JPH0541903A - Horizontal controller of counter-ground working machine - Google Patents

Abstract

PURPOSE:To prevent the hunting of a counter-ground working machine and simultaneously improve the follow-up property of the return of the machine to the horizontal state from a tilted state. CONSTITUTION:The output voltage VS of an inclination sensor 11 for detecting a laterally inclined attitude is compared with a standard voltage VR. An integration circuit is switched in response to the magnitude of the output voltage VS of the inclination sensor 11, and an electromagnetic valve 23 or 24 is operated by the output of an integration circuit having a different time constant. Such a controller as to switch the sensibility of an inclination-correcting start is disposed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground work machine connected to a power farm, and more particularly to a horizontal control device for expanding and contracting a hydraulic cylinder based on a detection value of an inclination sensor to correct the attitude of the ground work machine. It is a thing.

[0002]

2. Description of the Related Art Conventionally, when a ground work machine is connected to the rear part of a power farm machine for agricultural work, a tilt sensor is provided on the power farm machine or the ground work machine, and the left and right tilt postures are determined by the detection value of the tilt sensor. When tilting occurs, the solenoid valve operates to extend or contract the hydraulic cylinder, and the ground work machine is controlled to return to the horizontal state.

As shown in FIG. 8, the input signal of the inclination sensor has a waveform a having fine irregularities under the influence of engine vibration and tire lag vibration. If this signal is output as it is as the detection signal of the tilt sensor, vibration also occurs in the expansion and contraction operation of the hydraulic cylinder due to the operation of the solenoid valve, so-called hunting occurs. In order to prevent this hunting, for example, a signal within ± 1 ° like the waveform b is set as a dead band so that the tilt is not detected. Further, as shown in FIG. 9, an integrating circuit 2 is provided in the input portion of the tilt sensor 1,
The output signal from the tilt sensor 1 has a flat waveform.

[0004]

Conventionally, in order to prevent hunting, a dead zone is provided for detection of the tilt sensor and an integrating circuit is provided. If an integrating circuit is provided,
There is a delay from the inclination sensor detecting the inclination to the output of the signal, but this delay is constant regardless of the magnitude of the inclination. Therefore, when the inclination becomes large, there has been a problem that the expansion and contraction operation of the hydraulic cylinder due to the operation of the solenoid valve is not in time, and the return to the horizontal state is delayed.

Therefore, there is a technical problem to be solved in order to prevent the hunting of the ground working machine, improve the followability of the return to the horizontal state with respect to the inclination, and improve the workability. The present invention aims to solve this problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above object, and a ground work machine is connected to the rear part of a power agricultural machine, and a tilt sensor for detecting left and right tilt postures is provided, In a horizontal control device in which a solenoid valve is actuated based on a detection value of the tilt sensor to extend and contract a hydraulic cylinder to maintain the ground work machine in a horizontal state, the output voltage of the tilt sensor is compared with a reference voltage. The horizontal control device for a ground work machine is characterized in that the integration circuit can be switched depending on the output of the tilt sensor and the solenoid valve is operated by the output of the switched integration circuit. Is provided.

[0007]

The output voltage of the tilt sensor changes according to the tilt amount of the machine body or the ground work machine. This output voltage is compared with a reference voltage, and when it reaches a predetermined voltage, one integrating circuit is switched to the other integrating circuit. Since the time constants of the two integrating circuits are different and the solenoid valve is operated by the output of the switched integrating circuit, the switching of the integrating circuit changes the time until the solenoid valve starts operating.

That is, the time until the actuation of the solenoid valve is switched depending on the magnitude of the detected value of the tilt sensor, and when the tilt amount is small, the time until the actuation of the solenoid valve is lengthened, and the tilt amount is increased. In this case, the time required to start the operation of the solenoid valve can be shortened to accelerate the expansion / contraction operation of the hydraulic cylinder. Therefore, the followability of returning to the horizontal state is improved even if the amount of inclination is large.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a circuit diagram of the horizontal control device,
The output terminals of the tilt sensor 11 are comparators 12 and 13
Of the comparators 12 and 13 are connected in parallel, and the other ends of the comparators 12 and 13 on the input side are connected to terminals 14 and 15 of a series-connected resistor R _R. Furthermore, the tilt sensor 11
The output terminal of is also connected in parallel to one end on the input side of the comparators 16 and 17, and the other end on the input side of the comparators 16 and 17 is connected to the terminals 18 and 19 of the resistor R _R. A resistor R _R is provided to provide a reference voltage V _R to each of the comparators 12 and 13, 16 and 17, and a terminal 14
A reference voltage V _{R of} 3.0 V is taken out from the
, 2.7 V from the terminal 18, 2.5 V from the terminal 18, and 2.2 V from the terminal 19. The reference voltage V _R is connected to the input terminals of the comparators 12 and 13 and the input terminals of the comparators 16 and 17 in opposite phases.

A resistor is provided on the output side of the comparator 12.
R₁And capacitor C₁Is connected in series and grounded
R₁And capacitor C₁And constitute a first integrating circuit.
D₁Is a diode for preventing backflow. In addition,
Resistor R on the output side of₂Front through terminal 18
Note capacitor C₁Connected to the resistor R₂And capacitor C ₁
And form a second integrating circuit. Resistance of the first integrating circuit
R₁Is the resistance R of the second integrating circuit₂Much smaller
The resistance value is set to the resistance value, and the time constant of the first integrating circuit is set to the value of the second integrating circuit.
Make it smaller than the time constant. Furthermore, a terminal 18 is provided at the rear stage.
It is connected to one end on the input side of the comparator 19.

Meanwhile, the output side of the comparator 17 is the output side and the same configuration of the comparator 12, a resistor R ₁ and capacitor C ₁ is provided in series to the ground, resistors R ₁ and capacitor C ₁ and the first Configure an integrator circuit. The output side of the comparator 16 is the output side and the same configuration of the comparator 13, the resistor R ₂ is provided connected to the capacitor C ₁ via the terminal 20, the resistor R ₂ and capacitor C ₁
And form a second integrating circuit. As described above, the resistance value of the resistor R ₁ is much smaller than that of the resistor R ₂ , and the time constant of the first integrating circuit is smaller than that of the second integrating circuit. Furthermore,
The terminal 20 is connected to one end on the input side of the comparator 21 provided in the subsequent stage.

The reference voltage V _H divided from the terminal 22 of the resistor R ₃ is added to the other ends of the input sides of the comparators 19 and 21, and the output sides of the comparators 19 and 21 are connected via the resistor R ₄ , respectively. Connected to the base terminal of the transistor T ₁ or T ₂ . Further, the collector terminal of the transistor T ₁ is connected to the solenoid of one solenoid valve 23, and the collector terminal of the transistor T ₂ is connected to the solenoid of the other solenoid valve 24.

FIG. 2 shows the inclination angle α of the inclination sensor 11.
3 is a graph showing the relationship between the output voltage V _S and the output voltage V _S.
The inclination within the range of can be measured. When the tilt angle α is + 10 °, an output voltage V _{S of} 3.6 V is obtained, and the tilt angle α is -1.
An output voltage V _{S of} 1.6 V is obtained at 0 °. The output voltage V _S linearly changes between the inclination angle α of −10 ° and + 10 °, and the inclination angle α is + 4 °, for example.
There is an output voltage V _{S of} 3.0 V in the case of, 2.7 V in the case of α = + 1 °, 2.5 V in the case of α = −1 °, α = −
At 4 °, each output voltage V _S of 2.2 V is output.

Next, the horizontal control procedure will be described.
FIG. 3 shows a waveform of the inclination angle α read by the inclination sensor 11, and FIG. 3A shows a state where the inclination angle α is less than ± 1 °, and most of the waveform components are those of the engine. This is due to vibration or vibration due to tire lugs. The figure (b) shows the state where the inclination angle α is between + 1 ° and + 4 °, and the figure (C) shows the state where the inclination angle α exceeds + 4 °.

For example, as shown in FIG.
If is less than ± 1 °, tilt as shown in the graph in Figure 2.
Output voltage V of sensor 11_SIs between 2.5V and 2.7V
It is in. At this time, the output voltage V_SIs shown in Fig. 1
Reference voltage V of the comparator 12 _R= 3.0V, and
Reference voltage V of the palator 13_R= Doesn't reach 2.7V
So if both comparators 12 and 13 are on
No current flows to the output side of the comparators 12 and 13.
Yes. Further, the comparators 16 and 17 have their input terminals having opposite phases.
Since the comparator 16 is connected to the
1 output voltage V_SIs the reference voltage V_R= 2.5V or less, line up
In addition, the comparator 17 outputs the output voltage V_SIs the reference voltage V_R
= 2.2V or less, it will not turn on and the comparator
No current flows on the output side of the switches 16 and 17.

FIG. 4 shows a comparator 19 or
Is the voltage V applied to one input end of 21_LShows the waveform of
In the figure (a), the inclination angle α is less than ± 1 °.
Voltage V_LRepresents the waveform of. As previously mentioned,
When the inclination angle α is less than ± 1 °, the comparators 12 and 1
3 and both comparators 16 and 17 turn on
From the output side of each, the comparator 19 or 21
Voltage V at one end on the input side _LIs not added. Therefore,
Transistor T provided in the latter stage of the palator 19₁, And
Transistor T provided after comparator 21₂The twins
One is in the off state, and as shown in FIG.
Voltage V applied to the solenoid of valve 23 or 24_BIs zero
Therefore, the solenoid valves 23 and 24 do not operate. That is, the inclination
If the angle of inclination α is less than ± 1 °, it is due to the expansion and contraction of the hydraulic cylinder.
Inclination correction is not performed and the so-called dead zone occurs,
Prevents hunting due to vibration.

Here, as shown in FIG. 3B, the inclination angle α
Is between + 1 ° and + 4 °, the output voltage V _S of the tilt sensor 11 is 2.7 as shown in the graph of FIG.
It is between V and 3.0V. At this time, the output voltage V
_S is the reference voltage V _R of the comparator 13 shown in FIG.
The voltage becomes 2.7 V or more, the comparator 13 is turned on, and the power supply I ₂ flows to the output side. Since a second integrating circuit is provided on the output side of the comparator 13, the capacitor C
_{While 1} is being charged, the output voltage V _L gradually rises. Then, as shown in FIG. 4B, after the time t ₁ (about 200 ms) has elapsed since the tilt sensor 11 started to detect the tilt, the voltage V _L applied to one end on the input side of the comparator 19 is a reference. When the voltage exceeds V _H , the comparator 19
Is turned on and the transistor T ₁ is turned on. Therefore, as shown in FIG. 5B, the voltage V _B is applied to the solenoid of the solenoid valve with a delay of the time t ₁ to operate the solenoid valve 23, and the hydraulic cylinder extends or contracts to correct the inclination. Is done.

On the other hand, when the inclination angle α exceeds + 4 ° as shown in FIG. 3C, the output voltage V _S of the inclination sensor 11 becomes 3.0 V or more as shown in the graph of FIG. .. In that case, the output voltage V _S is the reference voltage V _R = 2.7V of the comparator 13 and the reference voltage V of the comparator 12.
_{When R} = 3.0V or more, both comparators 12 and 13 are turned on, and currents I ₁ and I ₂ flow to both output sides. The first integrator circuit provided on the output side of the comparator 12 has a smaller time constant than the second integrator circuit provided on the output side of the comparator 13, and the current I ₁ is applied to both the first and second integrator circuits. And I ₂ flow, the capacitor C ₁
Is instantly charged. Then, as shown in FIG. 4C, time t ₂ has elapsed since the inclination sensor 11 started to detect the inclination.
(Approx. 1 to 2 ms) elapses, and when the voltage V _L applied to one end on the input side of the comparator 19 exceeds the reference voltage V _H , the comparator 19 is turned on and the transistor T ₁ is turned on. .. Therefore, as shown in FIG.
After delaying by the time t ₂ , the voltage V is applied to the solenoid of the solenoid valve.
_B is added to operate the solenoid valve 23, and the hydraulic cylinder is expanded or contracted to perform tilt correction.

When the inclination angle α changes from -1 ° to -4 °, the output voltage V _S of the inclination sensor 11 becomes 2.5 V or less as shown in the graph of FIG. _S is the comparator 16 is turned on it becomes equal to or less than the reference voltage V _R = 2.5V the comparator 16. The comparator 16
Since the second integrating circuit is provided on the output side of the same as the above-mentioned comparator 13, it is delayed by the time t ₁ in exactly the same manner as the operation described above with reference to FIGS. 4 (b) and 5 (b). Then, the solenoid valve 24 is actuated, and the inclination is corrected.

Further, the inclination angle α becomes negative from -4 °.
In the case of the tilt sensor 11 as shown in the graph of FIG.
Output voltage V_SBecomes 2.2 V or less, and the output voltage V_S
Is the reference voltage V of the comparator 16._R= 2.5V and
Reference voltage V of comparator 17 _R= 2.2V or less,
Both comparators 16 and 17 are turned on. Obey
And the operation described above with reference to FIGS. 4 (c) and 5 (c)
Similarly, time t₂Solenoid valve 24 operates with a delay
Then, the tilt correction is performed.

Thus, when the inclination angle α is less than ± 1 °, it becomes a dead zone to prevent hunting, and the inclination angle α is +1.
In the range from ° to + 4 ° or from -1 to -4 °,
The inclination correction is started relatively slowly after a delay of time t ₁ . When the inclination angle α exceeds ± 4 °, the time t
_{After a} delay of ₂ , tilt correction starts very instantly. FIG. 6 shows another embodiment. Comparing only parts different from the circuit configuration of FIG. 1, the comparators 12 and 1 will be described.
A resistor R ₅ having an appropriate resistance value is provided in place of the resistor R ₁ provided on the output side of 7, and the resistor R ₅ and the capacitor C ₁ constitute an integrating circuit. Also, the comparators 13 and 16
In place of the resistor R ₂ provided on the output side of the diode D
Install ₂ in the opposite direction. The resistance from R _R terminal 14 is taken out reference voltage V _R of 2.7V, from the terminal 15 2.65V, from the terminal 18 2.55V, retrieved the reference voltage of 2.5V from the terminal 19 Be done.

When the inclination angle α is less than ± 0.5 °, it is calculated from the graph of FIG. 2 that the output voltage V _S of the inclination sensor 11 is between 2.55V and 2.65V. ,
At this time, neither the comparators 12 and 13 nor the comparators 16 and 17 are turned on, and the solenoid valve 23
And 24 do not work. Here, the inclination angle α is + 0.5 °
If this happens during the period from + 1 °, the output voltage V _S of the tilt sensor 11 is between 2.7V from 2.65V, the reference voltage V _R = 2.65 of the output voltage V _S is the comparator 13
When the voltage exceeds V, the comparator 13 is turned on. However,
The output side of the comparator 13 has a diode D in the reverse direction.
_{Since 2} is provided, no current flows through one end of the comparator 19 on the input side, and the solenoid valve 23 does not operate. That is, the tilt correction is not performed until the tilt angle α becomes + 1 °.

Then, the inclination angle α becomes more positive than + 1 °.
Output voltage V of the tilt sensor 11_SIs 2.7V
Thus, the output voltage V_SIs the reference of comparator 12
Voltage V_R= 2.7V or higher, the comparator 12 and
Both 13 are turned on. Therefore, the comparator 12
Current I on the output side₃Flows and the input side of the comparator 19
Voltage V at one end_LIs added, and the time is appropriately delayed by the integration circuit.
Total voltage V_LIs the reference voltage V_HWhen it exceeds the
The switch 19 turns on and the transistor T ₁Is on
Then, the solenoid valve 23 is operated and the inclination correction is performed.

As described above, when the inclination correction is performed and the inclination is returned to the horizontal state and the inclination angle α becomes + 1 ° or less, the output voltage V _S of the inclination sensor 11 becomes equal to the reference voltage V _{S.
When R} = 2.7V or less, the comparator 12 is turned off. Therefore, the current I ₃ on the output side of the comparator 12 also stops flowing, but since the comparator 13 is turned on, the discharge of electricity charged in the capacitor C ₁ is delayed, and it is added to one end on the input side of the comparator 19. The voltage V _L does not _fall below the reference voltage V _H, and the operation of the solenoid valve 23 continues for a while.

When the tilt angle α becomes + 0.5 ° or less due to the inertia of the lift arm or the like, the comparator 1
3 is turned off, the output side is inverted, and the electricity charged in the capacitor C ₁ passes through the diode D ₂ and is instantly sucked into the output pin of the comparator 13. Therefore, the voltage V _L applied to one end of the comparator 19 is the reference voltage V _{L.
The value} becomes _H or less, the solenoid valve 23 does not operate, and tilt correction stops.

Although not described, the comparators 16 and 17 are turned on when the inclination angle α is on the minus side, and the control operation is performed in exactly the same manner as when the inclination angle α is on the plus side. Therefore, the inclination correction is started after the inclination occurs when the inclination angle α becomes ± 1 ° or more,
Further, the tilt correction is performed, the tilt is returned to the vicinity of the horizontal state, and the tilt correction is stopped when the tilt angle α is ± 0.5 ° or less. That is, even when the dead zone is widened by making the angle at which the tilt correction starts and the angle at which the tilt correction is stopped different, the error in the stop position of the ground work machine becomes small and the work accuracy is improved. At the same time, a large dead zone can be taken, so that hunting can be prevented.

FIG. 7 shows still another embodiment. To explain only the portion different from the circuit diagram of FIG. 1, the number of comparators is set to two and the comparators 25 and 26 are provided, and the inclination sensor 11 is provided. Is connected in parallel to the input terminals of the comparators 25 and 26 in antiphase. The other ends of the input terminals of the comparators 25 and 26 are connected to the terminals 27 and 28 of the resistor R _X connected in series. Resistance R _X
Is provided for applying the reference voltage V _R to the comparators 25 and 26, and the reference voltage V _R of 2.7 V is applied from the terminal 27.
_R is taken out and the reference voltage V of 2.5 V is output from the terminal 28.
_R is taken out. On the output side of the comparator 25, a resistor R ₆ and a forward diode D ₁ and a resistor R ₇ and a reverse diode D ₂ are provided in parallel and connected to the capacitor C ₁ , and the resistor R ₆ and the capacitor R ₁ are connected. _First with C 1
And the resistor R ₇ and the capacitor C ₁ form a second integrator circuit. Resistance R ₇ is resistance R
_{Since the} resistance value is much smaller than ₆ , the time constant of the second integrating circuit is smaller than the time constant of the first integrating circuit. Further, since the diode D ₂ is provided in the reverse direction in the second integrating circuit, no current flows in the forward direction. The output side of the comparator 26 is also provided with a first integrator circuit and a second integrator circuit in the same manner.

Therefore, when the inclination angle α is less than ± 1 °,
From the graph of FIG. 2, the output voltage V of the tilt sensor 11_SIs 2.
Between 5V and 2.7V, in this case comparator
Both 25 and 26 do not turn on and the solenoid valves 23 and 2
No tilt correction is performed because 4 does not operate. And lean
If the angle of inclination α is more than + 1 °, the tilt sensor
11 output voltage V_SIs the reference voltage V of the comparator 25_R
= 2.7V or more, the comparator 25 turns on
It Therefore, the output side of the comparator 25 is inverted and turned off.
Alternately, the second integrator circuit is a diode D₂Due to
Current does not flow in the opposite direction, and the current I_FourIs flowing
The voltage V is applied to one end of the comparator 19._LIs added. That
Then, the voltage V is delayed by the first integrating circuit as appropriate._LBut
Reference voltage V _HIs exceeded, the comparator 19 turns on.
Switch to transistor T₁Is turned on and solenoid valve 2
3 is activated and tilt correction is performed.

As described above, when the inclination is corrected and the inclination is returned to the horizontal state and the inclination angle α becomes + 1 ° or less, the output voltage V _S of the inclination sensor 11 becomes the reference voltage V _R.
= 2.7V or less, the comparator 25 is turned off. Therefore, the output side of the comparator 25 is reversed and the current I ₄ stops flowing, and the electricity charged in the capacitor C ₁ passes through the second integrating circuit including the diode D ₂ and is instantaneously output to the output pin of the comparator 25. Be sucked. Therefore, the voltage V _L which is added to one end of the comparator 19 becomes equal to or lower than the reference voltage V _H, the inclination correction solenoid valve 23 is no longer actuated stops. Although the description is omitted,
When the inclination angle α becomes negative, the comparator 26
Is turned on, and the control action is performed in exactly the same manner as when the inclination angle α is on the plus side.

Therefore, the inclination correction is started after the inclination is generated when the inclination angle α becomes ± 1 ° or more. At that time, the inclination correction is appropriately timed by the first integrating circuit. It is possible to prevent hunting even when the dead zone is reduced by starting the. Further, when the inclination correction is performed and the inclination is returned to the vicinity of the horizontal state, and the inclination angle α becomes ± 1 ° or less, the inclination correction is instantaneously stopped by the second integrating circuit to reduce the dead band. Even when it is done, there is no delay in the correction stop due to the inertia of the lift arm.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention covers the modified ones.

[0032]

As described in detail in the above embodiment, the present invention makes it possible to select the time until the start of operation of the solenoid valve by switching the integration circuit according to the magnitude of the detected value of the tilt sensor. Therefore, when the amount of inclination is small, the delay time for starting the operation of the solenoid valve is made large and the inclination correction is started relatively slowly, and when the amount of inclination is large, the delay time is made small and extremely instantly. The tilt correction is started. Thus,
Hunting can be prevented when the amount of inclination is small, and
Even if the amount of inclination is large, the present invention exhibits various kinds of effects such as improvement in the followability of returning to the horizontal state.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a horizontal control device according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a tilt angle α and an output voltage V _{S in a} tilt sensor.

3A to 3C are graphs showing waveforms of an inclination angle α read by an inclination sensor, FIG. 3A showing a state where the inclination angle is less than ± 1 °, and FIG. ) Has a tilt angle of +1
The state between 0 ° and + 4 ° is shown, and FIG. 7C shows the state where the inclination angle exceeds + 4 °.

4A to 4C are graphs showing waveforms of a voltage V _L applied to one end of a comparator 19, and FIG. 4A shows a state where an inclination angle is less than ± 1 °. , (B) shows a state where the tilt angle is between + 1 ° and + 4 °,
FIG. 6C shows a state where the tilt angle exceeds + 4 °.

5 (a) to 5 (c) are graphs showing waveforms of voltage V _B applied to the solenoid of the solenoid valve, and FIG. 5 (a) shows a state where the inclination angle is less than ± 1 °. , The figure (b)
Shows a state where the inclination angle is between + 1 ° and + 4 °, and FIG. 7C shows a state where the inclination angle exceeds + 4 °.

FIG. 6 is a circuit diagram of a horizontal control device according to another embodiment of the present invention.

FIG. 7 is a circuit diagram of a horizontal controller according to still another embodiment of the present invention.

FIG. 8 is a graph showing an input signal of a conventional tilt sensor.

FIG. 9 is an explanatory diagram showing an integrating circuit provided in a conventional tilt sensor.

[Explanation of symbols]

11 Inclination sensor 12, 13, 16, 17 Comparator 19, 21, 25, 26 Comparator 23, 24 Solenoid valve V _S Inclination sensor output voltage V _R , V _H Reference voltage

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G05B 5/01 7740-3H // G05D 1/02 N 7828-3H

Claims (1)

[Claims] 1. A ground work machine is connected to a rear portion of a power farming machine,
In a horizontal control device, which is provided with an inclination sensor for detecting left and right inclination postures, an electromagnetic valve operates based on a detection value of the inclination sensor to extend and contract a hydraulic cylinder, and maintain a ground work machine in a horizontal state. Comparing the output voltage of the tilt sensor with a reference voltage, making the integrating circuit switchable according to the magnitude of the output of the tilt sensor, and operating the solenoid valve with the output of the switched integrating circuit. Horizontal control device for ground work equipment.