DE2249590B2 - STEERING CONTROL DEVICE FOR AN AGRICULTURAL MACHINE, IN PARTICULAR A COMBINE - Google Patents

Description

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The invention relates to a steering control device for an agricultural machine, in particular a combine harvester, with the features of the preamble of claim 1 or claim 2.

In the DT-OS 15 82 237 is a control device for self-driving mobile agricultural

Machines shown and described along a given guideline. The sensing device, with which the boundary between mown and uncut material can be scanned, consists of two toothed disks, the rotational state of which forms the controlled variable. In order to avoid overriding the machine, it is also proposed to arrange the feeler device firmly on the mower, preferably in combination with the stalk divider. The mower, together with the stalk divider, is arranged to be displaceable transversely to the direction of travel and is connected to a feedback control element. When the steering is turned, the mower and the feeler device are shifted in the direction of the steering direction. In order to compensate for the misalignment of the tracks when the machine runs at an angle on a slope or geometric deviations between the right and left turns of the steering or to be able to dampen an oversteer, the feedback is assigned a correction element, with the help of which the assignment of the steering angle to the lateral position while driving the sensing device can be changed or a superimposed displacement of the sensing device is possible. The correction element consists in detail of a double-acting hydraulic cylinder and a measuring element which has a cylinder filled with a liquid. in which a separating piston connected to the control element of the actuator is slidably suspended between springs. The chambers of the cylinder, which are separated by the piston, are connected to one another via a throttle line.

This solution to eliminate the adverse effects of skewing of the machine at work on a slope requires considerable technical effort to be implemented. Also this is Construction, due to the large number of elements required for the correction member, with one associated considerable manufacturing costs.

The object of the present invention is therefore to provide a regulating device with a simple structure for the lateral guide of agricultural machinery with the risk of oversteering the Machine when driving straight ahead or as a result of skewing when working on a slope, despite the simplest circuit design is reliably avoided.

The task set is electro-mechanical by the in the characterizing part of the Claim 1 listed measures solved.

In the characterizing part of claim 1, a solution to the problem presented is provided with the aid electrical components proposed.

A regulating device for the inclined position control of a road plow is already known become (US-PS 28 83 777), in which, if there are deviations from a predetermined side slope, by a Pendulum a directional control valve is operated. With this suggestion, however, no center position adjustment of Control members made, which would have the purpose of maximum travel to maintain stability of a control loop.

An advantageous embodiment of the subject matter according to claim 1 is dependent on claim 3 remove.

In dependent claim 4 it is proposed that the vehicle battery to be used as a pendulum mass.

Two exemplary embodiments of the invention are described in more detail below with reference to the drawing. It shows

1 shows the schematic structure of a slope compensation based on the electro-mechanical principle.

F i g. 2 the schematic structure of a slope compensation according to the purely electrical principle.

In the exemplary embodiment for the steering control device according to FIG. 1, the rear axle 1 of a combine harvester is shown only partially and in a greatly simplified manner. On it, the rear wheel 2 with a wheel carrier 3 is mounted pivotably about the axle pin 4, the steering deflection being effected by moving a piston rod 5 of the steering cylinder 6 The piston rod 5 is mounted on the wheel carrier 3, the steering cylinder 6 on the rear axle 1

The steering cylinder 6 is controlled via a solenoid valve 7 during the automatic control or via a steering valve 8 for manual steering. The system is acted upon by a feed pump i »with drive unit 10, which draws the corresponding amount of oil from an oil tank 11 either directly via the Steering valve 8 or via the solenoid valve 7 via line 12 or 13 to the steering cylinder, which results in the corresponding steering angle to the right or left.

On the axle pin 4, two arms 14 are fixedly attached to control the solenoid valve 7, which the Participate in steering movements. These arms 14 actuate the limit switch 15 or when the steering angle is too large 16, depending on whether the deflection was too large to the right or left. These two limit switches are on one Mounted swivel plate 17, the swivel axis 18 of which lies parallel to the axle bolt 4.

By scanning a straw wall by means of an encoder, the control unit 19 is in accordance with the Deviation from the nominal position via the solenoid valve 7 of the steering cylinder 6 is applied to the right or left and thus also achieved wheel steering. The deflection of the steering is determined by the limit switches 15 and 16 the relay 20 or the relay 21 limited.

Since straight-ahead travel on a side slope can only be achieved by counter-steering, if the swivel plate 17 is stationary, an unequal tax deflection would result for your approach 14 from the central position. To avoid this, a pendulum mass 22, which can for example consist of the vehicle battery, is pivotably attached in the combine harvester ^. small bumps in the floor, e.g. B. potholes, a shock absorber 23 is connected to it.

The connection between pendulum mass 22 and swivel plate 17 is established via a Bowden cable 24 produced so that when the combine harvester is tilted, the pendulum mass 22, the pivot plate 17 and thus also the limit switches 16 and 17 adjusted to the opposite side by the necessary counter-steering the arms 14 are shifted from the central position, so that the pivot plate 17 to the arms 14 again is in the central position d. This means that the adjustment range for the rear wheel 2 is retained, but its position is changed relative to the chassis

In Fig. 2 the hydraulic control has remained the same, but instead of the mechanical adjustment, a purely electrical system takes its place here. the Pendulum mass 2 has at its lower end a pick-up finger 25, which, depending on the inclination, has a Variable resistor 26 taps. This is connected to a variable resistor 27 in Connected in series, the latter via a pick-off finger 28 which is attached to the latching carrier 3 in an insulated manner can be tapped.

The solenoid valve 7 is controlled via an additional three-position switch 29, the sum of the both resistance values fall below a certain minimum limit value n-cht within a setting range and a certain maximum limit value must not exceed and the central position of the Adjustment range through the variable resistor 26 according to the inclined position of the combine Pendulum mass 22 is shifted electrically. If the pick-up finger 28 nevertheless reaches one of the two limit values of the setting range, then the solenoid valve 7 is switched via the three-position switch 29 switched off by means of relay 20 or relay 21.

For this purpose 2 sheets of drawings

Claims (4)

Claims: 22 1. Steering control device for an agricultural machine, in particular a combine harvester, which is guided along a predetermined guideline, such that a sensing device Detects deviations from the guideline and triggers a signal that the position of a directional control valve a steering cylinder of a hydrostatic Lenkanla- ι ο ge influenced, the steering cylinder so long in The sense of a steering angle to the left or right is applied until the sensing device outgoing signal is canceled and the directional control valve returns to its neutral position, thereby characterized that to limit maximum steering angles additional from Endschaltarn formed control members (15, 16) are provided, the actuation of which via two with the axle bolt (4) of a steered wheel (5) firmly connected arms (14) that participate in the steering angle takes place and are connected to the center position adjustment with a pendulum mass (22) in a The vertical plane is arranged to be oscillatable transversely to the longitudinal axis of the vehicle. 2. Steering control device for an agricultural machine, in particular a combine harvester, which is guided along a predetermined guideline, such that a sensing device Detects deviations from the guideline and triggers a signal that the position of a directional control valve a steering cylinder of a hydrostatic steering system, the steering cylinder so long in the The sense of a steering angle to the left or right is applied until the sensing device outgoing signal is canceled and the directional control valve returns to its neutral position, thereby characterized in that an additional control member is provided to limit maximum steering angles which is formed from a resistor (271 fixed to the vehicle) which is connected via a finger (28), which is arranged to be rotatable analogously to the steering angle, can be tapped and that a further resistor (26) can be tapped via a finger (25) which is connected to a pendulum mass (22), which is shown in a vertical plane is arranged transversely to the vehicle longitudinal axis so as to oscillate, is connected and that the central position of the adjustable area of the resistor (27) by adjusting the resistor (26) is shifted electrically. 3. Steering control device according to claim 1, characterized characterized in that the control members (15, 16) are held on a pivotably mounted plate (17) are connected to the pendulum mass (22) via a Bowden cable (24). 4. Steering control device according to claim 1 or 2, characterized in that the pendulum mass (22) is formed by the vehicle battery.