JPH02308702A - Apparatus for controlling posture of ground-working machine - Google Patents

Abstract

PURPOSE:To increase the controllable stroke range and stabilize tilling depth by controlling the above-ground height and the lateral drift of a ground-working machine based on the detection results of stroke sensors attached to a pair of right and left hydraulic actuators. CONSTITUTION:The average length of the right and left hydraulic actuators is calculated from the value set in a potentiometer (height setting device) 33 and, at the same time, the difference of the lengths of the right and left hydraulic actuators is calculated from the signal transmitted from an inclination sensor 34 mounted on a tractor. Target lengths of the right and left hydraulic actuators are set from the calculation results. When the length of the right actuator is shorter than the target value, a solenoid 46 is excited to extend the actuator and when the length is longer than the target value, a solenoid 47 is actuated to contract the right hydraulic actuator. Similar comparison processing is performed also on the left actuator and the hydraulic actuator is extended or contracted by the excitation of the solenoids of the left solenoid valves.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a posture control device for a ground work device connected to a power vehicle such as a tractor.

[Prior Art and its Problems] Conventionally, a ground work machine 30' such as a rotary tiller connected to the rear of a tractor 1 to 1' has a lift arm 13', 13' and a lower link as shown in FIG. are connected by two lift rods 27', 27', of which one lift rod 27' is constituted by a hydraulic actuator, which supplies and discharges hydraulic oil to it and controls the ground work equipment 30' in the left and right lateral directions. Tilt control was performed.

However, with conventional equipment like this, one side is fixed under the handle, so when maintaining the work equipment horizontally, simply extending and retracting the hydraulic actuator may control the plowing depth to be shallow or conversely to control the plowing depth to be deep. There was a problem that the plowing depth was not stable because of the control. Moreover, in this type of device, the single-acting main hydraulic actuator that constitutes the main hydraulic lifting device must be installed inside the cylinder case of the mission case, which increases the bulk of the device and creates space above the mission case. In addition, providing a seat above this would increase the minimum ground clearance, making it impossible to construct a low-bed tractor suitable for work inside a greenhouse.

[Means for Solving the Problems] The present invention is proposed in view of the above-mentioned problems, and enables a low-bed tractor, as well as the conventional method.
The present invention aims to provide a device that enables position control and rolling control of ground-based work equipment, and for this purpose, the following technical measures have been taken.

That is, the ground work equipment 30 is connected to the rear part of the power vehicle 1 via the link mechanism 17, and on the power vehicle 1 side there is a height setting device 33 for setting the height of the ground work equipment 30 and a tilting device in the left and right lateral directions. A lift rod 2 is provided, one end of which is connected to the fuselage, and the other end of which constitutes the link mechanism 17.
Double-acting hydraulic actuators 11.11 connected to 7.27 and raising and lowering the link mechanism 17 are provided at two places on the left and right of the end of the fuselage, and these hydraulic actuators 11.1
1 is a stroke sensor 28 that detects the amount of expansion and contraction.
．． 28 are provided close to each other, and both stroke sensors 28.
The controller 42 calculates and calculates the height and horizontal inclination of the ground work equipment 30 from the detected values of 28, and controls the work equipment to the posture set by the height setting device 33 and the inclination setting device 32. This is an attitude control device for a ground-based work machine characterized by the following features:

[Example] The present invention will be described in detail below based on one drawing.

First, to explain the configuration, 1 is a 1-rafter, an engine 2, a clutch housing 3. The fuselage is constructed by sequentially connecting the mission cases 4. mission case 4
A rear axle 7.7 is inserted into a cylindrical rear axle housing 6.6 fixed to both left and right sides of the vehicle, and rear axles 8, 8 are attached to the ends thereof. A frame member 10 for attaching the swing drawbar 9 is fixed to the lower part of the mission case 4, and the lower end portions of double-acting hydraulic actuators 11 and 11, which will be described later, are detachably attached to both sides of the frame member 10. . 14.14 is a lower link whose front end is pivotally connected to the lower end of the rear axle housing 6.6. Reference numeral 15 denotes a top link, the front end of which is pivotally attached to a top link holder 16 provided on the back of the fuselage.

Reference numeral 20.20 denotes a guide body fixed to both left and right sides of the rear upper part of the transmission case 4, and when viewed from the side, two guide plates 23.23 have guide grooves 22.22 that curve toward the front as they reach the top. They are provided facing each other. A bottle 25.25 is inserted and supported in this guide groove 22.22,
The hydraulic actuator 1 is located at the inner end of the bin 25.25.
1 piston rod 12.12 is connected. on the other hand.

The upper end of a lift rod 27.27 is pivotally attached to the bin 25.25 between the two guide plates 23.23, and the lower end of the lift rod 27.27 is attached to the lower link 14.
．． It is connected to the middle part of 14. Therefore, when pressure oil is supplied and discharged into the cylinder chamber of the hydraulic actuator 11.11, the piston rod 12.12 expands or shortens, causing the lift rods 27, 27 to move up and down, and the lower link 14.14 to move around the fulcrum at its front end. The ground working machine connected and supported by this three-point linkage mechanism 17 is configured to be rotated to move up and down. A stroke sensor 28.28 is attached to the rear surface of the hydraulic actuator 11.11 so as to be close thereto, and detects the amount of expansion and contraction of the piston rod 12.12. On the other hand, near the operator's seat of the tractor 1, there are a position lever 31 connected to the three-point linkage mechanism 17 for setting the elevation height of the ground-based work equipment 30, and a position lever 2 for setting the inclination angle of the ground-based work equipment 30 in the left and right lateral directions. A setting device 32 is provided.

33 is a potentiometer attached to the rotating base of the position lever 31; 34 is a tilt sensor installed on the transmission case 4 of the tractor 1 to detect the horizontal tilt; 36, 36 is a hydraulic pipe; 37 is the tractor 1
The PTO axis, 38.38, is the fender.

Next, the block diagram in FIG. 4 and the hydraulic circuit diagram in FIG. 5 will be explained. Height setting device 33 and tilt angle setting device 32 of the position lever 31. Tilt sensor 34. and stroke sensors 28 and 28 are connected to the CP'U via the A/D converter 41, respectively.
The control section 42 is connected to solenoids 44.45.46.47 for extending and contracting the two hydraulic actuators 11.11. 4
8 is a hydraulic pump, 50 is a diversion valve, 51.52 is a solenoid valve,
53 is a safety valve.

FIG. 6 shows a control flow for controlling the expansion and contraction of the hydraulic actuator 11.11 described above, and the contents of this control flow are stored in the memory of the control section 42 described above. To explain the operation based on this flow, first, the values of each setter and detector are read (step ■).

Next, the left and right hydraulic actuators 11.1 are adjusted based on the position of the position lever 31, that is, the value of the potentiometer 33.
1 is calculated (step ■), and at the same time, the difference between the left and right sides of the hydraulic actuator 11. The target lengths of the hydraulic actuators 11 and 11 are set (step ■), and if the length of the right hydraulic actuator 11 is smaller than the target value, the solenoid 46 is energized to extend the hydraulic actuator 11. On the contrary, if the length is larger than the target value, the solenoid 47 is energized to shorten the right hydraulic actuator 11 (step ■■), and the same comparison process is performed for the left hydraulic actuator 11, and the left hydraulic actuator 11 is shortened. Solenoid 4 of solenoid valve 52
4 or 45 to extend or shorten the hydraulic actuator 11 (step ■■).

In this way, by detecting the lengths of the left and right hydraulic actuators 11°11 with the stroke sensors 28.28 and calculating their average value, a reference for position control is obtained and the current height above the ground is known. One hydraulic actuator 11.1 can detect the horizontal tilt of the working machine 30 from the difference in the stroke sensors 28.28.
Although it is a single hydraulic actuator, it can perform position control and rolling control at the same time with high precision, and two hydraulic actuators 1
1.11 both extend and contract after setting the target length, so the control stroke becomes larger compared to conventional devices, and responsiveness can be improved.

[Effects of the Invention] Since the present invention is configured as described above, it has the following technical effects.

That is, since the height above the ground and the left and right lateral direction control of the ground work equipment 30 are performed based on the detection results of the stroke sensors 28.28 attached to the pair of left and right hydraulic actuators 11.11, the control is not performed as in the conventional case. Compared to a single-sided lift rod with a fixed length, the controllable stroke amount is increased, and the simpler structure also simplifies maintenance, making it possible to stabilize plowing depth during horizontal control. Furthermore, since the conventionally required cylinder case is no longer required, the vehicle height is lowered, thereby realizing a so-called low-bed tractor.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an overall side view, Fig. 2 is an enlarged side view of main parts, Fig. 3 is a rear view, Fig. 4 is a block diagram, and Fig. 5 is a block diagram. 6 is a hydraulic circuit diagram, FIG. 6 is a flowchart, and FIG. 7 is a rear view illustrating the operation of the mechanism. Explanation of symbols 1 Tractor 11.11 Hydraulic actuators 12, 12 Piston rod 14.14 Lower link 15 Top link 17 Three-point link mechanism 20.20 Guide body

Claims (1)

[Claims] A ground work machine 30 is connected to the rear part of the power vehicle 1 via a link mechanism 17, and the ground work machine 3 is connected to the power vehicle 1 side.
A lift rod 27 is provided with a height setting device 33 for setting the height of 0 and a slope setting device 32 for setting the inclination in the left and right directions.
, 27 and which move the link mechanism 17 up and down are provided at two places on the left and right of the end of the fuselage, and these hydraulic actuators 11, 11
a stroke sensor 28 that detects the amount of expansion and contraction of the
28 are provided close to each other, and both stroke sensors 28, 2
The controller 42 calculates and calculates the height and horizontal inclination of the ground work equipment 30 from the detected values of 8, and controls the work equipment to the posture set by the height setter 33 and the inclination setter 32. An attitude control device for a ground-based work machine, characterized in that: