JPH0534195B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a riding machine equipped with an all-wheel steering system.

(Prior Art) In a riding working machine such as an agricultural tractor having wheels on the front, rear, left and right sides of a vehicle body, a ground working machine such as a rotary working machine is mounted overhanging the rear of the vehicle body, and agricultural work is carried out.

Such a riding work machine is equipped with a front and rear wheel steering device in which both the front wheels and the rear wheels are steered by steering operation of a handle. As one of the steering methods, a lever that swings in conjunction with the steering wheel is placed at the front of the vehicle body, and an arm that connects and supports the tie rods for the left and right rear wheels is pivoted in the middle, and one half of this arm is A device in which the part and the lever are connected by a link is known. According to this, it becomes possible to steer the rear wheels in the opposite direction to the front wheels by steering the steering wheel, thereby obtaining a small turning radius and improving maneuverability of the vehicle.

(Problem to be solved by the invention) However, because the steering system has a so-called linear characteristic, in which the rear wheels are steered in the opposite direction to the front wheels even when the steering wheel is operated at a small steering angle, it is difficult to drive in general, especially when driving straight. Because the steering wheel response is sharp in the vicinity, it becomes difficult to maintain straight motion, and it is impossible to plow in a straight line while approaching the width near the edge of a bank or in a place with steep steps, making straight plowing work quite difficult.

The fact that the front and rear wheels are steered in opposite phases near straight-ahead travel means that there is normally a difference between the inner and outer wheels in the amount of steering between the front and rear wheels, as shown in Figure 9. The turning center r is located between the axle extension lines of the front and rear wheels in the steering state. Therefore, when a rotary working machine, for example, is connected to the rear of a working vehicle, the rotary working machine undergoes a large lateral movement N toward the outside of the turn, which causes the tilled soil to be pushed to one side.

On the other hand, even in the case of a normal front wheel steering vehicle in which the rear wheels are not steered at all, the turning center r during steering is on the extension line of the rear axle, as shown in Figure 10, so Although the lateral movement N of is smaller than the above, it cannot be ignored.

Furthermore, if the front and rear wheels can be steered in the same phase within a small steering angle operation range of the steering wheel, and the rear wheels can be steered relatively small relative to the front wheels, the turning center r when traveling straight will be rotated as shown in Figure 11. Since the position approaches the upper side of the rotary axis extension line of the machine, almost no lateral movement N to the outside of the turning occurs in the rotary work machine.

Therefore, in order to facilitate straight plowing work, it is most desirable to steer the rear wheels in the same direction as the front wheels and relatively small in the small steering angle operation range of the steering wheel.

In addition, when carrying out work by attaching the ground-contacting work machine to the front part of a work vehicle, the same effect can be obtained by making the turning angle of the front wheels smaller than the turning angle of the rear wheels.

The present invention has been made to solve the above-mentioned problems with riding work machines. For example, when a ground work machine is mounted on the rear of a work vehicle, the rear wheels are moved in the same direction as the front wheels. By equipping the front and rear wheels with a steering device that steers the front and rear wheels, it is possible to slightly steer the rear wheels in the same direction as the front wheels by operating the steering wheel at a small steering angle, and at the same time, it is possible to steer the rear wheels slightly in the same direction as the front wheels. It is assumed that the lateral movement to the outside can be almost ignored.
As a result, when working in a straight line with a work vehicle or ground-based work machine, even if the direction of travel is corrected, the work machine can finish in a nearly straight line without meandering, and it also prevents the tilled soil from shifting to one side during work. To provide a riding working machine that achieves smooth plowing work while suppressing soiling.

(Means for Solving the Problems) Accordingly, the present invention provides a riding working machine that is equipped with wheels on the front, rear, left, and right sides of the vehicle body, and is equipped with a ground-contacting work machine that overhangs the front or rear of the vehicle body.
It is possible to steer all wheels by steering the handle, and when operating the handle at a small steering angle, the wheel on the side to which the ground-contacting work equipment is attached is moved in the same direction as the wheel on the opposite side of the ground-touching work equipment, and also relative to the wheel on the side opposite to the ground-touching work equipment. In addition, when the steering wheel is operated at a large steering angle, the wheels on the side to which the ground-contacting work equipment is attached are turned in the opposite direction to the wheels on the opposite side of the ground-contacting work equipment, and at a relatively large steering angle. Equipped with a steering device for all wheels that steers with The invention is characterized in that the ground-contacting working machine is vertically movable via a lift device.

(Example) Examples will be described in detail below based on the accompanying drawings.

Fig. 1 is a cutaway side view of the riding work machine, and Fig. 2 is a plan view of the steering system. Mission case 5 is at the rear of 2.
The transmission input shaft 6 and the crankshaft 4 are connected by a propulsion shaft 8, a seat 9 is placed on the rear of the vehicle body, and front wheels 11 with the same diameter are mounted on the front, rear, left and right sides of the vehicle body.
11 and rear wheels 12, 12, such a work vehicle can perform front and rear wheel steering by operating a handle 31, and has four wheels.
Wheel drive is possible.

That is, reduction cases 13, 13 are disposed on both sides of the transmission case 5, and the input shaft thereof and the output shaft of the differential provided in the transmission case 5 are interlocked and connected, and the reduction output shafts 14, 14 are connected to each other.
Attach the rear wheels 12, 12 to the. and engine 3
A differential case 15 is disposed below, and connects a differential input shaft 16 and a transmission output shaft 7 with a propulsion shaft 17. Further, reduction cases 18, 18 are disposed on both sides of the differential case 15, and the input shaft and the differential output shaft, and the reduction output shaft 1
Attach the front wheels 11, 11 to 9, 19. A four-wheel drive system is thus constructed.

The four-wheel steering system is constructed as follows.

First, the reduction cases 18, 18 bearing the front wheels 11, 11 are made swingable around the king pins 21, 21, and the knuckle arms 22, which extend rearward,
22 is provided, and tie rods 23, 23 are connected to the knuckle arms 22, 22 by ball joints 24, 24. Further, the reduction cases 13, 13 bearing the rear wheels 12, 12 are also swingable around the king pins 26, 26, and the knuckle arms 2 extending inwardly.
7, 27 are provided, and tie rods 28, 28 are connected to the knuckle arms 27, 27 by ball joints 29, 29.

A gearbox 34 is provided at the bottom of the handle column 33 through which the steering shaft 32 of the handle 31 passes longitudinally, and this gearbox 34 is connected to the engine 3.
Placed at the rear. A pinion 35 that rotates in conjunction with the steering shaft 32 is disposed in the front part of the gear box 34, a sector gear 36 that meshes with the pinion 35 is provided, and a support shaft 37 integrated with the sector gear 36 hangs downwardly and protrudes below the gear box 34. let A lever 41 is integrally provided on the protrusion of this support shaft 37.

This lever 41 has a substantially bell-crank shape when viewed from above, and is fixed to the support shaft 37 at the corner of the intermediate portion, and connects the inner ends of front wheel tie rods 23, 23 with ball joints on the left and right sides of the tip of a half portion 42 extending forward. Connect and support at 45 and 45. Further, a link 51 is pivotally connected to the tip of the other half 43 extending to the rear side of the lever 41 by a pin 53.

On the other hand, the frame 2 in front of the transmission case 5
A support shaft 46 is set up on the support shaft 46, and an arm 47 having a substantially bell-crank shape in plan view is pivotally supported at the corner of the intermediate portion thereof, and a tip portion extending forward on both sides of the arm 47 is attached to the support shaft 46. The inner ends of the rear wheel tie rods 28, 28 are connected and supported by ball joints 49, 49.

In the above, the support shaft 37 of the lever 41 and the support shaft 46 of the arm 47 are both arranged on the width center line of the vehicle body, and the right half of the arm 47 has a protrusion 4 at its tip.
8 will be provided.

A link 55 is pivotally connected to this arm protrusion 48 by a pin 57.

Further, as shown in FIGS. 3 to 5, front and rear links 51 and 55 are pivotally connected via a switching plate 61. That is, the longitudinal direction of the switching plate 61 is oriented substantially in the left-right direction of the vehicle body, and the bending pin portion 52 at the rear end of the front link 51 is pivotally connected to one end thereof. The bent pin part 5 at the front end of the rear link 55 is attached to the bulge part 62.
6 are pivotally connected. In the figure, reference numerals 54 and 58 are clips for preventing the pin from coming off.

In this way, the lever 41 and the arm 47 are linked 5.
1, 55 and the switching plate 61, so that the switching plate 61 forms an intermediate link.

The switching plate 61 is formed with a long hole 63 extending in the longitudinal direction. That is, the pin portion 5 forming the pivot point of the rear link 55 connected to the intermediate portion of the plate 61
A long hole 63 extending substantially in the left-right direction with 6 as a boundary is formed.

A switching lever 65 passing through this elongated hole 63
is installed on the vehicle body side. The switching lever 65 has a substantially L-shaped side surface, has a grip portion 66a at the top of a vertical rod portion 66 that projects upward from the plate 61, and has a horizontal rod portion 67 attached to a channel type bracket 68 fixed on the frame 2. It penetrates and is swingably supported.
In addition, 68 in the figure is a fixing pin for the side rod portion.

With the above structure, if the switching lever 65 is fixed by any means in contact with one end of the elongated hole 63, the switching plate 61 forming the intermediate link will be able to swing about the lever vertical rod part 67 as a fulcrum. move.
Therefore, by appropriately switching the lever 65, the swinging fulcrum of the plate 61 is switched, and in particular, the plate fulcrum is switched substantially in the left-right direction at the pivot point with the rear link 55, so that the rear wheels 12, 12 can be rotated. front wheel 1
It is possible to steer in the same direction as 1 and 11, or in the opposite direction.

In this way, it becomes possible to steer the rear wheels 12, 12 in a desired direction, and the switching operation is also easily performed.

Moreover, since a simple structure consisting of a switching plate 61 and a lever 65 is added, the number of parts is small and there is no need to take up a large space.

Incidentally, in the embodiment, a case has been described in which the switching lever 65 is operated manually, but the lever 65 may be operated automatically by, for example, pressing a switch button.

As described above, the seventh wheel is installed at the rear of the riding work machine 1 equipped with a front and rear wheel steering device that can select the rear wheel steering direction.
As shown in the figure, the grounding work machine 81 is mounted in an overhanging manner.

The ground work machine is a rotary work machine 8 in the embodiment.
1, and above the rotary claw 82 is the fender 8.
A hitbox 85 extends forward from the center on the fender 84, a bracket 86 extends rearward, an arm 87 hangs down from the rear end, and a tail wheel 88 is provided at the lower end of the arm 87.

On the other hand, a hitbox 71 is provided at the rear of the riding work machine 1 so as to be swingable by a lift device 72.
The hitbox 71 is pivotally supported concentrically with a power take-off shaft 75 supported by the mission case 5. The hitbox 85 is connected to the hitbox 71 to connect the rotary work machine 81 with an overhang to the rear of the riding work machine 1, and transmission cases 76 and 77 are installed between the power take-off shaft 75 and the rotary shaft 83.

In the above, the switching lever 65 is operated to the end of the long hole 63 of the switching plate 61 on the side of the pivot point with the front link 51, thereby causing the rear wheels 12, 12 to move in the same direction as the front wheels 11, 11. Let it steer you.

When carrying out agricultural work using such a work vehicle, the rear wheels 12, 12 are slightly steered in the same direction as the front wheels 11, 11 in the small steering angle range of the steering wheel 31, as shown in FIG. Since r approaches the upper side of the extension line of the rotary shaft 83 of the rotary work machine 81, the rotary work machine 81 hardly undergoes lateral movement M to the outside of the turn, and it can be moved along the edge of a ridge or at a place with a steep difference in level while performing width adjustment. Plowing can be performed in a nearly straight line, and meandering of the rotary work machine 81 can be prevented.

In this way, it is possible to prevent the rotary working machine 81 from meandering when working in a straight line, so that the tilling work can be smoothly performed while suppressing the shifting of the tilled soil.

In particular, when the turning center r in the vicinity of straight travel is made to coincide with the extension line of the rotary shaft 83, the trajectory of the front and rear wheels is as shown in FIG. That is, in the small steering angle range of the handle 31, the handle 31 is rotated so that the turning center r is on the extension line of the rotary shaft 83.
When the vehicle is switched from side to side, a meandering trajectory F of the front wheels 11, 11 and a meandering trajectory R of the rear wheels 12, 12 appear alternately. However, although meandering trajectories F and R occur, the locus L of the longitudinal center line of the rotary working machine 81 becomes almost a straight line in the direction of movement.

Therefore, even if the riding work machine 1 is operated in a slightly meandering manner, the rotary work machine 81 can be maintained in a substantially straight forward state, so that the rotary work machine 81 does not undergo any lateral movement at all, or there is no lateral movement at all. However, since the amount of soil is so small that it can be ignored, it is possible to prevent the tilled soil from shifting to one side and improve straight tillability.

In addition, when working straight ahead, the rotary work machine 81 is lowered via the lift 72, the work machine 81 is grounded, and the rotary blade is rotated in the traveling direction.
Improves straightness.

Furthermore, when turning, the rotary working machine 81 is raised via the lift 72 and the handle is turned sharply, thereby making it possible to make a small turn, shorten the turning time, and improve work efficiency.

As for the switching mechanism, as shown in another embodiment shown in FIG. Alternatively, the switching lever 103 and the plate 61 may be pivotally connected by a rod 104.

By the way, the steering system for the front and rear wheels is not limited to the one in the embodiment, and the steering system for the front and rear wheels is not limited to the one in the embodiment. Any steering wheel can be used as long as it turns the steering wheel.

(Effects of the Invention) As described above, according to the present invention, in a riding work machine in which a ground-contacting work machine is attached overhanging the front or rear part, in a small steering angle range of the handle, the side on which the ground-contacting work machine is attached is Equipped with a front wheel steering device that slightly steers the wheels in the same direction as the wheels on the opposite side of the ground-contacting work machine, and the turning center in the small steering angle operation range of the handle is set on the lateral extension of the ground-contacting work machine, for example, tilling. Since it is provided near the extension line of the rotation axis, even when the course of the work vehicle is corrected, the lateral movement of the ground-contact work machine to the outside of the turn can be almost ignored. Therefore, it is possible to prevent the ground work machine from meandering, prevent the plowed soil from shifting to one side, and smoothly perform plowing work in the vicinity of straight travel.

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of the riding work machine, Fig. 2 is a plan view of the steering system, Fig. 3 is a plan view of the switching mechanism, Fig. 4 is a sectional view taken along the line of Fig. 3, and Fig. 5 is the same. −
6 is a plan view similar to FIG. 3 showing another embodiment, FIG. 7 is a cutaway side view of a riding work machine equipped with a ground-contacting work machine, and FIG. 8 is a front and rear wheel in the vicinity of going straight. FIG. 9 is a diagram showing an opposite phase pattern of the front and rear wheels, FIG. 10 is a diagram showing a pattern in which the rear wheels are not steered, and FIG. 11 is a diagram showing a same phase pattern. In addition, in the drawing, 1 is a riding working machine, 11 is a front wheel, and 12 is a riding work machine.
is the rear wheel, 23 is the tie rod for the front wheel, 28 is the tie rod for the rear wheel, 31 is the handle, 34 is the gearbox, 35 is the pinion, 36 is the sector gear, 37 is the support shaft, 41 is the lever, 46 is the support shaft, 47 is the arm , 51 is the front link, 55 is the rear link, 61
63 is a long hole, 65 and 103 are switching levers, 81 is a grounding work device, 83 is a rotating shaft, and r is a turning center.

Claims (1)

[Scope of Claims] 1. In a riding work machine equipped with wheels on the front, rear, left, and right sides of the vehicle body and equipped with a ground-contacting work machine overhanging the front or rear of the vehicle body, all wheels are steered by steering operation of a handle. It is possible,
In addition, when operating the steering wheel at a small steering angle, the wheels on the side on which the ground-contacting work equipment is attached are steered in the same direction as the wheels on the opposite side of the ground-contacting work equipment and at a relatively small steering angle, and at the same time, the wheels on the side on which the ground-contacting work equipment is attached are steered at a relatively small steering angle. In operation, it is equipped with an all-wheel steering device that steers the wheels on the side on which the ground-contacting work equipment is attached in the opposite direction to the wheels on the opposite side of the ground-contacting work equipment and at a relatively large steering angle. The turning center of the handle in a small steering angle range is provided near the extension of the rotation axis of the ground-contacting work machine, and a plurality of working blades are attached to this rotation axis, and the ground-contacting work machine is made vertically movable via a lift device. A riding work machine that is characterized by: 2. The riding working machine according to claim 1, wherein the axis of rotation of the grounding working machine coincides with the turning center of the handle in a small steering angle range.