JP2743528B2 - Left and right tilt attitude control device for ground work machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for controlling a left-right inclination posture of a ground working machine connected to a powered vehicle such as a tractor.

[Prior art and its problems] Conventionally, as this kind of device, a rotary tilling device is connected to the rear of a tractor via a three-point link mechanism so as to be able to move up and down, and a pair of right and left connecting a lift arm and a lower link. Of the lift rods, only one side is constituted by an extendable hydraulic cylinder, and hydraulic oil is supplied to the hydraulic cylinder to adjust the left-right inclination posture of the rotary tilling device. In particular, in recent years, many types of rotary tilling devices that automatically control the left and right postures to a desired posture have become widespread. In this case, a sensor for detecting the left and right inclination posture is installed on the tractor main body, and the hydraulic cylinder is provided. A stroke sensor for detecting the amount of expansion and contraction is provided beside the, and the rotary tilling device is controlled so as to always be in the set posture.

However, in the case where the stroke sensor is provided on the lateral side of the hydraulic cylinder, since the sensor is expensive, there is a disadvantage that the manufacturing cost of the entire apparatus is high.

[Means for Solving the Problems] The present invention has been proposed in view of the above problems, and has taken the following technical means. That is, the power vehicle 1
Attitude detecting means 18 for detecting the left-right inclination angle of the vehicle, attitude setting means 41 for setting the left-right inclination attitude of the ground working machine 14 connected to the vehicle 1, and an attitude for changing and adjusting the machine angle of the ground working machine 14 relative to the main body. Changing means 15a, and means for setting an output time for controlling the attitude changing means 15a based on a deviation between a value detected by the inclination detecting means 18 and a value set by the setting means 41, and only for the set time. A driving signal is output to the posture changing means 15a to maintain the ground work machine 14 in a predetermined posture, and a left-right inclination posture control device for the ground work machine is provided.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A description will be given using an agricultural tractor as an example. First, a description will be given of the configuration. Reference numeral 1 denotes a tractor, which has front wheels 2, 2 and rear wheels 3, 3 at the front and rear portions of the fuselage, respectively, and has a hydraulic cylinder case 5 fixedly provided at a rear upper portion of a transmission case 4. .
A single-acting hydraulic cylinder 6 is provided in the hydraulic cylinder case 5, and lift arms 7, 7 are pivotally supported on both left and right sides of the hydraulic cylinder case 5.

A rotary tilling device 14 as a ground work machine is connected to the rear end of the three-point link mechanism 12 including the top link 10 and the lower links 11, 11, between the lift arms 7, 7 and the lower links 11, 11. The lift rods 15, 15 are interposed and connected.

Of these lift rods 15, one of the lift rods 15 (on the right side in this embodiment) is constituted by an extendable hydraulic cylinder 15a.

Reference numeral 20 denotes a hydraulic operation lever, and a ground height setting device 21 for setting the height of the ground work is attached to a turning base of the operation lever 20. On the other hand, the rotation base of the one-side lift arm 7 is also provided with a rotation angle thereof, in other words, a ground height detector 23 for detecting the height of the ground work machine, and the height set by the hydraulic operation lever 20. The position control mechanism is configured so that the lift arms 7, 7 rotate and stop. 18
Is a tilt detector mounted and fixed on the side of the hydraulic cylinder case 5 of the tractor 1, which detects the left and right lateral tilt of the tractor 1.

Next, the configuration of the rotary tilling device 14 will be described. The rotary tilling device 14 includes a tilling unit 34, a main cover 35 that covers the upper part of the tilling unit 34, and a rear cover that is pivotally attached to the main cover 35. 36, etc., the lower end of the rear cover 36 is slid in contact with the ground so as to be elastically pressed to even out the cultivated soil surface, and the upper end of the main cover 35 is provided with a rotation of the rear cover 36. A tillage depth detector 37 for detecting an angle is provided.

FIG. 4 is a block diagram of the hydraulic control device. The ground height setting device 21 for setting the height of the working machine and the ground height detector 23 for detecting the actual positions of the lift arms 7, 7 are shown in FIG. A /
It is connected to a control unit 27 composed of a CPU via a D converter 25.
Reference numeral 28 denotes an elevating switch directly connected to the control unit 27 without passing through the A / D converter 25.When the switch 28 is turned on, the work implement 14 is raised to the maximum ascending position, and when turned off, the hydraulic It descends to the position determined by the operation lever 20. Dial-adjustable working depth setting device 40 provided near the cockpit
And a tillage depth detector 37 for detecting the tillage depth of the rotary tillage device 14.
Is connected to the control unit 27 via the A / D converter 25. Also, 4
1 is a tilt setter for adjusting the amount of tilt of the rotary tilling device 14 in the left and right direction. The tilt setter 41 and the tilt detector 18
It is connected to the control unit 27 via the D converter 25. Reference numeral 29 denotes a control valve for controlling the supply and discharge of hydraulic oil to and from the hydraulic cylinder 6, and is configured to be switchable by a lowering solenoid 30 and a highering solenoid 31. Reference numeral 42 denotes a control valve for the oil control cylinder 15a for tilt control.
3 and the shortening solenoid 44 can be switched as appropriate. In the figure, reference numeral 46 denotes a flow dividing valve, 47 denotes a hydraulic pump, and 48 denotes a relief valve. A variable throttle 50 is provided between the flow dividing valve 46 and the control valve 42 for adjusting the inclination, and a three-stage flow rate can be set by a flow rate switch 51 described later.

FIG. 5 shows the flow rate characteristics of the hydraulic oil which can be selected by the changeover switch 51, in which the horizontal axis represents the inclination amount of the body and the vertical axis represents the stroke amount. 54 is a switch for returning the rotary tillage device 14 to be parallel to the tractor 1, and 55 is a parallel position detector for detecting that the lengths of the left and right lift rods 15 and 15a match each other. An on / off switch 56 is housed on the side surface of the cylindrical body 55a, and the hydraulic cylinder 15a extends and contracts until the rod 55b inserted into the cylindrical body 55a presses the switch 56 of the detector 55.

Next, the operation will be described. FIG. 6 shows the contents of the program stored in the memory of the control unit 27.

When performing the tilt control to keep the rotary tillage device 14 horizontal, first, the set value of the tilt setter 41 and the detected value of the tilt detector 18 are read, and the difference between them is calculated.

Then, from the difference (xy) between the two, the rotary tilling device
Calculate the output time required to keep 14 approximately horizontal. In this embodiment, the inclination control is performed by regarding the deviation multiplied by the constant a as the output time of the timer, but the reference engine rotation at this time is that at the rated rotation.

Then, until the calculated output time is reached, the control valve 42
The extension solenoid 43 or the shortening solenoid 44 is excited, and the hydraulic cylinder 15a is controlled to expand and contract so that the rotary tillage device 14 is horizontal.

As described above, in this embodiment, the output time for keeping the work implement horizontal is calculated according to the difference between the tilt set value and the tilt detection value, and the extension solenoid 43 or the extension solenoid 43 of the control valve 42 is calculated for that time. Since the shortening solenoid 44 is configured to be excited, it is not necessary to provide an expensive analog type stroke sensor as in the related art, thereby realizing an inexpensive left-right attitude control device for a ground work machine. In the attitude control based on time alone, errors may be accumulated and accuracy may be reduced.However, if the timer set is configured to be reset when the parallel return switch 54 is pressed, the work is performed. There is no problem.

The flow rate changeover switch 51 described in this embodiment is
When the rotary installation width is changed, this is appropriately switched. More specifically, the lower link 11, 11
When the mounting width of the hydraulic cylinder 15a is large, the flow rate is increased to increase the amount of expansion / contraction of the hydraulic cylinder 15a per unit time (Fig. 5A). Conversely, when the mounting width of the lower links 11, 11 is smaller than the standard, , To reduce the flow rate (FIG. 5B). As described above, if the amount of hydraulic oil of the hydraulic cylinder 15a is changed according to the mounting width of the lower links 11, 11, complicated gain switching as described in JP-A-59-14707 can be achieved. There is no need to provide a mechanism, and the device can be manufactured at a low cost with a simple configuration. It is preferable that the flow rate is switched not only in the automatic control mode but also in the manual operation mode so that the operator can directly operate the variable throttle 50.

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

That is, the output time for controlling the attitude changing means 15a is calculated according to the difference between the set value set by the left and right tilt attitude setting means 41 of the powered vehicle 1 and the detection value detected by the tilt detecting means 18, and Since the drive signal is sent to the attitude changing means for the calculated time to maintain the ground work machine 14 in the predetermined attitude, the configuration is simpler than that of the conventional apparatus, and an inexpensive attitude control apparatus can be obtained. it can.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an overall side view, FIG. 2 is a perspective view, FIG. 3 is a rear view of a main part, FIG. 4 is a block diagram, and FIG. FIG. 6 is a flowchart. DESCRIPTION OF SYMBOLS 1… Powered vehicle (tractor) 7, 7… Lift arm 14… Ground work equipment (rotary tilling device) 15… Lift rod 15a… Hydraulic cylinder 18… Tilt detector 41… Tilt setting Unit 51 Flow rate changeover switch 54 Parallel return switch

Claims (1)

(57) [Claims] An attitude detecting means for detecting a left-right inclination angle of a power vehicle, an attitude setting means for setting a left-right inclination attitude of a ground working machine connected to the vehicle, and a ground working machine. Attitude changing means 15a for changing and adjusting the machine angle, and means for setting an output time for controlling the attitude changing means 15a based on a deviation between a value detected by the inclination detecting means 18 and a value set by the setting means 41; And a driving signal is output to the posture changing means 15a for a set time to maintain the ground work machine 14 in a predetermined posture.