JPS6361683A - Steering device for saddle ride-type vehicle - Google Patents

Abstract

PURPOSE:To promote the compactness of an oil hydraulic pump, by providing the oil hydraulic pump to be built in the end of an engine crankshaft so as to actuate a power steering device by pressure oil of said oil hydraulic pump. CONSTITUTION:A hydraulically operated power steering device 10, fixed to a frame 12 by a bracket 11, is mounted interposing between a handle shaft 5a and a steering shaft 6. The power steering device 10 operates by the pressure of oil, and the oil is supplied from an oil hydraulic pump 14, built in the end of an engine crankshaft 13, through a pressure oil pipe 15. If the handle 5a is turned by controlling a bar handle 5, a spool valve in the power steering device 10 is displaced through a planet gear mechanism, and power assisting fore acts by supplying the pressure oil.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) (Industrial Application Field) The present invention relates to a steering device for a straddle-type vehicle equipped with a bar handle for front wheel steering.

(Prior art) A straddle-type vehicle is supported by one or two front wheels and two rear wheels, is equipped with a straddle-type seat and a bar handle, is equipped with an engine, and allows a rider straddling the seat to ride on the bar. The vehicle is driven by operating the steering wheel and controlling the engine. The difference between this bar handle and round handle is
The lock-to-lock ratio is 180 degrees or less, the ratio of the steering wheel turning angle to the wheel turning angle is usually set to about 1.3:1, and operating parts such as a throttle and brake are attached, so the handling is heavy. They tend to be difficult to operate, especially those for riding on rough terrain, which use thick, low-pressure tires, making handling increasingly difficult. The problem was that physical strength was required.

(Problems to be solved by the invention) As described above, in a saddle type vehicle equipped with a bar handle,
There is a problem that the handling becomes heavy, and the present invention aims to improve this point and provides a steering device for a straddle-type vehicle that aims to provide light handling by adding a power steering device.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, a steering system for a saddle type vehicle according to the present invention includes a front wheel steering bar handle and a saddle type seat, and a saddle driven by a mounted engine. In a riding vehicle, the lower end of the support shaft of the bar handle and the upper end of the steering shaft are coaxially opposed to each other and connected by a hydraulic power steering device, and the hydraulic power of a hydraulic pump attached to the end of the engine crankshaft is applied to the power steering. The configuration is such that it is supplied to the equipment.

(Function) With the above configuration, when the bar handle is operated, the handle shaft swings, and following this swing angle, the steering shaft swings by the power steering device to steer the front wheels. The rotation of the steering shaft is mainly driven by the hydraulic pressure of a hydraulic pump linked to the engine crankshaft, and
There is almost no load on the steering wheel, making handling extremely light.

The hydraulic pump is compactly attached to the end of the engine crankshaft, and the power steering device is interposed between the lower end of the bar handle shaft and the steering shaft, which are coaxially opposed, and is connected to the end of the steering shaft to save space. There are no problems, and the operation is stable because it is driven by hydraulic pressure.

(Example) Hereinafter, the drawings showing the example of the present invention will be described in detail.

FIG. 1 is a side view of a straddle-type four-wheeled vehicle. two front wheels 1
It is supported by two rear wheels 2, a straddle-type seat 3 is arranged in the upper rear half, an engine 4 is mounted in the center, and a bar handle 5 can be drawn in the front upper part.

The lower end of the support shaft 5a of the bar handle 5 faces the upper end of a coaxial steering shaft 6. As the steering shaft 6 rotates, the steering plate 7 and the tie rod 8
, steers the left and right front wheels 1 via the knuckle arms 9.

A hydraulic power steering device 10 fixed to a frame 12 with a bracket 11 is interposed between the handle shaft 5a and the steering shaft 6. The power steering device 10 is operated by hydraulic pressure, and the hydraulic pressure is supplied by a hydraulic pump 14 attached to the end of the engine crankshaft 13.
It is supplied from the hydraulic vibrator 15 through the hydraulic vibrator 15.

As shown in FIGS. 2 and 3, in the power steering device 10, an input shaft 17 and an output shaft 18 coaxially opposed to each other are rotatably supported in a cylindrical housing 16, and both are supported by torsion. They are elastically connected by a bar 19. The lower end of the bar handle 5 is connected to the input shaft 17, and the upper end of the steering shaft 6 is connected to the output shaft 18.

Furthermore, carriers 20 and 21 of a planetary gear mechanism are extended oppositely from the inner ends of the input shaft 17 and the output shaft 18, respectively, and pivotally support floating leg gears 22 and 23. The floating leg gear 22 meshes with a ring gear 24 rotatably supported on the inner surface of the housing 16 and a sun gear 26 rotatably supported on the input and output shafts 17 and 18 to form a floating gear mechanism. Ru. The floating gear 23 meshes with the ring gear 25 fixed to the housing 16 and the sun gear 26 to form a floating gear mechanism.

Further, a driven gear 27 is fixed to the output shaft 18 and meshes with a rack gear 28 driven by a hydraulic cylinder device. The operation of the hydraulic cylinder device is controlled by a spool valve 29. This spool valve 2
9 is connected to the ring gear 24 through a pin 30, and is displaced forward and backward according to the forward and reverse displacement of the ring gear 24, causing the hydraulic cylinder to operate forward and backward, and outputting through the rack gear 28 and the driven gear 27. The shaft 18 is strongly driven to the right or left.

On the other hand, the hydraulic pump 14 that supplies hydraulic pressure to the power steering device is attached to the end of the crankcase 32 via a mounting base 31, as shown in FIG. do. 34 indicates the oil level, and the hydraulic pump 14 is submerged in the oil. The pump drive shaft 35 is directly connected to the end of the crankshaft 13 by a coupling 36. 37 is an outer gear, 38 is an inner gear, and this hydraulic pump is constructed in a trochoid type. The oil suction hole 39 opens directly into the oil in the cover 33, and the oil discharge hole 40 is connected to the power steering device 10 and the spool valve 29 via the hydraulic vibrator 15. The oil return vibrator 41 opens (41a) in the cover 33.

42 is an oil inlet provided in the cover 33.

It is configured as described above and operates as follows.

Hydraulic pressure is constantly sent to the power steering system when the engine is running. Operate the bar handle 5 to rotate the handle shaft 5a.
When rotated, the input @17 rotates, and if there is a load on the front wheel 1, that load is transmitted to the sun gear 26, so the ring gear 24 is rotationally displaced as the planetary gear 22 revolves. As a result, the spool valve 29 is displaced to one side via the bin 30, and the hydraulic cylinder device, which has been balanced and stopped until now, operates to drive the rack gear 28, and via the driven gear 27, outputs the output shaft 18. rotates in the same direction as the input shaft 17.

The rotation of the output shaft 18 is controlled by the planetary gear 23 and the sun gear 2.
6. The ring gear 24 is returned to its original position via the planetary gear 22, the spool valve 29 is restored, the hydraulic cylinder device is balanced, and the lug gear 28 is stopped. That is, in immediate response to the rotation of the input @ 17, the output shaft 18 is rotated in the same direction and at the same angle by hydraulic assistance. The rotation of the output shaft 18 rotates the steering shaft 6 to steer the front wheels 1 as described above. Therefore, handling of the bar handle 5 becomes extremely easy.

When the engine is stopped or when hydraulic power is insufficient even when the engine is running, when the torsion angle of the torsion bar 19 exceeds a certain level, a mechanical stopper acts and stops further rotation of the ring gear 24. The input shaft 17 is directly driven to the output shaft 18 through two planetary gear mechanisms.

〔Effect of the invention〕

As described above, the steering system for a straddle-type vehicle according to the present invention includes a hydraulic power steering system interposed between the bar handle shaft and the steering shaft, and assists with the hydraulic pressure of a hydraulic pump directly connected to the engine crankshaft. This allows efficient use of space for the power steering device and hydraulic pump, making it more compact, and also makes handling of this type of vehicle with a bar handle extremely light and stable. It is highly effective in improving the running performance of large models of straddle-type four-wheeled vehicles for traveling on rough terrain.

[Brief Description of the Drawings] Fig. 1 is a side view of a straddle-type four-wheeled vehicle showing an embodiment of the present invention, Fig. 2 is an enlarged vertical sectional view of the same power steering device, and Fig. 3 is a side view of the same power steering device. FIG. 4 is a longitudinal sectional view of the same hydraulic pump. 1...Front wheel, 3...Saddle type seat, 4...Engine, 5...Bar handle, 5a...Handle shaft, 6
...Steering shaft, 10...Power steering Hf12.13...Crankshaft, 14...Hydraulic pump.

Claims (1)

[Claims] In a straddle-type vehicle that is equipped with a bar handle for front wheel steering and a straddle-type seat and is driven by an installed engine, the lower end of the support shaft of the bar handle and the upper end of the steering shaft are coaxially opposed to each other by a hydraulic power steering device. A steering device for a straddle-type vehicle, characterized in that the power steering device is connected to the power steering device, and is configured to supply hydraulic pressure from a hydraulic pump assembled to the end of an engine crankshaft to the power steering device.