JPH01240373A - Steering device of vehicle - Google Patents

Abstract

PURPOSE:To prevent a steering angle from changing due to fluctuation of a swing arm by a method wherein in an assembly that a steering wheel is supported by the swing arm, a steering shaft is split into an upper and a lower portions and joined by an equal velocity joint member to have the center point of said member coincided with a supporting point of fluctuation of the swing arm. CONSTITUTION:In a saddle riding type four-wheel vehicle, right and left rear wheels are supported via a swing arm 25 on the rear of a car body, respectively, and front and rear wheels are steered up steering operation of a bar handle. In this case, the rear end of a relay rod 51 which transmits steering force of a steering shaft made in one piece with the bar handle to a mechanism for steering rear wheels is pivoted on an input lever 55 fixed on an upper pivot shaft 57, and a lower pivot shaft is jointed via an equal velocity ball joint 60 at the lower part of the upper pivot shaft 57. Then an output lever 68 fixed on the lower pivot shaft is jointed with a steering arm 75 via a relay rod 71 and said equal velocity ball joint 60 is provided so that its center point coincides with the supporting point of fluctuation of the swing arm 25.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a steering system for a vehicle equipped with wheels supported by a swing arm, and particularly to a steering device for transmitting steering force to the wheels supported by the swing arm via a rod member. This invention relates to the structure of a shaft member that is supported by the vehicle body with a lever member provided at the bottom and is rotatable in conjunction with steering wheel operation.

[Prior Art] In a vehicle such as a straddle-type four-wheel vehicle in which the rear wheel is supported on the vehicle body via a swing arm, a planetary gear type steering gear mechanism is provided on the steering shaft portion, and a rod member or lever member is connected to the rear wheel. The present applicant has already proposed a front and rear wheel steering device in which steering force is transmitted through a shaft member in Japanese Patent Application No. 1982-204698. Regarding the rear wheel steering mechanism, a shaft member connected from the steering link gear mechanism via a rod member and a lever member is rotatably supported on the rear side of the vehicle body, and a lever member, a rod member, etc. are connected from the lower part of the shaft member. The steering force is transmitted to the rear wheels through the steering wheel.

[Problems to be Solved by the Invention] Incidentally, in the rear wheel steering mechanism, although the connection point between the lever member and the rod member at the lower part of the shaft member is aligned with the swinging fulcrum of the swing arm relative to the vehicle body in the neutral steering state, During steering, the connection point between the lever member and the rod member shifts from the swinging fulcrum of the swing arm in the front-rear direction, so the swinging of the swing arm causes a slight change in the rear wheel steering angle.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle steering system in which the wheel steering angle does not change even when the swing arm swings.

[Means for Solving the Problems] In order to achieve the above-mentioned problems, the present invention supports a shaft member rotatable on the vehicle body l side in conjunction with the steering operation of the handle 40, and this shaft member A lever member 68 is provided at the lower part of the wheel 3, and the wheel 3 is supported by a swing arm 25 which is pivoted from the lever member 68 to the vehicle body 1 so as to be able to move vertically.
In a vehicle steering system in which a rod member 71 for transmitting steering force is provided at #1, the shaft member is divided into an upper shaft 57 that is supported toward the vehicle body and a lower shaft 58 that is provided with the lever member 68. A shaft 58 is rotatably supported on the swing arm 25 side, and the upper shaft 57 and lower shaft 58 are connected via a constant velocity joint 60, and the center of the constant velocity joint 60 is connected to the vehicle body l of the swing arm 25. It is characterized by being arranged so as to coincide with the swinging fulcrum P for.

[Function] The center of the constant velocity joint 60 that connects the upper shaft 57 supported on the vehicle body 1 side and the lower shaft 58 supported on the swing arm 25 side is aligned with the swing fulcrum P of the swing arm 25 on the vehicle body l side. Swing arm 2
5 swings up and down, the amount of steering transmitted from the upper shaft 57 to the lower shaft 58 does not change, and therefore the steering angle of the wheels 31 does not change.

[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, so that power from the engine 21 can be transmitted to both the front wheels 24 and the rear wheels 31. ing.

A steering shaft 41 having a bar handle 40 connected to its upper end is supported at its upper part through the head pipe 2 at the upper end of the front part of the frame 1 so as to be freely steerable, and the lower part of the steering shaft 41 is connected to the pipes 3 and 4 as shown in FIG. A steering arm 42 for steering the front wheels is attached to the lower end of the steering shaft 41 and is supported through a holder 7 provided on a plate 6 installed between the left and right sides of a pipe 5 connecting 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 etc.
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.

Also, a fixed sun gear 48 that meshes 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 arranged in a circular manner.

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 l 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 steering 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 lot 5
1 extends rearward along the main pipe 1O and the lower part of the seat pipe 20 at the upper part of the frame 1, 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 an input lever 55 is connected to this bifurcated portion 54 via a pivot shaft 56. The input lever 55 is integrally fixed to an upper center pivot 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 pole joint 60.

On the other hand, the swing arm 25 is connected to the pipe 1 at the rear of the frame 1.
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 l 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 41264. This constant velocity ball joint 60 allows the rotation from the upper center and pot shaft 57 to maintain a constant velocity state and to be accurately transmitted to the lower center pivot shaft 58. The ball 65 is supported by a retainer 66, and 67 is a tasto boot.

Here, as shown in FIGS. 7 and 8, the center of the constant velocity ball 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 outer periphery of the outer ring 63 of the lower center pivot 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
1 is arranged in alignment with axis #11 of the swing arm 25, and a steering arm 7 for rear wheel steering is connected to the bifurcated portion 73 at the rear end of the second relay rod 71 via a pivot shaft 74.
5 are connected.

The steering 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 extending between the left and right arm members 26 of the swing arm 25. steering arm 75
The second relay rod 71 is pivotally connected to a rear lever portion 76 that projects laterally, and is connected to a front lever portion 77 that projects forward via tie rods 38 or ball joints 79 for steering the left and right rear wheels. There is.

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

The rear wheel steering mechanism is configured as described above.

Therefore, the bar bundle 40 allows the steering shaft 4 to
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 bridge 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 to the first relay rod 51, the input lever 55, the center and pot shafts 57, 58, the output lever 68, the second relay rod 71. The rear wheels 31 are steered via the steering arm 75, tie rod 38, and knuckle arm 36.

Here, the maximum practical movement angle of the steering shaft 41 for steering operation using the bar handle 40 is about 50'', 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 near 0 to the center of the steering shaft 41 as in the embodiment, the rear wheel 31 will be set at 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 within 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.

In this way, the sun gear 48 is connected to the steering shaft 4.
The rear wheel steering angle generating planetary gear 45 which revolves with the steering shaft 41 is meshed with this sun gear 48, and the rear wheel steering angle directly connected to the front wheel steering is directly generated. The efficiency of steering transmission from the integrated eccentric arm 46 (eccentric shaft 47) to the rear wheel 31 side via the rear wheel steering relay rod 51.71 is improved.

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

By the way, in the embodiment, the steering shaft 41
A rear wheel steering relay rod 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 vibe 10 and the seat vibe 20 on the upper part of the vehicle body frame 1. In this way, the main vibe 10 is a large-diameter vibe, and the portion made up of the seat vibe 20 and the town vibe 12 has a structure that is rigid against torsion of the frame 1, 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 reducing the transmission rate of the rear wheel steering angle.

Furthermore, as in the embodiment, a steering arm 7 for rear wheel steering is provided.
5 at the intermediate portion of the swing arm 25 in the longitudinal direction, the second relay rod 71 can be shortened and the rear wheel steering angle transmission rate can be improved.

In the embodiments, the present invention is applicable to a straddle-type four-wheel vehicle, a straddle-type tricycle having one front wheel, a general passenger car, and even a front wheel steering system of a vehicle having a spin-farm type front wheel suspension system. Applicable.

[Effects of the Invention] As described above, according to the steering device according to the present invention, the center of the constant velocity joint that connects the upper shaft supported on the vehicle body side and the lower shaft supported on the swing arm side is located on the vehicle body side of the swing arm. Since it coincides with the swing fulcrum, even if the swing arm swings up and down, the amount of steering transmitted from the upper shaft to the lower shaft does not change, thus preventing changes in the steering angle of the wheels.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a straddle-type four-wheel vehicle equipped with a steering device according to the present invention, FIGS. 2 and 3 are a side view with a cutaway of the main part of the steering shaft portion and a front view thereof, and FIG. A plan view of the sun gear fixed part, FIGS. 5 and 6 are a schematic plan view and a perspective view of the rear wheel steering mechanism including the rear wheel suspension, FIG. 7 is a cutaway side view of the main part, and FIG. 8 is a center view of the rear wheel steering mechanism. FIG. 9 is a rear view of the center pivot shaft support portion, and FIG. 10 is a schematic plan view of the rear wheel steering angle generating gear portion. In the drawings, 1 is a vehicle body, 24 is a front wheel, 25 is a spin farm, 31 is a rear wheel, 40 is a handle, 41 is a steering link shaft, 42 is a front wheel steering arm, 45 is a planetary gear, 48 is a sun gear, and 51 is a 55 is an input arm, 57 is an upper shaft, 58 is a lower shaft, 60 is a constant velocity joint, 68 is an output lever, 71 is a second relay rod, 75 is a rear wheel steering arm,
P is the swing arm swing fulcrum. Patent applicant: Agent for Honda Motor Co., Ltd.
Patent Attorney Part 2 1) Part 1 Patent Attorney
Kuni Ohashi Production volume Patent attorney Small
Ari Yama August 71, 1988

Claims (1)

[Claims] A shaft member that is rotatable in conjunction with steering operation of a steering wheel is rotatably supported on the vehicle body side, a lever member is provided at the lower part of the shaft member, and the lever member allows the vehicle body to swing up and down. A steering system for a vehicle that includes a rod member that transmits a steering force to a wheel side that is supported by a swing arm that is movably supported, an upper shaft that supports the shaft member on the vehicle body side, and a lower part that is provided with the lever member. The lower shaft is rotatably supported on the swing arm side, the upper shaft and the lower shaft are connected via a constant velocity joint, and the center of the constant velocity joint is connected to the swing arm with respect to the vehicle body. A steering device for a vehicle, characterized in that the steering device is arranged to coincide with a swinging fulcrum.