JP2003245003A - Implement rolling-controlling device of tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems such that in a rolling-controlling device of a tractor, for detecting the inclination of an implement by the height difference of left and right lower links, a detection error (twist) of the link mechanism appears markedly caused by the height of the implement, a power exceeding the acting range of a rolling cylinder 6 is required, hydraulic or electric controlling parts are damaged, or a hydraulic pressure to the another actuator becomes insufficient. <P>SOLUTION: This rolling-control device for maintaining a prescribed angle for the vehicle of the tractor has a constitution for correcting the values of the lower link height difference sensors for detecting the height difference in accordance with the height of the implement, and also regulating the setting range of an inclination setting tool for setting the left and right inclination of the implement as narrower than a stroke amount of the rolling cylinder 6. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of a work implement rolling control device for a tractor. 2. Description of the Related Art Conventionally, agricultural tractors have been disclosed in
As disclosed in JP-A-63241, a tractor for vertically connecting a working machine (2) via a three-point link mechanism comprising left and right lower links (6, 6) and a top link (8), The tractor includes a tilt sensor (C) for detecting the left-right inclination of the work machine (2), a lift rod cylinder (12) for changing the left-right inclination of the work machine (2),
A link type lower link height difference detection mechanism (18, 17a, 17b, S) for detecting the left-right inclination of the work machine (2) based on the height difference of the left and right lower links (6, 7) is known. ing. In the tractor disclosed in the above publication, the first rolling control for maintaining the inclination of the work implement (R) horizontally, that is, in the above publication, with respect to the detection value of the "ground inclination sensor (C)" is performed. It is a configuration to perform. [0004] However, such as the conventional tractor, which detects the inclination of the working machine by the difference in height between the left and right lower links (see FIG. 1), the first rolling mode, that is, the first rolling mode, The tractor was designed for the paddy field work (rolling work etc.) that rolls the work machine only at a low position. In the case of adding a rolling control assuming a work or a ridge work, as shown in FIG. 2B, unless the link configuration of the lower link height difference detection mechanism forms an accurate parallelogram. In addition, the detection error (twist) of the link mechanism appears remarkably depending on the height of the working machine, so that not only the set inclination is changed, but also the operating range of the actuator is reduced. Exceeding output is required, causing problems such as damage to hydraulic and electric control components, and insufficient hydraulic oil to other actuators particularly when the actuator is driven by hydraulic pressure. [0005] In view of the above problems, the present invention provides a setting device of a control device in a work vehicle as follows. That is, in the present invention, the left and right lower links (1
L, 1R) and a top link (2), and a work machine (R) is connected to the work machine (R) via a three-point link mechanism (H) so as to be able to move up and down freely. (3), an actuator (6) for changing the left-right inclination of the work machine (R), and the left-right lower link (1L, 1R)
A first rolling mode for maintaining the inclination of the work machine (R) with respect to the horizontal, and a work machine (R).
A rolling mode setting device (28) having a second rolling mode for maintaining the inclination of the work machine (R) in each of the modes, and a tilt setting device (4, 30) for setting the left and right inclination of the work machine (R) in each of the modes. And the inclination setting device (4, 3
A work machine rolling control device for a work vehicle, comprising: a control means (10) for restricting the setting range according to 0) to be smaller than the tilt operation range of the work machine (R) in the second rolling mode. did. (Operation) In the work implement rolling control device for a work vehicle configured as described above, the first rolling mode for maintaining the inclination of the work implement (R) with respect to the horizontal and the inclination of the work implement (R) are set with respect to the vehicle. The second rolling mode can be maintained, but in the setting of the second rolling mode, the tilt operating range of the working machine (R), that is, the actuator (6)
Is restricted to a range narrower than the operating range of. According to the present invention, the operating range of the actuator (6) can be increased even when an error caused by twisting of the lower link height difference detecting mechanism is increased when the work machine of the tractor is rolled vertically and widely. If the output exceeds the limit, the oil continues to be relieved, causing damage to the hydraulic control parts, or insufficient hydraulic oil to other actuators, for example, the actuator for changing the height of the work machine (R) or the shifting actuator. The problem can be solved. An embodiment of the present invention will be described below with reference to an agricultural tractor T as a working vehicle. First, the configuration of the tractor T will be described. As shown in FIGS. 3 and 4, the tractor T has a diesel engine E inside a bonnet 11, a front axle case for supporting left and right front wheels 12F, 12F below the engine E, and a rear part of the engine E. , Transmission case 1 with transmission inside
3 and the rear wheel 12
The rear axle case 14 supporting the R and 12R is connected. A cabin 16 is formed above the transmission case 13 at the rear of the hood 11 so as to cover the periphery of the cockpit 14. Explaining the configuration inside the cabin 16, in front of the cockpit 14,
A handlebar post 18 is erected, and one side of the post 18 is provided with a forward / reverse switching lever 20 for switching between forward and backward travel of the vehicle.
Elevation switch (up switch 21u,
A work machine elevating one-touch lever 22 or the like that continuously raises or lowers a work machine R, which will be described later, between a set position and a work position by turning on a down switch 21d) is provided. On the side of the cockpit 14, a speed change lever 23 and a work implement elevating lever 24 are protruded, and a potentiometer 24s for detecting an operation angle is provided at the base of the lever 24. Thus, the height of the working machine R is appropriately changed. As shown in FIG. 5, a rolling mode setting device 28 for setting three types of rolling modes such as "manual", "parallel" and "automatic", and a piston of a rolling cylinder 6 described later are provided on the sides of the cockpit 14. Self-neutral return type manual tilt setting device 4 for telescopic operation
And a dial type automatic tilt setting device 30 that sets the tilt of the work implement R with respect to a horizontal reference, wherein the rolling mode is set to the “automatic” mode. In the rolling mode, "manual"
The mode is a mode in which the piston of the rolling cylinder 6 is extended and retracted in accordance with the operation time of the manual inclination setting device 4, and is used, for example, for attaching and detaching a work machine on an inclined ground.
The “parallel” mode is a mode in which the piston of the rolling cylinder 6 is expanded and contracted in accordance with the operation time of the manual tilt setting device 4 to maintain the left and right lower link height difference at that time. It is used for tilling work, mulching work, ridge work, etc. In the "horizontal" mode, the piston of the rolling cylinder 6 is operated to expand and contract in accordance with the position set by the automatic tilt setting device 30, and the tilt at that time is independent of the swing of the vehicle body, that is, the tilt sensor. In this mode, the angle with respect to the detection value of 3 is maintained, and is used, for example, in scraping work or tilling work in a paddy field. The setting devices 28, 4... And the sensor 2
Reference numeral 4 denotes a configuration which is connected to a controller 10 serving as control means together with the inclination sensor 3 provided below the cockpit 14. Next, the rear part of the vehicle body of the tractor T will be described. Lower links 1L and 1R projecting rearward are provided on the left and right rear sides of the transmission case 13, respectively.
A three-point link mechanism H is formed by providing a top link 2 protruding rearward in the upper part of the rear of the case 13, and a hydraulic cylinder for lifting and lowering the work implement is provided in the upper part of the rear of the transmission case 13. A cylinder case 40 to be installed is provided, and lift arms 41, 41 which are turned up and down by the expansion and contraction of a piston of the working machine lifting / lowering cylinder are provided on left and right sides of the case 40. Then, the lower link 1R on the right side in the rear view.
And the lift arm 41 are connected via a rolling cylinder 6 serving as an actuator for changing the inclination of the work implement R, and the left lower link 1L and the lift arm 41 are connected.
Are connected via a rod member 8. Reference numeral 4 in the figure denotes a lift arm angle sensor for detecting the height of the working machine R with respect to the machine, and reference numerals 43.
Denotes a ball joint for connecting each connecting member such as the link mechanism H so as to be rotatable up, down, left and right. Thereby, the height of the entire work implement R can be changed by driving the piston of the hydraulic cylinder for lifting and lowering the work implement, and by extending and retracting the piston of the rolling cylinder 6, the lower link 1L and the rod The work machine R can be rotated about the connection point (ball joint portion) of the member 8 to change the left-right inclination. As shown in FIG. 1, a sensor arm 44 is rotatably supported coaxially on the outside of the left and right lift arms 41, and the tip of the sensor arm 44 and the lower link 1L, 1R are connected to each other. A sensor rod 45 is connected to the base, and a lower link sensor (hereinafter, referred to as a potentiometer type) is attached to the rotation base of the sensor arm 44 on the left side in the figure.
While the housing of the lower link height difference sensor 5) is integrally formed, the rotation axis 46 of the other sensor arm 44 is made to pass through the inside of the drive shaft 47 of the lift arm 41, and the detection axis of the lower link height difference sensor 5 is detected. (Link type lower link height difference detection mechanism). Thus, when the piston of the rolling cylinder 6 expands and contracts, the right sensor arm 44
And the four-sided link mechanism enclosed by the sensor rod 45, the lower link 1R, and the vehicle body, and the four-sided link mechanism surrounded by the left sensor arm 44, the sensor rod 45, the lower link 1L, and the vehicle body, Left and right sensor arms 4
The relative angles of the left and right lower links 1L, 1
The height difference of R can be detected. Next, a control system of the tractor T will be described with reference to FIG. The controller 10 of the tractor T includes a CPU that processes signals from various sensors and setting devices, a RAM that temporarily stores these signal information, and a storage unit such as an EEPROM that stores a rolling control program of the present invention. Has become. The controller 10 includes a rolling mode setting unit 28, a manual inclination setting unit 4, an automatic inclination setting unit 30, an inclination sensor 3, a lower link height difference sensor 5, and a work implement lifting / lowering lever 24. A potentiometer 24s at the base, an up switch 21u, a down switch 21d, and a lift arm angle sensor 7, an inclination sensor 3 and the like, which are operated by a one-touch lever 22 for lifting and lowering the work equipment, are connected and provided. A solenoid 48 of a switching control valve for extending and retracting the piston of the rolling cylinder 6 is provided at the output portion.
A, 48B, and solenoids 49, 50 of a proportional flow control valve for rotating the lift arms 41, 41 up and down are connected and provided. Here, the problem to be solved by the present invention will be described with reference to FIGS. The lower link height difference sensor 5 of the tractor T detects the relative angle difference between the left and right lower links 1L and 1R as described above. Here, the sensor arm 44, the sensor rod 45, and the lower Link 1L (1
R) is formed in a trapezoidal shape whose lower side is longer than the upper side, and when the lift arm 41 is turned up and down, the angle of the left and right lower links 1L (1R) becomes (B) in FIG. )
As shown in (1), for example, it changes from α1 to α2. For this reason, in the conventional work machine rolling control, when the work machine R is driven up and down by the position control, the separately configured plowing depth control and the work machine load control, the set angle is not changed. In addition, there is a problem that the inclination of the working machine R changes, and especially when working in the “parallel” mode, despite the fact that the piston operation amount of the rolling cylinder has reached the limit, The controller 10 keeps energizing the solenoids 48A and 48B of the switching control valve in order to maintain the set angle of the work implement R, and has a problem that various hydraulic and electric control parts are damaged. Therefore, in the rolling control of the tractor T, the rolling control is performed as shown in FIG. The controller 10 turns on the power of the tractor T and reads the connection states and detected values of various sensors and setting devices in STEP1. Then, in STEP 2, the setting mode of the rolling mode setting device 28 is determined,
In response to this, each rolling control is executed in STEP 3 and thereafter, and thereafter, the position control and other controls such as the plowing depth control and the load control are performed, and the process returns. In the rolling control in the "manual" mode, as shown in FIG. 8, first, the operation of the manual tilt setting device 4 is determined in STEP1, and in STEP3, whether the setting operation is right-up or right-down, that is, It is determined whether the piston of the rolling cylinder 6 is shortened or extended, and the solenoids 48A and 48B of the switching control valve are energized accordingly (S
TEP4, 5) is performed to change the left-right inclination of the work machine R. When the setting operation is no longer detected, the process ends. In the rolling control in the "parallel (arbitrary inclination)" mode, as shown in FIG.
In EP1, the operation of the manual tilt setting device 4 is detected, and if this is YES, the solenoids 48A and 48B of the switching control valve are energized in accordance with the setting operation as described above (STE).
P2-6). Thereafter, the lower link height difference sensor 5 is stored in STEP 7 to store the tilt set by the tilt setter 4.
Is stored in the EEPROM, and in STEP8,
For example, it is determined whether or not there is a change in the detection value of the elevation difference sensor 5 due to an excessive load on the work implement R or a leak of oil from the cylinder 6, and if YES, the switching control is performed in the same manner as described above. The solenoids 48A and 48B of the valves are energized to correct the inclination of the working machine R from side to side. In STEP 9, at the time of the correction, the change of the lift arm angle sensor 7 is determined, that is, whether the height of the work implement R is changed is determined. Since the influence of the distortion of the link composed of the link 1L (1R), the sensor rod 45, and the sensor arm 44 is considered, a correction value set in advance to eliminate this in STEP 10 is integrated with the detection value of the height difference sensor 5, In step 11, the solenoids 48A, 48 of the switching control valve are adjusted so that the corrected height difference is obtained.
Apply current to 8B. Incidentally, the correction value is obtained by an experiment in which a distortion detected for each type of tractor, that is, for each type of link is obtained by an experiment.
Although this is set to the table value, it may be calculated by a conditional expression and integrated or added, or may be configured to correct the value of the power output to the solenoids 48A and 48B of the switching control valve. In the tilt setting operation in the "parallel (arbitrary tilt)" mode, conventionally, as shown in FIG. 10A, the rolling cylinder 6 is set at P1, and the lift arm 41, that is, the work implement R Is changed from the lowered position to the raised position, the amount of expansion and contraction of the rolling cylinder 6 is corrected. At this time, the stroke end of the cylinder 6 may be reached. Therefore, here, as shown in (B), the stroke set amount, that is, the left and right inclination set amount of the working machine R is regulated. In the rolling control in the "horizontal" mode, as shown in FIG. 11, first, a change in the set value of the automatic inclination setting device 30 is determined in STEP1, and if this is YES, the automatic control is performed in STEP2. Tilt setting device 30
Is determined (the amount of deviation of the dial from the horizontal position), and the solenoids 48A and 48A of the switching control valve are accordingly determined.
B is energized to change the inclination of work implement R. If the determination in STEP 1 is NO, the process proceeds to STEP 5 to determine whether or not the detected value of the inclination sensor 3 has changed. If YES, the automatic inclination setting unit 30 sets the value. The solenoids 48A and 48B of the switching control valve are energized so as to maintain the tilt. Thus, the sensor arm 44 of the tractor T, the lower link 1L (1R), the sensor rod 4
Even when distortion occurs in the virtual links on the four sides surrounded by 5 and a difference in height between the left and right of the lower link occurs, the work machine R is controlled by the rolling control of the work machine R, in this case, in the "parallel (arbitrary inclination)" mode. The left-right inclination can be accurately maintained, and there is no need to reset the inclination of the work machine R even if the height of the work machine R is changed unlike the related art. Since the setting range of the manual inclination setting device 4 is restricted to a range smaller than the stroke amount of the cylinder 6, the rolling cylinder 6 according to the height of the working machine R is controlled.
When the length of the cylinder 6 is corrected, the piston of the cylinder 6 does not reach the stroke end, and it is possible to prevent the hydraulic or electric parts from being damaged. In addition, when adding the "parallel (arbitrary inclination)" mode to a ready-made tractor that does not have the above-mentioned mode,
It is only necessary to change the program in the EEPROM or to set the correction coefficient.
Compared with a configuration in which mechanical components such as the sensor rod 45 and the like are improved, costs for the improvement can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a lower link height difference detecting mechanism. FIG. 2A is an operation diagram when a lifting arm is moved up and down by a rolling cylinder and a lift rod with the same length. (B) Operational diagram when the lift arm is raised and lowered with the rolling cylinder extended. FIG. 3 is a side view of the tractor. FIG. 4 is a rear view of the tractor. FIG. 5 is a plan view of various setting devices for rolling control. FIG. 6 is a diagram showing a connection state of a controller. FIG. 7 is a flowchart showing an outline of the entire control. FIG. 8 is a flowchart showing an outline of rolling control in a manual mode. FIG. 9 is a flowchart showing an outline of rolling control in a parallel (arbitrary tilt) mode. FIG. 10A is an operation diagram when the operation amount of the conventional rolling cylinder is corrected. (B) Operation diagram when the operation amount of the rolling cylinder of the present invention is corrected. FIG. 11 is a flowchart showing an outline of rolling control in an automatic mode. [Description of Signs] 1L Lower link 1R Lower link 2 Top link 3 Tilt sensor 4 Manual tilt setting device 5 Lower link height difference sensor 6 Rolling cylinder 4 Lift arm angle sensor 8 Lift rod 10 Controller T Tractor R Rotary work machine

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Claims (1)

Claims: 1. A tractor for connecting a working machine (R) to a working machine (R) via a three-point link mechanism (H) comprising left and right lower links (1L, 1R) and a top link (2). And
The tractor includes an inclination sensor (3) for detecting the left-right inclination of the vehicle body, an actuator (6) for changing the left-right inclination of the work machine (R), and a left-right lower part for detecting the left-right inclination of the work machine (R). Link type lower link height difference detection mechanism (44, 4) for detecting by the height difference of the link (1L, 1R)
And a second rolling mode for maintaining the inclination of the work implement (R) with respect to the vehicle and a second rolling mode for maintaining the inclination of the work implement (R) with respect to the vehicle. A rolling mode setting device (28), and a tilt setting device (4, 30) for setting the left-right tilt of the working machine (R) in each of the modes, and setting by the tilt setting device (4, 30). A work machine rolling control device for a tractor, comprising: control means (10) for restricting the range to be smaller than the tilt operation range of the work machine (R) in the second rolling mode.