JPS5999102A - Driving circuit for actuator - Google Patents

Abstract

PURPOSE:To improve the operatability of an actuator, by securing its excellent responsiveness to a changeover action in an operating direction of the actuator, while making the actuator possible to generate a desired vibration. CONSTITUTION:In case of letting a hydraulic cylinder 3 generate its vibration, a signal is outputted to each of pump control valves 11 and 12, while variable displacement pumps 1 and 2 discharge a fixed flow Q of pressure oil. Next, a signal is outputted to each of selector valves 7 and 8 from a transducer 6, and the discharge port of the variable displacement pump 1 and the bottom side of the hydraulic cylinder 3 are interconnected with each other as well as the suction port of the pump 1 and the rod side of the cylinder 3 are also interconnected through, thus the hydraulic cylinder entends its length. Afterward, a closing signal is outputted to each of these selector valves 7 and 8 while an opening signal to each of these selector valves 9 and 10, thus the hydraulic cylinder 3 contacts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuator drive circuit included in a hydraulic machine, and particularly to an actuator drive circuit in which one actuator is driven in a closed circuit using a plurality of hydraulic pumps.

FIG. 1 is a circuit diagram showing an example of this type of conventional actuator drive circuit. 1, 2 are hydraulic pumps, for example variable displacement pumps, 3 is an actuator driven by these variable displacement pumps 1.2,
For example, a hydraulic cylinder. 7, 8, 9, and 10 are switching valves, of which switching valves 7 and 8 are provided in the middle of a circuit that connects the hydraulic cylinder 3 and the variable displacement pump 1; Cylinder 3 and variable capacity pump 2
It is installed in the middle of the circuit that communicates with. 1. c, 3a
3b is a hydraulic power source connected to the pipe line 3aK, which connects the circuit containing the variable displacement pump 1 and the circuit containing the variable displacement pump 2. Further, 13 and 14 are pistons that control the discharge volumes of the variable displacement pumps 1 and 2, respectively;
12 is the number that controls 141 the movement direction of the pistons 13 and 14? It is a pump control valve.

Further, reference numeral 4 denotes an operating device that outputs a signal to drive the hydraulic cylinder 3, and a portion of the lever thereof is movable in the middle direction and in one direction as shown by the arrow 5. Further, for example, the operating fluid ff¥4 outputs a signal indicating "1" when the hydraulic cylinder 3 is driven, and outputs a signal indicating "o" when the hydraulic cylinder 3 is not affected by wind erosion. Reference numeral 6 denotes a conversion device that appropriately converts the signal output from the operating device 4 and outputs it to the switching valves 7, 8, 9, 10 and the pump control valves 11 and 12. It consists of a microcomputer having a central processing unit, a storage device, a large sword device, and an output device. The above-mentioned operating device 4 and conversion K (fT 6) constitute actuating means for actuating the pump control valve 11.12 and the switching valves 7, 8, 9.IQ.

In this way, the first “lJj”y actuator J
In the dynamic circuit 9, the drive of the hydraulic cylinder 3 is controlled, for example, according to the procedure shown in Ki 2-1.

That is, first, as shown in step 20, the conversion device 6 determines whether the iN number output from the operating device 4 is "1". If this determination is not satisfied, the hydraulic cylinder 3
This is the case when driving is not intended, and we return to the beginning. If the judgment of the upper Me is satisfied, this means that the hydraulic cylinder 3 is intended to be driven, and the process moves to step 21. This step 21
Then, in the same conversion coloring 6, it is determined whether the signal value of the signal outputted from the operating device 4 is 10 or not. If the judgment in step 21 is satisfied, the process moves to step 22, and if it is not satisfied, the process moves to step 23.

In step 22, the switching valves 7, 8°9.10 from the converter 6
, a signal is output to open these switching valves 7, 8, 9, and 10, and at the same time, the converter 6 is opened. Pump control valve 11.1
2, a signal is output to switch these pump control valves 11 and 12 to the right position in FIG. As a result, the circuits connecting the variable displacement pumps 1, 2 and the hydraulic cylinder 3 are brought into communication, and the pistons 13, 14 are respectively moved to the left in FIG. Therefore, the hydraulic source 3b
The pressure oil that is dissipated from the water is sucked in by the variable ground pumps 1 and 2 via the rr path 3a, and these variable displacement pumps 1 and 2
The pressure oil discharged from the hydraulic cylinders 2 and 2 is combined and supplied to the rod side of the hydraulic cylinder 3, thereby causing the hydraulic cylinder 3 to act in the direction of contraction. Note that after step 22, the process returns to the beginning.

In step 23, the converter 6 also switches the switching valve 7°8.9.
10, a signal is output to open these switching valves 7, 8, 9, 10, and at the same time, the conversion device 6 outputs a signal to open these switching valves 7, 8, 9, 10,
1 (g is output. As a result, the circuits connecting the variable displacement pump 1.2 and the hydraulic cylinder 3 communicate with each other, and the piston 13.1
4 move to the right in FIG. 1, contrary to the above. Therefore, pressure oil led from the hydraulic source 3b is sucked in by the variable displacement pump 1.2 via the pipe line 3a, and this 1ll
The pressure oils discharged from the variable pumps 1 and 2 are combined and supplied to the metom side of the hydraulic cylinder 3, thereby operating the hydraulic cylinder 3 in the direction of expansion. Note that after step 23, the process returns to the beginning.

In this way, variables 1. ．． 1? By merging the pressure oil discharged from the cylinders 1 and 2, the hydraulic cylinder 3 can be expanded and contracted.

By the way, in the conventional actuator drive circuit configured as described above, due to various types of construction 1λ, the operating direction of the actuator, for example, the hydraulic cylinder 3 shown in FIG.
In some cases, it is desired to rapidly and continuously change the direction of contraction and the direction of expansion to cause vibration in the actuator. For example, in a hydraulic excavator used as a construction machine, this occurs when mud adhering to a packet is removed from the packet, or when rock is crushed by the packet.

However, in the conventional actuator drive circuit described above, when attempting to cause such vibrations in the actuator, for example in the hydraulic cylinder 3 shown in FIG. 1, the pump control valves 11 and 12 must be switched. Therefore, the moving direction of the piston 13ν14 must be changed, and thereby the discharge direction of the variable displacement pump 1.2 must be changed, that is, the switching operation of the operating direction of the hydraulic cylinder 3,
It is necessary to supply pressure oil to the hydraulic cylinder 3 through the movement of the pistons 13 and 14. Therefore, the responsiveness to the switching operation of the hydraulic cylinder 3 is poor, and as a result, vibrations are caused. cannot be caused. Therefore, for example, in a hydraulic excavator, it is not possible to remove mud from the packet or crush rocks due to the vibrations described above.

The present invention has been made in view of the actual situation in the prior art, and its purpose is to provide an actuator drive circuit that can ensure excellent responsiveness to the switching operation of the actuating direction of the actuator. be.

To achieve this objective, the present invention provides one actuator and a plurality of hydraulic pressures Z for driving this actuator.
A closed door r (1) having a switching valve interposed between the hydraulic pump and the actuator (1) and an actuating means for operating the switching valve,
A switching device is provided that is connected to the actuating means and outputs a signal, and the actuating means operates the switching valve in response to the signal output from the switching device, and connects the discharge port of one of the plurality of hydraulic pumps and the actuator. A circuit that communicates with one port of the actuator, and a circuit that communicates the discharge port of another hydraulic pump of the plurality of hydraulic pumps with another port of the actuator are alternately connected and cut off. (It is configured to operate so that it can be repeated.

Hereinafter, the actuator drive circuit of the present invention will be explained based on the drawings. FIG. 3 is a circuit diagram showing an example Xi of the present invention. In order to simplify the explanation, FIG. 3 is drawn to correspond to FIG. 1 described above, and the same equipment and components as shown in FIG. 1 are designated by the same reference numerals.

In this third one, 15 is a switching device, conversion @ position 6
is connected to the converter 6, and when switched to the ON state, the converter 6
It is designed to output a signal to.

Note that the storage device of the conversion device 6 stores minute times tl+t2 corresponding to the cross section Ff S t on the bottom side and the cross section S2 on the rod side of the hydraulic cylinder 3, that is, t.
The time tl+t2 that satisfies the relationship 1/81'' t2/S2 is stored.Also, the conversion device f2
The central processing unit No. 6 also counts the time T and calculates the time T and the above-mentioned time t1. A comparison with t2 is made with flute 1. It looks like C5.

In one embodiment configured as described above, the drive iJ of the hydraulic cylinder 3 is controlled by the procedure shown in the fourth +*+.

That is, first, as shown in step 24, it is determined in the conversion device N6 whether the switching device 15 is in the ON state, that is, whether a signal is output from the switching device ife15. If this judgment is satisfied and there is 1L, then it is a good idea to cause vibration in the hydraulic cylinder 3, and as mentioned above, the judgment and operation according to steps 20 to 23 are performed, and the i11 hydraulic cylinder 3 is By merging the pressure oil discharged from the two variable displacement pumps 1 and 2, expansion, contraction, and expansion operations are performed.

If the judgment in step 24 is satisfied, this means that it is desirable to cause the hydraulic cylinder 3 to vibrate, and the process moves to step 25. In this move 11th move 25, the conversion device 6
A signal is output to the pump control valve 11 to switch it to the left position in FIG. 3, and a signal is output to the pump control valve 12 to switch it to the right position in FIG. , hand 111i 25 LC, the pump control valve 11.12 is switched to the position 1 and the right position, respectively, so that the piston 13.14 moves to the right and to the left, thereby causing the variable displacement pump 1, 2 is in a state where pressure oil is discharged at a constant flow rate Q in the leftward and rightward directions in the figure, respectively.

Then, as shown in step 26, a signal is output from the conversion device ij6 to the switching valves 7, 8, and these switching valves 7.8 are opened. As a result, the discharge port of the variable displacement pump 1 and one of the hydraulic cylinders 3, I? ) −J− i.e. y+
? ), and the suction port of the variable displacement pump 1 communicates with another hoard or rod side of the hydraulic cylinder 3. Therefore, the hydraulic cylinder 3 is driven in the extending direction by the pressure oil sucked into the variable capacity cylinder 1 from the hydraulic source 3b via the pipe line 3a.

Further, at the same time as the switching valve 7.8 is opened in step 26, the process moves to step 27, and the conversion device 6 calculates the count of time T by l·'? Therefore, this lLj interval T and F〒 interval 1. which are stored in advance. A comparison is made with When this time T becomes equal to time t1, the process moves to hand 1iR28. Note that the working distance of the hydraulic cylinder 3 during this time is tIQ/St.

Next, as shown in +11i'i2B, the converter 6 outputs a signal to the switching valves 7 and 8 to close these switching valves 7 and 8, and at the same time, the converter 6 outputs a signal to close the switching valves 7 and 8. Valves 9, 10 & l: The f door number which opens these switching valves 9, 10 is output. As a result, the circuit that connects the discharge port of the variable displacement pump 1 and the bottom (1111) of the hydraulic cylinder 3, and the circuit that connects the suction port of the variable displacement pump 1 and the Rondo Ogawa of the hydraulic cylinder 3 are cut off. , the discharge port of the variable displacement pump 2 and another port of the hydraulic cylinder 3, that is, the rond side, communicate with each other, and the circuit connecting the suction port of the variable displacement pump 2 with the bottom side of the hydraulic cylinder 3 communicates with each other. .Therefore, from the hydraulic source 3b to the pipe line 3a
By the pressure oil sucked into the variable volume R4 knob 2 via
The hydraulic cylinder 3 is driven in the direction of contraction. Also, at the same time as the switching valves 9 and 10 are opened in step 28 above, a time period T starts, and this time T and a pre-memorized time period 1. Which comparisons are made?

When this time T becomes equal to time t2, the process returns to the beginning. Note that the working distance of the hydraulic cylinder 3 during this period is tzQ
/S! becomes. Thereafter, similar operations are performed continuously during a short period of time.

In this way, in the above embodiment, the hydraulic cylinder 3
If it is intended to cause vibration in the hydraulic cylinder 3, the variable displacement pumps 1 and 2 are always in a state where they can discharge a constant amount, and the switching operation of the operating direction of the hydraulic cylinder 3 is controlled by the piston 13.
1-, i.e. for switching the direction of operation of the hydraulic cylinder 3, without intervening displacement movements of the switching valve 7.8.
Alternatively, it is possible to achieve response: I5 in the short time it takes to switch the switching valves 9 and 10, and therefore, the hydraulic cylinder 3 (main, (LFM distance rlffl t IQ/S
t = t z Q / 82 bolts (・T, contraction and extension fire are repeated alternately, desired C) 'lj''' movement is generated.

Example 7: For example, when applied to the drive circuit of the Nonoket cylinder that rotates the packets of a hydraulic excavator, it is possible to reduce the amount of dirt adhering to the packets.
U k , i''>rotation can be realized by generating vibrations in the packet cylinder by crushing rocks with a packet, etc.).

(In the above embodiment, F#2 is used to cause the hydraulic cylinder 3 to vibrate, and the pump control valve 11+ is used for the hydraulic cylinder 3.
12, switch to reigning 1h1 and cloth f-6 respectively (
N' M output is dead, but on the contrary, pump ti++
J (IllJ+ 11 and 12, each with cloth 1r''
11. In the above embodiment, the variable displacement pump 1.2 or "
) Flow of pressure oil discharged Jfl: Q yal - If lJ is kept constant 21) = 71 ibek, for example, off 4 -
'6 valves 7, 8, 9, 10 & Flow l,; - A convergence is formed by a valve having a flexible function, and the flow of pressure oil supplied to the bottom side of the hydraulic cylinder 3 is applied to the rod side. The brazing of the supplied pressure oil is Q2, and the minute time t stored in advance in the memory of the converter 6 is always constant.
In addition, detection may be performed so as to satisfy the relationship tQ1/5t=tQ2/82.

In addition, in FIG.
Although the systems that connect the systems are shown by electrical systems, some of these systems can also carry hydraulic signals (σ).

Moreover, in the above T example, the soup is 31! As shown in Figure 1, - two variable displacement pumps 1 and 2 are used to generate a voltage 11 in the hydraulic cylinder 3, but instead of the variable displacement pump 1, a plurality of hydraulic cylinders 7'' are provided. Alternatively, the pump 2 may be replaced with a plurality of hydraulic cylinders.

In addition, in the above-mentioned base example, the hydraulic cylinder 3 is used as an example of the actuator, but the present invention is not limited to this hydraulic cylinder 3 (also, the present invention is applicable to construction machinery such as hydraulic excavators). Hydraulic pressure of each f ↑ Koβ for several stocks
It is possible for i.

Since the actuator drive circuit of Hyobaki is constructed as described above, it is possible to maintain excellent responsiveness to the switching operation of the actuator's operating direction, and therefore, this actuator is The desired vibration level can be generated and this actuator is operated by the hydraulic pressure 4.
It has the effect of improving the workability of lp machines.

[Brief explanation of drawings]

The first problem is a circuit diagram showing example 7 of a conventional actuator drive circuit, the 21st example is a flowchart of an example of a control procedure performed in the conventional actuator drive circuit shown in FIG. Actuator I (4ill
A circuit diagram showing one embodiment of the υ circuit, FIG. 4 is a flowchart showing an example of the control circuit implemented in one embodiment of the main party shown in FIG. 3. -'Elj Variable amount Bonzopon...Hydraulic cylinder (actuator), 4...Operation device pupil, 6...Conversion device kettle, 7.8, 9.10...Switching valve, 11.12...
・Pump control valve, 13.14... Piston, 15...
・Switching device 1111111 helmet 11121ft 4, me Qin-

Claims (1)

[Claims] 1. It consists of a closed circuit that has one actuator, a plurality of hydraulic pumps that drive this actuator, and a switching valve that is interposed between these hydraulic pumps and the actuator, and that operates the switching valve. In the actuator drive circuit, the actuator drive circuit is provided with an actuating means and capable of driving the actuator by the confluence of pressure oil discharged from the plurality of hydraulic pumps, further comprising a switching device connected to the actuating means and outputting a signal. The actuating means includes a circuit for communicating the switching valve t1 with a discharge port of one of the plurality of hydraulic pumps and one port of the actuator in response to a signal output from the switching device;
A circuit connecting a discharge port of another one of the plurality of hydraulic pumps and another boat of the actuator is operated so that communication and interruption are repeated alternately. and J-stone actuator drive circuit.