JPH0549242B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an angle control device for a working machine such as a rotary, plow, or earth removal plate connected to a tractor, or a rice transplanter connected to a traveling vehicle, and in particular, the present invention relates to an angle control device for a working machine such as a rotary, plow, or soil removal plate connected to a tractor, or a rice transplanter connected to a traveling vehicle, and in particular, This paper proposes an angle control device for work equipment that aims to improve control stability.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to drawings showing embodiments of a rotary angle control device mounted on a tractor as a working machine.

FIG. 1 is a partially cutaway left side view of a tractor equipped with an angle control device according to the present invention (hereinafter referred to as the device of the present invention) and a rotary attached to the rear thereof, and FIG. 2 is a plan view of the main parts thereof. In the figure, 1 is a tractor main body, and 2 is a rotary attached to the rear of the tractor. It is installed so that it can be raised and lowered freely. That is, the front end of the top link 20 is connected and supported to the rear side of the hydraulic lift 10 via a top link hinge 22, and the rear end of the top link 20 is connected to the upper central part of the front end of the rotary 2, and the lower corner of both sides of the transmission case The front ends of a pair of left and right lower links 21, 21 are connected and supported through lower link pins 23, 23, and the rear ends of each lower link 21, 21 are connected to both sides of the front end of the rotary 2.

The hydraulic lift 10 has a pair of left and right lift arms 1.
The base ends of the lift arcs 1 and 11 are interlocked and connected, and the tip of the left lift arc 11 is connected to the upper end of a connecting rod 24. The connecting rod 24 is extendable and retractable with a turnbuckle, and its lower end is connected to the middle of the lower ring 21 on the left side. The upper end of a lift rod 25 is connected to a position near the tip of the right lift arm 11, a hydraulic cylinder 26 is integrally connected to the lower end thereof, and a piston rod 28 of the hydraulic cylinder 26 is connected to the middle of the right lower link 21. When the hydraulic lift 10 is driven, the lift arms 11 and 11 move together to raise and lower the entire rotary 2, and as will be described later, the rotary 2 is moved forward and backward by driving the piston rod 28 of the hydraulic cylinder 26.
It is designed to change the tilt angle in the left and right direction. In this embodiment, the rotary 2 is controlled to be in a horizontal state.

A tilt limit detection mechanism 30 for the rotary 2 is provided behind the hydraulic cylinder 26 . As shown in FIG. 3, this tilting limit detection mechanism 30 has a cylindrical cylinder 31 whose upper end is connected to the rear end of the lift arm 11, and a rod 32 whose lower end is connected to the lower link 21 on the right side of the cylinder 31. The upper end of the is slidably fitted inside. The cylinder 31 is equipped with a normally open limit switch 3 which is pressed by the upper end of the rod 32 and operates to define the retracting and advancing limit positions of the piston rod 28 of the hydraulic cylinder 26.
3. Normally closed limit switches 34 are mounted on the upper and lower sides at appropriate distances apart, and as will be described later, when the rotary 2 is positioned above, when the upper limit switch 33 is activated, or when the lower limit switch 34 is activated, When the limit switch 34 is deactivated, the piston rod 28 is retracted or advanced so that its upper end is located between the limit switches 33 and 34.

The length of the left connecting rod 24 can be changed using a turnbuckle, and the tilting angle of the rotary 2 in the left-right direction can be finely adjusted.

At the center of the top surface of the rotary cover 16 of the rotary 2,
A cylindrical tilt angle sensor 40 is provided, and outputs a signal corresponding to the tilt angle of its axis with respect to the vertical line. FIG. 4 is a perspective view showing the internal structure of the housing of the tilt angle sensor 40.
4, 44... are light receiving elements made of phototransistors, 45, 45... are light emitting elements made of LEDs, and 5 of each are arranged vertically at equal pitches, and are mounted in a cylindrical case so as to face each other in the longitudinal direction of the aircraft. is fixed to the inner surface of the A light-shielding plate 42 is pivotally supported at its upper end between the opposing light-emitting and light-receiving elements so as to be swingable in the left-right direction. An oil damper 43 is attached to the pivot shaft 41 of the light-shielding plate 42, and the light-shielding plate is installed so that when the tilt angle of the inclination angle sensor 40 or the rotary 2 changes, the light-shielding plate 42 becomes vertical and immediately stops. 42 is suppressed from swinging.
The light shielding plate 42 has light receiving elements 44, 44..., light emitting elements 4
Light-shielding windows 42a, 42b, 42c, 42d, 42e for 5 bits are provided at opposite height positions of the light receiving elements 44, 44...
2 ⁰ , 2 ¹ , 2 ² , 2 from the lowest shaded state
The circumferential length and phase of each light-shielding window are determined so that the ^ratio is ^3,24 . As a result, 5 of the light receiving elements 44, 44...
The output of the bit is a BCD ( Binary Coded Digital ) signal representing the tilt angle of the tilt angle sensor 40.

FIG. 5 is a hydraulic circuit diagram for drive control of the hydraulic cylinder 26 that controls the tilt angle of the rotary 2 in the left-right direction, and shows the hydraulic cylinder 26 and the hydraulic pump P.
A solenoid valve V is interposed between the two. Solenoid valve V
is a 4-port, 3-position switching type directional control valve, and when its solenoid Su is energized, the solenoid valve V is in the position of , and the pressure oil from the hydraulic pump P is supplied to the oil chamber on the piston rod advancing side of the hydraulic cylinder 26. Then, the pressure oil in the other oil chamber is returned to the tank, the piston rod 28 of the hydraulic cylinder 26 advances, and the right side of the rotary 2 rises. Also solenoid Sd
When the solenoid valve V is energized, the solenoid valve V is in the position, and pressure oil is supplied to the oil chamber on the piston rod entrance and exit side of the hydraulic cylinder 28, and the pressure oil in the other oil chamber is returned to the tank and is supplied to the piston rod of the hydraulic cylinder 26. 28 is retracted, and the right side of the rotary 2 is lowered.

FIG. 6 is an electronic circuit diagram of the main part of the device of the present invention.
In the figure, 67 is a battery whose negative pole is grounded to the body, and its positive pole is connected to the power supply terminal a ₃ of the input/output interface 52 of the microcomputer 50 via a key switch 78 . The microcomputer 50 includes a CPU (central processing unit) 5
1, an input/output interface 52, a RAM (random access memory) 53, a ROM (read-only memory) 54, and the like. Various switches and the like are connected to a large number of input ports a ₁ to _{a 9} of the input/output interface 52, and input ports a ₁ and a ₂ are connected to
Manual switches 68 and 69 that are operated and activated when changing the left-right tilt angle of the rotary 2 by manual operation are connected to each other, and when the manual switch 68 (or 69) operates, input port a ₁ (or a ₂ ) becomes high level and output port which will be explained later
A high level signal is output from b ₁ (or b ₂ ), causing the right side of the rotary 2 to rise (or fall). As described above, the input port _a3 serves as a power supply terminal connected to the positive terminal of the battery 67 via the key switch 78.

Two outputs of the logic judgment circuit 66, ie, command signals for raising and lowering the piston rod 28 of the hydraulic cylinder 26, are applied to the input ports _a4 and _a5 , respectively. The logic judgment circuit 66 issues command signals for raising and lowering the piston rod 28 based on the tilt angle of the rotary 2 detected by the tilt angle sensor 40.
That is, the BCD output signal of the tilt angle sensor 40 is amplified by an amplifier 61, then converted to a pure binary code by a code converter 62, and this pure binary code is input to a logic judgment circuit 66. Tilt angle sensor 4
0 emits 2 ⁵ = 32 signals ("0" to "31"), but the rotary 2 is horizontal and the central part of the light shielding plate 42 is connected to the light receiving elements 44, 44..., the light emitting elements 45, 45...
The signal is “15” or “16” when the
is output, and when the right side of the rotary 2 is lowered, the light shielding plate 42 connects the light receiving elements 44, 44..., the light emitting element 4.
5, 45, etc., it outputs signals "0" to "14", and when the right side of rotary 2 is raised, it outputs signals "17" to "31". The logic judgment circuit 66 sets the input port _A4 to a high level as a command signal for raising the piston rod 28 of the hydraulic cylinder 26 when the output is "0" to "14", and as a command signal for lowering the piston rod 28 when the output is "17" to "31". Input port _a5 is set to high level, and its output is set to low level when it is "15" or "16".

65 is a two-digit display, and the above-mentioned "0" to
The output of the code converter 62 is converted by the decoder 63 into a signal suitable for displaying the segment of the character "Japanese", and sent to the display 65 via the driver 64. Given.

A position control lever switch 71 is connected to the input port _A6 of the input/output interface 52, and is closed when the position control lever 14 is operated to a position where the rotary 2 should be raised to near its upper limit. The input port _a6 of the input/output interface 52 is set to a low level, and as will be described later, the angle control of the rotary 2 is prohibited and the rotary 2 is controlled so that the horizontal tilt angle is within a predetermined range.

The normally closed limit switch ₃₄ and the normally open limit switch 33 are connected to the input ports a 7 and a ₈ , respectively, and the input ports a ₇ and a ₈ are connected in their respective closed circuits.
is set to a low level, and when this becomes a low level, it is assumed that the rotary 2 has reached the left and right tilt limit, and the piston rod 2 of the hydraulic cylinder 26 is
8 is not driven.

An automatic switch 72 for automatically controlling the angle of the rotary 2 is connected to the input port _a9 , and the operation of the switch 72 brings the input port _a9 to a low level.

On the other hand, the output ports b ₁ and b ₂ of the input/output interface 51 are connected to one input terminal of AND gates 74 and 75, respectively, and the output port b ₃
is connected to a pulse oscillator 73, and the pulse oscillator 73 outputs a continuous signal or a pulse signal when the output from the output port _b3 is at a high level,
The output of the pulse oscillator 73 is connected to an AND gate 74,
75 and other inputs. The microcomputer 50 outputs a command to raise the rotary 2 to the right side with a high level signal from output port b ₁ , and a command to lower the rotary 2 to the right side with a high level signal from output port b ₂ . Together with the command signal, output port _b3 is also set to high level. The outputs of AND gates 74 and 75 are switch circuits 76 and 7, respectively.
7 and each switch circuit 76, 77
When turned on, solenoids Su and Sd are energized.

Now, the routine for controlling the angle of the rotary 2 will be explained based on FIG. When the key switch 78 is turned on, the microcomputer 50 starts control. First, it checks whether the manual switches 68 and 69 have been operated based on the states of the input ports a ₁ and a ₂ , and then turns on the manual switch 68 (for raising (or lowering)). or 69)
When is operated, the input port a ₁ (or a ₂ ) becomes high level, and the microcomputer 50 outputs a high level signal from the output port b ₁ (or b ₂ ) as a command signal to raise (or lower) the right side of the rotary 2. It also outputs a high level signal from the output port _b3 to drive the pulse oscillator 73, making its output continuously high level. As a result, the output of the AND gate 74 (or 75) is continuously at a high level, the solenoid Su (or Sd) is continuously excited, and the right side of the rotary 2 is continuously raised (or lowered).

Further, when the position control lever 14 is operated to raise the rotary 2 to an appropriate position, the position control lever switch 71 is turned on, input port _A6 becomes low level, and the microcomputer 50 operates input ports _A7 and _A8 . In other words, when the rotary 2 is tilted in the left-right direction and only the input port a ₇ (or a ₈ ) is at a low level, the solenoid Su (or Sd) is continuously energized and the right side of the rotary 2 is Raise (or lower) until both input ports a ₇ and a ₈ reach high level. This is because when traveling with the rotary 2 in the upper retracted position, if the left-right tilt angle of the rotary 2 is greater than a certain degree, there is a risk that the tractor body 1 may fall when turning, etc. It was designed to be avoided.

When the position control lever 14 is operated to lower the rotary 2 to an appropriate position, the position lever switch 35 is opened and the rotary 2 is in a state where automatic angle control is possible.When the automatic switch 72 is turned on, the input port _a9 becomes low level, and automatic angle control of the rotary 2 is performed based on the detection result of the inclination angle sensor 40. In this case, for a predetermined period of time (3 seconds) after the automatic switch 72 is turned on,
The tilt angle control of the rotary 2 is performed continuously, that is, the excitation of the solenoids Su and Sd is performed continuously, and thereafter is performed intermittently. That is, at the time when the automatic switch 72 is turned on, if the tractor 1 is in a downward direction to the right (or upward to the right) due to irregularities in the field, the rotary 2 will also be downward to the right (or upward to the right).
The inclination angle sensor 40 attached to the top surface is also in a state of descending to the right (or upward to the right), and the output signal of the inclination angle sensor 40 is "0" to "14" (or "17" to "31"). ”), the input port a ₄ (or a ₅ ) of the input/output interface 52 becomes high level, and high level signals are generated from the output ports b ₃ and b ₁ (or b ₂ ). As a result, the pulse oscillator 73 continuously outputs a high-level signal for a predetermined period of time (3 seconds) to continuously excite the solenoid Su (or Sd), causing the piston rod 28 of the hydraulic cylinder 26 to retract (or advance). Then, the right side of the rotary 2 rises (or falls), and this continues until the output signal of the inclination angle sensor 40 reaches "15" or "16", so the rotary 2 quickly becomes horizontal. During this time, the output of the tilt angle sensor 40 is monitored on the display 65.

Now, after a predetermined period of time has elapsed, when the rotary 2 is tilted due to irregularities in the field and the input port _a4 or _a5 becomes high level, the outputs of the output ports _b1 or _b2 and _b3 become high level. In this case, since a predetermined time has elapsed after the automatic switch 72 was turned on, the output of the pulse oscillator 73 becomes a pulse signal with a predetermined duty ratio, and the output of the AND gate 74 or 75 is synchronized with the pulse signal generated by the pulse oscillator 73. The solenoid becomes high level.
Su or Sd is intermittently excited and rotary 2
is driven intermittently. Therefore, since the rotary 2 is gently controlled to a horizontal position, unnecessary hunting can be prevented and the angle control accuracy of the working machine can be significantly improved.

In the above-mentioned embodiments, a rotary mounted on a tractor was explained as a working machine, but it is not limited to this. For example, a rotary plate mounted on the front of a tractor, a rice transplanter mounted on a traveling vehicle, etc. It can also be applied to angle control of work equipment.

As described in detail above, the present invention provides a work machine that controls the left and right tilt angle of the work machine by detecting the left and right tilt angle of the work machine with respect to a reference plane and driving the connecting member between the work machine and the machine to expand and contract. In the angle control device, immediately after the device is operated, the expansion and contraction of the connecting member is performed continuously for a predetermined period of time, and then intermittently, so that immediately after the start of work, the expansion and contraction of the connecting member is performed continuously. The connecting member is continuously driven to quickly obtain the required tilt angle. Therefore, the desired control state can be obtained so as to immediately follow the start of work regardless of the distance from the control dead zone.
Thereafter, by intermittent driving of the connecting member, hunting due to overcorrection of the inclination angle does not occur, and control accuracy and operation stability can be achieved.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention.
The figure is a partially cutaway left side view of a tractor equipped with the device of the present invention and equipped with a rotary as a working machine at the rear.
Fig. 2 is a plan view of the main part thereof, Fig. 3 is a longitudinal sectional view of the rotary tilt limit detection mechanism, Fig. 4 is a schematic perspective view of the inside of the tilt angle sensor, and Fig. 5 is the main part of the device of the present invention. A hydraulic circuit diagram, FIG. 6 is a block diagram showing the electronic circuit of the control system, and FIG. 7 is a flowchart for explaining the operation. 1...Tractor body, 2...Rotary, 11...
...Lift arm, 20...Top link, 21...
... Lower link, 24 ... Connection rod, 26 ... Hydraulic cylinder, 28 ... Piston rod, 30 ...
Tilt limit detection mechanism, 33, 34... limit switch, 40... tilt angle sensor, 42... light shielding plate, 4
4... Light receiving element, 45... Light emitting element, 50... Microcomputer, 66... Logic judgment circuit, 7
3...Pulse oscillator.

Claims (1)

[Claims] 1. In an angle control device for a working machine that controls the horizontal tilting angle of the working machine by detecting the horizontal tilting angle of the working machine with respect to a reference plane and driving the connecting member between the working machine and this machine to expand and contract, 1. An angle control device for a working machine, characterized in that the connecting member is driven to expand and contract continuously for a predetermined period of time immediately after an operation is performed, and then intermittently thereafter.