Length-to-meter piece calibration method

Abstract

The invention relates to the technical field of metering calibration, in particular to a length-to-meter calibration method, which sequentially executes the steps of preparation before calibration and original record checking, visual observation type appearance calibration, state-based special calibration, calibration result judgment and processing, and calibration recording and identification management, in-use parts exempt other form and location tolerance dimensional calibration of working surface roughness and drawing requirements, each calibration item formulates a clear tolerance requirement, a measurement method and an operation specification are adapted, and the working size calibration also formulates an elastic branding dimensional tolerance standard for the in-use parts. The method realizes standardization and systematization of meter calibration by length, gives consideration to calibration precision and actual use requirements, effectively avoids the influence of various interference factors on measurement results, improves the accuracy and consistency of calibration results, and improves the accuracy and consistency of the measurement results through whole-process data recording and identification management. And accurate metering support is provided for size detection of product processing and inspection.

Description

Technical Field

[0001] This invention relates to the field of metrology and calibration technology, specifically to a method for calibrating length-matching instruments. Background Technology

[0002] Length gauges are crucial measuring instruments in product processing and inspection. They are often used in conjunction with specialized measuring tools or gauge stands to measure product length dimensions. Based on shape, they can be categorized as straight-face gauges and angled-face gauges; based on structure, they can be classified as integral / split steel gauges, split light alloy gauges, etc. The calibration accuracy of length gauges directly affects the accuracy of product dimension measurement, and consequently, the quality of product processing. The existing calibration methods for length-to-measure components suffer from several problems, including non-standard calibration procedures, unclear distinction between calibration items for different states (new / repaired / in use), significant operational impact on the measurement accuracy of some calibration methods, and the lack of standardized procedures for temperature compensation and dimensional correction. These issues result in insufficient consistency and reliability of calibration results, failing to meet the requirements for high-precision product testing.

[0003] Therefore, a new technical solution needs to be designed to address this issue. Summary of the Invention

[0004] The purpose of this invention is to provide a method for calibrating length matching components, which solves the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for calibrating a length matching component, comprising the following steps: The methods and steps include the following: S1. Before calibration, check the original records, verify the relevant certificates and historical records of the part to be calibrated and fill in any missing information, record the calibration environment parameters and check the status of the calibration equipment. S2, visual calibration, uses visual inspection to check the surface condition, fastening structure and markings of the part to be calibrated. Unqualified parts are repaired before subsequent calibration. S3, Specialized Calibration by State, performs corresponding calibration items for newly manufactured, repaired, and in-use parts to be calibrated, completing the measurement and evaluation of working surface roughness (only for newly manufactured and repaired parts), datum surface flatness, working surface flatness, the relationship between datum surface and working surface, the relationship between working surfaces, working dimensions, and other geometric tolerances and dimensions required by drawings (only for newly manufactured and repaired parts). S4, Calibration result judgment and processing: Based on the calibration standards and drawing requirements, comprehensively judge the measurement results of each item and make a decision on whether to accept, repair and recalibrate, or scrap. S5, Calibration Record and Label Management, fully records calibration data throughout the entire process and generates calibration reports for archiving. For parts to be calibrated with different judgment results, corresponding labels are affixed and key information is marked.

[0006] In a preferred embodiment of the present invention, in step S1, for newly manufactured length gauges, the manufacturing certificate filled in by the gauge manufacturer is checked, and missing information such as name, model, object measuring part drawing number, gauge single number, manufacturing date, and storage location is supplemented; for repaired or used length gauges, historical calibration records and repair records are checked; at the same time, the temperature, humidity and other factors affecting calibration work in the calibration laboratory are recorded, and the integrity and effective calibration status of all calibration equipment are checked.

[0007] As a preferred embodiment of the present invention, the appearance calibration judgment criteria of S2 are as follows: newly manufactured and repaired length pairs have no defects such as rust or dents on the working surface and all surfaces of the instrument; length pairs in use have no defects that affect the use and calibration accuracy of the instrument; the fastening screws of the measuring blocks at both ends of the split length pairs are firm and reliable; the fastening screws of newly manufactured length pairs are sealed with sealing wax; and all non-working surfaces of the calibrated parts are marked with drawing numbers, manufacturing numbers and special markings specified in the drawings.

[0008] In a preferred embodiment of the present invention, in step S3, the newly manufactured and repaired length gauges undergo full-item calibration, which includes appearance, working surface roughness, datum plane flatness, working surface flatness, the relationship between the datum plane and the working surface, the relationship between the working surfaces, working dimensions, and other geometric tolerances and dimensions required by the drawings. The length gauges in use are calibrated only for six items: appearance, datum plane flatness, working surface flatness, the relationship between the datum plane and the working surface, the relationship between the working surfaces, and working dimensions. The working surface roughness and other geometric tolerances and dimensions required by the drawings are not calibrated.

[0009] In a preferred embodiment of the present invention, in step S3, the calibration tolerance requirement for the flatness of the reference surface is 0.003mm. If the drawing has special requirements, the drawing shall be followed. The calibration method can be either the coordinate measuring machine method or the plate coloring method. The calibration tolerance requirement for the flatness of the working surface is 0.003mm. If the drawing has special requirements, the drawing shall be followed. For newly manufactured and repaired length matching parts, the coordinate measuring machine method or the optical gap method can be used. For length matching parts in use, the optical gap method is preferred and the coordinate measuring machine method is used with caution.

[0010] In a preferred embodiment of the present invention, in step S3, the mutual relationship between the reference surface and the working surface is calibrated. For a straight surface, the perpendicularity of the working surface to the reference surface is calibrated, with a tolerance requirement of 0.005 mm. If the drawings have requirements, they shall be followed. The optical gap method or the three-coordinate measurement method is used. For an inclined surface, the three-coordinate measurement method is used to measure the angle between the working surface and the reference surface. The measurement results must meet the requirements of the drawings.

[0011] In a preferred embodiment of the present invention, in step S3, the mutual relationship calibration of the working surfaces involves calibrating the parallelism of the two working surfaces for the straight-faced dial indicator and calibrating the parallelism of the two working lines for the inclined-faced dial indicator. If the drawings specify tolerance requirements, those requirements shall be followed. Otherwise, for light alloy dial indicators, the nominal size ≤ 800mm and parallelism tolerance 5μm shall be maintained; for steel dial indicators, the nominal size ≤ 200mm and parallelism tolerance 2μm shall be maintained. ~ 5μm, >200 ~ 800mm parallelism tolerance of 5μm is required; for working dimension calibration, length measuring machine is preferred for straight-faced parts, and coordinate measuring machine is used when the length measuring machine cannot be used for special dimensions, and coordinate measuring machine is used for inclined-faced parts.

[0012] In a preferred embodiment of the present invention, in step S4, if the measurement results of all calibration items meet the requirements specified in the method and drawings, the calibration is deemed qualified; if the measurement result of a single item is unqualified but can be repaired or adjusted to meet the requirements, the calibration is deemed unqualified and the entire process must be recalibrated after repair; if the measurement results of multiple items are unqualified or cannot be repaired or adjusted to meet the requirements, the item is deemed scrapped and prohibited from being put into use.

[0013] In a preferred embodiment of the present invention, in step S5, the calibration record must include measurement data, calibration method, environmental parameters, equipment information, and judgment results. The calibration report is archived and retained after being signed and confirmed. The identification must include key information such as the calibration date and the next calibration date.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves standardized and systematic full-process calibration of newly manufactured, in-use, and repaired face-mounted and angled face-mounted gauges. By clearly defining the qualifications of calibration personnel, strictly controlling the temperature, humidity, and temperature equilibrium time requirements of the calibration environment, and using suitable professional calibration equipment, the professionalism and standardization of calibration work are guaranteed from the source. This method refines and standardizes each step of calibration preparation, appearance calibration, state-specific calibration, result judgment and processing, and record labeling management. Furthermore, it differentiates calibration items for newly manufactured, repaired, and in-use gauges, establishing clear tolerance requirements, measurement methods, and applicable scenarios for each calibration item for different types of gauges. It balances calibration accuracy with actual usage needs, effectively avoiding the influence of temperature, operation, and other factors on measurement results, and improving the accuracy, consistency, and reliability of calibration results. Simultaneously, this method requires complete recording of calibration process data and the formation of reports for archiving. Corresponding labeling management is implemented for gauges with different judgment results, achieving traceability of calibration work, facilitating subsequent quality control and re-inspection, and providing accurate metrological support for dimensional inspection in product processing and inspection stages, ensuring product processing quality. Attached Figure Description

[0015] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] Please see Figure 1 This invention provides a technical solution: a method for calibrating length matching parts, applicable to newly manufactured, in-use, and repaired straight-face and oblique-face matching parts. Before calibration, it is necessary to ensure that the operators have received professional training and obtained the qualification certificate of the calibrator. The ambient temperature of the calibration laboratory should be controlled at (20±1)℃. The length matching parts to be calibrated should be placed in this environment to balance the temperature for no less than 6 hours. Prepare calibration equipment such as surface roughness template, profilometer, grade 0 plate, grade 0 90° light transmittance ruler, coordinate measuring machine, length measuring machine, and thermometer. All equipment should be in good condition and effectively calibrated.

[0018] Example 1: Calibration of a newly manufactured steel integral surface-to-surface component In this embodiment, the part to be calibrated is a newly manufactured steel integral surface-mounted part with a nominal size of 180mm. The drawing requires a surface roughness Ra≤0.8μm for the working surface, with no special geometric tolerances or dimensional requirements. The specific calibration steps are as follows: Before calibration, check the original records: verify the manufacturing certificate of the instrument pair, confirm that the name, model, object measurement part drawing number, gauge number, manufacturing date, storage location and other information are filled in completely, record the calibration laboratory environment temperature as 20℃, humidity as 52%, and that there are no other factors that may affect the calibration work, check the integrity and effective calibration status of all calibration equipment, and confirm that the equipment is usable.

[0019] Visual inspection revealed that the working surfaces and other surfaces of the dial indicator were free of rust, dents, or other defects. The non-working surfaces clearly bore the drawing number and manufacturing number. Since the integral structure had no fastening screws, the visual inspection was deemed satisfactory.

[0020] State-specific calibration: This pair of parts is newly manufactured and requires full-item calibration. The calibration process for each item is as follows: (1) Surface roughness: First, a surface roughness template is used for comparison and initial judgment. Then, the Ra value of the working surface and the reference surface is detected by a profilometer. The detection result is 0.6μm, which meets the requirement of Ra≤0.8μm in the drawing.

[0021] (2) Flatness of the reference surface: The plate coloring method is selected. A red ink with a thickness of 0.002mm is evenly applied to the reference surface. It is then attached to a grade 0 plate and moved and bonded. It is observed that the coloring is uniform, there is no obvious missing color area, and the flatness error is less than 0.003mm, which meets the calibration requirements.

[0022] (3) Flatness of working surface: The light gap method is selected. A grade 0 light-transmitting ruler is used as the measurement baseline. The measurement is carried out in six directions: transverse, longitudinal and oblique. The light gap formed is compared with the standard light gap. The flatness error corresponding to the maximum value of the light gap is 0.002mm, which is less than the tolerance requirement of 0.003mm. It is judged to be qualified.

[0023] (4) Relationship between the reference surface and the working surface: The light gap method is used. The 0-grade 90° light-transmitting ruler is directly attached to the reference surface and the working surface to measure the light gap formed. The verticality error corresponding to the maximum value is 0.004mm, which is less than the tolerance requirement of 0.005mm. The verticality calibration is qualified.

[0024] (5) Relationship between working surfaces: To calibrate the parallelism of the two working surfaces, since there are no special requirements in the drawings, the parallelism tolerance of the nominal size of the steel dial indicator is ≤200mm and the tolerance is 2μm. The length measuring machine method is selected, and a spherical probe is installed. Nine measurement positions are evenly selected on the working surface. The difference between the maximum and minimum values ​​of the dimensions at each position is 1.5μm, which meets the parallelism tolerance requirement. Moreover, there is no temperature difference between the instrument and the dial indicator during the calibration process, so no dimensional correction is required.

[0025] (6) Working dimensions: The length measuring machine method is used. The average value of the measurement data of the above 9 measurement positions is taken as the actual working dimensions of the pair of dials. The deviation between the measurement results and the nominal dimensions is 0.002mm, which meets the size requirements of the drawing. The actual working dimensions are marked on the non-working surface according to the drawing.

[0026] (7) Other geometric tolerances and dimensions required by the drawings: Since there are no additional requirements in the drawings, no testing is required for this project.

[0027] Calibration result judgment and processing: All calibration measurement results of the new steel integral face-to-face dialing part meet the requirements of this method and drawings, and are judged to be qualified for calibration. No repair or scrapping is required.

[0028] Calibration record and labeling management: Completely record all measurement data, selected calibration methods, laboratory environmental parameters, equipment information and judgment results for this calibration, form a calibration report, and archive it after being signed and confirmed by the calibration personnel and reviewers; A qualified label is affixed to a conspicuous position on the calibration instrument, clearly indicating the calibration date, the next calibration date and the calibration unit information.

[0029] Example 2: Calibration of the surface component using a split inclined plane made of medium-light alloy In this embodiment, the part to be calibrated is a split inclined surface surface using a medium-light alloy, with a nominal size of 450mm and a part tolerance of 0.04mm. The drawing requires the angle between the working surface and the reference surface to be 30°. There are no other special requirements. The specific calibration steps are as follows: Before calibration, check the historical calibration records and usage and maintenance records of the instrument pair. There are no repair records and the information is complete. Record that the calibration laboratory environment temperature is 19.5℃ and humidity is 48%, and there are no other factors that may affect the calibration. Check the status of the calibration equipment and confirm that all equipment is available. Place the instrument pair in the laboratory environment for 8 hours to equilibrate the temperature, which meets the temperature equilibration time requirement.

[0030] Visual inspection revealed minor scratches on the working surfaces of the gauges, but these did not affect their use or calibration accuracy. The screws securing the measuring blocks at both ends were secure and reliable, with no looseness. The drawing number, manufacturing number, and other markings on the non-working surfaces were clearly identifiable. The visual calibration was deemed satisfactory.

[0031] State-specific calibration: This pair of gauges is in use and does not require calibration of the working surface roughness or other geometric tolerances and dimensions required by the drawings. Only the remaining six items need to be calibrated. The calibration process for each item is as follows: (1) Flatness of the reference surface: The three-coordinate measurement method is selected. The probe of the three-coordinate measuring machine is used to collect 9 measuring points evenly on the reference surface. The flatness error is directly evaluated and calculated. The result is 0.0028mm, which is less than the tolerance requirement of 0.003mm. It is judged to be qualified.

[0032] (2) Flatness of working surface: The light gap method is preferred. The light gap is measured in 5 different directions along the working surface to be measured. The flatness error corresponding to the maximum value of the light gap is 0.003mm, which meets the tolerance requirements and is judged to be qualified.

[0033] (3) Relationship between the reference plane and the working plane: The coordinate measuring machine was selected, and the probe was used to collect the relevant elements of the working plane and the reference plane. The angle between the two was measured and the result was 30.001°. The deviation from the 30° required by the drawing was within the allowable range and was deemed qualified. Because there was a 0.5℃ difference between the laboratory temperature and the standard temperature, the temperature compensation subroutine of the coordinate measuring machine was called to perform temperature compensation.

[0034] (4) Relationship between working surfaces: The parallelism of the two working lines is calibrated. Since there are no special requirements in the drawings, the parallelism tolerance of the nominal size of the light alloy dial indicator is ≤800mm and the tolerance is 5μm. The three-coordinate measurement method is selected, and 10 measuring points are evenly collected on each of the two working lines. After temperature compensation, the parallelism error is measured to be 3.8μm, which meets the tolerance requirements and is judged to be qualified.

[0035] (5) Working dimensions: The three-coordinate measurement method is selected to calibrate the distance between the two parallel working lines. After temperature compensation, the measurement results are within the tolerance range of the measured part. The actual dimensions of the instrument are required to be branded, and the original branded dimension tolerance has exceeded the drawing requirements. According to the standard that the product part tolerance is 0.04mm>0.03mm, the branded dimension tolerance t is determined to be 0.02mm. The branded dimension is enlarged to the nominal dimension ±0.02mm to ensure that the actual working dimensions are within the tolerance range of the measured part.

[0036] Calibration result judgment and processing: All measurement results of the light alloy split inclined surface dial indicator meet the requirements of this method and drawings, and are judged to be qualified for calibration. No repair or scrapping is required.

[0037] Calibration record and labeling management: Completely record the measurement data, calibration method, environmental parameters, temperature compensation, equipment information and judgment results of this calibration, form a calibration report, sign and confirm it and then file it; Affix a qualified label to the calibration instrument, mark the calibration date and the next calibration date, and mark the adjusted dimensional tolerance information.

[0038] The above two embodiments are merely typical application examples of the present invention. For repaired length matching parts, the calibration steps are the same as for new parts, performing full-item calibration. During the calibration process, it is necessary to check the calibration items of the repaired parts in conjunction with the repair records to ensure that all indicators of the repaired matching parts meet the calibration requirements. In the method of the present invention, the measurement methods for each calibration item can be reasonably selected according to the actual calibration conditions and the structural characteristics of the part to be calibrated. As long as they comply with the tolerance requirements, operating procedures, and compensation and correction principles specified in the present invention, they all fall within the protection scope of the present invention.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for calibrating a length matching component, characterized in that, The methods and steps include the following: S1. Before calibration, check the original records, verify the relevant certificates and historical records of the part to be calibrated and fill in any missing information, record the calibration environment parameters and check the status of the calibration equipment. S2, visual calibration, uses visual inspection to check the surface condition, fastening structure and markings of the part to be calibrated. Unqualified parts are repaired before subsequent calibration. S3, Specialized Calibration by State, performs corresponding calibration items for newly manufactured, repaired, and in-use parts to be calibrated, completing the measurement and evaluation of working surface roughness (only for newly manufactured and repaired parts), datum surface flatness, working surface flatness, the relationship between datum surface and working surface, the relationship between working surfaces, working dimensions, and other geometric tolerances and dimensions required by drawings (only for newly manufactured and repaired parts). S4, Calibration result judgment and processing: Based on the calibration standards and drawing requirements, comprehensively judge the measurement results of each item and make a decision on whether to accept, repair and recalibrate, or scrap. S5, Calibration Record and Label Management, fully records calibration data throughout the entire process and generates calibration reports for archiving. For parts to be calibrated with different judgment results, corresponding labels are affixed and key information is marked.

2. The method for calibrating a length-matching instrument according to claim 1, characterized in that: In S1, for newly manufactured length gauges, the manufacturing certificate filled in by the gauge manufacturer is checked, and missing information such as name, model, object measurement part drawing number, gauge single number, manufacturing date, and storage location is supplemented; for repaired or used length gauges, historical calibration records and repair records are checked; at the same time, the temperature, humidity and other factors affecting calibration work in the calibration laboratory are recorded, and the integrity and effective calibration status of all calibration equipment are checked.

3. The method for calibrating a length matching device according to claim 1, characterized in that: The appearance calibration criteria for S2 are as follows: newly manufactured and repaired lengths are free from defects such as rust and dents on the working surface and all surfaces of the instrument; lengths in use are free from defects that affect the use and calibration accuracy of the instrument; the measuring blocks at both ends of the split lengths are securely fastened with screws; the fastening screws of newly manufactured lengths are sealed with sealing wax; and all non-working surfaces of the calibrated parts are marked with drawing numbers, manufacturing numbers, and special markings specified in the drawings.

4. The method for calibrating a length-matching instrument according to claim 1, characterized in that: In S3, newly manufactured and repaired length gauges undergo full-item calibration, which includes appearance, working surface roughness, datum plane flatness, working surface flatness, the relationship between the datum plane and the working surface, the relationship between the working surfaces, working dimensions, and other geometric tolerances and dimensions required by the drawings. For length gauges in use, only six items are calibrated: appearance, datum plane flatness, working surface flatness, the relationship between the datum plane and the working surface, the relationship between the working surfaces, and working dimensions. Working surface roughness and other geometric tolerances and dimensions required by the drawings are not calibrated.

5. The method for calibrating a length matching device according to claim 1, characterized in that: In S3, the calibration tolerance for the flatness of the reference surface is 0.003mm. If the drawing has special requirements, the drawing shall be followed. The calibration method can be either the coordinate measuring machine method or the plate coloring method. The calibration tolerance for the flatness of the working surface is 0.003mm. If the drawing has special requirements, the drawing shall be followed. For newly made and repaired length matching parts, the coordinate measuring machine method or the optical gap method can be used. For length matching parts in use, the optical gap method should be used first, and the coordinate measuring machine method should be used with caution.

6. The method for calibrating a length matching component according to claim 1, characterized in that: In S3, the mutual relationship between the reference plane and the working plane is calibrated. For a straight surface, the perpendicularity of the working plane to the reference plane is calibrated, with a tolerance requirement of 0.005mm. If the drawings have requirements, they shall be followed. The optical gap method or the three-coordinate measurement method shall be used. For an inclined surface, the three-coordinate measurement method shall be used to measure the angle between the working plane and the reference plane. The measurement results shall meet the requirements of the drawings.

7. The method for calibrating a length matching device according to claim 1, characterized in that: In S3, the mutual calibration of the working surfaces involves calibrating the parallelism of the two working surfaces for a straight-faced dial indicator and calibrating the parallelism of the two working lines for an inclined dial indicator. If the drawings specify tolerance requirements, follow the drawings. Otherwise, for light alloy dial indicators with a nominal size ≤ 800mm and a parallelism tolerance of 5μm, and for steel dial indicators with a nominal size ≤ 200mm and a parallelism tolerance of 2μm. ~ 5μm, >200 ~ The parallelism tolerance is 5μm for 800mm. For working dimension calibration, the length measuring machine is preferred for straight-faced parts. When the length measuring machine cannot be used for special dimensions, the coordinate measuring machine is used. The coordinate measuring machine is used for inclined-faced parts.

8. The method for calibrating a length matching component according to claim 1, characterized in that: In step S4, if all calibration item measurement results meet the requirements specified in this method and drawings, the calibration is deemed qualified; if a single item measurement result is unqualified but can be repaired or adjusted to meet the requirements, the calibration is deemed unqualified and must be repaired before a full-process calibration is performed; if multiple item measurement results are unqualified or cannot be repaired or adjusted to meet the requirements, the item is deemed scrapped and prohibited from use.

9. The method for calibrating a length matching device according to claim 1, characterized in that: In S5, the calibration record must include measurement data, calibration method, environmental parameters, equipment information, and judgment results. The calibration report must be signed and confirmed before being archived and retained. The label must include key information such as the calibration date and the next calibration date.

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