4638 results about "Cylinder (engine)" patented technology

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 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 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 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 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.

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 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 discloses a vertical shaft duct piece splicing device and a construction method thereof, and belongs to the technical field of vertical shaft engineering construction.The vertical shaft duct piece splicing device comprises a moving trolley, an overturning assembly, a clamping mechanism and a lifting mechanism, a support of the overturning assembly is vertically arranged on the moving trolley, and an overturning plate is rotationally connected to the support and provided with two guide columns; the overturning oil cylinder is used for driving the overturning plate to be switched between the horizontal state and the vertical state. A base of the clamping mechanism is provided with two guide holes for two guide columns to penetrate through, a clamping piece is rotationally arranged in a rotating groove of the base, an elastic piece is installed in the rotating groove and connected with the clamping piece, and when a duct piece is placed on a turnover plate in a horizontal state, the clamping piece can be pushed to be rotationally inserted into a hanging hole of the duct piece, and the elastic piece is stretched. The lifting mechanism is arranged on the overturning plate and can drive the base to drive the clamping piece to vertically move downwards. The vertical shaft duct piece splicing construction method adopts the vertical shaft duct piece splicing device. The device is high in stability, high in assembly precision and low in safety risk.

The invention discloses a transverse fixed axle assembly capable of achieving Ackerman steering through mechanical linkage, and belongs to the technical field of engineering vehicle chassis. A rear axle is transversely and rigidly fixed to a frame through a shear-resistant box girder structure, and a front axle is connected to the frame through two springs; the rotating pair structures are symmetrically arranged at the two ends of the axle main body and comprise embedded heavy-duty bearings; one end of the steering knuckle arm is hinged to the axle main body through a rotating pair structure, and the other end is connected with the steering pull rod; one end, far away from the rotating pair structure, of the steering pull rod is connected with the steering oil cylinder; the steering pull rod of the front axle and the steering pull rod of the rear axle are crossed and hinged in an X shape, so that intersection points of axes of the front and rear wheels converge at an instantaneous steering center during steering. Abrasion and slipping of tires can be reduced, steering precision is ensured through a pure mechanical structure, the failure risk of an electric control system is avoided, and the system is suitable for heavy equipment such as mining trucks and port cranes.

The invention discloses a spraying system for an aeroengine icing test and a high-altitude icing simulation test bed, the spraying system comprises a spraying device, the spraying device comprises a spraying support and a plurality of atomizing pipe groups, and the plurality of atomizing pipe groups are detachably arranged on the spraying support. Each atomizing pipe group comprises a heat insulation coating barrel, a plurality of atomizing nozzles sequentially arranged in the length direction of the heat insulation coating barrel, a water supply pipe and an air supply pipe which are arranged in the heat insulation coating barrel in the length direction of the heat insulation coating barrel, and a heat insulation material filled in the heat insulation coating barrel; the inner side end, located in the heat insulation wrapping barrel, of the atomizing nozzle communicates with a water supply pipe and an air supply pipe, the opposite outer side end of the atomizing nozzle extends out of the heat insulation wrapping barrel, and at least one end of the water supply pipe and at least one end of the air supply pipe extend out of the spraying support to correspondingly introduce water and compressed air. According to the invention, the atomization pipe group can be taken out as required for deep maintenance, and meanwhile, the anti-freezing and anti-blocking capabilities of the water supply pipe and the air supply pipe in the test process are improved, so that the long-time duration of the icing test of the aero-engine is ensured.

A system for attaching a front engine of an aircraft, having: a vertical median plane, an engine pylon with a nose having a main female clevis, and a cylindrical housing around a vertical axis, a main link fastened to a front casing of the engine by a secondary ball-joint connection about a secondary axis perpendicular to the median plane by a secondary shaft, a main shaft, perpendicular to the median plane and forming a main ball-joint connection of the main link in the main female clevis about a main axis, the main and secondary axes in the plane perpendicular to the median plane, and an outer cylinder, coaxial with the vertical axis and a first end of which fastened in the cylindrical housing and a second end of which mounted, via an annular linear connection, around the vertical axis with respect to the front casing.

The invention provides a diesel engine cylinder fault diagnosis method and system based on MMFE-PSO-KELM, and the method comprises the steps: S1, collecting a vibration signal of the surface of a cylinder cover of a diesel engine cylinder and a rotating speed signal of a crankshaft, and carrying out the preprocessing of the vibration signal; s2, an MMFE algorithm is adopted to analyze and process the preprocessed vibration signals, and MMFE feature vectors rich in high-frequency and low-frequency fault mode information are constructed; s3, optimizing a regularization parameter C and a kernel function parameter sigma of the KELM model by using a PSO (Particle Swarm Optimization) algorithm, and searching an optimal parameter combination which maximizes the classification accuracy by taking the classification accuracy as a fitness function; and S4, constructing a KELM diagnosis model based on the optimal parameter combination, and performing fault diagnosis on the diesel engine cylinder by taking the high-frequency and low-frequency fault mode information extracted by the MMFE algorithm as input. According to the method, strong noise interference can be effectively inhibited, fault feature information can be comprehensively reserved, KELM key parameters can be optimized, and the accuracy and reliability of fault diagnosis of the diesel engine cylinder are improved.

The invention discloses an in-cylinder flame multi-characteristic parameter extraction and instantaneous evaluation method based on machine learning, and belongs to the technical field of power energy. Aiming at the problem that a traditional method is difficult to accurately extract flame transient characteristic parameters in a dynamic combustion environment, the method comprises the following steps: acquiring an in-cylinder flame image sequence through an endoscopic high-speed camera, and extracting an event driving key frame and a uniform time key frame by adopting optical flow analysis and fixed interval sampling; utilizing a double-flow feature extraction network to respectively obtain flame spatial form features and radiation features; capturing a flame parameter time evolution law through a time sequence convolutional network, and dynamically fusing key frame features in combination with a self-attention mechanism; and finally outputting flame temperature field and soot distribution prediction results. According to the method, instantaneous evaluation of the combustion process is realized, and a basis is provided for engine performance optimization and combustion fault diagnosis.

The invention relates to the technical field of magneto-rheological damper regulation and control, and discloses a reinforcement learning adaptive optimal regulation and control system of a magneto-rheological damper, which comprises a magneto-rheological damper body, the body is provided with a magnet exciting coil, a magneto-rheological fluid channel, a piston rod and a cylinder barrel, after the magnet exciting coil is electrified, a controllable magnetic field is established in the magneto-rheological fluid channel; the magnetic field intensity is continuously adjustable, the sensing network is composed of a displacement sensing unit, a speed sensing unit, an acceleration sensing unit, a temperature sensing unit and a magnetic field intensity sensing unit, and all the sensing units are fixed to the outer wall of the cylinder barrel in a non-contact mode and are coaxially arranged with the movement axis of the piston rod. A sensing network, an edge calculation node, a reinforcement learning decision-making unit and an online evolution engine are embedded in a heat conduction substrate and a shielding cover on the outer wall of the same cylinder barrel, the displacement angle and acceleration response between structural layers are remarkably reduced, and advanced protection that vibration is not displayed and damping is changed is achieved.

The invention belongs to the field of polishing, and relates to an ultrasonic polishing device and method for an air film hole of a turbine blade of an aero-engine, which can be used for efficiently and quickly polishing the air film hole of the turbine blade of the aero-engine. The technical scheme comprises an ultrasonic polishing unit and a clamp unit. The ultrasonic polishing unit comprises an ultrasonic tool head. The aero-engine turbine blade is fixed to the clamp unit, the ultrasonic tool head sends ultrasonic waves to the surface of the aero-engine turbine blade, and a film hole of the aero-engine turbine blade is polished. The whole ultrasonic tool head is a cylinder, the side face of the ultrasonic tool head is a conical cylindrical face, the end face, corresponding to the large-diameter end of the conical cylindrical face, of the ultrasonic tool head is an ultrasonic transmitting face, and the ultrasonic transmitting face of the ultrasonic tool head is a curved face matched with the surface of the aero-engine turbine blade. When the ultrasonic tool head conducts polishing operation on the air film hole of the aero-engine turbine blade, fluid dynamic pressure is generated at the hole opening of the air film hole.

The invention relates to the field of vehicle control, in particular to an intelligent oil-saving sliding control method and system for an AMT commercial vehicle and the commercial vehicle, and the method comprises the steps: obtaining a gradient threshold interval and hysteresis width corresponding to a current state based on the total load of the vehicle, the real-time vehicle speed and the real-time road gradient; whether the engine water temperature and the accelerator opening degree signal meet preset fuel-saving sliding admission conditions or not is judged in real time; when all the access conditions are met and the real-time gradient and the vehicle speed are within the threshold interval, gear combination of the AMT gearbox is maintained, an engine is controlled to enter a fuel cut-off mode, and the vehicle enters an intelligent fuel-saving sliding state based on engine reverse towing; and if the real-time gradient exceeds the safety range, engine fuel oil supply is immediately recovered, and the in-cylinder braking or exhaust braking function of the engine can be cooperatively activated, so that the fuel-saving sliding state is stably quitted. And on the premise of ensuring compliance and safety of the whole process, the fuel economy is effectively improved.

The invention discloses an automatic assembling device and method for an O-shaped ring in an oil injector hole of an engine cylinder cover, and relates to the technical field of engine cylinder covers. The feeding mechanism comprises a feeding base, and a vibrating screen mechanism, a stop block mechanism and a jacking mechanism which are connected to the feeding base; the vibrating screen mechanism is used for sequentially conveying a plurality of O-shaped rings into the mounting positions of the stop block mechanism; a supporting claw connected with an O-shaped ring is arranged in an installation position of the check block mechanism, and an opening and closing baffle assembly is arranged at the top of the installation position. The jacking mechanism is provided with a jacking plate and a jacking device, and the jacking device can jack the jacking plate to enable the O-shaped ring on the supporting claw to be ejected out. The assembling mechanism comprises a conveying mechanism, an assembling base, a driving device and a grabbing and clamping mechanism; the assembling base is movably connected to the conveying mechanism; the driving device is connected to the assembling base; the driving device drives the grabbing and clamping mechanism to move so as to grab the O-shaped ring on the supporting claw, and the O-shaped ring is pressed into an oil spraying hole of the cylinder cover.

The invention discloses an agricultural machinery steering axle tube beam formed by a seamless steel tube and a manufacturing method thereof, and relates to the technical field of engineering machinery parts, the agricultural machinery steering axle tube beam is of a symmetrical variable cross-section variable wall thickness hollow rectangular structure, is composed of a tube beam middle part, a tube beam neck part and tube beam two ends, and is in an inverted convex shape with a flush upper surface, consistent width and a raised middle lower part. The middle size of the tubular beam meets performance requirements and oil cylinder support mounting requirements, and a round hole for mounting a supporting bearing seat is formed in the tubular beam; the lower surfaces of the two ends of the tubular beam are higher, and arc-shaped grooves welded with main pin seats are formed in the outer sides; the upper surface and the width of the neck of the tubular beam are unchanged, and the lower surface gradually rises through two transition arcs and is connected with the middle of the tubular beam and the two ends of the tubular beam respectively. The pipe beam is manufactured by heating, reducing, bending, pressing and machining a seamless steel pipe, the impact resistance of a product is good, the weight is reduced by more than 15% compared with that of a welding structure, the material utilization rate reaches 95%, and the universality is high.

The invention provides a control method and device for consistency of all cylinders of an engine and a vehicle. The method comprises the steps that the rotating speed and torque of the engine are obtained, and the rotating speed and torque of the engine are obtained; determining that the engine is in a low-speed and low-load working condition under the condition that the engine rotating speed is in a first preset range and the engine torque is in a second preset range; under the condition that the engine is in the low-speed and low-load working condition, the camshaft phase is controlled to be delayed relative to the crankshaft phase, so that opening of an intake valve of the engine is delayed, and the problem that in the prior art, the actual EGR rate consistency of all cylinders of the engine is poor is solved.

The invention relates to the field of Stirling engines, and provides a Stirling engine oil-free lubrication cylinder sleeve and a Stirling engine, the Stirling engine oil-free lubrication cylinder sleeve comprises a cylinder sleeve body, and the inner hole wall of the cylinder sleeve body is divided into a high-speed section and low-speed sections located on the two sides of the high-speed section in the axial direction of the cylinder sleeve body; continuous net-shaped textures are arranged on the surface of the inner wall of the high-speed section, pit textures distributed in an array mode are arranged on the surface of the inner wall of the low-speed section, and the net-shaped textures and the pit textures form gradient surface textures in the axial direction of the cylinder sleeve body. The gradient surface texture is arranged on the inner surface of the cylinder sleeve according to the reciprocating speed characteristic of a piston, the high-speed section strengthens gas dynamic pressure bearing through the net-shaped texture, the low-speed section optimizes adhesion resistance and abrasive dust storage through the pit texture, the gas lubrication potential is fully released, friction reduction and service life prolonging of a dynamic sealing friction pair are achieved, and the service life is prolonged. The problems that a single surface structure of a traditional cylinder sleeve cannot be matched with the reciprocating speed difference of a piston, and the gas lubrication effect is insufficient are solved.

The media intelligent identification premature ejaculation rehabilitation training device comprises a front machine body shell and a rear machine body shell arranged on the back face of the front machine body shell, a pluggable front panel is arranged on the front face of the front machine body shell, and machine body keys are arranged on the front face of the front panel. And the device further comprises a first PCB, a steering engine, a force arm, a rotating shaft, a steering engine fixing part, a connecting rod, a middle frame part, a first magnetic part, a power supply cover, a vertex limiting part, a power supply, a second PCB, a light guide part, a top cover key, a third PCB, an inner cylinder, a rear machine body shell and a rear panel. Specific actions are identified and captured by training artificial intelligence through a large number of material contents for detailed labeling and classification, the specific actions are converted into structured data for high-precision angle mechanical linkage real-time synchronous movement, the data processing efficiency is improved, automatic and intelligent application is achieved, tedious operation and complex learning cost of a user are effectively reduced, and the user experience is improved. And compared with a similar reciprocating stretching mechanical structure, stronger immersion sensory experience is brought.

This invention discloses an exhaust system for a six-cylinder, four-valve engine, including a cylinder head and an exhaust pipe. The cylinder head contains coolant and has several cooling water passages. A guide edge is provided within the cylinder head, and guide holes are formed between the guide edge and the top and bottom surfaces of the cylinder head. A set of mounting holes is located above the guide holes on the front end face of the cylinder head. The exhaust pipe is fixed to the front end of the cylinder head through the mounting holes. The exhaust pipe has a segmented structure, and a sealing structure is provided at the joints of the segments. This invention eliminates dead zones in the coolant flow, improving coolant fluidity and preventing excessively high surface temperatures in the cylinder head's water passages. The installation of long bolts on the exhaust pipe, through control of positioning errors and fitting clearances, ensures that the bolts and holes do not interfere, preventing stress caused by interference and exhaust pipe breakage at high temperatures. The composition of the exhaust pipe has been improved, enhancing its high-temperature resistance.

An all-terrain vehicle (ATV) has a frame having front and rear ends, an internal combustion engine connected to the frame, the engine including a front portion and a rear portion, a single cylinder defining a cylinder axis, an air intake port defined in the front portion facing towards the front end of the frame, and an exhaust port defined in the rear portion facing towards the rear end of the frame. The ATV further has an exhaust assembly fluidly connected to the exhaust port. The exhaust assembly extends from the engine towards the rear end of the frame. The ATV further has a continuously variable transmission operatively connected to the engine, which includes a primary pulley being operatively connected to the engine, a secondary pulley, a drive belt looped around the primary and secondary pulleys, and a housing enclosing the primary pulley, the secondary pulley, and the drive belt.

The invention belongs to the field of engineering machinery, and discloses a forklift loader and a fork hydraulic system.The fork hydraulic system comprises a first oil cylinder and a second oil cylinder, rod cavities between the first oil cylinder and the second oil cylinder are communicated with each other, a rodless cavity of the first oil cylinder is connected with a first sidesway working oil way, and a rodless cavity of the second oil cylinder is connected with a second sidesway working oil way. A rodless cavity of the second oil cylinder is connected with a second lateral displacement working oil way; and a multi-way valve to which the first side shift working oil path and the second side shift working oil path are hydraulically connected. The two oil cylinders can be driven to generate synchronous transverse movement on the opposite sides, and therefore synchronous lateral movement hydraulic driving is achieved. The distance between the fork knives of the pallet fork is adjusted in a non-manual mode, goods can be conveniently taken by the pallet fork, the left-right position adjustment of heavy goods loaded by the pallet fork on the pallet fork portal frame can be achieved, and the heavy goods can be conveniently and accurately stacked.

An ultrasonic detection robotic arm device for an inner cavity of an aero-engine belongs to the technical field of aero-engine assembly quality detection and comprises a rotary indexing assembly, a lifting distance adjusting assembly, a telescopic distance adjusting assembly, a protective support cylinder, an ultrasonic detector host and an ultrasonic probe. The rotary indexing assembly is connected with an aero-engine blade disc rotor through an external tool; the upper end of the protective supporting cylinder is connected with the rotary indexing assembly; the lifting distance adjusting assembly is arranged on the inner side of the bottom end of the protection supporting cylinder. The telescopic distance adjusting assembly is arranged between the rotary indexing assembly and the lifting distance adjusting assembly; the ultrasonic detector host is arranged on the rotary indexing assembly; the ultrasonic probe is arranged on the telescopic distance adjusting assembly and is electrically connected with the ultrasonic detector host. Compared with a traditional manual mode for completing thickness dimension detection, the automatic thickness dimension detection device has the advantages that the manual labor intensity can be greatly reduced, the execution of the detection process is completed in an automatic mode, and the stability of the detection quality and the detection efficiency are effectively improved.

The utility model provides a landing leg oil cylinder and a hydraulic auxiliary supporting system, and belongs to the technical field of heavy machinery, the landing leg oil cylinder comprises a telescopic oil cylinder and a landing leg base located at the bottom of the telescopic oil cylinder, and the landing leg base is used for supporting the telescopic oil cylinder; the travel switch is provided with a switch contact, and the switch contact protrudes towards the ground, so that the travel switch is in contact with the ground before the landing leg base is in contact with the ground, and the landing leg base has a complete ground contact state and a non-complete ground contact state; the manual adjusting mechanism is arranged on the supporting leg base; in a state of completely contacting with the ground, the telescopic oil cylinder normally stretches out and draws back; in the state that the supporting leg base is not in complete contact with the ground, the supporting leg base is adjusted to be in complete contact with the ground through the manual adjusting mechanism. The hydraulic supporting leg oil cylinder can effectively solve the problem that the supporting stability of the hydraulic supporting leg oil cylinder is insufficient in a complex environment, and ensures that the supporting leg oil cylinder can be reliably withdrawn when a hydraulic system breaks down, so that the safety and the emergency evacuation capacity of an engineering vehicle are improved.

The invention belongs to the technical field of oil and gas well gas production engineering, and particularly relates to a sand prevention gas lift device. The sand prevention gas lift device comprises an eccentric cylinder; the gas lift valve is arranged on the outer side of the eccentric cylinder; the filter mechanism is arranged on the outer side of the eccentric cylinder and connected with the gas lift valve, and fluid outside the eccentric cylinder sequentially passes through the filter mechanism and the gas lift valve to enter the eccentric cylinder.