JPH0528972Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is an automatic control device that can ensure safety when starting the engine of a tractor connected to various types of work equipment such as a rotary tiller, and also when starting work. It is related to.

[Conventional technology]

Recent agricultural tractors are equipped with a control device that automatically controls the plowing depth of a working machine, such as a rotary tiller, towed by the tractor, and controls the rotary tiller so that it maintains the left and right horizontal posture.

In that case, leave the automatic/manual switch on the control device set to "automatic" and finish the work once.
When the tractor's power switch is turned on when work is resumed, automatic control is immediately started because the operating mode in the control device is in the "automatic" state. Therefore, if a work machine is controlled to move up and down, it will be dangerous if there is a person near the work machine.

In order to prevent this danger, the implementation of prior art
Publication No. -25765 provides a work mode (work mode) switching mechanism that artificially switches between a state in which automatic elevation control is performed and a neutral state in which this control is released, and when an engine starting operation is performed. , it is disclosed that the switching mechanism is configured to automatically switch to the vertical neutral state.

On the other hand, in Japanese Patent Application Laid-Open No. 57-86201, when starting a tractor, the set value on the lifting position setting device of the work equipment is compared with the detection signal from the height position detection sensor of the work equipment, and the two do not match. The construction is such that the lifting drive circuit of the working equipment is not unlocked for as long as possible.This prevents the working equipment from being inadvertently raised or lowered at the same time as the power switch is turned on. It is disclosed that even after it is confirmed that the height position matches the position set by the lift position setting device, the lowering drive circuit of the work equipment does not operate until the work equipment has been raised once. has been done.

[Problem that the invention attempts to solve]

Even if the above two prior arts are combined, when the power is turned on to restart the tractor, if the actual height position of the work equipment and the setting value of the lifting position setting device do not match, the lifting drive circuit of the working equipment will be locked. Therefore, it is necessary to change the setting value of the elevation position setting device, but it is not easy to immediately determine whether there is a mismatch in the higher side or lower side. Therefore, the operation of this elevation position setting device becomes a trial and error process, which becomes extremely troublesome. Moreover, after this match is confirmed, the work equipment must be raised manually and then the setting value set by the lift position setting device must be returned to the predetermined position before the "automatic" work can be started. Therefore, there was a problem that it was not possible to easily switch to "automatic" control operation after restarting the engine.

In addition, the device described in Japanese Patent Application Laid-open No. 152205/1983 as a prior art uses a setting signal from a position setting device manually operated by a position control lever and a detection signal from a level detector for the machine of the working device. electric position control means that operates the drive mechanism for lifting and lowering the working equipment until the working equipment is balanced; and the electric position control means that operates the driving mechanism for lifting and lowering the working equipment until the setting signal from the manually operated tilling depth setting device and the detection signal from the tilling depth detector of the working equipment are balanced. A raising/lowering control device for an agricultural working machine, which is equipped with an electric automatic plowing depth control means for operating a mechanism, and the lowering control state in the position control mode or the lowering control in the automatic plowing depth control mode when the engine is started. It is disclosed that when a state is detected, the descending control operation is checked and prevented, and when a neutral stable state or an ascending control state is detected in any control mode, the operation in that control mode is permitted. has been done.

This configuration is a step forward from the idea disclosed in Japanese Unexamined Patent Publication No. 57-86201, and when the position control lever is in the neutral stable state or the upward control state, its operation is controlled, but the downward control is When in this state, the lowering control operation is inhibited. Therefore, depending on the position of the position control mode, that is, the position of the position control lever, there is a danger that the working machine may immediately rise and come into contact with other workers located near the agricultural machine. .

These problems are the same even when the working machine towed by a tractor is a plow or the like.

The purpose of the present invention is to simplify the operation when restarting the engine, and also to ensure the safety of workers and the like.

[Means for solving problems]

For this reason, in the present invention, a drive means drives a working machine connected to a tractor so that it can be raised and lowered to a height position set by comparing signals from a working position detection sensor and a lifting position setting device operated by a position control lever. In a control device for raising and lowering via The operation mode of the control device enters the automatic control state by switching the automatic/manual switch to "manual" and then switching it to "automatic" again. A means for doing so is provided.

[Action/Effect]

With the above configuration, if you turn off the power to the tractor to interrupt work and then turn it on again, the work mode in the control device will not enter the automatic control state, but will simply prepare for operation. Just put it in the state.

Furthermore, no matter which position the automatic/manual switch for switching the operating mode of the control device to "automatic" or "manual" is in, the working machine will not move up or down.

If the work mode of the control device is set to "auto" at the end of the work and you want to resume work under automatic control, turn the changeover switch set to "automatic". By setting it to "manual" once and then to "automatic" again, the control device enters the automatic control state.

Therefore, if the work is interrupted while the work is being done under automatic control (e.g. due to running out of fuel, engine stalling, etc.), the work will be resumed under automatic control after the cause has been removed. In this case, by using the above-mentioned means, the work can be restarted from the same state as before the interruption of the work machine without changing the elevation position of the work machine.

In this way, according to the present invention, when resuming work, it is extremely easy to "automatically" after restarting the engine.
This has a remarkable effect compared to the conventional technology in that the control operation can be started.

Then, while the automatic/manual switch for switching the work mode between "automatic" and "manual" in the control device is set to "automatic", the work is finished, and when the work is resumed, the power switch of the tractor is turned on. Also, the operating mode in the control device does not immediately enter the "automatic" state, and therefore there is no risk that automatic control will start immediately and the work machine will be controlled to raise and lower, resulting in improved safety. play.

In this way, for example, the work mode of the lifting control device of a working machine can be set to "automatic" or "manual" according to the present invention.
If you leave the automatic/manual switch set to "auto" and turn on the tractor's power switch after finishing work and restarting work, the work mode in the control device will immediately change to "auto".
Although it is possible to prevent the system from entering the control state, it also has the effect of making it easy to return to the "automatic" control state.

〔Example〕

Next, an embodiment in which the present invention is applied to a rotary tiller will be described. In the figure, reference numeral 1 indicates a four-wheeled tractor, and reference numeral 2 indicates a pair of left and right lower links 3, 3 and a top spring at the rear of the tractor 1. A pair of left and right lift arms 6 are shown at the rear of the tractor 1 which are vertically movably connected to each other by 4 and 4. At the rear of the tractor 1, there is a pair of left and right lift arms 6 which are rotated up and down by the protrusion and retraction operation of a hydraulic cylinder 5 for controlling plowing depth, which is a hydraulic control drive means. ,6
is connected to one lower ring 3 via a rod 7 with a turnbuckle, and to the other lower ring 3 is a hydraulic cylinder 8 for horizontal control, and the magnitude of the relative left and right inclination angle between the tractor 1 and the rotary tiller 2 can be detected. The rotary tiller 2 can be raised and lowered and the plowing depth can be controlled by controlling a pulse-controlled electric control device 14 that is connected to each other via an attitude detection sensor 9 and has a built-in microcomputer, which will be described later. It is constructed so that it can maintain a horizontal state regardless of whether it is tilted left or right.

That is, the hydraulic cylinder 5 for tillage depth control is controlled via the switching valve 16 which is switched and operated by the control device 14, and the hydraulic cylinder 8 for horizontal control is controlled via the switching valve 19 which is switched and operated by the control device 14. Each is driven. Hydraulic pressure in a hydraulic circuit 10 for these hydraulic cylinders 5 and 8 is supplied by a hydraulic pump 12 that is rotationally driven by an engine 11 mounted on the tractor 1 via a belt.

Further, a flexible cover body 17 made of synthetic resin or the like is pivotally attached to the rear part of the rotary tiller 2 at its base end so as to be movable up and down, and the cover body 17 is supported by a spring 18 and a damper (not shown). is pushed toward the field side.

A plowing depth sensor 20, which is a work position detection sensor attached to the rotary tiller 2, is connected to the cover body 17 to sense the degree to which the free end (lower end) of the cover body 17 is directed downward, and the cover body 17 is in contact with the field. If the rotary tiller 2 is not in contact with the field, the rotary tiller 2, which is a working machine, will be in the air, and when the lower end of the cover body 17 comes into contact with the field, it will be difficult to determine whether or not the lower end of the rotary tiller 2 has landed on the field. It is also possible to detect how far the lower end of the rotary tiller is below the field surface. The plowing depth sensor 20 may be a rotary encoder or a variable resistor.

In the control section near the control seat 15, there is a plowing depth value setting device 2 for artificially setting a desired plowing depth set value H.
4. The plowing depth setting device 24 may be a rotary encoder or a rotary switch that is linked to the rotational operation of the plowing depth setting lever 23.

The position control lever 13 is used to manually select the height position of the rotary tiller 2 from the ground, and can be switched to a raised position, a neutral position, and a lowered position. That is, the height position of the rotary cultivator 2 is determined by the elevation position setting device 21, which is a rotary encoder that senses the set position in conjunction with the rotation of the position control lever 13.

Therefore, to manually raise the working machine before interrupting work, the position control lever is placed in the upper position, and the working machine itself is actually in the raised position. Conversely, when work is interrupted at the upper timing when the work equipment is in the lower position, the position control lever is also in the lower position.

In both of these states, when the tractor power is turned off and work is interrupted, the signal from the work position detection sensor and the signal from the lift position setter determined by the position control lever 13 match. Therefore, regardless of whether the position control lever that determines the lifting position of the working machine is in the raised position or the lowered position, the working equipment will not rise or fall.

In addition, with the tractor power turned off,
Even if the position control lever 13 is moved by mistake (even if the height position of the work machine is different from the actual height position of the work machine when the work is interrupted), the work machine will not be raised or lowered simply by restarting the engine, as will be described later.

The lifting position setting device 21, the working position detection sensor 20 which is a plowing depth sensor, the automatic/manual changeover switch 22 for switching the working mode in the control device 14 to "automatic" or "manual", and the power switch 35 of the tractor 1 are provided. Each is electrically connected to the control device 14.

Then, while the automatic/manual changeover switch 22 for switching the work mode in the control device 14 to "automatic" or "manual" remains in the "automatic" state, the work is interrupted and the tractor's power switch 35 is turned on.
After turning off the power switch 35, turn on the power switch 35 again.
When this happens, the work mode of the control device 14 does not immediately enter the "automatic" state, but only becomes ready for operation, and the switch 22 from the "automatic" state is once set to "manual" and then set to "automatic" again. , to improve safety by controlling the work mode of the control device 14 to enter the "automatic" state only after some kind of human operation such as moving the position control lever 13 to the down position or up position. be.

Note that the work is not carried out with the automatic/manual changeover switch 22 for switching the work mode in the control device 14 between "automatic" and "manual" in the "manual" state and the position control lever 13 in the raised position. After interrupting and turning off the power switch 35 of the tractor, when the power switch 35 is turned on again, the work will be started from the "manual" state.

The flowchart of this control is as shown in FIG. 4. At the start point, the lifting position setting device 21
, a detection signal of the working position detection sensor 20, a signal indicating the position of the automatic/manual changeover switch 22, and a tilling depth value setter 24 for setting the tilling depth set value H.
signals are set as initial values (step
S1).

In this state, turn on the tractor power switch 35.
When this happens (step S2), the power supply flag F becomes 1 (step S3). Next, in step S4,
If it is determined that the initial value is "auto" of the automatic/manual changeover switch 22, rotary tilling is performed by the tilling depth sensor 20, which detects the height position of the rotary tiller 2 in accordance with the initial state or the actual height position of the rotary tiller 2 changed thereafter. The detected value A of the height position of the machine 2 is read (step S5), and the detected value A is designated as the set value D of the elevation position setting device 21 in the initial state (steps S6 and S7).

Next, in step S8, once the changeover switch 22 from the "auto" state is set to "manual", the power flag F becomes 0 (step S9), and the initial state or the detected value A that has changed thereafter is read again and detected. The routine of instructing the value A as the set value D of the elevation position setting device 21 is repeated (steps S5 to S7). After that, in step S8, when the automatic/manual changeover switch 22 is set to "auto" again, it is determined that the power supply flag F is 0 (step S8).
S10), the set value H of the plowing depth value setter 24 is read for the first time (step S11), and the plowing work in the "automatic control" state is then executed (step S12).

Before the work is finished, the power switch 35 is turned on in step S2 while the automatic/manual changeover switch 22 remains in the "automatic" position.
When turned ON, the power supply flag F also becomes 1 in step S3, and in this state, it is determined to be "automatic" in step S4. When the worker resumes work, the operator selects "Automatic"
If the automatic/manual changeover switch 22 is not operated when it is desired to select ``automatic'', it is determined in step S8. Then, in step S10, the power supply flag F also remains at 1. As mentioned above, when the worker wants to select "automatic" when restarting work, when the worker moves the position control lever 13 to the upper or lower position (step S13), the power flag F is switched to 0. (Step S15), the set value H of the plowing depth value setter 24 is read (step S11), and the plowing work under the "automatic control" state is executed (step S12).

In other words, the tractor power switch 35
Even if it is turned on, the work mode is set to "auto" by turning the automatic/manual switch 22 to "manual" and then setting it to "automatic" again, or by manually operating the position control lever 13 by raising and lowering it. Only after the detected value A is changed does the control device 14 enter the "automatic control" state.

Note that a command is given to the control device 14 not to control the plowing depth when the rotary tiller 2 is in the raised position, which is greatly elevated from the field.

In addition, during normal plowing depth control work, the plowing depth sensitivity adjuster 25, which is set and operated by the operator, receives a pulse signal P that intermittently (intermittently) drives the switching valve 16 via the control device 14. per cycle T1
By increasing/decreasing the ON width T2, the speed at which the piston rod of the plowing depth control hydraulic cylinder 5 moves in and out can be set to be fast, medium, slow, etc.

When the operator sets the automatic/manual changeover switch 22 to the "auto" side during tillage depth control work, the tillage depth value detected by the tillage depth sensor 20 when the rotary tiller 2 is in the lowered position and plowing depth setting device 2
4, and if it is determined that the actual lowering position of the rotary tiller 2 is below the plowing depth setting value, the pulse signal P causes the plowing depth control hydraulic cylinder 5 to be activated. The switching valve 16 is driven in pulses so that the piston rod protrudes, bringing the plowing depth closer to the set value.On the other hand, when the rotary tiller 2 determines that the plowing depth is higher than the set plowing depth, the pulse signal P changes the plowing depth. The switching valve 16 is driven in pulses so that the piston rod of the control hydraulic cylinder 5 is moved back toward the set plowing depth.

At this time, the operator sets the sensitivity adjuster 25 and issues a command via the control device 14 so that the ON width 2 per cycle T1 of the pulse signal P is a predetermined width, thereby controlling the switching valve. 16 is driven intermittently (intermittently) to adjust the protrusion and retraction of the piston rod of the hydraulic cylinder 5 for tillage depth control.

That is, per cycle T1 of pulse signal P
When increasing the ON width T2, the width of the piston rod that moves with a single pulse signal P signal is large, so it moves in large increments, so it can move quickly, and the time to reach the plowing depth setting position H, that is, the response time. Shorten it to improve sensitivity (responsiveness).

On the other hand, per cycle T1 of pulse signal P
When the ON width T2 is made small, the width of the piston rod that moves in response to a single pulse signal P is small, and therefore it moves in small increments, which improves the convergence to the plowing depth setting position H.

Traveling gear shift lever 30 located near the pilot seat 15
The engine 11 is operated by a servo motor 32 that
The traveling speed change is performed by selecting either "automatic" or "manual" in relation to the traveling speed change transmission transmission 33. However, "manual" operation has priority over "automatic" operation.

The travel gear shift lever 30 has a rotary encoder 31 that senses the speed change state of the travel speed and inputs the signal to the control device 14, while the output shaft of the travel transmission 33, etc.
A rotation speed sensor 34 is provided as an example of a load sensor in consideration of the fact that the load is approximately proportional to the load of the rotation speed sensor 3.
The detection signal from 4 is input to the control device 14 as a feedback, and the servo motor 32 is intermittently driven to increase or decrease the traveling speed so that a predetermined engine load is achieved.

It goes without saying that the present invention is applicable not only to rotary tillers, but also to working machines towed by tractors, such as subsoilers for digging deep trenches in fields, plows for ordinary tillage, and the like.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view of a tractor with a rotary tiller, FIG. 2 is a plan view taken along the - line of FIG. 1, FIG. 3 is a control block diagram, and FIG. is a flowchart. 1...Tractor, 2...Rotary tiller, 3...
...Lower link, 4...Top link, 5...Hydraulic cylinder for tillage depth control, 6...Lift arm, 8
... Hydraulic cylinder for horizontal control, 9 ... Posture detection sensor, 10 ... Hydraulic circuit, 11 ... Engine,
12... Hydraulic pump, 13... Position control lever, 21... Lifting position setting device, 14...
...Control device, 15...Control seat, 16...Switching valve, 17...Cover body, 18...Spring, 20...
Tilling depth sensor, 22... Automatic/manual switching switch, 23... Tilling depth position setting lever, 24... Tilling depth value setting device, 31... Rotary encoder, 25...
...Sensitivity adjuster, 30...Traveling gear shift lever, 32...
... Servo motor, 33 ... Traveling transmission, 34
...Rotation speed sensor, 35...Power switch.

Claims (1)

[Scope of utility model registration request] Control that raises or lowers a working machine connected to a tractor so that it can be raised or lowered to a height position set by comparing signals from a work position detection sensor and a lifting position setter operated by a position control lever via a drive means. The device is provided with a means for setting the control device into an operation ready state when the tractor's power switch is turned on, and changing the operation mode of the control device, which is set to “auto” at the end of work, to “auto” or “auto”. By switching the automatic/manual switch to "manual" and then switching it to "automatic" again,
An automatic control device for a tractor, comprising means for causing the operation mode of the control device to enter an automatic control state.