JP2006240497A - Vehicular brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular brake device to apply a parking brake provided on front wheels or rear wheels after applying the total wheel brakes which is capable of suppressing occurrence of pitching behavior of a vehicle when starting the application of the parking brake successive to the application of the total wheel brakes. <P>SOLUTION: By operating pumps 15A, 15B before the hydraulic pressure of hydraulic source fluid passages 5A, 5B reaches a predetermined value while first normally-open solenoid valves 4A, 4B are closed, wheel brakes 6A, 6C for front wheels and wheel brakes 6B, 6D for rear wheels are applied. To obtain the parking-braked condition by operating the parking brake, the first normally-open solenoid valves 4A, 4B are closed, the pumps 15A, 15B are operated, and normally-open solenoid valves 78A, 78B are opened simultaneously with or after the closing of second normally-open solenoid valves 8B, 8D. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicular brake device that can obtain a parking brake state by operating a parking brake provided on one of a front wheel and a rear wheel after all the brakes are braked with the output hydraulic pressure of a pump. .

A vehicular brake device that obtains an automatic parking brake state by operating a wheel brake using a hydraulic pressure output from a pump used for automatic brake control such as vehicle behavior control and traction control during non-brake operation For example, it is known in Patent Document 1.
Japanese Patent Laid-Open No. 10-76931

  However, as disclosed in Patent Document 1, the automatic parking brake state of all the wheel brakes using the output hydraulic pressure of the pump that outputs the hydraulic pressure during non-brake operation is used. As long as the brake state continues, the operation of the pump and the operation of the solenoid valve for controlling the output hydraulic pressure of the pump will continue, and if the duration of the automatic parking brake state becomes long, a problem occurs in terms of energy consumption.

  On the other hand, the present applicant uses the hydraulic pressure output from the pump to operate a hydraulically operated parking brake so that the automatic parking brake state can be maintained while the pump is stopped. A vehicle brake device having a reduced amount and a simplified configuration has already been proposed (Japanese Patent Application No. 2003-34495). According to this proposed device, the brake operation of all-wheel brakes using the output hydraulic pressure of the pump is proposed. Following this, it will be possible to reduce energy consumption by maintaining the parking brake state of some wheels.

  By the way, in the above-mentioned proposed apparatus, the pump operation is stopped and a parking brake is provided in response to the hydraulic pressure in the hydraulic pressure source fluid path connected to the discharge side of the pump reaching the set pressure by the pump operation. The parking brake is operated so as to obtain the parking brake state by opening the solenoid valve interposed between the wheel brake side hydraulic pressure path connected to the wheel brake of the selected wheel and the parking control hydraulic pressure chamber of the parking brake. The parking brake state is maintained by closing the solenoid valve. However, when the parking brake is operated on the uphill / downhill road, the solenoid valve is opened to maintain the hydraulic pressure on the parking brake following the state in which the hydraulic pressure is applied to all the wheel brakes in order to maintain the vehicle stop state. When started, the pump operation is stopped, so that not only the wheel brake of the wheel provided with the parking brake but also the wheel brake of the wheel not provided with the parking brake, the brake fluid pressure decreases, and the vehicle There is a possibility that the vehicle will roll back due to a decrease in the overall braking force. However, the set pressure is set to a value capable of maintaining the stop of the vehicle in anticipation of the brake pressure drop.

  The present invention has been made in view of such circumstances, and it is possible for a vehicle to suppress the occurrence of rolling back of the vehicle when the parking brake operation is started following the brake operation of the all-wheel brake. An object is to provide a brake device.

  In order to achieve the above object, the present invention provides a hydraulic pressure generating means for outputting a hydraulic pressure in response to a brake operation, a front wheel brake for a front wheel, and a rear wheel brake for a rear wheel. A front-side and rear-wheel wheel brake side hydraulic passage that is individually connected to the front-wheel and rear-wheel wheel brakes, and a hydraulic pressure source hydraulic passage common to the front-wheel and rear-wheel wheel brake side hydraulic passages A pump connected to the hydraulic pressure source hydraulic pressure path on the discharge side so that the hydraulic pressure can be output in a non-brake operation state, and a first interposed between the hydraulic pressure source hydraulic pressure path and the hydraulic pressure generating means A normally open solenoid valve, a parking brake provided on one of the front wheels and the rear wheel, which can be operated to obtain a parking brake state according to the hydraulic pressure action on the control hydraulic pressure chamber for parking, Of the hydraulic brakes on the rear wheel brake side The brake side hydraulic pressure path corresponding to the wheel on which the parking brake is provided and the second normally open solenoid valve provided between the hydraulic pressure source hydraulic pressure path and the wheel on the side on which the parking brake is provided A parking brake passage connecting the brake-side hydraulic pressure path and the parking control hydraulic pressure chamber, a normally closed solenoid valve interposed in the parking brake passage, the pump, a first normally open solenoid valve, a second A control unit for controlling the operation of the normally open solenoid valve and the normally closed solenoid valve, and the control unit is configured to control the hydraulic pressure of the hydraulic pressure source hydraulic pressure path in a state where the first normally open solenoid valve is closed. The parking brake state is obtained by operating the parking brake after the front wheel brake and the rear wheel brake are operated by operating the pump until the value reaches a predetermined value. Therefore, after closing the first normally open solenoid valve and operating the pump, the second normally open solenoid valve is closed, and at the same time as or after the second normally open solenoid valve is closed. The normally closed solenoid valve is opened.

  According to the above configuration of the present invention, the front wheel brake and the rear wheel are operated by operating the pump until the hydraulic pressure of the hydraulic pressure source hydraulic pressure path reaches a predetermined value with the first normally open solenoid valve closed. In order to obtain the parking brake state by the operation of the parking brake after the wheel brake is operated, the hydraulic pressure in the hydraulic pressure source hydraulic pressure path is reduced by closing the first normally open solenoid valve and operating the pump. After that, since the second normally open solenoid valve is closed, the brake fluid pressure of the wheel brake of the wheel on which the parking brake is not provided increases, and the second normally open solenoid valve is closed. At the same time or after the valve is closed, the normally closed solenoid valve is opened to reduce the brake fluid pressure of the wheel brake on the side where the parking brake is provided, but the parking brake operates. It will be started. In other words, when the parking brake is started, the brake fluid pressure of the wheel brake on the wheel on which the parking brake is not provided does not decrease and continues to increase. Even when the hydraulic pressure is applied to the brake, the normally closed solenoid valve is opened to start the hydraulic pressure action on the parking brake. It is possible to suppress the occurrence of swaying.

  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 5 show an embodiment of the present invention, FIG. 1 is a hydraulic circuit diagram of a vehicle brake device, FIG. 2 is a longitudinal sectional view of a disc brake during non-parking brake, and FIG. FIG. 4 is a block diagram showing the configuration of a control system related to the parking brake, and FIG. 5 is a diagram showing changes in the brake hydraulic pressure and the vehicle turning back when the hydraulic pressure action is applied to the parking brake. is there.

  First, in FIG. 1, a tandem master cylinder M as a hydraulic pressure generating means for generating a brake hydraulic pressure corresponding to a brake operation amount of a vehicle driver, that is, a pedaling force applied to the brake pedal P by the vehicle driver, First and second output ports 1A, 1B, the first output port 1A is connected to the first output hydraulic pressure path 3A, the second output port 1B is connected to the second output hydraulic pressure path 3B, A hydraulic pressure sensor 13 for detecting the output hydraulic pressure from the master cylinder M is provided in the second output hydraulic pressure path 3B.

  The first and second output hydraulic pressure passages 3A and 3B are connected to the first and second hydraulic pressure source hydraulic pressure passages 5A and 5B via the first and second regulator valves 4A and 4B which are first normally open solenoid valves. Connected to. The first and second regulator valves 4A and 4B are linear solenoid valves that are electrically controlled so as to be able to switch between a fully open state and a fully closed state and to obtain a half open state between the fully open and fully closed states.

  The first hydraulic pressure source hydraulic path 5A is connected to the left front wheel wheel brake side hydraulic path 7A connected to the left front wheel brake 6A, which is a disc brake, via an inlet valve 8A, which is a normally open solenoid valve. And connected to the right rear wheel wheel brake side hydraulic pressure passage 7B connected to the right rear wheel wheel brake 6B, which is a disc brake, via an inlet valve 8B, which is a second normally open solenoid valve. The second hydraulic pressure source hydraulic pressure path 5B is connected to the right front wheel wheel brake side hydraulic pressure path 7C connected to the right front wheel brake 6C via an inlet valve 8C, which is a normally open solenoid valve. A left rear wheel wheel brake side hydraulic pressure passage 7D connected to the left rear wheel wheel brake 6D, which is a disc brake, is connected via an inlet valve 8D, which is a second normally open solenoid valve. Further, check valves 9A to 9D are connected in parallel to the respective inlet valves 8A to 8D.

  The inlet valves 8A to 8D are linear solenoid valves that are electrically controlled so as to be able to switch between a fully open state and a fully closed state and to obtain a half open state between the fully open and fully closed states.

  Between the first reservoir 12A corresponding to the first output hydraulic pressure path 3A and the left front wheel and right rear wheel wheel brake side hydraulic pressure paths 7A, 7B, an outlet valve 10A, which is a normally closed solenoid valve, 10B is provided, and a normally closed solenoid valve is provided between the second reservoir 12B corresponding to the second output hydraulic pressure path 3B and the wheel brake side hydraulic pressure paths 7C and 7D for the right front wheel and the left rear wheel. The outlet valves 10C and 10D are respectively provided.

  Thus, the inlet valve 8A, the check valve 9A and the outlet valve 10A, and the inlet valve 8B, the check valve 9B and the outlet valve 10B are connected to the first front wheel and right rear wheel wheel brake side hydraulic pressure passages 7A and 7B. The control valve means 11A and 11B which can be operated by controlling the hydraulic pressure of the pressure source hydraulic pressure path 5A are configured, and the inlet valve 8C, the check valve 9C and the outlet valve 10C, the inlet valve 8D, the check valve 9D and the outlet valve 10D. Constitutes control valve means 11C, 11D which can control the hydraulic pressure of the second hydraulic pressure source hydraulic pressure path 5B to act on the right brake wheel hydraulic pressure paths 7C, 7D for the right front wheel and the left rear wheel.

  The first and second reservoirs 12A and 12B are arranged on the suction side of the first and second pumps 15A and 15B driven by a common electric motor 14 capable of controlling the rotational speed, and brakes for the pumps 15A and 15B are provided. It is connected via one-way valves 16A and 16B and suction valves 17A and 17B that allow the flow of liquid, and the discharge side of the first pump 15A is a first hydraulic pressure source via a discharge valve 18A and a first damper 19A. Connected to the hydraulic pressure path 5A, the discharge side of the second pump 15B is connected to the second hydraulic pressure source hydraulic pressure path 5B via the discharge valve 18B and the second damper 19B.

  The first output hydraulic pressure path 3A is connected to the suction side of the first pump 15A, that is, between the one-way valve 16A and the suction valve 17A via the first suction valve 20A, which is a normally closed electromagnetic valve, and the second output fluid The pressure path 3B is connected to the suction side of the second pump 15B, that is, between the one-way valve 16B and the suction valve 17B via a second suction valve 20B which is a normally closed electromagnetic valve.

  Thus, by operating the electric motor 14 with the first and second suction valves 20A and 20B opened, the first and second pumps 15A and 15B are sucked and pressurized from the master cylinder M side. The brake fluid is discharged to the first and second hydraulic pressure source hydraulic pressure paths 5A and 5B. At this time, the first and second brake pressures are detected by pressure sensors 80A and 80B provided in the wheel brake side hydraulic pressure paths 7B and 7D connected to the right rear wheel and left front wheel brakes 6B and 6D. By controlling the operation of the regulator valves 4A, 4B, the hydraulic pressures of the first and second hydraulic pressure source hydraulic pressure paths 5A, 5B can be regulated, and the first and second hydraulic pressure source hydraulic pressure paths 5A, By controlling the constant hydraulic pressure of 5B with the control valve means 11A to 11C, different brake hydraulic pressures can be applied to the wheel brakes 6A to 6D, thereby controlling behavior stability and traction during vehicle travel. Automatic brake control such as control can be executed. In addition, the first and second regulator valves 4A and 4B can change the hydraulic pressure of the first and second hydraulic pressure source hydraulic pressure paths 5A and 5B to high and low.

  Further, when the brake is operated, the first and second regulator valves 4A and 4B are opened, and the first and second suction valves 20A and 20B are closed, so that each wheel may be locked. When there is no valve, the inlet valves 8A to 8D of the control valve means 11A to 11D are opened and the outlet valves 10A to 10D are closed, and output from the first output port 1A of the master cylinder M. The brake fluid pressure acts on the left front wheel brakes 6A and 6B via the inlet valves 8A and 8B. The brake hydraulic pressure output from the second output port 1B of the master cylinder M acts on the right front wheel brakes 6C and 6D via the inlet valves 8C and 8D.

  When the wheel is about to enter the locked state during the braking, the inlet valve corresponding to the wheel that is about to enter the locked state among the inlet valves 8A to 8D is closed and the outlet valves 10A to 10D are also closed. The outlet valve corresponding to the wheel is 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 12A or the second reservoir 12B, 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 inlet valves 8A to 8D are closed and the outlet valves 10A to 10D are closed, and when the brake fluid pressure is further increased. In this case, the inlet valves 8A to 8D may be opened and the outlet valves 10A to 10D may be closed.

  By controlling the demagnetization / excitation of each of the inlet valves 8A to 8D and the outlet valves 10A to 10D in this way, braking can be performed efficiently without locking the wheels.

  Thus, during the anti-lock brake control as described above, the electric motor 14 rotates and the first and second pumps 15A and 15B are driven in accordance with the operation of the electric motor 14. The brake fluid absorbed in the two reservoirs 12A, 12B is sucked into the first and second pumps 15A, 15B, and then the first and second dampers 19A, 19B, the first and second hydraulic pressure source hydraulic pressure paths 5A, 5B is returned to the first and second output hydraulic pressure passages 3A and 3B through the first and second regulator valves 4A and 4B. Such a recirculation of the brake fluid can prevent an increase in the depression amount of the brake pedal P due to the absorption of the brake fluid in the first and second reservoirs 12A and 12B. In addition, the pulsation of the discharge pressures of the first and second pumps 15A and 15B is suppressed by the action of the first and second dampers 19A and 19B, and the operation feeling of the brake pedal P is not hindered by the reflux.

  In FIG. 2, in the right rear wheel wheel brake 6 </ b> B, the first friction pad 25 and the second friction pad 26 are disposed opposite to each other of the brake disc 24 that rotates together with the wheel. These first and second friction pads 25 and 26 are composed of linings 25a and 26a that can come into contact with the brake disc 24, and back plates 25b and 26b fixed to the back surfaces of the linings 25a and 26a. The back plates 25b and 26b are supported by a bracket 27 fixed to the vehicle body so as to be movable in a direction along the axis of the brake piston 31. A brake caliper 28 straddling the first and second friction pads 25 and 26 is supported on the bracket 27 so as to be movable in the axial direction of the brake piston 31.

  The brake caliper 28 includes a first sandwiching arm 28a facing the back plate 25b of the first friction pad 25, and a second sandwiching arm 28b facing the back plate 26b of the second friction pad 26. The second sandwiching arms 28 a and 28 b are integrally connected by a bridging portion 28 c that passes through the outer periphery of the brake disc 24. The first pinching arm 28 a is provided with a cylinder hole 29, and a cup-shaped brake piston 31 is slidably fitted into the cylinder hole 29 via a seal member 30. The front end of the brake piston 31 opposed to the back plate 25b of the first friction pad 25 is connected to the open end of the cylinder hole 29 by a bellows-like dust cover 32, and the brake which faces the back of the brake piston 31. A hydraulic pressure chamber 33 is formed in the first pinch arm 28a, and the brake hydraulic pressure chamber 33 is connected to the right rear wheel wheel brake side hydraulic pressure path 7B via a port 34 provided in the first pinch arm 28a. The

  An adjusting mechanism 35 is provided in the first pinching arm 28a of the brake caliper 28. The adjusting mechanism 35 is connected to the brake piston 31 so as not to be relatively rotatable and is accommodated in the brake hydraulic pressure chamber 33. An adjustment nut 36, an adjustment bolt 37 whose front end is screwed to the adjustment nut 36, and a rear portion of the brake fluid pressure chamber 33, and is capable of moving in the axial direction while preventing rotation around the axis. And a relay piston 38 that is liquid-tightly and slidably fitted to the brake caliper 28, and is integrally and coaxially connected to the rear portion of the adjustment bolt 37 so as to be liquid-tight and slidable to the relay piston 38. And a small piston 39 that is fitted and elastically biased in a direction in which the relay piston 38 is frictionally engaged.

  A relay cylinder hole 40 having a diameter smaller than that of the cylinder hole 29 is coaxially provided at the end of the first clip arm 28a of the brake caliper 28 on the side opposite to the brake disk 24, and the rear portion of the stepped relay piston 38 is formed at the rear end. The front part is inserted into the rear part of the cylinder hole 29 and is slidably fitted into the relay cylinder hole 40 via the seal member 41. Moreover, the brake caliper 28 and the relay piston 38 are fitted with both ends of a regulation pin 42 that has an axis parallel to the cylinder hole 29 and the relay cylinder hole 40 and is disposed at a position offset from the axis of the cylinder hole 29. The As a result, the relay piston 38 is prevented from rotating around an axis that is coaxial with the cylinder hole 29 and the relay cylinder hole 40, and can be moved in the direction along the axis to be supported by the brake caliper 28. .

  The relay piston 38 is coaxially provided with a small cylinder hole 44 having a tapered clutch surface 43 at the front end opening. On the other hand, at the rear part of the adjusting bolt 37, a movable clutch body 45 that can be frictionally engaged with the clutch surface 43 and a small piston 39 that fits in a liquid-tight and slidable manner in the small cylinder hole 44 are coaxial. And it is connected continuously.

  The retainer 48 engaged and supported by the clip 47 attached to the inner surface of the cylinder hole 29 has one end of a clutch spring 49 that exerts a spring force that frictionally engages the movable clutch body 45 with the clutch surface 43 of the relay piston 38. The other end of the clutch spring 49 is in contact with the movable clutch body 45 via the ball bearing 50.

  The adjustment nut 36 and the adjustment bolt 37 are engaged with each other by a fast screw 51 having a plurality of threads and grooves having a coarse pitch. One end of an over-adjustment prevention spring 52 that exerts a spring force for urging the adjustment nut 36 toward the brake piston 31 is brought into contact with the adjustment nut 36 and engaged and supported by a clip 53 mounted on the inner surface of the brake piston 31. The other end of the over-adjustment prevention spring 52 is brought into contact with and supported by the retainer 54.

  The adjustment nut 36 and the brake piston 31 cannot be rotated relative to each other due to the concave-convex engagement of the contact portions, and the back plate 25b of the first friction pad 25 and the brake piston 31 cannot be rotated relative to each other due to the concave-convex engagement. It is.

  In such an adjustment mechanism 35, when hydraulic pressure is supplied to the brake hydraulic pressure chamber 33 during normal braking, the brake piston 31 that has received the hydraulic pressure elastically deforms the seal member 30, and the inside of the cylinder hole 29 is shown in FIG. When the first friction pad 25 is pressed against one side of the brake disc 24, the brake caliper 28 is moved to the right in the direction opposite to the moving direction of the brake piston 31, and the second clamping arm 28b is moved. The second friction pad 26 is pressed against the other side of the brake disc 24. As a result, the first and second friction pads 25 and 26 come into contact with both surfaces of the brake disc 24 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 33 does not cause the adjustment nut 36 to generate a load in the axial direction, but the movable clutch body 45 integrated with the adjustment bolt 37 that meshes with the adjustment nut 36. In this case, a rightward load having a size obtained by multiplying the cross-sectional area of the small piston 39 by the hydraulic pressure is generated, and a frictional engagement force corresponding to the load acts between the movable clutch body 45 and the clutch surface 43 of the relay piston 38. To do.

  Incidentally, since the hydraulic pressure acting on the brake hydraulic pressure chamber 33 during normal braking is relatively low, the frictional engagement force acting between the movable clutch body 45 and the relay piston 38 is also relatively small. Therefore, when the brake piston 31 moves forward with the progress of wear of the linings 25a and 26a of the first and second friction pads 25 and 26, the adjusting nut 36 moves forward together with the brake piston 31 by the elastic force of the over-adjustment prevention spring 52. Then, the movable clutch body 45 integrated with the adjustment bolt 37 meshing with the adjustment nut 36 is separated from the clutch surface 43 of the relay piston 38 against the hydraulic pressure acting on the brake hydraulic pressure chamber 33 and the elastic force of the clutch spring 49. It is.

  When the movable clutch body 45 moves away from the clutch surface 43 of the relay piston 38, the adjustment bolt 37 urged to the right by the hydraulic pressure acting on the movable clutch body 45 and the elastic force of the clutch spring 49 becomes an adjustment nut that cannot rotate. The movable clutch body 45 is engaged with the clutch surface 43 of the relay piston 38 again. At this time, the movable clutch body 45 can be smoothly rotated by the action of the ball bearing 50 disposed between the clutch spring 49 and the clutch spring 49.

  Thus, as the linings 25a and 26a wear on the first and second friction pads 25 and 26, the adjustment nut 36 moves relative to the left side with respect to the adjustment bolt 37 so as to compensate for the amount of wear. Therefore, the clearance between the linings 25a and 26a of the first and second friction pads 25 and 26 and the brake disk 24 during non-braking can be automatically maintained constant.

  When the hydraulic pressure acting on the brake hydraulic pressure chamber 33 is reduced in order to release the brake state, the brake piston 31 moves backward by the deformation restoring force of the seal member 30, but the backward movement force is adjusted via the adjustment nut 36 and the adjustment bolt 37. Since the movable clutch body 45 is engaged with the clutch surface 43 of the relay piston 38, the relative rotation of the adjustment bolt 37 with respect to the adjustment nut 36 is restricted. Therefore, the brake piston 31 can only move backward for the backlash between the adjusting nut 36 and the adjusting bolt 37, and the backlash is between the first and second friction pads 25, 26 and the brake disk 24. 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 33 rises to a predetermined value that causes the brake caliper 28 to be deformed, and the hydraulic pressure reaches the predetermined value. If exceeded, the movable clutch body 45 is strongly pressed against the clutch surface 43 of the relay piston 38 by hydraulic pressure, so that the movable clutch body 45 and the relay piston 38 are coupled so as not to be relatively rotatable. As a result, the adjustment bolt 37 is restrained to be non-rotatable, and the adjustment nut 36 that is originally non-rotatable stays on the adjustment bolt 37. While compressing the adjustment preventing spring 52, only the brake piston 31 moves forward leaving the adjusting nut 36. In this way, over-adjustment between the adjusting nut 36 and the adjusting bolt 37 when strong braking is performed is prevented.

  Referring also to FIG. 3, a parking brake 57 is attached to the right rear wheel wheel brake 6 </ b> B, and the parking brake 57 extends to the opposite side of the brake disc 24 so as to extend to the brake caliper. A parking piston 58 that comes into contact with the relay piston 38 from the rear side is slidably fitted to a casing 56 that is integrally connected to the first sandwiching arm 28a of the 28.

  The casing 56 forms a sliding hole 61 that is coaxial with the cylinder hole 29 of the brake caliper 28, and it is possible to obtain a parking brake state by a forward operation in accordance with the action of the control fluid pressure for parking on the back surface. The parking piston 58 is slidably fitted into the sliding hole 61 so as to contact the relay piston 38 from the rear, and the parking piston 58 is mechanically locked in the forward position. A lock mechanism 59 that automatically locks in response to the forward operation and unlocks in response to the operation of the parking release control hydraulic pressure is provided in the casing 56 on the rear side of the parking piston 58.

  The sliding hole 61 has a larger diameter than the relay cylinder hole 40 and is connected to the rear end of the relay cylinder hole 40 coaxially with the parking piston front sliding hole 61a and the parking piston front sliding hole 61a. The parking piston rear sliding hole 61b is coaxially connected to the rear end of the parking piston front sliding hole 61a, and the parking piston rear sliding hole 61b has a smaller diameter than the parking piston rear sliding hole 61b. A lock piston front sliding hole 61c that is coaxially connected to the rear end of the sliding hole 61b and a diameter larger than that of the lock piston front sliding hole 61c. The rear end of the lock piston includes a rear slide hole 61d coaxially connected to the rear end, and the rear end of the lock piston rear slide hole 61d is closed by a rear end wall 56a of the casing 56.

  An annular step 61e facing forward is formed on the inner surface of the casing 56 between the parking piston front sliding hole 61a and the parking piston rear sliding hole 61b, and the parking piston rear sliding hole 61a and the lock piston front An annular locking step 61f facing forward is formed on the inner surface of the casing 56 between the inner sliding holes 61c, and the casing is further formed between the locking piston front sliding hole 61c and the locking piston rear sliding hole 61d. On the inner surface of 56, an annular step portion 61g facing rearward is formed.

  The parking piston 58 has a large diameter portion 58a formed between a large diameter portion 58a and a large diameter portion 58a facing the rear, and a large diameter portion 58a slidably fitted in the parking piston front sliding hole portion 61a. A small-diameter portion 58b that is coaxially connected to the rear portion of the diameter portion 58a and that is slidably fitted into the parking piston rear sliding hole 61b is integrally formed. A pressing rod 58d for pressing the piston 38 from behind is integrally and coaxially connected.

  An annular parking control hydraulic pressure chamber 62 is formed between the casing 56 and the parking piston 58 between the step portion 58 c of the parking piston 58 and the step portion 61 e of the casing 56. Annular seal members 63 and 64 that are sealed from both sides are mounted on the outer surfaces of the large diameter portion 58a and the small diameter portion 58b of the parking piston 58. Moreover, the pressure receiving area of the parking piston 58 facing the parking control hydraulic pressure chamber 62 is set larger than the pressure receiving area of the small piston 39 facing the brake hydraulic pressure chamber 33.

  The lock mechanism 59 is slidably fitted to the casing 56 on the rear side of the parking piston 58 so that a forward biasing force acts when the parking piston 58 moves forward. Lock piston 65 that can be operated rearward, cylindrical holding cylinder 66 integrally and coaxially connected to the rear portion of the parking piston 58, and a plurality of circumferential positions of the holding cylinder 66. The holding cylinders 66 are held so as to be movable in the radial direction, and the holding cylinders 66 are inserted into the holding cylinders 66 so as to be capable of relative movement in the axial direction. And an insertion shaft 68 integrally connected to the front end of the lock piston 65 so as to be in contact with the inner side of the lock piston 65.

  The lock piston 65 is formed with a small diameter portion 65a formed between a small diameter portion 65a slidably fitted in the lock piston front sliding hole portion 61c and a rear portion of the small diameter portion 65a. A large-diameter portion 65b that is coaxially connected to the rear portion of the portion 65a and is slidably fitted into the lock piston rear sliding hole portion 61d is integrally provided.

  An annular parking release control hydraulic pressure chamber 69 is formed between the lock piston 65 and the casing 56 between the step portion 65c of the lock piston 65 and the step portion 61f of the casing 56, and the rear end wall 56a of the casing 56 and the lock piston. A spring chamber 70 is formed between 65, and an open chamber 71 opened to the outside is formed in the casing 56 between the parking piston 58 and the lock piston 65.

  Thus, on the outer surface of the small diameter portion 65 a of the lock piston 65, an annular seal member 72 that seals between the parking release control hydraulic pressure chamber 69 and the open chamber 71 is mounted, and the outer surface of the large diameter portion 65 b of the lock piston 65. Is attached with an annular seal member 73 for sealing between the parking release control hydraulic pressure chamber 69 and the spring chamber 70.

  A spring 74 is contracted between the rear end wall 56a and the lock piston 65, and the lock piston 65 is elastically biased toward the front side by the spring force of the spring 74. Moreover, the spring load of the spring 74 is set smaller than the spring load of the clutch spring 49 in the adjustment mechanism 35.

  .. Are provided at a plurality of positions spaced apart in the circumferential direction of the holding cylinder 66, and the spheres 67, 67... Are inserted and held in the holding holes 75, 75. Further, the insertion shaft 68 is configured such that each of the spheres 67, 67... Can be brought into rolling contact with the lock piston front sliding hole 61c in a state where the parking piston 58 is in the retreat limit as shown in FIG. When the parking piston 58 advances from the retreat limit and the lock piston 65 advances while the parking piston 58 moves forward, the parking piston rear sliding hole portion is formed in contact with the spheres 67, 67. The large-diameter shaft portion 68b on the rear side coaxially connected to the small-diameter shaft portion 68a can be pushed up outward along the radial direction of the holding cylinder 66 so as to come into contact with 61b, and the spherical bodies 67, 67. A portion is coaxially and integrally connected via a tapered step portion 68c that can change the position between the small diameter shaft portion 68a and the large diameter shaft portion 68b. .

  According to such a lock mechanism 59, when the parking piston 58 moves forward, the lock piston 65 is moved forward by the spring force of the spring 74, so that the large-diameter shaft portion 68b of the insertion shaft 68 at the front end of the lock piston 65 is moved. Each of the pushed up spheres 67, 67... Engages with the locking step portion 61f of the casing 56, thereby preventing the parking piston 58 from moving backward and maintaining the parking brake state. By applying the hydraulic pressure to the lock piston 65 and retracting the lock piston 65, the parking brake state can be released.

  A normally closed solenoid valve 78A is interposed in the parking brake passage 81A connecting the right rear wheel brake side hydraulic passage 7B communicating with the brake hydraulic chamber 33 and the parking control hydraulic chamber 62. The rear wheel brake side hydraulic pressure passage 7B is connected to the parking release control hydraulic pressure chamber 69 via a normally closed electromagnetic valve 79A.

  Thus, when the normally closed electromagnetic valve 78A is opened, the hydraulic pressure in the wheel brake side hydraulic pressure passage 7B can be applied to the parking control hydraulic pressure chamber 62 as the parking control hydraulic pressure. When the electromagnetic valve 79A is opened, the hydraulic pressure in the wheel brake side hydraulic pressure passage 7B acts on the parking release control hydraulic pressure chamber 69 as the parking release control hydraulic pressure.

  By the way, in obtaining the automatic parking brake state of the right rear wheel wheel brake 6B, as shown in FIG. 4, the electric motor 14 that drives the first pump 15A, the first regulator valve 4A, and the inlet valve 8B of the control valve means 11B. The operation of the outlet valve 10B and the normally closed solenoid valves 78A and 79A is controlled by the control unit C.

  The left rear wheel brake 8D is configured with a parking brake mechanism similar to the right rear wheel brake 8B described above. When obtaining the automatic parking brake state of the left rear wheel brake 8D, the right rear wheel As in the case of the wheel brake 8B, the electric motor 14 that drives the second pump 15B, the second regulator valve 4A, the second suction valve 20B, the inlet valve 8D and the outlet valve 10D of the control valve means 11D, A normally closed solenoid valve 78B (see FIG. 1) interposed in the parking brake passage 81B and a normally closed solenoid valve 79B (see FIG. 1) interposed between the left rear wheel wheel brake side hydraulic pressure path 7D and the lock mechanism. 1) may be controlled by the control unit C.

  When obtaining the automatic parking brake state, the control unit C switches between the following first to third modes in accordance with the vehicle speed, the passage of time, and the operating state of the engine. In the first mode, the vehicle speed is constant. Executed when the value drops below the value. In this first mode, the first and second regulator valves 4A and 4B are fully closed, the first and second suction valves 20A and 20B are opened, and the first and second pumps 15A and 15A are opened by the electric motor 14. 15B is driven, the normally closed solenoid valves 78A and 78B are kept in the closed state, and the inlet valves 8A to 8D of the control valve means 11A to 11D are held in the open state, which are detected by the pressure sensors 80A and 80B. The first and second suction valves 20A and 20B are closed in response to the hydraulic pressure of the wheel brake side hydraulic pressure passages 7B and 7D reaching a constant value, and the first and second pumps 15A and 15A by the electric motor 14 are closed. The operation of 15B is stopped. As a result, the lock mechanism 59 is maintained in the non-operating state, and all the hydraulic pressures of the first and second hydraulic pressure source hydraulic pressure paths 5A and 5B having a constant pressure are transmitted via the wheel brake side hydraulic pressure paths 7A to 7D. Will act on the brake fluid pressure chambers 33 of the wheel brakes 6A to 6D, and the brake pistons 31 are advanced by all the wheel brakes 6A to 6D, and all the wheel brakes 6A to 6D are braked.

  In the second mode, when the first and second regulator valves 4A and 4B are energized with a duty of 100% to fully close the first and second regulator valves 4A and 4B, heat damage may occur in the first and second regulator valves 4A and 4B. Therefore, the first mode is executed when the engine is operating for a predetermined time, for example, 30 seconds, and as shown in FIG. The first and second suction valves 20A and 20B are opened while the first and second regulator valves 4A and 4B are fully closed at the start time t1, and the first and second pumps 15A and 15B by the electric motor 14 are opened. Start driving. Next, at time t2 when the set time T1 has elapsed from the start time t1, the control unit C applies the right rear wheel brakes 6B and 6D to the left rear wheel brakes 6B and 6D with the normally closed solenoid valves 79A and 79B closed. The corresponding inlet valves 8B and 8D are closed, and the normally closed solenoid valves 78A and 78B are opened simultaneously with the closing of the inlet valves 8B and 8D or after the closing (in this embodiment).

  As a result, the brake fluid pressures of the left front wheel brakes 6A and 6C and the right front wheel brakes 6B and 6C, which are the wheel brakes of the wheels on which the parking brake 57 is not provided, continue to increase and simultaneously with the closing of the inlet valves 8B and 8D. By opening the normally closed solenoid valves 78A and 78B, the brake fluid pressure of the right rear wheel brakes 6B and 6D and the left rear wheel brakes 6B and 6D, which are the wheel brakes on the side where the parking brake 57 is provided, is reduced. However, the increase of the hydraulic pressure in the parking control hydraulic pressure chamber 62 in the parking brake 57 is started.

  Further, from time t3 when time T2 has elapsed from time t2, the control unit C operates the inlet valves 8B and 8D in the valve opening direction, and in controlling the operation of the inlet valves 8B and 8D in the valve opening direction. The control unit C gradually increases the opening degree of the inlet valves 8B and 8D from the fully closed state to the fully opened state so that the energization duty decreases sequentially from 100% to 90%, 80%,. Due to such stepwise opening changes of the inlet valves 8B and 8D, as shown in FIG. 5, the hydraulic pressures of the right and left front wheel brake side hydraulic passages 7A and 7C, that is, the right and left front wheel wheels The hydraulic pressures of the brakes 6A and 6C gradually decrease until they become equal to the hydraulic pressure of the parking control hydraulic pressure chamber 62 that is being increased, and such right and left front wheel brakes 6A and 6C. The gradual decrease in the hydraulic pressure makes it possible to prevent the occurrence of an oil hammer due to a rapid change in the hydraulic pressure.

  As the fluid pressure in the parking control fluid pressure chamber 62 increases, the parking piston 58 moves forward. After the parking piston 58 moves forward, the control unit C closes the normally closed solenoid valves 78A and 78B. To do. As a result, the hydraulic pressure in the parking control hydraulic pressure chamber 62 can be locked, and the advance position of the parking piston 58 can be held.

  When the parking piston 58 moves forward in this way, the relay piston 38 is advanced by the pressing rod 58d of the parking piston 58, and the relay piston 38 is connected to the brake piston 31 via the movable clutch body 45, the adjusting bolt 37, and the adjusting nut 36. Is kept pressed in the forward direction, and the parking brake state is maintained.

  In the process of obtaining the parking brake state, the relay piston 38 and the movable clutch body 45 are frictionally engaged with each other by the pressing force of the parking piston 58 so that the relative rotation is impossible. Therefore, the relative rotation of the adjustment bolt 37 and the adjustment nut 36 is restricted. Therefore, when the right rear wheel and left rear wheel brakes 6B and 6D function as parking brakes, the automatic adjustment by the adjustment mechanism 35 is not performed.

  In addition, the control unit C closes the first and second suction valves 20A and 20B after closing the normally closed solenoid valves 78A and 78B to lock the hydraulic pressure in the parking control hydraulic pressure chamber 62. The driving of the first and second pumps 15A, 15B by the electric motor 14 is stopped, and the first and second regulator valves 4A, 4B are operated in the valve opening direction. The first and second regulator valves 4A, 4A, In controlling the operation of the valve 4B in the valve opening direction, the control unit C controls the first and second regulator valves 4A and 4B with their energization duty in order to prevent an oil hammer from occurring due to a sudden change in hydraulic pressure. Is controlled to gradually increase from 100% to 90%, 80%, and so on, from the fully closed state to the fully open state.

  The third mode is executed when the operation of the engine is stopped after the execution of the second mode, and the control unit C opens the first and second solenoid valves 79A, 79B after opening the normally closed solenoid valves 79A, 79B. The second suction valves 20A and 20B are opened, the first and second pumps 15A and 15B are driven by the electric motor 14, and the first and second hydraulic pressure sources are driven by the first and second regulator valves 4A and 4B. The hydraulic pressure in the hydraulic pressure paths 5A and 5B is controlled to be less than the hydraulic pressure locked in the parking control hydraulic pressure chamber 62, and the normally closed solenoid valves 78A and 78B are opened.

  Thus, the lock piston 65 is moved forward by the spring force of the spring 74 in accordance with the release of the hydraulic pressure in the parking release control hydraulic pressure chamber 69, and the lock mechanism 59 is moved in response to the advance of the parking piston 58 and the lock piston 65. The spherical bodies 67, 67... Are locked so as to engage with the engaging step portion 61f. Thereafter, the control unit C opens the normally closed electromagnetic valves 78A and 78B to release the hydraulic pressure in the parking control hydraulic pressure chamber 62.

  Moreover, after releasing the hydraulic pressure in the parking control hydraulic pressure chamber 62, the control unit C stops driving the first and second pumps 15A, 15B by the electric motor 14, and opens the first and second regulator valves 4A, 4B. The first and second suction valves 20A, 20B are closed while operating in the valve direction, and the normally closed solenoid valves 78A, 78B are returned to the closed state. At this time, the operation of the first and second regulator valves 4A and 4B in the valve opening direction is performed from the fully closed state in order to prevent the occurrence of oil hammer due to a sudden change in hydraulic pressure, as described above. Control is performed so that the opening degree is gradually increased to the fully open state.

  When releasing the parking brake state obtained in the first mode, the control unit C opens the first and second suction valves 20A and 20B to thereby apply the hydraulic pressure acting on the wheel brakes 6A to 6D. At the same time, the normally closed electromagnetic valves 79A and 79B are opened to release the hydraulic pressure in the parking release control hydraulic pressure chamber 69.

  When the parking brake state obtained in the second mode is released, the control unit C opens the first and second suction valves 20A and 20B, and the electric motor 14 turns on the first and second pumps 15A and 15B. The wheel side brake hydraulic pressure passages 7A to 7D are controlled by controlling the operation of the first and second regulator valves 4A, 4B and adjusting the hydraulic pressure below the hydraulic pressure locked in the parking control hydraulic pressure chamber 62. 7D and the normally closed solenoid valves 78A and 78B; 79A and 79B are opened. As a result, the hydraulic pressure in the parking control hydraulic pressure chamber 62 is released at a speed corresponding to the hydraulic pressure difference between the parking control hydraulic pressure chamber 62 and the wheel brake side hydraulic pressure passages 7B and 7D.

  Moreover, after releasing the hydraulic pressure in the parking control hydraulic pressure chamber 62, the control unit C stops driving the first and second pumps 15A, 15B by the electric motor 14, and opens the first and second regulator valves 4A, 4B. The first and second suction valves 20A, 20B are closed while operating in the valve direction, and the normally closed electromagnetic valves 78A, 78B; 79A, 79B are returned to the closed state. At this time, the operation of the first and second regulator valves 4A and 4B in the valve opening direction is controlled so that the opening degree is gradually increased from the fully closed state to the fully opened state, as described above.

  When releasing the parking brake state obtained in the third mode, the control unit C opens the first and second suction valves 20A and 20B, and the electric motor 14 turns the first and second pumps 15A and 15B on. Actuate and control the operation of the first and second regulator valves 4A and 4B to apply the regulated hydraulic pressure to the wheel side brake hydraulic pressure paths 7A to 7D, and normally closed electromagnetic valves 78A and 78B; 79A , 79B are opened. Then, the hydraulic pressures in the brake hydraulic pressure chamber 33, the parking control hydraulic pressure chamber 62, and the parking release control hydraulic pressure chamber 69 increase simultaneously. In the pressure increasing process, first, the hydraulic pressure larger than the spring force of the spring 74 is obtained. Acts on the lock piston 65 so that the lock piston 65 moves backward, and then acts on the small piston 39 rather than the forward pressing force acting on the parking piston 58 by the fluid pressure in the parking control fluid pressure chamber 62. The hydraulic pressure in the reverse direction and the resultant force of the clutch spring 49 increase, and the parking piston 58 moves backward. As a result, the lock mechanism 59 is unlocked and the parking brake state is released.

  Next, the operation of this embodiment will be described. Until the hydraulic pressure in the first and second hydraulic pressure source hydraulic pressure paths 5A and 5B reaches a predetermined value with the first and second regulator valves 4A and 4B closed. In order to obtain a parking brake state by operating the parking brake 57 provided on the right rear wheel and the left rear wheel after all the wheel brakes 6A to 6D are braked by operating the first and second pumps 15A and 15B. The control unit C closes the first and second regulator valves 4A and 4B and activates the first and second pumps 15A and 15B, thereby allowing the first and second hydraulic pressure source hydraulic pressure paths 5A and 5B to operate. Since the hydraulic pressure is increased and then the inlet valves 8B and 8D are closed, the left front wheel which is the wheel brake of the wheel on which the parking brake 57 is not provided is provided. The brake fluid pressure of the right front wheel brakes 6A and 6C increases, and the parking brake 57 is provided by opening the normally closed solenoid valves 78A and 78B simultaneously with the closing of the inlet valves 8B and 8D. Although the brake fluid pressures of the right rear wheel brake and the left rear wheel brakes 6B and 6D, which are the wheel brakes of these wheels, are lowered, the operation of the parking brake 57 is started.

  That is, in FIG. 5, at time t2 when the parking brake 57 starts to operate, the brake fluid pressure of the left front wheel brakes 6A, 6C does not decrease and continues to increase. Even if the normally closed solenoid valves 78A and 78B are opened following the state in which the hydraulic pressure is applied to 6D and the hydraulic pressure action on the parking brake 57 is started, the brake force of the entire vehicle is reduced. Can be prevented. As a result, even when the parking brake is operated on the uphill / downhill road, as shown in FIG. 5, the amount of change in the vehicle swing at the start of the hydraulic action on the parking brake 57 is suppressed, so that the vehicle rollback is suppressed. It can be suppressed from occurring.

  On the other hand, in order to obtain the parking brake state by operating the parking brake 57 provided on the right rear wheel and the left rear wheel after the brakes of all the wheel brakes 6A to 6D are actuated, the conventional one is shown in FIG. As described above, when the operation of the parking brake 57 is started at time t4, the brake fluid pressures of the left front wheel brakes 6A and 6C and the right front wheel brakes, which are the wheel brakes of the wheels on which the parking brake 57 is not provided, also decrease. As a result, the braking force of the vehicle as a whole decreases and the vehicle rolls back, and according to the present invention, it is possible to suppress the occurrence of such rocking back.

  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.

  For example, in the above embodiment, the case where the lock mechanism 59 that mechanically maintains the operating state of the parking brake 57 is attached to the parking brake 57 has been described. However, the present invention is a vehicle brake device that does not include the lock mechanism 59. Is also applicable.

  In the above embodiment, the case where the parking brake 57 is provided on the rear wheel has been described. However, the present invention can also be applied to a vehicle brake device in which the parking brake 57 is provided on the rear wheel.

It is a hydraulic circuit diagram of the brake device for vehicles. It is a longitudinal cross-sectional view of the disc brake in a non-parking brake state. FIG. 3 is an enlarged view of a main part of FIG. 2. It is a block diagram which shows the structure of the control system relevant to a parking brake. It is a figure which shows the change of the brake fluid pressure at the time of the hydraulic-pressure action start to a parking brake, and vehicle rolling back. It is a figure corresponding to FIG. 5 of a prior art.

Explanation of symbols

4A, 4B: Regulator valves 5A, 5B, which are first normally open solenoid valves, hydraulic pressure source hydraulic pressure paths 6A, 6C, front wheel brakes 6B, 6D, rear wheel brakes 7A, 7C: Front wheel wheel brake side hydraulic passages 7B, 7D ... Rear wheel wheel brake side hydraulic passages 8A, 8B ... Inlet valves 15A, 15B with second normally open solenoid valves · Pump 57 ··· Parking brake 62 ··· Control fluid pressure chambers 78A and 78B for parking · Normally closed solenoid valves 81A and 81B ··· Parking brake passage C ··· Control unit M · · · hydraulic pressure Master cylinder as generating means

Claims (1)

  Hydraulic pressure generating means (M) for outputting hydraulic pressure in response to the brake operation, front wheel brakes (6A, 6C) mounted on the front wheels, and rear wheel brakes (6B, 6D) mounted on the rear wheels ), Front wheel and rear wheel wheel brake side hydraulic pressure paths (7A, 7C; 7B, 7D) individually connected to front wheel and rear wheel brakes (6A, 6C; 6B, 6D), front wheels and The hydraulic pressure source fluid pressure passage (5A, 5B) common to the rear wheel brake side fluid pressure passage (7A, 7C; 7B, 7D), and the fluid on the discharge side can output fluid pressure in a non-brake operation state. A pump (15A, 15B) connected to a pressure source hydraulic pressure path (5A, 5B), and a first one interposed between the hydraulic pressure source hydraulic pressure path (5A, 5B) and the hydraulic pressure generating means (M). 1 Normally open solenoid valve (4A, 4B) and hydraulic action on the control hydraulic pressure chamber (62) for parking Accordingly, a parking brake (57) provided on one of the front wheels and the rear wheels, which can be operated so as to obtain a parking brake state, and a wheel brake side hydraulic pressure path (7A, 7C; 7B, 7D), the second normally open provided between the brake side hydraulic pressure passage (7B, 7D) and the hydraulic pressure source hydraulic pressure passage (5A, 5B) corresponding to the wheel on which the parking brake (57) is provided. Type parking valve (8B, 8D) and parking side hydraulic pressure path (7B, 7D) corresponding to the wheel on which the parking brake (57) is provided and the parking control hydraulic pressure chamber (62) The brake passage (81A, 81B), the normally closed solenoid valve (78A, 78B) interposed in the parking brake passage (81A, 81B), and the pump (15A, 15B) ), A control unit (C) for controlling the operation of the first normally open solenoid valve (5A, 5B), the second normally open solenoid valve (8B, 8D) and the normally closed solenoid valve (78A, 78B). The control unit (C) includes the first normally open solenoid valve (4A, 4B) in a closed state until the hydraulic pressure in the hydraulic pressure source hydraulic pressure path (5A, 5B) reaches a predetermined value. By operating the pumps (15A, 15B), the front wheel brakes (6A, 6C) and the rear wheel brakes (6B, 6D) are braked, and the parking brake state by the operation of the parking brake (57) is changed. In order to obtain, the first normally open solenoid valve (5A, 5B) is closed and the pump (15A, 15B) is operated, and then the second normally open solenoid valve (8B, 8D) is closed, Closing the second normally open solenoid valve (8B, 8D) The vehicular brake device characterized in that the normally closed solenoid valve (78A, 78B) is opened simultaneously with the valve or after the valve is closed.

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