JPH01240374A - Steering device of front and rear wheels of vehicle - Google Patents

Abstract

PURPOSE:To increase transmission efficiency of steering force to rear wheels by a method wherein on a holder fixed on a steering shaft, a shaft of an epicycle gear which engages with a sun gear fixed on a car body is supported so that it is freely rotatable, and a relay rod for steering rear wheels is jointed with an eccentric arm formed in one piece with this epicycle gear. CONSTITUTION:In a saddle riding type four-wheel vehicle, a bar handle is fixed on the upper end of a steering shaft 41 which is inserted through a head pipe 2 provided at the front upper end of a body frame, and front and rear wheels are steered by steering operation of this bar handle. In this case, a holder 43 is fixed at the middle of the steering shaft 41 by spline joint or the like, and an epicycle gear 45 with an eccentric arm 46 formed in one piece is mounted on a vertical support shaft 44 supported by one side of this holder 43 so that the gear 45 is freely rotatable. This epicycle gear 45 is engaged with a sun gear 48 fixed on the car body. Then by jointing an eccentric shaft 47 protruding from the eccentric arm 46 with a relay rod 51 for steering rear wheels, steering force is transmitted to a mechanism for steering rear wheels via this rod 51.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a front and rear wheel steering mechanism for a vehicle that is equipped with a front wheel steering mechanism from a steering wheel to the front wheels and a rear wheel steering mechanism to the rear wheels to enable front and rear wheel steering. This invention relates to a steering device.

[Prior Art] In vehicles such as straddle-type four-wheel vehicles, a steering gear mechanism for front wheels and a rear wheel using a planetary gear mechanism is installed in the steering shaft part, and the steering characteristics of the front wheels and the steering gear mechanisms of the rear wheels are integrated. The present applicant has already proposed a front and rear wheel steering system in which the steering characteristics can be set individually in Japanese Patent Application No. 62-204698.

[Problems to be Solved by the Invention] By the way, since the planetary gear mechanism for generating the front wheel steering angle and the rear wheel steering angle is provided in the steering shaft portion, the steering angle generating device around the steering shaft becomes large. Becomes the property of

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve design freedom by compactly configuring a steering angle generating device without providing a gear mechanism for generating a front wheel steering angle. To provide a front and rear wheel steering device for a vehicle capable of improving steering transmission efficiency to the rear wheels by directly generating a rear wheel steering angle directly connected to front wheel steering from a planetary gear type gear mechanism.

[Means for Solving the Problems] In order to achieve the above problems, the present invention includes a front wheel steering mechanism from the handle 40 to the front wheels 24 and a rear wheel steering mechanism from the rear wheels 31 to enable front and rear wheel steering. In the front and rear wheel steering system for a vehicle, a holder 43 is fixed to the middle part of a steering shaft 41 which is provided with a handle 40 above and a front wheel steering arm 42 below, and a planetary gear 45 is rotatably attached to this holder 43. A sun gear 48 that is pivotally supported and meshes with the planetary gear 45 and through which the steering shaft 41 is rotatably inserted is fixed to the vehicle body 1 side, and an eccentric arm 46 is integrally provided with the planetary gear 45. It is characterized in that a relay rod 51 for rear wheel steering is connected.

[Function] The sun gear 48 is disposed on the same side as the steering shaft 41, and the planetary gear 45 for generating a rear wheel steering angle, which revolves together with the steering shaft 41, is meshed with the sun gear 48, so that the rear wheel steering angle, which is directly connected to the front wheel steering, can be adjusted. The rear wheel 31 can be generated directly, and is transmitted from the eccentric arm 46 integrated with the planetary gear 45 to the rear wheel steering relay rod 51.
Improves steering transmission efficiency to the sides.

Further, it is sufficient to simply provide the front wheel steering arm 42 below the steering shaft 41, and there is no need to provide a gear mechanism for generating the front wheel steering angle, so that the steering angle generating device becomes compact and the degree of freedom in design is improved.

[Example] Examples will be described below based on the accompanying drawings.

In the straddle-type four-wheel vehicle shown in FIG.
Left and right front wheels 24 are suspended at the front, and left and right rear wheels 31 are suspended at the rear of the frame via swing arms 25, and the power from the engine 21 is transmitted to both the front wheels 24 and the rear wheels 31 through a transmission circuit. It has become.

A steering shaft 41, which has a bar handle 40 connected to its upper end, is supported by its upper part through a head pipe 2 at the upper end of the front part of the frame l so as to be freely steerable, and the lower part of the steering shaft 41 is connected to pipes 3 and 4 as shown in FIG. The steering shaft 41 is supported through a holder 7 provided on a plate 6 installed between the left and right sides of the connecting pipe 5, and a steering link arm 42 for steering the front wheels is attached to the lower end of the steering shaft 41.
will be permanently installed. This steering arm 42 projects rearward and is connected to left and right front wheel steering tie rods (not shown), and both tie rods are connected to front wheel knuckle arms in a known manner. This constitutes a front wheel steering mechanism.

And above the middle part of the steering shaft 41 is a third
As shown in the figure, a steering bridge 43 forming a housing-like holder is fixed integrally by spline connection or the like.
The steering bridge 43 is provided with a vertical support shaft 44 that protrudes to one side, and a planetary gear 45 for steering the rear wheels is rotatably mounted on this support shaft 44. An eccentric arm 46 is integrated into the upper part of this planetary gear 45.
is formed, and an eccentric shaft 47 is integrally provided on the eccentric arm 46.

In addition, a fixed sun gear 48 is engaged with the planetary gear 45.
The sun gear 48 has a ring shape, and a steering shaft 41 is rotatably inserted into the sun gear 48 and disposed therein.

The sun gear 48 is fixed to the vehicle body, that is, the flange at the lower part of the sun gear 48 is attached to a flat surface 9 on a gusset 8 extending upwardly and extending between the left and right sides of the upper part of the pipe 4 at the front part of the frame 1 shown in FIG. 49 surroundings are connected with bolts and nuts.

In this way, a planetary gear type gear mechanism for generating a rear wheel steering angle is provided above the intermediate portion of the steering shaft 41, and the planetary gear 45 and the sun gear 48 are covered from the outside by the housing shape of the stearinter bridge 43.

A rear wheel steering relay rod 51 is connected to the eccentric shaft 47 of the rear wheel steering angle generating gear mechanism. This relay rod 5
1 extends rearward along the lower part of the main pipe 10 and the seat pipe 20 at the upper part of the frame l, and the relay rod 5
1. The length adjustment part 52 provided at the front end is connected to the ball joint 53.
It is coupled to the eccentric shaft 47 via. The rear end of this relay rod 51 forms an upper and lower bifurcated portion 54 as shown in FIGS. 5 to 8, and is connected to this bifurcated portion 54 via an input lever 55 and a pivot shaft 56. The input gear 55 is integrally fixed to the upper center and pot shaft 57 by spline connection or the like, and a lower center pivot shaft 58 is connected below the upper center pivot shaft 57 via a constant velocity ball joint 60.

On the other hand, the swing arm 25 is connected to the pipe 1 at the rear of the frame l.
1. The swing arm 25 is vertically swingably supported between the left and right sides of the bracket 13 connected to the connecting portion of 12 via a pivot shaft 30, and the swing arm 25 is attached to a front cross member 27 installed between the left and right arm members 26. Said lower center and pot shaft 5
8 is rotatably supported. Further, a 0-shaped pipe 16 is connected to the front and rear pipes 15 installed between the left and right sides of the pipes 12 and 14 at the rear of the frame 1 shown in FIG. shaped plate 17 and a flat plate 18 joined to the lower surface
The upper center pivot shaft 57 is rotatably supported within the vertical pipe 19 which is connected to the upper center pivot shaft 57 through the vertical pipe 19.

The constant velocity ball joint 60 includes an inner ring 61 integrally fixed to the upper center and the lower end of the pot shaft 57 by spline connection, an outer ring 63 integrally formed to the upper end of the lower center pivot shaft 58, and an inner ring groove 62. and a ball 65 interposed between the outer ring groove 64. This constant velocity ball joint 60 allows rotation from the upper center pivot shaft 57 to be accurately transmitted to the lower center pivot shaft 58 while maintaining a constant velocity state. Note that the ball 65 is supported by a retainer 66,
67 is Tastotsutsu.

Here, as shown in FIGS. 7 and 8, the center of the constant velocity pole joint 60 is arranged to coincide with the swing center P, which is the fulcrum of the swing arm 25.

Furthermore, an output lever 68 that protrudes to the side opposite to the input lever 55 is integrally fixed to the lower center and the outer periphery of the outer ring 63 of the pot shaft 58 by welding or the like.
8 is connected to a forked front end portion 72 of a second relay rod 71 via a pivot shaft 69. This second relay rod 7
A steering arm 75 for steering the rear wheels is connected to a bifurcated portion 73 at the rear end of the second relay rod 71 via a pivot shaft 74.

The steer link arm 75 is rotatably attached via a support shaft 78 to a bracket 29 provided so as to protrude forward from a rear cross member 28 which is installed between the left and right arm members 26 of the swing arm 25. steering arm 75
The second relay rod 71 is pivotally attached to a rear lever portion 76 that protrudes laterally, and is connected to a front lever portion 77 that protrudes forward via tie rods 38 or ball joints 79 for steering left and right rear wheels. has been done.

By the way, a rear axle tube 32 is connected to a differential housing 33 at the rear of the left and right arm members 26 of the swing arm 25.
and is supported via the tree housing 34,
A propulsion shaft (not shown) passes through one arm member 26 and is connected to the end of a rear axle tube 32 via a pivot shaft 37 to a knuckle arm 36 that supports a rear wheel axle 35 . A tie rod 38 is connected to this knuckle arm 36 via a ball joint 39.

The rear wheel steering mechanism is configured as described above.

Therefore, the steering shaft 4 is
1, the front wheels 24 are steered from the steering arm 42 at the lower end of the shaft 41 via the tie rod and knuckle arm, and the steering shaft 4
A planetary gear 43 supported by a steering ridge 43 that rotates together with the sun gear 48 revolves around the sun gear 48 while rotating. As the planetary gear 43 revolves while rotating, a rear wheel steering angle having non-linear characteristics is generated on the integral eccentric shaft 47. From the eccentric shaft 47 through the first relay rod 51, input gear 55, center and pot shafts 57, 58, output lever 68, second relay rod 71, steering link arm 75, tie rod 38, knuckle arm 36 The rear wheels 31 are steered.

Here, the practical movement angle of the steering shaft 41 is about 50'' at the maximum for the steering operation of the bar handle 40, and as shown in FIG. If the initial setting for the neutral steering state is made by matching the engagement pitch circle, the rear wheels 31 will be steered only in the opposite phase to the front wheels 24 from the trajectory of the eccentric shaft 47 shown by the two-dot chain line. If the center p of the core shaft 47 is initially set to be closer to the center O of the steering shaft 41 as in the embodiment, the rear wheel 31 will have a steering angle of 0 to 40, for example, from the locus of the eccentric shaft 47 shown by the - dotted chain line. Front wheel 2 in the range of °
4, the same phase steering can be performed, and in the steering angle range of 40 to 50 degrees, the steering is in the opposite phase.

However, in the embodiment, the steering shaft 41
A rear wheel steering relay lot 51 connecting between the center of the rear part of the vehicle body and the pot shaft 57 is arranged along the lower part of the main pipe 10 and the seat pipe 20 at the upper part of the vehicle body frame 1. In this way, the main pipe 1O is a large diameter pipe, and the portion composed of the seat pipe 20 and the town pipe 12 has a structure that is rigid against the torsion of the frame 1, etc., so that the relay rod 51 is not bent, etc. This also reduces the transmission rate of the rear wheel steering angle during steering, allowing a good steering angle to be transmitted to the rear wheels without decreasing the transmission rate.

The present invention may be applied to a straddle-type four-wheeled vehicle, a straddle-type tricycle having one front wheel, a general passenger car, etc. in the embodiment.

[Effects of the Invention] As described above, according to the front and rear wheel steering device according to the present invention, the planetary gear for generating a rear wheel steering angle, which revolves together with the steering shaft, is engaged with the sun gear that is disposed in rotation with the steering shaft. It is possible to directly generate the rear wheel steering angle, which improves the efficiency of steering transmission from the eccentric arm integrated with the planetary gear to the rear wheel side via the rear wheel steering relay rod. Since the front wheel steering arm is only provided below and there is no need to provide a gear mechanism for generating the front wheel steering angle, the steering angle generating device can be constructed compactly as a whole, and the degree of freedom in design can therefore be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a straddle-type four-wheel vehicle equipped with a front and rear wheel steering device according to the present invention, FIGS. The figure is a plan view of the sun gear fixing part, FIGS. 5 and 6 are a schematic plan view and perspective view of the rear wheel steering mechanism including the rear wheel suspension system, and FIG.
Figure 8 is a cross-sectional rear view of the center pivot shaft portion, Figure 9 is a rear view of the center and pot shaft support portion, and Figure 1O is a rear wheel steering angle generation gear portion. FIG. In addition, in the drawing, l is the vehicle body, 24 is the front wheel, 31 is the rear wheel, and 40
41 is a steering shaft, 42 is a front wheel steering arm, 45 is a planetary gear, 46 is an eccentric arm, 48 is a sun gear, and 51 is a rear wheel steering relay rod.・Patent applicant: Honda Motor Co., Ltd. agent Patent attorney (Part 2) 1) Volume: Patent attorney Kuni Ohashi Production volume: Patent attorney Koyama Written procedural amendment (Member number August 11, 1988)

Claims (1)

[Scope of Claims] A front and rear wheel steering device for a vehicle that is equipped with a front wheel steering mechanism from the handle to the front wheels and a rear wheel steering mechanism from the handle to the rear wheels to enable front and rear wheel steering, comprising: a handle provided above and a rear wheel steering mechanism provided below. A holder is fixed to the middle part of the steering shaft where the front wheel steering arm is installed, a planetary gear is rotatably supported on this holder, and a sun gear that meshes with this planetary gear and through which the steering shaft is rotatably inserted is fixed to the vehicle body side. A front and rear wheel steering device for a vehicle, characterized in that: an eccentric arm is integrally provided in the planetary gear, and a relay rod for rear wheel steering is connected to the eccentric arm.