JP2008275034A - Disc brake device - Google Patents

Abstract

Disclosed is a disc brake device capable of holding a piston in an appropriate adjustment position and suppressing brake noise.
In a disc brake device that applies a braking force to a wheel when each of a foot brake and a parking brake is operated, an initial position adjusting mechanism is configured such that the initial position of the piston 26 is parallel to the propulsion direction when the piston 26 rotates. Move to. The anti-rotation pin 36 is provided so as to protrude from the surface of the brake pad 32 on the piston 26 side, and is inserted into the anti-rotation groove 26a. The anti-rotation groove 26a is arranged in the direction of rotation of the disk rotor in a portion other than the center of the piston 26 so as to restrict the rotation of the piston 26 while allowing the brake pad 32 to move in the direction along the direction of rotation of the disk rotor. It is formed so as to extend long along.
[Selection] Figure 3

Description

  The present invention relates to a disc brake device, and more particularly to a disc brake device having both functions of a foot brake and a parking brake.

A so-called built-in caliper type disc brake device having both functions of a foot brake and a parking brake is known. In such a disc brake device, a mechanism for adjusting the sliding direction position of the piston that presses the brake pad is generally used so that the surface of the brake pad and the surface of the disc rotor are kept at an appropriate distance even when the brake pad is worn. Is provided. However, by providing such an adjustment mechanism, there is a possibility that the piston, which has been adjusted to an appropriate position when the piston rotates for some reason, moves in the sliding direction. For this reason, for example, a technique has been proposed in which a groove is provided in the piston, and an engagement protrusion provided on a brake pad is inserted into the groove to suppress the rotation of the piston (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 7-158668

  When the engaging protrusion is inserted into the groove in the manner described in the above-mentioned patent document, there is a possibility that the movement of the brake pad in the disc rotor rotation direction is also restricted at the same time. Furthermore, as a result of the inventor's earnest research and development, it has been found that such movement restriction of the brake pad may lead to brake squeal.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a disc brake device capable of holding a piston in an appropriate adjustment position and suppressing brake noise.

  In order to solve the above-described problems, a disc brake device according to an aspect of the present invention is configured such that when each of the foot brake and the parking brake is operated, the piston propels and the brake pad is pressed against the disc rotor so that the braking force is applied to the wheel. The disc brake device that provides the control device includes a regulating means for regulating the rotation of the piston while allowing the brake pad to move in the direction along the rotation direction of the disc rotor.

  According to this aspect, by enabling the movement of the brake pad in the direction along the rotation direction of the disc rotor, it is possible to suppress the occurrence of the squealing of the brake caused by locking the rotation of the piston.

  You may further provide the initial position adjustment mechanism which adjusts the initial position of the propulsion direction of a piston in the state in which neither a foot brake nor a parking brake is act | operating. The initial position adjusting mechanism may move the initial position of the piston in a direction parallel to the propulsion direction by rotating the piston.

  According to this aspect, the initial position of the piston can be appropriately held by restricting the rotation of the piston.

  The regulating means may have a groove part and a convex part inserted into the groove part. The convex portion is provided on the piston side surface of the brake pad so as to protrude from the brake pad, and the groove portion extends long along the rotational direction of the disk rotor in the portion other than the center of the brake pad side surface of the piston. It may be formed.

  According to this aspect, by providing such a groove part and a convex part, it becomes possible to easily restrict the rotation of the piston while allowing the brake pad to move in the direction along the rotation direction of the disk rotor. .

  A removal groove that connects the groove portion and the outer periphery of the piston may be further provided so that the convex portion can pass when the piston is moved in a direction perpendicular to the propulsion direction and retracted from the position on the piston side of the brake pad.

  When replacing a brake pad, the piston is moved away from the back side of the brake pad by moving the piston in a direction perpendicular to the propulsion direction with respect to the brake pad, and the brake pad is often removed from the back side. . According to this aspect, when the brake pad is exchanged by such a method, it is possible to avoid the fact that the groove portion and the convex portion are engaged and the piston cannot be moved in the direction perpendicular to the propulsion direction.

  The removal groove has a circular arc shape between the groove and the outer periphery of the piston so that the piston can be moved in a direction perpendicular to the propulsion direction so as to rotate around a predetermined location and retract from the position on the piston side of the brake pad. It may be connected to.

  At present, most of the disc brake devices adopt a structure in which the caliper unit is supported by two slide pins. When replacing the brake pad, one slide pin is pulled out and the other remaining one is used. In many cases, the caliper unit is retreated upward by moving the piston around the slide pin in a direction perpendicular to the propulsion direction. According to this aspect, when the brake pad is replaced by such a method, it is possible to avoid that the groove and the convex portion are engaged and the piston cannot be moved in the direction perpendicular to the propulsion direction.

  According to the disc brake device of the present invention, it is possible to hold the piston in an appropriate adjustment position and suppress brake noise.

  Hereinafter, embodiments of the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing in detail the configuration of the disc brake device 10 according to the first embodiment. The disc brake device 10 employs a built-in caliper type disc brake device capable of applying a braking force to the wheel when each of the foot brake and the parking brake is operated. One built-in caliper type disc brake device 10 is provided corresponding to each of the left rear wheel and the right rear wheel. The right front wheel and the left front wheel are each provided with a normal disc brake device that does not have a parking brake function. In FIG. 1, the left direction is the vehicle outer direction, and the right direction is the vehicle inner direction.

  The disc brake device 10 includes a caliper unit 12, a brake pad 32, and a disc rotor 34. The caliper unit 12 includes a caliper body 20, a piston 26, a wheel cylinder 14, and a parking brake mechanism 40.

  The disk rotor 34 is formed in a disk shape. Friction sliding surfaces 34 a are provided on both side surfaces of the disc rotor 34 in a range of a predetermined length from the vicinity of the outer periphery of the disc rotor 34 to the radially inward direction.

  The caliper body 20 has a cylinder housing 20a and a claw portion 20b. The cylinder housing 20a and the claw portion 20b face each other and are partially coupled to each other in part. Thus, the caliper body 20 is formed in a U shape.

  The piston 26 is formed in a cup shape having an outer diameter substantially the same as the inner diameter of the cylinder portion 20c. The wheel cylinder 14 is formed in a cup shape having an outer diameter substantially the same as the inner diameter of the piston 26. The wheel cylinder 14 is inserted into the piston 26 so that the opening side is in the same direction.

  Inside the cylinder housing 20a, there is provided a cylinder portion 20c that is a cylindrical space portion that opens toward the claw portion 20b. The piston 26 in which the wheel cylinder 14 is inserted is fitted into the cylinder portion 20c so that the outer bottom surface faces the claw portion 20b. Thus, a cylinder chamber in which hydraulic fluid is accommodated is formed by the inner bottom surface of the cylinder portion 20c and the inner periphery of the wheel cylinder 14.

  The caliper body 20 according to the first embodiment is a floating type. The caliper body 20 is supported by a mounting (not shown) by two slide pins (not shown) so as to be movable within a predetermined range in the left-right direction of the vehicle. At this time, the caliper body 20 is supported by the mounting so that the cylinder housing 20a is located in the vehicle interior direction, the claw portion 20b is located in the vehicle outer direction, and the central axis of the cylinder portion 20c is directed in the vehicle left-right direction. The caliper body 20 is disposed such that the friction sliding surface 34a of the disk rotor 34 is located between the claw portion 20b and the cylinder portion 20c.

  One brake pad 32 is disposed between the friction sliding surface 34a on the vehicle inner side and the piston 26, and between the friction sliding surface 34a on the vehicle outer side and the claw portion 20b. The brake pad 32 is restricted from moving in the radial direction of the disc rotor 34 by mounting, and is restricted from moving in the circumferential direction of the disc rotor 34 within a predetermined range. However, each of the brake pads 32 is supported by the mounting so as to be movable in the axial direction of the disk rotor 34, and both the foot brake and the parking brake are not operated. The rotor 34 is disposed at an initial position which is a position separated from the frictional sliding surface 34 a of the rotor 34.

  When the wheel cylinder pressure, which is the hydraulic fluid pressure in the wheel cylinder 14, is increased, the piston 26 is propelled toward the brake pad 32 on the vehicle inner side, and the brake pad 32 on the vehicle inner side is first pushed by the piston 26 and the vehicle. It is pressed against the internal friction sliding surface 34a. Next, the entire caliper body 20 slides in the vehicle interior direction by the reaction force, and the brake pad 32 on the vehicle exterior side is pushed by the claw portion 20b and is brought into contact with the friction slide surface 34a on the vehicle exterior side. Thus, a braking force is applied to the wheel by the frictional force between the brake pad 32 and the frictional sliding surface 34a of the disk rotor 34.

  When the wheel cylinder pressure in the wheel cylinder 14 is reduced, the piston 26 is propelled in a direction away from the claw portion 20b. As a result, each of the brake pads 32 is returned to the initial position, and the braking force applied to the wheels is released by being separated from the friction sliding surface 34a of the disk rotor 34.

  The parking brake mechanism 40 includes a spindle 22, a sleeve 24, a return spring 25, a connecting link 28, and a spindle lever 30. The wheel cylinder 14 is provided with an insertion hole opening in the axial direction on the piston 26 side, and a sleeve 24 formed in a cylindrical shape is inserted into the insertion hole so as to be slidable in the axial direction.

  Here, the spindle 22, the sleeve 24, and the return spring 25 constitute an initial position adjusting mechanism 16 that adjusts the initial position in the propulsion direction of the piston when both the foot brake and the parking brake are not operated. The sleeve 24 is disposed so as to contact the inner bottom surface of the piston 26. The sleeve 24 is provided with a screw hole penetrating in the axial direction. A male screw portion is formed on the outer periphery of the spindle 22, and the spindle 22 is screwed into the screw hole of the sleeve 24. The sleeve 24 is formed with a locking portion that protrudes radially outward. A return spring 25 is disposed between the locking portion and the inner bottom surface of the piston 26. The return spring 25 urges the spindle 22 and the wheel cylinder 14 against the piston 26 in a direction away from the inner bottom surface of the piston 26.

  As the brake pad 32 wears, the position in the propulsion direction of the piston 26 when the foot brake is operated moves to the left in FIG. For this reason, the spring force of the return spring 25 is weakened, and the friction force between the inner bottom surface of the piston 26 and the sleeve 24 is reduced by the return spring 25. At this time, the sleeve 24 rotates with respect to the spindle 22, and the axial position of the spindle 22 gradually moves toward the brake pad 32 with respect to the sleeve 24. Thus, the initial position adjusting mechanism 16 appropriately adjusts the position of the piston 26 in the propulsion direction, and appropriately maintains the distance between the brake pad 32 and the frictional sliding surface 34a of the disk rotor 34.

  One end of a connecting link 28 is in contact with the other end of the spindle 22. The spindle lever 30 is formed in a cylindrical shape, and a concave portion is provided on the outer peripheral portion thereof. The spindle lever 30 is inserted through the hole of the caliper body 20 so that the axial direction thereof is perpendicular to the axial direction of the piston 26. The other end of the connecting link 28 is in contact with the recess of the spindle lever 30.

  The other end of the wire whose one end is coupled to the parking brake lever is joined to the spindle lever 30. When the parking brake lever is turned to operate the parking brake and the wire is pulled, the spindle lever 30 is turned. When the spindle lever 30 rotates, the connecting link 28 slides from the concave portion of the spindle lever 30 toward the outer peripheral surface, thereby pushing the connecting link 28 and the spindle 22 toward the opening side of the cylinder portion 20c. As a result, the piston 26 is pushed out through the sleeve 24 and the return spring 25 in a direction protruding from the opening of the cylinder portion 20c, and the brake pad 32 is caused to slide on the disc rotor 34 in the same manner as when the wheel cylinder pressure is increased. A pressing force is applied to the wheels by pressing against the moving surface 34a.

  When the parking brake lever is rotated in the reverse direction to release the operation of the parking brake, the pulled wire is loosened and the spindle lever 30 is rotated in the reverse direction to the original initial position. As a result, the piston 26 is retracted into the cylinder portion 20c, and the brake pad 32 is separated from the friction sliding surface 34a of the disk rotor 34 in the same manner as when the wheel cylinder pressure is reduced, and the braking force applied to the wheel is released. Is done.

  Here, since the initial position adjusting mechanism 16 according to the first embodiment adjusts the initial position of the piston 26 by screwing the spindle 22 and the sleeve 24, the initial position of the piston 26 is rotated by the rotation of the piston 26. May be moved in a direction parallel to the propulsion direction. However, if the initial position of the piston 26 moves in this manner, it becomes difficult to maintain an appropriate distance between the brake pad 32 and the frictional sliding surface 34a of the disk rotor 34, and therefore it is necessary to suppress the rotation of the piston 26. There is. Here, it is conceivable that the rotation of the piston 26 is restricted by providing a detent pin on the rear surface of the brake pad 32 and inserting it into a groove provided on the brake pad 32 surface of the piston 26. However, if the rotation prevention pin is inserted into the groove to restrict the movement of the brake pad 32 in the direction parallel to the rotation direction of the disc rotor 34, the inventors have the possibility that the brake may squeal. It became clear as a result of earnest research and development.

  For this reason, the disc brake device 10 according to the first embodiment has a non-rotating groove and a detent that restrict the rotation of the piston 26 while allowing the brake pad 32 to move in a direction along the rotational direction of the disc rotor 34. Provide pins. This will be described in detail below with reference to FIG.

  FIG. 2 is a cross-sectional view taken along the line PP of FIG. 1 in the disc brake device 10 according to the first embodiment. For ease of understanding, FIG. 2 shows a state in which a part of the brake pad 32 is cut away so that the piston 26 can be seen.

  A detent pin 36 is provided on the back surface of the brake pad 32 so as to protrude from the back surface of the brake pad 32. Further, a rotation-preventing groove 26a is provided on the surface of the piston 26 on the brake pad 32 side. The non-rotating groove 26 a is formed on a straight line passing through the center of the piston 26 at two locations across the center of the piston 26 in a portion other than the center of the surface of the piston 26 on the brake pad 32 side. Further, the anti-rotation groove 26 a is formed as an elongated groove that is long in the linear direction passing through the center of the piston 26 and has a width slightly larger than the diameter of the anti-rotation pin 36. When the disc brake device 10 is assembled and the brake pad 32 and the piston 26 are disposed at appropriate positions, the rotation prevention groove 26a is in a state where the rotation prevention pin 36 is inserted. At this time, the anti-rotation groove 26 a is formed to extend long along the rotation direction of the disk rotor 34. In the first embodiment, each of the anti-rotation grooves 26 a is about twice as long as the diameter of the anti-rotation pin 36.

  As described above, since the rotation prevention groove 26a is formed long along the rotation direction of the disk rotor 34, the brake pad 32 can be moved in a direction parallel to the rotation direction of the disk rotor 34. The occurrence of brake squeal due to the provision of the stop groove 26a and the rotation stop pin 36 can be suppressed.

  In the state in which the rotation prevention pin 36 is inserted into the rotation prevention groove 26a, the length of the rotation prevention pin 36 and the rotation prevention groove 26a are prevented so that the engagement of the piston 26 is not released even if the piston 26 moves in the axial direction. The depth is set. Therefore, when replacing the brake pad 32, it is necessary to retract the caliper unit 12 including the piston 26 from the back side of the brake pad 32.

  Therefore, a removal groove 26b is formed on the surface of the piston 26 on the brake pad 32 side. The removal groove 26b moves the piston 26 in a direction perpendicular to the propulsion direction so that the rotation prevention pin 36 can pass when the piston 26 is retracted from the position of the brake pad 32 on the piston side. Connect the outer periphery.

  The removal groove 26b according to the first embodiment has a width that is slightly larger than the diameter of the rotation prevention pin 36, and the rotation prevention groove 26a and the outer periphery of the piston 26 are arranged with the rotation prevention pin 36 inserted into the removal groove 26b. It is formed to extend in the vertical direction so as to be linearly connected vertically downward. As a result, when the caliper unit 12 is moved vertically upward so that the brake pad 32 can be removed from the back side, the anti-rotation pin 36 can be moved within the removal groove 26b, and the anti-rotation pin 36 is prevented from rotating. Locking in the groove 26a can be avoided.

(Second Embodiment)
FIG. 3 is a cross-sectional view taken along the line PP of FIG. 1 in the disc brake device 10 according to the second embodiment. For easy understanding, FIG. 3 shows a state in which a part of the brake pad 32 is cut away so that the piston 26 can be seen. Unless otherwise specified, the configuration of the disc brake device 10 according to the second embodiment is the same as the configuration of the disc brake device 10 according to the first embodiment.

  Currently, in many disc brake devices, a caliper unit is supported by two slide pins for mounting. In the disc brake device having such a configuration, when replacing the brake pad, one of the slide pins is pulled out, and the caliper unit is moved upward around the remaining slide pin, whereby the brake pad 32 is moved. In many cases, the piston 26 is retracted from the rear surface side of the brake pad 32 so that the replacement can be performed.

  The disc brake device 10 according to the second embodiment also has two slide pins, and it is preferable that the method for retracting the piston 26 as described above can be performed. For this reason, the removal groove 26b according to the second embodiment connects the rotation stop groove 26a and the outer periphery of the piston 26 in an arc shape centering on the slide pin 38 so as to be adapted to such a retracting method of the piston 26. The removal groove 26b is the same as in the first embodiment in that the width of the removal groove 26b is slightly larger than the diameter of the anti-rotation pin 36. Thus, in order to replace the brake pad 32, when the caliper unit 12 is moved upward to rotate around the slide pin 38 and the piston 26 is moved in the direction perpendicular to the propulsion direction, the detent pin 36 can be moved in the removal groove 26b, and the caliper unit 12 can be easily rotated around the slide pin 38.

(Third embodiment)
FIG. 4 is a cross-sectional view taken along the line PP of FIG. 1 in the disc brake device 10 according to the third embodiment. For easy understanding, FIG. 4 shows a state in which a part of the brake pad 32 is cut away so that the piston 26 can be seen. Unless otherwise specified, the configuration of the disc brake device 10 according to the third embodiment is the same as the configuration of the disc brake device 10 according to the second embodiment.

  The piston 26 according to the third embodiment is provided with two recesses 26c on the surface on the brake pad 32 side with the center of the piston 26 interposed therebetween. Each of the recesses 26c is obtained by removing a portion on the outer side in the radial direction of the piston 26 remaining when the rotation preventing groove 26a and the removal groove 26b according to the second embodiment are formed. As a result, the material of the part can be saved, and a situation such as a crack of the part can be avoided.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention. Here are some examples.

  In the first to third embodiments, two rotation-preventing grooves 26 a or recesses 26 c are provided across the center of the piston 26 in order to restrict the rotation of the piston 26 in both the right and left rotation directions. However, the anti-rotation groove 26a or the recess 26c may be provided at one location. Thereby, for example, when the direction in which the piston 26 is easy to rotate is determined in advance from the structure of the initial position adjusting mechanism 16, the rotation in that direction can be restricted, and the initial position of the piston 26 is held at an appropriate position. Is possible.

It is sectional drawing which shows the structure of the disc brake apparatus which concerns on 1st Embodiment in detail. It is PP sectional drawing of FIG. 1 in the disc brake device which concerns on 1st Embodiment. FIG. 6 is a cross-sectional view taken along the line PP of FIG. 1 in the disc brake device according to the second embodiment. FIG. 7 is a cross-sectional view taken along the line PP of FIG. 1 in a disc brake device according to a third embodiment.

Explanation of symbols

  10 disc brake device, 12 caliper unit, 14 wheel cylinder, 16 initial position adjustment mechanism, 20 caliper body, 20a cylinder housing, 20b claw part, 20c cylinder part, 22 spindle, 24 sleeve, 25 return spring, 26 piston, 26a rotation Stop groove, 26b Detach groove, 26c Recess, 28 Connecting link, 30 Spindle lever, 32 Brake pad, 34 Disc rotor, 34a Friction sliding surface, 36 Non-rotating pin, 38 Slide pin, 40 Parking brake mechanism

Claims (5)

In a disc brake device that applies a braking force to a wheel by propelling a piston and pressing a brake pad against a disc rotor when each of a foot brake and a parking brake is operated,
A disc brake device comprising a regulating means for regulating the rotation of the piston while allowing the brake pad to move in a direction along the rotation direction of the disc rotor. An initial position adjusting mechanism that adjusts an initial position in the propulsion direction of the piston when neither the foot brake nor the parking brake is operated;
2. The disc brake device according to claim 1, wherein the initial position adjusting mechanism moves the initial position of the piston in a direction parallel to the propulsion direction by rotating the piston. The restricting means has a groove part and a convex part inserted into the groove part,
The convex portion is provided on the piston side surface of the brake pad so as to protrude from the brake pad,
3. The disc brake device according to claim 1, wherein the groove portion is formed so as to extend long along a rotation direction of the disc rotor in a portion other than the center of the surface on the brake pad side of the piston.   A removal groove that connects the groove and the outer periphery of the piston so as to allow the protrusion to pass when the piston is moved in a direction perpendicular to the propulsion direction and retracted from the position on the piston side of the brake pad. 4. The disc brake device according to claim 3, wherein   The removal groove is formed by connecting the groove portion and the outer periphery of the piston so that the piston can be moved in a direction perpendicular to the propulsion direction so as to be rotated about a predetermined position and retracted from the piston side position of the brake pad. The disc brake device according to claim 4, wherein the disc brake device is connected in an arc shape centered on a predetermined portion.

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