JP6926036B2 - Construction machinery - Google Patents

Description

The present invention relates to construction machinery such as hydraulic excavators.

Generally, a hydraulic excavator as a construction machine includes an engine as a power source, a hydraulic pump driven by the engine, and a hydraulic actuator operated by the discharge pressure of the hydraulic pump. At this time, the hydraulic actuator includes, for example, a boom cylinder for driving the boom mechanism, an arm cylinder for driving the arm mechanism, and a bucket cylinder for driving the bucket mechanism.

In such a hydraulic excavator, the speed of the hydraulic actuator may vary due to factors such as manufacturing errors of hydraulic parts and deterioration over time. In this case, the amount of work may vary from hydraulic excavator to hydraulic excavator. In addition to this, there may be differences in the operating speed of each hydraulic excavator. Therefore, in order to keep the quality of the machine constant, a method of adjusting the vehicle body output is known (Patent Document 1).

In the adjustment method described in Patent Document 1, the discharge pressure of the hydraulic pump is measured with respect to the hydraulic pump regulator when the flow rate is changed from the minimum pump flow rate to the maximum pump flow rate. Based on this measured discharge pressure, the hydraulic pump regulator control is calibrated so as to absorb the difference between the actual flow rate and the indicated value.

Japanese Unexamined Patent Publication No. 2014-177769

By the way, Patent Document 1 describes that the hydraulic pump regulator control is calibrated. In this case, since the discharge pressure of the hydraulic pump is adjusted, the speed of the entire front mechanism can be adjusted.

However, in order to adjust the operation of the front mechanism including the boom, arm and bucket, it is not enough to calibrate the discharge pressure of the hydraulic pump which is the power source. That is, when the speeds of the boom, arm, and bucket vary, the operation balance of the front mechanism is lost. In order to adjust the speed without disturbing the operation balance of the complicated front mechanism, it is necessary to calibrate the speed for each boom, arm, and bucket that are the front mechanism. On the other hand, when the discharge pressure of the hydraulic pump is adjusted as in the prior art, the speeds of a plurality of hydraulic actuators (boom cylinder, arm cylinder, bucket cylinder) provided in the front mechanism cannot be individually adjusted. Therefore, there is a problem that the operating speeds of the plurality of hydraulic actuators cannot be adjusted to a desired balance.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a construction machine capable of adjusting the speed of a hydraulic actuator.

In order to solve the above-mentioned problems, the present invention uses a hydraulic pump driven by an engine, a hydraulic actuator operated by pressure oil discharged from the hydraulic pump, and the hydraulic actuator according to a pilot pressure of an operating device. In a construction machine including a control valve that supplies pressure oil and an electromagnetic valve that is controlled by a controller and can adjust the pilot pressure, the controller determines the load of the hydraulic actuator and the operation amount of the operating device. Based on the pilot decompression control unit that calculates the pressure instruction value for reducing the pilot pressure, and the pressure instruction obtained by the pilot decompression control unit based on the operation amount of the operating device and the discharge pressure of the hydraulic pump. A pilot depressurization adjustment unit for obtaining a correction amount for adjusting a value is provided, and the pilot decompression adjustment unit determines that the hydraulic actuator has started operation based on the operation amount of the operation device, and determines that the hydraulic actuator has started operation. It is determined that the hydraulic actuator has reached the terminal position based on the discharge pressure of the pump, the operating time from the start of operation of the hydraulic actuator to the arrival at the terminal position is measured, and the operating time and the operating time are measured in advance. It is characterized in that the correction amount for reducing the time difference from the determined reference time is obtained.

According to the present invention, the speed of the hydraulic actuator can be adjusted by detecting the operating amount of the operating device and the discharge pressure of the hydraulic pump. Further, the required correction amount can be obtained by operating the hydraulic actuator for a short time. Therefore, the speed of the hydraulic actuator can be adjusted by the adjustment work in a short time.

It is a front view which shows the hydraulic excavator by embodiment of this invention. It is a main part perspective view which shows the inside of the cab in FIG. It is a front view which shows the monitor device in FIG. It is a block diagram which shows the hydraulic system applied to a hydraulic excavator. It is a hydraulic circuit diagram which shows the hydraulic system which drives an arm cylinder. It is a block diagram which shows the structure of a controller. It is explanatory drawing of the characteristic map which obtains the opening area from a cylinder thrust and a pilot pressure. It is explanatory drawing of the characteristic map which obtains a pressure instruction value from an opening area. It is explanatory drawing which shows the characteristic map which obtains the correction amount from the operation time of an arm cylinder. It is explanatory drawing which shows the characteristic map which obtains a current instruction value from a pressure correction value. It is a flowchart which shows the correction start determination process. It is a flowchart which shows the correction amount calculation process.

Hereinafter, as a construction machine according to the embodiment of the present invention, a hydraulic excavator will be taken as an example, and the details will be described with reference to the accompanying drawings.

Here, FIGS. 1 to 12 show embodiments of the present invention. As shown in FIGS. 1 and 2, the hydraulic excavator 1 is mounted on a self-propelled crawler-type lower traveling body 2 and a lower traveling body 2 serving as a means of transportation so as to be able to turn via a turning device 3. It is provided with an upper swivel body 4 and a work device 5 having an articulated structure provided on the front side of the upper swivel body 4 and performing excavation work and the like. The lower traveling body 2 includes a hydraulic motor 2A for performing a traveling operation. The swivel device 3 includes a hydraulic motor 3A for performing a swivel operation. Although the crawler type is illustrated as the lower traveling body 2, a wheel type may also be used.

The upper swivel body 4 includes a building cover 7 provided on the swivel frame 6 and accommodating an engine 20 and the like, and a cab 9 including a driver's seat 8. The monitoring device 10 is located in front of the driver's seat 8 and is provided in the cab 9. The monitoring device 10 is connected to the controller 41. The monitoring device 10 receives the signal from the controller 41 and displays the operation information of the machine. As shown in FIG. 3, when the speed of the working device 5 is adjusted, the monitoring device 10 displays the adjustment result. The monitor device 10 may include an input device such as a button or a touch panel. In this case, the monitoring device 10 may operate various processes of the controller 41. The operation device 11 includes, for example, an operation lever and an operation pedal, is located around the driver's seat 8, and is provided in the cab 9. The engine control dial 12 sets the target rotation speed of the engine 20 and is provided in the cab 9.

The working device 5 is a front actuator mechanism. The working device 5 is composed of, for example, a boom 5A, an arm 5B, and a bucket 5C, and a boom cylinder 5D, an arm cylinder 5E, and a bucket cylinder 5F for driving them. The working device 5 is attached to the swivel frame 6 and performs an up-and-down operation by extending or contracting the cylinders 5D to 5F. Although the case where the bucket 5C is used is illustrated in FIG. 1, various attachments such as a breaker may be used other than the bucket 5C.

As shown in FIG. 2, the operating device 11 is provided on both sides of the driver's seat 8 in the cab 9, for example, and includes operating levers 11A for working and turning. These operating levers 11A are tilted in an arbitrary direction to drive the working device 5 and perform the turning operation of the turning device 3. Further, the operating device 11 is located on the front side of the driver's seat 8 and includes an operating lever 11B and an operating pedal 11C for performing a traveling operation of the lower traveling body 2.

The gate lock lever 13 is located in the cab 9 on the entrance / exit side of the cab 9 with respect to the driver's seat 8. Specifically, the gate lock lever 13 is arranged on the left side of the driver's seat 8. The gate lock lever 13 can be tilted in the vertical direction. The state in which the gate lock lever 13 is raised is a locked state, and the vehicle body cannot operate even if the operating device 11 is tilted while the engine is running. On the other hand, if the gate lock lever 13 is lowered while the engine is running, the vehicle body can be operated.

Next, the configuration of the hydraulic system for controlling the operation of the work device 5 and the like mounted on the hydraulic excavator 1 will be described with reference to FIG.

The engine 20 is mounted on the turning frame 6. The engine 20 is composed of an internal combustion engine such as a diesel engine. Here, the operation of the engine 20 is controlled by the engine control unit 21 (hereinafter referred to as the ECU 21). The ECU 21 is composed of, for example, a microcomputer. The ECU 21 controls the output torque, rotation speed (engine rotation speed), etc. of the engine 20 based on the engine output command from the controller 41.

The hydraulic pump 22 (main pump) is mechanically connected to the engine 20. The hydraulic pump 22 is driven by the engine 20. The hydraulic pump 22 pressurizes the hydraulic oil stored in the tank 23, and uses it as pressure oil in the hydraulic motor 2A of the lower traveling body 2, the hydraulic motor 3A of the swivel device 3, and the cylinders 5D to 5F of the working device 5. Discharge. At this time, the cylinders 5D to 5F form a hydraulic actuator. The cylinders 5D to 5F are operated by the pressure oil discharged from the hydraulic pump 22. Similarly, the traveling hydraulic motor 2A and the turning hydraulic motor 3A are operated by the pressure oil discharged from the hydraulic pump 22.

The hydraulic pump 22 is composed of, for example, a swash plate type or an oblique shaft type variable displacement hydraulic pump, and its capacity can be adjusted according to the tilt angle of the swash plate or the oblique shaft. The hydraulic pump regulator 24 is, for example, a tilt control actuator that controls the tilt angle of the swash plate, and is provided on the hydraulic pump 22. The pressure oil discharged from the hydraulic pump 22 is sent to the hydraulic circuit 26 including the control valve 30. The flow rate and direction of the pressure oil are controlled by the hydraulic circuit 26, and the pressure oil is supplied to the hydraulic motors 2A and 3A and the cylinders 5D to 5F.

The engine 20 and the hydraulic pump 22 are controlled by a controller 41 described later. The controller 41 calculates the target engine speed and the target pump flow rate based on, for example, the operation amount of the operation device 11, the adjustment amount of the engine control dial 12, the discharge pressure of the hydraulic pump 22, and the like. The target engine speed is output to the ECU 21. The ECU 21 controls the fuel injection amount of the engine 20 according to the target engine speed. The target pump flow rate is converted into a current indicated value and output to the electromagnetic proportional valve 25 for the hydraulic pump 22. The electromagnetic proportional valve 25 drives the hydraulic pump regulator 24 according to the current indicated value, and changes the tilt angle of the hydraulic pump 22. Thereby, the output of the hydraulic pump 22 is controlled.

FIG. 5 shows a part of the hydraulic system of the hydraulic excavator 1. The actual hydraulic system includes a hydraulic motor 2A, 3A, a control valve 30 and a solenoid valve 40 for each cylinder 5D to 5F.

For the sake of simplification of the following description, the only hydraulic actuator to be operated is the arm cylinder 5E. Further, the solenoid valve 40 shall adjust the speed (extension speed) when the arm cylinder 5E is extended.

The control valve 30 is located between the hydraulic pump 22 and the arm cylinder 5E and is provided in the middle of the main pipelines 31A and 31B. The main pipelines 31A and 31B are a pair of oil passages that connect the hydraulic pump 22 and the tank 23 to the arm cylinder 5E. The control valve 30 is composed of a hydraulic pilot type directional control valve, and includes a pair of hydraulic pilot units 30A and 30B. The control valve 30 is switched from the neutral position (c) to the switching positions (a) and (b) by the pilot pressure from the pilot valve 38.

The control valve 30 supplies pressure oil to the arm cylinder 5E according to the pilot pressure of the operating device 11. Specifically, the control valve 30 is composed of a spool valve, and the spool (not shown) moves according to the pilot pressure of the operating device 11 supplied to the hydraulic pilot units 30A and 30B. As a result, the opening area of the control valve 30, which is the valve opening degree, changes according to the pilot pressure of the operating device 11. For example, when the pilot pressure of the operating device 11 is high and the opening area of the control valve 30 is large, the operating speed of the arm cylinder 5E becomes high. When the pilot pressure of the operating device 11 is low and the opening area of the control valve 30 is small, the operating speed of the arm cylinder 5E becomes slow.

The relief valve 32 on the high pressure side is located on the upstream side (hydraulic pump 22 side) of the control valve 30 and is connected to the main pipelines 31A and 31B. The relief valve 32 is normally closed. The relief valve 32 opens when the discharge pressure Pm of the hydraulic pump 22 exceeds the relief pressure. As a result, the relief valve 32 sets the maximum discharge pressure of the pressure oil by the main hydraulic pump 22, and relieves an excess pressure higher than this to the tank side.

The discharge pressure sensor 33 is provided on the upstream side (closer to the hydraulic pump 22) of the control valve 30. The discharge pressure sensor 33 detects the discharge pressure Pm of the hydraulic pump 22. The discharge pressure sensor 33 outputs the detected discharge pressure Pm to the controller 41.

The cylinder bottom pressure sensor 34 is provided so as to be connected to the oil chamber on the bottom side of the arm cylinder 5E. The cylinder bottom pressure sensor 34 detects the cylinder bottom pressure Pb, which is the pressure in the oil chamber on the bottom side of the arm cylinder 5E. The cylinder bottom pressure sensor 34 outputs the detected cylinder bottom pressure Pb to the controller 41.

The cylinder rod pressure sensor 35 is provided so as to be connected to the rod side oil chamber of the arm cylinder 5E. The cylinder rod pressure sensor 35 detects the cylinder rod pressure Pr, which is the pressure in the rod side oil chamber of the arm cylinder 5E. The cylinder rod pressure sensor 35 outputs the detected cylinder rod pressure Pr to the controller 41.

The pilot pump 36 is mechanically connected to the engine 20. The pilot pump 36 is driven by the engine 20. The pilot pump 36 supplies the pilot pressure to the hydraulic pilot units 30A and 30B of the control valve 30 via the pilot valve 38. A relief valve 37 on the low pressure side is connected to the discharge side of the pilot pump 36. The relief valve 37 sets the maximum discharge pressure of the pilot pump 36, and relieves an excess pressure higher than this to the hydraulic oil tank side.

The pilot valve 38 is a pressure reducing valve type pilot operated valve. The pilot valve 38 is provided in, for example, the cab 9 of the hydraulic excavator 1 and is provided in the operating device 11 (operating lever 11A) which is tilted by the operator. The pump port of the pilot valve 38 is connected to the pilot pump 36, and the tank port is connected to the hydraulic oil tank 23. Further, the output port of the pilot valve 38 is connected to the hydraulic pilot portions 30A and 30B of the control valve 30 via the pilot pipelines 39A and 39B.

Then, when the operator tilts the operating device 11, the pilot valve 38 supplies the pilot pressure corresponding to the operation amount to the hydraulic pilot units 30A and 30B of the control valve 30 through the pilot pipelines 39A and 39B. As a result, the control valve 30 is switched from the neutral position (c) shown in FIG. 5 to any of the switching positions (a) and (b).

The pilot valve 38 includes a pilot pressure sensor 38A that detects the pilot pressure P1. The pilot pressure sensor 38A is connected to the pilot line 39A and detects the pilot pressure P1 supplied to the pilot line 39A. The pilot pressure sensor 38A outputs the detected pilot pressure P1 to the controller 41.

The solenoid valve 40 is controlled by the controller 41, and the pilot pressure P1 can be adjusted. The solenoid valve 40 is provided in the middle of the pilot line 39A. The solenoid valve 40 adjusts the extension speed of the arm cylinder 5E according to the valve opening degree.

The solenoid valve 40 is always open. That is, the solenoid valve 40 is held at the communication position (d) shown in FIG. 2 when the current (decompression command) from the controller 41 is not supplied. Then, while the solenoid valve 40 is held at the communication position (d), the pilot pressure P1 is allowed to be supplied from the pilot valve 38 toward the hydraulic pilot portion 30A of the control valve 30. At this time, the control valve 30 is switched and controlled according to the pilot pressure P1.

Further, when the current from the controller 41 is supplied, the solenoid valve 40 is switched from the communication position (d) to the cutoff position (e). At this time, the valve opening degree of the solenoid valve 40 is set according to the current supplied from the controller 41. As a result, the solenoid valve 40 can adjust (reduce) the pilot pressure P1 supplied to the hydraulic pilot unit 30A of the control valve 30 according to the current supplied from the controller 41.

The controller 41 is composed of, for example, a microcomputer. The controller 41 includes two storage units 42 and 43. One storage unit 42 is composed of, for example, a read-only memory (ROM), and stores a program for correction start determination processing shown in FIG. 11 and a program for correction amount calculation processing shown in FIG. The other storage unit 43 is composed of, for example, a non-volatile memory, and stores a correction amount ΔP as a pilot decompression adjustment amount.

The controller 41 executes the programs of the correction start determination process and the correction amount calculation process stored in the storage unit 42. The controller 41 supplies the solenoid valve 40 with a current corresponding to the current command value I as a pilot depressurization command, and adjusts the valve opening degree of the solenoid valve 40. As a result, the controller 41 adjusts the pilot pressure P1 by using the solenoid valve 40. As shown in FIG. 6, the controller 41 includes a pilot decompression control unit 44 and a pilot decompression adjustment unit 45.

The pilot decompression control unit 44 calculates the pressure instruction value P2 for depressurizing the pilot pressure based on the load of the arm cylinder 5E serving as the hydraulic actuator and the operation amount of the operation device 11. The pilot decompression control unit 44 includes a cylinder thrust calculation unit 44A, an opening area calculation unit 44B, and a pressure instruction value calculation unit 44C.

The cylinder thrust calculation unit 44A calculates the cylinder thrust F of the arm cylinder 5E as the load of the arm cylinder 5E. The cylinder bottom pressure Pb detected by the cylinder bottom pressure sensor 34 and the cylinder rod pressure Pr detected by the cylinder rod pressure sensor 35 are input to the cylinder thrust calculation unit 44A. The cylinder thrust calculation unit 44A calculates the cylinder thrust F from the cylinder bottom pressure Pb and the cylinder rod pressure Pr based on the following equation of Equation 1. In the equation of Equation 1, Ab indicates the cylinder bottom pressure receiving area, and Ar indicates the cylinder rod pressure receiving area.

The opening area calculation unit 44B calculates the opening area S of the control valve 30 with reference to the characteristic map M1 shown in FIG. 7 based on the cylinder thrust F and the pilot pressure P1 as the operating amount of the operating device 11. .. When the pilot pressure P1 is low, the opening area S of the control valve 30 becomes small. When the pilot pressure P1 is high, the opening area S of the control valve 30 becomes large. When the cylinder thrust F is small, the opening area S of the control valve 30 is small. When the cylinder thrust F is large, the opening area S of the control valve 30 is large.

The pressure instruction value calculation unit 44C calculates the pressure instruction value P2 of the pilot pressure supplied to the hydraulic pilot unit 30A from the opening area S with reference to the characteristic map M2 shown in FIG. The pilot decompression control unit 44 calculates the pressure indicated value P2 of the pilot pressure for holding the cylinder thrust F. At this time, the pressure indicated value P2 is a value corresponding to the opening area S of the control valve 30. When the opening area S of the control valve 30 is small, the pressure indicated value P2 becomes small. When the opening area S of the control valve 30 is large, the pressure indicated value P2 becomes large. That is, the pressure indicated value P2 continuously increases as the opening area S increases.

The pilot decompression adjusting unit 45 adjusts the pressure indicated value P2 obtained by the pilot decompression control unit 44 based on the pilot pressure P1 as the operation amount of the operating device 11 and the discharge pressure Pm of the hydraulic pump 22. The correction amount ΔP of is obtained. The pilot decompression adjusting unit 45 determines that the arm cylinder 5E (hydraulic actuator) has started operation based on the operation amount of the operating device 11, and the arm cylinder 5E is moved to the terminal position based on the discharge pressure Pm of the hydraulic pump 22. Determine that it has been reached. The pilot decompression adjustment unit 45 measures the operation time T1 from the start of operation of the arm cylinder 5E to the arrival at the terminal position, and corrects the time difference ΔT between the operation time T1 and the predetermined reference time T0. Find the quantity ΔP.

The pilot decompression adjusting unit 45 includes an operating time measuring unit 45A for measuring the operating time from the start of operation of the arm cylinder 5E (flood actuator) to reaching the terminal position by the operation of the operating device 11, and the operating time T1. It includes a subtraction unit 45B for calculating the time difference ΔT from the reference time T0, and a correction amount calculation unit 45C for obtaining the correction amount ΔP based on the time difference ΔT.

The operating time measuring unit 45A measures the operating time T1 according to the operating speed (extension speed) of the arm cylinder 5E. At this time, when the operating device 11 is operated to the maximum from the state in which the working device 5 is in a predetermined initial posture, the operating time measuring unit 45A starts the operation of the arm cylinder 5E until it reaches the terminal position. Measure the operating time T1. Specifically, the operation time measuring unit 45A determines that the arm cylinder 5E has started operation based on the pilot pressure P1, and the arm cylinder 5E reaches the terminal position based on the discharge pressure Pm of the hydraulic pump 22. This is determined, and the operation time T1 from the start of operation of the arm cylinder 5E to the arrival at the terminal position by the operation of the operation device 11 is measured.

The subtraction unit 45B subtracts a predetermined reference time T0 from the operation time T1 to obtain the time difference ΔT (ΔT = T1-T0). At this time, the reference time T0 corresponds to the reference operating speed of the arm cylinder 5E. The reference time T0 is determined by the specifications of the working device 5. The reference time T0 is stored in advance in, for example, the storage unit 43. For example, when the specifications of the working device 5 are changed, the reference time T0 is updated to a different value.

The correction amount calculation unit 45C converts the time difference ΔT into pressure to obtain the correction amount ΔP of the pilot pressure. Specifically, the correction amount calculation unit 45C converts the time difference ΔT into the correction amount ΔP of the pilot pressure based on the characteristic map M3 shown in FIG.

When the time difference ΔT is a positive value, the operating time T1 is larger than the reference time T0, and the speed of the arm cylinder 5E is slow. In this case, the correction amount calculation unit 45C calculates the correction value ΔP that increases the pressure indicated value P2 so that the absolute value of the time difference ΔT becomes small.

On the other hand, when the time difference ΔT is a negative value, the operating time T1 is smaller than the reference time T0, and the speed of the arm cylinder 5E is high. In this case, the correction amount calculation unit 45C calculates the correction value ΔP for reducing the pressure instruction value P2 so that the absolute value of the time difference ΔT becomes small.

The controller 41 includes an addition unit 46 and a pressure / current conversion unit 47. The addition unit 46 adds the correction value ΔP output from the pilot decompression adjustment unit 45 to the pressure instruction value P2 output from the pilot decompression control unit 44 to calculate the pressure correction value P3 (P3 = P2 + ΔP). The pressure / current conversion unit 47 converts the pressure correction value P3 into the current command value I which is the pilot decompression command. Specifically, the pressure / current conversion unit 47 obtains the current command value I from the pressure correction value P3 based on the characteristic map M4 shown in FIG. At this time, when the pressure correction value P3 is large, the current command value I becomes small in order to increase the valve opening degree of the solenoid valve 40. When the pressure correction value P3 is small, the current command value I becomes large in order to reduce the valve opening degree of the solenoid valve 40.

For example, when the operation of the arm cylinder 5E (hydraulic actuator) is not restricted, the current command value I can be suppressed by setting the pressure correction value P3 high. In this case, the pilot pressure is not limited. On the other hand, when limiting the operation of the arm cylinder 5E, the current command value I increases by gradually setting the pressure correction value P3 low. In this case, the solenoid valve 40 for reducing the pilot pressure is driven, and the solenoid valve 40 operates in the direction of suppressing the pilot pressure P1. According to this characteristic, the arm cylinder 5E is operated without depressurizing to a certain lever region. As it approaches the full lever operation, the pilot pressure P1 is gradually reduced within a range that does not affect the operation of the arm cylinder 5E. As a result, fuel consumption can be reduced.

The controller 41 stores the correction amount ΔP calculated by the pilot decompression adjusting unit 45 in the storage unit 43. The controller 41 includes a selection switch 48 that selects either the pilot decompression adjustment unit 45 or the storage unit 43 and inputs the input to the addition unit 46. An external device 50 such as a computer can be connected to the controller 41. The controller 41 calculates the correction amount ΔP by the start trigger from the external device 50. In this case, the selection switch 48 connects the pilot decompression adjustment unit 45 to the addition unit 46. In other cases, the selection switch 48 connects the storage unit 43 to the addition unit 46. Therefore, in the normal use state, the controller 41 calculates the current command value I based on the correction amount ΔP stored in the storage unit 43.

Next, a case where the correction amount ΔP is calculated by the start trigger from the external device 50 will be described with reference to FIGS. 11 and 12.

The work situation for executing the calculation process of the pilot pressure correction amount ΔP is assumed to be, for example, immediately after the machine is assembled. The operator accesses the controller 41 mounted on the hydraulic excavator 1 from the external device 50, and starts work preparation for executing the calculation process of the correction amount ΔP. For example, if there is a service tool (external device 50) that is normally used for tests performed after machine assembly, add a front speed correction menu to that tool and press the start button from the external device 50. Then, the correction is executed.

FIG. 11 shows a flowchart of the correction start determination process. The operator accesses the controller 41 from the external device 50 by, for example, serial communication or CAN communication, and the processing of the pilot decompression adjustment unit 45 is activated.

In step S1, it is determined whether or not the start trigger by the external device 50 is valid. The start trigger is, for example, pressing information of the start button received from the external device 50. When the monitor device 10 starts the calculation of the correction amount ΔP by operating the touch panel, the start trigger is the operation information of the display device of the monitor device 10. If the start trigger is valid, it is determined as "YES" in step S1 and the process proceeds to step S2.

In step S2, it is determined whether or not there is an abnormality in the machine. For example, if various sensors (discharge pressure sensor 33, pilot pressure sensor 38A, cylinder bottom pressure sensor 34, cylinder rod pressure sensor 35) are disconnected or short-circuited, or if there is a serious abnormality in the machine itself, It may not be possible to accurately measure the front speed (the speed of the arm cylinder 5E). Therefore, it is one of the conditions for starting the calculation of the correction amount ΔP that there is no failure in the machine. When there is no abnormality in the machine, it is determined as "YES" in step S2, and the process proceeds to step S3.

In step S3, it is determined whether or not the engine speed is equal to or higher than the specified value. It is desirable to measure the front speed when the engine output is high. Therefore, it is necessary to determine whether or not the engine speed is set to high idle. Therefore, the specified value of the engine speed sets, for example, the speed required for the vehicle body to output a high output (high idle speed). When the engine speed is equal to or higher than the specified value, it is determined as "YES" in step S3, and the process proceeds to step S4.

In step S4, it is determined whether or not the hydraulic oil temperature is within the range of the specified value. If the hydraulic oil temperature is excessively low or high, the viscosity of the hydraulic oil may affect the pressure characteristics, and control that limits the vehicle body output may work from the viewpoint of preventing low and high temperatures. There is sex. Therefore, in step S4, the temperature condition of the hydraulic oil temperature is determined. When the hydraulic oil temperature is within the specified value range, it is determined as "YES" in step S4, and the process proceeds to step S5.

In step S5, it is determined whether or not the working device 5 is in the initial posture. When the front speed adjustment target is the arm 5B, the initial posture is the posture of the arm dump end. For example, when the adjustment target of the front speed is the boom 5A, the initial posture is the posture of the boom lowering end. When the front speed adjustment target is the bucket 5C, it is the posture of the bucket dump end. Step S5 is performed, for example, by visual confirmation by an operator. If an angle sensor is attached to each of the cylinders 5D to 5F, the posture of the working device 5 can be automatically determined by the controller 41. When the working device 5 is in the initial posture, it is determined as "YES" in step S5, and the process proceeds to step S6.

In step S6, in order to measure the front speed at the highest speed, it is determined whether or not the operation amount of the operation device 11 is the maximum (full lever operation). Whether or not the operation is full lever is determined by, for example, whether or not the pilot pressure P1 from the operating device 11 is equal to or higher than the specified value. For example, if the front speed adjustment target is the arm 5B, the operation amount of the operation device 11 for the arm 5B is determined. If the front speed adjustment target is the boom 5A, the operation amount of the operation device 11 for the boom 5A is determined. If the front speed adjustment target is the bucket 5C, the operation amount of the operation device 11 for the bucket 5C is determined. When the operation amount of the operation device 11 is maximum, it is determined as "YES" in step S6, and the process proceeds to step S7.

In this way, when the conditions are satisfied in all of steps S1 to S6, that is, when it is determined as "YES" in all of steps S1 to S6, the adjustment start flag F1 of the correction amount ΔP is enabled in step S7. .. On the other hand, if the condition is not satisfied in any of steps S1 to S6, that is, if "NO" is determined in any of steps S1 to S6, the adjustment start flag F1 of the correction amount ΔP is invalidated in step S8. do.

Next, the content of the correction amount calculation process executed by the pilot decompression adjustment unit 45 will be described with reference to FIG. FIG. 12 shows a flowchart of the correction amount calculation process.

In step S11, the adjustment start flag F1 is determined. If the adjustment start flag F1 is valid, it is determined as "YES" in step S11, and the process proceeds to step S12. In step S12, since the conditions for the correction amount calculation process are satisfied, the operation of the arm cylinder 5E is started. Therefore, the measurement of the operating time T1 of the arm cylinder 5E is started.

In the following step S13, it is determined whether or not the discharge pressure Pm of the hydraulic pump 22 is equal to or higher than the specified value Pm0. When the arm cylinder 5E reaches the terminal position after starting the operation, a high load acts on the arm cylinder 5E and the discharge pressure Pm of the hydraulic pump 22 increases. Therefore, when the discharge pressure Pm of the hydraulic pump 22 becomes the specified value Pm0 or more, it can be determined that the arm cylinder 5E has reached the end position. When the arm cylinder 5E reaches the terminal position which is the maximum extension position, the discharge pressure Pm of the hydraulic pump 22 increases and the relief valve 32 opens. Therefore, the specified value Pm0 is set to a value near the relief pressure of the relief valve 32, for example. When the discharge pressure Pm of the hydraulic pump 22 is less than the specified value Pm0 (Pm <Pm0), the arm cylinder 5E has not reached the terminal position, so the process proceeds to step S14. When the discharge pressure Pm of the hydraulic pump 22 is the specified value Pm0 or more (Pm ≧ Pm0), the process proceeds to step S15.

In step S14, it is determined whether or not the operating time T1 has passed the maximum measurement time Tmax (T1> Tmax). At this time, the maximum measurement time Tmax is set to the maximum time that can be allowed as the operation time T1. For example, when the operating amount of the operating device 11 is reduced during the measurement of the operating time T1, the behavior of the discharge pressure Pm of the hydraulic pump 22 changes. In this case, it becomes impossible to determine the end of measurement of the operation time T1 in step S13. Therefore, when the operation time T1 is longer than the maximum measurement time Tmax (T1> Tmax), it is determined as "YES" in step S13, and the correction amount calculation process is terminated. When the operation time T1 is shorter than the maximum measurement time Tmax (T1 ≦ Tmax), it is determined as “NO” in step S14, and the process returns to step S13.

In step S15, since the arm cylinder 5E has reached the terminal position, the measurement of the operating time T1 is stopped. In this case, the operating time T1 is the time taken when the arm cylinder 5E is moved from the initial position to the terminal position. Therefore, the operating time T1 corresponds to the front speed which is a performance index. The initial position is a position corresponding to the initial posture of the work device 5.

In the following step S16, it is determined whether or not the operation time T1 and the reference time T0 match (T1 = T0). When the operation time T1 and the reference time T0 match (T1 = T0), it is determined as "YES" in step S16. In this case, since it is not necessary to calculate the correction amount ΔP, the process ends as it is. If the operation time T1 and the reference time T0 do not match and there is a difference between them (T1 ≠ T0), it is determined as "NO" in step S16, and the process proceeds to step S17.

In step S17, the correction amount ΔP is calculated. Specifically, with reference to the characteristic map M3 shown in FIG. 9, as a pilot decompression adjustment amount, a correction amount ΔP capable of absorbing the time difference ΔT (ΔT = T1-T0) between the operating time T1 and the reference time T0 is used. calculate. Specifically, when the speed of the arm cylinder 5E is slow and the time difference ΔT becomes a positive value, the correction amount calculation unit 45C calculates a correction value ΔP that increases the pressure indicated value P2. When the speed of the arm cylinder 5E is high and the time difference ΔT becomes a negative value, the correction amount calculation unit 45C calculates the correction value ΔP for reducing the pressure instruction value P2. At this time, the operating time T1 and the time difference ΔT are included in the adjustment result. The operating time T1 and the T time difference ΔT are displayed on the monitoring device 10. The operating time T1 and the time difference ΔT may be notified to the operator through the external device 50.

Thus, according to the present embodiment, the controller 41 calculates the pressure indicated value P2 for reducing the pilot pressure based on the load of the arm cylinder 5E (hydraulic actuator) and the operation amount of the operating device 11. Pilot decompression adjustment unit 45 that obtains a correction amount ΔP for adjusting the pressure indicated value P2 obtained by the pilot decompression control unit 44 based on the operation amount of the control unit 44, the operation amount of the operation device 11, and the discharge pressure Pm of the hydraulic pump 22. And have.

Further, the pilot decompression adjusting unit 45 determines that the arm cylinder 5E (hydraulic actuator) has started operation based on the operation amount of the operating device 11, and the arm cylinder 5E is terminated based on the discharge pressure Pm of the hydraulic pump 22. It is determined that the position has been reached, the operation time T1 from the start of operation of the arm cylinder 5E to the end position is measured, and the time difference ΔT between the operation time T1 and the predetermined reference time T0 is reduced. The correction amount ΔP to be made is obtained.

At this time, the pilot decompression adjustment unit 45 includes an operation time measurement unit 45A for measuring the operation time T1 from the start of operation of the arm cylinder 5E (flood control actuator) to the arrival at the terminal position by the operation of the operation device 11. The subtraction unit 45B for obtaining the time difference ΔT by subtracting the reference time T0 from the operation time T1 and the correction amount calculation unit 45C for obtaining the correction amount ΔP based on the time difference ΔT are provided.

For example, when the time difference ΔT is a positive value, the operating time T1 is larger than the reference time T0, and the speed of the arm cylinder 5E is slow. In this case, the pilot decompression adjusting unit 45 calculates the correction value ΔP for increasing the pressure indicated value P2 so that the absolute value of the time difference ΔT becomes small. As a result, the pilot pressure supplied to the hydraulic pilot portion 30A of the control valve 30 tends to increase, so that the opening area S of the control valve 30 tends to increase, and the speed of the arm cylinder 5E increases.

On the other hand, when the time difference ΔT is a negative value, the operating time T1 is smaller than the reference time T0, and the speed of the arm cylinder 5E is high. In this case, the pilot decompression adjusting unit 45 calculates the correction value ΔP for reducing the pressure indicated value P2 so that the absolute value of the time difference ΔT becomes small. As a result, the pilot pressure supplied to the hydraulic pilot portion 30A of the control valve 30 tends to decrease, so that the opening area S of the control valve 30 tends to decrease, and the speed of the arm cylinder 5E decreases.

Therefore, the speed of the arm cylinder 5E can be adjusted only by detecting the operation amount of the operating device 11 and the discharge pressure Pm of the hydraulic pump 22. Further, the required adjustment amount can be obtained only by operating the arm cylinder 5E for a short time. Therefore, the speed of the arm cylinder 5E can be adjusted by a short-time adjustment work. As a result, the calibration man-hours immediately after assembly can be reduced, and the working time can be shortened.

Further, the speed can be adjusted for each hydraulic actuator such as the boom cylinder 5D, the arm cylinder 5E, and the bucket cylinder 5F. Therefore, as compared with the case of adjusting the discharge pressure Pm of the hydraulic pump 22, the operating speeds of the plurality of hydraulic actuators provided in the working device 5 can be adjusted to a desired balance.

Further, the hydraulic excavator 1 includes a storage unit 43 that stores a correction amount ΔP obtained by the pilot decompression adjustment unit 45. In addition to this, the controller 41 controls the solenoid valve 40 based on the pressure indicated value P2 calculated by the pilot decompression control unit 44 and the correction amount ΔP stored in the storage unit 43. Therefore, after the correction amount ΔP is obtained by the pilot decompression adjustment unit 45, the speed of the arm cylinder 5E, which is a hydraulic actuator, can be adjusted to a desired value based on the correction amount ΔP stored in the storage unit 43. can.

Further, when the reference time T0 is changed, the pilot decompression adjustment unit 45 obtains the correction amount ΔP by using the changed reference time T0. At this time, the reference time T0 corresponds to the reference operating speed of the arm cylinder 5E. For example, when the use of the arm cylinder 5E is changed by replacing the arm cylinder 5E, the reference time T0 is also changed. In this case, the operator operates the pilot decompression adjusting unit 45 by operating the external device 50 to obtain the correction amount ΔP. Thereby, the speed of the arm cylinder 5E can be adjusted according to the replaced arm cylinder 5E.

Further, the hydraulic excavator 1 includes a monitoring device 10 connected to the controller 41. In addition to this, the controller 41 operates the pilot decompression adjustment unit 45 based on the start trigger from the external device 50, and causes the monitor device 10 to display the adjustment result. The adjustment result includes, for example, an operating time T1 corresponding to the speed of the hydraulic actuator (arm cylinder 5E) and a corrected time difference ΔT. By visually observing the monitoring device 10, the operator can grasp that the speed adjustment of the arm cylinder 5E has been completed.

In the above-described embodiment, a case where the correction amount calculation process is executed by operating the external device 50 has been described as an example. The present invention is not limited to this, and the correction amount calculation process may be executed by operating, for example, the monitor device 10 mounted in advance on the hydraulic excavator 1 instead of the external device 50.

In the above-described embodiment, the case where the controller 41 adjusts the extension speed of the arm cylinder 5E has been described as an example. The present invention is not limited to this, and the controller 41 may adjust the reduction speed of the arm cylinder 5E. In this case, a solenoid valve (not shown) is provided in the pilot line 39B, and the controller 41 adjusts the reduction speed of the arm cylinder 5E by controlling the solenoid valve. The controller may also adjust the speed of the boom cylinder or the speed of the bucket cylinder.

In the above-described embodiment, the crawler type hydraulic excavator 1 has been described as an example of the construction machine. The present invention is not limited to this, and any construction machine provided with a hydraulic actuator driven by a hydraulic pump may be used. Therefore, the present invention may be applied to, for example, a hybrid type hydraulic excavator in which a hydraulic pump is driven by an engine and an electric motor, or may be applied to an electric hydraulic excavator in which a hydraulic pump is driven by an electric motor, and the wheel loader. It may be applied to various construction machines such as.

1 Hydraulic excavator (construction machinery)
5D boom cylinder (hydraulic actuator)
5E arm cylinder (hydraulic actuator)
5F bucket cylinder (hydraulic actuator)
10 Monitor device 11 Operating device 22 Hydraulic pump 30 Control valve 40 Solenoid valve 41 Controller 42, 43 Storage unit 44 Pilot decompression control unit 45 Pilot decompression adjustment unit 45A Operating time measurement unit 45B Subtraction unit 45C Correction amount calculation unit

Claims (5)

With a hydraulic pump
A hydraulic actuator operated by the pressure oil discharged from the hydraulic pump and
A control valve that supplies pressure oil to the hydraulic actuator according to the pilot pressure of the operating device,
In a construction machine equipped with a solenoid valve controlled by a controller and capable of adjusting the pilot pressure.
The controller
A pilot decompression control unit that calculates a pressure instruction value for depressurizing the pilot pressure based on the load of the hydraulic actuator and the operation amount of the operating device.
A pilot decompression adjusting unit for adjusting a correction amount for adjusting the pressure indicated value obtained by the pilot decompression control unit based on the operating amount of the operating device and the discharge pressure of the hydraulic pump is provided.
The pilot decompression adjusting unit determines that the hydraulic actuator has started operation based on the operation amount of the operating device, and determines that the hydraulic actuator has reached the terminal position based on the discharge pressure of the hydraulic pump. Then, the operation time from the start of the operation of the hydraulic actuator to the arrival at the end position is measured, and the correction amount for reducing the time difference between the operation time and the predetermined reference time is obtained. Construction machinery. In the construction machine according to claim 1,
The pilot decompression adjustment unit includes an operation time measuring unit that measures the operation time from the start of operation of the hydraulic actuator to the arrival at the end position by the operation of the operation device, and the reference time from the operation time. A construction machine comprising: a subtraction unit for obtaining the time difference by subtracting the above time difference, and a correction amount calculation unit for obtaining the correction amount based on the time difference. In the construction machine according to claim 1,
A storage unit for storing the correction amount obtained by the pilot decompression adjustment unit is provided.
The controller is a construction machine that controls the solenoid valve based on a pressure instruction value calculated by the pilot decompression control unit and the correction amount stored in the storage unit. In the construction machine according to claim 1,
The pilot decompression adjusting unit is a construction machine characterized in that when the reference time is changed, the correction amount is obtained by using the changed reference time. In the construction machine according to claim 1,
A monitoring device connected to the controller is provided.
The controller is a construction machine characterized in that the pilot decompression adjustment unit is operated based on a start trigger from an external device, and the adjustment result is displayed on the monitor device.

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