JP2008308136A - Anti-lock brake controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent insufficient increase of the braking force by a wheel brake on a road surface side of the high friction coefficient when reaching a friction coefficient split state. <P>SOLUTION: In a state of the slow-increasing mode based on the discrimination of a friction coefficient discrimination means 58 that a left-front wheel control mode setting means 59A and a right front wheel control mode setting means 59C are in the state of low friction coefficient during the anti-lock brake control, when a split state detection means 66 detects the friction coefficient split state in which the friction coefficient of a traveling road surface is different between right and left wheels based on the difference in the wheel corresponding vehicle body speed estimated respectively by wheel corresponding vehicle body speed estimation means 55A, 55C, the control mode setting means changes the control mode from the slow increasing mode to the rapid increasing mode corresponding to the front wheel on the high-speed side out of the left-front wheel control mode setting means 59A and the right front wheel control mode setting means 59C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an actuator capable of individually adjusting a braking force exerted by wheel brakes mounted on left and right wheels on the same axis, wheel speed detecting means for individually detecting wheel speeds of the left and right wheels, and a vehicle body. Body speed detecting means for detecting the speed, deceleration detecting means for detecting the deceleration of the vehicle, and friction coefficient determination for determining the level of the friction coefficient of the traveling road surface based on the deceleration detected by the deceleration detecting means Means for determining a lock tendency for each of the left and right wheels based on the wheel speed detected by the wheel speed detection means and the vehicle body speed detected by the vehicle body speed detection means, and the lock tendency determination The control mode for increasing or decreasing the braking force according to the determination result by the means is determined for each wheel brake of the left and right wheels, and the control mode is the increase mode. Control mode setting means for switching between a sudden increase mode when determined to be a high friction coefficient and a slow increase mode when determined to be a low friction coefficient according to the determination result of the friction coefficient determination means, The present invention relates to an anti-lock brake control device for a vehicle comprising actuator control means for controlling the operation of the actuator according to a control mode set by a control mode setting means.

An antilock brake control device for a vehicle that can switch between a sudden increase mode and a slow increase mode in a control mode for increasing the braking force of a wheel brake during the antilock brake control is already known, for example, in Patent Document 1 .
JP 2004-196235 A

  By the way, in such an anti-lock brake control device, the slow increase mode is selected when the friction coefficient of the running road surface is low, and the rapid increase mode is selected when the friction coefficient is high. However, one of the left and right wheels has a low friction coefficient. When the other wheel is in contact with the high friction coefficient road surface and the friction coefficient split state is entered, the low friction coefficient tends to be determined based on the decrease in vehicle deceleration. If it is determined that the coefficient of friction is the slow increase mode and the braking force is controlled in the slow increase mode, a sufficient increase in the braking force cannot be obtained with the wheel on the road surface side with the high friction coefficient. Insufficient braking force may occur.

  The present invention has been made in view of such circumstances, and anti-lock brake control for a vehicle in which an increase in braking force due to a wheel brake on a road surface side having a high friction coefficient does not occur when the friction coefficient is in a split state. An object is to provide an apparatus.

  In order to achieve the above object, the present invention separately detects an actuator capable of individually adjusting a braking force exerted by wheel brakes mounted on left and right wheels on the same axis, and wheel speeds of the left and right wheels. Wheel speed detecting means for detecting vehicle speed, vehicle speed detecting means for detecting vehicle speed, deceleration detecting means for detecting vehicle deceleration, and friction coefficient of the road surface based on the deceleration detected by the deceleration detecting means Friction coefficient determination means for determining the height of the vehicle, and a lock tendency for determining a lock tendency for each of the left and right wheels based on the wheel speed detected by the wheel speed detection means and the vehicle body speed detected by the vehicle body speed detection means A control mode for increasing or decreasing the braking force is determined for each wheel brake of the left and right wheels according to the determination result by the determination means and the determination result by the lock tendency determination means. Control mode setting for switching between a sudden increase mode when it is determined to be a high friction coefficient and a slow increase mode when it is determined to be a low friction coefficient according to the determination result of the friction coefficient determination means when the mode is an increase mode And an actuator control means for controlling the operation of the actuator in accordance with the control mode set by the control mode setting means. In the antilock brake control device for a vehicle, based on the wheel speed detected by the wheel speed detection means The wheel-corresponding vehicle speed estimating means for estimating the wheel-corresponding vehicle speed for each of the left and right wheels, and the friction coefficient of the traveling road surface based on the difference between the wheel-corresponding vehicle speed estimated by the wheel-corresponding vehicle speed estimating means Split state that detects friction coefficient split state that is different between right and left wheels And the control mode setting means is configured such that the split state detection means is in a state in which the moderate increase mode is selected based on the fact that the friction coefficient determination means determines that the friction coefficient is a low friction coefficient. According to the detection of the split state, the control mode on the wheel side of the left and right wheels having the higher vehicle speed corresponding to the wheel is switched from the slowly increasing mode to the rapidly increasing mode.

  The left front wheel brake BA and the right front wheel brake BC of the embodiment correspond to the wheel brake of the present invention, and the left front wheel WA and the right front wheel WC of the embodiment correspond to the wheel of the present invention.

  According to the above configuration of the present invention, when the anti-lock brake control is performed when traveling on the road surface in the friction coefficient split state, which is likely to be determined as the low friction coefficient based on the decrease in the deceleration of the vehicle, the low friction coefficient Even if the slow increase mode is selected, it is attached to the left and right wheels on the same axis, and the left and right wheel brakes that can control the braking force independently of each other are attached to the wheels on the high speed side. Since the braking force control of the wheel brake is switched from the slow increasing mode to the sudden increasing mode, the increase in braking force due to the wheel braking on the road surface side with the high friction coefficient is prevented from occurring on the road surface in the friction coefficient split state. be able to.

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

  1 to 6 show an embodiment of the present invention, FIG. 1 is a diagram showing a drive system and a brake system of a front-wheel drive vehicle, and FIG. 2 is a hydraulic system diagram showing a configuration of a brake hydraulic pressure control device. 3 is a longitudinal cross-sectional view of a normally open solenoid valve, FIG. 4 is a diagram showing a change in attraction force with respect to a change in the stroke of the valve shaft, FIG. 5 is a block diagram showing the configuration of the controller, and FIG. It is a figure which shows the relationship of wheel speed.

  First, in FIG. 1, power is transmitted from the power unit P to the left front wheel WA and the right front wheel WC which are driving wheels. The power unit P shifts the output of the engine E and the engine E to the left front wheel. It is comprised with the transmission T for transmitting to WA and the right front wheel WC. The left front wheel WA and the right front wheel WC are equipped with a left front wheel wheel brake BA and a right front wheel brake BC, which are drive wheel brakes. The driven wheel, the right rear wheel WB and the left rear wheel WD, A right rear wheel brake BB and a left rear wheel brake BD are mounted.

  Each of the wheel brakes BA to BD is a disc brake that operates by the action of hydraulic pressure, and the hydraulic pressure from the actuator 1 acts on each of the wheel brakes BA to BD. The actuator 1 can adjust the output hydraulic pressure of the tandem master cylinder M that outputs the hydraulic pressure by the brake operation of the brake pedal 2 to be applied to the wheel brakes BA to BD.

  The operation of the actuator 1 is controlled by a controller C. The controller C includes wheel speed detecting means 6A, 6C for driving wheels for detecting the driving wheel speeds of the left front wheel WA and the right front wheel WC as driving wheels. Detection value, detection values of driven wheel speed detection means 6B and 6D for detecting the driven wheel speeds of the right rear wheel WB and the left rear wheel WD, which are driven wheels, and the brake fluid pressure of each wheel brake BA to BD. Detection values of the brake pressure detection means 7A to 7D to be input are input.

  In FIG. 2, the actuator 1 corresponds to the first hydraulic passage 10A corresponding to the left front wheel brake BA and the right rear wheel brake BB, and to the right front wheel brake BC and the left rear wheel brake BD. The first hydraulic pressure passage 10B, the first and second reservoirs 11A and 11B different from the reservoir R provided in the master cylinder M, and the first and second reservoirs 11A are driven by a common single electric motor 13. , 11B can pump up the brake fluid and discharge it to the first and second hydraulic pressure passages 10A, 10B, and the first output port 3A and the first hydraulic pressure passage 10A of the master cylinder M. A normally open solenoid valve 15A interposed therebetween, a normally open solenoid valve 15B interposed between the second output port 3B of the master cylinder M and the second hydraulic pressure passage 10B, and a first Between the suction side of the pump 14A and the first output port 3A of the master cylinder M, and between the suction side of the second pump 14B and the second output port 3B of the master cylinder M. The normally closed solenoid valve 16B, the left front wheel brake pressure adjusting means 17A provided between the first hydraulic pressure path 10A and the left front wheel wheel brake BA, the first hydraulic pressure path 10A and the right rear wheel wheel brake BB. The right rear wheel brake pressure adjusting means 17B provided between the second hydraulic pressure path 10B and the right front wheel brake pressure adjusting means 17C provided between the right front wheel wheel brake BC, the second hydraulic pressure path 10B and the left rear wheel. Left rear wheel brake pressure adjusting means 17D provided between the vehicle wheel brakes BD.

  The left front wheel brake pressure adjusting means 17A is a normally open solenoid valve 18A provided between the first hydraulic pressure passage 10A and the left front wheel wheel brake BA, and a normal opening type solenoid valve 18A provided between the first reservoir 11A and the left front wheel wheel brake BA. A closed solenoid valve 19A and a check valve 20A connected in parallel to the normally open solenoid valve 18A to allow the brake fluid to flow from the left front wheel brake BA side to the first hydraulic pressure passage 10A side. Is done.

  According to such a left front wheel brake pressure adjusting means 17A, when the brake pedal 3 is depressed, the normally open solenoid valve 18A is opened when the normally closed solenoid valve 19A is closed. The brake force of the front left wheel brake BA can be increased by applying the hydraulic pressure of the output port 3A to the front left wheel brake BA, and both the normally open solenoid valve 18A and the normally closed solenoid valve 19A are provided. When closed, the brake fluid pressure of the left front wheel brake BA can be maintained to maintain the braking force of the left front wheel brake BA, and the normally open solenoid valve 18A is closed and the normally closed solenoid valve 19A is closed. By opening the valve, the brake fluid pressure of the left front wheel brake BA can be reduced to reduce the brake force of the left front wheel brake BA.

  The right rear wheel brake pressure adjusting means 17B includes a normally-open electromagnetic valve 18B provided between the first hydraulic pressure path 10A and the right rear wheel wheel brake BB, and between the first reservoir 11A and the right rear wheel wheel brake BB. A normally closed solenoid valve 19B provided and a check valve connected in parallel to the normally open solenoid valve 18B while allowing the brake fluid to flow from the right rear wheel brake BB side to the first hydraulic pressure passage 10A side. 20B, and by controlling the opening and closing of the normally open solenoid valve 18B and the normally closed solenoid valve 19B, the right rear wheel wheel brake BB is controlled in the same manner as the left front wheel brake pressure adjusting means 17A. The brake force can be controlled to increase, hold and decrease.

  The right front wheel brake pressure adjusting means 17C is a normally-open solenoid valve 18C provided between the second hydraulic pressure passage 10B and the right front wheel wheel brake BC, and a normal opening solenoid valve 18C provided between the second reservoir 11B and the right front wheel wheel brake BC. A closed solenoid valve 19C and a check valve 20C connected in parallel to the normally open solenoid valve 18C while allowing the brake fluid to flow from the right front wheel brake BC side to the second hydraulic pressure passage 10B side. In the same manner as the left front wheel brake pressure adjusting means 17A and the right rear wheel brake pressure adjusting means 17B, the right front wheel is controlled by controlling the opening and closing of the normally open type electromagnetic valve 18C and the normally closed type electromagnetic valve 19C. It is possible to switch and control the increase, retention and decrease of the brake force of the industrial wheel brake BC.

  The left rear wheel brake pressure adjusting means 17D is provided between a normally open solenoid valve 18D provided between the second hydraulic pressure path 10B and the left rear wheel wheel brake BD, and between the second reservoir 11B and the left rear wheel wheel brake BD. A normally closed solenoid valve 19D provided and a check valve connected in parallel to the normally open solenoid valve 18D while allowing the brake fluid to flow from the left rear wheel brake BD side to the second hydraulic pressure passage 10B side. 20D, and by controlling the opening and closing of the normally open solenoid valve 18D and the normally closed solenoid valve 19D, the left front wheel brake pressure regulating means 17A, the right rear wheel brake pressure regulating means 17B and the right As with the front wheel brake pressure adjusting means 17C, the braking force of the left rear wheel wheel brake BD can be controlled to be increased, held and decreased.

  Further, the first output port 3A of the master cylinder M and the first hydraulic pressure passage 10A are shut off by closing the normally open solenoid valve 15A, and the normally closed solenoid valve 16A is opened to open the first output of the master cylinder M. The first pump 14A is operated in a state where the port 3A is in communication with the suction side of the first pump 14A, and the normally open solenoid valves 18A, 18B in the left front wheel brake pressure adjusting means 17A and the right rear wheel brake pressure adjusting means 17B By controlling the opening and closing of the normally closed solenoid valves 19A and 19B, it is possible to control the increase, retention and decrease of the braking force of the left front wheel brake BA and the right rear wheel brake BB during non-braking operation. is there.

  Further, the second output port 3B of the master cylinder M and the second hydraulic pressure passage 10B are shut off by closing the normally open solenoid valve 15B, and the normally closed solenoid valve 16B is opened to open the second output of the master cylinder M. The second pump 14B is operated with the port 3B communicating with the suction side of the second pump 14B, and the normally open solenoid valves 18C, 18D in the right front wheel brake pressure adjusting means 17C and the left rear wheel brake pressure adjusting means 17D By controlling the opening and closing of the normally closed solenoid valves 19C and 19D, it is possible to control the increase, retention, and decrease of the braking force of the right front wheel brake BC and the left rear wheel brake BD during non-brake operation. is there.

  By the way, the braking force of the wheel brakes of the wheels WA to WD that are about to fall into the locked state during the braking operation in which the hydraulic pressure is applied to the wheel brakes BA to BD has the above increase, decrease, and holding modes. The anti-lock brake control is performed so that the normally closed electromagnetic valves 16A to 16D of the wheel brake pressure adjusting means 17A to 17D are turned on / off during the anti-lock brake control. On the other hand, the normally open solenoid valves 15A to 15D are on / off controlled and duty controlled in the middle between on and off, and each wheel brake BA according to the applied current of such an intermediate value. FIG. 3 shows the configuration of the normally open solenoid valve 15A among the normally open solenoid valves 15A to 15D configured to linearly change the fluid pressure on the BD side. It will now be described with ether.

  In FIG. 3, the normally open electromagnetic valve 15 </ b> A includes a solenoid portion 24 that exhibits electromagnetic force, and a valve portion 25 that is driven by the solenoid portion 24, and one surface 26 a of a fixed support block 26. The valve portion 25 is accommodated in a mounting hole 27 provided in the support block 26 so that the solenoid block 24 protrudes from one surface 26 a of the support block 26.

  The valve portion 25 includes a valve housing 28 that is formed of a magnetic metal into a stepped cylindrical shape. The valve housing 28 is fitted into the mounting hole 27 of the support block 26. A retaining ring 29 that engages with the valve housing 28 and prevents the valve housing 28 from being detached from the mounting hole 27 is fitted to the inner surface near the opening end of the mounting hole 27. In addition, annular seal members 30 and 31 are mounted at two positions spaced apart in the axial direction on the outer surface of the valve housing 28, and between the seal members 30 and 31, there is a gap between the support block 26 and the valve housing 28. An annular chamber 32 is formed.

  A cylindrical valve seat member 33 is press-fitted and fixed to the valve housing 28. In addition, a valve shaft 34 made of a nonmagnetic material is slidably fitted in the valve housing 28, and an output chamber 35 is formed between one end of the valve shaft 34 and the valve seat member 33, and faces the output chamber 35. A spherical valve element 36 that can be seated on a valve seat 33 a formed on the valve seat member 33 is fixed to one end of the valve shaft 34. Moreover, a return spring 37 is provided between one end of the valve shaft 34 and the valve seat member 33 to urge the valve shaft 34, that is, the valve body 36 in a direction away from the valve seat member 33.

  A filter 39 is attached to the valve housing 28 so as to be interposed between the hydraulic pressure path 38 provided in the support block 36 and the valve seat member 33 so as to be connected to the first hydraulic pressure path 10A. A filter 40 is mounted on the outer periphery of the valve housing 28 at a portion facing the annular chamber 32, and a passage 41 for allowing the output chamber 35 to communicate with the annular chamber 32 through the filter 40 is provided in the valve housing 28. . The annular chamber 32 communicates with the left front wheel wheel brake BA, and the support block 36 is provided with a hydraulic path 42 for communicating the annular chamber 32 with the left front wheel wheel brake BA. Further, the valve housing 28 is opened between the valve seat member 33 and the filter 39 when the pressure in the hydraulic pressure path 38 is lower than that in the annular chamber 32, and the brake fluid in the annular chamber 32 is returned to the hydraulic pressure path 38 side. A check valve 20A is provided.

  The solenoid part 34 guides the approaching / separating movement of the armature 46 with respect to the fixed core 45, the armature 46 that is coaxially connected to the other end of the valve shaft 34 in the valve part 35 and faces the fixed core 45. Guide cylinder 47, a bobbin 48 surrounding the guide cylinder 47, a coil 49 wound around the bobbin 48, a magnetic path frame 50 surrounding the coil 49, and the magnetic path frame 50 and the bobbin 48. The coiled spring 51 is provided.

  The fixed core 45 is formed in a cylindrical shape, and is coaxially and integrally connected to the center of one end of the valve housing 28. The guide tube 47 is formed in a thin bottomed cylindrical shape with a hemispherical closed end at one end made of a non-magnetic material such as stainless steel, and the tip of the fixed core 45 is connected to the other end of the guide tube 47. And the other end of the guide tube 47 is fixed to the fixed core 45 by welding, for example. In addition, the guide cylinder 47 protrudes from the one surface 36 a of the support block 36 in a mounted state in the mounting hole 37 of the valve housing 28.

  The bobbin 48 has a central hole 48 a through which the guide tube 47 is inserted and is formed of synthetic resin. A coil 49 is wound around the bobbin 48.

  The magnetic path frame 50 includes a magnetic path cylinder 52 that surrounds the bobbin 48 and the coil 49. At one end of the magnetic path cylinder 52, the closed end portion of the guide cylinder 47 protrudes from the center portion to the bobbin 48. The ring plate-like magnetic path plate 53 that abuts is caulked and engaged.

  On the other hand, the other end of the magnetic path cylinder 52 is integrally provided with a ring plate-like contact plate portion 52a that contacts the one end of the valve housing 28 around the fixed core 45, and this contact plate portion 52a. The base portion of the fixed core 45 is fitted to the inner periphery of the core. In addition, the other end of the coiled spring 51 whose one end is in contact with the contact plate portion 52 a is in contact with the bobbin 48.

  An armature 46 that can move toward and away from the fixed core 45 is housed in the guide tube 47, and one end of the valve shaft 34 that passes through the fixed core 45 movably is coaxial with the armature 46. Abutted. By the way, the valve shaft 34 is urged in a direction away from the valve seat member 33 by the spring force of the return spring 37, and the other end of the valve shaft 34 is always in contact with the armature 46. In response to the axial movement of the armature 46, the valve shaft 34, that is, the valve body 36 also moves in the axial direction.

  That is, in a state where the magnetic attractive force toward the fixed core 45 is not acting on the armature 46, the armature 46 is in a retracted position by the spring force of the return spring 37 until it is received at one end closed portion of the guide cylinder 47. At this time, the valve body 36 is separated from the valve seat member 33, and the normally open solenoid valve 15A is in the valve open state. When the armature 46 is magnetically attracted toward the fixed core 45 until the valve element 36 is seated on the valve seat member 33, the normally open solenoid valve 15A is closed.

  By the way, the resultant force of the hydraulic pressure of the output chamber 35 and the spring force of the return spring 37 acts on one end of the valve shaft 34, while the armature 46 is fixed to the other end of the valve shaft 34. The magnetic attraction force attracted to the core 45 side acts, and the valve shaft 34 is stroke-operated so that the resultant force of the fluid pressure and the spring force is balanced with the magnetic attraction force. Therefore, by controlling the energization amount to the coil 49 to be an intermediate value between on and off by, for example, duty control, the magnetic attraction force that attracts the armature 46 to the fixed core 45 side can be changed.

  On the other hand, the opposed surfaces 45 a and 46 a of the fixed core 45 and the armature 46 are formed as tapered surfaces that increase in diameter as they move away from the output chamber 35.

  When the opposing surfaces 45a and 46a of the fixed core 45 and the armature 46 are formed in a tapered surface in this way, the opposing distance between the fixed core 45 and the armature 46 (in a direction perpendicular to the tapered surface) compared to the axial stroke amount of the armature 46. The change in the suction force generated between the opposed surfaces 45a and 46a is smaller than the change in the axial stroke. Moreover, the suction force that actually acts in the axial direction is a sine component of the suction force generated between the opposing surfaces 45a and 46a, and with respect to the change in the suction force between the opposing surfaces 45a and 46a as the taper surface angle becomes acute. The change in the suction force in the axial direction is reduced.

  As a result, as shown by the solid line in FIG. 4, the suction force between the fixed core 45 and the armature 46 can be made substantially flat in the practical range between the fully closed and fully opened states of the valve portion 35. On the other hand, when the opposing surfaces of the fixed core 45 and the armature 46 are flat surfaces perpendicular to the axial direction, the opposing distance between the fixed core 45 and the armature 46 changes proportionally according to the axial stroke of the valve shaft 34. Therefore, as shown by the chain line in FIG. 4, the suction force between the fixed core 45 and the armature 46 changes greatly even in the practical range.

  In this way, the normally open solenoid valve 15A is on / off controlled and duty controlled to give an intermediate current between on and off so as to linearly change the hydraulic pressure on the left front wheel brake BA side. The other normally open solenoid valves 15B to 15D are configured similarly to the normally open solenoid valve 15A. On the other hand, the normally closed solenoid valves 16A to 16D are only on / off controlled. Thus, in the increase mode of the anti-lock brake control, the brake force of each of the wheel brakes BA to BD can be increased rapidly by turning on the normally open solenoid valves 15A to 15D, and the normally open type is also normally open. It is possible to moderately increase the brake force of each wheel brake BA to BD by duty-controlling the type solenoid valves 15A to 15D.

  In FIG. 5, the controller C uses the wheel speeds of the left front wheel WA, the right front wheel WC, the right rear wheel WB, and the left rear wheel WD, which are individually detected by the wheel speed detection means 6A, 6C, 6B, 6D. Wheel-corresponding vehicle speed estimating means 55A, 55C, 55B, 55D for estimating the wheel-corresponding vehicle speed for each of WA to WD, vehicle speed detecting means 56 for detecting the vehicle speed, and deceleration detecting means for detecting the deceleration of the vehicle 57, a friction coefficient determining means 58 for determining the level of the friction coefficient of the traveling road surface based on the deceleration detected by the deceleration detecting means 57, the wheel speed detected by the wheel speed detecting means 6A and the vehicle body speed. The left front wheel locking tendency determination means 59A for determining the locking tendency of the left front wheel WA based on the vehicle body speed detected by the detection means 56, and the wheel speed detected by the wheel speed detection means 6C. In addition, the right front wheel lock tendency determination means 59C for determining the lock tendency of the right front wheel WC based on the vehicle body speed detected by the vehicle body speed detection means 56, and the right rear wheel WB detected by the wheel speed detection means 6B and 6D. And a low select means 60 for selecting the lower one of the wheel speeds of the left rear wheel WD, the right front wheel based on the wheel speed selected by the low select means 60 and the vehicle body speed detected by the vehicle body speed detection means 56. In order to increase or decrease the braking force of the left front wheel wheel brake BA according to the determination result by the rear wheel lock tendency determination means 61 for determining the lock tendency of the WC and the left rear wheel WD and the left front wheel lock tendency determination means 59A. Left front wheel control mode setting means 62A for determining the control mode and right front wheel wheel according to the determination result by the right front wheel lock tendency determination means 59C. The right front wheel wheel brake BB and the left rear wheel brake BD according to the determination result by the right front wheel control mode setting means 62C for increasing / decreasing the brake force of the rake BC and the rear wheel lock tendency determination means 61. The operation of the left front wheel brake pressure adjusting means 17A in the actuator 1 is controlled in accordance with the control mode set by the rear wheel control mode setting means 63 for increasing or decreasing the braking force of the vehicle and the control mode setting means 62A for the left front wheel. Left front wheel actuator control means 64A; right front wheel actuator control means 64C for controlling the operation of the right front wheel brake pressure adjusting means 17C in the actuator 1 according to the control mode set by the right front wheel control mode setting means 62C; According to the control mode set by the rear wheel control mode setting means 63, the alarm is set. The rear wheel actuator control means 65 for controlling the operation of the right rear wheel brake pressure adjusting means 17B and the left rear wheel brake pressure adjusting means 17D, and the left front wheel WA and the right front wheel WC, which are coaxial, are individually supported in the actuator 1. Based on the difference between the wheel-corresponding vehicle body speeds estimated by the wheel-corresponding vehicle body speed estimating means 55A and 55C, it is detected that the friction coefficient of the road surface is different between the left and right wheels, and the result is as a result. Is input to the left front wheel control mode setting means 62A and the right front wheel control mode setting means 62C.

  Based on the wheel speed of the left front wheel WA by the wheel speed detection means 6A, the wheel-corresponding vehicle body speed estimation means 55A estimates the vehicle body speed using the wheel deceleration so that the deceleration does not exceed the set deceleration during the deceleration process. In the acceleration process, the vehicle speed is estimated using the wheel acceleration so as not to increase more than the set acceleration, and the vehicle speed corresponding to the wheel changes as shown in FIG. 6 with respect to the wheel speed. This is estimated by the wheel corresponding vehicle body speed estimating means 55A.

  The wheel corresponding vehicle body speed estimating means 55C, 55B, 55D is also the same as the wheel corresponding vehicle body speed estimating means 55A, and the right front wheel WC, the right rear wheel WB and the left detected by the wheel speed detecting means 6C, 6B, 6D. Based on the wheel speed of the rear wheel WD, the wheel corresponding vehicle body speed for each of the right front wheel WC, the right rear wheel WB, and the left rear wheel WD is estimated.

  The vehicle body speed detecting means 56 selects the highest value of the wheel corresponding vehicle body speeds estimated by the wheel corresponding vehicle body speed estimating means 55A to 55D as the vehicle body speed, and the deceleration detecting means 57 is the vehicle body speed detecting means 56. A vehicle deceleration is obtained by differentiating the vehicle body speed obtained in (1). Further, the friction coefficient discriminating means 58 discriminates the level of the friction coefficient of the traveling road surface based on the vehicle deceleration obtained by the deceleration detecting means 57.

  In consideration of the turning state of the vehicle, the vehicle body speed obtained by the vehicle body speed detecting means 56 may be corrected for turning based on the wheel speeds of the right rear wheel WB and the left rear wheel WD as driven wheels.

  The left front wheel lock tendency determination means 59A and the right front wheel lock tendency determination means 59C are coaxially mounted on the left front wheel WA on the left front wheel WA, and on the right front wheel wheel brake BC on the right front wheel WC. In order to control the braking force of the vehicle independently and independently, the lock tendency of the left front wheel WA is determined based on the wheel speed detected by the wheel speed detecting means 6A and the vehicle body speed detected by the vehicle body speed detecting means 56. At the same time, the locking tendency of the right front wheel WC is determined based on the wheel speed detected by the wheel speed detecting means 6C and the vehicle body speed detected by the vehicle body speed detecting means 56.

  The braking force of the right rear wheel wheel brake BB mounted on the right rear wheel WB and the left rear wheel wheel brake BD mounted on the left rear wheel WD, which are coaxial, is controlled collectively, and the wheel speed. Of the wheel speed of the right rear wheel WB detected by the detection means 6B and the wheel speed of the left rear wheel WD detected by the wheel speed detection means 6D, the lower one is selected by the row selection means 60. Based on the selected wheel speed and the vehicle body speed obtained by the vehicle body speed detection means 56, the rear wheel lock tendency determination means 61 determines the rear wheel lock tendency.

  The left front wheel control mode setting means 62A and the right front wheel control mode setting means 62C are arranged in accordance with the determination results of the left front wheel lock tendency determination means 59A and the right front wheel lock tendency determination means 59C. The control mode is set by switching the braking force increasing mode, holding mode, and decreasing mode of the BA and right front wheel brake BC. In particular, in the increasing mode, the determination by the friction coefficient determining means 58 is performed. Depending on the result, a rapid increase mode when it is determined to have a high friction coefficient and a slow increase mode when it is determined to be a low friction coefficient are switched.

  Further, the split state detection means 66 is in a friction coefficient split state in which the friction coefficient of the road surface is different between the left and right wheels based on the difference between the wheel corresponding vehicle body speeds estimated by the wheel corresponding vehicle body speed estimating means 55A and 55C. When the split state detection means 66 detects that the friction coefficient is in the split state, the left front wheel control mode setting means 62A and the right front wheel control mode setting means 62C A switching signal is input from the split state detecting means 66 to the control mode setting means on the wheel side having the higher vehicle speed corresponding to the wheel.

  A switching signal is input from the split state detection means 66 of the left front wheel control mode setting means 62A and the right front wheel control mode setting means 62C in a state in which the slow increase mode is selected based on the low friction coefficient. The controlled mode setting means switches the control mode from the slowly increasing mode to the rapidly increasing mode.

  Further, the rear wheel control mode setting means 63 is configured to increase the braking force of the right rear wheel wheel brake BB and the left rear wheel wheel brake BD according to the determination result by the rear wheel lock tendency determination means 61, and the holding mode. The control mode is set so as to switch between the decrease mode and the increase mode, and particularly in the increase mode, the rapid increase mode and the low friction when the friction coefficient determination means 58 determines that the friction coefficient is high according to the determination result. Switches the mode of slow increase when it is determined to be a coefficient.

  Next, the operation of this embodiment will be described. The left front wheel control mode setting means 59A and the right front wheel for determining the control mode at the time of antilock brake control of the braking force by the left front wheel brake BA and the right front wheel brake BC. When the control mode is the increase mode, the control mode setting means 59C determines the rapid increase mode when it is determined to be the high friction coefficient according to the determination result of the friction coefficient determination means 58 and the low friction coefficient. Although the mode of moderate increase is switched, the split state detection means 66 estimates the wheel corresponding vehicle speed for each of the left front wheel WA and the right front wheel WC while the slow increase mode is selected. The friction coefficient of the road surface is different between the left and right wheels based on the difference in vehicle speed corresponding to the wheels estimated at 55C. The control mode setting means corresponding to the front wheel on the high speed side among the left front wheel control mode setting means 59A and the right front wheel control mode setting means 59C when the friction coefficient split state is detected. Switch the mode from slow increase mode to rapid increase mode.

  That is, when anti-lock brake control is performed when driving on a road surface with a friction coefficient split that tends to be determined as a low coefficient of friction based on a decrease in vehicle deceleration, it is determined that the coefficient of friction is low and increases slowly. Even if the mode is selected, the high speed side of the left front wheel brake BA and the right front wheel brake BC that are mounted on the left and right front wheels WA and WC on the same axis and can control the brake force independently of each other. The brake force control of the wheel brakes mounted on the wheels of the vehicle will be switched from the slow increase mode to the sudden increase mode, and the braking force increase due to the wheel brake on the road surface side with the high friction coefficient on the road surface in the friction coefficient split state is insufficient. Can be prevented from occurring.

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

  For example, in the above embodiment, the brake force of the left front wheel brake BA and the right front wheel brake BC is individually controlled during anti-lock brake control, and the right rear wheel brake BB and the left rear wheel brake BD are braked. Although the force is controlled collectively, the braking force of the left front wheel brake BA, the right front wheel brake BC, the right rear wheel brake BB, and the left rear wheel brake BD is individually controlled. The present invention can also be applied to an antilock brake control device for a vehicle.

It is a figure which shows the drive system and brake system of a front-wheel drive vehicle. It is a hydraulic system diagram which shows the composition of a brake fluid pressure control device. It is a longitudinal cross-sectional view of a normally open type solenoid valve. It is a figure which shows the suction force change with respect to the stroke change of a valve shaft. It is a block diagram which shows the structure of a controller. It is a figure which shows the relationship between the vehicle speed corresponding to a wheel speed, and a wheel speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Actuator 6A, 6C ... Wheel speed detection means 56 ... Vehicle body speed detection means 55A, 55C ... Wheel corresponding vehicle body speed estimation means 57 ... Deceleration detection means 58 ... Friction coefficient discrimination Means 59A, 59C ... Lock tendency judgment means 62A, 62C ... Control mode setting means 64A, 64C ... Actuator control means 66 ... Split state detection means BA, BC ... Wheel brake WA ... Left front wheel WC as a wheel ... Right front wheel as a wheel

Claims (1)

  The actuator (1) capable of individually adjusting the braking force exerted by the wheel brakes (BA, BC) mounted on the left and right wheels (WA, WC) on the same axis, and the left and right wheels (WA, WC) Wheel speed detection means (6A, 6C) for individually detecting the wheel speed, body speed detection means (56) for detecting the vehicle speed, deceleration detection means (57) for detecting vehicle deceleration, Friction coefficient discriminating means (58) for discriminating the level of the friction coefficient of the road surface based on the deceleration detected by the speed detecting means (57), and the wheel speed detected by the wheel speed detecting means (6A, 6C). A lock tendency determining means (59A, 59C) for determining a lock tendency for each of the left and right wheels (WA, WC) based on the vehicle body speed detected by the vehicle body speed detecting means (56); A control mode for increasing or decreasing the braking force is determined for each wheel brake (BA, BC) of the left and right wheels (WA, WC) according to the determination result of (59A, 59C), and the control mode is an increase mode. Control mode setting means (62A) for switching between a rapid increase mode when it is determined that the friction coefficient is high and a slow increase mode when it is determined that the friction coefficient is low according to the determination result of the friction coefficient determination means (58). 62C) and actuator control means (64A, 64C) for controlling the operation of the actuator (1) according to the control mode set by the control mode setting means (62A, 62C). The left and right wheels (6A, 6C) based on the wheel speed detected by the wheel speed detecting means (6A, 6C). (A, WC) Wheel corresponding vehicle body speed estimating means (55A, 55C) for estimating the wheel corresponding vehicle body speed, and the difference between the wheel corresponding vehicle body speeds estimated by the wheel corresponding vehicle body speed estimating means (55A, 55C). Split state detection means (66) for detecting that the friction coefficient of the road surface is different between the left and right wheels based on the split state detection means (66), the control mode setting means (62A, 62C), The split state detecting means (66) detects the friction coefficient split state in a state where the slow increase mode is selected based on the fact that the friction coefficient determining means (58) determines that the friction coefficient is low. In response, the control mode on the wheel side of the left and right wheels (WA, WC) with the higher vehicle speed corresponding to the wheel is switched from the slowly increasing mode to the rapidly increasing mode. An antilock brake control device for a vehicle characterized by the above.

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