JPH02119707A - Hydraulic pressure controller in tractor - Google Patents

Abstract

PURPOSE:To provide the title controller so designed that when a ground working machine is lifted to the upper limit position, a control mode is forcedly put to changeover from plowing depth control mode to position control mode to mitigate shocks at the stopping of the working machine following suspension thereof. CONSTITUTION:When a working machine 13 is operated towards the suspension side, a controller is actuated so as to make a changeover of the control mode from plowing depth control mode to position control mode. Changeover to the position control mode will gradually decrease the amount of hydraulic fluid fed into a hydraulic cylinder 7 to effect acting of brake, resulting in decrease of the lifting speed of the working machine.

Description

[Detailed Description of the Invention] [Field of Application of Industry I-] This invention relates to a hydraulic control device for a tractor, and more specifically, it is used to control a tractor connected to a tractor, such as a rotary tiller. It is intended to be controlled.

[Prior Art] Tractors are usually equipped with Position Control 1-Rormo I
In addition to F, it is equipped with Debscon 1-Roll mode or Draft I-Con 1-Roll mode.

] Each control 7-1 is provided with a setting means for setting the position of the ground work machine and a detection means for detecting the actual position. Hanging the ground work equipment at the rotating base 1. A height setting device is provided to set the lift height, and a detector is provided at the base of the lift arm side to detect the rotation angle. The device is configured to operate the device to hold the ground work equipment in a set working position.

In these devices, control sensitivity is set for each control mode according to the purpose of the work. For example, one type of control sensitivity is determined for position control 1 to roll, and for depth control and trough I. - In the case of control 1 to roll, it is configured such that a plurality of sensitivities can be selected depending on the conditions, etc.

[The section that the invention tries to solve We! ] By the way, 1-
In the case of the conventional device described above, the operator switches between each control mode by operating an artificial switching means such as a switch, and then adjusts the control sensitivity according to the task, field conditions, etc. must be determined. In this case, if the control sensitivity is set to the sensitive side, the problem is that when the work equipment is hoisted to the maximum raised position, a shock is transmitted to the operator as soon as the work equipment is stopped. -).

For example, if the settings are set to 1 - 1 - 1 - and the sensitivity is set to the sensitive side, the work machine will stop at the 1 - eye position when hoisting work 4. As soon as the machine was released, a large shock was applied to the operator, making him feel uncomfortable.

This is because, in the case of 1 to 1,000, the initial flow rate of the hydraulic oil flowing into the hydraulic cylinder constituting the hydraulic cine lowering mechanism is large.

[Means for Solving the Problems] The present invention is proposed in view of the problems mentioned above. When the work equipment is lifted up, the operator is automatically switched to a state where there is less shock, and other In this case, the ground work machine is hydraulically controlled with a control sensitivity appropriate to the task II. For this reason, the present invention has taken the following technical measures.

That is, a height setting device 24 for setting the lifting height of the ground work equipment 13 connected to the tractor 1, and a height detector 2 for detecting the height of the lifted ground work equipment. A hydraulic control device for a tractor, comprising: a plowing depth setting device 27 for setting plowing depth Y of the ground work machine 13; and a detector 20 for detecting the plowing depth amount of the ground work machine 13, A position control mode in which the hydraulic lifting mechanism operates so that the setting value set by the height setting device 24 and the detection value detected by the height detector 21 substantially match, and the plowing depth setting device. The plowing depth control mode operates a hydraulic lifting mechanism so that the plowing depth setting device set at 27 and the plowing depth detection value detected by the plowing depth detector 20 substantially match, Mf
Hydraulic control for a tractor, characterized in that it is provided with a control device 38 that forcibly switches the control mode from the plowing depth control mode 1- to the position control mode when the ground work machine 13 is raised to the upper limit position. The configuration of the device i' is as follows.

[Embodiment and its operation] An embodiment of the present invention will now be described with reference to FIG.

First, to explain the structure, 4 is 1 to ratata,
Front wheels 2, 2 and rear wheels 3.3 are installed at the front and rear of the aircraft, respectively, and the engine power is applied 40 times to the rear wheels through a transmission mechanism (not shown) in the mission case 5. It is configured to transmit to axis 2.2.3.3. Inside the hydraulic cylinder case 6 at the rear of the machine, there is a hydraulic cylinder 7 for lifting and lowering the work equipment.On the left and right sides of the hydraulic cylinder case 6, lifts (~NoAs 8.8) are rotatably mounted. 9.9 is lower link, 10 is 1~
It's Tubrink. +j'l 'iiL") 1- There is a riff I- between the arm 8.8 and the lower link 10.10.
Rotsu 1-11.1F is interposed and connected, and 1-tube link 9. Lower link 1. At the rear end of the three-point linkage mechanism 12 consisting of
A live-type rotary tiller 13 is connected so that it can be raised and lowered.
1.

This rotary tilling device 13 covers a plurality of tilling claws 15 planted on the tilling shaft 1-13 and 1° of the tilling section.
:The cover 16, the cover 17 etc. which are pivotally attached to the transfer and end of the cover 1 (5), and the l'l'l rj+i
A plowing depth detector 20 such as a potentiometer for detecting the rotation angle of the pitcher 17 is attached to the rear end of the top surface of the i-cover 6. 21 was investigated by the IJ personnel department around the left rift 1-arm 8, and the rotation angle F of the rift 1-arm 8 was investigated.
j The operating panel 29F on the lateral side of the first pilot's seat 28, which is the detector that detects A setting device 24 for setting the vertical height of the rotary tiller 13 is provided at the base.

As will be described later, this setting device 24 is connected to the rotary tilling device 13.
The rotary tiller 3 cannot be lowered below the height determined by this setting.

27 is a plowing depth setting device provided on the panel 291;
3C) is a distance setting device that defines the maximum lifting height of the ground work equipment 13; 31 is a switch for lifting and lowering the work equipment; 32
is a 1-rough 1-force detector that detects the compressive force of the h-tube link 10.

As shown in FIG. 2, when the plow 13a is connected to the tractors 1 to 1 instead of the rotary tiller]; when the plow i3a is being towed, compressive force is applied to the plow links 1 to 1o, or this compressive force is This detector 32 detects the size.

When the control element -1~ is switched to the position control state and the Mif lift switch 31 is pressed 1/8', the rotary tilling device N13 is set by the hydraulic operation lever (position operation lever) 23. When the rotary tiller 13 is lowered to the lower limit position and the lift switch 31 is pressed again, the rotary tiller 13 is raised to the position IIt set by the I/interval setting device 30. Incidentally, instead of this lift switch 31, a hydraulic operation lever 23 is used to operate the rotary tilling device 7',
] 3 may be lowered by 1-1, and in this case, the low tiller 13 moves up and down according to the operating range of the hydraulic operating lever 2;

FIG. 5 is a block diagram of this control device ji'1', and the circuit configuration will be explained based on the figure.The detector 21 detects the rotation angle of the lift arm 8, the height of the lift arm 8 a setting device 24 for setting the plowing depth, and a plowing depth setting device 27 for setting the plowing depth.
, Lift 1-Ground work equipment suspended from arm 8.8] Setting the maximum lifting height of 3
0, a detector 32 that detects the force applied to the trough 1, and a plowing depth detector 20 that detects the plowing depth are connected to the CP via an A/D converter 35, respectively.
It is connected to a control device 38 consisting of a switch 45 and a lift switch 3 for switching the control mode.
1 is connected to the control device 38. This control device 38
In addition, the hydraulic cylinder turf for lifting is driven]
An ascending proportional solenoid valve 40 and a descending proportional solenoid valve 41 are connected via drive circuits 42 and 43, respectively.

The plowing depth setting device 27 in this embodiment also serves as a submersion device for two control modes: I~Rough 1- and Depth, and the rotary tillage device 13 is connected to the rear of 1~Ractor 1. When the control mode 1 is set to the trough 1 - control I - roll mode, the 1 becomes the raft setting device,
Depth control I-ro-rumo-1 with plow i3a installed
When , it becomes a depth control mode setting device.

Next, hydraulic flow characteristics will be explained based on the graphs shown in FIGS. 6 to 8. FIG. 6 shows the meteor characteristics in the case of position control, FIG. 7 in the case of depth control 1-roll, and FIG. 13 in the case of trough 1-control 1-roll. In both graphs, the horizontal axis shows the difference between the current position and the target position, that is, the amount of displacement, and the vertical axis shows the flow value sent to the hydraulic cylinder.

As can be seen from the graph, in the case of roll to position control 1, a fixed meteor characteristic (sensitivity) determined by one type of flow rate characteristic is determined, and in the case of depth control, three types of sensitivity and trat control are determined. In this case, two types of sensitivities are set, and the desired sensitivity is selected from depth and 1-rough 1 using a sensitivity switching knob (not shown). (The sensitivity of depth control 1 to roll and the number of stages of sensitivity switching of depth control 1 to roll 1 are not particularly limited.) The information regarding the sensitivity determined from the relationship between the displacement amount of C3 and the flowing beast is the memory of the control device. Some people (not shown) remember this.

The flow characteristics of the position control I-roll and the characteristics at dεε in the case of depth control will be compared. .

As is clear from Figures 6 and 7, in the case of depth control, there are two types of depth control: one with a steeper slope (more sensitive) than the position control 1-roll sweep characteristic, and the other with a more gentle sweep characteristic. If the slope is steep, the rotary tiller 13 is raised to 1-1.
When approaching the limit position of 1-mark, the shock when stopped is large. Conversely, in the case of a gentle slope, there is a drawback that it takes time to raise the rotary tiller 13.

For this reason, when raising the working machine 1-4, it is better to control in the position control mode, which causes relatively less shock at stop 1 and 1 and does not require 1-day time.

Next, we will compare the flow of 1-raft control 1-roll (4 points + 1 and the characteristic f in the case of position control 1-roll).

As is clear from Figures 6 and 8, position con I
Compared to the traft control (-roll), the meteor characteristic curve is steeper and the initial flow rate is larger.
・If you raise it up, the shock when you stop it will be that much bigger. For this reason, when the work machine is moved to 111-, it is better to use the position control.

This hydraulic control device 1!1''C suspends the
When the controller is operated toward the lower side, the control device i'' 738 operates so that the control mode is automatically changed to position control mode I-roll mode I-.

The timing for replacing IWJ k and 1 is when the 411 pressure operating lever 2; 3 is operated to the maximum lifting side, or when the Yl-down switch 31 is operated to the I-outside, or when the lift 1 It is sufficient that the hair arm 8.8 is configured to be switched so that it is switched when it actually reaches a certain lifting height (the position set by the height limit setting device 30), and is not particularly limited. , FIG. 9 shows the control sensitivity in the case of Teguscon 1-roll, where the vertical axis represents the angle of rift 1 to arms 8 and 8, and the horizontal axis represents time. Figure 1-0 shows the sensitivity curve for 1-rough 1 to control, and similarly, the vertical axis represents the rotation angle of the riff 1 hair arm 8.8, and the horizontal axis represents time. . In the figure, the portion indicated by a dotted line shows how the 1-rough 1~ control changes to position control. When the work equipment reaches the l-eye setting position and the amount of displacement decreases, if the trough 1~control remains, the flow will suddenly decrease and the impact will be large when the work equipment stops. When the mode is switched to position control mode, the amount of preparatory oil sent to the hydraulic cylinder 7 is gradually reduced, the braking is effective, and the rising speed is slowed down, so there is no bending point at the maximum rising position as shown by the solid line. The transition is smooth, and therefore the ground work equipment 13
When the work machine is hoisted to the first position i4 and stopped, the work machine can be stopped smoothly without causing any impact.

[Effects of the Invention] Since the present invention is constructed as described above, it has the following technical effects. That is, the ground work machine 13 is I:1-1-hanging 1-
When the ground work machine is operated to the upper limit position, control mode 1- immediately shifts from plowing depth control mode 1- to position control mode. Therefore, it is possible to perform plowing work comfortably without causing fatigue or discomfort to the operator.
Becomes Noh.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Figure 1 is a side view of a tractor and rotary tiller, Figure 2 is a side view of a tractor and plow, Figure 3 is a perspective view of a panel next to the driver's seat, and Figure 4 is a side view of a tractor and a rotary tiller. The figure is a side view, Figure 5 is a block diagram, Figures 6 to 8 are graphs representing the special issue of Ryuzere, Figure 9 is Depthcon 1-
A graph showing the sensitivity in the case of roll, Figure 10 is trough 1
It is a graph showing the sensitivity in the case of ~ control. Explanation of symbols 11 - Rakuta 13 Ground work equipment (rotary tillage device, plow) 20
Tilling depth detector Rotation angle detector Height setting device Tilling depth setting device 1, interval setting device To trough 1 detector

Claims (1)

[Scope of Claims] 1) A height setting device 24 that sets the lifting height of the ground work equipment 13 connected to the tractor 1, and a height detector 21 that detects the height of the lifted ground work equipment. , a hydraulic control device for a tractor, comprising a plowing depth setting device 27 for setting the plowing depth of the ground work machine 13, and a detector 20 for detecting the plowing depth of the ground work machine 13, the above-mentioned height setting A position control mode in which the hydraulic lifting mechanism is operated so that the set value set by the height detector 24 and the detected value detected by the height detector 21 substantially match, and the plowing depth setter 27 is set in the position control mode. a plowing depth control mode in which the hydraulic lifting mechanism operates so that the plowing depth set value and the plowing depth detection value detected by the plowing depth detector 20 substantially match;
A hydraulic control device for a tractor, comprising a control device 38 for forcibly switching a control mode from a plowing depth control mode to a position control mode when the tractor is raised to an upper limit position. 2) The hydraulic control system for a tractor according to claim 1, wherein the control sensitivity in the position control mode is one level, and the control sensitivity in the plowing depth control mode is switchable in a plurality of levels. 3) The hydraulic control system for a tractor according to claim 1, wherein the plowing depth control mode is a draft control mode or a depth control mode.