JP2008163594A - Control device of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To positively suppress the progress of damage to a hydraulic cylinder during operations. <P>SOLUTION: The extended amount of the hydraulic cylinder is detected from the operation amounts of operation amount detection means 36-38. The end of the stroke of the hydraulic cylinder is detected by angle detection means 33-35 and pressure detection means 30-32. The degree of fatigue and the degree of damage of the cylinder are estimated from the detected data by the damage treatment means 48 of a controller 42, and the occurrence of cavitation is detected according to the pressure signals. Based on the results above, to suppress the progress of the damage to the cylinder, the operation amount of the hydraulic cylinder against the operation amount of a remote control valve is limited to limit the discharged amount of a hydraulic pump. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for a construction machine, such as a hydraulic excavator or a crane, in which a hydraulic system undergoes damage such as fatigue or damage during work.

  Conventionally, as a maintenance management technique for preventing the occurrence of failures in construction machinery, the engine speed and other operating conditions are detected and recorded as described in Patent Document 1 and managed as necessary. A technique for displaying or warning on the side (hereinafter, known technique 1) is known.

Further, as shown in Patent Document 2, in a system in which a hydraulic pump is driven by an engine, in order to prevent engine stall due to a heavy load, the hydraulic oil temperature is detected and the absorption torque of the hydraulic pump is determined. A technique for torque control (hereinafter referred to as known technique 2) is also known.
JP 2005-149310 A JP-A-4-325784

  In a hydraulic construction machine such as a hydraulic excavator, various types of hydraulic equipment are subject to various damages during work. For example, a hydraulic cylinder wears and wears due to sliding resistance associated with its expansion and contraction operation. Further, when the hydraulic cylinder is stroked, the piston and head cover or rod cover collide with each other and are damaged.

  Furthermore, when cavitation occurs in the circuit, not only the hydraulic cylinder but also the inside of the hydraulic actuator and the inner surface of the pipe are deteriorated and damaged. Then, the accumulation of such damage causes a failure of the hydraulic actuator or the like and shortens their life.

  However, conventionally, since the detected operating status is recorded as disclosed in the publicly known technology 1 and only displayed or warned as necessary, even if this technology is diverted as the above damage management technology, While damage progresses, it is not very effective in preventing failure and improving life.

  Further, the known technique 2 is a technique that only prevents an engine stall due to an increase in load and avoids interruption of work, and does not function as long as the load is normal. .

  Accordingly, the present invention provides a construction machine control device that can positively suppress the progress of damage to a hydraulic system.

  According to the first aspect of the present invention, there are provided a plurality of hydraulic actuators, a hydraulic pump as a hydraulic source for each hydraulic actuator, operation means for issuing an operation command for each hydraulic actuator, and oil for each hydraulic actuator in accordance with the operation of the operation means. An actuator control valve for controlling the supply and discharge of the fuel, and a control means. The control means detects a factor causing damage to the hydraulic system including the hydraulic actuator during the operation of the hydraulic actuator, and based on the detection result It is configured to perform damage suppression control that suppresses the progress of damage.

  According to a second aspect of the present invention, in the configuration of the first aspect, the control means detects the amount of operation of the hydraulic cylinder, estimates the degree of fatigue of the cylinder as damage from the detected amount of cylinder operation, and estimates this It is configured to perform damage suppression control based on the degree of fatigue.

  According to a third aspect of the present invention, in the configuration of the second aspect, the control means is configured to detect an operation amount of the operation means for the hydraulic cylinder and to estimate a fatigue level of the cylinder from the operation amount. is there.

  According to a fourth aspect of the present invention, in the configuration of the first to third aspects, the control means detects that the hydraulic cylinder has ended the stroke, and estimates the damage degree of the cylinder as damage from the detection result. This is configured to perform damage suppression control based on the degree of damage.

  According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the hydraulic cylinder includes a boom cylinder that drives the boom, an arm cylinder that drives the arm, and a bucket cylinder that drives the bucket, and the control means includes the boom, the arm, and the bucket. The end of the cylinder is detected from the angle, the cylinder pressure, and the cylinder operating speed.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the control means detects that cavitation has occurred in the hydraulic circuit as a damage factor, and performs damage suppression control based on the number of occurrences of the cavitation. Is configured to do.

  According to a seventh aspect of the invention, in the configuration of the sixth aspect, the control means is configured to detect the occurrence of cavitation based on the circuit pressure.

  The invention according to an eighth aspect is the structure according to any one of the first to seventh aspects, wherein the control means is configured to increase the degree of damage suppression control in accordance with an increase in damage.

  A ninth aspect of the present invention is the configuration according to any one of the first to eighth aspects, wherein the control means is configured to limit the operation amount of the hydraulic actuator relative to the operation amount of the operation means as damage suppression control. .

  In a tenth aspect of the present invention, in any one of the first to ninth aspects, the control means is configured to limit the discharge amount of the hydraulic pump as the damage suppression control.

  According to an eleventh aspect of the present invention, in the configuration of the tenth aspect, an engine is provided as a power source for driving the hydraulic pump, and the control means is configured to reduce a load torque of the engine accompanying a limitation on the maximum discharge amount of the hydraulic pump. The control is configured to increase the degree of fluctuation of the engine speed relative to the fluctuation of the engine load torque.

  According to the present invention, a factor causing damage to a hydraulic system including a hydraulic actuator (claims 2 and 3 is an operation amount causing wear fatigue of the hydraulic cylinder, claims 4 and 5 are stroke ends damaging the hydraulic cylinder, claims) 6 and 7 detect the occurrence of circuit cavitation).

  And based on this detection result, damage suppression control that suppresses the progress of damage (Claim 9 controls the operation amount of the hydraulic actuator relative to the operation amount of the operating means, and Claim 10 limits the discharge amount of the hydraulic pump) Control).

  In this case, the invention according to claims 2 and 3 estimates the degree of fatigue of the hydraulic cylinder, and the inventions according to claims 4 and 5 estimate the degree of damage due to the stroke end of the hydraulic cylinder from the detected data. Damage control. On the other hand, in the inventions of claims 6 and 7, damage suppression control is performed based on the number of occurrences of cavitation.

  This damage suppression control can positively suppress the progress of damage. For this reason, the hydraulic actuator or the like can be normally operated until the next maintenance time to avoid the suspension of work, and the life of the hydraulic actuator or the like can be improved.

  According to the second and third aspects of the present invention, when the fatigue level of the hydraulic cylinder is estimated, the amount by which the hydraulic cylinder is actually expanded and contracted is detected. For example, the accuracy of estimating the degree of fatigue is higher than when detecting the operating time of the machine.

  According to the invention of claim 5, as a technique for detecting that the boom cylinder, the arm cylinder, and the bucket cylinder have ended the stroke in the hydraulic excavator (the collision of the piston and the head cover or the rod cover), the boom, arm, and bucket Since the speed is detected in addition to the angle and pressure, it is clearly distinguished from the state where the cylinder has just reached the end of the stroke or the high pressure has been raised at the end of the stroke. Can be detected.

  According to the eighth aspect of the invention, the degree of damage suppression control is increased in accordance with an increase in damage (cylinder fatigue / damage, number of occurrences of cavitation). For example, if the damage reaches a preset level, the rest is constant. Compared with the case where the suppression control is performed, the effect of suppressing the progress of damage is high.

  By the way, according to the invention of claim 10, as the damage suppression control, the discharge amount of the hydraulic pump is limited, so that the engine load torque (absorption torque of the hydraulic pump) becomes small. Accordingly, the range of fluctuations in engine speed with respect to fluctuations in load torque is reduced, and changes in engine sound are also reduced. For this reason, it is difficult for an operator to take an operation method peculiar to a construction machine in which a load state is grasped from an engine sound and fed back to the operation.

  In this respect, according to the eleventh aspect of the invention, since the control for increasing the degree of fluctuation of the engine speed with respect to the fluctuation of the load torque is performed in accordance with the reduction of the engine load torque accompanying the limitation of the pump discharge amount, Even if the fluctuation range of the torque is small, the fluctuation range of the engine speed is almost the same as that before the suppression control. For this reason, it is possible to ensure certain operability while performing suppression control.

  In the embodiment, a hydraulic excavator is taken as an example of an application target.

  In the hydraulic excavator, as schematically shown in FIG. 1, an upper swing body 2 is mounted on a crawler type lower traveling body 1 so as to be rotatable about a vertical axis, and a work attachment 3 is mounted on the upper swing body 2. Configured.

  The work attachment 3 includes a boom 4, an arm 5 attached to the tip of the boom 4, and a bucket 6 attached to the tip of the arm 5. Work is done.

  The hydraulic excavator includes, as hydraulic actuators, a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 (all of which are hydraulic cylinders) that drive the boom 4, arm 5, and bucket 6 of the work attachment 3. Left and right traveling motors 10 and 11 that drive the left and right crawlers) and a swing motor 12 that drives the upper swing body 2 to rotate (both are hydraulic motors) are provided.

  Further, as other hydraulic equipment, first and second hydraulic pumps 14 and 15 for supplying oil to each of the hydraulic actuators 7 to 12 using the engine 13 as a power source, and oil supply / discharge (operation direction and speed for each actuator). ) For controlling the hydraulic pilots, and remote control valves 22 to 27 as operation means for issuing operation commands to the actuators 7 to 12, and pilots from the remote control valves 22 to 27 are provided. The actuator control valves 16 to 21 are operated by the pressure, and the operations of the hydraulic actuators 7 to 12 are controlled.

  Here, the hydraulic actuators 7 to 12 and the actuator control valves 16 to 21 are arranged in the first group G1 on the left side in FIG. 1 using the first hydraulic pump 14 as a hydraulic source and on the right side in the figure using the second hydraulic pump 15 as a hydraulic source. The case where it divided into the 2nd group G2 is illustrated.

  In FIG. 1, 28 and 29 are main relief valves of both groups G1 and G2. In addition, although the individual relief valve is provided for every hydraulic actuator circuit, in order to avoid complication of drawing, the display of a code | symbol is abbreviate | omitted.

  In addition, the actuator control valves 16 to 21 and the remote control valves 22 to 27 are hereinafter referred to as boom control valves, boom remote control valves, and the like with the names of the respective control targets.

  In this embodiment, as means for detecting the operating state of each part, as shown in FIGS. 1 and 2, pressure detection for detecting the pressure on the head side and the rod side of each cylinder 7, 8, 9 of the boom, arm, and bucket. Means (common reference numerals 30, 31, and 32 are attached to each cylinder without distinguishing between the head side and the rod side), and angle detection means 33, 34, which detect the angles of the boom 4, the arm 5, and the bucket 6. 35 and operation amount detection means 36, 37, 38 for detecting the operation amounts of the remote control valves 22, 23, 24 for boom, arm, and bucket.

  There are also pump pressure detecting means 39 for detecting the discharge pressure (pump pressure) of both hydraulic pumps 14 and 15, and engine torque detecting means 40 for detecting the engine torque in order to obtain the load torque (pump absorption torque) of the engine 13. A detection signal from each of these detection means and a signal from the engine key switch 41 shown in FIG.

  Furthermore, as equipment for performing various controls in response to signals from the controller 42, pump capacity control means (so-called regulator) 43 for controlling pump capacity (= pump discharge amount), boom, arm, and bucket Boom, arm, and bucket control valve control means (pressure control valves) 44, 45, and 46 for limiting the pilot pressure sent from the remote control valves 22 to 24 to the control valves 16, 17, and 18 and the engine An engine speed control means 47 (shown only in FIG. 2) for controlling the speed is provided.

  An internal configuration of the controller 42 is shown in FIG.

  The controller 42 includes a damage processing means 48, a setting means 49, an engine load torque calculating means 50, a recording means 51, and a recording result display means 52.

  The damage processing means 48 includes a cylinder fatigue level / damage level estimation unit 53 that estimates the fatigue level and damage level of each cylinder 7, 8, 9 of the boom, arm, and bucket, and cavitation generation that calculates the number of cavitations generated in each cylinder circuit. It consists of a number calculation unit 54.

  The processing contents in the cylinder fatigue / damage estimation unit 53 and the cavitation occurrence number calculation unit 54 are as follows.

Cylinder fatigue level The fatigue level of each of the cylinders 7, 8, and 9 is considered to be an accumulation of sliding resistance generated during expansion and contraction. And this sliding resistance is proportional to these expansion / contraction operation amounts, and the expansion / contraction operation amount corresponds to the remote control valve operation amount.

  Therefore, the cylinder fatigue level / damage level estimation unit 53 calculates the fatigue level based on the operation amount input from the operation amount detection means 36, 37, 38 each time the corresponding remote control valve 22, 23, 24 is operated. Estimate and update the accumulated value.

Cylinder damage degree Each cylinder 7, 8, and 9 is damaged by a stroke end, that is, when a piston and a head cover or a rod cover collide with each other.

  The stroke end means that the boom angle, arm angle, bucket angle detected by each angle detecting means 33, 34, 35, each cylinder pressure detected by each cylinder pressure detecting means 30, 31, 32, It can be determined by the cylinder speed obtained by differential processing of the angle change.

That is, the degree of cylinder damage is
It can be calculated by the factor x cylinder pressure x cylinder speed.

  The reason why the speed is used here is to exclude the cylinder from the definition of the stroke end because the cylinder is not damaged even at a high pressure when stopped at the stroke end. Since the cylinder speed is determined by the cylinder flow rate, and the cylinder flow rate is proportional to the pressure, the degree of cylinder damage may be obtained by a coefficient × (square of cylinder pressure).

Cavitation When cavitation occurs in the cylinder circuit, the inside of the cylinder and the inner surface of the piping are deteriorated and damaged. The occurrence of cavitation can be detected when the circuit pressure becomes 0, in the vicinity thereof, or becomes negative.

  Therefore, the cavitation occurrence frequency calculation unit 54 detects the occurrence of cavitation from the pressure detected by each cylinder pressure detection means 30, 31, 32, and calculates the number of times this cavitation has occurred.

  On the other hand, the setting means 49 includes a pump capacity limit value setting unit 55, a boom control valve operation limit value setting unit 56, an arm control valve operation limit value setting unit 57, a bucket control valve operation limit value setting unit 58, an engine rotation. A number limit value setting unit 59 is provided.

  The pump capacity limit value setting unit 55 is controlled by the pump capacity control means 43 in order to suppress the progress of damage according to the increase in the cylinder fatigue degree / damage degree and the number of cavitation occurrences estimated or calculated by the damage processing means 48. Control is performed to limit the maximum pump displacement to be controlled, that is, the maximum pump discharge amount.

  The other control valve operation limit value setting units 56 to 58 for the boom are operated as pilot pressures (= operations of the remote control valves 22 to 24) controlled by the control valve control means 44 to 46 as damage suppression control of the cylinders 7 to 9. The operation amount of each control valve 16 to 18 is controlled.

  By limiting the maximum pump discharge amount and control valve operation amount, the operating speed of each cylinder 7-9 can be limited to prevent these rapid operations, and the progression of damage to the cylinders 7-9 and circuit piping can be suppressed. it can.

  When the pump discharge amount is limited as described above, the load torque of the engine 13 (the absorption torque of the hydraulic pump) is reduced. Accordingly, the range of fluctuations in engine speed with respect to fluctuations in load torque is reduced, and changes in engine sound are also reduced. For this reason, it is difficult for an operator to take an operation method peculiar to a construction machine in which a load state is grasped from an engine sound and fed back to the operation.

  Therefore, the engine load torque calculating means 50, the engine speed limit value setting unit 59, and the engine speed control means 47 solve such problems.

  The engine load torque calculation means 50 calculates the load torque absorbed by the hydraulic pumps 14 and 15 from the engine torque detected by the engine torque detection means 40 and sends it to the engine speed limit value setting unit 59 of the setting means 49.

  The engine speed limit value setting unit 59 increases the degree of fluctuation of the engine speed with respect to the load torque according to the decrease in pump discharge amount (pump capacity set by the pump capacity limit value setting unit 55). An engine speed limit value is set to the engine speed control unit 47, and the engine speed control means 47 performs engine speed control based on the set value.

  With this control, even if the actual fluctuation range of the load torque is small, the fluctuation range of the engine speed is almost the same as that before the suppression control. For this reason, it is possible to ensure certain operability while performing suppression control.

  The recording unit 51 stores the data detected by each detection unit, the engine load torque obtained by the engine load torque calculation unit 50, the cylinder fatigue / damage degree obtained by the damage processing unit 48, and the number of cavitations. The recorded result is displayed for the operator or manager by the recorded result display means 52 (including notification by radio or the like).

  This display may be performed constantly, or may be performed based on an operation (switch operation or the like) that prompts the display.

  The above processing contents are summarized as shown in FIGS.

  In FIG. 3, along with the start of control, maintenance information for the cylinders 7 to 9 obtained so far is acquired in step S1, and it is determined whether or not maintenance has been performed in step S2.

  If YES (maintenance completed), the cylinder fatigue level and the cylinder damage level in the recording means 51 are initialized (set to no fatigue and no damage level) in steps S3 and S4, and then the process proceeds to step S5.

  If NO (no maintenance), the process proceeds directly to step S5, where the previous cylinder fatigue level is acquired from the recording means 51 as the cylinder fatigue level one cycle before.

In step S6, the current cylinder fatigue level (cumulative value) is
(Cylinder fatigue before one cycle) + (Coefficient 1) x (Cylinder operating amount)
Calculate (estimate) as

In the following step S7, it is determined whether or not the cylinder has ended the stroke based on the data. If YES, the current cylinder damage level (cumulative value) is determined in step S8.
(Cylinder damage before one cycle) + (Coefficient 2) x (Cylinder pressure x Speed)
Calculate (estimate) as

  In step S9, the current cylinder fatigue level and damage level are recorded in the recording means 51, and in steps S10 and S11, the cylinder fatigue level and cylinder damage level are updated. Thereafter, the process proceeds to step S12 in FIG.

  In step S12, information on the number of cavitations so far is acquired, and in step S13, it is determined whether the hydraulic oil filter has been replaced (whether the cause of cavitation has been removed).

  If YES, the cavitation number information is initialized (set without cavitation) in step S14, and the process proceeds to step S15. If NO, the process proceeds directly to step S15.

  In step S15, the previous number of cavitations is acquired from the recording means as the number of cavitations one cycle before. In subsequent step S16, it is determined whether or not cavitation has occurred based on the pressure signal.

If YES, the current number of cavitations (cumulative value) is
Number of cavitations before one cycle + 1
In the case of NO, the process proceeds directly to step S18, where the current number of cavitations is recorded and the number of cavitations is updated in step S19.

  In step S20, a cylinder flow rate limit value corresponding to the degree of cylinder fatigue / damage is set.

  In step S21, a limit value of the pump discharge amount is set according to the cumulative value of the degree of cylinder fatigue / damage and the number of cavitation occurrences.

  This restricts the control valve operation amount and the pump discharge amount as described above, and suppresses the progress of damage to the cylinders 7 to 9 and the circuit piping.

  In this case, the degree of damage suppression control increases as the damage (cylinder fatigue level / damage level, number of cavitation occurrences) increases. For example, if the damage reaches a certain threshold value, the certain degree of suppression control is performed thereafter. Compared to the case, the effect of suppressing the progress of damage is high.

  Thereafter, it is determined whether or not the process is ended based on a signal from the engine key switch 41 in FIG. 2. If YES, the process ends, and if NO, the process returns to step S6 in FIG. 3 to continue the process. .

  FIG. 5 shows a flow for controlling the engine speed in accordance with a decrease in engine load torque due to the pump discharge amount limitation.

  After starting the control, the pump capacity limit value is obtained in step S31, and the load torque calculation value is obtained in step S32. Then, the engine speed control based on these values is performed in step S33.

  That is, as described above, the engine speed is controlled so as to increase the degree of fluctuation of the engine speed (target speed) with respect to the fluctuation of the load torque as the load torque decreases.

  Thereafter, it is determined whether or not the process is ended based on a signal from the engine key switch 41. If YES, the process ends. If NO, the process returns to step S31.

  This engine speed control may be started by operating a specific switch, for example, or automatically when the limit value set in steps S20 and S21 in FIG. 4 reaches a preset value. It may be started.

  By the way, in the said embodiment, as demonstrated with the flowchart of FIG.3, 4, cylinder fatigue degree and damage degree progress by every operation | work, and whenever the frequency | count of cavitation increases, restriction | limiting of the pump discharge amount for damage suppression, etc. However, it is also possible to adopt a configuration in which the damage suppression control is performed when the degree of fatigue exceeds a preset threshold value. In this case, the threshold value may be set to a plurality of levels, and the degree of restriction may be increased as the level increases.

  In addition, fatigue and damage occur not only in hydraulic cylinders but also in daily operations of hydraulic motors. Therefore, fatigue level and damage level are estimated and control of pump discharge limit based on this is performed. You may make it carry out according to a damage degree.

1 is an overall circuit configuration diagram of a hydraulic excavator including a control device according to an embodiment of the present invention. It is a block block diagram of the same apparatus. It is a flowchart for demonstrating the effect | action of the apparatus. FIG. 4 is a continuation flowchart of FIG. 3. It is a flowchart which shows the content of the engine speed control by the same apparatus.

Explanation of symbols

4 Boom of hydraulic excavator 5 Same arm 6 Same bucket 7, 8, 9 Cylinder for boom, arm and bucket 13 Engine 14, 15 Hydraulic pump 16, 17, 18 Control valve for boom, arm and bucket 22, 23, 24 Remote control valves for boom, arm and bucket (operating means)
30, 31, 32 Pressure detection means 33, 34, 35 Boom, arm and bucket angle detection means 36, 37, 38 Operating amount detection means 39 Pump pressure detection means 40 Engine torque detection means 42 Controller constituting control means 43 Pump Capacity control means 44, 45, 46 Control valve control means 47 Engine speed control means 48 Damage processing means 49 Setting means 50 Engine load torque calculation part 53 Cylinder fatigue / damage degree estimation part 54 Cavitation occurrence number calculation part 55 Pump capacity limit Value setting unit 56, 57, 58 Control valve operation limit value setting unit for boom, arm, and bucket 59 Engine speed limit value setting unit

Claims (11)

  A plurality of hydraulic actuators, a hydraulic pump as a hydraulic source for each hydraulic actuator, an operation means for issuing an operation command to each hydraulic actuator, and an actuator for controlling supply and discharge of oil to each hydraulic actuator in accordance with the operation of the operation means A control valve and a control means, which detects a factor causing damage to the hydraulic system including the hydraulic actuator during the operation of the hydraulic actuator, and based on the detection result, damage that suppresses the progress of the damage A construction machine control device configured to perform suppression control.   The control means is configured to detect the operation amount of the hydraulic cylinder, estimate the fatigue level of the cylinder as damage from the detected cylinder operation amount, and perform damage suppression control based on the estimated fatigue level. The construction machine control device according to claim 1, wherein:   3. The construction machine control device according to claim 2, wherein the control means is configured to detect an operation amount of the operation means for the hydraulic cylinder and to estimate a fatigue level of the cylinder from the operation amount.   The control means is configured to detect that the hydraulic cylinder has ended the stroke, estimate the damage level of the cylinder as damage from the detection result, and perform damage suppression control based on the estimated damage level. The construction machine control device according to any one of claims 1 to 3.   The hydraulic cylinder includes a boom cylinder for driving the boom, an arm cylinder for driving the arm, and a bucket cylinder for driving the bucket. The control means includes an angle of the boom, the arm and the bucket, a pressure of the cylinder, and an operating speed of the cylinder. The construction machine control device according to claim 4, wherein the control device is configured to detect that the cylinder has ended the stroke from.   6. The control means according to claim 1, wherein the control means is configured to detect the occurrence of cavitation in the hydraulic circuit as a damage factor, and to perform damage suppression control based on the number of occurrences of the cavitation. The control device for a construction machine according to item 1.   7. The construction machine control device according to claim 6, wherein the control means is configured to detect the occurrence of cavitation based on circuit pressure.   The control device for a construction machine according to any one of claims 1 to 7, wherein the control means is configured to increase a degree of damage suppression control in accordance with an increase in damage.   The control of the construction machine according to any one of claims 1 to 8, wherein the control means is configured to limit an operation amount of the hydraulic actuator with respect to an operation amount of the operation means as damage suppression control. apparatus.   The control device for a construction machine according to any one of claims 1 to 9, wherein the control means is configured to limit a discharge amount of the hydraulic pump as damage suppression control.   An engine is provided as a power source for driving the hydraulic pump, and the control means is the degree of fluctuation of the engine speed relative to the fluctuation of the engine load torque in accordance with the reduction of the engine load torque accompanying the limitation of the maximum discharge amount of the hydraulic pump. The construction machine control device according to claim 10, wherein control is performed to increase

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