JPH05137405A - Work-controlling apparatus for farm tractor - Google Patents

Abstract

PURPOSE:To activate a draft control while preventing the trouble to unable the traveling during farm working and to improve the turning performance in non-working state by diff-locking the rear wheel in plowing and releasing the diff-locked state in non-working state. CONSTITUTION:A diff-locking apparatus 14 is placed in a differential case 13 of the rear wheels 2, 2. The diff-locking apparatus is engaged in the plowing work to keep the rear wheels in diff-locked state and the diff-locking is released in the non-working state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mounts a plow working device on the rear side of a machine body through an elevating link and provides a traction load sensing means for detecting a work load acting on the plow working device as a traction load acting on the machine body. A work control device for an agricultural tractor including draft control means for raising and lowering the plow work device so that the towing load converges to a set value for towing based on a detection result of the towing load sensing means. ..

[0002]

2. Description of the Related Art In plow work, one of the right and left wheels (both front and rear wheels) is run in a laterally inclined posture with the wheels sunk into the cultivated land, so the ground pressure of the wheels on the cultivated land has dropped into the cultivated land. It is less than the ground contact pressure of the wheels, and the wheels are forced to run in a state where slippage is likely to occur on the cultivated land side wheels. When a large slip occurs on the uncultivated land side wheels, the power is not transmitted to the already cultivated land side wheels that are interlocked with each other via the differential device, and the vehicle cannot run. Therefore, in the past, when the driver felt that the vehicle was slipping, the diff device on the rear wheels, which were the main propulsion wheels, was diff-locked, and the plow work device was raised to lighten the load when necessary. I was doing an operation to avoid falling into the impossible.

[0003]

However, it is troublesome to perform the diff lock operation each time when it is detected that the vehicle is about to slip, and it is necessary to experience the fact that the vehicle is about to slip. For a shallow driver, the diff-lock operation is often delayed, and once a large slip occurs, the diff-lock operation is likely to make the vehicle unable to run unless the traction load is significantly reduced. Further, even if the diff lock is kept on during the running, it is generally impossible to get on the diff lock pedal and continue to step on the diff lock pedal in the actual situation where the diff lock operation is the depression of the pedal. Therefore, it has been difficult to stably perform the plow operation even in the draft control in a field where slips are likely to occur, such as in a field where the hardness and softness change is large or where the surface is rough.

An object of the present invention is to improve the operability during plow work and, at the same time, to avoid the slippage of the machine body to prevent the machine from slipping, and to effectively utilize draft control for stable plow work. Is to be able to do efficiently.

[0005]

The characteristic construction according to the present invention is provided with automatic diff lock switching means for switching the rear wheel to the diff lock state during plow work and to the diff lock release state during non-work. The effect is as follows.

[0006]

During operation, the rear wheels, which are the main propulsion wheels, are automatically diff-locked to secure their propulsion force, the slip condition is prevented, and the draft control means is operated effectively, The work can be continuously performed, and the diff lock can be automatically released during the non-work to prepare for the turning motion of the machine body.

[0007]

EFFECT OF THE INVENTION Since the diff lock can be automatically changed over, there is no need to perform the changeover operation for the diff lock during the plow work. By constantly driving the rear wheel, which becomes higher, with this diff lock, it is possible to avoid the situation in which the vehicle cannot run even when the wheels on the cultivated land are slipping, and it is possible to use continuous drafting control with continuous tillage. Now you can do it.

[0008]

EXAMPLE As shown in FIG. 5, a plow working device 5 is attached to a rear end of a machine body 3 having front wheels 1 and rear wheels 2 via a lifting link 4 to utilize a four-wheel drive agricultural tractor. Configure the working machine. The draft control means will be described.
In order to perform this control, it is necessary to detect the traction load acting on the plow work device 5. First, the elevating link 4 is provided with a pair of left and right lower links 4A, 4A and lift arms 4B, 4
As shown in FIG. 1, the rear end of the fuselage 3 supports laterally-supporting support shafts 6 at both ends, and the base ends of the lower links 4A and 4A are respectively rocked at both ends of the support shafts 6. It is attached so that it can move freely. The support shaft 6 receives the pulling load of the plow work device 5 and causes a bending so that the middle portion thereof projects toward the front. A differential transformer type sensor 7 is provided toward the middle portion where the bending occurs, and the pulling load is indirectly detected from the bending amount of the support shaft 6. Here, the sensor 7, the support shaft 6 and the like are referred to as traction load sensing means. The detection value from this sensor 7,
The set value for pulling output from the setter 8 for pulling and the feedback value from the lift arm sensor 13 are input to the control device 9, and the detected value from the sensor 7 converges on the set value for pulling. Thus, the plow working device 5 is moved up and down. That is, when the detected value is larger than the set value, the plow working device 5 is raised, and when the detected value is smaller than the set value, the plow working device 5 is lowered. Here, the towing load sensing means, the towing setter 8 and the like are referred to as draft control means.

Next, the forced raising control means for raising the plow working device 5 in preference to the draft control means will be described. This forcible raising control eliminates an unsuitable state of the towing operation due to wheel slip. As shown in FIGS. 1 and 2, electromagnetic induction sensors 10 and 10 for detecting the respective rotation speeds of the left and right front wheels 1 and 1 are provided, and the detection values from both sensors 10 and 10 are used as a control device 9. To determine the slip state. That is, as a slip calculation value based on the rotational speed difference between the left and right front wheels 1 and 1, the rotational speed difference ratio = the difference between the lateral rotational speeds / the sum of the lateral rotational speeds is obtained. The working height of the plow working device 5 is maintained so that the rotation difference ratio does not exceed the set value for slip determination output from the slip determination setting device 11. When the rotation difference ratio exceeds the set value, the plow work device 5 is raised to suppress the slip state.

The control flow of the draft control and the forced raising control will be described above. As shown in FIG. 2, the draft control is started and the plow working device 5 is moved up and down according to the state of the tow load (step 1). Then, the rotation difference ratio is sequentially calculated, and if a slip occurs, the plow working device 5 is raised to suppress the occurrence of the slip (step 2).

Although the draft control and the forced raising control have been described above, the diff lock automatic switching means for locking the diff of the rear wheel 2 during the plow work to prevent slip will be described next. As shown in FIG. 1, a differential lock device 14 is provided in a differential case 13 of the rear wheels 2 and 2, and a cylinder 1 for turning on / off the differential lock device 14 is provided.
5 is provided. The cylinder 15 may be either electric or hydraulic. On the other hand, a lift arm sensor 16 for detecting the rotation amount of the lift arm 4B is provided at the pivotal support portion of the lift arm 4B, and if the lift arm sensor 16 detects the upward movement of the lift arm 4B beyond the set amount, the ridge It is determined that the vehicle is turning around or traveling on the road. That is, when not working. If the lift arm sensor 16 is detecting the state of the lift arm 4B that does not exceed the set amount, it is determined that work is in progress.

Therefore, when working, the cylinder 1
In step 5, the diff lock device 14 is switched to the diff lock state, and when the non-work is in progress, the diff lock state is released. The slip state of the wheels can be avoided during work, the draft control can be more effectively performed, and the diff function can be sufficiently exerted when traveling on the road during non-work. Here, the cylinder 15, the lift arm sensor 16 and the like are referred to as a differential lock automatic switching means. The above control will be described with reference to the control flow shown in FIG.
It is judged whether or not the work is in progress based on the detection of, and if the non-work is in progress, the differential lock is released. If work is in progress, the steering wheel turning angle is determined, and if it is determined that the vehicle is not in a turning state, it is switched to the diff lock state and draft / forced rise control is performed.

Next, as a plow work mode, one wheel is grounded on the side of the cultivated land and the work is run in a state of being inclined to the side of the cultivated land. Therefore, since the lateral inclination of the airframe differs depending on the difference in the working depth, the rotation difference rate also differs depending on the working depth. Therefore, how to set the set value for slip determination becomes a problem, but here, it is determined as follows. As shown in FIG. 1, a work changeover switch 12 having a plurality of work operation positions of a cutting position A, a rolling control position B, an automatic plowing depth control position C, and a draft control position D is provided. An update operation position E for setting and updating the set value for slip determination is provided. When this update operation position E is selected, the control mode is set in which the set value for slip determination can be changed while maintaining the draft control state. The update operation position E is a push button switch, and when the operator presses this switch, the rotation speed is fetched from the front wheels 1, 1 to calculate the rotation difference rate, and this calculated value is set as a new slip determination setting. The value. And
As shown in the control flow of FIG. 3, if the operator operates the update operation position E during the work in which the operator thinks that an appropriate rotation difference ratio can be obtained, the slip determination set value can be automatically updated. Here, the push button switch provided at the update operation position E is referred to as an artificial operation means, and the push button switch, the electromagnetic induction type sensor 10, the control device 9, etc. are referred to as a set value changing means for slip determination.

[Other Embodiments] As a sensor of the traction load sensing means, a sensor using a strain gauge or a sensor using a piezoelectric element or the like may be used in addition to the differential transformer 7. As the front wheel rotation detecting means 10, a potentiometer other than the electromagnetic induction type may be used. As a method of calculating the slip calculation value, the rotation speed difference between the left and right front wheels 1, 1 may be used, or another method may be used as long as it is based on the rotation speed difference. As the automatic diff lock switching means, a mechanical link mechanism that links the diff lock device 14 and the lift arm 4B using a wire or an arm may be used. The differential lock automatic switching means may be a mechanical linkage mechanism that links the differential lock device 14 and the side clutch operating tool.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 Overall configuration diagram

FIG. 2 is a flow chart of draft control and forced rising control.

FIG. 3 is a flow chart of an update operation for forced rise control.

[Figure 4] Flow chart of overall control

[Figure 5] Overall side view

[Explanation of symbols] 2 Rear wheel 3 Airframe 4 Lifting link 5 Plow work device

Claims (1)

[Claims] 1. A plow working device (5) is attached to the rear of the machine body through an elevating link (4), and a work load acting on the plow working device (5) is sensed as a towing load acting on the machine body (3). Tow traction load sensing means,
Based on the detection result of the traction load sensing means, work control of an agricultural tractor including draft control means for raising and lowering the plow work device (5) so that the traction load converges to a set value for traction. A work control device for an agricultural tractor, which is provided with automatic diff lock switching means for switching the rear wheel (2) to a diff lock state during plow work and to a diff lock release state during non-work.