JP2009115172A - Disc brake - Google Patents

Abstract

Disclosed is a disk brake that can prevent the occurrence of dragging when a disk rotor is idle by making the piston protrusion amount uniform during braking.
A carrier 5 for holding a pair of pads arranged on both sides of a disk rotor and a caliper 7 having a piston for pressing the pads are formed as separate blocks. The caliper 7 is supported by the carrier 5 via the support pins 21 so as to be slidable in the axial direction. A coil spring 24 for centering the caliper 7 is interposed between the carrier 5 and the caliper 7.
[Selection] Figure 6

Description

  The present invention relates to a disc brake used for vehicle wheel braking or the like.

A disc brake used for vehicle wheel braking has a disc rotor integrally attached to the wheel side, a cylinder portion provided in a caliper attached to the vehicle body side, and a piston housed in a bore of the cylinder portion serving as a friction material. The disk rotor is pressed through the pad.
As this type of disc brake, an opposed piston type disc brake is known in which pads are arranged on both sides of the disc rotor in the disc axial direction, and both pads are pressed by a pair of opposed pistons. In this disc brake, the caliper is fixed to a non-rotating portion of the vehicle, and a pair of pads are slidably supported by the caliper by pins along the disc axial direction, and both ends of the pad in the disc rotating direction are mounted on the caliper. A receiving part for supporting is provided, and the receiving part receives a braking torque acting on the pad. (For example, refer to Patent Document 1).
In this opposed piston type disc brake, the piston is retracted by a specified amount after releasing the brake by the retracting function of the piston seal inside the caliper, so that the controllability of the pad clearance is improved.
JP 2006-207655 A

  In this conventional opposed piston type disc brake, the caliper is fixed to a non-rotating portion of the vehicle and is immovable. Therefore, in the state of the rotor falling down due to the heat of the disc rotor during braking, the disc rotor against the caliper Since the axial position of the outer periphery deviates from the normal position, the protruding amount of each of the opposed pistons becomes non-uniform. Even if the braking is released in a state where the protrusion amount is uneven and each piston is retracted by a predetermined amount, the uneven protrusion amount is not solved. When the rotor itself is cooled by idling of the disk rotor in this state, the axial position of the outer periphery of the disk rotor returns to the normal position with respect to the caliper, but the movement direction at this time has a large amount of protrusion. It will be in the direction of the piston. For this reason, the pad corresponding to the piston on the side with the larger amount of protrusion comes into contact with the disk rotor, so-called dragging occurs, and fluctuations in the thickness of the disk rotor are promoted by this dragging and the wavy deformation during idling of the disk rotor. This contributes to brake judder.

  Therefore, the present invention is intended to provide a disc brake that can prevent the occurrence of dragging when the disc rotor idles by making the piston protrusion amount uniform during braking.

  As a means for solving the above-mentioned problems, the invention according to claim 1 is characterized in that a pair of pads disposed on both sides of the disk rotor is supported so as to be slidable in the axial direction of the disk rotor and braking torque is applied to the pads. And a caliper that is slidably supported by the carrier and has pistons that are opposed to each other to press the pair of pads, and between the carrier and the caliper. And a spring means for centering the center of the caliper in the axial direction of the disc rotor to the center of the disc rotor.

  A second aspect of the present invention is the disc brake according to the first aspect, wherein the spring means biases the caliper with respect to the carrier in a direction in which the caliper is separated from the disc rotor.

  According to a third aspect of the present invention, in the disc brake according to the first aspect, the spring means biases the caliper toward the carrier in the direction of approaching the disc rotor.

  According to a fourth aspect of the present invention, in the disc brake according to the first aspect, the spring means biases the pad with respect to the carrier in a direction in which the pad is separated from the disc rotor, and the piston is interposed through the pad. The urging force is transmitted to the caliper.

  According to a fifth aspect of the present invention, in the disc brake according to any one of the first to fourth aspects, a pad spring that presses the pad in the radial direction of the disc rotor is provided between the carrier and the pad. The pad spring is provided with the spring means.

According to the present invention, the caliper that holds the piston is slidably supported by the carrier that receives the braking torque through the pad, and the center of the caliper in the disc rotor axial direction is centered between the carrier and the caliper with respect to the disc rotor center. Therefore, even if the axial position of the outer circumference of the disk rotor is shifted from the normal position with respect to the caliper due to the thermal collapse of the rotor caused by the heat of the disk rotor during braking, the caliper It is possible to follow the positional deviation in the axial direction of the outer periphery of the rotor, make the protruding amount of each opposed piston uniform, and prevent unnecessary contact between the pad and the brake rotor, so-called dragging, when the disk rotor is idle. Can be prevented.
Therefore, since the fluctuation of the thickness of the brake rotor due to the drag can be prevented, the occurrence of brake judder due to the thickness fluctuation can be effectively suppressed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the disc brake 1, a main body block shown in the figure is integrally attached to an axle supporting knuckle (not shown) by bolt fastening, and a disc rotor 3 (see FIGS. 3 and 4) that rotates integrally with a wheel is viewed from both sides. A braking force is generated by pressing. In the following, description will be given with the state of attachment to the vehicle, the radial direction of the disk rotor 3 in this attachment state will be referred to as the disk radial direction, the axial direction of the disk rotor 3 will be referred to as the disk axial direction, and the disk rotor 3 The circumferential direction is referred to as the disk circumferential direction.

  The main body block of the disc brake 1 is directly coupled to the knuckle by a bolt, and has a carrier 5 that mainly holds the pads 4 and 4 pressed against the disc rotor 3, and a caliper 7 that has a piston 6 that presses the pads 4 and 4. And. The disc brake 1 has a substantially arc-shaped disc passage recess 8 (FIG. 6) that allows passage of the outer peripheral edge of the disc rotor 3 so as to straddle the carrier 5 and the caliper 7. The caliper 7 is arranged in a polymerized form.

  The disc brake 1 is an opposed piston type brake, and pads 4 and 4 held by the carrier 5 are arranged on both sides of the disc rotor 3 in the disc axial direction. It arrange | positions at both sides of the disk rotor 3, respectively so that the back part of the pad 4 may be pressed. In this embodiment, two pistons 6, 6 are arranged side by side in the disk rotation direction on one side of the disk rotor 3, and the two pistons 6, 6 arranged in parallel are arranged on the pad 4 that is horizontally long in the disk circumferential direction. The back is pressed.

The caliper 7 includes an inner side cylinder portion 9 and an outer side cylinder portion 10 on the inner side and the outer side in the vehicle width direction with the disc rotor 3 interposed therebetween, and a bore for slidably receiving the piston 6 in each of the cylinder portions 9 and 10. 11 (see FIGS. 2 to 4) is formed along the disk axial direction. The inner and outer cylinder portions 9 and 10 are connected to each other by a bridge portion 12 that straddles the radially outer side of the disk rotor 3, and is surrounded by the bridge portion 12 and the cylinder portions 9 and 10 on both sides. The area is a disk passage recess on the caliper 7 side. The bores 11 in the caliper 7 are connected to each other by a supply / discharge passage (not shown) in the caliper 7, and brake fluid is supplied through a supply / discharge plug 13 arranged in the cylinder portion 9 on the inner side of the caliper 7. It is supposed to be eliminated.
In the case of this embodiment, the inner side cylinder part 9 and the outer side cylinder part 10 are integrally formed with the bridge part 12. However, these may be formed separately and combined with bolts as appropriate.

  The caliper 7 as a whole is formed in a substantially arc shape when viewed from the disk axial direction as shown in FIGS. 3 and 4, but the inner side cylinder portion 9 and the outer side cylinder portion 10 are arranged in the disk circumferential direction. At both ends, arm portions 15 for supporting the caliper 7 on the carrier 5 are extended. The bridge portion 12 connecting the cylinder portions 9 and 10 is formed with a pair of long hole-shaped confirmation windows 30 penetrating in the disc radial direction as shown in FIGS. The reduction degree of the pad 4 can be confirmed through the confirmation window 30 from the outside in the direction.

  On the other hand, as shown in FIG. 6, the carrier 5 is provided with an inner wall 16 and an outer wall 17 on the inner side and the outer side in the vehicle width direction with the disc rotor 3 interposed therebetween, and both edges of both walls 16 and 17 in the disc circumferential direction. The bridge portions 18 and 18 are formed by forming an arc such that the portion is continuous with the arc of the outer shape of the caliper 7, and the arc portions on both edges extend in the disc axial direction so that the inner wall 16 and the outer wall 17 are Are interconnected.

As shown in FIGS. 3 and 4, the pad 4 and the back metal 29 that supports the pad 4 can be slid in the disk axial direction at the upper part of each disk circumferential direction center region of the inner wall 16 and the outer wall 17. Guide portions 16a, 16a, 17a and 17a are provided. Each of the guide portions 16 a and 17 a is a receiving portion that receives the braking torque of the pad 4.
In addition, pad springs 27a and 28a formed of a stainless steel plate for improving the slidability of the pads 4 and 4 are provided between the guide portions 16a and 17a and the back metal 29 of the pad 4. The pads 4 are biased outward in the radial direction of the disk rotor by the pad springs 27a and 28a.
As shown in FIGS. 3 and 4, an extension portion 19 is provided at the lower end of the inner wall 16 (the inner end in the disc radial direction), and two positions of the extension portion 19 spaced apart in the disc circumferential direction are provided. Fastening holes 2 for bolting the carrier 5 to the knuckle are provided.

  Further, as shown in FIG. 6, guide holes 20 along the disk axial direction are formed on the outer surfaces of both ends of the inner wall 16 and the outer wall 17 in the disk circumferential direction. Each guide hole 20 is a portion in which a support pin 21 projecting from each arm portion 15 of the caliper 7 is slidably inserted. When the support pin 21 is fitted in each guide hole 20, The caliper 7 is supported so as to be slidable in the disk axial direction with respect to the carrier 5. In the case of this embodiment, the guide hole 20 on the inner wall 16 side and the guide hole 20 on the outer wall 17 side correspond one-on-one, and the corresponding ones are arranged on the same axis. However, the number of guide holes 20 on the inner wall 16 side and the outer wall 17 side may be different, for example, one on the inner wall 16 side and two on the outer wall 17.

  Each support pin 21 is disposed between an insertion shaft portion 21a inserted into the guide hole 20, a hexagonal flange portion 21b contacting the back surface of the arm portion 15, and between the hexagonal flange portion 21b and the insertion shaft portion 21a. A boss portion 21c having a diameter larger than that of the portion 21a, and a screw hole 21d is provided on an end surface of the hexagon flange portion 21b. A fastening bolt 22 penetrating the arm portion 15 on the caliper 7 side is screwed into the screw hole 21d, whereby the support pin 21 is integrally coupled to the corresponding arm portion 15. In the case of this embodiment, the support pin 21 is fixed to the arm portion 15 by a separate fastening bolt 22. However, the support pin 21 is attached to the arm portion 15 in various other forms such as directly screwed to the arm portion 15. Is also possible.

  Further, boss portions 23 project from the opening edge portions of the respective guide holes 20 on the carrier 5 side (inner wall 16 and outer wall 17), and the boss portions 21 c of the support pins 21 corresponding to the respective boss portions 23. Face to face. And between the boss | hub parts 23 and 21c of the carrier 5 and each support pin 21, the coil spring 24 fitted by the outer periphery of the insertion shaft part 21a of the support pin 21 is interposed. The coil spring 24 is a spring means for centering the center position of the caliper 7 in the disk rotor axial direction to the center position in the thickness direction of the carrier 5 (disk axis direction). The spring load of the coil springs 24 on both sides in the thickness direction is It is set almost the same. In the case of this embodiment, the coil spring 24 is used as a compression spring so as to urge the arm portions 15 on both sides in the thickness direction of the caliper 7 in a direction in which the arm portions 15 are separated from the carrier 5. However, the spring means can also be used as a tension spring so as to bias the arm portion 15 of the caliper 7 in the direction in which the arm portion 15 is brought close to the carrier 5. Further, the spring means is not limited to the coil spring 24, and other various springs can be employed. In FIG. 6, reference numeral 25 denotes a bellows-like seal member mounted over the periphery of the boss portions 23 and 21 c on the caliper 7 side and the support pin 21 side.

  By the way, the distance L between the boss portions 23 and 21c in the initial state (when the brake is not operated) is an external force such as centrifugal force when the disk rotor 3 is heated due to frictional heat during braking or when the vehicle turns. Thus, when the caliper 7 is displaced in the disc axial direction with respect to the carrier 5, the disc rotor 3 is set so as not to contact the pad 4 during non-braking. An automatic adjustment mechanism for pad wear due to a piston seal (not shown) is provided between the piston 6 incorporated in the caliper 7 and the bore 11. For this reason, even when the pad 4 is worn due to use over time, the distance between the pad 4 and the disk rotor 3 does not change due to the wear.

  The spring load of the coil spring 24 is preferably larger than a value obtained by integrating the centrifugal force when the vehicle turns and the mass of the caliper 7, but may be smaller than that in consideration of the spring assembly property. . That is, in this embodiment, since the distance L between the boss portions 23 and 21c is set to a distance at which the pad 4 and the disk rotor 3 do not contact during non-braking as described above, the coil spring 24 Even when an external force greater than the spring load is applied, the boss portions 23 and 21c function as a displacement regulating stopper, and unnecessary contact between the pad 4 and the disk rotor 3, that is, so-called dragging can be avoided.

  In the disc brake 1 configured as described above, when brake fluid is supplied to the bores 11 of the cylinder portions 9 and 10 during braking, the pistons 6 in the bores 11 are moved forward by receiving fluid pressure, 6 advances the corresponding pad 4 through the back metal 29. As a result, the pads 4 on both sides of the disk rotor 3 are similarly pressed against both surfaces of the disk 3, thereby applying a braking force.

  On the other hand, the braking torque acting on the pad 4 at this time is received by the guide portion of the carrier 5. Although this braking torque acts as a stress on the carrier 5, the carrier 5 and the caliper 7 are formed separately, and are engaged by fitting with the guide hole 20 and the support pin 21, and thus are caused by the braking torque. The stress does not act directly on the caliper 7. That is, in the disc brake 1, the guide portion of the carrier 5 regulates the displacement of the pad 4 in the disc circumferential direction and the disc radial direction, and the caliper 7 side is brought into contact with the back metal 29 integrated with the pad 4 only by the piston 6. Therefore, the caliper 7 is not directly subjected to the stress caused by the braking torque.

  For this reason, in the disc brake 1, the cylinder portions 9 and 10 of the caliper 7 do not bend and deform due to the stress caused by the braking torque, and the piston 11 is prevented from sliding due to the deformation or inclination of the bore 11. The problem that the pressing direction of the piston 6 is inclined does not occur. Therefore, in this disc brake 1, a stable operation of the piston 6 can always be obtained, and the occurrence of brake squeal can be prevented in advance.

Further, when axial displacement of the disk rotor 3 occurs due to frictional heat or the like due to repeated braking, and the position of the outer periphery of the disk rotor 3 with respect to the caliper 7 shifts in the axial direction, one pad 4 is first moved to the disk during braking. When abutting against the rotor 3, the entire caliper 7 is displaced to the side where the one pad 4 is present due to the abutting reaction force, so that the pads 4 on both sides abut against both sides of the disc rotor 3 uniformly. .
Therefore, in this disc brake 1, the protruding amounts of the opposed pistons 6, 6 are uniform regardless of the axial deformation of the disc rotor 3, and stable braking can be obtained on both sides of the disc rotor 3. At the same time, it is possible to prevent uneven wear of the pad 4, fluctuations in the thickness of the disk rotor and occurrence of judder.

  Further, the disc brake 1 is configured such that the caliper 7 holding the piston 6 is centered with respect to the carrier 5 by the coil spring 24. Even after cooling and returning to the normal axial position, the caliper 7 can be quickly returned to the initial position by the force of the coil spring 24. Further, it is possible to suppress the caliper 7 from being greatly displaced by the force of the coil spring 24 due to an external force such as a centrifugal force at the time of turning of the vehicle, and by the force of the coil spring 24 when the external force is released. It is possible to quickly return to the initial position. Accordingly, it is possible to prevent so-called dragging, in which the pad 4 comes into contact with the rotating disk rotor 3 due to unnecessary movement of the caliper 7.

  Further, in particular, in this embodiment, the boss portion 23 on the carrier 5 side and the boss portion 21c of the support pin 21 are disposed to face each other, and these boss portions 23 and 21c regulate excessive displacement of the caliper 7 with respect to the carrier 5. Therefore, unnecessary contact of the pad 4 with the disk rotor 3 can be prevented more reliably.

In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary.
For example, in the above embodiment, the coil spring 24 as a spring means is disposed between the boss portion 23 on the carrier 5 side and the arm portion 15 on the caliper 7 side to center the caliper 7. Centering may be performed by forming a biasing piece for biasing the caliper 7 in the direction of separating the caliper 7 from the disk rotor 3 or the direction of bringing the caliper 7 close to the disk rotor 3 in the pad springs 27a and 28a. Further, a pad return spring that urges the pad 4 in a direction away from the disk rotor 3 with respect to the carrier 5 is provided on the back metal 29 attached to each of the left and right pads 4, and the spring force of each pad return spring is changed to a piston. 6 may be applied to the caliper 7 as a biasing force for centering.

1 is a perspective view of a disc brake according to an embodiment of the present invention. The top view of the disc brake of the embodiment. The A arrow directional view of FIG. 2 of the disc brake of the embodiment. The arrow B view of FIG. 2 of the disc brake of the embodiment. The arrow C view of FIG. 2 of the disc brake of the embodiment. Sectional drawing corresponding to the DD cross section of FIG. 2 of the disc brake of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Disc brake 3 ... Disc rotor 4 ... Pad 5 ... Carrier 6 ... Piston 7 ... Caliper 24 ... Coil spring (spring means)
27a, 28a ... pad spring

Claims (5)

A carrier for supporting a pair of pads arranged on both sides of the disk rotor so as to be slidable in the axial direction of the disk rotor and receiving a braking torque on the pads;
The carrier comprises a caliper that is slidably supported by the carrier and has a piston provided oppositely to press the pair of pads.
A disc brake characterized in that a spring means is provided between the carrier and the caliper for centering the disc rotor axial center of the caliper to the disc rotor center.   2. The disc brake according to claim 1, wherein the spring means biases the caliper with respect to the carrier in a direction in which the caliper is separated from the disc rotor.   2. The disc brake according to claim 1, wherein the spring means biases the caliper toward the carrier in a direction in which the caliper approaches the disc rotor.   The said spring means urges | biases the said pad with respect to the said carrier in the direction spaced apart from the said disk rotor, and transmits urging | biasing force from the said piston to the said caliper via the said pad. Disc brake.   5. A pad spring for pressing the pad in the radial direction of the disk rotor is provided between the carrier and the pad, and the spring means is provided on the pad spring. Disc brake according to any one of the above.

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