JP2005255092A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize projection of the steering wheel into the cabin in a collision of a vehicle. <P>SOLUTION: The steering device turns left and right front wheels WL and WR by rocking left and right knuckles 27L and 27R by rotation operation of the steering wheel 15. The steering device comprises a hollow input shaft 14 connected to the steering wheel 15, a solid output shaft 17 connected to the right knuckle 27R, a ball screw mechanism 20 for converting the rotation of the input shaft 14 to the reciprocation in the axial direction of the output shaft 17 to rock the right knuckle 27R, and a tie rod 29 for interlocking and rocking the left and right knuckles 27L and 27R. Even if the output shaft 17 is pushed by an engine E and a transmission M moved back by collision impact of the vehicle and is moved back, the backward movement of the output shaft 17 is converted into the rotation of the input shaft 14 by the ball screw mechanism 20. Therefore, the projection of the steering wheel 15 into the cabin by the backward movement of the input shaft 14 can be minimized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a steering device that steers left and right front wheels by rotating a steering handle.

A hollow input shaft connected to the steering wheel, a solid output shaft fitted inside the input shaft and connected to the steering gear box, and a cylinder fitted axially slidably on the outer periphery of the output shaft And a ball screw mechanism that is arranged between the output shaft and the slider and converts the linear motion of the slider to the rotational motion of the output shaft, and the input shaft rotates by moving the slider in the axial direction by a motor. The ratio of the rotation angle of the output shaft to the angle, that is, the one that arbitrarily changes the steering angle ratio is known from Patent Document 1 below.
JP 2003-291826 A

  By the way, in the conventional steering device that transmits the rotation of the steering wheel from the steering shaft to the left and right front wheels via the steering gear box that houses the rack and pinion mechanism, the steering gear box is moved backward by the engine that moves backward when the vehicle collides. When pushed, the steering shaft connected to the steering gear box retreats and the steering handle protrudes into the vehicle compartment.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to minimize the protrusion of the steering handle into the passenger compartment when the vehicle collides.

  In order to achieve the above object, according to the first aspect of the present invention, in a steering device that steers the left and right front wheels by rotating the steering handle, an input shaft connected to the steering handle, A steering apparatus comprising: steering force converting means for converting rotational movement into reciprocating movement in the axial direction of the output shaft; and steering means for turning left and right front wheels by reciprocating movement in the axial direction of the output shaft. Is proposed.

  According to the invention described in claim 2, in addition to the configuration of claim 1, a steering device is proposed in which the steering force converting means is a ball screw mechanism.

  The ball screw mechanism 20 of the embodiment corresponds to the steering force conversion means of the present invention, and the knuckles 27L and 27R and the tie rod 29 of the embodiment correspond to the steering means of the present invention.

  According to the configuration of the first aspect, the rotation of the input shaft connected to the steering handle is converted into the reciprocating motion in the axial direction of the output shaft by the steering force converting device, and the steering device is operated by the reciprocating motion in the axial direction of the output shaft. Since the left and right front wheels are steered, it is possible to convert the load on the output shaft, which moves backward due to the impact of the collision of the vehicle, to the rotational movement of the input shaft by the steering force conversion means. Projection into the passenger compartment can be minimized.

  According to the second aspect of the present invention, since the steering force converting means is constituted by the ball screw mechanism, the steering force is reduced by reducing the frictional force when converting the rotational motion of the input shaft into the reciprocating motion of the output shaft in the axial direction. Moreover, since the ball screw mechanism is smaller than the conventional steering gear box, the layout is improved.

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

  First, the structure of the steering apparatus according to the first embodiment will be described with reference to FIG.

  A hollow input shaft 14 is rotatably supported by a steering column 11 fixed to the vehicle body via a pair of bearings 12 and 13, and a circular steering handle 15 is provided at the rear end of the input shaft 14. An output shaft 17 is supported by a slide guide 16 provided inside the input shaft 14 so as to be slidable in the axial direction. The input shaft 14 and the output shaft 17 are a ball screw mechanism 20 including a female screw portion 18 and a male screw portion 19. Connected. A pin 21 fixed to the output shaft 17 is slidably engaged with a guide groove of a guide member 22 provided in the steering column 11.

  The rear end of the rear rod 24 is connected to the front end of the output shaft 17 via the universal joint 23, and the front end of the rear rod 24 is slidably fitted to the rear end of the cylindrical front rod 25 so as to be a shear pin. 26. Of the left and right knuckles 27L and 27R that support the left and right front wheels WL and WR in a steerable manner, the front end of the front rod 25 is pivotally supported via a ball joint 28 on one (right side in the embodiment) knuckle 27R. The Then, both ends of the tie rod 29 extending in the vehicle width direction are pivotally supported by the left and right knuckles 27L and 27R via the ball joints 30 and 30, respectively.

  A worm 32 rotated by a motor 31 supported on the steering column 11 meshes with a worm wheel 33 fixed to the output shaft 17, and assist torque generated by the motor 31 is transmitted to the input shaft 14 to assist the steering operation by the driver. can do. A steering torque sensor 34 for detecting the steering torque input to the steering handle 15 is provided on the input shaft 14, and the electronic control unit 35 is an assist torque generated by the motor 31 based on the steering torque detected by the steering torque sensor 34. Control the size of.

  Next, the operation of the first embodiment having the above configuration will be described.

  When the driver operates the steering handle 15 to rotate the input shaft 14, the rotational motion is converted into a reciprocating motion in the axial direction of the output shaft 17 by the ball screw mechanism 20. At this time, the pin 21 fixed to the output shaft 17 is slidably guided in the guide groove of the guide member 22 provided in the steering column 11, so that the rotation of the output shaft 17 is prevented. The reciprocating motion of the output shaft 17 in the axial direction causes the right knuckle 27R to swing through the universal joint 23, the rear rod 24 and the front rod 25, and the left knuckle 27L connected to the right knuckle 27R by the tie rod 29. By swinging, the left and right front wheels WL and WR are steered in conjunction with each other. The electronic control unit 35 generates assist torque in the motor 31 in accordance with the magnitude of the steering torque detected by the steering torque sensor 34, and the assist torque is transmitted to the input shaft 14 via the worm 32 and the worm wheel 33 to be transmitted to the driver. Assist steering operation.

  Now, when the engine E and the transmission M are moved backward due to the collision of the vehicle, even if the front rod 25 is moved rearward by being pushed by the engine E and the transmission M, the shear pin 26 is sheared and the front portion with respect to the rear rod 24 As the rod 25 slides backward, the rear rod 24 is prevented from moving backward. Even if the rear rod 24 and the output shaft 17 move backward due to the impact of the collision, the input shaft 14 and the steering handle 15 only rotate via the ball screw mechanism 20, and the steering handle 15 enters the vehicle interior. Protrusion is minimized.

  In addition, by using the ball screw mechanism 20 that is small and has a small frictional force, the weight is reduced and the layout is improved as compared with the case of using a conventional rack-and-pinion type steering gear box that has a large frictional force. In addition to being able to improve, it is possible to obtain a direct steering feeling by improving the transmission efficiency of the steering torque.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the same reference numerals as those of the first embodiment are assigned to the components corresponding to the components of the first embodiment, thereby omitting the overlapping description.

  In the first embodiment, the rear rod 24 and the front rod 25 are coupled by the shear pin 26 to make it difficult for the impact of the collision to be transmitted to the output shaft 17, but in the second embodiment, the output shaft 17 and the right knuckle 27R are connected. By buckling the S-shaped bent portion provided on the rod 36, the impact of the collision is hardly transmitted to the output shaft 17. In the first embodiment, the input shaft 14 is driven by a motor 31 that generates assist torque. In the second embodiment, the tie rod 29 is directly driven. That is, the inner ends of a pair of links 38 and 38 are connected to both ends of a tie rod 29 arranged in the vehicle width direction via ball joints 37 and 37, and the outer ends of the links 38 and 38 are connected via ball joints 39 and 39. Are connected to the left and right knuckles 27L and 27R. A motor 31 is connected to the intermediate portion of the tie rod 29 via the ball screw mechanism 20.

  Thus, the second embodiment can achieve the same effects as the first embodiment described above.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the input shaft 14 is constituted by a hollow shaft and the output shaft 17 is constituted by a solid shaft, but the relationship can be reversed.

  Further, the steering device of the embodiment includes the knuckles 27L and 27R and the tie rod 29 as the steering means, but the present invention can also be applied to a steering device provided with any other type of steering means. .

The figure which shows the structure of the steering device which concerns on 1st Example. The figure which shows the structure of the steering device which concerns on 2nd Example.

Explanation of symbols

14 Input shaft 15 Steering handle 17 Output shaft 20 Ball screw mechanism (steering force conversion means)
27L knuckle (steering means)
27R knuckle (steering means)
29 Tie rod (steering means)
WL front wheel WR front wheel

Claims (2)

In the steering device that steers the left and right front wheels (WL, WR) by rotating the steering handle (15),
An input shaft (14) connected to the steering handle (15);
Steering force conversion means (20) for converting the rotational movement of the input shaft (14) into the reciprocating movement of the output shaft (17) in the axial direction;
Turning means (27L, 27R, 29) for turning the left and right front wheels (WL, WR) by the reciprocating motion of the output shaft (17) in the axial direction;
A steering apparatus comprising: The steering apparatus according to claim 1, wherein the steering force converting means (20) is a ball screw mechanism.

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