JP4560918B2 - Hydraulic brake device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic brake device for a vehicle, and more particularly, to a hydraulic brake device for a vehicle provided with an auxiliary hydraulic pressure source and pressure adjusting means in addition to a master cylinder.
[0002]
[Prior art]
Various types of hydraulic brake devices for vehicles are known. For example, Japanese Patent Application Laid-Open No. 11-20665 discloses a vehicle hydraulic brake device that includes an auxiliary hydraulic pressure source and a regulator in addition to a master cylinder. It is disclosed. In this publication, the output power hydraulic pressure of the auxiliary hydraulic pressure source is supplied to the regulator chamber in order to increase the braking force immediately at the time of emergency braking and to quickly and surely remove the braking force when the brake operation is released. Introducing a regulator that regulates the regulator hydraulic pressure according to the output brake hydraulic pressure of the master cylinder, and applying the brake hydraulic pressure output via this regulator to the power chamber formed behind the master piston In the assisting device, there is disclosed a device in which pressure limiting means for limiting the brake fluid pressure introduced into the regulator chamber according to the operation state of the brake operation member is provided.
[0003]
In the above publication, as a pressure limiting means, a hydraulic pressure path that introduces brake hydraulic pressure into the regulator chamber is provided, and the hydraulic pressure path is always connected, and when the brake operation member is operated suddenly, the hydraulic pressure path And a pressure reducing means that is arranged in parallel to the valve device and that reduces and outputs the brake fluid pressure introduced into the regulator chamber in accordance with predetermined characteristics. . Furthermore, when the operation state of the brake operation member is detected and the brake operation member is operated at a speed exceeding a predetermined speed, a sudden operation detection means for outputting a cutoff signal, and when the sudden operation detection means outputs a cutoff signal The thing provided with the normally open electromagnetic on-off valve which interrupts | blocks a hydraulic path is illustrated.
[0004]
[Problems to be solved by the invention]
According to the hydraulic brake device described in Japanese Patent Application Laid-Open No. 11-20665, so-called brake assist control can be performed. For example, during emergency braking, the braking force is immediately increased even if the amount of operation by the brake operation member is small. In addition, the brake force can be quickly and reliably removed when the operation of the brake operation member is released. As a pressure limiting means, a valve that is provided in a hydraulic pressure passage for introducing brake hydraulic pressure into the regulator chamber, is always connected to the hydraulic pressure passage, and shuts off the hydraulic pressure passage when the brake operation member is operated suddenly. It has been proposed to include a device and a pressure reducing means that is arranged in parallel with the valve device and that reduces and outputs the brake fluid pressure introduced into the regulator chamber in accordance with predetermined characteristics.
[0005]
It is described that the pressure reducing means can be constituted by a relief valve that communicates when the introduced brake fluid pressure exceeds a predetermined value. Further, the valve device detects an operation state of the brake operating member, and outputs a shut-off signal when the brake operating member is operated at a speed exceeding a predetermined speed, and the sudden operation detecting means It is described that it can be provided with a normally open electromagnetic on-off valve that shuts off the hydraulic path when a signal is output.
[0006]
Further, it is described that the pressure reducing means can be constituted by a proportional pressure reducing mechanism that reduces pressure substantially in proportion to the introduced brake fluid pressure. However, the relief valve provided to the pressure reducing means in the above publication sets a constant hydraulic pressure increase (jump amount) and cannot set an arbitrary jump amount. Further, the proportional pressure reducing mechanism also changes the hydraulic pressure gradient to a constant value and cannot be controlled to increase by an arbitrary jump amount.
[0007]
Therefore, the present invention provides a hydraulic brake device capable of setting an arbitrary jump amount for the brake hydraulic pressure characteristic in a vehicle hydraulic brake device including an auxiliary hydraulic pressure source and a pressure adjusting means in addition to a master cylinder. This is the issue.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a driving device for advancing the master piston in accordance with the operation of the brake operating member to boost the brake fluid in the reservoir and output the brake fluid pressure to the wheel cylinder. A master cylinder, an auxiliary hydraulic pressure source that boosts the brake fluid in the reservoir to a predetermined pressure and outputs a power hydraulic pressure, and is connected in communication with the auxiliary hydraulic pressure source and in communication with the reservoir; In a hydraulic brake device for a vehicle, comprising: a pressure adjusting unit that adjusts an output power hydraulic pressure of a pressure source to a predetermined pressure and drives the master piston by the adjusted hydraulic pressure; A solenoid valve interposed in the discharge-side hydraulic pressure path to be connected in communication, and controlling the opening and closing of the discharge-side hydraulic pressure path by controlling energization to the solenoid valve; By opening and closing control And a control means for controlling the hydraulic pressure on the discharge side of the pressure adjusting means to a predetermined pressure equal to or higher than the atmospheric pressure. The pressure adjusting means may be any means called a regulator, a hydraulic booster, a hydraulic servo, or the like.
[0009]
The hydraulic brake device includes a brake operation state detection unit that detects an operation state of the brake operation member as described in claim 2, and the control unit detects the brake operation state detection unit. According to the result, the electromagnetic valve may be controlled so that the hydraulic pressure on the discharge side of the pressure adjusting means increases by a hydraulic pressure set in advance based on the operating state of the brake operating member. Thereby, for example, when the operation of the brake operation member is performed rapidly, the hydraulic pressure on the discharge side of the pressure adjusting means becomes larger than when the operation of the brake operation member is performed gently. Can be controlled.
[0010]
Alternatively, as described in claim 3, vehicle state detection means for detecting a vehicle state quantity is provided, and the control means determines the vehicle state quantity according to the detection result of the vehicle state detection means. The electromagnetic valve may be controlled such that the hydraulic pressure on the discharge side of the pressure adjusting means is increased by a preset hydraulic pressure based on the above. The vehicle state includes vehicle speed, vehicle weight, etc., and the control means is controlled so that the hydraulic pressure on the discharge side of the pressure regulating means increases by a preset hydraulic pressure based on these amounts. It is good as well.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a hydraulic brake device according to an embodiment of the present invention. A master piston MP is driven forward in response to an operation of a brake pedal BP as a brake operation member to increase the brake fluid in a reservoir RV. The master cylinder MC that outputs the brake fluid pressure to the wheel cylinder WC, the auxiliary fluid pressure source AP that boosts the brake fluid in the reservoir RV to a predetermined pressure and outputs the power fluid pressure, and the auxiliary fluid pressure source AP are connected in communication. A pressure adjusting means RG that is connected to the reservoir RV, adjusts the output power hydraulic pressure of the auxiliary hydraulic pressure source AP to a predetermined pressure, and drives the master piston MP by the adjusted hydraulic pressure.
Further, an electromagnetic valve EV is interposed in the discharge side hydraulic pressure path DP that connects the pressure regulating means RG to the reservoir RV. Then, the control means CT controls the energization of the electromagnetic valve EV to control the opening and closing of the discharge side hydraulic pressure path DP, and the discharge side hydraulic pressure of the pressure adjusting means RG is controlled to a predetermined pressure equal to or higher than the atmospheric pressure.
[0012]
Thus, the master cylinder hydraulic pressure is output from the master cylinder MC to the wheel cylinder WC in accordance with the operation amount of the brake pedal BP. In this case, by controlling the electromagnetic valve EV by the control means CT, the characteristic is the same as shown by the broken line in FIG. 2 as compared with the characteristics of the conventional device that does not include the electromagnetic valve EV and the control means CT shown by the solid line in FIG. The master cylinder hydraulic pressure increased by a hydraulic pressure (jumping amount ΔP) set in advance based on the operating amount of the brake pedal BP with respect to the operating amount of the brake pedal BP is output. In addition, although the solenoid valve EV of this embodiment is comprised with the linear solenoid valve as shown in FIG. 1, it is good also as comprising with a normal on-off valve.
[0013]
As for the operation state of the brake pedal BP, the operation of the brake pedal BP can be detected by the brake switch BS, and the operation amount of the brake pedal BP can be detected by the stroke sensor ST. Based on these detection results, it can be determined whether or not the brake pedal BP has been operated rapidly. Thus, when the brake pedal BP is suddenly operated, the control means CT increases the jumping amount ΔP in accordance with the operation amount of the brake pedal BP detected as a result of detection. Thus, the solenoid valve EV is controlled. As a result, the pressure is increased by the jumping amount ΔP compared to when the brake pedal BP is operated gently. In detecting the operation amount of the brake pedal BP, a pedal depression force sensor (not shown), a master cylinder hydraulic pressure sensor (not shown), or the like may be used instead of the stroke sensor ST.
[0014]
Further, it is assumed that the vehicle state detection means for detecting the vehicle state quantity is provided, and according to the detection result of the vehicle state detection means, the control means CT controls a hydraulic pressure component (jumping) preset based on the vehicle state quantity. Amount ΔP) The electromagnetic valve EV may be controlled so that the hydraulic pressure on the discharge side of the pressure adjusting means RG increases. As the vehicle state detection means, for example, as shown by a broken line in FIG. 1, a wheel speed sensor WS is provided, and the vehicle body speed can be estimated based on the detection result. Of course, for example, an absolute speed of the vehicle body may be detected using an ultrasonic sensor, an optical sensor, or the like. Further, as indicated by a broken line in FIG. 1, a height sensor HS that outputs a height signal corresponding to the vehicle height value can be provided as vehicle state detection means, and the vehicle weight can be estimated based on the detection result.
[0015]
The control means CT is configured, for example, as shown in FIG. 3 and is connected to each of the above-described sensors to control energization and non-energization of the electromagnetic valve EV. An electric motor M, which will be described later, constituting the auxiliary hydraulic pressure source AP is also connected to the control means CT, and is driven and controlled thereby. In FIG. 3, the control means CT includes a microcomputer CM including a CPU, a ROM, a RAM, an input interface IT, and an output interface OT connected to each other via a bus. The output signals of the wheel speed sensor WS, brake switch BS, stroke sensor ST, and height sensor HS are respectively input to the CPU from the input interface IT via the amplifier circuit AI. In addition, a control signal is output from the output interface OT to the electric motor M via the drive circuit AO, and a control signal is output to the electromagnetic valve EV via the drive circuit AO. In the microcomputer CM, the ROM stores a program corresponding to the flowchart shown in FIG. 4, the CPU executes the program while an ignition switch (not shown) is closed, and the RAM is necessary for executing the program. Temporary variable data is temporarily stored.
[0016]
In the hydraulic brake device configured as described above, when a series of processing for controlling the electromagnetic valve EV is performed by the control means CT and an ignition switch (not shown) is closed, the microcomputer CM Then, execution of a predetermined program starts. Hereinafter, control of the solenoid valve EV will be described based on the flowchart of FIG.
[0017]
FIG. 4 is a flowchart of the control of the electromagnetic valve EV. First, in step 101, the microcomputer CM is initialized, and various calculation values are cleared. Next, the process proceeds to step 102, and output signals from the wheel speed sensor WS, the brake switch BS, the stroke sensor ST, the height sensor HS, and the like are read. Subsequently, in step 103, when the state of the brake switch BS is determined and the brake pedal BP is operated and the brake switch BS is turned on, the process proceeds to step 104, where the condition for starting energization of the solenoid valve EV is satisfied. It is determined whether or not there is. For example, when the vehicle body speed is estimated based on the detection signal of the wheel speed sensor WS and the differential body acceleration is equal to or higher than a predetermined acceleration, the wheel speed is equal to or higher than the predetermined speed, and the anti-skid control is not started, the brake is It is determined that assist control is necessary. Accordingly, at this time, it is determined that the condition for starting energization of the solenoid valve EV is satisfied, and the routine proceeds to step 105.
[0018]
In step 105, as will be described later with reference to FIG. 5, the control of the electromagnetic valve EV is started, and the discharge-side hydraulic pressure path DP is controlled to open and close. And it progresses to step 106 and it is determined whether the conditions which complete | finish the control of the solenoid valve EV are satisfied. For example, when the estimated vehicle body acceleration is lower than a predetermined acceleration and the wheel speed is lower than a predetermined speed, it is determined that the brake assist control is finished. When it is determined that the brake assist control is finished, the process proceeds to step 107, the energization current to the solenoid valve EV is reduced with a constant gradient, and the energization to the solenoid valve EV is finished.
[0019]
FIG. 5 shows the subroutine of step 105. First, in step 201, the jumping amount ΔP is set. Specifically, as shown in FIG. 6, for example, a map of the jumping amount ΔP set in advance based on the operation speed of the brake pedal BP is stored in the RAM of FIG. 3. Based on this map, a desired jumping amount ΔP is stored. Is set. For example, when the brake pedal BP is suddenly operated, the jumping amount ΔP is set to a larger value than when the brake pedal BP is gently operated.
[0020]
The jumping amount ΔP is set according to the operation speed of the brake pedal BP, but may be set according to the vehicle body speed. For example, as shown in FIG. 6, a map of the jumping amount ΔP set in advance based on the vehicle body speed (“vehicle speed” in FIG. 6) is prepared, and when the vehicle body speed is fast, the jumping amount ΔP is larger than when it is slow. You may set so that. Alternatively, as shown in FIG. 6, a map of the jumping amount ΔP set in advance based on the vehicle weight (“vehicle weight” in FIG. 6) is prepared, and when the vehicle weight is heavy, the jumping amount ΔP is larger than when it is light. You may set so that it may become a value.
[0021]
In the map of FIG. 6, the jumping amount ΔP increases in proportion to the increase of the brake pedal operation speed, the vehicle body speed or the vehicle weight. However, as shown in FIG. It may be set. The parameters of the brake pedal operation speed, the vehicle body speed, and the vehicle weight may be appropriately combined. For example, the jumping amount ΔP may be set so as to increase or decrease in accordance with all these changes.
[0022]
Next, in step 202, the drive current to the solenoid of the solenoid valve EV is set. Specifically, the map of FIG. 8 showing the drive current to the solenoid of the solenoid valve EV with respect to the desired jumping amount ΔP is stored in the RAM of FIG. 3, and the drive of the solenoid valve EV to the solenoid is based on this map. Current is set. Thus, in step 203, solenoid driving of the electromagnetic valve EV is started, the discharge side hydraulic pressure path DP is controlled to open and close, and the brake hydraulic pressure characteristic of the jumping amount ΔP is set as shown by the broken line in FIG. When the solenoid valve EV of the present embodiment is constituted by a normal solenoid on-off valve instead of a linear solenoid valve, this may be duty-controlled. In that case, the brake pedal operation speed, the vehicle body speed, and the vehicle weight A map for adjusting the duty ratio of the electromagnetic on-off valve may be prepared according to the above.
[0023]
9 and 10 show the structure of a hydraulic brake device according to an embodiment of the present invention. The pedal force applied to the brake pedal 3 (corresponding to the brake pedal BP in FIG. 1) is transmitted via the input rod 3a. Brake operating force is transmitted, and in response to this, the hydraulic pressure assisting device 20 (corresponding to the pressure regulating means RG in FIG. 1) assists the brake hydraulic pressure from the master cylinder 10 (corresponding to the master cylinder MC in FIG. 1). It is configured to be supplied to a wheel cylinder (not shown) mounted on each wheel of the vehicle. 9 shows the overall configuration, and FIG. 10 shows the hydraulic pressure assisting device 20 in an enlarged manner, but the control means CT in FIG. 1 is omitted.
[0024]
As shown in FIG. 9, the master cylinder 10 of the present embodiment has a master cylinder housing 1 of a cylinder body including a first cylinder 1 a and a second cylinder 1 b and a third cylinder 1 c accommodated therein. A tandem master cylinder in which master pistons 11 and 12 (corresponding to the master piston MP in FIG. 1) are accommodated in series. The first cylinder 1a is a bottomed cylindrical body, and a stepped hole is formed so that the inner diameter sequentially increases from the cylinder bore 1d toward the opening. The first cylinder 1a has liquid supply ports 1i and 1j and output ports 1m and 1n.
[0025]
The second cylinder 1b is a substantially cylindrical body and is formed with a cylinder bore 1e having the same diameter as the cylinder bore 1d. A flow path 1h is formed at the front end of the second cylinder 1b so as to communicate the inside of the first cylinder 1a with the liquid supply port 1i so that the cup-shaped seal member S1 expands forward. Has been placed. In addition, a cup-shaped seal member S2 is also arranged on the rear inner side of the flow path 1h so as to expand rearward. The third cylinder 1c is a cylinder that is polymerized at the rear part of the second cylinder 1b. An annular flow path 1f is formed between the third cylinder 1c and the third cylinder 1c is formed between the first cylinder 1a and the second cylinder 1b. It is comprised so that it may communicate with the cyclic | annular flow path 1g. An output port 1n is opened in the flow path 1g. A flow path 1k communicating with the liquid supply port 1j is formed on the side surface of the third cylinder 1c, and an annular member 17 is disposed at the opening of the flow path 1k.
[0026]
A cup-shaped seal member S3 that expands forward and a cup-shaped seal member S4 that expands rearward are disposed on both sides of the annular member 17, and the opening of the channel 1f is located in front of the seal member S3. The opening of the flow channel 1k is disposed above the seal member S4. In the cylinder bore 1d, a bottomed cylindrical master piston 11 is accommodated in a fluid-tight manner, and a first pressure chamber R1 is formed between the first cylinder 1a and the master piston 11. Has been. A master piston 12 is accommodated in the cylinder bore 1e, and is supported by the annular member 17 and the seal members S3 and S4 so as to be fluid-tightly slidable. A second pressure is interposed between the master piston 11 and the master piston 12. A chamber R2 is formed.
[0027]
The master piston 11 is in a rear end position when it is not in operation. A communication hole 11a formed in the skirt portion faces the flow path 1h, and the first pressure chamber R1 is connected to the reservoir 4 (see FIG. 1 corresponding to one reservoir RV). In addition, the master piston 12 is in a rear end position when not in operation, and a communication hole 12a formed in the skirt portion faces the seal member S3, and the second pressure chamber is connected via the flow path 1k and the liquid supply port 1j. R2 is configured to communicate with the reservoir 4. Thus, the seal member S3 is configured to allow the flow of the brake fluid from the flow path 1k side to the pressure chamber R2 side at the position of FIG. 9 and prevent the flow in the reverse direction. Further, the seal member S4 is configured to allow the flow of brake fluid from the flow path 1k side to the sealed chamber R3 side described later and prevent the flow in the reverse direction.
[0028]
A spring 13 is stretched between the front end surface in the first cylinder 1a and the concave bottom surface of the master piston 11, and the master piston 11 is urged rearward. Then, one end of the rod 14a is fixed to the bottom surface of the concave portion of the master piston 11, and the head on the other end side is disposed so as to be able to be engaged with the tip of the retainer 14b. The end position is regulated. Similarly, a spring 15 is stretched between the rear end surface of the master piston 11 and the bottom surface of the concave portion of the master piston 12, and is biased in a direction in which both are separated. Then, one end of the rod 16a is fixed to the bottom surface of the recess of the master piston 12, and the head on the other end is disposed so as to be able to be locked to the tip of the retainer 16b. The end position is regulated.
[0029]
A hydraulic pressure assisting device 20 is configured behind the master piston 12 via a sealed chamber R3. The first cylinder 1a constituting the master cylinder housing 1 is joined to the fourth cylinder 2a of the bottomed cylindrical body constituting the booster housing 2, and the cylinder bore 2b is larger than the cylinder bores 1d and 1e of the master cylinder. The power piston 21 is accommodated in a fluid-tight slidable manner. As shown in FIG. 10, land portions 21x and 21y are formed on the front and rear sides of the power piston 21, and seal members S5 and S7 are fitted to the power piston 21, respectively. Further, a seal member S6 is disposed on the inner surface of the cylinder bore 2b between them, and a seal member S8 is disposed around the bottom opening 2c of the fourth cylinder 2a. In order to actually arrange the seal members S5 to S7 as shown in FIG. 10, it is necessary to take a measure such as dividing the power piston 21 into two parts.
[0030]
Thus, a sealed chamber R3 is provided between the seal member S4 and the seal member S5, an annular drain chamber R4 is provided between the seal member S5 and the seal member S6, and an annular liquid supply chamber R5 is provided between the seal member S6 and the seal member S7. An annular power chamber R6 is formed between the seal member S7 and the seal member S8. As shown in an enlarged view in FIG. 10, the power piston 21 is formed with a recess 21a, a large-diameter cylinder bore 21b, a small-diameter cylinder bore 21c, and a large-diameter cylinder bore 21d in order from the front, and the cylinder bore 21b is connected to the drain chamber R4. A communication hole 21h that communicates with the fluid supply chamber R5 is formed, a communication hole 21g that communicates the cylinder bore 21c with the liquid supply chamber R5, and communication holes 21e and 21f that communicate the cylinder bore 21c with the power chamber R6.
[0031]
A plunger 22 is accommodated in the cylinder bore 21d in a fluid-tight manner, and an input rod 3a is connected to the rear thereof. A first spool 23 is slidably accommodated in the cylinder bore 21c in front of the plunger 22, and a second spool 24 is slidably accommodated in the cylinder bore 21b in front of the plunger 22. The recess 21a is provided with a reaction force rubber disk 25 as an elastic member for reaction force transmission, and a metal plate 26 is accommodated in close contact with the reaction force rubber disk 25 so as to be movable back and forth. 9 and 10, a slight gap is formed between the reaction force rubber disk 25 and the front end surface of the second spool 24 when not operating.
[0032]
As shown in an enlarged view in FIG. 10, annular grooves 23a and 23b are formed on the outer peripheral surface of the first spool 23, and an axial hole 23d that opens forward is formed, so that a radial communication hole 23c is formed. Is communicated with the annular groove 23a. When the first spool 23 is not in operation, as shown in FIG. 10, the annular grooves 23a and 23b face the openings of the communication holes 21e and 21f, respectively, and the power chamber R6 has the communication hole 21e, the annular groove 23a and the communication. It communicates with the hole 23d through the hole 23c. When the first spool 23 moves forward, the communication between the power chamber R6 and the hole 23d is cut off, the annular groove 23b faces the opening of the communication hole 21f and the communication hole 21g, and the power chamber R6 communicates with the communication hole 21g. .
[0033]
On the other hand, the second spool 24 is formed with an annular groove 24a on the rear outer peripheral surface thereof and an axial hole 24c that opens rearward and faces the opening of the hole 23d of the first spool 23. Further, it communicates with the annular groove 24a via the radial communication hole 24b, and further communicates with the drain chamber R4 via the communication hole 21h. In the state shown in FIG. 10, the first spool 23 and the second spool 24 are in contact with each other and move together, but there may be a case where a space is formed between them.
[0034]
The booster housing 2 is formed with a drain port 2d and input ports 2e and 2f that always communicate with the drain chamber R4. The drain port 2d is connected to the reservoir 4 via a normally-open electromagnetic valve 6 as shown in FIG. Communication connection is established. The electromagnetic valve 6 corresponds to the electromagnetic valve EV of FIG. 1 and is composed of a linear solenoid valve for fine control, but may be a normal on-off valve. On the other hand, the input ports 2e and 2f are connected to an auxiliary hydraulic pressure source 40 (corresponding to the auxiliary hydraulic pressure source AP of FIG. 1) shown in FIG. The auxiliary hydraulic pressure source 40 includes a hydraulic pump 42 driven by an electric motor 41. The input side is connected to the reservoir 4 and the output side is connected to the accumulator 44 via the check valve 43 and connected to the input port 2e. The communication port is connected to the input port 2f via the normally closed solenoid valve 5. If this solenoid valve 5 is also constituted by a linear solenoid valve, finer control can be performed. In the present embodiment, the pressure sensor P is connected to the accumulator 44 so that the auxiliary hydraulic pressure source 40 is maintained at a predetermined output hydraulic pressure. As described above, in the present embodiment, the pressure regulating means of the present invention is configured in the power piston 21. As the hydraulic pressure assisting device 20, various names such as a hydraulic pressure booster and a regulator are used, but any device may be used.
[0035]
Further, in the present embodiment, the booster housing 2 is formed with a flow path 2g communicating the sealed chamber R3 and the power chamber R6, and the normally open differential pressure responsive check valve 30 (hereinafter, referred to as the flow path 2g). Simply called a check valve 30). That is, it is always maintained in a communicating state, is closed according to the pressure difference between the power chamber R6 and the sealed chamber R3, and when the power chamber R6 is larger than the pressure in the sealed chamber R3 and the pressure difference is a predetermined value or more, The check valve 30 is closed and the two are blocked. On the other hand, when the hydraulic brake device is not operated, there is no pressure between the two and the check valve 30 is in the open position. Therefore, when the brake fluid is filled, by evacuating from the power chamber R6 side, The air in the sealed chamber R3 can be removed easily and reliably.
[0036]
In the hydraulic brake device configured as described above, when the brake pedal 3 is not operated, each component is in the state shown in FIGS. 9 and 10, the electromagnetic valve 5 is in the closed position, and the electromagnetic valve 6 is in the open position. Has been. The rear end surface of the master piston 12 is in contact with the metal plate 26, and the hydraulic pressure assisting device 20 is in an inoperative state. At this time, the sealed chamber R3 is under atmospheric pressure because it communicates with the reservoir 4 through the communication hole 1k and the liquid supply port 1j.
[0037]
On the other hand, the liquid supply chamber R <b> 5 is connected to the accumulator 44 of the auxiliary hydraulic pressure source 40, but the communication hole 21 g is blocked by the first spool 23. Further, in the power chamber R6, the electromagnetic valve 5 is in the closed position, the communication hole 21e, the groove 23a of the first spool 23 facing the same, the communication hole 23c and the hole 23d, the hole 24c of the second spool 24, the communication hole. 24b and groove 24a, the communication hole 21h of the power piston 21, and the port 4d communicate with the reservoir 4. Further, the power chamber R6 communicates with the sealed chamber R3 via the flow path 2g and the check valve 30. Thus, even if the auxiliary hydraulic pressure source 40 is driven, the power piston 21 is only given a backward pressing force due to the hydraulic pressure in the liquid supply chamber R5. Maintained in position.
[0038]
When the brake operation is performed and the plunger 22 is driven forward to advance the first spool 23, the communication hole 21e is blocked by the first spool 23, so that the communication between the power chamber R6 and the hole 23d is blocked. On the other hand, since the annular groove 23b faces the openings of the communication hole 21f and the communication hole 21g, the power hydraulic pressure is applied to the power chamber R6 via the input port 2e, the communication hole 21g, the annular groove 23b, and the communication holes 21f and 21e. Is introduced. At this time, since the power hydraulic pressure from the auxiliary hydraulic pressure source 40 is introduced into the liquid supply chamber R5, the land portion 21y (rearward) is applied in the direction of pressing the power piston 21 rearward by the power hydraulic pressure. The pressure of the annular area of the pressure receiving surface is configured to be balanced with the pressure of the effective cross-section integral of the power piston 21 by the hydraulic pressure introduced into the power chamber R6 according to the brake operation and the brake operation force. When the pressure difference between the power chamber R6 and the sealed chamber R3 at this time exceeds a predetermined value, the check valve 30 is closed and the flow path 2g is blocked by the check valve 30, so that the sealed chamber R3 is braked. It becomes a sealed space filled with liquid.
[0039]
In this way, during the assisting operation after the sealed chamber R3 is set to the sealed space, the pressing force applied to the annular area of the land portion 21y with respect to the brake operating force and the pressing force applied to the rear end surface of the power piston 21. In addition, the pressing force applied to the front end face of the power piston 21 due to the pressure in the sealed chamber R3 is controlled to be balanced. In the sealed chamber R3, since the effective sectional area of the land portion 21x of the power piston 21 is larger than the effective sectional area of the master piston 12, the master piston 12 moves forward with the forward movement of the power piston 21, and the master piston 12 In this state, the master piston 12 and the power piston 21 are fluidly coupled and move integrally. As described above, when the hydraulic pressure assisting device 20 assists, the power piston 21 and the master piston 12 are fluidly coupled via the brake fluid filled in the sealed chamber R3, and the gap between the power piston 21 and the master piston 12 is obtained. Since the power piston 21 and the master piston 12 move forward together with the master piston 12 moving forward, the stroke of the brake pedal 3 is shortened.
[0040]
In the above state, for example, when the brake pedal 3 is operated at a speed equal to or higher than a predetermined speed, or an operation amount is operated above a predetermined amount, Corresponding to the solenoid valve EV of FIG. Solenoid valve 6 shown in FIG. Is started, and the discharge side hydraulic path (corresponding to DP in FIG. 1) is controlled to open and close The electromagnetic valve 5 is controlled to open and close. This For example, when the brake pedal BP is suddenly operated, the jumping amount ΔP is set to a larger value than when the brake pedal BP is gently operated. And The output power hydraulic pressure of the auxiliary hydraulic pressure source 40 is supplied to the liquid supply chamber R5 and the power chamber R6, and the relative movement between the first spool 23 and the power piston 21 is controlled according to the opening / closing control of the electromagnetic valve 5. Thus, in this case, a brake hydraulic pressure that is equal to or higher than the hydraulic pressure at the time of normal hydraulic pressure assist is output, and an appropriate braking force can be ensured without being affected by insufficient pedaling force on the brake pedal 3.
[0041]
When the hydraulic pressure assisting device 20 fails, no power hydraulic pressure is supplied to the liquid supply chamber R5 and the power chamber R6, and the drain chamber R4 communicates with the reservoir 4 through the port 2d, and the sealed chamber. Since the inside of R3 communicates with the reservoir 4 via the flow path 1k and the port 1j, both remain at atmospheric pressure. Accordingly, when the input rod 3a is driven forward in accordance with the operation of the brake pedal 3, the second spool 24 comes into contact with the reaction force rubber disk 25 via the plunger 22 and the first spool 23, and this reaction force rubber. The master piston 12 is pressed through the disk 25 and the metal plate 26, and these move forward together. Since the brake hydraulic pressure output in this case is determined not by the effective sectional area of the land portion 21x of the power piston 21 but by the effective sectional area of the master piston 12, compared to the characteristics when the effective sectional areas of both pistons are the same. The pressure increase gradient at the time of failure of the hydraulic pressure assisting device 20 becomes large.
[0042]
【The invention's effect】
Since this invention is comprised as mentioned above, there exist the following effects. That is, according to the first aspect of the present invention, the discharge-side hydraulic pressure passage connecting the pressure regulating means to the reservoir is provided with an electromagnetic valve, and the discharge-side hydraulic pressure is controlled by controlling the energization of the electromagnetic valve. Control the opening and closing of the road, By opening and closing control Since the hydraulic pressure on the discharge side of the pressure adjusting means is controlled to a predetermined pressure equal to or higher than the atmospheric pressure, an arbitrary jump amount can be set for the brake hydraulic pressure characteristics of the hydraulic brake device having the pressure adjusting means. It can be set easily.
[0043]
In particular, in the hydraulic brake device according to claim 2, the control means is configured to control the hydraulic pressure adjustment means that is preset based on the operation state of the brake operation member according to the detection result of the brake operation state detection means. Since the solenoid valve is controlled so that the hydraulic pressure on the discharge side increases, for example, when the brake operation member is operated suddenly, the hydraulic pressure on the discharge side of the pressure adjusting means is Control is performed so that the pressure is higher than when the operation is performed gently, and an appropriate jump amount corresponding to the operation of the brake operation member can be set with respect to the brake hydraulic pressure characteristic during the brake assist control. .
[0044]
Further, in the hydraulic brake device according to claim 3, the control means is configured to set a hydraulic pressure that is set in advance based on the vehicle state quantity according to the detection result of the vehicle state detection means, on the discharge side of the pressure adjustment means. Since the solenoid valve is controlled to increase the hydraulic pressure, an appropriate jump amount corresponding to the vehicle state can be set for the brake hydraulic pressure characteristics. For example, when the vehicle body speed is fast, it can be controlled so that the hydraulic pressure on the discharge side of the pressure regulating means is larger than when it is slow, and when the vehicle weight is heavy, it can be controlled compared to when it is light. The hydraulic pressure on the discharge side of the pressure means can be controlled to be a large pressure.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a hydraulic brake device according to an embodiment of the present invention.
FIG. 2 is a graph showing a brake hydraulic pressure characteristic of the hydraulic brake device according to the embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a control unit in FIG. 1;
FIG. 4 is a flowchart showing a control example of a solenoid valve in one embodiment of the present invention.
5 is a flowchart showing a subroutine of solenoid valve control in the flowchart of FIG.
FIG. 6 is a graph showing an example of a jumping amount set according to a brake operation state and a vehicle state in an embodiment of the present invention.
FIG. 7 is a graph showing another example of the jumping amount set according to the brake operation state and the vehicle state in the embodiment of the present invention.
FIG. 8 is a graph showing the relationship between the drive current of the solenoid valve and the jumping amount in one embodiment of the present invention.
FIG. 9 is a cross-sectional view showing the overall structure of a hydraulic brake device according to an embodiment of the present invention.
FIG. 10 is a cross-sectional view of a hydraulic pressure assisting device portion according to an embodiment of the present invention.
[Explanation of symbols]
CT control means, ST stroke sensor, WS wheel speed sensor,
HS height sensor, MC, 10 master cylinder, RG pressure regulation means,
20 Hydraulic assist device, BP, 3 brake pedal,
RV, 4 reservoir, EV, 5, 6 solenoid valve,
MP, 11, 12 Master piston, AP, 40 Auxiliary hydraulic pressure source,
R1, R2 pressure chamber, R3 sealed chamber, R4 drain chamber,
R5 liquid supply room, R6 power room

Claims (3)

In accordance with the operation of the brake operation member, the master piston is driven forward to boost the brake fluid in the reservoir to output the brake fluid pressure to the wheel cylinder, and the brake fluid in the reservoir is boosted to a predetermined pressure to increase the power fluid. An auxiliary hydraulic pressure source that outputs pressure, and a hydraulic pressure source that is connected to the auxiliary hydraulic pressure source and connected to the reservoir, and regulates the output power hydraulic pressure of the auxiliary hydraulic pressure source to a predetermined pressure. And a pressure regulating means for driving the master piston in the vehicle. In the hydraulic brake device for a vehicle, an electromagnetic valve interposed in the discharge side hydraulic pressure path communicating with the reservoir, and the solenoid valve energization control to the opening and closing controls the discharge side hydraulic pressure passage of, further comprising a control means for controlling a predetermined pressure in the hydraulic pressure of the discharge side than the atmospheric pressure of the pressure regulating means by the switching control Features and That the hydraulic brake system of the vehicle.   Brake operation state detection means for detecting an operation state of the brake operation member is provided, and the control means is a liquid preset based on the operation state of the brake operation member according to the detection result of the brake operation state detection means. 2. The hydraulic brake device for a vehicle according to claim 1, wherein the electromagnetic valve is controlled such that the hydraulic pressure on the discharge side of the pressure adjusting means increases by a pressure.   Vehicle state detecting means for detecting a state quantity of the vehicle, wherein the control means adjusts the fluid pressure that is preset based on the state quantity of the vehicle according to the detection result of the vehicle state detecting means; 2. The hydraulic brake device for a vehicle according to claim 1, wherein the electromagnetic valve is controlled so that the hydraulic pressure on the discharge side of the vehicle increases.

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