JP2007170648A - Vehicular brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct a parking brake force generating means in a compact form along the longitudinal direction of a parking wire for generating traction force on the parking wire to establish a parking braking condition. <P>SOLUTION: The parking brake force generating means 60 has: a turning lever 66 to one end of which the parking wire 65 is connected; a hydraulic cylinder 69 connected to the other end of the turning lever 66 through the opposite side to the parking wire 65; and a ratchet mechanism 72 having a plurality of ratchet teeth 70 provided on the side face of the turning lever 66 side by side along a virtual circular arc SA, and arranged on the opposite side to the hydraulic cylinder 69 in relation to the turning lever 66. Herein, r1<r2 and r3≤r2 are established in the operated condition of the hydraulic cylinder 69, where r1 is a distance between a hydraulic pressure working point of the hydraulic cylinder 69 on the turning lever 66 and a turning center C, r2 is a distance between a connection point of the parking wire 65 to the turning lever 66 and the turning center C, and r3 is the radius of the virtual circular arc SA. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle brake device including a wheel brake capable of entering a parking brake state in response to the pulling of the parking wire, and a parking brake force generating means capable of generating a force for pulling the parking wire.

For example, Patent Document 1 discloses a vehicle brake device that pulls a parking wire by contracting a hydraulic cylinder to obtain a parking brake state of a wheel brake.
JP 2005-282605 A

  In the vehicle brake device disclosed in Patent Document 1 described above, it is necessary to operate the parking piston of the hydraulic cylinder for the amount of traction of the parking wire, and the parking brake force generating means including the hydraulic cylinder is provided with the parking wire. It becomes long in the longitudinal direction.

  Therefore, the rotation lever is driven to rotate by the hydraulic pressure generated by the hydraulic cylinder, and the parking wire is pulled along the longitudinal direction of the parking wire by pulling the parking wire by the rotation of the rotation lever. It can be considered to be compact. At this time, considering the boosting force of the turning lever, the distance from the turning center of the turning lever to the hydraulic pressure action point of the hydraulic cylinder is set from the turning center of the turning lever to the turning lever of the parking wire. There is also a setting that pulls the parking wire with a relatively small hydraulic pressure generated by the hydraulic cylinder, and pulls the parking wire by a sufficient amount. In this case, the stroke of the hydraulic cylinder has to be increased, and the parking brake force generating means becomes large.

  Further, when the rotation position of the rotation lever is restricted by the ratchet mechanism in order to maintain the rotation position of the rotation lever even when the hydraulic pressure action on the hydraulic pressure generating means is stopped, Depending on the length to the ratchet mechanism, the parking brake force generating means may be increased in size, and it is necessary to appropriately set the length from the rotation center of the rotation lever to the ratchet mechanism.

  The present invention has been made in view of such circumstances, and a vehicle in which parking brake force generating means for obtaining a parking brake state of a wheel brake can be configured compactly in a direction along the longitudinal direction of the parking wire. An object is to provide a brake device.

  In order to achieve the above object, the present invention provides a wheel brake capable of entering a parking brake state in response to the pulling of the parking wire, and a parking brake force generating means capable of generating a force for pulling the parking wire. In the vehicle brake device, the parking brake force generating means is capable of rotating around a rotation center and is forwardly operated in response to a hydraulic pressure action with a rotation lever connected to one end of the parking wire. The parking parking piston is provided from the opposite side of the parking wire to the other end of the rotating lever so as to rotate the rotating lever to the side of pulling the parking wire in accordance with the forward operation of the parking piston. A hydraulic cylinder that connects the front ends of the piston and the rotation center. A plurality of ratchet teeth provided on a side surface of the rotating lever side by side on a virtual arc and an engaging claw that engages with the ratchet teeth, and disposed on the opposite side of the hydraulic cylinder with respect to the rotating lever A hydraulic pressure acting point on the pivot lever of the hydraulic cylinder and a distance between the pivot centers, r1, a connection point of the parking wire to the pivot lever, and the pivot center. When the distance between them is r2, and the radius of the virtual arc line is r3, r1 <r2 and r3 ≦ r2 are set.

  According to the present invention, the rotation lever is rotated by the operation of the hydraulic cylinder to pull the parking wire, so that a complicated link mechanism is not required and the length of the hydraulic cylinder is set as short as possible. In the ratchet mechanism for holding the rotating position of the rotating lever while the parking wire is pulled, the ratchet teeth are arranged over a sufficient length. Can be set. Moreover, the distance r1 between the hydraulic pressure acting point on the pivot lever of the hydraulic cylinder and the pivot center is set to be smaller than the distance r2 between the connection point of the parking wire to the pivot lever and the pivot center. In order to pull the parking wire by a sufficient amount, the operation stroke of the hydraulic cylinder does not become too large, and the radius r3 of the virtual arc line where the ratchet teeth of the ratchet mechanism are arranged side by side is set to be less than the distance r2. Therefore, an increase in the size of the parking brake force generating means due to the arrangement of the ratchet mechanism can be suppressed.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 4 show an embodiment of the present invention, FIG. 1 is a diagram showing the overall configuration of a vehicle brake device, FIG. 2 is a longitudinal sectional view of a right rear wheel brake, and FIG. 3 is an equalizer. FIG. 4 is a longitudinal sectional view corresponding to FIG. 3 in a parking brake operating state.

  First, in FIG. 1, left and right front wheels, which are left and right drive wheels provided in a vehicle, are mounted with left and right front wheel brakes 5FL, 5FR, which are disc brakes, and left and right rear wheels, which are left and right driven wheels. Are mounted with left and right rear wheel brakes 5RL and 5RR, which are disc brakes each having a parking brake mechanism 50 shown in FIG. 2 to be described later, and left and right front wheel brakes 5FL and 5FR and left and right rear wheels. The wheel brakes 5RL and 5RR are the left front wheel brake 5FL and the right rear wheel brake 5RR of the first brake system B1, and the right front wheel brake 5FR and the left rear wheel brake of the second brake system B2. It is divided into 5RL.

  The master cylinder M that outputs the brake fluid pressure in response to the operation of the brake pedal P by the vehicle driver is a tandem type, and the master cylinder M corresponds to the pedaling force applied to the brake pedal P by the vehicle driver. The first and second output ports 1A and 1B for generating the brake fluid pressure are provided. The first output port 1A is connected to the first output fluid pressure path 3A corresponding to the first brake system B1, and the second output port. 1B is connected to a second output hydraulic path 3B corresponding to the second brake system B2.

  The first output hydraulic pressure path 3A is connected to the first hydraulic pressure path 20A via the first regulator valve 17A, and the second output hydraulic pressure path 3B is connected to the second hydraulic pressure path 20B via the second regulator valve 17B. Connected to.

  The first hydraulic pressure path 20A is connected to the left front wheel wheel brake 5FL via the hydraulic pressure control means 4FL and is connected to the right rear wheel wheel brake 5RR via the hydraulic pressure control means 4RR. The road 20B is connected to the right rear wheel wheel brake 5FR via the hydraulic pressure control means 4FR and to the left rear wheel wheel brake 5RL via the hydraulic pressure control means 4RL.

  The hydraulic pressure control means 4FL, 4RR include normally open solenoid valves 6FL, 6RR provided between the first hydraulic path 20A, the left front wheel brake 5FL and the right rear wheel brake 5RR, and their normally open solenoids. One-way valves 7FL, 7RR connected in parallel to the valves 6FL, 6RR, and normally closed solenoid valves 9FL, 9RR provided between the first reservoir 8A and the left front wheel brake 5FL and right rear wheel brake 5RR, Is provided.

  The hydraulic pressure control means 4FR, 4RL include normally open solenoid valves 6FR, 6RL provided between the second hydraulic path 20B, the right front wheel brake 5FR and the left rear wheel brake 5RL, and their normally open solenoids. One-way valves 7FR, 7RL connected in parallel to the valves 6FR, 6RL, and normally closed solenoid valves 9FR, 9RL provided between the second reservoir 8B and the right front wheel brake 5FR and the left rear wheel brake 5RL, Is provided.

  The first and second reservoirs 8A, 8B allow the brake fluid to flow to the pump 10A, 10B side on the suction side of the first and second pumps 10A, 10B driven by the common electric motor 11. The directional valves 19A and 19B are connected to each other, and the first and second hydraulic pressure passages 20 and 20B are connected to the first and second pumps 10A and 10B via the first and second suction valves 18A and 18B, respectively. Connected between the one-way valves 19A and 19B and connected to the discharge side of the first and second pumps 10A and 10B via the first and second dampers 13A and 13B.

  In such a hydraulic pressure control circuit, each normally open electromagnetic valve is operated during normal braking with the first and second regulator valves 17A and 17B opened and the first and second suction valves 18A and 18B closed. The valves 6FL to 6RR are demagnetized and opened, and the normally closed solenoid valves 9FL to 9RR are demagnetized and closed, so that the brake hydraulic pressure output from the first output port 1A of the master cylinder M is normal. It acts on the wheel brakes 5FL, 5RR for the left front wheel and the right rear wheel via the open electromagnetic valves 6FL, 6RR. The brake hydraulic pressure output from the second output port 1B of the master cylinder M acts on the right front wheel brakes 5FR and 5RL via the normally open solenoid valves 6FR and 6RL.

  When the wheel is about to enter the locked state during the brake, the normally open type electromagnetic valve corresponding to the wheel that is about to enter the locked state among the normally open type electromagnetic valves 6FL to 6RR is excited and closed. Of the normally closed solenoid valves 9FL to 9RR, the normally closed solenoid valve corresponding to the wheel is excited and opened. Thereby, a part of the brake fluid pressure of the wheel that is about to enter the locked state is absorbed by the first reservoir 8A or the second reservoir 8B, and the brake fluid pressure of the wheel that is about to enter the locked state is reduced. It will be.

  Further, when the brake fluid pressure is kept constant, the normally open solenoid valves 6FL to 6RR are excited and closed, and the normally closed solenoid valves 9FL to 9RR are demagnetized and closed. When increasing the fluid pressure, the normally open solenoid valves 6FL to 6RR may be demagnetized and opened, and the normally closed solenoid valves 9FL to 9RR may be demagnetized and closed.

  By controlling the demagnetization / excitation of the normally open solenoid valves 6FL to 6RR and the normally closed solenoid valves 9FL to 9RR as described above, braking can be performed efficiently without locking the wheels.

  By the way, during the antilock brake control as described above, the electric motor 11 is rotated, and the first and second pumps 10A and 10B are driven in accordance with the operation of the electric motor 11. Therefore, the first and second pumps are driven. The brake fluid absorbed in the reservoirs 8A and 8B is sucked into the first and second pumps 10A and 10B, and then passes through the first and second dampers 13A and 13B to the first and second output hydraulic pressure paths 3A and 3B. Refluxed. Such recirculation of the brake fluid can prevent an increase in the amount of depression of the brake pedal P due to the absorption of the brake fluid in the first and second reservoirs 8A and 8B. In addition, the pulsation of the discharge pressures of the first and second pumps 10A and 10B is suppressed by the action of the first and second dampers 13A and 13B, and the operation feeling of the brake pedal P is not hindered by the reflux.

  Further, during the non-braking operation, the first and second suction valves 18A and 18B are excited and opened, and the first and second pumps 10A and 10B are driven by the electric motor 11, and the first and second regulator valves 17A and 17B are driven. By adjusting the hydraulic pressure of the first and second hydraulic pressure paths 20A and 20B by 17B, traction control and vehicle stability control can be performed.

  In FIG. 2, in the right rear wheel wheel brake 5RR, a first friction pad 22 and a second friction pad 23 are arranged opposite to each other of a brake disc 21 that rotates together with the wheel. These first and second friction pads 22 and 23 are composed of linings 22a and 23a that can contact the brake disc 21, and back plates 22b and 23b fixed to the back surfaces of the linings 22a and 23a. The back plates 22b and 23b are supported by the bracket 24 fixed to the vehicle body so as to be movable in the axial direction of the brake piston 28. A brake caliper 25 straddling the first and second friction pads 22 and 23 is supported by the bracket 24 so as to be movable in the axial direction of the brake piston 28.

  The brake caliper 25 includes a first sandwiching arm 25a facing the back plate 22b of the first friction pad 22 and a second sandwiching arm 25b facing the back plate 23b of the second friction pad 23. The second sandwiching arms 25 a and 25 b are integrally connected by a bridging portion 25 c that passes through the outer periphery of the brake disc 21. The first pinching arm 25 a is provided with a cylinder hole 26, and a cup-shaped brake piston 28 is slidably fitted into the cylinder hole 26 via a seal member 27. The front end of the brake piston 28 facing the back plate 22b of the first friction pad 22 is connected to the opening end of the cylinder hole 26 by a bellows dust cover 29, and the brake facing the back of the brake piston 28. A hydraulic chamber 30 is formed in the first clamping arm 25a, and the brake hydraulic chamber 30 is connected to the normally open solenoid valve 6RR and the normally closed solenoid valve 9RR via a port 31 provided in the first sandwiching arm 25a. Connected.

  An adjusting mechanism 32 is provided in the first pinching arm 25a of the brake caliper 25. The adjusting mechanism 32 is connected to the brake piston 28 so as not to rotate relative thereto and is accommodated in the brake hydraulic pressure chamber 30. An adjusting nut 33, an adjusting bolt 34 whose front end is screwed to the adjusting nut 33, and a rear portion of the brake hydraulic pressure chamber 30 and capable of moving in the axial direction while preventing rotation around the axis. The relay piston 35 is fluid-tightly and slidably fitted to the brake caliper 25, and is integrally and coaxially connected to the rear portion of the adjustment bolt 34 so as to be liquid-tight and slidable to the relay piston 35. And a small piston 36 that is elastically biased in the direction of frictional engagement with the relay piston 35.

  A relay cylinder hole 37 having a diameter smaller than that of the cylinder hole 26 is coaxially provided at an end of the first caliper arm 25a of the brake caliper 25 on the side opposite to the brake disk 21. The front part is inserted into the rear part of the cylinder hole 26 and is slidably fitted into the relay cylinder hole 37 via the seal member 38. Moreover, the brake caliper 25 and the relay piston 35 are fitted with both ends of a regulation pin 39 that has an axis parallel to the cylinder hole 26 and the relay cylinder hole 37 and is disposed at a position offset from the axis of the cylinder hole 26. The As a result, the relay piston 35 is prevented from rotating around an axis that is coaxial with the cylinder hole 26 and the relay cylinder hole 37 and is also supported by the brake caliper 25 so as to be movable along the axis. .

  The relay piston 35 is coaxially provided with a small cylinder hole 41 having a tapered clutch surface 40 at the front end opening. On the other hand, at the rear portion of the adjusting bolt 34, a movable clutch body 42 that can be frictionally engaged with the clutch surface 40 and a small piston 36 that fits in the small cylinder hole 41 in a fluid-tight and slidable manner are coaxial. And it is connected continuously.

  A retainer 45 engaged and supported by a clip 44 mounted on the inner surface of the cylinder hole 26 has one end of a clutch spring 43 that exerts a spring force that frictionally engages the movable clutch body 42 with the clutch surface 40 of the relay piston 35. The other end of the clutch spring 43 comes into contact with the movable clutch body 42.

  The adjustment nut 33 and the adjustment bolt 34 are engaged with each other by a fast screw 47 having a plurality of threads and grooves with a coarse pitch. One end of an over-adjustment prevention spring 48 that exerts a spring force that biases the adjustment nut 33 toward the brake piston 28 is brought into contact with the adjustment nut 33 and engaged and supported by a clip 49 mounted on the inner surface of the brake piston 28. The other end of the over-adjustment prevention spring 48 is brought into contact with and supported by the retainer 50.

  The adjustment nut 33 and the brake piston 28 cannot be rotated relative to each other due to the concave-convex engagement of the contact portions, and the back plate 22b of the first friction pad 22 and the brake piston 28 cannot be rotated relative to each other due to the concave-convex engagement thereof. It is.

  In such an adjustment mechanism 32, when hydraulic pressure is supplied to the brake hydraulic pressure chamber 30 during normal braking, the brake piston 28 that has received the hydraulic pressure elastically deforms the seal member 27, and the inside of the cylinder hole 26 is shown in FIG. When the first friction pad 22 is pressed against one side of the brake disk 21, the reaction causes the brake caliper 25 to move to the right side opposite to the moving direction of the brake piston 28, and the second clamping arm 25b The second friction pad 23 is pressed against the other side of the brake disc 21. As a result, the first and second friction pads 22 and 23 come into contact with both surfaces of the brake disc 21 with an equal surface pressure, and a braking force for braking the wheel is generated.

  During the braking, the hydraulic pressure supplied to the brake hydraulic pressure chamber 30 does not cause the adjustment nut 33 to generate an axial load, but the movable clutch body 42 integrated with the adjustment bolt 34 that meshes with the adjustment nut 33. In this case, a rightward load having a size obtained by multiplying the sectional area of the small piston 36 by the hydraulic pressure is generated, and a frictional engagement force corresponding to the load acts between the movable clutch body 42 and the clutch surface 40 of the relay piston 35. To do.

  Incidentally, since the hydraulic pressure acting on the brake hydraulic pressure chamber 30 during normal braking is relatively low, the frictional engagement force acting between the movable clutch body 42 and the relay piston 35 is also relatively small. Therefore, when the brake piston 28 moves forward as the wear of the linings 22a and 23a of the first and second friction pads 22 and 23 progresses, the adjusting nut 33 moves forward together with the brake piston 28 by the elastic force of the over-adjustment prevention spring 48. Then, the movable clutch body 42 integrated with the adjustment bolt 34 meshing with the adjustment nut 33 is pulled away from the clutch surface 40 of the relay piston 35 against the hydraulic pressure acting on the brake hydraulic pressure chamber 30 and the elastic force of the clutch spring 43. It is.

  When the movable clutch body 42 moves away from the clutch surface 40 of the relay piston 35, the adjustment bolt 34 urged rightward by the hydraulic pressure acting on the movable clutch body 42 and the elastic force of the clutch spring 43 becomes an unrotatable adjustment nut. While moving at a fast screw 47 relative to 33, it moves to the right while the movable clutch body 42 engages with the clutch surface 40 of the relay piston 35 again.

  In this way, as the linings 22a, 23a wear on the first and second friction pads 22, 23, the adjustment nut 33 moves relative to the adjustment bolt 34 so as to compensate for the amount of wear. Therefore, the clearance between the linings 22a and 23a of the first and second friction pads 22 and 23 and the brake disc 21 during non-braking can be automatically maintained constant.

  When the hydraulic pressure acting on the brake hydraulic pressure chamber 30 is reduced in order to release the brake state, the brake piston 28 moves backward by the deformation restoring force of the seal member 27, but the backward movement force is adjusted via the adjusting nut 33 and the adjusting bolt 34. Since the movable clutch body 42 is engaged with the clutch surface 40 of the relay piston 35, the relative rotation of the adjustment bolt 34 with respect to the adjustment nut 33 is restricted. Therefore, the brake piston 28 can only move back by a stroke corresponding to the backlash between the adjusting nut 33 and the adjusting bolt 34, and the backlash is between the first and second friction pads 22, 23 and the brake disk 21. Proper clearance of minutes is given.

  When strong braking is performed, the automatic adjustment is performed until the hydraulic pressure in the brake hydraulic pressure chamber 30 rises to a predetermined value. When the hydraulic pressure exceeds the predetermined value, the movable clutch body 42 is moved. Since it is strongly pressed against the clutch surface 40 of the relay piston 35 by hydraulic pressure, the movable clutch body 42 and the relay piston 35 are coupled so as not to be relatively rotatable. As a result, the adjustment bolt 34 is restrained to be non-rotatable, and the adjustment nut 33 that is originally non-rotatable remains on the adjustment bolt 34. Therefore, when the brake piston 28 further moves forward due to elastic deformation of the brake caliper 25 due to hydraulic pressure, While compressing the adjustment prevention spring 48, only the brake piston 28 moves forward leaving the adjustment nut 33. In this way, over-adjustment between the adjusting nut 33 and the adjusting bolt 34 when strong braking is performed is prevented.

  The parking brake mechanism 50 is disposed at the outer end portion of the first pinching arm 25 a in the brake caliper 25, has an axis perpendicular to the axis of the cylinder hole 26, and has the first pinching arm via the needle bearing 53. A cam shaft 52 rotatably supported on the outer end of 25a, and a cam surface 54 formed on the cam shaft 52 facing the rear end of the relay piston 35 and the rear end of the relay piston 35 are connected to each other. And a lever 56 whose base end is fixed to one end of the cam shaft 52 protruding from the first sandwiching arm 25a.

  A wire 57RR is connected to the tip of the lever 56. When a traction force acts on the wire 57RR, the lever 56 and the cam shaft 52 rotate counterclockwise in FIG. 2 and are pushed by the cam surface 54. 55, the relay piston 35 is pushed forward (leftward in FIG. 2).

  Accordingly, when the right rear wheel brake 5RR is in the parking brake state, the wire 57RR may be pulled, and the relay piston 35 will push the brake piston 28 via the adjusting bolt 34 and the adjusting nut 33, The first and second friction pads 22 and 23 can be pressed against the brake disc 21 to obtain a braking force.

  The left rear wheel brake 5RL is also configured in the same manner as the right rear wheel brake 5RR described above. By applying a traction force to the wire 57RL (see FIG. 1), the left rear wheel brake 5RL is braked. The parking brake state can be obtained by operating.

  As shown in FIG. 1, an equal traction force acts on the wires 57 RR and 57 RL from an equalizer 58, and a traction force acts on the equalizer 58 from a parking brake force generating means 60.

  In FIG. 3, the equalizer 58 is configured such that an equalizer case 61 fixed to a vehicle body (not shown) of the vehicle and the wires 57RR and 57RL movably penetrating the equalizer case 61 are connected from the same direction. An equalizer plate 62 movably accommodated in the case 61, a support member 63 fixed to the equalizer case 61, and a spring force that urges the equalizer plate 62 toward the side on which the wires 57RR and 57RL are loosened are exhibited. Thus, the support member 63 and a return spring 64 contracted between the equalizer plate 62 are provided, and the equalizer case 61 is moved to the equalizer plate 62 at the center between the connecting portions of the wires 57RR and 57RL. One end of a parking wire 65 penetrating freely is connected to the wire. 57RR, is coupled from 57RL opposite.

  Thus, when the parking wire 65 is pulled, the pulling force is evenly transmitted to both the wires 57RL and 57RR via the equalizer plate 62, whereby parking by the right rear wheel wheel brake 5RR and the left rear wheel wheel brake 5RL is performed. The brake state will be obtained.

  The parking brake force generating means 60 is rotatable about the rotation center C, and the rotation lever 66 to which the other end of the parking wire 65 is connected to one end, and a first operation that moves forward according to the hydraulic pressure action. And the second parking pistons 67 and 68 and the rotation lever 66 in order to rotate the rotation lever 66 to the side to pull the parking wire 65 in accordance with the forward movement of the parking pistons 67 and 68. A hydraulic cylinder 69 that connects the front end of the first parking piston 67 from the side opposite to the parking wire 65 to the end, and a side surface of the rotation lever 66 aligned with a virtual arc SA centered on the rotation center C. And a plurality of ratchet teeth 70... And an engaging claw 71 that engages with the ratchet teeth 70. The said hydraulic cylinder 69 with respect to 6 and a ratchet mechanism 72 which is disposed on the opposite side.

  An intermediate portion of the rotation lever 66 is rotatably supported by a support body 73 attached to the vehicle body via a support shaft 74 whose axis is the rotation center C. The cylinder body 75 of the hydraulic cylinder 69 is formed integrally with the support body 73 so that one end on the rotating lever 66 side is opened and the other end is liquid-tightly closed by a lid member 76. The axis CL of the cylinder body 75 is inclined with respect to the extension line L so as to be closer to the longitudinal extension line L of the parking wire 65 as it moves away from the rotation lever 66.

  The first and second parking pistons 67 and 68 are slidably fitted to the cylinder body 75 while having the same seal outer diameter so that the second parking piston 68 is disposed behind the first parking piston 67. Combined. The first parking piston 67 has a front land portion 67a and a rear land portion 67b spaced apart in the axial direction so as to form an annular recess 67c therebetween, and the rear land portion 67b is a cylinder body. 75 is liquid-tightly fitted. The front land portion 67a is provided with a concave portion 85 along the one diameter line so as to open forward, and the other end portion of the rotating lever 66 inserted into the concave portion 85 is the closed end of the concave portion 85. Abut. The second parking piston 68 has a front land portion 68a and a rear land portion 68b spaced apart in the axial direction so as to form an annular recess 68c therebetween, and the rear land portion 68b is a cylinder body 75. The front land portion 68a is coaxially brought into contact with the rear end of the first parking piston 67.

  Thus, the first parking hydraulic pressure that allows the back surface of the first parking piston 67 to face the cylinder body 75 between the rear land portion 67b of the first parking piston 67 and the rear land portion 68b of the second parking piston 68. A chamber 77 is formed, and a second parking fluid pressure chamber 78 that faces the back surface of the second parking piston 68 between the lid member 76, which is the rear end wall of the cylinder body 75, and the rear land portion 67b of the second parking piston 68. Is formed.

  The first parking fluid pressure chamber 77 is connected to the first fluid pressure passage 20A of the first brake system B1 via a normally closed electromagnetic valve 79A attached to the cylinder body 75 and a pressure guide passage 80A (see FIG. 1). The second parking hydraulic pressure chamber 78 is connected to the second hydraulic pressure path 20B of the second brake system B2 via a normally closed electromagnetic valve 79B attached to the cylinder body 75 and a pressure guiding path 80B (see FIG. 1). Is done.

  Thus, the normally closed solenoid valve is in a state where the hydraulic pressure from the master cylinder M or the hydraulic pressure from the first and second pumps 10A and 10B is acting on the first and second hydraulic pressure paths 20A and 20B. When the valves 79A and 79B are opened to apply hydraulic pressure to the first and second parking hydraulic pressure chambers 77 and 78, as shown in FIG. 4, the first and second parking pistons 67 and 68 move forward, As a result, the turning lever 66 is turned in the direction of pulling the parking wire 65, and the right rear wheel wheel brake 5RR and the left rear wheel wheel brake 5RL are braked to obtain a parking brake state.

  The ratchet mechanism 72 is engaged with the rotating lever 66 rotated so as to obtain the parking brake state, and mechanically holds the rotating position of the rotating lever 66. It is rotatably supported on the support body 73 via another support shaft 81 having an axis parallel to the axis of the support shaft 74, and is springed by a torsion spring 82 in a direction to engage with one of the ratchet teeth 70. Be energized.

  According to such a ratchet mechanism 72, the engaging claw 71 is engaged with the ratchet tooth 70 when the rotating lever 66 rotated so that the ratchet teeth 70... Thus, the rotation position of the rotation lever 66 is locked to the machine.

  In addition, in the state where the rotation lever 66 is rotated according to the operation of the hydraulic cylinder 69, that is, the state shown in FIG. When the distance between the moving centers C is r1, the distance between the connecting point of the parking wire 65 to the rotating lever 66 and the rotating center C is r2, and the radius of the virtual arc SA is r3, r1 <r2 , R3 ≦ r2.

  The locked state of the rotating lever 66 by the ratchet mechanism 72 is released by a solenoid 83 attached to the support 73, and the solenoid 83 has a connecting rod 84 that is pulled in when energized. 84 is connected to the engaging claw 71 so as to forcibly rotate the engaging claw 71 to the side where the engagement with the ratchet teeth 70 is released when the solenoid 83 is energized. Thus, when the connecting rod 84 is pulled by the solenoid 83 to release the locked state of the rotating lever 66, the normally closed solenoid valve is used to facilitate the release of the ratchet teeth 70 and the engaging claws 71. 79A and 79B are opened once, and hydraulic pressure is applied to the first and second parking hydraulic pressure chambers 77 and 78 to extend the hydraulic cylinder 69 and rotate the rotary lever 66 while rotating the solenoid 83. Energize to.

  Next, the operation of this embodiment will be described. A force for pulling the parking wire 65 for operating the parking brake mechanisms 50 provided on the right rear wheel brake 5RR and the left rear wheel brake 5RL is generated. The parking brake force generating means 60 is rotatable about a rotation center C and has a rotation lever 66 to which a parking wire 65 is connected at one end, and first and second parking operations that move forward in response to a hydraulic pressure action. The parking lever 67 has the other end of the rotating lever 66 to rotate the rotating lever 66 to the side of pulling the parking wire 65 in accordance with the forward movement of the parking pistons 67, 68. A hydraulic cylinder 69 for connecting the front end of the first parking piston 67 from the opposite side of the wire 65; A plurality of ratchet teeth 70 provided on the side surface of the rotation lever 65 side by side on the virtual arc SA centered on the rotation center C and an engaging claw 71 that engages with the ratchet teeth 70. A ratchet mechanism 72 disposed on the opposite side of the hydraulic cylinder 69 with respect to the rotating lever 65 is provided.

  Thus, according to the configuration of the parking brake force generating means 60 that rotates the rotating lever 66 by the operation of the hydraulic cylinder 69 and pulls the parking wire 65, a complicated link mechanism is not required and the liquid is reduced. While it is possible to set the length of the pressure cylinder 69 as short as possible, the parking wire 65 can be pulled by a sufficient amount. The ratchet mechanism 72 for holding the ratchet teeth 70 can be disposed over a sufficient length.

  Moreover, since the hydraulic cylinder 69 has an axis CL that is inclined with respect to the longitudinal extension line L so as to approach the longitudinal extension line L of the parking wire 66 as it moves away from the rotation lever 66, the parking cylinder 69 The parking brake force generating means 60 can be configured compactly along the longitudinal direction of the wire 65.

  Further, the rotation lever 66, the hydraulic cylinder 69 and the ratchet mechanism 72 are disposed on the common support body 73, and a solenoid 83 for releasing the lock state of the rotation lever 66 by the ratchet mechanism 72 is also disposed on the support body 73. The turning lever 66, the hydraulic cylinder 69, the ratchet mechanism 72, and the solenoid 83 can be unitized to improve the ease of assembly to the vehicle body.

  Moreover, in the operating state of the parking brake force generating means 60, the distance between the hydraulic pressure acting point of the hydraulic cylinder 69 on the rotating lever 66 and the rotation center C is r1, and the rotating lever 66 of the parking wire 65 is Since r1 <r2 is set when the distance between the connecting point and the rotation center C is r2, the operation stroke of the hydraulic cylinder 69 becomes too large to pull the parking wire 65 by a sufficient amount. In addition, when the radius of the virtual arc SA on which the ratchet teeth 70d are arranged side by side is set to r3, r3 ≦ r2 is set, so that the parking brake force generating means 60 is enlarged by the arrangement of the ratchet mechanism 72. Can be suppressed.

  Further, the hydraulic cylinder 69 of the parking brake force generating means 60 is connected to the first hydraulic path 20A of the first brake system B1 and the second hydraulic path 20B of the second brake system B2, which are connected individually. The first and second parking pistons 67 and 68 with their rear faces facing the parking fluid pressure chambers 77 and 78 are slidably fitted to a common cylinder body 75, and the output fluid of the master cylinder M The parking brake mechanism 50 can be operated by operating the hydraulic cylinder 69 and rotating the rotation lever 66 by both the pressure and the output hydraulic pressure of the first and second pumps 10A and 10B. Moreover, even if one of the first and second hydraulic pressure paths 20A and 20B has a hydraulic pressure failure, the hydraulic pressure of the other hydraulic pressure path is transferred to the other of the first and second parking hydraulic pressure chambers 77 and 78. By acting, at least one of the first and second parking pistons 67, 68 can be operated forward, and the parking brake mechanism 50 can be reliably ensured even if any of the pair of brake systems B1, B2 fails. Can be activated.

  In addition, the first and second parking pistons 67 and 68 having the same seal outer diameter are slidable on the cylinder body 75 so as to be coaxially arranged so that the second parking piston 68 is disposed behind the first parking piston 67. , A second parking hydraulic pressure chamber 78 is formed between the rear end wall 76 of the cylinder body 75 and the second parking piston 68, and a first parking hydraulic pressure is established between the first and second parking pistons 67, 68. Since the chamber 77 is formed and the front end of the first parking piston 67 is connected to the other end portion of the rotating lever 66, the first and second parking fluids are in a state in which no hydraulic pressure is lost. By simultaneously applying the hydraulic pressure to the pressure chambers 77 and 78, the first parking piston 67 can be moved forward more quickly, It can accelerate the response speed at the time of key. Further, when the parking brake state is obtained with the output hydraulic pressure of the master cylinder M, the fluid loss in both the brake systems B1 and B2 is equalized, and the braking force is not unbalanced between the two brake systems B1 and B2.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

It is a figure which shows the whole structure of the brake device for vehicles. It is a longitudinal cross-sectional view of the wheel brake for right rear wheels. It is a longitudinal cross-sectional view of an equalizer and a parking brake force generation means. FIG. 4 is a longitudinal sectional view corresponding to FIG. 3 in a parking brake operating state.

Explanation of symbols

5RL: wheel brake for left rear wheel 5RR: wheel brake for right rear wheel 60 ... parking brake force generating means 65 ... parking wire 66 ... rotating levers 67, 68 ... parking piston 69 ... Hydraulic cylinder 70 ... Ratchet teeth 71 ... Engaging claw 72 ... Ratchet mechanism C ... Center of rotation SA ... Virtual arc

Claims (1)

  A wheel brake (5RL, 5RR) that enables a parking brake state according to the pulling of the parking wire (65), and a parking brake force generating means (60 that can generate a force to pull the parking wire (65). The parking brake force generating means (60) is rotatable about a rotation center (C) and is connected to one end of the parking wire (65). (66) and a parking piston (67, 68) that moves forward according to a hydraulic pressure action, and pulls the parking wire (65) according to the forward movement of the parking piston (67, 68). Opposite to the parking wire (65) at the other end of the pivot lever (66) to pivot the pivot lever (66) And a plurality of ratchet teeth (70) provided on a side surface of the rotation lever (66) side by side on a virtual arc (SA) centered on the rotation center (C). ) And an engaging claw (71) that engages with the ratchet teeth (70), and a ratchet mechanism (72) disposed on the opposite side of the rotating cylinder (69) from the hydraulic cylinder (69). ), The distance between the hydraulic pressure acting point of the hydraulic cylinder (69) on the rotary lever (66) and the rotary center (C) is r1, and the rotary lever of the parking wire (65) When the distance between the connection point to (66) and the rotation center (C) is r2, and the radius of the virtual arc (SA) is r3, r1 <r2 in the operating state of the hydraulic cylinder (69). , R3 ≦ r2 Vehicle brake apparatus according to symptoms.

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