JPS62198306A - Working height control system in field working machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention (±) relates to a working part height control system in a field working machine such as an agricultural tractor.

[Prior Art and Problems to be Solved by the Invention] Generally, in this type of field work machine, the height of a working part that is movable up and down on the traveling machine body is determined by a working part that detects the height of the working part. The control unit inputs the detection results from the height detection means and the set position detection means for detecting the set position of the operating tool, and automatically controls the height according to the set position of the operating tool. Some models employ a working part height control method (position control method). In this case, when controlling the vertical movement of one working part, if the working part over-actuates or there is a delay in the operating system, the position of the second working part is accurately positioned at the position corresponding to the setting of the operating tool. In fact, it is difficult to control the height, and if you try to control the vertical movement in this state, it will cause the so-called hunting phenomenon in which the working part swings up and down. A dead zone is set between the two detected values, and if the detected values fall within this dead zone, it is assumed that the two detected values match and the lifting and lowering movement of the work section is controlled.

On the other hand, if the set position of the operating tool and the height of the working part do not match at the start of work 1, turning on the key switch may cause the working part to suddenly change to the height corresponding to the set position of the operating tool. In order to avoid the risk of causing the workpiece to fall, it is regulated that the workpiece cannot be moved up or down until after the key switch is turned ON and the operating tool is set at a position corresponding to the height of the workpiece. Even in this case, the dead area remains narrow as described above, so it is difficult and troublesome to set the operating tool at a position that corresponds to the height of the work part at the beginning of work, but when setting the operating tool, The set position is often set too far,
In this case, since the set position of the operating tool passes a position that matches the height of the working part, the above-mentioned elevation ILra restriction is released, and therefore the working part suddenly moves to match the set position of the operating tool that has passed. It has become a problem because it has the disadvantage of being extremely dangerous.

[Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a working part height control method for a field work machine that can eliminate these drawbacks. There it is,
The detection results from the working part height detection means that detects the height of the working part that can be freely moved up and down on the traveling machine and the set position detection means that detects the set position of the operating tool are judged, and the key switch is tilted. At the time of start-up, the dead area between the two detection values is set to have a wide first dead area, and the operating tool is moved to a position corresponding to the height of the working part. After the operating tool is set within the dead area, the height of the working part is controlled in accordance with the set position of the operating tool by changing to the wide first dead area and then to the narrow second dead area.

According to the present invention, although this configuration does not impair the accuracy of ordinary vertical movement control,
This makes it easy to align the set position of the operating tool after turning on the key switch, and in this case, it is possible to reliably prevent the set position from going too far, thereby improving safety. .

[Example] Next, an example of the present invention will be described based on the drawings. In the drawings, reference numeral 1 denotes a traveling body of an agricultural tractor, and the traveling body 1 has an elevating link machine 4! A working section (rotary tilling section) 3 is connected via j2. A lift arm 5 extending from the hydraulic case 4 is interlocked and connected to a lower link 2a of the lifting link mechanism 2 via a lift rod 6, and when the lift arm 5 swings up and down by hydraulic operation, the working part 3 is raised and lowered. Everything about the device, including its movement, remains the same as before. Here, 7 is the front wheel, 8 is the rear wheel,
9 is a fender that covers the rear wheel 8.

10 is a position lever provided on one of the fenders 9 (the left one in the embodiment).

A lever angle detection sensor 11 for detecting the lever set angle is provided at the base end of the position lever 10, and the position lever 1 corresponds to the operating tool of the present invention.
0 set position detection means is configured. On the other hand, an arm angle detection sensor 12 is provided at the base end of the lift arm 5, which detects the swing angle of the lift arm 5, that is, the height of the working part 3. Each of these sensors 11.12
are configured by, for example, a potentiometer, and in the embodiment, they are arranged one to one so that the corresponding angle change rates are equal.
It is set to detect angles due to the following. The detection signals from both angle detection sensors 11 and 12 are transmitted to a control unit 13 configured by a microcomputer or the like.
The control unit 13 performs calculations based on these input detection signals 48 and issues control commands to the solenoids 14 and 148 for extending and retracting the lift arm S based on the results. The control procedure will be explained below with reference to a flowchart.

First, turn on the engine key switch and turn on the control unit 13.
When the controller 13 starts the detection value B from the arm angle detection sensor 12, the controller 13 sets the dead zone to a wide "first dead zone F" (that is, the first dead zone F is , the swing angle of the lift arm 5 is θ, and the first dead angle is α, then the angle is in the range O±α, and in the case of the embodiment, this dead angle α is approximately 10 degrees. The solenoid 14, 14a is controlled so that both of the solenoids 14 and 14a are set to call.

Then, the control unit 13 determines whether the detection value P from the lever angle detection sensor 11 is smaller than the detection value from the arm angle detection sensor 12 (P<L), and the position lever lO is If it is located at a lower position than the height corresponding position and is judged to be small (tight), further,
The value obtained by subtracting the first dead angle α from the arm side detection value (L-
The lever side detection value P is larger than α) (L−α<P
) is determined.

If it is determined that the lever side detection value P is smaller or equal (No), that is, the position lever lO is in the first dead area F.
If not included on the low angle side of.

By operating the position lever 10, the state will remain in standby until the detection value P from the lever angle detection sensor 11 becomes larger than the value (L-α), and in this state, the operation of other actuators is also disabled. It is set so that it is not possible. On the other hand, the position lever 10 is located at a higher position than the height position of the working part 3, and the lever side detection value P is smaller than the arm side detection value (P<L
), and if it is determined that it is not (NO), then the arm side detection value is greater than the value obtained by subtracting the dead angle α from the lever side detection value P (P - α). is large (
P-α<L), and if it is determined that the arm side detection value is small, that is, if the position lever lO is not included in the high angle side of the first dead area F (NO) , the detection value from the lever angle detection sensor 11 due to the lever operation of the position lever 1° is the above value (P-α)
It will remain in this state until it becomes larger than the current value, and in this state, it is set so that other actuators cannot operate, as described above.

Then, by operating the lever, the lever angle detection sensor 11
If it is determined that the detected value P from 1 falls within the first dead zone F, the process moves to the next step. And here, the lever side detection value P is smaller than the arm side detection value r, again (
If P<L) is determined to be small (IFs), it is further determined that (P + dead angle <L) is smaller than the lever side detection value P plus the dead angle. In this case, if the process continues as described above at the start, the dead angle will be determined based on the large first dead angle α, and in this case, as described above, Since the detected value P becomes L-α minus P by setting the position lever 10, it is sure that L<P.
+α, therefore, it is not possible to determine whether or not it is smaller than the value obtained by adding the first dead angle α to the lever side detection value P (NO).
) will be determined. Therefore, the solenoid 14.14a is controlled to maintain the position before the ear. In this control state, when operating the position lever 10 and considering the case where the position lever 10 moves out of the first dead area F, let's move the position lever 10 downward and move it downward to the first dead area F. [If an operation is performed to remove the lever side, the old judgment is made that the lever side detection value P is smaller than the arm side detection value, and then the detection value P is smaller than the arm side detection value.
is a window depending on whether P+α<L, and therefore, the control unit 13 issues a control command to the lowering solenoid 14 to open, thereby causing the lift arm 5 to move downward. On the other hand, if the position lever 10 is moved upward and the upper side is operated out of the first dead area F, the lever side detection value P is smaller than the arm side detection value, but the judgment is NO. and then the detection value is determined.

The window determines that P is L+α minus P, and as a result, the control unit 13 issues a control command to the lift solenoid 14a to open, thereby causing the lift arm 5 to move upward. Become. In this way, when the solenoid 14.14a is turned ON, the control unit 13 converts and sets the dead angle to the second dead angle β (α>β) smaller than the first dead angle α, and thereafter sets the dead angle to the second dead angle β (α>β). A narrow second dead area f set with two dead angles β (the second dead area f is a range of the angle θ±β if the swing angle of the lift arm 5 is 0; In this case, the second dead angle β is set to a value of about 1 to 2 degrees), a comparative judgment is made, and the vertical swing control of the lift arm 5 is performed based on this result. Thereafter, the setting is such that the vertical movement of the working part 3 is controlled with high precision using the narrow second dead zone f.

In the embodiment of the present invention configured as described above, after opening the key switch to start the control section 13 and subsequently start the engine, the position lever 10 is moved to a position corresponding to the height position of the working section 3. However, in the present invention, this lever set has a wide first dead area F.
This can be done extremely easily. That is, when the key switch is turned on, the control unit 13 determines whether or not the position lever 10 is set within the wide first dead area F where the dead angle is set to a large first dead angle α. If it is not set, the actuator remains in a state where it cannot be operated until the position lever 10 is set within the first dead zone F by lever operation, and if it is set, the state is released. The actuator can now be operated. Then, in this state, operate the position lever 10 to reach the first dead area F.
When it comes off, one of the solenoids 14 and 14a is turned on, causing the lift arm 5 to swing up and down, and the working part 3 to move up and down in accordance with the set position of the position lever 10. However, when the solenoid 14.14a is activated after setting the position in this way,
The control unit 13 performs vertical swing control of the rift 1-arm 5 using the narrow second dead area f set by the small second dead angle β.

In this way, in one aspect of the present invention, when the engine key is turned on, the position lever 10 waits for the lever set in the wide first dead area F, and therefore, the key switch is turned on. The lever set of the position lever 10 when set to 10 is extremely easy because it only needs to be adjusted in a wide dead area.

It is not a fraud that can significantly improve the operability, it can reliably prevent the position lever lO from going too far from the set position, and therefore it can eliminate unexpected lifting and lowering movements of the working part 3, It can be made extremely safe. Moreover, once the lever is set in this wide first dead area F, the position lever 10 can be operated to move the working part 3 to 31. In order to carry out the descent,
If you operate the lever outside of this first dead zone F,
This time, the vertical movement of the working part 3 is controlled using the narrow second dead area f. Therefore, even though the setting is made so that the first dead zone F is wide when starting with the key switch turned on, when operating the lever after the position is set, the second dead zone F, which is narrower than VC, is used to operate the lever. Highly accurate lifting and lowering movement control of the section 3 can be achieved, and excellent workability can be achieved through position control.

In addition, in the embodiment, since the lever side detection value P and the arm side detection value P are set and controlled in a one-to-one correspondence, the same hardware can be used in the control unit 13, and There is no need for calculations or software processing to make the two correspond, and this not only simplifies the theoretical circuit, but also speeds up the processing time, and allows fine and precise control without any calculation errors. Moreover, since the operator's lever operation angle directly corresponds to the elevation movement angle of the working part 3, it becomes possible to operate the lever intuitively, and it is possible to perform the lever operation reliably and with a feeling of actual work.

Further, the conversion from the wide first dead zone F to the narrow second dead zone f is automatically achieved by operating the position lever 10 whose position is set after opening the key switch to move the working part 3 up and down. As a result, the switching procedure is very natural, and there is no need for the operator to perform switching operations each time.

This results in extremely excellent operability, workability, and safety.

It should be noted that the present invention is of course not limited to the above-mentioned embodiments, and the essential points are a working part height detection means for detecting the height of a working part provided on the traveling machine body so as to be movable up and down, and an operating tool. The operating tool is set at a position corresponding to the height of the working part in a wide first dead area at the time of starting when the key switch is opened. After the operating tool is set within the first dead area, the working part height is controlled according to the setting position of the operating tool using the wide first dead area and the narrow second dead area. For example, the operating tool can be a dial type instead of a lever type, and the height of the working part can be detected without relying on the detection of the swing angle of the lift arm. You can adopt whatever you can.

[Operation and Effect] In summary, since the present invention is configured as described above, when the key switch is turned on, the operating tool is positioned at a position corresponding to the height of the working part in the wide first dead area. This means that the operating tool can be easily set and can be prevented from going too far, significantly improving safety. Moreover, after setting in the wide first dead area, the narrow second dead area is used instead of the wide first dead area to control the lifting and lowering of the working part with high precision.Therefore, the key switch Even though a wide dead area is set that is easy to match when ON, from then on, the narrow dead area allows for highly accurate lifting and lowering control of the working part, resulting in ideal lifting and lowering control of the working part that has never been possible before. It will be done.

[Brief explanation of drawings]

The drawings show an embodiment of the working part height control method for a field work machine according to the present invention, in which Fig. 1 is an overall side view with a part cut away of an agricultural tractor, and Fig. 2 is a control system. FIG. 3 is a block diagram of the mechanism, FIG. 3 is a timing chart showing the control state, and FIG. 4 is a flow chart showing the control procedure. In the figure, 1 is a traveling machine body, 3 is a working part, 10 is a position lever, 11 is a lever angle detection sensor, 12 is an arm angle detection sensor, and 13 is a control part.

Claims (1)

[Scope of Claims] 1) Detection results from a working part height detecting means for detecting the height of a working part provided on the traveling machine so as to be movable up and down, and a set position detecting means for detecting the set position of the operating tool. At startup when the key switch is opened, the dead area between the two detection values is set to have a wide first dead area, and the operating tool is set at a position corresponding to the height of the working part. After the operating tool is set within the first dead area, the working part height is controlled according to the set position of the operating tool by changing to the wide first dead area and using the narrow second dead area. A working part height control system for field work equipment characterized by: 2) The conversion from the first dead area to the second dead area is achieved by an operation to escape from the first dead area after the operating tool is set within the first dead area. A working part height control system in a field working machine according to claim 1, characterized in that: