JPS5981266A - Steering gear for vehicle - Google Patents

Abstract

PURPOSE:To allow a rear wheel steering mode to be selected according to various running conditions at low and high speeds, or operator's preference, by providing a transmission in a rear wheel steering system so as to manually change a steering ratio. CONSTITUTION:A front steering system and a rear steering system are connected with each other through linkages 24, 25 and 27, and rear wheels 16 are steered in such a manner as to be interlocked with front wheels. A transmission 40 is interposed among the linkages, and accordingly a gear ratio may be suitably selected by the operation of a shift lever 42. With this arrangement, it is possible to manually select a steering mode such that the rear wheels are reversely steered at low speeds to improve a steering operability, while driveability of a vehicle at high speeds may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle steering system that steers both front wheels and rear wheels by steering operation of a steering wheel.

In particular, the present invention relates to a steering system for a vehicle equipped with a manual transmission.

Required rotation i 1J for rear wheel steering taken from the front wheel steering system
The input is input to a rotating member that forms the input shaft of the rear wheel steering system through the coupling member, and the rotation of the front and rear wheels is caused in proportion to the steering angle by crank rotation of an output shaft such as an eccentric pin provided on the rotating member. The present applicant has previously provided a vehicle steering system (Japanese Patent Application No. 118698/1983) that simultaneously steers front and rear wheels in conjunction with each other to change the steering ratio.

According to such a steering device, it is possible to steer the rear wheels in the same direction as the front wheels by operating the steering wheel at a small steering angle, and it is also possible to steer the rear wheels in the opposite direction by operating the steering wheel at a large steering angle. In addition to improving maneuverability, the steering angle can be increased to obtain a small turning radius when making a U-turn or when manipulating people in a parking lot, resulting in good maneuverability of the vehicle.

By the way, if possible, the steering direction and steering ratio of the rear wheels relative to the front wheels should be adjusted according to various situations such as when parking, when driving at low speed on a narrow curved road, or when driving at high speed while driving, and the driver's preference. It is desirable to be able to change it freely.

Not only the above-mentioned steering device, but also a vehicle steering device that steers both the front and rear wheels proportionally to the steering angle,
It would be convenient if the rear wheel steering mode could be freely selected depending on the situation, preference, etc.

The present invention has been made in response to the above-mentioned needs, such as parallel parking, crowded garages, low-speed driving on narrow curved roads, normal driving, and high-speed driving in FX. An object of the present invention is to provide a steering device for a vehicle that allows the steering mode of rear wheels to be freely and manually changed according to the situation, driver's preference, etc.

In order to achieve such an object, the present invention provides a transmission that rotates in conjunction with a steering wheel and manually varies the rotation ratio of a rotating member forming an input shaft of the rear wheel steering system to the steering angle of the steering wheel. The gist is that the linkage member is interposed in the intermediate portion of the linkage member that connects the rear wheel steering system and the rear wheel steering system.

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a schematic configuration of a four-wheeled vehicle equipped with a steering system according to the present invention, and FIG. 2 is a side view showing an example of a schematic internal structure of a transmission forming a main part of the same.

The tip of the handle shaft 2 of the handle 1, which is a steered wheel, is incorporated into a rack-and-pinion type front wheel steering gear box 20, and, as is known, is engaged with a drive pinion at the tip of the handle shaft 2 within the gear box 20. A driven pinion (both not shown in the figure) meshes with the left half of the rack, and tie rods 3.3 are connected to both ends of rack shafts 21 that protrude from the left and right sides of the gear box 20, respectively. A knuckle arm 4 is attached to the outer end of the tie rod 3.3.
, 4 are connected, and the front wheel 6.6 is connected to the knuckle arm 4.
, 4 on an outwardly projecting axle 5.5.

□The front wheels are steered by operating the steering wheel 1. That is, by rotating the handle shaft 2, the pinion and rack are fully engaged and the rack shaft 21 is turned.
111 moves left and right with respect to the gear box 20, which causes both tie rods 3.3 to move left and right, and the supply arm 4.
rotates in the left-right direction, and the front wheels 6.6 are steered.

On the other hand, the rear part of the pinion shaft 22 of the driven pinion that meshes with the left half of the rack shaft 21 is led out rearward from the gear box 20, and is connected to the first linkage shaft 24 via the universal joint 23. The rear part of the linkage shaft 24 is incorporated into a case 41 of a transmission 40, which will be described later, and the second linkage shaft 25 also coaxially has its front part incorporated into the case 41.
A third linkage shaft 27, which is elongated, is further connected to the rear end of the second linkage force 25 via a universal joint 26. , or more driven binion shaft 22% 1st. The input shaft of the rear wheel steering system is connected to the rear end of the second and third linkage shafts 24, 25, and 27, that is, the rear end of the third linkage shaft 27 via an arbitrary joint 28. 31 are connected. .

The input shaft 31 is arranged in alignment with the left-right center line of the vehicle, and is a rotary member rotatably supported by an axes bracket 32. A crank arm 33 is integrally attached to the rear end of the input shaft 31. An eccentric pin 34 is provided protruding from the rear surface. - In the illustration, the eccentric pin 34 is initially set to be located vertically below the input shaft 3.1 in the neutral position for steering the rear wheels. .

The left and right tie rods 13.1 are commonly connected to the eccentric pin 34.
3 with loose fit. .

A rear wheel 16.16 is supported on an axle 15.15 projecting outwardly from a knuckle arm 1'4.14 connected to the outer end of the tie rod 13.13.

Incidentally, the internal structure of the transmission 40 is as shown in FIG. 2, for example, and is similar in structure to a known manual transmission.

That is, the lower ends of the shift levers 4 and 2 placed at appropriate locations in the vehicle interior are connected to the shift levers 43 and 43 in the case 41 of the transmission 40.
..., and the shift forks 44 supported by the shift rods 43... are fitted into the sleeves 45, respectively, and the output rotation of the first linkage shaft 24, which is the drive shaft, is controlled from low to low. Top gears 51, 52...55, reverse gear 56 and counter shaft 46 gears 61, 62...
By selective meshing transmission with 66 by operating the shift lever 42, the transmission is transmitted to the second linkage shaft 25, which is the driven shaft, at a desired gear ratio.

When the steering wheel 1 is operated, the rack shaft 21 of the front wheel steering gear box 20 moves left and right.

The rotation necessary for steering the rear wheels is output to the driven pinion shaft □22 which meshes with the left hand portion and rotates left and right.

The first linkage shaft 24 rotates either left or right.

In this case 1, for example, if the driven binion shaft 22 is related to the rack shaft 21 of the front wheel steering gear box 20 from below, or if it is related from above and an idle gear is interposed between the two 21 and 22, the transmission Rotation in the opposite direction to the handle shaft 2 is transmitted to the second linkage shaft 25 through the forward rotation gears 40, low to top gear 51, and rotation in the same direction is transmitted through the reverse gear 56. is transmitted.

- The eccentric pin 34 provided on the actual input shaft 31 performs crank rotation in the same direction as the second linkage shaft 25 via the third linkage shaft 27, so that the eccentric pin 34 in the left and right direction first becomes neutral. From the position until one rotation, the amount of deflection increases at a gradually decreasing speed, and thus swings to either the left or right on the tie rod 13, 13', which is loosely fitted and supported in common by the eccentric pin 34.

Next, from one rotation to the other, the eccentric pin 34 decreases the amount of deviation at a speed that gradually increases by 2, and the tie rod 13.
13 to return to the neutral position. Furthermore, from one rotation to one rotation, the eccentric bin 34 increases the amount of deviation in the opposite direction at a speed that gradually decreases by 4 degrees.
In this way, the tie rods 13, 13' are swung in a direction opposite to the initial direction.

Here, for example, if the connection state of the third gear 53 of the transmission 40 is configured as when the vehicle is normally running, the rear wheel
6.16 is steered. In FIG. 4, positive and negative rear wheel steering angle coordinates represent the same and opposite phases of the front wheel steering, respectively.

Next, when the shift lever 42 is operated to connect the low gear 51 of the transmission 40, the rear wheels are steered as shown by the dashed line.
Furthermore, when the reverse gear 56 is connected, the rear wheels are steered as shown by the broken line C, so that the turning performance of the vehicle can be adjusted as needed when driving at very low speeds such as parallel parking, crowded garages, and narrow winding roads. This will lead to improved performance.

Furthermore, when driving at high speeds, only a small amount of steering angle is used, so the top gear 55 of the transmission 40 is
When connected, the rear wheels are steered as shown by the two-dot chain line 2, and the in-phase steering ratio of the rear wheels 16 near the neutral position of the steering wheel 1 can be increased. This will further improve the maneuverability of the vehicle.

In the above explanation, the connection state of the seven-wheel gear 52 and the force gear 54 has been omitted, but their functions can be easily understood. In addition, when the transmission 40 is in the neutral state, the output rotation of the first linkage shaft 24 is not transmitted to the second linkage shaft 25, the rear wheels are hardly steered.

Although the transmission 40 has been described as a gear mechanism with five forward speeds and one reverse speed, the forward and reverse speeds and the respective number of speeds can be set arbitrarily, and of course, an appropriate mechanism such as a belt mechanism may be used.

Furthermore, the gear change operation of the transmission is performed only when the vehicle is traveling straight.

In the above embodiment, a manual transmission is incorporated into a vehicle steering system that simultaneously steers the front and rear wheels so as to change the steering ratio of the front and rear wheels in proportion to the steering angle. The present invention is also applied to a vehicle steering system that steers the vehicle proportionally to the steering angle of the steering wheel. This will be explained based on Figure 3.

First of all, the steering system of this embodiment has the same structure as described above from the front wheel steering system to the linkage member and around the rear wheels, so similar members are given the same reference numerals in the 100s and their explanations will be explained below. I would like to preface the omission.

An input shaft 131 is connected to the rear end of the third linkage shaft 127 via a universal joint 128, which is similar to that described above.
31 is incorporated into the rear wheel steering gear box 170, and connects the rack shaft 171 of a rack (both not shown in the figure) that meshes with the drive pinion at the rear end of the input shaft 131 of the gear box 170. Tie rods 113°1 are protruded from the left and right sides, respectively, at both ends of the rack shaft 171.
13 are connected.

Then the rear wheel 116. It can be seen that the '116 is steered together with the front wheels in proportion to the steering angle by the rack-and-binion mechanism of the input shaft 131 and the rack shaft 171.

In this embodiment as well, since the transmission 140 is interposed between the first and second linkage shafts 124 and 125, the fifth
As shown in the figure, rear wheel steering in various linear shapes can be performed manually.

In both of the above embodiments, the transmission is interposed between the first and second linkage shafts, but the point is that the manual transmission is interposed at the intermediate portion of the linkage member.

Further, the rear wheel steering system is not limited to those of both embodiments.

As is clear from the above description, according to the present invention, a manual transmission that can vary the rotation ratio of the rotating member forming the input shaft of the rear wheel steering system with respect to the steering angle of the steering wheel is interposed in the intermediate portion of the linkage member. The rear wheels can be freely steered manually according to various situations such as parallel parking, crowded garages, low-speed driving on narrow curved roads, normal driving, and sharp high-speed driving, as well as the driver's preference. It can be changed at

4. Brief explanation of the drawings.

The drawings show embodiments of the present invention, and FIG. 1 is a perspective view showing a schematic configuration of a first embodiment of a four-wheeled vehicle equipped with a steering device according to the present invention, and FIG. 2 shows the main parts of the same. FIG. 3 is a side view showing an example of a schematic internal structure of a transmission comprising a transmission, and FIG. 3 is a view similar to FIG. 1 of the second embodiment.

FIG. 4 is a diagram of the steering angle of the steering wheel versus the turning angle of the rear wheels of the first embodiment, and FIG. 5 is a diagram similar to FIG. 4 of the second embodiment.

In the drawing, 1 is a handle, 6 is a front wheel, 16 is a rear wheel, 22.
24, 25 and 27 are linkage members.

40 is a transmission; 31 is a rotating member.

Patent applicant: Honda Motor Co., Ltd. Agent: Patent attorney Yoichi Shimoda Same patent attorney Kunio Ohashi

Claims (1)

[Claims] In a vehicle steering system in which the rear wheels are steered together with the front wheels by steering operation of a steering wheel, a linkage member that connects the front wheel steering system and the rear wheel steering system is provided with a linkage member that rotates in conjunction with the steering wheel and that rotates in conjunction with the steering wheel. A steering system for a vehicle that includes a transmission that manually varies the rotation ratio of a rotating member forming an input shaft of a wheel steering system to a steering angle of a steering wheel.