JPS61122073A - Steering apparatus for automobile - Google Patents

Abstract

PURPOSE:To change the ratio of the turning angle of the wheels to the steering angle of a steering wheel in response to vehicle speed by controlling a transmission ratio variable structure on the basis of a vehicle speed detected signal. CONSTITUTION:A steering wheel shaft 10 is coupled to a pinion shaft 12 by means of a friction wheel type speed change structure 9 consisting of a first conical wheel 11, a second conical wheel 13 and a friction wheel 14. The conical wheel 14 is moved to an axial direction thereof by means of a motor 16 to change the transfer ratio of the volume of steering. And a controller 18 controls the motor 16 on the basis of a vehicle speed signal from a vehicle speed sensor 19 and a steering angle signal of a steering wheel from a steering angle sensor 20 to adjust the transfer ratio. Accordingly, it is possible to decrease the transfer ratio to make the stability of running excellent in high speed running, and it is possible to increase the transfer ratio to improve the sharpness in low speed running.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a steering device for an automobile that changes the transmission ratio of a steering wheel angle to wheels in accordance with vehicle speed.

(Prior art) An automobile steering device converts the rotation of a steering wheel into a lateral displacement of a tie rod through a steering gear device such as a rack-and-nion steering gear device, and moves the left and right wheels connected to both ends of the tie rod. However, in this case, the rotation 1 of the steering wheel (steering angle) and the turning angle of the wheels (steering angle) are usually maintained in a constant correspondence relationship. However, for example, when driving at high speeds, it is desirable to reduce the ratio of the turning angle to the steering angle to ensure driving stability, and when driving at low speeds, it is desirable to increase the ratio to make the vehicle's behavior more agile. I got a great driving feeling. This is desirable in terms of ease of parking, etc.

Therefore, as disclosed in, for example, Japanese Unexamined Patent Publication No. 58-224852, a speed-sensitive steering device has been proposed in which the ratio of the turning angle to the steering angle is changed depending on the vehicle speed. As shown in Fig. 6, a speed change IEIIF consisting of a pair of variable pitch pulleys C and D and a belt E wrapped between the two pulleys is interposed between the steering wheel and the steering column B. With,
The pitch diameter of the driven pulley D is controlled by a stepping motor G so that it becomes larger as the vehicle speed increases. According to this, the rotation transmission ratio from the steering wheel A to the steering column B becomes smaller at high speeds, and as a result, the turning angle of the wheels with respect to a constant steering wheel angle becomes small at high speeds and increases at low speeds, and the vehicle speed increases. Corresponding good steering characteristics can be obtained. However, according to this steering device, the transmission mechanism F using the variable pitch pulleys C and D has a relatively large structure, which increases the size of the entire device. However, when the speed of the belt E is extremely low, such as when rotating the handle, the pitch diameter of the pulley C1D cannot be controlled smoothly. When increasing the pitch diameter, it becomes difficult to change the pitch diameter smoothly. In other words, the driving pulley C in this speed change mechanism F is constantly biased so that the pitch diameter of the pulley C becomes large for the purpose of applying tension to the belt E. The tension of the belt E acts to reduce the pitch diameter of the driven pulley D. Therefore, in order to increase the pitch diameter of the driven pulley D, the belt E must be pushed outward against the above tension. In this case, if the running speed of the belt E is slow, this operation will not be performed smoothly.

(Object of the Invention) The present invention addresses the above-mentioned actual situation regarding steering devices for automobiles, and provides a steering device that can change the ratio of the steering angle of the wheels to the steering angle according to the vehicle speed. It is an object of the present invention to provide a steering device which is compactly constructed and which can smoothly transmit steering force to the wheels and can smoothly control the transmission ratio.

(Structure of the Invention) That is, the steering device for an automobile according to the present invention includes a friction wheel type variable transmission ratio mechanism in the steering force transmission path between the steering wheel and the steering gear device, and also detects the vehicle speed. The present invention is characterized by comprising a vehicle speed detecting means for detecting a vehicle speed, a controller for receiving a signal from the detecting means and outputting a control signal, and an actuator for controlling the variable transmission ratio mechanism in response to an I11 control signal from the controller. do.

The variable transmission ratio mechanism has a driving rotary body connected to a steering handle, a driven rotary body connected to a steering gear device, and is interposed between the two rotary bodies and whose peripheral surface is always connected to both rotary bodies. I am being touched! i! By controlling the abutment position between the friction wheel and both rotating bodies by the actuator, the rotation transmission ratio of the driven rotating body to the driving rotating body, that is, the rotational transmission ratio of the wheel to the steering angle of the steering wheel is controlled. The steering angle ratio is configured to change depending on the vehicle speed.

(Effects of the Invention) According to the steering device configured as described above, the ratio of the steering angle of the wheels to the steering angle of the steering wheel (transmission ratio) is reduced in order to obtain good running stability, for example, when driving at high speed. ,
In addition, when driving at low speeds, the above-mentioned ratio is increased to obtain agility, thereby achieving steering characteristics that correspond to the vehicle speed, and by using a friction wheel type transmission ratio variable mechanism as a means for converting the above-mentioned transmission ratio, the transmission ratio is increased. Variation of the ratio tIl1m can be performed smoothly, and the entire steering device is constructed compactly, so that it can be installed without requiring a large space in the engine room or inside the vehicle.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1.2 shows a first embodiment of the present invention. As shown in FIG. 1, a steering device 2 for steering left and right front wheels 1.1 has a steering handle (hereinafter referred to as a handle) 3 and a steering device 2 for steering left and right front wheels 1.1. , a pinion 4 to which rotational motion is transmitted from the handle 3, a center rod 5 formed with a rack 5a that meshes with the pinion 4 and movable in the lateral direction of the vehicle body, and a center rod 5 that allows movement of the center rod 5 in the lateral direction of the vehicle body. Left and right tie rods 6.6 that transmit power to the front wheels 1.1, and knuckle arms 7.
7, and the binion 4 and center rod 5 constitute a rack-and-binion type steering gear device 8.

However, this steering device 2 is provided with an I'JlI vehicle type transmission mechanism 9 in the middle of a path for transmitting the rotation of the handle 3 to the pinion 4 in the steering gear device 8. This friction wheel type transmission mechanism 9 has the above-mentioned handle 3.
A first conical wheel 11 is connected to the handlebar shaft 10 to the handlebar shaft 10, a second conical wheel 13 is connected to the handlebar shaft 12 to the handlebar shaft 12, It consists of a II friction wheel 14 interposed between second conical wheels 11 and 13. As shown in FIG. 2, the friction wheel 14 has a circumferential surface 14a as shown in FIG. The circumferential surface 11a of the second conical wheel 11.13.

13a. Furthermore, this friction wheel 14 is
The I′IJrM axle 15 is held on the III shaft 15 so as to be able to move axially and rotate integrally with the shaft 15, and the I′IJrM axle 15 is
A rack 15a is formed at the end of the rack 15a, which is held movably in the axial direction and meshes with a pinion 17 fixed to a rotating shaft 16a of the stepping motor 16.

On the other hand, the steering device 2 is equipped with a controller 18 that controls the rotation of the stepping motor 16. This controller 18 receives a vehicle speed signal a from a vehicle speed sensor 19 and a steering angle signal from a steering angle sensor 20 that detects the rotation angle of the steering wheel 3, and controls the stepping based on these signals a and b. The amount of rotation (including the rotation direction) of the motor 16 is set, and this is set as the control signal C.
The signal is output to the stepping motor 16 as a signal.

According to the above configuration, when the steering wheel 3 is rotated while the automobile is running, the rotation transmitted from the steering wheel shaft 10 to the first conical wheel 11 in the friction wheel type transmission mechanism 9 is transmitted via the friction wheel 14. is transmitted to the second conical wheel 13,
In this case, the peripheral surface 14a of the III friction wheel 14 and the first. Rotation is transmitted to the second conical wheel by a rotation transmission ratio determined according to the contact position of the second conical wheel 11.13 with the circumferential surfaces 11a, 13a.

Further, the rotation of the second conical wheel 13 is transmitted to the pinion 4 via the pinion shaft 12, and is converted into movement of the center rod 5 in the lateral direction of the vehicle body by the rack 5a meshing with the pinion 4. This movement is transmitted to the left and right tie rods 6.6 and knuckle arms 7.7 to steer the front wheels 1.1.

However, when the above-mentioned steering wheel 3 is rotated, the controller 18 to which the signal a from the vehicle speed sensor 19 and the signal from the steering angle sensor 20 are inputted will output the vehicle speed and steering angle indicated by the above-mentioned signals, respectively. In response, a control signal C is output, and the stepping motor 16 is rotated by the signal C, and the accompanying rotation of the pinion 17 fixed to the rotating shaft 16a of the motor 16 is caused by the rack 15a meshing with the pinion 17. This is translated into an axial movement of the friction axle 15, which causes the friction wheel 14 to move in the axial direction.

Therefore, 11! [The peripheral surface 14a of the car 14 and the first. Second
The contact position of the conical wheel 11.13 with the curved surface 118.degree. 13a moves, and the rotational transmission ratio of the second conical wheel 13 to the first conical wheel 11 changes in accordance with this moving distance. Therefore, the operation m of the handle, that is, the rotation m of the first conical wheel 11
is transmitted to the second conical wheel 13 in the amount of rotation that is increased or decreased according to the movement of the small SM 14 in the axial direction, and the front wheels are steered in accordance with the amount of rotation of the second conical wheel 13. become. In this case, if the friction wheel 14 moves in the direction of arrow The rotational transmission ratio becomes smaller.

Incidentally, since the rotation amount (including the rotation direction) of the stepping motor 16 is set depending on the vehicle speed and the magnitude of the steering wheel steering angle, the amount of axial movement of the friction axle 15 and the friction wheel 14, that is, the first The rotation transmission ratio of the second conical wheel 13 to the conical wheel 11 is changed according to the vehicle speed and the large knurling of the steering wheel steering angle. Therefore, the ratio of the wheel turning angle to the steering wheel steering angle also changes depending on the vehicle speed. and the magnitude of the steering wheel angle. As a result, by appropriately setting the rotation of the stepping motor 14 in advance in accordance with the vehicle speed and steering wheel angle, for example, the turning angle of the wheels with respect to a constant steering wheel angle can be made small when driving at high speeds, and small when driving at low speeds. It is also possible to control the ratio of the turning angle to the steering wheel angle to be further reduced when the steering angle is small, and further increased when the steering angle is large. Therefore, good driving stability is obtained when driving at high speeds or when the steering wheel angle is small, and good steering performance is obtained when driving at low speeds or when the steering wheel angle is large, making the behavior of the vehicle more agile. This makes it possible to control steering characteristics such as:

In particular, according to the above configuration, the first. Since the friction wheel type transmission mechanism 9 consisting of the second conical wheel 11, 13 and the friction wheel 14 is used, smooth variable control is possible whether the ratio is increased or decreased. Since the entire transmission mechanism 9 is constructed compactly, it can be installed in the engine room or interior of an automobile without requiring a large space.

Next, a second embodiment of the present invention will be described.

As shown in FIG. 3.4, the steering device M2' in the second embodiment includes a steering wheel shaft 10' and a pinion shaft 12', which are arranged orthogonally to each other. 22a is a toroidal surface. Second concave circular wheels 21, 22 and their peripheral surfaces 21a
, 22a, and a friction wheel type transmission mechanism 9' is provided. The friction wheel 23 has a circumferential surface 23a as the first friction wheel 23. It is rotatably held by a holding member 24 via a support shaft 25 so as to be in contact with the peripheral surfaces 21a and 22a of the second concave conical wheels 21 and 22, respectively, and a gear shaft 26 is attached to the holding member 24. A first gear 27 is connected thereto, and this first gear 27 and a second gear 28 fixed to a rotating shaft 16a' of a stepping motor 16' are meshed with each other.

Also in this embodiment, a control signal C' that is set based on the signals a' and b' from the vehicle speed sensor 19' and the steering angle sensor 20' is output from the controller 18' to the stepping motor 16'. The motor 16' is adapted to be rotated.

This rotation causes the holding member 24 and the support shaft 25 to rotate around the gear V26 via the second gear 28 and the first gear 27, and therefore the AM car 23 also rotates around the gear shaft 26 as shown in FIG. xL, y is rotated in one direction, and the circumferential surface 23a of the friction wheel 23 and the first and second concave circular wheels 21
．． 22, each peripheral surface 21a.

The contact position with 22a is moved. Therefore, the rotational transmission ratio of the second concave conical wheel 22 to the first concave conical wheel 21,
That is, the ratio of the steering angle of the front wheels to the steering angle of the steering wheel is changed.

Therefore, in this second embodiment, as in the first embodiment, it is possible to variably control the transmission ratio from the steering wheel angle to the steering angle of the front wheels according to the vehicle speed and the steering angle. It ensures good running stability when driving at high speeds or when the steering wheel angle is small, and also ensures good steering performance and controls the behavior of the car when driving at low speeds or when the steering wheel angle is large. It is possible to make it more agile. Furthermore, as the transmission ratio conversion means, the first. 2nd concave conical wheel 21, 22 To11!1g1123 Totena 811i
r! Since the AI type transmission 1!119' is used, the structure is compact like the first embodiment, and variable control of the transmission ratio is performed smoothly.

Furthermore, to explain a third embodiment of the present invention, as shown in FIG.
In this case, the handle shaft 10'' and the binion shaft 12'' are arranged in a straight line, and both wheels 10'', 12'' are arranged in a straight line.
'' are fixed to the ends of the first .
It is composed of a second disk 29.30 and an IFj friction wheel 31 arranged between annular concave surfaces 29a and 30a formed on opposing surfaces of these disks 29.30! A friction wheel type transmission rocker 9'' is provided.The I'm friction wheel 31 has its peripheral surface 31a in contact with the two annular concave surfaces a and 3Qa of the two discs 29 and 30, respectively. In this state, it is rotatably held by the holding member 32 via the first support shaft 33.

Further, a sector gear 34 is fixed to the holding member 32, and the holding member 32 and the sector gear 34 are rotatably held by a second support shaft 35, and the sector gear r3
A worm 36 fixed to the rotating shaft 16a'' of the stepping motor 16'' is meshed with the worm 4.

According to this, the vehicle speed sensor 19'' and the steering angle sensor 20''
A control signal C'' set by the controller 18'' based on the signals 3 II and b II from The holding member 32 is rotated around the second support shaft 35 via the sector gear 34, and the C friction wheel 31 is also rotated around the second support shaft 35.
It will be rotated around the support shaft 35 in the xIT and y11 directions. Therefore, the circumferential surface 31a of the friction wheel 31 and the first
．． The contact position of the second disc 29.30 with the annular concave surfaces 29a, 30a is moved. As a result, the rotation transmission ratio of the second disc 30 to the first disc 29 is changed, so that the transmission ratio from the steering angle of the steering wheel to the turning angle of the front wheels is also changed. Therefore, in this third embodiment as well, the first.
Similar to the second embodiment, good running stability is ensured when driving at high speeds or when the steering angle of the steering wheel is small, and good steering performance is ensured when driving at low speeds or when the steering angle of the steering wheel is large. Furthermore, by adopting the friction wheel type transmission mechanism 9'' as described above, the variable transmission ratio mechanism is configured compactly, and variable control of the nuclearization is made possible. It will be carried out smoothly.

In addition, the above 1. Second. In the third embodiment, the ratio of the steering angle of the steering wheel to the turning angle of the wheels is changed according to the vehicle speed and the size of the steering angle of the steering wheel, but it may be changed only according to the vehicle speed. . Furthermore, since a steering gear V device that makes it possible to change the ratio according to the steering angle has been put into practical use, it may be carried out by using this gear device.

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention. FIG. 1 is a schematic plan view showing the main parts of a steering device and an accompanying control circuit, and FIG. 2 is a friction wheel type steering device. FIG. 3 is an enlarged plan view of the main parts of the variable mechanism. 3 and 4 show the second embodiment, and FIG. 3 is a schematic plan view showing the main parts of the steering device and the control circuit associated therewith, and FIG.
The figure is a side view taken along arrows ■-■ in FIG. 3. FIG. 5 shows a third embodiment, and is a schematic plan view showing the main parts of the steering device and the control circuit associated therewith. FIG. 6 is a schematic configuration diagram showing a conventional example. 3... Steering handle, 9.9', 9''...
Il! Friction wheel type variable transmission ratio structure, 11.21.29...
Driving rotating body, 13, 22. 30... Driven rotating body,
14.23.31...Friction wheel, 16°16', 16"
...actuator (stepping motor>, 18.
18', 18''...controller, 19.19'
, 19''...Vehicle speed detection means (vehicle speed sensor).

Claims (1)

[Claims] (1) In the steering force transmission path between the steering handle and the steering gear device, there is a driving rotary body connected to the steering handle, a driven rotary body connected to the steering gear device, and a link between the two rotary bodies. In addition to providing a friction wheel type variable transmission ratio mechanism consisting of a friction wheel interposed in the
a vehicle speed detection means for detecting vehicle speed; a controller for inputting a signal from the vehicle speed detection means and outputting a control signal; A steering device for an automobile, comprising an actuator that variably controls the position of contact with the body.