214results about How to "Improve fatigue strength" patented technology

The invention discloses a preparation method of a medical titanium-zirconium alloy bar wire. The preparation method comprises the processes of ingot casting, forging, quenching, hot rolling, quenching, cold rolling, recrystallization annealing, severe plastic deformation, drawing, straightening, annealing and surface treatment. The microstructure of the alloy is regulated and controlled by introducing high-density defects into the material through severe plastic deformation and combining quenching heat treatment, preparation of the titanium-zirconium alloy with high strength and plasticity and good fracture toughness is achieved, and equiaxial ultra-fine grain titanium-zirconium alloy bars and wires with the diameter ranging from 1 mm to 8 mm and the length larger than 600 mm can be produced in batches. High strength and high fatigue strength can be obtained, and the requirements of dental medical instruments for raw materials are met.

The invention relates to the technical field of frame type hydraulic machines, and discloses a machining device and process of a stand column for a frame type hydraulic machine. The device comprises a welding center, and the welding center is composed of a positioning mechanism, a welding mechanism, a reversing assembly, a driving assembly, a preheating assembly, a grinding mechanism and a plurality of auxiliary supporting mechanisms; the welding center is further provided with an outer circular pipe and an inner circular pipe, the positioning mechanism is installed in the inner circular pipe, the driving assembly is integrally assembled on the positioning mechanism, directional conveying of the steel component during welding is achieved, meanwhile, the steel component is pressed, the welding stress is reduced, and the reversing assembly is installed in the outer circular pipe and used for supporting and driving the inner circular pipe to rotate in the axial direction. According to the technical scheme, the assembly type inner framework can play a supporting role from the interior of the square tube during welding, the assembly type inner framework and the square tube form a whole after welding, the structural stability of the stand column during use is effectively improved, and meanwhile steel members can be pressed from the corners of the stand column to reduce welding stress.

The invention provides a high-temperature alloy for manufacturing a nickel-copper alloy hot extrusion die, which is characterized by comprising the following components in percentage by weight: 0.02 to 0.08 percent of C, less than or equal to 0.15 percent of Si, less than or equal to 0.15 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.01 percent of S, 14.0 to 17.0 percent of Cr, 7.5 to 9.5 percent of Mo, 2.2 to 2.6 percent of Nb, 1.0 to 1.6 percent of Al, 2.2 to 2.8 percent of Ti, 0.005 to 0.015 percent of B, 0.01 to 0.05 percent of Zr, 21.0 to 24.0 percent of Fe and the balance of Ni. The preparation method of the alloy comprises the following processes: firstly, alloy raw materials are subjected to vacuum induction melting and then cast into ingots, then electroslag ingots are obtained through electroslag remelting, then the electroslag ingots are subjected to multi-heating-number forging, and then heat treatment is carried out. The highest use temperature of the alloy reaches 1000 DEG C, and the oxidation rate at 1000 DEG C is as low as 0.08 g / m < 2 >. H; at the temperature of 650 DEG C, the tensile strength reaches 1000 MPa, the yield strength reaches 850 MPa, the fatigue strength is higher than 400 MPa, and the lasting time of the load of 700 MPa reaches 80 h; the service life of a nickel-copper alloy hot extrusion die made of the alloy can reach 25000 times.

The utility model relates to a harmonic speed reducer, which comprises a wave generator, a flexible spline, a circular spline and a bearing base, the outer peripheral surface of the wave generator and the inner peripheral surface of the flexible spline are assembled and connected together, and the outer peripheral surface of the flexible spline and the inner peripheral surface of the circular spline are engaged together; a threaded hole is formed in the bottom of the circular spline, a bottom through hole is formed in the bearing base, and a connecting screw penetrates through the bottom through hole and the threaded hole to connect the bearing base and the circular spline together. The flexible spline has the advantages that the flexible spline is formed by forging, so that the fatigue resistance is improved, and the service life is prolonged; and the service life is further prolonged by improving the smoothness and wear resistance of the spline.

The invention discloses a molded surface pre-dispersion superplastic forming / diffusion bonding method, and belongs to the field of superplastic forming. The method solves the problem that when an ultrathin hollow multilayer structure is formed through an existing superplastic forming / diffusion bonding method, the wall thickness is not uniform due to excessive deformation of a core plate. According to the method, the core plate is subjected to large plastic deformation through a pre-reverse expansion method, stress concentration in a material is released, then the protruding part is subjected to plastic deformation through forward expansion, the core plate is subjected to plastic deformation in the reverse expansion stage, stress is more evenly distributed in the forward expansion stage, and therefore the situation that in a local area, the stress concentration in the material is reduced is avoided. And particularly, the phenomena of excessive deformation and thinning of high-strain parts such as fillets and the like are avoided, so that the uniformity of the wall thickness is greatly improved. The method provided by the invention comprises the following steps: (1) pre-forming a core plate and welding isolation ribs; (2) panel forming; (3) combining the core plate and the panel; (4) carrying out reverse expansion on the core plate; and (5) superplastic forming of the core plate.

The invention provides a grinding, spraying and rolling composite surface machining method for a gear tooth surface, which comprises the following steps of: determining the overall maximum elastic deformation of a gear to obtain a modified theoretical involute gear tooth profile; by means of the micro-line-segment theory, a micro-line-segment type involute gear tooth profile is obtained; by means of non-linear smooth fitting, a final modified involute gear tooth profile is obtained, and an initial gear is obtained through machining; on the basis of the initial gear, a gear shot blasting impact model is built, and a shot blasting gear is obtained; and on the basis of the shot blasting gear, a gear finishing and grinding model under gear tumbling finishing machining is built, and a finished gear is obtained. Grinding, shot blasting and barreling finishing are combined, through process coupling design, the overall performance of the gear is improved, higher manufacturing precision is achieved, the failure risk is reduced, the service life of the gear is prolonged, and the gear has the practical application value.

The invention discloses a fire grate device which comprises a fire grate driving mechanism for driving a movable fire grate to be ejected and withdrawn in a reciprocating mode, the fire grate driving mechanism comprises a base fixed to a rack and a driving beam linked with the movable fire grate, a driving oil cylinder is arranged on the base, and the action end of the driving oil cylinder is in linkage connection with the driving beam through a driving rod. The included angle between the extending direction of the driving oil cylinder action end and the garbage conveying direction is an acute angle; the action end of the driving oil cylinder is in linkage connection with a first hinge sleeve, a first hinge shaft is rotationally inserted into the first hinge sleeve, the end, facing the driving oil cylinder, of the driving rod is in linkage connection with a second hinge sleeve, a second hinge shaft is rotationally inserted into the second hinge sleeve, and an adapter rod is in linkage connection between the first hinge sleeve and the second hinge sleeve. The axis of the first hinged shaft and the axis of the second hinged shaft are perpendicular to each other and are both perpendicular to the axis of the switching rod, and the axis of one of the first hinged shaft and the second hinged shaft extends in the horizontal direction. The invention further discloses a garbage incinerator applying the fire grate device.

The utility model discloses a full-hydraulic steering gear with low steering torque, which comprises a valve sleeve body, a shifting pin hole and a valve core body, the valve core body is arranged in the valve sleeve body, a spring piece is arranged in the valve core body, the shifting pin hole is arranged in the valve sleeve body, a shifting pin is arranged on one side of the valve sleeve body, and the shifting pin hole is arranged on the other side of the valve sleeve body. A first reinforcing layer is arranged on the inner wall of the valve sleeve body, a second reinforcing layer is arranged on the inner wall of the first reinforcing layer, a wear-resistant coating is arranged on the outer wall of the second reinforcing layer, and the device has the advantages that carbonitriding is adopted for the coating at the second reinforcing layer, so that the hardness, the wear resistance and the fatigue strength of steel are mainly improved; the main purpose of the utility model is to improve the wear resistance and seizure resistance of steel. And reinforcing ribs are additionally arranged on the second reinforcing layer, so that the strength of the valve sleeve body is further improved.

The present invention discloses a low hysteresis, low temperature resistance, fatigue resistance soy protein composite gel electrolyte and a preparation method thereof, comprising: heating a soy protein aqueous solution to obtain a soy protein dispersion; mixing the soy protein dispersion and acrylamide to obtain a prepolymer; adding a crosslinking agent and an initiator to the prepolymer, heating the reaction to obtain a soy protein composite hydrogel; immersing the soy protein composite hydrogel in an ammonium sulfate solution first, and then immersing it in a zinc chloride and lithium chloride salt solution to obtain a low hysteresis, low temperature resistance, and fatigue resistance soy protein composite gel electrolyte. The hydrogel prepared by the present invention is a chain entanglement structure, and has the characteristics of low hysteresis at low temperature, high fatigue resistance, and the like.

The invention provides an inner hole automatic hammering and strengthening device and a using method, the inner hole automatic hammering and strengthening device comprises a hammering device mounted on a machine tool tailstock, a plurality of hammering heads capable of reciprocating in the radial direction are arranged on the peripheral side of the end of the hammering device, the hammering heads are arranged in a workpiece mounted on a machine tool chuck and used for hammering and strengthening the inner wall of the workpiece, and a sliding supporting seat is arranged on a machine tool sliding rail. The sliding supporting seat is used for supporting the hammering device; a sliding hammer core shaft is arranged in the hammering sleeve, the bottom of the hammering head is clamped on the hammer core shaft to slide, a pneumatic linear vibrator is arranged at one end of the transmission rod assembly, and the other end of the transmission rod assembly is connected with the hammer core shaft. The machining efficiency and precision of strengthening the inner wall of the inner hole are remarkably improved, the performance of the workpiece is enhanced, and the labor intensity and the production cost are reduced. The method is suitable for workpieces with various complex shapes and long inner holes, and the requirements of the modern manufacturing industry for efficient and high-quality production are met.

The invention discloses a method for improving the fatigue strength of a high-strength aluminum alloy friction welding joint through electric pulse aging treatment. The method is specifically implemented according to the following steps that 1, a 7050 aluminum alloy welding structural part is prepared through a linear friction welding method; 2, a needed strip-shaped sample is prepared on the welded joint through a linear cutting method, and then the surface of the sample is pre-ground; 3, clamping the strip-shaped sample treated in the step 2 between two copper electrodes of electric pulse equipment; 4, the electric pulse processing range is controlled by adjusting the clamping distance; the pulse current density is controlled by adjusting the electric pulse charging voltage, the pulse frequency and the pulse time; and 5, after electric pulse treatment, the sample is air-cooled to the room temperature, then aging treatment is conducted, the aging treatment temperature and time are regulated and controlled, and after the sample is cooled again to the room temperature, the high-cycle fatigue strength of the sample is tested. According to the method, the 7050 aluminum alloy friction welding joint structure is regulated and controlled through electric pulse and aging treatment, so that the high-cycle fatigue performance of the joint is improved.

The invention relates to the technical field of harmonic reducers, and discloses a flexible gear, a harmonic reducer and an industrial robotic.The flexible gear comprises a cylinder, a tooth part, a cylinder part, a bent part, a diaphragm part and a flange part are sequentially arranged in the axial direction of the cylinder, the wall thickness of the connecting position of the cylinder part and the bent part is t1, and the wall thickness of the connecting position of the cylinder part and the diaphragm part is t2. The wall thickness of the connecting position of the bent part and the diaphragm part is t2, the wall thickness of the connecting position of the diaphragm part and the flange part is t3, and t2 is larger than t3 and larger than t1. T2 is larger than or equal to t3 and larger than t1, so that the wall thickness of the joint of the diaphragm part and the flange part and the wall thickness of the joint of the bent part and the diaphragm part are large, the deformation bearing capacity of the flexible gear can be improved, stress concentration is reduced, the risk that the flexible gear is fractured and fails due to deformation is reduced, the fatigue strength of the flexible gear is improved, and the service life of the flexible gear is prolonged; therefore, the reliability of the harmonic reducer is improved.

The application discloses a kind of robot friction stir welding force-position hybrid control method, it is related to robot welding control technical field, comprising the following steps: step S10 establishes the hybrid strategy model based on constant displacement control and constant pressure control, the trajectory deviation caused by flexible deformation is compensated by robot dynamic offset function;The constant displacement control monitors welding depth in real time by laser sensor, the laser sensor is installed in 45° oblique direction to the outer wall of motorized spindle, and the collection point is located in the front side of the welding advancing direction, to avoid the interference of flash;The constant pressure control is collected axial upset force by six-dimensional force sensor, and force feedback type impedance control strategy is adopted.The robot friction stir welding force-position hybrid control method compensates the flexible deformation of robot by dynamic offset function, combined with the hybrid strategy of constant displacement and constant pressure control, solves the problem of uneven weld forming under single control mode.

A method for manufacturing high-strength, hydrogen-embrittlement-resistant bolts based on microsphere shot peening, and the bolts themselves, are disclosed. The manufacturing method includes: S1, cold heading and thread rolling of alloy structural steel billets to obtain bolt forming parts; S2, surface cleaning of the bolt forming parts, followed by overall surface peening with microspheres driven by high-pressure air; after overall peening, targeted strengthening peening treatment is performed on stress concentration areas such as thread roots, undercut grooves, and flange transition corners to obtain reinforced bolt parts; S3, the reinforced bolt parts are cleaned, dried, and phosphated to obtain finished bolt parts. This design, through a "overall + targeted" composite microsphere shot peening strategy, introduces a uniform residual compressive stress field and a micron-level fine-grained plastic deformation layer on the bolt surface, forming a thicker strengthening layer in stress concentration areas, significantly improving the fatigue strength and delayed fracture resistance of high-strength bolts, while ensuring uniform surface roughness and stable assembly friction coefficient.

The present invention belongs to the technical field of engine parts manufacturing, and relates to crankshaft processing and manufacturing, and specifically to a gauge and method for detecting the roughness of the fillet of a large crankshaft journal, comprising a roughness meter, a support frame, the support frame comprising a base plate, a column vertically arranged on the base plate, and a posture adjustment device, the posture adjustment device comprising a lifting seat and a connecting block, the lifting seat being movably mounted on the column, the lifting seat being provided with a first rotating shaft, the connecting block being provided with a second rotating shaft, the second rotating shaft being horizontally arranged, the roughness meter being rotatably mounted on the second rotating shaft through its tail end, when the roughness meter rotates around the second rotating shaft, the stylus of the roughness meter rotates or swings in a vertical plane; the detection method, adjusting the measuring rod to be parallel to the sampling arc chord, can adapt to the travel path of the stylus for measuring the concave arc surface, solves the problem that the roughness fillet of a large crankshaft cannot be quantitatively detected at present, and realizes the control of the consistency of fillet roughness in the production process.

Provided is a steel material which has excellent melt cracking resistance, excellent heat-working cracking resistance, and excellent machinability, and which is capable of achieving high fatigue strength when made into a component for a mechanical structure. This steel material has a chemical composition described in the description, Fn defined by formula (1) is 0.45-1.05, the number density of fine Bi particles, which are Bi particles having a circle-equivalent diameter of 0.1-1.0 [mu] m, at a position 0.08 R from the surface of the steel material (R is the radius) is 15.00 particles / mm2 or more, the number density of coarse Bi particles, which are Bi particles having a circle-equivalent diameter of 10.0 [mu] m or more, is 0.25 particles / mm2 or less, and the thickness of the steel material is 0.5 [mu] m or less. At a position 0.65 R deep from the surface of the steel material, the number density of the fine Bi particles is less than 15.00 particles / mm < 2 >, and the number density of the coarse Bi particles is more than 0.25 particles / mm < 2 >.

The invention discloses a die forging forming method for a high-strength, high-toughness and damage-tolerance type titanium alloy cylindrical part. The die forging forming method comprises the following steps of S1, raw material heating, S2, primary forging, S3, surface treatment, S4, secondary forging and S5, annealing. By means of the method, the raw material weight and the forging heating number can be reduced, the production cost is reduced, and meanwhile it can be guaranteed that all properties of the product are good, and the product quality stability is improved.

This invention discloses a multi-process synergistic method for strengthening and toughening titanium alloys. The method includes: firstly, pre-treating the titanium alloy surface with sandblasting; then, subjecting the pre-treated titanium alloy to solid embedding carburizing treatment; subsequently, under inert atmosphere protection, sequentially subjecting the carburized titanium alloy to solution treatment, rapid cryogenic treatment, and aging treatment; and finally, shot peening the surface of the heat-treated titanium alloy. This invention solves the problem in existing technologies where a single process is insufficient to synergistically improve the strength and toughness of titanium alloys, achieving a synergistic match between high strength and high hardness on the surface of the titanium alloy material and high toughness in the matrix.

According to the forging die with the fixing lock, a locking column is arranged in an upper die body, a locking hole is formed in a positioning column, a positioning groove is formed in a lower die body, and a locking point is arranged on the positioning groove, so that when the upper die body moves downwards to cover the lower die body, the locking point can be embedded into the locking hole of the positioning column; in this way, the upper die and the lower die can be mutually limited to be locked, the situation that due to mutual displacement between the upper die and the lower die, a blank inside deforms is avoided, in addition, locking and limiting can be achieved by embedding the locking points into the locking holes, the locking process is simple and rapid, and the machining efficiency is guaranteed.

The invention discloses an improved corrugated pipe dust-free drag chain shell and a self-cleaning conveying device thereof. A pipe cavity part is formed in an upper shell and a lower shell; corrugated parts are correspondingly arranged on the surfaces of the upper shell and the lower shell respectively, a platform surface is formed at the corrugated top of each corrugated part, so that a contact position A between the corrugated pipe dust-free drag chain shell and a bearing surface is in surface contact, and the platform surface at the corrugated top accounts for 20-60% of the corrugated top; the corrugated side parts on the two sides of the corrugated parts form a side plane, and the mutual extrusion positions B between the adjacent corrugated parts are also in surface contact; the depth D between the wave crest and the wave trough of the corrugated pipe is 6-7mm According to the dust-free drag chain with the corrugated pipe, the abrasion condition between the shell and the bearing face is smaller, surface contact between the adjacent corrugated parts is more beneficial to stress stability, the anti-bending bearing capacity is improved, the corrugated pipe is good in flexibility, bending, stretching and rotating of the corrugated pipe, internal cables and the like are facilitated, the surface of the corrugated pipe is cleaned through the self-cleaning conveying device, and the service life of the corrugated pipe is prolonged. And adverse effects on product production caused by dirt on the surface of the corrugated structure are avoided.

The invention discloses a combined structure of a crane cylinder and a hatch coaming of a multipurpose ship. Comprising a hatch coaming side plate, a hatch coaming panel, a panel reinforcing inclined plate, a panel reinforcing rib, a cylinder longitudinal partition plate, a cylinder longitudinal side plate, a cylinder longitudinal hole panel, a panel reinforcing toggle plate, a cylinder transverse side plate, a cylinder horizontal toggle plate, a cylinder center partition plate, a cylinder center plate, a cylinder center hole panel, a cylinder vertical rib plate, a hatch coaming horizontal rib and a hatch coaming horizontal partition plate. The partition plate comprises a manhole ring and a main deck. According to the combined structure of the crane barrel and the hatch coaming of the multipurpose ship and the mounting method, the combined structure is simple in structure, reasonable in arrangement, convenient to construct, overhaul and pass on site, high in structural strength, light in weight and good in rigidity and stability, the using function requirements of a deck crane and a hatch cover are met, working loads of the deck crane and the hatch cover during operation are effectively transmitted, and the service life of the deck crane and the hatch cover is prolonged. And the local total strength of the hull structure is involved, so that the fatigue strength and the service life of the deck crane cylinder and the hatch coaming structure are improved.

The invention discloses a cavitation shot peening surface strengthening method and system based on cooperation of high hydrostatic pressure and spherical focused ultrasound. The method comprises the following steps: establishing and maintaining a hydrostatic pressure environment higher than 0.1 MPa in a high-pressure processing cavity filled with a degassing liquid medium; the to-be-machined surface of the workpiece is positioned in a sound field focal region of the spherical focused ultrasound transducer; and in the high hydrostatic pressure environment, a transducer is driven to work so as to generate a cavitation bubble group in a space confinement range in a focal region of the transducer, and meanwhile, the workpiece is controlled to move according to a preset path, so that cavitation collapse impact acts on a target region on the surface of the workpiece. The device comprises a high-pressure processing cavity, a spherical focused ultrasonic transducer, a multi-degree-of-freedom movement mechanism and a control system. Through cooperation of high hydrostatic pressure constraint and the spherical focusing sound field, precise localization and energy strengthening of the cavitation effect are achieved, a plastic deformation layer can be efficiently and controllably introduced to the surface of a metal material, the surface hardness can be remarkably improved, a residual compressive stress layer is formed, surface layer grains are refined, and the method is suitable for precise surface strengthening of complex components.

The utility model relates to an anti-expansion vapor chamber which comprises an upper shell plate, a first liquid absorbing core, a lower shell plate, a second liquid absorbing core and a working medium, the upper shell plate is connected with the lower shell plate, and the upper shell plate and the lower shell plate are both provided with grooves used for forming an upper inner cavity and a lower inner cavity; a plurality of first supporting columns are distributed in the groove of the upper shell plate, and a plurality of through holes corresponding to the first supporting columns are distributed in the first wick, so that the first supporting columns penetrate through the through holes to mount the first wick in the upper inner cavity of the upper shell plate; a plurality of second supporting columns matched with the first supporting columns are distributed in the groove of the lower shell plate, and a plurality of through holes corresponding to the second supporting columns are distributed in the second wick, so that the two supporting columns penetrate through the through holes to mount the second wick in the lower inner cavity of the lower shell plate; the working medium is phase change liquid flowing in the groove, and heat of the upper shell plate and the lower shell plate is dispersed to the vapor chamber. The vapor chamber provided by the utility model has higher heat dissipation performance, and can overcome the problem that the expansion resistance of the vapor chamber is insufficient in the heat dissipation of the battery.

This invention provides a heat treatment method for stainless steel reed wire, relating to the field of reed wire heat treatment technology. The vertical take-up device includes a support frame and a rail; a movable component is mounted on the rail, and a winding structure is fixedly mounted on the top of the movable component; a wire transfer drum is fixedly mounted at the bottom of the vertical shaft, and the reed wire body is spirally wound around the outside of the wire transfer drum; auxiliary structures are provided on both sides of the top of the support frame, and a guide component is fixedly mounted on the outside of the support frame; precise wire guidance is achieved through the upper and lower guide rollers of the guide component, and the wire is clamped and fed by the wire transfer drum and auxiliary rollers, preventing wire deviation, shifting, and tangling from the source; the auxiliary structure can adjust the clamping force on the reed wire body, ensuring constant tension, tight and uniform wire arrangement, and neat coiling during the winding process, facilitating subsequent transportation, straightening, and stamping processing, thus solving the problems of wire deviation and shifting.

An additive manufacturing support device includes a building condition acquisition unit configured to acquire information on a shape model of an object and a load condition applied to the object; a stress analysis unit configured to determine a maximum principal stress direction generated in each portion of the object, by stress analysis based on the acquired shape model and load condition; and a trajectory determination unit configured to determine a forming direction of a weld bead on the basis of the maximum principal stress direction and the load condition.

The invention discloses a preparation method of a multi-principal alloy high-pressure oil pipe, and the method comprises the following steps: S1: mechanical grinding, mixing Fe powder, Co powder, Cr powder, Cu powder and Si powder and grinding to obtain a mixed powder; the atomic percentages of Fe powder, Co powder, Cr powder, Cu powder and Si powder are 65-x:20:10:5:x, and the range of x is 1-5; S2: green billet molding, pouring the mixed powder into a molding mold and pressing to form a FeCoCrCuSi metal green billet; S3: microwave sintering, sintering the FeCoCrCuSi metal green billet obtained in step S2 into a FeCoCrCuSi multi-principal alloy ingot by microwave heating; S4: tempering heat treatment, performing tempering heat treatment on the FeCoCrCuSi multi-principal alloy ingot; S5: cryogenic treatment, machining a center hole on the FeCoCrCuSi multi-principal alloy ingot and then placing it in liquid nitrogen for cryogenic treatment; S6: cold extrusion, performing cold extrusion on the FeCoCrCuSi multi-principal alloy ingot to make a pipe fitting. The present invention can improve the fatigue strength of the pipe fittings, so that the pipe fittings can be suitable for a working pressure of 200 MPa, and can also improve the wear resistance of the pipe fittings, reduce wear and tear, and extend the service life.

A foldable magnetic device for a door curtain comprises a plastic magnet and an adhesive tape, and is characterized in that one side of the plastic magnet is adhered to the adhesive tape; two symmetrical surfaces of the plastic magnet are provided with grooves (112) which are symmetrical to each other; the production process is characterized by comprising the steps of manufacturing the plastic magnet and pasting the adhesive tape. The plastic magnet is manufactured in the mode that CPE and magnetic powder are mixed and vulcanized, and after vulcanization, the plastic magnet is manufactured through the manufacturing processes of tabletting, multi-layer laminating, cutting, magnetizing, notching and the like. The CPE is chlorinated polyethylene. The door curtain has the beneficial effects that the door curtain can be folded at will, is convenient to store, and can be repeatedly used for multiple times; environmental pollution and production resource waste caused by the fact that door curtains in the prior art cannot be reused are avoided, environmental pollution is reduced, and ecological development is promoted; the softness of the magnetic attraction edge of a curtain product can be improved, the magnetic attraction force is dispersed, the connection attraction force between curtains is moderate, and the service life of the door curtain is prolonged.

A chain wheel with decompression holes and decompression pieces belongs to the technical field of chain wheels and comprises a chain wheel body, a plurality of decompression holes are evenly distributed on one side, close to a tooth root, of the chain wheel body around the axis, and the decompression pieces are arranged in the decompression holes. Impact force borne by the chain wheel body can be relieved through the pressure relief holes, the pressure relief pieces made of nitrile rubber are arranged in the pressure relief holes, and the nitrile rubber is installed in the pressure relief holes in an injection molding mode due to the fact that the nitrile rubber has the characteristics of high heat resistance, abrasion resistance, hardness and elasticity. The overall appearance size of the chain wheel can be prevented from being changed due to deformation of the decompression holes, impact loads are digested, and the service life of the chain wheel is prolonged.

The utility model relates to high-voltage measurement or relay protection equipment of an electric locomotive contact power supply system, in particular to a voltage transformer for an electric locomotive. Comprising a main insulator and a transformer body sealed in the main insulator, the lower portion of the main insulator is of a square structure, the front end and the rear end of the square structure are each provided with a protruding structure with the width gradually reduced, the upper portion of the main insulator is of a pagoda-shaped structure, and the top of the pagoda-shaped structure is provided with a primary wiring terminal. A secondary junction box is arranged at the bottom of the front end of the main insulator, a secondary wiring terminal is arranged in the secondary junction box, and the secondary wiring terminal is connected with the miniature circuit breaker assembly through a cable. The device is stable in insulation, strong in anti-interference capability, high in measurement precision, moisture-proof, waterproof, maintenance-free, small in size, simple in structure and totally closed, can greatly improve the reliability of power supply, and can be widely applied to various types of electric locomotives or newly designed types of locomotives.

A seamless steel pipe is obtained through hot rolling of spring steel, the seamless steel pipe is placed in a mold cavity, ultrahigh-pressure liquid is injected into the closed seamless steel pipe, meanwhile, axial thrust is applied to the two ends of a pipe blank, the middle of the seamless steel pipe is made to expand outwards, and the integral casing pipe elastic centralizer is obtained. An arc-shaped contour is formed by attaching the arc-shaped contour to a die, a plurality of hollowed-out parts are formed at the arc-shaped contour through methods such as laser cutting or stamping, elastic centralizing spokes are formed between the adjacent hollowed-out parts, and finally heat treatment and surface treatment are conducted on the whole. An internal high-pressure integral forming method is adopted, so that the integral casing elastic centralizer is not provided with a welding seam or a connecting mechanism, the problem of excessive stress concentration does not exist in the manufacturing process, the size precision and the profile tolerance of a generated arc profile are higher, the fatigue resistance is higher, the service life is longer, and the production cost is lower. The integral casing elastic centralizer manufactured by the method can smoothly pass through a narrowed and bent part under a well.