阅读说明：本技术 一种螺纹规用计量校准方法 (Metering calibration method for thread gauge ) 是由 赵艳 于 2020-10-27 设计创作，主要内容包括：本发明属于检定技术领域,涉及对于螺纹规的检定技术,尤其是一种螺纹规用计量校准方法。包括待检螺纹规,三坐标测量机和星型测头,待检螺纹规沿纵向固定于三坐标测量机的检测位置,三坐标测量机对星型测头进行标定；包括如下步骤：步骤1：将待检螺纹规固定于三坐标测量机的检测位置；步骤2：采用三坐标测量机对星型测头进行标定；步骤3：应用星型测头对沿螺纹轴线方向多角度测量螺纹轮廓；步骤4：重塑螺纹规的三维立体形状,建立螺纹量规模型；步骤5：将步骤4所述的螺纹量规模型和标准模型进行轴线重合旋转比较判定待检螺纹规的螺纹质量。(The invention belongs to the technical field of verification, relates to a verification technology of a thread gauge, and particularly relates to a metering calibration method for the thread gauge. The thread gauge to be detected is longitudinally fixed at the detection position of the three-coordinate measuring machine, and the three-coordinate measuring machine is used for calibrating the star-shaped measuring head; the method comprises the following steps: step 1: fixing a thread gauge to be detected at a detection position of a three-coordinate measuring machine; step 2: calibrating the star-shaped measuring head by using a three-coordinate measuring machine; and step 3: measuring the thread profile at multiple angles along the axis direction of the thread by using a star-shaped measuring head; and 4, step 4: remolding the three-dimensional shape of the thread gauge, and establishing a thread gauge model; and 5: and (4) comparing the thread gauge model in the step (4) with the standard model by means of axis coincidence rotation to judge the thread quality of the thread gauge to be detected.)

1. A thread gauge metering and calibrating method is characterized in that: the thread gauge to be detected is fixed at the detection position of the three-coordinate measuring machine along the axial direction, and the three-coordinate measuring machine is used for calibrating the star-shaped measuring head;

the method comprises the following steps:

step 1: fixing a thread gauge to be detected at a detection position of a three-coordinate measuring machine;

step 2: calibrating the star-shaped measuring head by using a three-coordinate measuring machine;

and step 3: measuring the thread profile at multiple angles along the axis direction of the thread by using a star-shaped measuring head;

and 4, step 4: remolding the three-dimensional shape of the thread gauge, and establishing a thread gauge model;

and 5: and (4) comparing the thread gauge model in the step (4) with the standard model by means of axis coincidence rotation to judge the thread quality of the thread gauge to be detected.

2. A thread gauge calibration method as defined in claim 1, wherein: the step 3 comprises the steps of,

step 3.1: an original coordinate system OXYZ is constructed, a star-shaped measuring head of a coordinate measuring machine is used for measuring, the axis of the cylindrical thread gauge is used as a Z axis, the end face of a thread is used as a center of a circle, and an X axis and a Y axis of a machine coordinate system are used as an X axis and a Y axis of a newly-built coordinate system. Four measuring pins scan the screw thread gauge along the Z axis, and the measured points are set as

Step 3.2: the transformation of the coordinate system to different angles is shown in fig. 2. The original point is still the central point O of the end face of the thread gauge and rotates by an angle theta around the Z axis_lObtaining a new coordinate system OX_lY_lZ_l. Angle of rotation theta_lThe formula is as follows:

θ_lθ ═ l (l ═ 1.2.3 … 45) formula 1

Wherein: theta ═ pi/180

Four pins scan the thread gauge along the Z-axis, shown in FIG. 2 in the rotating coordinate system OX_lY_lZ_lThe point set obtained by the lower measurement is

3. A thread gauge calibration method as defined in claim 1, wherein: the step 4 comprises the steps of,

step 4.1: establishing a volume model by using a homogeneous transformation method; will theta_lThe point set measured in the coordinate system is transformed into the original coordinate system OXYZ through the homogeneous coordinate, and the coordinate of any point set can be calculated through a formula 2 to obtain the coordinate corresponding to the original coordinate system OXYZ;

step 4.2: the gauge measurements are measured in the direction opposite the vector; when rotating the angle theta along the Z-axis direction_lThen, in a new coordinate system OX_lY_lZ_lWhen the same measurement is carried out, cosine error is introduced; let the coordinate of the center point P of the measuring head be (x)_P,y_P,z_P) By probing, the coordinate of the actual contact point B is (x)_B,y_B,z_B) Radius of stylus is R, actual measurement point coordinate (x)_B,y_B,z_B) Cosine error compensation is required, and the compensation formula is formula 3;

the measurement point set under the OXYZ coordinate system is obtained after the coordinate system is changed and is shown in formula 4;

and converting the measurement point set to the same coordinate system, and processing by using Matlab to obtain a scanning three-dimensional graph of the thread gauge.

4. A thread gauge calibration method as defined in claim 1, wherein: step 5 comprises determining the thread shape according to the requirements for cylindrical thread parameters in ISO1502 and ISO 68-1;

when a variable psi is greater than or equal to 0 and less than or equal to psi and less than or equal to (P-b)₁) Per 2, formula of threaded generatrixExpressed as:

when (P-b)₁)/2≤Ψ≤(P+b₁) The formula for the thread generatrix is:

when (P + b)₁) And/2 is less than or equal to psi and less than or equal to P, and the formula of the thread generatrix is represented as:

in the formula: d₀: the major diameter d: single pitch diameter b₁: width P: pitch α: upper half flank angle β: lower half flank angle γ: thread passing theoretical parameters (e.g. b)₁、d₀D, alpha, beta, gamma) to obtain the maximum model and the minimum model of the standard spiral ring gauge; the standard thread model is obtained through calculation, and a corresponding standard thread scale type can be established by using the formula.

5. A thread gauge calibration method as defined in claim 4, wherein: and (5) substituting the tolerance range of each parameter variable into a formula to obtain a standard thread column, performing axis coincident rotation with the remolded and scanned thread, and enveloping the standard thread column to check the interference condition to judge the quality of the thread.

Technical Field

The invention belongs to the technical field of verification, relates to a verification technology of a thread gauge, and particularly relates to a metering calibration method for the thread gauge.

Background

In modern high-precision measurement, thread gauges are subjected to measurement calibration before use to ensure reliability of connection between workpieces, interchangeability, accuracy of assembly and bearing capacity thereof, so that accurate measurement of thread gauges is of great interest in the field of measurement.

The traditional measuring method is to use a calibration gauge to judge the thread, the measuring accuracy mainly depends on the abrasion degree of the thread and personnel error, the exact parameters of the thread cannot be obtained through the measurement of the calibration gauge, and the quantitative analysis is not facilitated. Parametric feature based measurement methods have been developed for a long time. Directly, the method for measuring the pitch diameter of the thread mainly utilizes a length measuring machine and a double measuring ball, and the pitch diameter of the thread can be directly measured, so that the method is used for a long time in the domestic metering field; with the development of modern manufacturing industry in recent years, the scanning function of scanning measuring instruments and coordinate measuring machines scans the thread profile while calculating the main parameters of the thread. Meanwhile, with the continuous development of visual inspection technology, a non-contact method is also developed. However, with the increasing popularization of the technology and the increasing depth of the knowledge networking degree, the same thread gauge metering department uses different measuring methods, the measuring results are inconsistent, and the industrial production, the external trade and the like are seriously influenced.

When the calibration conclusions of the same thread gauge are different, the thread gauge can be accurately judged by using what method, and the position where the thread gauge does not conform to is pointed out, which is a problem to be researched and solved by the current metering department.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a measuring method for a thread gauge, which does not need any reference gauge, scans the thread gauge along the axial direction, establishes a remoulded model by acquiring the characteristics of threads, and performs an interference experiment with a standard model, so that the quality of the thread gauge can be calibrated, and the problem position of the thread gauge can be accurately judged.

The technical scheme adopted by the invention is as follows:

a thread gauge metering and calibrating method is characterized in that: the thread gauge to be detected is fixed at the detection position of the three-coordinate measuring machine along the axial direction, and the three-coordinate measuring machine is used for calibrating the star-shaped measuring head;

the method comprises the following steps:

step 1: fixing a thread gauge to be detected at a detection position of a three-coordinate measuring machine;

step 2: calibrating the star-shaped measuring head by using a three-coordinate measuring machine;

and step 3: measuring the thread profile at multiple angles along the axis direction of the thread by using a star-shaped measuring head;

and 4, step 4: remolding the three-dimensional shape of the thread gauge, and establishing a thread gauge model;

and 5: and (4) comparing the thread gauge model in the step (4) with the standard model by means of axis coincidence rotation to judge the thread quality of the thread gauge to be detected.

Further, the step 3 comprises the steps of,

step 3.1: an original coordinate system OXYZ is constructed, a star-shaped measuring head of a coordinate measuring machine is used for measuring, the axis of the cylindrical thread gauge is used as a Z axis, the end face of a thread is used as a center of a circle, and an X axis and a Y axis of a machine coordinate system are used as an X axis and a Y axis of a newly-built coordinate system. Four measuring pins scan the screw thread gauge along the Z axis, and the measured points are set as

Step 3.2: the transformation of the coordinate system to different angles is shown in fig. 2. The original point is still the central point O of the end face of the thread gauge and rotates by an angle theta around the Z axis_lObtaining a new coordinate system OX_lY_lZ_l. Angle of rotation theta_lThe formula is as follows:

θ_lθ ═ l (l ═ 1.2.3 … 45) formula 1

Wherein: theta ═ pi/180

Four pins scan the thread gauge along the Z-axis, shown in FIG. 2 in the rotating coordinate system OX_lY_lZ_lThe point set obtained by the lower measurement is

Further, the step 4 comprises the steps of,

step 4.1: establishing a volume model by using a homogeneous transformation method; will theta_lThe measured point set in the coordinate system passes through the homogeneous coordinateTransforming the coordinates of the arbitrary point set into an original coordinate system OXYZ, and calculating the coordinates of the arbitrary point set through a formula 2 to obtain coordinates corresponding to the original coordinate system OXYZ;

step 4.2: the gauge measurements are measured in the direction opposite the vector; when rotating the angle theta along the Z-axis direction_lThen, in a new coordinate system OX_lY_lZ_lWhen the same measurement is carried out, cosine error is introduced; let the coordinate of the center point P of the measuring head be (x)_P,y_P,z_P) By probing, the coordinate of the actual contact point B is (x)_B,y_B,z_B) Radius of stylus is R, actual measurement point coordinate (x)_B,y_B, z_B) Cosine error compensation is required, and the compensation formula is formula 3;

the measurement point set under the OXYZ coordinate system is obtained after the coordinate system is changed and is shown in formula 4;

and converting the measurement point set to the same coordinate system, and processing by using Matlab to obtain a scanning three-dimensional graph of the thread gauge.

Further, the step 5 comprises determining the thread shape according to the requirements of ISO1502 and ISO68-1 on the parameters of the cylindrical thread;

when a variable psi is greater than or equal to 0 and less than or equal to psi and less than or equal to (P-b)₁) The formula for the thread generatrix is:

when (P-b)₁)/2≤Ψ≤(P+b₁) The formula for the thread generatrix is:

when (P + b)₁) And/2 is less than or equal to psi and less than or equal to P, and the formula of the thread generatrix is represented as:

in the formula: d₀: the major diameter d: single pitch diameter b₁: width P: pitch α: upper half flank angle β: lower half flank angle γ: threading

By theoretical parameters (e.g. b)₁、d₀D, alpha, beta, gamma) to obtain the maximum model and the minimum model of the standard spiral ring gauge; the standard thread model is obtained through calculation, and a corresponding standard thread scale type can be established by using the formula.

Furthermore, in the step 5, the tolerance range of each parameter variable is substituted into a formula to obtain a standard thread column, the standard thread column and the remolded scanning thread perform axis coincident rotation, and the standard thread column is enveloped to check the interference condition to judge the quality of the thread.

The invention has the advantages and positive effects that:

in the invention, a star-shaped measuring head of a coordinate measuring machine is utilized to measure a thread gauge, and a coordinate system which takes the axis of a cylindrical thread gauge as a Z axis and the end face of a thread as a center and takes the X axis and the Y axis of the machine as the center is established to scan the thread gauge along the Z axis in four vector directions; the coordinate system is converted into different angles, and the thread model can be accurately reconstructed by using error compensation and a homogeneous coordinate equation. Secondly, a thread gauge model with a tolerance band is calculated and constructed based on the requirements of ISO1502 on the geometry of the cylindrical thread gauge. And carrying out axis coincidence rotation comparison on the measured thread gauge 3D model and the standard model, and determining the interference positions of the measured thread gauge at the crest and the root in the containment process. Therefore, the thread quality can be accurately judged through comparison of the actual model and the theoretical model.

According to the invention, a coordinate measuring machine is used for measuring the thread profile along the axis direction of the thread at multiple angles, the three-dimensional shape of the thread gauge is remolded, the standard thread three-dimensional model with a tolerance zone and the measuring model are coaxially rotated, and the position with least interference with the standard model is taken for analysis, so that the non-conforming condition of the thread can be accurately analyzed and judged.

In the invention, a reference gauge is not needed when the thread gauge is calibrated by adopting a method for remodeling a model, and the main source of uncertainty is errors caused by a coordinate measuring machine and a measuring method. After uncertainty analysis, compared with the traditional parameter measurement method and the traditional calibration method, the uncertainty of the three methods can meet the calibration requirement of the thread gauge. The method comprises the steps of scanning a thread gauge along the axial direction without any reference gauge, establishing a remoulded model by collecting the characteristics of threads, carrying out interference experiments with a standard model, calibrating the quality of the thread gauge by the remoulded method through a large number of measurement experiments, and accurately judging the problem position of the thread gauge. The star-shaped probe of the three-coordinate measuring machine is used for scanning 360 degrees, a thread model is reestablished and compared with a standard gauge model, and the detection precision is greatly improved. The remodeling process may determine the exact interference location of the thread gauge. The method can find out the failure reason of the thread gauge and provide theoretical support for the influence of different parameters on production and manufacturing design. The method can provide more reasonable theoretical guidance for the design of the threads. In future, the reconstructed model system is mainly optimized in an experiment so as to further improve the measurement accuracy.

Drawings

FIG. 1 is a schematic diagram of a probe scanning thread coordinate system rotation;

FIG. 2 is a schematic diagram of cosine error;

FIG. 3 is a diagram of a reshaped thread gauge model;

FIG. 4 is a representation of the respective thread symbols in the X-Z plane;

FIG. 5 is a diagram of a standard model;

FIG. 6 is a schematic view of a scanning thread gauge using a coordinate measuring machine;

FIG. 7 is a schematic diagram illustrating a lateral error of the Y axis during scanning in the X direction in the embodiment;

FIG. 8 is a schematic view of the X-direction thread profile in the example.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

A thread gauge metering and calibrating method is characterized in that: the thread gauge to be detected is fixed at the detection position of the three-coordinate measuring machine along the axial direction, and the three-coordinate measuring machine is used for calibrating the star-shaped measuring head;

the method comprises the following steps:

step 1: fixing a thread gauge to be detected at a detection position of a three-coordinate measuring machine;

step 2: calibrating the star-shaped measuring head by using a three-coordinate measuring machine;

and step 3: measuring the thread profile at multiple angles along the axis direction of the thread by using a star-shaped measuring head;

step 3.1: an original coordinate system OXYZ is constructed, a star-shaped measuring head of a coordinate measuring machine is used for measuring, the axis of the cylindrical thread gauge is used as a Z axis, the end face of a thread is used as a center of a circle, and an X axis and a Y axis of a machine coordinate system are used as an X axis and a Y axis of a newly-built coordinate system. Four measuring pins scan the screw thread gauge along the Z axis, and the measured points are set as

Step 3.2: the transformation of the coordinate system to different angles is shown in fig. 2. The original point is still the central point O of the end face of the thread gauge and rotates by an angle theta around the Z axis_lObtaining a new coordinate system OX_lY_lZ_l. Angle of rotation theta_lThe formula is as follows:

θ_lθ ═ l (l ═ 1.2.3 … 45) formula 1

Wherein: theta ═ pi/180

Four pins scan the thread gauge along the Z-axis, shown in FIG. 2 in the rotating coordinate system OX_lY_lZ_lThe point set obtained by the lower measurement is

And 4, step 4: remolding the three-dimensional shape of the thread gauge, and establishing a thread gauge model;

step 4.1: establishing a volume model by using a homogeneous transformation method; will theta_lThe point set measured in the coordinate system is transformed into the original coordinate system OXYZ through the homogeneous coordinate, and the coordinate of any point set can be calculated through a formula 2 to obtain the coordinate corresponding to the original coordinate system OXYZ;

step 4.2: the gauge measurements are measured in the direction opposite the vector; when rotating the angle theta along the Z-axis direction_lThen, in a new coordinate system OX_lY_lZ_lWhen the same measurement is carried out, cosine error is introduced; let the coordinate of the center point P of the measuring head be (x)_P,y_P,z_P) By probing, the coordinate of the actual contact point B is (x)_B,y_B,z_B) Radius of stylus is R, actual measurement point coordinate (x)_B,y_B, z_B) Cosine error compensation is required, and the compensation formula is formula 3;

the measurement point set under the OXYZ coordinate system is obtained after the coordinate system is changed and is shown in formula 4;

and converting the measurement point set to the same coordinate system, and processing by using Matlab to obtain a scanning three-dimensional graph of the thread gauge.

And 5: comparing the thread gauge model in the step 4 with the standard model by axis coincidence rotation to judge the thread quality of the thread gauge to be detected;

determining the thread shape according to the requirements on the parameters of the cylindrical thread in ISO1502 and ISO 68-1;

when a variable psi is greater than or equal to 0 and less than or equal to psi and less than or equal to (P-b)₁) The formula for the thread generatrix is:

when (P-b)₁)/2≤Ψ≤(P+b₁) The formula for the thread generatrix is:

when (P + b)₁) And/2 is less than or equal to psi and less than or equal to P, and the formula of the thread generatrix is represented as:

in the formula: d₀: the major diameter d: single pitch diameter b₁: width P: pitch α: upper half flank angle β: lower half flank angle γ: threading

By theoretical parameters (e.g. b)₁、d₀D, alpha, beta, gamma) to obtain the maximum model and the minimum model of the standard spiral ring gauge; the standard thread model is obtained by calculation, and a corresponding standard thread scale type can be established by using the formula; and (5) substituting the tolerance range of each parameter variable into a formula to obtain a standard thread column, performing axis coincident rotation with the remolded and scanned thread, and enveloping the standard thread column to check the interference condition to judge the quality of the thread.

The using method of the invention is as follows:

the quality of the thread gauge is determined by performing a measurement experiment on the thread gauge using the method of the present invention, using the thread gauge M30-6H-T as a calibration example. In addition, the embodiment is also subjected to measurement experiments by adopting parameter measurement and gauge calibration measurement methods respectively, so as to verify the feasibility of the method used by the invention.

1. The remoulded thread gauge adopts a three-coordinate measuring machine 'LeiTZ PMM XI 1.0707' and utilizes a QuinDOS 7 software system to measure the thread gauge, and the maximum allowable error MPE of the coordinate measuring machine is as follows: (0.6. + -. 600L) μm, wherein L is mm. The M30-6g-T thread ring gauge measurement procedure is described herein. And (4) radially scanning the thread by using a proper measuring head to obtain a single scanning point set.

The star probe of the CMM scans two perpendicular pairs of thread profiles in an axial direction at a time in a counter-clockwise direction as shown in FIG. 6. The coordinate system is converted into a fixed angle, the number of the measuring profiles is increased, the four measuring pins scan the thread gauge along the Z axis, and fig. 7 shows the transverse error of the Y axis when the measuring head scans the X direction. The Y-axis direction error is corrected to obtain the X-direction thread profile, as shown in fig. 8.

And (5) establishing a volume model by using a homogeneous transformation method. Will theta_lThe point set measured in the coordinate system is transformed into the original coordinate system OXYZ through the homogeneous coordinate, and the coordinate of any point set can be calculated through formula 2 to obtain the coordinate corresponding to the original coordinate system OXYZ. And reshaping the three-dimensional solid figure M30-6 g-T. And determining standard threads to establish a 3D model according to the requirements on the cylindrical thread parameters in ISO1502 and ISO 68-1. And substituting the tolerance range of each parameter variable into a formula to obtain a standard thread column, performing axis coincident rotation with the remolded scanning thread, and enveloping the standard thread column to check the interference condition to judge the quality of the thread.

2. The method for measuring the thread gauge parameters is specified in the national calibration specification JJF1345-2012 cylindrical thread gauge. Here calibrated with an IAC model number MSXP16060 thread scanner. The main parameters of the calibration result comprise single pitch diameter, pitch, major diameter/minor diameter and flank angle, and the national standard shows that the effective pitch diameter of the method is obtained by correcting the pitch accumulated error and the flank angle of a single pitch diameter measurement value.

The basic parameters of measurement are mainly basic major diameter, basic minor diameter, thread pitch, thread form angle and the like, and the thread parameters are obtained by directly scanning the thread profile along the axial direction and are obtained by calculation. Through multiple experimental measurements, under the condition that the same thread gauge, the same measuring instrument and the same measuring conditions are adopted, the scanning position has randomness, and the quality of the thread cannot be completely calibrated.

3. The thread proofreading gauge is used for comprehensively measuring the effective pitch diameter of the thread and is a method specified in the national standard GB3934-2003 'technical conditions for common thread gauges'. The standard particularly refers to the requirement of the standard on the thread gauge parameters when the judgment results of the working thread gauges are inconsistent.

It is specified in the calibrated thread plug gauge standard that a T-T calibrated thread plug gauge should be screwed through with a new thread ring gauge. The T-Z gauge allows the threaded portions at both ends of the through end thread ring gauge to be screwed together, but the screwing amount should not exceed one thread pitch. FIG. 8 shows a schematic drawing of the M30-6g-T thread gauge versus corrected thread gauge tolerance. As can be readily seen, the MN section is the overlap of the tolerance band of the ring gauge M30-6g-T and the calibrated plug gauge M30-6 g-TZ. In this case, the proof-reading plug gauge M30-6g-TZ detects a thread ring gauge M30-6g-T in the tolerance part of MN, i.e. the tolerance range is (27.6675-27.6735) mm, which produces different calibration results, so that the proof-reading plug gauge has certain errors in thread calibration. In the test, the M30-6g-T thread ring gauge is detected, and the result is that M30-6g-T meets the requirements of the calibration specification and the national standard.

Uncertainty analysis of three measurement methods

3.1 uncertainty analysis of remodeling methods

When the thread gauge is calibrated by the method for remodeling the model, a reference gauge is not needed, and the main source of uncertainty is errors caused by a coordinate measuring machine and a measuring method;

3.2 uncertainty analysis of the method of measuring parameters

The method for measuring the parameters of the thread gauge is calibrated by using a thread scanner of IAC corporation model MSXP 16060. The uncertainty of the measurement of the method mainly comprises a reference gauge, the indicating value error of a scanner, the measurement repeatability and the system error;

3.3 measurement uncertainty analysis of the calibration gauge method

The calibrated thread ring gauge uses a thread plug gauge according to ISO1502, and the calibrated thread plug gauge should be run through with the new thread ring gauge for T-T. The T-Z gauge allows for threading with the threaded portions at both ends of the lead end ring gauge, but the amount of threading should not exceed one T-T gauge pitch. The main sources of the uncertainty of the method are indication errors of a T-Z calibration thread plug gauge, errors brought by a measuring method and the like.

3.4 uncertainty comparison of the three measurement methods

The extended uncertainties for the three specific methods are shown in Table 1, where L is the pitch diameter of the gauge in μm.

TABLE 1 extended uncertainty List

Table 2.Expanded uncertainty list

The uncertainty of the three methods can meet the calibration requirement of the thread gauge. Although the numerical value obtained by the reconstruction method is not obviously smaller than that obtained by other methods, the judgment result is inconsistent by using a parameter measurement method and a checking and stopping rule method, and the method for reshaping the thread gauge can accurately judge the quality of the thread gauge and can directly detect the position which does not accord with the standard.

In the invention, a star-shaped measuring head of a coordinate measuring machine is utilized to measure a thread gauge, and a coordinate system which takes the axis of a cylindrical thread gauge as a Z axis and the end face of a thread as a center and takes the X axis and the Y axis of the machine as the center is established to scan the thread gauge along the Z axis in four vector directions; the coordinate system is converted into different angles, and the thread model can be accurately reconstructed by using error compensation and a homogeneous coordinate equation. Secondly, a thread gauge model with a tolerance band is calculated and constructed based on the requirements of ISO1502 on the geometry of the cylindrical thread gauge. And carrying out axis coincidence rotation comparison on the measured thread gauge 3D model and the standard model, and determining the interference positions of the measured thread gauge at the crest and the root in the containment process. Therefore, the thread quality can be accurately judged through comparison of the actual model and the theoretical model.

According to the invention, a coordinate measuring machine is used for measuring the thread profile along the axis direction of the thread at multiple angles, the three-dimensional shape of the thread gauge is remolded, the standard thread three-dimensional model with a tolerance zone and the measuring model are coaxially rotated, and the position with least interference with the standard model is taken for analysis, so that the non-conforming condition of the thread can be accurately analyzed and judged.

In the invention, a reference gauge is not needed when the thread gauge is calibrated by adopting a method for remodeling a model, and the main source of uncertainty is errors caused by a coordinate measuring machine and a measuring method. After uncertainty analysis, compared with the traditional parameter measurement method and the traditional calibration method, the uncertainty of the three methods can meet the calibration requirement of the thread gauge. The method comprises the steps of scanning a thread gauge along the axial direction without any reference gauge, establishing a remoulded model by collecting the characteristics of threads, carrying out interference experiments with a standard model, calibrating the quality of the thread gauge by the remoulded method through a large number of measurement experiments, and accurately judging the problem position of the thread gauge. The star-shaped probe of the three-coordinate measuring machine is used for scanning 360 degrees, a thread model is reestablished and compared with a standard gauge model, and the detection precision is greatly improved. The remodeling process may determine the exact interference location of the thread gauge. The method can find out the failure reason of the thread gauge and provide theoretical support for the influence of different parameters on production and manufacturing design. The method can provide more reasonable theoretical guidance for the design of the threads. In future, the reconstructed model system is mainly optimized in an experiment so as to further improve the measurement accuracy.