JP3050388B2 - Steering devices such as tractors - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a steering device such as a tractor, for example,
It can be used for a seedling transplanter or the like which runs a seedling by connecting a seedling plant to a vehicle body.

(Prior art) A car body used as an agricultural work machine such as a tractor needs to be advanced along a crop streak, a ridge and the like, and not only steering of a front wheel by a steering handle but also transmission of one of rear wheels. Steering operation is performed by disengaging the clutch or applying the steering brake.

(Problems to be Solved by the Invention) However, in such a steering mode in which the steering operation of the front wheels is mainly performed, it is difficult to correct the traveling immediately by the steering. Since the device also bends left and right with this, it is necessary to gradually correct the travel and correct the travel before the deviation is as large as possible, and the steering operation requires skill.

The present invention is intended to facilitate this steering operation, to make the vehicle body as parallel as possible, to correct the traveling in a short time, and to maintain good turning traveling.

(Means for Solving the Problems) According to the present invention, the front wheels and the rear wheels are steered and linked only to the front wheels based on the turning steering or the operation for the turning steering, and are mounted on the vehicle body. In an operation for work steering when the work device performs work, a steering device such as a tractor is characterized in that the front wheels and the rear wheels are steered and interlocked.

(Operation) In work steering in which a work device is mounted on a vehicle body and the vehicle is steered while performing work, the front wheel and the rear wheel are steered and linked by the work device taking a posture to perform work. The vehicle body is steered to the left or right side almost in parallel with the straight traveling work to move the working position of the working device. Further, when the vehicle enters the turning steering after the work steering, based on the turning steering or the operation for the turning steering, only the front wheels are steered and the turning is performed.

(Effects of the Invention) As described above, according to the present invention, the front wheels and the rear wheels are steered and linked by the operation for work steering when the work device is in the work posture with respect to the vehicle body, and the turning steering is performed. Since only the front wheels are steered and linked by the operation, the switching of the steering operation is automatically performed, so that accurate switching and the operation can be simplified.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.
The illustrated example illustrates a seedling planting machine. A tractor body 1 is provided with a steering wheel 2, a steering wheel 3, a power steering 4, a rod 5, a front wheel 6, etc.
A front wheel steering mechanism 9 for steering and rotating the front axle 7 around a steering shaft 8 having a caster angle A is provided, and the steering interlock is provided at the rear from the power steering 4 of the front wheel steering mechanism 9. A rear wheel steering mechanism 15 for steering and rotating a front axle 13 of a rear wheel 12 around a steering shaft 14 having a front and rear caster angle B or C via a switching device 10, a rod 11, etc. Both of the front wheels 6 and the rear wheels 12 have a four-wheel drive running configuration in which the power is transmitted from the engine 16 via the transmission shaft 17, the transmission 18, the transmission shaft 19, and the like.

The switching device 10 (FIG. 1) switches between a state in which the rear wheels 12 are not steered and a state in which the steering is performed.
The input shaft 20 that is linked and rotated from the rear, and the rod 11 on the rear wheel 12 side
A clutch 22 that is spline-fitted to the output shaft 21 is provided between the output shaft 21 and the output shaft 21 that rotates in conjunction with the input shaft 20. The steering mechanism 9 and the rear wheel steering mechanism 15 are linked as the same steering direction. Also, this clutch 22 is
Then, the rear wheel steering mechanism 15 is released from the front wheel steering mechanism 9 by pin engagement with the fixed seat 24 of the case, and the rear wheel 12 is fixed in a straight running position so as to be unable to steer.

A shifter 26 for operating such a clutch 22 against a weak spring 25 on the output shaft 21 includes a wire 27 and a strong spring.
A seedling plant 28, which is a working device, is connected to a piston 30 of a lift cylinder 29 that moves up and down by 41, and the clutch 22 is disengaged when the piston 30 is pushed out beyond a certain amount.

The lift cylinder 29 is extended and contracted by a lift control valve of a hydraulic circuit from a hydraulic pump. The lift cylinder 29 is provided at a rear end of the vehicle body 1, and is provided with a lift link mechanism 31 provided at a rear end of the vehicle body 1. The lift arm 32 is raised by connecting the piston to the lift arm 32 and pushing the lift arm 32 with the piston 30.

A seedling plant 28 is provided with a float 34 that slides on the soil surface on the lower side with respect to a machine body 33 connected to the rear end of the lift link mechanism 31, and a seedling is stored and repeated on the upper side. The seedling tank 35 to be ejected is interlocked so as to reciprocate left and right, and a seedling planting device 36 for separating and inserting the seedlings supplied from the seedling tank 35 is provided on the rear side. Linked configuration from axis. Numeral 37 denotes a fertilizing device, which is provided at the rear of the vehicle body 1 and is continuously connected with a fertilizing pipe 38 so that the fertilizing device 39 is provided on the float 34 of the seedling planting device 28. It is to be fertilized.

 40 is a cockpit.

When performing seedling planting work, by operating the elevating control valve,
The lift link mechanism 31 is lowered by the lift cylinder 29 to bring the float 34 of the seedling plant 28 into contact with the ground, and the forward running of the vehicle body 1 performs seedling planting. At this time, the piston 30 of the lift cylinder 29 is in the retracted state, so that the shifter 26 and the spring 25 cause the clutch 22 to rotate.
The pin is engaged with 23 and the clutch is engaged.
When the steering handle 2 is operated as shown in FIG.
The front wheels 6 are steered around the steering shaft 8 and the rear wheels 12
Are steered around the steering shaft 14 in the same direction. by this,
The vehicle body 1 is steered to the left or right almost in parallel, and the running is corrected.

Also, for such work steering during seedling planting, a seedling planting device is used.
By the vertical swing of the float 34, the elevation control valve of the hydraulic circuit is controlled, and the seedling plant 28 is moved up and down with respect to the vehicle body 1 so that the contact pressure of the float 34 is maintained constant. However, the expansion and contraction of the piston 30 of the lift cylinder 29 at this time is absorbed by the spring 41 and the clutch 22
Is not actuated from the entry position to the cut position against the spring 25.

When turning and turning to the turning stroke at the end of the seedling planting process, the seedling plant 28 is raised by the lift cylinder 29 to be in the non-working position. At this time, the extension of the piston 30 causes the shifter 26 to move the clutch 22 to the disengaged position against the spring 25 (FIG. 1). That is, the rotating body 23 of the clutch 22
Is disengaged from the pin and the pin is engaged with the fixed position of the fixed seat 24, so that the rear wheel steering mechanism 15 and the rear wheel 12 are fixed at the position of the straight traveling state. For this reason, as shown in FIG. 2, the steering by the steering handle 2 is interlocked only with the front wheels 6.

As described above, in the illustrated example, the swing steering operation is configured to be interlocked with the switching between the working posture and the non-working posture of the seedling plant 28 by the elevation control valve. In conjunction with the operation of the planting clutch for engaging and disengaging the clutch, the clutch of the switching device 10 is disengaged by disengaging the planting clutch.
Cut off 22 and set the clutch 22
May be configured to enter. Alternatively, the lift control valve may be operated, and the operation of the hydraulic lever of the hydraulic control valve for keeping the seedling plant 28 raised to a predetermined position by the lift cylinder 29 and the clutch 22 may be directly interlocked.
Further, the rear wheel transmission that interlocks the left and right rear wheels 12 is provided with a steering brake by a petal operation or the like. The braking operation of the petal or the like is performed so as to brake the rear wheels 12 on the turning steering side. The clutch 22 may be configured to switch to turning steering in conjunction with.

Further, in a configuration in which a high-speed traveling transmission is used during work steering and a low-speed traveling transmission is used during turning steering,
The clutch 22 may be switched in conjunction with the switching of the traveling speed.

Further, the vehicle body 1 is provided with an inclination sensor for detecting a front-back or left-right inclination angle, and the vehicle body is inclined by a predetermined angle or more by the inclination sensor or the like, so that the clutch 22 is disengaged and steering by only the front wheels 6 is performed. It may be configured to switch. This is effective when the vehicle enters and exits the field.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a steering interlocking mechanism showing one section, FIGS. 2 and 3 are plan views showing a partial action diagram, and FIG. FIG. 5 is a plan view of the side view of the planting machine. (Description of Signs) 1 Body 2 Steering Handle 6 Front Wheel 9 Front Wheel Steering Mechanism 10 Switching Device 12 Rear Wheel 15 Rear Wheel Steering Mechanism 22 Clutch 28 ... seedling plant, 29 ... lift cylinder

Claims (1)

(57) [Claims] 1. A steering device according to claim 1, wherein the steering of the front wheel and the rear wheel is linked to the steering of only the front wheel based on the turning steering or the operation for the turning steering. A steering device, such as a tractor, wherein the front wheels and the rear wheels are steered and linked in an operation for work steering.