KR102121879B1 - Apparatus for reducing driving impact of construction machine and control method for construction machine using same - Google Patents

Abstract

The traveling impact reduction device for a construction machine includes: a traveling operation portion generating a pilot pressure for controlling the hydraulic oil discharge amount of a hydraulic pump supplying hydraulic oil to a traveling motor of a construction machine, a sensor portion for detecting a change in operation of the traveling operation portion, a traveling operation portion And a pressure reducing valve installed between the hydraulic pump and a pressure reducing valve for controlling the pilot pressure supplied to the hydraulic pump, and receiving the operation change amount information from the sensor unit and operating the pressure reducing valve to gradually increase the pilot pressure when the operation change amount is greater than a preset size. And a control unit for controlling.

Description

Apparatus for reducing driving impact of construction machine and control method for construction machine using same

The present invention relates to a driving shock reduction device for a construction machine and a control method for a construction machine using the same, and more particularly, a driving shock reduction device for a construction machine that controls the flow rate of hydraulic oil discharged from a hydraulic pump and a construction machine using the same. It relates to a control method.

Construction machinery, for example, a wheel-type excavator may perform a forward or reverse operation using hydraulic oil discharged from a hydraulic pump. At this time, the flow rate of the hydraulic oil discharged from the hydraulic pump can be controlled by the operation degree of the traveling pedal.

However, when the driver suddenly presses the driving pedal abruptly, such as when suddenly starting from a stationary state, the flow rate of hydraulic oil discharged from the hydraulic pump may rapidly increase. Accordingly, driving acceleration may increase rapidly and an impact may be applied to the driver.

One object of the present invention is to provide a running impact reduction device for a construction machine.

Another object of the present invention is to provide a method for controlling a construction machine using the driving shock reduction device.

In order to achieve the above-described object of the present invention, an apparatus for reducing travel impact of a construction machine according to exemplary embodiments of the present invention is for controlling a hydraulic oil discharge amount of a hydraulic pump supplying hydraulic oil to a traveling motor of a construction machine. A driving operation unit for generating a pilot pressure, a sensor unit for detecting an operation change amount of the driving operation unit, a pressure reducing valve installed between the driving operation unit and the hydraulic pump to control the pilot pressure supplied to the hydraulic pump, and the sensor It includes a control unit for controlling the operation of the pressure reducing valve to receive the operation change amount information from the unit and the pilot pressure gradually increases when the operation change amount is greater than a predetermined size.

In exemplary embodiments, the magnitude of the pilot pressure generated from the driving operation portion increases at a first ratio, and the magnitude of the pilot pressure supplied from the pressure reducing valve to the hydraulic pump is less than the first ratio. Can be increased to

In example embodiments, the driving manipulation unit may include a driving pedal.

In example embodiments, the sensor unit may include an angle sensor for measuring an angle change of the driving pedal.

In example embodiments, the sensor unit may include a pressure sensor for measuring a change in the pilot pressure.

In example embodiments, the pressure sensor may include a pressure switch.

In exemplary embodiments, the arm valve may be an electronic proportional pressure reducing valve.

In example embodiments, the electromagnetic proportional pressure reducing valve may control the pilot pressure to be proportional to the magnitude of the received control signal.

In example embodiments, the electromagnetic proportional pressure reducing valve may control the pilot pressure to be inversely proportional to the magnitude of the received control signal.

In exemplary embodiments, the driving shock reducing device may further include a regulator installed between the pressure reducing valve and the hydraulic pump.

In example embodiments, the hydraulic pump may be a variable displacement hydraulic pump.

In exemplary embodiments, the driving shock reducing device is a work control unit for generating a third pilot pressure for controlling the hydraulic oil discharge amount of a hydraulic pump supplying hydraulic oil to the actuator of the construction machine, and the pressure reducing valve The control valve may further include a shuttle valve that selects and outputs a larger pressure from the controlled pilot pressure and the third pilot pressure generated from the operation manipulation unit.

In exemplary embodiments, the pressure reducing valve may be installed in a pilot line connecting the driving operation part and the shuttle valve.

According to exemplary embodiments, the apparatus for reducing travel impact of a construction machine may control the flow rate of hydraulic oil supplied to the travel motor to gradually increase even if the driver suddenly operates the travel pedal. Accordingly, it is possible to reduce a shock that may occur during driving.

However, the effects of the present invention are not limited to the above-mentioned effects, and may be variously extended without departing from the spirit and scope of the present invention.

1 is a hydraulic circuit diagram showing a traveling system of a construction machine according to exemplary embodiments.
Figure 2 is a graph showing the operating characteristics of the pressure reducing valve of Figure 1;
3 is a flowchart illustrating a method of controlling a construction machine using the traveling system of the construction machine of FIG. 1.
4 are graphs showing changes in pilot pressure and input current.
Fig. 5 is a hydraulic circuit diagram showing a traveling system of a construction machine according to exemplary embodiments.
6 is a graph showing the operating characteristics of the pressure reducing valve of FIG. 5.
7 are graphs showing changes in pilot pressure and input current.
Fig. 8 is a hydraulic circuit diagram showing a hydraulic system of a construction machine according to exemplary embodiments.

With respect to the embodiments of the present invention disclosed in the text, specific structural or functional descriptions are exemplified only for the purpose of illustrating the embodiments of the present invention, and the embodiments of the present invention can be implemented in various forms and the text It should not be construed as being limited to the embodiments described in.

The present invention can be variously changed and can have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, and it should be understood as including all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms may be used for the purpose of distinguishing one component from other components. For example, the first component may be referred to as the second component without departing from the scope of the present invention, and similarly, the second component may also be referred to as the first component.

When an element is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but there may be other components in between. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle. Other expressions that describe the relationship between the components, such as "between" and "immediately between" or "neighboring" and "directly neighboring to" should be interpreted as well.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms “include” or “have” are intended to indicate that a feature, number, step, action, component, part, or combination thereof described is present, and one or more other features or numbers. It should be understood that it does not preclude the presence or addition possibilities of, steps, actions, components, parts or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms, such as those defined in the commonly used dictionary, should be interpreted as meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

1 is a hydraulic circuit diagram showing a traveling system of a construction machine according to exemplary embodiments. Figure 2 is a graph showing the operating characteristics of the pressure reducing valve of Figure 1;

1 and 2, the traveling system of the construction machine includes a hydraulic pump 10 for supplying hydraulic oil, a traveling motor 20 for driving the construction machine by receiving hydraulic oil discharged from the hydraulic pump 10, traveling Main control valve (30) for controlling the supply direction of the hydraulic oil supplied to the motor 20, the driving control unit 40 for generating a pilot pressure for controlling the hydraulic pump 10 in response to the operator's operation ), and a driving shock reducing device for reducing the shock generated when the driver suddenly operates the driving manipulation unit 40.

The construction machine may include a wheel excavator, a wheel loader, and a forklift. Hereinafter, for convenience of description, the case where the construction machine is a wheel type excavator will be described. However, this does not limit the driving impact reduction device of the present invention to control a wheel excavator, and can be applied to wheel loaders and forklift trucks in substantially the same manner.

The hydraulic pump 10 is connected to the output shaft of the engine, and is driven as the output shaft rotates to discharge hydraulic oil. The hydraulic oil is stored in the oil tank (T), the hydraulic oil discharged from the hydraulic pump 10 may be supplied to the traveling motor 20, swing motor, and actuators via the main control valve 30. The supplied hydraulic oil can be recovered back to the oil tank (T). In this case, the actuator may include working devices such as a boom, an arm, and a bucket.

In example embodiments, the hydraulic pump 10 may be a variable displacement hydraulic pump. For example, the variable displacement hydraulic pump may be a swash plate type axial piston pump. At this time, the swash plate may be a disc installed obliquely with respect to the rotation axis of the hydraulic pump 10. The flow rate discharged from the hydraulic pump 10 may vary according to the inclination angle of the swash plate with respect to the rotation axis. That is, by controlling the inclination angle of the swash plate, it is possible to control the flow rate of the hydraulic oil discharged from the hydraulic pump 10. For example, when the inclination angle of the swash plate increases, the flow rate of hydraulic oil discharged from the hydraulic pump 10 may increase, and when the inclination angle of the swash plate decreases, the flow rate of hydraulic oil discharged from the hydraulic pump 10 may decrease. have.

The traveling motor 20 may receive hydraulic oil from the hydraulic pump 10 to generate traveling driving force. The driving driving force may be transmitted to the driving shaft via a transmission connected to the driving motor 20. Accordingly, the construction machine can be moved forward or backward.

The main control valve 30 may receive hydraulic oil from the hydraulic pump 10 and control pressure, flow rate, direction, etc. of hydraulic oil supplied to the traveling motor 20. For example, the main control valve may control the direction of the hydraulic oil supplied to the driving motor in response to an operator's operation signal, and the construction machine may move forward or backward according to the hydraulic oil supply direction, and the A variety of tasks can be performed using a working device.

1, only one hydraulic pump 10 and the driving motor 20 are illustrated as being connected to the main control valve 30, but are not limited thereto. For example, the main control valve can be connected to a plurality of hydraulic motors, it is possible to control the flow rate of the hydraulic fluid supplied to the swing motor and various actuators.

The driving operation unit 40 is installed in the cab of the construction machine, and can generate a pilot pressure corresponding to the operation of the driver. The pilot pressure is supplied to the hydraulic pump 10 to control the inclination angle of the swash plate, or it can be supplied to the main control valve 30 to control the flow rate of hydraulic oil supplied to the traveling motor 20. For example, the driving manipulation unit may be a driving pedal.

Specifically, the construction machine may include a pilot pump (not shown) for supplying control oil for controlling the swash plate and/or the main control valve 30. For example, the control oil may include substantially the same material as the hydraulic oil. The pilot pump is connected to the output shaft of the engine, and is driven as the output shaft rotates to discharge control oil. In this case, the discharged control oil can generate a pilot pressure corresponding to the driver's operation. For example, a pilot pressure corresponding thereto may be formed according to the degree to which the driver operates the driving manipulation unit 40. The pilot pressure is provided to the hydraulic pump 10 through the pilot line 50 to control the inclination angle of the swash plate.

In example embodiments, the pilot line 50 may include a first pilot line 52 and a second pilot line 54. In this case, the first pilot line 52 may be a pilot line between the pressure reducing valve 120 and the traveling operation unit 40, which will be described later, and the second pilot line 54 may include a pressure reducing valve 120 and a hydraulic pump. It may be a pilot line between (10).

In addition, hereinafter, the pressure of the control oil formed in the first pilot line 52 is defined as the first pilot pressure, and the pressure of the control oil formed in the second pilot line 54 is defined as the second pilot pressure. In this case, the first pilot pressure may be a pilot pressure having a size corresponding to a driver's operation signal, and the second pilot pressure may be controlled by the hydraulic pump 10 supplied to the hydraulic pump 10 to control the inclination angle of the swash plate. Pilot pressure.

In example embodiments, the driving shock reducing apparatus may further include a regulator 140 installed in the pilot line 50. The regulator 140 may control the flow rate and pressure of the hydraulic oil discharged from the hydraulic pump 10 to be kept constant regardless of the load.

The driving shock reduction device includes a pressure sensor 100 for measuring the pilot pressure generated by the driving manipulation unit 40, an angle sensor 110 for determining the manipulation degree of the driving manipulation unit 40, sensors 100, 110) receives the measured information from the control unit 130 for generating a control signal for controlling the pilot pressure based on this, and a pressure reducing valve 120 for controlling the magnitude of the pilot pressure according to the control signal It can contain.

The pressure sensor 100 is installed on the first pilot line 52 and can measure the magnitude of the first pilot pressure. The measured pressure information may be transmitted to the controller 130 through wireless communication, for example, a controller area network (CAN), a local interconnect network (LIN), or a FlexRay. Alternatively, the pressure sensor 100 may be directly connected to the control unit 130 through a wire.

For example, the pressure sensor can be a pressure switch. The pressure switch may be turned on or off by comparing the pressure inside the first pilot line 52 with a preset pressure. That is, when the first pilot pressure in the first pilot line 52 is greater than or equal to a preset pressure, the pressure switch is turned on, and pressure information may be transmitted to the controller 130. Alternatively, the pressure sensor 100 may transmit the first pilot pressure to the controller 130 at all times or periodically.

The angle sensor 110 is installed on one side of the traveling manipulation unit 40 and can measure the degree of manipulation of the traveling manipulation unit 40. For example, the angle sensor may measure a manipulation amount of the travel manipulation unit by detecting a change in inclination angle with respect to the direction of the earth gravity of the travel manipulation unit, or a relative position change between the floor surface of the cab and the travel manipulation unit. . The measured angle information may be transmitted to the controller 130 through wireless communication, for example, a controller area network (CAN), a local interconnect network (LIN), or a FlexRay. Alternatively, the angle sensor 110 may be directly connected to the control unit 130 through a wire.

In example embodiments, the driving shock reduction device may include only the pressure sensor 100 and not the angle sensor 110. Alternatively, the driving shock reduction device may include only the angle sensor 110 and not the pressure sensor 100.

The pressure of the control oil formed in the first pilot line 52, that is, the first pilot pressure may have a size determined according to the manipulation amount of the driver. At this time, the manipulation amount may be proportional to the degree to which the driver operates the driving manipulation unit 40. Accordingly, the angle of the driving manipulation unit 40 measured by the angle sensor 110 and the first pilot pressure measured by the pressure sensor 100 are values that can be converted to each other. Accordingly, the driving shock reducing apparatus may include only one sensor selected from the pressure sensor 100 and the angle sensor 110.

The pressure reducing valve 120 is installed on the pilot line 50 and may receive a control signal from the control unit 130. The pressure reducing valve 120 may control the magnitude of the second pilot pressure supplied to the hydraulic pump 10 to correspond to the received control signal.

For example, the pressure reducing valve may be an electronic proportional pressure reducing (EPPR) valve. The electromagnetic proportional pressure reducing valve may generate a pilot pressure corresponding to the magnitude of the received control signal, for example, the intensity of the current. That is, the magnitude of the second pilot pressure may be determined by the magnitude of the control signal received from the controller 130.

In example embodiments, the pressure reducing valve 120 may control the magnitude of the second pilot pressure to be inversely proportional to the magnitude of the control signal input from the controller 130.

As illustrated in FIG. 2, when the control signal of the first current C1 is input to the pressure reducing valve 120, the magnitude of the second pilot pressure may be the first pressure P1 (point A). When the control signal of the second current C2 is input to the pressure reducing valve 120, the magnitude of the second pilot pressure may be the second pressure P1 (point B). At this time, the second current C2 may be greater than the first current C1, and the first pressure P1 may be greater than the second pressure P2. That is, as the size of the control signal input to the pressure reducing valve 120 increases, the size of the second pilot pressure output through the second pilot line 54 may decrease.

The control unit 130 may receive pressure information of the first pilot line 52 and information about the operation amount of the driving operation unit 40 from the pressure sensor 100 and the angle sensor 110, respectively. The control unit 130 may determine whether the driving operation unit 40 is suddenly operated from the received information. When it is determined that the driver has suddenly operated the driving operation unit 40, the second pilot pressure may be gradually increased by outputting a control signal to the pressure reducing valve 120. When the second pilot pressure gradually increases, the inclination angle of the swash plate of the hydraulic pump 10 may also gradually increase, and the flow rate of hydraulic oil supplied to the traveling motor 20 may also gradually increase. Accordingly, a running shock due to the sudden operation of the driving manipulation unit 40 can be reduced. For example, the control unit may be an electronic control unit (ECU).

As described above, the apparatus for reducing travel impact of a construction machine according to exemplary embodiments controls the flow rate of hydraulic oil supplied to the travel motor 20 to gradually increase even when the driver suddenly operates the travel manipulation unit 40. can do. Accordingly, it is possible to reduce an impact that may occur during driving.

3 is a flowchart illustrating a method of controlling a construction machine using the traveling system of the construction machine of FIG. 1. 4 are graphs showing changes in pilot pressure and input current.

Referring to FIGS. 3 and 4, operation information on the driving operation unit is acquired (S100 ).

Specifically, when the driver operates the driving manipulation unit, a first pilot pressure corresponding to the manipulation amount may be formed in the first pilot line 52. The control unit 130 may receive information about the first pilot pressure from the pressure sensor 100 installed in the first pilot line 52. Alternatively, the control unit 130 may receive the angle information of the driving manipulation unit 40 from the angle sensor 110 installed in the driving manipulation unit 40. The control unit 130 may determine the operation degree of the driving operation unit 40 using the received pressure information or angle information. For example, the driving manipulation unit may be a driving pedal.

Subsequently, it is determined whether the driving operation unit is suddenly operated (S110).

In exemplary embodiments, when the first pilot pressure input from the pressure sensor 100 is greater than or equal to a preset pressure, the controller 130 may determine that the driver has suddenly operated the driving manipulation unit 40. . At this time, the set pressure may be set in consideration of the specifications of the construction machine, the type of the selected transmission stage, the working environment, and the like.

Alternatively, if the angle change of the driving manipulation unit 40 input from the angle sensor 110 is greater than or equal to a preset angle, the controller 130 may determine that the driver has suddenly operated the driving manipulation unit 40. At this time, the setting angle may be set in consideration of the specifications of the construction machine, the type of the selected shift stage, the working environment, and the like.

When it is determined that the traveling operation unit is suddenly operated, the pilot pressure is controlled to gradually increase the flow rate of the hydraulic oil discharged from the hydraulic motor (S120).

When the driver suddenly operates the driving operation unit 40, the flow rate and pressure of the hydraulic oil discharged from the hydraulic pump 10 may increase rapidly. In this case, the driving acceleration of the construction machine may be excessively large, resulting in a shock. In order to prevent the impact, the control unit 130 may control the swash plate angle of the hydraulic pump 10 to gradually increase. Accordingly, a sudden increase in the flow rate of the hydraulic oil discharged from the hydraulic pump 10 can be prevented, and it is possible to suppress the occurrence of running shock.

Specifically, when the driver operates the driving manipulation unit 40, a first pilot pressure corresponding to the manipulation amount may be formed in the first pilot line 52. The pressure sensor 100 may detect the first pilot pressure and provide it to the control unit 130. The control unit 130 may compare the first pilot pressure with a preset pressure to determine whether the driving manipulation unit 40 is suddenly operated. When it is determined that the driving operation unit 40 is suddenly operated, the control unit 130 may increase the current input to the pressure reducing valve 120. When the input current increases, the pressure reducing valve 120 may be switched to the right. Accordingly, the pilot pressure provided to the swash plate, that is, the second pilot pressure may be smaller than the first pilot pressure. Thereafter, the controller 130 may gradually decrease the input current. Accordingly, the second pilot pressure gradually increases until it becomes the same size as the first pilot pressure, and the hydraulic oil discharge flow rate from the hydraulic pump 10 may also gradually increase.

The above process in which the control unit 130 controls the pilot pressure is illustrated in detail in FIG. 4.

Referring to FIG. 4, in a state in which the driver has not operated the driving operation unit 40 at all (first zone, I), the first and second pilot pressures are respectively 0, and the current input to the pressure reducing valve 120 is also shown. It can be minimal.

Thereafter, when the driver suddenly operates the driving manipulation unit 40 (second zone, II), the first pilot pressure may rapidly increase corresponding to the manipulation amount of the driving manipulation unit 40. At this time, the control unit 130 may rapidly increase the intensity of the current input to the pressure reducing valve 120. As shown in FIG. 2, since the intensity of the current input to the pressure reducing valve 120 and the magnitude of the second pilot pressure are inversely related, the increase in the second pilot pressure may not be large. Thereafter, the controller 130 may gradually decrease the intensity of the current input to the pressure reducing valve 120. Accordingly, the second pilot pressure may be gradually increased until it has the same size as the first pilot pressure (third zone, III).

In example embodiments, the rate of decrease of the input current and the rate of increase of the second pilot pressure may be variously set in consideration of specifications of a construction machine, a type of a selected transmission stage, a working environment, and the like. In FIG. 4, the decrease in the input current over time is shown as having a straight line shape, but the present invention is not limited thereto. For example, the input current may decrease along a parabolic trajectory or stepwise along a stepped trajectory.

As described above, the control method of the construction machine according to the exemplary embodiments may gradually increase the flow rate of hydraulic oil supplied to the traveling motor 20. Accordingly, smooth driving without driving shock can be realized even if the driver suddenly operates the driving manipulation unit 40.

Fig. 5 is a hydraulic circuit diagram showing a traveling system of a construction machine according to exemplary embodiments. 6 is a graph showing the operating characteristics of the pressure reducing valve of FIG. 5. The driving system of FIG. 5 is substantially the same or similar to the driving system of the construction machine described with reference to FIG. 1 except for the pressure reducing valve 122. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

5 and 6, the traveling system of the construction machine is supplied to the hydraulic pump 10 for supplying hydraulic oil, the traveling motor 20 for receiving the hydraulic oil to drive the construction machine, and the traveling motor 20 When the main control valve 30 for controlling the hydraulic fluid to be operated, the traveling operation part 40 generating a pilot pressure for controlling the discharge amount of the hydraulic pump 10 in response to the driver's operation, and the traveling operation part 40 during sudden operation It may include a driving shock reducing device for reducing the possible driving shock.

The driving shock reducing device includes a pressure sensor 100 for measuring the pilot pressure generated according to the operation of the driving manipulation unit 40, an angle sensor 110 for measuring the manipulation amount of the driving manipulation unit 40, sensors 100, Control unit 130 for receiving the measured information from 110 and generating a control signal for controlling the magnitude of the pilot pressure, and a pressure reducing valve 122 for controlling the magnitude of the pilot pressure by receiving the control signal Can be.

The pressure reducing valve 122 may be installed on the pilot line 50 and receive a control signal from the control unit 130. The pressure reducing valve 122 may control the magnitude of the second pilot pressure supplied to the hydraulic pump 10 to correspond to the received control signal.

For example, the pressure reducing valve may be an electronic proportional pressure reducing (EPPR) valve. The electromagnetic proportional pressure reducing valve may generate a pilot pressure corresponding to the magnitude of the received control signal, for example, the intensity of the current. That is, the magnitude of the second pilot pressure may be determined by the magnitude of the control signal received from the controller 130.

In example embodiments, the pressure reducing valve 122 may control the magnitude of the second pilot pressure to be proportional to the magnitude of the control signal input from the controller 130.

As illustrated in FIG. 6, when the control signal of the third current C3 is input to the pressure reducing valve 122, the magnitude of the second pilot pressure may be the third pressure P3 (point D). When the control signal of the fourth current C4 is input to the pressure reducing valve 122, the magnitude of the second pilot pressure may be the fourth pressure P4 (point E). At this time, the fourth current C4 may be greater than the third current C3, and the fourth pressure P4 may be greater than the third pressure P3. That is, as the size of the control signal input to the pressure reducing valve 122 increases, the size of the second pilot pressure output through the second pilot line 54 may also increase.

As described above, the apparatus for reducing travel impact of a construction machine according to exemplary embodiments controls the flow rate of hydraulic oil supplied to the travel motor 20 to gradually increase even when the driver suddenly operates the travel manipulation unit 40. can do. Accordingly, it is possible to reduce an impact that may occur during driving.

7 are graphs showing changes in pilot pressure and input current. The control method of FIG. 7 is substantially the same or similar to the control method of the construction machine described with reference to FIGS. 3 and 4 except for changes in the input current and the second pilot pressure. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same steps are omitted.

Referring to FIG. 7, in a state in which the driver has not operated the driving control unit 40 at all (fourth zone, IV), the first and second pilot pressures are 0 respectively, and the current input to the pressure reducing valve 122 is also It can be minimal.

Thereafter, when the driver suddenly operates the driving manipulation unit 40 (Fifth Zone, V), the first pilot pressure may rapidly increase corresponding to the manipulation amount of the driving manipulation unit 40. At this time, the control unit 130 may gradually increase the intensity of the current input to the pressure reducing valve 122. As shown in FIG. 6, since the intensity of the current input to the pressure reducing valve 122 and the magnitude of the second pilot pressure are in a proportional relationship, the second pilot pressure may also gradually increase. Thereafter, the second pilot pressure may be gradually increased until it has the same size as the first pilot pressure (sixth zone, VI).

In example embodiments, the rate of increase of the input current and the rate of increase of the second pilot pressure may be variously set in consideration of specifications of the construction machine, the type of the selected transmission stage, the working environment, and the like. In FIG. 7, the increase in the input current over time is shown as having a straight shape, but the present invention is not limited thereto. For example, the input current may increase along a parabolic trajectory or stepwise along a stepped trajectory.

As described above, the control method of the construction machine according to the exemplary embodiments may gradually increase the flow rate of hydraulic oil supplied to the traveling motor 20. Accordingly, smooth driving without driving shock can be realized even if the driver suddenly operates the driving manipulation unit 40.

Fig. 8 is a hydraulic circuit diagram showing a hydraulic system of a construction machine according to exemplary embodiments. The hydraulic system of FIG. 8 is substantially the same or similar to the traveling system of the construction machine described with reference to FIG. 1 except for the operation control unit and the shuttle valve. Accordingly, the same components are denoted by the same reference numerals, and the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

Referring to FIG. 8, the hydraulic system of a construction machine includes a hydraulic pump 10 for supplying hydraulic oil, a traveling motor 20 for receiving the hydraulic oil to drive the construction machine, and working of the construction machine by receiving the hydraulic oil. The actuator 22 for driving the device, the traveling operation part 40 and the operation operation part 42 for generating the pilot pressure for controlling the discharge amount of the hydraulic pump 10 in response to the driver's operation, and the traveling operation part 40 It may include a driving shock reducing device for reducing the driving shock that may occur during a sudden operation.

In example embodiments, the travel manipulation unit 40 may generate a first pilot pressure for controlling the flow rate of the hydraulic oil supplied to the travel motor 20. For example, the travel manipulation unit 40 may include a travel pedal. The work manipulation unit 42 may generate a third pilot pressure for controlling the flow rate of the hydraulic oil supplied to the actuator 22 for driving the work device. For example, the operation manipulation unit 42 may include a joystick. The actuator 22 may include a swing motor, boom cylinder, arm cylinder or bucket cylinder.

The first pilot pressure generated from the driving operation unit 40 may be provided to the hydraulic pump 10 through the pilot line 50. The third pilot pressure generated from the operation manipulation unit 42 may be provided to the hydraulic pump 10 through the third pilot line 60.

In exemplary embodiments, both ends are connected to the pilot line 50 and the third pilot line 60, and further includes a shuttle valve 150 that selects a higher pressure among the two input pressures and outputs it through an outlet. can do.

Specifically, the pilot line 50 may include a first pilot line 52 and a second pilot line 54. The first pilot line 52 connects the driving operation part 40 and the pressure reducing valve 120, and the second pilot line 54 connects the pressure reducing valve 120 and the first end of the shuttle valve 150 inlet. have. The third pilot line 60 may connect the operation control unit 42 and the second end of the inlet of the shuttle valve 120. The fourth pilot line 70 may connect the outlet of the shuttle valve 150 and the regulator 140.

Accordingly, the shuttle valve 150 may select a larger pressure from the second pilot pressure controlled by the pressure reducing valve 120 and the third pilot pressure generated from the work manipulation unit 42 and output the selected pressure to the regulator 140. have.

Although described above with reference to the embodiments of the present invention, those skilled in the art may variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can.

10: hydraulic pump 20: traveling motor
22: actuator 30: main control valve
40: traveling control unit 42: operation control unit
50: pilot line 52: first pilot line
54: second pilot line 60: third pilot line
70: fourth pilot line 100: pressure sensor
110: angle sensor 120, 122: pressure reducing valve
130: control unit 140: regulator
150: Shuttle valve T: Oil tank

Claims (13)

A traveling operation unit generating a first pilot pressure for controlling the hydraulic oil discharge amount of the hydraulic pump supplying hydraulic oil to the traveling motor of the construction machine;
A joystick for generating a third pilot pressure for controlling the hydraulic oil discharge amount of the hydraulic pump supplied to the actuator for driving the working device of the construction machine;
A sensor unit for detecting an operation change amount of the driving operation unit;
A pressure reducing valve installed between the driving operation part and the hydraulic pump to control the first pilot pressure supplied to the hydraulic pump to output a second pilot pressure;
A shuttle valve selecting and outputting a larger pressure from the second pilot pressure output from the pressure reducing valve and the third pilot pressure generated from the joystick;
A regulator installed between the shuttle valve and the hydraulic pump to adjust the swash plate angle of the hydraulic pump by a pilot pressure applied from the shuttle valve; And
And a control unit for receiving operation change amount information of the driving operation unit from the sensor unit and controlling the operation of the pressure reducing valve so that the second pilot pressure gradually increases when the operation change amount is equal to or greater than a preset size,
The pressure reducing valve is an electronic proportional pressure reducing valve, and the magnitude of the first pilot pressure generated according to the operation degree of the driving control unit is controlled by the electronic proportional pressure reducing valve and the controlled second pilot pressure. It is supplied to the regulator to control the hydraulic oil discharge amount of the hydraulic pump,
The first pilot pressure generated from the driving operation unit is supplied to the regulator through a pilot line, and the third pilot pressure generated from the joystick is supplied to the regulator through a third pilot line, and the pilot line and the third Pilot lines are respectively connected to both ends of the shuttle valve,
The pressure reducing valve is a driving impact reduction device for a construction machine installed in the pilot line connecting the driving operation portion and the shuttle valve. According to claim 1, The magnitude of the first pilot pressure generated from the driving operation unit increases at a first ratio, and the magnitude of the second pilot pressure supplied from the pressure reducing valve to the hydraulic pump is smaller than the first ratio. A driving shock reduction device for construction machinery, characterized in that it increases at a ratio of 2. According to claim 1, wherein the traveling operation unit driving impact reduction device for a construction machine, characterized in that the traveling pedal. According to claim 3, The sensor unit driving impact reduction device for a construction machine, characterized in that it comprises an angle sensor for measuring the angle change of the traveling pedal. The apparatus of claim 1, wherein the sensor unit comprises a pressure sensor for measuring a change in the pilot pressure. According to claim 5, The pressure sensor is a driving shock reduction device for a construction machine, characterized in that the pressure switch. delete The apparatus of claim 1, wherein the electromagnetic proportional pressure reducing valve controls the first pilot pressure to be proportional to the magnitude of the received control signal. The apparatus of claim 1, wherein the electromagnetic proportional pressure reducing valve controls the first pilot pressure to be inversely proportional to the magnitude of the received control signal. delete The apparatus of claim 1, wherein the hydraulic pump is a variable displacement hydraulic pump. delete delete

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