JPH061B2 - Front-back attitude control device for ground work machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front-rear posture control device for a ground work machine such as a rotary plow connected to a tractor, and a work unit of the ground work machine is kept rotating. In order to control the front-back inclination of the ground work machine in order to improve the soil performance and the plowing performance during hoisting or cultivating work, the tractor and ground work are respectively reduced in the top link or extended. In order to safely rotate the universal joint shaft for power transmission between machines, it relates to a front-back attitude control device configured to perform expansion and contraction control of the top link according to the lifting position of the ground work machine, It is devised to reliably and easily prevent a mode switching error when the types of top links are different.

[Conventional technology]

The top link that connects the upper center of the ground work implement to the tractor is a long standard top link that is pivotally attached to the front position at the top of the top link hitch of the conventional tractor, and the rear link at the bottom of the top link hitch. There are two types of short special-type top links to be worn. Special-type top-links are used to make it possible to hoist a ground work machine high enough, and generally standard-type top-links are used. Therefore, the attitude of the ground work machine with respect to a certain vertical position in the front-rear direction is different for each of the top links.

Therefore, by controlling the expansion and contraction of this top link to control the front-rear posture of the ground work machine while maintaining the smooth rotation of the universal joint shaft, the mode of the posture controller according to the above model of the top link. It is necessary to definitely switch, but to determine by determining the model of the top link and to switch this mode without mistake, there is an operation error in manual switch switching,
As a result, there is a risk that the joint portion of the universal joint shaft will be damaged.

[Problems to be solved by the invention]

The present invention is intended to prevent a mistake in the mode switching operation that should be performed corresponding to the top link type and also to save this operation.

[Means for solving problems]

In order to solve the above problems, the present invention takes the following technical means.

That is, the left and right lower links (5) pivotally attached to the lower rear part,
The ground work implement (2) is connected to the tractor (1) so that it can be lifted and lowered via the (5) and the retractable top link (6) pivotally attached to the top link hitch (12) at the upper rear center. And tractor
The universal joint shaft (17) connected to the PTO shaft (15) of (1) is provided so as to drive the ground work machine (2), and the universal joint shaft (1
In order to allow the 7) to rotate smoothly, it has an attitude control section (18) configured to control the extension and contraction of the top link length corresponding to the respective vertical positions of the ground working machine (2). In the front-rear posture control device of the ground work machine, the top link (6) is pivotally attached to the top link hitch (12) at the top of the standard top link (Ts) and Special top link that is below and behind
Discrimination sensor for discriminating whether or not each (Ts) is attached
(S ₁ ) is provided so that the control mode of the posture control section (18) can be switched based on the discrimination information by the discrimination sensor (S ₁ ). Is.

[Examples and operations]

Next, one embodiment of the present invention will be described with reference to the drawings. First
As shown in the figure, on the rear part of the tractor (1), a pair of left and right lift arms is provided with a rotary tiller as an example of the ground working machine (2).
To (3) and (3), it consists of left and right lower links (5) and (5) that swing up and down via left and right lift rods (4) and (4), and a top link (6) in the upper center. It is connected by a three-point link mechanism (7), and this three-point link mechanism (7)
(3) and (3) are moved up and down by a hydraulic lifting mechanism that moves up and down by a lift cylinder (8) using hydraulic pressure.

The top link (6) is formed by the top link cylinder (9) and the piston (9a) so that it can expand and contract, and the expansion and contraction drive part (10), which is composed of something like an electromagnetic switching valve, causes the pressure oil of the oil pump to move. By controlling the supply and discharge to the top link cylinder (9) of the
The rear connecting pin (11), (11) of (5) rotates in the front-back direction as a fulcrum, and the top link (6) has
A pin (13) is attached to one of the upper front mounting holes (a ₁ ) (a ₂ ) ... of the top link hitch (12) provided in the center of the rear upper part of the tractor (1).
The standard type top link (Ts) pivotally attached by (Fig. 1 and Fig. 2 which is an enlarged view of the main part) and the pin (13) in the lower rear mounting hole (b) of the top link hitch (12). There are special type top links (T _P ) (Fig. 3) that are to be pivotally attached at, and the special type top links (T _P ) are shorter than the standard type top links (Ts). Has become.

The PTO shaft (15) of the tractor (1) and the input shaft (16) of the ground working machine (2) can be freely moved to drive a working part (14) such as a tiller of the ground working machine (2). Although connected by the joint shaft (17), the bending angle (α) of the universal joint shaft (17) with respect to the PTO shaft (15) and the bending angle (β) of the universal joint shaft (17) with respect to the input shaft (16) As shown in FIG. 4, it varies depending on the lifting height and the longitudinal posture of the ground work implement (2) with respect to the tractor (1). ) Is lifted and the top link (6) is controlled to expand and contract to control the posture of the ground work implement (2) in the front-rear direction, unreasonable force is applied to the joint part of the universal joint shaft (17). The flexible joint shaft (17) is configured so that the bending angle of the universal joint shaft (17) can be checked and the expansion and contraction of the top link (6) can be controlled within a safe range so that it can rotate smoothly. For the case of the attitude control system are, describing the application of the exemplary invention embodiment.

That is, it has been clarified that α = β should be set as the condition that the universal joint shaft (17) can be rotated most smoothly with the least occurrence of unreasonable force on the joint portion, and this is the most desirable standard. Curves (As) and (Ap) are shown in Fig. 5 (a) for the standard type top link (Ts) and in Fig. 5 (b) for the special type top link (Tp), and , Α + β <40 ° and α-β <5 as a condition to rotate sufficiently safely
It is known that it should be ゜, and the former is a safety curve.
(A ₁ ) and (A ₂ ) and the latter are shown as safety curves (A ₃ ) and (A ₄ ), respectively.

Then, an inclination angle sensor (S _θ ) composed of, for example, a rotary potentiometer for detecting a lift arm angle (θ) as an inclination angle in the front-rear direction with respect to the tractor (1) of the ground work machine (2). And a top link sensor (Sl), such as a linear movement type potentiometer for detecting the length of the top link (6), is provided, and the lift arm angle (So) input from the tilt angle sensor (So) is provided. based on θ), an attitude control unit composed of, for example, a microcomputer shown in the control block diagram of FIG.
The calculating means (19) of (18) is configured to calculate the standard top link length (Ls), the safety top link length (Lmin), and (Lmax) for each lift arm angle (θ).

That is, the calculation means (19) has the standard curve (A) shown in FIGS.
s), (Ap), safety curves (A ₁ ), (A ₂ ), (A ₃ ), (A ₄ ) are stored respectively, and are attached to the side of the top link hitch (12), for example. A discrimination sensor (S ₁ ) such as a limit switch
As shown in Fig. 3, when the pin (13) closes the normally open contact (S _1a ) by pushing the actuator (S _1c ), the special type top link
(Tp) The information that it is in use is displayed again, as shown in Fig. 2.
_1c ) is not pushed, the normally open contact (S _1a ) remains open, and information that the standard top link (Ts) is in use is input to the calculation means (19), and detected. The standard top link length corresponding to the lift arm angle (θ)
(Ls) and the like will be output from the calculation means (19) and input to the correction means (20) of the next stage.

The correction means (20) includes a top link length (L) from the top link sensor (Sl) and a top link length correction switch (near the driver's seat (24) as shown in FIG. S
_The target top link length (La) of the top link (6) to be controlled by inputting the correction instruction value (ΔL) by ₂ ) and the extension instruction value (Δl) by the top link extension step switch (S ₃ ) respectively. Is calculated.

That is, the top link length correction switch (S ₂ ) functions only when the top link control changeover switch (S ₄ ) is automatically switched, and it is the standard at that time depending on the operation position. The correction instruction value (ΔL) of (±) with respect to the top link length (Ls) is input to the correction means (21).

The top link expansion / contraction step switch (S ₃ ) functions regardless of the switching position of the top link control changeover switch (S ₄ ), and the arrow from the neutral position shown in FIG.
If you tilt it in the direction (+), and in the direction of the arrow Y, you will (-), and if you repeat the tilting operation at a small interval, for example, 3 times, or in the X direction, it is 3 times that of one operation. (+) Expansion / contraction instruction value (Δ
l) will be input to the correction means (20).

Further, in the correction means (20), as shown in the flow chart of FIG. 8, when the top link control changeover switch (S ₄ ) is manually operated, the target top link length (La) is equal to the top link expansion / contraction step (S ₃ ) Is only added to the expansion / contraction instruction value (Δl) to the current top link length (L), and if the top link expansion / contraction step switch (S ₃ ) is operated and then held in the neutral position as is, Expansion / contraction instruction value (Δl)
Is added as (-) so that the target top link length (La) returns to the original value.

Whether or not the PTO axis (13) is used is detected by the PTO axis sensor (S ₅ ), and when the PTO axis (15) is not used, the target top link length (La) = L + ΔL is set. .

When the PTO shaft (15) is used, the correction instruction value (ΔL) and the extension instruction value (Δl) by the top link length correction switch (S ₂ ) and the top link expansion / contraction step switch (S ₃ ).
The target toplink length (La) is added to the standard toplink length (La), and by holding the neutral position of the toplink telescopic step switch (S ₃ ), the telescopic instruction value up to that point (Δl) will be canceled.

And the target top link length obtained in this way
(La), safety top link length (Lmin), (Lmax), and top link length (L) are input to the comparison command means (21), and the target top link length (La) is the safety top link. Link length
It is checked whether it is within (Lmin) to (Lmax), and if it is out of this, the target top link length (La) is corrected to the nearest safety top link length, and then the top link The length (L) is the safety top link length (Lm
in) or (Lmax), the command to stop the PTO shaft (15) is output to the PTO drive unit (22) when the PTO automatic off switch is turned on, and the top link length is set.
A command is given from the comparison command unit (21) to the expansion / contraction drive unit (10) so that (L) matches the target top link length (La).

Then, the instruction for raising and lowering the ground work implement (2) is the raising and lowering position and the setting device.
(I ₁ ) indicates the target lift arm angle corresponding to the indicated height, for example, and the comparison command unit (21) instructs the lift drive unit (23) so that the lift arm angle (θ) matches this. However, in this case, the standard top link length (La), safety top link length (Lmin) and (Lmax) corresponding to the target lift arm angle are not immediately shown, but
An intermediate standard lift arm angle obtained by adding or subtracting one scale angle, for example, 1 ° to the current lift arm angle (θ) toward the target lift arm angle is selected, and the intermediate standard top link corresponding to this intermediate target lift arm angle is selected. The length and the intermediate safety top link length are calculated, and based on these, the above-mentioned correction and control are performed to avoid the sudden expansion / contraction control of the top link (6). When the lift arm angle (θ) approaches the target lift arm angle up to a certain value, a pulse command from the comparison command unit (21) is given to, for example, an electromagnetic switching valve of the expansion / contraction drive unit (10). As a result, the expansion and contraction of the top link (6) is decelerated, and abrupt changes in the bending angles (α) and (β) of the universal joint shaft (17) are avoided.

The control block diagram of FIG. 6 also shows the basic configuration of the automatic tilling resistance control and the automatic plowing depth control, but in addition, the left / right posture control of the ground work machine (2) can be used at the same time. It is a thing.

In order to detect the tilt angle of the ground work machine (2) with respect to the tractor (1) in the front-rear direction, in addition to the lift arm (3) described above, the weight attached to the ground work machine (2) or the lower link (5 Various methods can be used, such as the method of detecting the inclination in the front-back direction of).

The function of the attitude control unit (18) may be various ones other than the above-mentioned embodiment, for example, even when there is no top link telescopic step switch (S ₃ ), the present invention is
It is fully applicable.

As the discrimination sensor (S ₁ ), a photoelectric switch or the like can be used besides the above-mentioned embodiment.

〔The invention's effect〕

The front-back attitude control device for a ground work machine according to the present invention is configured as described above, and the currently installed top link (6) is a standard top link (Ts),
Or, if it is a special type 3P link (Tp), the discrimination sensor (S
_The position of the top link (6) is accurately input to the attitude control unit (18) by (1), and the length of the top link (6) is set to the ground work so that the universal joint shaft (17) can rotate smoothly. Since the expansion and contraction control is performed at each lifting position of the machine (2),
With the above type of top link (6), it was possible to eliminate the need for the conventional mode switching operation, and to eliminate the operational mistakes resulting from this switching operation. The work can be accomplished.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a side view in a working state, FIGS. 2 and 3 are enlarged side views of main parts of respective top link mounting portions, and FIG. 4 is a universal joint. Explanatory view showing the inclination of the shaft, FIGS. 5 (a) and 5 (b) are characteristic diagrams showing the desired length of the top link, FIG. 6 is a control circuit block diagram, FIG. FIG. 8 is a control flowchart. Explanation of symbols (1) …… Tractor (2) …… Ground work equipment (5) …… Lower link (6) …… Top link (12) …… Top link hitch (15) …… PTO shaft (17)… … Universal joint axis (18) …… Attitude control unit (S ₁ ) …… Discrimination sensor (Ts) …… Standard top link (Tp) …… Special top link

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nakashiro Mukai, No. 1 Hachikura, Tobe, Iyo-gun, Ehime Prefecture, Engineering Department, Iseki Agricultural Machinery Co., Ltd. (56) References

Claims (1)

[Claims] 1. A ground work machine is freely lifted and held by a tractor through left and right lower links pivotally attached to a lower rear portion and an extendable top link pivotally attached to a top link hitch in an upper rear center. It is provided to drive the ground work machine by the universal joint shaft connected to the PTO shaft of the tractor, and the universal joint shaft can be rotated smoothly so that the universal work machine can be rotated smoothly. In the front-rear posture control device for a ground work machine having a posture control unit configured to control the extension and contraction of the link length, the pivot position of the top link to the top link hitch is the front position at the top. The standard type top link and the special type top link below the pivoting position and the special type top link, which are located at the rear, are provided with a determination sensor. Based on different information, before and after the posture control device for ground working machine, characterized in that to be able to switch the control mode of the posture control unit.