JPH0794738B2 - Automatic vibration method of hydraulic excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) Soil quality is changed by changing the stroke and speed of a working machine cylinder of a hydraulic excavator having a working machine composed of a boom, an arm and a bucket, depending on the type of work. In the automatic vibration method of the hydraulic excavator, which gives an appropriate minute amplitude to the bucket to reduce excavation resistance to enable efficient excavation even in various types of work, the amplitudes in mutually opposite directions that maximize the absolute value An automatic vibration method for a hydraulic excavator, characterized in that an excessive vibration is reduced by providing an amplitude change region for a predetermined time between them.

(Prior Art) Conventionally, in a hydraulic excavating machine equipped with a work machine automatic vibration device such as a boom, an arm and a bucket, when a hard soil is encountered during excavation work, the work machine is not The excavation work was efficiently performed by vibrating with a rectangular wave having a required amplitude and frequency according to hardness etc., and fatigue of the operator was reduced. That is, as shown in FIG. 4, the vibration mode switch 4 selects one of the L, M, and S modes,
When any one of the boom independent vibration Bo, the arm independent vibration A, the bucket independent vibration Bu, and the skeleton Sk is selected in the work mode switch 5, the automation controller 33 according to the command signals from the vibration mode switch 4 and the work mode switch 5
A vibration signal kBo, kA, kBu corresponding to the selected vibration mode and work mode is output from the oscillator 39 to the adder 20. When the automatic vibration mode switch 6 is turned off, the switch 18 is connected to the A contact by the spring force by the magnet 17 to be in the manual mode, but when the automatic vibration mode switch 6 is turned on, the switch 18 is resisted by the magnet 17 against the spring force. Then, the automatic vibration mode is established by connecting to the B contact and the set vibration signal from the work mode switch 5 and the vibration mode switch 4 input to the adder 20 is converted into electric power according to the operation amount of the work machine levers 1a1, 1a2, lb. The operation signals from the signal conversion devices 2a1, 2a2, 2b are added and output to the work machine controller 37. Further, the automation controller 33, the work machine controller 37, the electronic control valve 21, and the work machine actuator 15 are described in the case where the work machine is a boom, but the arms and buckets are omitted because they are the same as the boom. Next, the operation of FIG. 4 will be described by taking an example of automatic boom vibration control. With the boom lever 1a1 in the neutral position, set the vibration mode switch 4 to any one of L, M, and S modes, set the work mode switch 5 to the boom independent vibration mode Bo, and then set the automatic vibration mode switch 6 When turned on, the repulsive force of the magnet 17 connects the switch 18 to the B contact, so that the transmitter 39 in the automation controller 33
To 33a, a boom signal having a rectangular wave is output to the work machine controller 37. The work machine controller 37 converts the rectangular wave boom signal input with the voltage into a current signal like 37a, and converts the current signal into 37b and 3b, respectively.
After converting the boom up current value and the boom down current value as in 7c, the electronically controlled poppet valves 10 to 13 of the electronically controlled operating valve 21 are converted.
Is output to the solenoids 8 and 9. When the boom raising current signal 37b is output to the solenoid 8, the electronically controlled povet valves 10 and 11 are opened according to the current signal, so that the pressure oil discharged from the hydraulic pump 14 is electronically controlled. The boom cylinder 15 is extended because it is supplied to the boom cylinder 15 via the povet valve 10, and the return oil from the boom cylinder 14 is discharged to the tank 16 via the electronically controlled povet valve 11. At this time, as you can see from 37c, solenoid 9
Since the boom lowering current signal is not output to, the electronically controlled povet valves 12 and 13 are closed. Further, when a boom lowering current is output to the solenoid 9, the discharge oil of the hydraulic pump 14 is supplied to the boom cylinder 15 via the electronically controlled povet valve 12 as in the case of the boom raising, so that the boom cylinder 15 is not operated. The return oil from the boom cylinder 15 that contracts is discharged to the tank 16 via the electronically-controlled hopet valve 13. The boom can be vertically vibrated by repeating the above operation. Since the same applies to the arm and the bucket, the same description as the above configuration will be omitted. The displacement of the boom cylinder 15 in the automatic vibration device shown in FIG. 4 with respect to time will be described with reference to FIG. After setting the vibration mode switch 4 and the work mode switch 5 as described above, the automatic vibration mode switch 6 is turned on.
Then, the amplitude of the boom starts automatic vibration a1 in the boom raising direction, a2 in the boom lowering direction, and cycle T. However, if the boom lever 1a1 is operated to the boom raising side during the automatic vibration, the cycle T does not change, but the boom Since the amplitude reference level moves to the boom raising side in accordance with the operation amount of the lever 1a1, the amplitude in the boom raising direction increases to a3, and the amplitude in the boom lowering direction decreases to a4. Where | a1 |
The relationship of + | a2 | = | a3 | + | a4 | is always maintained.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional technique, as can be seen from FIG. 5, a reverse operation is instantaneously made from the point A on the boom raising side to the point B on the boom lowering side in the rectangular wave. Therefore, the impact force acting on the bucket is increased and the excavation force is increased, but the shock to the excavator and the operator is also large. Especially for operators who dislike shocks, a soft mode was prepared in which the amplitude and period of the rectangular wave were made smaller than the S mode in the vibration mode, but since a rectangular wave is basically used, a sufficient cushioning effect is obtained. I couldn't do it.

(Means for Solving the Problems) The present invention has been made to solve the problems in the above-mentioned conventional technology, and the claim (1) claims at least one of the working machines in the hydraulic excavator. In a work machine automatic vibration device of a hydraulic excavator for automatically repeating control of a work machine actuator, an absolute value of each positive and negative amplitude of the operation signal of the work machine actuator maintains a maximum value for a predetermined time, and then a predetermined time According to the automatic vibration method for the hydraulic excavating machine, the amplitude of the absolute value in the opposite direction is monotonously changed to the maximum value. According to the automatic vibration method of the hydraulic excavator, the monotonous change of the amplitude at a predetermined time is set to be substantially linear, and the third (3) claim is the above (1) claim. Maintains 0 amplitude for a predetermined time After that, a rectangular wave for changing the direction of the amplitude is output from the transmitter to the work machine controller, and the absolute values in opposite directions become maximum during a predetermined time during which the work machine controller maintains the zero amplitude of the rectangular wave. The object is achieved by an automatic vibration method for a hydraulic excavating machine, which is characterized in that it is converted into an operation signal to an actuator for a working machine, which changes monotonously up to the amplitude.

(Operation) With the above configuration, since the amplitude changes to a shape close to a rectangular wave, a sufficient impact force can be applied to the excavated earth and sand, and the change rate of the amplitude with respect to time does not become infinite, Since such a modulation effect can be obtained, it is possible to prevent shocks to the excavating machine and the operator. Further, if the monotonic change of the amplitude in a predetermined time is made substantially linear, the control becomes simple and a sufficient modulation effect can be obtained.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a control circuit according to a first embodiment of the present invention. The same reference numerals are given to the same configurations as those of FIG. 4 showing the conventional technique, and the description thereof will be omitted. The difference between this embodiment and the conventional technique shown in FIG. 4 is that the vibration mode set in the oscillator 39 in FIG. 4 is 33a, while the vibration mode set in the oscillator 19 in FIG. Vibration mode is 3a
Therefore, in the working machine controller 37 of FIG. 4, the vibration signal is controlled like 37a, 37b, 37c and output to the electronically controlled operating valve 21, whereas in the working machine controller 7 of FIG. The vibration signal is controlled as in 7a, 7b, and 7c and is output to the electronically controlled operating valve 21, and the others are the same. Similar to the prior art shown in FIG. 4, the automation controller 3, the work machine controller 7, the electronic control valve 21, and the work machine actuator 15 are described for the case where the work machine is a boom. It is omitted because it is the same as. Next, the operation of the automatic vibration control of the boom will be described with reference to the configuration of FIG. With the boom lever 1a1 in the neutral position, set the vibration mode switch 4 to any one of L, M, and S modes, and set the work mode switch 5 to the boom independent vibration mode Bo,
When the automatic vibration mode switch 6 is turned on, the switch 18 is connected to the B contact due to the repulsive force of the magnet 17, so that the vibration mode signal indicated by 3a set in the transmitter 19 passes through the adder 20 and the work implement controller. 7 is output. The above
The vibration mode signal shown in 3a is a rectangular wave whose details are shown in FIG. 2 (A), in which the amplitude is changed after maintaining the amplitude of 0 for a predetermined time. The rectangular wave vibration mode signal input to the work machine controller 7 is converted as indicated by 7a. The vibration mode signal shown in 7a is a signal which, as shown in FIG. 2 (B) in detail, changes monotonically to the current signal of i2 in the opposite direction during Δt time after the current signal of i1 is maintained for a predetermined time. Is. The vibration mode signal of 7a is controlled in the work machine controller 7 by a boom raising signal and a boom lowering signal as shown by 7b and 7c, and is output to the electronic control operation valve 21. Therefore, in the boom cylinder 15 which is vibrated by the boom signal having the amplitude change region, a sudden change in the amplitude is alleviated and the effect of the vibration excavation by the rectangular wave can be fully utilized. The displacement of the boom cylinder 15 with time in the automatic vibration device shown in FIG. 1 will be described with reference to FIGS. 3 (A) and 3 (B). When the automatic vibration mode switch 6 is turned on after setting the vibration mode switch 4 and the work mode switch 5 as described above, the boom automatically vibrates according to the vibration mode signal set in the transmitter 19 shown in FIG. Although it starts, when the boom lever 1a1 is operated to the boom raising side during the automatic vibration, the operation signal of the boom lever 1a1 is added by the adder 20 to the vibration mode signal of 3a in FIG. As shown in (A), the amplitude reference level moves to the boom raising side according to the operation amount of the boom lever 1a1, and the state of 0 amplitude maintained for a predetermined time remains as is. Is entered. Therefore, the third
As shown in Fig. (B), the boom amplitude, which was a1 in the boom raising direction and a2 in the boom lowering direction, does not change the cycle T, but the reference level of the boom is raised according to the operation amount of the boom lever 1a1. As it moves to the side, the amplitude in the boom raising direction increases to a3, and the amplitude in the boom lowering direction decreases to a4. However, | a1 | ＋ | a2 | ＝ | a3 |
The relationship of + | a4 | is always maintained. FIG. 1C is a diagram showing a second embodiment of the present invention, in which the amplitude change region of the minute time Δt in the first embodiment is not a straight line but an amplitude of 0.
This is an example in which a curve having an inflection point at the point is used, and in this case, there is an effect that the rate of change of the amplitude with respect to time at the amplitude having the maximum absolute value can be further relaxed.
In the first and second embodiments, the electronically controlled povet valve has been described, but it goes without saying that a spool valve controlled by the solenoids 8 and 9 may be used.

(Effects of the Invention) As described in detail above, according to the present invention, the effect of the minute vibration due to the rectangular wave can be fully utilized, so that it is possible to efficiently excavate by reducing the excavation resistance of the earth and sand and to complete the rectangular wave. It is possible to prevent the change rate of the amplitude with respect to time from becoming infinite, so that there is no excessive vibration, shocks to the excavator and the operator can be prevented, the durability of the excavator can be improved, and the working environment is also improved. Can be greatly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a control circuit in the first embodiment of the present invention, FIG. 2 (A) is a diagram showing an output signal of an oscillator in the first embodiment of the present invention, and FIG. 2 (B) is a book. The figure which shows the operating signal of the actuator for working machines in 1st Example of invention, FIG.2 (C) is the figure which shows the operating signal of the actuator for working machines in 2nd Example, FIG.3 (A) is this invention. FIG. 3 is a diagram showing an input signal of the work implement controller when the operating device lever is operated in the first embodiment of FIG. 3, and FIG. 3B shows displacement of the boom cylinder with respect to time corresponding to the input signal of FIG. 3A. FIG. 4 is a diagram showing a control circuit in a conventional technique, and FIG. 5 is a diagram showing displacement of a boom cylinder in the conventional technique with respect to time. 1a1 …… Boom lever, 1a2 …… Bucket lever, 1b …… Arm lever, 2a1,2a2,2b …… Electric signal converter, 3 …… Automatic controller, 4 …… Vibration mode switch 5 …… Work mode switch, 6 ...... Automatic vibration switch, 7 ...... Work machine controller, 8,9 ...... Solenoid, 10 to 13 ...... Electronic control povet valve, 14 ...... Hydraulic pump, 15 ...... Boom cylinder, 21 ...... Electronic control valve

Claims (3)

[Claims] 1. A working machine automatic vibration device for a hydraulic excavator for automatically and repeatedly controlling at least one working machine actuator among working machines in a hydraulic excavator. Automatic vibration of a hydraulic excavating machine characterized in that after the absolute value of each positive and negative amplitude maintains the maximum value for a predetermined time, it changes monotonically to the amplitude where the absolute value in the opposite direction becomes the maximum during a predetermined time. Method. 2. The automatic vibration method for a hydraulic excavator according to claim 1, wherein the monotonous change in amplitude at a predetermined time is substantially linear. 3. The work machine controller according to claim 1, wherein a rectangular wave for changing the direction of the amplitude after maintaining 0 amplitude for a predetermined time is output from the transmitter to the work machine controller. In the above, in the predetermined time for maintaining the zero amplitude of the rectangular wave, the operation signal is converted into an operation signal to the working machine actuator that monotonously changes to an amplitude in which absolute values in opposite directions become maximum. Automatic vibration method of hydraulic excavating machine.