JP2012007713A - Device and method for controlling hydraulic working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust operation speed of a hydraulic actuator while emphasizing operability or fuel consumption.SOLUTION: A control unit 12 of a hydraulic shovel controls the supply of the working oil to the hydraulic actuator. A pressure regulating knob 21 to determine preliminarily the correction amount of the pilot pressure, which is set up by the control lever 13 according to the work, is prepared. The pilot pressure which is operated by a control lever is set for the pilot pressure pipeline 16. The pilot pressure is detected by a pressure sensor 20 and input into the control means 15, and the correction amount of the pilot pressure is determined by considering the correction signal about the correction rate of the pilot pressure which is determined by the pressure regulation knob 21. The signal of the correction amount is output to the electromagnetic proportional reducing valve 28 from the control means 15 and the pilot pressure is corrected. The pilot pressure corrected by the electromagnetic proportional reducing valve is supplied to a control valve 14, the supply volume of the working oil from the opening area and the pressure loss to the hydraulic actuator is set up by operating the stem prepared in an oil route 19, which increases and decreases the operation speed of the hydraulic actuator.

Description

  The present invention relates to a hydraulic working machine including a construction machine such as a hydraulic excavator, which adjusts a pilot pressure supplied to a control valve to satisfactorily control operability and fuel consumption of the hydraulic working machine such as a hydraulic actuator. The present invention relates to a control device and a control method.

A construction machine, for example, a hydraulic excavator, as its drive mechanism, performs hydraulic actuators that drive working machines such as arm cylinders, bucket cylinders, and boom cylinders, and swings and travels the upper swinging body and the lower traveling body. Each actuator is provided. When operating the hydraulic actuator, the operating speed of the hydraulic actuator is controlled by the amount of hydraulic oil flowing into the hydraulic actuator.
It is recognized that the flow rate of the hydraulic oil is set mainly by the opening area of the oil passage by the stem provided in the oil passage in the control valve and its differential pressure (pressure loss) before and after. When the flow rate of the hydraulic oil flowing into the hydraulic actuator is Q, the opening area is A, and the differential pressure across the pressure is ΔP, the hydraulic flow rate is set by the following equation.
Flow rate Q = Constant k * Opening area A * Differential pressure √ △ P

By the way, the opening area by the stem in the oil passage (hereinafter sometimes referred to as opening) is designed in consideration of the maximum operating speed and operability of each hydraulic actuator. In order to improve the operability of the hydraulic actuator, a hydraulic excavator Energy efficiency, that is, fuel consumption may be sacrificed. This point will be described by taking as an example a boom stem of a working machine provided in the control valve.
FIG. 5 shows a hydraulic excavator 1. An upper swing body 3 is provided on an upper part of a lower traveling body 2, and a work machine disposed on the upper swing body 3 so as to be movable up and down is disposed at a boom 4 and a tip. And an arm 5 provided with a bucket. Then, the ground leveling operation is performed by repeatedly performing the opening and closing operation of the arm and the raising and lowering operation of the boom in accordance with the procedure shown in FIGS. 5 (a), (b), and (c).

FIG. 6 is a diagram showing the relationship between the operation lever 7 and the opening area of the oil passage in the control valve. For example, when the operation lever 7 is operated for raising and lowering the boom 4, the pilot pressure corresponding to the operation amount is shown. Circulates through the pilot pipe 6 and activates the boom stem 10 provided in the boom oil path 9 in the control valve 8. Then, the opening area and the pressure loss of the oil passage 9 are adjusted by moving the stem 10 up or down with the pilot pressure for raising or lowering that changes according to the operation amount of the operation lever 7.
Here, FIG. 7 shows the relationship between the opening (opening area) of the stem 10 and the oil passage 9 and the pressure loss with respect to the operation ratio of the operation lever 7 in the raising operation and the lowering operation of the boom 4 in the above-described current hydraulic excavator 1. FIG. The pressure loss is the magnitude when the operation lever 7 is modulated.

In FIG. 7, for example, when the operating lever 7 is fully lowered and the stem 10 of the oil passage 9 is lowered by about 100.6 MPa, the pressure loss on the stem 10 is about 10.6 MPa. It is about 2.5 MPa. For this reason, the lower side pressure loss is set to be much larger than the higher side pressure loss. This is designed in consideration of the operability when the boom 4 and the arm 5 are interlocked, that is, the speed balance when interlocking the lowering operation of the boom 4 and the opening operation of the arm 5.
For example, when the leveling work is performed with the hydraulic excavator 1, the boom lowering operation is performed when moving from FIG. 5 (b) to (a) in the leveling work shown in FIGS. 5 (a), (b), and (c). And the arm opening operation are performed simultaneously, and both the operation levers 7 are operated simultaneously. At this time, the load pressure for the lowering operation of the boom 4 is much lower than the load pressure for the opening operation of the arm 5. Most of the oil flows into the oil passage 9 on the boom 4 side where the load pressure is low, and the lowering operation of the boom 4 is performed at a higher actuator speed than the opening operation of the arm 5.

However, in the existing excavator 1 of the open center system, when the operation amounts of the operation levers 7 for performing the lowering operation of the boom 4 and the opening operation of the arm 5 are approximately the same, the hydraulic pressures of the boom 4 and the arm 5 are set. The opening area of each oil passage is determined so that the actuator speeds are approximately the same.
The change characteristics of the opening and the pressure loss with respect to the operation ratio of the operation lever 7 shown in FIG. 7 indicate the characteristics of the stem 10 that emphasizes operability. In this stem 10, in order to control the speed of the opening operation of the arm 5 and the lowering operation of the boom 4 to the same level, the operating lever 7 that performs the boom lowering operation when the operation ratio of the operating lever 7 that performs the arm opening operation is 100%. It is necessary to input the operation ratio of 100%. In this case, the operator can operate the operation lever 7 without being aware of the balance of the input amounts of the operation levers 7 of the arm 5 and the boom 4 and the operability is good.
On the other hand, FIG. 8 shows the change characteristics of the opening area and the pressure loss with respect to the operation ratio of the operating lever 7 by the opening N and the pressure loss N in the lowering operation of the boom 4 in the stem 10 with an emphasis on fuel consumption. In addition, the change characteristic by the above-mentioned stem 10 placing importance on operability is shown by the opening S and the pressure loss S. The pressure loss indicates the magnitude when the operation lever 7 is modulated.

Here, in order to emphasize fuel efficiency, if it is attempted to reduce the pressure loss N of the oil passage 9 to about 2.5 MPa during the single-action lowering operation of the boom 4, the opening characteristic indicated by the opening N is required.
If the above-described leveling operation is performed using the fuel efficiency-oriented stem 10, as shown in FIG. 8, in order to control the speeds of both the boom lowering operation and the arm opening operation to the same level, pressure loss In order to control N to about 2.5 MPa or less, it is necessary to control the opening N with an emphasis on fuel consumption below the maximum value of the opening S when the operability is emphasized (the operation ratio of the operation lever 7 is 100%).
For this purpose, the amount of operation of the operation lever 7 when the boom is lowered must be suppressed to a maximum of about 70%, and the controllable range of the operation lever 7 is narrowed. become. In such a case, the fuel consumption can be suppressed, but the operation of the operation lever 7 is difficult.
From the above description, since there may be a contradictory relationship between improvement in the operability of the operation lever 7 and reduction in fuel consumption in the hydraulic excavator 1, the opening characteristic of the stem 10 needs to be designed in consideration of the balance between the two. is there.

JP 2002-295409 A

However, in the hydraulic excavator control device according to the prior art as shown in FIG. 7 described above, the opening characteristics of the oil passage by the stem by the operation of the operation lever are uniform, even if the operation skill of the operator is different. When a skilled operator who can operate without difficulty even in the case of a stem with a narrow speed control range of the actuator by the operation lever shown in FIG. There has been a problem that fuel efficiency is unnecessarily deteriorated by using a control device that emphasizes performance.
Further, in the hydraulic working machine, a pressure reducing valve is provided between the operation lever and the control valve, and the pilot pressure is reduced in accordance with a signal such as an operation amount of another actuator, and the opening characteristic of the operation lever shown in FIG. However, this technique also has the same problem as the above-described conventional technique in that the operation is controlled without reflecting the operator's operation skill and intention.

In addition, the hydraulic excavator described in Patent Document 1 has an opening area designated by the operator with the operation volume regardless of the operation amount of the operation lever, in order to improve the operability of the operation lever. I have control. As a result, the larger the load on the boom cylinder, the smaller the opening area of the cut valve, so that the boom cylinder can be activated at the initial stage of the operation lever.
However, in this hydraulic excavator, the set opening area of the cut valve can be adapted to the size of the load assumed for the operation on the boom raising side, and it can be operated according to the operator's operating skill and the difficulty of work. There is nothing that controls the balance between performance and fuel consumption, and it does not improve the above-mentioned drawbacks.

  In view of such circumstances, the present invention provides a control device and a control method for a hydraulic working machine that can selectively adjust the operating speed of a hydraulic actuator to either an operability-oriented type or a fuel efficiency-oriented type. For the purpose.

A control device for a hydraulic working machine according to the present invention is a control device for a hydraulic working machine that controls the supply of hydraulic oil to a hydraulic actuator. Pressure adjusting means for determining the pilot pressure correction ratio, control means for determining a pilot pressure correction amount based on a correction signal relating to the pilot pressure correction ratio determined by the pressure adjusting means, and output from the control means The proportional pressure reducing means for correcting the pilot pressure based on the correction amount signal, and the hydraulic oil supply amount to the hydraulic actuator are set based on the pilot pressure corrected by the proportional pressure reducing means to control the operating speed of the hydraulic actuator. A control valve is provided.
According to the present invention, it is determined in advance whether the work to be performed by the hydraulic working machine is a fuel efficiency-oriented type or an operability-oriented type, and the correction ratio of the pilot pressure is selected and determined in advance by the pressure adjusting means. Then, the operating member is operated to set the pilot pressure based on the operating amount, and the pilot pressure correction amount is determined based on the correction ratio determined by the pressure adjusting means to correct the pilot pressure. Based on the corrected pilot pressure, the amount of hydraulic oil supplied to the hydraulic actuator can be set in the control valve to control the operating speed of the hydraulic actuator.

  In particular, when fuel economy is important, the pressure adjustment means, for example, determines whether the pilot pressure should be reduced or a small correction ratio, and sets the amount of hydraulic oil supplied to the hydraulic actuator based on the pilot pressure. Ensure large speed. On the other hand, when emphasizing the operability of the operating member, the pilot pressure is determined to be a large correction ratio by the pressure adjusting means, and the pilot pressure set by the operating member is reduced based on this correction ratio to the hydraulic actuator. Since the amount of hydraulic oil supplied is set, the operating speed becomes relatively small, and it becomes easy to perform minute operations.

In addition, the pressure adjustment means sets the position where the pilot pressure correction amount is the smallest as the fuel efficiency priority position, and the position where the pilot pressure correction amount is the highest as the operability priority position, between the fuel efficiency priority position and the operability priority position. It is preferable to determine the correction ratio of the pilot pressure.
Therefore, when the operator with high operating skill operates the hydraulic actuator or when the work does not require high operating skill, etc., the correction amount of the pilot pressure is set to 0 or compared by the pressure adjusting means held at the fuel-consideration position. The hydraulic actuator operating speed is increased by a pilot pressure set by the operation member or a pressure close thereto. On the other hand, when work requiring a high operating skill or an operator with a low operating skill is operating, the pilot pressure correction amount is largely controlled by the pressure adjusting means held at the operability-oriented position to reduce the pilot pressure. Let In this case, the operating speed of the hydraulic actuator with respect to the operation of the operation member can be reduced by the pressure obtained by reducing the pilot pressure set by the operation member.

Further, the control valve is preferably provided with an oil passage for supplying hydraulic oil to the hydraulic actuator and an advancing / retracting stem for controlling the opening area of the oil passage, and the operation of the stem is preferably controlled by pilot pressure.
The pilot pressure adjusted by the controller adjusts the stem advance / retreat stroke to increase / decrease the opening area of the oil passage, and control the flow rate of hydraulic oil supplied to the hydraulic actuator to increase / decrease the hydraulic actuator operating speed. can do.

The control means includes current control means for determining the correction amount of the pilot pressure as a current value based on the pilot pressure set by the operation member and the pilot pressure correction ratio determined by the pressure adjustment means. Also good.
In this case, since the correction amount obtained by taking into account the pilot pressure set by the operation member and the correction ratio of the pilot pressure determined by the pressure adjusting means is determined as the current value, it is relatively accurate. Can correct the pilot pressure.
Further, the control means may include a current control means for determining a pilot pressure correction amount set by the operation member as a current value based on a pilot pressure correction ratio determined by the pressure adjusting means.
In this case, the correction of the pilot pressure is determined as the current value only by the correction ratio of the pilot pressure determined by the pressure adjusting means, so that the pilot pressure can be corrected with a simple configuration.

A control method of a hydraulic working machine according to the present invention is a hydraulic working machine control method for controlling supply of hydraulic oil from a hydraulic pump to a hydraulic actuator.
Select a pilot pressure correction ratio that controls the operating speed of the hydraulic actuator and pre-determine it by the pressure adjustment means,
Operate the operating member to set the pilot pressure based on the operating amount,
The pilot pressure correction amount is determined based on the pilot pressure correction ratio determined by the pressure adjusting means to correct the pilot pressure,
According to the present invention, the operation speed of the hydraulic actuator is controlled by setting the amount of hydraulic oil supplied to the hydraulic actuator based on the corrected pilot pressure. It is determined whether the fuel efficiency type or operability priority type, and the correction ratio of the pilot pressure for controlling the operating speed of the hydraulic actuator by the pressure adjusting means is determined in advance. Then, the pilot pressure can be set based on the operation amount of the operation member, the pilot pressure described above can be corrected based on the correction ratio determined by the pressure adjusting means, and the operation speed of the hydraulic actuator can be controlled to increase or decrease.
In particular, when fuel efficiency is important, the operating speed of the hydraulic actuator is increased based on the pilot pressure set by the operation member, and when importance is placed on the operability of the operation member, the correction ratio determined in advance by the adjusting means Based on the above, the pilot pressure is greatly reduced, and the operation speed of the hydraulic actuator is relatively reduced to facilitate the minute operation.

According to the control device and control method for a hydraulic working machine according to the present invention, the operating speed of the hydraulic actuator can be adjusted by selecting, in advance, either the importance of fuel efficiency or the importance of operability which are in conflict with each other by the pressure adjusting means. That is, it is determined in advance whether the work performed by the hydraulic working machine is fuel-consumption-oriented or operability-oriented, and the correction ratio determined by the pressure adjusting means is determined by selecting and determining the pilot pressure correction ratio by the pressure adjusting means. The correction amount of the pilot pressure is determined on the basis of this, and the supply amount of the hydraulic oil to the hydraulic actuator is controlled based on the corrected pilot pressure, so that the operation speed of the hydraulic actuator can be controlled to be faster or slower.
In particular, when importance is attached to fuel consumption, the operating speed of the hydraulic actuator can be largely controlled by controlling the pilot pressure not to be reduced by the pressure adjusting means or by reducing the correction ratio. When the operability of the operation member is important, the pilot pressure correction ratio is largely controlled by the pressure adjusting means, and the operation speed of the hydraulic actuator is relatively decreased to facilitate a minute operation or a precise operation. .

In the control device for a hydraulic working machine according to the present invention, the pressure adjusting means uses the position where the pilot pressure correction amount is the smallest as the fuel efficiency priority position and the position where the pilot pressure correction amount is the highest as the operability priority position. The pilot pressure correction ratio was determined between the priority position and the operability priority position.
When an operator with a high operating skill operates the hydraulic actuator, or when the work does not require a high operating skill, the pilot pressure correction amount is reduced to 0 or relatively small by the pressure adjusting means held at the fuel efficiency priority position. The hydraulic actuator operating speed is increased by the pilot pressure set by the operation member or a pressure close thereto. On the other hand, when work requiring a high operating skill or an operator with a low operating skill is operating, the pilot pressure correction amount is largely controlled by the pressure adjusting means held at the operability-oriented position to reduce the pilot pressure. Let In this case, the operating speed of the hydraulic actuator with respect to the operation of the operation member can be reduced by the pressure obtained by reducing the pilot pressure set by the operation member.

  In the control device for a hydraulic working machine according to the present invention, the control valve is provided with an oil passage for supplying hydraulic oil to the hydraulic actuator, and an advancing / retracting stem for controlling the opening area of the oil passage. Since the operation of the stem is controlled, the opening / closing area of the oil passage is adjusted by adjusting the stem's advance / retreat stroke with the pilot pressure adjusted by the control device, and the flow rate of the hydraulic oil supplied to the hydraulic actuator is controlled. Thus, the operating speed of the hydraulic actuator can be adjusted up or down.

The control means includes current control means for determining the correction amount of the pilot pressure as a current value based on the pilot pressure set by the operation member and the pilot pressure correction ratio determined by the pressure adjusting means. Therefore, the correction amount obtained by taking into account the pilot pressure set by the operation member and the pilot pressure correction ratio determined by the pressure adjusting means can be determined as the current value, and the relative accuracy can be determined. Good pilot pressure correction can be performed.
Alternatively, the control means includes current control means for determining the correction amount of the pilot pressure set by the operation member as a current value based on the correction ratio of the pilot pressure determined by the pressure adjustment means. The correction amount can be determined as a current value only by the correction ratio of the pilot pressure determined by the pressure adjusting means, and the pilot pressure can be corrected with a simple configuration.

It is a principal part block diagram of the control apparatus arrange | positioned between the control lever and the control valve in the hydraulic shovel by embodiment of this invention. It is an enlarged view of the adjustment knob shown in FIG. It is a block diagram of the control apparatus shown in FIG. It is a block diagram of the control apparatus by a modification. (A), (b), (c) is a work process figure which shows the leveling work by the working machine of a hydraulic excavator. It is a principal part block diagram of the control apparatus arrange | positioned between the operating lever and control valve in the conventional hydraulic shovel. It is a figure which shows the relationship between the opening area of the stem for booms, and pressure loss with respect to the operation amount of the operation lever in the conventional hydraulic shovel. It is a figure which shows the relationship between the opening area of a boom stem with respect to the operation amount of an operation lever in case the pressure loss maximum value at the time of single-action operation of a boom is set, and pressure loss.

Hereinafter, a control device in a hydraulic excavator according to an embodiment of the present invention will be described with reference to the accompanying drawings. The configuration of the hydraulic excavator will be described using the same reference numerals for the same or similar parts and members as those of the above-described conventional technology.
FIG. 1 is a main part configuration diagram showing a control device for a hydraulic actuator in a hydraulic excavator 1 according to an embodiment of the present invention. In the present embodiment, for example, a control device for a hydraulic actuator that is a hydraulic cylinder that operates a working machine of the excavator 1 will be described.
The hydraulic excavator 1 according to the present embodiment includes a control device 12 that controls the amount of hydraulic oil supplied from the hydraulic tank to each hydraulic actuator, here, the hydraulic actuator for the boom 4 by operating the operation lever 13. . The control device 12 shown in FIG. 1 operates an operation lever 13 as an operation member that opens and closes the arm 5 and moves the boom 4 up and down, and an operation that supplies the cylinder of the boom 4 from the hydraulic pump by operating the operation lever 13. A control valve 14 for controlling the flow rate of oil is provided, and a control means 15 is connected to a pilot pressure line 16 provided between the operation lever 13 and the control valve 14.

The operation lever 13 can be rotated between a neutral (neutral) position and a full lever position on the raising side and the lowering side of the boom 4, for example, and the operation ratio is 0% at the neutral position and at the full lever position. 100%. In the present embodiment, the operation ratio of the operation lever 13 at the full lever position may be set to about 70% as shown in FIG.
The operation amount of the operation lever 13 is converted into hydraulic pressure and output as a pilot pressure toward the control valve 14 through the pilot pressure line 16.
Further, the control valve 14 moves the boom stem 18 forward or backward with respect to the oil passage 19 in accordance with the pilot pressure input from the pilot pressure line 16, so that the stem 18 in the oil passage 19 is moved back and forth. The opening area A can be adjusted up or down. The oil passage 19 constitutes a flow path for supplying hydraulic oil from a hydraulic pump (not shown) to the boom cylinder.

In the control device 12 according to the present embodiment, the pressure sensor 20 is disposed in the pilot pressure line 16, and the operation amount of the operation lever 13 is detected from the pilot pressure Po of the pilot pressure line 16 and controlled as a pilot pressure detection signal. Input to means 15.
An adjustment knob 21 is provided as a pressure adjusting means in the vicinity of the operation lever 13 in the cab of the hydraulic cylinder 1. As shown in FIG. 2, the adjustment knob 21 can rotate over a predetermined angular range (for example, N = 0; S = 100 mm) between the E position and the F position. That is, the adjustment knob 21 selects an arbitrary position between the E position instructing emphasis on fuel efficiency and the F position instructing emphasis on operability for the opening area of the stem 18 controlled by the operation amount of the operation lever 13. The correction control can be performed by stopping the operation.
Incidentally, when the adjustment knob 21 is positioned at the E position, “fuel consumption is emphasized”, and the pilot pressure Po output by the operation amount of the operation lever 13 is not reduced. Further, when the adjustment knob 21 is positioned at the F position, “operability is emphasized”, and the pilot pressure Po output by the operation amount of the operation lever 13 is corrected by a predetermined amount.

The control means 15 is set by a primary control pilot pressure control means 23 for setting a primary control pilot pressure P1 by inputting a signal of a pilot pressure Po detected by the operation lever 13 detected by the pressure sensor 20 and an adjustment knob 21. And a proportional gain 24 for outputting a correction signal H related to the pilot pressure based on the position signal. In the primary control / pilot pressure control means 23, the pilot pressure Po, which is input information, and the primary control pilot pressure P1 are in a proportional relationship, for example.
Then, a signal obtained by adding the correction signal H of the proportional gain 24 to the primary control pilot pressure P1 by the adder 25 is input to the current value control means 26 as the secondary control pilot pressure P2. The current value control means 26 has a proportional relationship between the secondary control pilot pressure P2 and the pilot pressure control current value D, and sets the pilot pressure control current value D based on the secondary control pilot pressure P2. Output a signal.

  The pilot pressure line 16 is provided with an electromagnetic proportional pressure reducing valve 28 on the downstream side of the pressure sensor 20, and the electromagnetic proportional pressure reducing valve 28 can be switched between a first switching valve 28a and a second switching valve 28b. . When the first switching valve 28a is in the operating position, that is, in the pilot pressure line 16 (see FIG. 1), the pilot pressure Po set by the operation amount of the operation lever 13 can be input to the control valve 14 without reducing it. When the second switching valve 28b is in the operating position, that is, in the pilot pressure line 16 (see FIG. 1), the pilot pressure Po can be reduced in accordance with the current value D output from the control means 15.

In this control device 12, when the adjustment knob 21 is held at the “E” position where “important fuel efficiency” is set, for example, the current value D output from the control means 15 is 0 mA, and is set by the operation amount of the operation lever 13. The pilot pressure Po is not reduced.
Further, when the adjustment knob 21 is held at the F position of “emphasis on operability”, for example, the current value D output from the control means 15 is DimA (> 0) and is set by the operation amount of the operation lever 13. The pilot pressure Po thus reduced is reduced according to the current value Di. Therefore, the pilot pressure Pi applied to the stem 18 in the control valve 14 is reduced, and the stroke of the stem 10 is reduced. In this case, the cylinder speed of the boom 4 becomes slow, and the reduction change of the pressure loss of the stem 10 in the oil passage 19 becomes small.
The adjustment knob 21 can be held at any position between the E position and the F position (for example, 0 to 100 mm), and the corrected pilot pressure P is the pilot pressure Po and F position set at the E position. It is proportionally controlled according to the holding position of the adjustment knob 21 with respect to the set pilot pressure Pi.

The control device 12 of the hydraulic excavator 1 according to the present embodiment has the above-described configuration. Next, a control method of the control device 12 will be described.
First, when an operator with a high operating skill gets on board or when a work that does not require a high operating skill is performed, it is not necessary to focus on operability, and it is required to perform an operation that places importance on fuel efficiency. In this case, the operator sets the adjustment knob 21 to the E position “emphasis on fuel consumption” prior to the operation.
When the excavator 1 starts to be driven and the operation lever 13 is operated to move the boom 4 up and down, the operation amount of the operation lever 13 is converted into the pilot pressure Po and flows through the pilot pressure line 16. This pilot pressure Po is detected by a pressure sensor 20 provided in the pilot pressure line 16, is input to the primary control pilot pressure control means 23 of the control means 15, and is output as the primary control pilot pressure P1.

On the other hand, since the adjustment knob 21 is set to the E position “emphasis on fuel consumption”, the adder 25 uses the correction signal H corresponding to the position signal input from the adjustment knob 21 to the proportional gain 24 and the primary control pilot pressure P1. The current value added and outputted from the current value control means 26 to the electromagnetic proportional pressure reducing valve 28 is 0 mA, and the pilot pressure Po in the pilot pressure line 16 is not reduced.
Therefore, the raising or lowering pilot pressure applied to the stem 18 is set to the pilot pressure Po set by the operation amount of the operation lever 13, and the stem 18 of the oil passage 19 in the control valve 14 is operated to open the oil passage 19. The area is determined. For this reason, an operation with a relatively high priority on fuel consumption is performed. In particular, as shown in FIG. 8, when the operation amount of the operation lever 13 is set to 70% at the maximum and the pressure loss N (= about 2.5 MPa, for example) due to the opening N at that position, as shown in FIG. Compared with a conventional hydraulic excavator set to the opening S and the pressure loss S, fuel consumption can be reduced.

On the other hand, when an operator having a relatively poor operating skill gets on board or when an operation requiring a high operating skill is performed, it is necessary to emphasize operability rather than fuel consumption. In this case, the operator sets the adjustment knob 21 to the F position “emphasis on operability” prior to the operation.
When the operation lever 13 of the excavator 1 is operated to move the boom 4 up and down, for example, the operation amount of the operation lever 13 is converted into the pilot pressure Po and flows through the pilot pressure line 16. This pilot pressure Po is detected by the pressure sensor 20 provided in the pilot pressure line 16 and is input as a signal to the primary control pilot pressure control means 23 of the control means 15 to obtain the primary control pilot pressure P1 corresponding to the pilot pressure Po. Calculated and output.

On the other hand, since the adjustment knob 21 is set to the F position “emphasis on operability”, the correction signal H corresponding to the position signal input to the proportional gain 24 from the adjustment knob 21 is added by the adder 25 to the primary control pilot pressure P1. To the secondary control pilot pressure P2, and this pilot pressure signal P2 is input to the current control means 26. In the current control means 26, the corresponding current value D is calculated from the secondary control pilot pressure P2 and output to the electromagnetic proportional pressure reducing valve 28.
The electromagnetic proportional pressure reducing valve 28 reduces the pilot pressure Po flowing in the pilot pressure line 16 at a rate set by the current value D. The reduced pilot pressure Pi (<Po) is input to the control valve 14 and becomes the lower side (or higher side) pilot pressure of the boom stem 18. Therefore, the stroke of the stem 18 is reduced as compared with the case where the pilot pressure Po that does not reduce pressure is applied, and the change in the opening area of the oil passage 19 that supplies the hydraulic oil to the boom cylinder is reduced, so the speed of the boom cylinder is reduced. To do.
Therefore, the vertical movement of the boom 4 with respect to the operation amount of the operation lever 13 becomes relatively small, and it becomes easy to finely operate the work machine, so that a highly accurate operation is possible.

The adjustment knob 21 can be stopped and held at any position between the E position “emphasis on fuel consumption” and the F position “importance on operability”. In that case, the pressure reduction ratio with respect to the pilot pressure Po is set by the ratio from the E position to the F position to the stop position.
In the above description, the control method of the boom cylinder by the control device 12 has been described. However, the supply of hydraulic oil to various hydraulic actuators such as an arm cylinder and a bucket cylinder can be controlled.

As described above, the control device 12 of the hydraulic excavator 1 according to the present embodiment adjusts the operation characteristics in the direction in which the cylinder operating speed of each actuator for the boom corresponding to the operation amount of the operation lever 13 becomes slower by the adjustment knob 21. Therefore, it is possible to design each stem with a configuration that prioritizes the reduction in pressure loss during single action shown in FIG. 8 (for example, the maximum operation amount of the operation lever 13 is about 70% and the maximum pressure loss is about 2.5 MPa). Then, when an operator with a high operating skill gets on board or when the operation does not require a high operating skill, the adjustment knob 21 is set to a fuel-consumption-oriented type, for example, as shown in FIG. 8 (pressure loss N, opening N The fuel consumption can be reduced as compared with a conventional general hydraulic excavator (see FIG. 7).
In addition, when an operator with a low operating skill gets on or when a work requiring a high operating skill is performed, the cylinder operating speed with respect to the operating amount of the operating lever 13 is set by setting the adjustment knob 21 to an operation-oriented type. Therefore, highly accurate operation can be realized.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications and the like can be made without departing from the spirit of the present invention, and these configurations are also included in the present invention.
For example, in the control device 12 according to the above-described embodiment, the pilot pressure Po set by the operation amount of the operation lever 13 is detected by the pressure sensor 20 and input to the primary control pilot pressure control means 23 of the control means 15. The pilot pressure Po is provided as a calculation element of the current value D for correcting the pressure reduction. Instead, the current value D for controlling the pilot pressure Po to be reduced only by the position signal determined by the rotation of the adjustment knob 21 is provided. You may make it calculate.

That is, in FIG. 4 shown as a modified example, the position signal determined by rotating the adjustment knob 21 is input to the current value control means 26 of the control means 15, and the current value control means 26 sets the secondary control pilot pressure P2. Instead, based on the position signal of the adjustment knob 21, a current value D corresponding to a preset position signal (for example, in a proportional relationship) is determined. Then, in the electromagnetic proportional pressure reducing valve 28 to which the current value D is input, the pilot pressure Po determined by the operation lever 13 flowing through the pilot pressure line 16 is controlled to be reduced according to the current value D.
Thereby, the opening characteristic by the operation lever 13 can be adjusted.
In this modified example, the pilot pressure Po is roughly corrected as compared with the control device 12 according to the above-described embodiment, but the pilot pressure Po pressure sensor 20 need not be provided in the pilot pressure line 16, so Can be simplified and the cost can be reduced.

  Needless to say, the present invention is not limited to a working machine for a construction machine including the hydraulic excavator 1 but can be applied to a hydraulic working machine used for various hydraulic devices.

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 4 Boom 12 Control apparatus 13 Operation lever 14 Control valve 15 Control means 16 Pilot pressure pipe 18 Stem 19 Oil path 20 Pressure sensor 21 Adjustment knob 23 Primary control pilot pressure control means 24 Proportional gain 26 Current value control means 28 Electromagnetic proportional Pressure reducing valve

Claims (6)

In a control device for a hydraulic working machine that controls the supply of hydraulic oil to a hydraulic actuator,
An operation member for setting a pilot pressure based on the operation amount;
Pressure adjusting means for determining a correction ratio of the pilot pressure set by the operation member;
Control means for determining a pilot pressure correction amount based on a correction signal related to the pilot pressure correction ratio determined by the pressure adjusting means;
Proportional pressure reducing means for correcting the pilot pressure based on a correction amount signal output from the control means;
And a control valve for controlling the operating speed of the hydraulic actuator by setting the amount of hydraulic oil supplied to the hydraulic actuator based on the pilot pressure corrected by the proportional pressure reducing means.   The pressure adjustment means uses the position where the pilot pressure correction amount is the smallest as the fuel efficiency priority position, the position where the pilot pressure correction amount is the highest as the operability priority position, and the pilot pressure between the fuel efficiency priority position and the operability priority position. The control device for a hydraulic working machine according to claim 1, wherein the correction ratio is determined.   The control valve is provided with an oil passage for supplying hydraulic oil to the hydraulic actuator and a stem that can be advanced and retracted to control the opening area of the oil passage, and the operation of the stem is controlled by pilot pressure. The control device of the hydraulic working machine described in 1.   The control means includes current control means for determining a pilot pressure correction amount as a current value based on the pilot pressure set by the operating member and the pilot pressure correction ratio determined by the pressure adjusting means. Control device for hydraulic working machine described in any one of 1 to 3   4. The control means according to claim 1, further comprising a current control means for determining, as a current value, a correction amount of the pilot pressure set by the operation lever based on a correction ratio of the pilot pressure determined by the pressure adjusting means. Control device for hydraulic working machine described in any of the above In a control method of a hydraulic working machine that controls supply of hydraulic oil from a hydraulic pump to a hydraulic actuator,
Select a pilot pressure correction ratio that controls the operating speed of the hydraulic actuator and pre-determine it by the pressure adjustment means,
Operate the operating member to set the pilot pressure based on the operating amount,
The pilot pressure correction amount is determined based on the pilot pressure correction ratio determined by the pressure adjusting means to correct the pilot pressure,
A control method for a hydraulic working machine, wherein an operating oil supply amount to a hydraulic actuator is set based on a corrected pilot pressure to control an operating speed of the hydraulic actuator.

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