JP2005325969A - Brake device used for service and parking in common - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake device for parking brake device used for service and parking in common capable of enhancing reliability of parking brake. <P>SOLUTION: The service and parking brake device A is provided with a cup-like piston 19 incorporated into a cylinder 17a, a braking lining 13a which engages with a disk rotor 11 by the cup-like piston 19 being pushed and moved by braking liquid which is supplied to a braking chamber R1, a truncated conical block 25 incorporated within the brake chamber R1 and a rod 27 penetrating an axial portion of the truncated conical block 25. The device is also provided with a spindle 29 extending from the rod 27 in the radial direction of the piston within the cup-like piston 19, a wedge member 31 incorporated on the supporting shaft 29 so as to make it possible to move in the radial direction of the piston and to make it impossible to move in the axial direction of the cylinder and a control piston 33 controlling an axial motion of the rod 27. The inner peripheral portion of the cup-like piston 19 has a contact surface S of the wedge 31 which takes a construction of enlarging the diameter toward the opening end of the cup-like piston 19 and each of which the outer peripheral portion is capable of engaging/disengaging. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention can be employed as a brake device for a vehicle, and is not only used as a service brake but also mechanically locked after generating a braking force by hydraulic pressure when used as a parking brake. Thus, the present invention relates to a service and parking brake device configured to obtain a braking force.

This type of common and parking brake device is described, for example, in Patent Document 1 below, which includes a cylinder having a cup-shaped piston disposed opposite to a brake pad assembly, and a cup-shaped piston. A frustoconical block fixed to the bottom wall of the cylinder with a certain distance from the inner circumference, and an inner circumference of the cup-shaped piston inserted between the frustoconical block and the bottom of the cup-shaped piston. A second piston having a slightly smaller diameter, and a tapered surface that is movable in the radial direction and fixedly attached in the axial direction, and is arranged so as to surround the conical surface of the frustoconical block. A plurality of wedge members, and a piston extending from the second piston along the axial center thereof, penetrating the frustoconical block, and having a tip projecting outside the cylinder. And a wedge member that moves in the axial direction together with the second piston by the cam means, and a cam means that regulates a stroke of the second piston by contacting the tip of the piston shaft. A service and parking brake device is shown that is allowed to move between a position where it is pressed against the inner surface of the cup-shaped piston and a position where the pressure is released.
Japanese Patent Publication No. 61-5017

  In the above-mentioned common and parking brake device of Patent Document 1, the inner peripheral surface of the cup-shaped piston is a cylindrical surface, and the contact surface with which the outer peripheral portion of each wedge member contacts is parallel to the moving direction of the cup-shaped piston. At the position where each wedge member is pressed against the inner surface of the cup-shaped piston (the parking brake operating position that restrains the movement of the cup-shaped piston), the cup-shaped piston is pushed back by the reaction force from the brake pad assembly, Even if slippage occurs in the direction in which the braking force is released between the contact surface of the outer peripheral portion and the cup-shaped piston, the restraining force by each wedge member does not increase, and the pressing and holding force of the cup-shaped piston by each wedge member decreases as it is. There is a concern about the reliability of the parking brake.

  In the common and parking brake device of Patent Document 1 described above, since the inner peripheral surface of each wedge member is tapered, the tapered inner peripheral surface of each wedge member is a frustoconical block at a specific position. Although it is in surface contact with the conical surface, it is in a line contact state at a position other than the specific position, and an excessive surface pressure may be generated at the engagement portion between each wedge member and the truncated cone block.

  The present invention has been made to solve the above-described problems, and is a cup-shaped piston that is assembled to a cylinder so as to be movable in the cylinder axial direction and forms a brake chamber in the cylinder, and the cup-shaped piston. Includes a brake lining that is pushed by the brake fluid supplied to the brake chamber to engage the braked rotating body and brake the braked rotating body. A frustoconical block that is coaxially arranged in the cup-shaped piston and fixed to the bottom wall of the cylinder, and is assembled so as to penetrate through the axial center of the frustoconical block and moves in the cylinder axis direction. A possible rod, a plurality of support shafts provided at the inner end of the rod on the brake chamber side and extending in the radial direction of the piston within the cup-shaped piston, It is assembled to the shaft so that it can move in the piston radial direction but not in the cylinder axial direction, and is arranged so as to surround the conical surface of the frustoconical block, and engages with the frustoconical block at the inner periphery. And a plurality of wedge members movable along the hypotenuse of the conical surface and a stroke control means provided on the outer end side of the rod for controlling the axial movement of the rod. A brake device, wherein a wedge contact surface is formed on an inner peripheral portion of the cup-shaped piston so that an outer peripheral portion of each wedge member can be engaged and disengaged in a shape expanding toward an opening end portion of the cup-shaped piston. It is characterized by being formed.

  In the service and parking brake device according to the present invention, the outer peripheral portion of each wedge member that is engaged with the frustoconical block at the inner peripheral portion is formed at the inner peripheral portion of the cup-shaped piston. Since the cup-shaped piston is not restrained from moving in the cylinder axial direction by each wedge member in the state of being separated from the wedge contact surface, the cup-shaped piston can be freely moved to the cylinder shaft by supplying and discharging brake fluid to and from the brake chamber. It is possible to move in the direction, and the brake device can be used as a service brake.

  In addition, when the brake fluid is supplied to the brake chamber and the brake lining is pushed by the cup-shaped piston to brake the braked rotating body, the rod is moved from the fixed position to the cylinder shaft by the operation of the stroke control means. When moving in the direction, each wedge member moves in the cylinder axial direction together with the rod and moves outward in the piston diameter with respect to each support shaft, and each wedge engaged with the frustoconical block at the inner peripheral portion The outer peripheral part of the member is engaged and pressed against the wedge contact surface formed on the inner peripheral part of the cup-shaped piston, and each wedge member restrains the movement of the cup-shaped piston in the cylinder axial direction. In this state, each wedge member is fitted between the conical surface of the frustoconical block and the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston, thereby mechanically coupling the frustoconical block and the cup-shaped piston. Therefore, even when the brake fluid is discharged from the brake chamber, the cup-shaped piston is held in the operating position (position where the brake lining brakes the braked rotating body), and the brake device is used as a parking brake. .

  By the way, in the regular and parking brake device according to the present invention, the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston has a shape that expands toward the opening end portion of the cup-shaped piston. Is used as a parking brake, and the cup-shaped piston is pushed back by the reaction force from the brake lining while the brake lining pushed by the cup-shaped piston is braking the braked rotating body, The cup-shaped piston moves slightly even if slippage occurs in the direction in which the braking force is released between the outer periphery of the wedge member and the wedge-contact surface of the cup-shaped piston, that is, toward the open end of the cup-shaped piston. As a result, the engagement pressure contact force (surface pressure) between the wedge contact surface of the cup-shaped piston and the outer peripheral portion of each wedge member increases, and the inner peripheral portion of each wedge member and the frustoconical block Tsu engagement pressure contact force between the conical surfaces of the click (surface pressure) is increased. For this reason, the binding force of the cup-shaped piston by each wedge member increases, and each wedge member restricts further movement of the cup-shaped piston. Therefore, the state in which the pressing and holding force of the cup-shaped piston by each wedge member is increased is maintained, the decrease of the parking brake force is prevented, and the reliability of the parking brake can be improved.

  In the service and parking brake device according to the present invention, a plurality of receiving grooves are formed on the conical surface of the truncated cone-like block so as to extend along the oblique sides and slidably receive the inner peripheral portion of each wedge member. When the cross-sectional shapes of the respective receiving grooves are substantially the same in the moving direction of the respective wedge members, the engaging portions of the respective wedge members and the truncated cone-like blocks are irrespective of the movement of the respective wedge members. Then, the surface contact state is maintained, and it is possible to avoid generation of excessive surface pressure.

  In the service and parking brake device according to the present invention, the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston forms a concentric conical surface on the inner peripheral portion of the cup-shaped piston. Formed by drilling a plurality of engaging grooves extending along the oblique side of the surface, and the cross-sectional shape of each engaging groove is substantially the same in the moving direction of each wedge member, Regardless of the movement of the wedge member, the surface contact state is maintained at the engagement portion between each wedge member and the cup-shaped piston, and excessive surface pressure can be avoided.

  In the service and parking brake device according to the present invention, the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston is formed by forming a conical conical surface on the inner peripheral portion of the cup-shaped piston. In such a case, the moldability of the inner peripheral portion of the cup-shaped piston can be made easily and inexpensively. In this case, positioning of each wedge member in the circumferential direction with respect to the cup-shaped piston becomes unnecessary.

  In implementing the present invention, the stroke control means has a pressure receiving area larger than the pressure receiving area of the rod and is coaxially disposed on the outer end side of the rod, and slides in the cylinder axial direction on the cylinder. A control piston that is movably assembled to form a control chamber and that pushes the rod toward the cup-shaped piston by brake fluid supplied to the control chamber, and brake fluid can be supplied to and discharged from the brake chamber A switching valve that is branched from a hydraulic circuit and is interposed in a branched hydraulic circuit that can supply and discharge brake fluid to and from the control chamber, and a switching valve that can switch communication / blocking between the brake chamber and the control chamber; It is also possible to provide a reservoir that is connected to a switching valve and can store brake fluid discharged from the control chamber when communication between the brake chamber and the control chamber is interrupted. That.

  In this case, when communication between the brake chamber and the control chamber is ensured by the switching valve, the brake piston of the same pressure is supplied to the brake chamber and the control chamber, thereby holding the control piston in a fixed position. It is possible. As a result, the rod, each support shaft, and each wedge member are held in place, and the outer peripheral portion of each wedge member engaged with the frustoconical block at the inner peripheral portion becomes the inner peripheral portion of the cup-shaped piston. It is possible to hold the state separated from the formed wedge contact surface. In this state, since the cup-shaped piston is not restrained from moving in the cylinder axial direction by each wedge member, the cup-shaped piston can freely move in the cylinder axial direction by supplying and discharging brake fluid to and from the brake chamber and the control chamber. It is possible to use the brake device as a service brake.

  Also, when the brake fluid is pressurized and supplied to the brake chamber while the communication between the brake chamber and the control chamber is blocked by the switching valve, the cup-shaped piston moves forward in the cylinder axial direction and pushes the brake lining. And an operation in which the brake fluid discharged from the control chamber is accommodated in the reservoir by moving the rod, each support shaft, and each wedge member backward from the fixed position toward the control chamber in the cylinder axis direction, On the side of the cup-shaped piston, the brake lining engages the braked rotating body and brakes, and each wedge member moves in the cylinder axial direction together with the rod. The outer peripheral portion of each wedge member that moves and engages with the frustoconical block at the inner peripheral portion is brought into engagement pressure contact with the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston. Is Operation is obtained which restrains movement of the Jo piston into the cylinder axis direction. In this state, each wedge member is fitted between the conical surface of the frustoconical block and the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston, thereby mechanically coupling the frustoconical block and the cup-shaped piston. Therefore, even when the brake fluid is discharged from the brake chamber, the cup-shaped piston is held in the operating position (position where the brake lining brakes the braked rotating body), and the brake device is used as a parking brake. .

  To release the parking brake described above, the brake fluid is pressurized and supplied to the brake chamber and the control chamber in a state where the brake chamber and the control chamber are communicated by the switching valve, and the cup-shaped piston is moved forward in the cylinder axial direction. In addition, the control piston is moved forward to the fixed position by moving it forward in the cylinder axial direction. At this time, as the control piston moves to the fixed position, the rod, the support shafts, and the wedge members move to the fixed position, and the wedges engaged with the frustoconical block at the inner peripheral portion. The outer peripheral part of a member will be in the state which removed from the wedge contact surface currently formed in the inner peripheral part of a cup-shaped piston. In this state, as the brake fluid is depressurized and discharged from the brake chamber and the control chamber, the cup-shaped piston moves in the cylinder axial direction while the rod, each support shaft, and each wedge member are held in place. Moves backward and the parking brake is released.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows an embodiment in which the present invention is applied to a movable caliper type disc brake. A service and parking brake device A of this embodiment includes a master cylinder MC that operates in response to an operation of a brake pedal BP, In a brake system for a four-wheel vehicle equipped with a brake hydraulic pressure control unit CU capable of skid control and traction control, it is adopted for left and right rear wheels (one is not shown). In this brake system for a four-wheeled vehicle, normal disc brake devices (not shown) are employed for the left and right front wheels.

  The regular / parking brake device A includes an inner pad 13 and an outer pad 15 that sandwich and brake a disc rotor 11 (a braked rotating body that rotates integrally with a wheel (not shown)) from the inside and the outside. A movable caliper 17 and a cup-shaped piston 19 are provided to push 13 and 15 toward the disk rotor 11. The pads 13 and 15 and the movable caliper 17 are each mounted to a mounting (not shown) mounted on the vehicle body so as to be slidable along the rotor axial direction.

  The inner pad 13 is composed of a brake lining 13a and a back plate 13b, and can be engaged and disengaged with respect to the disc rotor 11 by the brake lining 13a, and is a cup-shaped piston assembled to the cylinder 17a of the movable caliper 17. 19 is configured to be pushed toward the disk rotor 11. On the other hand, the outer pad 15 is constituted by a brake lining 15a and a back plate 15b, and can be engaged / disengaged with respect to the disc rotor 11 by the brake lining 15a, and the reaction claw portion 17b of the movable caliper 17 allows the disc rotor to be engaged / disengaged. 11 is configured to be pushed toward the head 11.

  The cup-shaped piston 19 is unable to rotate around the cylinder axis through the piston seal 21 and moves in the cylinder axis direction (substantially parallel to the rotor axis direction) via the piston seal 21 in the large-diameter inner hole 17a1 formed in the cylinder 17a of the movable caliper 17. A brake chamber R1 filled with brake fluid is formed in the cylinder 17a. The brake chamber R1 is connected to a hydraulic circuit 23a that constitutes a part of the brake hydraulic circuit 23, and brake fluid can be supplied and discharged through the hydraulic circuit 23a. The piston seal 21 is configured to be deformed toward the rotor side when the piston 19 is pressed toward the disk rotor 11, and has a function of pulling back the piston 19 by returning the deformation when the pressure is released ( Retract function).

  In this embodiment, as shown in FIGS. 1 to 3, the cylinder 17 a of the movable caliper 17 is provided with a truncated cone-shaped block 25, rods 27, a plurality of (four) support shafts 29, and a plurality of (4 ) Wedge members 31 and a control piston 33 are assembled. A switching valve 35 is interposed in the branch hydraulic circuit 23b branched from the hydraulic circuit 23a, and a reservoir 37 is connected to the switching valve 35.

  The frustoconical block 25 has a conical surface 25a whose diameter decreases toward the closed end of the cup-shaped piston 19, and is arranged coaxially in the cup-shaped piston 19 in the brake chamber R1. The large-diameter end 25b is fitted and fixed together with the sleeve 39 to the bottom wall of the cylinder 17a of the movable caliper 17. A seal ring 41 is assembled on the outer periphery of the large-diameter end portion 25b of the truncated cone-shaped block 25, so that the space between the bottom wall of the movable caliper 17 and the cylinder 17a is liquid-tightly sealed.

  Further, as shown in FIGS. 1 to 3, the conical surface 25 a of the truncated cone-shaped block 25 extends along the hypotenuse and accommodates the inner peripheral portion of each wedge member 31 slidably ( Four (4) receiving grooves 25a1 are formed. Each receiving groove 25a1 is provided at equal intervals in the circumferential direction, and its cross-sectional shape is rectangular as is apparent from FIGS. 2 and 3, and the moving direction of each wedge member 31 (the oblique side of the conical surface 25a) In the extending direction).

  The rod 27 is assembled so as to penetrate through the axial center portions of the truncated cone-shaped block 25 and the sleeve 39, and is movable in the cylinder axial direction. The rod 27 is liquid-tight between the truncated cone-shaped block 25 and the sleeve 39. The outer periphery of the rod 27 is sealed in a liquid-tight manner by the seal ring 43 assembled to the. Further, the rod 27 is in contact with and engaged with the control piston 33 at the outer end portion penetrating the sleeve 39.

  As shown in FIGS. 1 and 2, the support shafts 29 are provided at equal intervals in the circumferential direction at the inner end of the rod 27 on the brake chamber R <b> 1 side. Each wedge member 31 is supported so as to be movable in the piston radial direction but not in the cylinder axial direction.

  Each wedge member 31 is assembled to each support shaft 29 so as to be movable in the piston radial direction but not in the cylinder axial direction, and is disposed so as to surround the conical surface 25a of the truncated cone block 25. As the rod 27 moves in the cylinder axial direction, it moves in the piston radial direction while moving in the cylinder axial direction. Each wedge member 31 is biased toward the inside of the piston diameter by a garter spring 45 attached to the outer periphery of the intermediate portion, and is formed on the conical surface 25a of the truncated cone-shaped block 25 at the inner peripheral portion having a rectangular cross section. The housing groove 25a1 is slidably engaged.

  Further, as shown in FIGS. 1 and 2, each wedge member 31 has an outer peripheral portion formed in an arc shape in cross section, and each wedge formed on the inner peripheral portion of the cup-shaped piston 19 at the outer peripheral portion. The contact surface S can be engaged and disengaged. Each wedge contact surface S has a plurality of (four) engaging grooves 19a1 extending along the oblique side of the conical surface 19a in a concentric conical surface 19a formed on the inner peripheral portion of the cup-shaped piston 19. It is formed by this, and it is set as the shape which expands toward the opening edge part of the cup-shaped piston 19. As shown in FIG. Each engagement groove 19a1 is provided at equal intervals in the circumferential direction, and its cross-sectional shape is an arc shape as is apparent from FIGS. 2 and 3, and the moving direction (conical surface) of each wedge member 31. 19a) (the extending direction of the hypotenuse of 19a).

  The control piston 33 constitutes a stroke control means for controlling the axial movement of the rod 27 by the switching valve 35, the reservoir 37, and the like. The control piston 33 has a pressure receiving area larger than the pressure receiving area of the rod 27, is coaxially arranged on the outer end side of the rod 27, and has a small diameter inner hole 17 a 2 formed in the cylinder 17 a via a seal ring 47. The control chamber R2 filled with the brake fluid is formed in the cylinder 17a. The chamber formed between the control piston 33, the rod 27, and the sleeve 39 is an air chamber R3 (see FIG. 4).

  Further, the control piston 33 can push the rod 27 toward the cup-shaped piston 19 by the brake fluid supplied to the control chamber R2, and the cup-shaped as the brake fluid is discharged from the control chamber R2. It can move in a direction away from the piston 19 and allows the rod 27 to move in the cylinder axial direction toward the control chamber R2. The control chamber R2 is connected to the branch hydraulic circuit 23b, and can supply and discharge brake fluid through the branch hydraulic circuit 23b.

  The switching valve 35 is a three-port two-position electromagnetic switching valve that is controlled to be energized / de-energized by the electric control unit ECU, and is branched from a hydraulic circuit 23a that can supply and discharge brake fluid to and from the brake chamber R1. In addition, a branch hydraulic pressure circuit 23b capable of supplying and discharging brake fluid is provided, and communication / blocking of the brake chamber R1, the control chamber R2, and the reservoir 37 can be switched.

  The reservoir 37 is connected to the switching valve 35 and can store the brake fluid discharged from the control chamber R2 when communication between the brake chamber R1 and the control chamber R2 is blocked by the switching valve 35. The brake fluid stored in the reservoir 37 is communicated between the brake chamber R1 and the control chamber R2 by the switching valve 35 when no brake fluid is supplied from the brake fluid pressure control unit CU to the branch fluid pressure circuit 23b. It is configured to be discharged toward the branch hydraulic circuit 23b.

  The brake hydraulic pressure control unit CU is controlled by the electric control unit ECU in a well-known manner when the vehicle is running, and can perform skid control and traction control, and can operate the parking brake switch SW when the vehicle is stopped. The operation of the common and parking brake device A can be controlled by controlling the operation together with the switching valve 35 by the electric control unit ECU. The configuration of the brake fluid pressure control unit CU is well known per se, and the description thereof is omitted.

  In the service and parking brake device A of this embodiment configured as described above, when the parking brake switch SW is turned off and used as a service brake, as shown in FIG. The brake chamber R1 and the control chamber R2 are in a non-energized state, and the liquid flow from the branch hydraulic circuit 23b to the reservoir 37 is restricted by a check valve incorporated in the switching valve 35. For this reason, when the brake fluid is pressurized and supplied from the brake fluid pressure control unit CU to the fluid pressure circuit 23a, the brake fluid is pressurized and supplied from the fluid pressure circuit 23a to the brake chamber R1, and branches from the fluid pressure circuit 23a. The brake fluid is pressurized and supplied to the control chamber R2 through the hydraulic circuit 23b and the switching valve 35.

  By the way, when communication between the brake chamber R1 and the control chamber R2 is ensured by the switching valve 35, the brake fluid R1 and the control chamber R2 are pressurized and supplied to the brake chamber R1 and the control chamber R2. The pressing force due to the difference in pressure receiving area acts on the rod 27 and the control piston 33, and the rod 27 and the control piston 33 are held at the fixed positions shown in FIG. Accordingly, as shown in FIGS. 1 to 3, the outer peripheral portion of each wedge member 31 is held in a state of being separated from each wedge contact surface S formed on the inner peripheral portion of the cup-shaped piston 19. The piston 19 can be moved in the cylinder axis direction. Therefore, at this time, the cup-shaped piston 19 can be advanced and retracted in the cylinder axial direction by supplying and discharging the brake fluid to and from the brake chamber R1, and the brake device A can be operated as a service brake. .

  Accordingly, at this time, the cup-shaped piston 19 is pushed toward the disc rotor 11 in the cylinder axial direction while the piston-shaped piston 19 is deformed toward the rotor by the brake fluid supplied under pressure to the brake chamber R1, and the inner cylinder is pushed. While pressing the pad 13 against the disc rotor 11, the reaction force causes the movable caliper 17 to be pushed toward the inner side, and the reaction claw portion 17 b of the movable caliper 17 presses the outer pad 14 against the disc rotor 11. Further, at this time, the force generated when both the pads 13 and 14 press the disk rotor 11 is received by the mounting that supports both the pads 13 and 14 and generates a braking force that prevents the rotation of the disk rotor 11. . In this braking state, the structural member such as the movable caliper 17 is bent and deformed in response to the pressure supply of the brake fluid, and the retracting function can also be obtained by returning the bending deformation of the structural member such as the movable caliper 17 when the brake is released. .

  When the brake fluid pressure supply from the brake fluid pressure control unit CU to the brake chamber R1 is removed and the pressure is removed, the retract function and the movable caliper 17 obtained by returning the deformation of the piston seal 21 are returned. Due to the retract function obtained by returning the deformation of the constituent members, the cup-shaped piston 19 moves to the inner side, and the movable caliper 17 moves to the outer side, so that the pads 13 and 14 are pushed to the disk rotor 11. Movement and pressing are removed. Thereby, the rotational braking of the disk rotor 11 by both the pads 13 and 14 is released.

  Moreover, in the regular and parking brake device A of this embodiment, the parking brake switch SW is turned on when the parking brake switch SW is turned off when the vehicle is stopped and is used as a parking brake. The switching valve 35 is energized by the electric control unit ECU during the set time T1 from the time when the parking brake switch SW is turned on, and during the set time T2 (T1> T2) from the time when the parking brake switch SW is turned on. Then, the brake fluid pressure control unit CU is brought into the pressurization control state by the electric control unit ECU, and a predetermined amount of brake fluid is pressurized and supplied from the brake fluid pressure control unit CU to the regular / parking brake device A.

  Therefore, at this time, the state shown in FIG. 1 is changed to the state shown in FIG. 4 between the time point when the parking brake switch SW is turned on and the set time T2, and the communication between the brake chamber R1 and the control chamber R2 is established. Is cut off by the switching valve 35 and the brake fluid is pressurized and supplied from the brake fluid pressure control unit CU to the brake chamber R1, and the cup-shaped piston 19 is pushed toward the disc rotor 11 in the cylinder axial direction. The parking brake operation in which the inner pad 13 is pressed against the disk rotor 11 and the movable caliper 17 is pushed toward the inner side by the reaction force, and the reaction claw portion 17b of the movable caliper 17 presses the outer pad 14 against the disk rotor 11. Is obtained.

  At this time, the rod 27, the support shafts 29, the wedge members 31 and the control piston 33 are moved backward from the fixed positions shown in FIG. 1 toward the control chamber R2 in the cylinder axis direction and discharged from the control chamber R2. The brake fluid is stored in the reservoir 35, the brake lining 13a is engaged with the disc rotor 11 on the cup-shaped piston 19 side, and the brake member 13 is braked. At the same time, it moves in the cylinder axis direction and moves outward of the piston diameter with respect to each support shaft 29, and moves along each receiving groove 25 a 1 of the frustoconical block 25 as shown in FIGS. 4 to 6. The outer peripheral portion of each wedge member 31 is brought into engagement pressure contact with each wedge contact surface S formed on the inner peripheral portion of the cup-shaped piston 19, and each wedge member 31 is a cylinder of the cup-shaped piston 19. Operation for restraining the movement in the axial direction is obtained.

  In this state, each wedge member 31 is formed between the truncated cone-shaped block 25 and the cup-shaped piston 19, specifically, the receiving groove 25 a 1 formed on the conical surface 25 a of the truncated cone-shaped block 25 and the conical surface 19 a of the cup-shaped piston 19. Since the frustoconical block 25 and the cup-shaped piston 19 are mechanically coupled with each other by being fitted between the engagement grooves 19a1 (wedge contact surface S), after that (after the set time T2 has elapsed), the brake fluid Even when the pressure control unit CU is released from the pressurization control state by the electric control unit ECU and is brought into the depressurization state, the cup-shaped piston 19 remains in the operating position even when the brake fluid is discharged from the brake chamber R1 to the brake fluid pressure control unit CU. (The position where the brake lining 13a brakes the disc rotor 11) is held, and the brake device is used as a parking brake.

  Note that the switching valve 33 is maintained in the energized state after the set time T2 has elapsed until the set time T1 is reached, so that the brake chamber R1 is directed toward the brake fluid pressure control unit CU through the fluid pressure circuit 23a. The brake fluid is discharged and discharged, and the brake fluid that has flowed into the reservoir 37 is kept in the reservoir 37. Further, after the set time T1 has elapsed, the switching valve 33 is in a non-energized state, the brake chamber R1 and the control chamber R2 are in communication, and the brake fluid from the brake chamber R1 to the brake fluid pressure control unit CU Since the depressurization discharge has been completed, the brake fluid discharged from the reservoir 37 to the branch hydraulic pressure circuit 23b flows toward the brake hydraulic pressure control unit CU.

  In the common and parking brake device A of this embodiment, when the parking brake switch SW is turned off from the state where the parking brake switch SW is turned on and the operation of the parking brake is released, the parking brake switch SW is turned off. The brake fluid pressure control unit CU is controlled by the electric control unit ECU in a state where the switching valve 35 is maintained in a non-energized state for a set time T3 (a time substantially equal to the set time T2) from the time point. A predetermined amount of brake fluid is pressurized and supplied from the control unit CU to the service and parking brake device A, and the brake fluid is depressurized and discharged after a set time T3.

  Therefore, at this time, the brake fluid is pressurized and supplied to the brake chamber R1 and the control chamber R2 in a state where the brake chamber R1 and the control chamber R2 are communicated by the switching valve 35, and the cup-shaped piston 19 is moved in the cylinder axial direction. While moving forward, the control piston 33 moves forward in the cylinder axis direction and moves to a fixed position. At this time, as the control piston 33 moves to the fixed position, the rod 27, the support shafts 29, and the wedge members 31 move to the fixed position, and the inner circumferential portion of the receiving groove 25a1 of the truncated cone block 25 is moved. The outer peripheral portion of each wedge member 31 engaged in the state is separated from each wedge contact surface S formed on the inner peripheral portion of the cup-shaped piston 19. In this state, as the brake fluid is depressurized and discharged from the brake chamber R1 and the control chamber R2, the cup-shaped piston is maintained with the rod 27, the support shafts 29, and the wedge members 31 held in place. 19 moves backward in the cylinder axis direction and the parking brake is released.

  The above-described operation can be similarly obtained when the brake linings 13a and 15a of the pads 13 and 15 are worn. FIGS. 1 to 3 show that the pads 13 and 15 are in a new state and the brake is released. Is shown. 4 to 6 show the pads 13 and 15 in a new state and the parking brake operating state. 7 and 8 show that the pads 13 and 15 are fully worn and the parking brake is activated.

  By the way, in the regular and parking brake device A of this embodiment, each wedge contact surface S formed on the inner peripheral portion of the cup-shaped piston 19 has a shape that expands toward the opening end of the cup-shaped piston 19. Therefore, when the brake device A is used as a parking brake and the brake lining 13a pushed by the cup-shaped piston 19 is braking the disc rotor 11, the cup-shaped piston 19 is brake lining 13a. In the direction in which the braking force is released between the outer peripheral portion of each wedge member 31 and each wedge contact surface S of the cup-shaped piston 19, that is, toward the opening end side of the cup-shaped piston 19. If the cup-shaped piston 19 slightly moves even if the occurrence of the occurrence of the occurrence of the occurrence of the occurrence, the wedge contact surfaces S of the cup-shaped piston 19 and the wedge members 31 The engaging pressure contact force between the peripheral portion (surface pressure) is raised, it engages contact force between the conical surfaces 25a of the inner peripheral portion and the truncated cone-like block 25 of the wedge member 31 (surface pressure) is increased. For this reason, the binding force of the cup-shaped piston 19 by each wedge member 31 increases, and each wedge member 31 restricts further movement of the cup-shaped piston 19. Therefore, the state in which the pressing and holding force of the cup-shaped piston 19 by each wedge member 19 is maintained is maintained, the decrease of the parking brake force is prevented, and the reliability of the parking brake can be improved.

  In the common and parking brake device A of this embodiment, a plurality of conical surfaces 25a of the frustoconical block 25 extend along the hypotenuse and slidably accommodate the inner peripheral portion of each wedge member 31. Since the receiving grooves 25a1 are formed and the cross-sectional shapes of the receiving grooves 25a1 are substantially the same in the movement direction of the wedge members 31, the wedge members 31 and the truncated cones are moved regardless of the movement of the wedge members 31. In the engaging portion of the block 25, the surface contact state is maintained, and it is possible to avoid excessive surface pressure.

  Further, in the common and parking brake device A of this embodiment, each wedge contact surface S formed on the inner peripheral portion of the cup-shaped piston 19 is concentric with the inner peripheral portion of the cup-shaped piston 19. And a plurality of engagement grooves 19a1 extending along the oblique sides of the conical surface 19a are formed. The cross-sectional shape of each engagement groove 19a1 is determined in the moving direction of each wedge member 31. Since they are substantially the same, regardless of the movement of each wedge member 31, the surface contact state is maintained at the engagement portion between each wedge member 31 and the cup-shaped piston 19, and it is possible to avoid the generation of excessive surface pressure. .

  In the above-described embodiment, the stroke control means for controlling the axial movement of the rod 27 is configured by the control piston 33, the switching valve 35, the reservoir 37, etc., but this stroke control means may be implemented as another configuration. Is possible. Further, in the above-described embodiment, the conical surface 25a of the frustoconical block 25 is formed with a plurality of receiving grooves 25a1 that extend along the oblique sides and slidably receive the inner peripheral portion of each wedge member 31. Although implemented as described above, the present invention can also be carried out without this accommodation groove.

  In the above-described embodiment, each wedge contact surface S formed on the inner peripheral portion of the cup-shaped piston 19 is formed on the conical conical surface 19 a formed on the inner peripheral portion of the cup-shaped piston 19. It is formed by drilling a plurality of (four) engaging grooves 19a1 extending along the oblique side of the surface 19a. The wedge contact surface formed on the inner periphery of the cup-shaped piston is the cup-shaped piston. It is also possible to carry out the process by forming a conical concentric surface on the inner peripheral part (implementing without the engaging groove 19a1 of the above embodiment). In this case, it is possible to manufacture the inner peripheral portion of the cup-shaped piston easily and inexpensively. In this case, positioning of each wedge member in the circumferential direction with respect to the cup-shaped piston becomes unnecessary.

  In the above embodiment, the number of wedge members 31 is four, but the number of wedge members 31 can be appropriately increased and decreased, and is not limited to the above embodiment. . In the above embodiment, an example in which the present invention is applied to a disc brake (a brake in which the braked rotating body is a disc rotor) has been described. However, the present invention is a drum brake (a brake in which the braked rotating body is a brake drum). ) Can be implemented with appropriate modifications.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram which shows schematically one Embodiment of the brake system containing the regular and parking brake apparatus by this invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 1. It is operation | movement explanatory drawing when the regular and parking brake apparatus shown in FIG. 1 act | operates as a parking brake. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. It is parking brake operation | movement explanatory drawing when the brake lining of each pad is a full wear state in the common use parking brake apparatus shown in FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Disc rotor, 13, 15 ... Pad, 13a, 15a ... Brake lining, 17 ... Movable caliper, 17a ... Cylinder, 17b ... Reaction claw part, 19 ... Cup-shaped piston, 19a ... Conical surface, 19a1 ... Engagement groove, DESCRIPTION OF SYMBOLS 21 ... Piston seal, 23 ... Brake hydraulic circuit, 23a ... Hydraulic circuit, 23b ... Branch hydraulic circuit, 25 ... Frustum block, 25a ... Conical surface, 25a1 ... Accommodating groove, 27 ... Rod, 29 ... Support shaft 31 ... Wedge member, 33 ... Control piston, 35 ... Switching valve, 37 ... Reservoir, R1 ... Brake chamber, R2 ... Control chamber, S ... Wedge contact surface

Claims (5)

A cup-shaped piston that is assembled to a cylinder so as to be movable in the cylinder axial direction and forms a brake chamber in the cylinder, and the cup-shaped piston is pushed by brake fluid supplied to the brake chamber. A brake lining that is pushed to engage the braked rotor and brake the braked rotor;
A frustoconical block that is coaxially disposed in the cup-shaped piston in the brake chamber and is fixed to the bottom wall of the cylinder, and is assembled so as to penetrate the axial center of the frustoconical block. A rod movable in the cylinder axial direction, a plurality of support shafts provided at an inner end of the rod on the brake chamber side and extending in the piston radial direction in the cup-shaped piston, and a piston diameter on each of the support shafts It is assembled so as to be movable in the direction and non-movable in the cylinder axial direction, and is disposed so as to surround the conical surface of the truncated cone-shaped block, and is engaged with the truncated cone-shaped block at the inner periphery. A common and parking brake device comprising a plurality of wedge members movable along the oblique side of the conical surface, and stroke control means provided on the outer end side of the rod for controlling the axial movement of the rod There,
A wedge contact surface is formed on the inner peripheral portion of the cup-shaped piston so that the outer peripheral portion of each wedge member can be engaged and disengaged in a shape that expands toward the opening end of the cup-shaped piston. A regular and parking brake device characterized by   2. The service / parking brake device according to claim 1, wherein the conical surface of the frustoconical block has a plurality of receiving grooves that extend along the hypotenuse and slidably receive the inner peripheral portion of each wedge member. And the cross-sectional shape of each of the receiving grooves is substantially the same in the moving direction of each wedge member.   The common / parking brake device according to claim 1 or 2, wherein the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston forms a conical conical surface on the inner peripheral portion of the cup-shaped piston. The plurality of engaging grooves extending along the oblique sides of the conical surface are formed, and the cross-sectional shapes of the engaging grooves are substantially the same in the moving direction of the wedge members. A common and parking brake device.   The common / parking brake device according to claim 1 or 2, wherein the wedge contact surface formed on the inner peripheral portion of the cup-shaped piston forms a conical conical surface on the inner peripheral portion of the cup-shaped piston. This is a regular and parking brake device. The common / parking brake device according to any one of claims 1 to 4, wherein the stroke control means has a pressure receiving area larger than the pressure receiving area of the rod and is coaxial with the outer end side of the rod. A control piston which is disposed and slidably assembled to the cylinder in the cylinder axial direction to form a control chamber and pushes the rod toward the cup-shaped piston by brake fluid supplied to the control chamber; Branching from a hydraulic circuit capable of supplying and discharging brake fluid to the brake chamber and interposing a branch hydraulic circuit capable of supplying and discharging brake fluid to and from the control chamber to communicate / block the brake chamber and the control chamber A switching valve that can be switched between and the brake fluid that is connected to the switching valve and that is discharged from the control chamber when communication between the brake chamber and the control chamber is interrupted Regular and parking brake system, characterized in that it comprises a reservoir.

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