1133 results about "Cylinder head" patented technology

The invention relates to the technical field of compressor cylinder covers, in particular to a compressor partition plate hole machining clamp which comprises a support, four sets of positioning mechanisms, a fixing mechanism and a power mechanism, the four sets of positioning mechanisms are evenly distributed on the support, each set of positioning mechanism comprises a mandrel and an elastic clamp arranged on the mandrel in a sleeving mode, and workpieces are arranged on the elastic clamps in a sleeving mode; the fixing mechanism and the positioning mechanism are correspondingly arranged, and the fixing mechanism comprises a mounting plate arranged on the outer side of the mandrel, a plurality of sets of supporting assemblies arranged on the mounting plate in a circumferential array mode and pressing assemblies arranged corresponding to the supporting assemblies; the power mechanism is installed on the support and drives the supporting assembly, the positioning mechanism and the pressing assembly to act in sequence to clamp a workpiece. The workpiece is placed on the multiple sets of supporting units, the supporting faces of the two sets of turning plates in each set of supporting units can be rotated from opposite arrangement to upward arrangement to support the workpiece, after the workpiece is supported, the positioning mechanism and the pressing assembly fix the workpiece, and the problem that in the prior art, the workpiece positioning precision is poor is solved.

Invention relates to a fuel ignitor (10) for gaseous fuel comprising a body assembly (12) having a longitudinal axis (A), and a first axial end and a second axial end. The ignitor body assembly (12) comprises a. a prechamber (20) arranged at the first axial end and having a tip, and more than two jet openings (22) arranged to the tip of prechamber (20) at the first axial end, b. a fuel inlet (26) arranged to open into the prechamber (20), c. first cavity (28) arranged to extend from the second axial end of the body assembly (12) to proximity to the prechamber (20), wherein a solenoid actuated gas admission valve unit (29) is arranged in the first cavity (28), d. second cavity arranged to extend from the second axial end of the body assembly (12) to the prechamber (20), wherein an ignition device (31) is arranged in the second cavity in cooperation with the prechamber (20) so as to initiate combustion of fuel in the prechamber (20), when in use, e. cooling channels (32) arranged at the first axial end of the ignitor body assembly (12) arranged in heat transfer connection with the prechamber (20). Invention relates also to a cylinder head - fuel ignitor combination, a gas operated internal combustion engine and method of converting an existing internal combustion piston engine.

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 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 relates to the technical field of engine cylinder body and cylinder cover surface defect detection, and discloses a visual detection method for engine cylinder body and cylinder cover surface defects, which comprises the following steps of: acquiring engine cylinder body and cylinder cover surface images under various different imaging conditions, preprocessing, extracting a feature vector of each pixel block, distributing weights by using a weight function, and calculating the surface defects of the engine cylinder body and cylinder cover. The method comprises the following steps: extracting a suspected defect area, introducing a loss function for verification, constructing a causal graph, calculating the probability of each defect type through causal inference, providing a decision basis for final output decision, and finally outputting a defect result. By integrating multi-angle illumination, multi-spectral imaging and laser scanning systems, rich information of the surface under different physical characteristics can be obtained, and it is ensured that various types of defects can present high contrast characteristics under at least one imaging mode.

The invention discloses an automatic laying and forming process for a reinforcing ring of a carbon fiber fully-wound gas cylinder end socket, and relates to the technical field of carbon fiber wound gas cylinders. Technological parameters are simulated and optimized; the laying line type is imported into software to plan the motion track of the robot; carbon fiber prepreg is adopted, single-layer prepreg laying is conducted between every two spiral layers of the gas cylinder according to the optimal process parameters, and the laminating state of the prepreg is monitored in real time. Full-automatic precise laying can be achieved, and the production efficiency and consistency are improved; the material utilization rate is improved; the manufacturing cost is reduced; the laying wrinkle defect is eliminated, and the gas cylinder bearing safety is improved; process parameters are quantified and optimized, and the performance of the carbon fibers is fully released.

A sliding arrangement for use in an internal combustion engine is described, comprising a cylinder liner (1) and at least one piston ring (10), wherein the liner (1) has a through-bore defining an inner surface (S) which in turn defines three sections: a first section (2) near the end of the piston stroke, facing the cylinder head (at top dead center, TDC); a second, middle section (3); and a third section (4) near the end of the piston stroke, facing the crankshaft of the engine (at top dead center, TDC), wherein (i) the TDC section (2) of the liner (1) has a surface finish with a first roughness value defined by a structure of recesses and projections (“valleys” and “raised areas”); the middle section (3) of the liner (1) has a surface finish with a second roughness value defined by a structure of recesses and projections (“valleys” and “raised areas”);(1) the BDC section (4) of the cylinder liner (1) has a surface finish with a third roughness value defined by a structure of recesses and projections (“valleys” and “raised areas”), and the roughness value of the middle section (3) is significantly lower than the roughness value of the TDC section (2), and is defined by an essentially very smooth structure of recesses and projections (“valleys” and “raised areas”); and (ii) a ceramic coating (R) is applied to at least part of the contact surface of the piston ring (10) by the physical vapor deposition (PVD) process.

This invention relates to the field of compressor technology, specifically to a pump body assembly, a compressor, and an air conditioner. The pump body assembly includes a cylinder and an oil guiding structure. A partition is fitted onto one side of the cylinder, and a cylinder head is fitted onto the other side. The cylinder has a vane groove for mounting a vane. A first oil groove extending axially along the cylinder is provided on the side wall of the vane groove. An oil hole is provided on the partition, opposite to the side of the vane away from the cylinder head, and the oil hole communicates with the first oil groove. The oil guiding structure guides lubricating oil to the oil hole, allowing the lubricating oil to flow into the first oil groove. A back pressure cavity is formed between the side of the vane away from the partition and the cylinder head. The oil guiding structure also guides lubricating oil into the back pressure cavity, providing a force to the vane relative to the partition. According to the technical solution of this invention, the back pressure cavity provides back pressure to the vane, balancing the axial impact of the lubricating oil in the oil hole on the vane, resulting in a more balanced axial force on the vane and thus reducing wear on the vane's end face.

The invention relates to the technical field of cylinder covers of vehicle engines, and provides a coating system and a coating for a cylinder cover metal mold. The coating formed on the inner surface of the cylinder cover metal mold based on the coating system has the advantages that the service life of the mold coating is prolonged, and casting defects can be reduced. The coating system comprises a first material liquid and a second material liquid; the first material liquid comprises a first coating and a first solvent for dilution, and the first coating comprises the following components in percentage by mass: 20-30% of silicon dioxide powder, 10-20% of aluminum oxide powder, 1-7% of magnesium oxide powder, 35-45% of a binder, 2-8% of titanium oxide powder and 5-25% of water; the second material liquid comprises a second coating and a second solvent for dilution; the second coating comprises the following components in percentage by mass: 20-30% of silicon dioxide powder, 10-20% of aluminum oxide powder, 1-7% of magnesium oxide powder, 35-45% of a binder, 2-8% of titanium oxide powder and 5-25% of water; the dilution multiple of the first coating is greater than that of the second coating.

The invention discloses a fuel injection method and device of an engine, a vehicle and a storage medium, a cylinder cover of the engine is provided with a fuel injector, a glow plug is arranged below an air inlet channel, the fuel injector is configured to inject fuel into a combustion chamber of the engine, and the glow plug is configured to heat the combustion chamber of the engine. The method comprises the steps that under the condition that an engine starting instruction is received, the cooling water temperature of an engine is obtained; under the condition that the temperature of the cooling water is smaller than or equal to a first preset temperature threshold value, the glow plug is controlled for heating; and under the condition that the temperature of the glow plug reaches the second preset temperature threshold value, the motor of the vehicle is controlled to drag the engine to rotate at the preset rotating speed, and the fuel injector is controlled to conduct single-time injection into the combustion chamber in the later period of the compression stroke. According to the fuel injection method, the problem that single-fuel cold start of the methanol engine is difficult in cold weather can be solved, the success rate of cold start of the engine is increased, and the cost can be reduced.

The invention discloses a system for preheating a cold-state cylinder body through waste gas and a preheating method. The system comprises a preheating pipeline unit, a waste gas turbocharging unit, a temperature monitoring unit, an exhaust valve assembly and a control unit. The preheating pipeline unit comprises an annular preheating main pipeline and a converging pipeline, and a plurality of preheating sub-pipelines are distributed on the periphery of an engine cylinder body; the exhaust gas turbocharging unit comprises a turbine and a gas compressor; the control unit is used for controlling opening and closing of the exhaust valve assembly according to the numerical value of the temperature monitoring unit, so that a main pipeline is preheated through waste gas when an engine is cooled and started, and three-dimensional preheating is conducted on a cylinder body after it is judged that the preheating main pipeline reaches the uniform thermal field according to a first threshold value. And starting the exhaust gas turbocharging unit according to the second threshold value, and enabling all exhaust gas to flow through the exhaust gas turbocharging unit to execute a turbocharging function until a third threshold value is reached. Firstly, a uniform thermal field is established on a preheating main pipeline to heat a cylinder cover, and then the cylinder body is preheated in the circumferential direction of the cylinder body.

1. Name of the designed product: cylinder head of motorcycle engine. 2. Use of the designed product: the designed product is used for motorcycle engine and belongs to motorcycle accessories. 3. Design points of the designed product: in shape. 4. Picture or photo best indicating the design points: perspective view.

The application discloses a device and method for adjusting the radial installation angle of the jet hole of a precombustion chamber spark plug, which comprises a sleeve, a sleeve extension rod and a torque wrench, the sleeve extension rod is connected with the sleeve, the torque wrench is arranged on the upper portion of the sleeve extension rod, the sleeve is an outer hexagonal sleeve, and the device further comprises an angle pointer and an angle scale dial, the angle scale dial is fixed on a cylinder head, and the angle pointer is buckled on the sleeve extension rod and located above the angle scale dial. The device increases the angle pointer and the angle scale dial on the basis of the sleeve extension rod and the torque wrench, can adjust the jet hole angle of the precombustion chamber spark plug, and makes the jet hole of the precombustion chamber spark plug be at an angle more favorable to the combustion in the cylinder.

This invention discloses a frustum-shaped chill for the firing surface of cylinder heads in sand casting, belonging to the technical field of casting process auxiliary parts. The chill includes a chill body with multiple circular bosses evenly distributed along the radial direction on its top surface for precise positioning within the sand mold. The top surface of the body has crisscrossing venting grooves to expel gases generated during the solidification of the sand core and molten metal. The body is divided into upper and lower frustum sections, with the upper frustum being higher than the lower frustum, forming a gradient cooling structure. Through structural optimization, this invention achieves precise and controllable cooling of the cylinder head firing surface, reducing defects such as shrinkage porosity, looseness, and gas porosity to near zero, improving casting density and yield, and is suitable for sand casting production of various aluminum engine cylinder heads.

A novel cylinder stroke control mechanism, belonging to the technical field of cylinder auxiliary equipment, includes photoelectric sensors, a limiting plate, and a detection circuit. The limiting plate is fixedly installed on the front end of the piston rod of the cylinder. Two fixing holes are located on both sides of the cylinder head on one side of the piston rod, and two photoelectric sensors are fixedly installed in the two fixing holes respectively. The detection circuit is installed in a component box and electrically connected to the detection circuit. This novel mechanism is mainly used in conjunction with cylinder control. In actual operation, when the piston of the cylinder drives the piston rod and the limiting plate to move left or right, the limiting plate will approach the probe of the first photoelectric sensor and move away from the probe of the second photoelectric sensor, respectively. Thus, under the action of the detection circuit, the solenoid valve can be closed to stop air intake when the piston and / or piston rod reach their respective stroke positions, and the piston and piston rod will stop working after reaching the corresponding stroke, making the cylinder operation as smooth as possible and the output power stable.

This utility model provides an anti-impact tread cleaner. A connecting seat is hinged to a piston rod, and a buffer sleeve is installed in the hinge hole. The piston rod has a mounting hole, into which a spring rod is inserted. The spring rod has a spring seat at its front end and is installed in a mounting hole on the rear cylinder head at its rear end. A return spring is sleeved on the spring rod, with its front end abutting against the spring seat on the piston rod and its rear end abutting against a gasket installed in the piston rod mounting hole. Each tooth of the rack has a trapezoidal cross-section, with the angle of the force-bearing surface on both sides being 73° to 77°. The angle of the side of the limiting pin that mates with the force-bearing surface is the same as the angle of the force-bearing surface. An exhaust hole is provided near the connecting seat at the end of the piston rod, and a first filter screen is provided on the exhaust hole. An air inlet is provided on the rear cylinder head, and a second filter screen is installed in the air inlet. This design prevents the rack from deforming upon abnormal impact, allowing the tread cleaner to operate normally. The filter screen can be reused after replacement, and the overall buffer sleeve increases the deflection angle of the connecting seat connected to the grinding wheel.

A combustion powered fastener driving tool including a combustion chamber ring configured to connect the combustion chamber to the cylinder head, the combustion chamber ring configured to reduce turbulence and velocity of vaporized fuel dispensed into the combustion chamber from the fuel cell.

The utility model provides a feeding device and an engine cylinder body and cylinder cover press-fitting machine, the feeding device comprises a support, the support is provided with an adapter, a supporting disc and a first horizontal driving piece used for horizontally driving the supporting disc to move between a first position and a second position, and the adapter is internally provided with a material receiving cavity communicated with the bottom of the adapter. An opening communicated with the material receiving cavity is further formed in the adapter; the supporting disc is located below the adapter when located at the first position and used for receiving the guide pipe falling through the opening and the material receiving cavity. The machine further comprises a rack, the feeding device is arranged on the rack, the rack is further provided with a press-fitting mechanism and a vibration disc, the press-fitting mechanism is located at the second position, and the supporting disc is used for conveying the guide pipe to the second position and assembling the guide pipe to the output end of the press-fitting mechanism. Automatic receiving, stable conveying and accurate moving of the guide pipes are achieved, production interruption caused by manual feeding is avoided, and therefore the production efficiency is improved.

1. The name of the design product: cylinder cover of gasoline chain saw (25th). 2. The use of the design product: cylinder cover of gasoline chain saw. 3. The design points of the design product: in shape. 4. The picture or photo that can best show the design points: perspective view.

The utility model discloses a dismounting tool for a valve guide pipe of a cylinder cover. The dismounting tool comprises a supporting frame, the lifting platform is vertically arranged in the supporting frame in a sliding mode, a jack is fixedly connected to the top of the lifting platform, an installation pipe used for installing an ejector rod is fixedly connected to the bottom of the lifting platform, and a reset piece is fixedly connected between the lifting platform and the connecting cross beam. Notches at the two ends are clamped on the outer side of the supporting frame, it is guaranteed that the lifting table can vertically slide, and operation is easy, convenient and stable. A reset piece (spring) is fixedly connected between the lifting table and the connecting cross beam, after the jack extends to eject the valve guide pipe out, the spring can drive the lifting table to automatically reset, a fixing plate in the clamping assembly is adjustably installed, and through arrangement of a rotating base and a limiting arc plate, the angle of a workpiece can be flexibly adjusted, so that the valve guide pipe corresponds to the position of an installation pipe.

This application belongs to the technical field of ultra-high pressure compressors, specifically relating to a monitoring method and system for ultra-high pressure compressors. The cylinder pressure and working volume of the cylinder mechanism of an ultra-high pressure compressor can reflect the operating state of the compressor. The cylinder mechanism of the ultra-high pressure compressor includes a cylinder body forming a piston chamber, a middle body and a cylinder head respectively disposed at both ends of the cylinder body, a tie rod bolt connecting the middle body and the cylinder head, and a piston component that slides against the wall of the piston chamber. The cylinder pressure refers to the pressure between the piston component and the cylinder head, and the resulting pressure can cause the cylinder head and middle body to separate from the cylinder body. The tie rod bolt is used to balance the pressure; therefore, the axial strain of the tie rod bolt can reflect the cylinder pressure. In this application, the cylinder pressure is indirectly obtained by directly measuring the axial strain of the tie rod bolt, thereby avoiding drilling holes in the cylinder body to install sensors for direct measurement of the cylinder pressure, thus avoiding damage to the cylinder mechanism and reducing the safety risks associated with measuring the cylinder pressure.

The utility model belongs to the technical field of motorcycle engines, and relates to an air cylinder head structure of a motorcycle engine, which comprises an air cylinder head, a cam shaft is arranged at the top of the air cylinder head, a timing chain wheel is sleeved on the cam shaft, a combustion chamber is arranged below the cam shaft, and a decompression ejector rod for ejecting an exhaust valve open is arranged in the cam shaft in a sliding mode. A centrifugal mechanism for driving the decompression ejector rod to slide is arranged on the timing chain wheel, a first sparking plug and a second sparking plug which are inclined are arranged on the left side and the right side of the combustion chamber respectively, and the included angle between the second sparking plug and the bottom plane of the air cylinder head is smaller than that between the first sparking plug and the bottom plane of the air cylinder head. The air cylinder head is provided with an avoiding groove for avoiding the timing chain wheel and a sleeve base extending in the direction of the avoiding groove, and a sleeve for installing a second spark plug is arranged in the sleeve base. The cylinder head structure of the motorcycle engine is compact in layout, stable in structure and capable of achieving the purpose of further saving energy and reducing consumption.

The application relates to a mechanism and data driving-based engine cylinder cover milling surface quality prediction method and belongs to the technical field of automatic prediction. The method comprises the following steps: determining key evaluation indexes and influence factors of cylinder cover milling surface quality; collecting process parameters and surface roughness values, combining with a cylinder cover milling mechanical state to construct a milling force and thermal mechanism model based on a semi-analytical method and a heat source method, obtaining state variable data, and storing the state variable data into a historical database after preprocessing; constructing a surface roughness prediction model based on ADE algorithm optimization SVR, taking process parameters and mechanism model output state variable data as data driving model input, taking surface roughness values as output, and obtaining an optimal parameter combination of SVR by training historical data; and predicting the milling surface roughness by using real-time process parameters and mechanism model output state variable data. The method has the advantages of strong model state representation capability and low state variable data acquisition cost, and can realize accurate prediction of cylinder cover milling surface quality.

This invention belongs to the field of clamping fixture technology, specifically a clamping fixture for casting production and processing and its operating method. The clamping fixture includes a crossbeam, with a hydraulic cylinder fixedly connected to the top of the crossbeam and a set of hangers fixedly connected to the bottom of the crossbeam. Each set of hangers has a set of crossbars fixedly connected to it, and each set of crossbars is slidably connected to a limiting seat. A movable seat is fixedly connected to the bottom of each of the two limiting seats, and a mounting arm is fixedly connected to the bottom of each of the two movable seats. Mounting plates are fixedly connected to the bottom of opposite sides of each of the two mounting arms. Floating chucks are provided on the mounting plates, and support components are provided on each of the two mounting arms. This invention, by setting multiple sets of floating chucks on the mounting plates on both sides, can tightly fit the outer walls of both sides of the cylinder head, better clamping and fixing the cylinder head. By setting the support components, after the floating chucks clamp the cylinder head, they can support the cylinder head from below, reducing the working pressure of the floating chucks and preventing excessive clamping force from damaging the cylinder head surface.

This invention discloses a composite gating system and casting method for a lightweight, high-strength, and tough diesel engine cylinder head. The composite gating system includes a sprue, a runner, a stepped ingate, and a top riser. The lower end of the sprue is connected to the runner. The runner is connected to the stepped ingate. The stepped ingate includes a bottom ingate and a middle ingate. The bottom ingate extends downward from the runner and connects to the lower part of the diesel engine cylinder head cavity. The middle ingate extends from the runner and connects to the middle part of the diesel engine cylinder head cavity. The top riser is located at the hot spot of the diesel engine cylinder head, and auxiliary risers are also provided in some hot spot areas. This invention addresses the characteristics of medium-entropy eutectic alloys, such as high melting point, poor fluidity, easy oxidation, and narrow solidification range, by designing a dedicated composite gating system and supporting casting process. This solves the shortcomings of traditional diesel engine cylinder heads in terms of lightweight, strength, toughness, and high-temperature performance, providing a reliable guarantee for improving the overall performance of diesel engines.

The utility model relates to the technical field of motorcycle part machining, in particular to motorcycle cylinder head spark plug tapping equipment. Comprising a tapping machine body and a material receiving mechanism, and the material receiving mechanism comprises a belt conveyor, a material receiving barrel, an inclined guide plate, a first limiting block, a second limiting block, a positioning plate, a clamp table, a limiting plate, a receiving device and a limiting device. A spark plug is clamped and conveyed to a clamp of the clamp table through the feeding robot to be fixed, then a part can be subjected to tapping machining through the tapping machine body after being fixed, the part is taken through the feeding robot after tapping is completed, the workpiece is placed on a conveying belt of the belt conveyor, the workpiece is conveyed into the material receiving barrel through the belt conveyor, and the material receiving barrel is used for receiving the spark plug. And then the parts fall onto the inclined guide plate and slide into the receiving device to be automatically collected, feeding machining can be carried out during collection, and therefore the machining efficiency can be improved when motorcycle cylinder head sparking plug tapping machining is carried out.

The invention relates to a combustion system, an engine and a vehicle. The combustion system comprises an air inlet channel, an exhaust channel, an air inlet valve, an exhaust valve, a cylinder cover, a cylinder sleeve and a piston, a cylinder cover combustion chamber is arranged in the combustion system, and at least one of the inner surface of the cylinder cover combustion chamber, the surface, facing the interior of the combustion system, of the air inlet valve, the surface, facing the interior of the combustion system, of the exhaust valve and the top surface of the piston is provided with a thermal barrier coating.

The utility model relates to a kind of high-efficiency high-reliability low-noise full-electric control power-driven action device for ship, including two servo electric cylinders, tiller, roller type support structure, base and mounting base;Tiller middle part is equipped with shaft hole, and one pin hole is respectively equipped in tiller both ends;Center shaft is fixedly worn in shaft hole, and center shaft lower end is connected in the bearing hole set in the front end of mounting base by bearing;One front pin shaft is respectively inserted and installed in the pin hole of tiller both ends;Two servo electric cylinders head are respectively rotated with two front pin shafts by centripetal joint bearing, and two servo electric cylinders tail are respectively rotated with rear pin shaft fixed in the front end of base by centripetal joint bearing;Base lower end is fixedly connected with the upper portion of the rear end of mounting base;Two groups of roller type support structures are connected in the bottom of servo electric cylinder, and two groups of roller type support structures are rolling contact with the upper end of mounting base.The device can greatly improve system operation efficiency, reduce noise and improve system continuous operation reliability.

A gasket (20) configured to be positioned between a spark plug and a cylinder head of an internal combustion engine when a threaded section of the spark plug is screwed to the cylinder head. The gasket includes an annular body (23) and projections (25). The annular body is arranged around a threaded relief section of the spark plug where no threads are formed near the threaded section. Each of the projections extends radially inward from the annular body.The annular body, the thread relief section and the threaded section are shaped such that they satisfy a relationship of φb mm ≤ φa mm ≤ φc mm - 0.9 mm, where φa is an inner diameter of a circle (S1) defined to extend along the inner surfaces of the projecting ends (26a) of the inclined sections and centered on an annular center point (Cp) of the annular body, φb is the outer diameter of the thread relief section and φc is the nominal thread diameter of the threaded section.

The utility model discloses a belt conveyor tensioning oil cylinder head fixing device, which relates to the technical field of hydraulic cylinders, and comprises a mounting plate, an adjusting mechanism is arranged on the surface of the mounting plate, the adjusting mechanism comprises an adjusting base and a positioning ring, a fixing mechanism is arranged on the surface of the adjusting base, and the positioning ring is arranged on the fixing mechanism. The fixing mechanism comprises a fixing shell, a clamping ring and a connecting plate, the surface of the connecting plate is fixedly connected with a limiting barrel, and the surface of the limiting barrel is sleeved with a fixing sleeve. The fixing device can fix the tensioning oil cylinders of multiple models, the cylinder heads of the tensioning oil cylinders are positioned through the fixing shell, the stability of the tensioning oil cylinders is improved, the fixing sleeve is fixed through the connecting plate and the limiting barrel, the tensioning oil cylinders of different specifications can be fixed by replacing the proper fixing sleeve, and the fixing device is convenient to use. And the installation convenience of the tensioning oil cylinder is improved.