A method for measuring coaxiality by combining axiality

Abstract

The present application provides a method for measuring coaxiality by combined axiality, and the method for measuring coaxiality by combined axiality includes the following steps: measuring the reference cylinder and the measured cylinder respectively; confirming the evaluation method according to the structures of the reference cylinder and the measured cylinder; and determining the coaxiality of the measured cylinder relative to the reference cylinder according to the evaluation method and the measured reference cylinder and the measured cylinder. In the above technical scheme, it is more reasonable to control the assembly characteristics of the inner hole of the drive shaft at both ends and the outer circle of the bearing assembly at both ends by using combined cylindricity and combined straightness, the measurement variation is small, and the measurement is convenient, which can effectively evaluate and control the coaxial requirements of the parts.

Description

Technical Field

[0001] One or more embodiments of the present specification relate to the field of automobile technology, and more particularly to a method for combining axiality with coaxiality measurement. Background Art

[0002] The assembly characteristics of the inner holes of the drive shafts at both ends of the differential require that the sizes of the two inner holes are theoretically equal and that the inner hole axes are on the same straight line; the outer circles of the bearings at both ends of the differential may only require that the inner hole axes are on the same straight line because the bearing models used at both ends are not necessarily the same. One way is to use cylindricity and coaxiality to control the assembly characteristics of the inner holes of the drive shafts at both ends, and then establish a joint reference with the inner hole centerline of the derived elements of the inner holes of the drive shafts at both ends, and use coaxiality or runout to control the assembly characteristics of the outer circles of the bearings at both ends of the differential. Through the analysis of the measurement data, it is concluded from the perspective of measurement that it is more reasonable to use joint cylindricity and joint straightness to control the assembly characteristics of the inner holes of the drive shafts at both ends and the outer circles of the bearings at both ends.

[0003] There are two existing implementation solutions:

[0004] The first solution is to establish a joint datum through the axis of the derived elements of the inner holes or outer circles at both ends, and evaluate the coaxiality of the derived elements of the inner holes or outer circles at both ends respectively. The definition of coaxiality is that the extracted (actual) center line of the measured cylinder should be confined within a cylinder with a diameter equal to the tolerance requirement value and with the datum axis as the axis. The deviation between the extracted (actual) center line of the measured cylinder and the datum axis can be decomposed into two parts: the deviation caused by the offset and the deviation caused by the angle.

[0005] A joint datum is established through the axes of the derived elements of the inner holes or outer circles at both ends, and the coaxiality of the derived elements of the inner holes or outer circles at both ends is evaluated respectively. When the deviation caused by the relative offset of the two axes is the main deviation, the true coaxiality of the two cannot be measured. Two shaft diameters of the camshaft are selected for measurement test. These two shaft diameters are not on a straight line, and the center line is theoretically offset by 93mm. The measurement results are as follows: the coaxiality of the outer circle at the left end to the joint datum is 7.5455mm, and the coaxiality of the outer circle at the right end to the joint datum is 4.9325mm, which is obviously wrong. Judging from the measurement results, the coaxiality evaluation through the joint datum cannot measure the deviation caused by the relative offset of the two axes, and the robustness of the evaluation through the joint datum is not good.

[0006] Another solution is to use the derived element axis of the inner hole or outer circle at one end as the evaluation reference to evaluate the coaxiality of the derived element axis of the inner hole or outer circle at the other end. When the two ends are selected as the references respectively, the theoretical model of the evaluation method and the evaluation results will be different (D01≠D02). This difference is affected by the sampling length. The shorter the sampled cylindrical surface, the greater the difference. Summary of the invention

[0007] In view of this, the purpose of one or more embodiments of the present specification is to propose a method for measuring coaxiality by combining axiality to improve the measurement effect of coaxiality.

[0008] In a first aspect, a method for measuring coaxiality by combining axiality is provided, the method comprising the following steps:

[0009] Measure the reference cylinder and the measured cylinder respectively;

[0010] Confirm the evaluation method based on the structure of the reference cylinder and the cylinder being tested;

[0011] According to the evaluation method and the measured reference cylinder and the measured cylinder, the coaxiality of the measured cylinder relative to the reference cylinder is determined.

[0012] In the above technical scheme, the assembly characteristics of the inner hole of the drive shaft at both ends and the outer circle of the bearing at both ends are controlled by using the combined cylindricity and the combined straightness, which is more reasonable, has small measurement variation, and is convenient for measurement, which can effectively evaluate and control the coaxial requirements of the parts.

[0013] In a specific possible implementation scheme, the steps of measuring the reference cylinder and the measured cylinder separately include:

[0014] Each cylindrical collection point shall be no less than three sections; each section shall have no less than 8 collection points.

[0015] In a specific implementation scheme, each cylindrical collection point has no less than three cross sections; each cross section has no less than 8 collection points, specifically:

[0016] The reference cylinder and the measured cylinder are detected by the measuring needle.

[0017] In a specific possible implementation scheme, the measuring needle meets the following requirements: when the reference cylinder and the measured cylinder are hole-shaft parts with a diameter ≤100 mm, the measuring needle diameter is not greater than 3 mm.

[0018] In a specific possible implementation scheme, the evaluation method is confirmed according to the structures of the reference cylinder and the cylinder to be measured; specifically:

[0019] According to the structures of the reference cylinder and the cylinder to be measured, a common axis with the smallest error is calculated through iterative calculation.

[0020] In a specific possible implementation scheme, the common axis with the smallest error is calculated through iterative calculation according to the structures of the reference cylinder and the measured cylinder, specifically:

[0021] When the measured cylinder and the reference cylinder are both external cylinders, the minimum circumscribed cylinder is selected, and the common axis with the minimum error is calculated through iterative calculation.

[0022] In a specific possible implementation scheme, the common axis with the smallest error is calculated through iterative calculation according to the structures of the reference cylinder and the measured cylinder, specifically:

[0023] When the measured cylinder and the reference cylinder are both inner cylinders, the largest inscribed cylinder is selected, and the common axis with the smallest error is calculated through iterative calculation.

[0024] In a specific possible implementation scheme, the common axis with the smallest error is calculated through iterative calculation according to the structures of the reference cylinder and the measured cylinder, specifically:

[0025] When the reference cylinder and the measured cylinder are of the type one inside and one outside, the 3D straight line construction function is selected, the centers of all collected cross-sectional circles are called, and the least squares common axis is calculated through iterative operations.

[0026] In a second aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for executing the first aspect and any possible design in the first aspect is implemented.

[0027] According to a third aspect, a non-transitory computer-readable storage medium is provided, wherein the non-transitory computer-readable storage medium stores computer instructions, wherein the computer instructions are used to cause the computer to execute the method according to the first aspect and any possible design of the first aspect.

[0028] In a fourth aspect, a computer program product is also provided, comprising instructions, which, when executed on a computer, enables the computer to execute the method in the first aspect of the present application and any possible design in the first aspect.

[0029] In addition, the technical effects brought about by any possible design method in the second to fourth aspects can be referred to the effects brought about by different design methods in the method part, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate one or more embodiments of the present specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only one or more embodiments of the present specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1A schematic diagram of a part to be tested provided in an embodiment of the present application;

[0032] Figure 2 A flow chart comparing coaxiality and combined axiality provided in the embodiments of the present application;

[0033] Figure 3 A probability diagram of coaxial axiality provided by an embodiment of the present application;

[0034] Figure 4 A probability diagram of the joint axiality provided by an embodiment of the present application;

[0035] Figure 5 A structural block diagram of a method for measuring coaxiality by combined axiality provided in an embodiment of the present application;

[0036] Figure 6 A structural block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0038] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in one or more embodiments of this specification should be understood by people with ordinary skills in the field to which this disclosure belongs. The "first", "second" and similar words used in one or more embodiments of this specification do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] The present invention relates to an alternative scheme and a method for measuring the coaxiality tolerance control of automobile parts with coaxial requirements, and is particularly suitable for parts with short lengths between the reference element and the measured element, and large errors when directly measuring the coaxiality at a long distance. The present invention is based on an alternative scheme and a method for measuring the coaxiality tolerance control of the inner holes of the drive shaft assembly at both ends of the differential case as an example, but can also be applied to other housings and shafts with coaxial requirements. Coaxial requirements are generally key characteristics of parts, and they need to be accurately measured and evaluated.

[0040] When the length of the measured element is short and the distance is far, the error when directly measuring the coaxiality is large. When the tolerance band of the part is narrow (the requirements are stricter), if the variation of the measurement system is too large, the state of the part cannot be accurately evaluated, thereby affecting the quality control of the part and further affecting the quality of higher-level systems.

[0041] The present invention provides an alternative solution and a measuring method for controlling the coaxiality tolerance of a short element, which has small measurement variation and is convenient for measurement and can effectively evaluate and control the coaxial requirements of parts.

[0042] The present invention illustrates the advantages of the alternative scheme of the present invention from the perspective of measurement system analysis in the field of measurement technology. The present invention is further limited to the same differential case that the measurement sample is not replaced, the measurement equipment, personnel, and measurement strategy remain unchanged, the time span of data acquisition is short, and the measurement environment temperature remains unchanged. The present invention is explained from the two aspects of accuracy (bias) and precision (repeatability). As shown in Figure 1, the combined cylindricity of the inner holes with diameter ΦD1 at both ends and the coaxiality of the inner hole with diameter ΦD1 at the right end relative to the inner hole with diameter ΦD1 at the left end are selected to illustrate the scheme.

[0043] like Figure 2 As shown, when deciding to use coaxiality or combined axiality, the following steps are used for verification.

[0044] Step 1: Determine the true value;

[0045] Specifically, determine the true value of coaxiality and the true value of combined cylindricity: select a differential case as the research object, measure the coaxiality of one end of the inner hole of the drive shaft assembly relative to the other end and the combined cylindricity of both ends. This study uses the three-coordinate measurement method, and the true value (Z) is determined by the average value of multiple measurements using a roundness meter with higher accuracy. The roundness meter measurement data is shown in Table 1. Coaxial Z1 = 0.01597mm, Z1 is the true value of coaxiality; Z2 = 0.00996mm, Z2 is the true value of combined cylindricity.

[0046] Table 1

[0047] Serial number 1 2 3 4 Coaxiality(mm) 0.01596 0.01622 0.01596 0.01574 Combined cylindricality (mm) 0.01007 0.00996 0.00987 0.00995

[0048] Step 2: Determine the bias; specifically, determine the bias of coaxiality and combined cylindricity:

[0049] First, obtain the measurement data. Install the differential case to be measured on the three-coordinate measuring table, compile a measurement program for subsequent measurement, and keep the measurement datum consistent with the roundness instrument measurement datum. Automatically collect points through the equipment to eliminate the influence of human operation and the inconsistency between each measurement. Repeat the measurement 15 times. The measurement data is shown in Table 3.

[0050] Table 3

[0051]

[0052]

[0053] Secondly, make sure the measurement data is accurate. This step confirms that the data obeys the normal distribution to show that there are no special factors affecting the measurement system during the measurement process, and further shows that the measurement process is stable. First, the normality test is performed on the two sets of coaxiality and combined cylindricity data. The test results are shown in Figure 3 and Figure 4. Figure 3 and Figure 4 It can be seen that the normal probability diagram of coaxiality based on the left end is P value = 0.275 ≥ 0.05, and the normal probability diagram of combined cylindricity is P value = 0.453 ≥ 0.05. After inspection, both sets of data obey the normal distribution, indicating that the measurement data is accurate and the measurement process is stable.

[0054] Again, determine the bias of the measurement data, subtract the corresponding true values ​​(Z1, Z2) from the measurement data of coaxiality and combined cylindricity in Table 3 to obtain the data in Table 4, and perform a hypothesis test on the data in Table 4 that the bias is 0. Since the standard deviation σ of the population is unknown, a single sample t test is used. The test results show that the P values ​​of the two are ≤0.05, indicating that the bias of the measurement system is not zero, the bias of coaxiality is 0.001323mm, and the bias of combined cylindricity is 0.001173mm. The size of this bias can be ignored relative to the tolerance band width of the measurement object, and does not affect the conclusion determination of the present invention.

[0055] Table 4

[0056]

[0057]

[0058] Step 3: Determine repeatability; Specifically, determine the repeatability of coaxiality and combined cylindricity: The data acquisition process in Table 4 meets the repeatability requirements (repeatability (EV) is the variation of the measured value when an operator uses the same measuring instrument to measure the same characteristic of the same part multiple times). The repeatability of all measurement systems is 6 times the variance of the data in Table 4. The analysis results are: EV coaxiality = 6×0.001286mm=0.007716mm, (0.05mm×10%)<EV coaxiality<(0.05mm×30%); EV combined cylindricity = 6×0.0001447mm=0.0008682mm. Since the measurement system did not change during the test, the reproducibility of the measurement system was negligible (AV=0), so GRR=EV. Therefore, GRR coaxiality <(0.05mm×30%), and the measurement system meets the repeatability requirements for coaxiality. According to the definition of coaxiality and cylindricity, cylindricity is approximately half of coaxiality, that is, 0.025mm, so the GRR combined cylindricity is less than (0.025mm×10%), and the repeatability of the measurement system for the combined cylindricity meets the requirements.

[0059] Step 4: Robustness comparison. Specifically, the robustness evaluated by joint cylindricity is compared with the robustness evaluated based on a single end.

[0060] Table 5 shows two groups of measured data. The sampling objects, sampling methods, sampling positions and evaluation methods of these two groups of data are exactly the same. The only difference is the benchmark. Group I data is the left inner hole evaluated based on B as the benchmark, and Group II data is the right inner hole evaluated based on A as the benchmark. The two groups of data are now subjected to a paired data double-sample t-test. When P value = 0, there is a significant difference between the two, and the difference is 0.01272. The hypothesis test also leads to the conclusion that when the benchmark and the evaluated elements are interchanged, the test results will produce significant differences, and the robustness of the evaluation based on a single end as the benchmark is not good.

[0061] Table 5

[0062]

[0063]

[0064] During the measurement process, Figure 4The combined cylindricity in Table 5 and the left end reference coaxiality and right end reference coaxiality in Table 5 are evaluated simultaneously, and the three data with the same serial number are obtained by the same measurement process. The above data are statistically analyzed, among which the standard deviation of the combined cylindricity measurement data is 0.000145, which is only 11% of the standard deviation of the left end reference coaxiality measurement data 0.001286, and 9% of the standard deviation of the right end reference coaxiality measurement data 0.001657. It can be concluded that the combined cylindricity evaluation has a smaller variation in the measurement results and better robustness.

[0065] From the above description, it can be seen that the use of combined coaxiality instead of coaxiality for coaxial control has small measurement variation and convenient measurement, which can effectively evaluate and control the coaxial requirements of parts.

[0066] refer to Figure 5 When measuring coaxiality, the combined coaxiality method provided in the embodiment of the present application includes the following steps:

[0067] Step 001: measure the reference cylinder and the measured cylinder respectively;

[0068] Specifically, when measuring the reference cylinder and the measured cylinder, the reference cylinder and the measured cylinder are detected by a measuring needle. The measuring needle meets the following requirements: when the reference cylinder and the measured cylinder are hole-shaft parts and their diameters are ≤100mm, the diameter of the measuring needle is not greater than 3mm.

[0069] When testing the cylinder to be tested and the reference cylinder, the number of points collected for each cylinder shall be no less than three sections, and the number of points collected for each section shall be no less than 8. Specifically, the principle of collecting points is: for the trigger probe, the number of points collected for each cylinder shall be no less than three sections, and the number of points collected for each section shall be no less than 8. If the probe has a scanning function, the number of points collected for each section can be set to more than 600.

[0070] Step 002: confirming the evaluation method according to the structures of the reference cylinder and the cylinder to be measured;

[0071] Specifically, according to the structures of the reference cylinder and the cylinder to be measured, the common axis with the smallest error is calculated through iterative calculation.

[0072] When both the measured cylinder and the reference cylinder are external cylinders, the smallest circumscribed cylinder is selected and the common axis with the smallest error is calculated through iterative calculation.

[0073] When both the measured cylinder and the reference cylinder are inner cylinders, the largest inscribed cylinder is selected and the common axis with the smallest error is calculated through iterative calculation.

[0074] When the reference cylinder and the measured cylinder are of the same type, one is inside and the other is outside, select the 3D straight line construction function, call the centers of all collected cross-section circles, and calculate the least squares common axis through iterative calculations.

[0075] For example, after the cylinders (reference cylinder and measured cylinder) are collected, the two cylinders are called at the same time. According to the principle of establishing the benchmark in the standard, the evaluation method selects the minimum circumscribed cylinder (when the two cylinders are both external cylinders) or the maximum inscribed cylinder (when the two cylinders are both internal cylinders). Through the iterative operation of the software, the common axis with the smallest error is calculated as the benchmark. When the two cylinder types are one inside and one outside, select the 3D straight line construction function, call the center of all the collected cross-section circles, select the best fit method for evaluation, and calculate the least squares common axis as the benchmark through the iterative operation of the software.

[0076] Step 003: Determine the coaxiality of the measured cylinder relative to the reference cylinder based on the evaluation method and the measured reference cylinder and the measured cylinder.

[0077] Specifically, call the coaxiality evaluation function, fill in the corresponding elements at the positions of the measured element and the reference element for evaluation, export the results, and the measurement is completed.

[0078] From the above description, it can be seen that it is more reasonable to control the assembly characteristics of the inner hole of the drive shaft at both ends and the outer circle of the bearing assembly at both ends by adopting the combined cylindricity and combined straightness. The measurement variation is small and the measurement is convenient, which can effectively evaluate and control the coaxial requirements of the parts.

[0079] When the diameters of the two outer circles or inner holes being evaluated are not the same, it is obviously inappropriate to use the combined cylindricity method for evaluation. Figure 1 For the differential bearing assembly outer circle in the figure, we convert the coaxiality into the joint straightness of the axis of the two outer circles to derive the element for evaluation. The test measurement data are shown in Table 6. After statistical analysis of the data in Table 6, the standard deviation of the measurement data of the joint straightness is 0.000045, which is only 7.4% of the standard deviation of the measurement data of the left-end reference coaxiality 0.000609 and 6.8% of the standard deviation of the measurement data of the right-end reference coaxiality 0.000661. It can be concluded that the measurement result has smaller variation and better robustness when evaluated by joint straightness.

[0080] Table 6

[0081]

[0082]

[0083] An embodiment of the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for executing the first aspect and any possible design in the first aspect is implemented.

[0084] An embodiment of the present application also provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a computer to execute the first aspect and any possible design method in the first aspect.

[0085] It should be noted that the method of one or more embodiments of this specification can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of one or more embodiments of this specification, and the multiple devices will interact with each other to complete the method.

[0086] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0087] For the convenience of description, the above devices are described in terms of functions divided into various modules. Of course, when implementing one or more embodiments of this specification, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0088] The apparatus of the above-mentioned embodiment is used to implement the corresponding method in the above-mentioned embodiment, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.

[0089] Figure 6 A more specific schematic diagram of the hardware structure of an electronic device provided in this embodiment is shown, and the device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other in communication within the device through the bus 1050.

[0090] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0091] The memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.

[0092] The input / output interface 1030 is used to connect the input / output module to realize information input and output. The input / output module can be configured in the device as a component (not shown in the figure), or it can be externally connected to the device to provide corresponding functions. The input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0093] The communication interface 1040 is used to connect a communication module (not shown) to realize communication interaction between the device and other devices. The communication module can realize communication through a wired mode (such as USB, network cable, etc.) or a wireless mode (such as mobile network, WIFI, Bluetooth, etc.).

[0094] The bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040).

[0095] It should be noted that, although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, it can be understood by those skilled in the art that the above device may also only include the components necessary for implementing the embodiments of the present specification, and does not necessarily include all the components shown in the figure.

[0096] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0097] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. In line with the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present specification as described above, which are not provided in detail for the sake of simplicity.

[0098] In addition, to simplify the description and discussion, and in order not to obscure one or more embodiments of the present specification, known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, the device may be shown in the form of a block diagram so as to avoid obscuring one or more embodiments of the present specification, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which one or more embodiments of the present specification will be implemented (i.e., these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it is apparent to those skilled in the art that one or more embodiments of the present specification may be implemented without these specific details or with variations in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0099] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0100] One or more embodiments of this specification are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of this disclosure.

Claims

1. A method for measuring coaxiality by combining axiality, which is used for measuring the coaxiality of a cylinder to be measured relative to a reference cylinder, characterized in that: The measuring method comprises the following steps: Measure the reference cylinder and the measured cylinder respectively; Confirm the evaluation method based on the structure of the reference cylinder and the cylinder being tested; Determine the coaxiality of the measured cylinder relative to the reference cylinder according to the evaluation method and the measured reference cylinder and the measured cylinder; The evaluation method is confirmed based on the structure of the reference cylinder and the cylinder being tested; specifically: According to the structures of the reference cylinder and the cylinder to be measured, a common axis with the smallest error is calculated through iterative calculation; According to the structures of the reference cylinder and the measured cylinder, the common axis with the smallest error is calculated through iterative calculation, specifically: When the measured cylinder and the reference cylinder are both external cylinders, the smallest circumscribed cylinder is selected, and the common axis with the smallest error is calculated through iterative calculation; According to the structures of the reference cylinder and the measured cylinder, the common axis with the smallest error is calculated through iterative calculation, specifically: When the measured cylinder and the reference cylinder are both inner cylinders, the largest inscribed cylinder is selected, and the common axis with the smallest error is calculated through iterative calculation; According to the structures of the reference cylinder and the measured cylinder, the common axis with the smallest error is calculated through iterative calculation, specifically: When the reference cylinder and the measured cylinder are of the type one inside and one outside, the 3D straight line construction function is selected, the centers of all collected cross-sectional circles are called, and the least squares common axis is calculated through iterative operations.

2. The method for measuring coaxiality by combined axiality according to claim 1, characterized in that: The method of measuring the reference cylinder and the measured cylinder separately comprises: Each cylindrical collection point shall be no less than three sections; each section shall have no less than 8 collection points.

3. The method for measuring coaxiality by combined axiality according to claim 2, characterized in that: Each cylindrical collection point has no less than three cross sections; each cross section has no less than 8 collection points, specifically: The reference cylinder and the measured cylinder are detected by the measuring needle.

4. The method for measuring coaxiality by combining axiality according to claim 3, characterized in that: The measuring needle meets the following requirements: when the reference cylinder and the measured cylinder are hole-shaft parts with a diameter ≤100 mm, the measuring needle diameter is not greater than 3 mm.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method for measuring coaxiality by combined axiality as described in any one of claims 1 to 4 is implemented.

6. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method for measuring coaxiality by combined axiality as described in any one of claims 1 to 4.

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