. At that time, the caliper slightly slides on the support.

However, in such a conventional floating caliper type disc brake, the predetermined gap between the disc and the inner pad is surely formed by elastic deformation of the seal ring. The gap between the outer pad and the outer pad tends not to be surely formed. Therefore, when the vehicle is running,
There is a technical problem that the outer pad slides on the disk to generate a drag torque, which causes deterioration of the fuel efficiency of the vehicle and causes abnormal noise due to the sliding.
Such defects become more obvious as the disc manufacturing and mounting precision increases.

[0004]

The present invention has been made in view of the above conventional technical problems, and the structure thereof is as follows. According to the configuration of the invention of claim 1, the support 4 fixed to the non-rotating portion of the vehicle, the caliper 5 supported on the support 4 in a floating manner, and the cylinder portion 6 of the rear arm 5a of the caliper 5 are slidably fitted. Piston 8
The inner pad 10 pushed out by the outer pad 14, the outer pad 14 supported by the forearm 5b of the caliper 5, the cylinder portion 6 and the piston 8.
And a seal ring 12 whose engagement position gradually changes according to the wear amount of 0 and 14, and the seal ring 1 is provided during braking.
While elastically deforming the piston 2, the piston 8 is projected in one direction, the caliper 5 is moved in the other direction with respect to the support 4, and the inner pad 10 and the outer pad 14 pinch the disk 1 that rotates with the wheel to brake. When a torque is generated and the brake is released, the piston 8 is returned and moved in the other direction by the first length L _{1 due} to the elastic deformation of the seal ring 12 to form a gap between the disc 1 and the inner pad 10. A caliper type disc brake, in which elastic members 18, 28a, 28b whose engaging positions gradually change according to the wear amount of the outer pad 14 are interposed between the support 4 and the caliper 5, and during braking, While elastically deforming the elastic members 18, 28a, 28b, the caliper 5 is moved in the other direction, and when braking is released,
Due to the elastic return deformation of the elastic members 18, 28a, 28b, the caliper 5 is moved back in one direction by the second length L ₂ shorter than the first length L _1, and when the brake is released, A floating caliper type disc brake is characterized in that a first gap Δ is formed between the inner pad 10 and a second gap δ between the disc 1 and the outer pad 14. The invention according to claim 2 is the floating caliper type disc brake according to claim 1, characterized in that a linear bearing 24 for supporting the floating of the caliper 5 is interposed between the support 4 and the caliper 5. .

[Action]

According to the first aspect of the present invention, when the piston 8 is projected in one direction during braking, the inner pad 10 is pressed against the disk 1, and the reaction force causes the caliper 5 to move in the other direction. The outer pad 14 is pressed against the other side surface of the disc 1. At that time, the elastic members 18, 28a,
28b is elastically deformed by the second length L ₂ . When the outer pad 14 is worn over a predetermined amount, the relative movement amount between the caliper 5 and the support 4 increases beyond a predetermined range, so that the elastic member 18, 28a, 28b of the support 4 or. The engagement position with the caliper 5 side gradually changes according to the wear amount of the outer pad 14. On the other hand, when both pads 10 and 14 are worn over a predetermined amount, the piston 8 (or the caliper 5) of the seal ring 12
The engagement position with and gradually changes depending on the amount of wear.

Next, when the brake is released, the seal ring 1
2 elastically returns and deforms, the piston 8 returns and moves in the other direction by the first length L _1, and a gap is formed between the inner pad 10 and one side surface of the disk 1. At the same time, the elastic members 18, 28a, 28b in the engaged state elastically return and deform. As a result, the caliper 5 is moved to the second length L ₂ in one direction.
Then, the second gap δ is formed between the outer pad 14 and the disc 1. The second gap δ matches the second length L ₂ which is the elastic return deformation amount of the elastic members 18, 28a, 28b.

The second length L ₂ by which the caliper 5 returns in one direction when the brake is released is set to be smaller than the first length L ₁ regardless of the amount of wear of the outer pad 14. Thus, when the brake is released, the first gap Δ is reliably formed between the inner pad 10 and the disc 1 in the state where the second gap δ is formed between the outer pad 14 and the disc 1. The drag between the pad and both pads 10 and 14 is surely prevented.

According to the invention of claim 2, the floating of the caliper 5 with respect to the support 4 causes the linear motion bearing 2 to move.
Smoothly done by 4. Therefore, the elastic member 18,
Based on the elastic return deformation amounts of 28a and 28b, the caliper 5 accurately returns in one direction by the second length L ₂ .
As a result, the second gap δ is reliably formed between the outer pad 14 and the disc 1 when the braking is released.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show an embodiment of the present invention.
In the drawings, reference numeral 1 denotes a disc-shaped disc, which is fixed to a member that rotates integrally with a vehicle wheel (not shown), such as a wheel or a flange portion of an axle shaft, by bolts and nuts. Rotate. On the other hand, a support 4 is firmly fixed to a non-rotating portion (not shown) of the vehicle, such as a knuckle or an axle tube. A carrier 5 straddling the disc 1 is slidably (floatably) supported in one direction (a rotation axis direction of the disc 1 (left and right direction in FIG. 1)) on the support 4, and a rear arm 5a ( One cylinder portion 6 is formed at one end of the disc 1 in the direction of the rotation axis. This Caliper 5
Ears 15 and 1 formed on both sides of the disc 1 in the rotation direction.
5, the pin 1 fixed in parallel to the support 4 in the hole 15a
Since 6 are slidably fitted in each other, they are guided by the pair of pins 16 to move in the direction of the rotation axis of the disc 1.

A cylinder 8 formed on the rear arm 5a of the caliper 5 is provided with a seal ring 12 shown in FIGS. 2 to 4 so that a piston 8 is slidably fitted in the rotational axis direction. The inner pad 10 is in pushable contact with the piston 8. Also, the forearm 5b of the carrier 5
The outer pad 1 is provided at (the other end in the rotation axis direction).
4 is abutted and supported. In addition, this outer pad 1
4 can also be integrally attached to the forearm 5b by a detachable connecting means, for example, a bolt. Then, during braking, as shown in FIG. 4, the piston 8 is projected in one direction while elastically deforming the seal ring 12, and the inner pad 10 and the outer pad 14 pinch the disc 1 to generate a braking torque. When the brake is released, the piston 8 is moved by the elastic return deformation of the seal ring 12 as shown in FIG.
The first gap L shown in FIG. 2 can be formed between the disc 1 and the inner pad 10 by returning and moving by the first length L ₁ shown in FIG.

The pair of pins 16 fixed to the support 4 are
As shown in FIG. 1, it comprises a shaft member 16a penetrating the support 4 and a bush 16b screwed to the shaft member 16a, and the outer peripheral surface of the bush 16b slides in the hole 15a of the caliper 5. 24 is a bush 16b and a hole 15
It is a linear motion bearing (linear motion bearing) interposed in a moving part between the caliper 5 and a, and has a function of reducing sliding resistance of the caliper 5 with respect to the support 4 and giving the caliper 5 smooth movement. Reference numerals 20 and 21 denote sealing boots that cover between the ears 15 and 15 of the caliper 5 and the ends of the bush 16b, respectively.

1 and 5 between the pins 16 of the support 4, more specifically, the bushes 16b, and the ears 15 of the caliper 5, and the position where the linear motion bearing 24 is avoided. The elastic member 18 is interposed as shown in FIG. The elastic member 18 is formed in an annular shape by a rubber elastic body (rubber or elastomer), and a plurality of elastic members 18 are arranged on each pin 16. The elastic member 18 is elastically deformed to prevent the caliper 5 from moving in the other direction. Allow and let the brake release
It functions to give the return movement in one direction to the caliper 5. That is, at the time of releasing the braking, the elastic member 18 elastically returns and deforms from the state shown in FIG. 6 to move the caliper 5 in the one direction by the second length L _2, and when the braking is released, the disc 1 and the outer pad 14 are disconnected. Between the second gap δ shown in FIG.
To form. On the other hand, when the outer pad 14 is worn, the caliper 5 largely moves in the other direction according to the amount of wear of the outer pad 14 during braking, and the elastic member 18
The position of the close contact with the pin 16 of is gradually changed.

Specifically, as shown in FIGS. 1 and 5, a plurality of annular grooves 22 are formed in the ears 15, 15 of the caliper 5.
The outer peripheral portion of the elastic member 18 is embedded in each annular groove 22, and the inner peripheral surface of each elastic member 18 is elastically brought into close contact with the outer peripheral surface of the pin 16. As shown in FIG. 5, a shallow annular groove portion 22 a is formed on the inner peripheral portion of the annular groove 22.
The elastic deformation of the elastic member 18 is allowed within a, and the sliding guide of the hole 15a by the pin 16 is precisely performed. Here, the elastic return deformation amount of the elastic member 18, that is, the second length L ₂ that moves the caliper 5 in one direction when releasing the braking is the first length that is the elastic return deformation amount of the seal ring 12. It is set to be smaller than L ₁ and set to a range of 1/5 to 4/5 of the first length L ₁ , preferably 1/2. Between the pins 16 and the ears 15, 15 of the caliper 5, a plurality of elastic members 1 are arranged in the rotation axis direction of the disc 1.
The reason for disposing 8 is to generate a large elastic return force according to the weight of the caliper 5, and if the caliper 5 can be returned and moved in one direction, one elastic pin is provided for each pin 16. It is also possible to arrange only the member 18.

Next, the operation of the above embodiment will be described.
When the vehicle is running, a brake pedal (not shown) is depressed to supply pressure fluid (brake hydraulic fluid) to the cylinder portion 6, the inner pad 10 is pushed out in one direction together with the piston 8, and one side surface of the disc 1 that rotates with the wheels. The inner pad 10 is pressed against. At that time, the seal ring 12
Elastically deforms by the first length L ₁ . Both pads 10, 14
When the wear amount exceeds a predetermined amount, the piston 8 moves with respect to the seal ring 12 according to the wear amount.
Therefore, the return length of the piston 8 is always the seal ring 1
This corresponds to the first length L ₁ which is the elastic return deformation amount of 2.

On the other hand, when the inner pad 10 is pressed against the disc 1, the reaction force causes the caliper 5 to move in the other direction, and the outer pad 14 contacting the forearm 5b is pressed against the other side surface of the disc 1. When the caliper 5 is moved, the hole 15a slides with respect to each pin 16. As a result, the disc 1 and thus the wheels are braked. The braking torque generated in both pads 10 and 14 is directly transmitted to the support 4 (or via the pin 16 and the caliper 5) and supported.

When the hole 15a slides with respect to each pin 16 during braking, each elastic member 18 elastically deforms by the second length L ₂ as shown in FIG. If the outer pad 14 is worn over a predetermined amount,
Since the relative movement amount between the pin 16 and the hole 15a becomes large beyond a predetermined range, the caliper 5 and each elastic member 18
Moves in the other direction with respect to each pin 16, and each elastic member 18
The position of close contact with each of the pins 16 gradually changes according to the wear amount of the outer pad 14.

Next, when the pressurized liquid is discharged from the cylinder portion 6 to release the braking, the seal ring 12 elastically returns and deforms so that the piston 8 is retracted into the cylinder portion 6 by the first length L _1. To the other direction, a gap is formed between the inner pad 10 and one side surface of the disk 1.
At the same time, each elastic member 18 elastically returns and deforms. As a result, the caliper 5 is moved back in the one direction by the second length L _2, and the second caliper is moved between the outer pad 14 and the disc 1.
A gap δ is formed. The second gap δ matches the second length L ₂ which is the elastic return deformation amount of the elastic member 18. Since the linear motion bearing 24 is interposed in the moving portion between the bush 16b and the hole 15a, the caliper 5 smoothly moves with respect to the support 4 based on the elastic return deformation of each elastic member 18. , The return movement of the caliper 5 in the one direction by the second length L ₂ is surely performed.

The second length L ₂ by which the caliper 5 returns in one direction when the brake is released is set to be smaller than the first length L ₁ . Thus, when the brake is released, the first gap Δ is reliably formed between the inner pad 10 and the disc 1 in the state where the second gap δ is formed between the outer pad 14 and the disc 1. And both pads 1
The dragging with 0 and 14 is surely prevented. If the second length L ₂ is set within the range of 1/5 to 4/5 of the first length L ₁ , the first and second gaps Δ and δ are appropriately formed to prevent dragging, 1 2 the length L ₂ of the first length L ₁
If it is set to / 2, the first and second gaps Δ and δ are formed to be the same, and drag can be prevented even better. The elastic member 18 has the same action even if the inner peripheral portion is fixed to each pin 16 and the outer peripheral portion is brought into close contact with the hole 15a of the caliper 5.

7 to 9 show another example of the structure of the elastic member. Each pin 16 of the support 4 and the ear 1 of the caliper 5 are shown.
Elastic member 28 arranged between the holes 15a of the holes 5, 15
Each of a and 28b is made of spring steel. Since it is not necessary to maintain liquid tightness between each pin 16 and the ears 15 and 15 of the caliper 5, elastic members 28a and 28b made of spring steel can be used in place of the rubber elastic body. Is. One elastic member 28a is fixed to each pin 16 of the support 4 at a predetermined interval, and one elastic member 28b is fixed to each of the ears 15 and 15 of the caliper 5. The elastic members 28 a and 28 b have a function of returning the caliper 5 in the one direction by the second length L ₂ when releasing the braking, and forming a second gap δ between the disc 1 and the outer pad 14. Then, each elastic member 28a, 28
b is formed in an annular shape, and the outer peripheral portion of the one elastic member 28a and the inner peripheral portion of the other elastic member 28b can be engaged with each other with a predetermined width, and the elastic deformation of each is facilitated. Slits 28c and 28d are formed at predetermined intervals in the direction. Therefore, the elastic members 28a and 28b that engage with each other elastically deform between the slits 28c and 28d.

The distance between the elastic members 28a on one side is
The elastic member 28b is always elastically engaged with the other elastic member 28b during braking, and the return movement amount of the caliper 5 due to the elastic engagement with the other elastic member 28b, that is, the elastic member 28 to be engaged.
2nd length L which is the elastic return deformation amount of a and 28b
₂ is the first length L which is the elastic return deformation amount of the seal ring 12 regardless of the wear amount of the outer pad 14.
_It is set to be smaller than ₁ and is 1 of the first length L ₁ .
It is set so that it is formed with a range of / 5 to 4/5, preferably 1/2.

According to this structure example, however, the inner pad 10 is pressed against the disc 1 during braking, the reaction force causes the caliper 5 to move in the other direction, and the outer pad 14 causes the other side face of the disc 1 to move. Pressed against. When the caliper 5 moves, the hole 15a slides with respect to each pin 16, and the elastic members 28a and 28b elastically deform by the second length L ₂ as shown in FIG. If the outer pad 14 is worn over a predetermined amount,
Since the relative movement amount of the pin 16 and the hole portion 15a becomes larger than the predetermined range, the other elastic member 28b moves over one elastic member 28a and moves in the other direction,
The second elastic member 28a is elastically engaged. Thus,
The engagement position of the other elastic member 28b with respect to the one elastic member 28a and further with respect to each pin 16 gradually changes according to the wear amount of the outer pad 14.

Next, at the time of releasing the braking, the seal ring 1
2 elastically returns and deforms, the piston 8 returns and moves in the other direction by the first length L _1, and a gap is formed between the inner pad 10 and one side surface of the disk 1. At the same time, the elastic members 28a and 28b in the engaged state elastically return and deform. As a result, the caliper 5 is moved back in one direction by the second length L ₂ , and the second gap δ is formed between the outer pad 14 and the disc 1. The second gap δ matches the second length L ₂ that is the elastic return deformation amount of the elastic members 28a and 28b in the engaged state.

The second length L ₂ by which the caliper 5 returns in one direction when the brake is released is set to be smaller than the first length L ₁ regardless of the wear amount of the outer pad 14. . Thus, when the brake is released, the first gap Δ is reliably formed between the inner pad 10 and the disc 1 in the state where the second gap δ is formed between the outer pad 14 and the disc 1. And both pads 10, 14
The dragging with and is reliably prevented. Second length L
_{If 2} is set in the range of 1/5 to 4/5 of the first length L ₁ , the first and second gaps Δ and δ are appropriately formed to prevent dragging, and the second length L ₂ Is set so as to be formed with half of the first length L ₁ as the center, the first and second gaps Δ and δ are formed to be substantially the same, and drag can be prevented even better.

The elastic members 28a and 28b are provided with a plurality of other elastic members 28b at the same or different intervals as the one elastic member 28a and engage with each other.
The return movement amount (second length L ₂ ) in one direction of the caliper 5 at the time of releasing the braking can also be set by the resultant force of a and 28b. Furthermore, the opposing elastic members 28a, 28
It is also possible that b is formed as a protrusion on one side and elastically deformed only on the other side.

By the way, in the above embodiment, the elastic members 18, 28a, 28b are arranged between the pins 16 of the support 4 and the ears 15, 15 of the caliper 5 to make the caliper 5 elastic. Although it was slidably supported by the support 4 via the members 18, 28a, 28b, another dedicated member was provided between the support 4 and the caliper 5 instead of the pin 16 and the ears 15, 15. Each elastic member 18, 28 is provided between separate members.
It is also possible to obtain the same effect as that of the above embodiment by interposing a and 28b. Further, the present invention can be similarly applied to a floating caliper type disc brake in which the caliper 5 slides in the groove of the support 4. In these cases, the elastic members 18, 28
The shape of a and 28b is not limited to a ring shape, and it is possible to give a rectangular shape or another shape.

Further, with the elastic members 18 made of a rubber elastic body attached to the ears 15 and 15 of the caliper 5, the pins 16 are inserted into the holes 15a of the caliper 5 while slightly compressing the elastic members 18. At this time, the inner peripheral portion of the elastic member 18 may collide with the insertion end portion of the pin 16 and the elastic member 18 may be damaged. Therefore, as shown in FIG. 5, a chamfered portion 16c can be formed in advance on the peripheral edge of the insertion tip portion of each pin 16. As a result, the elastic member 18 is arranged at a predetermined position of each pin 16 while the peripheral edge of the elastic member 18 is guided by the chamfered portion 16c and gradually compressed. Thus,
The elastic member 18 can be assembled between the hole 15a and the pin 16 by elastically compressing it by a predetermined amount with almost no damage.

In the present invention, in order to eliminate the drag torque when the weight of the caliper 5 acts, the caliper 5 is elastically deformed to restore the caliper 5 when the braking is released. The second length L ₂ is moved back in one direction to form a second gap δ between the disc 1 and the outer pad 14, and a linear bearing 24 is interposed between the support 4 and the caliper 5. As shown in FIG. 5, the ear portion 1 of the caliper 5 can be seen from the above.
Gaps may be formed between the pins 5 and 15 and the pins 16 so that the caliper 5 can be floated as much as possible and supported by the support 4. Therefore, for example, in a floating caliper type disc brake for a vehicle, the caliper 5 is provided with the elastic members 18, 28a, 28b so as not to come into contact with the support 4 itself in at least a normal state other than when the vehicle is bound and rebounded. If it is supported, the linear bearing 24 can be omitted.

[0028]

As can be understood from the above description,
According to the floating caliper type disc brake of the present invention, a gap is reliably formed between the disc and both pads when braking is released. As a result, when the vehicle is traveling, the outer pad is prevented from always sliding on the disc to generate drag torque, which improves the fuel efficiency of the vehicle and eliminates the noise caused by the sliding. As a result, the product value will be significantly improved. The above effect can be satisfactorily obtained as the manufacturing and mounting accuracy of the disc is increased and the outer pad is less likely to be kicked by the rotating disc.

[Brief description of drawings]

FIG. 1 is a partially cutaway view showing a floating caliper type disc brake according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a sectional view showing a seal ring of the same.

FIG. 4 is an explanatory view of the action of the seal ring.

FIG. 5 is a sectional view showing an elastic member of the same.

FIG. 6 is an explanatory view of the action of the elastic member.

FIG. 7 is a cross-sectional view showing an elastic member according to another structural example.

FIG. 8 is an explanatory view of the action of the elastic member.

FIG. 9 is a view showing a half portion of the elastic member.

[Explanation of symbols]

1: Disc, 4: Support, 5: Caliper, 5a: Rear arm, 5b: Forearm, 6: Cylinder part, 8: Piston, 1
0: inner pad, 12: seal ring, 14: outer pad, 18, 28a, 28b: elastic member, 24:
Linear motion bearing, L ₁ : first length, L ₂ : second length,
Δ: first gap, δ: second gap.

Claims (2)

[Claims] 1. A support (4) fixed to a non-rotating part of a vehicle, a caliper (5) rotatably supported by the support (4), and a rear arm (5a) of the caliper (5).
Inner pad (10) pushed out by a piston (8) slidably fitted into the cylinder part (6) of the
And the outer pad (14) supported by the forearm (5b) of the caliper (5) and the cylinder portion (6) and the piston (8), and the wear amount of both pads (10, 14). And a seal ring (12) whose engagement position gradually changes according to the
While elastically deforming the piston, the piston (8) is projected in one direction and the caliper (5) is moved in the other direction with respect to the support (4) so that the inner pad (10) and the outer pad (14) work together with the wheel. The rotating disk (1) is clamped to generate a braking torque, and when the braking is released, the piston (8) is first moved by elastic deformation of the seal ring (12).
A floating caliper type disc brake that returns to the other direction by a length (L ₁ ) to form a gap between the disc (1) and the inner pad (10), the support (4) and the caliper ( 5), the elastic members (18, 28a, 28b) whose engaging positions gradually change according to the wear amount of the outer pad (14) are interposed, and during braking, the elastic members (18, 28a, 28b). The caliper (5) is moved in the other direction while elastically deforming the elastic member, and when the braking is released, the elastic members (18, 28a, 28)
The elastic return deformation of b) causes the caliper (5) to return to one direction by the second length (L ₂ ) shorter than the first length (L ₁ ) and when the braking is released, 1) and the inner pad (10) are formed with a first gap (Δ), and the disc (1) and the outer pad (14) are formed with a second gap (δ). Floating caliper type disc brake. 2. The floating caliper type of claim 1, wherein a linear bearing (24) for supporting the floating of the caliper (5) is interposed between the support (4) and the caliper (5). Disc brake.