50 results about "Tool material" patented technology

The invention relates to the technical field of machining, and discloses an intelligent cutter handle capable of monitoring cutter wear in real time and triggering replacement reminding, which comprises a cutter handle main body, a sensor module, a control module, a wireless transmission module, a power supply module and an upper computer system in communication connection with the wireless transmission module, a connecting structure matched with a mainstream machine tool connector is arranged at one end of the cutter handle body, and a clamping part for clamping a cutting tool is arranged at the other end of the cutter handle body. According to the intelligent cutter handle capable of monitoring cutter abrasion in real time and triggering reminding of cutter replacement, the vibration sensor, the cutting force sensor, the torque sensor, the temperature sensor and the acoustic emission sensor are integrated in the cutter handle body, and the cutter abrasion state is accurately judged in combination with a trained and tested machine learning model based on historical abrasion data of the cutter; a plurality of wear judgment threshold sets are stored in a convolutional neural network model analysis algorithm unit in a machine learning model, and each threshold set corresponds to different cutter materials, workpiece materials and cutting parameter combinations respectively; if yes, calling a threshold set matched with the current machining condition information for judgment, and outputting a corresponding result by the model, so that real-time and automatic judgment on the tool wear state is realized, manual experience analysis is not needed, the accuracy and timeliness of judgment are remarkably improved, and the working efficiency is improved. And reduction of machining quality or cutter breakage caused by misjudgment of sudden wear as normal wear or delayed response is effectively avoided.

The invention discloses a three-dimensional graphene-carbon fiber network and double-phase high-entropy alloy synergistic strengthening and toughening ceramic cutter material as well as a preparation method and application thereof. The material is prepared from the following components in parts by mass: 87.8 to 90.9 parts of aluminum oxide, 8 to 10 parts of AlCoCrFeNi five-element equal-atomic-ratio high-entropy alloy, 1 to 2 parts of carbon fiber and 0.1 to 0.2 part of graphene. The preparation method comprises the steps of preparation of graphene grafted carbon fibers, preparation of AlCoCrFeNi high-entropy alloy powder, preparation of aluminum oxide-high-entropy alloy-graphene grafted carbon fiber composite ceramic powder and spark plasma sintering. The ceramic cutting tool material is used for preparing high-speed cutting tools. According to the preparation method, a plastic toughening mechanism of a double-phase high-entropy alloy is organically combined with a multi-stage toughening effect of a three-dimensional graphene-carbon fiber network, and a composite ceramic material with high hardness and high fracture toughness is obtained through spark plasma sintering, so that the adaptability of a cutter under a high-speed cutting condition is remarkably improved, and the service life of the cutter under the high-speed cutting condition is remarkably prolonged.

The utility model discloses an adhesive tape operation device capable of automatically heating and cooling, which comprises a support base, a stabilizing column, a support column, an operation platform, an operation table, an emergency stop button, an upper pressing wheel cylinder button, a double-hand starting button, a material roller, a limiting roller column, a gluing brush, a profiling tool material table and a hot air table, the stabilizing columns are installed and connected to the corresponding positions of the surfaces of the supporting columns, the operation platform is installed and connected to the ends of the supporting columns, the operation table is installed and connected to the surface of the operation platform, the scram button and the upper pressing wheel air cylinder button are installed and connected to the surface of the operation table, and the two-hand starting buttons are installed and connected to the two sides of the operation table. A product and an adhesive tape are manually stuck and put into the tool, the end passes through the upper and lower pressing wheels, and the adhesive tape bypasses the guide wheel; when a cylinder button is pressed down, an upper pressing wheel cylinder presses down to clamp the product and the adhesive tape, a rubber pipe electromagnetic valve, a hot air port and a cold air port are opened, and a starting button motor is pressed down to start upper and lower wheels to clamp the product and the adhesive tape to complete pasting.

The application discloses a normal distribution-based cutting parameter determination method, device, equipment and medium, the normal distribution-based cutting parameter determination method comprises the following steps: obtaining the expected tool life of a target tool corresponding to an expected cutting parameter, and performing normal distribution verification on the expected tool life to generate an expected normal distribution model; based on the tool material of the target tool and the workpiece material of the workpiece to be machined, traversing a tool database to determine a candidate standard normal distribution model matched with the tool material and the workpiece material; based on the expected normal distribution model and the candidate standard normal distribution model, a target standard normal distribution model is determined; the cutting parameter corresponding to the target standard normal distribution model is determined as the cutting parameter of the target tool. Through the technical scheme, the service life of the tool and the reliability of the cutting data are improved.

The application relates to a fascia release device and a traditional Chinese medicine moxibustion technical field, in particular to a bianshu knife tool material and a processing method. A bianshu knife tool material is mainly made of bianshu stone powder, an organic silicon binder and an additive. The content of the organic silicon binder in the bianshu knife tool material is 12-20 wt%. The content of the additive in the bianshu knife tool material is 2-8 wt%. The total mass of the organic silicon binder and the additive accounts for 18-20 wt% of the total mass of the bianshu knife tool material. The bianshu knife tool material has good biocompatibility, skin affinity, processing performance and mechanical strength. The bianshu knife tool prepared by using the bianshu knife tool material can be internally provided with a heating element, can provide temperature assistance for fascia release, can improve the fascia release effect, can slowly release essential oil under the operation of a touching hand method, can reduce the probability of new damage to the human body under the assistance of the essential oil, and can further improve the fascia release effect.

A bucket for a ladder is disclosed. The bucket provides an area for workspace or for storage of tools or materials in addition to that provided by the ladder by itself. The bucket is configured to be removably attachable to the top of the ladder when in use or removably attached to the ladder and preferably within the boundaries of the ladder when not in use.

The utility model relates to the technical field of construction supports, and discloses a residential building construction support which comprises a supporting plate, a first supporting rod is fixedly connected to the left side of the supporting plate, a second supporting rod is fixedly connected to the right side of the supporting plate, and a crawling ladder is fixedly installed on the supporting plate. Connecting columns are fixedly connected to the inner sides of the first supporting rod and the second supporting rod, clamping rods are fixedly connected to the connecting columns, a net plate is arranged on the upper side of the supporting plate, clamping rings are fixedly connected to the outer side of the net plate, clamping holes are formed in the clamping rings, and limiting nuts are arranged on the clamping rods. The upper sides of the first supporting rod and the second supporting rod are fixedly connected with top plates. According to the utility model, the net plate is firmly fixed on the bracket through the clamping ring, the clamping rod and the limiting nut, so that the whole bracket structure has higher strength and stability, can bear the weight of constructors, construction tools, materials and the like, and ensures the safety of the construction process.

The application discloses a kind of co-high-entropy carbide cermet materials and preparation method and application thereof, belong to the field of cermet material.The co-high-entropy carbide cermet material provided by the application is with (WVMoTaTi) C ceramic as matrix, directly adding its corresponding metal elements (W element, V element, Mo element, Ta element, Ti element) as binder phase by discharge plasma coupling high-frequency induction sintering.The preparation method is to mix all raw materials in proportion first, then ball mill, dry to obtain mixed powder, and discharge plasma coupling high-frequency induction sintering is used.The application provides a kind of co-high-entropy carbide cermet material with high-entropy carbide solid solution and high-entropy alloy coexisting, which has excellent comprehensive mechanical properties, high precision and high-speed cutting ability, and shows irreplaceable importance in tool material, precision machining and other fields.

The present application relates to the technical field of ceramic matrix composite, in particular to a high-strength and high-toughness high-entropy carbide ceramic matrix composite tool material and a preparation method thereof.The present application uses metal Ni as the metal binder phase of high-entropy carbide ceramic, uses nano-Al2O3 as the ceramic binder phase, and simultaneously introduces graphene as the toughening phase of high-entropy carbide ceramic, so as to realize the synergistic improvement of multiple performances such as hardness, bending strength and fracture toughness of high-entropy ceramic material.Through the multi-scale cross-dimension coupling and regulation of micron-level metal Ni, nano-level ceramic Al2O3 and two-dimensional graphene nanosheet, and by using a suitable spark plasma sintering process, the high-entropy carbide ceramic matrix composite material with optimal performance configuration is obtained.This material has potential application value in the field of tool preparation and application.

This utility model relates to the field of tool hardness testing technology, and particularly to a tool hardness testing device, including a testing bracket, a support platform slidably mounted on the testing bracket, a testing support plate rotatably mounted on the support platform, and a pressure application device above the testing support plate; a first limiting device and a second limiting device perpendicularly arranged to the first limiting device are provided on the testing support plate; the first limiting device includes a first limiting module and a second limiting module symmetrically arranged to the first limiting module, the first limiting module including a first limiting upright plate, the first limiting upright plate being vertically fixed to the testing support plate. The tool hardness testing device of this utility model has a clamping device that can achieve clamping and testing of tool materials of different sizes.

The invention relates to the technical field of numerical simulation and ultra-precision machining, and particularly discloses a laser-assisted cutting tool wear simulation test method and device, and the method comprises the following steps: S1, building a tool material model through an LAMMPS language; s2, setting system boundary conditions, ensuring unification of physical quantity units and the boundary conditions, and ensuring simulation accuracy and comparability; s2, establishing an ionic group model right above the tool material model established in S1, setting an interaction potential function between atoms, and ensuring that a simulation result accords with an actual physical process; s3, layering the initial model set in the S1, setting an integral time step length and total relaxation time, and enabling the relaxation system model to reach a stable state through a conjugate gradient method and an isothermal isometric system; and S4, setting an incident angle and a speed of the ionic group, outputting an atomic parameter, a thermodynamic parameter and a visual image in the process of bombarding the tool material by the ionic group, and carrying out subsequent analysis and result verification.

The utility model relates to the field of automobile manufacturing especially relates to a door sill automation tool material taking device. The utility model provides a door sill automation tool material taking device that can detect the door sill color and flatness in the material taking process, guarantees product quality and improves production efficiency. A door sill automation tool material taking device, including the material placing table, workstation and mechanical arm etc.

The invention discloses cubic boron nitride composite powder, a preparation method of the cubic boron nitride composite powder, a cubic boron nitride cutter material and a cutter, and belongs to the field of cutter materials.The cubic boron nitride composite powder comprises cubic boron nitride particles, the cubic boron nitride particles comprise first cubic boron nitride particles with the particle size of 30-50 [mu] m and second cubic boron nitride particles with the particle size of 1-10 [mu] m; a binder; and the microbead comprises a Sn-3. 5Ag alloy and a SiO2 shell layer, and the Sn-3. 5Ag alloy is coated with the SiO2 shell layer. According to the cubic boron nitride composite powder provided by the invention, the compactness, fracture toughness and other properties of the cubic boron nitride cutter material can be remarkably improved, and dynamic in-situ self-repairing of the cubic boron nitride cutter material in the cutting process can be realized, so that the service life of a cubic boron nitride cutter is prolonged, and the application prospect is wide.

The application provides a hard alloy cutter material for high-temperature alloy machining and a preparation method thereof, and belongs to the technical field of hard alloy cutter preparation. The application adopts a cobalt component gradient idea to adjust the hardness of each layer structure, obtains a more wear-resistant high-temperature structure, and low cobalt components can inhibit the mechanical machining sticking of a high-temperature alloy workpiece, realize high-precision and high-efficiency machining, the spraying slurry can improve the interfacial bonding strength between gradient layers, reduce the interfacial stress, and ensure the comprehensive performance of the cutter. The gradient structure is designed to be axisymmetric, which can significantly reduce the internal stress of the structure, improve the performance, increase the usable area of the cutter, and prolong the service life of the cutter. The results of the embodiments show that the hard alloy cutter material has a gradient structure, the fracture toughness is greater than or equal to 12 MPa.m 1 / 2 , the microhardness is greater than or equal to 20.1 GPa, the bending strength is greater than or equal to 3530 MPa, and the high-temperature (1000 DEG C) hardness is greater than or equal to 16.8 GPa.

The application discloses a split additive tool capable of controlling the temperature of a shoulder and a method thereof, which comprises a main shaft, an adapter handle and a split shoulder connected in sequence from top to bottom; the adapter handle is provided with an inner flow channel, and the split shoulder is provided with an annular temperature control circulating groove; the inner flow channel and the annular temperature control circulating groove are communicated; a sealing chamber is sleeved on the adapter handle, and the inlet and outlet of the inner flow channel of the adapter handle are communicated to a temperature control fluid circulating system through the sealing chamber to form a loop; and the adapter handle and the split shoulder are detachably fixed. The adapter handle, the main shaft and the shoulder are split, the inner flow channel is arranged in the adapter handle, the annular temperature control circulating groove is arranged in the split shoulder, the temperature of the split shoulder is controlled through the temperature control fluid circulating system, the service temperature of the additive tool is reduced, the tool material life is prolonged, the heat conduction of the tool upward is blocked, the tool temperature from affecting the adapter handle and the main shaft is avoided, and the blocking of the additive base material caused by softening is controlled; meanwhile, the shoulder can be replaced, and the material utilization rate is improved.

The invention provides a friction stir welding stirring head material and a preparation method thereof. Based on 100 wt.% of the total weight of the friction stir welding stir head material, the friction stir welding stir head material comprises 95.0 wt.% to 99.0 wt.% of W5Re and 1.0 wt.% to 5.0 wt.% of HfC. The friction stir welding stirring head material has high relative density, high hardness and excellent wear resistance.

The present application belongs to the technical field of hard alloy material, and particularly relates to a ceramic binder phase gradient hard alloy cutter material and a preparation method thereof. The present application takes cubic structure TiN and hexagonal closest packing structure ZrO2 as a composite ceramic binder phase, cooperates solid solution activation sintering and micro liquid phase strengthening sintering, and sets the grain size as nanometer scale, cooperates silicon carbide nanowire and two-step discharge plasma sintering, and comprehensively uses various sintering advantages to realize high density configuration of the ceramic binder phase hard alloy cutter material. The present application combines component toughening and structure toughening, designs a multi-level organization configuration of micro layer and macro gradient, prevents and eliminates cracks layer by layer, essentially breaks through the old thought of simple composite of complex components, proposes to load traditional toughening phase by low-dimensional toughening phase (graphene, silicon carbide nanowire), introduces traditional toughening mechanism and new toughening mechanism such as graphene, and simultaneously applies gradient structure to introduce surface residual compressive stress toughening, and finally forms a multi-level toughening mechanism with multi-element and multi-scale characteristics.

A server (10) connected via a network (20) to one or more machines (30) performing cutting operations, wherein a database (16) shared by the respective machines (30) is stored in the server, the database (16) containing at least processing result information used in steps included in a cutting operation performed by the machine (30), and information on the frequency of use of the processing result information, wherein the frequency of use is the number of machining programs generated based on the processing result information; a processing result information presentation request for presenting processing result information that meets cutting conditions, entered by an operator of the machine (30), is received from the machine (30) when the processing result information presentation request is received.The machining result information, which fulfills the cutting conditions, is extracted from the database (16) and presented to the machine; based on the frequency of use of the machining result information, a machining program is generated based on the machining result information, which is selected by the operator from parts of the machining result information from the machine (30) and presented to the machine (30); the machining result information includes configuration information of the machine (30), a workpiece material, a type of one-step cutting operation included in the cutting operation process, a type of tool used in the cutting operation, a tool material and a tool diameter, a cutting speed during the cutting operation, and a feed rate during the cutting operation.and the cutting conditions include at least one of the machine configuration information, a workpiece material, a type of cutting operation in a step included in the cutting operation process, a type of tool used in the cutting operation, a material of the tool, and a tool diameter.

The invention discloses a preparation method and application of a ceramic cutter material for high-temperature alloy finish machining, and belongs to the technical field of ceramic materials. The invention aims to solve the problems that the existing cutter material is easy to deform and is quickly worn, the cutter tip is easy to break, the surface quality after processing is poorer, the groove is seriously worn in the high-speed finish machining process, and the service life of the cutter is seriously limited. The high-hardness and high-chemical-stability (Zr, W) C solid solution serves as a matrix, active metal is adopted to induce the matrix to separate out a needle-shaped second phase to achieve self-toughening, the high-hardness and high-toughness carbide-based ceramic cutter material is developed, the grain size is more uniform and small, the high-temperature performance is stable, the mechanical property and oxidation resistance are excellent, and the relative density is gt; the hardness at room temperature is 25-35 GPa, and the fracture toughness is 5.0-6.5 MPa.m < 1 / 2 >. The preparation method is of great significance to preparation of high-toughness ceramic cutter materials.

The utility model relates to the technical field of shield tunneling machines, and discloses a high-strength shield tunneling machine cutter which comprises a machine body, the front end of the machine body is fixedly connected with a machine head, the inner wall of the machine head is fixedly connected with a fixing plate, the top of the fixing plate is fixedly connected with a second motor, and the output end of the second motor is fixedly connected with a fixing rod. A plurality of fixed gears are fixedly connected to the outer wall of the fixed rod at equal intervals, a square inner hollow block is fixedly connected to the front side of the top of the fixed plate, and a plurality of racks are slidably connected to the interior of the square inner hollow block. According to the utility model, when the rack moves, the spray head on the outer wall is driven to spray water mist and cooling liquid to the tool bit for cooling, so that the problems that the hardness and the toughness of a tool material are reduced due to high temperature generated after the tool bit performs crushing work for a long time, the cutting efficiency is reduced, and the tool needs to be replaced more frequently are solved; and inconvenience is caused to subsequent construction work.

The invention discloses a craftsman skill knowledge graph automatic construction method based on originator spoken voice, and relates to the cross technical field of artificial intelligence, natural language processing and knowledge graph construction, and the method is characterized in that the method comprises the steps: collecting the naturally spoken voice data of an originator through a wearable device; extracting five-dimensional features of a semantic text, a rhythm feature, an emotional feature, a taboo mark and a rhythm template of the voice by using a voice processing system; the five-dimensional features are input into a skill model, a dynamic knowledge graph is constructed in real time, graph nodes comprise actions, tools, materials, strength, taboo and emotion types, and edge relations comprise causals, time sequences, conditions and emotion weights; the quality of the atlas is monitored through a health function, and real-time correction of voice feedback of the craftsman is supported; the atlas is automatically iterated and evolved every day, and version management and multi-format export are supported. According to the method, the skill knowledge graph can be automatically constructed and optimized from the spoken voice efficiently and accurately, and the method is suitable for non-privileged skill and industrial scenes.

This invention belongs to the field of building construction technology, and particularly relates to a temporary sealing device for post-construction pouring strips. It includes a main sealing component, with a water-stop strip at the lower end of an elastic support base. The main sealing component, as the primary protective structure, spans across the post-construction pouring strip. The elastic support bases at both lower ends of the main sealing component abut against the concrete surfaces on both sides of the pouring strip, forming a stable support. The water-stop strip serves to block water. The main sealing component is fixed to the pre-embedded reinforcing bars in the pouring strip via fastening components, forming a stable support structure. This effectively prevents the device from shifting under wind or external forces. The entire device forms a complete physical barrier, not only preventing rainwater from entering the pouring strip but also blocking tools, materials, and construction debris that may fall during construction, ensuring the cleanliness of the pouring strip area and providing favorable conditions for subsequent pouring strip construction. This avoids the labor costs and time delays caused by debris falling in and requiring additional cleaning.

The invention relates to the technical field of grinding tool materials, in particular to a preparation method of abrasive belt paper containing nano ceramic particles, which comprises the following steps: carrying out silane coupling agent surface modification on the nano ceramic particles, carrying out high-energy ball milling and ultrasonic synergistic deagglomeration to obtain a stable dispersion liquid, mixing the stable dispersion liquid with thermosetting resin to form slurry, coating a primer treated paper base with the slurry, and drying to obtain the abrasive belt paper containing the nano ceramic particles. And realizing vertical orientation arrangement of the particles under the assistance of an external field, and finally carrying out gradient curing to obtain the product. The problems of nanoparticle aggregation, weak interface bonding and disordered distribution can be effectively solved, the grinding efficiency and the surface precision of the abrasive belt paper are remarkably improved, and the service life of the abrasive belt paper is remarkably prolonged.

The application relates to the technical field of cermet materials, and discloses a high-entropy dual-phase cermet tool material and a preparation method thereof.The raw material of the high-entropy dual-phase cermet tool material comprises 30-60 parts by weight of high-entropy ceramic phase metal powder, 40-70 parts by weight of high-entropy alloy phase powder and 0.5-2 parts by weight of guanidine graphene; the high-entropy alloy phase powder comprises Fe powder, Co powder, Ni powder, Cr powder and Mn powder; the guanidine graphene contains a large number of Schiff base guanidine groups on the surface, forms an iron-cobalt-nickel alloy layer on the surface of the high-entropy ceramic phase metal powder, and forms a strong chemical coordination effect with metal elements such as iron, cobalt and nickel in the high-entropy alloy phase powder, so that the interface strength is improved; and a three-stage sintering process is adopted, so that the material has higher compression strength, Rockwell hardness and fracture toughness.

The invention belongs to the technical field of petroleum drilling and production engineering, and particularly relates to the technical field of soluble temporary plugging tool materials, in particular to a soluble bridge plug prepared based on magnesium slag and a powder metallurgy method, a material and a method. The soluble bridge plug material comprises the following raw material components in percentage by mass: 20-30 wt% of superfine magnesium slag powder, 60-70 wt% of metal magnesium powder, 3-5 wt% of electrolytic copper powder and 5-7 wt% of sodium chloride powder. Through an innovative pretreatment process, namely a hydrothermal stabilization process, the harmfulness of free calcium oxide (f-CaO) in the magnesium slag is solved, high-added-value resource utilization of industrial solid waste is achieved, and meanwhile the soluble bridge plug which is lower in cost and reliable in performance is obtained.

The present application relates to a kind of diamond nanoparticles infiltrates the method for reinforcing hard alloy and the composite material made, belongs to hard alloy strengthening field.The method is first mixed, dry screen powder by ball milling under argon protection to WC, Co, VC powder, then preliminary WC-Co hard alloy sample is prepared by spark plasma sintering process.The key step is to uniformly coat nano diamond dispersion liquid after the surface of sintered sample is polished, and cover protection plate, be placed in the crucible covered with diamond powder, in argon atmosphere, stage heating to 1250 DEG C and heat preservation 3h are carried out heat treatment, so that diamond nanoparticles infiltrate matrix, finally by ultrasonic cleaning to remove residue.The method significantly improves the hardness of hard alloy, the sample after processing significantly increases the vickers hardness compared with untreated sample without reducing core fracture toughness, effectively enhances the wear resistance of material, process is simple and controllable, suitable for high stress working condition tool material.

The invention relates to the technical field of numerical simulation and ultra-precision machining, and particularly discloses a simulation test method and device for wear of a black metal cutting cutter, and the method comprises the following steps: S1, building a model: compiling a three-dimensional geometric model of a black metal and diamond cutter action system through an LAMMPS language; s2, determining a simulation dimension as three dimensions, setting a unit, defining an atom type and a lattice structure, performing regional division on the black metal model and the diamond cutter model, setting a Newton layer, a constant-temperature layer and a fixed layer respectively, and setting an interaction potential function between atoms to describe interaction between the atoms, so as to ensure that a simulation result accords with an actual physical process; setting an integral time step length and total relaxation time, relaxation the system model through a conjugate gradient method and an isothermal isovolumetric method to enable the system model to reach a stable state, and setting a motion track of the black metal friction cutter; and S3, the change trend of the lattice structure of the tool material in the friction process and the non-crystallization phenomenon are obtained, and the tool abrasion condition is analyzed.

The present application relates to a kind of high-strength copper alloy explosion-proof tool 3D printing sand casting process, belong to the technical field of casting of explosion-proof tool. Including the following steps: S1, using 3D printing technology to make sand mold;S2, the 3D printing sand mold of design needs to be printed is layered;S3, according to the material matching requirement of beryllium bronze, aluminum bronze explosion-proof tool material matching, according to the proportioning is added to the furnace and is smelted, the copper alloy melt of smelting is poured into the cavity of three-dimensional solid sand mold of step S2, and metal is completely filled cavity and is poured;S4, after pouring, wait for melt cooling and solidification;After the cooling of casting, remove three-dimensional solid sand mold, obtain casting;Then, the post-processing procedure of casting is carried out, and the final finished product is obtained.The present application realizes that copper alloy explosion-proof tool can be efficiently, mass-produced, process is stable, controllable, greatly reduces the influence of human factors.

The utility model discloses an outer wall construction interlayer protection structure, including construction scaffold, construction scaffold is by connecting rod, cross bar and connecting piece, connecting piece is connected between connecting rod and cross bar, the inside of construction scaffold is provided with falling protection mechanism, the top of connecting piece is provided with assembly docking mechanism, falling protection mechanism includes: protection subassembly and connecting fixed component, the utility model discloses the U type hanging buckle, spacing rod and locking rod of design can realize the protection grid frame of letting fast installation in the inside top of cross bar and connecting rod, to reach the protection grid frame can effectively block personnel and small -size construction tool, material (such as spanner, screw, small -size pipe fitting etc.) from the top of scaffold falling, avoid the harm of causing to the personnel, equipment and building below.