870 results about "Joint surface" patented technology

The invention relates to the field of geotechnical engineering, and discloses a self-stress anchor rod failure evolution simulation method for jointed rock mass bolting-grouting reinforcement, which comprises the following steps: S1, constructing a three-dimensional rock mass model containing a joint structure in an FLAC3D platform, and defining joint surface space distribution and geometric parameters; s2, a bolting-grouting structure is introduced into the three-dimensional rock mass model, an anchor rod, a grouting body and the contact relation between the anchor rod and the grouting body and the rock mass are set, and an anchor rod load transfer model is established; s3, a loading path is set, displacement control is adopted as a loading mode, and a certain included angle is formed between the loading direction and the joint surface; and S4, establishing a numerical model in FLAC3D, performing grid division, and setting a rock mass material constitutive model and contact surface parameters. By accurately controlling the loading direction and the loading angle in simulation and analyzing the change influence of different loading paths on the failure mode of the bolting-grouting structure, the problem that the traditional simulation method neglects the change of the failure mode under different loading conditions is solved.

The invention designs an assembly process error modeling method considering heat, and realizes rapid and accurate calculation of thermal deformation of an assembly junction surface affected by heat in the part assembly process. In the part assembling process, heat generated in the assembling process is an important influencing factor influencing the assembling precision. In order to realize rapid calculation of thermal deformation in a part assembling process, a prediction model of thermal deformation of an assembling joint surface in the part assembling process is constructed by utilizing a physical information neural network. According to the method, a full-connection neural network architecture is adopted, and boundary condition constraints are introduced into a loss function item for joint optimization training. Through minimization of a loss function, a driving model learns displacement distribution characteristics of an assembly joint surface under thermal deformation, and a mapping relation between a space coordinate point and a corresponding displacement amount is established. The model finally realizes the real-time prediction capability of the thermal deformation field of the assembly joint surface.

The invention belongs to the technical field of direct shear-seepage tests of rock joints, and discloses a numerical test method for direct shear-seepage of rock joints under different boundary conditions, which comprises the following steps of: establishing a joint surface numerical model by using finite element software, and performing tests for simulating joint shear mechanical behaviors by applying different boundary conditions. And the contact state and the opening distribution of the joint surface under different shear displacements are obtained, so that the shear stress evolution mechanism of the joint surface is better revealed, and the mechanical behavior of the rough joint surface in the shear process is accurately expressed. According to the method, the evolution law of mechanical properties in the joint shearing process can be reflected, the influence of shearing deformation on the joint seepage characteristics can be reflected, joint opening data distribution is imported into programming software to be processed, a joint seepage numerical model is constructed, then multi-physics field simulation analysis software is imported, and the joint seepage performance is improved. The flow velocity, the osmotic pressure and the streamline distribution characteristics in the flowing process are calculated, so that the joint permeability characteristics are analyzed.

The invention provides a machining method for a three-petal type stator machining assembly with two-stage blades of an aero-engine. The machining method can solve the problems that the two-stage blades in a three-petal type stator are difficult to machine, parts are large in deformation after spraying and combined machining, and the shape and position sizes such as the blade profile tolerance, the flow channel profile tolerance and the concentricity of assembly parts at the front end and the rear end of the stator are out of tolerance. The method comprises the following steps of blank inspection, rough turning of an inner shape and an outer shape, rough milling of an outer shape, milling, finish milling, clamp trimming, finish trimming, finish turning, finish milling, finish turning, inspection, spraying, turning of a large-end coating, turning of a small-end coating, grinding of a blade tip, clamp trimming of a mark, fluorescent penetrant inspection and final inspection. The method is characterized in that: The working procedures between the outer shape rough milling step and the inspection step specifically comprise segmentation, stress relief heat treatment, joint surface and hole milling, grinding, combination, benchmark trimming, two end and inner shape fine turning, outer shape finish milling, splitting, blade shape finish milling, clamp trimming, combination, large end benchmark fine trimming, small end finish turning, small end lace and hole finish milling and large end finish turning. .

The invention discloses a vacuum brazing quality detection method for a heat dissipation structure and related equipment, and the method comprises the steps: obtaining heat flux density distribution data of the heat dissipation structure, and dividing the heat dissipation structure into different functional regions according to a thermal efficiency index; differential thermal pulses are applied to the heat dissipation structure in the vacuum brazing process, and thermal pulse response data and technological process monitoring data are obtained; calculating a thermal response characteristic parameter, comparing the thermal response characteristic parameter with a preset parameter range, identifying an abnormal state and generating a process adjustment instruction; performing time-space synchronization processing on the thermal response characteristic parameters and technological process monitoring data, and determining defect types, positions and severity; and performing a thermal load test to obtain heat conduction characteristic data, and quantitatively evaluating the structural integrity and the heat conduction performance of the brazed joint surface. According to the method, the defects of the internal joint surface can be detected in real time in the vacuum brazing process, the heat dissipation performance is accurately evaluated, and the limitation of a traditional detection method in coping with a complex geometric structure is solved.

The invention discloses a machine tool structural part material matching design method for forward design of a machine tool. The method comprises the steps that 1, material attribute parameters such as damping loss factors and elasticity modulus of materials are obtained through experiments; 2, calculating a fixed joint surface parameter based on a Jiyun Xiaopian integral method, and calculating a sliding and rolling joint surface parameter based on a product manual; 3, establishing a finite element model considering parameters of the joint surface, and extracting static and dynamic response values of key nodes of the machine tool through a simulation result; 4, determining the complexity of the model through DOE analysis, and constructing a response surface model of the response variable and the independent variable; 5, global search is conducted in the design space based on a multi-target rime optimization algorithm, the material combination mode of all structural parts is optimized, and the machine tool reaches the optimal balance point on the multiple dynamic performance indexes on the basis that the static rigidity is met; and step 6, comparing and analyzing static and dynamic properties before and after material matching optimization through a simulation result, and verifying a material matching effect.

A connection structure has an extension direction and includes a fitting part, a fixing part, and a turning part. The fitting part includes two joint surfaces. The fixing part includes a surface. The turning part is connected between the fitting part and the fixing part, and the turning part is inclined relative to the fitting part and the fixing part. One of the two joint surfaces of the fitting part faces a same direction as the surface of the fixing part. An offset distance is between one of the two joint surfaces and the surface along a direction vertical to the extension direction. Thus, the connection structure of the present disclosure can prevent two different antenna modules in the electronic device from interfering with each other.

The invention relates to the technical field of steel structure welding, in particular to a full-penetration back-gouging-free welding process for a welding seam between a web plate and a wing plate of a crane beam. Comprising the following steps: preparing a web groove; welding steel plate pairs; web plates and wing plates are placed; backing a weld bead on the groove surface; welding the back surface once; and the other welding beads are formed on the groove surface. According to the full-penetration back-gouging-free welding process for the weld joint between the web and the wing plate of the crane beam, the weld joint penetration depth of groove surface welding and non-groove surface welding can better fuse the joint surface of the web and the wing plate, the sections of the two weld beads can be partially overlapped by selecting proper process parameters, and therefore full-penetration welding is ensured.

A polymer double-cavity prefilled syringe comprises a barrel with a bypass, the barrel is provided with a finger handle and an adapter, a needle seat is arranged on the adapter, a needle body is fixed on the needle seat, and a protective cap is arranged on the outer side of the needle body. A front plunger, a middle plunger and a rear plunger are arranged in the barrel, and the rear plunger abuts against a plunger rod. The cylinder is formed by integral injection molding of polymer, a group of ribs which are arranged side by side and protrude towards the interior of the cylinder are arranged on the inner wall of the cylinder, the axial length of each rib is larger than that of the middle plunger, the bypass is formed by a gap between every two adjacent ribs, and the outer diameter of the cylinder is larger than that of the adapter; the protective cap is tightly connected with the needle seat, a first anti-falling mechanism is arranged on the joint face of the protective cap and the needle seat, and an inner cavity of the protective cap is communicated with the outside through a bacteria-blocking, hydrophobic and breathable filter membrane. The bypass is formed in the mode that the protruding edges protrude inwards, demolding is convenient, integrated injection molding machining can be conducted through polymers, cost is low, damage is not prone to occurring, and the using effect is good. The outer surface of the cylinder is smooth, the heat conduction performance is good, and the vacuum freeze-drying efficiency is high.

The invention relates to a dangerous rock mass automatic cutting and accurate model construction method based on point cloud data, and belongs to the field of dangerous rock mass segmentation and three-dimensional model construction. According to the method, the point cloud data obtained by the unmanned aerial vehicle and the inclination angle information of the joint surface are combined, the automatic method capable of achieving accurate segmentation of the joint surface of the dangerous rock mass and generating the accurate model is provided, and the real joint surface in the accurate model of the dangerous rock mass is a curved surface grid. The method aims at improving the modeling efficiency and accuracy of the three-dimensional model of the dangerous rock body, and complexity and errors caused by manual segmentation are avoided; the method can overcome the problem that a dangerous rock body model is inaccurate due to traditional plane structural plane cutting, and the accurate model can make statics analysis and dynamics research on the dangerous rock body more accurate, so that a guarantee is provided for the dangerous rock body to possibly bring human life and property safety risks.

The invention discloses an aluminum wiring terminal, a wiring terminal unit and an assembling method, and the method comprises the steps: carrying out the laser etching of a joint surface of an aluminum conductive sheet, forming a pretreated conductive sheet with a micro-nano structure, depositing a protective coating on the joint surface, and carrying out the curing, and obtaining a conductive sheet with a protective coating. And then crimping and assembling with an insulating shell assembly to form a crimping assembly, and fixing bolts are arranged in the insulating shell assembly. Applying resonance fastening of characteristic frequency to a fixing bolt in the crimping assembly, injecting a lubricating medium in the fastening process, performing synchronous detection and verification of multi-physical field parameters on the fastening assembly, and feeding back detection data to a production control system to optimize assembly process parameters; the micro-nano structure is constructed on the joint surface of the conducting strip and the protective coating is deposited, so that the interface conductivity and oxidation resistance are remarkably improved, online detection and dynamic feedback optimization are integrated, and the consistency and reliability of the product are improved.

The invention discloses a machine tool dynamic characteristic finite element calculation method based on bolting joint surface parametric modeling, and belongs to the technical field of bolting joint surface and machine tool overall modeling and simulation. According to the method, a gantry machine tool reduced scale model is taken as an example, contact parameter calculation is conducted on bolting joint surfaces based on the fractal theory, then finite element parametric modeling is conducted on the bolting joint surfaces through an abaqus basic connector unit, and dynamic performance analysis of the whole machine is completed. Compared with a test method, the accuracy of the method is proved. According to the method, more accurate and more efficient calculation of the dynamic performance of the machine tool is realized, and a theoretical basis is provided for subsequently exploring the influence of each combination surface on the dynamic performance of the whole machine.

The invention provides a preparation method of a CoCrNi medium-entropy alloy / 316L stainless steel composite sheet, and belongs to the field of metal matrix composite material forming. The preparation method comprises the following steps: preparing the CoCrNi medium-entropy alloy / 316L stainless steel composite thick plate by adopting an explosive welding method; cutting a blank with good interface bonding from the composite thick plate; then multi-fire and multi-pass hot rolling is carried out; performing multi-pass cold rolling on the hot-rolled plate after annealing; and stress relief annealing is conducted after cold rolling, and the medium-entropy alloy / stainless steel composite sheet is obtained after air cooling. The CoCrNi medium-entropy alloy / 316L stainless steel composite sheet obtained by the method is uniform in thickness, flat and straight in joint surface, excellent in mechanical property, simple in production process and suitable for industrial production.

The invention relates to the technical field of material brazing, and provides a welding method for quartz glass, which comprises the following steps: preparing nano-silver paste; coating the nano-silver paste on the bonding surface of the quartz glass and the material to be connected; the bonding surface of the quartz glass and the bonding surface of the to-be-connected material are in contact and abut against each other, and the nano-silver paste is melted to form a welding joint; and cooling the welding joint, the quartz glass and the material to be connected. According to the welding method for the quartz glass, the connecting strength between the quartz glass and the to-be-connected material can be improved, and the situation that the quartz glass cracks is reduced.

The utility model discloses a post-cast ultra-high performance concrete structure between a prefabricated top plate and prefabricated walls, which is characterized in that wall joint surfaces of the two prefabricated walls are arranged on two sides of a top plate joint surface of the prefabricated top plate to form a groove structure with a concave cross section; a plurality of top plate overhanging steel bars in one-to-one correspondence are arranged on the two top plate combination surfaces and are arranged in an inner row and an outer row in the thickness direction of the prefabricated top plate; each pair of coaxially-arranged top plate overhanging steel bars in the two rows of top plate overhanging steel bars close to the outside of the two prefabricated top plates are provided with additional steel bars; a plurality of transverse steel bars are arranged on the additional steel bars in the width direction of the groove structure; and ultra-high performance concrete is poured in the groove structure. During construction, the prefabricated wall and the prefabricated top plate are manufactured firstly; then temporarily fixing in place through a temporary support; additional steel bars and transverse steel bars are arranged, and finally ultra-high performance concrete is poured. The device is convenient to install, the project construction period can be shortened, the construction risk is reduced, and good social and economic benefits are achieved.

The invention provides an acceptance method and equipment for a concrete construction joint, and the method comprises the steps: obtaining the point cloud data of the surface of the construction joint after the concrete construction joint is coated with a retarder and is subjected to roughening in a final setting stage, and reconstructing a three-dimensional surface topography model of the surface of the construction joint according to the point cloud data; performing triangular meshing on the three-dimensional surface topography model to obtain the area of each triangular mesh surface and the projection area of each triangular mesh surface on the concrete construction joint plane; the ratio of the total area and the total projection area of all the triangular mesh faces is obtained to serve as a current roughness evaluation index of the surface of the construction joint; and according to the current roughness evaluation index and a preset construction quality requirement, generating an acceptance opinion of the construction joint. The quantitative roughness evaluation index is obtained based on the point cloud data of the surface of the construction joint, and acceptance is performed according to the roughness evaluation index, so that whether the construction joint treatment meets the requirement can be quickly and accurately judged, and the construction quality of the concrete construction joint and the stability and reliability of the structural performance are ensured.

The utility model discloses a combined hydraulic clamp for processing a semicircular hole, a slip groove and a spigot surface of a bearing cover, which comprises a clamp bottom plate, a positioning piece, a clamping piece and a workpiece, the workpiece, the positioning piece and the clamping piece are arranged on the clamp bottom plate, the clamping piece comprises an auxiliary supporting cylinder, a side pressing cylinder and a main lever cylinder, and the auxiliary supporting cylinder is arranged below the workpiece; a side pressing cylinder is arranged on the separating and combining surface of the workpiece for pressing; a main shaft hole for a main lever cylinder to press the workpiece is further formed below the workpiece, the positioning piece comprises a round positioning pin and a diamond positioning pin, and the end face of the round positioning pin and the end face of the diamond positioning pin are equal in height to form one-face two-pin full positioning. The bearing cover part boring and finish-milling face centralized production can be achieved, the problem that the perpendicularity quality of a bearing cover spigot pair two large faces and the perpendicularity quality of a spigot pair splitting and combining face are difficult to guarantee are solved, the equipment utilization rate is greatly improved, the number of operators is reduced, and the production cost is greatly reduced.

The utility model relates to the technical field of nitriding furnaces, in particular to an inlet air cooling device of an ultra-deep well type nitriding furnace, which comprises a fan connected to the nitriding furnace and used for cooling inlet air, a butterfly valve for adjusting the inlet air rate is additionally arranged on the fan, and the pipeline joints of the butterfly valve, the nitriding furnace and the fan are all arranged to be of flange structures. A plurality of arc-shaped rings which can stretch out and draw back in the arc direction are installed on the connecting face through bolts, the arc-shaped rings form a closed ring body structure after being stretched, and the outer portion of the ring body structure is sleeved with a sealing ring used for sealing and isolation. The number of parts required for assembly is reduced, and meanwhile, a stable supporting effect on the sealing ring is achieved, so that all joint surfaces of the nitriding furnace are tighter, and air cooling is smooth and free of leakage; by additionally arranging the rotatable L-shaped limiting plate, additional locking and supporting effects are provided for the joint face, and the sealing performance of the flange joint is enhanced.

The present invention discloses an online monitoring method and platform for weld quality in a sheet metal welding process, and relates to the field of welding technology. The method comprises: determining a welding call sequence through welding sequence analysis, extracting joint surface parameters of a reference sheet metal part and a first sheet metal part, performing material change synchronization analysis, and generating a welding parameter sequence. In the process of using welding parameters to control the welding of a battery-type welder, quality monitoring is performed based on a weld image and weld defect nodes are output. Welding control and defect identification of the remaining sheet metal parts are performed according to the welding call sequence, and a weld defect node set is output. The technical problem that the prior art cannot monitor weld defects in a sheet metal welding process in real time and accurately is solved, and the weld quality in a sheet metal welding process is monitored in real time, and the position and type of weld defects are accurately located, so that welding defects can be discovered and corrected in a timely manner, and the welding quality can be ensured to meet the technical effect of standards.

The invention discloses a part joint degree thermal resistance testing method based on natural convection cooling, and relates to the technical field of thermal resistance testing. The problems that in the prior art, testing time is long, efficiency is low, drying cost is increased, and production efficiency is reduced are solved. Through test preparation, real-time monitoring and control, temperature difference calculation and repeated test verification, the thermal conductivity and the processing quality of the joint surface of the component can be quickly judged, the production efficiency is effectively improved, the test cost is reduced, the test conditions are accurately controlled, the thermal steady state is quickly achieved, the test time is remarkably shortened, the test efficiency is improved, and the test cost is reduced. Meanwhile, the drying cost is reduced, the production efficiency is improved, the stability and the reliability of a test result are ensured through repeated testing and verification, the processing quality of a component joint surface can be accurately evaluated, whether the joint process is qualified or not is quantitatively evaluated by establishing a standard temperature difference threshold value, and the reliability of the test result is enhanced.

The utility model relates to a tower fan and a base assembly thereof. The base assembly comprises a base plate and a connecting piece, the base plate comprises two bottom plates, the bottom plates are provided with joint faces, and the two bottom plates are attached to the joint faces in a face-to-face mode and buckled to form the base plate; a through hole is formed in the joint surface of the chassis in a penetrating manner; the connecting piece comprises a first connecting body and a second connecting body, and the first connecting body and the second connecting body are in threaded connection at the through hole and abut against the two opposite sides of the base plate respectively so as to jointly clamp the two base plates. Quick connection can be achieved by buckling the two bottom plates, and locking through a threaded connecting piece is not needed. The first connecting body and the second connecting body are quickly connected at the through holes in a threaded connection mode, and meanwhile the first connecting body and the second connecting body jointly clamp the two bottom plates on the two opposite sides of the base plate, so that the two bottom plates can be prevented from moving relatively, the connection reliability of the two bottom plates is improved, and the whole base plate has good supporting strength.

The utility model aims to provide a copper-aluminum composite material embedded with a plurality of narrow copper strips, which relates to the technical field of copper-aluminum compositing, and comprises an aluminum substrate and a plurality of narrow copper strips embedded in the aluminum substrate, and the plurality of narrow copper strips are parallel to one another; the first surfaces of the narrow copper strips are flush with the first surface of the aluminum substrate, and the second surfaces of the narrow copper strips are embedded into the aluminum substrate. Through the technical scheme, the composite material has the technical effects that (1) the composite material consists of the aluminum substrate and the plurality of narrow copper strips embedded into the aluminum substrate, the combination surfaces of the copper strips and the aluminum substrate are increased, the composite strength is increased, and the service life of the composite material is prolonged; cutting or stamping is easy; and (2) the conductivity of copper is superior to that of aluminum, and the aluminum is light in weight and low in cost. By embedding the narrow copper strip, the conductivity of the material is improved under the condition that the weight is not obviously increased; and (3) the connection problems of welding, lapping, riveting and the like of the copper-aluminum adapter in an electric power system and a circuit are solved, the stable connection of the adapter is realized, and the service life is prolonged.

To provide a conjugate of laminate molded resin part that is resistant to bending loads and can be made large.SOLUTION: A conjugate of laminate molded resin part 10 is a rectangular prism with square end faces and is composed of a laminate molded resin part 11 having an inverted cone-shaped joint surface 11a, a laminate molded resin part 12 having a cone-shaped joint surface 12a, and an adhesive layer 13 that fits and joins the inverted cone-shaped joint surface 11a of the laminate molded resin part 11 and the cone-shaped joint surface 12a of the laminate molded resin part 12. A longitudinal direction X perpendicular to a laminate direction Y of the laminate molded resin part 11 and the longitudinal direction X perpendicular to the laminate direction Y of the laminate molded resin part 12 are made continuous with each other.SELECTED DRAWING: Figure 1

The invention relates to the technical field of cables, in particular to a cable joint connection fault detection device which comprises a detection mechanism, the detection mechanism comprises a detection box, the two sides of the top of the inner wall of the detection box are fixedly connected with downward pressing positioning assemblies, and the two sides of the bottom of the inner wall of the detection box are fixedly connected with supporting plates. A contact impedance tester is arranged on the front side of the top in the detection box, mounting boxes are arranged on the two sides of the bottom of the detection box, and cooling fans are fixedly mounted in the mounting boxes; the lifting and attaching mechanism comprises a lifting hydraulic cylinder, the lifting hydraulic cylinder is fixedly connected to the top of the detection box, the output end of the lifting hydraulic cylinder penetrates through the bottom of the detection box, and the contact impedance tester can be attached to cable joints of different sizes through an attaching assembly in the lifting and attaching mechanism. And the rotary cleaning mechanism can clean the surface of the joint needing to be detected in the lifting process of the lifting plate.

The invention discloses a method and a device for determining assembly fastening force of a bolt joint part, and relates to the technical field of intelligent manufacturing. The method comprises the steps that three-dimensional point cloud measurement data of a target joint surface are acquired, and the three-dimensional point cloud measurement data comprise geometric distribution error data and / or position error data; generating a target digital twin model according to the target three-dimensional point cloud measurement data; according to the target digital twin model, stress states of a target joint part corresponding to the target joint surface are simulated, and the stress states comprise a static stress state and / or a dynamic stress state; and according to the stress state simulation information, determining a target assembly fastening force of the target joint part. According to the method, the manual dependence degree in the bolt joint part assembling fastening force determination process can be reduced, so that the labor cost in the bolt joint part assembling fastening force determination process is reduced, and the determination precision and the determination efficiency of the bolt joint part assembling fastening force can be improved.

The invention belongs to the field of machining, and discloses a modeling calculation method and system for dynamic rigidity of a cutter handle-main shaft combination part, and the method comprises the following steps: S1, modeling a geometric structure and dynamic displacement of the combination part; s2, performing multi-scale modeling on the contact surface morphology and solving the normal spacing variation of the joint part; s3, joint surface micro-convex body contact characteristic modeling is carried out; s4, modeling the non-linear stiffness of the infinitesimal junction surface; and S5, constructing an integral dynamic stiffness matrix of the joint part. According to the modeling calculation method for the dynamic stiffness of the cutter handle-main shaft combination part, high-precision modeling of the dynamic characteristics of the cutter handle-main shaft combination part is achieved through a step Timoshenko straight beam model and a distributed nonlinear spring layer in combination with a slicing method and a fractal contact theory. The method is suitable for high-precision nonlinear dynamic modeling of a numerical control machine tool, a machining center and the like, and vibration, deformation and stability problems in the machining process can be effectively predicted.

The invention discloses a modeling method for three-dimensional jointed rock masses with different roughness degrees and penetration degrees, which comprises the following steps of: 1, setting shape and size parameters of the rock masses, and generating a model space according to the shape and size parameters of the rock masses; step 2, setting joint parameters; and step 3, joint orientation control. And step 4, joint form control. And 5, modeling the residual space as a rock material to obtain a final jointed rock mass model. According to the method, morphological characteristics of real joints can be reflected, the obtained model is more practical, and a more accurate numerical model is provided for subsequent simulation analysis; according to the method, the spatial distribution characteristics of the joint surfaces can be freely controlled, and the analysis of the mechanical characteristics of the rock mass under multi-joint or different joint distribution conditions is facilitated. According to the method, the three-dimensional jointed rock mass model can be conveniently and quickly obtained, and the modeling process can be simplified. And the jointed rock mass model generated each time has non-repeatability, so that the randomness of the jointed rock mass model is ensured.

The utility model provides a sand blasting shielding tool for casting an electrode of a resin insulating spacer, which comprises a first shielding piece, a second shielding piece and a third shielding piece, and the first shielding piece is provided with a first joint surface close to a first surface of the electrode so as to shield the first surface; the second shielding piece is provided with a second joint surface which is close to a second surface, opposite to the first surface, of the electrode so as to shield the second surface, particularly, the first shielding piece comprises a first wear-resistant material part for providing a first joint surface, and a second wear-resistant material part for providing a second joint surface; the second shielding piece comprises a second wear-resistant material part for providing a second joint surface, and the first wear-resistant material part and the second wear-resistant material part are made of wear-resistant plastic materials. According to the sand blasting shielding tool, the first wear-resistant material part and the second wear-resistant material part which are made of the wear-resistant plastic materials are arranged, so that the wear-resistant performance is effectively improved, the service life of the tool is prolonged, and the cost problem caused by frequent replacement of the tool is further solved.

The invention discloses a bimetal thin strip rolling composite interface strengthening method and device based on middle-pass roller roughening. The method comprises the steps that basic parameters of a bimetal thin strip and rolling capacity parameters of a rolling mill are obtained; calculating the limit composite thickness of each pass based on the rolling mill capacity parameters and the basic parameters; based on the limit composite thickness, the number of passes needed by the rolling technology is determined; testing the surface appearance of the composite strip rolled in each pass, and determining the evolution rule of the surface roughness; and based on a surface roughness evolution rule, a texturing roller is adopted for rolling in the middle pass, and a smooth roller is adopted for rolling in the last pass. The texturing roller is introduced into the middle pass, so that the dissimilar metal bonding area is remarkably increased, the interface bonding strength is effectively improved, meanwhile, the deformation resistance difference of dissimilar metal is balanced, the material coordinating deformation capacity is improved, and the phenomena of brittle compound generation and shear stress concentration at the interface are restrained; therefore, the overall performance and quality of the composite thin strip are remarkably improved.

The utility model discloses a large-pipe-diameter eccentric reducing inclined three-way pipe which is located between a main pipe and a branch pipe and comprises an inclined three-way main pipe, an inclined three-way branch pipe and a joint face located at the joint of the inclined three-way main pipe and the inclined three-way branch pipe. The joint surface is in a saddle shape; the inclined three-way branch pipe is an eccentric reducing pipe, the radial section of the inclined three-way branch pipe is in a circular ring shape, and the inner diameter and the outer diameter of the inclined three-way branch pipe are gradually increased in the direction close to the inclined three-way main pipe. The inscribed angle at the joint surface is increased from alpha to alpha + theta, the contact angle is increased, the stress of a welding seam is reduced, the structural safety of a pipe fitting is improved, and the possibility of tension crack of the welding seam is reduced; in addition, the external connection angle alpha at the joint surface is kept unchanged while the internal connection angle at the joint surface is increased, the length of the inclined tee pipe fitting in the radial direction of the main pipe is reduced, the size of the inclined tee is optimized, and the arrangement space is reduced.