JP2008296706A - Brake fluid pressure control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress variation of braking force and operation feeling when control is performed such that a brake fluid pressure of a part of a wheel brake becomes a higher pressure than an output fluid pressure of a fluid pressure generation means in a brake fluid pressure control device for a vehicle for controlling operation of a fluid pressure control unit such that the brake fluid pressure of the wheel brake of a part of the respective wheel brakes is made to a fluid pressure of higher pressure than the fluid pressure of the fluid pressure generation means during brake operation. <P>SOLUTION: In the state that the fluid pressure control unit is controlled by a controller such that the fluid pressure of the wheel brake of a part of the wheel brakes is increased than the output fluid pressure of the fluid pressure generation means during brake operation, the fluid pressure of the non-increase pressure wheel brake gives hysteresis characteristic to a brake operation amount. Thereby, the fluid pressure control unit is controlled by the controller C so as to become a target fluid pressure operated by the non-increase pressure wheel target fluid pressure operation part 28. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a hydraulic pressure generating means for outputting a hydraulic pressure corresponding to a brake operation; a wheel brake mounted on each of a plurality of wheels so as to operate with the hydraulic pressure; and between the hydraulic pressure generating means and the hydraulic pressure path A normally open solenoid valve interposed in the pressure source, a pressure source connected to the hydraulic pressure path so as to generate a hydraulic pressure higher than an output hydraulic pressure of the hydraulic pressure generating means, and the hydraulic pressure path A hydraulic pressure control unit including pressure adjusting means interposed between the hydraulic pressure path and the plurality of wheel brakes so as to adjust the hydraulic pressure of the wheel and act on the plurality of wheel brakes; The hydraulic pressure output from the pressure source to the hydraulic pressure path is controlled by opening / closing operation of the normally open solenoid valve, and the hydraulic pressure of some of the wheel brakes among the wheel brakes is output from the hydraulic pressure generating means. And increase the hydraulic pressure of the remaining non-intensified wheel brake. A controller for controlling the operation of the fluid pressure control unit as possible to the fluid pressure corresponding to the output hydraulic pressure of the hydraulic pressure generating means; relates to a vehicular brake hydraulic pressure control device comprising a.

In order to perform vehicle behavior stabilization control during the brake operation by the driver, the brake fluid pressure of some of the wheel brakes is set to be higher than the fluid pressure of the fluid pressure generating means. A vehicular brake hydraulic pressure control device for controlling the operation of a hydraulic pressure control unit is already known, for example, in Japanese Patent Application Laid-Open No. H10-228707.
JP 2002-37047 A

  By the way, in such a vehicle brake hydraulic pressure control device, the remaining non-increase is controlled in such a state that the brake hydraulic pressure of some wheel brakes is controlled to be higher than the hydraulic pressure of the hydraulic pressure generating means. The pressure wheel brake needs to be controlled to correspond to the output hydraulic pressure of the hydraulic pressure generating means for outputting the hydraulic pressure corresponding to the brake operation in order to ensure the braking force required by the driver. However, since the output hydraulic pressure of the hydraulic pressure generating means changes due to the hydraulic pressure fluctuation such as the suction pulsation of the pressurization source of the hydraulic pressure control unit, the detection value of the brake operation amount detecting means for detecting the brake operation amount also changes. The hydraulic pressure of the remaining non-intensifying wheel brakes varies in the same manner, and changes may occur in braking force and operation feeling.

  The present invention has been made in view of such circumstances, and controls the brake fluid pressure of a part of the wheel brake during the brake operation so as to be higher than the output fluid pressure of the fluid pressure generating means. It is an object of the present invention to provide a vehicle brake hydraulic pressure control device that suppresses changes in power and operation feeling.

  In order to achieve the above object, a first aspect of the present invention provides a hydraulic pressure generating means for outputting a hydraulic pressure corresponding to a brake operation; and a wheel brake mounted on each of a plurality of wheels so as to be operated by the hydraulic pressure. A normally-open solenoid valve interposed between the hydraulic pressure generating means and the hydraulic pressure path, and in the hydraulic pressure path so as to generate a hydraulic pressure higher than the output hydraulic pressure of the hydraulic pressure generating means. A pressure source to be connected; and pressure adjusting means interposed between the hydraulic pressure path and the plurality of wheel brakes so as to adjust the hydraulic pressure of the hydraulic pressure path to be applied to the plurality of wheel brakes. A hydraulic pressure control unit; controlling the hydraulic pressure output from the pressurizing source to the hydraulic pressure path during the brake operation by opening / closing the normally open solenoid valve; When the hydraulic pressure is increased above the output hydraulic pressure of the hydraulic pressure generating means And a controller for controlling the operation of the hydraulic pressure control unit so that the hydraulic pressure of the remaining non-intensifying wheel brake can be set to a hydraulic pressure corresponding to the output hydraulic pressure of the hydraulic pressure generating means. The hydraulic pressure control device includes a brake operation amount detection means for detecting a brake operation amount, wherein the controller gives a hysteresis characteristic to the brake operation amount detected by the brake operation amount detection means. Includes a non-intensified wheel target hydraulic pressure calculation unit that calculates the target hydraulic pressure of the wheel brake, and controls the hydraulic pressure of some wheel brakes to be higher than the output hydraulic pressure of the hydraulic pressure generating means during brake operation In this state, the hydraulic pressure control unit is controlled so that the hydraulic pressure of the non-intensified wheel brake becomes the target hydraulic pressure calculated by the non-intensified wheel target hydraulic pressure calculation unit. .

  According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the hysteresis is set such that a response characteristic when the brake operation amount increases is higher than a response characteristic when the brake operation amount decreases. Characteristic is set.

  The regulator valve 7 of the embodiment corresponds to the normally open solenoid valve of the present invention, the pump 18 of the embodiment corresponds to the pressurizing source of the present invention, and the master cylinder output pressure detection sensor 22 of the embodiment of the present invention. Corresponding to the brake operation amount detecting means, the master cylinder M of the embodiment corresponds to the hydraulic pressure generating means of the present invention.

  According to the first aspect of the present invention, the hydraulic pressure control unit is controlled by the controller so that the hydraulic pressure of some of the wheel brakes among the wheel brakes is higher than the output hydraulic pressure of the hydraulic pressure generating means during the brake operation. In this state, the hydraulic pressure of the remaining non-intensified wheel brake is set to the target hydraulic pressure calculated by the non-intensified wheel target hydraulic pressure calculation unit so as to add hysteresis characteristics to the brake operation amount. Since the control unit is controlled by the controller, when the pressure source is activated to increase the hydraulic pressure of some wheel brakes, the target hydraulic pressure of the remaining non-intensified wheel brake is detected by the brake operation amount detection means. It is possible to suppress fluctuations associated with value fluctuations, and to suppress changes in braking force and operation feeling.

  According to the second aspect of the present invention, since the hysteresis characteristic is set so that the responsiveness is higher when the brake operation amount is increased than when the brake operation amount is decreased, the fluid is required to ensure the braking force required by the driver. The target hydraulic pressure of the non-intensifying wheel brake to be controlled corresponding to the output hydraulic pressure of the pressure generating means can be immediately increased in accordance with the increase of the output hydraulic pressure of the hydraulic pressure generating means, and the braking force intended by the driver Can be ensured.

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

  1 to 3 show one embodiment of the present invention, FIG. 1 is a hydraulic system diagram showing the configuration of a vehicle brake hydraulic pressure control device, and FIG. 2 is a block diagram showing a partial configuration of a controller. FIG. 3 is a diagram showing a change in the target hydraulic pressure according to the output hydraulic pressure of the master cylinder and the output hydraulic pressure of the master cylinder in comparison with the conventional one.

  First, in FIG. 1, a brake operation force generated by a passenger's brake operation is input from the brake pedal 1 to a master cylinder M as a hydraulic pressure generating unit that outputs a hydraulic pressure corresponding to a brake operation. The master cylinder M is configured in a tandem type, and includes a first output port 3 corresponding to a left front wheel brake BA and a right rear wheel brake BB each configured as a disc brake, and a wheel brake. And a second output port 4 corresponding to a right front wheel brake (not shown) and a left rear wheel brake (not shown). The first and second output ports 3 and 4 are hydraulically controlled. It is connected to the wheel brakes BA, BB.

  The portion on the first output port 3 side and the portion on the second output port 4 side of the hydraulic pressure control unit 5 have the same configuration. Hereinafter, the first output port 3 side of the hydraulic pressure control unit 5 will be described. Only the portion will be described, and the description of the portion on the second output port 4 side in the hydraulic pressure control unit 5 will be omitted.

  The hydraulic pressure control unit 5 includes a hydraulic pressure path 6 common to the left front wheel brake BA and the right rear wheel brake BB, and a normally open position interposed between the hydraulic pressure path 6 and the first output port 3. Regulator valve 7 as a solenoid valve, a one-way valve 8 connected in parallel to the regulator valve 7 allowing the brake fluid to flow to the hydraulic pressure passage 6 side, the hydraulic pressure passage 6 and the wheel for the left front wheel The inlet valve 9 interposed between the brakes BA, the inlet valve 10 interposed between the hydraulic pressure path 6 and the right rear wheel wheel brake BB, and the flow of the brake fluid to the hydraulic pressure path 6 side One-way valves 11 and 12 that are connected in parallel to the inlet valves 9 and 10, respectively, a single reservoir 13 that is common to the left front wheel brake BA and the right rear wheel brake BB, and the left front wheel It is interposed between the wheel brake BA and the reservoir 13. A mouth valve 14, a right rear wheel wheel brake BB and an outlet valve 15 provided between the reservoir 13, and a pump 18 as a pressure source whose suction side is connected to the reservoir 13 via a one-way valve 16. A damper 19 connected to the discharge side of the pump 18, an orifice 20 provided between the damper 19 and the hydraulic pressure path 6, between the suction side of the pump 18 and the one-way valve 16, and a first output port And a suction valve 21 provided between the three. The pump 18 is driven by an electric motor 17, and the electric motor 17 is common to a portion on the first output port 3 side and a portion on the second output port 4 side of the hydraulic pressure control unit 5. .

  The regulator valve 7 and the inlet valves 9 and 10 are normally open linear solenoid valves, the outlet valves 14 and 15 are normally closed linear solenoid valves, and the suction valve 21 is a normally closed solenoid valve. is there. Further, between the first output port 3 and the regulator valve 7, a master cylinder output hydraulic pressure detection sensor 22 as a brake operation amount detection means for detecting an output hydraulic pressure of the master cylinder M to detect a brake operation amount by the brake pedal 1. Between the inlet valves 9, 10 and the left front wheel brake BA and the right rear wheel brake BB, the brake acting on the left front wheel brake BA and the right rear wheel brake BB. Brake fluid pressure detection sensors 23 and 24 for detecting fluid pressure are connected to each other.

  Thus, the inlet valve 9 and the outlet valve 14 open the inlet valve 9 and close the outlet valve 14 to connect between the hydraulic pressure path 6 and the left front wheel brake BA and to the left front wheel. A pressure increasing mode for shutting off the wheel brake BA and the reservoir 13, and closing the inlet valve 9 and opening the outlet valve 14 shuts off the hydraulic pressure path 6 and the wheel brake BA for the left front wheel. The decompression mode for connecting the front wheel brake BA and the reservoir 13 and the hydraulic valve 6 and the reservoir 13 are disconnected from the left front wheel brake BA by closing both the inlet valve 9 and the outlet valve 14. The pressure adjusting means 25 that can switch the holding mode is configured. In the pressure increasing mode, the hydraulic pressure in the hydraulic pressure path 6 acts on the wheel brake BA for the left front wheel, and in the pressure reducing mode, the vehicle for the left front wheel. Releasing the hydraulic pressure of the brake BA to the reservoir 13, the hydraulic pressure of the left front wheel brake BA is held in the holding mode.

  The inlet valve 10 and the outlet valve 15 open the inlet valve 10 and close the outlet valve 15 to connect the hydraulic pressure path 6 and the right rear wheel wheel brake BB, and for the right rear wheel. A pressure increasing mode in which the wheel brake BB and the reservoir 13 are disconnected, and the hydraulic valve 6 and the right rear wheel wheel brake BB are disconnected by closing the inlet valve 10 and opening the outlet valve 15. And the pressure reducing mode for connecting the right rear wheel wheel brake BB and the reservoir 13, and closing the inlet valve 10 and the outlet valve 15 together, the hydraulic pressure path 6 and the reservoir 13 are connected to the right rear wheel wheel. The pressure adjusting means 26 is configured to switch the holding mode to be cut off from the brake BB. In the pressure increasing mode, the hydraulic pressure in the hydraulic pressure path 6 acts on the right rear wheel wheel brake BB, and in the pressure reducing mode. Releasing the hydraulic pressure of the rear wheel brake BB to the reservoir 13, in the holding mode the hydraulic pressure of the right rear wheel brake BB is held.

  In such a fluid pressure control unit 5, the pump 18 sucks and pressurizes brake fluid from the master cylinder M side by operating the electric motor 17 with the suction valve 21 excited and opened. The fluid is discharged to the hydraulic pressure path 6 between the valve 7 and the inlet valves 9 and 10. At this time, by controlling the operation of the regulator valve 7, the hydraulic pressure in the hydraulic pressure path 6 can be adjusted.

  That is, the pump 18 and the regulator valve 7 apply a regulated hydraulic pressure to the hydraulic pressure passage 6, and the hydraulic pressure is applied to the inlet valves 9 and 10 and the outlet valves 14 and 15 of the switching valve means 25 and 26. By controlling, different brake fluid pressures can be applied to the left front wheel brake BA and the right rear wheel brake BB. At this time, when the brake pedal 1 is operated, the pump 18 is driven by the electric motor 17 and the operation of the regulator valve 7 is controlled, so that one of the wheel brakes BA and BB has a master wheel brake. It is possible to perform a behavioral stability control at the time of brake operation by applying a hydraulic pressure higher than the output hydraulic pressure of the cylinder M.

  The regulator valve 7, the inlet valves 9 and 10, the outlet valves 14 and 15, the electric motor 17 and the suction valve 21 of the hydraulic pressure control unit 5 are controlled by a controller C. Detection values of the hydraulic pressure detection sensor 22 and the brake hydraulic pressure detection sensors 23 and 24 are input, respectively.

  In FIG. 2, in the controller C, one of the left front wheel brake BA and the right front wheel brake BB is increased more than the output hydraulic pressure of the master cylinder M during the brake operation. The part that controls the hydraulic pressure control unit 5 so that the wheel brakes are non-intensifying wheel brakes and the hydraulic pressure corresponding to the output hydraulic pressure of the master cylinder M is based on the detection value of the master cylinder output hydraulic pressure detection sensor 22. Master cylinder pressure increase / decrease determination means 27 for determining whether the output hydraulic pressure of the master cylinder M is increased or decreased, that is, whether the brake pedal 1 is operated to increase or decrease pressure, Non-intensifying wheel target hydraulic pressure calculation for calculating the target hydraulic pressure of the non-intensifying wheel brake based on the detection value of the master cylinder output hydraulic pressure detection sensor 22 And a 28.

  The non-intensifying wheel target hydraulic pressure calculation unit 28 is a target of non-intensifying wheel brake in a state where the output hydraulic pressure of the master cylinder M is increased based on the detection value of the master cylinder output hydraulic pressure detection sensor 22. Non-pressure-increasing wheel in a state where the output hydraulic pressure of the master cylinder M is reduced based on the detected value of the target hydraulic pressure calculating means 29 for calculating the hydraulic pressure and the master cylinder output hydraulic pressure detection sensor 22 The target hydraulic pressure calculating means 30 for calculating the target hydraulic pressure of the brake, and the target hydraulic pressure calculating means 29, 30 for increasing pressure or reducing pressure according to the determination result of the master cylinder pressure increasing / decreasing determining means 27 And selecting means 31 for selecting the calculation result as a target hydraulic pressure.

  Here, the target fluid pressure for increasing pressure calculated by the target fluid pressure calculating means 29 for increasing pressure is PTHi, the target fluid pressure for decreasing pressure calculated by the target hydraulic pressure calculating means 30 for decreasing pressure is PTLo, and the master The output hydraulic pressure of the master cylinder M detected by the cylinder output hydraulic pressure detection sensor 22 is PRMC, the previous value of the target hydraulic pressure of the non-intensified wheel brake is PTn1, and the hysteresis amount of the output hydraulic pressure of the master cylinder M is PTHYS. In the pressure increase target hydraulic pressure calculation means 29, PTHi = max (PRMC, PTn1), and the larger one of the output hydraulic pressure PRMC of the master cylinder M and the previous value PTn1 of the target hydraulic pressure is: It is calculated as the target hydraulic pressure PTHi for increasing pressure. Further, the target hydraulic pressure calculation means 30 at the time of depressurization sets PTLo = min (PRMC + PTHYS, PTn1) as follows: the smaller of the value obtained by adding the hysteresis amount PTHYS to the output hydraulic pressure PRMC of the master cylinder M and the previous target value PTn1 Is calculated as the target hydraulic pressure PTLo for pressure reduction.

  On the other hand, the master cylinder pressure increase / reduction determination means 27 determines that the pressure is increased when the output hydraulic pressure PRMC of the current master cylinder M is equal to or higher than the previous output hydraulic pressure PRMC, and the output hydraulic pressure of the current master cylinder M is determined. When the PRMC is less than the previous output hydraulic pressure PRMC, it is determined that the pressure is reduced. When the master cylinder pressure increase / decrease determination means 27 determines that the pressure is increased, the selection means 31 sets the target hydraulic pressure PT. When PTHi is selected and the master cylinder pressure increase / decrease determination means 27 determines that the pressure is decreasing, PTLo is selected as the target hydraulic pressure PT.

  That is, the non-intensifying wheel target hydraulic pressure calculation unit 28 provides a hysteresis characteristic to the detection value of the master cylinder output hydraulic pressure detection sensor 22 corresponding to the brake operation amount so as to provide the target hydraulic pressure PT of the non-intensifying wheel brake. When the brake operation amount increases, the hysteresis amount is set to “0” so that the response characteristic when the brake operation amount increases is higher than the response characteristic when the brake operation amount decreases. Hysteresis characteristics are set.

  Next, the operation of this embodiment will be described. During the brake operation by the brake pedal 1, the hydraulic pressure of some of the wheel brakes BA and BB is increased more than the output hydraulic pressure of the hydraulic pressure generating means 5. In the state where the hydraulic pressure control unit 5 is controlled by the controller C, the hydraulic pressure of the remaining non-pressure-increasing wheel brake gives a hysteresis characteristic to the brake operation amount so that the non-pressure-increasing wheel target hydraulic pressure calculation unit 28 Since the hydraulic pressure control unit 5 is controlled by the controller C so as to achieve the target hydraulic pressure calculated in step 4, when the pump 18 is operated to increase the hydraulic pressure of some wheel brakes, the remaining non-pressurized wheels As shown in FIG. 3A, the target hydraulic pressure of the brake fluctuates with the fluctuation even if the detection value of the master cylinder output hydraulic pressure detection sensor 22 fluctuates after the start of control at time t0. Doo is to be suppressed, it is possible to suppress the change of the braking force changes and the operation feeling.

  Moreover, since the hysteresis characteristic is set so that the response is higher when the brake operation amount is increased than when the brake operation amount is decreased, even if the brake pedal 1 is further increased from time t2 to time t3. The target hydraulic pressure of the non-pressurizing wheel brake can be immediately increased according to the increase in the output hydraulic pressure of the master cylinder M, and the braking force intended by the driver can be ensured reliably.

  On the other hand, as shown in FIG. 3 (b), when the detection value of the master cylinder output hydraulic pressure detection sensor 22 fluctuates after the start of the control at time t0, the target hydraulic pressure is changed with the fluctuation in the conventional one. It fluctuates and the braking force and operation feeling change.

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

1 is a hydraulic system diagram showing a configuration of a vehicle brake hydraulic pressure control device. It is a block diagram which shows the partial structure of a controller. It is a figure which shows the change of the target hydraulic pressure according to the output hydraulic pressure of a master cylinder, and the output hydraulic pressure of a master cylinder in contrast with the conventional one.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 ... Fluid pressure control unit 6 ... Fluid pressure path 7 ... Regulator valve 18 which is a normally open solenoid valve ... Pump 22 which is a pressurizing source ... Master which is a brake operation amount detection means Cylinder output pressure detection sensors 25, 26 ... pressure adjusting means 28 ... non-intensified wheel target hydraulic pressure calculation unit BA, BB ... wheel brake C ... controller M ... hydraulic pressure generating means. Master cylinder

Claims (2)

  Hydraulic pressure generating means (M) for outputting hydraulic pressure in accordance with the brake operation; wheel brakes (BA, BB) mounted on a plurality of wheels so as to operate with hydraulic pressure; and the hydraulic pressure generating means ( M) and a normally open solenoid valve (7) interposed between the fluid pressure passage (6) and the fluid pressure generating means (M) so as to generate a fluid pressure higher than the output fluid pressure. The pressure source (18) connected to the hydraulic pressure path (6) and the hydraulic pressure of the hydraulic pressure path (6) are adjusted so as to act on the plurality of wheel brakes (BA, BB). A hydraulic control unit (5) including pressure regulating means (25, 26) interposed between the pressure path (6) and the plurality of wheel brakes (BA, BB); and the pressurizing source (18) during brake operation. ) To control the hydraulic pressure output to the hydraulic pressure path (6) by opening / closing the normally open solenoid valve (7). Among the wheel brakes (BA, BB), the hydraulic pressure of some of the wheel brakes is increased above the output hydraulic pressure of the hydraulic pressure generating means (M), and the hydraulic pressure of the remaining non-pressurized wheel brake is generated as the hydraulic pressure. And a controller (C) for controlling the operation of the hydraulic pressure control unit (5) to enable the hydraulic pressure to correspond to the output hydraulic pressure of the means. The controller (C) includes a brake operation amount detection means (22) for detecting, and the controller (C) adds a hysteresis characteristic to the brake operation amount detected by the brake operation amount detection means (22) so as to provide the non-pressure-increasing wheel. A non-intensifying wheel target hydraulic pressure calculation unit (28) for calculating a target hydraulic pressure of the brake is included, and the hydraulic pressure of some wheel brakes is set to be higher than the output hydraulic pressure of the hydraulic pressure generating means (M) during the brake operation. Pressure increase The hydraulic pressure control unit (5) so that the hydraulic pressure of the non-intensified wheel brake becomes the target hydraulic pressure calculated by the non-intensified wheel target hydraulic pressure calculation unit (28). Brake hydraulic pressure control device for vehicles characterized by controlling.   2. The brake hydraulic pressure control for a vehicle according to claim 1, wherein the hysteresis characteristic is set such that a response characteristic when the brake operation amount increases is higher than a response characteristic when the brake operation amount decreases. apparatus.

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