JPH11157463A - Front-wheel steering system of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a front-wheel steering system that is simple in structure, easy in working and inspection, and facile in the replacement of a hydraulic cylinder, as maintaining any interchangeability with the conventional front axle case, in this front-wheel driving and front wheel power steering vehicle. SOLUTION: A cylinder mounting hole is installed in a front-wheel driving front axle case 1, two hydraulic cylinders 26 and 27 are locked at locked at symmetrical sides as holding a separate plate 30, set up in the center of the cylinder mounting hole, between, while other ends of two pistons 21 and 22 to be slidably fitted in these symmetrical hydraulic cylinders 26 and 27 are connected to two knuckle arms 11 and 12 steering front wheels, and thereby these symmetrical hydraulic cylinders 26 and 27 are constituted so as to became a single-acting cylinder each.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front-wheel drive, front-wheel steering vehicle, and more particularly to a front-wheel steering apparatus for a front-wheel drive, front-wheel power steering vehicle.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Publication No. 59-230865, a front axle housing for suspending a front wheel is pivotally supported by a center pivot body frame provided at the left and right central portions thereof. In a running vehicle, a steering device for a running vehicle is provided in which a tie rod for steering a front wheel is moved by a steering drive mechanism mounted on a front axle housing, and Japanese Patent Publication No. 56-539.
As disclosed in Japanese Patent Application Publication No. 64-64, in a power steering device including an angle detecting means for steering operation, a switching means responsive to the angle detecting means, and an operating body responsive to the switching means, a left-right swing type wheel is provided. A power steering device that also uses a tie rod is already known.

[0003]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Publication No.
JP-A-230865 and JP-A-56-86.
Any of those known in Japanese Patent No. 53964 discloses a double-acting hydraulic cylinder for power steering to form and also serve as a tie rod for connecting the left and right front wheels. It became complicated, required high processing accuracy, and required labor for processing and inspection.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and in a vehicle of front wheel drive and front wheel power steering, a cylinder (1) is provided on a front axle case (1) for front wheel drive. 26), (27)
Mounting hole (28), and the cylinder mounting hole (28)
The hydraulic cylinders (26) and (27) are fixed on the left and right sides with a separate plate (30) disposed in the center of the piston, and the pistons are slidably fitted to the left and right hydraulic cylinders (26) and (27). The other ends of (21) and (22)
The above-mentioned problem has been solved by connecting the left and right hydraulic cylinders (26) and (27) to single-acting cylinders by connecting the knuckle arms (11) and (12) for steering the front wheels. .

(Operation) In the vehicle of the present invention of front-wheel drive and front-wheel power steering, when the driver steers to the right or left during running, the steering wheel is steered to the side, and the left and right hydraulic cylinders are actuated. Of (26) and (27), only the hydraulic cylinder on the side (for example, (26)) operates to rotate the knuckle arm (11) on the side and steer the front wheel on the side to the side. And tie rods (2
The front wheel on the other side is also steered to the side via 5) to steer the vehicle to the side.

The same applies to steering to the other side.

[0007] The reference numerals in parentheses are for comparison with the drawings, but do not limit the configuration of the present invention.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a front axle case 1 of a tractor for front wheel drive and front wheel power steering.

The upper part of FIG. 1 shows the front of the tractor, and the lower part shows the rear. The left side indicates the left side with respect to the traveling direction of the tractor, and the right side indicates the right side.

The front axle case 1 includes a left front axle case 2 having a built-in gear unit for driving front wheels,
It comprises a right front axle case 3 having a built-in drive unit for transmitting the power of the gear device to the right side. The right front axle case 3 is fastened to a right side surface of the left front axle case 2 with a plurality of bolts 4 to form an integral front axle Case 1 is formed.

The front axle case 1 is pivotally supported by a center pin (not shown) at the center of a front front bracket 5 and a rear rear bracket 6. Front bracket 5 and rear rear bracket 6
Have their upper surfaces fixed to the lower surface of the frame of the tractor body.

Accordingly, the entire front axle case 1 is swingably supported by the tractor main body, and when the left and right front wheels run on uneven surfaces on uneven terrain, the front axle case swings around the center pin with respect to the tractor main body. Will move.

A left kingpin case 7 and a right kingpin case 8 are fixed to the outer ends of the left and right front axle cases 2 and 3, respectively. The left and right kingpin cases 7 and 8 are vertically separated into a left kingpin 9 and a right kingpin 10, respectively.
I support.

On the upper portions of the left and right kingpin cases 7 and 8, left and right knuckle arms 11 and 12 forward and left and right tie rod arms 14 and 15 are integrated. The arms 16 and 17 are interlocked with the left and right front wheels, respectively.

The front knuckle arms 11 and 12 are connected to left and right pistons 21 and 22 via rods 18 and rod ends 19, respectively.
4, 15 are connected to a tie rod 25 via a tie rod end 23, so that the left and right arms 16, 17 are interlocked.

FIG. 2 is a right side view of the front axle case 1.

As shown in FIG. 2, a hydraulic cylinder 26,
27 mounting holes 28 are provided, and in the center of the mounting holes 28,
Separate plate 30 with O-ring 29 mounted on the outer periphery
And hydraulic cylinders 26 and 27 having O-rings 29 mounted at two locations on the inside and outside are fitted and fixed on both left and right sides of the separate plate 30.

As shown in FIG. 1, the hydraulic cylinders 26 and 27 have stepped portions 26a and 27a at the outer diameter portion of the fitting hole 28.
And is fixed to the boss portion 2a of the left front axle case 2 from the side by a bolt 32 by a semicircular holding metal member 31 as shown in FIG. 2 and positioned in contact with the stepped portions 26a and 27a. Have been.

O-rings 33 are mounted on the inner diameters of the outer ends of the hydraulic cylinders 26 and 27, and the left and right pistons 21 and 22 are slidably fitted into the inner diameters of the hydraulic cylinders 26 and 27 so that both surfaces of the separate plate 30 are at the top. Oil chambers 35 and 36 are formed.

The boss 2a and the hydraulic cylinder 26,
27, near the top of the oil chambers 35 and 36,
Hydraulic pumps and hydraulic ports 37 and 38 connected to a hydraulic tank are provided between the rings 29.

The outer ends of the pistons 21 and 22 are
8, through the rod end 19, the knuckle arm 11, 1
The left and right kingpin cases 7 and 8 are steered through the knuckle arms 11 and 12 by the movement of the pistons 21 and 22.

Further, as shown in FIG.
By further inserting the second pistons 41 and 42 into the interior of the piston 22 to form a double piston structure,
22 and the movement amounts of the pistons 41 and 42 are added, so that the turning angles of the knuckle arms 11 and 12 can be increased, and the steering angles of the left and right kingpin cases 7 and 8 can be increased.

Next, the operation of this embodiment will be described.

Based on the above structure, in the tractor of the present invention, when steering to the left or right during traveling, when the operator steers the steering wheel to the side, the hydraulic ports 37, 38 are provided.
High-pressure oil flows into the oil chamber 35 or 36 from the
Of the left and right hydraulic cylinders 26 and 27, only the hydraulic cylinder on that side (for example, 26) operates to move the piston 21 on the side outward, and the knuckle arm 11 on the side
Is turned to steer the front wheel on the side to the side, and the front wheel on the other side is also steered to the side via the tie rod 25 to steer the vehicle to the side.

The same applies to steering to the other side.

[0027]

According to the present invention, in a vehicle driven by front wheel drive and front wheel power steering, a mounting hole for a cylinder is provided in the front axle case for driving the front wheel, and a separate plate disposed in the center of the mounting hole for the cylinder is sandwiched. The left and right hydraulic cylinders are fixed on both sides, and the other end of the piston slidably fitted to the left and right hydraulic cylinders is connected to a knuckle arm that steers the front wheels, and the left and right hydraulic cylinders are each single-acting. Because it is configured as a cylinder, the structure of the constituent members is simplified, the processing accuracy is high, the processing and inspection man-hours are reduced, the possibility of foreign matter is reduced, and the hydraulic cylinder can be easily replaced. In addition, compatibility with the conventional front axle case can be maintained.

[Brief description of the drawings]

FIG. 1 is a plan view of a front axle case of a tractor.

FIG. 2 is a right side view of a front axle case of the tractor.

FIG. 3 is a plan view of a front axle case of a tractor having a double structure piston.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front axle case 8 King pin case 11 Knuckle arm 14 Tie rod arm 16 Arm 21 Piston 26 Hydraulic cylinder 28 Mounting hole 30 Separate plate 31 Presser fitting

Claims (2)

[Claims] In a vehicle driven by front wheel drive or front wheel power steering, a mounting hole for a cylinder is provided in a front axle case for driving the front wheel, and a left and right side of the vehicle is separated by a separate plate disposed at the center of the cylinder mounting hole. A front wheel steering device for a vehicle, wherein a hydraulic cylinder is fixed, and the other end of a piston slidably fitted to the left and right hydraulic cylinders is connected to a knuckle arm for steering a front wheel. 2. The front wheel steering apparatus according to claim 1, wherein each of the left and right hydraulic cylinders is a single-acting cylinder.