JPH05137406A - Work-controlling apparatus for farm tractor - Google Patents

Abstract

PURPOSE:To suppress the slip of the rear wheel by lifting a plow-working apparatus in such a manner as to keep the slip value calculated from the rotational speed difference between the right and left front wheels below a preset level. CONSTITUTION:The rotational speeds of the right and left front wheels 1, 1 are detected by electromagnetic induction sensors 10, 10 and inputted into a controller 9 to calculate the slip value based on the rotational speed difference between the right and left front wheels. A plow-working apparatus 5 is lifted to keep the slip value below a preset level and suppress the generation of slip.

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 Conventionally, draft control has been performed with only a towing load as a measurement target.

[0003]

Since the plow work is to plow plowing by advancing the machine body with a high propulsion force, when slippage occurs at the wheels and the propulsion force is reduced, the work capacity is significantly reduced. , There is a risk of being unable to work,
In general, a driver perceives the occurrence of slip, and prioritizes draft control to forcibly raise and adjust the plow work device to perform continuous work. However, it takes a considerable amount of skill to detect the occurrence of slip and adjust the plow working device upwardly and appropriately, and an inexperienced driver may be unable to work due to a delay in the rising timing, or may climb too much. It tended to be unreasonably shallow tillage. Therefore, it is conceivable to control that the plow work device is automatically forcibly raised by detecting that the slip of the wheel has exceeded the set value, and it has been proposed to use a ground follow-up type idle wheel as the slip detection means. It was The slip detecting means calculates the slip by comparing the rotational speed (circumferential speed) of the idle wheel that follows the ground contact with the rotational speed (circumferential speed) of the rear wheels that are the main propulsion wheels. It is difficult to make the rolling wheel properly follow the ground scene under various conditions and roll it.For example, in a field with severe unevenness or a field with many stumps and weeds, the free rolling wheel properly grounds and rolls. It did not move, and it was difficult to perform the above-mentioned forced rise control under all conditions. Also,
In this forced raising control, the plow working device is raised after a slip more than the set value actually occurs, so the control tends to be delayed, and it is extremely difficult to set the slip value for the forced raising. An object of the present invention is to reasonably set a measurement target of a detection unit that detects a slip state while performing a forced raising control that raises a plow working device in priority to a draft control based on a slip calculation value. The point is to provide a device capable of performing a rapid forced rise control.

[0004]

The characteristic configuration according to the present invention includes front wheel rotation detecting means for detecting the rotation speeds of the left and right front wheels, respectively, and a difference in rotation speed between the left and right front wheels obtained from the detection result of the front wheel rotation detecting means. In order to maintain the slip calculated value based on the above, the value for slip determination is maintained below the set value for slip determination, the draft control means is provided with a forced raising control means for raising the plow working device in an ascending manner. The effects are as follows.

[0005]

[Operation] When the towing load becomes large, the airframe receives a forwardly rising moment with the rear wheel as the center of rotation. Then, the ground contact load on the front wheels tends to decrease, and the slip generation starts. On the other hand, in the plow work, one of the left and right wheels falls on the cultivated land after the plow work, and the other wheel rides on the uncultivated land and travels, so that the machine body is tilted to the left or right. Therefore, the vehicle runs in a state in which the ground load of the wheels on the uncultivated land side is smaller than the ground load of the wheels on the cultivated land side. Therefore, in such a state, when the vehicle body rises slightly forward, the ground load of the wheels on the uncultivated land further decreases, and slip occurs on the front wheels on the uncultivated land side. Therefore, it was found that a slippage occurred due to a rotation speed difference between the left and right front wheels, and the forcible raising control means was activated to raise the plow working device to raise the slip on the rear wheels, which are the main propulsion wheels. Suppress the occurrence.

[0006]

EFFECTS OF THE INVENTION By setting the rotation detecting means on the front wheels, it is possible to catch the occurrence timing of the slip earlier than when it is set on the rear wheels. I was able to work satisfactorily continuously without falling into. Moreover, since a dedicated idle wheel for slip calculation is not required, the structure is simple and convenient for practical use.

[0007]

EXAMPLE As shown in FIG. 4, a plow working device 5 is attached to a rear end of a machine body 3 having a front wheel 1 and a rear wheel 2 through an elevating link 4, and a four-wheel drive type agricultural tractor is used. 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 towing set value output from the towing setter 8 and the feed back value from the lift arm sensor 13 are input to the control device 9, and the detection value from the sensor 7 converges to the towing set value. The plow working device 5 is moved up and down so as to do so. 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 FIG. 1 and FIG. 4, electromagnetic induction type sensors 10 and 10 for detecting the respective rotational speeds of the left and right front wheels 1 and 1 are provided, and the detection values from both sensors 10 and 10 are controlled by a controller 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 depending on the state of the tow load (step 1). Then, the rotation difference ratio is sequentially calculated, and if a slip occurs, the plow work device 5 is raised to suppress the occurrence of the slip (step 2).

As a plow work mode, one wheel is grounded on the side of the cultivated land and the work travels 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, the cutting position A, the rolling control position B,
A work changeover switch 12 having a plurality of work operation positions of an automatic tilling depth control position C and a draft control position D is provided, and this work changeover switch 12 is provided with an update operation position E for setting and updating a set value for slip determination. .. 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. Then, as shown in the control flow of FIG. 3, if the operator pushes the update operation position E during the work in which the operator thinks that an appropriate rotation difference ratio is obtained, the set value for slip determination can be automatically updated.

[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.

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 configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 Overall control 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] Overall side view

[Explanation of symbols]

 1 Front wheel 3 Airframe 4 Lifting link 5 Plow work device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigekazu Hasegawa 64 Ishizukita-cho, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd.

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. The device is provided with front wheel rotation detection means for detecting the rotation speeds of the left and right front wheels (1), (1), respectively, and is based on the rotation speed difference between the left and right front wheels obtained from the detection result of the front wheel rotation detection means. A work control device for an agricultural tractor, which is provided with a forced raising control means for raising the plow working device (5) in preference to the draft control means so that the slip calculation value is maintained below the set value for slip determination. .