JPS61209503A - Front and rear posture controller of earth 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] [Field of Industrial Application] This invention relates to a longitudinal attitude control device for a ground work machine such as a rotary or a plow connected to a tractor.
When hoisting the work W6 of the ground work machine while it is rotating, or to improve the flying performance during plowing work, the top link is reduced in order to control the forward and backward inclination of the ground work machine, or , a longitudinal attitude control device that limits the extension and contraction of the top link to ensure safe rotation of the ninth universal joint shaft that transmits power between the tractor and ground work equipment during each extension operation. This is what we propose.

[Conventional technology]

Next to ensuring sufficient lifting height or improving plowing performance, the length of the top link is controlled manually and automatically to expand and contract to adjust the longitudinal posture of the ground work equipment relative to the tractor. A control device for lifting and lowering a working machine is known as Japanese Unexamined Patent Publication No. 14710/1983.

The working part of the ground work machine is driven by a universal joint shaft that connects the PTO shaft of the tractor and the input shaft of the ground work machine, but the bending angle of the joint part of the universal joint shaft with respect to the PTO shaft or the input shaft. will vary depending on the lifting height and the above-mentioned longitudinal attitude. If this becomes too large, problems such as damage to the joint bottle will rapidly increase, so when lifting and lowering the ground work equipment, When extending or contracting the link, it must be confirmed that the bending angle of the joint is within a safe range and does not become excessive. However, conventionally known control devices.

Since such a confirmation means is not provided, there is a risk that the bending angle will be excessive.

Therefore, the applicant was asked to:
The length of the top link at which the universal joint shaft can be rotated most safely is calculated, and the top link is controlled to this length, proposed by a friend, Patent Application No. 59-253777, Patent Application No. 59
-258790 earlier, but
If the elevation of the ground work equipment and the expansion and contraction of the top link are controlled along the standard curve showing the relationship between the top link length and inclination angle, which indicates the safest condition, the range of attitude control becomes narrower. This is inconvenient because only one forward and backward tilting posture can be taken for one plowing depth value.

In addition, the lift cylinder and top link cylinder for raising and lowering the work equipment have different volumes, strokes, and control valve performance, so the lift arm angle and top link cylinder, which are the current lift arm angle and top link length When specifying a link length and making changes to it, it is difficult to expect an ideal control process in which the operations of both cylinders end at approximately the same point in time; arise.

As a result, when designation is repeatedly performed, there is always bias and control is not performed well.

It was found that the universal joint shaft can be rotated safely within a short period of time according to the ideal bending angle that can be rotated most safely.
If control is performed to allow short-time binding, the range of attitude control will be widened, and the matching of the operations of both cylinders will also be improved, allowing stable ratio control.

[Problem that the invention seeks to solve]

This invention sets a short allowable time for safe rotation at each bend angle that deviates from the ideal bend angle, and maintains the bend angle within this allowable time for attitude control. In addition to widening the width of the lift cylinder, we have also devised ways to improve the matching of the operations of the lift cylinder and top link cylinder, resulting in stable ratio control.

[Elaborate means to solve problems]

In order to solve all of the above problems, this invention takes the following technical measures.

That is, the tractor (11
A nine ground work machine (2) connected to the ground work machine (2) so as to be able to rise and fall freely is provided so as to be driven by a universal joint shaft α9 connected to the PTO shaft αj of the tractor (1), and the posture of the ground work machine (2) in the longitudinal direction is In the longitudinal attitude control device for a ground-based work machine configured to be controlled by the expansion and contraction movement of the top link (6), a tilt angle sensor (Sθ) detects the inclination angle of the ground-based work machine (2) in the longitudinal direction with respect to the tractor (1). and a top link sensor (S6) that detects the length of the top link (6).
), and a safety area storage part al that stores the allowable time for safe rotation at each bend angle of the universal joint shaft, and a safety area storage part al that stores the allowable time for safe rotation in the safety area where the top link (6) is located. Calculation means (2) that calculates the length of the safety top link in a safety range with a longer allowable time when the retention time detection unit σ value to be detected and the retention detection time exceeds the retention allowable time according to the inclination angle at that time. ) and a command means (to) for giving a command to the telescopic drive unit aI so that the top link (6) matches the length of the safety top link. It is a device.

[Example and operation]

Next is 15j of this invention! An example will be explained based on the drawings.

As shown in Fig. 2, a rotary tilling device as an example of a ground work device (2) is attached to the rear of the tractor (1), with a pair of left and right lift arms (3) (31), and a pair of left and right lift rods (4).
) (4) Left and right lower links that swing up and down through the
5) (5) and the top link (6) at the upper center are connected by a three-point linkage mechanism (7), and this three-point linkage mechanism (7) has its lift arm f31 f3)
The lifting and lowering operation is performed by a hydraulic lifting mechanism that uses hydraulic pressure to move up and down using a companion lift cylinder (8).

Top link (6) C. The top link cylinder (6) is formed to be extendable and retractable by the top link cylinder (9) and the piston (9a), and is connected to the top link cylinder of the pressure oil of the oil pump by the operation of the telescopic drive unit α1, which is made up of something like an electromagnetic switching valve. (9), the ground work machine (2) rotates in the front and back direction using the lower link (51 (connection pin αnant at the rear of 51) as a fulcrum, and the ground work machine (2)
2) To the friend who drives the working part C13t' like the tiller,
The PTO shaft I of the tractor (1) and the input II (141) of the ground work machine (2) are connected by the universal receiver @ (1!9). α) and the bending angle of the universal joint shaft α9 with respect to the input shaft I (β).

As shown in Fig. 3, the height of the ground work equipment (2) relative to the tractor (1) varies depending on the lifting height and the posture in the longitudinal direction. It has been found that the condition that generates the least force and can rotate most smoothly is α = β, and as shown in Figure 4, this is shown as the most desirable standard curve curve. Ru.

The conditions for the safe rotation of the universal joint shaft tilt are as follows:
It is known that α+β×f□(tl and α−β<f,(tl), but t is the allowable time for the belt to rotate safely at each bending angle, and in the same figure, t are longer and shorter (however, 11>1゜>1.>1
4 and tl is infinite) Safety of universal joint axis tilt-11
4 (Sa,), (Sa,), (Sa,) ... and (
Sb1), (Sb, ), (Sb3)... One example of all the sky is shown.

That is, for example, the safety curve C3a2) which is one safety margin
(Sb) If there is a tension link length D for each lift arm angle (θ) between (Sb) and cD, it is possible to safely maintain the full rotation due to the allowable strapping time (t), and safety-11 (
If it is between Sayo)-8b1), it can be rotated continuously without restriction, and if it is to the left or right outside of the safety curves 0a,) and (Sb4), it is a dangerous area.

For example, the lift arm angle (θ) t-
A tilt angle sensor (Sa) consisting of a rotary potentiometer, for example, is provided, and the top link has a length L)? A top link sensor (31
) T- is provided, and based on the lift arm angle (θ) inputted from the tilt angle sensor (Sa, +1?), the safety top 1) link lengths Lmin) and (Lmax) for each lift arm angle (θ) are calculated.

That is, the safety range storage section αaVc stores the standard plane &(2) illustrated in FIG. 4, and safety-1 (SaI) as the respective safety ranges.

(Sb, ), (Sa,), (Sb, ), ... are stored, and the detected current lift arm angle (I91
Find the safety range where the top link (6) is located from and the top link length ■.

Retention time detection part a configured by incorporating something like a timer
At step 9, the retention time in the safety area is detected, and on the other hand, the allowable retention time in the safety area is read out from the safety area storage unit, and the command means (1) determines the retention detection time as the allowable retention time. It is compared and judged whether or not it exceeds the retention time, and if the retention detection time is within the retention allowable time, no command is issued; if the retention detection time exceeds the retention tolerance time, the retention time permissible time has become so long. The top link length υ in the next safety range is selected as the safety top link length, and the top link (6) is controlled to expand and contract in order to bring the top link length υ closer to this selected friend safety top link length. The command means (2) issues commands to the telescopic drive member as shown in FIG. Lift arm angle (θ) and top link length CL) t
-1 This is carried out by each operator's setting instructions, and is a process in the middle of transitioning from the current longitudinal posture to the lift arm angle (θ) and top link length ■ in the longitudinal posture to be changed. In this step, while the above-described detection and determination of the retention time is carried out, the command means (2) finally sets the lift arm angle to match the set lift arm angle (top link length at θ1). The command is output to the expansion/contraction control section α1, and a continuous ascending or descending command is outputted to the elevating/lowering drive section (2). The above safety curve (Sa, ), (Sb1)
.

(Sa, ), (Sb,), ... are the universal joint shafts (i
The size of the rotational speed of s changes the shape of the book, especially the width of each safety margin, and the same safety margin is further subdivided according to the rotational speed.

The above-mentioned 7j IJ Aftome (3
), various methods can be used for mounting on the ground work machine (2), such as a nine-fold weight or a method of detecting the longitudinal inclination of the lower link (5).

〔Effect of the invention〕

The longitudinal attitude control device for a ground-based work machine according to the present invention is configured as described above, and has a flexible joint shaft (is folding angle).
In addition to the most ideal angle, it is possible to maintain the bending angle within a short allowable time for safe rotation, so the width of attitude control is better than the method that controls the bending angle to the most ideal angle. , becomes sufficiently wide, and the usability of longitudinal attitude control becomes the same as above, and moreover, the mutual movement speeds of the lifting and lowering movements in attitude control and the extension and contraction movements of the top link (6) are better matched. , the ratio becomes stable and the ratio control is performed.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Figure WJ1 is a control circuit block diagram, the second factor is a side view in a working state, Figure 3 is a plan view of the main parts in Figure 2, and Figure 4 is a top link diagram. It is a characteristic factor that shows a safety curve. Code explanation (1)...Tractor (2)...
・Ground work equipment (5)...Lower link (6
)...Top link a0...Expansion control @ a3-...PTO axis αS...
・Universal joint shaft 0...Safety area memory section αto・
...Retention time detection unit ■...Calculation means (S
a)... Tilt angle sensor (Kinuta) - Top link sensor patent applicant Takashi Hayashi, patent attorney for Iseki Agricultural Machinery Co., Ltd. Figure 3 Figure 4 Tiger 7 #1 - &21--

Claims (1)

[Claims] A ground work machine is connected to the tractor via the left and right lower links and the extendable top link at the top of the center, so that it can be raised and lowered, and is driven by a universal joint shaft connected to the PTO shaft of the tractor. A longitudinal attitude control device for a ground-based work equipment configured to control the longitudinal attitude of the work equipment by an expansion/contraction operation of a top link, comprising: an inclination angle sensor that detects an inclination angle of the ground-based work equipment in the longitudinal direction with respect to a tractor; It has a top link sensor that detects the length of the top link, a safety range storage unit that stores the allowable time for safe rotation of the universal joint shaft at various bending angles, and a safety range storage unit that stores the allowable time for safe rotation of the universal joint shaft, and a top link sensor that detects the length of the top link. A retention time detection unit that detects retention time; and a calculation means that calculates a safety top link length in a safety range where the allowable time is longer when the retention detection time exceeds the retention allowable time according to the inclination angle at that time. A longitudinal attitude control device for a ground work machine, comprising a command means for giving a command to a telescopic drive unit to make the top link match the length of the safety top link.