JP2010058681A - Suspension with steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension with a steering device capable of obtaining at least one turning mode out of a normal run, a perfect lateral move, large turning steering, and on-the-spot turning by a simple control. <P>SOLUTION: A steering device includes front and rear wheel side steering shafts 6fL-6rR, a turning means for turning these steering shafts according to the steering of a driver, direction-changing gear sets 7fL-7rR for changing the direction of the axis of rotation between knuckles 9fL-9rR and the front and rear wheel side steering shafts, and forward-reverse changing means 5f, 5r for changing the forward-reverse direction of the divided right and left steering shafts on the front and rear wheel side. A suspension has lower side link members 13fL-13rR and upper side suspension members 11fL-11rR for rockingly supporting the knuckles by a vehicle body 30. The link function of the suspension is realized by supporting the steering shafts 6fL-6rR by the link member in a rocking manner with respect to the vehicle body and the knuckles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a suspension with a steering device that is used in a vehicle such as an automobile and can steer front and rear wheels in accordance with a driver's steering operation.

As a conventional steering device that allows the front and rear wheels to be steered in accordance with the driver's steering operation, the actuator is either the length of the tie rod, the distance between the left and right tie rods, or the angle between each wheel and the knuckle arm. It is known that the driver can select and set the normal running, the oblique parallel movement, and the small turning mode (see, for example, Patent Document 1).
JP-A-4-262971

  However, in the conventional steering device, in order to set the vehicle traveling mode such as the normal traveling, the oblique parallel movement, and the small turn, an actuator is provided for each of the front, rear, left and right tie rods to control a total of four actuators simultaneously. So the control was complicated. Also, since a link mechanism such as a tie rod is used, there is a limit to the turning angle of the wheel, complete lateral movement to turn the wheel 90 °, turning operation to obtain a large turning angle of the wheel, A steering mode such as field rotation was not possible.

  The present invention has been made paying attention to the above-mentioned problem, and an object of the present invention is to provide a suspension with a steering device that can increase the turning angle of a wheel while simplifying control of an actuator. It is to provide.

  For this purpose, the suspension with a steering device according to the present invention uses a turning gear set for transmitting the rotation of the steering shaft to the knuckle and a forward / reverse switching means for changing the rotation direction of the steering shaft. The suspension is connected to allow a part of the steering device to function as a suspension link.

  In the present invention, the steering gear is used with the turning gear set for transmitting the rotation of the steering shaft by the steering means to the knuckle and the forward / reverse switching means for changing the rotation direction of the steering shaft. The turning angle can be increased. In addition, since the steering shaft is supported by the link member in a state where it can swing with respect to the vehicle body and the knuckle, it functions as a suspension link, so the number of suspension links can be reduced, resulting in lower costs and weight. It becomes possible.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
In the following description, the reference numerals of the parts are “f” for the front wheel side, “r” for the rear wheel side, “L” for the left side of the vehicle, and right side of the vehicle. In the description, "R" is attached as a subscript to each item (the same applies to the drawings). Moreover, the arrow which does not attach | subject the code | symbol in a figure represents a rotation direction.

  FIG. 1 shows an overall outline of a vehicle provided with a suspension with a steering device as a first embodiment of the present invention. In this embodiment, the vehicle is an electric vehicle.

  The vehicle has four front and rear wheels 10fL, 10fR, 10rL, and 10rR. These wheels 10fL, 10fR, 10rL, 10rR are rotatably supported by suspensions schematically shown in FIGS. In addition, these wheels are configured such that the left and right front wheels 10fL and 10fR can be steered by the front wheel steering device SF, and the left and right rear wheels 10rL and 10rR can be steered by the rear wheel steering device SR. The vehicle includes an electronic control system, which will be described later, for controlling the front wheel steering device SF and the rear wheel steering device SR.

  In this embodiment, a part of the front wheel steering device SF is assembled to the front wheel side suspension, and this is provided with a link function of the front wheel side suspension. Similarly, a part of the rear wheel steering device SR is assembled to the rear wheel side suspension, and this is provided with a link function of the rear wheel side suspension.

First, the front wheel side steering device SF will be described with reference to FIGS. 1, 2, 4 and 5.
As shown in FIGS. 1 and 2, a steering wheel (steering wheel) 1 provided in a passenger compartment and operated by a driver has an upper steering shaft, a column tube, and the like that rotate in response to the steering operation. A steering wheel side steering shaft 24 including a lower steering shaft is connected. A steering force assist motor 15f is provided in the middle of the steering wheel side steering shaft 24, and the assist force generated here can be applied to the steering wheel side steering shaft 24. The steering wheel side steering shaft 24 is provided with a steering angle sensor 2f for detecting the steering angle and steering speed of the steering wheel 1.

  A steering wheel side gear 3a is provided at the lower end portion of the lower steering shaft protruding out of the passenger compartment, and this steering wheel side gear 3a is provided in the middle of the right intermediate rotation shaft 4fR having a rotation axis extending in the vehicle width direction. Mesh with the wheel side gear 3b provided on the wheel. By the steering gear set 3 including the steering wheel side gear 3a and the wheel side gear 3b, the rotation of the steering wheel 1 can be changed to the rotation of the right intermediate rotation shaft 4fR, and the rotation direction can be reduced. It becomes possible. The left intermediate rotation shaft 4fL is disposed concentrically with the right intermediate rotation shaft 4fR and on the left side of the right intermediate rotation shaft 4fR.

  The steering wheel 1, the steering wheel side steering shaft 24, the steering force assist motor 15f, the steering gear set 3, and the left and right intermediate rotation shafts 4fL and 4fR described above correspond to the steering means of the present invention.

  A forward / reverse switching mechanism 5f is provided between the left and right intermediate rotation shafts 4fL and 4fR to connect them. The forward / reverse switching mechanism 5f is a mechanism that can selectively switch the rotation around the axis of the right intermediate rotation shaft 4fR to either the rotation in the same direction or the rotation in the opposite direction. Details thereof will be described later. The forward / reverse switching mechanism 5f corresponds to forward / reverse switching means of the present invention.

  As shown in FIG. 2, the intermediate rotation shafts 4fL and 4fR on the left and right sides are supported by the housings 31 such that intermediate portions thereof are rotatable around the shaft centers by bearings BfL and BfR, respectively. The housing 31 is attached to the vehicle body 30 and holds the forward / reverse switching mechanism 5f and the steering gear set 3 in addition to the bearings BfL and BfR. In FIG. 2, the housing 31 is cut out in cross section except for the forward / reverse switching mechanism 5 f, and the steering gear set 3, the left and right intermediate rotation shafts 4 fL, 4 fR, and the bearings BfL, BfR are included therein. I can see it.

  In addition, the left and right steering shafts 6fL and 6fR that extend outward in the vehicle width direction are respectively connected to the vehicle inner ends of the left and right intermediate rotation shafts 4fL and 4fR. And is pivotably connected in the vertical direction. As the first joints 17L and 17R, joints that restrict only the rotational displacement between the shafts to which they are connected and have the same rotational direction and the same rotational displacement are used. The left steering shaft 6fL and the right steering shaft 6fR correspond to the steering shaft of the present invention.

  As shown in FIGS. 2, 4 and 5, the left steering shaft 6fL and the right steering shaft 6fR are suspension link members attached to the vehicle body 30 so as to be swingable in the vertical direction. The upper surfaces of 13fL and 13fR are connected and supported by bearings 16L and 16R held by brackets so as to be rotatable about the axis. These bearings 16L and 16R allow rotational displacement around the axis, but restrain displacement in the axial direction and radial direction. Therefore, the left steering shaft 6fL and the right steering shaft 6fR can swing integrally with the link members 13fL and 13fR in the vertical direction with the first joints 17L and 17R as the swing center.

  Drive-side gears 71 are respectively provided at the vehicle outer ends of the left steering shaft 6fL and the right-side steering shaft 6fR, and the drive-side gear 71 is meshed with a driven gear 72 provided on the knuckle 9FL, 9fL side. The drive side gear 71 and the driven gear 72 constitute cross shaft gears 7fL and 7fR which are gears that transmit the motion between the two shafts crossing each other. Specifically, as the cross shaft gears 7fR and 7fR, bevel gears, spiral bevel gears, zero roll bevel gears and the like are used. As a result, the turning directions of the left steering shaft 6fL and the right steering shaft 6fR can be changed, and the turning angles of the knuckles 9fL and 9fL can be driven in accordance with the steering angle of the steering wheel 1. The cross shaft gears 7fL and 7fR correspond to the turning gear set of the present invention.

Here, the configuration of the forward / reverse switching mechanism 5f is based on FIG.
As the forward / reverse switching mechanism 5f, a double pinion type planetary gear is used. That is, as shown in FIG. 6A, the forward / reverse switching mechanism 5f includes the sun gear 51, the ring gear 53, the first pinion that meshes with the sun gear 51, the first pinion that meshes with the first gear, and the ring gear 53. Each of the two pinions has a carrier 52 that rotatably supports the pinion. The sun gear 51 is connected to the vehicle inner end of the right intermediate rotation shaft 4fR, and the carrier 52 is connected to the vehicle inner end of the left intermediate rotation shaft 4fL. Note that these connection relationships may be reversed. The gear ratio between the sun gear 51 and the ring gear 53 is set to 0.5. As a result, the right intermediate rotation shaft 4fL and the left intermediate rotation shaft 4fR can be rotated at the same rotation angle and the same rotation speed regardless of whether the rotation direction is the same or the reverse rotation direction. .

A lock mechanism 54 composed of an electromagnetic two-way clutch is arranged on the outer periphery of the ring gear 53, and the ring gear 54 is fixed to the housing 57, or is rotatably separated between them. Switchable. Similarly, the sun gear 51 and the carrier 52 can be integrally coupled or disconnected by an integral rotary clutch 55 formed of an electromagnetic two-way clutch, and can be switched between them. As a result, the right intermediate rotation shaft 4fL and the left intermediate rotation shaft 4fR can be selected to rotate in the same direction or in the opposite direction.
The lock mechanism 54 and the integral rotary clutch 55 are configured as described below, and are switched and controlled by energization / non-energization of the electromagnet 56.

  As shown in FIG. 6 (b), the lock mechanism 54 has a ring-shaped inner ring rolling surface 54 a of the lock mechanism 54 formed on the outer peripheral surface side of the ring gear 53, and the outer ring is fixed to the case 57. The moving surface 54b is formed into a regular polygon and functions as a cam surface. A plurality of rollers 54 are housed between the inner ring rolling surface 54a and the outer ring rolling surface 54b, and these rollers 54 are held at equal intervals in the circumferential direction by a spring 54g and a cage 54d.

When the electromagnet 56 is not energized, the holder 54d of the lock mechanism 54 is rotatable. As a result, the cage 54d is rotated by the rotating ring gear 53, and the roller 54c cannot move in a narrow space between both rolling surfaces, and the lock mechanism 54 is locked. As a result, the ring gear 53 is locked. This locking occurs in any rotational direction.
On the other hand, when the electromagnet 56 is energized, the armature 54e connected to the retainer 54d is attracted by the electromagnetic force to the outer ring plate 54f fixed to the housing 57. As a result, the retainer 54d is a portion that is movable in the circumferential direction. A wide gap is formed between both rolling surfaces by being held at the center position. In this state, since the roller 54c does not bite into the narrow space between the two rolling surfaces and is locked, the ring gear 53 can rotate in any direction.

  As shown in FIG. 6 (c), the integral rotation clutch 55 is connected to the outer ring 55b having a circumferential rolling surface connected to the carrier 52, and the right intermediate rotation shaft 4fR. An inner ring 55a having a rectangular rolling surface, a plurality of rollers 55c provided between the rolling surfaces, a retainer 55d that holds the rollers 55c at equal intervals in the circumferential direction, and the roller 55c are attached to a neutral position. And a spring 55g.

When the electromagnet 56 is not energized, the roller 55c is held at the neutral position by the spring 55g, that is, the position where the gap between the two rolling surfaces is large, so that the inner ring 55a rotates idle. Accordingly, the right intermediate rotation shaft 4fR and the left intermediate rotation shaft 4fL are separated from each other in rotation direction, and can be rotated in opposite directions.
On the other hand, when the electromagnet 56 is energized, the armature 55e is attracted to the rotor 55f fixed to the carrier 52 by electromagnetic force. Therefore, when the inner ring 55a rotates, the roller 55c moves to a narrow position between both rolling surfaces. The bite locks. As a result, the right intermediate rotation shaft 4fR and the left intermediate rotation shaft 4fL are integrally rotated at the same rotation direction and the same rotation angle.

  On the other hand, the rear wheel steering device SR does not include the steering wheel 1 or the steering wheel side steering shaft 24 of the front wheel steering device SF, and includes a steering motor 15r instead of the steering force assist motor 15f. That is, in the rear wheel steering apparatus SR, the forward / reverse rotation mechanism 5r is interposed between the left and right intermediate rotation shafts 4rL and 4rR, and the intermediate rotation shafts 4rL and 4rR can be switched between the same direction rotation and the reverse direction rotation. It is said. The forward / reverse rotation mechanism 5r is configured in the same manner as the forward / reverse rotation mechanism 5f on the front wheel side shown in FIG.

  Note that the forward / reverse switching mechanism 5r on the rear wheel side is the forward / reverse switching means of the present invention, the left and right wheel side steering shafts 6rL and 6rR are the steering shaft of the present invention, and the left and right cross-axis gears. 7rL and 7rR correspond to the turning gear set of the present invention, the suspension supports 11rL and 11rR correspond to the upper suspension member of the present invention, and the lower links 13rL and 13rR correspond to the link member of the present invention, respectively.

The steered motor 15r can drive the right intermediate rotation shaft 4rR. The steered motor 15r is provided with a motor angle sensor 2r that detects the rotation angle, and the rotation angle, rotation speed, and the like can be measured.
The other configuration is the same as that of the front wheel steering apparatus SF, and thus the description thereof is omitted.

  The vehicle is equipped with an electronic control system for controlling the front wheel steering device SF and the rear wheel steering device SR. That is, the electronic control system of the steering apparatus includes a steering mode setting switch 20, a control unit 21, an actuator driver 22, a steering angle sensor 2f, a motor angle sensor 2r, a vehicle speed sensor 2s, and the like.

  The steering mode setting switch 20 is provided in the interior of the vehicle so that the driver can operate it, and is connected to a control unit 21 composed of a microcomputer or the like to input a steering mode setting signal. Accordingly, any one of the steering modes such as “normal traveling”, “small turn”, “spot rotation”, and “lateral movement” can be selected by pressing the selection switches 20a to 20d corresponding to these steering modes. is there. Here, in “normal driving”, the steering is mainly the steering of the front wheels or the steering of the front wheels, the “small turning” is the steering that cuts the front and rear wheels in opposite phases, and the “spot rotation” is the left and right wheels. This is a steering mode in which the steering is turned to the opposite phase, and in the “lateral movement”, the rear wheels of the front wheels are turned by 90 ° in the same phase.

  The control unit 21 includes a steering mode setting switch 20, a steering angle sensor 2f for detecting a steering angle and a steering speed, a motor angle sensor 2r for detecting the rotation angle of the steering motor 15r, and a vehicle traveling speed. A vehicle speed sensor 2s and the like are connected, and a steering mode setting signal, a steering angle signal, a motor angle signal, a vehicle speed signal, and the like are input, and the target turning direction and the target rear wheel turning amount of the left and right wheels are calculated according to these signals. The target assist signal for determining the amount of assist torque to be applied to the steering force assist motor 15f of the front wheel steering device SF and the steering motor 15r of the rear wheel steering device SR is determined. For example, in this calculation / determination, the assist torque amount is increased as the steering angle signal and the steering speed are increased, and the assist torque amount is decreased as the vehicle speed is increased. Signals calculated based on detection signals from these sensors are output to the actuator driver 22 to supply electric power to the steering force assist motor 15f and the steering motor 15r.

Next, the suspension of this embodiment will be described.
4 and 5 show only the suspension used for the front wheel on the left side of the vehicle, the suspension used for the front wheel on the right side of the vehicle is also configured to be symmetrical with the vehicle left part with respect to the vehicle longitudinal centerline. In addition, the suspensions of the rear wheels on the left and right sides of the vehicle are configured in the same manner as in FIGS. In this way, the front, rear, left and right suspensions have substantially the same configuration, but it goes without saying that the spring constant of the spring, the damping force of the shock absorber, etc. may be varied depending on the distribution of the vehicle weight. .

  The suspension on the front wheel side includes suspension supports 11fL and 11fR, lower links 13fL and 13fR, knuckles 9fL and 9fR, a connecting rod 19 and the like on the left and right sides of the front side of the vehicle. The suspension supports 11fL and 11fR correspond to the upper suspension member of the present invention.

  The left and right suspension supports 11fL and 11fR are each composed of a coil spring, a strut with a built-in shock absorber, and the like, and can extend and contract along the axial direction. The suspension supports 11fL and 11fR support the upper ends of the suspension supports 11fL on the vehicle body 30, respectively, extend slightly downward toward the outside of the vehicle, and fix the lower portions thereof to the knuckles 9fL and 9fR, respectively.

  The left and right lower links 13fL and 13fR are provided with a cylindrical portion 131 at the inner end of the vehicle body, and are attached to the bracket 31 on the vehicle body 30 side with a bolt 33 via a rubber bush 32 inserted therein. The cylindrical portion 131 and the bolt 33 are arranged such that their axial centers (swing centerline S1 shown in FIG. 5) extend in the vehicle front-rear direction. The lower links 13fL and 13fR extend from the cylinder-shaped portion 131 on the vehicle body 30 side outward in the vehicle width direction, and can swing about the swing center line S1 in the vertical direction with respect to the vehicle body 30.

  More specifically, the lower links 13fL and 13fR have a shape that extends in the width direction from the cylinder-shaped portion 131 toward the vehicle front and downward and is bent slightly upward from the middle portion to extend along the vehicle width direction. . With this bent shape, the first joints 17 of the left and right steering shafts 6fL and 6fR are positioned on the swinging center axis S1 that is the swinging center axis of the cylindrical portion 131 and the bolt 33. As a result, even if the lower links 13fL and 13fR and the steering shafts 6fL and 6fR swing together, the steering shafts 6fL and 6fR and the bearings 16L and 16R can be prevented from shifting in the axial direction. In addition, it is possible to suppress the meshing of the cross shaft gears 7fL and 7fR. In this embodiment, a constant velocity joint is used as the first joint. The lower links 13fL and 13fR correspond to the lower link member of the present invention.

  The left and right knuckles 9fL and 9fR have their upper end portions fixed to the lower portions of the struts of the suspension supports 11fL and 11fR with bolts B1 and B2, respectively, and lower end portions thereof connected to the lower links 13fL and 13fR via the connecting rod 19. Connect. A through hole is provided in the middle part of the knuckles 9fL and 9fR, a bearing (not shown) is disposed, and the drive shafts 8fL and 8fR are passed through the through holes and supported rotatably.

  The left and right drive shafts 8fL and 8fR have left and right front wheels 10fL and 10fR attached to the outer ends of the vehicles, respectively, and the outputs of the drive motors 14fL and 14fR fixed to the knuckles 9fL and 9fR on the inner ends of the vehicles. Connect the shafts respectively. Accordingly, the drive motors 14fL and 14fR function as wheel-in motors.

  The connecting rod 19 includes a first rod 19a and a second rod 19b with a second joint 18 interposed therebetween. The first rod 19a is fixed to the lower portions of the knuckles 9fL and 9fR, and the second rod 19b is fixed to the upper surfaces of the lower links 13fL and 13fR.

  The second joint 18 constrains the displacement in the rotational direction of the axial centers of the first rod 19a and the second rod 19b, and the first rod 19a and the second rod 19b rotate around these axial centers at the same rotational angle. Like that. In addition, the second joint 18 can swing with the first rod 19a and the second rod 19b mechanically coupled to restrict displacement in the axial direction while having different angles between the axial centers. By doing so, relative displacement between the knuckles 9fL and 9fR fixed to the suspension supports 11fL and 11fR and the lower links 13fL and 13fR is allowed. In this embodiment, a constant velocity joint is used as the second joint.

  The driven gear 72 of the cross shaft gears 7fL and 7fR is fixed in the middle of the second rod 9b. The cross shaft gears 7fL and 7fR are built in the casing 25 provided on the second rod 19b and / or the lower links 13fL and 13fR so as to prevent the mud and water from being applied. The vicinity of the driven gear 72 of the second rod 9b and the vicinity of the driving gear 71 of the steering shafts 16fL and 16fR are rotatably supported by bearings B1 and B2 attached to the casing 25. Thereby, the meshing of the cross shaft gears 7fL and 7fR is kept good.

  The above description has focused on the front-wheel-side suspension, but the rear-wheel-side suspension is configured in the same manner as the front-wheel-side suspension as shown in FIGS.

Next, the operation of the suspension with a steering device configured as described above will be described.
The steering torque input from the steering wheel 1 and / or the steering force assist motor 15f rotates the steering wheel side steering shaft 24, decelerates by the steering gear set 3, and rotates around the axis extending in the vehicle width direction. The right intermediate rotating shaft 4fR is rotated after being converted.

  The rotation of the right intermediate rotation shaft 4fR is transmitted to the right steering shaft 6fR via the first joint 17fR at the vehicle outer end. At the same time, the rotation of the right intermediate rotation shaft 4fR is transmitted to the forward / reverse switching mechanism 5f to which the vehicle inner end is connected. In the forward / reverse switching mechanism 5f, the left intermediate rotation shaft 4fL has the same rotation angle and rotation speed as the rotation of the right intermediate rotation shaft 4fR, and according to the steering mode selected by the driver with the steering mode setting switch 20. It rotates in the same rotation direction (forward rotation) or reverse rotation direction (reverse rotation) as the rotation of the determined right intermediate rotation shaft 4fR. The left intermediate rotation shaft 4fL rotates the left steering shaft 6fL via the first joint 17fL.

  Rotation of the left and right steering shafts 4fL and 4fR can change the direction of the rotation axis by the cross shaft gears 7fL and 7fR, respectively. As a result, according to the operation of the steering wheel 1 and the setting of the steering mode setting switch 20, the knuckles 9fL and 9fR that support the front wheels 10fL and 10fR are suspended through the second joints 18fL and 18fR, and the suspension supports 11fL and 11fR. And turn / steer with respect to the lower links 13fL and 13fR.

On the other hand, depending on the setting of the steering mode setting switch 20, the steering operation also steers the rear wheels 10rL and 10rR supported by the suspension with the steering device on the rear wheel side as follows.
Power is supplied to the steering motor 15r according to the operation of the steering wheel 1 and the setting of the steering mode setting switch 20, thereby rotating the right intermediate rotation shaft 4rR. The right intermediate rotation shaft 4rR rotates the right steering shaft 6rR via a first joint 17rR connected to the vehicle outer end. At the same time, the left intermediate rotation shaft 4rL has the same rotation angle and rotation speed as the rotation of the right intermediate rotation shaft 4rR, and the right side determined according to the steering mode selected by the driver with the steering mode setting switch 20 It rotates in the same rotation direction as the rotation of the intermediate rotation shaft 4rR or in the reverse rotation direction. The left intermediate rotation shaft 4rL rotates the left steering shaft 6rL via the first joint 17rL.

  Rotation of the left and right steering shafts 4rL and 4rR can change the direction of the rotation axis by the cross shaft gears 7rL and 7rR, respectively. As a result, depending on the operation of the steering wheel 1 and the setting of the steering mode setting switch 20, the knuckles 9rL and 9rR for supporting the rear wheels 10rL and 10rR are suspended via the second joints 18rL and 18rR, the suspension support 11rL, 11rR and lower links 13rL and 13rR are rotated and steered.

  Hereinafter, the steering states in the respective steering modes of the front and rear wheels 10fL, 10fR, 10rL, and 10rR that are steered as described above will be described.

First, the case where the driver selects the “turn around” steering mode switch 20 c of the steering mode setting switch 20 will be described.
In this case, the turn setting signal is input to the control unit 21 from the steering mode setting switch 20, and the control unit 21 sends the command signal to the actuator driver 22 in response to this signal. The actuator driver 22 supplies driving power to the steering force assist motor 15f and the steering motor 15r, and sends a reverse signal to the forward / reverse switching mechanisms 5f and 5r on the front and rear wheels, respectively, to switch them to the reverse mode. .

  As a result, as shown in FIG. 7, the intermediate rotation shafts 4fL, 4fR on the front wheel side rotate in opposite directions, and the intermediate rotation shafts 4rL, 4rR on the rear wheel side also rotate in opposite directions. By these rotations, the left and right steering shafts 6fL and 6fR on the front wheel side also rotate in opposite directions, and the left and right steering shafts 6rL and 6rR on the rear wheel side also rotate in opposite directions. These rotations are the front and rear left and right wheels 10fL, 10fR, 10rL, supported by the knuckle 9fL, 9fR, 9rL, 9rR via the cross shaft gears 7fL, 7fR, 7rL, 7rR and the second joints 18fL, 18fR, 18rL, 18rR, Steer 10rR.

  In this case, the turning amount is one point as shown in FIG. 7 by an extension line indicated by an alternate long and short dash line inside the drive shafts 8fL, 8fR, 8rL, and 8rR supported by the respective knuckles 9fL, 9fR, 9rL, and 9rR. Make the size so that it intersects with. At this time, the front, rear, left and right wheels 10fL, 10fR, 10rL, 10rR are steered along the same circumference. The direction of rotation is determined by the direction of rotation of the steering wheel 1. As a result, the vehicle can turn around. Assuming that the rotational drive direction during normal forward movement of the vehicle is normal rotation, when the vehicle is rotated clockwise, the left wheel drive motors 14fL and 14rL drive the front and rear left wheels 10fL and 10rL to rotate forward, and the right wheel The right and left front wheels 10fR, 10rR are driven in reverse by the side drive motors 14fR, 14rR. In the case of counterclockwise rotation, the front and rear left and right wheels 10fL, 10fR, 10rL, and 10rR are driven in the opposite rotation direction to the clockwise direction by the drive motors 14fL, 14rL, 14fR, and 14fR.

Next, the case where the driver selects the “complete lateral movement” steering mode switch 20d of the steering mode setting switch 20 will be described.
Also in this case, the control unit 21 outputs the complete movement setting signal and switches the forward / reverse switching mechanisms 5f and 5r on the front and rear wheels side to the reverse rotation mode, as in the “spot turn” steering mode. On the other hand, as shown in FIG. 8, the turning amount when the “completely lateral movement” steering mode is set is larger than that in the “in-place” steering mode, and the front and rear wheels 10fL, 10fR, 10rL, 10rR Each vehicle is steered along the vehicle width direction.

  Which direction to proceed is determined by the direction of rotation of the steering wheel 1. In order to move the vehicle to the right, the front left wheel 10fL and the rear right wheel 10rR are driven forward by the front left wheel side drive motor 14fL and the rear right wheel side drive motor 14rR to drive the front right wheel side. The front right wheel 10fR and the rear right wheel 10rL are driven in reverse by the motor 14fR and the drive motor 14rL on the rear left wheel side. When traveling in the left direction, the front and rear left and right wheels 10fL, 10fR, 10rL, and 10rR are driven in the rotation direction opposite to that when traveling in the right direction.

Next, a case where the driver selects the “small turn” steering mode switch 20b of the steering mode setting switch 20 will be described.
In this case, the control unit 21 outputs a small turn setting signal to switch only the forward / reverse switching mechanism 5r on the rear wheel side to the reverse rotation mode. On the other hand, as shown in FIG. 9, the turning amount when the “small turn” steering mode is set is a line extending to the vehicle inner side of the drive shafts 8fL, 8fR, 8rL, and 8rR of the front and rear left and right wheels 10fL, 10fR, 10rL, and 10rR. Are gathered at the turning center O of the vehicle. Therefore, the turning angle α of the inner wheel (right wheel 10fR, 10rR in the case of FIG. 9) is set larger than the turning angle β of the outer wheel (left wheel 10fL, 10rL in the case of FIG. 9).

  When turning to the right as shown in FIG. 9 in the small turn steering mode or to the left as opposed to this, when driving forward, the front and rear left and right wheels 10fL, 10fR, 10rL are driven by the drive motors 14fL, 14fR, 14rL, 14rR. All of 10rR are driven forward. At the time of reverse, all the front and rear left and right wheels 10fL, 10fR, 10rL, 10rR are driven in reverse by the drive motors 14fL, 14fR, 14rL, 14rR.

Next, a case where the driver selects the “normal travel” steering mode switch 20a of the steering mode setting switch 20 will be described.
In this case, when the control unit 21 determines that the vehicle is traveling at a low speed based on the vehicle speed signal from the vehicle speed sensor 2S, only the front wheels 10fL and 10fR are steered and the rear wheels 10rL and 10rR are steered as shown in FIG. do not do. Therefore, although the front wheel side steering force assist motor 15f can be driven according to the steering angle of the steering wheel 1, the rear wheel side steering motor 15r is kept stopped. Further, the control unit 21 outputs a normal travel setting signal to set the front and rear forward / reverse switching mechanisms 5f and 5r to the forward rotation mode.

  The front wheels 10fL and 10fR correspond to the steering wheel 1 according to the operation of the steering wheel 1, the steering wheel side steering shaft 24, the steering gear set 3, the intermediate rotation shafts 4fRL and 4fR, the forward / reverse switching mechanism 5f, the first joints 17fL and 17fR, the steering. Rotation is transmitted in the order of the shafts 6fL and 6fR, the cross shaft gears 7fL and 7fR, the second joints 18fL and 18fR, the knuckles 9fL and 9fR, and the front wheels 10fL and 10fR are steered. At this time, the steering force assist motor 15f reduces the steering operation force of the driver by increasing the assist force as the operation angle of the steering wheel 1 is larger and the vehicle speed is lower.

On the other hand, when the control unit 21 determines that the vehicle is traveling at a high speed, the same phase steering of the front wheels and the rear wheels is performed as shown in FIG. Further, the assist force of the steering force assist motor 15f decreases as the speed increases, but may be zero at a predetermined high speed or higher.
The front wheels 10fL and 10fR are steered in the same manner as in the normal running steering mode at the low speed, but the rear wheels 10rL and 10rR are driven by the steering motor 15r with the intermediate rotation shafts 4rL and 4rR, and the first joint 17rL, The steering shafts 6rL and 6rR connected at 17rR are rotated according to the steering angle of the steering wheel 1. In this case, since the forward / reverse switching mechanism 5r on the rear wheel side is in the forward rotation mode, the left and right wheels 10rL and 10rR of the rear wheels have the same steering direction.

  Further, the cutting angles α and β ′ at the inner ring (front and rear right wheels 10fR and 10rR in FIG. 10) are larger than the cutting angles α ′ and β at the outer ring (front and rear left wheels 10fL and 10rL in FIG. 10), respectively. Also, α> α ′ and β> β ′ are set. As a result, it is possible to ensure the maneuverability and stability of the vehicle at high speed.

  In these normal travel steering modes, all of the front, rear, left and right wheels 10fL, 10fR, 10rL, and 10rR are driven forward by the drive motors 14fL, 14fR, 14rL, and 14rR during forward travel. At the time of reverse, all the front and rear left and right wheels 10fL, 10fR, 10rL, 10rR are driven in reverse by the drive motors 14fL, 14fR, 14rL, 14rR.

  The steering mode setting switch 20 is set to the normal traveling steering mode by default. That is, when the engine is started, the normal running steering mode is always set so that the wheels are returned to the neutral state when they are left in the state of in-situ rotation, small turning and lateral movement.

  The suspension with a steering device of the first embodiment configured as described above can achieve the effects listed below.

  (1) In the suspension with the steering device of the first embodiment, the cross shaft gears 7fL, 7fR, 7rL, which transmit the rotation of the steering shafts 6fL, 6fR, 6rL, 6rR by the steering means to the knuckles 9fL, 9fR, 9rL, 9rR, 7rR and forward / reverse switching means 5f, 5r for changing the rotation direction of the steering shafts 6fL, 6fR, 6rL, 6rR are used in the steering device, so that fewer actuators are required and simpler than the conventional steering device. The steering device can be controlled with simple control.

  (2) Further, since the suspension with the steering device of the first embodiment does not use a tie rod, the wheel can be cut with a larger cutting angle than the conventional steering device, which is impossible with the conventional steering device. In addition, it is possible to travel at a large turning angle of the wheel, complete lateral movement by turning the wheel by 90 °, and in-situ rotation of the vehicle by left-right wheel reverse phase.

  (3) Further, in the suspension with the steering device of the first embodiment, the steering shaft 6fL, 6fR, 6rL, 6rR is used as a link member in a state that it can swing with respect to the vehicle body 30 and the knuckle 9fL, 9fR, 9rL, 9rR. Since the lower links 13fL, 13fR, 13rL, and 13rR function as suspension links, the number of suspension links can be reduced, and the cost and weight can be reduced.

  (4) The lower links 13fL, 13fR, 13rL, and 13rR are formed by attaching the cylindrical portions 131 that are attached to the vehicle body 30 to the first joints 17FL, 17fR, and 6fR of the steering shafts 6fL, 6fR, 6rL, and 6rR on the extension lines thereof. The steering shafts 6fL, 6fR, 6rL, and 6rR may remain straight because the 17rL and 17rR are positioned and the vehicle outer portions are bent downward. In addition, it is possible to avoid twisting between the lower links 13fL, 13fR, 13rL, and 13rR and the steering shafts 6fL, 6fR, 6rL, and 6rR with a simple configuration.

  (5) In the suspension with the steering device of the first embodiment, the forward / reverse switching mechanism 5f, 5r is a double pinion planetary gear, and the ring gear 53 and the case 57 fixed to the vehicle body 30 are connected. A lock mechanism 54 for separating and an integral rotary clutch 55 for connecting / disconnecting the sun gear 51 and the carrier 52 are provided. Further, the lock mechanism 54 and the integral rotary clutch 55 are constituted by electromagnetic two-way clutches, one of the left and right steering shafts 6fL, 6fR, 6rL, 6rR is connected to the sun gear 51, and the other is connected to the carrier 52. Connected. Therefore, it is possible to change the steering direction of the left and right wheels by switching between forward and reverse rotation with a simple configuration. In this case, since the gear ratio between the sun gear 51 and the ring gear 53 is set to 0.5, the left and right steering shafts 6fL, 6fR, 6rL, 6rR can rotate in the same direction or in the reverse direction. The cutting angle of the left and right wheels can be made the same.

  (6) The lock mechanism 54 used in the suspension with the steering device of the first embodiment fixes the ring gear 53 to the case 57 when not energized and releases the lock when energized. The integral rotation clutch 55 releases the connection between the sun gear 51 and the carrier 52 when not energized, and connects them when energized. Accordingly, normal two-wheel steering is possible when the power is not supplied. As a result, the “normal travel” steering mode is the normal travel steering mode even when the forward / reverse switching mechanism 5f, 5r becomes abnormal due to a wire break or the like. It is possible to run on. In addition, since the steering wheel 1 to the knuckle 9FL, 9fR, 9rL, 9rR are mechanically connected, the driver can directly steer the wheel even when the steering system is abnormal, A fail-safe function can be provided without using control.

(7) In the suspension with the steering device according to the first embodiment, the lock mechanism 54 and the integral rotation clutch 55 are operated by sharing one electromagnet 56, so that the forward / reverse switching mechanisms 5f and 5r are simplified. In addition, the cost can be reduced, and the interlock between the lock mechanism 54 and the integral rotation clutch 55 can be prevented simultaneously.
(8) In the suspension with the steering device of the first embodiment, the steering mode setting switch 20, the steering angle sensor 2f, and the vehicle speed sensor 2s are provided, and the steering mode signal, the steering angle signal, and the vehicle speed signal are sent to the control unit 21. Since it is input, the control unit 21 can set the optimum turning amount of the front and rear wheels based on these input signals.

Next, a second embodiment of the present invention will be described with reference to the drawings.
In the second embodiment, the basic configuration is the same as that of the first embodiment, but the configuration of the forward / reverse switching mechanism is partially different. That is, in the second embodiment, a dog clutch, that is, a meshing clutch, is used instead of the integral rotary clutch 55 of the first embodiment.

In the forward / reverse switching mechanism of the second embodiment, as shown in FIG. 11A, a protrusion 55k shown in FIG. 11B is provided on the side surface on the right steering shaft 4fR connected to the sun gear 51. The clutch gear 55h is mounted so as to be movable along the axial direction by a spline or the like. For this reason, a groove is provided on the outer periphery of the clutch gear 55h so that the lever 55j is slidably fitted so that the actuator 58 can move in the axial direction.
On the other hand, the carrier plate 55j is provided with a groove 55m that can be fitted to the protrusion 55k as shown in FIG. Therefore, by moving the clutch gear 55h in the axial direction and separating the projection 55k and the groove 55m in the axial direction, the sun gear 51 and the carrier 52 are separated from each other, and the clutch gear 55h is moved in the axial direction to cause the projection 55k. By engaging with the groove 55m, the sun gear 51 and the carrier 52 can be switched so as to rotate together.

  It should be noted that by adjusting the neutral position and toe adjustment of the left and right wheels in the engaged state of the integral rotary clutch 55, there is no shift in the neutral position of the wheel due to the disconnection / connection of the clutch 55 and the toe error, It becomes possible to prevent steering performance and uneven wear of tires.

The suspension with the steering device of the second embodiment can obtain the following effects in addition to the effects (1) to (8) of the first embodiment described above.
(9) In the steering apparatus of the second embodiment, the integral rotation clutch 55 is a dog in which the sun gear side steering shafts 4fR, 4rR and the carrier side steering shafts 4fL, 4rR mesh with each other at a predetermined phase, for example, 180 °. -Since the clutch is used, the phase shift between the left and right wheels can be made substantially zero. Further, since the dog clutch is used in this embodiment, the cost can be reduced as compared with the case where a friction plate clutch or the like is used.

  As described above, the first embodiment and the second embodiment of the suspension with a steering device according to the present invention have been described. However, the suspension with a steering device according to the present invention is not limited to the above-described embodiment. Modifications and changes are possible.

  The suspension with a steering device of the present invention is not limited to a vehicle in which a wheel-in motor is incorporated in each wheel, but also to other drive type vehicles including a hybrid electric vehicle using an internal combustion engine and an electric motor as a power source. Applicable.

  In the embodiment, a cross-gear gear is used as the turning gear set, but a face gear, a hypoid gear, or the like may be used instead. In particular, although the latter is more expensive, it can be arranged so that the two axes do not intersect with each other, which is effective when the suspension geometry is different or when interference with other parts is avoided.

  In the embodiment, the first joints 17fL, 17fR, 17rL, and 17rR are set so as to be positioned on the swing center axis S1 of the cylindrical portion 131 of the lower links 13fL, 13fR, 13rL, and 13rR. It is also possible to place it at a position away from the central axis. In this case, when the lower link 13fL, 13fR, 13rL, 13rR and the steering shaft 6fL, 6fR, 6rL, 6rR swing, the driving gear 71 and the driven gear of the cross shaft gears 7fL, 7fR, 7rL, 7rR These gears are securely supported by the casing 25 so that a normal meshing with 72 can always be ensured. At the same time, the steering shafts 6fL, 6fR, 6rL, and 6rR are divided at locations inside the bearings 16L and 16R so as to be slidable in the axial direction by splines, or the first joints 17fL, 17fR, 17rL, and 17rR. The lower links 13fL, 13fR, 13rL, 13rR and the steering shafts 6fL, 6fR, and the steering shafts 6fL, 6fR, and the like are used when swinging, such as by using a slidable constant velocity joint or absorbing elastic deformation of the rubber bush. It is necessary to prevent 6rL and 6rR from being twisted.

  In the embodiment, the second joints 18fL, 18fR, 18rL, 18rR are provided between the cross shaft gears 7fL, 7fR, 7rL, 7rR and the knuckles 9fL, 9fR, 9rL, 9rR, but the knuckles 9fL, 9fR, 9rL are provided. , 9rR and the bearing 16 may be provided. In this case, the second rod 19a is connected only to the lower ends of the second joints 18fL and 18fR, and is supported by the casing 25 and the axle housing that incorporate and support the cross shaft gears 7fL, 7fR, 7rL, and 7rR. Thus, the meshing of the cross shaft gears 7fL, 7fR, 7rL, 7rR is always kept normal.

  The second rod 19a provided with the driven gear 72 of the cross shaft gears 7fL, 7fR, 7rL, 7rR is the vehicle of the lower link 13fL, 13fR, 13rL, 13rR and the lower end of the second joint 18fL, 18fR in the above embodiment. Although the outer end portion is connected, the connection with the lower links 13fL, 13fR, 13rL, and 13rR can be abolished. In this case, the second rod 19a is connected to only the lower ends of the second joints 18fL and 18fR, and the second rod 19a and the steering shaft are supported by the casing 25 that houses and supports the cross shaft gears 7fL, 7fR, 7rL, and 7rR. Even if 6fL, 6fR, 6rL, and 6rR are connected in a rotatable state, the load received is different between the lower link 13fL, 13fR, 13rL, and 13rR and the steering shaft 6fL, 6fR, 6rL, and 6rR. Although it is necessary to change the strength, it is possible to obtain similar actions and effects.

  It is desirable to use constant velocity joints for the first joint and the second joint, but the present invention is not limited to this, and other types of joints may be used.

  In the embodiment, the suspension supports 11fL and 11fR are used to support the upper end portion of the knuckle as the upper suspension member. However, the suspension member is not limited to this, and extends in the vehicle width direction so as to be swingable from the vehicle body side, for example. Alternatively, an upper link may be used. In this case, the spring and the shock absorber are preferably attached between the vehicle body and the lower links 13fL and 13fR.

  In the embodiment, a stabilizer is not drawn on the lower links 13fL, 13fR, 13rL, and 13rR in the embodiment, but between the left and right wheels 10fL and 10fR of the front wheel and between the left and right wheels 10rL and 10rR of the rear wheel, respectively. A stabilizer may be provided. In particular, it is desirable to provide a vehicle that travels at a high speed.

  In the embodiment, in the “normal travel” steering mode, the rear wheels 10rL and 10rR are kept at zero turning during low-speed traveling, and only the front wheels are steered according to the steering operation of the steering wheel 1; The wheels are steered in the same phase as the front wheels, but depending on the vehicle, the understeer characteristic may be imparted by slightly steering the rear wheels in the opposite phase to the front wheels. In the same phase control of the front wheels and the rear wheels, the front wheels and the rear wheels may be actively set to have the same turning amount so as to enable so-called oblique traveling. In this case, the steering mode setting switch 20 is also provided with a switch in the “oblique traveling” steering mode.

  In the steering device of the present invention, in the embodiment, the steering means is mechanically connected from the steering wheel 1 to the intermediate rotation shafts 4fL, 4fR, 4rL, 4rR, and the steering shafts 6fL, 6fR, 6rL, 6rR is driven, but the steering wheel 1 and the steering shaft 6fL, 6fR, 6rL, 6rR are mechanically separated from each other, so that a so-called steer-by-wire steering system is configured. Good. Further, the structure of the steering means may be further increased by increasing the number of joints or allowing the relative displacement in the rotational direction to be restrained but allowing sliding in the axial direction.

1 is a plan view schematically showing a vehicle including a suspension with a steering device and an electronic control system thereof according to a first embodiment of the present invention. It is the schematic diagram which looked at the front of vehicles provided with the suspension with a steering device of this example from the vehicles front. It is the schematic diagram which looked at the rear surface of the vehicle provided with the suspension with a steering device of the present embodiment from the vehicle front side. FIG. 2 is a plan view schematically showing an enlarged view of a suspension with a left front steering device in the vehicle among the suspension with a steering device shown in FIG. FIG. 5 is a view of the suspension with a left front steering device of FIG. 4 as viewed from the rear of the vehicle. It is a figure which shows the forward / reverse switching mechanism used for the steering apparatus of the suspension with a steering apparatus of a present Example, (a) is a figure which shows the whole structure typically, (b) is a locking mechanism used with a forward / reverse switching mechanism. Sectional drawing (c) is a sectional view of an integral rotary clutch used in the forward / reverse switching mechanism. It is a figure which shows the steering state in the spot rotation steering mode which uses the suspension with a steering device of a present Example as a front-and-rear wheel and makes a right-and-left wheel into an antiphase. It is a figure which shows the steering state in the perfect lateral movement steering mode of a vehicle which uses the suspension with a steering device of a present Example as a front-and-rear left-right wheel in the same phase. It is a figure which shows the steering state in the small turn steering mode which makes a front-and-rear wheel an opposite phase using the suspension with a steering device of a present Example. It is a figure which shows the steering state in the diagonal parallel steering mode which makes only a front wheel into the same phase using the suspension with a steering device of a present Example. It is a figure which shows the forward / reverse switching mechanism used for the suspension with a steering device which becomes 2nd Example of this invention, (a) is a figure which shows the whole structure typically, (b) is a protrusion of the forward / reverse switching mechanism. The figure which shows the provided clutch gearwheel, (c) is a figure which shows the carrier plate of the forward / reverse switching mechanism provided with the groove | channel which can mesh | engage with a protrusion.

Explanation of symbols

SF Front wheel side steering device SR Rear wheel side steering device S1 Swing center line 1 Steering wheel (steering means)
3 Steering gear set 5f, 5r Forward / reverse rotation switching mechanism (forward / reverse switching means)
6fL, 6fR, 6rL, 6rR Steering shaft 7fL, 7fR, 7rL, 7rR Cross shaft gear (turning gear set)
71 Drive gear 72 Driven gear 8fL, 8fR, 8rL, 9rR Drive shaft 9fL, 9fR, 9rL, 9rR Knuckle 11fL, 11fR, 11rL, 11rR Suspension support (upper suspension member)
13fL, 13fR, 13rL, 13rR Lower link (lower link member)
14fL, 14fR, 14rL, 14rR Drive motor 15f Steering force assist motor 15r Steering motor 16L, 16R Bearing 17fL, 17fR, 17rL, 17rR First joint 18fL, 18fR, 18rL, 18rR Second joint 20 Steering mode setting switch 21 Control / control Unit 22 Actuator / Driver 24 Steering wheel side steering shaft (steering means)
25 Casing 30 Car body

Claims (5)

A front wheel side steering shaft and a rear wheel side steering shaft that are arranged between the left and right wheels of the front and rear wheels and can rotate around the axis, respectively, and the front wheel side steering shaft and the rear wheel side according to the driver's steering Steering means for respectively rotating the steering shaft, a lower end portion of a knuckle that rotatably supports the wheel, and the front wheel side steering shaft and the rear wheel side steering shaft are respectively inserted between the rotating shaft centers. The turning gear set for transmitting the rotation by changing the direction and the front wheel side steering shaft and the rear wheel side steering shaft are inserted between the left and right parts, respectively, so that the rotation directions of the divided left and right steering shafts are correct. A steering device having forward / reverse switching means for switching to one of the reverse directions;
The lower end of the knuckle is connected to the outer end of the vehicle so as to be swingable. The lower link member extends in the width direction of the vehicle body and is swingably connected to the vehicle body, and one end is connected to the upper end of the knuckle. An upper side suspension member connected and pivotally connected to the vehicle body side at the other end, and suspensions respectively supporting the left and right wheels of the front and rear wheels,
With
A suspension with a steering device, wherein the steering shaft is supported by the link member so as to be swingable with respect to the vehicle body and the knuckle and functions as a link of the suspension. The suspension with a steering device according to claim 1,
A suspension with a steering device, wherein the front wheel side steering shaft and the rear wheel side steering shaft are respectively connected to the link member via bearings that allow displacement of the steering shaft in the rotational direction. In the suspension with a steering device according to claim 1 or 2,
The front wheel side steering shaft and the rear wheel side steering shaft steer the vehicle inner end portion of the steering shaft via a first joint that enables the steering shaft to swing in the vertical direction. A suspension with a steering device, wherein the suspension is connected to each means. The suspension with a steering device according to any one of claims 1 to 3,
A suspension with a steering device, wherein a second joint for restraining displacement in the rotational direction of these shaft centers is interposed between the bearing and the lower end of the knuckle. The suspension with a steering device according to any one of claims 1 to 3,
A suspension with a steering device, wherein a second joint is interposed between a lower end portion of the knuckle and the turning gear set.

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