CN108253915B - Calibration method - Google Patents

Abstract

The invention relates to a calibration method, which includes a base plate and six standard balls. The six standard balls are divided into two groups. Each group contains three standard balls. The three standard balls in each group are surrounded together so that the measuring ball It can be tangent to three standard balls at the same time. The two sets of standard balls are respectively fixed in two directions of the substrate; during the calibration process, the probe is used to contact and measure the three standard balls in the six-ball sample. The ball is more likely to limit the sliding of the probe and has high positioning accuracy. It can effectively avoid the shortcomings of easy sliding of the probe in traditional tooth pitch and tooth thickness calibration, thereby effectively improving the accuracy of tooth pitch and tooth thickness calibration.

Description

a calibration method

Technical field

The invention relates to the technical field of measuring instrument calibration, and in particular to a six-ball template and a calibration method.

Background technique

Measuring instruments are necessary tools for scientific research, education and teaching, engineering measurement and other fields. With the development of science and technology and the advancement of the times, various types of measuring instruments have been vigorously developed and are used more and more widely in social life. High-precision and high-reliability measuring instruments have always been the focus of research and exploration by researchers in this field.

Measuring instruments are usually equipped with a probe, which serves as a sensor to collect relevant parameters of the measured object. The development level of the probe directly affects the measurement accuracy and efficiency of the measuring instrument. Precision probes are usually divided into two types: contact probes and non-contact probes. Contact probes are divided into mechanical probes, trigger probes and scanning probes; non-contact probes are divided into laser probes. Probes and optical video probes.

The mechanical probe is an earlier type of probe used in precision measuring instruments. This probe conducts measurements through direct contact between the probe end and the measured object. It is mainly used for manual measurement. This type of probe has a simple structure and is easy to operate. Its shortcomings are low accuracy and low measurement efficiency, and it is rarely used in the field of industrial measurement. Trigger probes and scanning probes are the most widely used in the industrial field; trigger probes and scanning probes usually include a stylus and a measuring ball. During the measurement process, the measuring ball is used to contact the measured object to achieve Collection of relevant parameters; among them, the trigger probe has the advantages of simple structure, easy use, and high trigger accuracy. Compared with the trigger probe, the scanning probe has higher accuracy, stronger functions, and more adaptability. It is wide and has both single point measurement and continuous scanning measurement functions.

An important parameter in gear measurement is tooth pitch and tooth thickness. These parameters are usually calibrated using standard gears, that is, measured on the standard gear graduation circle by measuring instruments. However, due to the positioning accuracy of the measuring instrument and the problem of probe sliding when the probe contacts the tooth surface, there is usually a certain deviation in the calibration values of tooth pitch and tooth thickness.

Contents of the invention

The purpose of the present invention is to improve the deficiencies in the prior art and provide a six-ball template and a calibration method. During the calibration process, the probe is in contact with three standard balls in the six-ball template to measure the three standards. The ball is more likely to limit the sliding of the probe and has high positioning accuracy. It can effectively avoid the shortcomings of easy sliding of the probe in traditional tooth pitch and tooth thickness calibration, thereby effectively improving the accuracy of tooth pitch and tooth thickness calibration.

The technical solutions adopted by the present invention to solve the technical problems are:

A six-ball model includes a base plate and six standard balls. The six standard balls are divided into two groups. Each group contains three standard balls. The three standard balls in each group are surrounded together so that the measuring balls can be connected with each other. The three standard balls are tangent to each other at the same time, and the two sets of standard balls are respectively fixed in two directions of the substrate.

In the six-ball model, there are two groups of standard balls, each group containing three standard balls respectively. The three standard balls are respectively set on the base plate and surrounded together. The three standard balls can be tangent to each other or to each other. When the distance is different, you only need to balance the diameter of the standard ball and the center distance between the two balls to ensure that the measuring ball of the probe can be tangent to the three standard balls at the same time; the measuring instrument is performing tooth distance and tooth thickness calibration. At certain times, the measuring ball of the measuring head can contact the three measuring balls in a group at the same time, forming three contact points. The three contact points form a three-point support for the measuring ball, making it easier to limit the sliding of the measuring ball during the measurement process. , improve positioning accuracy, thereby effectively improving the accuracy of tooth pitch and tooth thickness calibration.

Preferably, the substrate is a flat plate. When the substrate is a flat plate, it is not only convenient for the substrate to be set or fixed on a measuring instrument for calibrating the tooth pitch and tooth thickness; it is also convenient for using a standard measuring instrument to measure the distance between the two sets of standard balls.

Preferably, two of the three standard spheres in each group are tangent to each other. Each standard ball is fixed on the base plate. The three standard balls in each group are arranged on the base plate in a tangent position relationship. During the production and manufacturing process of the six-ball prototype, the three standard balls can be conveniently placed. Divide them into one group and fix them in a suitable position, which is helpful to shorten the processing time; in addition, after the three standard balls in each group are arranged tangentially on the base plate, it also facilitates the later calibration of tooth pitch and tooth thickness. Each ball is positioned during the process, thereby simplifying the process of calculating the theoretical position when the probe contacts the three standard balls in each group at the same time, making the calculation simpler and more convenient.

Preferably, the six standard balls have the same diameter. The diameter of each standard ball in the six-ball model is the same, which is beneficial to simplifying the production and manufacturing process. It also facilitates the later calibration process of tooth pitch and tooth thickness. The measuring ball on the probe head contacts the three standard balls in each group at the same time. It also simplifies the process of calculating the theoretical position of the probe when it is in simultaneous contact with three calibration balls in each set.

Preferably, the accuracy of the standard ball is not lower than the accuracy of the measuring ball on the probe head. The standard ball in the six-ball model is the reference ball when the measuring instrument performs tooth pitch and tooth thickness calibration. Its accuracy has a great impact on the accuracy of the tooth pitch and tooth thickness calibration. Therefore, it is necessary to design the six-ball model at the beginning. Try to reduce or eliminate this effect. As long as the accuracy of the standard ball is not lower than the manufacturing accuracy of the measuring ball itself, the impact of the standard ball as a reference ball on the calibration accuracy of tooth pitch and tooth thickness will be minimized and can be ignored.

Preferably, the accuracy of the standard ball is one level higher than the accuracy of the measuring ball on the measuring head. The higher the accuracy of the standard ball, the more troublesome the manufacturing process, the longer the cycle, and the higher the cost; when the accuracy of the standard ball is one level higher than the accuracy of the measuring ball, the accuracy of the standard ball will affect the error of tooth pitch and tooth thickness calibration. It is smaller and can also well balance the production cost of the six-ball prototype.

Preferably, the standard ball is made of ruby, ceramic, glass or tungsten carbide. Since the accuracy requirements for standard balls are very high, the standard balls must also have high hardness, high wear resistance, anti-static, anti-magnetic, good insulation properties, low thermal conductivity, good acid and alkali resistance, and extremely low surface roughness. and other characteristics, thus preventing environmental factors from affecting the standard balls in the six-ball model, which in turn affects the accuracy of tooth pitch and tooth thickness calibration; among commonly used materials, ruby, ceramics, glass, tungsten carbide, etc. The materials all have the above characteristics and meet the requirements of standard balls.

Preferably, the radius or diameter parameters of the standard balls and the standard spacing parameters between the two sets of standard balls are marked on the substrate. The radius or diameter parameters of the standard balls and the standard spacing parameters between the two sets of standard balls are data measured using standard measuring instruments after the six-ball sample is completed. The data are reliable and highly accurate, making it easy to use the six-balls. Reference for sample.

A calibration method includes the following steps:

(1) Obtain the radius or diameter parameters and ball center position parameters of each standard ball in the six-ball template.

(2) Obtain the radius or diameter parameters of the measuring ball in the measuring instrument;

(3) Based on the data obtained in steps (1) and (2), calculate and obtain the theoretical position parameters of the measuring ball when it contacts the three standard balls in each group at the same time;

(4) Control the measuring ball of the measuring instrument to measure the three standard balls in the corresponding group at the theoretical position, obtain the position parameters A and B of the two sets of standard balls respectively, and obtain the measurement distance between the two sets of standard balls through calculation Parameter L, where L=|A-B|;

(5) Compare the measured spacing L in step (4) with the standard spacing L ₀ to determine the accuracy of the measuring instrument and complete the calibration of the tooth pitch and tooth thickness; among them, the standard spacing L ₀ is the six-dimensional space obtained by using a standard measuring instrument. The distance between two sets of standard balls in the ball template.

The whole process of using the six-ball template to calibrate the tooth pitch and tooth thickness of the measuring instrument is simple. The three standard balls in the six-ball template will form a three-point stable support for the measuring ball, thus greatly reducing the sliding error of the measuring ball of the measuring instrument. , which can effectively improve the calibration accuracy of tooth pitch and tooth thickness.

Compared with the existing technology, using a six-ball template and a calibration method provided by the present invention, during the calibration process, the measuring head is in contact with three standard balls in the six-ball template, and the three standard balls are easier to limit. The sliding and positioning accuracy of the probe can effectively avoid the shortcomings of easy sliding of the probe in traditional tooth pitch and tooth thickness calibration, thereby effectively improving the accuracy of tooth pitch and tooth thickness calibration.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a probe commonly used in the measuring instrument provided by the present invention.

Figure 2 is an isometric view of a six-ball template provided in Embodiment 1 of the present invention.

Figure 3 is a top view of a six-ball template provided in Embodiment 1 of the present invention.

Figure 4 is a schematic diagram of the measuring ball provided in Embodiment 1 of the present invention when it is in contact with three standard balls in the six-ball model at the same time.

Figure 5 is a geometric relationship diagram for calculating the theoretical position of the measuring ball when calibrating the tooth pitch and tooth thickness using a six-ball template provided in Embodiment 4 of the present invention.

FIG. 6 is a schematic diagram of the measurement distance between two sets of standard balls measured by a measuring instrument when using a six-ball template for calibrating tooth pitch and tooth thickness provided in Embodiment 4 of the present invention.

Figure 7 is a schematic diagram of a six-ball template provided in Embodiment 4 of the present invention, in which the diameters of the six standard balls are different, but the three standard balls in each group are all tangent to each other.

Figure 8 is another geometric relationship diagram for calculating the theoretical position of the measuring ball when calibrating the tooth pitch and tooth thickness using a six-ball template provided in Embodiment 4 of the present invention.

Marking instructions in the figure

The first standard ball 1; the second standard ball 2; the third standard ball 3; the fourth standard ball 4; the fifth standard ball 5; the sixth standard ball 6; base plate 7; probe 8; probe 9; probe 10 ;Mark information 11.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the present invention.

Among the measuring instruments introduced in the background art, the commonly used probe structure is as shown in Figure 1. In the figure, mark 8 is the probe, mark 9 is the stylus, and mark 10 is the stylus ball.

Example 1

Please refer to Figure 2 and Figure 3. This embodiment provides a six-ball template, including a base plate 7 and six standard balls. The six standard balls are divided into two groups, each group containing three standard balls. The three standard balls are surrounded together so that the measuring ball 10 can be tangent to the three standard balls at the same time. The two sets of standard balls are respectively fixed in two directions of the base plate 7 .

In this embodiment, the three standard balls in each group are tangent to each other. The first standard ball 1, the second standard ball 2 and the third standard ball 3 in Figure 2 are tangent to each other. The standard ball 4, the fifth standard ball 5 and the sixth standard ball 6 are tangent to each other; each standard ball is fixed on the base plate 7, and the three standard balls in each group are in a tangent position relationship. Set on the base plate 7, when the measuring instrument is calibrating the tooth pitch and tooth thickness, the measuring ball 10 of the measuring head 8 can be in contact with three measuring balls 10 in a group at the same time, as shown in Figure 4, forming three contacts. The three contact points form a three-point support for the measuring ball 10, which makes it easier to limit the sliding of the measuring ball 10 during the measurement process, improve the positioning accuracy, and thereby effectively improve the accuracy of the tooth pitch and tooth thickness calibration; in addition, in each group, After the three standard balls are arranged tangentially on the base plate 7, it is also convenient to position each ball during the later calibration process of tooth pitch and tooth thickness, thereby simplifying the calculation of the probe 8 and the three standard balls in each group. The process of contacting the theoretical position at the same time makes the calculation more concise and convenient.

In a further solution, the diameters of the six standard balls in the six-ball template are the same; this, on the one hand, helps simplify the production and manufacturing process; on the other hand, it also facilitates the later calibration process of tooth pitch and tooth thickness. The measuring ball 10 on the measuring head 8 is in simultaneous contact with the three standard balls in each group, which can also simplify the process of calculating the theoretical position when the measuring head 8 is in simultaneous contact with the three standard balls in each group.

In this embodiment, the base plate 7 is a flat plate; because when the base plate 7 is a flat plate, it is not only convenient for the base plate 7 to be set or fixed on a measuring instrument for calibrating the tooth pitch and tooth thickness; it is also convenient to use a standard measuring instrument to measure the two dimensions. The spacing between sets of standard balls.

The accuracy of the standard ball is not lower than the accuracy of the measuring ball 10 on the measuring head 8; the standard ball in the six-ball sample is the reference ball when the measuring instrument performs tooth pitch and tooth thickness calibration, and its accuracy is critical to the accuracy of the tooth pitch and tooth thickness calibration. It has a great influence, so it is necessary to reduce or eliminate this influence as much as possible at the beginning of the design of the six-ball model. As long as the accuracy of the standard ball is not lower than the manufacturing accuracy of the measuring ball 10 itself, the standard ball serves as a reference ball for the tooth. Only then will the influence of pitch and tooth thickness calibration accuracy be minimized and can be ignored.

Specifically, in this embodiment, the accuracy of the standard ball is one level higher than the accuracy of the measuring ball 10 on the measuring head 8 . The higher the accuracy of the standard ball, the more troublesome the manufacturing process, the longer the cycle, and the higher the cost; when the accuracy of the standard ball is one level higher than the accuracy of the measuring ball 10, the accuracy of the standard ball will affect the calibration error of tooth pitch and tooth thickness. The impact is small, and it can also well balance the production cost of the six-ball prototype.

Since the accuracy requirements for standard balls are very high, the standard balls must also have high hardness, high wear resistance, anti-static, anti-magnetic, good insulation properties, low thermal conductivity, good acid and alkali resistance, and extremely low surface roughness. and other characteristics, thus preventing environmental factors from affecting the standard balls in the six-ball model, which in turn affects the accuracy of tooth pitch and tooth thickness calibration; among commonly used materials, ruby, ceramics, glass, tungsten carbide, etc. The materials all have the above characteristics and meet the requirements of the standard ball. Therefore, materials such as ruby, ceramic, glass, or tungsten carbide can be used to make the standard ball. In this embodiment, the standard ball is made of ceramic material. Specifically, Silicon nitride material among ceramic materials; silicon nitride is a very hard and wear-resistant ceramic material that can be processed into spheres with high precision and can also be polished to an extremely smooth surface finish, thereby improving the quality of the standard sphere as much as possible Accuracy, reducing the impact of the accuracy of the standard ball on the calibration accuracy of tooth pitch and tooth thickness.

In a further solution, the substrate 7 is also marked with the diameter parameter (or radius parameter) of the standard ball and the standard spacing parameter between the two sets of standard balls, as shown in Figure 2 or Figure 3; where, the radius of the standard ball Or the diameter parameters and the standard spacing parameters between the two sets of standard balls are all data measured using standard measuring instruments after the six-ball sample is produced. The data are reliable and highly accurate, making it easy to refer to when using the six-ball sample.

Example 2

The main difference between this embodiment 2 and the above-mentioned embodiment 1 is that in this embodiment, the three standard balls in each group of the six-ball template can be separated from each other, that is, the three standard balls are not necessarily tangent; However, the three standard balls are set on the base plate and surrounded together. At this time, it is necessary to balance the diameter of the standard ball and the center distance between the two balls to ensure that the measuring ball of the probe can be in contact with the three standard balls at the same time. cut; so that when the measuring instrument is calibrating the tooth pitch and tooth thickness, the measuring ball of the measuring head can contact the three measuring balls in a group at the same time, forming three contact points, and the three contact points form three points on the measuring ball. Support makes it easier to limit the sliding of the measuring ball during the measurement process, improve positioning accuracy, and effectively improve the accuracy of tooth pitch and tooth thickness calibration.

Example 3

The main difference between this embodiment 3 and the above-mentioned embodiment 1 is that in this embodiment, the diameters of the six standard balls in the six-ball template are not necessarily all the same; but the three standard balls are arranged on the base plate. and surrounded together. At this time, it is necessary to balance the diameter of the standard ball and the center distance between the two balls to ensure that the measuring ball of the probe can be tangent to the three standard balls at the same time; so that the measuring instrument can perform tooth pitch and When calibrating the tooth thickness, the measuring ball of the probe can contact three measuring balls in a group at the same time, forming three contact points. The three contact points form a three-point support for the measuring ball, making it easier to limit the measurement process. The sliding of the ball improves the positioning accuracy, thereby effectively improving the accuracy of tooth pitch and tooth thickness calibration.

Example 4

This embodiment provides a calibration method, which includes the following steps:

(1) Obtain the radius or diameter parameters and ball center position parameters of each standard ball in the six-ball template.

(2) Obtain the radius or diameter parameters of the measuring ball in the measuring instrument;

(3) Based on the data obtained in steps (1) and (2), calculate and obtain the theoretical position parameters of the measuring ball when it contacts the three standard balls in each group at the same time;

(4) Control the measuring ball of the measuring instrument to measure the three standard balls in the corresponding group at the theoretical position, obtain the position parameters A and B of the two sets of standard balls respectively, and obtain the measurement distance between the two sets of standard balls through calculation Parameter L, where L=|A-B|;

(5) Compare the measured spacing L in step (4) with the standard spacing L ₀ to determine the accuracy of the measuring instrument and complete the calibration of the tooth pitch and tooth thickness; among them, the standard spacing L ₀ is the six-dimensional space obtained by using a standard measuring instrument. The distance between two sets of standard balls in the ball template.

Example 1: Regarding the six-ball template in Example 1, the diameters of the six standard balls are the same, and the three standard balls in each group are tangent to each other. The calibration process is as follows:

Step 1: Obtain the radius or diameter parameters and ball center position parameters of each standard ball in the six-ball template.

In this step, you can use a standard measuring instrument to measure the diameter parameters (or radius parameters) of the standard balls in the six-ball template, or directly refer to the diameter parameters (or radius parameters) of the standard balls marked on the substrate, so as to easily obtain the standard balls. The radius of is R;

Further, after establishing an appropriate coordinate system, it can be seen that the coordinates of the center of the first standard sphere 1 are D(x ₁ ,y ₁ ,z ₁ ), and the coordinates of the center of the second standard sphere 2 are E(x ₂ ,y ₂ ,z ₂ ), the center coordinate of the second standard sphere 3 is F(x ₃ ,y ₃ ,z ₃ ).

Step 2: Obtain the radius or diameter parameters of the measuring ball in the measuring instrument.

In this step, the radius or diameter parameter of the measuring ball in the measuring instrument can be obtained directly from the supporting instructions of the measuring head, or a standard measuring instrument can be used for on-site measurement to obtain the radius r of the measuring ball.

Step 3: Based on the data obtained in steps 1 and 2, calculate the theoretical position parameters of the measuring ball when it contacts the three standard balls in each group at the same time.

In this step, assume that the theoretical position of the measuring ball when it is in contact with three standard balls at the same time is O, and assume that the coordinates of point O are (x ₀ , y ₀ , z ₀ ), to be found;

As shown in Figure 5, when the measuring ball is in contact with three standard balls at the same time, the line connecting the centers of the three standard balls and the center of the measuring ball can form a triangular pyramid O-DEF, where (Which/> is the module of the vector, indicating the distance between point D and point E. The rest are similar and will not be described again below),/> Among them, the coordinates of D, E, and F have been obtained in the first step, so:

By solving them simultaneously, the coordinates of point O (x ₀ , y ₀ , z ₀ ) can be obtained, thereby obtaining the theoretical position parameters when the measuring ball contacts the three standard balls in each group at the same time.

Step 4: Control the measuring ball of the measuring instrument to measure the three standard balls corresponding to the theoretical position O. The measurement method for the other position is the same, so the measuring instrument will obtain the position parameters A and B of the two sets of standard balls respectively, and pass Calculate and obtain the measurement distance parameter L between the two sets of standard balls, where L=|A-B|, as shown in Figure 6.

Step 5: Compare the measured spacing L in step 4 with the standard spacing L ₀ to determine the accuracy of the measuring instrument and complete the calibration of the tooth pitch and tooth thickness; where the standard spacing L ₀ is the six-ball sample obtained using a standard measuring instrument. The standard distance between the two sets of standard balls.

The whole process of using a six-ball template to calibrate the tooth pitch and tooth thickness of the measuring instrument is simple, and three standard balls are used to form a three-point stable support for the measuring ball, which greatly reduces the sliding error of the measuring ball of the measuring instrument and can effectively Improve the calibration accuracy of tooth pitch and tooth thickness.

It can be seen from the above formula that the theoretical position of point O when the measuring ball contacts the three standard balls in each group at the same time is only related to the radius r of the measuring ball and the radius R of the standard ball, and is related to the radius R of the three standard balls. It does not matter whether the two are tangent to each other, so it can be understood that in Example 2, when the six standard balls in the six-ball template have the same diameter, but the three standard balls in each group are separated (that is, not tangent to each other) , the steps and calculation formulas for calibrating the tooth pitch and tooth thickness of the measuring instrument are the same as in Example 1.

Example 2: Regarding the six-ball template in Example 3, the diameters of the six standard balls are different, but the three standard balls in each group are all tangent to each other, as shown in Figure 7. The calibration process is as follows:

Step 1: Obtain the radius or diameter parameters and ball center position parameters of each standard ball in the six-ball template.

In this step, you can use a standard measuring instrument to measure the diameter parameters (or radius parameters) of the standard balls in the six-ball sample, or directly refer to the diameter parameters (or radius parameters) of the standard balls marked on the substrate, so as to easily obtain the first The radius of the standard sphere is R ₁ , the radius of the second standard sphere is R ₂ , and the radius of the third standard sphere is R ₃ (only one set of standard spheres is calculated here, and the calculation method for the other set of standard spheres is the same).

Further, after establishing an appropriate coordinate system, it can be seen that the coordinates of the center of the first standard sphere 1 are D(x ₁ ,y ₁ ,z ₁ ), and the coordinates of the center of the second standard sphere 2 are E(x ₂ ,y ₂ ,z ₂ ), the center coordinate of the second standard sphere 3 is F(x ₃ ,y ₃ ,z ₃ ).

Step 2 is the same as step 2 above;

Step 3: Based on the data obtained in steps 1 and 2, calculate the theoretical position parameters of the measuring ball when it contacts the three standard balls in each group at the same time.

In this step, assume that the theoretical position of the measuring ball when it is in contact with three standard balls at the same time is O, and assume that the coordinates of point O are (x ₀ , y ₀ , z ₀ ), to be found;

As shown in Figure 8, when the measuring ball is in contact with three standard balls at the same time, the line connecting the centers of the three standard balls and the center of the measuring ball can form a triangular pyramid O-DEF, where And/> Among them, the coordinates of D, E, and F have been obtained in the first step, so:

By solving them simultaneously, the coordinates of point O (x ₀ , y ₀ , z ₀ ) can be obtained, thereby obtaining the theoretical position parameters when the measuring ball contacts the three standard balls in each group at the same time.

Steps 4 and 5 are the same as the above-mentioned steps 4 and 5 respectively, and will not be described again here.

In the same way, it can be understood that when the diameters of the six standard balls in the six-ball model are different, and the three standard balls in each group are separated from each other (that is, not tangent to each other), the measuring instrument performs tooth pitch and tooth thickness calibration. The steps and calculation formula are the same as Example 2.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be covered by the protection scope of the present invention.

Claims (8)

1. The calibration method is characterized by comprising a six-ball template, wherein the six-ball template comprises a substrate and six standard balls, the six standard balls are divided into two groups, each group comprises three standard balls, the three standard balls in each group are enclosed together, so that a measuring ball can be tangent with the three standard balls at the same time, and the two groups of standard balls are respectively fixed in two directions of the substrate; the calibration method comprises the following steps:

(1) Obtaining radius or diameter parameters and center position parameters of each standard ball in the six-ball template;

(2) Obtaining radius or diameter parameters of a measuring ball in a measuring instrument;

(3) According to the data obtained in the steps (1) and (2), calculating to obtain theoretical position parameters when the measuring ball is contacted with three standard balls in each group simultaneously;

(4) The method comprises the steps of controlling a measuring ball of a measuring instrument to measure three standard balls in a corresponding group at a theoretical position, respectively obtaining position parameters A and B of two groups of standard balls, and obtaining a measuring interval parameter L between the two groups of standard balls through calculation, wherein L=A-B;

(5) The measurement distance L in the step (4) is compared with the standard distance L ₀ Comparing, determining the precision of the measuring instrument, and finishing the calibration of the tooth pitch and the tooth thickness; wherein, the standard distance L ₀ Is the spacing between two sets of standard balls in the six-ball template obtained using standard measuring instruments.

2. The method of calibrating according to claim 1, wherein the substrate is a flat plate.

3. The method of calibrating according to claim 1, wherein the three standard spheres in each set are tangential in pairs.

4. The calibration method according to claim 1, wherein the six standard spheres have the same diameter.

5. The method according to any one of claims 1 to 4, wherein the accuracy of the standard ball is not lower than the accuracy of the ball on the probe.

6. The method of claim 5, wherein the standard sphere has a precision one level higher than the sphere on the probe.

7. The method of calibrating according to claim 6, wherein the standard sphere is made of ruby or ceramic or glass or tungsten carbide material.

8. The method of calibrating according to claim 7, wherein the substrate is marked with parameters of radius or diameter of standard balls and parameters of standard spacing between two sets of standard balls.