JP2010173470A - Control device of vehicular braking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a vehicular braking device capable of responding to a request of quick speed reduction while suppressing the capacity of a pump which generates a pump-up pressure pressurized by a master cylinder pressure. <P>SOLUTION: The control device of the vehicular braking device supplies the master cylinder pressure to a wheel cylinder before a boosting force limit point of a masterback and controls the supply of the pump-up pressure generated by the pump to the wheel cylinder on and after the boosting force limit point so as to obtain a target wheel cylinder pressure. When a negative pressure in a negative pressure chamber of the masterback does not reach to a predetermined negative pressure and the boosting force limit point falls off while a non-braked state is required, the pump-up pressure is generated in advance by driving the pump. Therefore, the pressure rising by the pump-up pressure on and after the boosting force limit point can be performed with satisfactory responsiveness even when the capacity of the pump is relatively small. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device applied to a vehicle brake device that generates a hydraulic pressure in accordance with a brake operation force boosted by a negative pressure booster.

  Patent Document 1 includes a master cylinder that generates a master cylinder hydraulic pressure in response to a brake operation force boosted by a master back (negative pressure type booster), while the master cylinder liquid with respect to the required braking force during braking. A brake fluid pressure control device is disclosed that pressurizes the assist fluid pressure generated by driving the pump to the master cylinder fluid pressure when the pressure is insufficient.

JP 2006-192945 A

  By the way, in the brake hydraulic pressure control device disclosed in Patent Document 1, when a request for rapid deceleration occurs when the negative pressure of the master back (negative pressure booster) is not sufficiently secured, only the master cylinder hydraulic pressure is generated. However, since the required deceleration (brake hydraulic pressure) cannot be realized, it is necessary to raise the assist hydraulic pressure with good response and pressurize to the master cylinder hydraulic pressure.

  However, in order to raise the assist hydraulic pressure with good response, it is necessary to use a pump with a large capacity, which causes problems such as an increase in size, weight, and cost of the pump.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a vehicle brake device that can respond to a request for rapid deceleration while suppressing the capacity of the pump.

  Therefore, in the present invention, in the vehicle brake device that generates the first hydraulic pressure according to the brake operation force boosted by the negative pressure type booster and generates the second hydraulic pressure by the pump, the required braking force is reduced. In response to the increase, when the first hydraulic pressure is switched to the second hydraulic pressure and supplied to the wheel cylinder of the wheel, and the negative pressure of the negative pressure type boosting means is less than the predetermined negative pressure at the time of non-braking request The pump is driven to stand by in a state where the second hydraulic pressure is generated.

  According to the above invention, when the negative pressure of the negative pressure type boosting means is less than the predetermined negative pressure, the boost limit point is lowered. Since it is necessary to quickly raise and increase the second hydraulic pressure to compensate for the decrease, it is possible to increase the pressure with the second hydraulic pressure with good response by driving the pump in advance and waiting in a state where the second hydraulic pressure is generated. I did it.

It is a block diagram of the engine in embodiment of this invention. Sectional drawing which shows the variable valve lift mechanism VEL in embodiment of this invention (AA sectional drawing of FIG. 3). The side view of the said variable valve lift mechanism VEL. The top view of the said variable valve lift mechanism VEL. The perspective view which shows the eccentric cam used for the said variable valve lift mechanism VEL. Sectional drawing which shows the effect | action at the time of the low lift of the said variable valve lift mechanism VEL (BB sectional drawing of FIG. 3). Sectional drawing which shows the effect | action at the time of the high lift of the said variable valve lift mechanism VEL (BB sectional drawing of FIG. 3). FIG. 6 is a valve lift characteristic diagram corresponding to the base end surface of the swing cam and the cam surface in the variable valve lift mechanism VEL. The characteristic figure of the valve lift of the variable valve lift mechanism VEL. The perspective view which shows the rotational drive mechanism of the control shaft in the said variable valve lift mechanism VEL. Sectional drawing which shows the variable valve timing mechanism VTC in embodiment of this invention. It is a hydraulic circuit diagram of the brake device in the embodiment of the present invention. It is a diagram for explaining the boosting action of the master back in the embodiment of the present invention. It is a flowchart which shows the standby control of the pump in embodiment of this invention. It is a flowchart which shows the process which sets the command hydraulic pressure in the standby state in embodiment of this invention. It is a flowchart which shows the detail of the increase correction process of the command hydraulic pressure in the standby state in embodiment of this invention. It is a flowchart which shows 2nd Embodiment of the standby control of the pump which concerns on this invention. 6 is a time chart showing a change in pump-up pressure due to standby control in the embodiment of the present invention together with a master cylinder pressure, a master back negative pressure, an intake negative pressure, a brake operation amount, an accelerator opening, and the like.

Embodiments of the present invention will be described below.
FIG. 1 is a diagram illustrating a configuration of a vehicle engine and a vehicle brake device according to the embodiment.

An engine 101 shown in FIG. 1 is a spark ignition type gasoline internal combustion engine.
The intake pipe 102 of the engine 101 is provided with an electronically controlled throttle 104 that opens and closes a throttle valve 103b by a throttle motor 103a.

Then, air is sucked into the combustion chamber 106 through the electronic control throttle 104 and the intake valve 105.
The fuel is injected from a fuel injection valve 130 disposed in the intake port 102A of each cylinder.

  The fuel in the combustion chamber 106 is ignited and burned by spark ignition by the spark plug 172, and the combustion exhaust is discharged from the combustion chamber 106 through the exhaust valve 107 and purified by the front catalytic converter 108 and the rear catalytic converter 109. Released into the atmosphere.

  The exhaust valve 107 is driven to open and close by a cam 111 integrally formed with the exhaust camshaft 110 while maintaining a constant valve lift, valve operating angle, and valve timing.

  On the other hand, in the intake valve 105, the variable valve lift mechanism (VEL) 112 and the variable valve timing mechanism (VTC) 113 continuously change the valve lift amount, the valve operating angle, and the center phase of the valve operating angle. It has become.

Each ignition plug 172 is directly attached with an ignition module 171 comprising a power transistor and an ignition coil.
The engine control unit (ECU) 114 incorporating the microcomputer sets the target opening degree of the throttle valve 103b and the target opening characteristic of the intake valve 105 so that the target intake air amount and the target intake negative pressure can be obtained. Based on the target, the electronic control throttle 104, the variable valve lift mechanism 112 and the variable valve timing mechanism 113 are controlled.

  Specifically, the intake air amount of the engine 101 is controlled by controlling the opening characteristics of the intake valve 105 by the variable valve lift mechanism 112 and the variable valve timing mechanism 113, and intake negative pressure is generated by the electronic control throttle 104. Control.

  That is, the generation of the intake negative pressure by the electronic control throttle 104 is not for controlling the intake air amount, but a device (master described later) that uses the intake negative pressure (intake pipe negative pressure) of the engine 101 as a negative pressure source. For supplying a negative pressure to the bag 132a, the evaporated fuel processing device, the blow-by gas processing device, or the like).

Therefore, according to the engine 101, it is possible to operate under a condition where the intake negative pressure is small (close to atmospheric pressure), and to improve fuel consumption performance and output performance by reducing pumping loss.
The electronic control throttle 104, the fuel injection valve 130, and the ignition module 113 are also controlled by an engine control unit (ECU) 114.

  The engine control unit 114 includes an accelerator pedal sensor 116 for detecting the opening APO of the accelerator pedal 111 operated by the driver, an air flow sensor 115 for detecting the intake air amount QA of the engine 101, and an angle signal POS of the crankshaft 120. The output crank angle sensor 117, the throttle sensor 118 for detecting the opening TVO of the throttle valve 103b, the water temperature sensor 119 for detecting the coolant temperature TW of the engine 101, and the power for transmitting the output torque of the engine 101 to the drive wheels of the vehicle A vehicle speed sensor 182 that detects a vehicle traveling speed (vehicle speed) VSP from an output shaft rotation 181A of an automatic transmission 181 that constitutes a transmission system, and an air-fuel ratio AF of an air-fuel mixture of the engine 101 is detected based on an oxygen concentration in exhaust gas. Air-fuel ratio sensor 129, engine 10 Detection signals from the intake pressure sensor 142 that detects the intake pipe pressure PB.

Based on the angle signal POS from the crank angle sensor 117, the engine control unit 114 calculates the engine speed NE.
The engine 101 temporarily adsorbs evaporated fuel generated in the fuel tank 133 to the canister 135 via the evaporated fuel passage 134, and purges the evaporated fuel released from the canister 135 with the purge control valve 136. There is provided an evaporative fuel processing device for sucking into an intake passage downstream of the throttle valve 103b through a purge passage 137 having

  Further, the engine 101 sends blow-by gas accumulated in the crankcase to an intake passage downstream of the throttle valve 103b via a blow-by gas purge passage 139 in which a PCV (positive crankcase ventilated valve) 138 is interposed. A blow-by gas processing device is provided for sucking and introducing fresh air upstream of the throttle valve 103b into the crankcase via the fresh air passage 140 and the cylinder head.

  Also, a brake hydraulic circuit (brake device) including a master back 132a that uses the intake pipe negative pressure of the engine 101 as a negative pressure source and boosts the brake operation force is provided.

  The brake hydraulic circuit includes a master back 132a (brake booster) that boosts the operating force (brake operating force) of the brake pedal 131, and a master cylinder pressure (first brake pressure) according to the brake operating force boosted by the master back 132a. A master cylinder 203 (first hydraulic pressure generating means) that generates one hydraulic pressure) and a hydraulic unit 202 that supplies the master cylinder pressure to the wheel cylinders 204 to 207 of each wheel (four wheels).

  An intake negative pressure downstream of the throttle valve 103b is introduced into the negative pressure chamber of the master back 132a via a negative pressure introduction pipe 132c. In the middle of the negative pressure introduction pipe 132c, A mechanical check valve (one-way valve) 210 that opens when the pressure downstream of the throttle valve 103b becomes lower than the pressure in the master back 132a is interposed.

That is, the master back 132a is a negative pressure type booster that uses the intake negative pressure of the engine 101 as a negative pressure source and boosts the brake operation force by the negative pressure.
A brake control unit (BCU) 201 with a built-in microcomputer is provided for controlling a later-described solenoid valve and motor included in the hydraulic unit 202.

  The brake control unit (BCU) 201 includes a negative pressure sensor 132b (negative pressure detecting means) for detecting a negative pressure (booster negative pressure) BNP in the negative pressure chamber of the master back 132a, and a stroke amount BS of the brake pedal 131. A brake pedal sensor 208 that detects (depressing amount of the brake pedal), a hydraulic pressure sensor 209 that detects the master cylinder pressure MCP, an operation force sensor 217 that detects the depression force (brake operation force F) of the brake pedal 131, and the like. A signal is input.

  The engine control unit 114 and the brake control unit 201 are connected to each other by a communication circuit 211 so as to be able to communicate with each other, and transmit and receive detection results of various sensors and the like.

2 to 4 show the structure of the variable valve lift mechanism (VEL) 112 in detail.
The variable valve lift mechanism shown in FIGS. 2 to 4 includes a pair of intake valves 105, 105, a hollow intake camshaft 13 rotatably supported on the cam bearing 14 of the cylinder head 11, and the intake camshaft 13. Two eccentric cams 15 and 15 (drive cams) that are pivotally supported by the shaft, a control shaft 16 that is rotatably supported by the same cam bearing 14 above the intake camshaft 13, and the control shaft 16, a pair of rocker arms 18 and 18 supported by a control cam 17 so as to be swingable, and a pair of independent rockers disposed at upper ends of the intake valves 105 and 105 via valve lifters 19 and 19, respectively. And moving cams 20 and 20.

  The eccentric cams 15 and 15 and the rocker arms 18 and 18 are linked by link arms 25 and 25, and the rocker arms 18 and 18 and the swing cams 20 and 20 are linked by link members 26 and 26.

The rocker arms 18, 18, the link arms 25, 25, and the link members 26, 26 constitute a transmission mechanism.
As shown in FIG. 5, the eccentric cam 15 has a substantially ring shape and includes a small-diameter cam main body 15a and a flange portion 15b integrally provided on the outer end surface of the cam main body 15a. A cam shaft insertion hole 15 c is formed through the shaft, and the shaft center X of the cam body 15 a is eccentric from the shaft center Y of the intake cam shaft 13 by a predetermined amount.

  The eccentric cam 15 is press-fitted and fixed to both sides of the intake camshaft 13 not interfering with the valve lifter 19 via a cam shaft insertion hole 15c, and the outer peripheral surface 15d of the cam body 15a is the same cam. Is formed in the profile.

As shown in FIG. 4, the rocker arm 18 is bent in a substantially crank shape, and a central base portion 18 a is rotatably supported by the control cam 17.
A pin hole 18d into which a pin 21 connected to the tip end of the link arm 25 is press-fitted is formed at one end 18b protruding from the outer end of the base 18a, while the inner end of the base 18a is formed. A pin hole 18e into which a pin 28 connected to one end portion 26a (described later) of each link member 26 is press-fitted is formed in the other end portion 18c projecting from the portion.

The control cam 17 has a cylindrical shape, is fixed to the outer periphery of the control shaft 16, and the position of the axis P1 is eccentric from the axis P2 of the control shaft 16 by α as shown in FIG.
The swing cam 20 has a substantially horizontal U shape as shown in FIGS. 2, 6, and 7, and an intake camshaft 13 is fitted into a substantially annular base end portion 22 so as to be rotatably supported. A support hole 22a is formed in a penetrating manner, and a pin hole 23a is formed in the end 23 located on the other end 18c side of the rocker arm 18.

  Further, a base circle surface 24a on the base end portion 22 side and a cam surface 24b extending in an arc shape from the base circle surface 24a toward the end edge side of the end portion 23 are formed on the lower surface of the swing cam 20. The circular surface 24 a and the cam surface 24 b come into contact with predetermined positions on the upper surfaces of the valve lifters 19 in accordance with the swing position of the swing cam 20.

  That is, when viewed from the valve lift characteristics shown in FIG. 8, as shown in FIG. 2, the predetermined angle range θ1 of the base circle surface 24a becomes the base circle section, and the predetermined angle range θ2 from the base circle section θ1 of the cam surface 24b changes. This is a so-called ramp section, and further, a predetermined angle range θ3 from the ramp section θ2 of the cam surface 24b is set to be a lift section.

  The link arm 25 includes an annular base portion 25a and a projecting end 25b projecting at a predetermined position on the outer peripheral surface of the base portion 25a. At the center position of the base portion 25a, the cam body of the eccentric cam 15 is provided. A fitting hole 25c is formed in the outer peripheral surface of 15a so as to be freely rotatable, and a pin hole 25d through which the pin 21 is rotatably inserted is formed in the protruding end 25b.

  Further, the link member 26 is formed in a straight line having a predetermined length, and circular pin ends 26a and 26b have pin holes 18d in the other end 18c of the rocker arm 18 and the end 23 of the swing cam 20, respectively. , 23a, and pin insertion holes 26c and 26d through which end portions of the pins 28 and 29 are rotatably inserted are formed. In addition, snap rings 30, 31, and 32 that restrict the axial movement of the link arm 25 and the link member 26 are provided at one end of each pin 21, 28, and 29.

  In the above configuration, the valve lift amount changes as shown in FIGS. 6 and 7 depending on the positional relationship between the axis P2 of the control shaft 16 and the axis P1 of the control cam 17, and the control shaft 16 is rotated. By driving, the position of the axis P2 of the control shaft 16 with respect to the axis P1 of the control cam 17 is changed.

  The control shaft 16 is rotationally driven within a predetermined rotational angle range by a DC servo motor (actuator) 121 with the configuration shown in FIG. 10, and the angle of the control shaft 16 is adjusted by the actuator 121. By changing it, the valve operating angle of the intake valve 105 continuously changes with the valve lift amount (see FIG. 9).

In FIG. 10, the DC servo motor 121 is arranged so that the rotation shaft thereof is parallel to the control shaft 16, and a bevel gear 122 is pivotally supported at the tip of the rotation shaft.
On the other hand, a pair of stays 123a and 123b are fixed to the tip of the control shaft 16, and a nut 124 is swingably supported around an axis parallel to the control shaft 16 connecting the tips of the pair of stays 123a and 123b. The

  A bevel gear 126 meshed with the bevel gear 122 is pivotally supported at the tip of the screw rod 125 meshed with the nut 124, and the screw rod 125 is rotated by the rotation of the DC servo motor 121. The position of the nut 124 that meshes with the 125 is displaced in the axial direction of the screw rod 125 so that the control shaft 16 is rotated.

  Here, the direction in which the position of the nut 124 is brought closer to the bevel gear 126 is the direction in which the valve operating angle (valve lift amount) is reduced, and conversely, the direction in which the position of the nut 124 is moved away from the bevel gear 126 is the valve operating angle ( The valve lift amount is increasing.

  As shown in FIG. 10, an angle sensor 127 for detecting the angular position AP of the control shaft 16 is provided at the tip of the control shaft 16, and the actual angular position detected by the angle sensor 127 is the target angle. The engine control unit 114 feedback-controls the energization operation amount of the DC servo motor 121 so as to match the position.

  Note that the structure of the variable valve lift mechanism (VEL) 112 that makes the valve operating angle and the valve lift amount of the intake valve 105 variable is not limited to the above structure, and various known structures can be appropriately employed. it can.

FIG. 11 shows the structure of the variable valve timing mechanism (VTC) 113.
The variable valve timing mechanism 113 of this embodiment is a hydraulic mechanism, and is fixed to the cam sprocket 51 (timing sprocket) rotated by a crankshaft 120 via a timing chain and the end of the intake camshaft 13 and cams. A rotation member 53 rotatably accommodated in the sprocket 51, a hydraulic circuit 54 for rotating the rotation member 53 relative to the cam sprocket 51, and a relative rotation position of the cam sprocket 51 and the rotation member 53 are determined in advance. And a lock mechanism 60 that selectively locks in position.

  The cam sprocket 51 includes a rotating part (not shown) having a tooth part meshed with a timing chain (or timing belt) on the outer periphery, and a housing that is disposed in front of the rotating part and rotatably accommodates the rotating member 53. 56, and a front cover and a rear cover (not shown) for closing the front and rear openings of the housing 56.

  The housing 56 has a cylindrical shape in which both front and rear ends are formed, and four partition wall portions 63 having a trapezoidal shape in cross section protrude on the inner peripheral surface at intervals of 90 ° along the circumferential direction of the housing 56. It is installed.

  The rotating member 53 is fixed to the front end portion of the intake camshaft 13, and four vanes 78 a, 78 b, 78 c, 78 d are provided on the outer peripheral surface of the annular base 77 at 90 ° intervals.

  Each of the first to fourth vanes 78a to 78d has a substantially inverted trapezoidal cross section, and is disposed in a recess between the partition walls 63. The recesses are separated from each other in the rotational direction, and the vanes 78a to 78d. An advance side hydraulic chamber 82 and a retard side hydraulic chamber 83 are formed between both sides and both side surfaces of each partition wall 63.

The lock mechanism 60 is configured such that the lock pin 84 engages with an engagement hole (not shown) at the rotation position (reference operation state) on the maximum retard angle side of the rotation member 53.
The hydraulic circuit 54 includes two systems, a first hydraulic passage 91 that supplies and discharges hydraulic pressure to the advance side hydraulic chamber 82 and a second hydraulic passage 92 that supplies and discharges hydraulic pressure to the retard side hydraulic chamber 83. These hydraulic passages 91 and 92 are connected to a supply passage 93 and drain passages 94a and 94b through passage switching electromagnetic switching valves 95, respectively.

  The supply passage 93 is provided with an engine-driven oil pump 97 that pumps oil in the oil pan 96, while the downstream ends of the drain passages 94 a and 94 b communicate with the oil pan 96.

  The first hydraulic passage 91 is connected to four branch passages 91 d that are formed substantially radially in the base 77 of the rotating member 53 and communicate with the advance-side hydraulic chambers 82. It is connected to four oil holes 92 d that open to the retard side hydraulic chamber 83.

The electromagnetic switching valve 95 is configured such that an internal spool valve body relatively switches and controls the hydraulic passages 91 and 92, the supply passage 93, and the drain passages 94a and 94b.
The ECU 114 changes the rotational phase of the intake camshaft 13 with respect to the crankshaft 120 by controlling the energization amount to the electromagnetic actuator 99 that drives the electromagnetic switching valve 95 based on the duty control signal. Advancing and retarding the center phase of the operating angle.

  For example, when a control signal (OFF signal) with an on-duty of 0% is output to the electromagnetic actuator 99, the hydraulic oil pressure-fed from the oil pump 47 is supplied to the retard-side hydraulic chamber 83 through the second hydraulic passage 92. At the same time, the hydraulic oil in the advance side hydraulic chamber 82 is discharged from the first drain passage 94 a into the oil pan 96 through the first hydraulic passage 91.

  Therefore, the internal pressure of the retard side hydraulic chamber 83 is high and the internal pressure of the advance side hydraulic chamber 82 is low, and the rotating member 53 rotates to the maximum retard side via the vanes 78a to 78b. The center phase of the valve operating angle of the intake valve 105 is retarded.

  On the other hand, when a 100% on-duty control signal (ON signal) is output to the electromagnetic actuator 99, the hydraulic oil is supplied into the advance side hydraulic chamber 82 through the first hydraulic passage 91 and the retard side hydraulic pressure is supplied. The hydraulic oil in the chamber 83 is discharged to the oil pan 96 through the second hydraulic passage 92 and the second drain passage 94b, and the retard side hydraulic chamber 83 becomes low pressure.

For this reason, the rotating member 53 rotates to the maximum advance side via the vanes 78a to 78d, and thereby the central phase of the valve operating angle of the intake valve 105 is advanced.
In this manner, the phase of the intake camshaft 13 with respect to the crankshaft 120 continuously changes from the most retarded position to the most advanced position within the range in which the vanes 78a to 78d can relatively rotate within the housing 56, The central phase of the operating angle of the valve 105 changes continuously.

  As the variable valve timing mechanism 113, in addition to the mechanism using hydraulic pressure as described above, brake torque is applied to the camshaft as disclosed in JP2003-129806A and JP2001-241339A. A variable valve timing mechanism using an electric motor as a drive source as disclosed in JP 2007-262914 A may be used.

FIG. 12 is a diagram showing details of the hydraulic unit 202 in the brake hydraulic circuit (brake device).
The hydraulic unit 202 shown in FIG. 12 is provided with two independent master cylinder pressure supply pipes 2001A and 2001B connected from the master cylinder 203 to the wheel cylinders 204 and 205 of the left and right front wheels FR and FL, respectively.

The master cylinder pressure supply pipes 2001A and 2001B are respectively provided with shutoff valves 2002A and 2002B.
In addition, a pump 2004 (second hydraulic pressure generating means) driven by a motor 2003 is provided. The pump 2004 sucks brake fluid in the reservoir tank 2018 from the suction port, and boosts and discharges the sucked brake fluid. .

Here, the hydraulic pressure discharged from the pump 2004 is referred to as pump-up pressure (second hydraulic pressure).
A discharge port of the pump 2004 and one port of IN valves 2005A to 2005D for controlling supply of pump-up pressure to the wheel cylinders 204, 205, 206, and 207 are connected by a pump-up pressure supply pipe 2006. Yes.

  The pump-up pressure supply pipe 2006 is branched into two on the downstream side of the discharge port of the pump 2004, and the branched pipe is further branched into two and connected to one port of each of the IN valves 2005A to 2005D. Is done.

  On the downstream side of the first branch point X of the pump-up pressure supply pipe 2006, mechanical check valves (one-way valves) 2007A and 2007B that allow only the flow toward the IN valves 2005A to 2005D are interposed. ing.

  The other ports of the IN valves 2005A to 2005D and one port of the OUT valves 2020A to 2020D that control the relief of the hydraulic pressure from the wheel cylinders 204, 205, 206, and 207 are respectively connected to the first supply / discharge piping 2008A. Connected by ~ 2008D.

The other ports of the OUT valves 2020 </ b> A to 2020 </ b> D are connected to a reservoir pipe 2009 that connects the pump 2004 suction port and the reservoir tank 2018.
Further, second supply / exhaust pipes 2010A, 2010B are provided for connecting the middle of the first supply / discharge pipes 2008A, 2008B and the master cylinder pressure supply pipes 2001A, 2001B downstream of the shutoff valves 2002A, 2002B, respectively. .

  In addition, pump-up pressure supply / discharge piping 2011A and 2011B that connect the middle of supply / discharge piping 2008C and 2008D and the wheel cylinders 206 and 207 of the left and right rear wheels RR and RL are provided.

  In addition, a relief pipe 2012 that connects the pump-up pressure supply pipe 2006 immediately after the discharge port of the pump 2004 and the reservoir pipe 2009 just before the suction port of the pump 2004 is provided, and the relief pipe 2012 includes: A mechanical relief valve 2013 is provided that opens when the hydraulic pressure on the pump discharge side exceeds the set pressure.

  The shut-off valves 2002A and 2002B and the OUT valves 2020C and 2020D are solenoid valves that are energized in the valve opening direction by a spring and are closed by energization of the electromagnetic coil. The IN valves 2005A to 2005D and the OUT valve 2020A. , 2020B is an electromagnetic valve that is urged in the valve closing direction by a spring and opens when the electromagnetic coil is energized.

  The wheel cylinders 204, 205, 206, and 207 are respectively provided with wheel cylinder pressure sensors 2015A to 2015D for detecting wheel cylinder pressure, and detection signals (wheel cylinder pressure signals) of the wheel cylinder pressure sensors 2015A to 2015D are provided. ) Is input to the brake control unit 201.

  In the above configuration, there is no path for supplying the master cylinder pressure to the wheel cylinders 206 and 207 of the left and right rear wheels RR and RL, and the wheel cylinders 206 and 207 of the rear wheels RR and RL are not provided. Is supplied with a pump-up pressure (second hydraulic pressure) generated by the pump 2004.

  In the non-energized state of the IN valves 2005C and 2005D and the OUT valves 2020C and 2020D for controlling the supply and discharge of the pump up pressure to the wheel cylinders 206 and 207, the IN valves 2005C and 2005D are closed, and the OUT valves 2020C and 2020D are opened. Become.

  In this case, the pump up pressure from the pump 2004 is blocked by the IN valves 2005C and 2005D, while the OUT valves 2020C and 2020D are in an open state, so that the wheel cylinders 206 and 207 and the reservoir tank 2018 are connected to the OUT valve 2020C. , 2020D and the hydraulic pressure of the wheel cylinders 206, 207 is relieved to the reservoir tank 2018, and the hydraulic pressure of the wheel cylinders 206, 207 (wheel cylinder pressure) is reduced.

  On the other hand, in the energized state of the IN valves 2005C and 2005D and the OUT valves 2020C and 2020D, the IN valves 2005C and 2005D are opened, and the OUT valves 2020C and 2020D are closed.

  In this case, the pump up pressure from the pump 2004 is supplied to the wheel cylinders 206 and 207 via the IN valves 2005C and 2005D and the pump up pressure supply / discharge piping 2011A and 2011B, while the wheel cylinders 206 and 207 and the reservoir tank are supplied. Since the connection with 2018 is interrupted by the OUT valves 2020C and 2020D, the hydraulic pressure (wheel cylinder pressure) of the wheel cylinders 206 and 207 increases.

  Further, when the IN valves 2005C and 2005D are de-energized and the OUT valves 2020C and 2020D are energized, the IN valves 2005C and 2005D are closed and the OUT valves 2020C and 2020D are also closed. Since the supply of the pump-up pressure to is stopped and the relief from the wheel cylinders 206 and 207 is also stopped, the wheel cylinder pressure is maintained.

  Therefore, by controlling the energization / non-energization of the IN valves 2005C and 2005D and the OUT valves 2020C and 2020D, the hydraulic pressure (wheel cylinder pressure) of the wheel cylinders 206 and 207 of the rear wheels RR and RL can be controlled.

On the other hand, the master cylinder pressure and the pump-up pressure can be supplied to the wheel cylinders 204 and 205 of the left and right front wheels FR and FL, respectively.
That is, when the IN valves 2005A and 2005B and the OUT valves 2020A and 2020B are not energized, the IN valves 2005A and 2005B and the OUT valves 2020A and 2020B are both closed. At this time, the shutoff valves 2002A and 2002B are also de-energized. Then, the master cylinder pressure is supplied to the wheel cylinders 204 and 205.

  On the other hand, if the shutoff valves 2002A and 2002B are energized, the shutoff valves 2002A and 2002B are closed, and the supply of the master cylinder pressure to the wheel cylinders 204 and 205 is cut off.

  When the OUT valves 2020A and 2020B are de-energized and the IN valves 2005A and 2005B are energized in the energized state (closed state) of the shut-off valves 2002A and 2002B, the OUT valves 2020A and 2020B are closed and the IN valve 2005A , 2005B is opened, so that the pump-up pressure is supplied to the wheel cylinders 204, 205.

  Further, when the shutoff valves 2002A and 2002B are energized (closed state), when the IN valves 2005A and 2005B are deenergized and the OUT valves 2020A and 2020B are energized, the IN valves 2005A and 2005B are closed, and the OUT valve The pump-up pressure is released from the wheel cylinders 204 and 205 by opening the valves 2020A and 2020B.

  Further, if the IN valves 2005A and 2005B and the OUT valves 2020A and 2020B are deenergized while the shutoff valves 2002A and 2002B are energized (closed state), the supply of pump-up pressure to the wheel cylinders 204 and 205 is stopped. In addition, the relief from the wheel cylinders 204 and 205 is stopped, so that the wheel cylinder pressure is maintained.

  Accordingly, the energization / non-energization of the IN valves 2005A and 2005B and the OUT valves 2020A and 2020B is controlled in the energized state (closed state) of the shutoff valves 2002A and 2002B, so that the wheel cylinders 204 and 205 of the front wheels FR and FL are controlled. The hydraulic pressure (wheel cylinder pressure) can be controlled.

  The brake control unit 201 obtains a target (required braking force) of the wheel cylinder pressure, and, for the front wheels FR and FL, a master cylinder obtained by the master back 132a boosting the brake operating force at a predetermined boost ratio. It is set as a value corresponding to the pressure, and the rear wheels RR and RL are set to values lower than the targets of the front wheels FR and FL.

  For the rear wheels RR and RL, the IN valve 2005C and 2005D and the OUT valve 2020C and 2020D are controlled so that the actual wheel cylinder pressure approaches the target, thereby supplying pump-up pressure and maintaining the wheel cylinder pressure.・ Controls relief of wheel cylinder pressure.

  On the other hand, for the front wheels FR and FL that require a higher braking force than the rear wheels, before the boost limit point where the master back 132a does not boost the brake operating force at a predetermined boost ratio, the master cylinder Pressure (first hydraulic pressure) is supplied to the wheel cylinders 204 and 205, and after the boost limit point, the supply of the master cylinder pressure is cut off, and instead pump-up pressure is supplied to the wheel cylinders 204 and 205, The wheel cylinder pressure (brake hydraulic pressure) corresponding to the boost ratio is obtained even after the boost limit point.

  That is, in the braking force control of the front wheels FR, FL, in the region where the master back 132a boosts the brake operation force with a predetermined boost ratio and the required braking force is smaller than the threshold value, the braking force is increased by the master cylinder pressure. In a region where the required braking force is greater than or equal to the threshold value, the supply of the master cylinder pressure is cut off, and for a request for a higher braking force, the wheel cylinder pressure is increased by supplying the pump-up pressure.

The control function of the brake control unit 201 for switching from the master cylinder pressure to the pump-up pressure corresponds to the hydraulic pressure supply means.
The boost limit point can be detected as the time when the ratio between the master cylinder pressure and the depression force (brake operating force F) of the brake pedal 131 is sequentially calculated and the ratio changes compared to the previous value.

  FIG. 13 shows the correlation between the master cylinder pressure and the depression force (brake operating force F) of the brake pedal 131 for each negative pressure (booster negative pressure) BNP in the negative pressure chamber of the master back 132a.

  After the boost limit point, the master cylinder pressure is lower than the brake hydraulic pressure PWC corresponding to the boost ratio, so that the pump hydraulic pressure is supplied to obtain the brake hydraulic pressure PWC. As shown in FIG. In addition, when the booster negative pressure BNP is small (when the pressure in the negative pressure chamber of the master back 132a is high), the boost limit point is lowered, so that it is required to switch to the pump-up pressure at an early stage.

  In particular, when sudden braking is requested, the target wheel cylinder pressure after switching from the start of braking to the timing for switching from the master cylinder pressure to the pump-up pressure (boost limit point) and switching to the pump-up pressure is shortened. The increase in the change becomes faster.

  Therefore, in order to make the actual wheel cylinder pressure follow the change of the target wheel cylinder pressure with good response even when the sudden braking is requested from the state where the booster negative pressure BNP is small, the capacity (discharge flow rate) of the pump 2004 is reduced. It is required to use a large one.

However, if the large-capacity pump 2004 is used, the pump becomes larger, the weight becomes heavier, and the cost becomes higher.
Therefore, in this embodiment, standby control in which a pump up pressure is generated by driving the pump 2004 in advance in preparation for the next braking from before the occurrence of a braking request (before the brake pedal is depressed) is established. By executing it occasionally, the desired response can be obtained even if the capacity of the pump 2004 is reduced, and the standby control will be described in detail below.

  As described above, the function as the standby control means in the present embodiment is provided as software by the brake control unit 201 as shown in the flowchart of FIG.

The flowchart in FIG. 14 shows a routine for performing execution determination of the standby control, and this routine is interrupted and executed every certain minute time.
First, in step S501, the vehicle speed VSP, the engine speed NE, the master cylinder pressure MCP, the stroke amount BS of the brake pedal 131 (the amount of depression of the brake pedal), the negative pressure (booster negative pressure) BNP in the negative pressure chamber of the master back 132a. For example, a signal indicating the state of the vehicle / engine / brake device is read.

  In step S502, whether or not the negative pressure (booster negative pressure) BNP in the negative pressure chamber of the master back 132a is smaller than a predetermined value (1), in other words, the pressure in the negative pressure chamber of the master back 132a is a predetermined value ( It is determined whether it is higher than 1).

  In the present application, the negative pressure is shown as a negative pressure when the atmospheric pressure is set to 0 mmHg, and a large negative pressure means that the absolute value of the negative pressure shown as a negative value is large and is more than the atmospheric pressure. It shall indicate a low state.

  The predetermined value (1) is a pressure (negative pressure) lower than the atmospheric pressure, and the vehicle is decelerated at a predetermined deceleration (for example, about 1 G) by generating the master cylinder pressure MCP by a standard brake pedal operation. As a value capable of generating a braking force, it is previously adapted by experiment or simulation.

  When it is determined in step S502 that the negative pressure in the negative pressure chamber of the master back 132a is equal to or higher than the predetermined value (1) (when it is determined that the pressure is lower than the predetermined value (1)), the master It is determined that the boost limit point in the back 132a is sufficiently high, and the process proceeds to step S510.

In step S510, control (standby control) that drives the pump 2004 (motor 2003) and waits in a pump-up pressure generation state when non-braking is requested is prohibited.
That is, when the boost limit point in the master back 132a is high, the time from the start of braking until reaching the boost limit point becomes longer. If the drive of the pump 2004 is started from the start of braking, Can be increased, and this makes it possible to supply the pump-up pressure following the increasing change in the required braking force.

  Therefore, it is not necessary to drive the pump 2004 from the time of non-braking request, and prohibiting the standby control in step S510 causes the pump 2004 to be driven unnecessarily at the time of non-braking request and wastes power. Can be suppressed.

  On the other hand, the negative pressure in the negative pressure chamber of the master back 132a is less than the predetermined value (1) (the negative pressure chamber pressure (booster negative pressure) BNP in the master back 132a is closer to the atmospheric pressure than the predetermined value (1)). If a request for sudden deceleration (rapid braking) is generated in this state, the pump up pressure is switched to an earlier stage by a lower boost limit point. If driven, there is a possibility that the brake pressure cannot be raised with good response by the pump-up pressure.

  Accordingly, when it is determined in step S502 that the pressure (booster negative pressure) BNP in the negative pressure chamber of the master back 132a is closer to the atmospheric pressure than the predetermined value (1), the process proceeds to step S503 and subsequent steps, and the standby control is performed. Determine whether there is a need for.

In step S503, it is determined whether or not the shift position of the automatic transmission 181 is a parking range (P range).
If the shift position is in the P range, it is assumed that the driver does not intend to travel at the present time, and therefore no sudden braking request is generated, and the process proceeds to step S510, and standby control is prohibited.

As a result, driving of the pump 2004 in a state in which no braking request is expected is avoided, and power consumption due to unnecessary pump driving can be suppressed.
When the vehicle is in the reverse range (R range), the general vehicle speed is low even if the vehicle is traveling backward, and when the vehicle is traveling in the neutral range (N range), Therefore, since slow deceleration is required, and sudden braking is rarely required halfway, if any of the P range, R range, and N range, the process proceeds to step S510, and standby control is performed. Can be banned.

  On the other hand, if it is determined in step S503 that the shift position of the automatic transmission 181 is not in the P range, in other words, if it is a forward range such as a drive range (D range), the process proceeds to step S504.

  When a manual transmission is combined as a transmission, when the shift position is in the neutral range (N range), it is considered that a sudden braking request is not generated, and the process proceeds to step S510 and standby control is prohibited. Further, when the clutch pedal is depressed, the process proceeds to step S510 as in the case of the neutral range (N range), and standby control can be prohibited.

  In step S504, it is determined whether or not it is a braking request based on whether or not the stroke amount BS of the brake pedal 131 (the amount of depression of the brake pedal) and the depression force F are equal to or greater than a threshold value.

  If it is time to request braking, the process proceeds to step S510, and standby control, which is control prepared for braking in the non-braking state, is prohibited. If it is time to request non-braking, the process proceeds to step S505.

Note that it is possible to determine whether or not it is a braking request based on whether the brake switch is on or off.
If the brake request is requested and the process proceeds to step S510, the pump 2004 is driven from the time when the brake request is generated, or the pump 2004 is driven after the required brake force becomes equal to or greater than the threshold value.

  Further, when the master cylinder pressure is supplied to the wheel cylinder when braking is requested and the master back negative pressure is small, the pump 2004 is driven at a relatively low discharge pressure as in the standby control, The discharge pressure of the pump 2004 can be increased to the target value at the time of braking when the pump up pressure is switched to the condition for supplying the wheel cylinder (boost limit point).

In step S505, it is determined whether or not the vehicle speed VSP at that time is higher than a predetermined value (2).
If the vehicle speed VSP is higher than the predetermined value (2), the process proceeds to step S506. If the vehicle speed VSP is equal to or less than the predetermined value (2), it is determined that standby control is unnecessary, and the process proceeds to step S510.

  When the vehicle speed VSP is low, the demand for braking force is small. Therefore, even if the boost limit point in the master back 132a is low, the demand for boosting the brake fluid pressure by the pump-up pressure is low. Judge that it is enough after being done.

  The predetermined value (2) is a predetermined value even if the pump 2004 is started after a braking request is generated in a state where the negative pressure in the negative pressure chamber of the master back 132a is smaller than the predetermined value (1). It is set near the maximum vehicle speed VSP at which deceleration can be obtained.

Accordingly, the predetermined value (2) can be set to a lower vehicle speed as the pressure in the negative pressure chamber of the master back 132a is higher (as the negative pressure in the negative pressure chamber is smaller).
In step S506, it is determined whether or not the accelerator opening APO is less than a predetermined value (3).

  If the accelerator opening APO is equal to or greater than the predetermined value (3), it is determined that the driver does not intend to decelerate, and the process proceeds to step S510, standby control is prohibited, and the accelerator opening APO is determined to be a predetermined value (3). ), The process proceeds to step S507.

  That is, when the accelerator opening APO is equal to or greater than the predetermined value (3), at least the current state does not immediately shift to the sudden deceleration state, and the standby control is started later without performing the standby control from the current time. Thus, it is determined that the pump-up pressure can be generated before the actual deceleration operation, and the process proceeds to step S510, and standby control is prohibited.

  Therefore, whether or not the predetermined value (3) can be shifted to the pump-up pressure generation state within the time from when the accelerator pedal is depressed to when the brake pedal is switched to when the braking force is generated. The higher the opening is set, the longer it takes to shift to the pump-up pressure generation state.

  When it is determined in step S506 that the accelerator opening APO is less than the predetermined value (3) and the process proceeds to step S507, the unit time per unit time obtained by subtracting the previous value of a predetermined time from the current value of the accelerator opening APO. It is determined whether or not the change amount ΔAPO of (ΔAPO = current value APO−previous value APO) is equal to or greater than a predetermined value (4).

  That is, even when the accelerator opening APO is less than the predetermined value (3), the accelerator opening APO is increasing and changing, or even when the accelerator opening APO is decreasing, the changing speed is slow. Therefore, it can be determined that the driver does not intend to decelerate and the standby control is unnecessary.

  Therefore, a value equal to or greater than 0 is set as the predetermined value (4) so that the driver's intention to decelerate can be determined, so that the state where the accelerator opening APO is constant or increasing is determined. Alternatively, a negative value adapted to an absolute value so as not to include a case where the accelerator is intended to be decelerated is not set as the predetermined value (4), and the accelerator opening APO is constant or increased. It is made to judge the state which has changed slightly.

  If it is determined in step S507 that the amount of change ΔAPO is greater than or equal to the predetermined value (4), it is determined that the driver does not intend to decelerate, and the process proceeds to step S510 to prohibit standby control. If the change amount ΔAPO is less than the predetermined value (4), it is determined that the driver has an intention to decelerate (at least there is no intention to accelerate), and the process proceeds to step S508.

  In step S508, it is determined whether or not the temperature TM of the motor 2003 that rotationally drives the pump 2004 detected by the motor temperature sensor 215 is less than a predetermined value (5).

  The predetermined value (5) is set based on the allowable temperature of the motor 2004 (pump system). When the temperature TM of the motor 2003 is equal to or higher than the predetermined value (5), the motor temperature TM is further increased. In order to reduce the temperature and to lower the temperature, the process proceeds to step S510 to prohibit the standby control.

  If the process proceeds to step S508, it is originally a condition that the standby control should be executed. Therefore, if the motor temperature is high and the standby control cannot be executed, an engine intake negative pressure is used as an alternative measure. Can be controlled.

  For example, in the system in which the intake air amount is controlled by changing the opening characteristics such as the closing timing of the intake valve 105 and the valve lift amount while the throttle valve is opened near the fully open position as in this embodiment, the intake air A higher intake negative pressure can be generated by fixing the opening characteristic of the valve 105 to a reference value and switching to intake air amount control by a throttle valve.

  When the lean air-fuel operation is performed in which the engine air-fuel ratio is set to lean and the throttle opening is increased to increase the intake air amount to generate the required torque, the air-fuel ratio is made rich (for example, the theory By switching to the air-fuel ratio) and by reducing the throttle opening accordingly, a higher intake negative pressure can be generated.

  On the other hand, if the temperature TM of the motor 2003 is less than the predetermined value (5), it is determined that the temperature condition allows the motor 2003 to be permitted, and the process proceeds to step S509 to perform standby control.

  In the above-described embodiment, the standby control is executed when all the conditions of Steps S502 to S508 are satisfied. For example, when the non-braking is requested (the brake pedal is not depressed), the master back When the negative pressure (booster negative pressure) BNP of the negative pressure chamber 132a is small, the standby control is executed, and the non-braking and negative pressure conditions include the shift position, the vehicle speed VSP, the accelerator opening APO, and the motor temperature. One or more can be combined, and standby control can be executed when the condition is satisfied.

  As described above, it is possible to prevent the pump 2004 from being driven unnecessarily by determining whether the brake request is generated or not, and whether the brake force is required to exceed a predetermined level. Power consumption due to the driving of 2004 can be suppressed.

  Further, when the motor temperature is high, the motor 2003 is driven by the standby control, so that the motor temperature can be prevented from exceeding the allowable temperature, and the motor 2003 can be protected under a high temperature condition.

Next, the details of the standby control in step S509 will be described with reference to the flowchart of FIG.
In step S601, the reference command hydraulic pressure (pump drive amount) of the pump-up pressure in the standby state is set according to the vehicle speed VSP at that time.

When the vehicle speed VSP is high, there is a high possibility that a large braking force is required. Therefore, the reference command hydraulic pressure is increased as the vehicle speed VSP is increased.
Note that the command hydraulic pressure set in step S601 is set to a value lower than that at the time of braking when the pump-up pressure is supplied to the wheel cylinder, and suppresses power consumption and temperature rise of the motor 2003 during non-braking (standby state). On the other hand, when braking is started, the pressure can be increased with good response up to the command hydraulic pressure during braking.

In step S602, it is determined whether or not the occurrence frequency of high deceleration G (rapid deceleration) is high, that is, whether or not there is a high possibility that rapid deceleration is frequently performed.
When the possibility of frequent rapid deceleration is high, the process proceeds to step S603 to correct the pump-up pressure in the standby state higher than when the possibility of rapid deceleration is low. The reference command hydraulic pressure set in S601 is corrected to increase, and then the process proceeds to step S604, and the correction result in step S603 is determined as the final command hydraulic pressure.

  On the other hand, if it is not a condition where the possibility of frequent rapid deceleration is high, the process bypasses step S603 and proceeds to step S604, and the reference command hydraulic pressure set in step S601 is directly determined as the final command hydraulic pressure. To do.

  The pump detects the pressure in the pump-up pressure supply pipe 2006 between the pump 2004 and the check valves (one-way valves) 2007A and 2007B so that the actual pump-up pressure becomes the final command hydraulic pressure. Based on the detected pressure of the up pressure sensor 216 and the final command hydraulic pressure, the energization amount of the motor 2003 (drive amount of the pump 2004) is feedback-controlled.

  It is desired that the command hydraulic pressure be as low as possible within a range where a desired response can be obtained as a response to boosting the brake hydraulic pressure by the pump-up pressure, thereby reducing power consumption in the motor 2003 in the standby state. be able to.

  The standby control is a control that is performed when a non-braking request is required (the brake pedal is not depressed). Since the IN valves 2005A to 2005D are held in the closed state, they are generated by the standby control. The pump-up pressure is supplied to the wheel cylinders 204 to 207 so that no braking force is generated.

  However, if the pump 2004 is driven in advance to generate a pump-up pressure when non-braking is requested, a negative pressure (booster negative pressure) BNP in the negative pressure chamber of the master back 132a is small, so that a braking request is generated. When a request to switch from the master cylinder pressure to the pump-up pressure at an early stage occurs, the brake fluid pressure can be quickly raised by supplying the pump-up pressure, thereby generating a desired braking force with good response. be able to.

  When driving the pump 2004 after the braking request is generated, in order to increase the pump up pressure with good response, it is necessary to provide the pump 2004 with a large capacity. If the pump 2004 is driven to generate the pump-up pressure, the pump capacity requirement is reduced, and a pump having a small capacity can be used.

  If the pump capacity can be reduced, the size of the pump 2004 can be reduced, the weight of the pump 2004 can be reduced, the unit cost of the pump 2004 can be kept low, and the inrush current at the start of the motor 2003 can be reduced. As a result, the capacity of the elements of the drive circuit and the fuse can be reduced.

  In addition, a pump having a relatively small capacity can be used as the pump 2004 while ensuring responsiveness by always driving the pump 2004 in a non-braking request state. In this case, however, the pump 2004 is always driven. It is necessary to use a pump with durability, and the power consumption of the motor 2003 using the battery as a power source increases, and the fuel efficiency of the engine decreases due to the battery charging.

  In contrast, in the present embodiment, the standby control is executed only when a condition such as a high pressure in the negative pressure chamber of the master back 132a (low negative pressure) is established, and therefore the pump 2004 is driven unnecessarily. This can suppress the decrease in fuel efficiency.

  In addition, in the correction setting of the command hydraulic pressure according to the frequency of occurrence of the high deceleration G in step S603, the higher the possibility that the rapid deceleration is frequently performed, the larger the increase in the reference command hydraulic pressure is. Conversely, when the possibility of sudden deceleration is small, the reference command hydraulic pressure can be corrected to decrease.

Here, the determination process of the occurrence frequency of the high deceleration G (rapid deceleration) in the step S602 will be described in detail according to the flowchart of FIG.
In step S701, it is determined from the engine rotational speed NE, the accelerator opening APO, the shift frequency, and the like whether or not the vehicle is in a sport running state.

  That is, from the history of the engine speed NE, the operating ratio in the high engine speed range or the maximum value of the engine engine speed NE in the past predetermined period is judged. When the speed is high, it can be determined that the vehicle is in a sports driving state.

  Similarly, from the history of the accelerator opening APO, the operation ratio in the high accelerator opening range in the past predetermined period, the maximum value of the accelerator opening, the change rate of the accelerator opening, etc. are judged, and the high accelerator opening range It is possible to determine that the vehicle is in the sport running state when the driving ratio at is high, when the maximum value of the accelerator opening is high, or when the changing speed of the accelerator opening is high on average.

Further, the frequency of shifting the shift position by the shift lever is determined, and when these shift frequencies are high, it can be determined that the vehicle is in the sport running state.
Further, when a sports mode in which the timing of upshifting is shifted to a higher vehicle speed side is selected as the automatic shift mode, it can be determined that the sports running state is set.

Further, it is possible to determine the sports running state from the change in the vehicle speed VSP, the front / rear G / lateral G of the vehicle, the steering speed, and the like.
Further, whether or not the vehicle is in a sports running state can be determined from a sports mode switch operated by the driver.

  As described above, when it is determined that the driving state is a sporting state in which rapid acceleration / deceleration is performed by the driver's intention, the occurrence frequency of the high deceleration G is high, so the process proceeds to step S603, where the reference command liquid The pressure increase correction is performed.

On the other hand, if it is determined in step S701 that the vehicle is not in a sport running state, the process proceeds to step S702.
Even if it is determined that the vehicle is not in the sport running state from the engine rotational speed NE, the accelerator opening APO, the shift frequency, etc. It is preferable to carry out an increase correction of the reference command hydraulic pressure while maintaining the above.

This is because sports travel is based on the driver's intention, and it may be temporarily impossible to perform sports travel against the driver's intention.
In step S702, it is determined whether the driver's field of view is good.

  When the driver's visibility is poor, that is, when driving at night or when the visibility is hindered by weather conditions such as rain, snow, fog, sand, etc., obstacle recognition in the direction of travel of the vehicle Since (discovery) is delayed, there is a high possibility that sudden braking will be performed. Therefore, the process proceeds to step S603, and increase correction of the reference command hydraulic pressure is performed.

  Here, whether the driver ’s visibility is good or bad (judgment such as driving at night, weather, etc.) is determined based on the analysis of the images taken by the in-vehicle camera, lighting of the headlight / fog lamp, raindrop sensor Judgment can be made from signals, wiper operation, weather information and road traffic information received from the outside, detection results by in-vehicle radar, and the like.

  In addition, since weather conditions such as rain and fog may repeat strength and weakness, if it is determined that the driver's field of view is poor, even if the view is switched to a good field of view, the final period of poor visibility will be It is preferable to maintain the determination and to perform an increase correction of the reference command hydraulic pressure.

On the other hand, if it is determined that the driver's field of view is good, the process proceeds to step S703, and a quick braking request for avoiding a collision with an obstacle ahead of the vehicle is determined.
Specifically, obstacles in the vehicle traveling direction (previous) are analyzed based on analysis of images taken by the in-vehicle camera, detection results by in-vehicle radar, road traffic information received from the outside, vehicle position information by GPS, etc. And the like, and whether or not rapid braking is required for collision avoidance based on the current vehicle speed and the distance to the obstacle.

When it is determined that there is a high possibility that sudden braking is required for avoiding a collision, the process proceeds to step S603, and the reference command hydraulic pressure is increased.
If there is no obstacle ahead and there is a low possibility of sudden braking for avoiding a collision, the process proceeds to step S704 after the obstacle is avoided and passed.

In step S704, it is determined from the position information of the vehicle using the GPS, road traffic information, or the like whether there is an intersection or an accident-prone point in the traveling direction of the vehicle.
If there are intersections and accident-prone points in the traveling direction of the vehicle, it is considered that the frequency of sudden braking (high deceleration G) is higher than in the case where there are no intersections or accident-prone points, so proceed to step S607. Increase correction of the reference command hydraulic pressure is performed.

  On the other hand, when there is no intersection or frequent accident point in the traveling direction of the vehicle, since the frequency of sudden braking (high deceleration G) is low, the process proceeds to step S604, bypassing step S603, and set in step S601. The reference command hydraulic pressure is determined as it is as the final command hydraulic pressure.

  In other words, when it is determined whether sports driving, poor visibility, collision avoidance, intersection or accident occurrence point, it is determined that the frequency of sudden braking (high deceleration G) is high, and the reference command hydraulic pressure is increased. If it is not a sport run, poor visibility, collision avoidance, intersection or accident occurrence point, it is determined that the frequency of sudden braking (high deceleration G) is low and the reference command hydraulic pressure is finalized as it is Command pressure

  In addition, when the vehicle is traveling on a downward slope, if the slope is steep, the frequency of sudden braking (high deceleration G) is expected to increase. In this case, the reference command hydraulic pressure can be increased and corrected, and the steep downhill traveling state can be determined from the position information of the vehicle and the detection result of the inclination sensor.

The flowchart of FIG. 17 shows a second embodiment of standby control that replaces the standby control shown in the flowchart of FIG.
In step S801, vehicle speed VSP, engine rotation speed NE, master cylinder pressure MCP, stroke amount BS of brake pedal 131 (depression amount of brake pedal), negative pressure (booster negative pressure) BNP in the negative pressure chamber of master back 132a, etc. Information indicating the state of the vehicle, engine, and brake device is read.

In the next step S802, it is determined whether or not the negative pressure in the negative pressure chamber of the master back 132a is equal to or greater than a predetermined value (1).
Here, the predetermined value (1) is the same value as the predetermined value (1) in step S502 and is a pressure (negative pressure) lower than the atmospheric pressure, and the master cylinder pressure MCP by standard brake pedal operation is As a value that can generate a braking force that decelerates the vehicle at a predetermined deceleration (for example, about 1 G) by the generation, it is adapted in advance by experiments and simulations.

  When the negative pressure in the negative pressure chamber of the master back 132a is smaller than the predetermined value (1) (when the pressure in the negative pressure chamber of the master back 132a is closer to the atmospheric pressure than the predetermined value (1)). Since the boost limit point of the master back 132a is lowered and high responsiveness is required by boosting by the pump-up pressure, the pump 2004 is driven in advance in preparation for boosting by the pump-up pressure (pump-up pressure is reduced). In step S806, standby control is performed.

The details of the standby control in step S806 are as shown in the flowcharts of FIGS.
On the other hand, the negative pressure in the negative pressure chamber of the master back 132a is not less than a predetermined value (1) (the pressure in the negative pressure chamber is lower than the predetermined value (1)), and the negative pressure stored in the master back 132a is When the boost limit point of the master back 132a is high and the pump 2004 is driven after the braking request is generated, the pump up pressure after the boost limit point can be boosted with good response. Determines that standby control is not required under the negative pressure condition, and proceeds to step S803.

  In step S803, it is determined whether the lateral acceleration (lateral G) of the vehicle is greater than or equal to a predetermined value, thereby determining whether the lateral G is generated (turning state of the vehicle). If this occurs (the turning state of the vehicle), the process proceeds to step S806 to perform standby control.

  When the process proceeds to step S803, a sufficient negative pressure is stored in the master back 132a, and even if the pump 2004 is driven after the braking request is generated, the pressure increase by the pump up pressure after the boost limit point is responsive. Although it can be performed, the occurrence of lateral G indicates the feasibility of vehicle behavior control (VDC).

  With the vehicle behavior control, when the vehicle is likely to cause a side slip or a tail swing due to an emergency avoidance of a slippery road surface or an obstacle, the occurrence of a side slip or a tail swing is suppressed by brake control and engine output control, This is a control for improving the stability of the vehicle. In the brake control in the vehicle behavior control, a braking force is generated by the pump-up pressure.

  Therefore, if there is a possibility that the lateral G is generated and the brake control may be performed by the vehicle behavior control, the vehicle is kept waiting in a state where the pump-up pressure is generated in advance, and the brake control by the vehicle behavior control is performed. The braking force can be generated with good response.

  When pumping pressure is generated after a braking force is generated by vehicle behavior control, a pump with a large capacity (large maximum discharge amount) is used to generate pumping pressure with good response. Although it is necessary, if the pump up pressure is generated in advance by predicting the execution of the vehicle behavior control in the state where the lateral G is generated, the responsiveness of the brake hydraulic pressure control is ensured even if a relatively small pump is used. it can.

  If the pump capacity can be reduced, the pump can be downsized, the weight of the pump can be reduced, and the pump cost can be reduced. In addition, the inrush current at the start of the motor can be reduced, thereby reducing the capacity of the drive circuit elements and fuses. Can be small.

  If it is determined in step S803 that there is no lateral G, the process proceeds to step S804, and it is determined whether or not a motor operation start request (a pressure increase request due to pump-up pressure) is expected.

The state in which the motor operation start request is expected indicates, for example, a case where any of the following conditions is satisfied.
(A) The negative pressure in the master back 132a is used for boosting and is reduced to a predetermined value or less.

(B) The negative pressure in the master back 132a is used for boosting, and the negative pressure reduction rate is faster than a predetermined value.
(C) The deceleration of the vehicle (the reduction speed of the vehicle speed) is increasing.

(D) The change in the deceleration of the vehicle is large.
If it is determined in step S804 that motor operation is expected, the process proceeds to step S806 and standby control is performed.

As a result, the pump 2004 can be driven before the pressurization of the pump-up pressure is actually started, and the pump-up pressure can be increased with good response.
In addition to the above conditions, the expectation of a motor operation start request (pump up pressure request) is the brake pedal stroke, master cylinder pressure, vehicle speed, intake negative pressure, master back negative pressure, accelerator opening, etc. It can also be judged from.

  Also, if the motor 2003 cannot be operated because the temperature of the motor 2003 has reached an operation prohibition temperature or the like, the necessary master back negative pressure is set to satisfy the deceleration request without increasing the pump-up pressure. It is possible to take measures such as controlling the engine as a negative pressure source so that it is generated or increasing the regeneration amount in a vehicle equipped with a regenerative brake.

  FIG. 18 is a time chart showing the pump-up pressure when the standby control is executed together with the master cylinder pressure, the master back negative pressure, the intake negative pressure, the brake operation amount, the accelerator opening, and the like.

  In the example shown in FIG. 18, the brake pedal is released by releasing the foot from the accelerator pedal and stepping on the brake pedal at time t1 to boost the brake operating force by the boosting action of the master back 132a to generate the master cylinder pressure. .

  At time t2, when the foot is once released from the brake pedal, the master cylinder negative pressure, which has been on a downward trend, starts to rise due to the introduction of the intake negative pressure. However, when the brake pedal is depressed again at time t3, After the cylinder negative pressure decreases again, the cylinder negative pressure is held constant at the position where the brake pedal is depressed, and this time, it shows an upward trend.

  However, at time t4 when the master back negative pressure is not sufficiently recovered, the brake pedal is switched to the accelerator pedal, and the intake negative pressure becomes smaller than the master back negative pressure (the intake pressure is lower than the master back pressure). As a result, the master back negative pressure is kept constant while the accelerator pedal is depressed.

  When the master back negative pressure during depression of the accelerator pedal (during non-braking) is less than a predetermined value, standby control is performed in which the pump 2004 is driven in advance for the next braking.

  At time t5, the accelerator pedal is switched to the brake pedal. However, when the brake pedal is depressed while the master back negative pressure is low, the boost limit point L of the master back 132a is reached immediately. Therefore, switching from the master cylinder pressure to the pump up pressure is required.

  However, in the present embodiment, as described above, the pump 2004 is driven in advance and waits in the pump-up pressure generation state, so even if the pump capacity is small compared to the case where the pump-up pressure is not in standby state, The pump-up pressure can be raised to the required pressure with good response.

  On the other hand, when the standby control is not performed, the pump 2004 is not driven while the accelerator pedal is being depressed before the time t5 (during non-braking), and the driving of the pump 2004 is started after the time t5. become.

  Therefore, even when the time from the time t5 to the boost limit point L is short, the pump 2004 having a large capacity is used in order to increase the pump-up pressure after the boost limit point L without a response delay. Need to do.

  As the pump capacity increases, the size of the pump increases, the weight of the pump increases, the pump cost increases, and the inrush current at the start of the motor that drives the pump increases. It is necessary to increase the capacity.

In the example shown in FIG. 18, when the master cylinder negative pressure is small even during braking, the pump is driven to generate the pump-up pressure.
At time t6, since the master cylinder pressure has caught up with the target wheel cylinder pressure, the pump up pressure is switched to the master cylinder pressure.

  In the above embodiment, the system is such that the pump cylinder pressure is supplied to the wheel cylinders of the rear wheels without supplying the master cylinder pressure, but the master cylinder pressure is supplied to the wheel cylinders of the front wheels and the rear wheels. After reaching the boost limit point L of the master back 132a, the above standby control is applied to the system in which the pump-up pressure is applied to the wheel cylinders of the front wheels and the rear wheels. Obtainable.

Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) In the control device for a vehicle brake device according to any one of claims 1 to 3,
The control device for a vehicle brake device, wherein the standby control means sets the drive amount of the pump at the time of non-braking request based on prediction of the occurrence frequency of sudden braking.

According to such a configuration, it is possible to suppress unnecessary driving of the pump, and it is possible to suppress a decrease in fuel consumption performance.
(B) In the control device for a vehicle brake device according to claim (a),
The control device for a vehicle brake device, wherein the standby control means predicts an occurrence frequency of sudden braking based on at least one of weather, an obstacle, and road traffic information.

  According to this configuration, it is possible to accurately predict the frequency of sudden braking by predicting the frequency of sudden braking based on at least one of weather, obstacles, and road traffic information. It is possible to suppress driving and suppress a decrease in fuel consumption performance.

  DESCRIPTION OF SYMBOLS 101 ... Internal combustion engine, 112 ... Variable valve lift mechanism (VEL), 113 ... Variable valve timing mechanism (VTC), 114 ... Engine control unit (ECU), 115 ... Air flow sensor, 116 ... Accelerator pedal sensor, 117 ... Crank angle sensor 118 ... Throttle sensor, 131 ... Brake pedal, 132a ... Master back (negative pressure boosting means), 132b ... Negative pressure sensor (negative pressure detecting means), 201 ... Brake control unit (BCU), 202 ... Hydraulic unit, 203 ... master cylinder (first hydraulic pressure generating means), 204 to 207 ... wheel cylinder, 208 ... brake pedal sensor, 209 ... hydraulic pressure sensor, 217 ... operating force sensor, 2002A, 2002B ... shut-off valve, 2003 ... motor, 2004 ... Pump (second hydraulic pressure generating means) 2005A~2005D ... IN valves, 2020A~2020D ... OUT valves, 2015A~2015D ... wheel cylinder pressure sensor

Claims (4)

A negative pressure type booster that boosts the brake operating force using negative pressure;
First hydraulic pressure generating means for generating a first hydraulic pressure in response to a brake operating force boosted by the negative pressure boosting means;
Second fluid pressure generating means for generating a second fluid pressure by a pump;
A control device applied to a vehicle brake device including:
Hydraulic pressure supply means for switching from the first hydraulic pressure to the second hydraulic pressure to supply the wheel cylinder of the wheel in response to an increase in the required braking force;
Negative pressure detecting means for detecting the negative pressure of the negative pressure boosting means;
Standby control means for driving the pump and waiting in the state of generation of the second hydraulic pressure when the negative pressure of the negative pressure boosting means is less than a predetermined negative pressure at the time of non-braking request;
A control device for a brake device for a vehicle, comprising:   The state where the negative pressure of the negative pressure type boosting means in the standby control means is less than a predetermined negative pressure is a state where a predetermined deceleration cannot be generated when a braking request is generated. The control device for a vehicle brake device according to claim 1.   The standby control means is a case where the negative pressure of the negative pressure type boosting means is less than a predetermined negative pressure at the time of non-braking request, and the shift position, vehicle speed, accelerator opening, accelerator opening of the transmission 2. The pump is driven to stand by in a state where the second hydraulic pressure is generated when at least one of a change and a temperature of a motor driving the pump satisfies a predetermined standby execution condition. Or the control apparatus of the brake device for vehicles of 2.   The standby control means sets the drive amount of the pump at the time of non-braking request according to at least one of vehicle speed, engine rotation speed, accelerator opening, accelerator opening change, and shift frequency. The control device for a vehicle brake device according to any one of claims 1 to 3.

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