JP2006160166A - Steering mechanism of wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a steering angle of wheels by using a single actuator. <P>SOLUTION: A steering mechanism of wheels is comprised of a pair of front and rear rods 11, 12, a knuckle 13 (wheel support member), and a drive mechanism K (a lever 21, the actuator 30), or the like. Each of the rods 11, 12 is arranged in the rear and front of a rotation center axis line L1 of the wheel 40, respectively, and extended in a wheel width direction to be pivoted on the knuckle 13 at respective outer ends 11a, 12a. The lever 21 is extended in rear and front directions of the vehicle to be pivoted on inner ends 11b, 12b of the respective rods 11, 12 at rear and front ends 21a, 21b, and rotatably pivotally supported on a vehicle body 50 by a pin 24 at a generally central part 21c. The actuator 30 is connected to the lever 21 to rotate the lever 21. Pivot centers P1, P2 of the respective rods 11, 12 and the lever 21 are set more inwards in the vehicle than a rotation center P3 of the lever 21 in a status in which the steering angle of the wheel 40 is zero. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wheel steering mechanism, and more particularly, to a wheel steering mechanism that can reduce the incision of a wheel into a vehicle during turning.

As one of the steering mechanisms of this type of wheel, a pair of front and rear is disposed forward and rearward with respect to the rotation center axis of the wheel, extends in the vehicle width direction, and is pivotally attached to the wheel support member at each outer end. Some include rods and a drive mechanism that moves these rods in the vehicle width direction.
JP 2004-168092 A

  In the wheel steering mechanism described in Patent Document 1 described above, the drive mechanism is composed of a pair of front and rear actuators that respectively move a pair of front and rear rods. In this steering mechanism, each actuator moves each rod corresponding to the turning direction of the wheel outward in the vehicle width direction, thereby turning the wheel while being pushed outward in the vehicle width direction. As a result, even when using wide wheels, for example, which have recently been highly requested for use, it is possible to set the wheels so that the shoulders inside the vehicle and the vehicle body do not interfere with each other when the maximum turning angle is set. It is possible to secure a small turning of the vehicle.

  By the way, in the wheel steering mechanism described in Patent Document 1 described above, the drive mechanism is constituted by a pair of actuators in order to ensure the turning angle of the wheel. For this reason, there exists a problem that the steering mechanism of a wheel becomes expensive.

  Therefore, in order to cope with the above-described problems, an object of the present invention is to provide a wheel steering mechanism in which an effect equivalent to that of the above-described conventional technique can be configured with a single actuator.

  In order to achieve the above object, in the present invention, a pair of front and rear members arranged forward and rearward with respect to the rotation center axis of the wheel, extending in the vehicle width direction and pivotally attached to the wheel support member at each outer end. And a driving mechanism for moving the rods in the vehicle width direction. The driving mechanism extends in the front-rear direction of the vehicle, and the inner ends of the rods at the front and rear ends. A lever that is pivotally attached to the vehicle body so as to be pivotable in plan view, and a single actuator that is assembled to the vehicle body and connected to the lever to rotate the lever. And the pivoting center of the rod and the lever is set to be inward of the vehicle with respect to the rotation center of the lever when the wheel turning angle is zero.

  When the wheels are steered, the lever is pivoted in the steered direction by one actuator, and by pivoting this lever, one of the rods moves outward in the vehicle width direction and the other moves inward in the vehicle width direction. . In this case, since the pivoting center of both rods and the lever is set to be inward of the vehicle with respect to the rotation center of the lever with the wheel turning angle being zero, it moves outward in the vehicle width direction. The displacement amount of the rod to be moved is larger than the displacement amount of the rod that is displaced inward in the vehicle width direction. Therefore, since the turning center of the wheel moves outward in the vehicle width direction by a distance corresponding to the difference between the displacement amounts of both rods, for example, even when wide wheels are used, It can be set so that the inner shoulder portion and the vehicle body do not interfere with each other, and the turning angle of the wheel is sufficiently secured. By the way, in the present invention, the lever and the single actuator are used to obtain the same effect as the above-described conventional technique, so that the wheel steering mechanism can be configured at low cost.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a right side of a wheel steering mechanism according to the present invention. This steering mechanism moves a suspension S having a pair of front and rear rods 11 and 12 as a suspension lower arm and both rods 11 and 12 in the vehicle width direction. The drive mechanism K is comprised. Since the left side of the wheel steering mechanism is configured in the same manner as the right side, the right side steering mechanism will be described as a representative here, and the description of the left side will be omitted.

  The suspension S is a double wishbone type suspension including the rods 11 and 12, the knuckle 13, the radius rod 14, and a suspension upper arm (not shown), and the drive mechanism K includes the lever 21 and the single actuator 30. is there.

  Both rods 11 and 12 are disposed forward and rearward with respect to the rotation center axis L1 of the wheel 40, respectively, extend in the vehicle width direction, and forward and rear arms 13a of the knuckle 13 at the outer ends 11a and 12a. , 13b through ball joints 15, 16 respectively. The knuckle 13 functions as a wheel support member, and turns the wheel 40 around the turning center O1. The radius rod 14 is connected to the vehicle body 50 via the ball joint 17 at the front end 14a and connected to the arm of the knuckle 13 (not shown) via the ball joint 18 at the rear end 14b.

  The lever 21 extends in the front-rear direction of the vehicle, and is connected to the inner ends 11b, 12b of the rods 11, 12 at the front and rear ends 21a, 21b via ball joints 22, 23, respectively. The central portion 21c is assembled so as to be rotatable around the axis of a pin 24 that is erected on the vehicle body 50 in a substantially vertical direction. The pin 24 slightly protrudes upward from the upper surface of the lever 21, and both the rods 11 and 12 are positioned above the upper end of the pin 24 via the ball joints 22 and 23, and the front end and the rear end 21 a, Since it is connected to 21b, the pin 24 does not interfere with the rods 11 and 12. The lever 21 is connected to the tie rod 31 of the actuator 30 assembled to the vehicle body 50 via the ball joint 32.

  The actuator 30 includes a steering gear 33 that simultaneously steers the right wheel 40 and the left wheel in the same direction. The above-described tie rod 31 and a rack shaft connected to the inner end of the tie rod 31 at one end. (Not shown), a pinion shaft (not shown) for moving the rack shaft in the vehicle width direction, a tie rod (not shown) connected to the other end of the rack shaft and connected to the left lever (not shown), etc. It is constituted by.

  By the way, in this embodiment, in the state where the cutting angle of the wheel 40 is zero, the ball centers P1, P2 of the ball joints 22, 23, which are pivot centers of the rods 11, 12, and the lever 21, are the lever 21. Is set to be inward of the vehicle with respect to the shaft center P3 of the pin 24, which is the rotation center of the vehicle. Further, the shaft center P3 of the pin 24 is located on the rotation center axis L1 of the wheel 40, and the rods 11 and 12 are arranged so as to be substantially symmetrical with respect to the rotation center axis L1 of the wheel 40. . When the turning angle of the wheel 40 is zero, the distance from the axis center P3 of the pin 24 to the turning center O1 of the wheel 40 is set to be a predetermined distance D1.

  Therefore, for example, when the wheel 40 is steered leftward, as shown in FIG. 2, the lever 21 is rotated counterclockwise by the actuator 30, and the rear rod 12 is turned in the vehicle width by the rotation of the lever 21. While moving outward in the direction, the front rod 11 moves inward in the vehicle width direction. In this case, the ball centers P1, P2 of the ball joints 22, 23 are set to be inward of the vehicle with respect to the shaft center P3 of the pin 24 in a state where the turning angle of the wheel 40 is zero. The displacement amount of the rear rod 12 that moves outward is larger than the displacement amount of the front rod 11 that moves inward in the vehicle width direction.

  Therefore, the turning center O1 of the wheel 40 moves by the distance Dy in the front-rear direction according to the difference between the displacement amounts of the rods 11 and 12, and moves by the distance Dx outward in the vehicle width direction. A distance D2 from the shaft center P3 of 24 to the turning center O1 of the wheel 40 is a distance (D1 + Dx) larger than the predetermined distance D1. As a result, even when a wide wheel 40 is used, it can be set so that the shoulder portion 40a on the vehicle inner side of the wheel 40 and the vehicle body 50 do not interfere with each other when the maximum turning angle is set. Sufficiently secured.

  In other words, when compared with a normal steering mechanism (steering mechanism in which the wheel is steered around a kingpin shaft at a predetermined position) indicated by a broken line in FIG. When S1 (the amount of change in the inner end position of the wheel 40 in the vehicle width direction) is the same, this is indicated by a two-dot chain line in FIG. 3 as compared with the turning angle θ1 of the wheel by the normal steering mechanism. The turning angle θ2 of the wheel 40 by the steering mechanism of the embodiment becomes larger.

  As for the left wheel, as in the case of the right wheel 40, the left lever is rotated counterclockwise by the actuator 30, and the rotation of the lever 21 moves the front rod outward in the vehicle width direction. Since the rear rod moves inward in the vehicle width direction, the turning center of the left wheel moves outward in the vehicle width direction by a distance Dx. Therefore, in this case, when the maximum turning angle is set, the setting can be made so that the shoulder portion on the rear side of the left wheel inside the vehicle and the vehicle body 50 do not interfere with each other, and the cutting angle of the left wheel is sufficiently secured.

  When turning the wheel to the right, the turning angle of the wheel is sufficiently secured as in the case of turning the wheel to the left. Thus, according to the present embodiment, the lever 21 and the single actuator 30 are used to ensure the cutting angle of the wheel 40 (the same applies to the left wheel), so the wheel steering mechanism is It can be configured at low cost.

  Moreover, in this embodiment, the wheel tread of a wheel expands because all the steering centers of a wheel move outward in a vehicle width direction. Thereby, the front roll rigidity at the time of turning becomes high, and the effect which improves the running stability at the time of vehicle turning is also acquired.

  In this embodiment, the distance between the ball centers of the ball joints 15 and 16 connecting the outer ends 11a and 12a of the rods 11 and 12 and the front and rear arms 13a and 13b of the knuckle 13 is determined by the 12 is set to be larger than the distance between the ball centers of the ball joints 22 and 23 connecting the inner ends 11b and 12b of the twelve and the front and rear ends 21a and 21b of the lever 21. As a result, since the wheel 40 is displaced in the toe-out direction during braking, the steering characteristic during braking becomes understeer, and the vehicle behavior during braking can be stabilized.

  In order to set the steering characteristic at the time of braking to understeer by a normal steering mechanism, for example, the lower arm is inclined and arranged, but in this case, it is difficult to ensure rigidity against the lateral force, and the actuator In many cases, it is difficult to set the steer characteristic due to restrictions on the arrangement. However, according to this embodiment, it is possible to arrange the rods 11 and 12 as described above without being restricted in the arrangement of the actuator 30, and the effect that the steering characteristic can be easily set is also obtained. .

  In the above-described embodiment, the distance between the ball centers of the ball joints 15 and 16 that connect the outer ends 11a and 12a of the rods 11 and 12 and the front and rear arms 13a and 13b of the knuckle 13 is the The inner ends 11b, 12b of the twelve and the front and rear ends 21a, 21b of the lever 21 are set so as to be larger than the distance between the ball centers of the ball joints 22, 23. , 16 is set so that the distance between the ball centers of the ball joints 22, 23 is almost the same as the distance between the ball centers 22, 23, or the distance between the ball centers of the ball joints 15, 16 is It is also possible to carry out by setting the distance to be smaller than the distance between the ball centers.

  The case where the wheel steering mechanism according to the present invention is applied to a steering mechanism having a double wishbone suspension has been described above. However, the present invention is not limited to this, and the wheel steering mechanism according to the present invention is, for example, a steering mechanism having a strut suspension. It can also be applied to a steering mechanism having a multi-link suspension.

It is the top view which showed the right side in the steering mechanism of the wheel by this invention schematically with the skeleton. FIG. 2 is a plan view showing a left turning time of the wheel steering mechanism shown in FIG. 1. FIG. 3 is a plan view showing a wheel turning angle in the state shown in FIG. 2 in comparison with a wheel turning angle in a normal steering mechanism.

Explanation of symbols

S ... Suspension, K ... Drive mechanism, 11, 12 ... A pair of front and rear rods, 13 ... Knuckle (wheel support member), 21 ... Lever, 24 ... Pin, P1, P2 ... Ball center of ball joints 22 and 23 Center), P3 ... axis center of pin 24 (rotation center of lever 21), 30 ... actuator, 40 ... wheel, L1 ... rotation center axis of wheel 40, O1 ... turning center of wheel 40, 50 ... vehicle body

Claims (1)

A pair of front and rear rods that are disposed forward and rearward with respect to the center axis of rotation of the wheel, extend in the vehicle width direction and are pivotally attached to the wheel support members at the respective outer ends, and these rods in the vehicle width direction are provided. In a wheel steering mechanism with a moving drive mechanism,
The drive mechanism is a lever that extends in the front-rear direction of the vehicle, is pivotally attached to the inner end of each rod at the front and rear end portions, and is pivotally supported on the vehicle body at a substantially central portion so as to be rotatable in plan view. And a single actuator that is assembled to the vehicle body and connected to the lever to rotate the lever, and the pivoting center of the rod and the lever is the same lever when the turning angle of the wheel is zero. A wheel steering mechanism that is set to be inward of the vehicle with respect to the center of rotation of the vehicle.

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