JP4385022B2 - Brake device for vehicle - Google Patents

Description

  The present invention relates to a vehicle brake device.

Output the hydraulic pressure according to the operation of the brake operation member. Adjust the output hydraulic pressure of the hydraulic pressure supply source according to the output hydraulic pressure of the master cylinder and apply it to the wheel brake. The output hydraulic pressure of the hydraulic pressure supply source is abnormal. For example, Patent Literature 1 already discloses a vehicle brake device in which an output hydraulic pressure of a master cylinder is applied to a wheel brake when the pressure decreases.
Japanese Patent No. 2876336

  By the way, in what was disclosed by the said patent document 1, in addition to the control valve which adjusts the hydraulic pressure of a hydraulic pressure supply source according to the output hydraulic pressure of a master cylinder, it outputs from the said control valve for anti-lock brake control. The hydraulic pressure control means for controlling the hydraulic pressure is provided, and the hydraulic pressure circuit becomes complicated. Various control circuits for automatic brake control have been proposed. If these control circuits are also added, the circuit configuration of the vehicle brake device becomes complicated, resulting in an increase in cost.

  The present invention has been made in view of such circumstances, and it is possible to arbitrarily control the ratio of the wheel brake hydraulic pressure to the output hydraulic pressure of the hydraulic pressure generating means with a simple and inexpensive hydraulic circuit configuration. In addition, an object of the present invention is a vehicle brake device that enables automatic brake control and anti-lock brake control.

  In order to achieve the above object, the invention described in claim 1 includes a hydraulic pressure generating means for outputting a hydraulic pressure in accordance with a brake operation, a wheel brake for operating a brake in accordance with an action of the hydraulic pressure, and the hydraulic pressure generation. A hydraulic pressure supply source capable of outputting a hydraulic pressure higher than an output hydraulic pressure of the means independently of the hydraulic pressure generating means, a reservoir, and an output hydraulic pressure of the hydraulic pressure generating means acting on the forward side. And a normally closed valve provided between the wheel brake and the hydraulic pressure supply source so as to have a first drive piston that causes the hydraulic pressure of the wheel brake to act backward, and to open by forward movement of the first drive piston. A mold opening / closing valve and a second drive piston for causing the hydraulic pressure of the hydraulic pressure generating means to act on the forward side and for causing the hydraulic pressure of the wheel brake to act on the backward side, and for the forward actuation of the second drive piston A normally open type on-off valve provided between the wheel brake and the reservoir so as to be closed, a first electric actuator for applying a driving force in the forward and backward directions to the first drive piston, and a second drive And a second electric actuator that applies a driving force in the forward and backward directions to the piston.

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the hydraulic pressure supply source is connected to the normally closed on / off valve side between the hydraulic pressure supply source and the normally closed on / off valve. A first direction valve that allows only the brake fluid to flow between the first one-way valve and the normally-closed on-off valve between the first-way valve and the normally-closed on-off valve. It is connected to the hydraulic pressure generating means through a second one-way valve that allows only circulation.

  The master cylinder M of the embodiment corresponds to the hydraulic pressure generating means of the present invention, the first solenoid 69 of the embodiment corresponds to the first electric actuator of the present invention, and the second solenoid 70 of the embodiment corresponds to the first solenoid of the present invention. It corresponds to 2 electric actuators.

  According to the first aspect of the present invention, when the first and second electric actuators are deactivated, the hydraulic pressure from the hydraulic pressure supply source in which the hydraulic pressure of the hydraulic pressure generating means is changed at a predetermined ratio is set to the wheel brake. In addition, by operating the first and second electric actuators, the ratio of the hydraulic pressure of the wheel brake to the output hydraulic pressure of the hydraulic pressure generating means can be arbitrarily controlled, and automatic brake control can be performed. It is also possible to perform anti-lock brake control, and it is simple and inexpensive that includes a normally closed on-off valve and a normally open on-off valve, and first and second electric actuators that apply driving force to these valves. With the configuration, it is possible to control the ratio of the hydraulic pressure of the wheel brake with respect to the output hydraulic pressure of the hydraulic pressure generating means by controlling the amount of liquid to be secured by the hydraulic pressure generating means and contributing to miniaturization. It is possible to enable automatic brake control and antilock brake control to.

  According to the second aspect of the present invention, when the output hydraulic pressure of the hydraulic pressure supply source is abnormally lowered, the hydraulic pressure from the hydraulic pressure generating means can be controlled to act on the wheel brake.

  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.

FIGS. 1 to 17 show an embodiment of the present invention. FIG. 1 is a simplified diagram showing a partial circuit configuration of a vehicle brake device, and FIG. 2 is a simplified master cylinder in a non-operating state. FIG. 3 is a view corresponding to FIG. 2 for illustrating the operating state of the master cylinder when the hydraulic pressure supply source fails, and FIG. 4 is an output fluid amount and output fluid corresponding to the operation stroke and operation input of the master cylinder. FIG. 5 is a diagram illustrating a change in pressure, FIG. 5 is a diagram corresponding to FIG. 2 for illustrating an operating state of the master cylinder when the first brake system fails, and FIG. 6 is a master when the second brake system is failed. FIG. 7 is a diagram corresponding to FIG. 2 for showing the operating state of the cylinder, FIG. 7 is an enlarged cross-sectional view showing the hydraulic pressure control unit in the normal operating state, and FIG. 8 is the output hydraulic pressure of the master cylinder increasing to P _1. The operating state of the hydraulic control unit during the process To figure 9 Figure 10 shows the output hydraulic pressure of the master cylinder P ₃ indicating the示特of the operating state of the hydraulic control unit in the course of the output hydraulic pressure of the master cylinder pressure increased from P ₁ to P ₂ FIG. 11 is a diagram showing characteristics indicating the operating state of the hydraulic pressure control unit in the process of depressurization from FIG. 11, FIG. 11 is a diagram showing hydraulic pressure control characteristics during normal operation of the hydraulic pressure control unit, and FIG. FIG. 13 is a diagram showing the operating state of the hydraulic pressure control unit during forced pressure increase when the pressure is not increased, and FIG. 13 shows the operation of the hydraulic pressure control unit during forced pressure increase / decrease pressure when the hydraulic pressure is output from the master cylinder. FIG. 14 is a diagram illustrating a hydraulic pressure control characteristic at the time of forced pressure increase, FIG. 15 is a diagram illustrating a hydraulic pressure control characteristic at the time of forced pressure reduction, and FIG. 16 is a state in which no hydraulic pressure is output from the master cylinder. Hydraulic pressure control unit when the hydraulic pressure of the hydraulic pressure supply source drops FIG. 17 is a diagram illustrating an operating state of the hydraulic pressure control unit when the hydraulic pressure of the hydraulic pressure supply source is lowered with the hydraulic pressure being output from the master cylinder.

  First, in FIG. 1, the left and right front wheels and the left and right rear wheels included in the four-wheel vehicle are respectively mounted with wheel brakes B, which are disc brakes, and these wheel brakes B are respectively connected to the left front wheel and the right side of the first brake system SA. Rear wheel brakes B ... and right front wheel and left rear wheel brakes B of the second brake system SA are grouped into groups.

  The hydraulic pressures of the wheel cylinders 21 included in the wheel brakes B are controlled by the hydraulic pressure control units 22 corresponding to the wheel brakes B, respectively. A tandem master cylinder M and a hydraulic pressure supply source 23 and a reservoir R capable of outputting a hydraulic pressure higher than the output hydraulic pressure of the master cylinder M independently of the master cylinder M are connected.

  Thus, the master cylinder M individually corresponds to the first and second brake systems SA and SB with the first and second output ports 25 and 26 for outputting the hydraulic pressure corresponding to the brake operation of the brake pedal 24. Prepare.

  The hydraulic pressure supply source 23 is used for rotationally driving the first and second pumps 27A and 27B and the first and second pumps 27A and 27B individually corresponding to the first and second brake systems SA and SB. The operation of the electric motor 28 common to both the pumps 27A and 27B, the first and second accumulators 29A and 29B connected to the discharge sides of both the pumps 27A and 27B, and the first and second pumps 27A and 27B, respectively. Hydraulic pressure sensors 30A and 30B for individually detecting the hydraulic pressures of the accumulators 29A and 29B are provided for control.

  Further, the reservoir R has first and second oil sump chambers 31A and 31B individually corresponding to the first and second brake systems SA and SB, and the first oil sump chamber 31A sucks in the first pump 27A. The second oil sump chamber 31B is connected to the suction side of the second pump 27B.

  Incidentally, the configuration for controlling the hydraulic pressure of the wheel cylinders 21 in each wheel brake B is the same, and in the following description, one wheel brake B in the second brake system SB, for example, the wheel brake of the right front wheel. The configuration for controlling the hydraulic pressure of the wheel cylinder 21 included in B will be described in detail, and detailed description of the other wheel brakes B ... will be omitted.

  The tandem master cylinder M includes a first hydraulic pressure output unit 32A corresponding to the first brake system SA and a second hydraulic pressure output unit 32B corresponding to the second brake system SB. The second hydraulic pressure output units 32A and 32B are arranged in a cylinder body 33 common to the 32A and 32B so that the second hydraulic pressure output unit 32B is arranged in front of the first hydraulic pressure output unit 32A. It is set up.

  The first hydraulic pressure output portion 32A is slidably fitted to the cylindrical cylinder body 33 whose front end is closed by the front end wall 33a and rear end is closed by the rear end wall 33b. The first small piston 36 fitted to the first large piston 35 to enable relative sliding in a limited range, and the cylinder body 33 so as to function as a wall portion facing the first large piston 35. And a wall piston 37 forming a first output hydraulic pressure chamber 38 between the first large piston 35 and a front end of the first large piston 35, and being contracted between the wall piston 37 and the first large piston 35. The first small load spring 39 and the first small piston 36 are connected in series to the first small load spring 39 via the first large piston 35 and are compressed between the first large piston 35 and the first small piston 36. 1 large load spring 40, and the first Spring load of the load spring 40 is set larger than the spring load of the first small force spring 39.

  Moreover, as the operation stroke of the brake pedal 24 increases between the wall piston 37 and the first large piston 35, the first small piston 36 slides in the axial direction relative to the first large piston 35 as described later. There is an interval that allows the first large piston 35 to be brought closer to the wall piston 37 when moved to a position where movement is restricted.

  The first large piston 35 has an end plate 35 a having a plurality of communication holes 41 at the front end and is formed in a cylindrical shape. The first release chamber 42 is formed with the rear end wall 33 b of the cylinder body 33. It is formed between them and is slidably fitted to the cylinder body 33. Thus, the first release chamber 42 communicates with the first release port 43 provided in the cylinder body 33 regardless of the axial position of the first large piston 35. The first release port 43 is connected to the first release passage 44. The first oil sump chamber 31A of the reservoir R communicates with the first oil sump chamber 31A.

  An input rod 45 that is linked and connected to the brake pedal 24 movably penetrates the rear end wall 33b of the cylinder body 33 and is coaxially inserted from the rear into the first large piston 35. A disk-shaped first small piston 36 is fixed at a position spaced rearward from the front end of the rod 45.

  Between the front end of the first small piston 36 and the end plate 35a of the first large piston 35, a first liquid chamber 46 communicating with the first output hydraulic pressure chamber 38 through the communication hole 41 is formed. The hydraulic pressure of the first output hydraulic pressure chamber 38 acts on the front end of the first small piston 36. The first large load spring 40 is contracted between the end plate 35 a of the first large piston 35 and the first small piston 36.

  Moreover, the axial relative movement of the first small piston 36 with respect to the first large piston 35 is such that the input rod 45 abuts against the end plate 35a and extends radially inward from the rear end of the first large piston 35. The first restriction piston 35 is limited to a position where the first small piston 36 comes into contact with the first restriction flange 35b.

  Thus, the first output port 25 is provided in the cylinder body 33 so as to communicate with the first output hydraulic pressure chamber 38 regardless of the axial movement of the first large piston 35, and the first output port of the first brake system SA. A hydraulic path 47 is connected to the first output port 25. Further, a first release hole 48 extending in the radial direction is provided in an axially intermediate portion of the first large piston 35, and no brake operating force is input from the brake pedal 24 to the input rod 45 as shown in FIG. The first large piston 35 retracts to a position where the volume of the first release chamber 42 is minimized, and the first small piston 36 contacts the first restricting flange 35b and retracts to the retract limit position with respect to the first large piston 35. In this state, the first release port 43 is communicated with the first liquid chamber 46 through the first release hole 48, and the first small piston 36 is in the retreat limit position with respect to the first large piston 35 as shown in FIG. The position of the first release hole 48 is set to a position where the space between the first liquid chamber 46 and the first release hole 48 is blocked by the first small piston 36.

  The second hydraulic pressure output portion 32B is relatively fixed in a limited range while keeping the axial relative position between the second large piston 51 slidably fitted to the cylinder body 33 and the cylinder body 33 constant. A second small piston 52 that is slidably fitted to the second large piston 51 and a part of the first hydraulic pressure output portion 32A are slidably fitted to the cylinder body 33. A wall piston 37 forming a second output hydraulic pressure chamber 53 between the rear end of the second large piston 51 and a second small load spring 54 contracted between the wall piston 37 and the second large piston 51; A second large load spring 55 that is contracted between the second large piston 51 and the second small piston 52 so as to be connected in series to the second small load spring 54 via the second large piston 51, The spring load of the second large load spring 55 is the second small load spring 54. It is set larger than the spring load.

  Moreover, between the wall piston 37 and the second large piston 51, the axial direction of the second large piston 51 with respect to the second small piston 52 is described later as the operation stroke of the brake pedal 24 increases. When moving to a position where relative sliding is restricted, an interval is provided that allows the wall piston 37 to be further closer to the second large piston 51.

  The second large piston 51 is formed in a cylindrical shape having an end plate 51 a having a plurality of communication holes 56 at the rear end, and the second release chamber 57 is formed with the front end wall 33 a of the cylinder body 33. It is formed between them and is slidably fitted to the cylinder body 33. Thus, the second release chamber 57 communicates with the second release port 58 provided in the cylinder body 33 regardless of the axial position of the second large piston 51, and the second release port 58 is connected to the second release passage 59. To communicate with the second oil sump chamber 31B of the reservoir R.

  The restriction rod 60 is inserted coaxially from the front into the second large piston 51 with the front end abutting against the front end wall 33a of the cylinder body 33. The restriction rod 60 is spaced forward from the rear end of the restriction rod 60. A disk-shaped second small piston 52 is fixed at the opened position.

  Between the rear end of the second small piston 52 and the end plate 51a of the second large piston 51, a second liquid chamber 61 is formed that communicates with the second output hydraulic pressure chamber 53 through the communication hole 56. The hydraulic pressure of the second output hydraulic pressure chamber 53 acts on the rear end of the second small piston 52. The second large load spring 55 is contracted between the end plate 51 a of the second large piston 51 and the second small piston 52.

  Thus, the first large load spring 40, the first small load spring 39, the second small load spring 54, and the second large load spring 55 arranged in series are interposed between the second small piston 52 and the first small piston 36. The second small piston 52 is held at a position where the front end of the restriction rod 60 is in contact with the front end wall 33a of the cylinder body 33, and the second small piston 52 extends in the direction along the axis of the cylinder body 33. The position 52 is constant. Further, the same load acts on the wall piston 37 common to the first and second hydraulic pressure output portions 32A and 32B from both sides in the axial direction.

  The axial relative movement of the second small piston 52 with respect to the second large piston 51 is such that the second small piston 52 abuts against the second restricting flange 51b projecting radially inward from the front end of the second large piston 51. The rear end of the restriction rod 60 is limited to a position where it abuts against the end plate 51 a of the second large piston 51.

  Thus, the second output port 26 is provided in the cylinder body 33 so as to communicate with the second output hydraulic pressure chamber 53 regardless of the axial movement of the second large piston 51, and the second output port 26 of the second brake system SB. A hydraulic path 62 is connected to the second output port 26. Further, a second release hole 63 extending in the radial direction is provided in an axially intermediate portion of the second large piston 51, and no brake operating force is input from the brake pedal 24 to the input rod 40 as shown in FIG. In the state where the second large piston 51 is retracted to the retreat limit position with respect to the second small piston 52 by bringing the second small piston 52 into contact with the second restricting flange 51b, the second release port 58 is in the second state. When the second large piston 51 advances from the retreat limit position with respect to the second small piston 52 as shown in FIG. 1, the second liquid chamber 61 and the second release hole are connected to the second liquid chamber 61 via the release hole 63. The position of the second release hole 63 is set at a position where the space between the three small pistons 52 is blocked.

  In the master cylinder M, the space between the first and second output hydraulic pressure chambers 38 and 53 is sealed by the outer periphery of the wall piston 37, and between the first output hydraulic pressure chamber 38 and the first release port 43 and the second output hydraulic pressure. The space between the chamber 53 and the second release port 58 is sealed at the outer periphery of the first and second large pistons 35 and 51, and the space between the first liquid chamber 46 and the first release chamber 42, and the second liquid chamber 61 and the second release chamber 57. The gap is sealed at the outer periphery of the first and second small pistons 36 and 52, and the illustration of the seal member used for such sealing is omitted.

  In such a master cylinder M, the brake pedal 24 is operated in a normal state in which the hydraulic pressure failure of the first and second brake systems SA and SB and the abnormal output hydraulic pressure of the hydraulic pressure supply source 23 are not reduced. During normal operation with a small stroke, in the first hydraulic pressure output unit 32A, the first small piston 36 receives the first small piston 36 in response to the operation force being input from the brake pedal 24 through the input rod 45 to the first small piston 36. The first large piston 35 on which the spring load of the one small load spring 39 is acting is pressed through the first large load spring 40 having a larger spring load than the first small load spring 39, and the first small load spring 39 is pressed. The input rod 45 is pushed in as shown in FIG. 1 in a state where the load spring 39 and the second large load spring 55 exert the same spring force. Further, in the second hydraulic pressure output portion 32B, the wall piston 37 is moved to the first large load spring 40 in response to an operation force being input from the brake pedal 24 to the wall piston 37 via the first hydraulic pressure output portion 32A. The second large piston 51 on which a large spring load is acting is pressed through the second small load spring 54.

  As a result, in the first hydraulic pressure output portion 32A, the rate of change of the volume of the first output hydraulic pressure chamber 38 toward the decreasing side with respect to the operation stroke, that is, the rate of change of the output fluid amount is small, and the spring force of the first large load spring 40 is reduced. Since the input rod 45 is pushed in against this, the hydraulic pressure change rate with respect to the operation input increases. Further, in the second hydraulic pressure output portion 32B, the rate of change of the volume of the second output hydraulic pressure chamber 53 toward the reduction side with respect to the stroke of the wall piston 37, that is, the rate of change of the output fluid amount is small. Since the wall piston 37 is pushed in against the spring force, the hydraulic pressure change rate with respect to the operation input increases.

  In the region where the stroke of the brake pedal 24 is large, in the first hydraulic pressure output portion 32A, as shown in FIG. 3, the front end of the input rod 45 comes into contact with the end plate 35a of the front end of the first large piston 35, so When the axial movement of the piston 36 and the first large piston 35 disappears and the first small piston 36 and the first large piston 35 move substantially integrally, the first small load spring 39 is compressed. The first large piston 35 moves, and in such a large stroke region, the change rate of the output fluid amount with respect to the operation stroke is large, and the change rate of the fluid pressure with respect to the operation input is small. In the second hydraulic pressure output part 32B, as shown in FIG. 3, the rear end of the regulating rod 60 comes into contact with the end plate 51a of the second large piston 51 by increasing the stroke of the wall piston 37. When the relative movement in the axial direction of the large piston 51 and the second small piston 52 is eliminated and the second large piston 51 is substantially fixed to the second small piston 52, the wall piston 37 is moved to the second small load spring. Therefore, the change rate of the output fluid amount with respect to the operation stroke is large, and the change rate of the fluid pressure with respect to the operation input is small.

That is, in the master cylinder M, as shown in FIGS. 4A and 4B, in the small stroke region until the operation stroke reaches the predetermined stroke S _O , the change rate of the output fluid amount with respect to the operation stroke is small, and When the brake fluid pressure in which the change rate of the output fluid pressure with respect to the operation input is increased is output from the first and second output ports 25 and 26, and the operation stroke becomes a large stroke region exceeding the predetermined stroke S _O , The brake fluid pressure is output from the first and second output ports 25 and 26 with a large change rate of the output fluid amount with respect to the operation stroke and a small change rate of the output fluid pressure with respect to the operation input. Thus, the operation stroke of the brake pedal 24 is increased when the output hydraulic pressure of the hydraulic pressure supply source 23 is abnormally lowered, and a relatively large amount of brake fluid is applied to the wheel cylinder 21 of the wheel brake B as a master cylinder. M can be supplied.

  Further, when a hydraulic pressure failure occurs in the first brake system SA, as shown in FIG. 5, the hydraulic pressure in the first output hydraulic pressure chamber 38 decreases, so that an operation input from the brake pedal 24 to the input rod 45 is performed. The force acts on the wall piston 37 via the first large load spring 40 and the second small load spring 39 connected in series in the first hydraulic pressure output portion 32A, and the operation stroke is generated from the second hydraulic pressure output 32B. And the brake fluid pressure which changes the fluid amount and the fluid pressure according to the operation input is output.

  Further, when a hydraulic pressure failure occurs in the second brake system, as shown in FIG. 6, the hydraulic pressure in the second output hydraulic pressure chamber 53 decreases, so that the wall piston 37 is connected to the second hydraulic pressure output portion 32B side. The acting load is only the spring force of the second large load spring 55 and the second small load spring 54 connected in series, and the liquid amount and the hydraulic pressure according to the operation stroke and the operation input from the first hydraulic pressure output unit 32A. The brake fluid pressure that changes is output.

  Referring again to FIG. 1, the hydraulic pressure control unit 22 applies the output hydraulic pressure of the master cylinder M to the forward side (the lower side in FIG. 1) and also applies the hydraulic pressure of the wheel cylinder 21 in the wheel brake B to the backward side (see FIG. 1). And a normally closed type opening / closing provided between the wheel cylinder 21 and the hydraulic pressure supply source 23 so as to be opened by a forward operation of the first driving piston 72. Valve 67 and a second drive piston that causes the output hydraulic pressure of the master cylinder M to act on the forward side (lower side in FIG. 1) and the hydraulic pressure of the wheel cylinder 21 to act on the backward side (upward side in FIG. 1). 73 and between the wheel cylinder 21 and the reservoir R so as to be closed by the forward movement of the second drive piston 73. A normally open type on-off valve 68, a first solenoid 69 for applying a driving force in the forward and backward directions to the first driving piston 72, and a driving force in the forward and backward directions for the second driving piston 73. A second solenoid 70.

  In FIG. 7, the normally closed on-off valve 67 and the normally open on-off valve 68 are provided in parallel with a common casing 71, and the casing 71 includes a valve chamber 74, a valve chamber 74, A first sliding hole 76 having a first partition 75 interposed therebetween, a second sliding hole 78 having a second partition 77 interposed between the first sliding hole 76, and a second sliding hole. A first guide hole 80 having a third partition wall 79 interposed between the first partition wall 79 and an end opposite to the third partition wall 79 closed by the first end wall 81 is provided coaxially with the first drive piston 72. It is done.

  The first drive piston 72 is liquid-tightly connected to the first sliding hole 76 by the first rod 82 penetrating the second partition wall 77, the third partition wall 79, and the first end wall 81 in a liquid-tight and axially movable manner. The disc-shaped first piston portion 83 that fits slidably, the disc-like second piston portion 84 that fits liquid-tightly and slidably into the second slide hole 78, and the first guide. A disk-shaped first guide flange 85 that is slidably fitted into the hole 80 is fixedly provided.

  A first hydraulic chamber 86 is formed between the first piston portion 83 and the first partition 75, and a second hydraulic chamber 87 is formed between the first piston portion 83 and the second partition 77, and the second partition 77. A space generated in the casing between the second piston portion 84 is opened to the outside, and a third hydraulic pressure chamber 88 is formed between the second piston portion 84 and the third partition wall 79.

  A first valve hole 89 communicating with the first hydraulic pressure chamber 86 is coaxially provided in the first partition 75, and a tapered valve seat 90 facing the valve chamber 74 side is provided with the first valve hole 89 at the center. A spherical first valve body 91 that can be seated on the first valve seat 90 and close the first valve hole 89 is accommodated in the valve chamber 74, and the casing 71 and the first valve body 91 are accommodated in the valve chamber 74. In the meantime, a first spring 92 that biases the first valve body 91 toward the side on which the first valve body 91 is seated on the first valve seat 90 is contracted.

  A first valve shaft 93 having an outer diameter that can be inserted into the first valve hole 89 is coaxially and integrally provided at an end of the first rod 82 of the first drive piston 72 facing the first hydraulic chamber 86. Thus, the tip end portion of the first valve shaft 93 can contact the first valve body 91. Further, between the first piston portion 83 of the first drive piston 72 and the first partition 75, a second spring 94 that biases the first drive piston 72 toward the side that separates the first valve shaft 93 from the first valve body 91. Is reduced.

  The first rod 82 in the first drive piston 72 is connected to a first solenoid 69 attached to the casing 71, and the first solenoid 69 is connected to the first drive piston 72 in its forward direction (in FIG. 7). A bidirectional solenoid that applies driving force in the downward direction and the backward direction (upward in FIG. 7). The driving force applied from the first solenoid 69 to the first driving piston 72 is applied to the first solenoid 69. It is adjusted by voltage control or PMW control of the first solenoid 69.

  The casing 71 includes a third sliding hole 96, a reservoir communication chamber 98 in which a fourth partition wall 97 is interposed between the third sliding hole 96, and a fifth partition wall between the reservoir communication chamber 98. 99, the sixth partition wall 101 is interposed between the fourth sliding hole 100 and the fourth sliding hole 100, and the end opposite to the fifth partition wall 99 is closed by the second end wall 103. The second guide hole 102 is provided coaxially with the second drive piston 73.

  The second drive piston 73 is liquid-tightly and slidable in the fourth sliding hole 100 by the second rod 104 penetrating the sixth partition wall 101 and the second end wall 103 in a liquid-tight and axially movable manner. A disc-like third piston portion 105 to be fitted and a disc-like second guide flange portion 106 to be slidably fitted into the second guide hole 102 are fixedly provided.

  A fourth hydraulic pressure chamber 107 is formed between the third piston portion 105 and the fifth partition wall 99, and a fifth hydraulic pressure chamber 108 is formed between the third piston portion 105 and the sixth partition wall 101.

  A second valve hole 109 communicating with the fourth hydraulic pressure chamber 107 is provided coaxially in the fifth partition wall 99, and a tapered second valve seat 110 facing the fourth hydraulic pressure chamber 107 side is provided with the second valve hole 109. Is formed so as to face the center. The fourth hydraulic pressure chamber 107 accommodates a spherical second valve body 111 that can be seated on the second valve seat 110, and a second valve shaft 112 that is coaxially connected to the second valve body 111. The portion opposite to the two-valve body 111 is fitted to the second rod 104 of the second drive piston 73 so as to be capable of axial relative sliding. Moreover, a very weak third spring 113 is contracted between the second drive piston 73 and the second valve body 111, and a fourth spring 114 is contracted between the sixth partition wall 101 and the third piston portion 105.

  The end of the third sliding hole 96 opposite to the fourth partition 97 is closed, and the third sliding hole 96 includes a large-diameter hole 96a on the side opposite to the fourth partition 97, and the fourth. The small-diameter hole portion 96b on the partition wall 97 side is formed by forming an annular step portion 96c facing the side opposite to the fourth partition wall 97 so as to be coaxially connected, and faces the third sliding hole 96 side. A restricting protrusion 97 a is provided at the center of the fourth partition wall 97.

  The first simulator piston 115 is slidably fitted into the large-diameter hole portion 96 a of the third sliding hole 96, and the first simulator spring 116 is contracted between the casing 71 and the first simulator piston 115. . Further, the second simulator piston 117 is slidably fitted in the small diameter hole portion 96b of the third sliding hole 96, and a simulator chamber 119 is formed between the second simulator piston 117 and the fourth partition wall 97. The second simulator spring 118 is contracted between the second simulator piston 117. In addition, the first simulator piston 115 is provided with a third rod 120 coaxially connected to the second simulator piston 117, and the second projecting piston 117 is liquid-tightly connected to the restricting protrusion 97a and the fourth partition wall 97. A fourth rod 121 that passes through coaxially and freely moves is coaxially connected. The fourth rod 121 abuts the second valve body 111 from the reservoir communication chamber 98 side through the second valve hole 109, and The two-valve body 111 can be pressed so as to be separated from the second valve seat 110.

  The reservoir communication chamber 98 of the normally closed on-off valve 67 communicates with the second oil reservoir chamber 31B of the reservoir R through the release passage 125, and the fourth hydraulic pressure chamber 107 communicates with the wheel cylinder 21 of the wheel brake B through the first passage. Communicate via 126. The fourth hydraulic pressure chamber 107 of the normally open type on-off valve 68 and the first hydraulic pressure chamber 86 of the normally closed type on-off valve 67 are communicated with each other via a first communication passage 127 provided in the casing 71. That is, the hydraulic pressure of the wheel cylinder 21 acts on the fourth hydraulic pressure chamber 107 and the first hydraulic pressure chamber 86. The valve chamber 74 and the third hydraulic pressure chamber 88 of the normally closed on-off valve 67 communicate with each other via a second communication path 128 provided in the casing 71, and the second communication path 128 is a hydraulic pressure supply source. The second accumulator 29B is connected to the second accumulator 29B through the second passage 129. In addition, the second passage 129 is provided with a first one-way valve 130 that allows only the brake fluid to flow from the hydraulic pressure supply source 23 to the normally closed on-off valve 67 side. Thus, a high hydraulic pressure from the hydraulic pressure supply source 23 acts on the valve chamber 74 and the third hydraulic chamber 88 of the normally closed on-off valve 67.

  The fifth hydraulic chamber 108 and the simulator chamber 119 in the normally open on-off valve 68 and the second hydraulic chamber 87 of the normally closed on-off valve 67 communicate with each other through a third communication passage 131 provided in the casing 71. The second hydraulic pressure chamber 87 communicates with a second output hydraulic pressure passage 62 that communicates with the second output port 26 in the master cylinder M. In addition, the middle of the second output hydraulic pressure passage 62 and the second passage 129 between the first one-way valve 130 and the normally closed on-off valve 67 are connected by the third passage 132. Secondly, only the flow of the brake fluid from the second output hydraulic pressure passage 62 to the second passage 129 side, that is, the flow of the brake fluid from the second output port 26 of the master cylinder M to the normally closed on-off valve 67 side is permitted. A one-way valve 133 is interposed. Further, the second output hydraulic pressure passage 62 is provided with a hydraulic pressure sensor 134 that detects the output hydraulic pressure of the master cylinder M.

By the way, in the normally closed on-off valve 67, the seal area when the first valve body 91 is seated on the first valve seat 90 is A ₁ , and the seal area of the first rod 82 at the portion penetrating the second partition wall 77 is A _5. The seal area of the sliding contact portion of the second piston portion 84 with respect to the second sliding hole 78 in the first drive piston 72 is A ₇ , and the seal area of the first rod 82 in the portion penetrating the third partition wall 79 is A _9. A ₁ = A ₅ = A ₉ and A ₁ = A ₇ -A ₉ .

The spring load of the first spring 92 is F _SP5 , and the spring load of the second spring 93 is F _SP1, and the seal area of the sliding contact portion of the first drive piston 72 to the first sliding hole 76 of the first piston portion 83 is set. Is A ₃ , the output hydraulic pressure of the master cylinder M acting on the second hydraulic pressure chamber 87 is P _MC , the hydraulic pressure of the wheel cylinder 21 acting on the first hydraulic pressure chamber 86 is P _WC , the valve chamber 74 and the third When the output hydraulic pressure of the hydraulic pressure supply source 23 acting on the hydraulic pressure chamber 88 is P _S , (P _S × A ₁ + P _WC × A ₃ + F _SP5 + F _SP1 ) is closed in the normally closed on-off valve 67. acts as a valve force, also will be _{{P S × (a 7 -A} 9) + P MC × (a 3 -A 5) + P WC × a 1} acts as opening force, their valve opening force and in a state where the valve closing force are balanced, P _WC = P _MC - a _{(F SP1 + F SP5) /} (a 3 -A 1).

In the normally open type on-off valve 68, the seal area when the second valve element 111 is seated on the second valve seat 110 is A ₂ , and the seal area of the second rod 104 in the portion that penetrates the sixth partition wall 101 is A _6. A ₂ = A ₆ . Further, when the spring load of the second simulator spring 118 is F _SP3 and the spring load of the fourth spring 114 is F _SP2 , F _SP3 > F _SP2 .

The seal area of the sliding contact portion of the fourth slide hole 100 of the third piston 105 and A _4, the sliding contact portion of the second simulator piston 117 to the large-diameter hole portion 96b of the third slide hole 96 the sealing area a _10, the seal area of the fourth rod 121 of the portion passing through the fourth partition wall 97 is taken as a _8, higher output fluid pressure P _MC of the master cylinder M acts on the simulator chamber 119, second In the normally open type on-off valve 68 in a state where the simulator piston 117 moves so as to separate the fourth rod 121 from the second valve body 11, (A ₄ −A ₂ ) × P _WC acts as the valve opening force. _{, {(P MC × (a} 4 -A 6) + F SP2} acts as a valve closing force, in the state where those opening force and closing force are balanced, because it is a ₆ = a _2, P _WC = P _MC + F _SP2 / (A ₄ −A ₂ ).

The output fluid in the master cylinder M acts on the simulator chamber 119 pressure P _MC is low, as shown in Figure 8, the first simulator piston 115 abuts against the stepped portion 96c, the second simulator piston 117 and the fourth rod 121 In the normally open type on-off valve 68 at the position where it abuts against the second valve body 111, {F _SP3 + (A ₄ −A ₂ ) × P _WC } acts as the valve opening force, and the master cylinder M of the output pressure P _MC is P ₀ (= ₀₎ from _{P 1 {= (F SP3 -F} SP2) / (a 4 -A 2 + a 10 -A 8)} until until increases the normally open The mold opening / closing valve 68 is open.

Also when the output hydraulic pressure P _MC of the master cylinder M becomes the P _1, as shown in Figure 9, the normally closed on-off valve 67 remains closed, the output fluid pressure P _MC of the master cylinder M When increasing from P ₁ to P ₂ {= (F _SP1 + F _SP5 ) / (A ₃ −A ₁ )}, the normally closed on-off valve 67 is opened for the first time.

Further when the output hydraulic pressure P _MC of the master cylinder M is in the depressurization process, the output hydraulic pressure high hydraulic pressure P _MC than the fluid pressure _{P 2 P 3 {= F SP3} / (A 10 -A 8)} when a fourth rod 121 as shown in Figure 10 is to abut against the second valve body 111, to the output pressure P _MC of the master cylinder M becomes lower than the pressure P ₃ Accordingly, closing of the normally open type on-off valve 68 is started.

, As shown in Figure 11, from the output fluid pressure P _MC of the master cylinder M reaches P ₂ In this way normal operating conditions the first and second solenoids 69 and 70 and the non-operating state, output fluid relative pressure _{P MC {(F SP1 + F} SP5) / (a 3 -A 1)} only low hydraulic pressure in the master cylinder M becomes possible to act on the wheel cylinders 21, also in the depressurizing process, the master cylinder M becomes _{{F SP1 / (a 4 -A} 2)} as high that the state is maintained for the output hydraulic pressure P _MC.

In FIG. 12, in the state where the hydraulic pressure is not output from the master cylinder M, the normally open type on-off valve 68 is opened. In this state, the first solenoid 69 _applies the driving force of FIN to the first driving piston 72. When the driving force of F _OUT is applied to the second driving piston 73 from the second solenoid 70, the opening / closing of the normally open type on / off valve 68 and the opening / closing of the normally closed type on / off valve 67 can be arbitrarily controlled. In the non-brake operation state, the brake fluid pressure can be applied to the wheel cylinder 21 of the wheel brake B to obtain the automatic brake state.

Further, as shown in FIG. 13, with the hydraulic pressure being output from the master cylinder M, the driving force of F _IN is applied to the first driving piston 72 from the first solenoid 69, and the driving of F _OUT is performed from the second solenoid 70. By applying a force to the second drive piston 73, the opening / closing of the normally open type on / off valve 68 and the opening / closing of the normally closed type on / off valve 67 can be arbitrarily controlled. As shown in FIG. Furthermore, it is higher than the hydraulic pressure P _WC of the wheel cylinder 21 obtained during normal operation by {F _IN / (A ₃ −A ₁ )}, and is higher than the output hydraulic pressure P _MC of the master cylinder M by P _INC {= P _{WC -P MC = (F iN -F} S P 1 -F SP5) / (a 3 -A 1)} can be allowed to act on the wheel cylinders 21 in only high liquid pressure as increased pressure discrepancy. In the depressurization process, the hydraulic pressure can be increased by {F _OUT / (A ₄ −A ₂ )} than the hydraulic pressure P _WC of the wheel cylinder 21 obtained during normal operation.

Further, at the time of forced pressure reduction, as shown in FIG. 15, the output fluid of the master cylinder M is lower than the fluid pressure P _WC of the wheel cylinder 21 obtained during normal operation by {F _IN / (A ₃ −A ₁ )}. it can be allowed to act on the pressure P P _DEC than _{MC {= P WC -P MC =} (F OUT + F SP2) / (a 4 -A 2)} by the wheel cylinders 21 a lower fluid pressure in about increasing pressure discrepancy. In the depressurization process, the hydraulic pressure can be lowered by {F _OUT / (A ₄ −A ₂ )} than the hydraulic pressure P _WC of the wheel cylinder 21 obtained during normal operation.

When the output hydraulic pressure of the hydraulic pressure supply source 23 is abnormally lowered and no hydraulic pressure is output from the master cylinder M, the normally closed on-off valve 67 is closed and normally opened as shown in FIG. Although the mold opening / closing 68 is opened, when the hydraulic pressure is output from the master cylinder M with a large operation stroke of the brake pedal 24, the normally open mold is introduced by introducing the hydraulic pressure into the simulator chamber 119 as shown in FIG. The on-off valve 68 can be closed, and in this state, the output hydraulic pressure of the master cylinder M is introduced into the valve chamber 74 of the normally-closed on-off valve 67 via the second one-way valve 133, so that the normally-closed on-off valve is opened. the valve 67, P _WC = P _MC - can now be operated so as to satisfy _{(F SP1 + F SP5) /} (a 3 -A 1), to supply hydraulic pressure to the wheel cylinders 21.

  Next, the operation of this embodiment will be described. The tandem master cylinder M includes a first hydraulic pressure output unit 32A corresponding to the first brake system SA and a second hydraulic pressure output unit corresponding to the second brake system SB. In the first hydraulic pressure output portion 32A, the first large piston 35 slidably fitted to the cylinder body 33 is capable of axial relative sliding within a limited range. A first small piston 36 is fitted, and a first output hydraulic pressure chamber 38 is formed in the cylinder body 33 between the wall piston 37 and the first large piston 35 facing the first large piston 35. A first small load spring 39 is provided between the large pistons 35 so that the first large load spring 40 connected in series to the first small load spring 39 via the first large piston 35 is connected to the first small load spring 39. Also increase the spring load An input rod 45 is provided between the first large piston 35 and the first small piston 36 so as to push the first small piston 36 against the spring force of the first large load spring 39 and the first small load spring 40. A small piston 36 is connected coaxially, and the wall piston 37 applies the same load as that applied from the first output hydraulic chamber 38 side from the second output hydraulic chamber 53 side opposite to the first output hydraulic chamber 38 side. The cylinder body 33 is fitted to the cylinder body 33 so as to be slidable in the axial direction, and the first small piston is interposed between the wall piston 37 and the first large piston 35 in accordance with an increase in the operation stroke of the brake pedal 24. There is an interval that allows the first large piston 35 to be brought closer to the wall piston 37 when 36 moves to a position where axial relative sliding with the first large piston 40 is restricted.

  Therefore, in a region where the stroke of the brake pedal 24 is small, the input rod 40 pushes the first large piston 35 in a state where the first small load spring 39 and the first large load spring 40 exert the same spring force. The change ratio of the volume of the first output hydraulic pressure chamber 38 to the decreasing side with respect to the operation stroke, that is, the change ratio of the output fluid amount is small, and the input rod 40 is pushed in against the spring force of the first large load spring 40. Therefore, the hydraulic pressure change rate with respect to the operation input becomes large.

  Further, the operation stroke of the brake pedal 24 is increased, there is no relative movement in the axial direction of the first small piston 36 and the first large piston 35, and the first small piston 36 and the first large piston 35 move substantially integrally. Then, the first large piston 35 moves while compressing the first small load spring 39, and in such a large stroke region, the rate of change of the output fluid amount with respect to the operation stroke is large and the operation input The change rate of the hydraulic pressure becomes small.

  In the second hydraulic pressure output part 32B, relative to the second large piston 51 slidably fitted to the cylinder body 33 in a limited range while keeping the axial relative position to the cylinder body 33 constant. The second small piston 52 is fitted so as to be slidable, and the cylinder is interposed between the wall piston 37 and the second large piston 51 slidably fitted to the cylinder body 33 while facing the second large piston 51. A second output hydraulic pressure chamber 53 is formed in the body 33, and a second small load spring 54 is contracted between the wall piston 37 and the second large piston 51. The second large load spring 55 connected in series with the load spring 54 is compressed between the second large piston 51 and the second small piston 52 with a larger spring load than the second small load spring 54, and the wall piston 37. The brake pedal 4 moves the wall piston 37 toward the side close to the second large piston 51 against the spring force of the second large load spring 55 and the second small load spring 54 via the first hydraulic pressure output portion 32A. The second large piston 51 is connected to the second small piston 52 as the operation stroke of the brake pedal 24 increases between the wall piston 37 and the second large piston 51. The wall piston 37 is spaced apart from the second large piston 51 when moved to a position where the relative sliding in the axial direction is limited.

  Therefore, in a region where the stroke of the wall piston 37 is small, the wall piston 37 pushes in the second large piston 51 while the second large load spring 55 and the second small load spring 54 exert the same spring force. The rate of change of the volume of the second output hydraulic chamber 53 toward the reduction side with respect to the stroke of the wall piston 37, that is, the rate of change of the output fluid amount is small, and the wall piston 37 resists the spring force of the second large load spring 55. Since the push-in operation is performed, the hydraulic pressure change rate with respect to the operation input increases.

  Further, when the stroke of the wall piston 37 is increased, the relative movement in the axial direction of the second small piston 52 and the second large piston 51 is restricted, and the large piston 51 is substantially fixed to the cylinder body 33. The wall piston 37 moves while compressing the second small load spring 54. In such a large stroke region, the change rate of the output fluid amount with respect to the operation stroke is large, and the change rate of the fluid pressure with respect to the operation input is small. Become.

  That is, the master cylinder M reduces the change rate of the output fluid amount relative to the operation stroke in the small operation stroke region and increases the change rate of the output fluid pressure relative to the operation input, and changes the output fluid amount relative to the operation stroke in the large operation stroke region. It is possible to increase the ratio and reduce the change amount of the output hydraulic pressure with respect to the operation input.

  The hydraulic pressure control unit 22 for controlling the hydraulic pressure of the wheel cylinder 21 provided in each wheel brake B causes the output hydraulic pressure of the master cylinder M to act on the forward side and the hydraulic pressure of the wheel cylinder 21 on the backward side. A normally closed on-off valve 67 provided between the wheel cylinder 21 and the hydraulic pressure supply source 23 so as to be opened by a forward operation of the first drive piston 72, The second drive piston 72 has a second drive piston 72 that applies the output hydraulic pressure of the cylinder M to the forward side and the hydraulic pressure of the wheel cylinder 21 to the reverse side, and is closed by the forward operation of the second drive piston 72. A normally open type on-off valve 68 provided between the wheel cylinder 21 and the reservoir R, and a first drive piston A first solenoid 69 for imparting the forward and the driving force of the backward direction down 72, in which and a second solenoid 70 for applying a driving force of the forward and backward direction to the second drive piston 72.

  According to such a hydraulic pressure control unit 22, when the first and second solenoids 69, 70 are deactivated, the hydraulic pressure of the master cylinder M is changed at a predetermined ratio to be applied to the wheel cylinder 21. Further, by operating the first and second electric solenoids 69 and 70, the ratio of the hydraulic pressure of the wheel cylinder 21 to the output hydraulic pressure of the master cylinder M can be arbitrarily controlled, and automatic brake control and anti-static It is also possible to perform lock brake control. At this time, the amount of fluid required to operate the wheel cylinder 21 is secured by the fluid pressure supply source 23. Therefore, the amount of fluid sufficient to operate the fluid pressure control unit 22 from the master cylinder M, that is, a normally closed type opening / closing. Since it is sufficient to output a liquid amount sufficient to open the valve 67, it is possible to contribute to the miniaturization of the master cylinder M.

  That is, the fluid pressure control unit 22 is simple and inexpensive including the normally closed on-off valve 67 and the normally open on-off valve 68, and the first and second solenoids 69 and 70 for applying driving force to the valves 67 and 68. With this configuration, the master cylinder M suppresses the amount of fluid that should be secured by the fluid pressure generating means and contributes to miniaturization of the master cylinder M, and the ratio of the fluid pressure of the wheel cylinder 21 to the output fluid pressure of the master cylinder M is arbitrarily set Control, and automatic brake control and anti-lock brake control can also be performed.

  In addition, a first one-way valve 130 is provided between the hydraulic pressure supply source 23 and the normally closed on-off valve 67 to allow only brake fluid to flow from the hydraulic pressure supply source 23 to the normally closed on-off valve 67 side. The connection between the one-way valve 130 and the normally closed on-off valve 67 is connected to the master cylinder M via a second one-way valve 133 that allows only the flow of brake fluid from the master cylinder M to the normally closed on-off valve 67 side. Therefore, when the output hydraulic pressure of the hydraulic pressure supply source drops abnormally, the hydraulic pressure from the master cylinder M can be controlled to act on the wheel cylinders 21 of the wheel brakes B.

  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 simplifies and shows the partial circuit structure of the brake device for vehicles. It is a longitudinal cross-sectional view which simplifies and shows the master cylinder of a non-operation state. FIG. 3 is a view corresponding to FIG. 2 for illustrating an operating state of a master cylinder when a hydraulic pressure supply source fails. It is a figure which shows the change of the output fluid quantity and output fluid pressure with respect to the operation stroke and operation input of a master cylinder. FIG. 3 is a view corresponding to FIG. 2 for illustrating an operating state of the master cylinder when the first brake system fails. FIG. 3 is a view corresponding to FIG. 2 for illustrating an operating state of the master cylinder when the second brake system fails. It is sectional drawing which expands and shows the hydraulic-pressure control unit in a normal operation state. The output hydraulic pressure of the master cylinder is a diagram showing an operating state of the hydraulic pressure control unit in the process of pressure increase up to P _1. The operating state of the hydraulic pressure control unit of the output hydraulic pressure of the master cylinder is in the process of pressure increase from P ₁ to P ₂ is a diagram showing a示特property. The output hydraulic pressure of the master cylinder is a diagram showing a示特of the operating state of the hydraulic pressure control unit of the process of vacuum from P _3. It is a figure which shows the hydraulic-pressure control characteristic at the time of normal operation | movement to a hydraulic-pressure control unit. It is a figure which shows the operating state of the hydraulic pressure control unit at the time of forced pressure increase in the state where the hydraulic pressure is not output from the master cylinder. It is a figure which shows the operating state of the hydraulic control unit at the time of the forced increase and pressure reduction pressure in the state where the hydraulic pressure is output from the master cylinder. It is a figure which shows the hydraulic-pressure control characteristic at the time of forced pressure increase. It is a figure which shows the hydraulic-pressure control characteristic at the time of forced pressure reduction. It is a figure which shows the operating state of the hydraulic pressure control unit at the time of the hydraulic pressure abnormality fall of the hydraulic pressure supply source in the state where the hydraulic pressure is not output from the master cylinder. It is a figure which shows the operating state of the hydraulic-pressure control unit at the time of the hydraulic-pressure abnormality fall of the hydraulic-pressure supply source in the state in which the hydraulic pressure is output from the master cylinder.

Explanation of symbols

23 ... Hydraulic pressure supply source 67 ... Normally closed type on / off valve 68 ... Normally open type on / off valve 69 ... First solenoid 70 as a first electric actuator ... Second as a second electric actuator 2 solenoid 72 ... first drive piston 73 ... second drive piston 130 ... first one-way valve 133 ... second one-way valve B ... wheel brake M ... hydraulic pressure generating means Master cylinder R ... Reserver

Claims (2)

  The hydraulic pressure generating means (M) for outputting the hydraulic pressure according to the brake operation, the wheel brake (B) for operating the brake according to the action of the hydraulic pressure, and the output hydraulic pressure of the hydraulic pressure generating means (M) A hydraulic pressure supply source (23) capable of outputting a high hydraulic pressure independently of the hydraulic pressure generating means (M), a reservoir (R), and an output hydraulic pressure of the hydraulic pressure generating means (M) Has a first drive piston (72) that acts on the forward side and hydraulic pressure of the wheel brake (B) on the reverse side, and is opened by the forward movement of the first drive piston (72). A normally closed on-off valve (67) provided between the wheel brake (B) and the hydraulic pressure supply source (23) and the hydraulic pressure output from the hydraulic pressure generating means (M) are caused to act forward and the wheel brake. Second drive to apply the hydraulic pressure of (B) to the backward side A normally open type on-off valve (68) provided between the wheel brake (B) and the reservoir (R) so as to be closed by a forward operation of the second drive piston (73) with a stone (73); A first electric actuator (69) that applies a driving force in the forward and backward directions to the first drive piston (72), and a second electric that applies the drive force in the forward and backward directions to the second drive piston (73). A vehicle brake device comprising an actuator (70).   Only the flow of the brake fluid from the hydraulic pressure supply source (23) to the normally closed on-off valve (67) side is allowed between the hydraulic pressure supply source (23) and the normally closed on-off valve (67). A first one-way valve (130) is provided, and between the first one-way valve (130) and the normally closed on-off valve (67), from the hydraulic pressure generating means (M) to the normally closed on-off valve (67 2. The vehicle brake device according to claim 1, wherein the brake device is connected to the hydraulic pressure generating means (M) via a second one-way valve (133) that allows only the brake fluid to flow to the first side.

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