JP4501553B2 - Vehicle braking force control device - Google Patents

Description

  The present invention relates to a vehicle braking force control device, and more particularly, to a vehicle braking force control device that includes a braking force generation device that generates a braking force by pressing a pressing member against a pressed member of a wheel. Related to the device.

  As one of braking force control devices for vehicles such as automobiles, as described in the following Patent Document 1 relating to the application of the applicant of the present application, wheel cylinders provided on each wheel, and the detected traveling state of the vehicle A braking force control device having a hydraulic control device for controlling supply / discharge of high pressure hydraulic pressure from a hydraulic pressure generation source to the wheel cylinder and increasing / decreasing the hydraulic pressure in the wheel cylinder according to a traveling state when Necessary and sufficient for behavior control by detecting or estimating the lateral force acting on the wheel and changing the pressure increase time so that the pressure increase time by the hydraulic control device becomes longer as the lateral force at the start of pressure increase by the hydraulic control device is larger 2. Description of the Related Art A braking force control device configured to increase rapidly to a certain pressure has been conventionally known.

According to such a braking force control device, the pressure increase time is changed so that the pressure increase time by the hydraulic control device becomes longer as the lateral force at the time of pressure increase start by the hydraulic control device becomes larger. The pressure in the wheel cylinder is suddenly increased so that the oil amount exceeds the dead zone region, thereby reliably preventing the behavior control response from deteriorating due to knockback.
JP-A-8-80824

  However, the braking force control device according to the above proposal improves the response of the behavior control due to the knockback by improving the increase of the braking force at the start of the behavior control. It is impossible to solve the delay of the braking force generation due to the knockback in the engine.

  In the braking force control device according to the above proposal, it is assumed that the hydraulic circuit of the braking device is normally a hydraulic circuit in which wheel cylinders of left and right wheels or diagonal wheels are connected to each other. In addition, there is a problem that the braking force control device according to the above proposal cannot be applied to a vehicle having a general hydraulic circuit in which left and right wheel or diagonal wheel cylinders are not connected to each other.

  Further, generally, a gap between a pressed member such as a brake disk of a wheel and a pressing member such as a brake pad pressed against the wheel due to a knocking back, that is, a lateral force acting on the wheel during turning of the vehicle or the like. The phenomenon in which the braking force increases is more noticeable on the outer wheel side than on the inner wheel side. Therefore, the delay in braking force generation due to knockback during normal braking is different between the left and right wheels. Although the vehicle may be deflected due to the difference in braking force between the left and right wheels at the start of braking, such a problem cannot be solved by the braking force control device according to the above proposal.

The present invention has been made in view of the conventional problems such as the in above the braking force control apparatus for a vehicle, the main object of the present invention, lateral force when high lateral forces on the wheels acts the in the situation of reduced after increasing Rukoto to reduce the gap between the pressing member is pressed member and the pressing contrast of at least the turning outer wheel, the braking due to the subsequent in knock-back during normal braking This is to reduce the deflection of the vehicle due to the delay in power generation and the difference in braking force between the left and right wheels.

The main problem described above is that according to the present invention, the braking force is increased and the braking force is generated by pressing the pressing member against the pressed member of the wheel. In the power control device, an index value of the vehicle lateral force is obtained, and at least the braking pressure of the turning outer wheel is set to a predetermined value in a situation where the vehicle is in a turning state and the index value of the vehicle lateral force decreases after exceeding a peak value. Thus it is achieved a braking force control apparatus for a vehicle, characterized in that pressure increase in the pressure (the first aspect).

  According to the present invention, in order to effectively achieve the above-mentioned main problems, in the configuration of claim 1, the predetermined pressure is high when the peak value of the vehicle lateral force index value is high. The lateral force index value is configured to be higher than when the peak value is low (configuration of claim 2).

  Further, according to the present invention, in order to effectively achieve the above-described main problems, in the configuration of claim 1 or 2, the predetermined pressure is higher when the vehicle speed is higher than when the vehicle speed is low. (Structure of claim 3).

According to the present invention, in order to effectively achieve the main problems described above, in the configuration according to any one of claims 1 to 3 , the turning outer wheel may be requested by a request other than the increase in the braking pressure. When the braking force or the driving force is applied, the increase of the braking pressure is stopped (configuration of claim 4).

  Further, according to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 4, the request other than the increase in the braking pressure is a passenger braking request, a passenger acceleration request, A braking / driving force control request for wheel slip suppression and a braking / driving force control request for vehicle running stabilization control are included (configuration of claim 5).

According to the present invention, in order to effectively achieve the main problems described above, in the configuration according to any one of claims 1 to 5 , when a change in a predetermined traveling state occurs in the vehicle, The brake pressure increase is stopped (structure of claim 6).

  According to the present invention, in order to effectively achieve the above main problem, in the configuration of claim 6, the change in the predetermined traveling state is an increase of a vehicle deceleration more than a predetermined value or an occupant's The wheel speed is configured not to be based on the driving operation but to decrease or exceed a predetermined value, or to be in a drift-out state greater than a predetermined value.

According to the present invention, in order to effectively achieve the above main problems, in the configuration according to any one of claims 1 to 7, the braking pressure is increased during the braking pressure increase. A driving force is applied to wheels other than the wheel where the pressure is applied, and the influence of the increase in the braking pressure on the running state of the vehicle is reduced (configuration of claim 8).

According to this configuration 1, the braking pressure of at least turning outer wheel at a situation where the index value of the vehicle lateral force vehicle is a turning state is lowered past the peak value is boosted to a predetermined pressure In addition, at least the gap between the pressed member of the turning outer ring and the pressing member pressed against it is reliably reduced, thereby reliably reducing the delay in braking force generation caused by knockback during normal braking thereafter. In addition, it is possible to effectively reduce the deflection of the vehicle due to the difference in braking force between the left and right wheels at the start of braking.
In a situation where the index value of the vehicle lateral force decreases beyond the peak value, in other words, the braking pressure is increased to a predetermined pressure when the gap between the pressed member and the pressing member no longer increases. Therefore, compared with the case where the braking pressure is increased before the vehicle lateral force index value exceeds the peak value, the predetermined pressure can be lowered and the braking pressure increasing time can be shortened. As a result, the possibility of the vehicle being unnecessarily decelerated and the possibility of the vehicle being deflected can be reliably reduced, and the gap between the pressed member and the pressing member can be effectively and reliably reduced. it can.

  In general, the degree of knockback becomes more pronounced as the vehicle lateral force increases and the lateral force acting on the wheels increases. According to the configuration of the second aspect, the predetermined pressure is higher when the peak value of the vehicle lateral force index value is higher than when the peak value of the vehicle lateral force index value is low. Depending on the degree of turning, the brake pressure is increased without excess or deficiency, and the braking force is delayed due to knockback or the braking force difference between the left and right wheels at the start of braking. It is possible to appropriately suppress the deflection of the vehicle caused by the above, and it is possible to reliably reduce the braking pressure being increased unnecessarily high and the change in the vehicle speed caused thereby.

  In general, the adverse effect of knockback becomes more pronounced as the vehicle speed increases. According to the configuration of the third aspect, since the predetermined pressure is higher when the vehicle speed is high than when the vehicle speed is low, the predetermined pressure is variably set according to the degree of the adverse effect of the knockback, thereby increasing the vehicle speed. Regardless of excess or deficiency, it is possible to increase the brake pressure increase appropriately, and to appropriately suppress the delay of the braking force generation caused by knockback and the vehicle deflection caused by the difference in braking force between the left and right wheels at the start of braking. In addition, the braking pressure can be increased unnecessarily high and the change in the vehicle speed caused by this can be reliably reduced.

  According to the fourth aspect of the present invention, when the braking force or the driving force is applied to the turning outer wheel due to a request other than the increase of the braking pressure, the increase of the braking pressure is stopped. It is possible to reliably prevent the braking force or the driving force from being applied to any of the wheels due to the request or the request from being satisfied.

  According to the configuration of claim 5, requests other than the increase in braking pressure are a passenger braking request, a passenger acceleration request, a braking / driving force control request for suppressing wheel slip, and a vehicle running stabilization control. The braking / driving force control request for occupant braking, the accelerating request for occupant, the braking / driving force control request for suppressing wheel slip, and the braking / driving force control request for vehicle running stabilization control are ensured. Can be satisfied.

  According to the configuration of the sixth aspect, since the increase of the braking pressure is stopped when a change in the predetermined traveling state occurs in the vehicle, the traveling state of the vehicle is increased by the increase of the braking pressure for suppressing the knockback. It is possible to reliably prevent an excessive adverse effect.

  According to the above configuration, the change in the predetermined traveling state is an increase in the vehicle deceleration greater than a predetermined value, a decrease in the wheel speed that is not based on the driving operation of the occupant, or a drift out greater than the predetermined value. Therefore, it is possible to reliably prevent the vehicle deceleration from being increased excessively, the wheel speed being excessively adversely affected, and the vehicle from being excessively drifted out by increasing the braking pressure for suppressing knockback. be able to.

  According to the configuration of the eighth aspect, the driving force is applied to the wheels other than the wheel where the braking pressure is increased during the increase of the braking pressure, and the influence of the increased braking pressure on the running state of the vehicle is affected. Therefore, the influence of the increase in the braking pressure on the running state of the vehicle can be reliably reduced.

[Preferred embodiment of problem solving means]
According to one preferable aspect of the present invention, in the structure of the above first to seventh aspects, the braking pressure of the turning outer front wheel is increased to a predetermined pressure (Preferable aspect 1).

  According to another preferred embodiment of the present invention, in the configuration of claim 1 or claims 4 to 7, the predetermined pressure is configured to be a constant value (preferred embodiment 2).

According to the aspect of the present invention, in the configuration of the claims 1 to 8, the index value of the vehicle lateral force is configured to be a lateral acceleration of the vehicle (preferred embodiment 3).

  According to another preferred aspect of the present invention, in the configuration of the first to seventh aspects, the braking pressure is not increased when the index value of the vehicle lateral force is equal to or less than the reference value. (Preferred aspect 4)

  According to another preferred aspect of the present invention, in the configuration of claim 3, the peak value of the vehicle speed when the vehicle is turning is obtained, and when the peak value of the vehicle speed is high, the peak value of the vehicle speed is low. It is comprised so that a predetermined | prescribed pressure may be made high compared with (preferable aspect 5).

  According to another preferred aspect of the present invention, in the configuration of claim 8, the increase amount of the driving force is obtained based on the increase amount of the braking pressure (preferred aspect 6).

  According to another preferred aspect of the present invention, in the configuration of claim 8, the vehicle is a rear-wheel drive vehicle or a four-wheel drive vehicle, and the braking pressure of the turning outer front wheel is increased to a predetermined pressure. The driving force is applied to the left and right rear wheels (preferred aspect 7).

  According to another preferred aspect of the present invention, in the configuration of claim 8, the vehicle has an independent driving device for each wheel, and the braking pressure of the front outer wheel is increased to a predetermined pressure. It is comprised so that a driving force may be provided to the turning outer rear wheel (preferred aspect 8).

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing a first embodiment of a vehicle braking force control apparatus according to the present invention applied to a rear wheel drive vehicle.

  In FIG. 1, 10FL and 10FR respectively indicate the left and right front wheels of the vehicle 12 as driven wheels, and 10RL and 10RR respectively indicate the left and right wheels of the vehicle driven by the engine not shown in the drawing through the drive system. The rear wheel is shown. The left and right front wheels 10FL and 10FR, which are steered wheels, are steered via tie rods 18L and 18R by a rack and pinion type power steering device 16 that is driven in response to turning of the steering wheel 14 by the driver.

  The braking force of each wheel is controlled by controlling the braking pressure of the wheel cylinders 24FR, 24FL, 24RR, 24RL of the braking force generator by the hydraulic circuit 22 of the braking device 20. Although not shown in FIG. 1, the braking force generator includes a brake disk as a pressed member of a wheel and brake pads as pressing members disposed on both sides thereof, and wheel cylinders 24FR, 24FL, 24RR. When the braking pressure of 24RL is increased, the brake pad is pressed against the brake disc, thereby generating a braking force according to the braking pressure.

  As will be described later, the hydraulic circuit 22 includes an oil reservoir, an oil pump, various valve devices, etc., and the braking pressure of each wheel cylinder is electronically controlled as will be described in detail later according to the depression operation of the brake pedal 26 by the driver during normal times. It is controlled by the control device 30. The braking force control device of the present invention is very effective when the braking force generator is an opposing caliper type braking force generator. In the illustrated embodiment, at least the braking force generators for the left and right front wheels are opposed calipers. For example, a drum-type braking force generator may be used.

  As shown in detail in FIG. 2, the braking device 20 includes a master cylinder 28 that pressure-feeds brake oil in response to a driver's depressing operation of the brake pedal 26. A dry stroke simulator 116 is provided between the brake pedal 26 and the master cylinder 28.

  The master cylinder 28 has a first master cylinder chamber 28A and a second master cylinder chamber 28B, and these master cylinder chambers have a brake hydraulic pressure supply conduit 118 for the left front wheel and a brake hydraulic pressure control conduit for the right front wheel, respectively. One end of 120 is connected. Wheel cylinders 122FL and 122FR for controlling the braking force of the left front wheel and the right front wheel are connected to the other ends of the brake hydraulic pressure control conduits 118 and 120, respectively.

  In the middle of the brake hydraulic pressure supply pipes 118 and 120, normally open type electromagnetic on / off valves (master cut valves) 124L and 124R are provided, respectively. The electromagnetic on / off valves 124L and 124R are respectively connected to the first master cylinder chamber 28A and the second master cylinder chamber 28A. It functions as a shut-off valve that controls communication between the master cylinder chamber 28B and the corresponding wheel cylinders 24FL and 24FR. In addition, a wet stroke simulator 128 is connected to a brake hydraulic pressure supply conduit 118 between the master cylinder 28 and the electromagnetic opening / closing valve 124FL via a normally closed electromagnetic opening / closing valve 126.

  A reservoir 130 is connected to the master cylinder 28, and one end of a hydraulic pressure supply conduit 132 is connected to the reservoir 130. An oil pump 136 driven by an electric motor 134 is provided in the middle of the hydraulic supply conduit 132, and an accumulator 138 for accumulating high hydraulic pressure is connected to the hydraulic supply conduit 132 on the discharge side of the oil pump 136. One end of a hydraulic discharge conduit 140 is connected to the hydraulic supply conduit 132 between the reservoir 130 and the oil pump 136.

  Although not shown in FIG. 2, a conduit is provided to connect the suction-side hydraulic supply conduit 132 and the discharge-side hydraulic supply conduit 132 of the oil pump 136, and the accumulator 138 is disposed in the middle of the conduit. A relief valve is provided that opens when the pressure exceeds a reference value and returns oil from the discharge-side hydraulic supply conduit 132 to the suction-side hydraulic supply conduit 132.

  The hydraulic supply conduit 132 on the discharge side of the oil pump 136 is connected to the brake hydraulic supply conduit 118 between the electromagnetic on-off valve 124L and the wheel cylinder 24FL by the hydraulic control conduit 142, and the electromagnetic on-off valve 124R and the wheel by the hydraulic control conduit 144. It is connected to the brake hydraulic pressure supply conduit 120 between the cylinder 24R, the hydraulic control conduit 146 to the left rear wheel wheel cylinder 24RL, and the hydraulic control conduit 148 to the right rear wheel wheel cylinder 24RR. .

  Normally closed electromagnetic linear valves 150FL, 150FR, 150RL and 150RR are provided in the middle of the hydraulic control conduits 142, 144, 146 and 148, respectively. The hydraulic control conduits 142, 144, 146, 148 on the side of the wheel cylinders 24FL, 24FR, 24RL, 24RR with respect to the linear valves 150FL, 150FR, 150RL, 150RR are connected to the hydraulic discharge conduits 140 by hydraulic control conduits 152, 154, 156, 158, respectively. In the middle of the hydraulic control conduits 152, 154, 156, 158, normally closed electromagnetic linear valves 160FL, 160FR, 160RL, 160RR are provided, respectively.

  The linear valves 150FL, 150FR, 150RL, and 150RR function as pressure increase valves (holding valves) for the wheel cylinders 24FL, 24FR, 24RL, and 24RR, respectively. The linear valves 160FL, 160FR, 160RL, and 160RR are wheel cylinders 24FL, 24FR, 24RL, and The linear valves function as a pressure reducing valve for 24RR, and thus constitute a pressure increasing / reducing control valve for controlling supply / discharge of high pressure oil to / from each wheel cylinder from the accumulator 138 in cooperation with each other.

  Thus, the electromagnetic on-off valve 126, the linear valves 150FL, 150FR, 150RL, and 150RR, the linear valves 160FL, 160FR, 160RL, and 160RR constitute the hydraulic circuit 22. Note that the electromagnetic on / off valves 124L and 124R are maintained in the open state during non-control when no drive current is supplied to the electromagnetic on / off valves, linear valves and motor 134, and the electromagnetic on / off valve 126, linear valves 150FL, 150FR, 150RL, 150RR, The linear valves 160FL, 160FR, 160RL, and 160RR are kept closed (non-control mode).

  As shown in FIG. 2, in the brake hydraulic pressure control conduit 118 between the first master cylinder chamber 28A and the electromagnetic on-off valve 124L, the pressure in the control conduit is detected as the first master cylinder pressure Pm1. One pressure sensor 66 is provided. Similarly, the brake pressure control conduit 120 between the second master cylinder chamber 28B and the electromagnetic on-off valve 124R is provided with a second pressure sensor 68 for detecting the pressure in the control conduit as the second master cylinder pressure Pm2. It has been. The brake pedal 26 is provided with a stroke sensor 70 for detecting a brake pedal depression stroke St by a driver, and a hydraulic pressure supply conduit 132 on the discharge side of the oil pump 134 detects a pressure in the conduit as an accumulator pressure Pa. A sensor 72 is provided.

  The brake hydraulic pressure supply pipes 118 and 120 between the electromagnetic opening / closing valves 124L and 124R and the wheel cylinders 24FL and 24FR respectively have the pressure in the corresponding pipes set to the pressure in the wheel cylinders 24FL and 24FR (braking pressure of the left and right front wheels) Pbfl. , Pressure sensors 74FL and 74FR for detecting Pbfr are provided. Further, in the hydraulic control conduits 146 and 148 between the electromagnetic on-off valves 150RL and 150RR and the wheel cylinders 24RL and 24RR, respectively, the pressure in the corresponding conduit is set to the pressure in the wheel cylinders 24RL and 24RR (braking pressure of the left and right rear wheels). Pressure sensors 74RL and 74RR that detect Pbrl and Pbrr are provided.

  The electromagnetic open / close valves 124L and 124R, the electromagnetic open / close valve 126, the electric motor 134, the linear valves 150FL, 150FR, 150RL, and 150RR, and the linear valves 160FL, 160FR, 160RL, and 160RR are controlled by the electronic control unit 30 as described in detail later. . Although not shown in detail in FIG. 1, the electronic control unit 30 includes a microcomputer and a drive circuit. The microcomputer includes, for example, a central processing unit (CPU), a read only memory (ROM), and a random access memory (ROM). RAM) and input / output port devices, which are connected to each other via a bidirectional common bus.

  The electronic control unit 30 includes a signal indicating the first master cylinder pressure Pm1 and the second master cylinder pressure Pm2 from the pressure sensors 66 and 68, a signal indicating the depression stroke St of the brake pedal 12 from the stroke sensor 70, and a pressure sensor. A signal indicating the accumulator pressure Pa is input from 72, and a signal indicating a signal indicating the pressure Pbi (i = fl, fr, rl, rr) in the wheel cylinders 24FL to 24RR is input from the pressure sensors 74FL to 74RR, respectively.

  The electronic control unit 30 also receives signals indicating the wheel speeds Vwi (i = fl, fr, rl, rr) of the left and right front wheels and the left and right rear wheels from the wheel speed sensor 76i (i = fl, fr, rl, rr), respectively. A signal indicating the vehicle longitudinal acceleration Gx and the vehicle lateral acceleration Gy is input from the longitudinal acceleration sensor 78 and the lateral acceleration sensor 80, respectively, and a signal indicating the vehicle yaw rate γ is input from the yaw rate sensor 82, and the steering angle sensor. A signal indicating the steering angle θ is input from 84.

  The electronic control unit 30 stores a control routine according to the flowcharts shown in FIGS. 2 to 6 as described later. For example, as described in Japanese Patent Application Laid-Open No. 2002-187537 of the above-mentioned Patent Document 2, the electronic control unit 30 The target deceleration Gpt of the vehicle is calculated from the map corresponding to the graph shown in FIG. 8 based on the average value Pm of the master cylinder pressures Pm1 and Pm2 detected by the sensors 66 and 68, and the depression detected by the stroke sensor 70 is calculated. Based on the stroke St, the vehicle target deceleration Gst is calculated from the map corresponding to the graph shown in FIG.

  Then, the electronic control unit 30 calculates a weight α (0 ≦ α ≦ 1) for the target deceleration Gst from the map corresponding to the graph shown in FIG. 9 based on the target deceleration Gpt, and the target deceleration Gpt and the target deceleration are calculated. The final target deceleration (driver's required deceleration) Gt is calculated as a weighted sum of the speeds Gst, and the basic target braking pressure Pbti (i = fl, fr, rl, rr) of each wheel is calculated based on the final target deceleration Gt. The target drive current Iti (i = fl, fr, rl, rr) for the linear valves 150FL to 150RR or 160FL to 160RR is calculated based on the deviation between the basic target brake pressure Pbti and the actual brake pressure Pbi, and the target drive The braking force of each wheel is controlled by controlling the braking pressure Pbi of each wheel to the target braking pressure Pbti by applying a driving current to each linear valve based on the current Iti.

  In this case, when the braking control mode is the pressure increasing mode, the electronic control unit 30 controls the valve opening amounts of the linear valves 150FL, 150FR, 150RL, and 150RR according to the target wheel cylinder pressure Pti, and the braking control mode is the pressure reducing mode. When the braking control mode is the holding mode, the linear valves 150FL to 150RR and 160FL to 160RR are closed when the opening amounts of the linear valves 160FL, 160FR, 160RL, and 160RR are controlled according to the target wheel cylinder pressure Pti. To maintain.

  The electronic control unit 30 controls the braking pressure Pi of each wheel to be the basic target braking pressure Pti during normal braking. However, the anti-skid control (ABS control), traction control (TRC control), or braking force control, which will be described later. When the target braking pressure Pti for behavior control by is calculated, the braking pressure of the wheel is controlled to become the target braking pressure Pti for each control.

  The electronic control unit 30 calculates the vehicle body speed Vb and the braking slip amount SBi (i = fl, fr, rl, rr) of each wheel based on the wheel speed Vwi of each wheel in a manner known in the art. When the braking slip amount SBi becomes larger than the reference value for starting the anti-skid control and the anti-skid control start condition is satisfied, the braking slip amount of the wheel falls within the predetermined range until the anti-skid control end condition is satisfied. The anti-skid control is performed by calculating the target braking pressure Pti (i = fl, fr, rl, rr) of the wheel in order to achieve the target braking pressure Pti to be the target braking pressure Pti.

  Also, the electronic control unit 30 calculates the vehicle body speed Vb and the acceleration slip amount SAi (i = fl, fr, rl, rr) of each wheel based on the wheel speed Vwi of each wheel in a manner known in the art. When the acceleration slip amount SAi becomes larger than the traction control start reference value and the traction control start condition is satisfied, the acceleration slip amount of the wheel is set within a predetermined range until the traction control end condition is satisfied. Traction control is performed by calculating a target braking pressure Pti (i = fl, fr, rl, rr) of the wheel and controlling the braking pressure Pi to be the target braking pressure Pti.

  The electronic control unit 30 also includes a spin state quantity SS indicating the degree of vehicle spin and a drift-out state quantity DS indicating the degree of vehicle drift-out based on the vehicle state quantity such as the lateral acceleration Gy of the vehicle that changes as the vehicle travels. And the target braking pressure Pti (i = fl, fr, rl, rr) for each wheel for stabilizing the behavior of the vehicle based on the spin state amount SS and the drift-out state amount DS is calculated. By controlling the braking pressure Pi to be equal to the target braking pressure Pti, behavior control is performed by controlling the braking force that stabilizes the behavior of the vehicle.

  The above-described behavior control by the anti-skid control, the traction control, and the braking force control itself does not form the gist of the present invention, and these controls are executed in any manner known in the art. In particular, particularly in anti-skid control and traction control, the braking pressure may be increased or decreased so that the slip ratio falls within a predetermined range.

  Further, the electronic control unit 30 calculates the peak values Gymax and Gymin of the lateral acceleration Gy of the vehicle according to the flowchart shown in FIG. 3, and determines the situation where the turning degree of the vehicle has passed the peak based on the peak values Gymax and Gymin. When the target pressure increase braking pressure Pcj (j = fl or fr) of the outer front wheel is calculated and the target pressure increase braking pressure Pcj is higher than the corresponding basic target brake pressure Pbtj, the brake pressure Pj of the front outer wheel is determined to be The braking pressure of the front outer wheel is increased until the target increased braking pressure Pcj is exceeded, and the brake pad is pressed against the brake disc, thereby ensuring a delay in braking force generation caused by knockback during normal braking. And the deflection of the vehicle due to the difference in braking force between the left and right wheels at the start of braking.

  Next, the main routine of the braking force control in the illustrated embodiment 1 will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 2 is started when the electronic control unit 30 is activated, and is repeatedly executed at predetermined time intervals until an ignition switch (not shown) is turned off.

  First, in step 50, a signal indicating the vehicle's lateral acceleration Gy detected by the lateral acceleration sensor 80 is read. In step 100, a later-described process is performed based on the depression stroke St and the master cylinder pressures Pm1, Pm2. The basic target braking pressure Pbti (i = fl, fr, rl, rr) of each wheel corresponding to the driver's braking operation amount is calculated according to the routine shown in FIG.

  In step 200, the peak values Gymax and Gymin of the lateral acceleration Gy of the vehicle are calculated according to the routine shown in FIG. 5 described later. In step 300, knockback is performed according to the routine shown in FIG. 6 described later. A target pressure-increasing braking pressure Pptfl or Pptfr for the front outer wheel for turning is calculated.

  In step 500, it is determined whether or not the target pressure increase braking pressure Pptfl or Pptfr of the front outer wheel is larger than the corresponding basic target braking pressure Pbtj (j = fl or fr), and a negative determination is made. In step 550, the target braking pressure Pti (i = fl, fr, rl, rr) of each wheel is set to the basic target braking pressure Pbti. If an affirmative determination is made, the left front wheel is If it is a turning front wheel, the left front wheel target braking pressure Ptfl is set to Pptfl. If the right front wheel is a turning outside front wheel, the right front wheel target braking pressure Ptfr is set to Pptfr and other wheels. The target braking pressure Pti is set to the basic target braking pressure Pbti, and when step 550 or 600 is completed, in step 650, the braking pressure Pi of each wheel is controlled to become the corresponding target braking pressure Pti.

  Next, the basic target braking pressure Pbti calculation routine executed in step 100 will be described with reference to the flowchart shown in FIG.

  First, at step 110, the target deceleration Gst of the vehicle is calculated from a map corresponding to the graph shown in FIG. 7 based on the depression stroke Sp of the brake pedal 26 detected by the stroke sensor 70. The average value Pma of the master cylinder pressures Pm1 and Pm2 detected by the pressure sensors 66 and 68 is calculated. In step 120, the average value Pma of the master cylinder pressures Pm1 and Pm2 is calculated in the graph shown in FIG. The target deceleration Gpt of the vehicle is calculated from the corresponding map.

In step 125, the weight α (0 ≦ α) for the target deceleration Gpt based on the master cylinder pressure Pm from the map corresponding to the graph shown in FIG. 9 based on the final target deceleration Gt calculated in the previous cycle. ≦ 1) is calculated, and in step 130, the final target deceleration Gt of the vehicle is calculated as a weighted sum of the target deceleration Gpt and the target deceleration Gst according to the following equation 1.
Gt = α · Gpt + (1−α) Gst (1)

In step 135, Ki (i = fl, fr, rl, rr) is used as a braking force distribution ratio (positive constant) for each wheel, and the basic target braking pressure Pbti (i = fl, fr, rl) for each wheel. , Rr) is calculated according to Equation 2 below.
Pbti = Ki ・ Gt (2)

  Next, the peak value Gymax and Gymin calculation routine executed in step 200 will be described with reference to the flowchart shown in FIG.

  First, in step 210, it is determined whether or not the absolute value of the lateral acceleration Gy of the vehicle is larger than a reference value Gyo (positive constant). If a negative determination is made, in step 215, the flag Fbrk is determined. After the value is reset to 0, the process proceeds to step 300. When an affirmative determination is made, the process proceeds to step 220.

  In step 220, it is determined whether or not the flag Fbrk is 0, that is, whether or not the increase of the braking pressure of the front outside wheel is prohibited. If the determination is negative, step 220 is performed. Proceed to 255, and if an affirmative determination is made, proceed to step 225.

  In step 225, it is determined whether or not the driver has performed an acceleration / deceleration operation by operating the brake pedal or the accelerator pedal. If an affirmative determination is made, the process proceeds to step 255 and a negative determination is made. Sometimes go to step 230. Whether the acceleration / deceleration operation (braking operation) by the brake pedal operation is performed is determined by, for example, the average value Pma of the master cylinder pressure being greater than or equal to the reference value Pmao (positive constant) or the depression stroke St of the brake pedal 26 May be performed by determining whether or not is greater than or equal to a reference value Sto (a positive constant). Whether the acceleration / deceleration operation by the accelerator pedal operation is being performed is determined by, for example, the absolute value of the differential value φd of the accelerator opening φ input from an engine control device not shown in FIG. It may be performed by determining whether or not it is greater than or equal to a positive constant).

  In step 230, it is determined whether the anti-skid control, the traction control, or the braking force control by the vehicle behavior control is being executed for the front outer wheel, and if an affirmative determination is made, the process proceeds to step 255. If a negative determination is made, the process proceeds to step 235.

  In step 235, it is determined whether or not the braking pressure increase control for the outer front wheel is being executed. If a negative determination is made, the process proceeds directly to step 260. If an affirmative determination is made, step 240 is performed. Proceed to

  In step 240, for example, by determining whether the differential value Vd of the vehicle speed V is less than or equal to the reference value Vdo (negative constant) or whether the vehicle longitudinal acceleration Gx is less than or equal to the reference value Gxo (negative constant), It is determined whether or not the vehicle speed decrease due to the increase of the braking pressure of the front wheel on the outside of the turn is large. If an affirmative determination is made, the process proceeds to step 255. If a negative determination is made, 245 is determined. Proceed to

  In step 245, for example, a determination is made as to whether or not the differential value of the wheel speed Vwfr or Vwfl of the front wheel outside the turn is equal to or less than the reference value Vwdo (negative constant). If the determination is affirmative, the process proceeds to step 255. If the determination is negative, the process proceeds to step 250.

  In step 250, it is determined whether or not the drift-out control is being executed as the behavior control by controlling the braking force. If an affirmative determination is made, the process proceeds to step 260, and if a negative determination is made, the step is performed. Proceed to 255.

  In step 255, for example, a reference yaw rate γt of the vehicle is calculated based on the vehicle speed V and the steering angle θ in a manner known in the art, and sign · (γt−γ ) Is greater than or equal to the reference value, it is determined whether or not the vehicle behavior change (drift-out state) is large. If a negative determination is made, the process proceeds to step 265, where affirmative When the determination is made, in step 260, the lateral acceleration peak values Gymax and Gymin of the vehicle are reset to 0, and the flag Fbrk is set to 1 before proceeding to step 300.

  In step 265, the vehicle lateral acceleration peak value Gymax is set to the larger value of the current lateral acceleration Gy of the vehicle and the previous value Gymaxf of the peak value Gymax, and the vehicle lateral acceleration peak value Gymin is set to the vehicle's lateral acceleration peak value Gymax. The current lateral acceleration Gy and the previous value Gyminf of the peak value Gymin are set to the smaller value, and then the routine proceeds to step 300.

  Next, a routine for calculating the target pressure-increasing braking pressure Pptj executed in step 300 will be described with reference to the flowchart shown in FIG.

  First, in step 310, K is set to a positive constant larger than 0 and smaller than 1, and it is determined whether or not the lateral acceleration Gy of the vehicle is smaller than K · Gymax, that is, the lateral acceleration Gy of the vehicle is a peak value Gymax. It is determined whether or not the vehicle is in a situation where the turning degree of the left turn of the vehicle is decreased. If a negative determination is made, the process proceeds to step 330. If an affirmative determination is made, the left is determined in step 320. The front wheel coefficient Kfl is set to 0, and the right front wheel coefficient Kfr is set to 1.

  Similarly, in step 330, it is determined whether or not the lateral acceleration Gy of the vehicle is greater than K · Gymin, that is, the vehicle's lateral acceleration Gy exceeds the peak value Gymin and the turning degree of the vehicle turning right decreases. It is determined whether or not the vehicle is in a situation. If an affirmative determination is made, the left front wheel coefficient Kfl is set to 1 and the right front wheel coefficient Kfr is set to 0 in step 340, so a negative determination is made. Is performed, the coefficients Kfr and Kfl are set to 0 in step 350, and then the routine proceeds to step 420.

In step 370, Fcfo is set as the basic pressure increase braking pressure (positive constant) of the front outer wheel, and the target pressure increase braking pressure Pcfr for the right front wheel and the target pressure increase brake pressure Pcfl for the left front wheel are expressed by the following equations 3 and 4 is calculated.
Pcfr = Kfr · Pcfo (3)
Pcfl = Kfl ・ Pcfo (4)

  In step 380, it is determined whether or not the braking pressure Pfr of the right front wheel is equal to or higher than the target increased braking pressure Pcfr. If an affirmative determination is made, in step 390, the coefficient Kfr and the peak of the lateral acceleration are determined. After the values Gymax are reset to 0, the process proceeds to step 400. When a negative determination is made, the process proceeds to step 400 as it is.

  In step 400, it is determined whether or not the braking pressure Pfl of the left front wheel is equal to or higher than the target increased braking pressure Pcfl. If a negative determination is made, the process proceeds to step 420 as it is, and an affirmative determination is made. In some cases, the coefficient Kfl and the vehicle lateral acceleration peak value Gymin are reset to 0 in step 410, and then the routine proceeds to step 420.

  In step 420, the target pressure increase braking pressure Pcfr and the left front wheel target pressure increase braking pressure Pcfl are calculated according to the above equations 3 and 4, respectively, and then the process proceeds to step 500.

  Thus, according to the first embodiment shown in the figure, in step 100, the basic target braking pressure Pbti (i = fl, fr, rl, rr) of each wheel is calculated based on the depression stroke St and the master cylinder pressures Pm1, Pm2. In step 200, the peak values Gymax and Gymin of the lateral acceleration Gy of the vehicle are calculated, and in step 300, it is determined based on the peak values Gymax and Gymin that the turning degree of the vehicle has passed the peak, and the vehicle When the degree of turning exceeds the peak, the target pressure increase braking pressure Pptfl or Pptfr for the front outer wheel for suppressing knockback is calculated, and the target pressure increase braking pressure Pcj corresponds in steps 500 to 650. When higher than the basic target braking pressure Pbtj, the braking pressure of the front outer wheel is increased until the braking pressure Pj of the outer front wheel becomes equal to or higher than the target increased braking pressure Pcj.

  Therefore, according to the first embodiment shown in the figure, when the vehicle turns with a large lateral force acting on the wheels, particularly on the outer front wheel, the degree of turning has passed the peak. In this case, the braking pressure Pfl or Pfr of the turning outer wheel is automatically increased to the target pressure-increasing braking pressure Pptfl or Pptfr, respectively, and the brake pad is pressed against the brake disc, thereby causing knockback in the subsequent braking. It is possible to surely reduce the delay in generating the braking force and reduce the deflection of the vehicle due to the difference in braking force between the left and right wheels at the start of braking.

  As shown in FIG. 10, steps 215 and 220 of the peak value calculation routine shown in FIG. 5 may be omitted, and the processing of the flag Fbrk in step 260 may be omitted (Modification 1). .

  FIGS. 11 and 12 respectively show a calculation routine for the peak values Gymax and Gymin and a calculation routine for the target boost braking pressure Pptj in the second embodiment of the vehicle braking force control apparatus according to the present invention applied to the rear wheel drive vehicle. It is a flowchart to show. In FIG. 11 and FIG. 12, the same steps as those shown in FIG. 5 and FIG. 6 are assigned the same step numbers as those shown in FIG. 5 and FIG.

  In the second embodiment, steps 210 to 255 of the routine for calculating the peak values Gymax and Gymin are executed in the same manner as in the first embodiment. In step 260, the peak value of the lateral acceleration of the vehicle is obtained. Gymax, Gymin, and the peak value Vmax of the vehicle speed are each reset to 0, and the flag Fbrk is set to 1.

  In step 265, the vehicle lateral acceleration peak value Gymax is set to the larger of the current lateral acceleration Gy of the vehicle and the previous value Gymaxf of the peak value Gymax, and the vehicle lateral acceleration peak value Gymin is set to the vehicle. The current lateral acceleration Gy and the previous value Gyminf of the peak value Gymin are set to the smaller value, and the vehicle speed peak value Vmax is set to the larger value of the current vehicle speed V and the previous value Vmaxf of the peak value Vmax. .

  Further, steps 310 to 340, 380, and 400 of the routine for calculating the target pressure-increasing braking pressure Pptj are executed in the same manner as in the first embodiment described above. In step 350, the coefficients Kfr and Kfl are set to zero. At the same time, the vehicle speed peak value Vmax is set to zero.

  When step 320 is completed, in step 360, the basic target pressure increase braking pressure Pcf is calculated from the map corresponding to the graph shown in FIG. 13 based on the absolute value of the vehicle lateral acceleration peak value Gymax and the vehicle speed peak value Vmax. When step 340 is completed, in step 365, based on the absolute value of the vehicle lateral acceleration peak value Gymin and the vehicle speed peak value Vmax, the basic target pressure increase braking pressure Pcf is calculated from the map corresponding to the graph shown in FIG. Is calculated.

In steps 370 and 420, the target pressure increase braking pressure Pcfl for the left front wheel and the target pressure increase braking pressure Pcfr for the right front wheel are calculated according to the following equations 5 and 6, respectively.
Pcfr = Kfr · Pcf (5)
Pcfl = Kfl ・ Pcf (6)

  In step 390, the coefficient Kfr, the lateral acceleration peak value Gymax, and the vehicle speed peak value Vmax are reset to 0. In step 410, the coefficient Kfl, the vehicle lateral acceleration peak value Gymin, and the vehicle speed peak value are reset. Vmax is reset to 0 respectively.

  Thus, according to the illustrated second embodiment, as in the first embodiment described above, when the vehicle has a large lateral force and the vehicle turns, with a high lateral force acting on the wheels, particularly the front outer wheels, the vehicle turns. In a situation where the turning degree has passed the peak, the braking pressure Pfl or Pfr of the turning outer wheel is automatically increased to the target boosting braking pressure Pptfl or Pptfr, respectively, and the brake pad is pressed against the brake disc, thereby Thus, it is possible to reliably reduce the delay in the generation of the braking force due to the knockback at the time of braking, and to reduce the deflection of the vehicle due to the braking force difference between the left and right wheels at the start of braking.

  In particular, according to the second embodiment shown in the figure, the target boost braking pressures Pptfl and Pptfr are variably set based on the absolute value of the lateral acceleration peak value Gymax or Gymin and the vehicle speed peak value Vmax, and the maximum lateral force during turning is set. The higher the value, the higher the value, so the target pressure boosting pressure Pptfl, Pptfr can be set to the optimum value according to the maximum lateral force during turning, and the target pressure increasing braking pressure Pptfl, Pptfr is constant. As compared with the case of the above-described first embodiment, the pressure increase of the front outer wheel is achieved without excess and deficiency, the delay of the braking force generation caused by the knockback is accurately reduced, and the left and right wheels at the start of braking It is possible to accurately reduce vehicle deflection caused by a difference in braking force between the two.

  In the second embodiment, as in the case of the first modification, steps 215 and 220 of the peak value calculation routine shown in FIG. 11 are omitted, and the processing of the flag Fbrk in step 260 is omitted. (Modification 2).

  In the illustrated embodiment 2, the target boost braking pressures Pptfl and Pptfr are variably set based on the absolute value of the lateral acceleration peak value Gymax or Gymin and the vehicle speed peak value Vmax. The target pressure-increasing braking pressures Pptfl and Pptfr are corrected so as to be variably set based on the absolute value of the lateral acceleration peak value Gymax or Gymin by being calculated from the map corresponding to the graph shown in FIG. Well (Modification 3), even if the target pressure-increasing braking pressures Pptfl and Pptfr are calculated from a map corresponding to the graph shown in FIG. 15 to be variably set based on the peak value Vmax of the vehicle speed. Good (Modification 4).

  FIG. 16 is a block diagram showing a control system of a third embodiment of the vehicle braking force control apparatus according to the present invention applied to a rear wheel drive vehicle, and FIG. 17 shows an increase in the braking pressure of the front outer wheel in the third embodiment. It is a flowchart which shows the calculation routine of the driving force of the vehicle accompanying control.

  In the third embodiment, the electronic control unit 30 communicates with the engine control unit 90, and the engine control unit 90 is operated by the driver from the accelerator opening sensor 92 as shown in FIG. A signal indicating the accelerator opening φ as an operation amount of the accelerator pedal that is not performed, a signal indicating the shift stage Sp of the automatic transmission not shown in FIG. 16 from the automatic transmission control device 94, the engine speed and so on Information necessary for engine control is input. The engine control device 90 calculates the target engine torque Tet based on the accelerator pedal operation by the driver based on the accelerator opening φ and the like in a manner known in the art, and the engine torque Te is normally set to the target engine torque Tet. The engine 96 is controlled so that

  In addition, the electronic control unit 30 increases the braking pressure of the front outer wheel as necessary during turning of the vehicle according to any of the above-described embodiments and modifications, thereby suppressing knockback and increasing the braking pressure of the front front wheel. When the pressure is applied, a target engine torque Tebt that reduces the effect of increasing the braking pressure of the front outer wheel is calculated according to the routine shown in FIG. 17 and a signal indicating the target engine torque Tebt is output to the engine control device 90. The engine control device 90 controls the engine 96 so that the engine torque Te becomes the target engine torque Tebt when a signal indicating the target engine torque Tebt is input from the electronic control device 30.

  Next, a routine for calculating the target engine torque Tebt in the illustrated third embodiment will be described with reference to the flowchart shown in FIG. Note that the control according to the flowchart shown in FIG. 17 is started when the electronic control unit 30 is activated, and is repeatedly executed at predetermined intervals until an ignition switch (not shown) is turned off.

  First, in step 710, it is determined whether or not the braking pressure of the front outer wheel is increased. When a negative determination is made, the control according to the routine shown in FIG. When a positive determination is made, in step 720, a signal indicating the target engine torque Tet and a signal indicating the shift stage Sp of the automatic transmission are read from the engine control device 90.

In step 730, the gear ratio Kg of the entire drive system is estimated based on the gear stage Sp of the automatic transmission, the cross-sectional areas of the left and right front wheel cylinders 24FR and 24FL are Awc, the brake friction coefficient is μb, With the effective tire diameter of the left and right front wheels as Rt and the effective diameter of the brake disc as Rb, an engine torque increase amount ΔTe for offsetting the influence of the increase in the braking pressure of the front outer wheel is calculated according to the following equation (7).
ΔTe = (Pcfr + Pcfl) · Awc · μb · Rt ² / Rb / Kg (7)

  In step 740, the target engine torque Tebt is calculated as the sum of the target engine torque Tet and the engine torque increase amount ΔTe, and a signal indicating the target engine torque Tebt is output to the engine controller 90.

  Thus, according to the illustrated third embodiment, the operational effects of the above-described embodiments or modifications can be obtained, and the engine torque increase amount ΔTe for offsetting the influence of the increase in the braking pressure of the front outer turning wheel can be obtained. Since the output torque of the engine 96 is increased, an unnecessary decrease in the vehicle speed V and the decrease in the longitudinal acceleration Gx caused by the increase in the braking pressure of the front outside wheel can be reliably prevented.

  In particular, according to the illustrated third embodiment, the engine torque increase amount ΔTe is calculated based on the target pressure increase braking pressures Pptfl and Pptfr according to the above equation 7, so that the engine torque increase amount ΔTe is increased by the increase in the braking pressure of the front outer wheel. The output torque of the engine 96 can be increased without delay compared to the case where the calculation is based on the degree of change in the vehicle speed V when pressure is applied or the amount of decrease in the longitudinal acceleration Gx.

  According to each of the above-described embodiments and correction examples, when it is determined in step 225 that the driver is performing an acceleration / deceleration operation by operating the brake pedal or the accelerator pedal, If it is determined that anti-skid control, traction control, or vehicle behavior control is being executed for the outer front wheel, the vehicle lateral acceleration peak values Gymax and Gymin are set to 0 in step 260, respectively. Since the flag Fbrk is set to 1 and the brake front pressure increase is prohibited, the acceleration / deceleration operation, anti-skid control, traction control, or vehicle behavior control by the driver is prohibited. It is possible to surely prevent the control of the braking force by the hindrance from being hindered by the increase in the braking pressure of the front wheel outside the turn.

Further, according to each of the above-described embodiments and correction examples, in the situation where the braking pressure of the front outer wheel is increased, it is caused by the increase of the braking pressure of the outer front wheel in step 240. When it is determined that the change in the vehicle speed is large, or when it is determined in step 245 that the change in the wheel speed of the outer front wheel is large, or in steps 250 and 255, Even when it is determined that the vehicle behavior change (drift-out state) is large due to the increase of the braking pressure, the lateral acceleration peak values Gymax and Gymin of the vehicle are respectively determined in step 260. When the flag Fbrk is set to 1 while being reset to 0, it is prohibited to increase the braking pressure of the front outer wheel, so the vehicle speed and wheel rotation are increased by increasing the braking pressure of the front outer wheel. State, it is possible to reliably prevent the adverse effect on the behavior of the vehicle.
[Reference Example 1]

Figure 18 is a flowchart showing a cut-off control routine in the wheel cylinders in Reference Example 1 of the braking force control apparatus applied car tanks to the rear wheel drive vehicle. The control according to the flowchart shown in FIG. 18 is also started when the electronic control unit 30 is activated, and is repeatedly executed at predetermined time intervals until an ignition switch (not shown) is turned off.

  First, at step 810, a signal indicating the lateral acceleration Gy of the vehicle detected by the lateral acceleration sensor 80 is read. At step 820, it is determined whether or not the flag Ffr is 1, that is, knockback. For the purpose of prevention, it is determined whether or not the wheel cylinder 24FR of the right front wheel is shut off. If an affirmative determination is made, the process proceeds to step 850, and if a negative determination is made, the process proceeds to step 830.

  In step 830, it is determined whether or not the lateral acceleration Gy of the vehicle is greater than or equal to the control start reference value Gys (positive constant). If a negative determination is made, the process proceeds to step 920, where an affirmative determination is made. When it is determined that the flag Ffr is set to 1 in step 840, the process proceeds to step 870.

  In step 850, it is determined whether or not the lateral acceleration Gy of the vehicle is equal to or less than the control end reference value Gye (a positive constant smaller than Gys). If an affirmative determination is made, the process proceeds to step 870. When a negative determination is made, in step 860, the electromagnetic on-off valve 124R, the linear valve 150FR, and the linear valve 160FR are closed or maintained in the closed state, whereby the right front wheel wheel cylinder 24FR is shut off or shut off. Maintained.

  In step 870, the flag Ffr is reset to 0, and in step 880, the solenoid valve 124R, the linear valve 150FR, and the linear valve 160FR are released from being closed to shut off the right front wheel wheel cylinder 24FR. Is released.

  Similarly, in step 920, it is determined whether or not the flag Ffl is 1, that is, whether or not the wheel cylinder 24FL of the left front wheel is shut off for the purpose of preventing knockback. If yes, the process proceeds to step 950, and if negative determination is made, the process proceeds to step 930.

  In step 930, it is determined whether or not the lateral acceleration Gy of the vehicle is equal to or less than the control start reference value -Gys. If a negative determination is made, the control by the routine shown in FIG. 18 is temporarily terminated. If an affirmative determination is made, the flag Ffl is set to 1 at step 940, and then the routine proceeds to step 970.

  In step 950, it is determined whether or not the lateral acceleration Gy of the vehicle is equal to or greater than the control end reference value -Gye. If an affirmative determination is made, the process proceeds to step 970. If a negative determination is made, step 970 is performed. In 970, the electromagnetic on-off valve 124L, the linear valve 150FL, and the linear valve 160FL are closed or maintained in a closed state, whereby the wheel cylinder 24FL for the left front wheel is shut off or maintained in a shut-off state.

  In step 970, the flag Ffl is reset to 0, and in step 980, the solenoid valve 124L, the linear valve 150FL, and the linear valve 160FL are released from the closed state, thereby shutting off the wheel cylinder 24FL of the left front wheel. Is released.

Thus, according to the reference example 1 shown in the figure, when the lateral acceleration Gy of the vehicle is large, the wheel cylinder 24FR or 24FL of the outer front wheel is shut off or maintained in the shut off state. Even if this occurs, the lateral force does not move the brake pad away from the brake disc, and therefore knockback can be reliably prevented.

In the first reference example, the same determination as in steps 225 and 230 in each of the above-described embodiments and correction examples is performed, and the driver performs an acceleration / deceleration operation by operating the brake pedal or the accelerator pedal. Or when the braking force control by the anti-skid control or the traction control or the vehicle behavior control is executed for the outer front wheel of the turning, the wheel cylinder 24FR or 24FL of the outer front wheel of the turning may be modified so as not to be shut off. .

  Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, in each of the above-described embodiments, the target pressure increase braking pressure Pptfl or Pptfr of the outer front wheel is calculated based on the peak values Gymax and Gymin of the lateral acceleration Gy of the vehicle, and the target pressure increase braking pressure Pcj corresponds. When it is higher than the basic target braking pressure Pbtj, the braking pressure of the front outer wheel is increased until the braking pressure Pj of the front outer turning wheel becomes equal to or higher than the target increased braking pressure Pcj. When the braking pressure of the vehicle is increased to a predetermined value set in advance, the braking pressure of the front outer wheel may be modified so that it is performed until a predetermined time elapses after the start condition is satisfied. .

  Further, in each of the above-described embodiments, the braking pressure of each wheel is controlled by the linear valves 150FL to 150RR functioning as pressure increasing valves (holding valves) and the linear valves 160FL to 160RR functioning as pressure reducing valves. However, as long as the braking pressure of each wheel can be individually controlled, the hydraulic circuit 22 for increasing or decreasing the braking pressure of each wheel may be of any structure known in the art.

  In each of the above-described embodiments, the communication between the master cylinder 28 and the wheel cylinders 24FL to RR is blocked by the electromagnetic on-off valves 124L and 124R even during normal operation. In the control device, the master cylinder 28 and the wheel cylinders 24FL to RR are normally connected to each other, and when the braking pressure is controlled for a specific purpose, the communication between the master cylinder 28 and the wheel cylinders 24FL to RR is cut off. You may apply to the vehicle which has a braking device.

  In each of the above embodiments, the vehicle lateral force index values are the peak values Gymax and Gymin of the vehicle lateral acceleration Gy, but the vehicle lateral force index values are the vehicle yaw rate, the tie rod axial force, and the steering. The determination may be made based on at least one of torque and lateral force of the front wheel.

  In each of the above-described embodiments, only the braking pressure of the turning outer front wheel is increased. However, particularly when the rear wheel is a counter caliper type disc brake, Only the braking pressure may be increased, or it may be modified so as to increase the braking pressure of the outer front wheel and the outer rear wheel.

  In each of the above-described embodiments, the vehicle is a rear wheel drive vehicle driven by an engine. However, in the case of a vehicle having an individual drive device for each wheel, such as an in-wheel motor vehicle, for example, The braking pressure of the front outer wheel is increased and the driving force of the rear rear wheel is increased to offset the influence of the increase in the braking pressure of the front front wheel based on the amount of increase in the braking pressure of the front front wheel. A large amount may be calculated, and the driving force of the turning outer rear wheel may be increased based on the increased amount.

  Furthermore, in each of the embodiments described above, the vehicle is a rear wheel drive vehicle, but the vehicle to which the present invention is applied may be a front wheel drive vehicle or a four wheel drive vehicle.

1 is a schematic configuration diagram showing a first embodiment of a braking force control device according to the present invention applied to a rear wheel drive vehicle. FIG. It is explanatory drawing which shows the braking device shown by FIG. 3 is a flowchart illustrating a main routine of braking force control in the first embodiment. FIG. 4 is a flowchart showing a calculation routine of a basic target braking pressure Pbti executed in step 100 of FIG. It is a flowchart which shows the calculation routine of the peak value Gymax and Gymin performed in step 200 of FIG. It is a flowchart which shows the calculation routine of the target pressure increase braking pressure Pptj performed in step 300 of FIG. It is a graph which shows the relationship between the depression stroke St of a brake pedal, and the target deceleration Gst. It is a graph which shows the relationship between the average value Pma of a master cylinder pressure, and target deceleration Gpt. It is a graph which shows the relationship between the weight (alpha) with respect to the last final target deceleration Gtf and the target deceleration Gpt. 6 is a flowchart showing a peak value calculation routine in Modification Example 1 which is a modification example of Embodiment 1; It is a flowchart which shows the calculation routine of the peak value in Example 2 of the braking force control apparatus of the vehicle by this invention applied to the rear-wheel drive vehicle. 7 is a flowchart illustrating a calculation routine for a target pressure-increasing braking pressure Pptj in the second embodiment. It is a graph which shows the relationship between the absolute value of the peak values Gymax and Gymin of the vehicle lateral acceleration, the peak value Vmax of the vehicle speed, and the basic target increased braking pressure Pcf. It is a graph which shows the relationship between the absolute value of the peak values Gymax and Gymin of the lateral acceleration of a vehicle, and basic target pressure increase braking pressure Pcf. It is a graph which shows the relationship between the peak value Vmax of vehicle speed, and the basic target pressure increase braking pressure Pcf. It is a block diagram which shows the control system of Example 3 of the braking force control apparatus of the vehicle by this invention applied to the rear-wheel drive vehicle. FIG. 10 is a flowchart showing a calculation routine for a driving force of a vehicle that accompanies a control for increasing the braking pressure of the front outer wheel in a third embodiment. Reference Example 1 of the braking force control apparatus applied car tanks to the rear wheel drive vehicle is a flowchart showing a cut-off control routine in the wheel cylinders.

Explanation of symbols

10FR to 10RL Wheel 20 Braking device 28 Master cylinder 30 Electronic control device 66, 68, 72 Pressure sensor 70 Stroke sensor 76i Wheel speed sensor 78 Longitudinal acceleration sensor 80 Lateral acceleration sensor 82 Yaw rate sensor 84 Steering angle sensor 90 Engine control device 96 Engine

Claims (8)

In a vehicle braking force control device equipped with a braking force generator for each wheel that generates a braking force by increasing the braking pressure and pressing the pressing member against the pressed member of the wheel, the vehicle lateral force index value The vehicle braking force is characterized in that at least the braking pressure of the outer turning wheel is increased to a predetermined pressure in a situation in which the vehicle is in a turning state and the index value of the vehicle lateral force decreases beyond a peak value. Control device.   The vehicle control system according to claim 1, wherein the predetermined pressure is higher when the peak value of the vehicle lateral force index value is higher than when the peak value of the vehicle lateral force index value is low. Power control device.   3. The vehicle braking force control apparatus according to claim 1, wherein the predetermined pressure is higher when the vehicle speed is high than when the vehicle speed is low. According to any one of claims 1 to 3, characterized in that stops the pressure increase of the brake pressure when braking or driving force to the turning outer wheel by increasing pressure or outside of request for the braking pressure is applied A braking force control device for a vehicle.   The requests other than the increase in the braking pressure include a braking request for the occupant, an acceleration request for the occupant, a braking / driving force control request for suppressing wheel slip, and a braking / driving force control request for controlling the running stability of the vehicle. The vehicle braking force control device according to claim 4. The vehicle braking force control device according to any one of claims 1 to 5 , wherein the increase in the braking pressure is stopped when a change in a predetermined traveling state occurs in the vehicle.   The change in the predetermined traveling state is an increase of a vehicle deceleration more than a predetermined value, a decrease change of a wheel speed that is not based on a driving operation of an occupant, or a drift-out state of a predetermined value or more. Item 7. The vehicle braking force control device according to Item 6. A driving force is applied to wheels other than the wheel where the braking pressure is increased during the increase of the braking pressure, and the influence of the increased braking pressure on the running state of the vehicle is reduced. The braking force control device for a vehicle according to any one of claims 1 to 7.

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