JPH02254023A - Front wheel acceleration device of tractor - Google Patents

Abstract

PURPOSE:To make always smooth and safe turning of a tractor according to the running conditions in a field by providing a device for restraining transmission of acceleration when front wheels are oscillated at more than a specified limit, on a device with which the tractor is turned by transmitting acceleration to the rear wheels while the front wheels are steered. CONSTITUTION:A tractor 6 is so constructed that the power of an engine E is transmitted to both front and rear wheels 1 and 2 to drive four wheels, and a front wheel speed increasing device 3 is provided in a power line to the front wheels 1. A change-over valve 12 for switching over the front wheel speed increasing device 3 is provided to rotate the front wheels 1 at the same speed as and at higher speed than the rear wheels 2. Also, a steering sensor 13 is provided on a steering wheel 7 and an oscillating sensor 14 is provided on a front axles 4. In addition, the control valve 12 is changed over and controlled by a front wheel speed increasing control device 15 according to the signals detected by the sensors 13 and 14. Namely, a device for restraining the acceleration of the front wheels 1 as required is constructed with the above-mentioned parts 12 to 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a front wheel speed increasing device for increasing the speed of the front wheels of a tractor during steering and turning.

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION When turning by steering a tractor, it is possible to improve turning performance and make it easier to turn in a small radius by transmitting rotation of the front wheels at a higher speed than the transmission rotation of the rear wheels. However, such switching to increased speed transmission for the front wheels is often dangerous depending on the driving conditions. Particularly in fields where the surface is extremely uneven and the vehicle body is prone to tilting or rocking, the vehicle may overturn when turning.

Means for Solving Problems The present invention provides a front wheel speed increasing device (3) that steers the front wheels (1) and turns while transmitting speed increase to the rear wheels (2).
A front wheel speed increasing device for a tractor comprising a front wheel speed increasing check device (5) that prevents the speed increasing transmission from occurring due to rocking of the front axle (4) of the front wheel (1) above a certain level. The structure is as follows.

Functions and Effects of the Invention When performing work with the vehicle body traveling straight, the front wheels (1)
The front wheels (2) are rotated at almost the same speed as the rear wheels (2), but when turning by steering on a headland in a field, the front wheels (1) are turned by steering by operating the control handle, etc. When the state is entered, the front wheel speed increasing device (3) is switched from the equal range of transmission to the speed increasing range, and the front wheels (1) are transmitted and rotated at a higher speed than the transmission of the rear wheels (2).

However, when the front axle (4) of the front wheel (1) rolls largely from side to side due to uneven ground, etc. during this turn, the front axle (4) swings beyond a certain level, causing the front wheel speed increase control device (5) to ), the heavy wheel speed increasing device (3) does not work, and (1) even though the I wheel (1) is turning, power is transmitted over an equal distance at almost the same speed as the rear wheel (2).

In this way, speed increase during steering and turning of the front wheel (1) is controlled by the magnitude of the swing of the front axle (4) itself that supports the front wheel (1), so Detection of driving conditions is quick and allows safe turning.

Embodiment When rotating, the tractor body (6) is equipped with an engine (E) at the front, and the front axle (1), which can be freely steered by the control handle (7), is rotated in a rolling manner around the center pivot. A rear axle (10) is mounted on both ends of a freely movable front axle (4), a driver's seat (8) is provided at the rear, and a rear wheel (2) protrudes to both left and right sides of the transmission case (9). )
be mounted on the shaft. In addition, a working device such as a tilling device is connected to the rear end of the vehicle body (6) using a lower link, a top link, etc.
The lift arm (11) is configured to transmit power through the power take-off shaft.
The structure is such that the elevation is controlled by the vertical movement of the. The engine (E) transmits power to the front wheels (1) and the rear wheels (2) to create a four-wheel drive mode, and a front wheel speed increasing device (3) is provided on the transmission path to the front wheels (1). (1) Rear wheel (
2), where the power is transmitted at almost the same speed, and the rear wheels (2)
), and a switching valve (12) is provided for switching the front wheel speed increasing device (3). Further, a differential device is provided on the front axle (4) and the rear axle (10) to transmit power.

A steering sensor (13) is installed on the steering wheel shaft of the steering wheel (7) to detect the rotation angle of the steering wheel shaft.
In addition, a rocking sensor (14) for detecting the rocking angle of the front axle (4) around the center pivot is provided, and each of these sensors (13) (14) is connected to a front wheel acceleration sensor equipped with a microcomputer. The control device (15) is manually operated to control switching of the switching valve (2).

The steering sensor (13) detects the rotation angle of the steering wheel shaft when the front wheels (1) are largely steered to the turning range, and switches the front wheel speed increasing device (3) to the speed increasing range. Control output. Further, when the rotation angle of the handle shaft returns to the straight-ahead or straight-line steering range, the front wheel speed increasing device (3) is switched to the equidistant range.

The rocking sensor (14) detects when the front axle (4) rolls more than a certain amount with respect to the vehicle body (6), and controls the switching valve (12) from the front wheel speed increase control device (15). The output to the front wheels (1) is stopped, and transmission to the front wheels (1) in the increasing speed range is not performed despite the turning detection by the steering sensor (13).

[Brief explanation of drawings]

The drawings show one embodiment of the invention, with FIG. 1 being a side view and FIG. 2 being a block diagram. In the figure, reference numeral (1) indicates a front wheel, (2) a rear wheel, (3) a front wheel speed increasing device, (4) a front axle, and (5) a front wheel speed increasing check device. Figure 1 Figure 2

Claims (1)

[Claims] A front wheel speed increasing device (3) that turns while steering the front wheels (1) and transmitting speed increase to the rear wheels (2) is equipped with A front wheel speed increase check device (5) that restrains the speed increase transmission from occurring due to rocking.
) A front wheel speed increasing device for a tractor.