JP2001178209A - Working portion elevation controller of working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working portion elevation controller which can suitably change a position for accelerating a working portion-lifting speed in response to a working state to always reduce shocks and engine loads due to the initial operations of a hydraulic actuator and can quickly lift the working portion to a prescribed lifting position to stabilize the travel of the vehicle body. SOLUTION: When a rotary working machine 1 is lifted from a working position to a non-working position, the revolution speed of an engine is detected. When the revolution speed of the engine is not changed in a prescribed quantity, the working machine 1 is presumed to be grounded and is therefore lifted at a low speed. When the revolutional speed of the engine is enhanced in a prescribed quantity, the working machine 1 is estimated to be floated above the ground surface, and the lifting speed is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction of a working unit elevating control device of a working vehicle having a ground working machine such as an agricultural tractor or a bull tozer.

[0002]

2. Description of the Related Art Conventionally, agricultural tractors and the like are provided with a ground working unit such as a rotary working machine or a plow working machine which is connected to be able to move up and down. It is known that the ascending speed is increased at a height arbitrarily set by an operator when ascending the working section or at a height set at the time of production and shipment.

[0003] A tractor equipped with these control devices is designed to reduce the shock and load caused by the initial operation of the hydraulic actuator by, for example, maintaining the ascent speed of the rotary work machine at a low speed in the ground. In this case, the vehicle body quickly ascends to a predetermined height and stably runs the vehicle body.

[0004]

However, if the speed-up position of the working unit is fixed as in the prior art, if the hardness and softness are different at various places in the workplace, the amount of settlement of the vehicle body is different, so that an appropriate value is always required. There was a problem that the ascending speed could not be changed depending on the position. That is, when the sinking amount of the vehicle body is large, the ascending speed is increased in a state where the working unit is in the soil, and there is a problem that a load causes a shock or an engine stop. Conversely, if the ascending speed is increased at a high position when the sinking amount of the vehicle body is small, there is a problem that it takes time to reach a predetermined raising position, and the vehicle body fluctuates particularly during a turning operation.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a working unit elevation control device for a working vehicle as follows. That is, according to the first aspect of the present invention, in a work vehicle including a ground working unit 1 connected to be able to move up and down and a sensor 2 for detecting a working state of the working unit 1, the working unit 1 is moved from a working position to a non-working position. When ascending to
Is detecting a condition that is assumed to be grounded,
When the working unit 1 ascends at a low speed and thereafter detects a state where the working unit 1 is assumed to have floated above the surface of the ground,
A working unit elevating control device for a working vehicle, comprising a control means 3b for increasing the ascending speed.

According to the second aspect of the present invention, the sensor for detecting the contact state of the working unit 1 or the state of floating above the ground surface is a pickup sensor 2b for detecting the number of revolutions of the engine 4, and the sensor 2b The working unit lifting / lowering control device for a working vehicle according to claim 1, wherein the ascending speed of the working unit 1 is increased based on the detected value of the working unit.

According to the third aspect of the present invention, the sensor for detecting the grounding state of the working unit 1 or the state of floating above the ground surface is a potentiometer 2a for detecting an operating part that moves up and down following the ground surface. The working machine lifting / lowering control device for a working vehicle according to claim 1, wherein the ascending speed of the working unit 1 is increased based on the detection value of the potentiometer 2a.

According to the present invention, the sensor for detecting the grounding state of the work unit 1 or the state of floating above the ground surface is a strain sensor 2c for detecting the traction load of the work unit 1, The working unit lifting / lowering control device for a working vehicle according to claim 1, wherein the ascending speed of the working unit 1 is increased based on the detected value of 2c.

[0009]

According to the working vehicle lift control device for a working vehicle constructed as described above, the position at which the speed of raising the working vehicle is increased is appropriately changed according to the working condition. And the engine load can be reduced, and the vehicle body can be quickly moved to a predetermined ascending position to allow the vehicle body to run stably.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings for an agricultural tractor as a working vehicle. As shown in FIG. 1, the tractor 10 includes a diesel engine 4 inside a bonnet 11, and the rotational power of the engine 4 is appropriately reduced by various transmissions in a transmission case 13 to a rear wheel 14 or front and rear wheels 15. 14
It is configured to travel to the vehicle.

At the rear of the bonnet 11, a meter panel provided with various instruments and a handle post 17 projecting a steering handle 16 are provided. By rotating the handle 16, the front wheel 15 is steered left and right, and the steering amount is adjusted. Is detected by the steering angle sensor 57.

From the side of the handle post 17, an accelerator lever 20, a forward / reverse switching lever 21, and a one-touch lever for lifting and lowering the working machine are provided so as to protrude therefrom, and a friction member is interposed at the rotation base of the accelerator lever 20. It is configured to hold the accelerator setting position of the operator, and provided at the rotation base of the forward / reverse switching lever 21 is a limit switch type reverse operation detection switch 22 which is means for detecting the forward / backward operation of the vehicle. I have. The limit switch 23 is also provided at the rotation base of the one-touch lever for lifting and lowering the work equipment.
By turning on the lever by turning the lever up and down, the rotary working machine 1 described below is continuously raised or lowered between a working position and a raising position set by a raising position setting dial 24 separately provided, or It is configured to descend.

A left and right brake pedal 1 for independently braking the left and right rear wheels 14 is provided below the steering handle 16.
9 and an accelerator pedal. Further, an infrared sensor 25 is provided on the rear surface of the handle post 17 so that the cockpit 2
Irradiation is performed in the direction of No. 6 to detect the presence of a person inside the cabin, that is, an operator. Thereby, the controllers 3a and 3b, which are control units described later,
In this configuration, when the presence of a person in the cabin of the tractor 10 is not detected, traveling and lifting and lowering of the working machine are checked.

A shift lever for switching the shift position of the transmission and a position lever 30 for setting the height of a working machine connected to the rear portion are provided on the side of the cockpit 26 so as to protrude therefrom.
A potentiometer 34 for detecting an operation position is provided at the rotation base of the position lever, and a working depth setting device 31, a PTO on / off switch 32,
Further, an on / off switch 33 for turning control including the work machine raising control of the present invention is provided.

At the rear of the transmission case 13 of the tractor 10, there is provided a cylinder case 36 in which a hydraulic cylinder 35 for elevating and lowering the working machine is provided. It has become. Further, a three-point link mechanism including a top link and left and right lower links is provided at a rear portion of the vehicle body, and the rotary working machine 1 which is a ground working unit is connected to the link mechanism. On one side of the lift arm 37, a lift arm angle sensor 38 is provided at the rotation base, and the controller 3a adjusts the detection angle of the position lever 30 and the set angle of the lift arm 37 in FIG. As shown in (1), the solenoid 40s of the work implement raising proportional pressure control valve 40 or the solenoid 41s of the work implement lowering control valve 41 is energized to move the work implement 1 up and down. Note that reference symbol T in FIG. 2 denotes a hydraulic tank also serving as a transmission case, reference symbol R denotes a pressure reducing valve, and reference symbol P.
Denotes a hydraulic pump driven by the engine 4.

The rotary work machine 1 has a configuration in which a rotary cover 43 is provided above a rotary claw 42 that rotates around the vehicle body horizontal axis, and a rear cover 44 is connected to the rear of the rotary claw 42 so as to be vertically rotatable following the ground surface. I have. The vertical state of the rear cover 44 is determined by the potentiometer type rear cover angle sensor 2b,
That is, it is configured to detect a ground contact state with the field.

Next, the power transmission configuration of the tractor 10 will be described with reference to FIG. The rotational power output from the engine 4 is intermittently connected by the main clutch 45, transmitted to the forward / reverse switching device 46, the main transmission device 47, and the auxiliary transmission device 48, and transmitted via the rear wheel differential mechanism 49 to the rear wheels 14. It is configured to transmit to. The rotational power output from the auxiliary transmission 48 is transmitted to the front wheel drive clutch 51, the front wheel differential mechanism 52, and the front wheels 15 via the front wheel drive shaft 50 in order.

The left and right drive shafts connected to the rear wheel differential mechanism 49 are provided with brake discs 53, respectively, and these brake discs 53 are expanded and contracted by the energizing output of the controller 3b. It is configured to operate and crimp.

In FIG. 1, reference numeral 2a denotes a pickup sensor (hereinafter referred to as an engine rotation sensor) for detecting the output rotation speed of the engine 4, which is configured to indirectly detect the ground operation state of the tractor 10. Reference numeral 56 denotes a vehicle speed sensor. Next, a controller that is a control unit of the tractor 10 will be described with reference to FIG. The controller is provided below the cockpit 26 and includes a working machine elevating controller 3a for controlling the working machine and a traveling controller 3b for controlling the traveling relationship. It has a CPU that processes signals, an EEPROM that stores a control program, a RAM that temporarily stores sensor signals, and the like, and a timer.

The controller 3a for lifting and lowering the working machine is provided with a potentiometer 3 at the base of the position lever at the input section.
4. The limit switch 23 of the one-touch lever for lifting and lowering the working machine, the lift arm angle sensor 38, the raising position setting dial 24, the PTO ON / OFF switch 32, the cultivation depth setting device 31, and the rear cover angle sensor 2b are connected to each other. still,
When a plow working machine is connected to the tractor 10, a strain sensor 2c for detecting a traction load of the working machine 1 is connected to a connection portion of the rear cover angle sensor 2b. The output unit is provided with a solenoid 40s of a proportional pressure control valve for raising the working machine and a solenoid 41s of a proportional pressure control valve for lowering the working machine connected thereto.

The traveling controller 3b includes a steering angle sensor 57, a turning control on / off switch 33, an engine rotation sensor 3a, a vehicle speed sensor 56, and a forward / reverse switching device for detecting turning operation of the vehicle. A reverse operation detection switch 22 for the lever base and an infrared sensor 25 for detecting the presence of an operator are connected and provided.

Further, solenoids 58s, 59s of proportional pressure control valves for sending pressure oil to the brake hydraulic cylinders 54, 54 of the left and right rear wheels 14, 14 are connected to the output portion. Further, both controllers 3a and 3b are configured to transmit and receive both sensor information by communication.

The work implement lifting / lowering controller 3b of the tractor 10 configured as described above performs work implement elevation control as shown in the flowcharts of FIGS. When the engine key switch of the tractor 10 is first turned on, the connection state and setting state of various sensors and switches are read by the controller 3b. First, it is determined whether or not the presence of the operator is detected by the infrared sensor 25. If the determination is NO, the solenoids 40s, 4 of the control valves 40, 41 related to the lifting and lowering of the work implement are determined.
The power supply to 1 s is suppressed or the power supply is stopped.

Next, it is determined whether the turning control ON / OFF switch 33 is ON, and whether the vehicle speed is low enough to be assumed to be the working speed. Further, when the rotary work machine 1 is connected (rear cover angle). In the case where the sensor 2b is connected), it is determined whether or not the PTO on / off switch 32 is "on". When all these are YES, the subroutine of the turning control including the work implement elevating control and the brake control is performed. (FIG. 6). When the subroutine of the turning control is not entered according to the above judgment, these processes are jumped to perform various other controls, and the process returns.

In the turning control, first, the steering angle sensor 57 determines whether or not the vehicle body is at a value that is assumed to be headland turning. If the answer is YES, the timer is operated, and communication with the traveling controller 3a is performed. To perform the solenoid 5 of the predetermined proportional pressure control valve 58 (59).
Power is applied for 8 s (59 s) to apply a brake to the rear wheel 14 on the inside of the turn, and further raise the work implement 1 at a low speed.

During this time, the engine rotation sensor 2a
The engine speed is detected as to whether the engine speed has increased by a predetermined value or more, that is, whether the work implement 1 is in a field scene (ground surface).
It is determined whether or not the engine load has risen upward and the engine load has been reduced. If the result is YES, the amount of electricity supplied to the solenoid 40s of the proportional pressure control valve for raising the working machine is increased, and the rising speed is switched to high speed. The lifting of the working machine is stopped by the set value of the raising position setting dial 24.

Thereafter, the steering angle sensor 57 is again operated.
The brake output is stopped when the vehicle body returns to the straight traveling state after determining the detected value of the above. After the turning operation is completed, it is determined whether there is a switch from the reverse operation to the forward operation within a predetermined time by the timer, and if this is YES, the solenoid 40s (41) of the proportional pressure control valve is determined.
Power is supplied to s) to lower the work implement 1 at a low speed. As a result, during the tilling operation, the work machine 1 is automatically lowered only when the alignment is not successful and the vehicle moves backward or when the operation is shifted to the headland work, so it is necessary to manually lower the work machine 1 many times. Therefore, the leveling work of the tractor 10 can be made more efficient.

In the step (part A in the figure) relating to the work implement elevation control in the above-mentioned flowchart, the work state is detected from the change in the engine speed. 2b. That is, when the state in which the rear cover 44 rises by a predetermined value or more is detected, the ascent speed of the work implement 1 may be changed to a high speed assuming that the rear cover 44 has floated above the ground surface.

When a plow working machine is connected to the tractor 10, the work state is detected by the value of the strain sensor 2c for detecting the traction load, instead of the rear cover angle. That is, when the towing load becomes lighter than a predetermined value,
Assuming that the work machine 1 has floated above the ground surface, the ascent speed of the work machine may be changed to a high speed.

In the tractor 10 configured as described above,
Since the position at which the lifting speed of the working machine is increased is appropriately changed according to the working state, the shock caused by the initial operation of the hydraulic cylinder 35 for lifting and lowering the working machine, the engine load can be reduced, and the predetermined rising position can be quickly reduced. And the vehicle body can run stably.

[Brief description of the drawings]

FIG. 1 is an overall side view of a tractor.

FIG. 2 is a partial hydraulic circuit diagram of the tractor.

FIG. 3 is a transmission mechanism diagram of a tractor.

FIG. 4 is a diagram showing a connection state of a controller.

FIG. 5 is a control flowchart (1).

FIG. 6 is a control flowchart (2).

FIG. 7 is a control flowchart (3).

[Explanation of symbols]

 Reference Signs List 1 rotary work machine 2a engine rotation sensor 2b rear cover angle sensor 2c distortion sensor 3a work machine elevating controller 3b traveling controller 4 engine 10 tractor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B304 KA17 LA02 LA06 LB05 LB15 MA02 MA04 MB03 MC08 PB06 QA02 QA03 QA08 QA22 QB12 QB19 QC02 QC03 QC04 QC06 QC12 QC14 RA02 RA03 RA08

Claims (4)

[Claims] 1. A work vehicle provided with a ground working unit 1 which is vertically movable and a sensor 2 for detecting a working state of the working unit 1, when the working unit 1 is raised from a working position to a non-working position. Meanwhile, when the work unit 1 is detecting a state assumed to be in a ground contact state, the work unit 1 is lifted at a low speed, and then a state in which the work unit 1 is assumed to have risen above the surface of the ground is detected. A working unit elevating control device for a working vehicle, wherein a control unit 3b for increasing the ascending speed is sometimes provided. 2. A sensor for detecting the contact state of the working unit 1 or a state in which the working unit 1 floats above the ground surface is a pickup sensor 2b for detecting a rotation speed of the engine 4.
The work unit lifting / lowering control device for a work vehicle according to claim 1, wherein the ascending speed of the work unit 1 is increased based on the detection value of the sensor 2b. 3. A sensor for detecting the contact state of the working unit 1 or a state of floating above the ground surface is a potentiometer 2a for detecting an operating part that moves up and down following the ground surface, and the detection of the potentiometer 2a. The work machine lifting / lowering control device for a work vehicle according to claim 1, wherein the ascent speed of the work unit 1 is increased based on the value. 4. A sensor for detecting the contact state of the work unit 1 or a state of floating above the ground surface is a strain sensor 2c for detecting a traction load of the work unit 1, and based on a detection value of the sensor 2c. The work unit lifting / lowering control device for a work vehicle according to claim 1, wherein the work unit 1 increases the ascending speed.