1314results about "Mechanical diameter measurements" patented technology

There is provided an inside-diameter measuring unit capable of automating inside-diameter measurement and a control method for automatic inside-diameter measurement. An inside-diameter measuring part is supported by a support frame part via a floating joint part. The floating joint part includes a rotation-allowing mechanism part and a translation-allowing mechanism part. A measuring head part of the inside-diameter measuring part is inserted into a hole by a robot arm part. The inside-diameter measuring part adjusts its position and posture autonomously by the reaction force when a contact point pushes against the inner wall of the hole to align the axis of the inside-diameter measuring part with the axis of the hole. An electric inside-diameter measuring unit can automatically measure the inside diameter of a hole.

There is provided an inside-diameter measuring unit capable of automating inside-diameter measurement and a control method for automatic inside-diameter measurement. An inside-diameter measuring part is supported by a support frame part via a floating joint part. The floating joint part includes a rotation-allowing mechanism part and a translation-allowing mechanism part. A measuring head part of the inside-diameter measuring part is inserted into a hole by a robot arm part. The inside-diameter measuring part adjusts its position and posture autonomously by the reaction force when a contact point pushes against the inner wall of the hole to align the axis of the inside-diameter measuring part with the axis of the hole. An electric inside-diameter measuring unit can automatically measure the inside diameter of a hole.

The invention provides a wheel center positioning method and system of a railway vehicle. Wherein the first detection unit and the second detection unit are mounted on two sides of the wheel, and the chord length of the wheel is measured through the first detection unit. When the second unit triggers detection, the second unit is controlled to move for a semi-chord distance in the same direction, and initial positioning of the wheel center is determined. Dynamic contact spot deformation and rim degradation data are fused, a collaborative analysis model is constructed, the nonlinear relation between the abrasion gradient and contact spot offset is extracted through deep learning, and dynamic correction is generated. And millimeter-level dynamic compensation is carried out on the positioning center based on the dynamic correction, stability control over the wheel-rail contact center in the transverse direction, the vertical direction and the rotating dimension is achieved, and stress concentration caused by rim abrasion is restrained. According to the technical scheme provided by the invention, the wheel-rail contact center positioning precision and stability are improved.

A drift bar is lowered into a well. The drift bar has a density that is less than a density of a wellbore fluid residing in the well. A tubular is lowered into the well below a surface level of the wellbore fluid residing in the well. The tubular defines an inner bore having an inner diameter that is greater than an outer diameter of the drift bar. The drift bar is positioned to pass through the inner bore of the tubular as the tubular is lowered into the well. After the tubular is positioned below the surface level, an absence or presence of the drift bar floating at the surface level is detected. An absence or presence of a restriction in the inner bore of the tubular is determined in response to detecting the presence or absence, respectively, of the drift bar floating at the surface level.

There is provided an inside-diameter measuring unit capable of automating inside-diameter measurement and a control method for automatic inside-diameter measurement. An inside-diameter measuring part is supported by a support frame part via a floating joint part. The floating joint part includes a rotation-allowing mechanism part and a translation-allowing mechanism part. A measuring head part of the inside-diameter measuring part is inserted into a hole by a robot arm part. The inside-diameter measuring part adjusts its position and posture autonomously by the reaction force when a contact point pushes against the inner wall of the hole to align the axis of the inside-diameter measuring part with the axis of the hole. An electric inside-diameter measuring unit can automatically measure the inside diameter of a hole.

The utility model discloses a flow-state solidified soil flowability testing device, which belongs to the technical field of civil engineering testing, and comprises a base, a supporting disc is clamped in the middle of the top surface of the base, a measuring mechanism is arranged on one side of the base, a filler cylinder is arranged right above the supporting disc, and a flow-state solidified soil flowability testing device is arranged on the filler cylinder. A supporting disc is fixedly connected to the top surface of the filling barrel, a pair of handles is fixedly connected to the side edge of the supporting disc, the filling barrel is filled with a flow-state solidified soil body, an inner ring is fixedly connected to the center of the top surface of the supporting disc, and an outer ring is fixedly connected to the position, close to the side edge, of the top surface of the supporting disc. The slump and expansion degree of the fluid-state solidified soil can be rapidly measured, the measurement efficiency is improved, the supporting assembly is arranged, the fluid-state solidified soil modules can be rapidly replaced, and therefore the multiple fluid-state solidified soil modules can be conveniently measured, and the measurement efficiency is further improved.

The invention discloses a sealing ring inner diameter detection device and an inner diameter detection method thereof.The sealing ring inner diameter detection device comprises an outer taper pipe and a guide pipe, the guide pipe and one end of the outer taper pipe can be connected in an inserted mode, the outer circumferential face of the guide pipe is movably sleeved with a push pipe, the outer taper pipe is a pipe with the diameter gradually changing from small to large, and when the guide pipe and the outer taper pipe are connected in an inserted mode, the push pipe is inserted into the guide pipe. The small-caliber end of the outer taper pipe is arranged in the push pipe, scales are arranged on one side of the outer taper pipe side by side, and the outer taper pipe is sleeved with a sealing ring. The device is simple in structure and convenient to operate, can quickly and accurately measure the inner diameter of the rotary Glyd ring, and can detect the roundness, elasticity, wear degree, hardness and other performances of the rotary Glyd ring at the same time.

The invention discloses a bearing ring inner gauge fast detection machine, and aims to solve the problems that an existing fast detection machine cannot be seamlessly connected with an assembly line and cannot realize batch fast detection, the fast detection machine comprises a rack, and a conveying mechanism, a feeding mechanism, a discharging mechanism and an inner diameter detection mechanism are arranged on the rack. The conveying mechanism is connected with an external detection device, an automatic batch detection process is achieved, and the detection efficiency is improved. The inner diameter detection mechanism adopts a go / no-go gauge detection method, a drive assembly drives a go / no-go gauge assembly, whether the inner diameter is qualified or not is accurately judged in cooperation with a sensor, and a locking assembly can flexibly adjust the position of a no-go gauge part. The conveying track is provided with a through hole and a sensor for accurate feedback. The cleaning mechanism cleans the inner wall before detection, thereby ensuring the detection accuracy and protecting the go-no go gauge assembly. The limiting plate guides the go-no go gauge assembly to be inserted, and the detection stability is improved. The device is simple and visual in structure and low in cost, and can effectively meet the bearing production detection requirements.

The invention belongs to the technical field of detection, and particularly relates to a flange plate detection device and a detection method thereof. The flange plate detection device comprises a lifting disc which is arranged in a detection table in a lifting manner; the plurality of detection pieces are vertically arranged on the lifting disc, and one detection piece is matched with one fixing hole of the flange plate; the distance between two adjacent detection pieces is consistent with the hole distance of a qualified flange plate; the interior of the detection table is hollow, a bearing plate is horizontally arranged in the middle of the detection table, and the detection piece penetrates through the bearing plate; a plurality of limiting plates are arranged on the inner side wall of the detection table in a sliding mode, and one limiting plate corresponds to one detection piece and is in linkage with the lifting disc; when the lifting disc moves upwards, the limiting plates synchronously slide inwards in the radial direction so as to limit axial movement of the flange disc. The lifting disc drives the detection pieces to be inserted into the corresponding fixing holes, and the detection pieces axially move along the inner walls of the fixing holes so as to detect whether the hole diameter of the fixing holes and the hole distance between the adjacent fixing holes are qualified or not.

A method for controlling header height comprising generating a signal as an object passes through a row unit; establishing a signal threshold, wherein when the signal threshold is exceeded a shelled ear event is detected; comparing the signal to the signal threshold; and emitting an alarm with the signal exceeds the signal threshold.

The utility model discloses an automobile windscreen wiper output shaft detection mechanism which comprises a positioning plate, a first positioning disc is fixedly installed on one side of the top end of the positioning plate, a second positioning disc is fixedly installed on the top end of the first positioning disc, and a fixing lining is fixedly installed in the positioning plate. According to the automobile windscreen wiper output shaft detection mechanism of the utility model, the parts are circular parts, only the cylindrical grinding is needed to match the clearance, the flat grinding is needed to match the sliding surface to ensure the luminosity and the sliding flexibility, the grinding by a bench worker is not needed during the final assembly, the whole processing technology is very simple, the production efficiency is high, and the cost is low. The cost is low; a closed ring is formed between the positioning discs, lubricating oil can be added without flowing out, rustiness between parts is avoided, and smooth sliding is guaranteed; the detection mechanism is high in applicability and low in cost, is used in a production field, and has a great reference value in the aspect of detection and popularization of output shafts of other front and back scraping products.

The invention relates to the technical field of tension detection, and discloses an automobile wire harness tension detection device which comprises a machine base, a sliding rail is fixedly installed at the top of the machine base, a sliding frame is slidably connected to the left half portion of the sliding rail, an annular clamping piece is rotatably connected to the sliding frame, and transverse blocking pieces are arranged on the surface of the annular clamping piece in an array mode. The left side of the sliding frame is connected with a tension sensor, the right half portion of the sliding rail is slidably connected with a clamping pulling piece, and the left side of the bottom end of the clamping pulling piece is connected with an air cylinder. When the rotating disc is pushed to rotate relative to the base and the fixed clamping plate and the movable clamping plate are driven to clamp the wire harness, the lantern ring rotates relative to the embedded disc, and the first length scales and the second length scales are staggered, so that the diameter of the wire harness is measured, and the diameters of multiple parts of the wire harness can be measured at the same time by enabling the wire harness to penetrate through the multiple clamping openings. Detecting whether the thickness of the wire harness is uniform; in the process, the second length scale is driven to be inserted into the clamping opening, and the wire harness is prevented from falling off.

Disclosed is a workpiece diameter measurement method including the steps of: measuring coordinates of a point P that is on an outer circumferential surface of a cylindrical workpiece that is supported such that a rotary axis of a main spindle of a machine tool and a central axis of the cylindrical workpiece coincide with each other, the coordinates having a maximum or minimum coordinate in a first direction that is orthogonal to the rotary axis; calculating a distance D2 in the first direction between the point P and a reference point Q that is a point at which a distance D1 in the first direction from the rotary axis is known; and calculating a workpiece diameter of the cylindrical workpiece based on the distance D1 and the distance D2.

The utility model discloses a cone shaft size measuring tool which comprises a calibration gauge and a measuring gauge. One end of the calibration gauge is provided with a measuring surface, the measuring surface is provided with taper, one end of the measuring gauge is provided with a first reference surface and a second reference surface, a step is arranged between the first reference surface and the second reference surface, the step is provided with a through hole along the axial direction of the measuring gauge, and the inner side of the through hole is a working surface. The working face is provided with taper, and the measuring face is matched with the working face. The measuring tool provided by the utility model is simple in structure and principle, flexible and convenient to operate and low in cost, is a comprehensive inspection tool, and can inspect the taper of the measured cone shaft and the diameter of the measured cone shaft. The device is suitable for the measurement of the detected cone shaft with high precision requirements, is accurate in detection result and high in detection efficiency, can be used for large-scale detection, and has good popularization and application values.

The invention discloses a hole part batch go-no go gauge detection device, and relates to the linear dimension metering technology field, the go-no go gauge detection device comprises a workbench, a clamping module, a transmission module, a go-no go gauge scale block, a detection pressure limiting module and a burr removing module, the clamping module is used for workpiece positioning clamping, the transmission module is used for workpiece feeding and discharging, the detection pressure limiting module is used for detection pressure limiting, and the burr removing module is used for detection pressure limiting. A workpiece is conveyed into different modules, the go-no-go scale block is used for detecting and judging whether the aperture of a to-be-detected hole of the workpiece meets the specified dimensional tolerance requirement or not, and the detection pressure limiting module is used for ensuring that the detection pressure of the go-no-go scale block on the to-be-detected hole of the workpiece is kept consistent, so that the detection accuracy is improved; the burr removing module removes burrs in a to-be-detected hole of a workpiece before detection of the go-no-go scale block, the burrs are prevented from influencing the detection accuracy, and meanwhile, a visual sensor is arranged on the go-no-go scale block and used for directly detecting whether the hole diameter of the to-be-detected hole of the workpiece meets the standard or not and detecting whether the go-no-go scale block works normally or not.

The utility model discloses a measuring tool for an automobile part test, and relates to the technical field of part detection, the measuring tool comprises an inspection mechanism and a measuring mechanism, and the inspection mechanism is used for conveying to-be-detected automobile parts; the measuring mechanism is used for measuring the outer diameter of the to-be-measured automobile part; the measuring mechanism comprises a front first measuring assembly and a rear second measuring assembly, the first measuring assembly is used for measuring the to-be-measured automobile part with the outer diameter smaller than / equal to the theoretical maximum outer diameter, and the second measuring assembly is used for measuring the to-be-measured automobile part with the outer diameter larger than the theoretical maximum outer diameter. The automobile parts can be submitted for inspection in batches by arranging the inspection mechanism, and the first measuring assembly and the second measuring assembly are arranged on the conveying path of the inspection mechanism, so that whether the outer diameters of the submitted parts meet the design standard or not can be quickly detected by using the first measuring assembly and the second measuring assembly; and the measurement and detection efficiency of parts can be effectively improved.

The invention provides an inner diameter measuring device which can obtain an accurate measurement result even in an environment where large electromagnetic noise is generated in a state that the inner diameter measuring device is installed on a mechanical arm. An inner diameter measuring device for measuring the inner diameter of a hole formed in a workpiece, the inner diameter measuring device being removably attached to the tip of a robot arm (14), the inner diameter measuring device comprising: at least two measuring elements (270) that abut against the inner wall surface of the hole formed in the workpiece, the at least two measuring elements (270) being configured so that the at least two measuring elements (270) are in contact with the inner wall surface of the hole formed in the workpiece, and the at least two measuring elements (270) being in contact with the inner wall surface of the hole formed in the workpiece; the data converting and transmitting part converts analog data related to the displacement of the at least two measuring pieces into digital data representing the inner diameter of the hole and then transmits the digital data to external equipment.

The utility model relates to the technical field of aircraft assembling and manufacturing, in particular to a rivet upset head rapid detection clamping plate which comprises a clamping plate handle, two ends of the clamping plate handle are respectively provided with a first detection clamping plate and a second detection clamping plate, and the first detection clamping plate and the second detection clamping plate are respectively and rotatably connected with one corresponding end of the clamping plate handle through hinges. The ends, away from the clamping plate handle, of the first detection clamping plate and the second detection clamping plate are each provided with a go-end notch and a not-go-end notch, and the go-end notches are communicated with the not-go-end notches. The caliber of the go-end notch at one end of the same detection clamping plate is equal to the minimum value of the allowable diameter of the rivet pier head of the standard model for detection, and the caliber of the no-go-end notch at one end of the same detection clamping plate is equal to the maximum value of the allowable diameter of the rivet pier head of the standard model for detection. And the thickness of the same detection clamping plate is equal to the minimum height of the formed rivet pier head of the standard model for detection. The technical problems that rivet upset head forming is detected in a narrow area, and rivet upset heads of different specifications are detected at a time are solved.

The utility model discloses appearance detection equipment for a motor stator, which comprises a frame, a measuring tool arranged on the frame and a testing assembly arranged on the frame, and the testing assembly is slidably connected to the frame through a servo press and can move up and down along the height direction of the frame. The testing device is used for testing a stator placed on the measuring tool. The testing assembly comprises a testing support detachably connected to the servo press, the testing support is elastically provided with an inner diameter go gauge, and when the servo press drives the inner diameter go gauge located on the testing support to move towards the stator, the inner diameter go gauge has two states relative to the stator, marking that the inner diameter of the stator meets the standard; the inner diameter go gauge abuts against the upper end face of the stator and indicates that the inner diameter of the stator does not meet the standard.

The utility model relates to a reinforcing steel bar size detector, which comprises a detection plate, a diameter measuring plate and a length measuring plate, a front baffle plate is integrally arranged at one end of the detection plate, the diameter measuring plate is slidably connected inside the detection plate, and a sliding plate slidably connected inside the front baffle plate is arranged on the outer wall of one side of the diameter measuring plate. The front baffle is rotatably connected with a bidirectional screw rod through a bearing, the sliding plate sleeves the bidirectional screw rod in a threaded manner, and the diameter measuring plate sleeves the detection plate in a sliding manner. According to the radius measuring structure, the two sliding plates can move towards the reinforcing steel bar in the semicircular placing groove at the same time, the diameter of the reinforcing steel bar can be measured conveniently, the diameter measuring function is achieved, the elastic force of the spring of the length measuring structure can push the length measuring plate to move towards the end of the reinforcing steel bar in the semicircular placing groove, and the length of the reinforcing steel bar can be measured; therefore, the detector has the functions of measuring the diameter and the length at the same time, is multifunctional, and is more convenient to use.

The systems and methods described in this specification relate to installing a wellbore completion setup of a wellbore based on a probability within a reservoir. The systems and methods measure one or more properties of the formation and receive data representing the one or more measured properties. The systems and methods use the one or more properties as input conditions to a finite element model of the wellbore. The systems and methods solve the finite element model to determine stresses of the formation surrounding the wellbore. The systems and methods determine a size of one or more rock fragments based on whether the determined stresses from the finite element model are greater than a threshold stress of a failure criterion. The systems and methods determine the probability, select the wellbore completion setup of the wellbore based on the bridging probability, and install the selected wellbore completion setup in the wellbore.

The invention belongs to measuring equipment, particularly relates to the field of steel pipe diameter detection, and discloses a steel pipe diameter detection device which comprises a handle, a sleeve is provided with a measuring mechanism, and the measuring mechanism penetrates through one end of the sleeve and is in threaded connection with the outer side of a lead screw. According to the steel pipe diameter detection device, measurement can be carried out from the end portion of a steel pipe or from the side face of the steel pipe, measurement modes are diversified, a supporting cylinder and a sleeve are held to rotate a handle, a lead screw rotates to drive a sliding block, a limiting rod and a first piston to move rightwards, and two first abutting balls abut against the inner wall of the steel pipe; when the distance between the two first abutting balls reaches the maximum, the distance between the outer walls of the two first abutting balls is the inner diameter of the steel pipe, due to the fact that the distance between the initial positions of the two first abutting balls is fixed and known, the moving distance of the first abutting balls can be known by observing the first scales, and the thickness of the side wall of the steel pipe can be known by observing the second scales. Therefore, the outer diameter of the steel pipe can be calculated.

The utility model relates to a hydrocyclone sand setting nozzle measuring device which comprises a main body shell and a lead screw, the lead screw is transversely and rotatably arranged in the main body shell through rotating shafts at the two ends, the lead screw is connected with a moving plate through a ball nut, and the outer edge of the moving plate is attached to the inner wall of the main body shell. The movable plate is vertically and symmetrically connected with a plurality of guide columns parallel to the lead screw, the other ends of the guide columns slidably penetrate through the main body shell and then are connected to a guide plate, and a first probe is installed on the outer side of the guide plate; a driving device and a dustproof shell are arranged on the end, away from the guide plate, of the body shell, the output end of the driving device is connected to the lead screw, and a second probe is installed on the outer side of the dustproof shell. According to the measuring device, the two probes are attached to the inner wall of the sand setting nozzle to measure the inner diameter of the sand setting nozzle in a high-precision mode, meanwhile, the sliding groove marked with vernier scales and the sliding rod are combined to further verify the measuring results of the two probes, the measuring accuracy is improved, the abrasion condition of the sand setting nozzle can be accurately and effectively evaluated, and guidance is provided for maintenance or replacement of the sand setting nozzle.

Provided is an inner diameter measuring apparatus that can obtain an accurate measurement result, while being mounted on a robot arm even in an environment in which large electromagnetic noise occurs. An inner diameter measuring apparatus is mounted on a tip part of a robot arm in a detachable manner to measure an inner diameter of a hole formed in a workpiece. The inner diameter measuring apparatus includes at least two contactors and a data conversion and transmission part. The at least two contactors are in contact with an inner wall face of the hole formed in the workpiece. The data conversion and transmission part converts analog data about displacements of the at least two contactors into digital data representing the inner diameter of the hole and transmits the digital data to an external device.

The invention belongs to the technical field of agronomy, and provides a high-throughput measurement method for the transverse diameter and the longitudinal diameter of a pineapple fruit based on image processing, which comprises the following steps: measuring the transverse diameter and the longitudinal diameter of the pineapple fruit by using a vernier caliper to obtain transverse diameter and longitudinal diameter data of the fruit, and constructing a training set and a test set; the method for automatically measuring the longitudinal stem and the transverse diameter of the pineapple fruit based on an open source computer vision library (OpenCV) is established, an efficient and accurate method is provided for high-throughput accurate evaluation of pineapple germplasm resource fruits, and accurate data support is provided for genetic analysis and gene mining of pineapple fruit size characters. And a good foundation is laid for the breeding of a new variety of the large-fruit pineapple.

An agricultural harvester (10) includes a frame and a crop cleaning assembly (62) supported on the frame (26). The crop cleaning assembly (62), in turn, includes an oscillating component (64, 66, 68) configured to oscillate relative to the frame (26) in a manner that conveys crop material across the oscillating component (64, 66, 68). Furthermore, the agricultural harvester (10) includes a RADAR sensor (102, 102A, 102B, 102C, 102D) configured to emit an output signal directed at the crop material present on the oscillating component (64, 66, 68) and detect an echo signal reflected by the crop material present on the oscillating component (64, 66, 68). Additionally, the agricultural harvester (10) includes a computing system (126) communicatively coupled to the RADAR sensor (102, 102A, 102B, 102C, 102D). In this respect, the computing system (126) is configured to determine a thickness of the crop material present on the oscillating component (64, 66, 68) based on detected echo signal.

This invention discloses a novel cup rim measuring instrument, belonging to the field of measuring instrument technology. It aims to solve problems encountered when using conventional calipers to measure the rim of paper cups, such as significant influence from sample molding, substantial human error, insufficient accuracy, and the inability to avoid seam errors. The measuring instrument includes a base, a measuring cup pan, a dial, a steel bar, a calibration block, a turntable, a digital micrometer, an adjusting block, a locking structure, and an elastic reset component. High-precision measurement is achieved by using a flexible steel bar to conform to the cup rim contour, combined with the digital micrometer. A tension spring provides uniform preload, and the locking structure fixes the length of the steel bar. The mating structure between the adjusting block and the measuring head ensures accurate data. This measuring instrument offers precise and stable measurements, is easy to operate, and is suitable for various types of paper cups, especially for paper cup production quality inspection scenarios with high requirements for measurement accuracy and consistency.

The utility model belongs to the field of cement fluidity detection, and discloses a cement mortar fluidity detection device which comprises a measuring disc, and a vibration mechanism is arranged at the bottom of the measuring disc; the inner side of the outer circular ring is matched with the measuring disc, an inner circular ring is fixed to the inner side of the outer circular ring, and the bottom surface of the inner circular ring abuts against the measuring disc; the measuring mechanism comprises a movable unit and a measuring scale, the movable unit is movably installed on the outer circular ring and located above the inner circular ring, and the measuring scale is installed on the movable unit. Through the arrangement of the outer circular ring and the inner circular ring, the outer circular ring, the inner circular ring and the measuring mechanism can be integrally placed on the measuring disc in a hanging and overlapping manner, so that when the measuring disc needs to be cleaned, loaded and unloaded, the outer circular ring and the like do not interfere with the work of a worker, and the worker can better control the measuring disc.

The invention relates to the technical field of worm measurement, in particular to a worm size precision detection device which comprises a mounting plate, two assembly blocks are fixedly connected to the upper end of the mounting plate, air cylinders are fixedly connected to the ends, close to each other, of the two assembly blocks, and mounting blocks are fixedly connected to the upper ends of the two assembly blocks. The worm is placed between the two assembling blocks and arranged in the middle, then the two air cylinders are started, piston rods arranged in the two air cylinders are made to get close to the middle, the worm in the middle is gradually clamped through the clamping rods, and when the clamping rods get close gradually, the marking needles can be driven to get close gradually; the measuring value of the worm can be obtained by reading the value, marked by the marking needle, on the marking plate, and through the design, measuring and clamping of the worm are more integrated, and the detecting and clamping efficiency is improved.

The invention provides a method for determining the machining size of a copper tile on a water turbine. The method comprises the steps that firstly, a shell is placed and fixed; 2, measuring the size of the accommodating chamber: selecting a measurement group along the circumferential direction, and calculating a measured average value X; 3, the outer diameter H2 of the copper tile needing to be machined is determined, and the outer diameter H2 of the copper tile needing to be machined is calculated according to the average value X in the step 2 and the preset interference fit amount r; 4, the inner diameter H3 of the copper tile is determined, specifically, the outer cylindrical surface of the pivot is measured, and the inner diameter H3 of the copper tile needing to be machined is calculated according to the preset design gap amount s; therefore, according to the outer diameter H2 and the inner diameter H3 of the copper tile obtained in the step 3 and the step 4, the size needing to be machined of the copper tile is obtained. In this way, the actual machining size of the copper tile is determined according to the size of the shell and the size of the pivot which are matched with the copper tile. Therefore, the matching precision can be improved.