JP2017177858A - Vehicular brake fluid pressure controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular brake fluid pressure controller which can suppress unnecessary extension of a drive time of a motor and discomfort of a crew member caused by operation sound of the motor during ABS control.SOLUTION: A vehicular brake fluid pressure controller 1 comprises: an inlet valve 13 interposed at a fluid pressure passage from a fluid pressure source to a wheel brake; an outlet valve 14 interposed at a fluid pressure passage from the wheel brake to a reservoir; a pump 17 interposed at a fluid pressure passage from the reservoir to the fluid pressure source; an electric motor 21 driving the pump 17; and a control unit 100 which performs a control in which the brake fluid reserved in the reservoir is returned to the fluid pressure source side by ABS control and driving of the electric motor 21. The control unit 100 starts driving of the electric motor 21 when starting a pressure reduction control and sets target discharge time based on a road surface friction coefficient. The control unit stops the electric motor 21 even during ABS control in a case that the target discharge time has passed since completion of the pressure reduction control.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle brake hydraulic pressure control device.

  A vehicle configured to be able to execute anti-lock brake control is a reservoir that temporarily stores brake fluid released from wheel brakes during pressure reduction control, and a pump that discharges brake fluid stored in the reservoir to the master cylinder side. And a motor for driving the pump. For example, Patent Document 1 includes a motor output control unit that controls a motor output, and the motor output control unit is configured to reduce the motor output as the road surface friction coefficient is smaller. Is disclosed.

JP-A-8-207726

  By the way, although the prior art reduces the noise caused by the excessive torque of the motor by reducing the motor output as the road surface friction coefficient is smaller, the driving of the motor does not stop until the antilock brake control is finished. For this reason, during the anti-lock brake control, there has been a problem that the driving time of the motor becomes unnecessarily long, or the passenger feels uncomfortable due to the operation sound of the motor.

  Therefore, the present invention provides a vehicle brake hydraulic pressure that can suppress an unnecessarily long driving time of the motor during anti-lock brake control, and can prevent an occupant from feeling uncomfortable due to the operation sound of the motor. An object is to provide a control device.

In order to solve the above problems, a vehicle brake hydraulic pressure control device according to the present invention includes an inlet valve interposed in a hydraulic pressure path from a hydraulic pressure source to a wheel brake, and a hydraulic pressure path from the wheel brake to a reservoir. By an interposed outlet valve, a pump interposed in a hydraulic pressure path from the reservoir to the hydraulic pressure source, a motor that drives the pump, an antilock brake control, and a pressure reduction control of the antilock brake control A controller that executes control to return the brake fluid accumulated in the reservoir to the hydraulic pressure source side by driving the motor.
The controller starts driving the motor when starting the pressure reduction control, sets a target discharge time based on a road surface friction coefficient, and when the target discharge time has elapsed since the end of the pressure reduction control Stops the motor even during the anti-lock brake control.

  According to this configuration, when the target discharge time has elapsed since the end of the pressure reduction control, the motor is stopped even during the antilock brake control, so that the motor drive time during the antilock brake control is unnecessary. It is possible to suppress the increase in length and to suppress the passenger from feeling uncomfortable due to the operation sound of the motor.

  In the apparatus described above, the control unit may be configured to reset the target discharge time when the next pressure reduction control is started before the target discharge time has elapsed from the end of the pressure reduction control. it can.

  According to this, since the target discharge time is reset for each pressure reduction control, the motor can be driven in an appropriate time after the end of each pressure reduction control.

  In the above-described apparatus, the control unit estimates a reservoir usage amount corresponding to an increase amount of the brake fluid in the reservoir from an initial state, and the motor is based on the estimated reservoir usage amount and the target discharge time. The target rotational speed can be set.

  According to this, since the target rotational speed of the motor is set based on the amount of brake fluid in the reservoir and the target discharge time set based on the road surface friction coefficient, the rotational speed at which the operating sound is not noticeable can be obtained. .

  In the above-described device, the control unit is configured to reduce a brake that has flowed into the reservoir from the wheel brake based on a fluid pressure at the start of the decompression control and a fluid pressure at the end of the decompression control in the decompression control. The amount of liquid consumed corresponding to the amount of liquid is estimated, the amount of discharge corresponding to the amount of brake fluid discharged from the reservoir is estimated from the number of revolutions of the motor, and the amount of discharged liquid, the amount of liquid consumed, and the use of the reservoir The reservoir use amount can be obtained based on the previous value of the amount.

  According to this, by calculating the reservoir usage amount using the previous values of the consumption liquid amount, the discharge amount, and the reservoir usage amount, for example, the reservoir usage amount can be accurately compared with the case where the reservoir usage amount is calculated only from the consumption liquid amount. Can be requested.

  In the apparatus described above, the control unit may set the target discharge time to a shorter time as the road surface friction coefficient is higher.

  According to this, road noise becomes large on the high friction coefficient road, so that the operating sound can be made inconspicuous even if the motor is driven at a high rotational speed for a short time. Further, since road noise is reduced on the low friction coefficient road, the driving sound can be made inconspicuous by driving the motor over a long time at a small rotational speed.

  In the above-described apparatus, when the anti-lock brake control is started, the control unit estimates the road surface friction coefficient based on the hydraulic pressure of each wheel brake and the wheel deceleration of each wheel. Can do.

  According to this, the road surface friction coefficient can be estimated at the initial stage when the antilock brake control is started. As a result, for example, when anti-lock brake control is executed on a low friction coefficient road, compared to the method of setting the road surface friction coefficient to a high friction coefficient at the initial stage when anti-lock brake control is started, the low friction coefficient road is changed. Accordingly, since the number of rotations of the motor can be reduced, the operation sound can be made inconspicuous.

  In the above-described device, the control unit may be configured to estimate the road surface friction coefficient based on vehicle body deceleration when the pressure increase control is executed at least twice during the antilock brake control. .

  According to this, the road surface friction coefficient can be accurately estimated.

  ADVANTAGE OF THE INVENTION According to this invention, during anti-lock brake control, it can suppress that the drive time of a motor becomes unnecessarily long, or it can suppress that a passenger | crew feels uncomfortable by the operation sound of a motor.

It is a lineblock diagram of vehicles provided with a brake fluid pressure control device for vehicles concerning an embodiment. It is a block diagram which shows the structure of a hydraulic unit. It is a block diagram which shows the structure of a control part. It is a figure which shows a hydraulic pressure estimation map (a) and a consumption liquid amount estimation map (b). It is a figure which shows a discharge amount estimation map. It is a figure which shows a target discharge time setting map. It is a flowchart which shows the process by a control part. It is a time chart which shows the control by a control part. It is a time chart which shows the control by a control part.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the vehicle brake fluid pressure control device 1 is a device that appropriately controls the braking force applied to each wheel 3 of a vehicle 2 that is a four-wheeled vehicle. The vehicular brake hydraulic pressure control device 1 mainly includes a hydraulic unit 10 provided with a hydraulic path and various parts, and a control unit 100 for appropriately controlling various parts in the hydraulic unit 10.

  Each wheel 3 is provided with a wheel brake FL, RR, RL, FR, and each wheel brake FL, RR, RL, FR is braked by a hydraulic pressure supplied from a master cylinder 5 as a hydraulic pressure source. A wheel cylinder 4 is provided. The master cylinder 5 and the wheel cylinder 4 are each connected to a hydraulic unit 10. The brake fluid pressure generated in the master cylinder 5 in accordance with the depression force of the brake pedal 6 is supplied to the wheel cylinder 4 after being controlled by the control unit 100 and the fluid pressure unit 10.

  A pressure sensor 91 that detects the hydraulic pressure of the master cylinder 5 (master cylinder pressure Pm) and a wheel speed sensor 92 that detects the wheel speed Vw of each wheel 3 are connected to the control unit 100. The control unit 100 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an input / output circuit, and inputs from the pressure sensor 91 and the wheel speed sensor 92 and the ROM The control for increasing / decreasing the hydraulic pressures of the wheel brakes FL, RR, RL, FR is executed by performing various arithmetic processes based on the programs and data stored in.

  As shown in FIG. 2, the hydraulic unit 10 is disposed between the master cylinder 5 and the wheel brakes FL, RR, RL, FR. The two output ports 5a, 5b of the master cylinder 5 are connected to the inlet port 11a of the hydraulic unit 10, and the outlet port 11b is connected to each wheel brake FL, RR, RL, FR. In normal times, a hydraulic pressure path is formed from the inlet port 11a to the outlet port 11b in the hydraulic pressure unit 10 so that the pedal force of the brake pedal 6 is transmitted to the wheel brakes FL, RR, RL, FR. It has come to be.

  The hydraulic pressure unit 10 is provided with four inlet valves 13, four outlet valves 14, and four check valves 13a corresponding to the wheel brakes FL, RR, RL, FR. The hydraulic unit 10 includes a motor for driving the two reservoirs 16, the two pumps 17, the two orifices 17a, and the two pumps 17 corresponding to the respective output hydraulic pressure paths 19A corresponding to the output ports 5a and 5b. As an example, an electric motor 21 is provided.

The inlet valve 13 is a normally open proportional solenoid valve arranged in a hydraulic pressure path (upstream of each wheel brake FL, RR, RL, FR) from the master cylinder 5 to each wheel brake FL, RR, RL, FR. is there. The inlet valve 13 is normally open, thereby allowing the brake hydraulic pressure to be transmitted from the master cylinder 5 to the wheel brakes FL, RR, RL, FR. In addition, the inlet valve 13 is blocked by the control unit 100 when the wheel 3 is about to be locked, thereby cutting off the hydraulic pressure transmitted from the brake pedal 6 to each wheel brake FL, RR, RL, FR.
Although not shown in detail, the valve body of the inlet valve 13 is urged toward the master cylinder 5 by an electromagnetic force corresponding to the applied current, and the urging force causes the fluid of the wheel brakes FL, RR, RL, FR. The pressure can be adjusted.

  The outlet valve 14 is connected to the reservoir 16, the pump 17 and the master cylinder 5 from the hydraulic path on the wheel cylinder 4 side of the inlet valve 13 to the master cylinder 5 from each wheel brake FL, RR, RL, FR. It is a normally closed solenoid valve arranged on the pressure path. Specifically, the outlet valve 14 is interposed in a hydraulic pressure path from each wheel brake FL, RR, RL, FR to the reservoir 16. The outlet valve 14 is normally closed, but is released by the control unit 100 when the wheel 3 is about to be locked, so that the hydraulic pressure applied to each wheel brake FL, RR, RL, FR is supplied to each reservoir. Escape to 16.

  The check valve 13a is connected to each inlet valve 13 in parallel. The check valve 13a is a valve that only allows the brake fluid to flow from each wheel brake FL, RR, RL, FR side to the master cylinder 5 side, and the inlet valve 13 when the input from the brake pedal 6 is released. Even when is closed, the brake fluid is allowed to flow from each wheel brake FL, RR, RL, FR side to the master cylinder 5 side.

The reservoir 16 has a function of absorbing brake fluid that is released when each outlet valve 14 is opened.
The pump 17 is disposed on a hydraulic pressure path from the reservoir 16 to the master cylinder 5. The pump 17 has a function of sucking the brake fluid absorbed in the reservoir 16 and returning the brake fluid to the master cylinder 5 through the orifice 17a.

  The opening and closing states of the inlet valve 13 and the outlet valve 14 are controlled by the control unit 100, so that the hydraulic pressure in the wheel cylinder 4 of each wheel brake FL, RR, RL, FR (hereinafter referred to as “wheel cylinder pressure Pw”). ) To control. For example, in a normal state in which the inlet valve 13 is open and the outlet valve 14 is closed, if the brake pedal 6 is depressed, the hydraulic pressure from the master cylinder 5 is transmitted to the wheel cylinder 4 as it is to increase the pressure. If the valve 13 is closed and the outlet valve 14 is opened, the brake fluid flows out from the wheel cylinder 4 to the reservoir 16 side to be in a reduced pressure state. If both the inlet valve 13 and the outlet valve 14 are closed, the wheel cylinder pressure Pw Is held. In addition, when the master cylinder pressure Pm is increasing and the outlet valve 14 is closed, an appropriate current that does not reach the fully closed state is supplied to the inlet valve 13, the wheel from the master cylinder 5 corresponds to the current. Inflow of the brake fluid into the cylinder 4 is restricted, and the wheel cylinder pressure Pw can be gradually increased.

Next, details of the control unit 100 will be described.
As shown in FIG. 3, the control unit 100 includes a wheel deceleration calculation unit 111, a vehicle body deceleration calculation unit 112, a hydraulic pressure estimation unit 113, a rotation speed acquisition unit 114, and an antilock brake (hereinafter referred to as “ABS”). Control means 120, road surface friction coefficient (hereinafter referred to as “road surface μ”) estimation means 131, consumption liquid amount estimation means 132, discharge amount estimation means 133, target discharge time setting means 141, reservoir usage amount estimation means 142, target rotation Number setting means 150, valve drive section 160, motor drive section 170 and storage device 190 are provided.

  The wheel deceleration calculation unit 111 has a function of calculating the wheel deceleration Aw of each wheel 3 based on the wheel speed Vw of each wheel 3 acquired from the wheel speed sensor 92. Here, the deceleration has the same meaning as acceleration, and when it is a negative value, it indicates that the vehicle is decelerating, and when it is a positive value, it indicates that the vehicle is accelerating. The wheel deceleration Aw can be calculated, for example, by subtracting the previous value from the current value of the wheel speed Vw. The wheel deceleration calculation unit 111 outputs the calculated wheel deceleration Aw of each wheel 3 to the ABS control unit 120 and the road surface μ estimation unit 131.

  The vehicle body deceleration calculation means 112 has a function of calculating the vehicle body deceleration Ac based on the wheel speed Vw of each wheel 3 acquired from the wheel speed sensor 92. The vehicle body deceleration Ac can be calculated, for example, by subtracting the previous value from the current value of the vehicle body speed Vc calculated from the wheel speed Vw. During the ABS control, the vehicle body deceleration Ac is calculated from the wheel speed Vw at the start of the previous pressure increase and the wheel speed Vw at the start of the current pressure increase. The vehicle body deceleration calculation unit 112 outputs the calculated vehicle body deceleration Ac to the road surface μ estimation unit 131.

  Based on the master cylinder pressure Pm acquired from the pressure sensor 91 and the control history of the inlet valve 13 and the outlet valve 14 output from the ABS control unit 120, the hydraulic pressure estimation unit 113 is configured to adjust the wheel cylinder pressure of each wheel 3. It has a function to estimate Pw. The hydraulic pressure estimation means 113 outputs the estimated wheel cylinder pressures Pw to the road surface μ estimation means 131 and the consumed liquid amount estimation means 132.

  The rotational speed acquisition unit 114 has a function of acquiring information on the rotational speed of the electric motor 21. Specifically, the rotation speed acquisition unit 114 acquires the counter electromotive voltage of the electric motor 21 as information on the rotation speed of the electric motor 21. The rotation speed acquisition unit 114 outputs the acquired information on the rotation speed of the electric motor 21 to the discharge amount estimation unit 133.

  The ABS control means 120 determines whether or not to execute ABS control based on the wheel speed Vw of each wheel 3 acquired from the wheel speed sensor 92 and each wheel deceleration Aw calculated by the wheel deceleration calculation means 111. A function to determine for each wheel 3 and to determine for each wheel 3 an instruction for hydraulic pressure control during ABS control (an instruction to select one of pressure reduction control, holding control and pressure increase control) when it is determined to execute. Have.

  Specifically, the ABS control means 120 calculates the slip amount SL of each wheel 3 based on the wheel speed Vw of each wheel 3 and the vehicle body speed Vc estimated from each wheel speed Vw. As the slip amount SL, for example, a value obtained by subtracting the wheel speed Vw from the vehicle body speed Vc, a slip ratio represented by (Vc−Vw) / Vc, or the like can be used.

  Then, the ABS control means 120 determines that the wheel 3 is likely to be locked when the slip amount SL is equal to or greater than the predetermined pressure-reduction threshold SLth and the wheel deceleration Aw is 0 or less. Is determined to be decompression control. Further, the ABS control means 120 determines that the hydraulic pressure control instruction is the holding control when the wheel deceleration Aw is larger than zero. Further, the ABS control means 120 determines that the hydraulic pressure control instruction is the pressure increase control when the slip amount SL is less than the pressure reduction threshold SLth and the wheel deceleration Aw is 0 or less. The ABS control unit 120 outputs information on the determined hydraulic pressure control instruction (instruction for pressure reduction, holding, or pressure increase) to the valve drive unit 160.

  The road surface μ estimation means 131 has a function of estimating the road surface μ. Specifically, the road surface μ estimating means 131, when starting the ABS control, the wheel deceleration Aw of each wheel 3 calculated by the wheel deceleration calculating means 111 and each wheel cylinder pressure Pw estimated by the hydraulic pressure estimating means 113. Based on the above, the road surface μ corresponding to each wheel 3 is estimated. Specifically, the road surface μ estimation means 131 estimates the road surface μ corresponding to each wheel 3 based on the wheel deceleration Aw of each wheel 3, each wheel cylinder pressure Pw, and the road surface friction coefficient estimation map.

  Here, the road surface friction coefficient estimation map is a map for associating the magnitude (absolute value) of the wheel deceleration Aw, the wheel cylinder pressure Pw, and the road surface μ, and is set in advance by experiments or simulations. . The road surface friction coefficient estimation map is set so that the road surface μ decreases as the wheel deceleration Aw increases, and the road surface μ decreases as the wheel cylinder pressure Pw decreases. The road surface μ estimating means 131 estimates the road surface μ by linear interpolation when the wheel cylinder pressure Pw and the wheel deceleration Aw are values other than those shown in the road surface friction coefficient estimation map.

When the pressure increase control is executed twice during the ABS control, the road surface μ estimation means 131 estimates the road surface μ based on the vehicle body deceleration Ac calculated by the vehicle body deceleration calculation means 112 thereafter. To do. Specifically, the road surface μ estimation means 131 sets the road surface μ to a lower value as the vehicle body deceleration Ac is smaller.
The road surface μ estimation unit 131 outputs the estimated road surface μ to the target discharge time setting unit 141.

  The consumption liquid amount estimation means 132, in the ABS control decompression control, based on the wheel cylinder pressure Pw at the start of the decompression control and the wheel cylinder pressure Pw at the end of the decompression control, the wheel brakes FL, RR, RL, FR In other words, each wheel 3 has a function of estimating the amount of consumed fluid corresponding to the amount of brake fluid that has flowed into the reservoir 16. Specifically, the liquid consumption amount estimation means 132 estimates the current value of the wheel cylinder pressure Pw for each unit time ΔT based on the previous value of the wheel cylinder pressure Pw, the unit time ΔT, and the hydraulic pressure estimation map. To do.

  Here, as shown in FIG. 4A, the hydraulic pressure estimation map is a map showing the change over time of the wheel cylinder pressure Pw during the pressure reduction control of the ABS control, and is set in advance for each wheel 3 by experiments or simulations. Has been. For example, when the previous value of the wheel cylinder pressure Pw is Pw3, the consumed liquid amount estimation unit 132 estimates the current value of the wheel cylinder pressure Pw as Pw2 based on the unit time ΔT and the hydraulic pressure estimation map. .

  Then, the consumed liquid amount estimating means 132 estimates the consumed liquid amount Vs based on the estimated current value of the wheel cylinder pressure Pw, the previous value of the wheel cylinder pressure Pw, and the consumed liquid amount estimation map.

  Here, as shown in FIG. 4B, the consumed liquid amount estimation map is a map for associating the wheel cylinder pressure Pw with the hydraulic pressure loss, and is set in advance by experiments or simulations. The consumption liquid amount estimation map is set so that the hydraulic pressure loss decreases as the wheel cylinder pressure Pw decreases. For example, when the previous value of the wheel cylinder pressure Pw is Pw3 and the current value is Pw2, the consumed liquid amount estimation unit 132 determines the hydraulic pressure loss at the wheel cylinder pressure Pw3 based on the consumed liquid amount estimation map. D3 and hydraulic pressure loss D2 at the time of wheel cylinder pressure Pw2 are estimated. Then, the liquid consumption amount Vs is estimated by subtracting the hydraulic pressure loss D2 from the hydraulic pressure loss D3.

  The consumption liquid amount estimation means 132 calculates the consumption liquid amount Vs for each unit time ΔT during the pressure reduction control. As a result, the wheel cylinder pressure Pw (for example, Pw3) at the start of the pressure reduction control and the pressure reduction control are calculated. Based on the wheel cylinder pressure Pw (for example, Pw1) at the end, the total amount of liquid consumption during the pressure reduction control is estimated. The consumed liquid amount estimating unit 132 outputs the estimated consumed liquid amount Vs to the reservoir usage amount estimating unit 142.

  The discharge amount estimation means 133 has a function of estimating a discharge amount corresponding to the amount of brake fluid discharged from the reservoir 16 by driving the pump 17 from the rotational speed of the electric motor 21 in the ABS control pressure reduction control. . Specifically, the discharge amount estimation unit 133 determines the discharge amount Vd based on the rotation number (back electromotive voltage) of the electric motor 21 acquired by the rotation number acquisition unit 114 and the discharge amount estimation map every unit time ΔT. Is estimated.

  Here, as shown in FIG. 5, the discharge amount estimation map is a map for associating the back electromotive voltage of the electric motor 21 with the discharge amount Vd, and is set in advance by experiments or simulations. The discharge amount estimation map is set so that the discharge amount Vd increases as the back electromotive voltage of the electric motor 21 increases. The discharge amount estimation unit 133 outputs the estimated discharge amount Vd to the reservoir usage amount estimation unit 142.

  The target discharge time setting unit 141 has a function of setting the target discharge time Td based on the road surface μ estimated by the road surface μ estimation unit 131. Specifically, the target discharge time setting unit 141 sets the target discharge time Td based on the road surface μ and the target discharge time setting map. Here, as shown in FIG. 6, the target discharge time setting map is a map for associating the road surface μ with the target discharge time Td, and is set in advance by experiments or simulations. The target discharge time setting map is set so that the target discharge time Td becomes shorter as the road surface μ is higher. Thereby, the target discharge time setting means 141 sets the target discharge time Td to a longer time as the road surface μ is lower, and sets the target discharge time Td to a shorter time as the road surface μ is higher.

Further, the target discharge time setting means 141, when the next pressure reduction control is started before the target discharge time Td elapses from the end of the pressure reduction control during the ABS control, the road surface μ and the target discharge time setting map. Based on the above, the target discharge time Td is reset.
The target discharge time setting unit 141 outputs the set target discharge time Td to the target rotation number setting unit 150 and the motor driving unit 170.

The reservoir usage amount estimation means 142 has a function of estimating a reservoir usage amount corresponding to an increase amount from the initial state (empty state) of the brake fluid in the reservoir 16 in the ABS control pressure reduction control. Specifically, the reservoir usage amount estimation unit 142 determines the discharge amount Vd estimated by the discharge amount estimation unit 133, the consumption liquid amount Vs estimated by the consumption liquid amount estimation unit 132, and the previous reservoir usage amount every unit time ΔT. Based on the value Vr _n−1 , the reservoir usage amount Vr _n is obtained. Specifically, the reservoir usage amount estimation means 142 adds the value obtained by subtracting the discharge amount Vd from the consumption liquid amount Vs to the previous value Vr _n−1 of the reservoir usage amount, so that the reservoir usage amount Vr _n (current value). Is calculated (Vr _n = Vr _n-1 + (Vs−Vd)). Reservoir amount estimating means 142 outputs the reservoir usage Vr _n estimated the target rotational speed setting means 150.

Target rotational speed setting means 150, a target discharge time Td target discharge time setting unit 141 has set, on the basis of the reservoir the amount Vr _n the reservoir amount estimating means 142 estimates, the target rotational speed of the electric motor 21 It has a function to set. Specifically, the target rotation speed setting means 150 sets the discharge time counter value TdC from the target discharge time Td. Specifically, the target rotation speed setting means 150 sets the target discharge time Td to the discharge time counter value TdC during the pressure reduction control of the ABS control, and after the pressure reduction control (during holding control and pressure increase control), For each unit time ΔT, a value obtained by subtracting the unit time ΔT from the previous value of the discharge time counter value TdC is set as the discharge time counter value TdC.

Then, the target rotational speed setting means 150 calculates a target discharge amount Vt by dividing the reservoir usage Vr _n in the discharge time counter value TDC, and the target discharge quantity Vt calculated on the basis of the target rotation speed setting map The target rotational speed Rt is set. Here, the target rotation speed setting map is a map for associating the target discharge amount Vt with the target rotation speed Rt, and is set in advance by experiments or simulations. The target rotation speed setting map is set so that the target rotation speed Rt increases as the target discharge amount Vt increases.
The target rotational speed setting means 150 outputs information on the set target rotational speed Rt to the motor drive unit 170.

  The valve drive unit 160 has a function of controlling the wheel cylinder pressure Pw by controlling the inlet valve 13 and the outlet valve 14 based on the information on the hydraulic pressure control instruction output from the ABS control means 120. ing.

  Specifically, the valve drive unit 160 closes the inlet valve 13 and opens the outlet valve 14 by causing a current to flow through the inlet valve 13 and the outlet valve 14 when the hydraulic pressure control instruction is pressure reduction control. Control is performed to reduce the wheel cylinder pressure Pw. Further, when the hydraulic pressure control instruction is holding control, the valve drive unit 160 causes both the inlet valve 13 and the outlet valve 14 to flow by supplying current to the inlet valve 13 and not flowing current to the outlet valve 14. Both are closed and controlled to maintain the wheel cylinder pressure Pw.

  Further, when the hydraulic pressure control instruction is the pressure increase control, the valve driving unit 160 closes the outlet valve 14 by not supplying current to the outlet valve 14 and does not supply current to the inlet valve 13, or By flowing a drive current corresponding to the indicated hydraulic pressure, the pressure difference between the upstream and downstream of the inlet valve 13 is controlled to increase the wheel cylinder pressure Pw at the intended pressure increase rate.

  The motor driving unit 170 controls the driving of the electric motor 21 that drives the pump 17 based on information output from the target discharge time setting unit 141, the target rotation speed setting unit 150, and the like, thereby reducing the ABS control pressure reduction. It has a function of executing a control to return the brake fluid accumulated in the reservoir 16 by the control from the reservoir 16 side to the master cylinder 5 side.

  Specifically, the motor driving unit 170 starts driving the electric motor 21 when starting the pressure reduction control of the ABS control. Specifically, the motor drive unit 170 causes the electric motor 21 to be driven at the target rotational speed Rt by causing a current corresponding to the target rotational speed Rt set by the target rotational speed setting means 150 to flow through the electric motor 21 during the ABS control. To drive. Then, when the target discharge time Td has elapsed from the end of the pressure reduction control, the motor drive unit 170 stops the flow of the current corresponding to the target rotational speed Rt even during the ABS control, thereby The drive of the motor 21 is stopped.

  The storage device 190 is a device that stores threshold values, maps, estimated values, calculated values, and the like for processing by the above-described units.

Next, processing by the control unit 100 configured as described above will be described. Note that the process of FIG. 7 is repeatedly performed every predetermined control cycle (unit time ΔT).
As shown in FIG. 7, the control unit 100 first determines whether or not ABS control is being performed (S11). Then, when the ABS control is not being performed (S11, No), the control unit 100 ends the current process.

On the other hand, when the ABS control is being performed (S11, Yes), the control unit 100 estimates the road surface μ (S21). Further, the control unit 100 estimates the consumed liquid amount Vs (S22) and estimates the discharge amount Vd (S23). Then, the control unit 100, the discharge amount Vd, fluid consumption Vs and on the basis of the previous value _{Vr n-1} reservoir usage with estimating the reservoir amount Vr _n (S24), the target discharge time based on road surface μ Td is set (S25). Further, the control unit 100 sets the target speed Rt of the electric motor 21 on the basis of the reservoir the amount Vr _n and target discharge time Td (S26).

  Then, the control unit 100 drives the electric motor 21 at the set target rotational speed Rt (S31), and returns the brake fluid accumulated in the reservoir 16 from the reservoir 16 to the master cylinder 5 side. Then, the control unit 100 determines whether or not the target discharge time Td has elapsed since the end of the pressure reduction control (S41). When the target discharge time Td has not elapsed (S41, No), the control unit 100 ends the current process. On the other hand, when the target discharge time Td has passed (S41, Yes), since almost all of the brake fluid in the reservoir 16 returns to the master cylinder 5 side and the reservoir 16 is substantially empty, the control unit 100 is electrically driven. The driving of the motor 21 is stopped (S51), and the current process is terminated.

Note that when the ABS control holding control or pressure increasing control is subsequently performed after step S51, the amount of brake fluid in the reservoir 16 does not increase from the empty state, and therefore the control unit 100 performs step S24. in estimates that reservoir usage Vr _n is 0. Thereby, the control part 100 sets the target rotation speed Rt of the electric motor 21 to 0 in step S26. As a result, the control unit 100 ends the current process without driving the electric motor 21 even during the ABS control.

Next, an example of control by the control unit 100 will be described.
As shown in FIG. 8, when the ABS control is started (ON) and the pressure reduction control is started at time t1, the inlet valve 13 is closed and the outlet valve 14 is opened, so that the brake fluid is discharged from the wheel cylinder 4. It flows into the reservoir 16 and the reservoir usage amount Vr _n (the amount of brake fluid in the reservoir 16) increases.

Further, when starting the ABS control for each control cycle (unit time [Delta] T), the reservoir amount Vr _n and the target discharge time Td, the discharge time counter value TDC, the target speed Rt is set, the set target speed Rt Thus, the electric motor 21 is driven. During the pressure reduction control (time t1 to t2), the pump 17 is driven by driving the electric motor 21 and a part of the brake fluid is discharged from the reservoir 16 side to the master cylinder 5 side. If towards the amount of brake fluid flowing into the reservoir 16 is large, the reservoir amount Vr _n gradually increases.

At time t2, the pressure-reducing control is completed and starts the holding control, that the outlet valve 14 is closed, since the flow of brake fluid from the wheel cylinder 4 into the reservoir 16 is stopped, an increase in reservoir amount Vr _n Stops. Then, since the brake fluid by the drive of the pump 17 based on the target speed Rt it is discharged from the reservoir 16 to the master cylinder 5 side, the reservoir amount Vr _n decreases.

At time t3, when starting the next pressure reduction control before (before discharge time counter value TdC is 0) the target discharge time Td from the end (time t2) of the pressure reduction control has elapsed, again reservoir amount Vr _n increases I will do it.

Then, at time t4, the pressure reduction control is ended again to start holding control, the increase in reservoir amount Vr _n stops, master from the brake fluid within the reservoir 16 by the drive of the pump 17 based on the target speed Rt discharged into the cylinder 5 side, it decreases again reservoir usage Vr _n.

Then, at time t5, when the target discharge time Td elapses from the end of the pressure reduction control (time t4) (when the discharge time counter value TdC becomes 0), the reservoir 16 becomes almost empty, so the ABS control is in progress (ON). Even if it exists, the drive of the electric motor 21 stops. Thereafter, as shown at time t5 to t6, since the reservoir amount Vr _n is 0, even during the ABS control, unless again the pressure reduction control is started, will not be electric motor 21 is driven.

By the way, in the present embodiment, the target discharge time Td is set based on the road surface μ and the target discharge time setting map of FIG. 6, and therefore when the road surface μ is low as shown in FIG. By setting Td to a long time Td _Low (large value), the discharge time counter value TdC becomes a large value TdC _Low , and when the road surface μ is high, the target discharge time Td is set to a short time Td _High (small value). As a result, the discharge time counter value TdC becomes a small value TdC _High . The target speed Rt is to be set based on the target discharge amount Vt calculated by dividing the reservoir usage Vr _n in the discharge time counter value TDC, when the road surface μ is low, a large discharge time counter value TDC When the value TdC _Low is set, the target rotational speed Rt is set to a small rotational speed Rt _Low , and when the road surface μ is high, the discharge time counter value TdC is a small value TdC _High so that the target rotational speed Rt is a large rotational speed Rt. Set to _High .

Therefore, on the low μ road where the road noise is reduced, as shown by a solid line in FIG. 9, the electric motor 21 takes a long time (target discharge time Td _Low ) at a small target rotation speed Rt _{Low from} time t12 to t14. By driving the operation sound of the electric motor 21 can be made inconspicuous. On the other hand, on a high μ road where road noise increases, as indicated by a two-dot chain line in FIG. 9, the electric motor 21 has a large target rotational speed Rt _High and a short target time (target discharge time Td _High ) from time t12 to t13. Even if is driven, the operation sound of the electric motor 21 can be made inconspicuous.

According to the above, the following effects can be obtained in the present embodiment.
When the target discharge time Td set based on the road surface μ elapses from the end of the pressure reduction control, the electric motor 21 is stopped even during the ABS control. Therefore, the drive time of the electric motor 21 during the ABS control. Can be prevented from becoming unnecessarily long, or an occupant can be prevented from feeling uncomfortable due to the operating sound of the electric motor 21.

  Further, when the next pressure reduction control is started before the target discharge time Td elapses from the end of the pressure reduction control, the target discharge time Td is reset based on the road surface μ. Is reset. Thereby, after completion | finish of each pressure reduction control, the electric motor 21 can be driven in appropriate time.

Further, since the target rotational speed Rt of the electric motor 21 is set based on the amount of brake fluid in the reservoir 16 (reservoir usage amount Vr _n ) and the target discharge time Td set based on the road surface μ, the vehicle 2 The rotational speed at which the operating sound of the electric motor 21 is not conspicuous can be set according to the road surface μ of the traveling road surface.

Further, fluid consumption Vs, so obtaining a reservoir amount Vr _n by using the previous value Vr _n-1 of the discharge amount Vd and the reservoir usage, for example, than only fluid consumption Vs when obtaining a reservoir usage, a reservoir amount Vr _n can be accurately determined.

  Further, since the target discharge time Td is set to a shorter time as the road surface μ is higher, even if the electric motor 21 is driven in a short time at a large speed on a high μ road where the road noise increases, the operation noise becomes inconspicuous. be able to. In addition, since the target discharge time Td is set to a longer time as the road surface μ is lower, on the low μ road where the road noise is reduced, the operation sound is generated by driving the electric motor 21 over a long time with a small rotation speed. It can be inconspicuous.

  Further, since the road surface μ is estimated on the basis of each wheel cylinder pressure Pw and the wheel deceleration Aw of each wheel 3 when the ABS control is started, the road surface μ can be estimated at the initial stage when the ABS control is started. . Thereby, for example, when the ABS control is executed on the low μ road, compared with the method of setting the road surface μ to the high μ at the initial stage when the ABS control is started, the electric motor 21 is controlled according to the low μ road. Since the rotation speed can be reduced, the operation sound of the electric motor 21 can be made inconspicuous.

  Further, when the pressure increasing control is executed twice during the ABS control, the road surface μ is estimated based on the vehicle body deceleration Ac thereafter, so that the road surface μ can be accurately estimated.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
For example, the present invention may be applied to a vehicle brake hydraulic pressure control device that executes attitude control of a vehicle other than ABS control together with ABS control.

  Moreover, in the said embodiment, when the control part 100 performed pressure increase control twice during ABS control, after that, it was the structure which estimates road surface micro | micron | mu based on vehicle body deceleration Ac. It is not limited to. For example, when the pressure increasing control is executed three times or more during the ABS control, the controller may be configured to estimate the road surface μ based on the vehicle body deceleration thereafter. Further, the controller may be configured to estimate the road surface μ based on each wheel cylinder pressure and the wheel deceleration of each wheel regardless of the number of executions of the pressure increase control.

  Moreover, in the said embodiment, although the control part 100 was the structure which uses the estimated wheel cylinder pressure Pw for control, it is not limited to this. For example, the control unit may be configured to use a wheel cylinder pressure acquired from a sensor that detects a wheel cylinder pressure of each wheel for control.

In the above embodiment, the control unit 100, the control for each cycle, but there was a configuration for calculating the reservoir amount Vr _n and the target rotational speed Rt, but is not limited thereto. For example, the control unit may be configured to calculate the reservoir usage amount and the target rotation number at the end of one decompression control.

  Here, an example will be described. Regarding the reservoir usage amount, as shown in FIG. 4A, when the decompression control ends, the wheel cylinder pressure Pw3 at the start of the decompression control, the control time Tc of the decompression control, Based on the pressure estimation map, the wheel cylinder pressure Pw1 at the end of the pressure reduction control is estimated. Then, as shown in FIG. 4B, based on the wheel cylinder pressures Pw1 and Pw3 and the consumption liquid amount estimation map, the hydraulic pressure loss D1 at the wheel cylinder pressure Pw1 and the wheel cylinder pressure Pw3 The hydraulic loss D3 is estimated. Then, by subtracting the hydraulic pressure loss D1 from the hydraulic pressure loss D3, the amount of liquid consumed during the pressure reduction control is estimated. Further, for each unit time during the pressure reduction control, the discharge amount is estimated based on the motor rotation speed (back electromotive voltage) and the discharge amount estimation map shown in FIG. 5, and each discharge amount per unit time is integrated. To estimate the total discharge volume. Then, the reservoir usage amount can be calculated by adding a value obtained by subtracting the total discharge amount from the consumption liquid amount during the pressure reduction control to the reservoir usage amount at the end of the previous pressure reduction control. As for the target rotation speed, the target discharge amount is calculated by dividing the reservoir usage amount by the target discharge time set based on the road surface μ at the end of the pressure reduction control, and the calculated target discharge amount and the target rotation speed setting are calculated. Can be set based on the map.

DESCRIPTION OF SYMBOLS 1 Vehicle brake fluid pressure control apparatus 3 Wheel 5 Master cylinder 13 Inlet valve 14 Outlet valve 16 Reservoir 17 Pump 21 Electric motor 100 Control part FL Wheel brake FR Wheel brake RL Wheel brake RR Wheel brake

Claims (7)

An inlet valve interposed in the hydraulic pressure path from the hydraulic pressure source to the wheel brake, an outlet valve interposed in the hydraulic pressure path from the wheel brake to the reservoir, and a hydraulic pressure from the reservoir to the hydraulic pressure source A pump interposed in the road; a motor for driving the pump; and brake fluid stored in the reservoir by anti-lock brake control and pressure-reducing control of the anti-lock brake control. A brake fluid pressure control device for a vehicle including a control unit that executes control to return to
The controller is
While starting the motor when starting the pressure reduction control, set a target discharge time based on the road surface friction coefficient,
The vehicular brake hydraulic pressure control device, wherein when the target discharge time has elapsed from the end of the pressure reduction control, the motor is stopped even during the anti-lock brake control.   The said control part resets the said target discharge time, when the next pressure reduction control is started before the said target discharge time passes after completion | finish of the said pressure reduction control. Brake fluid pressure control device for vehicles. The controller is
Estimating the amount of reservoir used corresponding to the amount of increase in brake fluid from the initial state in the reservoir,
The vehicle brake hydraulic pressure control apparatus according to claim 1 or 2, wherein a target rotational speed of the motor is set based on the estimated amount of use of the reservoir and the target discharge time. The controller is
In the decompression control,
Based on the fluid pressure at the start of the decompression control and the fluid pressure at the end of the decompression control, an amount of consumed fluid corresponding to the amount of brake fluid flowing into the reservoir from the wheel brake is estimated,
Estimating the discharge amount corresponding to the amount of brake fluid discharged from the reservoir from the rotational speed of the motor,
4. The vehicular brake hydraulic pressure control apparatus according to claim 3, wherein the reservoir usage amount is obtained based on the discharge amount, the consumption liquid amount, and the previous value of the reservoir usage amount.   The vehicular brake hydraulic pressure control device according to any one of claims 1 to 4, wherein the controller sets the target discharge time to a shorter time as the road surface friction coefficient is higher. .   The said control part estimates the said road surface friction coefficient based on the hydraulic pressure of each wheel brake, and the wheel deceleration of each wheel, when starting the said anti-lock brake control. The brake fluid pressure control device for a vehicle according to any one of claims 5.   The said control part estimates the said road surface friction coefficient based on vehicle body deceleration, when the said pressure increase control is performed at least twice during the said anti-lock brake control. Brake fluid pressure control device for vehicles.

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