7418 results about "Cylinder (engine)" patented technology

The invention provides a low-speed and ultrahigh-pressure die-casting process method for automobile part die-casting, and relates to the field of automobile part manufacturing. The method includes the following steps that firstly, a mold is prepared, secondly, molten metal is prepared, thirdly, a casting is cooled and demolded, and fifthly, follow-up treatment is conducted. The defects that in the high-speed mold filling process of a common high-pressure casting technology, gas is likely to be involved in the molten metal, and consequently air holes, shrinkage porosity and the like are generated in the casting are overcome; and when key parts such as automobile engine cylinder bodies and hubs are produced, air hole defects possibly cause the problems of air leakage of engines, insufficient hub strength and the like. And meanwhile, for parts with thin walls and complex structures, uniform filling of molten metal in a mold is difficult to ensure by a traditional die-casting process, the defects of cold shut, insufficient pouring and the like are easy to occur, and the qualified rate and the production efficiency of products are reduced.

The invention provides a multi-dimensional supporting leg structure for lightweight steel ring splicing equipment, and relates to the field of tunnel engineering. The mounting base is fixedly connected with the frame, the telescopic driving mechanism is arranged between the mounting base and the supporting leg assembly, the angle adjusting mechanism is arranged between the cylinder barrel and the mounting base, and the self-locking mechanism is used for locking the cylinder barrel and the piston rod when the driving unit fails. The telescopic driving mechanism is composed of a cylinder barrel, a piston rod and a driving unit, the angle adjusting mechanism is driven through a first rotating shaft and a second rotating shaft which are perpendicular to each other and corresponding rotation, so that the cylinder barrel achieves double-shaft swing adjustment, the self-locking mechanism is composed of a locking rack, a movable tooth claw, a reset spring, an electromagnet and a permanent magnet, and power-on unlocking and power-off self-locking are achieved. According to the structure, the supporting polygon is obviously enlarged under the complex basic condition, the anti-overturning stability of equipment is improved, reliable supporting is kept when a hydraulic system fails, and the safety and adaptability of steel ring splicing operation in a tunnel are improved.

The invention relates to the technical field of tensile tests, and discloses a building sealant stretching performance test device, which comprises a test box, a first clamp, a loading block, a linear driver and a driving mechanism, a door plate is mounted on the front of the test box; the first clamp is installed at the top in the test box, the loading block is arranged in the test box, located below the first clamp and driven by the linear driver to move up and down, a through loading channel is formed in the loading block, and a cylinder is arranged in the loading channel and driven by the driving mechanism to rotate; a through assembly channel is formed in the cylinder body, and a transversely-arranged guide rail body is installed in the assembly channel. According to the invention, by carrying out stretching, torsion, inclined stretching, tearing stretching, winding stretching and testing in a low-pressure environment on the sealant, the mechanical properties of the sealant under complex working conditions can be comprehensively evaluated, the testing precision and reliability are improved, the actual engineering requirements are met, and meanwhile, the testing safety and environmental protection property are ensured.

The invention discloses a welding device and method for a rocket engine jet pipe, and belongs to the technical field of aerospace engine welding. The welding device for the rocket engine jet pipe comprises a first tool used for clamping a to-be-welded scalloped segment of the engine jet pipe, a second tool used for clamping a to-be-welded barrel and a gas protection supporting cover used for conducting inert gas protection on the front face of a welding seam of the engine jet pipe. The first tool comprises a first inner supporting piece, the first inner supporting piece is sleeved with a pressing plate, and the pressing plate is provided with a first pressing structure for pressing the edge of the scalloped segment; the second tool comprises a second inner supporting piece and a third inner supporting piece which are used for supporting the barrels, and a pressing mechanism for pressing the splicing positions of the adjacent barrels is arranged outside the second inner supporting piece or the third inner supporting piece. By the adoption of the welding device and method for the rocket engine jet pipe, the problems that an existing engine jet pipe is prone to being oxidized when welded in the atmosphere, defects are generated, and the welding cost is high can be solved.

A pre-ignition prevention system for a turbulent jet ignition (TJI) engine having dual spark plugs includes an ion sensing system and a controller configured to receive the ion sense signal from the ion sensing system, detect, using the ion sense signal, a misfire event where a firing of a first spark plug fails to completely combust a fuel / air pre-charge in a pre-chamber of a cylinder of the TJI engine, in response to detecting the misfire event, detect, using the ion sense signal, an exhaust stroke heat release event after a firing of the second spark plug indicative of a remaining portion of a primary fuel / air charge in the main chamber and, in response to detecting the exhaust stroke heat release event, adjust fueling for at least one subsequent combustion cycle to prevent pre-ignition of the remaining portion of the primary fuel / air charge in the main chamber.

The invention discloses a modularized replaceable self-resetting energy consumption type bridge pier anti-collision system, and belongs to the technical field of bridge engineering structure safety. The system includes an annular rubber pad, an annularly disposed damper module, and a shape memory alloy (SMA) tow. The damper module comprises a cylinder body, high-viscosity fluid, a reset spring, a piston and a force transmission plate. The cylinder body is fixed to the pier in a surrounding mode through bolts and rubber pads, the inner wall of the cylinder body is connected with the piston through a reset spring, the piston rod end is hinged to the force transmission plates, and the SMA wire bundles are connected with the force transmission plates. When an external impact load acts on the force transmission plate, the fluid damper provides viscous energy consumption, and the SMA wire bundle, the spring and the rubber pad provide deformation energy consumption; after the collision is finished, the system can be reset to the initial position under the synergistic effect of the SMA wire bundle, the spring and the rubber pad. By means of the modular design, efficient energy consumption and self-resetting can be achieved; and meanwhile, a single damper can be quickly replaced after being damaged, so that the maintenance efficiency and the system recoverability are greatly improved.

The invention discloses a method for calculating stress and deformation of a roller carrier supporting thin-walled cylinder under the action of dead weight, which comprises the following specific steps of: S1, calculating the bending moment and deflection of a cylinder body in the longitudinal direction by adopting an overhanging beam model in the longitudinal direction, and determining the optimal position of the roller carrier in the longitudinal direction according to the maximum bending moment minimization and the maximum deflection minimization of a beam; s2, transversely utilizing symmetry to establish a semicircular curved beam model, and calculating bending moment and displacement in a transverse plane of the cylinder by adopting a Temosinke beam theory; s3, calculating the maximum stress in the cylindrical surface according to the in-surface bending moment, and determining the optimal half wrap angle required by the strength; and S4, calculating the ovality and root-mean-square roundness of the curved beam according to the displacement, and determining the optimal half wrap angle required by deformation. According to the method, the maximum stress and the deformation shape of the thin-walled cylinder are accurately predicted, and the optimal wrap angles of the roller carrier under the strength requirement and the deformation requirement can be determined to be 67.4 degrees and 90 degrees respectively, so that the optimal wrap angle is suggested to be between 67.4 degrees and 90 degrees in engineering.

The invention relates to the technical field of structural engineering shock isolation, in particular to a quasi-zero stiffness shock isolation device based on hydraulic negative stiffness and a design method thereof. A quasi-zero stiffness shock isolation device based on hydraulic negative stiffness comprises a vertical bearing unit which comprises at least one vertical spring, and the two ends of the vertical spring are connected to the top face of a lower connecting plate and the bottom face of an upper connecting plate respectively; the negative stiffness unit comprises a hydraulic oil cylinder and a piston rod, the piston rod extends into the hydraulic oil cylinder, and the hydraulic oil cylinder and the piston rod are hinged to the lower connecting plate and the upper connecting plate respectively, or the hydraulic oil cylinder and the piston rod are hinged to the upper connecting plate and the lower connecting plate respectively; the distance between the upper connecting plate and the lower connecting plate is increased or decreased to drive the length of the piston rod extending into the hydraulic oil cylinder to change so as to provide negative stiffness. The problems that in the prior art, when a nonlinear vibration isolation system provides negative stiffness in a metal horizontal spring compensation mode, a quasi-zero stiffness working zone is narrow, the bearing capacity is low, and the requirement for installation precision is high are solved.

The utility model relates to the technical field of air tightness detection, and discloses an air tightness detection device for an automobile engine cylinder cover, which comprises a detection box, supporting cylinders are fixed at four corners of the outer wall of the detection box, a top cover is arranged on the top surface of the detection box, and the detection box and the top cover are made of sound insulation plates. And detection assemblies are arranged in the detection box and on the top surface of the top cover, and each detection assembly comprises a placement frame fixed on the bottom surface of the top cover. According to the utility model, a cooling system filled with an engine cylinder cover is filled with gas through the air pump, then the hydraulic cylinder is started to drive the placement rack to move into the detection box, and the detection box and the top cover are made of sound insulation plates, so that the interior of the detection box is kept in a quiet and relatively closed environment; at the moment, the engine cylinder cover is detected in four directions through the four ultrasonic receivers, and when leaked gas passes through a leakage hole, ultrasonic waves are generated and detected, so that airtightness detection of the engine cylinder cover is realized.

The invention relates to the field of pipeline detection, in particular to a pipeline leakproofness detection device for constructional engineering construction detection, which comprises a base, a detection cylinder is mounted above the base, a first plugging piece is movably connected in the detection cylinder, and the first plugging piece seals the end part of a to-be-detected pipeline and clamps and fixes the pipeline. The pipeline is driven to move; a first plugging piece is installed at one end of the pipeline, a second plugging piece is installed at the other end of the pipeline, an air hole is formed in the second plugging piece, and air is injected into the pipeline after the two ends of the pipeline are plugged through the first plugging piece and the second plugging piece; the transmission assembly comprises a horizontally-arranged transmission rod, the transmission rod is driven by a motor, a second gear is arranged on the transmission rod in a sliding mode, through the structure of the detection marking assembly, when the pipeline passes through the lower portion of the detection marking assembly, the position of the leakproofness defect on the surface of the pipeline is detected and marked, and therefore follow-up repair of the pipeline is facilitated; and the whole pipeline is prevented from being discarded to cause waste.

The invention relates to the technical field of detection and conveying, in particular to a steel structure engineering fastening detection device which comprises a first supporting frame, a second supporting frame, an alignment assembly, a loading assembly and a moving assembly, and the loading assembly comprises a loading air cylinder, a mounting block, a loading block and a deformation detection module; the moving assembly comprises a lifting air cylinder, a lifting block, a conveying roller, a first sliding block, an elastic piece and a driven roller, the first sliding block is arranged on the first supporting frame in a sliding mode, the elastic piece is arranged between the first sliding block and the first supporting frame, the conveying roller is rotationally arranged on the first sliding block, and the lifting block is fixed above the first sliding block; the output end of the lifting air cylinder is connected with the lifting block, and the driven roller is slidably arranged on the second supporting frame. The steel structure can be automatically driven to move for cyclic detection, so that the use is more convenient, and the working efficiency is improved.

The invention discloses an air-fuel ratio control method for a high-pressure direct injection engine in a diesel-natural gas dual-fuel cylinder, and relates to the technical field of engine control, and the air-fuel ratio control method comprises the following steps: collecting diesel mass flow, natural gas volume flow and natural gas component data, and determining a diesel-natural gas mixing ratio; a basic target air-fuel ratio is obtained by combining the real-time rotating speed of an engine, the load and the diesel oil-natural gas mixing proportion; based on the pressure and temperature of the intake manifold and the rotating speed of the engine, the target air-fuel ratio after model correction is obtained; the working condition load change rate is detected, the pre-optimized air-fuel ratio trajectory MAP is called, and a transient correction target value is generated; calculating the deviation between the transient correction target value and the measured value of the air-fuel ratio sensor and the deviation change rate, and outputting an air-fuel ratio correction value; and the final target air-fuel ratio is calculated and sent to an air flow control valve to execute air inlet adjustment. The method is suitable for engine application scenes requiring high-precision and self-adaptive control to improve combustion efficiency and reduce emission.

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 engine casting molds, in particular to a cylinder sleeve limiting system of a high-pressure casting aluminum alloy slope type box, which comprises a mold, a core pulling device fixed on the mold and a limiting assembly connected in the mold in a sliding manner, and the core pulling device is used for driving the limiting assembly to axially move in a mold cavity; the limiting assembly comprises a sliding base connected to the mold in a sliding mode, a sliding block fixed to the sliding base and an insert fixed to the sliding block, and two symmetrically-arranged expansion blocks are connected to the insert in the diameter direction in a sliding mode. A cavity is formed in the center of the insert, an expansion pin is slidably connected into the cavity, and the expansion pin controls the end heads of the two expansion blocks to synchronously eject out or retract towards the peripheral face of the insert through axial movement. A channel is formed in the center of the expansion pin, an air inlet is formed in the sliding seat, one end of the channel is communicated with the cavity in the center of the insert, and the other end of the channel is communicated with the air inlet of the sliding seat. According to the scheme, the cylinder sleeve positioning precision of the engine box can be improved, and the casting process quality is guaranteed.

The invention discloses a dual-fuel engine combustion control method based on hydrogen-ammonia energy ratio and gas distribution overlap angle regulation and control, which comprises the following steps: 1) fuel ratio control: acquiring current operation state parameters of an engine, determining a target AER according to preset mapping, regulating ammonia gas supply quantity and hydrogen supply quantity to enable the actual AER to reach the target AER, and controlling the fuel ratio; the AER is adaptively set according to engine load and combustion stability conditions; 2) valve timing control: adjusting the opening time of an intake valve or the closing time of an exhaust valve through a variable valve timing mechanism so as to change a valve timing overlap angle VOA, wherein the VOA is set to be a negative value, a small overlap angle or a positive overlap angle according to the working condition of an engine; (3) injection time sequence optimization is conducted, specifically, the injection time of ammonia gas and the in-cylinder direct injection time of hydrogen are controlled respectively, and coordinated optimization of a fuel injection strategy and valve timing is achieved; and 4) closed-loop steady-state control: monitoring a combustion state and an emission index in real time, comparing the combustion state and the emission index with a threshold value to serve as a feedback signal, and correcting the target AER and VOA settings in time. According to the dual-fuel engine combustion control method based on regulation and control of the hydrogen-ammonia energy ratio and the gas distribution overlapping angle, the energy ratio of hydrogen fuel and ammonia fuel and the overlapping opening angle of an intake valve and an exhaust valve are dynamically adjusted under different working conditions, so that the combustion reaction rate and temperature are coordinated, and the stable and efficient combustion process is achieved; and harmful emissions of NOx, unburned ammonia and the like are obviously reduced.

The invention discloses an internal combustion engine in-cylinder transient self-adaptive exposure control method based on FPGA acceleration, and belongs to the technical field of internal combustion engine endoscopic visualization. In order to solve the technical problem of image overexposure or underexposure caused by violent illumination change in the combustion process in an internal combustion engine cylinder, a real-time exposure detection unit is fused with a camera built-in sensor and an endoscope added sensor to monitor light intensity data; the adaptive exposure control unit accelerated by the FPGA adopts adaptive PID control and fuzzy logic control to generate a parameter adjustment direction, the adaptive PID dynamically adjusts gain based on a machine learning model, and the fuzzy logic outputs a decision according to a fuzzy rule base of brightness, light intensity and errors; the parameter adjusting unit adjusts the aperture size, the shutter speed and the light sensitivity in a linkage mode according to the target and actual gray scale difference value, and millisecond-level multi-parameter exposure control is achieved. Overexposure of a highlight area and loss of details of a low-light area are effectively avoided, and stable and clear images are obtained in the whole combustion process.

A fuel reforming system for a vehicle includes a reciprocating engine mounted on a vehicle, a decomposer that decomposes a hydrocarbon fuel into carbon and a hydrogen gas and that stores the carbon, a hydrocarbon fuel supply unit that supplies the hydrocarbon fuel to the decomposer, and a hydrogen gas supply unit that supplies the hydrogen gas into a cylinder. The reciprocating engine performs a cycle including a compression stroke, an expansion stroke, and a re-compression stroke. The decomposer decomposes the hydrocarbon fuel into the carbon and the hydrogen gas utilizing the heat and the pressure of a combustion gas in the re-compression stroke. The decomposer includes a catalyst to which the carbon adheres and a water vapor adsorption portion in which water vapor is adsorbed.

The utility model discloses a fuel cell tractor, and relates to the technical field of vehicles. The fuel cell tractor comprises a frame, a cab and a hydrogen cylinder, the cab and the hydrogen cylinder are arranged above the frame, the hydrogen cylinder is arranged behind the cab, a driving system, a fuel cell engine and a power cell module are arranged at the bottom of the frame, the fuel cell engine, the power cell module and the driving system are electrically connected in sequence, and the hydrogen cylinder transmits hydrogen to the fuel cell engine. The fuel cell engine converts hydrogen into electric energy and transmits the electric energy to the power cell module, the power cell module transmits the electric energy to the driving system, a fuel cell cooling system is arranged above the hydrogen bottle, and the fuel cell cooling system dissipates heat of the fuel cell engine. The chassis layout of the fuel cell tractor can be simplified.

The utility model discloses a special gauge for measuring an engine cylinder cover hole, which relates to the technical field of cylinder cover hole measurement and comprises a base, a horizontal platform is arranged right above the circle center of the base, and an adjusting assembly for driving the horizontal platform to adjust the inclination is rotatably arranged on the upper surface of the base. A positioning assembly is arranged between the lower surface of the horizontal platform and the base, the circle center of the lower surface of the horizontal platform is fixedly connected with a detection rod which penetrates through the positioning assembly and is in sliding connection with the positioning assembly, and the circumferential side of the bottom end of the detection rod is in sliding connection with a measuring device. According to the special detection tool for measuring the engine cylinder cover hole, the positioning assembly is arranged above the base, so that the supporting rod drives the sliding rod to slide synchronously under the action of downward movement of the nut, then the supporting rod abuts against the inner wall of the hole under the action of the hooks, and when the multiple hooks tightly abut against the inner wall of the hole, the base and the hole are concentric, so that the detection accuracy is improved. And the detection rod and the base are coaxial, so that the hole can be conveniently positioned.

The invention discloses a sealing device for a jet pipe of a solid rocket engine. The sealing device comprises a front supporting body, a rear supporting cylinder and a sealing plug cover. The front section of the front supporting body is a circular-truncated-cone-shaped positioning cylinder, the rear section of the front supporting body is a circular-ring-shaped connecting cylinder, and internal threads are machined on the rear section of the inner wall of the circular-ring-shaped connecting cylinder. An external thread is machined on the outer wall of the rear supporting cylinder, a positioning circular plate is vertically fixed to the rear end of the rear supporting cylinder, and the outer edge of the positioning circular plate is machined to be a circular truncated cone face. The front supporting body and the rear supporting cylinder are inserted inwards from the two ends of the spray pipe respectively and then are in threaded butt joint, the outer wall of the front supporting body is tightly attached to the inner wall of a convergence section of the spray pipe and the inner wall of a spray throat, and the outer edge of a positioning circular plate of the rear supporting cylinder is tightly attached to the inner wall of an expansion section of the spray pipe. And the sealing blanking cap is in threaded connection with the front end of the rear supporting cylinder. According to the spray pipe sealing device, ignition pressure can be reliably established, and residues are few during separation.

The invention relates to a reliability test method and device for an emergency diesel engine of a nuclear power plant and a storage medium, and the test method comprises the following steps: obtaining the operation condition information of the emergency diesel engine, and obtaining the estimated total use time of parts of a connecting rod power assembly of the emergency diesel engine based on the operation condition information; structural information of a connecting rod power assembly of the emergency diesel engine is obtained, a dynamic calculation model of the connecting rod power assembly is constructed based on the structural information and the operation condition information, and the dynamic calculation model is used for simulating operation of the connecting rod power assembly in preset time; obtaining a wear coefficient of the part, and inputting the wear coefficient and the estimated total use duration into the dynamic calculation model to obtain the part wear loss of the connecting rod power assembly and the maximum wear loss of the cylinder sleeve; and determining the reliability of the emergency diesel engine according to the part abrasion loss and the maximum abrasion loss of the cylinder sleeve. The test method can guarantee reliable operation of the emergency diesel engine.

The invention discloses a multi-parameter identification method for a valve-controlled cylinder electro-hydraulic servo system, and belongs to the field of servo technology control. The method comprises the following steps: firstly, carrying out mathematical modeling according to components and a working principle of the valve-controlled cylinder electro-hydraulic servo system to obtain a system model and to-be-identified parameters; secondly, an improved multi-strategy firefly algorithm is provided, the randomness and uniformity of an initial solution are enhanced through an improved Chebyshev polynomial, the global search capability of the algorithm is improved, an updating algorithm is introduced to modify a step length factor of the firefly algorithm, and balance between local search and global exploration is achieved; finally, parameters of the established model are identified through an improved algorithm, simulation and experimental analysis are conducted, and according to the result, the accuracy of the model can be effectively improved, the robustness of the model can be improved, and reliable theoretical and practical support is provided for actual engineering application of the high-precision electro-hydraulic servo system.

A method for mitigating preignition events in a hydrogen internal combustion engine. The method includes providing a dosing system in fluid communication with a dosing cylinder of a cylinder block of the hydrogen internal combustion engine; introducing a lubricant including a base oil, a polymer, or mixtures thereof to an intake area of the dosing cylinder via the dosing system; and initiating operating conditions for the hydrogen internal combustion engine.

The invention discloses a double-connecting-rod type nut tightening device for a deep disc cavity of an aero-engine, and relates to the technical field of aero-engine manufacturing, the double-connecting-rod type nut tightening device comprises a biaxial truss, a horizontal rotating mechanism, a double-connecting-rod mechanism and a tightening mechanism; wherein the horizontal rotating mechanism is mounted at the output end of the biaxial truss and comprises an outer cylinder rotationally connected with the output end of the biaxial truss; the double-connecting-rod mechanism comprises an overturning shell and an overturning driving part, the overturning shell is installed at the lower end of the outer cylinder in a vertical overturning mode, and the overturning driving part is used for driving the overturning shell to vertically overturn by 90 degrees; the tightening mechanism comprises a first motor, a transmission inner shaft, a second screw rod, a linkage piece and a ratchet wheel head. The nut in the rotor of the aero-engine can be tightened in a mechanical mode, the problem that the nut is not easy to tighten due to the fact that the internal space of the rotor of the aero-engine is narrow is solved, convenience is brought to installation of the aero-engine, and the production efficiency is improved.

The invention provides a liquid ammonia in-cylinder direct injection engine combustion system and method with an active pre-combustion chamber, and relates to the technical field of internal combustion engines, the liquid ammonia in-cylinder direct injection engine combustion system comprises a cylinder cover and a cylinder sleeve arranged below the cylinder cover, the pre-combustion chamber is vertically arranged in the center of the cylinder cover, a liquid ammonia injector is arranged on one side of the pre-combustion chamber, and the active pre-combustion chamber is arranged in the cylinder sleeve. A hydrogen ejector and a spark plug are arranged on the pre-combustion chamber; and spraying holes are formed in the pre-combustion chamber and located in the bottom of the pre-combustion chamber, and the spraying holes of the pre-combustion chamber face one side of the liquid ammonia ejector. According to the liquid ammonia in-cylinder direct injection engine combustion system and method with the active pre-combustion chamber, the effect that diffusion combustion is promoted through premixed combustion of ammonia fuel is achieved, accurate control over the combustion initial point and the heat release rate is achieved, and the requirements for the low hydrogen energy ratio, high ignition efficiency and high heat efficiency of an ammonia fuel engine in the full working condition range are met.

The invention discloses an engine EGR system, a control method and a vehicle. The engine EGR system comprises a turbocharger, a first valve, an electric compressor, an intercooler, an EGR cooler and at least one air cylinder. The exhaust end of the air compression assembly is connected with the first end of the intercooler, and the second end of the intercooler is connected with the air inlet end of the air cylinder. The first end of the first valve is connected with the exhaust end of the air compression assembly, the second end of the first valve is connected with the second end of the EGR cooler, the third end of the first valve is connected with the first end of the electric air compressor, and the second end of the electric air compressor is connected with the intercooler; air enters through the air inlet end of the air compression assembly, and the first valve controls the intervention condition of the electric air compressor by adjusting the opening degree of the first valve. Air passes through the intercooler and the air cylinder to generate waste gas, and at least part of the waste gas flows into the turbine assembly and is exhausted. According to the engine EGR system provided by the invention, the intervention condition of the electric gas compressor is controlled through the action of the first valve, so that the purpose of adapting to multiple working conditions and multiple scenes is achieved.

The utility model discloses an engine cylinder cover valve collet assembling auxiliary device which comprises a roller way, a cylinder cover positioning device installed on the roller way and a power mechanism driving a press-fitting plate to move up and down. The power mechanism comprises an oil cylinder and is characterized by further comprising an oil cylinder rod mounting plate, the oil cylinder rod mounting plate is mounted below the roller way, the middle of the oil cylinder rod mounting plate is connected with the end of an oil cylinder rod of the oil cylinder, and guide rods are fixedly mounted at the two ends of the oil cylinder rod mounting plate respectively; longitudinal frames are fixedly mounted at the upper ends of the guide rods; the press-fitting plate is located above the roller way, and the two ends of the press-fitting plate are connected to the longitudinal frame. The press-fitting plate is further provided with a transverse middle long groove extending in the length direction of the press-fitting plate, a plurality of longitudinal grooves which are longitudinally arranged and intersect with the middle long groove, and a plurality of transverse grooves which are transversely arranged. The press-fitting device has the advantages of being compact in structure, high in working efficiency, capable of adapting to installation of various valve lock clamps without replacing the press-fitting plate and the like.

The utility model relates to a thin-wall steel pipe cutting device, and aims to solve the problems of uneven pipe orifice, low precision and the like caused by a traditional cutting mode. The equipment is composed of a rack component, a cutting component and a die clamping component. The die clamping component clamps the steel pipe through the die clamping air cylinder, and the steel pipe is conveyed to a machining station through the feeding air cylinder. The cutting component comprises a servo motor, a gear set, a fixed cutter shaft and a movable cutter shaft, the servo motor drives the blade to rotate, and the cutter pushing air cylinder controls the blade to be pushed out for cutting. The inclined planes of the circular-truncated-cone-shaped blades on the fixed cutter shaft and the movable cutter shaft face opposite directions, accurate cutting can be achieved, notches are neat and smooth, and the size height is accurate. The machining method comprises the steps of feeding, clamping, feeding, blade rotating, pushing-out cutting and the like. The machining quality and efficiency of the thin-wall steel pipe can be improved, the follow-up machining workload is reduced, strict engineering requirements are met, and wide application prospects are achieved.

The invention belongs to the technical field of engineering hydraulic oil cylinders, and particularly relates to a hydraulic oil cylinder with a filtering mechanism for reducing pollutant accumulation. An air inlet pipe is directly connected with an external cold air source, cold air can be directly diffused in a device box and wraps a hydraulic oil cylinder body, and meanwhile a motor drives fan blades to rotate through a third rotating shaft; according to the oil cylinder cooling device, flowing of cold air in the device box body can be accelerated, the heat dissipation effect of the oil cylinder can be enhanced, heat accumulation caused by local retention of the cold air can be avoided, meanwhile, suspended dust generated by cleaning of the cleaning brush, small impurities which are not settled in the cold air and falling objects in the using process of the cleaning brush can be sucked, and the cleaning effect is improved. And the cleaning rod rotates under the rotation of the third rotating shaft, so that the impurities blocked by the second filter screen are cleaned, and the impurities enter a first collecting box through a connecting pipe.

The invention relates to the technical field of energy storage and transportation, and discloses a rapid prediction method for cylinder damage of metal pressure-bearing equipment under an explosive load, and the method comprises the steps: obtaining the parameters of the to-be-predicted metal pressure-bearing equipment and the maximum unit area impulse I of the explosive load acting on the pressure-bearing equipment; calculating a cylinder section deflection angle theta of the pressure-bearing equipment; and comparing the calculated deflection angle theta of the section of the cylinder with a preset damage grade criterion so as to judge the damage grade of the cylinder of the pressure-bearing equipment. According to the prediction method, the prediction steps are calculated based on formulas, the calculation process is rapid, simple and convenient, and a complex finite element model of the pressure-bearing equipment does not need to be constructed and solved, so that the prediction efficiency is greatly improved, meanwhile, the professional skill requirements and learning cost of engineers are reduced, and the technical threshold is reduced.