JP2011021694A - Revolution hydraulic control device for working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a revolution hydraulic control device for a working machine capable of decreasing the relief loss during revolution acceleration, with a simple constitution. <P>SOLUTION: The output of a hydraulic pump 2a when the working machine is in revolution is controlled. First a revolution manipulated variable P<SB>H</SB>concerning the revolution motion is detected by a revolution manipulated variable detecting means 11, and the increment per unit time of the revolution manipulated variable P<SB>H</SB>is limited by a rise limiting means 13, and is used as a limit revolution manipulated variable F. Further the output of the hydraulic pump 2a is controlled to the magnitude depending on the limit revolution manipulated variable F by using a pump output controlling means 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an output control device for a hydraulic pump during a turning operation of a work machine.

  In a work machine represented by a hydraulic excavator, an upper swing body is configured to be swingable with respect to a lower traveling body using a hydraulic motor. On the other hand, since the inertial mass of the work machine is large, the hydraulic pressure in the hydraulic circuit becomes extremely high when the hydraulic motor is started up and accelerated, causing a hydraulic oil relief loss. Conventionally, various techniques for reducing such relief loss have been proposed.

  For example, Patent Document 1 discloses a technique for reducing a relief loss by reducing a discharge flow rate of a hydraulic pump when a swing motor is operated. In this technology, the pilot pressure from the pilot valve linked to the swing lever is detected, the hydraulic pressure on the circuit between the flow control valve and the swing motor is detected, and the swash plate angle of the hydraulic pump is determined based on these values. I have control. With such a configuration, it is said that relief loss can be reduced and deterioration of the turning motor due to heat generation and high temperature can be prevented.

JP-A-9-195322

  However, in the technique described in Patent Document 1, hydraulic oil is discharged from the hydraulic pump in an amount obtained by adding a relief flow rate q required for accelerating the swing motor to a required flow rate Qn required according to the swing speed. In addition, since the swash plate of the hydraulic pump is controlled, hydraulic oil corresponding to the relief flow rate q is always lost until the swing motor stops accelerating. That is, with this technique, the relief loss cannot be made smaller than the relief flow rate q until the discharge flow rate from the hydraulic pump reaches the maximum flow rate.

Further, in the conventional technology as described in Patent Document 1, there are a large number of control sensors and control valves, and it is necessary to remodel a standard system of a work machine significantly, resulting in a cost increase. There is.
The present invention has been made in view of such a problem, and an object of the present invention is to provide a swing hydraulic control device for a work machine that can reduce relief loss during swing acceleration with a simple configuration. To do.

  In order to achieve the above object, a swing hydraulic control device for a work machine according to a first aspect of the present invention provides an engine mounted on the work machine, a hydraulic pump driven by the engine, and a swing operation of the work machine. A turning operation amount detection means for detecting the turning operation amount, and a rise restriction means for outputting a restricted turning operation amount in which an increase amount per unit time of the turning operation amount detected by the turning operation amount detection means is limited; And pump output control means for controlling the output of the hydraulic pump to a magnitude corresponding to the limited turning operation amount output from the rise restriction means.

  According to a second aspect of the present invention, there is provided a swing hydraulic control device for a work machine according to the present invention, in addition to the configuration according to the first aspect, wherein the rising limit means sets a limiter for setting an upper limit value of the swing operation amount, and the swing operation. An integrator that outputs a sum of values output from the limiter to which the amount is input as the limited turning operation amount, and a subtractor that subtracts the limiting turning operation amount from the turning operation amount and inputs the amount to the limiter And a reset means for resetting the limited turning operation amount accumulated by the integrator when the turning operation amount is not detected.

  According to a third aspect of the present invention, there is provided a swing hydraulic control device for a work machine according to the present invention. And the pump output control means controls the output of the hydraulic pump to a standard output when detecting the other operation in the other operation detecting means, and non-detection of the other operation in the other operation detecting means. Sometimes, the output of the hydraulic pump is controlled to a magnitude corresponding to the limited turning operation amount instead of the standard output.

  According to a fourth aspect of the present invention, there is provided a swing hydraulic control device for a work machine according to the present invention, in addition to the configuration according to any one of the first to third aspects. A power shift pressure transmission circuit that regulates the length and an electromagnetic proportional valve interposed on the power shift pressure transmission circuit, and the opening degree of the electromagnetic proportional valve is controlled in accordance with the limited turning operation amount It is characterized by.

According to the turning hydraulic pressure control device for a working machine of the present invention (Claim 1), by limiting the time increase rate of the turning operation amount, the turning operation is performed slowly even during a sudden turning operation. Equivalent pump output control is possible, and relief loss during turning acceleration can be reduced.
Furthermore, in the present invention, each configuration such as the turning operation amount detection means, the rise restriction means, and the pump output control means is simple, and the relief loss during turning acceleration can be reduced with almost no sensors.

Further, according to the turning hydraulic control device for a working machine of the present invention (Claim 2), the turning operation is not continued as it is by resetting the limited turning operation amount when the turning operation is stopped. Operability can be acquired.
Further, according to the swing hydraulic control device for a working machine of the present invention (Claim 3), the pump output becomes the standard output when detecting the swing operation and other operations (for example, the boom operation and the travel operation), so that there is no delay. Other operations can be performed.

  Further, according to the swing hydraulic control device for a working machine of the present invention (Claim 4), the output of the hydraulic pump is accurately and easily controlled by controlling the opening of the electromagnetic proportional valve on the power shift pressure transmission circuit. can do.

1 is a hydraulic circuit diagram illustrating an overall configuration of a circuit related to a turning operation of a work machine to which a turning hydraulic control device according to an embodiment of the present invention is applied. It is a graph which shows the hydraulic pump characteristic in this turning hydraulic control apparatus. It is a control block diagram concerning this turning hydraulic control device. It is a graph for demonstrating the effect | action of this turning hydraulic control apparatus, (a) is a time-dependent fluctuation | variation of a turning pilot pressure, (b) is a time-dependent change of the rotation speed of a turning motor, (c) is supplied from a hydraulic pump. The change over time of the hydraulic pressure, (d) shows the change over time of the flow rate of the hydraulic oil supplied from the hydraulic pump, and (e) shows the change over time of the filter output of the swing hydraulic control device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[1. Circuit configuration]
The present invention is applied to the hydraulic circuit of the hydraulic excavator shown in FIG. Here, a circuit relating to a swing motor 6 that swings the upper swing body of the hydraulic excavator in a horizontal direction with respect to the lower traveling body and a hydraulic cylinder 17 that drives the boom to extend and contract is schematically shown. The description relating to the circuit is omitted.

This hydraulic circuit includes a first hydraulic circuit L1 for supplying hydraulic oil to the swing motor 6, a second hydraulic circuit L2 for supplying hydraulic oil to the hydraulic cylinder 17, an operation pilot circuit L3 for the swing motor 6, a negative control pressure transmission circuit L4, and A power shift pressure transmission circuit L5 is provided.
A first hydraulic pump 2a is disposed on the first hydraulic circuit L1, and a second hydraulic pump 2b is disposed on the second hydraulic circuit L2. Both of these hydraulic pumps 2 a and 2 b are driven by the engine 1. Hereinafter, these hydraulic pumps 2a and 2b are collectively referred to simply as a hydraulic pump 2.

The hydraulic pump 2 is provided with a regulator 3. The regulator 3 individually controls the maximum output and discharge flow rate of each hydraulic pump 2a, 2b. Hereinafter, the one provided along with the first hydraulic pump 2a is referred to as a first regulator 3a, and the one provided along with the second hydraulic pump 2b is referred to as a second regulator 3b.
In the first hydraulic circuit L1, a turning control valve 4a is interposed between the first hydraulic pump 2a and the turning motor 6. Similarly, in the second hydraulic circuit L2, a boom control valve 4b is interposed between the second hydraulic pump 2b and the hydraulic cylinder 17.

The swing control valve 4a and the boom control valve 4b are configured as flow control valves that variably control the flow rate and flow direction of hydraulic oil by switching the flow control spool (stem) position to a plurality of positions. Built in. A circuit for driving the flow control spool of the turning control valve 4a is an operation pilot circuit L3.
Relief valves 5 and 5 are interposed on the respective center bypasses of the first hydraulic circuit L1 and the second hydraulic circuit L2. These relief valves 5 and 5 are provided for taking out the working hydraulic pressure of each center bypass as a so-called negative control pressure. The negative control pressure transmission circuit L4 is branched from the center bypass on the upstream side (hydraulic pump 2 side) of the relief valves 5 and 5, and is connected to the regulators 3a and 3b.

  Three hydraulic fluid passages are formed in parallel to the turning motor 6 on the downstream side (the turning motor 6 side) of the turning control valve 4a. Relief valves 7a and 7b are interposed in two of these flow paths one by one. One relief valve 7a regulates the upper limit pressure of the hydraulic oil flowing from the right side of the swing motor 6 in FIG. 1, and the other relief valve 7b is the upper limit of the hydraulic oil flowing from the left side of the swing motor 6. Specifies the value.

Further, a makeup valve 8 (vacuum prevention valve) is interposed on the remaining flow path. The make-up valve 8 is a valve for preventing the occurrence of vacuum when the swing motor 6 is decelerated or braked. When the circuit pressure on the hydraulic oil discharge side of the swing motor 6 is reduced, the hydraulic oil is supplied from the tank 16 side. Functions to replenish.
The operation pilot circuit L3 is a pilot circuit that connects both ends of the flow control spool of the turning control valve 4a and the remote control valve 9. In the remote control valve 9, a turning pilot pressure (so-called remote control pressure) having a magnitude corresponding to an operation amount input to a turning lever (not shown) is generated, and the turning pilot pressure is applied to any of the flow control spools according to the operating direction of the turning lever. It is introduced into one end.

Further, the remote control valve 9 incorporates a shuttle valve 10 for detecting the turning pilot pressure and a turning lever pressure sensor 11 (a turning operation amount detecting means). The shuttle valve 10 is a high-pressure selection valve that selects one of the high-pressure pilot pilot pressures introduced to both ends of the flow control spool.
The turning lever pressure sensor 11 detects the magnitude of the turning pilot pressure P _H (the amount of turning operation) selected by the shuttle valve 10. Thus, regardless of the operating direction of the pivot lever, swiveling pilot pressure P _H of the size corresponding to the operation amount is detected by the pivot lever pressure sensor 11. Here detected swirl pilot pressure P _H is inputted to the controller 13.

  The negative regulator pressure transmission circuit L4 and the power shift pressure transmission L5 are connected to the first regulator 3a and the second regulator 3b. These regulators 3 perform control to reduce the discharge flow rate of the hydraulic pump 2 as the negative control pressure introduced from the negative control pressure transmission circuit L4 increases. Thereby, the pump output (product of hydraulic pressure and flow rate) at the time of full lever operation is kept constant. On the other hand, the magnitude of the pump output is set according to the magnitude of the power shift pressure input from the power shift pressure transmission circuit L5.

For example, when the power shift pressure is the lowest pressure, the relationship between the discharge flow rate Q from the hydraulic pump 2 and the discharge pressure P is indicated by an initial constant horsepower line S as shown in FIG. In this case, the discharge flow rate Q and the discharge pressure P vary along the initial constant horsepower line S between the state S ₁ and the state S ₂ . When the power shift pressure increases, the constant horsepower line moves to the upper right as shown by the white arrow in FIG. 2, and the pump output is increased. When the power shift pressure is the highest pressure, the relationship between the discharge flow rate Q and the discharge pressure P is indicated by the final constant horsepower line E. In this case, the discharge flow rate Q and the discharge pressure P vary along the final constant horsepower line E between the state E ₁ and the state E ₂ .

  In this embodiment, a power shift electromagnetic proportional valve 12 (electromagnetic proportional valve) that controls the magnitude of the power shift pressure is interposed on the power shift pressure transmission circuit L5. In general, the magnitude of the power shift pressure is set according to the number of revolutions of the engine 1 or an operation state of an accelerator dial switch (not shown). In this embodiment, except for the case where only the turning lever is operated, such a conventional general power shift pressure is set.

  The power shift electromagnetic proportional valve 12 is a proportional valve whose opening degree is controlled by the controller 13. As shown in FIG. 1, a pilot pump 15 and a tank 16 are connected to the upstream side of the power shift electromagnetic proportional valve 12 in the power shift pressure transmission circuit L5. When a drive signal is input from the controller 13 to the power shift electromagnetic proportional valve 12, the opening degree is controlled according to the magnitude of the drive signal, and a power shift pressure having a magnitude corresponding to the opening degree is supplied to the regulator 3 side. It has come to be communicated.

The electromagnetic proportional valve 12 and the power shift pressure transmission circuit L5 function as pump output control means for controlling the output of the hydraulic pump 2 in accordance with the calculation result in the controller 13.
The controller 13 is an electronic control unit constituted by a microcomputer, and is provided as an LSI device in which, for example, a well-known microprocessor, ROM, RAM, and the like are integrated. As shown in FIG. 1, a turning lever pressure sensor 11 and another lever pressure switch 14 (other operation detecting means) are connected to the controller 13.

The other lever pressure switch 14 detects the presence / absence of an operation input to an actuator other than the swing motor 6. For example, when an operation input to a hydraulic actuator including the hydraulic cylinder 17 is detected, an ON signal Is input to the controller 13.
The controller 13 controls the opening degree of the power shift electromagnetic proportional valve 12 based on input information from the turning lever pressure sensor 11 and the other lever pressure switch 14. The opening degree of the power shift electromagnetic proportional valve 12 is controlled differently between when only the swing motor 6 is driven and when at least an actuator other than the swing motor 6 is driven. Accordingly, when the swing motor 6 alone is driven and when an actuator other than the swing motor 6 is driven, the variation in the magnitude of the power shift pressure is different, and the control mode of the output of the hydraulic pump 2 is also different.

[2. Control configuration]
The controller 13 is programmed with software for performing the control schematically shown in FIG. That is, the controller 13 includes a filter 20, a neutral detector 24, a standard horsepower setting device 25, a signal switching device 26, and a signal converter 27.

Neutral detector 24 (reset means), and outputs an ON signal R when pivoting lever pressure sensor 11 turning pilot pressure P _H input from is equal to or less than the predetermined neutral value P _H0. The predetermined neutral value P _H0 here is set to a minute size corresponding to the play of the turning lever during the neutral operation. Therefore, the neutral detector 24 functions to detect the neutral operation of the turning lever and output the ON signal R. The ON signal R is input to the integrator 23 of the filter 20.

Filter 20 (rising limiting means) is to limit the rise of the revolving pilot pressure P _H supplied from the turning lever pressure sensor 11 (the amount of increase per unit time). As shown in FIG. 3, the filter 20 includes a subtracter 21, a limiter 22, and an integrator 23.
Subtractor 21 is for inputting a turning pilot pressure P _H input, to calculate the deviation P ₁ of the filter output F outputted from the integrator 23 to be described later (restricted rotation operation amount) limiter 22 is there. The filter output F here is a value calculated in the previous control cycle. Further, the limiter 22 functions to limit the upper limit value of the deviation P ₁ .

For example, as shown in FIG. 3, when the deviation P ₁ is greater than or equal to a predetermined value P _1A , the limiter output P ₂ is limited to the predetermined value P _1A . If the deviation P ₁ is less than the predetermined value P _1A , the deviation P ₁ becomes the limiter output P ₂ as it is.
The integrator 23 is a limiter output P ₂ is integrated (accumulated). The filter output F as the calculation result of the integrator 23 is input to the signal switch 26 and simultaneously fed back to the subtractor 21. The filter output F is a parameter corresponding to the magnitude of the power shift pressure when the swing motor 6 is driven.

Considering a series of calculation cycles from the subtractor 21 to the integrator 23 as a unit time, the maximum value of the increase amount of the filter output F per unit time is limited to a predetermined value P _1A . That filter 20 functions to limit the increase of the revolving pilot pressure P _H per unit time within a predetermined value.
Further, when the ON signal R from the neutral detector 24 is input, the integrator 23 resets the integration result so far and ends the integration. Thus, when the turning lever is neutrally operated, the integrated value is cleared and the filter output F becomes F = 0.

The standard horsepower setting unit 25 sets a standard pump output F ₀ when an actuator other than the turning motor 6 is driven. The pump output F ₀ set in the standard horsepower setting unit 25 is input to the signal switching unit 26 in parallel with the filter output F. In the present embodiment, the standard pump output F ₀ is set according to the rotational speed of the engine 1, the operation state of an accelerator dial switch (not shown), and the like.

The signal switching unit 26 selects one of the filter output F and the output F ₀ according to the input signal from the other lever pressure switch 14. That is, when the ON signal is not input from the other lever pressure switch 14 (when only the swing motor 6 is driven), the filter output F is selected, and when the ON signal is input (the actuator other than the swing motor 6 is connected). When in operation) output F ₀ is selected. One selected here is input to the signal converter 27.

The signal converter 27 converts the output selected by the signal switch 26 into a drive signal for the power shift electromagnetic proportional valve 12. Here, for example, in a state where the filter output F is being input, the opening degree of the power shift electromagnetic proportional valve 12 is controlled to be slowly opened, so that the rising speed (rising speed) of the power shift pressure becomes slow. In the state where the output F ₀ is input, the opening degree of the power shift electromagnetic proportional valve 12 is immediately changed so that the power shift pressure has a magnitude corresponding to the standard horsepower.

[3. Action]
The operation of the hydraulic excavator to which the present control device is applied will be described with reference to FIG.
[3-1. During single operation of turning]
When pivoting lever is operated, turning the pilot pressure P _H corresponding to the operation amount is detected by the pivot lever pressure sensor 11, it is input to the controller 13. The controller 13, together with the deviation P ₁ of the filter output F is calculated in the turning pilot pressure P _H and the previous control cycle by the subtracter 21, the upper limit value of the deviation P ₁ by the limiter 22 to a predetermined value P _1A limit Is done. The output of the limiter 22 is integrated by the integrator 23, and the filter output F in the current control cycle is obtained.

For example, as shown in FIG. 4 (a), pivoting lever at time t ₀ is assumed to be full-lever operation. Turning pilot pressure P _H is abruptly increased from the time t _0, the maximum pressure P _HMAX corresponding to the maximum operation amount. In contrast, in the controller 13, since the rise of the revolving pilot pressure P _H is restricted, the filter output F increases with gentle slope as shown in FIG. 4 (e). Note that, as the upper limit value P _1A of the deviation P ₁ in the limiter 22 is smaller, the increase gradient of the filter output F is smaller and gentler.

  Such a filter output F is input to the signal converter 27 and converted into a drive signal for the power shift electromagnetic proportional valve 12, and the power shift pressure is controlled to rise gently. The power shift pressure transmitted to the regulator 3a via the power shift pressure transmission circuit L5 is slowly increased in pressure with its rising speed limited. Thereby, the constant horsepower line of the first hydraulic pump 2a set by the first regulator 3a moves over time from the initial constant horsepower line S side in FIG. 2 to the final constant horsepower line E side.

At this time, the discharge pressure P of the first hydraulic pump 2a rises greatly from time t ₀ as shown in FIG. 4 (c), the rotational speed of the swing motor 6 also, the time t _0, as shown in FIG. 4 (b) Gradually increase from. Further, since the flow rate of the hydraulic oil flowing into the turning motor 6 corresponds to the rotation speed, it increases along a straight line connecting the points A and C as shown by a thin solid line in FIG.
On the other hand, according to the control of the present control device, the output of the first hydraulic pump 2a is limited. Therefore, as shown by the thick solid line in FIG. The discharge flow rate Q is controlled along a polygonal line that decreases and passes from point A to point C via point D. Of the hydraulic oil discharged from the first hydraulic pump 2 a, an amount of hydraulic oil corresponding to a triangular region surrounded by points A, C, and D is discharged from the relief valve 7.

  If the output restriction of the first hydraulic pump 2a as described above is not performed, the discharge flow rate changes from point A to point C via point B as shown by a broken line in FIG. It fluctuates along the line that leads to In this case, the amount of hydraulic oil corresponding to the triangular area surrounded by the points A, B, and C is discharged from the relief valve 5. Therefore, it can be seen that the relief amount at the time of turning acceleration is significantly reduced by the output limitation of the present control device.

Further, when the flow rate of the working oil flowing actually into the swing motor 6 and the discharge flow rate Q of the first hydraulic pump 2a is equal to time t _1, the relief of the hydraulic fluid from the relief valve 5 is stopped, the discharge pressure P is Decrease gradually. For example, when the output state of the first hydraulic pump 2a is assumed to be the state E ₂ in the FIG. 2 at time t _1, the discharge flow rate Q is moved along the final constant horsepower curve E As the discharge pressure P is reduced , reaching the state E ₁ to time t- _2. At this time, the output horsepower of the first hydraulic pump 2a is held by the action of the first regulator 3a.

Thereafter, when the turning operation is completed at time t ₃ and the neutral operation of the turning lever is detected by the neutral detector 24, the integration result in the integrator 23 is reset, and the filter output F is reset to F = 0. . Further, the discharge flow rate Q of the first hydraulic pump 2a decreases, and the rotational speed of the turning motor 6 also decreases. Subsequent rotation of the turning motor 6 is inertial rotation.
[3-2. During linked operation]
When other actuators are operated in conjunction with the turning operation (for example, when the hydraulic cylinder 17 is expanded or contracted), an ON signal from the other lever pressure switch 14 is input to the controller 13. In response to this, the signal switch 26 selects the standard pump output F ₀ set by the standard horsepower setter 25, and the signal converter 27 controls the power shift electromagnetic proportional valve 12 based on the output F _0. The

[4. effect]
As described above, according to the swing hydraulic pressure control apparatus, a new system is used by limiting the time increase rate of the swing operation amount with a simple system using the swing lever pressure sensor 11 and the other lever pressure switch 14. The relief loss during acceleration of the swing motor 6 can be reduced with little addition. In addition, when this control apparatus is applied to a hydraulic excavator having a hydraulic swing lever, it can be handled only by adding the swing lever pressure sensor 11 and rewriting the software in the controller 13, thereby reducing the manufacturing cost. can do.

In the swing hydraulic control apparatus, the discharge flow rate Q of the hydraulic pump 2 is not directly controlled, but the output horsepower of the hydraulic pump 2 is controlled. Therefore, as the discharge pressure P of the hydraulic pump 2 decreases. The discharge flow rate Q approaches the required flow rate required for the turning motor 6. Thus, for example, as shown in FIG. 4 (d), the relief loss can be zero at time t ₂ is the process of turning acceleration, it is possible to obtain a better energy efficiency.

In addition, since it is configured to control the opening degree of the power shift electromagnetic proportional valve 12 interposed on the power shift pressure transmission circuit L5, it can be easily applied to the hydraulic circuit of a conventional general hydraulic excavator. In addition, the output horsepower of the hydraulic pump 2 can be accurately controlled.
When the turning lever is operated to the neutral position, the filter output F is reset to F = 0, so that the turning operation is not continued as it is and good operability can be obtained.

Further, when an operation other than turning (for example, boom operation or traveling operation) is performed, the power shift electromagnetic proportional valve 12 is set so that the standard pump output F ₀ set in the standard horsepower setting device 25 is obtained. Since it is controlled, the output horsepower of the hydraulic pump 2 can be set to the standard output, and other operations can be performed without delay.

[5. Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment described above, the filter 20, by inputting the deviation P ₁ of the filter output F calculated in the turning pilot pressure P _H and the previous control cycle input from the turning lever pressure sensor 11 to the limiter 22 The calculation for limiting the rising of the turning pilot pressure P _H is performed. Instead of such a configuration, the increase amount per unit time of the turning pilot pressure P _H input from the turning lever pressure sensor 11 is directly set. It is good also as a structure which performs the calculation restrict | limited to.

Further, in the above-described embodiment, the detected pivot pilot pressure P _H in the turning lever pressure sensor 11 is inputted to the controller 13, the hydraulic swing control apparatus of the present invention to a hydraulic excavator having control lever of the electric In the case of applying the above, it can be considered that the configuration is such that an electric signal corresponding to the lever operation amount is directly input to the controller 13.
Even in such a configuration, an effect equivalent to that of the above-described embodiment can be obtained by limiting the rise of the turning operation amount by the filter 20 and limiting the output of the hydraulic pump 2.

  INDUSTRIAL APPLICABILITY The present invention can be used in the entire manufacturing industry of work machines equipped with a swing motor such as a hydraulic excavator and a hydraulic crane.

DESCRIPTION OF SYMBOLS 1 Engine 2 Hydraulic pump 3 Regulator 4 Main control valve 4a Swing control valve 4b Boom control valve 5 Relief valve 6 Swing motor 7 Relief valve 8 Make-up valve 9 Remote control valve 10 Shuttle valve 11 Swing lever pressure sensor (turning operation amount detection means)
12 Power shift solenoid proportional valve (pump output control means, solenoid proportional valve)
13 Controller 14 Other lever pressure switch (Other operation detection means)
15 Pilot pump 16 Tank 17 Hydraulic cylinder 20 Filter (rising limit means)
21 Subtractor 22 Limiter 23 Integrator 24 Neutral detector (reset means)
25 Standard horsepower setting device 26 Signal switching device 27 Signal converter L1 First hydraulic circuit L2 Second hydraulic circuit L3 Operation pilot circuit L4 Negative control pressure transmission circuit L5 Power shift pressure transmission circuit (pump output control means)

Claims (4)

An engine mounted on a work machine;
A hydraulic pump driven by the engine;
A turning operation amount detection means for detecting a turning operation amount related to the turning operation of the work machine;
Rising limit means for outputting a restricted turning operation amount that restricts an increase amount per unit time of the turning operation amount detected by the turning operation amount detection means;
Pump output control means for controlling the output of the hydraulic pump to a magnitude corresponding to the limited turning operation amount output from the rising restriction means;
A swing hydraulic control device for a working machine, comprising: The rise limiting means is
A limiter for setting the upper limit value of the turning operation amount;
An integrator that outputs, as the limited turning operation amount, a sum of values output from the limiter to which the turning operation amount is input;
A subtractor that subtracts the limited turning operation amount from the turning operation amount and inputs the subtraction operation amount to the limiter;
2. The swing hydraulic pressure control device for a work machine according to claim 1, further comprising reset means for resetting the limited swing operation amount accumulated by the integrator when the swing operation amount is not detected. Further comprising other operation detecting means for detecting the presence or absence of other operations related to operations other than turning of the work machine,
The pump output control means
At the time of detection of the other operation in the other operation detection means, the output of the hydraulic pump is controlled to a standard output,
The output of the hydraulic pump is controlled to a magnitude corresponding to the limited turning operation amount within a range equal to or less than the standard output when the other operation is not detected by the other operation detecting means. Or the turning hydraulic pressure control apparatus of the working machine of 2. The pump output control means
A power shift pressure transmission circuit that regulates the magnitude of the output of the hydraulic pump;
An electromagnetic proportional valve interposed on the power shift pressure transmission circuit,
The swing hydraulic pressure control device for a work machine according to any one of claims 1 to 3, wherein the opening degree of the electromagnetic proportional valve is controlled in accordance with the limited swing operation amount.

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