JPS61205402A - Front and rear posture control apparatus 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] [Industrial Application Field] 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 working part of a ground work machine while it is still rotating, or in order to improve the flying performance and plowing performance during plowing work, the top link can be reduced in order to control the forward and backward inclination of the ground work machine, or We proposed a longitudinal attitude control device that limits the extension and contraction of the top link to ensure safe rotation of the universal joint shaft for power transmission between the tractor and ground work equipment during each extension operation. It is something to do.

[Conventional technology]

In order to ensure sufficient lifting height or to improve plowing performance, the length of the top link is controlled to extend or contract by manual or automatic operation, and the posture of the ground work equipment in the longitudinal direction relative to the tractor is controlled. A working machine elevation control device is known as Japanese Patent Application Laid-open No. 14710/1983.

The working part of the ground work machine is driven by a universal joint shaft that connects the circular axis of the tractor and the input shaft of the ground work machine. The bending angle of the part will vary depending on the lifting height and the above-mentioned front and rear same posture, and if this becomes too large, problems such as damage to the joint bottle will increase rapidly, so it is difficult to raise and lower the ground work machine. It must be ensured that the bending angle of the joint is within a safe range and does not become excessive when the top link is extended or retracted. However, since conventionally known control devices do not have such confirmation means, there is a risk that the bending angle will become excessive.

Therefore, the applicant proposed that for each inclination angle in the longitudinal direction of the ground work machine,
Japanese Patent Application No. 59-253777 and Japanese Patent Application No. 59-2 propose a method of calculating the top link length at which the universal joint shaft can rotate safely and controlling the top link to this length.
58790, the size of the bending angle that can be rotated at a safe pressure changes depending on the magnitude of the load acting on the universal joint shaft. When it is small, the universal joint shaft can rotate safely even if the bending angle becomes large. Therefore, if the length range of the top link that can be safely rotated for each inclination angle is changed in relation to the work load, it is possible to make it wider than the technique of the above-mentioned application filed by the applicant. Therefore, the range of longitudinal posture control becomes wider, which is advantageous in actual work.

[Problem that the invention seeks to solve]

This invention increases the range of longitudinal posture control by making the length range of the top link in which the universal joint shaft can rotate safely in relation to the size of the work load wider than that of the above-mentioned existing application. This is what I did.

[Means for solving problems]

That is, the left and right lower links (5) (5) and the expandable top link (6) 9! : Via tractor (1
) is provided so as to be driven by a universal joint shaft 09 connected to the PTO shaft (+1) l'c of the tractor (1), and the ground work machine (2) is connected to the
In the longitudinal attitude control device for a ground work machine configured to control the front and rear same attitude of the ground work machine by the extension and contraction operation of the top link (6), the inclination angle of the ground work machine (2) in the front and back direction with respect to the tractor (1) is controlled. a tilt angle sensor (J) to detect;
Equipped with a top link sensor (SL) that detects the length of the top link (6) and a load sensor (Sd) that detects the work load acting on the ttS, the flexible joint shaft a4 Means for calculating the length of the safety top link in accordance with each inclination angle when the safe rotation range is reached in relation to the above, and top link control for controlling the expansion and contraction of the top link within the safety top link length. This is a longitudinal attitude device for a ground work machine having a control unit comprising means.

[Example and operation]

Next, one embodiment of the present invention will be described based on the drawings. Second
As shown in the figure, the ground work equipment (
As an example of 2), move the rotary tiller device to the left and right pair of lift arms 13) + 3), and move the left and right 7 trods (4).
The left and right lower links (5) swing up and down via (4).
) (5) and a top link (6) at the upper center.This three-point linkage mechanism (7) connects its lift arms (3) (3) using hydraulic pressure. The elevator is lifted and lowered by a hydraulic lifting mechanism that is rotated up and down using a lift cylinder (8).

The top link (6) is formed to be extendable and retractable by a top link cylinder (9) and a piston (9a), and is configured to control the top link of the pressure oil of the oil pump by the operation of an extendable drive unit (IG) consisting of something like an electromagnetic switching valve. By controlling the supply and discharge to and from the cylinder (9), the ground work machine (2) can control the connection bin αυaUt− at the rear of the lower link (5) (5).
It rotates in the front and back direction as a fulcrum, and in order to drive the working part a2 such as the tiller of the ground work machine (2), the PTO shaft a3 of the tractor (R) and the input shaft of the ground work machine (2) α4 is connected by a universal joint shaft QS.

The bending angle (φ
And the bending angle of the universal joint shaft α9 with respect to the input shaft I.

As illustrated in FIG. 3, the universal joint shaft 051 changes depending on the lifting height and longitudinal posture of the ground work equipment (2) attached to the tractor (1), and the joint part of the universal joint shaft 051 It has been found that the condition that produces the least amount of unreasonable force and allows for the smoothest rotation is α = β.
As shown in Figure @4, this is shown as the most desirable standard picture @(At).

The conditions for the safe rotation of the universal joint shaft ncj are α+β(f+(dl) and α−β(fz(di), but r ldl , fz (dl
can be determined by the load (dl) acting on the universal joint shaft 0!9. For example, as the load d decreases, f x (dl, r! (d) increases, and in the same figure, the load For example, city and dt (where city < d
The safety curve for the universal joint axis a in case 2) (Sts
), (St and (Sh) are shown as examples respectively. That is, for example, when the load is d, the safety curve (S
If the top link length LJ for each lift arm angle is between tt) and 0 (rotation), the universal joint shaft rotor can be rotated easily and safely.

Then, an inclination angle sensor (Sd) consisting of a one-turn type potentiometer for detecting, for example, the lift arm angle as the inclination angle in the longitudinal direction with respect to the tractor (1) K of the ground work machine (2). ) for detecting the length of the top link (6).
t>, and based on the lift arm angle (θ) input from the inclination angle sensor (99), the control unit a8, which is made up of a microcomputer, etc., shown in the control block diagram in FIG. In the correction means α9, the respective lift arm angles (safety top link length 1 inch) and (I) nax) are calculated.

That is, the standard curve (Ao, safety curve (Stt) e (9tt) t (
8tt) e (shz)... is memorized, and PT
Load sensor (sd) that detects the load acting on the O-axis 03
is input to the calculation means a9 via the interface, and the corresponding safety curves (8tt), (Sh...) are read out from the safety curve storage section (■) according to the rotational speed, and calculated for each lift arm angle (θ). Safety top link length l
m1n) and (hnax), and on the other hand, the length of the top link (6) is determined by the top link length setting device (11), which is composed of something like a potentiometer.
In other words, since the longitudinal posture of the ground work machine (21) is specified and the specified top link length and the current length of the top link (6) are input, this specified top link length is the safety top link length. Saku Itn in)～(L
The comparison command means C determines whether the values are within the range max
υ, and if it deviates from this, the specified top link length is corrected by the calculation correction means a1 to the nearest safe top link length, and the length of the top link (6) is adjusted to this specified top link length. The configuration is such that a command is given from the comparison command means 12υ to the telescopic drive unit Ql so that the positions match.

For example, a torque sensor that detects the torque acting on the PTO shaft 03 may be used as the load sensor (Sd), but since the installation location and detection output extraction means are troublesome, the illustrated example is used as a simple detection means. Now, as shown in the block diagram of Fig. 5, we will start with something like a rotary potentiometer that is activated by the rocking movement of the rear cover (■) whose lower edge slides into contact with the soil surface and swings up and down. Ground working machine 12) detected by the plowing depth sensor (Sb)
The plowing depth detection value is set by the plowing depth setting device (■2), which is provided to control the ground working machine (2) to a predetermined plowing depth by raising and lowering the lift arms (3) (3). When the permissible range of plowing depth set value is within the pronation for a certain period of time (T) as shown in FIG. It is determined that the load (d2) of When the ground working machine (2) is in the lowering operation and the working part 03 is not in contact with the ground, the load (dl) acting on the universal joint shaft 69 is is a small value just for rotating a member such as one working part α, and in this way, a simple load sensor (Sd) whose detection characteristic value is the plowing depth value is a small value.
are using.

The above safety curve (Stt), (8ht), (8
t*), (She)-...! ! , several types can be set depending on the size of the plowing depth setting value. Then, when performing control operations to reach the target vertical height of ground work equipment (2) '4-, the safety top link lengths Lmin) and (Imax) corresponding to the target lift arm angle are not immediately displayed; An intermediate target lift arm angle that is the same as the target lift arm angle and is obtained by adding or subtracting one scale angle, for example, P゛ to the current lift arm angle (θ), is selected, and an intermediate safety top corresponding to this intermediate target lift arm angle is selected. The top link (6
), and when the lift arm angle (θ) approaches the target lift arm angle to a certain value, the comparison command means (21) issues, for example, a pulse-like command. Telescopic drive! flsQI is applied to, for example, an electromagnetic switching valve to slow down the expansion and contraction movement of the top link (6), thereby avoiding sudden fluctuations in the bending angle (φ) of the universal joint shaft a9.

In order to detect the inclination angle of the ground work machine (2) in the longitudinal direction with respect to the tractor (1), it is necessary to Various methods can be used, such as the method of detecting the longitudinal inclination in 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 calculates the safety top link length in relation to the load acting on the universal joint shaft (151). Top link (6) inside?
For example, when the work load is small, the length range of the top link (6) that can be used is wider than that of a large knife (and the longitudinal posture of the ground work machine (2) is also wider). In this way, it has become possible to control the posture in the longitudinal direction with no waste and with a large degree of freedom in accordance with the load acting on the universal joint shaft α9.

[Brief explanation of the drawing]

The figures show one practical example of the present invention, Fig. 1 is a control circuit block diagram, Fig. 2 is a side view in a working state, and Fig. 3 is a W
FIG. 4 is a characteristic diagram showing the safety curve of the top link, FIG. 5 is a control block diagram showing an example of a load sensor, and FIG. 6 is a characteristic diagram of the load sensor. Code explanation (1)...Tractor (2)...
・Ground work equipment (5)...Lower link (6
)...Top link 0...PTO axis
0!9... Universal joint shaft OI...
Control unit (819)...Tilt angle sensor (Sd
)...Load sensor (S')...Top link sensor patent Applicant: Iseki Agricultural Machinery Co., Ltd. Figure 3b Rough Tsushiku Nagamu Figure 5

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; Equipped with a top link sensor that detects the length of the top link and a load sensor that detects the load acting on the universal joint shaft, allowing the universal joint shaft to rotate safely in relation to its bending angle and the size of the work load. The control unit includes a means for calculating the length of the safety top link in accordance with each inclination angle when the safety top link is within the range, and a top link control means for controlling the expansion and contraction of the top link within this safety top link length. A longitudinal attitude control device for ground-based work equipment.