JP2966081B2 - Construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a boom, an arm, a bucket, an actuator for driving these, a control valve for controlling the driving of the actuator, and a pressure discharged from the control valve. The present invention relates to a construction machine such as a hydraulic shovel provided with a flow rate indicating means such as a controller for indicating a flow rate of oil.

[Conventional technology]

FIG. 6 is a side view showing a hydraulic shovel as an example of this type of conventional construction machine.

The hydraulic shovel shown in FIG. 6 includes a bucket 1 for excavating earth and sand, an arm 2 connected to the bucket 1, a front including a boom 3 connected to the arm 2, and the like, and a boom 3 connected to the cab. And a traveling body 6 provided below the revolving body 5.
Further, in addition to the above-described bucket cylinder 7, arm cylinder 8, and boom cylinder 9 for rotating the bucket 1, the arm 2, and the boom 3, respectively, a swing motor (not shown) for swinging and running the swing body 5 and the running body 6, respectively. An actuator such as a traveling motor is provided. Although not shown, a control valve for controlling the driving of these actuators, and an operating means provided corresponding to the control valve and instructing the opening amount of the control valve, that is, operating an operating lever provided in the cab 4 The controller includes a controller that controls the control valve by outputting a flow command signal corresponding to the amount to a drive unit of the control valve, and a hydraulic pump that supplies pressure oil to the actuator via the control valve. Further, a front position sensor such as a bucket angle sensor 10, an arm angle sensor 11, and a boom angle sensor 12 for performing trajectory control and the like for controlling the position of the blade edge of the bucket 1 to a desired position is provided.

In such a hydraulic shovel, for example, as shown in FIG. 7, in order to perform trajectory control for causing the cutting edge position B of the bucket 1 to reach a target position A on the ground, the angle sensors 10, 11, and The controller obtains the current cutting edge position B of the bucket 1 from the signal output from
Performs a predetermined calculation so that is equal to the target position A,
The target speed of each of the boom cylinder 9, the arm cylinder 8, and the bucket cylinder 7, that is, the actuator is determined, and a flow rate command signal corresponding to the target speed is output to a drive unit of a control valve associated with the actuator. As a result, the corresponding control valve is driven, pressure oil is supplied to each actuator from the hydraulic pump via the control valve, and each actuator is operated so that the cutting edge position B of the bucket 1 approaches the target position A. Controlled.

[Problems to be solved by the invention]

By the way, in general, there is a manufacturing error in a device including a control valve, and this manufacturing error has a technical limit even if it is manufactured with considerably high accuracy, and the flow rate supplied to the actuator fluctuates due to the manufacturing error. As a result, the desired actuator speed may not be obtained. That is, the target flow rate corresponding to the flow rate command signal output from the controller to the control valve does not match the flow rate actually supplied to the actuator, so that the cutting edge position B of the bucket 1 does not reach the target position A. In some cases, accurate trajectory control cannot be performed. Conventionally, feedback control has been performed to perform such trajectory control.However, this feedback control does not take into account the above-described manufacturing error. Therefore, the actuator speed becomes slow, and there is a problem in workability.

The present invention has been made in view of the above-described situation in the related art, and has as its object to supply a target flow rate corresponding to a flow rate command signal and an actual actuator to an actuator regardless of a manufacturing error of a device including a control valve. Another object of the present invention is to provide a construction machine capable of matching a flow rate.

[Means for solving the problem]

In order to achieve the above object, the present invention provides at least one working machine element such as a boom that performs an operation such as a construction work, an actuator that drives the working machine element, and a flow rate of pressure oil supplied to the actuator. A construction valve comprising: a control valve for controlling; a flow rate indication means for indicating a flow rate of the pressure oil discharged from the control valve; and a speed detection means for detecting an operation speed of the work machine element. Calculating a rate of change in the operating speed of the work implement element detected by the determining means, and determining whether or not the value of the rate of change is smaller than a predetermined value; When it is determined that the flow rate is smaller than the operating speed of the work machine element detected by the speed detecting means and the flow rate of the pressure oil indicated by the flow rate indicating means, the flow rate indicating means instructs. A correction value calculating means for calculating a correction value for correcting the flow rate of the oil, is obtained and a correction value storing means for storing a correction value the correction value calculation means has calculated.

[Action]

When the control valve is switched from the neutral position to the operating position by an operator's operation of the operation lever or the like, and the flow rate indicating means indicates the flow rate of the pressure oil discharged from the control valve, the pressure oil of the flow rate indicated by the actuator is Flows, and the work machine element starts operating at a speed corresponding to the flow rate of the pressure oil discharged from the control valve. The speed detecting means detects an operating speed of the working machine element in operation. The determining means calculates a change rate of the operating speed of the work implement element detected by the speed detecting means, and determines whether the value of the change rate is smaller than a predetermined value. When the determining means determines that the value of the change rate is smaller than the predetermined value, the correction value calculating means determines the relationship between the operating speed of the work implement element detected by the speed detecting means and the flow rate of the pressure oil indicated by the flow rate indicating means. A correction value for correcting the flow rate of the pressure oil indicated by the flow rate indicating means is calculated based on the flow rate. The correction value storage means stores the correction value calculated by the correction value calculation means. After that, when the flow rate instructing means instructs the flow rate of the pressure oil discharged from the control valve, the flow rate instructing means instructs the flow rate of the pressure oil corrected by the correction value stored in the correction value storage means.

〔Example〕

Hereinafter, an embodiment of a construction machine of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a main part of one embodiment of the present invention, FIG. 2 is a diagram showing a relationship between a flow rate command signal to a control valve set by a controller shown in FIG. 1 and a correction gain, FIG. 3 is a flow chart showing processing contents in the controller shown in FIG. 1, FIG. 4 is a view showing a relationship between a flow rate command signal to a control valve before correction and an actual actuator speed, and FIG. FIG. 5 is a diagram showing a relationship between a flow command signal to a control valve and an actual actuator speed. This embodiment is an example in which the present invention is applied to the same one as the hydraulic excavator shown in FIG.

As can be seen from FIG. 1 showing the main part of the structure, this embodiment includes an actuator 20 such as a boom cylinder, an arm cylinder, a bucket cylinder, and the like.
A control valve 21 for controlling the drive of each of the 20,
To indicate the opening amount of the control valve 21,
Electric operation lever that outputs an operation signal according to the operation amount
22, a front position sensor 23 comprising a boom angle sensor, an arm angle sensor, a bucket angle sensor, etc., and outputting a position of the bucket 1 or the like driven by each actuator as a front position signal, and a control valve.
A correction instruction device that outputs a correction instruction signal C for instructing execution of a correction for preventing an influence due to a manufacturing error of a device including 21.
24 and have. In addition, the controller 25 is provided, and the controller 25 includes an input unit 26 for inputting an operation signal, a front position signal, and a correction instruction signal output from the operation lever 22, the front position sensor 23, and the correction instruction device 24 described above. A reference rate of change G set in advance corresponding to a change in the speed of each actuator relating to the boom, the arm, and the bucket, and corresponding to a very gradual change in the speed at which the speed can be determined, and FIG. A storage unit 27 for storing the relationship between the flow command signal to the control valve 21 and the correction gain, and at least the control valve
A calculation unit 28 that calculates a correction gain according to the magnitude of the manufacturing error of the device including 21 and performs a calculation to correct the flow command signal based on the correction gain, and an output unit that outputs the flow command signal to the control valve 21 29. Although not shown, a boom, arm, bucket, revolving unit, traveling unit, etc. equivalent to those shown in FIG.
A hydraulic pump or the like for supplying pressure oil for driving each actuator is provided.

In the embodiment configured as described above, when the correction instruction device 24 is operated and the operation lever 22 is operated to drive the front of the boom, the arm, and the bucket, the processing shown in FIG. 3 is performed by the controller 25. The processing shown in FIG. 3 is performed for each of the actuators such as the boom cylinder, the arm cylinder, and the bucket cylinder. However, since the processing is equivalent, for example, the driving of the arm cylinder will be described.

That is, an operation signal F for driving the arm cylinder is output from the operation lever 22, a front position signal W indicating the arm position is output from the front position sensor 23, and a correction instruction signal C is output from the correction instruction device 24. And
V is the actual actuator speed, that is, the arm cylinder speed, N is the rate of change of the speed per unit time, G is a reference change rate set in advance corresponding to the speed change of the arm cylinder, and G is a value for driving the arm cylinder. It is assumed that a flow command signal to the control valve 21 corresponding to the target flow rate is X, a correction gain is K, and a flow command signal corrected by the correction gain K is Y.

First, as shown in step S1 of FIG. 3, a correction instruction signal C, an operation signal F, and a front position signal W are input to the arithmetic unit 28 via the input unit 26. Next, the procedure proceeds to step S2, where it is determined whether the correction instruction signal C has been input by the arithmetic unit 28. Now that the correction instruction signal C has been input, the process proceeds to step S3. In step S3, the actuator speed, that is, the arm cylinder speed V is obtained from the front position signal W, and a calculation for obtaining the speed change rate N is performed. Then, the process proceeds to step S4. In this step S4, the reference change rate G stored in the storage unit 27 is read out to the calculation unit 28, and in step S3
It is determined whether or not the change rate N obtained in the step is equal to or smaller than the reference change rate G, that is, whether or not the arm cylinder is being driven so slowly that excavation work or the like by operation of the arm cylinder is not intended. If this judgment is affirmed, the procedure moves to step S5. In step S5, a correction gain K is obtained. In order to obtain the correction gain K, first, as shown in FIG. 4, an arm flow obtained from the flow command signal X to the control valve 21 corresponding to the operation signal F and the actual actuator speed, that is, the front position signal W described above. A relationship with the cylinder speed V is obtained, and a correction gain K is obtained by dividing the flow command signal X by the actual arm cylinder speed V based on this relationship. Next, the procedure proceeds to step 6, where the flow rate command signal X
Is stored in the storage unit 27. Next, the process proceeds to step S7, where the flow rate command signal X is output to the control valve 21 for the arm cylinder. In response to this, the control valve 21 opens by an amount corresponding to the operation amount of the operation lever 22, that is, the flow command signal X, and is supplied from a hydraulic pump (not shown) to the actuator 20 or the arm cylinder via the control valve 21 to drive the arm cylinder. You. Hereinafter, the same operation is performed while the correction instruction signal C is input, and finally, the flow rate shown in FIG. 2 corresponds to the relationship between the flow rate command signal X shown in FIG. 4 and the actual arm cylinder speed. The relationship between the command signal X and the correction gain K is obtained. The time for obtaining the correction gain K is set in advance in accordance with the speed and stroke of the arm cylinder, and when the set time has elapsed since the correction instruction signal C was input to the arithmetic unit 28, for example, the correction instruction device 24 is OFF
And the output of the correction instruction signal C stops. When this state is reached, the determination in step S2 is not affirmed, and the routine goes to step S8.
If the determination in step S4 is not affirmative even if the correction instruction signal C has been input, it is determined that the operation is being performed via the arm cylinder, and the process proceeds to step S8. In step S8,
The relationship shown in FIG. 2 stored in the storage unit 27 is read out, the correction gain K corresponding to the flow rate command signal X corresponding to the operation signal F output from the operation lever 22 is selected, and the flow rate command signal X Is multiplied by a correction gain K to obtain a flow command signal Y, that is, Y = K · X.
Next, the process proceeds to step S9, where the output unit 29 outputs the corrected flow rate command signal Y to the arm cylinder control valve 21. In the case of K> 1, the control valve 21 is controlled to be more open than expected and the actuator
20, that is, a relatively large flow is supplied to the arm cylinder, the arm cylinder speed is increased, and when K <1, the control valve 21 is controlled to close to supply a relatively small flow to the arm cylinder. The arm cylinder speed decreases. Thereby, the flow rate command signal Y to the control valve 21 and the actual actuator speed V
That is, the arm cylinder speed is related as shown in FIG.
That is, the flow command signal Y and the actuator speed V have a proportional relationship, and a desired operation can be performed with the arm cylinder speed proportional to the operation amount of the operation lever 22.

In the above description, only the arm cylinder has been described, but the boom cylinder and the bucket cylinder are similarly controlled.

In the embodiment constructed as described above, the relationship between the flow rate command signal X of the control valve 21 and the actual actuator speed V is curved as shown in FIG. Was
In actual operation, the flow command corrected by calculating the product of the flow command signal X corresponding to the operation signal F output from the operation lever 22 and the corresponding correction gain K read from the storage unit 27. A signal Y is obtained, and the corrected flow command signal Y is output to the control valve 21 to thereby control the flow command signal Y output from the controller 25 and the pressure flowing out of the control valve 21 as shown in FIG. The relationship between the oil flow rate and, therefore, the actuator speed V can be linearly proportional.

As described above, the operation amount of the operation lever 22 can be made proportional to the actuator speed V regardless of the production error of the control valve 21 and the like, so that the front operating position can be accurately controlled. You don't have to demand strict production precision when you make it,
Production costs for pressurized oil equipment can also be reduced.

In the above embodiment, the correction gain K obtained by dividing the flow rate command signal X to the control valve 21 by the actual actuator speed V is used as a correction element corresponding to at least the magnitude of the manufacturing error of the device including the control valve 21.
And a flow rate command signal X corresponding to the operation signal F is calculated to obtain a corrected flow rate command signal Y.
The present invention is not limited to this, and the correction element is set to a correction signal value F that gives a correction flow rate corresponding to the deviation width between the theoretical target actuator speed corresponding to the preset flow command signal and the actual actuator speed. (X), the flow command signal Y to be given to the control valve 21 by adding the correction signal value F (X) to the flow command signal X before correction may be obtained.

Further, in the above description, the boom angle sensor, the arm angle sensor, and the bucket angle sensor are described as the front position sensor 23, but the present invention is not limited to this, and may be provided with a stroke sensor or the like.

Further, in the above-described embodiment, the correction instruction device 24 is provided, and the correction operation of the flow command signal excluding the influence of the manufacturing error of the device including the control valve 21 is performed according to the correction instruction signal C output from the correction instruction device 24. But
Without providing such a correction instruction device 24, for example, when the lever 22 is operated at the time of starting, the correction operation may be performed.Also, a forced correction instruction device is provided, and The above-described correction operation may be forcibly performed even during the driving of the actuator by the output of the forced correction instruction signal.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to make the target flow rate corresponding to the flow rate command signal coincide with the flow rate actually supplied to the actuator regardless of the manufacturing error of the device including the control valve. It is possible to obtain the actuator speed following the operation amount of the operation means, and to correctly obtain the correction value for correcting the flow rate of the pressure oil discharged from the control valve. Further, the manufacturing error of the device including the control valve can be reduced as compared with the related art, and there is an effect that the manufacturing cost of the device including the control valve can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a construction machine according to an embodiment of the present invention, and FIG. 2 is a diagram showing a relationship between a flow rate command signal to a control valve set by a controller shown in FIG. 1 and a correction gain. FIG. 3 is a flowchart showing processing contents in the controller shown in FIG. 1, FIG. 4 is a diagram showing a relationship between a flow rate command signal to a control valve before correction and an actual actuator speed, and FIG. FIG. 6 is a diagram showing a relationship between a flow rate command signal to the control valve after correction and an actual actuator speed, FIG. 6 is a side view showing a hydraulic shovel as an example of a conventional construction machine, and FIG. It is explanatory drawing which shows the locus | trajectory control performed in the hydraulic shovel shown in FIG. 20… Actuator, 21… Control valve, 22
Operating lever, 23 Front position sensor, 24 Correction instruction device, 25 Controller, 26 Input unit, 27
... storage unit, 28 ... calculation unit, 29 ... output unit.

Claims (1)

(57) [Claims] At least one work machine element such as a boom for performing an operation such as a construction work, an actuator for driving the work machine element, a control valve for controlling a flow rate of pressure oil supplied to the actuator, In a construction machine comprising flow rate indicating means for indicating a flow rate of pressure oil discharged from the control valve and speed detecting means for detecting an operation speed of the working machine element, the work machine detected by the speed detecting means Determining means for calculating a change rate of the operation speed of the element to determine whether the value of the change rate is smaller than a predetermined value; and determining that the value of the change rate is smaller than a predetermined value. Correcting the flow rate of the pressure oil indicated by the flow rate indicating means based on the relationship between the operating speed of the work machine element detected by the speed detecting means and the flow rate of the hydraulic oil indicated by the flow rate indicating means. Construction machine, wherein the correction value calculating means for calculating a value, that had a correction value storing means for storing a correction value the correction value calculation means has calculated.