JPH02254068A - Front wheel speed increasing device for tractor - Google Patents

Abstract

PURPOSE:To enable execution of safe and effective turn steering by a method wherein a restraining device to prevent speed increase transmission from being executed under a given condition during turn is mounted to a front wheel speed increasing device to turn front wheels as speed increase transmission is made on rear wheels. CONSTITUTION:A front wheel speed increasing device 3 mounted in the transmission route of front wheels 1 can be switched to an equal speed area wherein transmission to front wheels 1 is effected at the same speed as that at which transmission to rear wheels 2 is effected and a speed increase area wherein transmission to the front wheels is made in a speed ratio approximately 2 times as high as that in which transmission to rear wheels 2 is effected. The front wheel speed increasing device 3 is switched in a way that a switching valve 13 is controlled by a front wheel speed increasing control device to input an output signal from a steering sensor 14. In this case, when one of a load sensor 16 to detect a load exerted on a front wheel axle 14, a brake sensor 17, a speed change switch 19 to detect a speed change to a high speed position, and an inclination sensor 20 to detect inclination of a car body outputs a detecting signal, constraint is performed so that an output from a constraining device 4 to the switching valve 13 is stopped.

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.

BACKGROUND ART AND PROBLEMS TO BE SOLVED BY THE INVENTION Turning performance can be improved by transmitting rotation of the front wheels at a higher speed than the transmission rotation of the rear wheels when turning by steering a tractor. When the increased speed transmission of the front wheels when the tractor turns is highly dangerous, a restraining device is provided to prevent the increased speed transmission of the front wheels from being performed by detecting these various conditions. However, while being aware of these restraining conditions, dryers often want to intentionally turn using speed-up transmission.

Means for Solving the Problems The present invention provides a front wheel speed increasing device (3) that steers the front wheels (1) and turns while transmitting speed increasing transmission to the rear wheels (2).

A front wheel speed increase check control (4) that prevents the speed increase transmission from being carried out by detecting conditions during turning, and a check release device ffi that prevents the front wheel speed increase check control (4) from performing the check. A front wheel speed increasing device for a tractor is provided with (5).

Functions and Effects of the Invention When working with the vehicle running straight, the front wheels (1) are rotated at the same speed as the rear wheels (2). When turning in the direction, the front wheels (1) are steered by vibration of the steering wheel and enter the turning state, and the front wheel speed increaser (3) is switched from the equal range of transmission to the speed increase range. , the front wheels (1) are driven to rotate at a higher speed than the rear wheels (2).

However, by detecting a certain condition during this turn, the front wheel speed increasing device 'r1 (4) operates and does not plow the front wheel speed increasing device 2213) and does not switch the front wheel (1) to the speed increasing range. At this time, even if the front wheel speed increase check control (4) is in a state where the front wheel speed increase check control (4) is in a state of checking speed increase, the check release device [5] is operated by the driver or by operating it in advance. The speed increase is not checked by the device (5), and turning is performed by transmitting the speed increase to the front wheels ill based on the driver's intention. Therefore, safe and effective turning maneuvers can be performed.

Example When rotating, the tractor body (6) is equipped with an engine (7) at the front, a front wheel (]) that can be freely steered by a control handle (8), and a driver's seat at the rear. (9)
The rear wheel (2) is mounted on the rear axle 00 of the transmission case (1 [I). Also, the rear end of the vehicle body (I) is equipped with a lower link, a top link, etc., and is used for work such as tilling equipment. The devices are connected to each other so that power is transmitted through a power extraction shaft, and the vertical movement of the lift arm 0δ is used to control the vertical movement. The engine (A) transmits power to the front wheels (1) and the rear wheels (2) to form a four-wheel drive mode, and a front wheel speed increasing device [3] is provided on the transmission path to the front wheels (1).

Transmission from the front wheel (1) to the rear wheel (2) involves an equal range where the transmission is at the same speed, and an increasing range where the transmission from the rear wheels 1i & (2) is at a speed ratio that is twice as high. A switching valve (1) is provided to switch the front wheel speed increasing device d(3).

In addition, the front axle o4 and the rear axle Tl on which the front wheels +1) are mounted
11 is provided with a differential device for power transmission.

The steering wheel shaft of the steering wheel (8) is provided with a steering sensor (to) that detects the rotation angle of the steering wheel shaft, and a front wheel speed increaser device f having a microcomputer is provided.
The steering sensor o4 is input to the front wheel (13) and controlled to switch the switching valve (13).
) is significantly steered into the turning range, the rotation angle of the steering wheel shaft is detected and a control output is provided to switch the front wheel speed increasing device (3) to the speed increasing range.

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.

Front wheel speed increase control (4) includes a load sensor OQ that detects the load acting on the front axle (b), a brake sensor (ω that detects the braking force acting on the front wheel @■ and the rear axle (lυ), and a shift lever (1υ). a shift switch fFJ that detects that the traveling gear is being shifted to a high speed position;

The front wheel acceleration control device t! inclines the inclination sensor 4, which detects when the vehicle body (6) is significantly tilted to the left or right due to driving on a slope, etc. Input to OcJ and select one of these sensors oe
, tri, IFJ-, or (to), the control structure is such that the traction 1 is performed so that the output to the switching valve (11) is stopped even during a steering turn.

A check release device (5) consisting of a turn signal switch is provided near the control handle (8), and when the operator operates this turn signal switch, the check release device ff
(5) can be put to work. This restraint release device (
5) is controlled so that the front wheel speed increase check control (4) is activated to switch to the speed increase range and turn despite the detection of any sensor flG, (m, (l, or (2)). do.

[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 the front wheels, (2) indicates the rear wheels, (3) indicates the front wheel speed increase device, (4) indicates the front wheel speed increase check control, and (5) indicates the check release device.

Claims (1)

[Claims] The front wheel speed increasing device (3), which turns while steering the front wheels (1) and transmitting speed increase to the rear wheels (2), is prevented from performing this speed increase transmission by detecting conditions during turning. Front wheel speed increase check control (4) and this front wheel speed increase check device (4)
Check release device (5) that prevents checking by
A front wheel speed increasing device for a tractor.