JPH0559746A - Controller for tractor-drawn scraper - Google Patents

Abstract

PURPOSE:To raise the efficiency of excavating operation by a method in which speed sensors are provided for a tractor and a scraper wheel, a slip amount is calculated from the turning speeds of both the tractor and the scraper wheel, and the height of a ball is automatically adjusted to control the amount of excavation without slip. CONSTITUTION:When a tractor is traveled to drag a scraper, measurement is made for every given periods by sensors 8-12 and measured signals (V)EL, (V)ER, (V)SL, and (V)SR and BH from the sensors 8-12 are put in a controller 13. The measured signals BH are compared with an allowable range to confirm that the height of a ball is within allowable range. If it is out of the allowable range, the height of the ball is moved to a preset one, and the difference between the turning speed of the tractor and the turning speed of the wheel of scraper is calculated in the controller 13. When the difference E is in positive value, a judgement that the traveling system of the tractor is slipped is made and a command is given to correct the position of the ball to given height for a ball drive mechanism 14. The height of the ball is adjusted by the drive mechanism 14, and the load from the ground's surface to the ball can be reduced to eliminate slipping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a towed scraper that cuts the ground surface, and more particularly, to improve the excavation loading efficiency by automatically controlling the towing performance of a tow tractor to pull the scraper to an optimum state. To a towed scraper control device.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional towed scraper has a bowl 3 provided between a front wheel 1 and a rear wheel 2.
The bowl 3 is supported with one end of the chassis on the rear wheel 2 side as a fulcrum, and the front part moves up and down in accordance with the stroke of the hydraulic cylinder 4 provided on the front wheel 1 side, and the bowl front part can be opened and closed. An apron 5 is provided. And
A towing tractor 7 is provided via a coupling device 6 provided on the front wheel 1 side
Towed by. There are two types of running systems for tractor tractors, a sash type with shoes attached and a wheel type with tires attached.

The operation for cutting the ground surface is first shown in FIG.
As shown in FIG. 2, the bowl 3 is opened by opening the apron 5 and extending the stroke of the hydraulic cylinder 4.
Cutting edge 1
It is carried out by letting 7 dig into the ground and pulling with the towing tractor 7 in this state. That is, when this work is performed, the soil on the ground surface is scraped by the cutting edge 17 and the bowl 3
Enter inside.

[0004]

However, in such a conventional scraper, because the soil condition is not uniform, when the load received by the scraper from the soil on the ground surface increases, the traction force of the tractor is reduced. The reaction force from the scraper exceeds the limit of the ground friction of the traveling system of the traction tractor, which causes slipping, resulting in a reduction in work efficiency and a reduction in the life of the suspension mechanism.

Conventionally, in order to deal with such a problem,
The tractor tractor is equipped with an operating lever that controls the stroke of the hydraulic cylinder, so that the driver can operate the tractor tractor while operating the bowl forward tilt angle appropriately so that slip does not occur, that is, when slipping is likely to occur. Raise the bowl to reduce the load to prevent slipping, and if the towing speed is fast, lower the bowl when working.
The operability was extremely poor.

Further, the maximum traction performance is exhibited immediately before the slip occurs, but it requires extremely high skill to operate so as to obtain the maximum traction performance without causing slip. There was also a problem that only limited experts could work. The present invention has been made in view of such conventional problems, and provides a control device for a towed scraper that improves operability and traction performance, and further improves excavation loading efficiency. With the goal.

[0007]

In order to achieve such an object, the present invention measures the rotational speed of the traveling system of the towed tractor and the rotational speed of the traveling wheels of the scraper one by one, and rotates the tractor traveling system. If the speed is higher than the rotation speed of the scraper traveling wheels, it is determined that the drive wheels are slipping, and the amount of bite into the ground of the bowl is temporarily reduced to determine the rotation speed of the tractor traveling system and the rotation speed of the scraper traveling wheels. When is almost equal, the amount of bite into the ground of the bowl is automatically controlled so as to maintain the amount of bite set in advance.

[0008]

With the control device for a towed scraper of the present invention having such a structure, it is possible to automatically prevent slippage of the traveling system of the tow tractor and obtain the maximum tow performance. Further, since it is not necessary for the driver to operate the scraper so as not to slip, the operability of the tow tractor can be improved.

[0009]

FIG. 1 is an explanatory view showing an embodiment of the present invention. The basic structure of the scraper is the same as in FIG. In FIG. 1, reference numeral 8 denotes a vehicle speed sensor that measures the rotation speed of the right front wheel of the scraper and outputs a measurement signal (V) ER, which is provided on the support shaft or the like of the right front wheel. Reference numeral 9 denotes a vehicle speed sensor that measures the rotation speed of the left front wheel of the scraper and outputs a measurement signal (V) EL, and is provided on the support shaft of the left front wheel.

Reference numeral 10 is a stroke sensor for measuring the stroke of a hydraulic cylinder for raising and lowering the bowl and outputting a measurement signal BH. A potentiometer or the like is applied to the stroke sensor 10. Reference numerals 11 and 12 denote speed sensors. The speed sensor 11 measures the rotation speed on the right side of the traveling system of the towing tractor and outputs a measurement signal (V) SR. The speed sensor 12 also measures the rotation speed on the left side of the tractor traveling system. Is measured and a measurement signal (V) SL is output. Reference numeral 13 is a control unit provided in the driver's seat of the tow tractor or in the cockpit, and the measurement signal (V) transmitted from each sensor 8-12.
Receives ER, (V) EL, BH ,, (V) SR, (V) SL,
The optimum height of the bowl is calculated from these measurement signals.
The control unit 13 has a built-in microcomputer system and the like for performing arithmetic processing.

Reference numeral 14 is a drive mechanism for driving the left and right hydraulic cylinders for controlling the height of the bowl, and controls the stroke of the hydraulic cylinders according to the calculation result calculated by the control unit 13. Reference numeral 15 is a drive mechanism provided on the front surface of the bowl for opening and closing an apron. Reference numeral 16 denotes an operation unit provided in the driver's seat of the tow tractor or in the cockpit, and the control unit 13
Is provided with an operation switch for instructing to start the control operation, a display device for displaying the operation of the control unit 13, and the like.

Further, the processing function of the control unit 13 will be explained. An average value {(V) ER + (V) of the signals (V) ER and (V) EL transmitted from the vehicle speed sensors 8 and 9 of the scraper. By calculating EL} / 2, this is taken as the average rotation speed (V) EA of the front wheels, and similarly from the signals (V) SR and (V) SL transmitted from the vehicle speed sensors 11 and 12 of the towing tractor. The average vehicle speed of the tractor is calculated as (V) SA, and the average rotation speed (V) EA is subtracted from the average vehicle speed (V) SA to calculate the difference signal ΔE. The magnitude relationship of the average rotation speeds of the wheels is determined.

When the difference signal ΔE is ΔE = (V) SA- (V) EA> 0, it is judged that the traveling system of the tow tractor is slipping, and the bowl drive mechanism 14 is operated to move the bowl. The hydraulic cylinder is driven so as to be raised by a predetermined height, for example, an amount set by the operation unit 16. That is, the stroke is shortened.

On the contrary, when the difference signal ΔE is ΔE = (V) SA− (V) EA ≦ 0, the bowl is lowered by a predetermined height with respect to the bowl drive mechanism 14 (preliminarily set by the operation section 16). Drive the hydraulic cylinder so that When the operation switch of the operation unit 16 is instructed to start the work, the hydraulic cylinder of the apron drive mechanism 15 is operated to open the apron.

Further, since the elevation range of the bowl is determined by the topography, soil quality, etc., it is judged by the measurement signal BH from the sensor 10 whether or not the height of the bowl is adjusted within this range, and this range is determined. The bowl drive mechanism 14 is caused to control the hydraulic cylinder so that the bowl does not move to the outside. That is, as shown in FIG. 3, the height of the bowl 3 when the cutting edge 17 is in contact with the ground surface is defined as the reference height BHo, and the height of the bowl 3 when the bowl 3 is tilted forward to the maximum height. BHm, and the difference between these heights is the maximum span BS.

When the terrain is downhill within the range of the maximum span BS, a load is constantly applied so that the scraper does not overtake the tow tractor, so that the bowl height is prevented from rising above BH1. When the soil quality is light, the bowl height BH1 is set lower. The bowl height BH2 indicates the bowl height when it is desired not to lower the bowl any further, and is set depending on the soil condition or the case where further cutting is not desired.

Next, the operation of the embodiment having such a structure during the flattening work will be described with reference to the flow chart of FIG. First, in steps 100 to 110, the driver opens the apron with the operation switch of the operation unit 16, and further, the height of the bowl (that is, the amount of bite into the ground) BH
1 is set and the operation start is instructed, the control unit 13 sets the bowl height BH3 (the operation unit 1
6 is set in advance).

Then, when the scraper is towed while traveling on the tow tractor, the sensors 8 to 12 perform measurement at predetermined intervals. FIG. 2 shows the operation for each cycle. First, at step 120, the control unit 13 causes the sensors 8 to 1 to operate.
Measurement signals from 2 (V) EL, (V) ER, (V) SL,
(V) Input SR and BH. Next, at step 130, the measurement signal BH is compared with the allowable ranges BH1 and BH2 to confirm that the height of the bowl is within the allowable range. If it is out of the allowable range, the height of the bowl is moved to the preset height BH1 or BH2.

Next, at step 140, a difference ΔE between the rotational speed of the traveling system of the towing tractor and the rotational speed of the scraper wheels is calculated. That is, the control unit 13 calculates ΔE = {(V) SR + (V) SL} / 2-{(V) EL + (V) ER} / 2. Next, at step 150, if the difference ΔE is a positive value, it is determined that the traveling system of the traction tractor is slipping, and the process proceeds to step 160 to set the bowl position to the bowl drive mechanism 14 at a predetermined position. When an instruction to increase the height is given, the bowl drive mechanism 14 operates to adjust the height of the bowl. As a result, the load on the bowl from the ground is reduced and slip is reduced.

On the other hand, when the difference ΔE is a negative value or zero, the process proceeds to step 180 to instruct to lower the bowl by a predetermined height, and the bowl drive mechanism 14 adjusts the height of the bowl. Then, when the operation for one cycle is completed, the process moves to step 120 again, and the process is repeated continuously. Then, by repeating this process, when a slip occurs, it is gradually set to a state in which the optimum traction performance is obtained.

To stop the work, the stop switch of the operation unit 16 is operated to stop the work interruption process (step 2).
00) is performed. As described above, according to this embodiment, it is possible to perform the cutting work with the height of the bowl (in other words, the amount of the bite of the bowl to the ground) set in advance as the center, and the traveling system of the towing tractor. Since the slip is reduced, optimum traction performance can be obtained, and further, since the driver does not have to operate due to experience, operability and workability can be improved.

In this embodiment, the presence or absence of slip is determined by comparing the average rotation speed of the left and right wheels of the scraper with the left and right rotation speeds of the traveling system of the tractor tractor. The rotation speed of one wheel may be applied to the comparison target. Further, instead of the rotation speed of the traveling system of the tow tractor, a speed setter for the scraper may be provided and the same control may be performed.

Furthermore, the slip state is affected by the amount of earth and sand that has entered the bowl, that is, the loading amount. That is, if the load is large, slipping is likely to occur. Therefore, the loading amount is detected, and when the loading amount is large, when the bowl is lowered by a predetermined amount, the lowering amount is slightly reduced so as to lower the slip, and the work efficiency can be improved.

[0024]

As described above, according to the present invention,
The slip of the traveling system of the tow tractor can be automatically prevented, and maximum tow performance can be obtained. Further, since it is not necessary for the driver to operate so as not to slip, operability can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a scraper control device according to the present invention.

FIG. 2 is a timing chart explaining the operation of the embodiment of FIG.

FIG. 3 is an explanatory view explaining the function of the scraper in the present invention.

FIG. 4 is a side view showing the structure of a conventional scraper.

FIG. 5 is an explanatory diagram for explaining the operation of the conventional scraper.

[Explanation of symbols]

 1: Front wheel 2: Rear wheel 3: Bowl 4: Hydraulic cylinder 5: Apron 6: Coupler 7: Traction tractor 8: Scraper right wheel speed sensor 9: Scraper left wheel speed sensor 10: Bowl stroke sensor 11: Tractor Right shoe speed sensor 12: tractor left shoe speed sensor 13: control unit 14: bowl operating mechanism 15: apron operating mechanism 16: operating unit 17: cutting edge

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuke Kosai 2-16-46 Minami-Kamata, Ota-ku, Tokyo Tokimetsuku Co., Ltd. (72) Inventor Takeyuki Takeuchi 2--1646 Minami-Kamata, Ota-ku, Tokyo No. In stock company Tokimetsuku (72) Inventor Kenji Sashida 4-9-9 Akasaka, Minato-ku, Tokyo Japan Land Development Co., Ltd. (72) Inventor Masahiro Nomura 2758-6 (72) Invention, Ozenji, Tama-ku, Kawasaki-shi, Kanagawa Takeo Nakayama 4036-1, Nakatsu, Aikawa-cho, Aiko-gun, Kanagawa Prefecture Kokudo Koki Co., Ltd.

Claims (4)

[Claims] 1. A rotation detector of a traveling system of a towing tractor, a rotation speed detector of traveling wheels of a scraper, a calculator for calculating a slip of the traveling system of a towing tractor from measurement signals of the detectors, Based on the slip amount calculated by the calculator,
A controller for a towed scraper, comprising: a bowl control device that raises a scraper bowl to prevent slipping when slipping is likely to occur, and lowers the bowl when slippage is unlikely to occur. 2. A rotation speed detector for traveling wheels of the scraper,
A speed setter that sets the speed of the scraper, detects the difference between the rotation speed of the traveling wheel of the scraper and the set speed of the speed setter by the rotation speed detector, and the scraper of the scraper so that this difference signal becomes zero. A towed scraper control device comprising: a bowl control device for raising and lowering the bowl. 3. The towed scraper control device according to claim 1 or 2, wherein a stroke detector is further provided in a cylinder for controlling the height of the bowl, and the stroke detector detects the stroke. A control device for a towed scraper, wherein the amount of raising and lowering operation of the bowl is controlled in accordance with the slip amount or the difference signal. 4. The towed scraper control device according to claim 1 or 2, further comprising a load amount detector for detecting a load amount of the scraper, wherein a bowl raising / lowering operation amount is slipped. A control device for a towed scraper, which is adapted to correspond to the loading amount as well as to the amount or difference signal.