JP2539036Y2 - Elevation control device for working unit in work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a lifting / lowering control device for a working unit in a working vehicle such as a tractor.

[Problems to be Solved by the Related Art and the Invention] Generally, in this type of working vehicle, in order to protect the work unit and ensure safety, the work unit is automatically raised based on the reverse operation of the aircraft. There is one that performs reverse climb control. However, in such a case, even in the burying work and the trenching work performed while the body is moving backward, the work section is arbitrarily lifted, so that such work cannot be performed. In order to solve this problem, it has been proposed that the reverse climb control can be released by a switching operation. However, in this case, a separate switching switch is provided, which causes an increase in the number of parts. Also, in conjunction with ON-OFF of the so-called automatic tillage depth control, which automatically controls the working unit based on the detection value of the tillage depth detection sensor, ON-O
It is also proposed to perform FF switching, but in this case, there is a concern that the working part may be damaged because the reverse rise control does not work in the ridge work etc. performed with the automatic plowing depth control turned off. Atsuta.

[Means for Solving the Problems] The present invention has been conceived in view of the above-described circumstances and has an object to provide an ascent / descent control device for a working unit in a working vehicle that can eliminate these disadvantages. A lifting and lowering control unit for controlling the lifting and lowering operation of the working unit; a tillage depth automatic control means for raising and lowering the working unit based on a detection value of a tillage depth detection sensor connected to the lifting and lowering control unit; In a working vehicle provided with reverse ascending control means for automatically raising the working unit based on the reverse operation,
Reverse climbing control switching means for executing reverse climbing control based on the judgment that the tillage depth sensor is in the connected state, and canceling the reverse climbing control based on the judgment that the tillage depth sensor is in the disconnected state. Is provided.

According to the present invention, the reverse climb control can be switched by using this configuration without providing a specially-designed switching switch.

[Example] Next, an example of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a traveling body of an agricultural tractor, and a rotary tilling type working unit 3 is connected to a rear portion of the body 1 via a lifting link mechanism 2 so as to be able to move up and down. Arm 5 associated with the extension and retraction of the hydraulic cylinder 4
The basic configuration, such as raising and lowering by swinging, is the same as the conventional one.

Reference numeral 6 denotes a rear cover provided at the rear end of the working unit 3 so as to be vertically swingable. The rear cover 6 is configured to swing up and down as the working unit 3 changes in plowing depth. The moving angle is determined by a tillage depth detection sensor
Is to be detected. The rear cover 6 of the embodiment is configured to move up and down by driving the electric cylinder 9.

Reference numeral 10 denotes a coupler for connecting the tillage depth detection sensor 8 to a control unit 11, which will be described later. The coupler 10 includes a detachable control unit-side coupler 10a and a sensor-side coupler 10b. A loop circuit 12 for inputting a detection signal indicating whether or not the coupler 10 is connected to the control unit 11 is wired to the side coupler 10b.

Reference numeral 13 denotes a side panel provided on the side of the driver's seat. The side panel 13 includes a shift lever 14 for performing a shift operation such as forward / reverse switching, and a lifting / lowering operation for performing a lifting / lowering operation of the working unit 3. Operation lever 15 and lifting operation switch 1
6. Tillage setting volume 17 for setting tillage depth for automatic tillage depth control, automatic switching switch 18 for switching automatic control, raising regulation setting volume 19 for setting upper limit of working unit 3, inclination A tilt setting volume 20 for performing automatic control tilt setting, a mode switching switch 21 for performing control mode switching of the control unit 11, a sensitivity adjustment switch 22 for adjusting sensitivity of automatic control, and a rear cover 6 are moved. Arm manual switch 23 for manual operation of the lift arm 5 for manual operation of the lift arm 5
Operation tools such as 24 are provided.

The control unit 11 is configured using a so-called microcomputer (CPU, ROM, RAM) or the like, and is disposed below the side panel 13. The control unit 11 receives an operation signal from the operation tools and receives an operation signal. A lever angle detection sensor 25 for detecting the lever angle of the lifting operation lever 15, a reverse operation detection switch 26 for detecting that the shift lever 14 has been operated backward, and an arm angle detection sensor 27 for detecting the swing angle of the lift arm 5. The tillage depth detection sensor 8 for detecting the swing angle of the rear cover 6 and the rear cover position detection sensor for detecting the rotational position of the rear cover 6
29. A detection signal is input from sensors such as an engine rotation sensor 30 for detecting the engine speed, and the hydraulic cylinder 4 and the working unit 3 for swinging the lift arm 5 are determined based on these input signals. By outputting an operation signal to an actuator such as a lift rod cylinder 31 for tilting operation, an electric cylinder 9 for rotating the rear cover 6, etc., various controls such as a reverse ascent control and a lift arm control, which will be described later, are performed. I have.

The reverse raising control automatically raises the working unit 3 in preference to other working unit raising / lowering controls (automatic plowing control, manual lifting / lowering control, etc.) based on the reverse operation of the shift lever 14. The control is ON-O based on the connection state of the coupler 10.
It has become to be FF. That is, in the reverse ascending control, first, it is determined whether the coupler 10 is in the connected state, and when it is determined that the coupler 10 is in the connected state, the working unit 3 is automatically raised based on the reverse operation. If it is determined that the above conditions are satisfied, these controls are avoided.

On the other hand, the lift arm control includes a plowing depth automatic control in which the lift arm 5 is swung up and down so that the detection value of the plowing depth detection sensor 8 and the set value of the plowing depth setting volume 17 match,
Detection value of arm angle detection sensor 27 and lever angle detection sensor 25
When the operation command of the lift arm 5 is output in the manual lifting control in which the lift arm 5 is swung up and down so as to make the detected values coincide, the operation signal is sent to the electromagnetic hydraulic valve 32 in the hydraulic circuit shown in FIG. , But
The operation signal is an inching signal (intermittent signal), and the period of the inching signal and the duty ratio (ON time and OF
F time ratio) is changed based on the engine speed. That is, since the hydraulic pressure delivery amount of the hydraulic pump 33 changes with the change in the engine speed, the cycle of the inching signal and the duty ratio are determined based on the engine speed so that the change in the operating speed of the hydraulic cylinder 4 does not change. Is changing.

By the way, in the lift arm control of the present embodiment,
Consideration has been given to operating the hydraulic cylinder 4 at a predetermined speed even when the engine speed cannot be detected due to a failure of the engine speed sensor 31 or the like. That is, the engine rotation sensor
If it is determined that the detected value of 31 is 0, the inching data at the time of the rated rotation is provisionally used. Then, whether or not the lift arm 5 operates at a predetermined speed is determined based on the detected value of the arm angle detection sensor 27 based on the inching data at the time of the rated rotation. While the inching data is stored, if NO is determined, the lift arm 5 can be extended and contracted at a predetermined speed by changing the cycle and duty ratio of the inching data based on the detection value of the arm angle detection sensor 27. ing.

In the embodiment of the present invention configured as described above, when the coupler 10 of the tillage depth detecting sensor 8 is in the connected state, the working unit 3 is automatically raised based on the reverse operation, while the coupler 10 is in the disconnected state. In the case of, the automatic ascent is canceled. In other words, during automatic plowing depth control when the coupler 10 is in the connected state or during ridge work (the coupler 10 is in the connected state because the rotary tilling work section 3 is used), the reverse rise control is activated, and the coupler 10 is in the disconnected state. The reverse ascent control is released at the time of burying work or trenching work (the coupler 10 is in a disconnected state because the working part is replaced) and when the working part 3 is replaced. Therefore, the switching of the reverse drive control is appropriately performed without performing the switching operation of the special switch, etc., and as a result, it is possible to reduce the number of parts by eliminating the need for the dedicated switching switch. The operability can be improved by omitting the switch operation. In addition, unlike the method that switches the on-off switching of the reverse climbing control in conjunction with the automatic on-off control of the working depth, the reverse climbing control also works in the ridge work where the automatic descending control is turned off. Therefore, the working unit 3 can be surely protected not only during the automatic plowing depth control but also in other operations.

Further, in the embodiment, even when the engine rotation sensor 31 fails, the lift arm 5 is operated at a predetermined speed based on the feedback signal from the arm angle detection sensor 27. Can be prevented as much as possible.

The present invention is not limited to the above embodiment,
For example, as the tillage depth detection sensor, it is needless to say that various types such as a potentiometer, a capacitance type, and an ultrasonic type can be used. The determination of whether or not the coupler is in the connected state may be made by another method such as by determining whether or not a detection signal is input to the tillage depth detection sensor, without relying on the signal fed back by the loop wiring. Needless to say, this is acceptable.

[Effects] In summary, since the present invention is configured as described above, it is possible to increase the working unit automatically based on the reverse operation of the traveling body, and to increase the backward movement of the working unit. The control is switched between the execution state and the release state depending on whether or not the tillage depth detection sensor is in the connection state. Therefore, switching of the reverse ascending control is performed without performing switching operation of the special switch, etc. As a result, it is possible to reduce the number of parts by eliminating the need for a dedicated switching switch. Omission can also improve the operability. Moreover,
The reverse climb control is not switched in conjunction with the automatic plowing depth control ON-OFF. be able to.

[Brief description of the drawings]

1 is a side view of a tractor, FIG. 1 is a side view of a tractor, FIG. 2 is a plan view of the same, and FIG. FIG. 4 is a plan view of a side panel, FIG. 5 is a hydraulic circuit showing a hydraulic mechanism, FIG. 6 is a block diagram of a control mechanism, FIG. 7 is a flow chart of reverse ascent control, and FIG. FIG. 8 is a flow chart of the lift arm control. In the figure, 1 is a traveling body, 3 is a working unit, 4 is a hydraulic cylinder,
5 is a lift arm, 8 is a tillage detection sensor, 10 is a coupler,
11 is a control unit.

Claims (1)

(57) [Scope of request for utility model registration] An elevating control unit for controlling an elevating operation of the working unit, an automatic plowing depth control means for elevating the working unit based on a detection value of a tillage depth sensor connected to the elevating control unit;
In a traveling vehicle provided with a reverse ascending control unit that automatically raises the working unit based on a backward operation of the traveling aircraft, the lifting control unit may be configured to determine that the tillage depth sensor is connected. A lifting / lowering control device for a working unit in a working vehicle, comprising: a reverse ascent control switching means for executing reverse ascent control based on the determination based on the determination that the vehicle is in a disconnected state, and canceling the reverse ascent control. .