JPS5826281B2 - heron - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a working vehicle in which various ground working devices are detachably connected to the machine body, and the attached ground working device is raised and lowered by a lift 1 drive mechanism.

In this type of work vehicle, it is desired that the relative heights of the various attached ground work devices to the ground be maintained constant and work with a stable ground action depth is possible.

However, in fields where work vehicles work, there may be soft ground in some areas, which may cause changes in the amount of subsidence of the machine itself into the mud, resulting in a large displacement of the ground action depth of the ground work equipment. In addition, there is a risk that an excessive load will be applied to the engine, causing the engine to stop.

For this reason, in the past, ground work equipment had to be raised and lowered manually, but proper adjustment required considerable skill and was troublesome. It was quite difficult to maintain a stable ground action depth.

The present invention has been made with the above problems in mind, and
In the above-mentioned work vehicle, an engine load detection device that detects the amount of variation in the load on the engine, a position deviation detection device that detects the amount of variation in the vertical position relative to the machine body of the attached ground work device with respect to an artificially selected setting value, and A propulsion soil resistance deviation detection device is provided to detect the amount of variation in the propulsion soil resistance applied to the attached ground work device with respect to a set value as the aircraft advances, and the engine load detection device and the position deviation detection device are both connected to the attached ground work device. A control state in which the lifting drive mechanism of the device is connected as an input to a mechanism for lifting and lowering, and the ground working device is automatically controlled to lift so that the sum of the detection results by the rain detection device becomes a constant value, and the position deviation A control state in which only the detection device is input connected to the lifting operation mechanism for the lifting drive mechanism to automatically raise and lower the attached ground work device to a set height position, and a control state in which only the propulsion soil resistance deviation detection device is connected to the lifting operation mechanism for the lifting drive mechanism. A switching mechanism can be provided to selectively switch the attached ground working device to one of the control states for changing its height position in accordance with fluctuations in propulsion soil resistance. characterized by something.

In other words, when a device driven by the power of the engine of the aircraft, such as a rotary tiller, is attached as the ground work device, the switching mechanism connects the engine load detection device and the position deviation detection of the ground work device. By switching to a control state based on the detection results of the device, the required height position of the ground work equipment can be maintained approximately constant in relation to engine load fluctuations and the work equipment position. If a traction work device such as a soil cultivator or plow that does not require power is attached, the control state can be switched to a state based on the detection results of only the propulsion soil resistance deviation detection device.
As a result, the required height position of the ground working equipment can be maintained approximately constant while changing the height position of the ground working equipment in relation to the fluctuation of propulsion soil resistance and the working equipment position. Even if a ground work device is attached, the required height position (ground action depth) of various types of ground work devices can be maintained approximately constant by switching the switching mechanism accordingly, which prevents the aircraft from sinking, etc. Despite this, we were able to perform good work that automatically maintained a stable ground action depth.

In addition, by switching the switching mechanism to switch to a control state based on the detection results of only the position deviation detection device, the ground work device will be automatically set to the required height position (ground action depth) set manually. As a result, the required height position can be set accurately and quickly at the start of work, and work efficiency can be improved.

In particular, the above-mentioned control states can be expressed very easily by the switching mechanism provided to switch and connect each detection device and the lifting operation mechanism, and can be made to appear in accordance with various work devices and work conditions. Control can be performed efficiently.

Embodiments of the present invention will be described in detail below based on the drawings.

The figure shows the rear of a tractor 8, which consists of front wheels 1, 1, rear wheels 2, 2, engine 3, bonnet 4, instrument panel 5, steering bundle 6, driver's seat 7, etc., which are vertically raised and lowered by hydraulic drive. A pair of lift arms 9.9 and top link 1
0 and a pair of left and right lower links 11.
A working vehicle 15 is shown in which a tilling rotary device 14 and various ground work devices such as a soil cultivator are removably connected to each other. is being transmitted to.

Furthermore, this work vehicle is equipped with a control device that produces the control states described below.

To explain this control device with reference to FIG. 2, 17
is a rotation speed detector that detects the rotation speed of the engine 3 as a pulse signal, and uses an hour meter cable led to the vicinity of the instrument panel 5, and a toothed disk fixed to the hour meter drive shaft. , a light emitting diode and a phototransistor supported on a fixed side.

Reference numeral 18 denotes an F-V converter, which converts the pulse signal from the rotation speed detector 17 into a voltage signal according to its frequency.

19 is a rotation speed indicator. Reference numeral 20 denotes a speed setting device, which is constituted by a potentiometer linked to an accelerator lever 21 shown in FIG.

Reference numeral 22 designates a phase corrector, and when a speed setting device 20 such as a volume is attached to the accelerator lever 21, the displacement of the setting device 20 may not start from the zero point depending on the installation condition. It is configured to draw a potential starting from zero.

Reference numeral 23 denotes a graph corrector, which corrects the non-linear relationship between the movement of the accelerator lever 21 and the engine rotational speed by converting it into a linearity that is easy to handle.

A first subtractor 24 receives the rotational speed detection signal E from the rotational speed detector 17 as a negative input and receives the speed setting signal A from the speed setting device 20 as a positive input, and calculates a decrease in the engine rotational speed.

Reference numeral 25 denotes a setting device for the ground working depth of the ground working device, which is constituted by a volume that is linked to the band lever 26 shown in Fig. 1. If the plowing depth is set to dog, the output will be small, and the second traveling work It acts as a sensitivity setting device during draft control.

Reference numeral 27 is a lifting circuit during turning, and when traveling around the edge of a bank, etc., by switching a snap switch 28, the plowing depth setting device 25 is activated.
is configured to apply the same voltage as the maximum voltage of .

29 is an adder which adds the load fluctuation signal A-E from the first subtractor 24 and the plowing depth setting signal H from the plowing depth setting device 25 during the row draft control of the first traveling work control. This is to prevent the ground work equipment from lowering below the set position even if the load fluctuates.

Reference numeral 30 denotes a lift arm detector composed of a volume linked to the lift arm 10, and the output is set to decrease as the lift arm 10 descends.

31 is a position corrector for correcting the zero point of the lift arm detector 30.

32 is a load detector that detects the load acting on the top link 10 in the compressive direction during plow work when a soil cultivator or the like is connected as a ground work device, and is configured so that the output voltage is maximum at zero displacement. There is.

33 is a second subtracter, which receives the setting signal H from the setting device 25 as a positive input during position control and takes the lift arm detection signal from the lift arm detector 30 as a negative input, as will be described later.
The addition signal (A-E') from the adder 29 during traveling work control
) +H is a positive input, the lift arm detection signal is a negative input, and during the second traveling work control, the setting signal H is a positive input, the load signal from the load detector 32 is a negative input, and both signals are subtracted. .

34 is a first comparator, and if the subtraction signal from the second subtracter 333 is positive, the dead zone setting value α of the first dead zone setting device 35 is set.
, the ascending solenoid valve 37 is opened via the first amplifier 36, and 38 is a second comparator, and the first comparator 3
4, if the subtraction signal is negative, it is determined to be the dead zone setting value α of the first dead zone setting device 39, and the second amplifier 4''0
The lowering solenoid valve 41 is opened via the
3. This constitutes a mechanism for raising and lowering the 3.

The first and second dead zone setters 35, 39 each have a solenoid valve 37,
The setting value α is set within a range in which each electromagnetic valve 37, 41 does not overrun.

Reference numeral 42 denotes a descending prohibition circuit which issues a descending prohibition signal to the second amplifier 40 when the engine speed drops below the self-recovery capability during the first traveling operation control, and the deviation value of the engine speed at that time is equal to the first rotational speed. It is set by the deviation setter 43.

The rotation speed at which the engine 4 itself has a self-recovery ability that is equal to or higher than the lowering prohibition rotation speed deviation value set in the first rotation speed deviation setting device 43 is defined as the non-control rotation speed, and the non-control rotation speed is set in advance by the speed setting. It is set by the device 20.

Reference numeral 44 is a forced increase circuit that issues a forced increase signal when the engine speed suddenly decreases.The rotation speed at that time is set to a speed that does not cause the engine 4 to stop, and the deviation value of this forced increase speed is It is set by the second rotation speed deviation setter 45.

Reference numeral 46 denotes a first input signal generator, which intermittently drives the first amplifier 36 using the forced rise signal.

47 is a ground level setting device, and 48 is a third comparator, which compares the lift arm detection signal from the lift arm detector 30 with the ground level setting signal G from the ground level setting device 47, and sets the lift arm 10. When the robot descends to a certain height, the second input signal generator 49 is activated.

The second input signal generator 49 drives the second amplifier 40 intermittently.

50 is a positive potential adding circuit which applies a positive potential to the plowing depth setter 25 to create a negative state in order to perform subtraction using a single power supply.

Reference numerals 51, 52, 53, 54 and 55 are rotary changeover switches which are linked to one knob and act as a changeover mechanism to change over each control mechanism as described later.

56 is a manual changeover switch for manual lifting, 57 is a limit switch that detects the upper limit of the lift arm 10, 58 is a limit switch that detects the lower limit of the lift arm 10,
These limit switches 57 and 58 are connected to the lift arm 10.
Detecting this, the electromagnetic valve 3γ, 41 opens and closes the power supply, and functions as a safety switch.

59 is a ground action depth indicator.

Therefore, after setting the rotary switches 51 to 55 to the manual terminals, by switching the manual changeover switch 56 to the up or down side, the up/down solenoid valve 37 or the down solenoid valve 38 can be manually operated to control the lifting drive mechanism 13. activate it,
The ground working device 14 is configured to be manually controlled to move it up and down to a required position.

Note that this manual control mechanism is mainly used in emergencies.

Furthermore, by setting the rotary switches 51 to 55 to the P terminal, a control state is established in which the ground work device 14 is automatically raised or lowered to an arbitrary set height position manually selected by the band lever 26 based on position deviation fluctuations. It is configured to perform position control for appearance.

That is, when the operator operates the band lever 26 to the required position, a predetermined depth is set with the ground action depth setting value 25, and the signal H and the lift arm detection signal from the lift arm detector 30 are The second subtractor 33 performs subtraction to constitute a positional deviation detection device for determining the positional deviation of the working device 14 .

Then, depending on the sign of the subtraction value, the lift arms 10, 1
If the operating direction of 0 is determined and positive, the first comparator 3
4 compares the dead band setting value set in the first dead band setting device 35 with the subtraction value, and if it is negative, the second comparator 38 compares the setting value set in the second dead band setting device 39 with the subtraction value. The ground working device is raised or lowered by operating the drive raising and lowering mechanism 13 by the raising and lowering operation mechanism until the difference becomes zero.

Incidentally, when descending during this operation, the third comparator 4
8 compares the lift arm detection signal from the lift arm detector 30 and the ground level setting signal G,
When the detection signal G reaches the setting signal G, the second intermittent signal generator 49 is activated to generate an intermittent pulse signal to drive the second amplifier 40 intermittently, and the ground work equipment is gradually lowered. It will be done.

Also, during this position control, the snap switch 28
If you switch to the traveling lifting circuit 27 side, the band lever 2
The same voltage as when 6 is set to the up position is applied to the second subtractor 33.
The snap switch 28 is configured to be energized to raise the ground working device, and the snap switch 28 is operated at the same time as the end of the -stroke.

Moreover, by setting the rotary switches 51 to 55 to the RD terminal, when the tilling rotary device 14 or the like is connected as a ground work device as shown in the example diagram, the engine can be turned off while the device 14 is being driven by the output of the engine 3. The rotary device 14 is configured to perform first traveling work control in which traveling ground work is performed while maintaining the rotary device 14 in a controlled state of raising and lowering the rotary device 14 so that the sum of the load fluctuation amount and the positional deviation amount of the device 14 becomes a constant value. ing.

That is, when the nozzle drive lever 26 is operated to a predetermined position, the depth of action is set by the ground action depth setting device 25.
The signal H is inputted to the second subtracter 33 via the adder 29, and as a result, the height position of the rotary device 14 is adjusted as in the position control mechanism based on the detection result of the position deviation detection device described above. controlled.

Further, during traveling work in this state, the rotation speed detector 17 detects the rotation speed of the engine 3 as a pulse signal,
After the detection signal is converted into a voltage signal by the F-V exchanger 18, it is input as a negative value to the first subtractor 24 as the rotation speed detection signal E, and the speed is set at the start by operating the accelerator lever 21. The speed setting signal A set in the subtractor 20 is also input as a positive value to the first subtractor 24, and the difference between both signals A and E is the decrease in the rotational speed of the engine 3 (that is, the amount of change in plowing depth). constitutes an engine load detection device that calculates the

If the engine speed decrease calculated from this engine load detection device is within the uncontrolled speed (within the so-called self-recovery capability range) due to the tractor 28 settling in a minute range, etc., the engine speed remains uncontrolled. The work is continued, and then the engine speed returns to the required speed due to the ability of the engine 3 to recover by itself, and the engine speed becomes uncontrolled due to the tractor 8 sinking significantly on soft ground, etc. If the rotation speed falls below the number and above the forced increase rotation speed, the subtraction signal A-E is sent to the adder 29.
is added to the ground action depth signal H, and the added signal (A
-E')+H and the lift arm detection signal ri are subtracted by the second subtractor 33, and based on the subtracted signal, the rotary device 14 is raised in the same manner as in the position control described above.

At this time, if the engine speed is higher than the lowering prohibited rotational speed set between the non-controlled rotational speed and the forced increase rotational speed, the above operation will be performed, but if the engine speed is lower than the lowering prohibited rotational speed. , the subtraction signal A-E is input to the lowering prohibition circuit 42, and even if the engine speed temporarily recovers, the operation of the lowering solenoid valve 41 is gradually blocked, and the engine 3's engine speed is stopped. Prevents henching, etc.

Furthermore, when the engine speed drops below the rising speed (that is, when the rotary device 14 goes deep into the mud), the subtraction signals A-E are input to the forced rise circuit 44, and the first intermittent By the intermittent signal of the signal generator 46,
Lifting solenoid valve 3 via the first amplifier 36 in the lifting operation mechanism
7 is forcibly and intermittently operated to forcibly lift the rotary device 14 to a desired position, thereby reducing the load on the engine 3.

Furthermore, by connecting the rotary switches 51 to 55 to the D terminal, when a soil cultivator or the like is connected as a ground work device, the propulsion soil resistance (traction resistance) that increases in the direction of the cultivator as the tractor 8 moves forward can be adjusted. In accordance with the change, a second traveling work control is performed in which a control state in which traveling and ground work is performed while changing the height position of the ground work device is performed.

That is, in this case, the ground action setting device 25 is
It will be used as a sensitivity setting device, and this sensitivity setting device 25 and a load detector 32 received from the ground work device are connected to a second subtractor 33 to constitute a propulsion soil resistance deviation detection device.

Then, when the band lever 26 is operated to a predetermined position and a predetermined traction force is set, the subtraction signal HD of the second subtractor 33 is
is input to the lifting/lowering operation mechanism, whereby the ground work device is lowered to a predetermined position where it receives a predetermined traction resistance (propulsion soil resistance).

When the traction resistance increases for some reason and a load in the compression direction acts on the top link 10, the load detection signal of the load detector 32 decreases accordingly, and the second
If the subtraction signal H-D of the subtractor 33 becomes positive and is smaller than the dead zone setting value α of the first dead zone setting device 35, the rising solenoid valve 37 is output via the first comparator 34 and the first amplifier 36
is activated and the working device is raised.

Furthermore, when the traction load decreases due to changes in field conditions, etc., the working device descends until the set traction force is reached due to the opposite effect to that described above.

[Brief explanation of drawings]

The drawings show an embodiment of a working vehicle according to the present invention, with FIG. 1 being an overall side view and FIG. 2 being a block diagram of a control device. 3... Engine, 8... Aircraft, 13.
...Elevating drive mechanism, 14...Ground work device, 51, 52°53, 54, 55...Switching mechanism.

Claims (1)

[Claims] 1 Various ground work devices 14 are removably connected to the fuselage 8, and the attached ground work devices 14 are connected to the lifting drive mechanism 1.
In the work vehicle 15 configured to move up and down at step 3, the engine load detection device detects the amount of variation in the load on the engine 3, and the variation in the vertical position relative to the machine body of the attached ground work device 14 relative to the artificially selected set value and a propulsion soil resistance deviation detection device that detects the amount of variation with respect to the set value of the propulsion soil resistance of the attached ground work device 14 as the aircraft 8 advances,
Both the engine load detection device and the position deviation detection device are connected as inputs to a mechanism for lifting and lowering the lifting drive mechanism 13 of the attached ground work device 14, so that the sum of the detection results by the rain detection device is constant. A control state in which the ground work device 14 is automatically controlled to raise and lower the ground work device 14 so that the attached ground work device 14
... to a set height position, and by inputting and connecting only the propulsion soil resistance deviation detection device to the lifting operation mechanism, the attached ground work device 14... A working vehicle is provided with a switching mechanism 51, 52, 53, 54, 55 for selectively switching to one of the control states for changing the height position of the work vehicle.