JPS6119403A - Front and rear direction 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 Field of Application This invention is capable of securing sufficient ground clearance when temporarily hoisting a ground-based working machine during work, for example, for turning movement, etc. Moreover, the present invention relates to a longitudinal attitude control device for a ground-based work machine that eliminates the need to interrupt the transmission of working power.

Conventional technology A ground work machine such as a rotary tiller, which is connected to a towing machine through a three-point link mechanism consisting of left and right lower links and a short top link at the upper center, is connected to the PT of the towing machine.
The power of the O-axis is transmitted to the input shaft of the ground work machine via the universal joint shaft. In order to ensure the ground clearance of the ground-based work equipment during lifting, the top link is configured with an extendable top link cylinder, and by contracting the top link during lifting, the lower part of the ground-based work equipment can be moved backwards. I know of one that has a forward-leaning posture that allows it to spring upwards. During the lifting operation, as schematically shown in Fig. 4, when the cultivating body 0) of the ground work machine is lifted to the solid line position, the PTO shaft (2), the universal joint shaft (3) ), the input shaft (4) is at the position indicated by the solid line, but when the top link is reduced at this lifting position, the tilling body (1
) rises as shown by the dotted line, and the universal joint shaft (3) and input shaft (
4) It will be moved to the dotted line position, and the universal joint shaft (3
) and the input shaft (4) change to an obtuse bending angle (C) due to the reduction of the top link, so that the input shaft (4) of the universal joint shaft (3) ) will vary greatly.

Conventionally, the lifting operation was performed by first stopping the rotation of the PTO shaft (2), then lifting the ground work equipment to a predetermined height.
Finally, the top link is reduced to one degree, and the bending angle is suddenly changed while the universal joint shaft (3) and input shaft (4) are stopped.
This prevents damage to the universal joint shaft (3), etc. However, when the PTO shaft (2) comes to a complete stop at the working position, the tilled soil remains stuck to the claws of the tiller body (2), and in the lifted state, this stuck soil overhangs the traction machine and lifts the tiller. This is dangerous as it adds to the weight of the suspended ground work equipment, reducing the stability of the towing machine in the longitudinal direction.Furthermore, if the amount of reduction of the top link is too large, it may cause folding. The bending angle may also become excessive and the joint portion may be damaged.

Problems to be Solved by the Invention This invention prevents sudden changes in the bending angle of the universal joint shaft and input shaft during lifting operations, and performs lifting operations without stopping the PTO shaft. It has been devised so that it can be done.

Means for Solving the Problems In order to solve the above problems, the present invention has taken the following technical measures. In other words, the ground work machine (2) is connected to the traction machine (1) through the three-point linkage mechanism (7) and raised and lowered by the hydraulic lifting mechanism (8), and its longitudinal posture is adjusted to suit the ground work. The top link (6) of the three-point linkage mechanism (7) is arranged so that as the aircraft (2) rises, it gradually shifts to a forward leaning position.
Wow, it is configured to perform reduction control.

Embodiments and Functions>k- An embodiment of the present invention will be explained based on the drawings. As shown in Figure 1, a rotary tilling device, which is an example of a ground work device (2), is connected to a pair of left and right lift arms (3) at the rear of a tractor as a towing machine (1), and left and right lift rods. (The left and right lower links (5), (5) that swing up and down via Q(4), and the top link (6) at the upper center
) A three-point linkage mechanism (7) K, thus connected,
This three-point linkage mechanism (7) is connected to its lift arm (31).
, (33) A hydraulic lifting mechanism (lifting and lowering operation is carried out from 81') that uses hydraulic lift cylinders to move up and down. The top link (6) has a top link cylinder (9) and a piston (9a). By controlling the supply and discharge of pressure oil from the oil pump I to the top link cylinder (9) through the operation of the electromagnetic switching valve (IQ), the ground work machine (2) 5) The connecting bin at the rear of the 153 rotates in the front and back direction as a fulcrum, and the electromagnetic switching valve (IQ
The control is carried out by the longitudinal inclination sensor (S,), the longitudinal inclination setting value peak, the vertical position sensor (S,), the twin link length sensor (
Based on the output of the control device α2 consisting of a microcomputer, the expansion drive circuit a3 and the reduction drive circuit I are
Each is performed by operating. That is, a longitudinal tilt sensor (S,) e, which transmits the longitudinal swing of the pendulum to the detection axis of a rotary potentiometer, a traction machine (installed on the 1st floor,
Connect the detection axis of the rotary potentiometer to the lift arm (3
) and rotates with the lift arm (3).
) is a lifting position sensor (S, ) that detects the lifting position of the
The detection axis of the linear sliding type potentiometer is connected to the piston (9
a) The top link length sensor (S3) is fixed at K and detects the length of the top link (9). The detected values of (S, ) are determined by the control device α
2 multiplexer (input to I!9, forward and backward tilt setting device (I) consisting of something like a rotary potentiometer) ff
Input to i multiplexer (to) and ground work equipment (2)
The longitudinal inclination setting device (I) inputs the predetermined longitudinal inclination posture of the A/n as a potential, and these detected values and set values are used as the
The control computer aη corrects the longitudinal inclination setting value of the longitudinal inclination setter (n) based on the detected longitudinal inclination value of the towing machine (1), and then converts it into a digital value using the D converter←Q. The relative longitudinal inclination setting value to be controlled with respect to the towing machine (1) K of the ground work machine (2) is determined, and the detected value of the current vertical position of the ground work machine (2) (in the example, the height of the lift arm (3) relative to the horizontal plane) is determined. Ground work equipment (2
) is controlled to the above-mentioned relative longitudinal inclination setting value (in the example, the longitudinal inclination angle (θ) at which the ground work equipment (2) should be maintained with respect to the vertical plane) is calculated. Then, the top link (6) is reduced until this top link length A matches the top link length detected by the top link length detector (S,). The reduction operation of the link (6) is performed by adjusting the link length 4 corresponding to each lift arm angle (dJ) in the control computer αη so that the length of the top link (6) gradually decreases as the detected value of the vertical position increases. ) is calculated and outputted to the drive circuit Q4 so that the detected value of the top link matches this top link length A, thereby preventing damage to the knuckle bin, etc. of the universal joint shaft (3). In order to That is, the lift arm angle (
The configuration is such that the above-mentioned top link length 4) is specified as φ increases. That is, when each lift arm angle (dJ), the top link length A for controlling the ground work machine (2) at various longitudinal inclination angles (θ) can be determined geometrically. As shown in Fig. 3, the PTO axis (2) is determined by the lift arm angle (b) and the top link length 4).
, the bending angle between the universal joint shaft (3) and the input shaft (4) (
a), (bl can also be found geometrically, so
As shown by the dotted line in Figure 3, a control characteristic curve in which the difference between the bending angles (al and (b) is, for example, 5°, 4°, etc.) is stored in the control computer 0.7+. The lift arm angle ((1)
The top link length 4) corresponding to the above is specified, and the drive circuit α4 is thereby controlled. When the longitudinal inclination angle (θ) calculated based on the calculation in the figure reaches r, the reduction control of the top link (6) ends. When descending, the above-mentioned control sound at the time of lifting can be reversed. Front and rear tilt sensor (S,)
may be installed on the side of the ground work machine (2), and in this case, control becomes easier, but the installation of the longitudinal inclination sensor needs to be replaced each time the ground work machine (powder is replaced). In contrast, in the illustrated example, such labor is not necessary.In addition, the elevation position detection is performed using the operating angle of the operating lever @ of the hydraulic elevation mechanism Qυ, and the elevation operation linked to the elevation operating lever (2). For example, a potentiometer may be used to detect one of the moving distances of a link in the mechanism.

Effects of the Invention As described above, the present invention provides a ground-based working machine that is connected to the traction machine (1) through the three-point linkage mechanism (7) and raised and lowered by the hydraulic lifting mechanism (8). The orientation is
The top link (6 of the three-point linkage mechanism (7)
), the PTO shaft (2) for driving the ground work machine (21) during lifting operations.
, the sudden change in the bending angles of the universal joint shaft (3) and the input shaft (4) causes the top link (6) to be sequentially reduced as the ground work equipment (2) gradually assumes a forward leaning posture. As a result, even if the ground work equipment (2) is hoisted to a sufficient height while being driven, the universal joint shaft (3)
), etc., and for example, there is no need to stop the drive during turning operation, making it easier to perform this turning operation, which requires many parts to be operated. This eliminates the need for soil to remain stuck to the plowing nails by climbing, which prevents the weight of the oparts from increasing during hoisting, and improves stability.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is an overall side view, FIG. 2 is a block diagram of the control device, FIG. 3 is a control characteristic diagram, and FIG. 4 is a ground work machine. It is an explanatory view showing a suspended state. Code explanation

Claims (1)

[Claims] A ground work machine connected to a towing machine via a three-point linkage mechanism and raised and lowered by a hydraulic lifting mechanism is configured so that its longitudinal attitude gradually shifts to a forward tilted position as the ground work machine rises. 1. A longitudinal attitude control device for a ground work machine, characterized in that the top link of the three-point linkage mechanism is configured to perform contraction control.