JP2011093516A - Camber control device - Google Patents

Abstract

[PROBLEMS] To extend the life of a tire and improve fuel efficiency.
A vehicle body, a plurality of wheels, a camber variable mechanism that is disposed on a predetermined wheel among the wheels and imparts camber to the wheels, and whether the traveling state of the vehicle is stable A running stable state determination processing unit that determines whether or not, and a camber applying processing unit that applies a negative camber to the predetermined wheel when the running state of the vehicle is stable. Since the negative camber is applied when the running state of the vehicle is stable, the frequency at which the negative camber is applied can be reduced, and the time during which the negative camber is applied can be shortened. it can.
[Selection] Figure 1

Description

  The present invention relates to a camber control device.

  2. Description of the Related Art Conventionally, there has been provided a vehicle that can give a negative camber (negative camber) to a rear wheel.

  In this type of vehicle, when the vehicle travels straight, that is, when the vehicle travels straight, the tires of the left rear and right rear wheels can generate canvas lasts in opposite directions. In addition, the stability of the vehicle when traveling straight (hereinafter referred to as “travel stability”) can be increased. Further, when the vehicle is turned by operating the steering wheel, that is, when the vehicle is turned, a centrifugal force is generated in the vehicle, so that the outer peripheral wheel (outer wheel) of the left rear and right rear wheels is grounded. The load increases, and the canvas last generated in the tire on the outer peripheral wheel becomes larger than the canvas last generated in the tire on the inner peripheral wheel (inner ring). Therefore, since sufficient centripetal force can be generated in the vehicle, the stability of the vehicle when turning (hereinafter referred to as “turning stability”) can be increased. Note that the ground load is a load by which the tire presses the road surface.

  However, in general, when the vehicle is driven at a low speed with cambers applied to the wheels, uneven wear occurs in the tire, and the life of the tire is shortened.

  Therefore, in the vehicle, by detecting the vehicle speed and applying a negative camber to the rear wheels only while the vehicle is running at high speed, the occurrence of uneven wear on the tire is suppressed. (For example, refer to Patent Document 1).

JP-A-60-193781

  However, in the conventional vehicle, since the negative camber is frequently applied and the time during which the negative camber is applied is long, the occurrence of uneven wear on the tire cannot be sufficiently suppressed. . Further, while the vehicle is running at a high speed, the negative camber continues to be applied to the rear wheels, so that the rolling resistance of the tire increases correspondingly, and the fuel consumption deteriorates.

  An object of the present invention is to provide a camber control device that can solve the problems of the conventional vehicle, extend the life of the tire, and improve fuel efficiency.

  For this purpose, in the camber control device of the present invention, the vehicle body, a plurality of wheels rotatably arranged with respect to the body, and a predetermined wheel among the wheels are arranged. A camber variable mechanism for applying camber, a traveling stable state determination processing means for determining whether or not the traveling state of the vehicle is stable, and a negative load on the predetermined wheel when the traveling state of the vehicle is stable. Camber providing processing means for providing the camber.

  According to the present invention, in the camber control device, a vehicle body, a plurality of wheels disposed rotatably with respect to the body, and a predetermined wheel among the wheels are provided. A camber variable mechanism for applying camber, a traveling stable state determination processing means for determining whether or not the traveling state of the vehicle is stable, and a negative load on the predetermined wheel when the traveling state of the vehicle is stable. Camber providing processing means for providing the camber.

  In this case, when the traveling state of the vehicle is stable, a negative camber is applied to the predetermined wheel. Therefore, the frequency with which the negative camber is applied can be reduced, and the negative camber is reduced. The granted time can be shortened.

  Therefore, it is possible to sufficiently suppress the occurrence of uneven wear on the tire of the predetermined wheel, and to prolong the life of the tire.

  Further, since the negative camber is not continuously applied to the predetermined wheel while the vehicle is running, the rolling resistance of the tire can be reduced accordingly. Therefore, fuel consumption can be improved.

It is a control block diagram of the vehicle in the 1st Embodiment of this invention. It is a conceptual diagram of the vehicle in the 1st Embodiment of this invention. It is sectional drawing of the wheel in the 1st Embodiment of this invention. It is a 1st main flowchart which shows operation | movement of the control part in the 1st Embodiment of this invention. It is a 2nd main flowchart which shows operation | movement of the control part in the 1st Embodiment of this invention. It is a figure which shows the subroutine of the steering stability camber necessity determination process in the 1st Embodiment of this invention. It is a figure which shows the subroutine of the straight travel stable camber necessity determination process in the 1st Embodiment of this invention. It is a figure which shows the subroutine of the ground load determination process in the 1st Embodiment of this invention. It is a figure which shows the subroutine of the straight travel stable camber necessity determination process in the 2nd Embodiment of this invention. It is a figure which shows the subroutine of the straight travel stable camber necessity determination process in the 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a conceptual diagram of the vehicle in the first embodiment of the present invention.

  In the figure, 11 is a body that is a vehicle body, 12 is an engine as a drive source, WLF, WRF, WLB, and WRB are arranged on the left front, right front, and left rear that are rotatably arranged with respect to the body 11. And the right rear wheel. The front wheels are constituted by the wheels WLF and WRF, and the rear wheels are constituted by the wheels WLB and WRB.

  In the present embodiment, the vehicle has a rear-wheel drive structure, and the wheels WLB and WRB function as drive wheels. The engine 12 and the wheels WLB and WRB are connected to an automatic transmission 19 as a transmission, a propeller shaft 17 as a first transmission shaft, a differential 18 and a drive shaft 46 as a second transmission shaft. , And the rotation generated by driving the engine 12 is changed at a predetermined speed ratio in the automatic transmission 19 and transmitted to the wheels WLB and WRB. In this embodiment, the vehicle has a rear-wheel drive structure, but may have a front-wheel drive structure or a four-wheel drive structure. it can. Further, instead of the engine 12, an engine as a first drive source and a drive unit comprising a generator / motor as a second drive source may be arranged to form a hybrid vehicle, or the first A drive unit comprising an engine as a drive source, a generator as a second drive source, and a motor as a third drive source is arranged to form a hybrid vehicle, or a motor as a drive source is provided. It can also be arranged to constitute an electric vehicle.

  Further, 13 is a steering wheel as an operation unit for steering the vehicle and as a steering member, 14 is an accelerator pedal as an operation unit for accelerating the vehicle and as an acceleration operation member, and 15 A brake pedal as an operation unit for braking the vehicle and as a braking operation member.

  31 and 32 are disposed between the body 11 and the wheels WLB and WRB, respectively, rotate the wheels WLB and WRB, give cambers to the wheels WLB and WRB, and give cambers. It is an actuator as a camber variable mechanism for canceling. In the present embodiment, the actuators 31 and 32 are arranged between the body 11 and the wheels WLB and WRB, but between the body 11 and the wheels WLF and WRF. An actuator can be disposed, or an actuator can be disposed between the body 11 and the wheels WLF, WRF, WLB, WRB.

  By the way, the wheels WLF, WRF, WLB, and WRB include a wheel (not shown) formed of an aluminum alloy or the like, and a tire 36 that is fitted to the outer periphery of the wheel. As the tire 36, a low rolling resistance tire is used in which the loss tangent is reduced in the entire width direction so that the rolling resistance generated by deformation of the tread is reduced. In the present embodiment, the width of the tire 36 is made smaller than that of a normal tire in order to reduce the rolling resistance, but the tread pattern, which is a tread groove pattern, is shaped to reduce the rolling resistance, The material of at least the tread portion can be made to have a low rolling resistance.

  The loss tangent represents the degree of energy absorption when the tread is deformed, and can be represented by the ratio of the loss shear elastic modulus to the storage shear modulus. The smaller the loss tangent, the less energy is absorbed by the tread, so the rolling resistance generated in the tire 36 is reduced and the wear generated in the tire 36 is reduced. On the other hand, the greater the loss tangent, the more energy is absorbed by the tread, so the rolling resistance generated in the tire 36 increases and the wear generated in the tire 36 increases.

  In the vehicle having the above-described configuration, the rolling resistance of the tire 36 is reduced, so that the fuel consumption can be improved.

  Next, the structure of the actuators 31 and 32 for giving cambers to the wheels WLB and WRB and releasing the camber will be described. In this case, since the structures of the actuators 31 and 32 are the same, only the wheel WLB and the actuator 31 will be described.

  FIG. 3 is a cross-sectional view of the wheel according to the first embodiment of the present invention.

  In the figure, WLB is a wheel, 21 is a wheel, 31 is an actuator, and 36 is a tire.

  The actuator 31 includes a motor 41 as a drive unit for camber control fixed to a knuckle (not shown) as a base member, a movable plate 43 as a movable member arranged to be swingable with respect to the knuckle, the motor A crank mechanism 45 serving as a motion direction conversion mechanism that converts the rotational motion of 41 into a swing motion of the movable plate 43, the drive shaft 46 that transmits the rotation of the engine 12 (FIG. 2) to the wheel 21, and the like. The wheel 21 is rotatably supported with respect to the movable plate 43 and is connected to the drive shaft 46.

  The crank mechanism 45 is rotatably arranged with respect to the worm gear 51 as the first conversion element attached to the output shaft of the motor 41 and the knuckle, and meshes with the worm gear 51. A worm wheel 52 as a second conversion element, and an arm 53 as a third conversion element for connecting the worm wheel 52 and the movable plate 43 and as a connection element. The arm 53 is connected to the worm wheel 52 through a first connecting portion at a position eccentric from the rotation axis of the worm wheel 52 at one end, and is connected to the second end at the upper end of the movable plate 43 at the other end. It is connected to the movable plate 43 through the connecting portion. In this case, the movable plate 43 constitutes a fourth conversion element.

  The worm gear 51 and the worm wheel 52 convert the direction of the axis of the rotational motion of the worm gear 51 and the worm wheel 52, and the worm wheel 52 and the arm 53 convert the rotational motion of the worm wheel 52 into the straight motion of the arm 53, The straight movement of the arm 53 is converted into the swinging movement of the movable plate 43 by the arm 53 and the movable plate 43.

  Therefore, when the motor 41 is driven, the worm gear 51 and the worm wheel 52 are rotated, the arm 53 is advanced and retracted, and the movable plate 43 is rotated and swung. As a result, a camber equal to the angle at which the movable plate 43 is tilted with respect to the normal on the road surface is given to the wheel WLB.

  Next, the vehicle control apparatus having the above-described configuration will be described.

  FIG. 1 is a control block diagram of a vehicle in the first embodiment of the present invention.

  In the figure, 16 is a control unit as a first control device constituting the computer, 20 is a second control device and an automatic transmission control unit as a transmission control unit, and 61 is a first storage unit. ROM, 62 is a RAM as a second storage unit, 63 is a vehicle speed sensor as a vehicle speed detection unit for detecting the vehicle speed, and 64 is a steering angle as a steering amount representing an operation amount of the steering wheel 13 (FIG. 2). Steering sensor as a steering amount detection unit for detecting the steering wheel and a steering operation amount detection unit, 65 a yaw rate sensor as a yaw rate detection unit for detecting the yaw rate of the vehicle, and 66 a first acceleration detection for detecting lateral G Lateral G sensor as a part, 67 is a front / rear G sensor as a second acceleration detecting part for detecting front and rear G, and 68 is applied to each wheel WLB, WRB. A camber sensor as a camber detection unit for detecting a camber, 71 is an accelerator sensor as an accelerator operation amount detection unit for detecting a depression amount (accelerator opening degree) indicating an operation amount of the accelerator pedal 14, and 72 is an operation of the brake pedal 15. A brake sensor 73 serving as a brake operation amount detection unit for detecting a stepping amount (brake stroke) representing the amount, a suspension 73 serving as a suspension detection unit for detecting a stroke of a suspension device (not shown) of each wheel WLB, WRB, ie, a suspension stroke. Stroke sensor 75 is a load sensor as a load detection unit that detects the load applied to each wheel WLB, WRB, and 76 is a collapse allowance that is a deformation amount of the tire 36, that is, a tire collapse allowance detection unit that detects the tire collapse allowance. This is a tire collapse sensor. The body 11, the actuators 31, 32, the control unit 16, the wheels WLB, WRB and the like constitute a camber control device.

  The steering sensor 64 can detect the steering angle of the wheels WLF and WRF, the steering angular velocity, etc., instead of the steering angle, as the steering amount. The accelerator sensor 71 can detect the depression amount of the accelerator pedal 14, The stepping speed, stepping acceleration, and the like representing the amount of operation of the accelerator pedal 14 can be detected, and the brake sensor 72 replaces the amount of depression of the brake pedal 15 and the stepping speed, stepping acceleration, etc. representing the amount of operation of the brake pedal 15. Can be detected.

  The suspension stroke sensor 73 is composed of a height sensor, a magnetic sensor, etc., the load sensor 75 is composed of a load cell (strain sensor) disposed in the suspension device, and the tire collapse allowance sensor 76 is connected to the tire 36. It is constituted by an arranged load cell (strain sensor).

  The controller 16 controls the entire vehicle, and the automatic transmission controller 20 controls the entire automatic transmission 19. The automatic transmission 19 selectively connects gear elements of a transmission mechanism having planetary gears as a predetermined number of differential rotation devices, a sun gear, a ring gear, and a carrier constituting the planetary gear, Friction engagement elements consisting of clutches and brakes for fixing elements to an automatic transmission case as a casing, hydraulic servos for engaging and disengaging the friction engagement elements, and engagement with the hydraulic servos A valve for supplying hydraulic pressure is provided.

  Then, a shift processing means (not shown) of the automatic transmission control unit 20 performs a shift process, reads the depression amount of the accelerator pedal 14, the vehicle speed, etc., and determines a predetermined speed among a plurality of shift stages based on the depression amount, the vehicle speed, etc. When the shift output of the shift stage is generated, the engagement hydraulic pressure is supplied to a predetermined hydraulic servo based on the shift output, and the friction engagement element is engaged / disengaged. As a result, rotation of a gear ratio corresponding to the gear position is output from a predetermined gear element and transmitted to the propeller shaft 17. The speed ratio represents the ratio of the rotational speed input to the automatic transmission 19 to the rotational speed output from the automatic transmission 19, and when the speed ratio is 1 or more, the automatic transmission 19 When the underdrive shift suitable for traveling is performed and the gear ratio is smaller than 1, the automatic transmission 19 performs the overdrive shift suitable for high-speed traveling.

  By the way, in the present embodiment, a low rolling resistance tire is used as the tire 36. In this case, however, the rigidity of the tire 36 is low, so that traveling stability and turning stability are reduced accordingly. Therefore, in the present embodiment, it is determined whether or not a predetermined camber provision condition is satisfied so that running stability and turning stability can be increased even if the tire 36 is a low rolling resistance tire. When a predetermined camber provision condition is satisfied, the actuators 31 and 32 are operated, and a predetermined negative camber θ is imparted to the wheels WLB and WRB.

  In this case, if uneven wear occurs in the tire 36 as the vehicle travels with the camber θ applied to each of the wheels WLB and WRB, the life of the tire 36 is shortened.

  Therefore, in the present embodiment, in order to suppress the occurrence of uneven wear in the tire 36, when the vehicle is running with the camber θ applied to each wheel WLB, WRB, a predetermined camber is used. It is determined whether or not the release condition is satisfied. When the camber release condition is satisfied, the actuators 31 and 32 are operated, and the application of the camber θ to the wheels WLB and WRB is released.

  Next, the operation of the control unit 16 for imparting camber θ to each wheel WLB, WRB or canceling the provision of camber θ will be described.

  FIG. 4 is a first main flowchart showing the operation of the control unit in the first embodiment of the present invention. FIG. 5 is a second main flowchart showing the operation of the control unit in the first embodiment of the present invention. FIG. 6 shows a subroutine of the steering stability camber necessity determination process according to the first embodiment of the present invention, and FIG. 7 shows a subroutine of the straight travel stability camber necessity determination process according to the first embodiment of the present invention. FIGS. 8A and 8B are diagrams showing a subroutine of the ground load determination process in the first embodiment of the present invention.

  First, a determination index acquisition processing unit (not shown) of the control unit 16 performs a determination index acquisition process, and is a determination index necessary for assigning camber θ to each wheel WLB, WRB or canceling the assignment of camber θ. In this embodiment, the vehicle state representing the state of the vehicle and the operation state representing the state of operation of each operation unit by the driver who is the operator are acquired (steps S1 and S2).

  Therefore, the determination index acquisition processing means includes sensors of each sensor such as the yaw rate sensor 65, the lateral G sensor 66, the front / rear G sensor 67, the camber sensor 68, the suspension stroke sensor 73, the load sensor 75, and the tire collapse allowance sensor 76. The output is read, and the yaw rate, lateral G, front / rear G, camber θ, suspension stroke, load, tire collapse allowance, etc. are acquired as the vehicle state. The determination index acquisition processing unit calculates a roll angle based on the suspension stroke, and acquires the roll angle as a vehicle state. In addition, a roll angle sensor can also be acquired by arrange | positioning a roll angle sensor as a roll angle detection part, and reading the sensor output of this roll angle sensor. Further, the gear ratio acquisition processing means of the determination index acquisition processing means performs a gear ratio acquisition process, reads a shift command sent from the automatic transmission control unit 20 to the automatic transmission 19, and converts the ROM 61 into a shift command. The gear ratio recorded correspondingly is read and acquired as the vehicle state.

  The determination index acquisition processing means reads the sensor output of each sensor such as the steering sensor 64, the accelerator sensor 71, and the brake sensor 72, and sets the steering angle, the amount of depression of the accelerator pedal 14, and the depression of the brake pedal 15 as operation states. Get quantity etc. Further, the determination index acquisition processing unit acquires, as an operation state, a steering angular velocity representing a rate of change of the steering angle and a steering angular acceleration representing the rate of change of the steering angular velocity based on the steering angle.

  Next, the steering stability camber necessity determination processing means as the first camber necessity determination processing means (not shown) of the control unit 16 performs the steering stability camber necessity determination processing as the first camber necessity determination processing, It is determined whether or not a camber provision condition for turning is satisfied when the vehicle turns (steps S3 and S4). For this purpose, the steering stability camber necessity determination processing means reads the steering angle, determines whether or not the steering angle is equal to or greater than a threshold (threshold) value γth (step S3-1), and the steering angle is equal to or greater than the threshold γth. If it is, it is determined that the turning camber provision condition is satisfied (step S3-2).

When the camber grant condition is satisfied, the camber determination processing unit (not shown) of the control unit 16 performs camber determination processing, reads the camber θ, and the camber θ
−5 [°] ≦ θ <α [°]
Whether or not the camber θ is given to each wheel WLB, WRB is determined (step S5). The value α is a camber in a steady state set in advance for each vehicle.

When the camber θ is given to each wheel WLB, WRB, the control unit 16 finishes the process, and when the camber θ is not given, the camber control processing unit (not shown) of the control unit 16 performs the camber control process. . That is, the camber grant processing means of the camber control processing means performs camber grant processing and operates the actuators 31 and 32 to apply the camber θ to each wheel WLB and WRB.
−5 [°] ≦ θ <α [°]
Is given (step S6).

  At this time, as the camber θ is applied to each of the wheels WLB and WRB, the canvas last is generated in the direction facing the tires 36 of the wheels WLB and WRB, but the vehicle is turned leftward. Since the centrifugal force is generated in the vehicle, the ground contact load of the outer wheel WRB (outer wheel) increases, and the canvas last generated in the tire 36 of the wheel WRB is applied to the tire 36 of the inner wheel WLB (inner wheel). It becomes larger than the generated canvas last. Further, when the vehicle is turned rightward, the ground contact load of the outer wheel WLB (outer wheel) increases, and the canvas last generated in the tire 36 of the wheel WLB becomes larger on the inner wheel WRB (inner wheel). It becomes larger than the canvas last generated in the tire 36.

  Therefore, since sufficient centripetal force can be generated in the vehicle, even if a low rolling resistance tire is used as the tire 36, the turning stability can be increased.

  On the other hand, in the steering stability camber necessity determination process, when the camber provision condition for turning is not satisfied, the control unit 16 as a second camber necessity determination processing unit (not shown) and the traveling stable state determination The straight traveling stability camber necessity determination processing means as the processing means performs the straight traveling stability camber necessity determination processing as the second camber necessity determination processing and the traveling stable state determination processing. Whether the traveling condition of the vehicle is stable and whether the first and second traveling stability conditions are satisfied or not is determined whether or not the camber provision condition for straight traveling is satisfied (steps S7 and S8).

  Therefore, the straight traveling stability camber necessity determination processing means reads the vehicle speed and the steering angle, calculates the vehicle speed based on a predetermined time immediately before reading the vehicle speed, in the present embodiment, the vehicle speed for the past X [seconds]. Value, in this embodiment, the average vehicle speed is calculated, and the steering amount calculation value is calculated based on a predetermined time immediately before reading the steering angle, and in this embodiment, the steering angle during the past Y [seconds]. In this embodiment, the average steering angle is calculated, whether the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1, and whether the average steering angle during the past Y [seconds] is smaller than the threshold value γth1. (Step S7-1), the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1, and the average steering angle during the past Y [seconds] If the threshold γth1 smaller than the running state of the vehicle is stable and camber giving condition for the straight running is judged to be satisfied (step S7-2). In the present embodiment, when the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1, the first traveling stability condition is satisfied, and the average steering angle during the past Y [seconds] is greater than the threshold value γth1. If it is smaller, the second running stability condition is satisfied. The threshold value γth1 is set smaller than the threshold value γth.

  When the camber provision condition is satisfied, the camber determination processing unit reads the camber θ and determines whether or not the camber θ is applied to each wheel WLB, WRB (step S9). When the camber θ is not applied to the wheels WLB and WRB, the camber applying processing unit operates the actuators 31 and 32 to apply the camber θ to the wheels WLB and WRB (step S10).

  At this time, as the camber θ is applied to each of the wheels WLB and WRB, a canvas last is generated in a direction opposite to the tires 36 of the wheels WLB and WRB. Therefore, a low rolling resistance tire is used as the tire 36. However, when an external force is applied to the wheels WLB and WRB, the canvas last in the direction opposite to the external force increases. Therefore, the restoring force of the vehicle is increased and the running stability can be increased.

  Incidentally, as described above, if uneven wear occurs in the tire 36 as the vehicle travels with the camber θ applied to each wheel WLB, WRB, the life of the tire 36 is shortened.

  Therefore, the ground load determination processing means as the camber release determination processing means (not shown) of the control unit 16 performs the ground load determination processing as the camber release determination processing to determine whether or not the camber release condition is satisfied (step S11). , S12). For this purpose, the contact load determination processing means uses, as a contact load index, tire collapse allowance, suspension stroke, front / rear G, yaw rate, roll angle, load, brake stroke, accelerator opening, steering angle, steering angular velocity, steering angular acceleration, etc. And determine whether each ground load index is equal to or greater than the respective threshold (steps S11-1 to S11-11). In the present embodiment, any one of the ground load indices, If at least the tire crushing allowance is equal to or greater than the threshold, it is determined that the ground contact load causes uneven wear in the tire 36, and it is determined that the camber release condition is satisfied (step S11-12).

  When the camber release condition is satisfied in the ground load determination process, the camber release processing means of the camber control processing means performs the camber release process and operates the actuators 31 and 32 to apply camber to each wheel WLB and WRB. The addition of θ is canceled (step S13).

  In addition, when it is determined in the steering stability camber necessity determination process and the straight-line stability camber necessity determination process that the camber grant condition is not satisfied, the camber determination processing means reads the camber θ, and each wheel WLB, It is determined whether camber θ is given to WRB (step S14).

  And when camber (theta) is provided to each wheel WLB and WRB, the said camber cancellation | release process means starts the time-measurement by the timer not shown as a time-measurement process part incorporated in the control part 16, and predetermined time passes. Then (step S15), the actuators 31 and 32 are operated to release the camber θ from the wheels WLB and WRB (step S16).

  Thus, in the present embodiment, when the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1, and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1, each wheel WLB, Since camber θ is given to WRB, camber θ is given to each wheel WLB, WRB only while the vehicle is traveling at high speed or medium speed on a road such as an expressway, a main road, etc. The camber θ is not given when the vehicle is traveling at a low speed on a road other than the above, or when there is a traffic jam on a road such as an expressway or a main road. Further, when the camber release condition is satisfied while the vehicle is running with the camber θ applied to the wheels WLB and WRB, the application of the camber θ to the wheels WLB and WRB is cancelled. Accordingly, the frequency at which the camber θ is applied can be reduced, and the time during which the camber θ is applied can be shortened, so that occurrence of uneven wear in the tire 36 can be sufficiently suppressed. . As a result, the life of the tire 36 can be extended.

  Further, since the camber θ is not continuously applied to the wheels WLB and WRB while the vehicle is running, the rolling resistance of the tire 36 can be reduced accordingly. Therefore, fuel consumption can be improved.

  In this embodiment, when the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1 and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1, each wheel WLB, WRB The camber θ is given, but in a vehicle equipped with a navigation device, the vehicle position of the vehicle is detected by a GPS sensor as a current position detection unit, and the vehicle position is an expressway, a main road, etc. When the average vehicle speed for the past X [seconds] is equal to or greater than the threshold value vth1 and the average steering angle for the past Y [seconds] is smaller than the threshold value γth1, the camber θ is applied to each wheel WLB, WRB. Can be granted.

  In that case, in the navigation device, the vehicle position determination processing means of the control unit performs the vehicle position determination process, and based on the map data recorded in the information recording unit, the vehicle position is such as an expressway, a main road, etc. It is determined whether the vehicle is on the road, and the determination result is sent to the control unit 16. In the straight traveling stability camber necessity determination process, the vehicle position is on a road such as an expressway or a main road, the average vehicle speed during the past X [seconds] is equal to or higher than the threshold value vth1, and the past Y [second When the average steering angle is smaller than the threshold γth1, it is determined that the camber provision condition is satisfied.

  Further, the straight traveling stability camber necessity determination processing means reads the traffic information acquired by the navigation device from the traffic information center, etc., determines whether there is traffic congestion on the road based on the traffic information, etc. The vehicle position is on a road such as an expressway or a main road, there is no traffic jam on the road, the average vehicle speed for the past X [seconds] is equal to or greater than the threshold value vth1, and for the past Y [seconds] When the average steering angle is smaller than the threshold value γth1, it is determined that the camber provision condition is satisfied.

  Further, in the present embodiment, the steering stability camber necessity determination processing unit determines whether the steering angle is equal to or greater than a threshold value γth, and the camber provision condition is satisfied when the steering angle is equal to or greater than the threshold value γth. The average steering angle is calculated as the steering amount calculation value, and it is determined whether the average steering angle is equal to or greater than a threshold. When the average steering angle is equal to or greater than the threshold, It can be determined that the camber grant condition is satisfied.

  In the present embodiment, the straight-line stable camber necessity determination processing means has an average vehicle speed for the past X [seconds] equal to or greater than a threshold value vth1, and an average steering angle for the past Y [seconds] is a threshold value γth1. If the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1, and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1, the camber provision condition is satisfied. It is determined that the average vehicle speed during the past X [seconds] is greater than or equal to the threshold value vth1 and whether the steering angle has not exceeded the threshold during the past Y [seconds], When the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1 and the steering angle does not exceed the threshold during the past Y [seconds], the camber provision condition is satisfied. Judgment can be made.

  By the way, in the present embodiment, in the straight traveling stability camber necessity determination process, the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1, and the average steering angle during the past Y [seconds] is the threshold value γth1. If it is smaller, it is determined that the camber provision condition is satisfied, and if the average vehicle speed during the past X [seconds] is lower than the threshold value vth1, it is determined that the camber provision condition is not satisfied.

  However, for example, in a road situation where it is preferable to improve the driving stability at all times, such as when the road traffic is heavy or when traveling on an uphill road, the average vehicle speed during the past X [seconds] is Even if it is lower than the threshold value vth1, it is desirable to give camber θ to each wheel WLB, WRB.

  Accordingly, a second embodiment of the present invention will be described in which camber θ can be applied to each wheel WLB, WRB even when the average vehicle speed during the past X [seconds] is lower than the threshold value vth1. To do. In addition, about the thing which has the same structure as 1st Embodiment, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure.

  FIG. 9 is a diagram showing a subroutine of the straight-line stable camber necessity determination process in the second embodiment of the present invention.

  In this case, the straight travel stability camber necessity determination processing means as the second camber necessity determination processing means and the traveling stability state determination processing means reads the vehicle speed and the steering angle, and reads the predetermined speed immediately before reading the vehicle speed. In this embodiment, the vehicle speed calculation value is calculated based on the vehicle speed in the past X [seconds], and in this embodiment, the average vehicle speed is calculated, and the predetermined time immediately before the steering angle is read In the embodiment, the steering amount calculation value is calculated based on the steering angle during the past Y [seconds]. In this embodiment, the average steering angle is calculated, and the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1. And whether the average steering angle during the past Y [seconds] is smaller than the threshold γth1 (step S7-11), and during the past X [seconds] When the average vehicle speed is equal to or higher than the threshold value vth1 and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1, the driving state of the vehicle is stable, and the camber provision condition for straight driving is satisfied. (Step S7-12).

  Further, when the average vehicle speed during the past X [seconds] is lower than the threshold value vth1, or when the average steering angle during the past Y [seconds] is equal to or greater than the threshold value γth1, the straight traveling stable camber necessity determination processing means The gear ratio of the machine 19 and the average steering angle are read, and it is determined whether the gear ratio is smaller than 1 and the average steering angle during the past Y [seconds] is smaller than the threshold γth1 (step S7-13). When the ratio is smaller than 1 and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1, it is determined that the traveling state of the vehicle is stable and the camber provision condition is satisfied (step S7-12). ).

  When the speed ratio is 1 or more or the average steering angle during the past Y [seconds] is greater than or equal to the threshold value γth1, the straight traveling stability camber necessity determination processing means ends the process. In the present embodiment, when the average vehicle speed during the past X [seconds] is equal to or higher than the threshold value vth1, the first traveling stability condition is satisfied, and the average steering angle during the past Y [seconds] is the threshold value γth1. When smaller, the second traveling stability condition is satisfied, and when the speed ratio is smaller than 1, the third traveling stability condition is satisfied.

  Thus, even when the average vehicle speed during the past X [seconds] is lower than the threshold value vth1, the gear ratio is smaller than 1 and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1. Is determined that the camber grant condition has been met and camber θ is assigned to each wheel WLB, WRB. Therefore, when the road traffic is heavy or the road is running on an uphill road, Stability can be increased.

  In the present embodiment, after determining whether or not the first and second traveling stability conditions are satisfied, it is determined whether or not the second and third traveling stability conditions are satisfied. Is determined whether the first to third traveling stability conditions are satisfied, the first traveling stability condition or the third traveling stability condition is satisfied, and the second traveling stability condition is satisfied. Thus, it can be determined that the camber grant condition is satisfied.

  By the way, in the first embodiment, in the straight traveling stable camber necessity determination process, the average vehicle speed during the past X [seconds] is equal to or higher than the threshold value vth1, and the average steering angle during the past Y [seconds]. Is smaller than the threshold value γth1, it is determined that the camber provision condition is satisfied. For example, when the average steering angle during the past Y [seconds] is equal to or greater than the threshold value γth1, it is determined that the camber provision condition is not satisfied. Is done.

  However, for example, when a curve having a relatively large radius of curvature continues, a steering wheel 13 as an operation unit for steering the vehicle and as a steering member in order to temporarily avoid unevenness on the road or the like. In a road situation where it is preferable to continuously increase the driving stability, such as when the operation is greatly operated (FIG. 2), the average steering angle during the past Y [seconds] is greater than or equal to the threshold γth1 Even so, it is desirable to give camber θ to each wheel WLB, WRB.

  Therefore, even if the average steering angle during the past Y [seconds] is greater than or equal to the threshold value γth1, the third embodiment of the present invention is such that camber θ can be imparted to each wheel WLB, WRB. Will be described. In addition, about the thing which has the same structure as 1st, 2nd embodiment, the same code | symbol is provided and the effect of the embodiment is used about the effect of the invention by having the same structure.

  FIG. 10 is a diagram showing a subroutine of the straight-ahead stable camber necessity determination process according to the third embodiment of the present invention.

  In this case, the straight travel stability camber necessity determination processing means as the second camber necessity determination processing means and the traveling stability state determination processing means reads the vehicle speed and the steering angle, and reads the predetermined speed immediately before reading the vehicle speed. In this embodiment, the vehicle speed calculation value is calculated based on the vehicle speed in the past X [seconds], and in this embodiment, the average vehicle speed is calculated, and the predetermined time immediately before the steering angle is read In the embodiment, the steering amount calculation value is calculated based on the steering angle during the past Y [seconds]. In this embodiment, the average steering angle is calculated, and the average vehicle speed during the past X [seconds] is equal to or greater than the threshold value vth1. And whether the average steering angle during the past Y [seconds] is smaller than the threshold γth1 (step S7-21), and during the past X [seconds] When the average vehicle speed is equal to or higher than the threshold value vth1 and the average steering angle during the past Y [seconds] is smaller than the threshold value γth1, the driving state of the vehicle is stable, and the camber provision condition for straight driving is satisfied. Is determined (step S7-22).

  Further, when the average vehicle speed during the past X [seconds] is lower than the threshold value vth1, or when the average steering angle during the past Y [seconds] is equal to or greater than the threshold value γth1, the straight traveling stable camber necessity determination processing means The gear ratio of the machine 19 is read and it is determined whether or not the gear ratio is smaller than 1 (step S7-23). If the gear ratio is smaller than 1, the traveling state of the vehicle is stable, and the straight traveling camber It is determined that the grant condition is satisfied (step S7-22).

  When the speed ratio is 1 or more, the straight-line stable camber necessity determination processing means ends the process. In the present embodiment, when the average vehicle speed during the past X [seconds] is equal to or higher than the threshold value vth1, the first traveling stability condition is satisfied, and the average steering angle during the past Y [seconds] is the threshold value γth1. When smaller, the second traveling stability condition is satisfied, and when the speed ratio is smaller than 1, the third traveling stability condition is satisfied.

  Thus, even if the average steering angle during the past Y [seconds] is equal to or greater than the threshold value γth1, if the gear ratio is smaller than 1, it is determined that the camber provision condition is satisfied, and each wheel WLB, Since the camber θ is given to the WRB, for example, when a curve with a relatively large curvature radius continues, even when the steering wheel 13 is largely operated to temporarily avoid unevenness on the road, etc. The running stability can be continuously increased.

  In this embodiment, after determining whether or not the first and second traveling stability conditions are satisfied, it is determined whether or not the third traveling stability condition is satisfied. It is determined whether or not the third traveling stability condition is satisfied, and when the first traveling stability condition or the second traveling stability condition is satisfied and the third traveling stability condition is satisfied, the camber applying condition is It can be determined that it has been established.

  In the present embodiment, the straight-line stable camber necessity determination process is performed based on the gear ratio of the automatic transmission 19, but the transmission of a continuously variable transmission, a manual transmission, or the like Based on the speed ratio, it is possible to determine whether or not the straight traveling stable camber is necessary.

  In the case of a continuously variable transmission, the gear ratio acquisition processing means reads a shift command sent from the continuously variable transmission control unit as the transmission control unit to the continuously variable transmission, and responds to the shift command from the ROM. The recorded gear ratio is read and acquired as the vehicle state. In the case of a manual transmission, the gear ratio acquisition processing means reads a signal indicating the gear ratio from a shift lever or the like as a gear shift instruction device and acquires it as a vehicle state.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

11 Body 16 Control unit 31, 32 Actuator WLF, WRF, WLB, WRB Wheel

Claims (5)

The body of the vehicle,
A plurality of wheels arranged rotatably with respect to the body;
A camber variable mechanism that is disposed on a predetermined wheel of the wheels and that imparts camber to the wheel;
Traveling stable state determination processing means for determining whether the traveling state of the vehicle is stable;
A camber control device comprising camber applying processing means for applying a negative camber to the predetermined wheel when the running state of the vehicle is stable. While having a vehicle speed detector for detecting the vehicle speed,
The traveling stable state determination processing means determines whether or not a vehicle speed calculation value calculated based on a vehicle speed at a predetermined time is equal to or greater than a threshold value. The camber control device according to claim 1, wherein the camber control device determines that it is stable. While having a steering amount detection unit for detecting the steering amount,
The traveling stable state determination processing means determines whether or not a steering amount calculation value calculated based on a steering amount at a predetermined time is smaller than a threshold value. The camber control device according to claim 1, wherein the camber control device determines that is stable. And having a gear ratio acquisition processing means for acquiring a gear ratio of a transmission disposed in the vehicle,
The camber control device according to any one of claims 1 to 3, wherein the traveling stable state determination processing unit determines that the traveling state of the vehicle is stable when the speed ratio is smaller than one.   The camber control device according to claim 1, wherein the predetermined wheel is a rear wheel.

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