Hydraulic control system for construction machinery and control method thereof

Abstract

The present invention relates to a hydraulic control system for a construction machine and a control method therefor, comprising: a main pump driven by an engine provided in the construction machine; a fan pump for supplying hydraulic oil to a cooling fan so as to cool the engine; and a controller (EPOS) configured to control operation of the engine, the main pump, and the fan pump.

Description

Technical Field

[0001] The present invention relates to a hydraulic control system of an engineering machine, and more particularly, to a hydraulic control system of an engineering machine capable of quickly restoring an engine speed after an automatic idling function of the engineering machine is released. Background Art

[0002] Construction machinery has a function that reduces fuel consumption and noise by reducing the engine speed to a set speed when the machine is idle for a set period of time without performing any work. This is called the auto idle function.

[0003] When the automatic idle function is released, the engine speed needs to rise to the initial setting level in order to start working again. At this time, the recovery time for the engine speed to rise to the initial setting level depends on the dynamic characteristics of the engine and the load conditions of the equipment (main pump, fan pump).

[0004] If the recovery time for raising the engine speed to the initially set level is slow, the operator may feel that the engine is weak, so it is important to restore the engine speed in a quick time.

[0005] In conventional construction machinery, since no separate control function is added during the process of restoring the engine speed to the initially set level after the automatic idle function is released, the engine speed recovery time is determined by the characteristics of the engine and the pump.

[0006] Accordingly, when the dynamic characteristics of the engine are not good, the automatic idle speed is set higher to speed up the engine speed recovery time. In this case, there is a problem of reduced fuel consumption and noise improvement effect when the automatic idle function is activated. Summary of the invention

[0007] Technical issues

[0008] The present invention provides a hydraulic control system and a control method for an engineering machinery, which control the operation of a main pump and a fan pump to reduce the load of the main pump and the fan pump after the automatic idle function of the engineering machinery is released, so that the engine can quickly restore the initially set speed.

[0009] Technical Solution

[0010] According to one embodiment of the present invention, the present invention includes: a main pump, which is driven by an engine installed in an engineering machinery; a fan pump, which supplies working oil to a cooling fan in a manner of cooling the engine; and a controller (EPOS), which is configured to control the operation of the engine, the main pump and the fan pump. When the automatic idle function of the engineering machinery is released, the controller limits the operation of the fan pump within a set time to reduce the load of the fan pump so that the engine speed is restored from the automatic idle speed to the set speed setting value.

[0011] Furthermore, the fan pump is driven by the engine.

[0012] Furthermore, the controller does not restrict the operation of the fan pump after the set time.

[0013] In addition, it also includes: a fan pump control valve, which is configured to limit the load of the fan pump. When the automatic idle function is released, the controller controls the control value of the fan pump control valve to a set minimum control value within a set time so that the load of the fan pump is below a set benchmark.

[0014] In addition, when the auto idle function of the construction machine is released, the controller limits the operation in a manner that reduces the load of the main pump within a set time so that the engine speed is restored from the auto idle speed to the set speed setting value.

[0015] In addition, it also includes: a main pump control valve, which limits the load of the main pump; and a pressure sensor, which measures the discharge flow pressure of the main pump. The controller stores a table of maximum torque values ​​corresponding to the speed of the engine. The controller derives the torque value of the main pump from the discharge flow of the main pump and the measured values ​​of the discharge flow pressure of the main pump, and when the automatic idle function is released, adjusts the control value of the main pump control valve to a set control value within a set time to reduce the torque value of the main pump to less than the minimum torque value stored in the table.

[0016] In addition, it also includes: an instrument panel, which transmits whether the automatic idle function is turned on / off and the set speed setting value to the controller; and a joystick pilot pressure sensor, which senses the driver's joystick operation value and transmits it to the controller, and the controller executes or releases the automatic idle function according to whether the automatic idle function is turned on / off and the operation or driving signal of the construction machinery.

[0017] Furthermore, a joystick pilot pressure sensor is included, which senses a joystick operation value of a driver and transmits the sensor to the controller. When the joystick operation value is equal to or greater than a predetermined reference, the controller limits the operation of the fan pump.

[0018] Furthermore, the controller derives a torque value of the main pump from a discharge flow rate of the main pump and a measured value of a discharge flow rate pressure of the main pump, and when the torque value of the main pump is greater than a predetermined value, the controller limits the operation of the fan pump.

[0019] According to another embodiment of the present invention, the present invention includes: a step of inputting an off signal of the automatic idle function during the execution of the automatic idle function; and a step of restoring the engine speed to a set speed setting value by limiting the operation of the fan pump within a set time to reduce the load of the fan pump when the automatic idle function is released.

[0020] Furthermore, in the step of restoring the engine speed to a set speed setting value, when the automatic idle function is released, the operation of the main pump is restricted for a set time so that the load of the main pump is reduced.

[0021] Furthermore, in the step of restoring the engine speed to the set speed setting value, when the joystick operation value is equal to or greater than a prescribed reference, the operation of the fan pump is restricted.

[0022] Furthermore, the step of restoring the engine speed to a set speed setting value includes a step in which a controller adjusts a control value of a fan pump control valve connected to the fan pump within a set time so that a load of the fan pump is below a set reference.

[0023] In addition, in the step of restoring the speed of the engine to the set speed setting value, it also includes:

[0024] The controller comprises a step of deriving the discharge flow of the main pump; the controller comprises a step of deriving the torque value of the main pump using the discharge flow of the main pump and the pressure measurement value of the discharge flow of the main pump; and when the torque value of the main pump is above a specified value, limiting the operation of the fan pump.

[0025] In addition, in the step of restoring the speed of the engine to the set speed setting value, it also includes: a step in which the controller derives the discharge flow of the main pump; a step in which the controller derives the torque value of the main pump using the discharge flow of the main pump and the pressure measurement value of the discharge flow of the main pump; a step in which the controller compares the derived torque value of the main pump with a table of maximum torque values ​​stored corresponding to the speed of the engine; and a step in which the controller adjusts the control value of the main pump control valve connected to the main pump to a set control value within a set time so that the torque value of the main pump is reduced to less than the minimum torque value stored in the table.

[0026] Furthermore, before the step of restoring the engine speed to a set speed setting value, when a travel or work signal is not input from the joystick pilot pressure sensor within a set time after an off signal of the automatic idle function is input, the automatic idle function is maintained.

[0027] In addition, before the step of executing the automatic idle function of the engineering machinery, it also includes: the step of inputting an on signal of the automatic idle function during the operation or driving of the engineering machinery; and the step of confirming whether the operation or driving signal is input from the joystick pilot pressure sensor within a set time.

[0028] Furthermore, in the step of restoring the rotation speed of the engine to the set rotation speed setting value, the operations of the main pump and the fan pump are not restricted after the set time.

[0029] Details of other embodiments are included in the detailed description and accompanying drawings.

[0030] Effects of the Invention

[0031] The hydraulic control system for construction machinery of the present invention has the following effects.

[0032] First, after the automatic idle function is released, the load of the fan pump and the main pump can be reduced by adjusting the output value of the valve that limits the load of the fan pump and the main pump within the set time, and the engine speed can quickly restore the set speed setting value.

[0033] Secondly, when the automatic idle function is enabled, there is no need to set the engine's standby speed to a higher level, thereby reducing fuel consumption and noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram showing the configuration of a hydraulic control system for a construction machine according to an embodiment of the present invention.

[0035] Figure 2 and Figure 3This is a flow chart showing a control process of a hydraulic control system for a construction machine according to an embodiment of the present invention.

[0036] Figure 4 1 is a graph showing a process of changing the engine speed according to the control method of the hydraulic control system of the construction machine according to one embodiment of the present invention. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below based on the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be implemented in many different ways and is not limited to the embodiments described in this specification.

[0038] It should be noted that the drawings are schematic and not to scale. For the sake of clarity and convenience, the relative sizes and proportions of the parts shown in the drawings are shown enlarged or reduced, and any size is only exemplary and not limiting. In addition, for the same structural elements or components appearing in more than two figures, the same reference numerals are used to reflect similar features.

[0039] The embodiments of the present invention specifically illustrate the ideal embodiments of the present invention. As a result, many variations from the illustrations are contemplated. Therefore, the embodiments are not limited to the specific configurations of the regions shown, but also include variations in configurations that may result, for example, from manufacturing.

[0040] Figure 1 The structure of the hydraulic control system of an engineering machine according to an embodiment of the present invention is shown. Figure 1 First, the structure of the hydraulic control system of the engineering machinery will be described.

[0041] A hydraulic control system for a construction machine according to an embodiment of the present invention includes an engine 10 , a main pump 20 , a fan pump 30 , a swash plate angle sensor 21 , a pressure sensor 22 , and a controller 40 .

[0042] The engine 10 receives fuel and provides power in a manner that drives the construction machine. The power provided by the engine 10 is transmitted to the main pump 20 .

[0043] The main pump 20 supplies hydraulic oil to an attachment such as a boom and a bucket (not shown) provided on the construction machine. One or more main pumps 20 may be provided. The number of main pumps 20 may vary depending on the attachments (not shown) provided on the construction machine.

[0044] The hydraulic pressure discharged from the main pump 20 is transmitted to the main control valve 70 , and is then transmitted from the main control valve 70 to each auxiliary device.

[0045] The fan pump 30 is driven by the engine 10. The fan pump 30 supplies hydraulic oil so as to activate a cooling fan (not shown) provided to cool the engine 10.

[0046] On the other hand, the fact that the fan pump 30 is driven by the engine 10 is not limited to the present embodiment, and the fan pump 30 may not be driven by the engine 10, and thus may be selectively applied.

[0047] The swash plate angle sensor 21 is provided in the main pump 20. When a plurality of the main pumps 20 are provided, the swash plate angle sensor 21 is provided in each of the main pumps 20, and thus a plurality of the swash plate angle sensors 21 are provided. The swash plate angle sensor 21 measures the angle of the swash plate of the main pump 20. The swash plate angle measurement value measured by the swash plate angle sensor 21 is transmitted to the controller 40 and used to derive the discharge flow rate of the main pump 20.

[0048] The pressure sensor 22 is provided in the main pump 20. Specifically, it is installed at the discharge end of the main pump 20. The pressure sensor 22 measures the pressure formed by the discharge flow of the main pump 20. The pressure measurement value measured by the pressure sensor 22 is transmitted to the controller 40.

[0049] The controller 40 is configured to control operations of the engine 10 , the main pump 20 , and the fan pump 30 .

[0050] When the auto idle function of the construction machine is released, the controller 40 limits the operation of the main pump 20 and the fan pump 30 within a set time so that the load of one or more of the main pump 20 and the fan pump 30 is reduced, so that the speed of the engine 10 is restored from the auto idle speed to the set speed setting value. In addition, the operation of the main pump 20 and the fan pump 30 is not limited after the set time. The process of the controller 40 limiting the main pump 20 and the fan pump 30 will be described in more detail later.

[0051] The hydraulic control system of the engineering machine further includes an instrument panel 50 , a joystick pilot pressure sensor 60 , a main pump control valve 23 , and a fan pump control valve 31 .

[0052] The instrument panel 50 is disposed in the cab (not shown) of the engineering machine. When the operator selects to turn on / off the automatic idle function of the engineering machine, the control panel 50 can transmit the selection to the controller 40 and the set speed setting value of the engine 10 can be input to the controller 40.

[0053] The controller 40 executes or releases the automatic idle function according to whether the automatic idle function is turned on / off and a working or driving signal of the construction machine.

[0054] The controller 40 utilizes the information of whether the automatic idle function is turned on / off and the set speed setting value of the engine 10 received from the instrument panel 50 for controlling the main pump 20 .

[0055] The joystick pilot pressure sensor 60 is provided on a joystick pilot line (not shown). The joystick pilot pressure sensor 60 senses an operation value of a state in which an operator operates a joystick (not shown) and transmits it to the controller 40. Specifically, when the operator operates the joystick (not shown) to one of the states of operation, driving, neutral, and parking, the operation value at this time is sensed and transmitted to the controller 40.

[0056] The controller 40 may determine whether the automatic idle function is maintained or released based on the lever operation value transmitted from the lever pilot pressure sensor 60 .

[0057] For example, when the controller 40 receives the on signal of the automatic idle function from the instrument panel 50, the controller 40 may not immediately execute the automatic idle function. After the controller 40 receives the on signal of the automatic idle function from the instrument panel 50, when it is confirmed that the operation or travel signal is not input from the joystick pilot pressure sensor 60 within a set time, the controller 40 executes the automatic idle function to control the speed of the engine 10 to operate at the automatic idle speed.

[0058] On the other hand, after receiving the off signal of the automatic idle function from the instrument panel 50 , if the controller 40 does not receive the working or traveling signal from the joystick pilot pressure sensor 60 within a set time, the automatic idle function is maintained.

[0059] On the contrary, after receiving the off signal of the automatic idle function from the instrument panel 50 , the controller 40 releases the automatic idle function when receiving the working or traveling signal from the joystick pilot pressure sensor 60 within a set time.

[0060] As such, the controller 40 receives signals from the instrument panel 50 and the joystick pilot pressure sensor 60 and controls the automatic idle function of the engine 10 .

[0061] Furthermore, when receiving an off signal of the automatic idle function and releasing the automatic idle function, the controller 40 limits the operation of the fan pump 30 when the operation value of the joystick is equal to or greater than a predetermined reference according to a signal input from the joystick pilot pressure sensor 60 .

[0062] On the other hand, when the torque value of the main pump 20 is high, the controller 40 determines that the construction machine is in full operation. Therefore, when the torque value of the main pump 20 is greater than a specified value, the controller 40 limits the operation of the fan pump 30.

[0063] The main pump control valve 23 is provided between the controller 40 and the main pump 20. In this embodiment, the main pump control valve 23 is provided as an electronic proportional pressure reducing valve. The main pump control valve 23 limits the load of the main pump 20 according to a signal input from the controller 40.

[0064] In this embodiment, after the automatic idle function of the engineering machine is released, in order to quickly restore the speed of the engine 10 to the set speed setting value, the main pump control valve 23 controls the operation of the main pump 20 to reduce the load of the main pump 20. The specific control process will be described later.

[0065] The fan pump control valve 31 is provided between the controller 40 and the fan pump 30. The fan pump control valve 31 controls the load of the fan pump 30 according to a signal input from the controller 40.

[0066] In this embodiment, when the automatic idle function of the engineering machine is released, in order to quickly restore the speed of the engine 10 to the set speed setting value, the fan pump control valve 31 controls the operation of the fan pump 30 to reduce the load of the fan pump 20. The specific control process will be described later.

[0067] When a large load is applied to the construction machinery, such as when the bucket is loaded with work objects, the work is temporarily interrupted and the machine enters the automatic idling state. At this time, if the interrupted work (full operation) is restarted, the equipment will move slowly. As mentioned above, by limiting the work of the fan pump 30 and the main pump 20, reducing the load will help to quickly restore the RPM of the engine 10, so that the operator can also work at a faster speed after the automatic idling.

[0068] In the present embodiment, the main pump control valve 23 and the fan pump control valve 31 are configured as electronic proportional pressure reducing valves (EPPR valves). Therefore, the controller 40 applies the control values ​​of the main pump control valve 23 and the fan pump control valve 31 as current values. On the other hand, the main pump control valve 23 and the fan pump control valve 31 are not limited to electronic proportional pressure reducing valves, and thus can be variously changed according to the environment.

[0069] On the other hand, the hydraulic control system of the engineering machine is provided with a pump regulator 24 , 32 . The pump regulator 24 , 32 is provided in each pump, that is, in each of the main pumps 20 and the fan pump 30 .

[0070] The pump regulators 24 and 32 set and adjust the pump pressure. When the automatic idle function is released and the controller 40 applies the set control values ​​to the main pump control valve 23 and the fan pump control valve 31, the pump regulators 24 and 32 adjust the angles of the swash plates of the main pump 20 and the fan pump 30. Accordingly, the main pump 20 and the fan pump 30 are restricted to reduce the load.

[0071] Refer to the following Figure 2 and Figure 3 A control process of a hydraulic control system for an engineering machine according to an embodiment of the present invention will be described in detail.

[0072] First, when the operator wants to temporarily stop working or traveling with the construction machine, the automatic idle function is executed. At this time, an on signal of the automatic idle function is input from the instrument panel 50 to the controller 40 (step S210).

[0073] When an on signal of the automatic idle function is input from the instrument panel 50 , the controller 40 confirms whether a working or traveling signal is input from the lever pilot pressure sensor 60 within a set time ( S215 ).

[0074] The above step S215 is a step for confirming whether the engineering machine has no action within a set time. Therefore, in the above step S215, when no operation or driving signal is input within the set time, the automatic idling function is executed (step S220). At this time, the speed of the engine 10 is converted to the automatic idling speed.

[0075] On the contrary, in the above-mentioned step S215, when the working or driving signal is input within the set time, it is determined that the automatic idling function is not to be executed, and thus the automatic idling function is not executed.

[0076] During the execution of the automatic idle function, it is confirmed whether an off signal of the automatic idle function is input from the user (step S225 ), or whether a working or traveling signal is input from the joystick pilot pressure sensor 60 (step S230 ).

[0077] When an off signal of the automatic idle function is input, or a working or traveling signal is input from the joystick pilot pressure sensor 60 , the controller 40 releases the automatic idle function of the construction machine.

[0078] On the other hand, even if an off signal of the automatic idle function is input, when a work or travel signal is not input from the joystick pilot pressure sensor 60 , the automatic idle function of the construction machine is maintained.

[0079] When the automatic idle function is released, the speed of the engine 10 should be restored to the set speed setting value. At this time, the controller 40 limits the operation of the fan pump 30 and the main pump 20 to reduce the load of one or more of the fan pump 30 and the main pump 20 so that the speed of the engine 10 can be quickly restored to the set speed setting value (step S235).

[0080] In this embodiment, the loads of the fan pump 30 and the main pump 20 are both limited.

[0081] Will refer to Figure 3 The process of the above-mentioned step S235 is explained in more detail.

[0082] When the automatic idle function is released, if the operation value of the joystick transmitted from the joystick pilot pressure sensor 60 is greater than a predetermined reference, the controller 40 limits the operation of the fan pump 30. To limit the operation of the fan pump 30, specifically, the control value of the fan pump control valve 31 is adjusted to a set minimum control value so that the load of the fan pump 30 is less than a set reference.

[0083] (Step S310)

[0084] For example, the load of the fan pump 30 being below a set reference means that the speed (RPM) of the fan pump 30 is below a set reference speed. That is, a set minimum current value is applied to the fan pump control valve 31, and accordingly, when the speed (RPM) of the fan pump 30 decreases, the load decreases.

[0085] On the other hand, when the automatic idle function is released, the controller 40 may limit the operation of the fan pump 30 based on other references in addition to the operation value of the joystick as described above.

[0086] When the controller 40 receives the discharge flow pressure measurement value of the main pump 20 (step S321) and derives the discharge flow value of the main pump 20 (step S322), the controller 40 derives the torque value of the main pump 20 from the discharge flow pressure measurement value and the discharge flow value (step S323).

[0087] When the derived torque value of the main pump 20 is equal to or greater than a predetermined value, the controller 40 limits the operation of the fan pump 30 .

[0088] As described above, the control value of the fan pump control valve 31 is adjusted to set the minimum control value to limit the operation of the fan pump 30. This is because when the torque value of the main pump 20 is high, the controller 40 determines that the construction machine is in full operation and limits the operation of the fan pump 30.

[0089] On the other hand, when the automatic idle function is released, the controller 40 limits the operation of the main pump 20 so that the load of the main pump 20 is also reduced (step S330). To this end, first, the controller 40 receives the swash plate angle measurement value of the main pump 20 from the swash plate angle sensor 21 (step S331). Then, the controller 40 receives the pressure measurement value of the flow rate discharged by the main pump 20 from the pressure sensor 22 (step S332).

[0090] The controller 40 derives the discharge flow value of the main pump 20 from the set speed setting value of the engine 10 and the swash plate angle measurement value transmitted from the instrument panel 50 (step S333). The controller 40 may store a set calculation formula or table for deriving the discharge flow of the main pump 20. Therefore, the set speed setting value and the swash plate angle measurement value are substituted into the set calculation formula or table to derive the discharge flow value of the main pump 20. Since the set calculation formula or table can be set in a variety of ways by the manufacturer and designer of the engineering machine, it is not specified.

[0091] Then, the torque value of the main pump 20 is derived from the derived discharge flow rate value and the pressure measurement value of the discharge flow rate (step S334).

[0092] The controller 40 stores a table of maximum torque values ​​corresponding to the rotation speed of the engine 10. The controller 40 compares the torque value derived in step S334 with the stored table.

[0093] The controller 40 controls the main pump 20 so that the torque value of the main pump 20 does not exceed the smallest torque value among the maximum torque values ​​stored in the table. Specifically, the control value of the main pump control valve 23 is adjusted to a set control value so that the load of the main pump 20 can be reduced to below the set reference (step S335). The load of the main pump 20 is reduced to below the set reference because the fan pump 30 also applies a set current value to the main pump control valve 23 so that the speed (RPM) of the main pump 20 is reduced to below the set reference. Accordingly, as the speed (RPM) of the main pump 20 decreases, the load of the main pump 20 decreases.

[0094] In this way, the controller 40 can limit the operation of the main pump 20 and the fan pump 30 to reduce the load of the main pump 20 and the fan pump 30 as in the above step S235, so that the speed of the engine 10 can be quickly restored to the set speed setting value.

[0095] Figure 4 2 is a graph showing a process in which the engine speed changes due to the operation restrictions of the fan pump 30 and the main pump 20 when the automatic idling operation of the construction machine is released. Figure 4 In the interval where the construction machinery works at the automatic idle speed, the engine 10 rotates at the automatic idle speed. In addition, when the construction machinery is to be started again, as the automatic idle speed is released, the operation of the fan pump and the main pump is restricted, so that it can be confirmed that the engine speed is quickly restored as shown in the A area.

[0096] In the engineering machine, after the automatic idle function is released, the controller 40 limits the operation of the main pump 20 and the fan pump 30 to reduce the load of the main pump 20 and the fan pump 30 as described above, so that the set speed setting value can be quickly restored. In addition, since the load of the main pump 20 and the fan pump 30 can be limited, it is not necessary to increase the automatic idle speed of the engine 10 when the automatic idle function is executed, so the effect of improving fuel efficiency and reducing noise of the engineering machine can be maintained.

[0097] Although the embodiments of the present invention are described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains will appreciate that the present invention may be implemented in other specific forms without changing its technical concept or essential features.

[0098] Therefore, the embodiments described above should be understood in all aspects as illustrative rather than restrictive, the scope of the present invention is reflected by the claims described below, and all changes or deformations derived from the meaning, scope and equivalent concepts of the claims should be interpreted as falling within the scope of the present invention.

Claims

1. A hydraulic control system for engineering machinery, characterized in that: include: A main pump driven by an engine provided in the construction machinery; a fan pump that supplies operating oil to a cooling fan in a manner that cools the engine; a controller configured to control the operation of the engine, the main pump and the fan pump, When the automatic idle function of the construction machine is released, the controller limits the operation of the fan pump within a set time to reduce the load of the fan pump so that the speed of the engine is restored from the automatic idle speed to a set speed setting value.

2. The hydraulic control system for construction machinery according to claim 1, characterized in that: The fan pump is driven by the engine.

3. The hydraulic control system for construction machinery according to claim 1, characterized in that: The controller does not restrict the operation of the fan pump after the set time.

4. The hydraulic control system for construction machinery according to claim 1, characterized in that: Also included is a fan pump control valve configured to limit the load of the fan pump, When the automatic idle function is released, the controller adjusts the control value of the fan pump control valve within a set time so that the load of the fan pump is less than a set reference.

5. The hydraulic control system for construction machinery according to claim 1, characterized in that: When the automatic idle function of the construction machine is released, the controller limits the operation in a manner that reduces the load of the main pump within a set time so that the speed of the engine is restored from the automatic idle speed to a set speed setting value.

6. The hydraulic control system for construction machinery according to claim 5, characterized in that: Also includes: a main pump control valve, which limits the load of the main pump; as well as a pressure sensor that measures the discharge flow pressure of the main pump, The controller stores a table of maximum torque values ​​corresponding to the rotation speed of the engine. The controller derives the torque value of the main pump from the discharge flow of the main pump and the measured value of the discharge flow pressure of the main pump, and when the automatic idle function is released, adjusts the control value of the main pump control valve to a set control value within a set time to reduce the torque value of the main pump to less than the minimum torque value stored in the table.

7. The hydraulic control system for construction machinery according to claim 1, characterized in that: Also includes: an instrument panel that transmits whether the automatic idle function is turned on / off and the set speed setting value to the controller; as well as a joystick pilot pressure sensor, which senses the joystick operation value of the driver and transmits it to the controller, The controller executes or releases the automatic idle function according to whether the automatic idle function is turned on / off and a working or driving signal of the construction machine.

8. The hydraulic control system for construction machinery according to claim 1, characterized in that: A joystick pilot pressure sensor is included, which senses the joystick operation value of the driver and transmits it to the controller, When the joystick operation value is equal to or greater than a predetermined reference, the controller limits the operation of the fan pump.

9. The hydraulic control system for construction machinery according to claim 1, characterized in that: The controller derives the torque value of the main pump from the discharge flow rate of the main pump and the discharge flow pressure measurement value of the main pump. When the torque value of the main pump is greater than or equal to a predetermined value, the controller limits the operation of the fan pump.

10. A control method for a hydraulic control system of an engineering machinery, characterized in that: include: Steps for implementing the automatic idle function of construction machinery; A step of inputting a shut-off signal of the automatic idle function during the execution of the automatic idle function; as well as When the automatic idle function is released, the step of restoring the engine speed to a set speed setting value by limiting the operation of the fan pump for a set time so that the load of the fan pump is reduced.

11. The control method of the hydraulic control system of engineering machinery according to claim 10, characterized in that: In the step of restoring the speed of the engine to a set speed setting value, When the automatic idle function is released, the operation of the main pump is restricted within a set time so that the load of the main pump is reduced.

12. The control method of the hydraulic control system of engineering machinery according to claim 10, characterized in that: In the step of restoring the speed of the engine to a set speed setting value, When the joystick operation value is equal to or greater than a predetermined reference, the operation of the fan pump is restricted.

13. The control method of the hydraulic control system of engineering machinery according to claim 12, characterized in that: The step of restoring the speed of the engine to a set speed setting value includes: The controller adjusts a control value of a fan pump control valve connected to the fan pump within a set time so that a load of the fan pump is less than a set reference.

14. The control method of the hydraulic control system of engineering machinery according to claim 10, characterized in that: In the step of restoring the speed of the engine to the set speed setting value, it also includes: The controller derives a discharge flow rate of the main pump; The controller derives a torque value of the main pump using a discharge flow rate of the main pump and a pressure measurement value of the discharge flow rate of the main pump; and The step of limiting the operation of the fan pump when the torque value of the main pump is equal to or greater than a predetermined value.

15. The control method of the hydraulic control system of engineering machinery according to claim 11, characterized in that: In the step of restoring the speed of the engine to the set speed setting value, it also includes: The controller derives a discharge flow rate of the main pump; The controller derives a torque value of the main pump using a discharge flow rate of the main pump and a pressure measurement value of the discharge flow rate of the main pump; The step of comparing the torque value of the main pump with a stored table of maximum torque values ​​corresponding to engine speeds; and The step of adjusting the control value of the main pump control valve connected to the main pump to a set control value within a set time so as to reduce the torque value of the main pump to be less than the minimum torque value stored in the table.

16. The control method of the hydraulic control system of engineering machinery according to claim 10, characterized in that: Before the step of restoring the engine speed to a set speed setting value, when a travel or work signal is not input from a joystick pilot pressure sensor within a set time after an off signal of the automatic idle function is input, the automatic idle function is maintained.

17. The control method of the hydraulic control system of engineering machinery according to claim 10, characterized in that: Before the step of executing the automatic idling function of the engineering machinery, the method further includes: The step of inputting a start signal of an automatic idle function during operation or driving of the engineering machine; and Procedure to confirm whether the operation or travel signal is input from the joystick pilot pressure sensor within the set time.

18. The control method of the hydraulic control system of engineering machinery according to claim 10, characterized in that: In the step of restoring the speed of the engine to a set speed setting value, The operations of the main pump and the fan pump are not restricted after the set time.

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