JP2008265728A - Vehicle brake system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle brake system capable of achieving a brake-by-wire construction mountable to a vehicle like conventional common brake systems while maintaining the feature which is mechanical connection of brake pedal operation to wheel brakes. <P>SOLUTION: The vehicle brake system is provided with a booster 27, a master cylinder 25, the wheel brakes 30, and a hydraulic pressure control device 43 interposed between the master cylinder 25 and the wheel brakes 30. The system is further provided with a stroke sensor 52 for detecting a brake operating stroke, a simulator for 51 for applying to a brake pedal 20 a pseudo reaction force with respect to the brake operating stroke, a play element 53 arranged between the booster 27 and the hydraulic pressure control device 43 and absorbing the brake operating stroke by a predetermined amount, and an electronic control device 13 for controlling the hydraulic pressure control device 43 based on an input from the stroke sensor 52. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle brake device that realizes a brake-by-wire that connects a brake operation portion and a brake braking portion with an electrical signal.

  In the so-called brake-by-wire, in which the brake operation part composed of a brake pedal and the like and the brake braking part composed of a wheel brake or the like are connected by an electrical signal, the brake operation part and the brake braking part are mechanically interrupted. The brake pedal does not generate unpleasant vibration due to fluctuations in the braking force when the antilock brake is activated. Also, in the case of an electric vehicle or hybrid vehicle equipped with a regenerative brake device, even if the regenerative braking force fluctuates for some reason, the braking force by the wheel brake is regenerated without making the brake pedal feel uncomfortable. There is an advantage that it can be varied to compensate for power fluctuation.

  On the other hand, in a complete brake-by-wire, in order to avoid a situation in which the brake does not operate in the event of an electric system failure, for example, as described in Patent Document 1, a master cylinder pressure is generated with a brake pedal, In order to reduce the probability of complete failure of the electrical system by disconnecting the master cylinder from the wheel brake when the electrical system is normal and connecting the master cylinder and wheel brake when the electrical system fails. A method of duplicating the power source has been proposed.

  Further, Patent Document 2 includes a simulator that can be operated by a brake pedal, and an operation sensor signal provided in the simulator is sent to an electronic control unit that controls a pressure source in accordance with this signal, and the output of the pressure source Is a brake-by-wire actuator for operating a brake system of an automobile, which is connected to a distribution device for braking force to operate a wheel brake, and further includes means for enabling a brake with a driver's muscle force in the event of failure, A brake pedal or a member articulated to the brake pedal to mechanically decouple the brake pedal from the force reaction of the brake system of the vehicle in a by-wire mode; A brake-by-wire actuator is described in which an air travel distance is provided between the two.

  Moreover, although not brake-by-wire, as a method for realizing cooperative control with a regenerative brake, for example, in Patent Document 3, a brake operating force of a driver is increased according to a predetermined boost ratio by a booster, and the booster is A wheel brake (wheel cylinder) that generates a base hydraulic pressure corresponding to the brake operating force increased by a connected master cylinder, and the generated base hydraulic pressure is connected by a route through the master cylinder and a hydraulic control valve. A hydraulic brake device capable of generating a basic hydraulic braking force on each wheel and applying a control hydraulic pressure formed by driving a pump to the wheel brake to generate a controlled hydraulic braking force on each wheel. A vehicular brake device is described.

Further, in Patent Document 3, when a brake operation force is input, a predetermined regenerative braking force is generated on any of the wheels, so that a target braking force corresponding to the brake operation force is obtained together with the basic hydraulic braking force. A regenerative braking device is provided, and fluctuation detecting means for detecting a fluctuation of the regenerative braking force actually generated by the regenerative braking device with respect to a predetermined regenerative braking force. And when a fluctuation | variation is detected by the fluctuation | variation detection means, the control liquid pressure is formed by driving the pump of a hydraulic brake device and controlling a hydraulic pressure control valve, and based on the control hydraulic pressure on a wheel. There is described a vehicle brake device having a braking force compensation means for generating a pressure braking force and compensating for a lack of regenerative braking force due to the fluctuation detected by the fluctuation detection means.
JP 2003-11808 (paragraphs 0025 and 0026, FIGS. 1 and 5) JP 2005-532220 A (paragraphs 0046 to 0048, FIG. 1) Japanese Patent Laying-Open No. 2005-349880 (paragraphs 0031 and 0042, FIG. 1)

  The vehicle brake device described in Patent Document 1 can improve the reliability against a complete failure of the electric system, but an increase in cost due to the dual power supply is inevitable.

  The vehicle brake device described in Patent Document 2 is normal even when the electric system fails because the operation of the brake pedal is always mechanically connected to the wheel brake without relying on an electrical signal. A braking force equivalent to that at times can be secured. However, on the other hand, if it is a conventional general vehicle, it is necessary to install a brake-by-wire actuator at a position where an operation input from a brake pedal to which the negative pressure booster and the master cylinder are attached, Since a device for individually controlling wheel brakes such as ABS is required, cost and restrictions on vehicle mounting design are increased.

  Since the brake device for a vehicle described in Patent Document 3 is also mechanically connected to the wheel brake at all times by the operation of the brake pedal, the reliability against failure can be increased. On the other hand, in this device, the regenerative braking force cannot bear all of the vehicle braking force. In addition, even if the regenerative braking force fluctuates during braking, the sum of the braking force and the brake operating force for operating the brake pedal can be made constant. At that time, the master cylinder is driven by a pump that generates control hydraulic pressure. Because the brake fluid is consumed, it is inevitable that the stroke of the brake pedal will fluctuate. If you try to increase the maximum regenerative braking force, the stroke variation of the brake pedal will increase and the driver may feel uncomfortable. . These problems are a natural consequence of the fact that the vehicle brake device described in Patent Document 3 does not realize brake-by-wire.

  The present invention has been made to solve the conventional problems, and the vehicle is maintained in the same manner as a conventional general brake system while maintaining the characteristic that the operation of the brake pedal is mechanically connected to the wheel brake. An object of the present invention is to provide a vehicle brake device capable of realizing a mountable brake-by-wire.

  In order to solve the above-mentioned problem, the structural feature of the invention described in claim 1 is that a booster that increases the brake operating force of the driver and a working fluid on the master cylinder side can be sucked and discharged to the wheel brake side. The idle element that absorbs a predetermined amount of the brake operation stroke of the driver is disposed between the hydraulic pump and the hydraulic pressure control device having the hydraulic pressure control valve. Thus, when the brake pedal is stepped on, the play pedal can absorb the operation stroke of the brake pedal, and based on the detection signal of the stroke sensor that detects the operation stroke of the brake pedal, the hydraulic control device is controlled by the electronic control device. The required control fluid pressure is supplied to the wheel brake.

  According to the invention according to claim 1 configured as described above, even when a failure occurs in the electric system, a brake-by-wire that can ensure a braking force according to a normal state can be provided.

  According to a second aspect of the present invention, in the first aspect, the play element is limited by a spring inserted between the output member of the booster and the input member of the master cylinder and the maximum length of the spring. That is, it is composed of a stroke absorbing mechanism composed of hanging elements. Thereby, in the initial stage of depression of the brake pedal, the stroke of the master cylinder is suppressed by the stroke absorbing mechanism as compared with the stroke of the booster.

  According to the invention according to claim 2 configured as described above, the output of the booster can be made small so as to deform the stroke absorbing mechanism, and the hydraulic pressure of the hydraulic chamber of the master cylinder can be reduced to that. Only a small amount of pressure can be generated.

  The structural feature of the invention described in claim 3 is that, in claim 1, the play element has one end facing the hydraulic circuit between the master cylinder and the hydraulic control device, and the other end facing atmospheric pressure. That is, it is configured by a liquid amount absorbing mechanism including a piston fitted in a cylinder in a fluid-tight and slidable manner and a spring that biases the piston toward the hydraulic circuit. As a result, in the initial stage of depression of the brake pedal, the fluid amount is absorbed by the fluid amount absorbing mechanism, so that the fluid pressure in the fluid pressure chamber of the master cylinder is reduced.

  According to the invention according to claim 3 configured as described above, without changing the configuration of the booster and the master cylinder, only by adding a liquid amount absorption mechanism to the hydraulic circuit of the hydraulic control device, A play element can be easily provided, and the same effect as that of claim 2 can be expected.

  According to a fourth aspect of the present invention, in the first aspect, the play element is provided with a damper mechanism for limiting a play absorption speed. As a result, the operation stroke absorption speed of the brake pedal by the play element when the brake pedal is depressed is limited.

  According to the invention according to claim 4 configured as described above, for example, at the time of sudden braking operation, the play absorption speed of the play element can be limited, so that the ability of the pump for generating the control hydraulic pressure is unnecessarily increased. Therefore, the responsiveness at the time of sudden braking required as a brake system can be ensured.

  The structural feature of the invention described in claim 5 is that, in claim 3, a limiting element for limiting the flow rate of the liquid absorbed by the liquid amount absorbing mechanism is provided on the inlet side of the liquid amount absorbing mechanism.

  According to the invention according to claim 5 configured as described above, during the sudden braking operation, the liquid flow rate absorbed by the liquid amount absorption mechanism can be limited by the limiting element, and a considerable amount of the discharge liquid amount from the master cylinder can be reduced. Since the amount of fluid can be supplied to the wheel brake, the responsiveness at the time of sudden braking required as a brake system can be secured without unnecessarily increasing the capacity of the pump for generating the control fluid pressure. .

  A structural feature of the invention according to claim 6 is that, in any one of claims 1 to 5, the booster is configured not to transmit the operation reaction force to the input member. is there. As a result, a pseudo reaction force mainly by the simulator is applied to the brake pedal.

  According to the invention according to claim 6 configured as described above, when the so-called consumed liquid amount of the wheel brake fluctuates from the design value, the range of play is exceeded, or the electrical system is damaged, etc. Even when the pump does not operate, no reaction force is generated from the booster to the brake pedal, so that the relationship between the depression force and the stroke of the brake pedal can be kept as determined by the simulator. Furthermore, since a reaction force transmission mechanism such as a rubber disk included in the negative pressure booster is not required, the stroke absorbing mechanism can be more easily mounted.

  According to a seventh aspect of the present invention, a structural feature of the invention according to any one of the first to sixth aspects includes a regenerative braking device that generates a regenerative braking force on the wheel, and the electronic control device is a regenerative braking device. The regenerative braking device, the pump of the hydraulic pressure control device, and the hydraulic pressure control valve so that the sum of the regenerative braking force by the wheel brake and the braking force by the wheel brake operated by the hydraulic pressure output from the hydraulic pressure control device matches the target braking force. It is to control. As a result, the hydraulic braking force by the hydraulic pressure control device only needs to be generated by the difference between the target braking force and the effective regenerative braking force. By appropriately setting the play by the play element, the brake operation force is small. It becomes possible to bear virtually all of the target braking force with the regenerative braking force.

  According to the invention according to claim 7 configured as described above, even when the braking force of the wheel brake is increased or decreased in response to the fluctuation of the regenerative braking force, there is no sense of incongruity in the feeling of operating the brake pedal. . In addition to braking by muscular force, there are three types of means for applying braking force: a regenerative braking device, a booster that generally uses negative pressure as a power source, and a battery-operated hydraulic control device pump. Therefore, the reliability of the system can be improved.

  The structural feature of the invention described in claim 8 is that, in claim 7, the predetermined amount absorbed by the play element is a deceleration equal to the maximum deceleration that the regenerative braking device can produce only by deceleration by the wheel brake. It is set to an amount close to the stroke amount of the master cylinder.

  According to the invention according to claim 8 configured as described above, the play element can be effectively acted, and thereby, virtually all of the target braking force when the brake operation force is small is borne by the regenerative braking force. Energy efficiency can be improved.

  According to a ninth aspect of the present invention, there is provided a liquid amount absorbing mechanism for absorbing a predetermined amount of a brake operation stroke of the driver between the master cylinder and the hydraulic pressure control device, That is, a cut valve is provided between the volume absorption mechanism and the pressure cylinder to cut off the communication between the master cylinder and the liquid volume absorption mechanism when pressure oil is no longer discharged from the pump due to a system abnormality. Thus, when the system is abnormal, the liquid consumption of the master cylinder is not consumed by the liquid absorption mechanism by the cut valve.

  According to the invention according to claim 9 configured as described above, even when the pump fails, the liquid consumption of the master cylinder is not consumed by the liquid absorption mechanism by closing the cut valve. Therefore, the pedal stroke does not increase, and a braking force almost equal to that during normal control can be ensured.

  The structural feature of the invention described in claim 10 is that, in claim 9, the cut valve is constituted by an electromagnetic valve which is closed when no power is supplied.

  According to the invention which concerns on Claim 10 comprised as mentioned above, a cut valve can be immediately closed by failure of an electric system.

  According to the eleventh aspect of the present invention, in the ninth or tenth aspect of the present invention, the cut valve is closed when the pump of the hydraulic pressure control valve fails when there is a differential pressure due to the hydraulic pressure control valve. After that, the differential pressure of the hydraulic control valve is reduced. As a result, even if the pump breaks down while the brake pedal is depressed, it is possible to prevent the fluid volume from flowing through the fluid volume absorbing mechanism and the wheel brake pressure from being lowered.

  According to the eleventh aspect of the present invention configured as described above, the liquid amount absorbing mechanism is not filled up by the control of the hydraulic pressure control valve, and the liquid amount absorbing mechanism can function properly.

  Hereinafter, a brake-by-wire vehicle brake device according to a first embodiment of the present invention will be described with reference to the drawings. 1 and 2, the vehicle brake device 10 includes a hydraulic brake device 11 and a brake ECU 13 that controls the hydraulic brake device 11.

  The hydraulic brake device 11 includes left and right front wheel brakes 30fl and 30fr and left and right rear wheel brakes 30rl and 30rr provided on the left and right front wheels 23fl and 23fr and the left and right rear wheels 23rl and 23rr, respectively. Yes. The left and right front wheel brakes 30fl, 30fr and the left and right rear wheel brakes 30rl, 30rr are separated from each other by the driver operating the brake pedal 20, and the front wheel brake system 24f and the rear wheel brake system 24f having substantially the same configuration are provided. A braking force is generated by the wheel brake system 24r.

  In FIG. 1 and FIG. 2, the configuration and operation of the component parts constituting the front wheel and rear wheel brake systems 24f and 24r are the same, and therefore the corresponding component parts have the same arithmetic numerals with Roman letters f, A reference symbol to which r is added is attached to distinguish the front and rear. Furthermore, the same component parts in the left and right wheels are distinguished from each other by adding l and r after Roman letters f and r that distinguish the front and rear wheels. In the specification, when components are shown without distinction between front, back, left, and right, only the corresponding arithmetic numbers are given as reference numbers.

  Reference numeral 25 denotes a dual master cylinder. Master pistons 21f and 21r (see FIG. 2) for generating brake fluid pressures in the two fluid pressure chambers 25f and 25r are slidably fitted into the master cylinder 25, respectively. As the master pistons 21f and 21r slide, an amount of brake fluid corresponding to the strokes of the master pistons 21f and 21r is sent from the hydraulic chambers 25f and 25r to the paths 26f and 26r. Reference numeral 28 denotes a reserve tank for storing brake fluid, which replenishes the brake fluid to the hydraulic chambers 25f and 25r of the master cylinder 25.

  Reference numeral 27 denotes a negative pressure type booster as a booster interposed between the brake pedal 20 and the master cylinder 25. As the negative pressure booster 27, a publicly known one can be used. As shown in FIG. 3, an input rod 61 connected to the brake pedal 20, a diaphragm 62 on which intake negative pressure of the engine is applied, and a diaphragm 62 The valve piston 63 is connected, a spring 64 that biases the valve piston 63 toward the brake pedal 20, and an air valve portion 65 that is built in the valve piston 63 and is opened and closed by operating the brake pedal 20. On both sides of the diaphragm 62, a variable pressure chamber 66 into which air can be introduced and a low pressure chamber 67 into which intake negative pressure of the engine is introduced are disposed.

  When the brake pedal 20 is operated, the air valve portion 65 is activated, the communication between the variable pressure chamber 66 and the low pressure chamber 67 partitioned by the diaphragm 62 is cut off, and the atmosphere is introduced into the variable pressure chamber 66. A pressure difference is generated between the variable pressure chamber 66 and the low pressure chamber 67. Due to this pressure difference, the valve piston 63 is moved forward together with the diaphragm 62 against the urging force of the spring 64, following the operating stroke of the brake pedal 20.

  The negative pressure booster 27 does not use a rubber disk that is normally used to transmit a part of the output to the brake pedal 20 side, and is used to press the air valve 65 when the brake pedal 20 is operated. A force other than a small force such as a spring 68 is prevented from being transmitted to the brake pedal 20 side.

  The simulator 51 applies a pseudo reaction force to the brake operation stroke to the brake pedal 20. The simulator 51 is composed of a plurality of springs 56 and the like so as to make a predetermined amount of stroke according to the operating force of the brake pedal 20, and one end of the spring 56 is coupled to the brake pedal 20 and the other end is coupled to a fixed portion of the vehicle. Yes. One end of the spring 56 may not be the brake pedal 20 but may be another component that moves in synchronization with the brake pedal 20.

  The simulator 51 is provided with a stroke sensor 52. The stroke sensor 52 detects the stroke of the brake pedal 20, and transmits the detection signal to the brake ECU 13. The brake ECU 13 stores the target braking force with respect to the output value of the stroke sensor 52 and the hydraulic braking force generated on the wheel 23 when the hydraulic pressure is supplied to the wheel brake 30 in advance in a memory as a map, a table or an arithmetic expression. Yes.

  Reference numeral 53 denotes a stroke absorbing mechanism as a play element that absorbs a predetermined amount of the brake operation stroke of the driver, and is disposed between the valve piston 63 of the negative pressure booster 27 and the master piston 21f of the master cylinder 25. As shown in FIG. 4 in an enlarged manner, the stroke absorbing mechanism 53 includes two suspension elements 55a and 55b that are engaged with each other so as to be relatively movable by a predetermined amount, and a spring 54 that is interposed between the suspension elements 55a and 55b. It is constituted by. That is, one suspension element 55a abuts on the valve piston 63, and the other suspension element 55b abuts on the master piston 21f. Normally, the suspension element 55b is moved forward relative to the suspension element 55a by the spring force of the spring 54. The suspension elements 55a and 55b are held at positions where they are engaged with each other, the maximum length of the spring 54 is limited, and a play amount a is set.

  The set load of the spring 54 is desirably larger than the set load of the spring 22 applied to the master piston 21f.

  As shown in FIGS. 1 and 2, the front and rear brake systems 24f and 24r are respectively provided with solenoid hydraulic pressure proportional control valves 32f and 32r that form hydraulic pressure control valves. The inlet port 32r is connected to the hydraulic chambers 25f and 25r of the master cylinder 25 through paths 26f and 26r, respectively. The solenoid hydraulic pressure proportional control valve 32 performs pressure control so that the hydraulic pressure at the outlet port is higher than the hydraulic pressure at the inlet port by a control differential pressure from zero according to the control current applied to the linear solenoid 33. A check valve that allows liquid flow from the inlet port to the outlet port is connected between the inlet port and the outlet port of the solenoid hydraulic pressure proportional control valves 32f and 32r. In the case of normal control, the solenoid hydraulic pressure proportional control valve 32 is shifted to the open position by the deactivation of the linear solenoid 33, and the inlet port and the outlet port are directly connected.

  A path 26f connected to the outlet of the solenoid hydraulic pressure proportional control valve 32f is branched to the left and right front wheel brakes 30fl and 30fr via an ABS control valve 37f including solenoid opening / closing valves 34fl and 34fr and 36fl and 36fr. It is connected. Similarly, the path 26r connected to the outlet of the solenoid hydraulic pressure proportional control valve 32r is branched to the left and right rear wheel brakes 30rl and 30rr, and the ABS control valve including solenoid opening / closing valves 34rl and 34rr and 36rl and 36rr. 37r is connected.

  The discharge ports of the pumps 38f and 38r that are rotationally driven by the motor 39 are connected to the outlet ports of the solenoid hydraulic pressure proportional control valves 32f and 32r and the ABS control valves 37f and 37r via check valves that block the flow of liquid to the discharge ports. Connected between imports. The suction ports of the pumps 38f and 38r are connected to the inlet ports of the solenoid hydraulic pressure proportional control valves 32f and 32r via the pressure control valves 45f and 45r communicated with the outlet ports of the ABS control valves 37f and 37r. The response valves 45f and 45r are provided with reservoirs 46f and 46r that are configured by sealing a bottomed casing with a piston urged by a weak compression spring. When the reservoirs 46f and 46r are empty, the valves are opened, The suction ports 38f and 38r communicate with the hydraulic chambers 25f and 25r of the master cylinder 25. The response valves 45f and 45r also serve as temporary liquid reservoirs for the ABS control valves 37f and 37r.

  A pump 38, a motor 39, a solenoid hydraulic pressure proportional control valve 32, and the like apply a control hydraulic pressure formed by driving the pump 38 to the wheel brake 30, and a control hydraulic braking force is applied to the wheel 23 corresponding to the wheel brake 30. A control fluid pressure control device 43 that can be generated is configured. The control hydraulic pressure control device 43 is interposed between the master cylinder 25 and the wheel brake 30 and generates a control hydraulic pressure by driving the pump. The control hydraulic pressure control device 43, the negative pressure booster 27, the master cylinder 25, and the wheel brake 30 constitute the hydraulic brake device 11.

  The brake ECU 13 sets a target braking force to be generated on the wheel 23 according to the brake pedal stroke, calculates a hydraulic braking force based on the target braking force, and generates a hydraulic braking force on the wheel 23 by using the wheel brake 30. Determine the control fluid pressure that must be supplied to In addition, the brake ECU 13 is connected to the linear solenoid 33 of the solenoid hydraulic pressure proportional control valve 32 so that the hydraulic pressure of the brake fluid supplied to the wheel brake 30 from the pump 38 rotated by the motor 39 becomes the control hydraulic pressure. Apply control current.

  Further, the brake ECU 13 executes each program based on detection signals from a hydraulic pressure sensor 29, a wheel speed sensor (not shown) for detecting the wheel speed of each wheel 23, and the control signal is sent to a solenoid hydraulic pressure proportional control valve 32r. , 32f, ABS control valves 37f, 37r, motor 39, etc., and the hydraulic pressure controlled by the wheel brake 30 is supplied to generate a desired hydraulic braking force on the wheel 23.

  The brake ECU 13 constitutes an electronic control device that controls the hydraulic pressure control device 43 based on the input from the stroke sensor 52.

  Next, the operation of the vehicle brake device 10 according to the above-described first embodiment will be described. When the brake pedal 20 is stepped on, the input rod 61 of the negative pressure booster 27 moves forward, the air valve portion 65 enters the atmosphere introduction state, and the atmosphere is introduced into the variable pressure chamber 66. As a result, the valve piston 63 of the negative pressure booster 27 moves forward until it almost catches up with the input rod 61, and pushes the stroke absorbing mechanism 53. At this time, since the set load of the spring 54 of the stroke absorbing mechanism 53 is set to be larger than the set load of the spring 22 of the master cylinder 25, the stroke absorbing mechanism 53 is not deformed at the initial stage of depression of the brake pedal 20. First, the master pistons 21f and 21r of the master cylinder 25 move forward, and the communication between the hydraulic chambers 25f and 25r of the master cylinder 25 and the reserve tank 28 is blocked. As a result, the hydraulic pressure in the hydraulic chambers 25f and 25r of the master cylinder 25 increases, and a load obtained by multiplying the hydraulic pressure and the cylinder diameter of the master cylinder 25 acts on the stroke absorbing mechanism 53. The spring 54 is compressed and the play amount a is absorbed. As a result, the valve piston 63 of the negative pressure booster 27 is moved forward relative to the master pistons 21f and 21r.

  In this way, even if the brake pedal 20 is depressed, the stroke of the master pistons 21f and 21r of the master cylinder 25 is compared with the stroke of the valve piston 63 of the negative pressure booster 27 by the absorbing action of the stroke absorbing mechanism 53. Therefore, the hydraulic chambers 25f and 25r of the master cylinder 25 generate only a small pressure corresponding to the pressure.

  However, since the reaction force corresponding to the operation stroke is generated in the brake pedal 20 by the simulator 51, the driver is informed of the operation stroke (depression amount) of the brake pedal 20 regardless of the hydraulic pressure generated in the master cylinder 25. A corresponding reaction force is applied. The operation stroke of the brake pedal 20 is detected by the stroke sensor 52. When this detection signal is input to the brake ECU 13, the brake ECU 13 activates the control program shown in FIG.

  By starting the control program, the temporary memory such as a counter and a flag is reset and initialized (step S1), and the program after step S2 is executed every time a certain minute time elapses.

  Based on the relationship between the brake pedal stroke and the target braking force stored in the memory, the brake ECU 13 obtains a target braking force to be generated on the wheel 23 by a map, a table, or an arithmetic expression (step S3). Based on this, the hydraulic braking force is calculated (step S4), and the control hydraulic pressure that must be supplied to the wheel brake 30 in order to generate this hydraulic braking force on the wheel 23 is obtained by a map, a table, or an arithmetic expression (step S5). . Then, the motor 39 is activated to drive the pump 38 and the linear solenoid 33 of the solenoid hydraulic pressure proportional control valve 32 so that the hydraulic pressure of the brake fluid supplied from the pump 38 to the wheel brake 30 becomes a predetermined control hydraulic pressure. A control current is applied to (step S6).

  Thus, the liquid supplied from the pump 38 is controlled to a required control hydraulic pressure by the solenoid hydraulic pressure proportional control valve 32 and supplied to the wheel brake 30. Accordingly, the hydraulic brake device 11 causes the wheel 23 to generate a hydraulic braking force corresponding to the target braking force. In order to control the pressure of the wheel brake 30 with higher accuracy, the hydraulic pressure detected by the hydraulic pressure sensor 29 may be fed back and controlled.

  In the brake device 10 described above, if the electronic control system fails, hydraulic pressure is generated in the master cylinder 25 after the stroke absorbing mechanism 53 is deformed to the maximum by the operation of the negative pressure booster 27, and wheel brakes are generated. 30 generates a hydraulic braking force. In this case, the relationship between the brake pedal stroke and the braking force increases the brake pedal stroke by the amount of play, and the amount of deformation of the simulator 51 increases accordingly. Although the brake pedal depressing force for generating power is increased, a sufficient braking force can be ensured as a single failure state.

  Further, when a failure occurs in the negative pressure supplied to the negative pressure booster 27, the input rod 61 can be moved by directly pushing the valve piston 63, as in a general negative pressure booster. Is possible. However, since it is necessary to overcome the force of the spring inside the negative pressure type booster 27, the brake pedal force at the start of movement becomes larger than normal, but as described above, the electronic control system is normal and the brake pedal is If the pump 38 is operated according to the stroke, the hydraulic pressure in the master cylinder 25 is kept low, so that almost no increase in the brake pedal pressing force other than the spring force inside the negative pressure booster 27 occurs. As a result, the relationship between the brake pedal stroke and the braking force remains the same as normal, and in the relationship between the brake pedal depression force and the braking force, the brake pedal depression force for producing the same braking force by the amount of the spring force inside the booster is Although it becomes large, a sufficient braking force can be secured as a single failure state.

  Thus, by having two means for increasing the brake fluid pressure, that is, the negative pressure booster 27 and the pump 38 of the control fluid pressure controller 43, even when a failure occurs in the electrical system, Brake-by-wire that can ensure the equivalent braking force can be obtained, and a system that is highly reliable against failure can be obtained.

  FIG. 6 shows a second embodiment of the present invention. In contrast to the first embodiment, the amount of liquid is replaced with a stroke absorbing mechanism 53 comprising a spring 54 and suspension elements 55a and 55b as play elements. The difference is that the absorption mechanism 153 is used and that the reaction force is returned to the brake pedal side by a rubber disk 69 or the like so that the negative pressure booster 27 can use an existing structure. Accordingly, in the following description, points different from the first embodiment will be described, and the same components will be denoted by the same reference numerals and the description thereof will be omitted.

  The liquid amount absorbing mechanism 153 includes a bottomed cylinder 57 having one end facing a path 126 branched from a path 26r connected to the hydraulic chamber 25r of the master cylinder 25 and the other end facing atmospheric pressure. A piston 59 biased by a compression spring 58 having a small spring force is fitted to the cylinder 57. It is desirable that the maximum absorption liquid amount of the liquid amount absorption mechanism 153 is set equal to an amount obtained by multiplying the play amount (maximum deformation amount) a of the stroke absorption mechanism 53 in the first embodiment by the master cylinder diameter.

  In the second embodiment, when the brake pedal 20 is stepped on, the input rod 61 of the negative pressure booster 27 moves forward, and the atmosphere is introduced into the variable pressure chamber 66, thereby the negative pressure booster. The 27 valve pistons 63 move forward until they almost catch up with the input rod 61. As a result, the master pistons 21f and 21r of the master cylinder 25 move forward, the communication between the hydraulic chambers 25f and 25r of the master cylinder 25 and the reserve tank 28 is cut off, and the hydraulic pressure of the master cylinder 25 increases. As the hydraulic pressure of the master cylinder 25 increases, the piston 59 of the liquid amount absorption mechanism 153 is slid in the cylinder 57 against the urging force of the compression spring 58, and the liquid amount is absorbed according to the sliding amount of the piston 59. Therefore, the hydraulic chambers 25f and 25r of the master cylinder 25 generate only a small hydraulic pressure. As a result, as in the first embodiment, the negative pressure booster 27 that increases the brake fluid pressure and the pump 38 of the control fluid pressure controller 43 can provide a highly reliable system against failure. it can.

  In the second embodiment, the simulator 51 for generating the reaction force corresponding to the operation stroke in the brake pedal 20 is provided, so there is no merit by returning the reaction force to the brake pedal side, but during normal operation If limited, the output of the negative pressure booster 27 is reduced as described above. Therefore, even if the negative pressure booster 27 that returns a reaction force to the brake pedal 20 is used, the reaction force to the brake pedal 20 is reduced. Therefore, there is an advantage that the existing negative pressure type booster 27 can be used as it is because the operation equivalent to that described in the first embodiment can be expected.

  FIG. 7 shows a third embodiment of the present invention. Compared to the second embodiment, the liquid flow rate absorbed by the liquid amount absorption mechanism 153 at the inlet of the liquid amount absorption mechanism 153 as a play element. The only difference is that a limiting element 70 is added to limit the absorption rate by the liquid absorption mechanism 153. The limiting element 70 includes an orifice 71 and a check valve 72 that is connected in parallel to the orifice 71 and allows only the flow from the cylinder 57 to the path 26r.

  According to the third embodiment, the brake fluid flowing into the cylinder 57 is restricted by the restriction element (orifice) 70 during the sudden braking operation by the driver, so that the absorption speed by the fluid amount absorption mechanism 153 is restricted. . As a result, a considerable amount of the liquid discharged from the master cylinder 25 is supplied to the wheel brake 30 via the check valve connected in parallel to the solenoid hydraulic pressure proportional control valve 32 in the closed state. It becomes like this. As a result, the responsiveness at the time of sudden braking required as a brake system can be secured without unnecessarily increasing the capacity of the pump 38 for generating the control hydraulic pressure. The above-described limiting element 70 constitutes a damper mechanism that limits the play absorption speed of the play element (liquid amount absorption mechanism 153).

  The limiting element (damper mechanism) 70 for limiting the play absorption speed of the above-described play element can also be applied to the stroke absorption mechanism 53 described in the first embodiment. In this case, as the damper mechanism, stroke absorption is possible. A stroke damper that limits the deformation speed of the spring 54 of the mechanism 53 is suitable.

  8 to 10 show a fourth embodiment of the present invention, in which a cut valve 80 that can be opened and closed by electronic control is provided on the inlet side of the liquid amount absorption mechanism 153 in the third embodiment. Is. The cut valve 80 is configured to close the cut valve 80 and prevent the liquid amount from being supplied to the liquid amount absorbing mechanism 153 when, for example, the pump 38 of the control hydraulic pressure control device 43 fails. As a result, when the brake pedal 20 is depressed, the amount of fluid pushed out from the master cylinder 25 is all supplied to the wheel brake 30 side, and the pedal stroke is not increased until the braking force is generated. The braking force according to the can be ensured.

  For example, as shown in FIG. 8, the cut valve 80 is configured by an electromagnetic valve that closes when no current is applied to the solenoid 80a so as to be able to cope with the case where the power from the automobile battery is dropped. ing. The cut valve 80 is normally kept open, but when the pump 38 fails, the current is applied to the solenoid 80a by controlling the current to the solenoid 80a to OFF or when the power is turned off. By disappearing, the cut valve 80 is switched to the closed state so that the liquid amount is not supplied to the liquid amount absorbing mechanism 153.

  In addition, as a failure of the pump 38, for example, when the motor 39 is disconnected and the pump 38 is not driven, or when the motor 39 is not rotated due to a bite of foreign matter or the like, an appropriate disconnection detecting means or rotating It is detected by the detection means and it is determined that the pump 38 has failed.

  FIG. 9 shows a flowchart for detecting the failure of the pump 38 and closing the cut valve 80. When a command to drive the pump 38 is issued, the program is started, and the motor 39 is started in step S11. Thus, the pump 38 is pressurized. Next, in step S12, it is determined whether or not there is an abnormality in the terminal voltage of the motor 39. If there is no abnormality, in the subsequent step S13, it is determined whether or not the rotational speed of the motor 39 is abnormal. If there are no abnormalities, the program returns.

  However, if it is determined in step S12 or step S13 that there is an abnormality, the process proceeds to step S14 to confirm that there is some abnormality in the electronic control system. Then, it progresses to step S15, the command which closes the cut valve 80 is output, and a program is returned.

  Thus, when the pump 38 is driven, the cut valve 80 is detected by detecting that the pump 38 is not discharging necessary oil due to, for example, a malfunction of the electronic control system due to an abnormal terminal voltage or rotational speed of the motor 39. Therefore, when the brake pedal 20 is operated when the electronic control system fails, the liquid amount pushed out from the master cylinder 25 is not supplied to the liquid amount absorbing mechanism 153, and all of the liquid amount is pushed to the wheel. Since it is supplied to the brake 30 side, the braking force according to the pedal stroke can be ensured without extending the pedal stroke until the braking force is generated.

  By the way, if the pump 38 is out of order while the brake pedal 20 is depressed, reducing the pressure difference between the solenoid hydraulic pressure proportional control valves 32f and 32r before closing the cut valve 80 causes the fluid amount absorbing mechanism 153 to enter the fluid level. Since the pressure flows and the pressure of the wheel brake 30 decreases at the same time, when there is a differential pressure by the solenoid hydraulic pressure proportional control valves 32f and 32r, as shown in FIG. 10, a failure of the pump 38 is detected (T1). First, the cut valve 80 is closed (T2), and thereafter (T3), the differential pressure C between the solenoid hydraulic pressure proportional control valves 32f and 32r is controlled to be small so as not to decrease the pressure B of the wheel brake 30. ing. In FIG. 10, A indicates the pressure of the master cylinder 25.

  According to the fourth embodiment described above, the cut valve 80 is composed of an electromagnetic valve and is automatically closed when the power is not supplied. Therefore, the cut valve is immediately closed when the electrical system fails. be able to. In addition, when the pump 38 fails when there is a differential pressure due to the solenoid hydraulic pressure proportional control valves 32f and 32r, the pressure difference between the solenoid hydraulic pressure proportional control valves 32f and 32r is decreased after the cut valve 80 is closed. Therefore, the liquid quantity absorption mechanism 158 is not filled up by the control of the solenoid hydraulic pressure proportional control valves 32f and 32r, and the liquid quantity absorption mechanism 158 can function properly.

  The cut valve 80 described above can be closed during a sudden braking operation in addition to preventing the liquid amount from being supplied to the liquid amount absorbing mechanism 153 when the pump 38 fails. Also in this case, since the inflow of the brake fluid to the fluid amount absorbing mechanism 153 is prevented by closing the cut valve 80, the entire amount of the fluid discharged from the master cylinder 25 can be supplied to the wheel brake 30 side.

  FIGS. 11 to 13 show a fifth embodiment of the present invention. The difference from the first embodiment is that a regenerative braking force is used to generate a braking force on the wheel brake 30. It is a point that has been configured. Therefore, in the following, differences from the first embodiment will be mainly described, the same components are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIG. 11, the vehicle brake device includes a hybrid vehicle brake device 10, and the hybrid vehicle brake device 10 includes a hydraulic brake device 11, a regenerative brake device 12, a hydraulic brake device 11, and a regenerative brake device. 12 includes a brake ECU 13 that controls the vehicle 12 in a coordinated manner, a hybrid ECU 15 that controls the electric motor 14 via an inverter 16 in accordance with a request value from the brake ECU 13, and the like. The brake ECU 13 constitutes an electronic control device that controls the regenerative brake device 12 and the hydraulic pressure control device 43.

  The rotating shaft of the electric motor 14 is decelerated by a gear train and is always rotationally connected to the left and right front wheels 23fl and 23fr. The inverter 16 converts the DC discharge power of the in-vehicle battery 17 into AC power according to the control signal supplied from the hybrid ECU 15 and supplies the AC power to the electric motor 14. The AC power generated by the electric motor 14 is charged with DC. It converts into electric power and charges the vehicle-mounted battery 17.

  The regenerative braking device 12 includes an electric motor 14 that is rotationally connected to the front wheel 23f, and a regenerative braking force generator 44 that regeneratively brakes the electric motor 14 to generate a regenerative braking force on the front wheel 23f to which the electric motor 14 is rotationally connected. And have. The regenerative braking force generator 44 includes a hybrid ECU 15, an inverter 16, and the like.

  The brake ECU 13 sets a target braking force to be generated on the wheel 23 in accordance with the brake pedal stroke, instructs the regenerative braking force generator 44 as a regenerative braking force, and regenerative braking force based on this command. The execution regenerative braking force generated by the generator 44 is input, the hydraulic braking force that is the difference between the target braking force and the effective regenerative braking force is calculated, and supplied to the wheel brake 30 to generate the hydraulic braking force on the wheel 23. Determine the control fluid pressure that must be done. In addition, the brake ECU 13 is connected to the linear solenoid 33 of the solenoid hydraulic pressure proportional control valve 32 so that the hydraulic pressure of the brake fluid supplied to the wheel brake 30 from the pump 38 rotated by the motor 39 becomes the control hydraulic pressure. The cooperative control program shown in FIG. 12 for applying the control current is stored.

  The regenerative braking device 12 is controlled in a range where regenerative braking is possible at each time point determined by the state of the battery 17 and the state of the motor 14. That is, the limit value of the regenerative braking force depending on the state of charge of the battery 17 and the limit value of the regenerative braking force based on the number of rotations of the motor 14 corresponding to the vehicle speed are respectively calculated, and the smaller one is determined as the regenerative braking range. The

  Although not shown, in the fifth embodiment, the stroke absorbing mechanism 53 similar to that described in the first embodiment is provided in the negative pressure booster 27. It is desirable that the play amount 53 of 53 be an amount close to the stroke amount of the master cylinder 25 when the deceleration equal to the maximum deceleration that the regenerative braking device 12 can produce is only decelerated by the wheel brake 30.

  Next, the operation of the hybrid vehicle brake device 10 according to the fifth embodiment will be described. When the brake pedal 20 is depressed, as described in the first embodiment, the input rod 61 of the negative pressure type booster 27 moves forward, the air valve portion 65 enters the atmosphere introduction state, and the atmosphere enters the variable pressure chamber 66. be introduced. As a result, the valve piston 63 of the negative pressure booster 27 moves forward until it almost catches up with the input rod 61, and pushes the stroke absorbing mechanism 53. At this time, since the set load of the spring 54 of the stroke absorbing mechanism 53 is set to be larger than the set load of the spring 22 of the master cylinder 25, the stroke absorbing mechanism 53 is not deformed at the initial stage of depression of the brake pedal 20. First, the master pistons 21f and 21r of the master cylinder 25 move forward, and the communication between the hydraulic chambers 25f and 25r of the master cylinder 25 and the reserve tank 28 is blocked. As a result, the hydraulic pressure in the hydraulic chambers 25f and 25r of the master cylinder 25 increases, and a load obtained by multiplying the hydraulic pressure and the cylinder diameter of the master cylinder 25 acts on the stroke absorbing mechanism 53. The spring 54 is compressed and the play amount a is absorbed. As a result, the valve piston 63 of the negative pressure booster 27 is moved forward relative to the master pistons 21f and 21r.

  In this way, even if the brake pedal 20 is depressed, the stroke of the master pistons 21f and 21r of the master cylinder 25 is compared with the stroke of the valve piston 63 of the negative pressure booster 27 by the absorbing action of the stroke absorbing mechanism 53. Therefore, the pressure in the pressure chambers 25f and 25r of the master cylinder 25 is generated only by a small pressure commensurate with it.

  However, since the reaction force corresponding to the operation stroke is generated in the brake pedal 20 by the simulator 51, the driver is informed of the operation stroke (depression amount) of the brake pedal 20 regardless of the hydraulic pressure generated in the master cylinder 25. A corresponding reaction force is applied. The operation stroke of the brake pedal 20 is detected by the stroke sensor 52. When this detection signal is input to the brake ECU 13, the brake ECU 13 activates the cooperative control program shown in FIG.

  By starting the cooperative control program, the temporary memory such as a counter and a flag is reset and initialized (step S21), and the program after step S22 is executed every time a certain minute time elapses.

  Based on the relationship between the brake pedal stroke and the target braking force stored in the memory, the brake ECU 13 obtains a target braking force to be generated on the wheel 23 by a map, a table or an arithmetic expression (step S23), and calculates the target braking force. The regenerative braking force is output to the hybrid ECU 15 (step S24). The hybrid ECU 15 controls the opening and closing of the inverter 16 according to the regenerative braking force (target braking force), regeneratively brakes the electric motor 14, generates regenerative braking force on the wheels 23, and regeneratively detected by a sensor (not shown). Based on the electric current, the electric regenerative braking force actually generated on the wheel 23 by the electric motor 14 is calculated and input to the brake ECU 13 (step S25).

  The brake ECU 13 calculates the hydraulic braking force that is the difference between the target braking force and the effective regenerative braking force (step S26), and determines whether this hydraulic braking force is 0 (step S27). That is, when all of the target braking force is covered by the regenerative braking force and the difference between the target braking force and the effective regenerative braking force is 0, it is determined that it is not necessary to generate the control hydraulic pressure, and the process returns to step S2. .

  On the other hand, when the hydraulic braking force of the difference between the target braking force and the effective regenerative braking force is not zero, the control that must be supplied to the wheel brake 30 in order to cause the wheel 23 to generate a hydraulic braking force equal to the difference. The hydraulic pressure is obtained from a map, a table, or an arithmetic expression (step S28). Then, the motor 39 is started to drive the pump 38 and the linear solenoid 33 of the solenoid hydraulic pressure proportional control valve 32 is controlled so that the hydraulic pressure of the brake fluid supplied from the pump 38 to the wheel brake 30 becomes the control hydraulic pressure. A current is applied (step S29).

  Thus, the liquid supplied from the pump 38 is controlled to a required control hydraulic pressure by the solenoid hydraulic pressure proportional control valve 32 and supplied to the wheel brake 30. Accordingly, the hydraulic brake device 11 causes the wheel 23 to generate a hydraulic braking force equal to the difference between the target braking force and the effective regenerative braking force. When a change in the regenerative braking force actually generated by the regenerative braking device 12 with respect to the predetermined regenerative braking force is detected in step S26 or the like, the pump 38 of the hydraulic brake device 11 is driven in steps S27 to S29 or the like. At the same time, the control hydraulic pressure is generated by controlling the solenoid hydraulic pressure proportional control valve 32, and the control hydraulic pressure braking force based on the control hydraulic pressure is generated in the wheel 23 to compensate for the lack of the regenerative braking force due to the detected fluctuation. To do.

  FIG. 13 is a diagram showing the relationship between the brake pedal stroke and the braking force. Line A represents the target braking force, and line B represents the braking force obtained by subtracting the maximum regenerative braking force that can be generated by the regenerative braking force generator 44 from the target braking force. Line C shows the hydraulic braking force determined by the characteristics of the wheel brake 30 with respect to the brake pedal stroke when the stroke absorbing mechanism 53 is not deformed. Line D shows the stroke absorbing mechanism 53 temporarily. When fully deformed, the hydraulic braking force determined by the characteristics of the wheel brake 30 with respect to the brake pedal stroke is shown.

  Here, in realizing the target braking force, the target braking force (A in FIG. 13) is the hydraulic braking force (C in FIG. 13) when the stroke absorbing mechanism 53 is not deformed as shown in FIG. The braking force (B in FIG. 13) obtained by subtracting the maximum regenerative braking force from the target braking force is preferably always smaller, and the hydraulic pressure control when the stroke absorbing mechanism 53 is completely deformed as shown in FIG. It is desirable that it is always greater than the power (D in FIG. 13).

  If these two conditions are satisfied, the required hydraulic braking force may be generated regardless of whether the regenerative braking force cannot be generated at all or can be generated to the maximum depending on the state of charge of the battery 17 and the rotational state of the motor 14. Is less than the amount obtained by multiplying the stroke of the input rod 61 and the cross-sectional area of the master cylinder 25, and is obtained by subtracting the maximum deformation of the stroke absorbing mechanism 53 from the stroke of the input rod 61. It becomes larger than the amount obtained by multiplying the cross-sectional area of the cylinder 25.

  From this, when the required hydraulic braking force is generated, the stroke absorbing mechanism 53 is always deformed to an intermediate state (intermediate between no deformation and maximum deformation). As a result, the output of the negative pressure booster 27 is a small output sufficient to deform the stroke absorbing mechanism 53 to an intermediate state, and the hydraulic pressures of the hydraulic chambers 25f and 25r of the master cylinder 25 are also reduced. Only a reasonable amount of pressure is generated. Therefore, when the target braking force is low, virtually all of it can be borne by the regenerative braking force.

  By the way, if the target braking force is larger than the hydraulic braking force determined by the characteristics of the wheel brake 30 with respect to the brake pedal stroke, assuming that the stroke absorbing mechanism 53 is not deformed, the stroke absorbing mechanism 53 is not deformed. If the hydraulic brake force does not reach the target braking force and the regenerative braking force is not generated with the amount of liquid delivered from the master cylinder 25, the pump 38 sucks and discharges the liquid in the reserve tank 28 through the master cylinder 25. Will do. In this case, since suction is forced from the state where the communication between the master cylinder 25 and the reserve tank 28 is blocked, the suction resistance increases and the responsiveness deteriorates. As a result, excess liquid is sucked into the master cylinder 25, and there is a risk that play will be insufficient if a regenerative braking force is generated thereafter. However, these problems can be compromised if the target braking force only partially exceeds the desired range.

  In addition, when the braking force obtained by subtracting the maximum regenerative braking force that can be generated by the regenerative braking force generator 44 from the target braking force is assumed to cause the stroke absorbing mechanism (play element) 53 to be completely deformed, When the braking force is smaller than the hydraulic braking force determined by the characteristics of the wheel brake 30, when the regenerative braking force is generated to the maximum, even if the stroke absorbing mechanism is deformed to the maximum, it is generated with the amount of fluid delivered from the master cylinder 25. The sum of the applied hydraulic braking force exceeds the target braking force. However, in this case as well, since the negative pressure booster 27 is configured as described above, the brake pedal feeling does not change and the only problem is that the actual braking force exceeds the target braking force. This problem can be compromised if is only slightly below the desired range.

  As described above, also in the fifth embodiment, by having two means for increasing the brake fluid pressure, that is, the negative pressure booster 27 and the pump 38 of the control fluid pressure controller 43, it is possible to prevent the failure. A highly reliable system can be obtained. Moreover, by appropriately setting the play by the stroke absorbing mechanism 53, the regenerative braking force can bear virtually all of the target braking force when the brake operating force is small, and energy efficiency can be improved. It becomes.

  In the hybrid vehicle brake device according to the fifth embodiment described above, the stroke absorbing mechanism 53 similar to that described in the first embodiment is used as a play element that absorbs a predetermined amount of the brake operation stroke of the driver. As described in the example, in the hybrid vehicle brake device, the play element includes the stroke absorption mechanism 53, the liquid amount absorption mechanism 153 shown in FIG. 7, and the restriction element 70 for limiting the liquid flow rate at the inlet shown in FIG. It can be replaced with the added liquid amount absorbing mechanism 153 or the liquid amount absorbing mechanism 153 using the cut valve 80 shown in FIG.

  In the fifth embodiment described above, the vehicle brake device 10 is applied to a hybrid vehicle. However, the vehicular brake device 10 can also be applied to an electric vehicle having an electric motor 14 connected to wheels 23.

  In the above-described embodiment, the front and rear piping is provided for the FF vehicle, but the front and rear piping may be provided for the FR vehicle. Further, the hydraulic pressure sent from the hydraulic chamber 25f of the dual master cylinder 25 to the FF vehicle or the FR vehicle is supplied to the right front wheel 23fr and the left rear wheel 23rl wheel brakes 30fr, 30rl, and the hydraulic chamber 25r. The hydraulic pressure sent out from the vehicle may be supplied to the left front wheel 23fl and the right rear wheel 23rr wheel brakes 30fl, 30rr.

  In the above-described embodiment, the negative pressure booster 27 is used as the booster. However, the hydraulic pressure generated from the pump is accumulated in the accumulator, and this hydraulic pressure is applied to the piston to act on the brake pedal 20. A hydraulic booster that boosts the operating force may be used.

  In the above-described embodiment, the hydraulic pressure from the pump 38 driven by the motor 39 is supplied to the wheel brake 30 by the solenoid hydraulic pressure proportional control valve 32 controlled by the linear solenoid 33. However, the hydraulic pressure control valve is not limited to the solenoid hydraulic pressure proportional control valve 32. Instead of this, an ON-OFF type electromagnetic valve is controlled. A valve may be provided, and the electromagnetic valve may be duty controlled to generate a predetermined control hydraulic pressure.

1 is a system diagram of a vehicle brake device illustrating a first embodiment of the present invention. It is a figure which shows a hydraulic brake device. It is detail drawing which shows the related structure of a brake pedal, a booster, and a master cylinder. It is a principal part enlarged view of FIG. 3 which shows a stroke absorption mechanism. It is a figure which shows a control program. It is detail drawing which shows the connection structure of the brake pedal which shows the 2nd Embodiment of this invention, a booster, and a master cylinder. It is a systematic diagram of the brake device for vehicles which shows the 3rd Embodiment of this invention. It is a systematic diagram of the brake device for vehicles which shows the 4th Embodiment of this invention. It is a figure which shows the flowchart which closes a cut valve. It is a figure which shows the time chart which controls a hydraulic-pressure control valve. It is a systematic diagram of the brake device for vehicles which shows the 5th Embodiment of this invention. It is a figure which shows a cooperative control program. It is a figure which shows the relationship between a brake pedal stroke and braking force.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Hybrid vehicle brake device, 11 ... Hydraulic brake device, 12 ... Regenerative brake device, 13 ... Brake ECU (electronic control device), 14 ... Electric motor, 15 ... Hybrid ECU, 16 ... Inverter, 17 ... In-vehicle battery, DESCRIPTION OF SYMBOLS 20 ... Brake pedal, 23 ... Wheel, 25 ... Master piston, 27 ... Booster device, 29 ... Fluid pressure sensor, 30 ... Wheel brake, 32 ... Fluid pressure control valve (solenoid fluid pressure proportional control valve), 38 ... Pump, DESCRIPTION OF SYMBOLS 39 ... Motor, 43 ... Control hydraulic pressure control device, 44 ... Regenerative braking force generator, 45 ... Pressure-reducing valve, 51 ... Simulator, 52 ... Stroke sensor, 53, 153 ... Play element (stroke absorption mechanism, fluid quantity absorption mechanism) 54 ... Spring, 55a, 55b ... Suspension element, 55 ... Spring, 57 ... Cylinder, 58 ... Spring, 59 ... Piston, 70 Restriction element (damper mechanism), 80 ... cut-off valve.

Claims (11)

A booster (27) for increasing the brake operating force of the driver;
A master cylinder (25) operatively connected to the booster;
A wheel brake (30) of each wheel (23) connected to the master cylinder;
A pump (38) interposed between the master cylinder and the wheel brake and capable of sucking at least the working fluid on the master cylinder side and discharging it to the wheel brake side; and from the wheel brake side to the master cylinder side A hydraulic control device (43) having a hydraulic control valve (32) capable of restricting the movement of the working fluid;
In addition,
A stroke sensor (52) for detecting a brake operation stroke;
A simulator (51) for applying a pseudo reaction force to the brake operation stroke to the brake pedal;
A play element (53, 153) disposed between the booster and the hydraulic control device for absorbing a predetermined amount of a brake operation stroke of the driver;
An electronic control device (13) for controlling the hydraulic pressure control device based on an input from the stroke sensor;
With
A brake device for a vehicle.   2. The spring element (54) according to claim 1, wherein the play element is inserted between an output member of the booster and an input member of the master cylinder and a suspension element (55a, 55b) for limiting the maximum length of the spring. A brake device for a vehicle, characterized in that it is a stroke absorbing mechanism comprising:   2. The play element according to claim 1, wherein the play element is fluid-tight and slidable on a cylinder (57) having one end facing a hydraulic circuit between the master cylinder and the hydraulic control device and the other end facing atmospheric pressure. A vehicular brake device comprising a piston (59) fitted to the cylinder and a spring (58) for urging the piston toward the hydraulic circuit.   The vehicle brake device according to claim 1, wherein the play element is provided with a damper mechanism (70) for limiting a play absorption speed.   The vehicle brake device according to claim 3, wherein a limiting element (70) for limiting a flow rate of the liquid absorbed by the liquid amount absorbing mechanism is provided on an inlet side of the liquid amount absorbing mechanism.   6. The vehicle brake device according to claim 1, wherein the booster is configured not to transmit an operation reaction force to the input member. The regenerative brake device (12) for generating a regenerative braking force on the wheel according to any one of claims 1 to 6,
The electronic control unit calculates a target braking force based on an input from the stroke sensor, and a regenerative braking force by the regenerative braking device and a braking force by the wheel brake operated by an output hydraulic pressure of the hydraulic pressure control device. The regenerative brake device, the pump of the hydraulic pressure control device, and the hydraulic pressure control valve are within a range in which the regenerative braking device can be regeneratively braked so that the sum of A vehicular brake device characterized by controlling.   The predetermined amount absorbed by the play element according to claim 7 is an amount close to a stroke amount of the master cylinder when a deceleration equal to a maximum deceleration that can be generated by the regenerative brake device is generated only by deceleration by the wheel brake. A brake device for a vehicle characterized by being set. A booster (27) for increasing the brake operating force of the driver;
A master cylinder (25) operatively connected to the booster;
A wheel brake (30) of each wheel (23) connected to the master cylinder;
A pump (38) interposed between the master cylinder and the wheel brake and capable of sucking at least the working fluid on the master cylinder side and discharging it to the wheel brake side; and from the wheel brake side to the master cylinder side A hydraulic control device (43) having a hydraulic control valve (32) capable of restricting the movement of the working fluid;
In addition,
A stroke sensor (52) for detecting a brake operation stroke;
A simulator (51) for applying a pseudo reaction force to the brake operation stroke to the brake pedal;
A liquid amount absorbing mechanism (153) disposed between the master cylinder and the hydraulic pressure control device and absorbing a predetermined amount of a brake operation stroke of the driver;
A cut valve that is disposed between the master cylinder and the liquid amount absorbing mechanism, and shuts off communication between the master cylinder and the liquid amount absorbing mechanism when pressure oil is no longer discharged from the pump due to a system abnormality. (80)
A brake device for a vehicle.   10. The vehicle brake device according to claim 9, wherein the cut valve is an electromagnetic valve and is closed when not energized. In Claim 9 or Claim 10, when the pump of the hydraulic pressure control valve fails when there is a differential pressure due to the hydraulic pressure control valve, the difference between the hydraulic pressure control valves is closed after the cut valve is closed. A vehicular brake device characterized in that the pressure is reduced.

Images