1585 results about "Engineering machiner" patented technology

The invention relates to the technical field of engineering machinery control, and discloses a carry-scraper electrical control system and method based on intelligent control, and the system comprises a sensor module, a man-machine interaction module, a control module, an execution module, and a communication module. The method comprises the following steps: collecting real-time operation data and an operator instruction, generating a predictive deterministic map by a control module, and outputting a final control instruction for energy consumption optimization according to the predictive deterministic map to drive the carry-scraper. And meanwhile, the system continuously monitors the state of the equipment to realize fault early warning, calculates an energy consumption optimization index, and finally graphically displays the operation data, the fault early warning and the energy consumption index through the man-machine interaction module. According to the invention, an intelligent algorithm is integrated, so that accurate control and early warning of faults can be realized, energy consumption is optimized, and safety and economy are improved; and through simplified man-machine interaction, the defects of poor adaptability, complex operation and high energy consumption of a traditional system are overcome.

The invention discloses a load simulation loading system based on an engineering mechanical power system and a control method thereof, and relates to the technical field of mechanical power system simulation. The load simulation loading system comprises an engineering machinery power system, a load loading system, a whole vehicle control unit and an upper computer platform. The engineering machinery power system comprises a first oil tank, a main pump, a pilot pump, a pilot control handle, a signal control valve and a multi-way valve. The load loading system comprises a three-position four-way reversing valve, a proportional overflow valve, a first proportional throttle valve, a second proportional throttle valve, an electromagnetic valve, a third proportional throttle valve and a variable pump, wherein the three-position four-way reversing valve, the proportional overflow valve and the first proportional throttle valve are connected to the multi-way valve, the second proportional throttle valve and the electromagnetic valve are connected to an outlet of the proportional overflow valve, and the third proportional throttle valve is connected between the second proportional throttle valve and the second oil tank. And the three-position four-way reversing valve is constructed to enable an inlet of the proportional overflow valve to be communicated with one of the oil port A and the oil port B of the multi-way valve in a switching manner, and an outlet of the proportional overflow valve to be communicated with the other one of the oil port A and the oil port B in a switching manner.

A control method for a compensation torque of a range extender (2) for an engineering machinery vehicle. The method comprises: determining a feedforward torque on the basis of driver demand power, and controlling a range extender (2) to operate with the feedforward torque; on the basis of the difference between the actual generating power of the range extender (2) and the driver demand power, calculating a power compensation torque; on the basis of actual operating conditions of an engineering machinery vehicle, determining whether to add other compensation torques; if the other compensation torques are to be added, setting a final compensation torque to be the sum of the power compensation torque and the other compensation torques; if the other compensation torques are not to be added, setting the final compensation torque to be the power compensation torque; and sending to the range extender (2) the final compensation torque, which then serves, together with the feedforward torque, as a generating torque of the range extender. Therefore, the generating power of the range extender (2) can change according to the driver demand power, and torque compensation is performed on the basis of the actual operating conditions, thereby ensuring the effective available power of a system.

The invention discloses a double-seat cooperative safety control method and system for engineering machinery, relates to the technical field of engineering machinery control, and provides the following scheme that the method comprises the steps that a first operation instruction stream of a main driving seat and a second operation instruction stream of a co-driving seat are collected in real time, and a working condition parameter set of the engineering machinery is synchronously obtained; the operation instruction stream comprises all degree-of-freedom motion parameters of the engineering machinery, inputting the first operation instruction stream into a pre-constructed long-short-term memory model, outputting a prediction operation instruction stream in a future time window, and based on a difference vector of the first operation instruction stream and a second operation instruction stream on each degree-of-freedom motion parameter. According to the method, through the index curve fitting model and Simpson integral calculation, the defect that the co-pilot intervention weight is difficult to quantify is overcome, the dynamic intervention weight based on the physical equidistant interval absolute integral value is realized, and the accuracy of the control signal of the engineering machinery is improved.

The invention relates to the technical field of engineering machinery manufacturing, in particular to an excavator part machining treatment device which comprises a fixing base, a support is fixedly connected to the fixing base, a driving mechanical arm capable of driving horizontal two-dimensional motion is installed at the top of the inner side of the support, and a sliding disc is fixedly connected to the lower end of the driving mechanical arm. The bottom face of the sliding disc is fixedly connected with a driving cylinder, and the lower end of the driving cylinder is fixedly connected with an inverted-U-shaped frame. According to the excavator part machining treatment device, three core procedures of drilling, inner wall grinding and end face grinding are integrated, through cooperative control of the driving mechanical arm, the driving air cylinder and the motor, full-process part machining can be completed without equipment replacement or repeated clamping, the part transferring and positioning time is effectively shortened, and the machining efficiency is improved. The problem that traditional step-by-step machining is low in efficiency is solved, and the machining efficiency is improved.

The invention relates to the technical field of engineering machinery, and discloses an engineering machinery active safety control method and device based on multi-parameter analysis, and the method comprises the steps: collecting the multi-modal data of an environment where the engineering machinery is located based on a multi-modal data collection device, and constructing a dynamic model of the engineering machinery and the environment according to the multi-modal data, analyzing the multi-modal data through a dynamic model to obtain an environment data analysis result and an equipment data analysis result, determining an operation risk level of the engineering machinery according to the environment data analysis result and the equipment data analysis result, and determining an optimal working path of the engineering machinery according to the multi-modal data. And generating a safety control strategy according to the operation risk level and the optimal working path. Therefore, by implementing the method, the evaluation accuracy of the operation risk can be improved, the probability of misoperation of operators is reduced, the operation accuracy and reliability of the engineering machinery are enhanced, and the operation efficiency, the operation stability and the operation safety of the engineering machinery are further improved.

The invention discloses vibroflotation equipment, and relates to the technical field of engineering machinery, and the vibroflotation equipment comprises a machine body assembly, a sleeve pulling device and a vibroflotation device. In the vibroflotation equipment, a machine body assembly is provided with a stand column, and the stand column is provided with a first guide rail; the sleeve pulling device is arranged on the first guide rail in a liftable manner and is used for pulling a sleeve; the vibroflotation device is arranged on the first guide rail in a liftable mode, is matched with the sleeve pulling device in a penetrating mode and is used for vibroflotation of the foundation, and the sleeve pulling device and the vibroflotation device work cooperatively. According to the vibroflotation equipment, the sleeve can be pulled out cooperatively during vibroflotation, the pile body quality is good, and the construction efficiency is high.

The invention relates to the technical field of engineering machinery control, in particular to a fuel efficiency optimization method and system based on multi-modal visual fusion, and the method comprises the steps: obtaining an environment image around engineering machinery, generating a disparity map, and carrying out the three-dimensional reconstruction; according to the reconstructed image and a pre-stored engineering machinery joint model, obtaining three-dimensional coordinates and spatial postures of the movable arm joint; classifying the current working conditions of the engineering machinery according to the three-dimensional coordinates and the spatial attitude of the movable arm joint, the state parameters of the engineering machinery and the reconstructed image, and determining the action states and slope repairing angles under different working condition types; and according to the working condition type, the action state and the slope repairing angle, based on a pre-constructed fuel mapping database, obtaining a corresponding load intensity coefficient, an engine rotating speed, a main pump pressure, a fuel supply correction coefficient and torque compensation, and adjusting the current state parameters of the engineering machinery to realize fuel optimization.

The invention discloses a drill rod lowering control method, system and equipment of a rotary drilling rig and a medium, and belongs to the technical field of engineering machinery control. The drill rod lowering control method of the rotary drilling rig comprises the steps that if a drill rod lowering instruction is received, an electric main hoisting mechanism is controlled to lower a telescopic drill rod to a target drill hole; the current lowering depth of the telescopic drill rod is determined; the difference value between the hole depth of the target drill hole and the current lowering depth is set as the to-be-lowered depth; if the to-be-lowered depth is larger than the depth threshold value, the current lowering speed of the telescopic drill rod is set according to the current bearing weight, the power head height, the current lowering depth and the length of the sub drill rod; and if the to-be-lowered depth is smaller than or equal to the depth threshold value, a motor of the electric main hoisting mechanism is controlled to output reverse torque, and the motor of the electric main hoisting mechanism is controlled to stop rotating when a preset condition is met. The lowering speed of the telescopic drill rod can be reasonably controlled, and the service life of the rotary drilling rig is prolonged.

Disclosed in the present invention are a gear shifting process control method and system for an electric drive transmission of engineering machinery. The method comprises: in response to having received a gear-shifting signal, acquiring a required gear, a current gear, an electric-motor output torque and a slope signal; on the basis of the electric-motor output torque and the slope signal, determining a gear-shifting load type, and on the basis of the required gear and the current gear, determining a gear-shifting requirement type; if the gear-shifting load type is light- and medium-load gear shifting and the gear-shifting requirement type is an upshift requirement, sending an instruction to execute light- and medium-load upshift control; and if the gear-shifting load type is the light- and medium-load gear shifting and the gear-shifting requirement type is a downshift requirement, sending an instruction to execute light- and medium-load downshift control. During light- and medium-load upshift control or light- and medium-load downshift control, rotation speeds on a pre-clutch side and a post-clutch side are rapidly synchronized, thereby reducing the sliding friction work of a clutch and shortening a gear-shifting time.

The invention relates to the technical field of electro-hydraulic integrated driving, in particular to a hydraulic synchronous control system and method based on traveling wave and magnetic field composite driving, the system comprises a plurality of hydraulic cylinders, and each hydraulic cylinder comprises a piston rod assembly and a cylinder barrel; the piston rod assembly comprises a metal push rod on the inner layer, a three-phase winding module arranged around the metal push rod on the middle layer and a lining barrel on the outer layer. Each hydraulic cylinder corresponds to one pressure sensor, one displacement sensor and one controller. The cylinder barrel serves as a secondary conductor, eddy current is generated through traveling wave magnetic field induction, and axial thrust is generated. In a no-load state, the controller switches the current direction to generate auxiliary oil absorption thrust; during loading, current parameters are dynamically adjusted according to displacement, pressure and speed feedback, and synchronous compensation and speed regulation are achieved. The linear motor has the characteristics of high thrust density of a hydraulic system and quick response of the linear motor, and is suitable for high-precision engineering machinery and aerospace hydraulic actuating mechanisms.

The invention provides an engineering mechanical equipment remote monitoring system and method based on the Internet of Things, and relates to the technical field of equipment operation monitoring, and the method comprises the steps: carrying out the cross-scale feature response of a dynamic impact signal of engineering mechanical equipment through an intelligent calculation node, and obtaining a frequency domain migration feature and an energy attenuation feature; carrying out gradient operation on the operation thermal field data of the engineering mechanical equipment to obtain heat flow evolution characteristics; utilizing a coupling analysis model dynamics interaction map; performing space-time resonance convolution prediction on node states and edge relations of the dynamic interaction atlas based on the displacement track to obtain a state prediction curve of the engineering mechanical equipment; and according to the state prediction curve and a preset scheduling instruction, an adaptive feedback network is constructed at an edge computing node of the Internet of Things, and then remote monitoring scheduling is performed on the engineering mechanical equipment based on the adaptive feedback network, so that operation state prediction and scheduling closed-loop control of the engineering mechanical equipment can be realized; therefore, the remote monitoring stability of the engineering mechanical equipment is improved.

A construction machine includes a travel actuator, an attachment actuator, a storage, an information obtaining device, and a hardware processor configured to perform braking control of at least one of the travel actuator and the attachment actuator in response to determining that a dangerous situation is going to occur based on information obtained by the information obtaining device and information stored in a database in the storage.

The invention relates to the field of engineering machinery control, and discloses a self-adaptive control system and method for a land ladle overturning machine. The system comprises a multi-mode sensing unit, a central control unit, a hydraulic execution unit and a man-machine interaction terminal, according to the method, dip angle / pressure / visual data are fused in real time, a ladle overturning track is dynamically corrected based on the material gravity center offset, when the overturning probability exceeds a threshold value, progressive hydraulic pressure reduction is started, and an energy consumption feedback model is constructed to optimize execution parameters. The problems that the overturning risk is high and the energy consumption difference is large due to the fact that a traditional ladle overturning machine lacks perception are solved, the abnormal interruption rate is reduced by 76% or above, and the comprehensive energy efficiency is improved to 82%.

The invention discloses a large oil cylinder V-group seal external leakage automatic detection system, which comprises a piston rod, a cylinder barrel, and a V-group seal, a step seal, a Glyd ring and a dustproof ring which are sequentially arranged on the inner surface of the cylinder barrel, and a leakage detection port is arranged between the V-group seal and the step seal; the leakage detection system is composed of a manual ball valve connected with a leakage detection port, a pressure sensor, an electromagnetic ball valve, a detection oil tank and a flow meter. The V-group sealing compression amount adjusting assembly comprises a fixing nut, an adjusting screw rod and a wedge-shaped block, and the adjusting screw rod is rotated to drive the wedge-shaped block to move to achieve stepless adjustment of the compression amount. The control module processes sensor data through an industrial personal computer and controls an execution element. The system can monitor the sealing state in real time and automatically adjust the compression amount, and is mainly used for monitoring and maintaining the sealing performance of the super-long oil cylinder in the fields of large engineering machinery, maritime ships and the like.

The invention relates to the technical field of radiator welding, and particularly discloses a welding device for an engineering machinery radiator. Comprising a circular concave shell, the outer side of the circular concave shell is sleeved with and rotationally connected with a first annular electric sliding rail, the outer side of the first annular electric sliding rail is fixedly connected with an auxiliary driving assembly, the top of the first annular electric sliding rail is fixedly connected with a correction angle block, the inner side of the circular concave shell is fixedly connected with an arc-shaped grinding block, and an arc-shaped through hole is formed in the inner side of the circular concave shell; according to the welding device for the engineering machinery radiator, the two round concave shells are used for conducting inner clamping type fixing on the end portions of the main pipe from the two ends of the main pipe, and the situation that when branch pipe butt welding operation is conducted on the main pipe, the main pipe shakes and deflects due to the influence of external force, and the welding effect is affected is prevented; the arc-shaped grinding blocks are arranged on the inner wall of the circular concave shell to grind and flatten the end face of the pre-fixed main pipe, and the situation that the butt welding effect of the branch pipes is affected due to the fact that the end face of the main pipe is uneven when the main pipe is fixed and is integrally in an inclined state is avoided.

The invention relates to a health management method and device for engineering mechanical equipment. The engineering mechanical equipment comprises the system, and the system comprises parts needing to be monitored. The method comprises the following steps: acquiring a monitoring index associated with a part from a pre-constructed index library; acquiring monitoring data related to the monitoring indexes; obtaining maintenance knowledge which is associated with the parts and comprises the monitoring indexes from a pre-constructed maintenance knowledge base, wherein the maintenance knowledge comprises maintenance measures for the parts; determining the risk level of the part based on the monitoring data and a preset risk level threshold; in response to the fact that the risk level of the part is within the maintenance risk level range, a maintenance strategy for the part is determined based on the maintenance measures for the part; and pushing the maintenance strategy for the part so as to execute the maintenance measure for the part.

The invention belongs to the technical field of engineering machinery, and discloses a transmission system and engineering machinery. The transmission system comprises an integrated shell, a motor assembly, a brake assembly and a speed reducer assembly, the motor assembly, the brake assembly and the speed reducer assembly are arranged in the integrated shell and distributed in the first direction, an output piece of the motor assembly is in transmission connection with an input piece of the speed reducer assembly through the brake assembly, and an output piece of the speed reducer assembly is connected with the hub. The integrated shell is provided with a cooling channel set, and the cooling channel set can conduct heat dissipation on the motor assembly, the brake assembly and the speed reducer assembly at the same time. By arranging the integrated shell, the structure of a transmission system can be simplified, the cost can be reduced, the machining consistency is good, the supporting rigidity is better, and transmission errors caused by structural deformation are reduced; the cooling channel group is arranged on the integrated shell, so that the motor assembly, the brake assembly and the speed reducer assembly can be cooled at the same time by only one cooling system, the utilization rate of the cooling system is improved, the cooling efficiency is high, and the service life of the system is prolonged.

This invention relates to the field of booms, and discloses a rotary drive mechanism, a boom, and engineering machinery. The rotary drive mechanism includes an annular piston (10) and a stator. The annular piston (10) is provided with piston teeth having protruding curved tooth surfaces and piston teeth having inclined flat tooth surfaces. The stator is provided with stator teeth having protruding curved tooth surfaces and stator teeth having inclined flat tooth surfaces. The annular piston (10) can be driven to move axially relative to the stator. Through the above-described technical solution, the combination of the meshing of curved tooth surfaces and the meshing of flat tooth surfaces can ensure smooth transmission in the initial meshing stage, reduce noise, and allow the subsequent meshing stage to convert axial movement into uniform rotation, providing a more stable torque output.

The invention relates to a quick changer (1) for changing an attachment on a construction machine, comprising: a carrier (2), which has a first receptacle (4) for a first coupling element on one side thereof and a second receptacle (5) for a second coupling element on the other side thereof; and a drive device (12) movably arranged at the support (2) in order to move the at least one locking element (13) associated with the first receptacle (4) between an extended locking position and a retracted release or replacement position, a plurality of hydraulic quick couplings being arranged at the drive device (12) in order to supply the additional device with hydraulic fluid. According to the invention, only three hydraulic quick couplings (19A, 19B, 19C) arranged next to one another are arranged on the drive device (12), of which two outer hydraulic quick couplings (19A, 19B) lie in the same plane and in contrast, the inner hydraulic quick coupling (19C) lying therebetween is offset in height upwards.

The utility model discloses a slewing bearing platform for a large ocean floating crane system, which belongs to the technical field of engineering machinery and comprises a supporting seat, a rotating component is arranged on the upper surface of the supporting seat and comprises an outer gear ring, the outer gear ring is arranged on the upper surface of the supporting seat and is rotatably connected with the supporting seat, and the outer gear ring is connected with the supporting seat. An outer gear ring is arranged on the upper surface of the supporting seat, an inner gear ring is arranged on the inner wall of the outer gear ring, the inner wall of the outer gear ring is rotationally connected with the outer wall of the inner gear ring, the inner gear ring is fixedly connected to the upper surface of the supporting seat, a plurality of rolling bodies are connected into the inner gear ring, and gear teeth are formed in the inner wall of the inner gear ring. The oil storage ring is directly installed on the inner ring, the space of the inner ring is fully utilized, extra space is not occupied, the whole system is more compact, the annular structure of the oil storage ring can better adapt to the shape of the slewing bearing platform, and it is guaranteed that lubricating oil is evenly distributed in all directions.

The utility model discloses a supporting leg device for engineering machinery and the engineering machinery, the supporting leg device comprises a horizontal supporting leg assembly, the horizontal supporting leg assembly comprises a first supporting leg, a second supporting leg and a third supporting leg which are distributed in the horizontal direction, the first supporting leg can be transversely and movably embedded in a bottom frame of the engineering equipment, and the second supporting leg can be transversely and movably embedded in a bottom frame of the engineering equipment; the second supporting leg is nested in the first supporting leg in a transverse moving manner, and the third supporting leg is nested in the second supporting leg in a transverse moving manner; the vertical supporting leg assembly is vertically and telescopically arranged on the third supporting leg; the horizontal hydraulic cylinder is in driving connection with the first supporting leg; the first pulley assembly is used for pulling the second supporting leg to extend or retract relative to the first supporting leg; and the second pulley assembly is used for pulling the third supporting leg to extend or retract relative to the second supporting leg. The supporting leg device for the engineering machinery has the advantages of being simple in structure, low in control difficulty and low in cost.

The invention discloses an integrated parameter design method and system suitable for an engineering mechanical structure, and the method comprises the steps: firstly, determining design parameters of the engineering mechanical structure; secondly, an integrated parameter template of the structure is established, and the integrated parameter template comprises a three-dimensional model template, a two-dimensional drawing template and a finite element model template; then, constructing driving parameters of a three-dimensional model based on the design parameters of the structure; and finally, establishing a relation between the driving parameters and the integrated parameter template, and realizing integrated design of three-dimensional model parameter change, two-dimensional drawing automatic updating and finite element model automatic updating through parameter driving. According to the method, the development period of the engineering mechanical structure can be shortened, and the product delivery efficiency is improved.

The invention belongs to the technical field of engineering machinery, and particularly relates to a damping device, in particular to a nitrogen spring score cylinder and a working method thereof. The nitrogen spring score cylinder comprises a piston rod, a piston rod, a piston rod and a piston rod, the two sealing pieces are arranged in sealing grooves in the outer wall of the piston rod, and the outer walls of the sealing pieces abut against the inner wall of the cylinder body; the oil storage piece is arranged on the outer wall of the piston rod in a sleeving mode and located between the two sealing pieces; the two linkage adjusting pieces are located on the two sides of the oil storage piece respectively and correspond to the sealing pieces respectively; when the piston rod moves leftwards, the linkage adjusting piece located on the right side of the oil storage piece moves rightwards to extrude the sealing piece on the right side to expand outwards and deform. When the piston rod moves rightwards, the linkage adjusting piece located on the left side of the oil storage piece moves leftwards to extrude the sealing piece on the left side to expand outwards and deform; when the linkage adjusting piece moves outwards relative to the oil storage piece, the grease in the oil storage piece moves outwards along with the linkage adjusting piece so that the grease can drip to the outer wall of the piston rod.

A construction machine is capable of returning the posture of an earth removal plate (blade) from a rocking posture to a predetermined normal posture. A stay is mounted on the construction machine body to move in upward and downward directions. The earth removal plate is mounted on the distal end portion of the stay, and is rockably movable in forward and rearward directions by an angle cylinder controlled by a flow of hydraulic fluid in response to receiving an instruction about rocking the earth removal plate. A normalization switch gives an instruction to set the posture of the earth removal plate to a predetermined normal posture from the rocking posture. The posture of the earth removal plate is set to the predetermined normal posture from the rocking posture in response to the instruction from the normalization switch.

An engineering machinery electro-hydraulic steering flexible safety control device and method. The device comprises a first controller (3), an electric control handle (2), an electro-hydraulic steering unit (1), a steering cylinder (5) and an electric control pump (4); the electric control handle (2) is connected to the first controller (3) and sends a steering request signal to the first controller (3), so that the first controller (3) generates a CAN signal or a PWM signal; the electro-hydraulic steering unit (1) comprises an electric control steering module (1.1) and a reversing valve (1.2) which are connected to each other, the electric control steering module (1.1) is further connected to the first controller (3) separately by means of a CAN signal line and a PWM signal line, and the reversing valve (1.2) is further communicated with the steering cylinder (5); the electric control pump (4) is separately connected to the first controller (3) and the reversing valve (1.2); and the electric control steering module (1.1) responds to the CAN signal or the PWM signal sent by the first controller (3), and outputs a pilot pressure on the basis of the CAN signal or the PWM signal to actuate the reversing valve (1.2) to shift. In the device, when a fault has occurred in the CAN signal line, the PWM signal line takes over the steering request signal, thereby guaranteeing that a vehicle continues to steer and achieving the safety of vehicle steering.

The invention relates to the technical field of engineering machinery control, and discloses a hydraulic control system under a variable load piling working condition, which comprises a multi-dimensional state acquisition module, a fluid parameter observation module, a signal reconstruction decoupling module, a virtual impedance mapping module and a fluid phase locking control module. The acquisition module acquires a basic physical state; the observation module solves the effective volume elastic modulus of the hydraulic oil based on a fluid continuity equation; the reconstruction module utilizes the modulus to correct signal lag, reconstructs external load force through an inverse dynamic model and decouples environmental acoustic impedance; the mapping module dynamically generates a target mechanical impedance parameter according to the environment impedance; and the control module calculates an ideal instruction based on the target parameter, corrects the gain by utilizing the fluid modulus and locks the rebound peak phase to adjust the action time sequence of the valve core. Control distortion caused by fluid parameter drift is solved, active flexible adaptation to variable load geology is achieved, energy hedging is avoided, and operation efficiency is improved.

Title: Quick coupler for public works machinery Device forming a coupler, comprising a coupler, or quick coupler (1), intended to be secured to a public works machine, such as an excavator, a connection device (2), intended to be secured to a tool, such as a bucket (3), comprising at least one coupling pin (5), respectively a coupling hook intended to couple with at least one associated coupling hook, respectively a coupling pin, of the quick coupler, and locking means intended to lock the quick coupler to the connection device, is characterized in that it comprises guide means (800, 810) intended to guide the pivoting movement of the quick coupler relative to the connection device after coupling in order to lock the device, in particular self-centering means intended to allow relative self-centering of the quick coupler and the connection device. Figure for the abstract: Fig. 20

To provide a hydraulic driving device of a construction machine which can inhibit complication of a structure of a hydraulic circuit.SOLUTION: A hydraulic driving device 101 of a construction machine 100 includes: a hydraulic pump 22 configured to discharge working fluid; a hydraulic cylinder 8 having a head side chamber 8H and a rod side chamber 8R; a first passage 31 connecting the hydraulic pump 22 with the head side chamber 8H; a second passage 32 connected to the rod side chamber 8R; a third passage 33 connecting the first passage 31 with the second passage 32; and a regeneration control valve 53 disposed in the third passage 33. The regeneration control valve 53 has a spool which may be switched between a regeneration position where the working fluid discharged from the rod side chamber 8R is allowed to flow from the second passage 32 into the first passage 31 and return to the head side chamber 8H and a meter-in position where the working fluid discharged from the hydraulic pump 22 is allowed to flow from the first passage 31 into the second passage 32 and be supplied to the rod side chamber 8R.SELECTED DRAWING: Figure 2

This construction machine is provided with: a flow rate control valve as a hydraulic device that adjusts the flow rate supplied to a hydraulic cylinder that drives a work device; and a control device that controls the hydraulic cylinder so as to satisfy the condition that the work tool moves without exceeding the target surface. The control device calculates a target speed of the hydraulic cylinder at which the work tool satisfies the condition on the basis of information on the target surface and detection information from a detection device that detects the orientation of the work device, and controls the work tool when the target value of the hydraulic device corresponding to the calculated target speed is less than a lower limit value at which the accuracy of flow control can be ensured. On the basis of the limited speed of the hydraulic cylinder obtained from the lower limit value, a target speed of the hydraulic cylinder at which the work tool satisfies the condition is re-calculated, and the hydraulic device is controlled by a target value corresponding to the re-calculated target speed.