JP2011093414A - Camber angle control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camber angle control device for a vehicle, used for a four-wheel drive vehicle in which the driving force of front wheels and rear wheels are distributed and controlled according to the traveling state of the vehicle, and which improves the life of tires and secures the traveling stability of the vehicle by suppressing partial wear on the tires. <P>SOLUTION: The camber angle control device 100 for the vehicle, used for a four-wheel drive vehicle in which the driving force of the front wheels 2FL, 2FR and the rear wheels 2RL, 2RR are distributed and controlled according to the traveling state of the vehicle 1 includes: state quantity acquiring parts 61b, 61c acquiring the state quantity of the vehicle 1; a rear wheel braking and driving force acquiring part acquiring the presence of the braking and driving force of the rear wheels 2RL, 2RR; a traveling state acquiring parts 63a, 80 acquiring the traveling state of the vehicle 1; a camber angle adjusting mechanism 44-50 adjusting the camber angle of the rear wheels 2RL, 2RR; and a control unit 100 controlling the camber angle adjusting mechanism 44-50 based on the state quantity acquiring parts 61a, 61b, 61c and the rear wheel braking and driving force acquiring part and the traveling state acquiring parts 63a, 80. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a camber angle control device for a vehicle that is used in a vehicle having a camber angle adjustment mechanism that adjusts a camber angle of a wheel, and in particular, suppresses uneven wear of a tire to improve the life of the tire and improve the vehicle life. The present invention relates to a camber angle control device for a vehicle that can ensure traveling stability.

  2. Description of the Related Art Conventionally, there has been known a technique for ensuring traveling stability of a vehicle by adjusting a camber angle of a wheel according to the traveling state of the vehicle. With regard to this type of technology, for example, Patent Document 1 discloses a technology for improving the limit performance of a vehicle during cornering traveling by detecting the vehicle speed and applying a negative camber to the wheel at a predetermined vehicle speed or higher. Yes.

JP-A-60-193781

  However, in the technique disclosed in Patent Document 1 described above, when a vehicle travels on a highway or a main road for a long time at a speed higher than a predetermined vehicle speed, a negative camber is continuously applied to the wheels during that time. As a result, the life of the tire is shortened and the ground contact surface of the tire is non-uniform so that the running stability of the vehicle is lowered.

  In particular, the influence of uneven wear is greater in the case of a four-wheel drive vehicle that can also drive the rear wheels, compared to a front wheel drive vehicle that is a driven wheel with a light rear wheel load.

  The present invention solves the above-described problem, and is used in a four-wheel drive vehicle in which the driving force of the front wheels and the rear wheels is distributed and controlled according to the running state of the vehicle. An object of the present invention is to provide a camber angle control device for a vehicle capable of improving the life of a tire and ensuring the running stability of the vehicle.

  Therefore, the present invention provides a vehicle camber angle control device used in a four-wheel drive vehicle in which the driving force of front wheels and rear wheels is distributed and controlled according to the running state of the vehicle. An acquisition unit, a rear wheel braking / driving force acquisition unit that acquires presence / absence of braking / driving force of the rear wheel, a traveling state acquisition unit that acquires a traveling state of the vehicle, and a camber angle that adjusts a camber angle of the rear wheel An adjustment mechanism, and a control unit that controls the camber angle adjustment mechanism based on the state quantity acquisition unit, the rear wheel braking / driving force acquisition unit, and the traveling state acquisition unit.

  Further, the control unit is such that the state quantity of the vehicle acquired by the state quantity acquisition unit is a predetermined stable state, and the rear wheel braking / driving force acquisition unit does not acquire the braking / driving force of the rear wheel, When the traveling state of the vehicle acquired by the traveling state acquisition unit is a predetermined straight traveling state, the camber angle adjusting mechanism controls the camber angle of the rear wheel to a negative camber.

  According to the first aspect of the present invention, in the vehicle camber angle control device used for a four-wheel drive vehicle in which the driving force of the front wheels and the rear wheels is distributed and controlled in accordance with the running state of the vehicle, the state quantity of the vehicle is determined. A state quantity acquisition unit to acquire, a rear wheel braking / driving force acquisition unit to acquire presence / absence of braking / driving force of the rear wheel, a driving state acquisition unit to acquire the driving state of the vehicle, and a camber angle of the rear wheel And a control unit that controls the camber angle adjustment mechanism based on the state quantity acquisition unit, the rear wheel braking / driving force acquisition unit, and the running state acquisition unit. It is possible to suppress uneven wear, improve the tire life, and ensure the running stability of the vehicle.

  According to a second aspect of the present invention, the control unit is such that the vehicle state quantity acquired by the state quantity acquisition unit is in a predetermined stable state, and the rear wheel braking / driving force acquisition unit acquires the rear When the braking / driving force of the wheel is not acquired and the traveling state of the vehicle acquired by the traveling state acquisition unit is a predetermined straight traveling state, the camber angle adjusting mechanism controls the camber angle of the rear wheel to a negative camber. Therefore, it is possible to ensure the running stability of the vehicle when the vehicle is running in a predetermined straight traveling state with two-wheel drive.

It is the schematic diagram which showed typically the vehicle interior by which the camber angle control apparatus for vehicles in 1st Embodiment is mounted. It is a front view of the suspension apparatus of a 2nd state. It is a front view of the suspension device in the first state. It is the block diagram which showed the electrical structure of the camber angle control apparatus for vehicles. It is a flowchart which shows a state quantity determination process. It is a flowchart which shows a driving | running | working state judgment process. It is a flowchart which shows a camber control process.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram schematically showing a vehicle 1 on which a control unit 100 according to the first embodiment is mounted. Note that arrows UD, LR, and FB in FIG. 1 indicate the up-down direction, the left-right direction, and the front-rear direction of the vehicle 1, respectively.

  First, a schematic configuration of the vehicle 1 will be described. As shown in FIG. 1, the vehicle 1 includes a body frame BF, a plurality of (four wheels in this embodiment) wheels 2 that support the body frame BF, and a plurality of wheels 2 (in this embodiment, left and right). A wheel drive device 3 (3FL, 3FR, 3RL, 3RR) such as an in-wheel motor for rotationally driving the front wheels 2FL, 2FR and the left and right rear wheels 2RL, 2RR, and a plurality of suspensions of the wheels 2 on the vehicle body frame BF. The suspension device 4 mainly includes a suspension device 4 and a steering device 5 that steers a part of the plurality of wheels 2 (in this embodiment, left and right front wheels 2FL and 2FR).

  Next, the detailed configuration of each part will be described. As shown in FIG. 1, the wheel 2 includes left and right front wheels 2FL and 2FR positioned on the front side (arrow F direction side) of the vehicle 1, and left and right rear wheels positioned on the rear side (arrow B direction side) of the vehicle 1. Wheels 2RL and 2RR are provided. In the present embodiment, the left and right front wheels 2FL, 2FR and the left and right rear wheels 2RL, 2RR are configured as drive wheels that are rotationally driven by the wheel drive device 3 (3FL, 3FR, 3RL, 3RR), and the vehicle. The driving force is distributed and controlled according to the traveling state of 1.

  As described above, the wheel driving device 3 is a device for rotationally driving the left and right front wheels 2FL, 2F and the left and right rear wheels 2RL, 2RRR, and as will be described later, the electric motor 3a (3FLa, 3FRa, 3RLa, 3RRa). ) (See FIG. 3).

  In the present embodiment, the left and right front wheels 2FL, 2FR wheel drive devices 3FL, 3FR and the left and right rear wheels 2RL, 2RR wheel drive devices 3RL, 3RR can be controlled independently. For example, normally, only the left and right front wheels 2FL and 2FR are driven, and the rear wheels 2RL and 2RR are driven at the time of start, fully open acceleration, four-wheel drive and braking.

  In the present embodiment, the wheel drive device 3 (3FL, 3FR, 3RL, 3RR) is configured such that an electric motor 3a (3FLa, 3FRa, 3RLa, 3RRa) such as an in-wheel motor is disposed on each wheel 2. As another form, the wheel drive device 3 may be connected to the left and right front wheels 2FL, 2FR and the left and right rear wheels 2RL, 2RR via a differential gear and a drive shaft (not shown).

  When the driver operates the accelerator pedal 61, a rotational driving force is applied from the wheel drive device 3 to the left and right front wheels 2FL, 2FR and / or the left and right rear wheels 2RL, 2RR, and the left and right front wheels 2FL, 2FR and / Or the left and right rear wheels 2RL, 2RR are driven to rotate according to the amount of operation of the accelerator pedal 61.

  The suspension device 4 functions as a so-called suspension for mitigating vibration transmitted from the road surface to the vehicle body frame BF via the wheels 2, and is configured to be extendable. As shown in FIG. Are provided corresponding to each. In addition, among the suspension devices 4 in the present embodiment, the suspension device 4 disposed on the rear wheels 2RL and 2RR also has a function as a camber angle adjustment mechanism that adjusts the camber angles of the rear wheels 2RL and 2RR.

  Here, the detailed configuration of the suspension device 4 for the rear wheels 2RL and 2RR will be described with reference to FIG. FIG. 2 is a front view of the suspension device 4RR for the right rear wheel 2RR. Here, only the configuration that functions as the camber angle adjustment mechanisms 44 to 50 will be described, and the configuration that functions as the suspension is the same as a known configuration, and thus the description thereof is omitted. In addition, since the configuration of the camber angle adjusting mechanisms 44 to 50 of each suspension device 4 is common to the rear wheels 2RL and 2RR, the suspension device 4RR corresponding to the right rear wheel 2RR is illustrated in FIG. 2 as a representative example. To do.

  As shown in FIG. 2, the suspension device 4 transmits a knuckle 43 supported by the vehicle body frame BF via a strut 41 and a lower arm 42, an RR motor 44RR that generates a driving force, and a driving force of the RR motor 44RR. The worm wheel 45 and the arm 46 are configured to mainly include a movable plate 47 that is swingably driven with respect to the knuckle 43 by the driving force of the RR motor 44RR transmitted from the worm wheel 45 and the arm 46. .

  The knuckle 43 supports the wheel 2, and as shown in FIG. 2, the upper end (upper side in FIG. 2) is connected to the strut 41, and the lower end (lower side in FIG. 2) is connected to the lower arm 42 via a ball joint. It is connected to.

  The RR motor 44RR applies a driving force for swing driving to the movable plate 47, is constituted by a DC motor, and has a worm (not shown) formed on its output shaft 44a.

  The worm wheel 45 transmits the driving force of the RR motor 44RR to the arm 46, meshes with a worm formed on the output shaft 44a of the RR motor 44RR, and constitutes a staggered shaft gear pair together with the worm.

  The arm 46 transmits the driving force of the RR motor 44RR transmitted from the worm wheel 45 to the movable plate 47, and has one end (right side in FIG. 2) via the first connecting shaft 48 as shown in FIG. The other end (left side in FIG. 2) is connected to the upper end (upper side in FIG. 2) via the second connection shaft 49 while being connected to a position eccentric from the rotation shaft 45 a of the worm wheel 45.

  The movable plate 47 supports the wheel 2 in a rotatable manner. As described above, the upper end (upper side in FIG. 2) is coupled to the arm 46, and the lower end (lower side in FIG. 2) is interposed via the camber shaft 50. The knuckle 43 is pivotally supported so as to be swingable. The movable plate 47 can also serve as a case of the wheel drive device 3 (3RR) such as an in-wheel motor.

  According to the suspension device 4 configured as described above, when the RR motor 44RR is driven, the worm wheel 45 rotates and the rotational motion of the worm wheel 45 is converted into linear motion of the arm 46. As a result, when the arm 46 moves linearly, the movable plate 47 is driven to swing with the camber shaft 50 as the swinging shaft, and the chamber angles of the rear wheels 2RL and 2RR are adjusted.

  In this embodiment, each motor 44, worm wheel 45, arm 46, movable plate 47, each connecting shaft 48, 49, and camber shaft 50 constitute camber angle adjusting mechanisms 44-50. In the present embodiment, the connecting shafts 48 and 49 and the rotating shaft 45a of the worm wheel 45 are in the direction (arrow R direction) from the body frame BF toward the wheel 2 in the first connecting shaft 48, the rotating shaft 45a, The first camber state (the state shown in FIG. 3) that is arranged in a straight line in the order of the two connecting shafts 49 and the rotating shaft 45 a, the first connecting shaft 48, and the second connecting shaft 49 are arranged in a straight line in that order. The camber angles of the rear wheels 2RL and 2RR are adjusted so that either one of the second camber state (the state shown in FIG. 2) is reached.

  Thereby, in the state in which the camber angles of the rear wheels 2RL and 2RR are adjusted, even if an external force is applied to the rear wheels 2RL and 2RR, no force in the direction of rotating the arm 46 is generated, and the rear wheels 2RL and 2RR The camber angle can be maintained.

  Further, in the present embodiment, in the first camber state (the state shown in FIG. 3), the camber angle of the rear wheels 2RL and 2RR is a predetermined angle in the minus direction (-3 ° in the present embodiment, hereinafter referred to as “first camber”). The negative camber is applied to the rear wheels 2RL and 2RR. On the other hand, in the second camber state (the state shown in FIG. 2), the camber angles of the rear wheels 2RL and 2RR are adjusted to 0 ° (hereinafter referred to as “second camber angle”).

  Returning to FIG. The steering device 5 is a device for steering an operation of the steering 63 by the driver to the left and right front wheels 2FL, 2FR, and is configured as a so-called rack and pinion type steering gear.

  According to the steering device 5, the operation (rotation) of the steering 63 by the driver is first transmitted to the universal joint 52 via the steering column 51, and the pinion 53 a of the steering box 53 is changed while the angle is changed by the universal joint 52. Is transmitted as rotational motion. Then, the rotational motion transmitted to the pinion 53a is converted into a linear motion of the rack 53b, and the tie rod 54 connected to both ends of the rack 53b moves by the linear motion of the rack 53b. As a result, the tie rod 54 pushes and pulls the knuckle 55, so that a predetermined steering angle is given to the wheel 2.

  The accelerator pedal 61 and the brake pedal 62 are operation members operated by the driver, and the traveling speed and braking force of the vehicle 1 are determined according to the operation state (depression amount, depressing speed, etc.) of the pedals 61 and 62. The wheel drive device 3 is driven and controlled. The steering 63 is an operation member operated by the driver, and the left and right front wheels 2FL and 2FR are steered by the steering device 5 according to the operation state (steer angle, steer angular velocity, etc.).

  The control unit 100 is a device for controlling each part of the vehicle 1 configured as described above. For example, the camber angle adjusting mechanism 44 (see FIG. 4) according to the operation state of the pedals 61 and 62 and the steering 63. ) Is controlled.

  Next, a detailed configuration of the control unit 100 will be described with reference to FIG. FIG. 4 is a block diagram showing an electrical configuration of the control unit 100. As shown in FIG. 4, the control unit 100 includes a CPU 71, a ROM 72, and a RAM 73, which are connected to the input / output port 75 via the bus line 74. The input / output port 75 is connected to a device such as the wheel drive device 3.

  The CPU 71 is an arithmetic unit that controls each unit connected by the bus line 74, and the ROM 72 is a control program executed by the CPU 71 (for example, the program of the flowcharts shown in FIGS. 5 to 7), fixed value data, or the like. Is a non-rewritable non-volatile memory.

  The RAM 73 is a memory for storing various data in a rewritable manner when the control program is executed, and as shown in FIG. 4, a camber flag 73a, a state amount flag 73b, and a running state flag 73c are provided.

  The camber flag 73a is a flag that indicates whether or not the camber angles of the rear wheels 2RL and 2RR are adjusted to the first camber angle. The CPU 71 determines that the rear wheel is in a state where the camber flag 73a is on. It is determined that the camber angles of 2RL and 2RR are adjusted to the first camber angle.

  The state quantity flag 73b is used to determine whether the vehicle 1 is stable or unstable, and is a flag that indicates whether the state quantity of the vehicle 1 satisfies a predetermined condition. A state quantity determination process (see FIG. 5) described later. ) Is switched on or off at the time of execution. The state amount flag 73b in the present embodiment is switched on when at least one of the operation amounts of the accelerator pedal 61, the brake pedal 62, and the steering 63 is equal to or greater than a predetermined operation amount, and the CPU 71 Determines that the state quantity of the vehicle 1 satisfies a predetermined condition when the state quantity flag 73b is on.

  The traveling state flag 73b is used to determine whether the vehicle 1 is traveling straight ahead at a high speed or otherwise, and is a flag that indicates whether the traveling state of the vehicle 1 is a predetermined straight traveling state. It is switched on or off when executing (see FIG. 6). The traveling state flag 73c in the present embodiment is switched on when the traveling speed of the vehicle 1 is equal to or higher than the predetermined traveling speed and the operation amount of the steering 63 is equal to or smaller than the predetermined operation amount. Determines that the traveling state of the vehicle 1 is a predetermined straight traveling state when the traveling state flag 73c is on.

  As described above, the wheel drive device 3 is a device for rotationally driving the left and right front wheels 2FL, 2FR and the left and right rear wheels 2RL, 2RR (see FIG. 1). The left and right front wheels 2FL, 2FR and the left and right front wheels 2FL, 2FR Each electric motor 3FLa, 3FRa, 3RLa, 3RRa that imparts a rotational driving force to the rear wheels 2RL, 2RR, and a drive control circuit that drives and controls the electric motors 3FLa, 3FRa, 3RLa, 3RRa based on instructions from the CPU 71 (FIG. (Not shown). However, the wheel drive device 3 is not limited to the electric motors 3FLa, 3FRa, 3RLa, and 3RRa, and other drive sources can naturally be employed. Examples of other drive sources include a hydraulic motor and an engine.

  The motor 44 is a device for adjusting the camber angle of the rear wheels 2RL and 2RR. As described above, the driving force for swinging the movable plate 47 (see FIGS. 2 and 3) of each suspension device 4 is provided. Are mainly provided with a RL motor 44RL, RR motors 44RL to 44RR, and a drive control circuit (not shown) for controlling the motors 44RL and 44RR based on instructions from the CPU 71. Yes.

  The acceleration sensor device 80 is a device for detecting the acceleration of the vehicle 1 and outputting the detection result to the CPU 71. The acceleration sensor device 80a includes a longitudinal acceleration sensor 80a, a lateral acceleration sensor 80b, and the acceleration sensors 80a and 80b. It mainly includes an output circuit (not shown) that processes the detection result and outputs it to the CPU 71.

  The longitudinal acceleration sensor 80a is a sensor that detects and acquires the acceleration in the longitudinal direction (arrow FB direction in FIG. 1) in the vehicle 1 (body frame BF), that is, the so-called longitudinal G. The lateral acceleration sensor 80b is the vehicle 1 This is a sensor that detects and acquires the acceleration in the left-right direction (the direction of arrow LR in FIG. 1) of the (body frame BF), so-called lateral G. In the present embodiment, each of the acceleration sensors 80a and 80b is configured as a piezoelectric sensor using a piezoelectric element.

  Further, the CPU 71 time-integrates the detection results (front-rear G, lateral G) of the respective acceleration sensors 80a, 80b input from the acceleration sensor device 80, and calculates speeds in two directions (front-rear direction and left-right direction), respectively. At the same time, the traveling speed of the vehicle 1 can be acquired by synthesizing these two-direction components.

  The accelerator pedal sensor device 61a is a device for detecting and acquiring the operation amount of the accelerator pedal 61 and outputting the detection result to the CPU 71, and an angle sensor (not shown) for detecting the depression amount of the accelerator pedal 61. And an output circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the CPU 71.

  The brake pedal sensor device 62a is a device for detecting and acquiring the operation amount of the brake pedal 62 and outputting the detection result to the CPU 71, and an angle sensor (not shown) for detecting the depression amount of the brake pedal 62. And an output circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the CPU 71.

  The steering sensor device 63a is a device for detecting and acquiring the operation amount of the steering 63 and outputting the detection result to the CPU 71, an angle sensor (not shown) for detecting the steering angle of the steering 63, It mainly includes an output circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the CPU 71.

  The rear wheel braking / driving force sensor device 64a is a device for detecting and acquiring whether the rear wheels 2RL and 2RR are generating braking / driving force, and outputting the detection result to the CPU 71, and the rear wheels 2RL and 2RR. Are mainly provided with a rotation sensor (not shown) for detecting the rotation of the electric motors 3RLa and 3RRa, and an output circuit (not shown) for processing the detection result of the rotation sensor and outputting it to the CPU 71.

  In the present embodiment, each angle sensor is configured as a contact-type potentiometer using electric resistance. Further, the CPU 71 time-differentiates the detection results (operation amounts) of the angle sensors input from the sensor devices 61a, 62a, and 63a, and acquires the depression speeds of the pedals 61 and 62 and the steering angular speed of the steering 63. be able to. Further, the CPU 71 can obtain the steering angular acceleration of the steering 63 by differentiating the obtained steering angular velocity of the steering 63 with respect to time.

  Here, in this embodiment, for example, the accelerator pedal sensor device 61a, the brake pedal sensor device 62a, and the steering sensor device 63a correspond to the state quantity acquisition unit, and the rear wheel braking / driving force sensor device 64a acquires the rear wheel braking / driving force. The longitudinal acceleration sensor 80a and the steering sensor device 63a correspond to the traveling state acquisition unit.

  As another input / output device 90 illustrated in FIG. 4, for example, the current position of the vehicle 1 is acquired using GPS, and the acquired current position of the vehicle 1 is associated with map data in which information on roads is stored. The navigation apparatus etc. which are acquired in this way are illustrated.

  Next, the state quantity determination process will be described with reference to FIG. FIG. 5 is a flowchart showing the state quantity determination process. This process is a process that is repeatedly executed by the CPU 71 (for example, at intervals of 0.2 seconds) while the power of the control unit 100 is turned on, and determines whether the state quantity of the vehicle 1 satisfies a predetermined condition. It is processing to do.

  Regarding the state quantity determination processing, the CPU 71 first acquires the operation amount (depression amount) of the accelerator pedal 61, the operation amount (depression amount) of the brake pedal 62, and the operation amount (steer angle) of the steering 63 (S1, S2). S3), it is determined whether or not at least one of the obtained operation amounts of the pedals 61 and 62 and the operation amount of the steering 63 is equal to or greater than a predetermined operation amount (S4). In the process of S4, the operation amounts of the pedals 61 and 62 and the operation amount of the steering 63 acquired in the processes of S1 to S3 respectively correspond to the operation amounts of the pedals 61 and 62 and the operation amount of the steering 63, respectively. Then, the threshold value stored in advance in the ROM 72 (in this embodiment, when the vehicle 1 accelerates, brakes or turns while the camber angle of the rear wheels 2RL and 2RR is the second camber angle, the rear wheels 2RL and 2RR Is compared with a limit value at which it is determined that there is a risk of slipping), and it is determined whether or not the current operation amount of each pedal 61 and 62 and the operation amount of the steering 63 are equal to or greater than a predetermined operation amount.

  As a result, when it is determined that at least one of the operation amounts of the pedals 61 and 62 and the operation amount of the steering 63 is equal to or greater than the predetermined operation amount (unstable state) (S4: Yes) Then, the state quantity flag 73b is turned on (S5), and the state quantity determination process is terminated. That is, in this state quantity determination process, when at least one of the operation amounts of the pedals 61 and 62 and the operation amount of the steering 63 is equal to or greater than a predetermined operation amount, the state quantity of the vehicle 1 is a predetermined amount. Judge that the unstable state is satisfied.

  On the other hand, if it is determined as a result of the processing of S4 that both the operation amount of each pedal 61, 62 and the operation amount of the steering 63 are smaller than the predetermined operation amount (stable state) (S4: No), The amount flag 73b is turned off (S6), it is determined that the state amount of the vehicle 1 satisfies a predetermined stable state, and this state amount determination process is terminated.

  Next, the traveling state determination process will be described with reference to FIG. FIG. 6 is a flowchart showing the running state determination process. This process is a process that is repeatedly executed by the CPU 71 (for example, at intervals of 0.2 seconds) while the power of the control unit 100 is turned on, and whether or not the traveling state of the vehicle 1 is a predetermined straight traveling state. This is a process for determining whether or not.

  Regarding the travel state determination process, the CPU 71 first acquires the travel speed of the vehicle 1 (S11), and determines whether the acquired travel speed of the vehicle 1 is equal to or lower than a predetermined speed (S12). In the process of S12, the travel speed of the vehicle 1 acquired in the process of S11 is compared with the threshold value stored in advance in the ROM 72, and whether or not the current travel speed of the vehicle 1 is equal to or higher than a predetermined speed. Determine whether.

  As a result, when it is determined that the traveling speed of the vehicle 1 is smaller than the predetermined speed (S12: No), the traveling state flag 73c is turned off (S16), and this traveling state determination process is terminated.

  On the other hand, when it is determined that the traveling speed of the vehicle 1 is equal to or higher than the predetermined speed as a result of the processing of S12 (S12: Yes), the operation amount (steer angle) of the steering 63 is acquired (S13). It is determined whether or not the acquired operation amount of the steering 63 is equal to or less than a predetermined operation amount (S14). In the process of S14, the operation amount of the steering wheel 63 acquired in the process of S13 and the threshold value stored in advance in the ROM 72 (in this embodiment, the state quantity of the vehicle 1 in the state quantity determination process shown in FIG. And a value smaller than the operation amount of the steering 63 for determining whether or not a predetermined condition is satisfied), it is determined whether or not the current operation amount of the steering 63 is equal to or greater than the predetermined operation amount. .

  As a result, when it is determined that the operation amount of the steering 63 is equal to or less than the predetermined operation amount (S14: Yes), the traveling state flag 73c is turned on (S15), and this traveling state determination process is ended. . That is, in this traveling state determination means, when the traveling speed of the vehicle 1 is equal to or higher than a predetermined speed and the operation amount of the steering 63 is equal to or smaller than the predetermined operation amount, the traveling state of the vehicle 1 is a predetermined straight traveling state. It is judged that.

  On the other hand, when it is determined that the operation amount of the steering wheel 63 is larger than the predetermined operation amount as a result of the processing of S14 (S14: No), the traveling state flag 73c is turned off (S16), and this traveling state determination processing Exit.

  Next, camber control processing will be described with reference to FIG. FIG. 7 is a flowchart showing camber control processing. This process is a process that is repeatedly executed by the CPU 71 (for example, at intervals of 0.2 seconds) while the control unit 100 is powered on, and a process for adjusting the camber angles of the left and right rear wheels 2RL and 2RR. It is.

  Regarding the camber control process, the CPU 71 first determines whether or not the state quantity flag 73b is on (S41). If it is determined that the state quantity flag 73b is on (S41: Yes), It is determined whether or not the flag 73a is on (S42). As a result, when it is determined that the camber flag 73a is off (S42: No), the RL motor 44RL and the RR motor 44RR are operated, and the camber angles of the left and right rear wheels 2RL, 2RR are set to the first camber angle. The negative camber is applied to the left and right rear wheels 2RL, 2RR (S43), the camber flag 73a is turned on (S44), and the camber control process is terminated.

  As a result, when the state quantity of the vehicle 1 satisfies the predetermined condition, that is, at least one of the operation quantity of each pedal 61 and 62 and the operation quantity of the steering 63 is equal to or greater than the predetermined operation quantity. If it is determined that the rear wheels 2RL and 2RR are unstable when the vehicle 1 accelerates, brakes or turns while the camber angle of the wheels 2RL and 2RR is the second camber angle, it is determined that the rear wheels 2RL and 2RR are unstable. , 2RR is provided with a negative camber, the canvas last generated on the rear wheels 2RL, 2RR can be used to ensure the running stability of the vehicle 1.

  On the other hand, if it is determined that the camber flag 73a is on as a result of the processing of S42 (S42: Yes), the camber angles of the rear wheels 2RL and 2RR have already been adjusted to the first camber angle, so S43 And the process of S44 is skipped and this camber control process is complete | finished.

  On the other hand, when it is determined that the state quantity flag 73b is OFF as a result of the processing of S41 (S41: No), information from the rear wheel braking / driving force sensor device 64a is acquired, and the rear wheels 2RL, It is determined whether or not the four-wheel drive or regenerative state in which braking / driving force is generated in 2RR (S45).

  If it is determined that the front wheel drive state where braking / driving force is not generated in the rear wheels 2RL and 2RR (S45: No), it is determined whether or not the traveling state flag 73c is on (S46), and the traveling state is determined. If it is determined that the flag 73c is on (S46: Yes), it is determined whether or not the camber flag 73a is on (S42).

  As a result, when it is determined that the camber flag 73a is off (S42: No), the RL motor 44RL and the RR motor 44RR are operated, and the camber angles of the left and right rear wheels 2RL, 2RR are set to the first camber angle. The negative camber is applied to the left and right rear wheels 2RL, 2RR (S43), the camber flag 73a is turned on (S44), and the camber control process is terminated.

  As a result, when the driving state of the vehicle 1 is a predetermined straight traveling state in the front wheel driving state in which no braking / driving force is generated in the rear wheels 2RL and 2RR of the vehicle 1, that is, the traveling speed of the vehicle 1 is a predetermined speed. When the operation amount of the steering 63 is equal to or less than the predetermined operation amount and the vehicle 1 is traveling straight at a relatively high speed, the rear wheel 2RL is provided with a negative camber on the rear wheels 2RL and 2RR. , 2RR can be used to ensure the straight running stability of the vehicle 1.

  On the other hand, if it is determined that the camber flag 73a is on as a result of the processing of S42 (S42: Yes), the camber angles of the rear wheels 2RL and 2RR have already been adjusted to the first camber angle, so S43 And the process of S44 is skipped and this camber control process is complete | finished.

  On the other hand, if it is determined as a result of the processing in S45 that the braking / driving force is generated on the rear wheels in a four-wheel drive or regenerative state (S45: Yes), is the camber flag 73a on? It is determined whether or not (S47). As a result, when it is determined that the camber flag 73a is on (S48: Yes), the RL motor 44RL and the RR motor 44RR are operated to set the camber angles of the left and right rear wheels 2RL and 2RR to the second camber angle. In step S48, the camber flag 73a is turned off (S49), and the camber control process is terminated.

  As a result, when the state quantity of the vehicle 1 does not satisfy the predetermined condition and the vehicle is determined to be stable and the braking / driving force is generated in the rear wheels 2RL and 2RR, that is, If there is no need to ensure the running stability of the vehicle 1 and there is a risk of uneven wear, the negative camber is not applied to the rear wheels 2RL and 2RR, thereby avoiding the influence of the canvas last. Thus, fuel saving can be achieved.

  On the other hand, if it is determined that the camber flag 73a is OFF as a result of the processing of S47 (S47: No), the camber angles of the rear wheels 2RL and 2RR have already been adjusted to the second camber angle, so S48 And the process of S49 is skipped and this camber control process is complete | finished.

  As a result of the process of S46, when it is determined that the traveling state flag 73c is off (S46: No), it is determined whether or not the camber flag 73a is on (S47). As a result, when it is determined that the camber flag 73a is on (S47: Yes), the RL motor 44RL and the RR motor 44RR are operated to set the camber angles of the left and right rear wheels 2RL and 2RR to the second camber angle. The negative camber is no longer applied to the rear wheels 2RL and 2RR (S48), the camber flag 73a is turned off (S49), and the camber control process is terminated.

  Thereby, it is determined that the state quantity of the vehicle 1 does not satisfy the predetermined condition and the vehicle is stable, and the braking force is not generated in the rear wheels 2RL and 2RR. When the traveling state of 1 is not a predetermined straight traveling state, that is, when it is not necessary to prioritize and ensure the traveling stability of the vehicle 1, by canceling the negative camber to the rear wheels 2RL and 2RR, By avoiding the influence of canvas last, fuel saving can be achieved.

  On the other hand, if it is determined that the camber flag 73a is OFF as a result of the processing of S47 (S47: No), the camber angles of the rear wheels 2RL and 2RR have already been adjusted to the second camber angle, so S48 And the process of S49 is skipped and this camber control process is complete | finished.

  According to the present embodiment, in the vehicle camber angle control device used for the four-wheel drive vehicle in which the driving force of the front wheels 2FL, 2FR and the rear wheels 2RL, 2RR is distributed and controlled according to the traveling state of the vehicle 1, the vehicle 1 State quantity acquisition units 61a, 62a, 63a for acquiring the state quantity of the vehicle, a rear wheel braking / driving force acquisition unit 64a for acquiring presence / absence of braking / driving force of the rear wheels 2RL, 2RR, and traveling for acquiring the traveling state of the vehicle 1 State acquisition units 80a, 63a, camber angle adjusting mechanisms 44-50 for adjusting the camber angles of the rear wheels 2RL, 2RR, state quantity acquisition units 61a, 62a, 63a, rear wheel braking / driving force acquisition unit 64a, and travel state acquisition Control unit 100 that controls camber angle adjustment mechanisms 44 to 50 based on the parts 80a and 63a, thereby suppressing uneven wear of the tires and improving the life of the tires and running the vehicle It is possible to ensure a qualitative.

  Further, according to the present embodiment, the control unit 100 determines that the state quantity of the vehicle 1 acquired by the state quantity acquisition units 61a, 62a, and 63a is a predetermined stable state, and the rear wheel braking / driving force acquisition unit 64a When the braking / driving force of the wheels 2RL and 2RR is not acquired and the traveling state of the vehicle 1 acquired by the traveling state acquisition units 80a and 63a is a predetermined straight traveling state, the camber angle adjusting mechanisms 44 to 50 enable the rear wheels 2RL, Since the 2RR camber angle is controlled to a negative camber, it becomes possible to ensure the running stability of the vehicle when the vehicle is running in a predetermined straight traveling state by two-wheel drive.

  In the present embodiment, the camber angle adjusting mechanisms 44 to 50 are provided only on the rear wheels 2RL and 2RR, but the camber angle adjusting mechanisms 44 to 50 may also be provided on the front wheels 2FL and 2FR. In this case, when releasing the negative camber of the rear wheels 2RL and 2RR, the negative camber of the front wheels 2FL and 2FR is also released.

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Wheel, 2FL ... Left front wheel, 2FR ... Right front wheel, 2RL ... Left rear wheel, 2RR ... Right rear wheel, 4 ... Suspension device, 44-50 ... Camber angle adjustment mechanism, 61a ... Accelerator pedal sensor device (State quantity acquisition unit), 62a ... brake pedal sensor device (state quantity acquisition unit), 63a ... steering sensor device (state quantity acquisition unit / running state acquisition unit), 64a ... rear wheel braking / driving force sensor device, 80 ... acceleration Sensor device (running state acquisition unit), 100... Control unit, BF.

Claims (2)

In the camber angle control device for a vehicle used in a four-wheel drive vehicle in which the driving force of the front wheels and the rear wheels is distributed and controlled according to the running state of the vehicle,
A state quantity obtaining unit for obtaining a state quantity of the vehicle;
A rear wheel braking / driving force acquisition unit for acquiring presence / absence of braking / driving force of the rear wheel;
A traveling state acquisition unit that acquires a traveling state of the vehicle;
A camber angle adjusting mechanism for adjusting the camber angle of the rear wheel;
A control unit that controls the camber angle adjustment mechanism based on the state quantity acquisition unit, the rear wheel braking / driving force acquisition unit, and the traveling state acquisition unit;
A camber angle control device for a vehicle characterized by comprising: The controller is
The state quantity of the vehicle acquired by the state quantity acquisition unit is a predetermined stable state,
The rear wheel braking / driving force acquisition unit does not acquire the braking / driving force of the rear wheel,
When the traveling state of the vehicle acquired by the traveling state acquisition unit is a predetermined straight traveling state,
The vehicle camber angle control device according to claim 1, wherein the camber angle adjusting mechanism controls the camber angle of the rear wheel to a negative camber.

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