JPH0253402A - Tractor rolling control device - Google Patents

Abstract

PURPOSE:To improve the measurement accuracy of the action time of a rolling cylinder and to enable smooth control of rolling by stopping the present rolling control output after the lapse of a prescribed time excluding the time performing the lifting operation by a lift control valve. CONSTITUTION:After the lapse of a prescribed period from the start of rolling control, the controlling action is stopped at the position to interrupt the rolling control in the same direction provided that the rolling control condition is maintained. The measurement is interrupted for a prescribed period during the period to output a lifting motion of a lift arm 12 with a lift control valve B and is continued for a prescribed period after the interruption of the lifting- side output of the lift control valve B. Since a lifting hydraulic circuit 4 contains large volume of oil and has high oil pressure during the output operation of the lift arm 12, the acting period of a cylinder 1 is measured in improved accuracy to enable smooth rolling control even if the supply of oil from a rolling hydraulic circuit 2 to the rolling cylinder 1 is almost terminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a rolling control device for a tractor working machine or the like.

Conventional technology and the section to be solved by the invention Control hydraulic pressure by dividing it from a hydraulic pump through a diversion valve into a lifting hydraulic circuit that controls lifting and lowering of a working device and a rolling hydraulic circuit that controls rolling of this working device. In hydraulic circuits that move, the maximum oil pressure of the lifting hydraulic circuit is generally set to be lower than the maximum oil pressure of the rolling hydraulic circuit, so the hydraulic pressure on the lifting hydraulic circuit side is faster, and the rolling hydraulic circuit Hydraulic operation on the side tends to be delayed.

The lift control valve installed in the lift hydraulic circuit operates the lift cylinder for raising and lowering the work equipment to the rise side or the fall side. Although it sends high hydraulic pressure especially to the rise side, it stops the lift cylinder and moves it to the neutral position. When maintaining the hydraulic pump, the configuration can be such that a large load is not applied to the hydraulic pump. However, in a rolling hydraulic circuit, when a stroke sensor is provided to detect the amount of expansion and contraction of the hydraulic cylinder, and when rolling control is performed while performing feedback control on the amount of detected expansion and contraction of the hydraulic cylinder, the stroke sensor reaches the limit position of expansion and contraction. When the rolling control valve becomes unable to detect the rolling position or angle of the working equipment and cannot return to the neutral position, the relief valve is activated.
Oil temperature rises.

Means for Solving the Problems This invention provides a hydraulic pump (P) to a rolling control valve (
The hydraulic pressure circuit (2) is connected to the rolling cylinder (1) via A), and the lifting hydraulic circuit (4) is connected to the lift cylinder (3) via the lifting control valve (B). When the stroke sensor (5) that detects the expansion/contraction control amount of the rolling cylinder fil no longer expands or contracts, the current value is determined by the elapse of a certain period of time excluding the time when the lift control valve (B) is outputting an upward movement. A rolling control device for a tractor working machine or the like is configured to stop rolling control output.

Functions and Effects of the Invention Hydraulic pressure that is divided into the rolling hydraulic circuit (2) and the lifting hydraulic circuit (4) by driving the hydraulic pump (P) is transferred to the rolling cylinder ( 1), the rolling cylinder (1) is expanded and contracted to maintain and control the working device in a horizontal horizontal position. At this time, feedback control is performed while the stroke sensor (5) detects the expansion and contraction of the rolling cylinder (1).

At this time, when the stroke sensor (5) starts detecting the amount of expansion and contraction, a certain period of time is simultaneously measured from this.

This fixed period of time excludes the time during which the lift control valve (B) outputs a lift. In this way, the expansion/contraction control output of the rolling cylinder (1) is stopped after a predetermined period of time has elapsed. Therefore, rolling control is stopped at that position.

Therefore, when the rolling cylinder reaches its full extent in 1), no further expansion or contraction is performed by hydraulic pressure after a predetermined period of time has elapsed, and no large hydraulic pressure is generated in the hydraulic circuit. Moreover, the fixed time period after the expansion and contraction output of the rolling cylinder [1] excludes the time during which the lift control valve CB) is outputting the lift control valve (CB).
The rolling cylinder (
Even if there is a delay in the oil pressure supply to the rolling cylinder (1), the rolling cylinder can be performed by calculating only the time required for the expansion and contraction of the rolling cylinder (1) and accurately measuring a certain period of time.

Embodiment In addition, when rotating, the tractor body (6) is equipped with an engine (7) at the front, has a front wheel (9) that can be operated with a steering handle (8), and a rear axle (1ω). Cockpit (1)
) At the rear of the lift arm (1), a pair of left and right lower links +141 are raised and lowered via a lift rod (13), and a tilling device (If9) is provided which can be raised and lowered by means of a top link OSI, etc. .

On the side of the pilot's seat (1), there is a position lever (for selecting and operating the lifting position of the lift arm (1δ) and a tilling depth setting dial 1 for setting the tilling depth by the tilling device (IIEI) fl). The lift arm α is hydraulically operated by a lift cylinder (3) whose piston is actuated by being electromagnetically switched from a neutral position to a raised position or a lowered position by a lift control valve (B) of a lift hydraulic circuit (4). .

In addition, a lift arm sensor (12) such as a potentiometer is provided at the base of the lift arm 025 to detect the vertical rotation angle. 12 [) is a tilt sensor that detects the horizontal tilt angle of the vehicle body (6). It is a sensor.

Of the lift rods (131) that connect the lift arm (1♂ and the pair of left and right lower links (14), the left and right lift rods (131) connect the lift arms (1♂ and the lower links (14) A rolling cylinder (1) is provided that extends and contracts between the rolling cylinder t
The working device (10
The rolling cylinder (
A telescopic stroke sensor (5) is provided between the lift arm (IZ) on the 1) side and the lower link (14) to detect the amount of expansion and contraction of the rolling cylinder (1), and this detection is performed by a microcomputer. Control unit (CPU) with
is fed back to determine whether the rolling posture of the working equipment by the rolling control valve (A) has reached the left-right horizontal state.

21) is a tilling depth sensor, which detects the vertical movement angle of a leveling plate (2δ) that levels the tilled soil surface when the working device (IGI is a tilling device), and detects the tilling depth from this angle. While using the lift arm (+21), the tilling work device (l
[i] is controlled up and down to control the tilling depth set by the tilling depth setting dial (Ill). (To) is a control mode changeover switch.

In the hydraulic circuit, (T) is the tank port, 1241
25) is a relief valve, and 25) is a diversion valve between the lifting hydraulic circuit (4) and the rolling hydraulic circuit (2). For example, the hydraulic pressure in the hydraulic pump (P) is 150 kg/d.

The maximum hydraulic pressure of the lifting hydraulic circuit (4) is 150 kg/ad, and the maximum hydraulic pressure of the rolling hydraulic circuit (2) is 40 kg.
/a#, the hydraulic pressure of the rolling hydraulic circuit (2) is operated in a range significantly lower than the hydraulic pressure of the lifting hydraulic circuit (4). A check valve (
2e is provided, and this check valve c! After a few days, it is sent to the lifting hydraulic circuit (4) side, and then again.

Rolling cylinder during switching of rolling control valve (A) (
The return oil from 1) is similarly sent to the lifting hydraulic circuit (4) through the check valve Qe.

(5) is a check valve, and the rolling cylinder (1)
This check valve (
5) is configured with a back pressure circuit (28) that can be slightly opened, and when applying hydraulic pressure to the extension side to control rolling, the back pressure from this back pressure circuit f21 is used to open the check valve (υ) and close the rolling cylinder (1). ) is configured to operate the piston in the extension side.

When the rolling control is started based on the left and right tilt detection of the vehicle body (6) by the tilt sensor (21), the rolling cylinder (1) is extended or shortened by the rolling control valve (A), and the rolling control is performed and the rolling control is performed at a certain level. The time is measured. This fixed time sets the maximum time required for the rolling cylinder (1) to extend or shorten. Therefore, when this fixed specified time has elapsed, the rolling control is stopped. It is treated as if the left or right limit position has been reached.Therefore, once a certain period of time has elapsed since rolling control was started, the vehicle will stop at that position unless the rolling control conditions change. , the rolling control in the same direction is not continued.Also, while the lift arm (one lift control valve (B)) is outputting to the upward side, measurement for a certain period of time is interrupted, Measurement continues for a certain period of time after the output to the lifting side of the lift arm (1δ) stops.During the output operation of the lift arm (1δ), the amount of oil in the lifting hydraulic circuit (4) is large and the oil pressure is high. Since it is a rolling hydraulic circuit (2)
Even if the supply to the rolling cylinder (1) is almost not performed, this state is regarded as the same as a neutral position where no rolling control is performed, and the rolling cylinder (1) is
) to perform smooth rolling control by more accurately measuring the length of time the roller is being expanded and contracted.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a hydraulic circuit diagram, Fig. 2 is a partial slope view, Fig. 3 is a side view, Fig. 4 is a control block diagram, and Fig. 5 is a hydraulic circuit diagram. A flowchart is shown. In the figure, (1) is the rolling cylinder, (2) is the rolling hydraulic circuit, (3) is the lift cylinder, (4) is the lifting hydraulic circuit, (5) is the stroke sensor, (A) is the rolling control valve, ( B) shows the lift control valve.

Claims (1)

[Claims] The rolling hydraulic circuit (2) connects the hydraulic pump (P) to the rolling cylinder (1) via the rolling control valve (A), and the lift cylinder (1) via the lifting control valve (B).
When the stroke sensor (5) that detects the expansion/contraction control amount of the rolling cylinder (1) stops changing, the lift control valve ( A rolling control device for a tractor working machine, etc., which is configured to stop the current rolling control output after a certain period of time excluding the time during which the upward output is being performed in B).