High-precision guide rail double-tool iterative assembly method

Abstract

The application discloses a high-precision guide rail double-tool iterative assembly method, which is characterized by the following steps: rough adjustment of the flatness of an installation surface through an electronic level, fine measurement of the straightness of a guide rail through a self-collimating instrument, directional correction through the establishment of an error separation model, and formation of a closed loop of 'detection-correction-retest'. The method solves the problems of fuzzy error identification and low correction efficiency of traditional methods, is suitable for high-precision assembly and adjustment of precision mechanical guide rails, and significantly improves assembly precision and efficiency.

Description

Technical Field

[0001] This invention relates to the field of mechanical assembly technology, specifically to a high-precision method for detecting and correcting the flatness, straightness, and coplanarity of guide rails based on the collaboration of an electronic level and an autocollimator. This method is applicable to the high-precision assembly and adjustment of guide rails in automated equipment, precision machine tools, and other applications. Background Technology

[0002] In precision mechanical assembly, the flatness, straightness, and coplanarity of guide rails are core indicators determining the motion accuracy of the equipment. Traditional testing methods have the following shortcomings: 1. Limitations of a single tool: While electronic levels can detect flatness, they are difficult to accurately identify straightness errors in the guide rail itself. Although autocollimators can accurately measure straightness and parallelism, they lack efficient handling of macroscopic errors on the mounting surface.

[0003] 2. Blindness in error correction: Existing methods do not clearly distinguish between mounting surface errors and guide rail body errors, resulting in inaccurate repair directions and often requiring multiple reworks.

[0004] 3. Low assembly and adjustment efficiency: The single measurement-adjustment mode is difficult to achieve rapid error convergence, especially for guide rails with insufficient accuracy, which requires a lot of time.

[0005] To address the aforementioned issues, existing high-precision guide rail assembly and adjustment methods mostly focus on single tools or static adjustments, failing to establish a closed-loop process of "coarse adjustment – ​​fine measurement – ​​iterative correction." Therefore, there is an urgent need for an efficient assembly method that utilizes dual tools in synergy and provides error-oriented correction. Summary of the Invention

[0006] (a) Technical problems to be solved A high-precision guide rail assembly method based on the coordinated use of an electronic level and an autocollimator is provided to achieve: 1. Two-dimensional error separation: Clearly distinguish between the flatness error of the mounting surface and the straightness error of the guide rail body; 2. Iterative correction closed loop: Through the cycle of "coarse adjustment - fine measurement - correction - re-verification", the error is quickly converged; 3. Highly efficient and precise assembly: Improves the accuracy of guide rail flatness, straightness and coplanarity detection and assembly efficiency.

[0007] (II) Technical Solution A high-precision guide rail dual-tool iterative assembly method includes the following steps: Step 1: Use an electronic level to coarsely adjust the flatness of the mounting surface (datum surface construction). 1. Segmented measurement: The mounting surface 5 is divided into n equal segments along the length direction, where n = guide rail length (m) × 2~4, which meets the requirements of the pitch method in GB / T11336-2004, forming n+1 equally divided measuring points 2. The height value Hi (i=1, 2, ..., n+1) is measured point by point using an electronic level 3.

[0008] The arrangement of the first and last measuring points can be adjusted according to the width of the measuring tool (such as an electronic level): if the tool is wide, the first and last measuring points can be recessed to a certain distance from the end face of the guide rail (to avoid the tool being suspended in the air and affecting the measurement stability), and the middle measuring points are kept at equal intervals, which still meets the core requirements of the pitch method of "equal segmentation and full stroke coverage".

[0009] 2. Difference Calculation: First, calculate the average value of the three measurements taken by the electronic level. Then the benchmark value .

[0010] H0 is the horizontal baseline of the mounting surface 5, which is the display baseline set by the electronic level 3 after the guide rail mounting surface 5 of the base 1 is initially leveled.

[0011] Measured value sequence h i =H i -H0+h i-1 The linear benchmark theoretical value sequence hi′=K×i, where i=1,2,…,n+1 (corresponding to n+1 measurement points). Difference Δh i =h i -h i ′.

[0012] 3. Adjustment of study period: According to Δh i Mark the highest point of mounting surface 5 (the difference is positive), use a high-precision bridge ruler (flatness ≤0.005mm) to grind mounting surface 5, and scrape it until the single-segment inclination value is ≤0.015mm.

[0013] Step 2: Autocollimator 7 precisely measures the straightness of guide rail 9 (body error identification) 1. Vertical straightness inspection: An aluminum plate 11 and a plane mirror 12 are installed on the guide rail slider 10. The autocollimator 7 is placed on the light tube bracket 6 and positioned at one end of the guide rail 9, with the collimation direction parallel to the end face of the guide rail 9.

[0014] Move the guide rail slider 10 to each measuring point 8 position x i (Number of measuring points ≥ guide rail length (m) × 2, distance of the first and last measuring points from the guide rail end face ≤ 50mm), record the reading θ from collimator 7. i (arcseconds), converted to linear deviation L is the distance between adjacent measuring points (mm), which is the length of the measuring section.

[0015] 2. Horizontal parallelism inspection: Adjusting blocks 13 are intersectingly distributed on both sides of the guide rail 9, and each adjusting block 13 is equipped with adjusting block screws 14. Rotate the autocollimator 7 90° in the sensitive direction. Adjust the adjusting block screws 14 on both sides of the guide rail to make the horizontal parallelism ≤0.015mm / m, which meets the "precision grade double guide rail parallelism" requirement in GB / T17421.1-2019 "General Rules for Machine Tool Inspection". This tolerance is 1.5 times the vertical straightness tolerance (industry practice).

[0016] Step 3: Error Source Isolation and Targeted Refinement Based on the vertical straightness deviation Δtotal,i (unit: mm, corresponding position x) of guide rail 9 measured by autocollimator 7 in step 2, the deviation is calculated as follows: i (The detection length is Lmm). The residual error Δmounting,i of the mounting surface 5 and the body error Δguideway,i of the guide rail 9 are separated through the following steps, and the correction object and repair amount are determined. Directional repair is then carried out immediately. 1. Establish an error superposition model Following the error formula defined in the patent, the total deviation consists of the linear superposition of two types of errors: Δtotal,i=Δmounting,i+Δguideway,i Where Δtotal,i is the total deviation of measuring point i (mm), Δmounting,i is the error of mounting surface 5 (low-frequency slowly varying component, mm), and Δguideway,i is the error of guideway 9 (including local high-frequency component, mm).

[0017] 2. Solving for parameters using the least squares method Based on the least squares principle, using the measured Δtotal,i and the corresponding measurement point position x i (m), the parameters a0 (initial deviation, mm) and a1 (tilt slope, mm / m) of the mounting surface error model are obtained by fitting, and the fitting model is Δmounting,i=a0+a1x i The guideway body error is calculated using the residual: Δguideway,i = Δtotal,i − (a0 + a1x) i ).

[0018] 3. Error Separation Judgment and Repair Implementation a. Error Dominance Analysis For each measuring point i, calculate the absolute value of the mounting surface error Δmounting,i |a0+a1x i| The proportion of the total deviation Δtotal,i. If the proportion exceeds 60%, the measurement point is determined to be dominated by the residual error of mounting surface 5. If the residual Δguideway,i locally exceeds the limit, and the deviation of a single measurement point is greater than the straightness of the guide rail in the vertical direction (mm / m) × the detection length L (m) / 1000 (the straightness of the guide rail in the vertical direction refers to the upper limit of the tolerance required by the design), it is determined to be dominated by the error of the guide rail body 9. Taking into account the conditions of all measuring points, the overall error of the mounting surface is evaluated. Even if some measuring points are not the main source of error on mounting surface 5, if there is a certain degree of error on mounting surface 5 as a whole, and these errors still affect the overall accuracy at the high points marked in step 1, then mounting surface 5 still needs to be reworked to a certain extent.

[0019] b. Research Decision-Making and Implementation: Mounting Surface 5 Repair: If the overall error of mounting surface 5 requires repair, use a high-precision bridge ruler (flatness 0.005mm) to push and scrape the high points of mounting surface 5 (where the difference is positive). The repair amount is adjusted according to the overall error assessment results of mounting surface 5. If the overall error is small, the amount of scraping in a single step is controlled at 3-5μm; if the overall error is large, the amount of scraping in a single step is controlled at 5-10μm.

[0020] Repair and refining of guide rail 9 body: For measuring points where the error of guide rail 9 body is the main factor, repair or replace the guide rail by scraping the high points on the upper end surface of guide rail 9. The repair amount is the reverse compensation value of the measured residual value. Use a triangular scraper to scrape the over-limit area on the upper end surface of guide rail 9 at fixed points, and use the blue oil spot detection method to detect the contact rate (≥80%) to ensure the repair accuracy is ±2μm.

[0021] Step 4: Coplanarity Detection and Iterative Verification of Dual Guide Rails Bridge plate bridging measurement: Use an adjustable bridge plate 4 (e.g., 50-500mm) to bridging the corresponding measuring points of the two guide rails 9, and use an electronic level 3 to measure the height difference ΔH. ij , requires |ΔH ij |≤0.01mm / m.

[0022] Iterative verification: If the deviation is exceeded, repeat steps 1-4 until the vertical straightness per meter is ≤0.01mm / m, the horizontal parallelism per meter is ≤0.015mm / m, and the coplanarity meets the standard.

[0023] The beneficial effects of this invention compared to the prior art are: 1. Advantages of dual-tool collaboration: The electronic level quickly establishes the reference mounting surface, and the autocollimator accurately locates the guide rail body error, forming a layered control of "surface reference - line accuracy".

[0024] 2. Error-oriented correction: By separating error sources through mathematical models, blind research is avoided, and research efficiency is improved by more than 50%.

[0025] 3. Improved accuracy and efficiency: By coarsely adjusting the single-segment tilt value to ≤0.015mm using an electronic level, and combining fine measurement and iterative refinement using an autocollimator, the system ultimately achieves vertical straightness ≤0.01mm / m, horizontal parallelism ≤0.015mm / m, and coplanarity ≤0.01mm, reducing the assembly cycle by 30%. This system is suitable for achieving precision-level assembly accuracy for ordinary guide rails. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the dual-tool collaborative detection layout of the present invention (1-base, 2-measuring point, 3-electronic level, 4-adjustable bridge plate, 5-mounting surface, 6-optical tube bracket, 7-autocollimator, 8-measuring point, 9-guide rail, 10-guide rail slider, 11-aluminum plate, 12-plane mirror, 13-adjusting block, 14-adjusting block screw, 15-guide rail A, 16-guide rail B, 17-steel plate, 18-meter base, 19-micrometer head). Figure 2 This is a schematic diagram of the mounting surface of the electronic level detection rail of the present invention. Figure 3 This is a schematic diagram of the self-collimator detection guide rail of the present invention. Figure 4 This is a schematic diagram of the electronic level of the present invention detecting the coplanarity of the two guide rails. Figure 5 This is a schematic diagram of the self-collimator detection splicing long guide rail of the present invention. Figure 6 The flowchart of the error source separation algorithm of the present invention is shown below. Figure 7 The iterative correction closed-loop flowchart of the present invention Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments. The invention is explained through illustrative embodiments and descriptions, but is not intended to limit the invention.

[0028] Example 1: Taking a rectangular linear guide rail (2m in length, ISO 230-1 standard accuracy grade, requiring flatness ≤0.05mm / m, straightness ≤0.01mm / m, and coplanarity ≤±0.01mm) of a precision electromechanical product as an example, the two-tool iterative assembly process is described in detail: Step 1: Use an electronic level to roughly adjust the flatness of the mounting surface. 1. Segmented Measurement and Data Acquisition The guide rail mounting surface is 2.02m long and designed according to "n=2×2~4=4~8 segments". In practice, it is divided into 4 segments with 5 measuring points. The first and last measuring points are 80mm from the guide rail end face. This is because the width of the electronic level used is 150mm; the inward reduction avoids measurement deviation caused by the tool being suspended above half the width, ensuring stable readings. The spacing between the measuring points in the middle 4 segments is 465mm≤500mm, conforming to the equidistant requirements of the pitch method in GB / T11336-2004. The electronic level 3 (using the coarse measuring range, nominal graduation value 0.01mm / m) was used to measure the mounting surface 5 (guide rail 1) point by point, and the displayed values ​​are shown in Table 1 below: Table 1. Level indicator readings

[0029] The measurement values ​​in the table are in the level display units (digits).

[0030] 2. Benchmark value calculation and measured value conversion Average value calculation:

[0031] Baseline value K:

[0032] If the horizontal base number H0 of the mounting surface 5 is 500, then K = 540 - 500 = 40.

[0033] Measured value h i :h i =H i -H0+h i-1 =H i -500+h i -1 Based on the above measured value h i The calculation formula yields the sequence of measured values ​​from the 1st to the 5th measurement points. For example: h1 = 545 - 500 = 45 for the 1st measurement point, h2 = 533 - 500 + 45 = 78 for the 2nd measurement point, and so on... The sequence of measured values ​​is: 45, 78, 100, 164, 197.

[0034] 3. Calculation of single-segment inclination value Theoretical value of linear reference h i ′: h i =K×i=40, 80, ..., 200 Difference Δh i =h i -h i ′: For example: Measurement point 1: 45−40=+5, and so on... The sequence of linear benchmark theoretical values ​​and their differences are shown in Table 2 below: Table 2. Linear benchmark theoretical value sequence and differences (before scraping)

[0035] The maximum absolute value of the difference, |Δhmax|, is 20 (characters). Converted to a single-segment inclination value, this is 0.01 mm / m × 0.465 m × 20 = 0.093 mm. 4.Study According to Δh i Mark the high point of mounting surface 5 (with a positive difference value). Use a high-precision bridge ruler (flatness ≤ 0.005 mm) to grind and scrape the mounting surface 5. The sequence of linear reference theoretical values ​​and the difference values ​​after scraping are shown in Table 3 below: Table 3. Linear benchmark theoretical value sequence and difference (after scraping)

[0036] The maximum absolute value of the difference, |Δhmax|, is 3 (characters). Converted to a single-segment inclination value, this is 0.01 mm / m. ×0.465m×3=0.01395mm≤0.015mm Using the same method described above, an electronic level was used to measure the mounting surface of the other guide rail, and a high-precision bridge ruler was used to scrape and grind it to meet the requirements.

[0037] Step 2: Use autocollimator 7 to precisely measure the straightness of the guide rail. 1. Vertical straightness inspection Plane reflector 12 installation: Fix aluminum plate 11 on guide rail slider 10, install plane reflector 12 (flatness ≤ 0.001mm), autocollimator 7 (accuracy 0.1″) is placed on light tube bracket 6, positioned at the left end of guide rail, collimated light is perpendicular to the end face of guide rail.

[0038] Data Acquisition: The guide rail is 2m long, designed with "≥2×2=4 measuring points". Five typical measuring points are actually selected: 8 (0m (≤50mm from left end), 0.5m, 1.0m, 1.5m, 2.0m (≤50mm from right end)). The guide rail slider is moved 10 to the five typical measuring points 8 (0m, 0.5m, 1.0m, 1.5m, 2.0m), and the reading θ is recorded. i These are +5″, -8″, -15″, -10″, and +3″ respectively, converted to linear deviation (according to the formula). : For example: θ at 1.0m i When the value is -15″, Δtotal,i = -0.036mm, which indicates that the middle section of the guide rail 9 body is concave.

[0039] 2. Horizontal parallelism adjustment Using one of the guide rails as a reference (fixed and not adjusted), the parallelism of the other guide rail to be adjusted is first roughly adjusted by using a dial indicator. Adjustment blocks 13 and adjustment block screws 14 are distributed crosswise on both sides of the guide rail to be adjusted. An aluminum plate 11 is fixed on the guide rail slider 10, and a plane mirror 12 is placed on the aluminum plate 11. The autocollimator 7 is placed at one end of the guide rail to be adjusted, with the optical axis parallel to the length of the guide rail and aligned with the center of the plane mirror 12.

[0040] Rotate the autocollimator 90° in the sensitive direction 7 (switch to horizontal lateral detection mode), move the guide rail slider to each measuring point throughout its full stroke (same as the measuring point positions for vertical straightness detection), and record the horizontal lateral deviation θ. i (arc seconds): θ i To indicate that the guide rail to be adjusted has shifted outward, tighten the inner adjusting block screw 14 and loosen the outer adjusting block screw 14; θ i If the result is negative, the operation is reversed until the horizontal parallelism is ≤0.015mm / m.

[0041] The actual measured value of this embodiment after adjustment is 8μm / m (0.008mm / m), which is better than the precision grade standard GB / T17421.1-2019.

[0042] Step 3: Error Source Isolation and Targeted Refinement 1. Application Examples of Least Squares Method Based on the autocollimator data from step 2 (5 measuring points, positions xi=0, 0.5, 1.0, 1.5, 2.0m, measuring length L=500mm, and the total vertical deviation Δtotal,i is converted to +0.012, +0.005, -0.036), -0.010, +0.008mm. Calculate the mean: =1.0m, =-0.0044mm Fitting coefficients: a1 = -0.02 mm / m, a0 = 0.0156 mm Mounting surface 5 error model: According to the formula Δmounting,i=a0+a1x i Δmounting,i=0.0156-0.02ximm, substitute the position x point by point. i calculate: Table 4 Calculation values ​​of mounting surface error

[0043] Guide rail 9 body error: Calculate the total deviation Δguideway,i using the formula Δtotal,i = Δtotal,i - Δmounting,i, combined with the measured value of Δtotal,i: Table 5 Calculation values ​​of guide rail body error

[0044] 2. Improved object determination a. For each measuring point, analyze the proportion of error in the mounting surface 5 and the error in the guide rail body 9.

[0045] At 2.0m, the error of mounting surface 5 is -0.0244mm, which is opposite to the trend of the total deviation of +0.008mm. Moreover, the absolute value of the error of mounting surface 5 accounts for less than 60% of the total deviation, so it is determined that the error of mounting surface 5 is not the main factor at this position. At 1.0m, the residual error of guide rail 9 body is -0.0316mm out of tolerance (>0.01mm / m×0.5m=0.005mm), which is determined to be the main error of guide rail 9 body.

[0046] b. Taking into account the conditions of each measuring point, determine the overall correction strategy: If the overall error of mounting surface 5 is not dominant at some measuring points, but still has a certain degree of error, and the error at the high point marked in step 1 still affects the overall accuracy, then mounting surface 5 needs to be repaired to a certain extent.

[0047] For measuring points where the error of the guide rail 9 body is the main factor (such as at 1.0m), the focus should be on the repair and refining of the guide rail 9 body.

[0048] 3. Process implementation. Mounting surface refining: For the high points marked in step 1 (such as measuring points 1 and 4 in Table 2), reassess their impact on the overall accuracy. If the mounting surface 5 error corresponding to these high points, although not dominant at some measuring points, still contributes to the overall mounting surface 5 error and affects the mounting accuracy and coplanarity of the guide rail 9, then refining is performed. After using a high-precision bridge gauge to grind the visible points, remove the material from the high points with a scraper. However, the refining amount should be adjusted appropriately based on the overall mounting surface 5 error assessment results to avoid over-refining. For example, if the overall mounting surface 5 error is small, the single grinding amount can be appropriately reduced to 3-5 μm.

[0049] Repair and refining of guide rail 9: Apply blue oil to the recessed area (1.0m) in the middle section of guide rail 9, use a high-precision bridge ruler to mark the point, and scrape off 0.0316mm of material. After retesting, the deviation at this measuring point is reduced to -0.003mm.

[0050] Step 4: Coplanarity Detection and Iterative Verification of Dual Guide Rails 1. Measurement of bridge deck bridging An adjustable bridge plate 15 is used to bridge the two guide rails 9, corresponding to the measuring points (170mm apart). An electronic level 16 is placed in the middle of the bridge plate. The level is selected with a nominal graduation of 0.01mm / m in the coarse measuring range, and the display unit is (digits). The actual height difference conversion formula is: ΔH ij (μm)=0.01mm / m×170(mm)×ΔH ij (characters) ÷ 1000 × 1000 = 1.7 × ΔH ij (Character).

[0051] Where: ΔH ij (The number) represents the reading displayed on the level instrument, ΔH. ij (μm) represents the corresponding actual height difference.

[0052] The measured height difference at the third measuring point was -6, corresponding to -6 × 1.7 = -10.2 μm (slightly out of tolerance). The preload of the guide rail mounting screws was adjusted to meet the requirements.

[0053] 2. Iterative verification results After one cycle of "inspection-repair-re-inspection", the flatness error was reduced to 0.018mm / m, and the straightness in the vertical direction and the parallelism in the horizontal direction were both ≤0.008mm / m, meeting the tolerance requirement of ≤0.01mm / m. The coplanarity was tested by the adjustable bridge plate 4, and the maximum height difference was 0.009mm, which met the accuracy index of ±0.01mm.

[0054] The high-precision guide rail dual-tool iterative assembly method provided by this invention is also applicable to the high-precision splicing of long guide rails: Example 2: A rectangular linear guide for a large precision electromechanical product (total length 5.6m, made of three single guide sections of 1.8m to 2m spliced ​​together, with a total straightness requirement of ≤0.05mm). For segmented splicing guide rails, in addition to the steps described in Example 1, the following special processing steps are added: 1. Before installing each section of guide rail 9, use an electronic level 3 to independently level the mounting surface 5 of each section, and control the difference in reference value within ±2 (level display unit, digits); 2. During splicing, overlapping measuring points are set at the joints, and the difference between the measured values ​​of the electronic level 3 of adjacent sections is required to be ≤3 (level display unit, digits). The reference continuity is ensured by grinding the end face of the guide rail 9 at the joint. 3. Coordinated adjustment of horizontal parallelism of splicing guide rails and splicing error: Both guide rails (guide rail A 15 and guide rail B 16) are three-section spliced, with adjustment blocks 13 and adjustment block screws 14 on both sides of each section, adopting an alternating strategy of "coarse adjustment with dial indicator → fine adjustment with single rail". a. Initial coarse adjustment: Using guide rail B 16 as a reference (fixed), fix a steel plate 17 on the guide rail slider 10, attach the dial indicator base 18 to the steel plate 17, and press the dial indicator head 19 against the side of guide rail A 15. Move the guide rail slider 10 to measure the lateral deviation at the joint, and fine adjust it by adjusting the guide rail A 15 adjustment block screw 14 to make the deviation ≤0.02mm.

[0055] b. Fine-tuning of guide rail A15: Fix an aluminum plate on the guide rail slider 10 of guide rail A15, install a plane mirror 12, place the autocollimator 7 at one end (optical axis aligned with the plane mirror, parallel to the guide rail), rotate the sensitive direction 90° to measure the horizontal deviation θ of each segment. i Fine-tune to θ i ≤15″.

[0056] c. Secondary adjustment of the dial indicator: Using the finely adjusted guide rail A 15 as the reference, the guide rail slider 10 is mounted on the dial indicator base 18 and the side of the original reference guide rail B 16 is tapped. The joint of guide rail B 16 is re-measured and finely adjusted so that the deviation between the two rails is ≤0.015mm / m.

[0057] d. Fine-tuning of guide rail B 16: Replace the plane mirror 12 with guide rail B 16, move the collimator 7 to one end for retesting, and fit the deviation data by the least squares method across the segment. Finally, the parallelism of the double rails along the entire length reaches 0.009mm / m, and the splicing step is ≤0.008mm.

[0058] By using two cycles of "coarse adjustment → fine adjustment", the other guide rail is recalibrated using the already adjusted guide rail, and cross-segment fitting is combined to eliminate splicing reference drift and avoid adjustment chaos.

[0059] After three iterations of refinement, the vertical straightness error of the 5.6m three-section spliced ​​guide rail 9 is 0.05mm (equivalent to 0.0089mm / m, ≤0.01mm / m), the maximum coplanarity deviation is 8μm, and the horizontal parallelism is tested by the adjustable bridge plate 4. The requirement is that the horizontal deviation at the joint of adjacent sections is ≤0.005mm / 500mm (corresponding to 20″ arcseconds). The final measured horizontal parallelism error is ≤0.01mm / m (better than the precision grade tolerance of 0.015mm / m in GB / T17421.1-2019), which meets the high-precision motion requirements of large precision electromechanical products.

[0060] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A high-precision guide rail dual-tool iterative assembly method, characterized in that, Includes the following steps: Step 1: Use an electronic level (3) to measure the guide rail mounting surface (5) in sections, calculate the reference value and refine the flatness; Step 2: Use an autocollimator (7) to check the vertical straightness and horizontal parallelism of the guide rail (9), identify the residual error of the mounting surface and the error of the guide rail body. The vertical straightness tolerance is ≤0.01mm / m and the horizontal parallelism tolerance is ≤0.015mm / m. Step 3: Based on the error separation model, perform directional repair on the mounting surface (5) or the guide rail (9) body, and detect the coplanarity of the two guide rails through the adjustable bridge plate (4); Step 4: Repeat steps 2-3 until the accuracy meets the standard; The error separation model is fitted using the least squares method, with the formula: Δtotal = Δmounting + Δguideway, where Δmounting is the mounting surface error (mm / m) and Δguideway is the guideway body error (mm / m). The research object is determined by the error dominance criterion. a) If the percentage of mounting surface error Δmounting is greater than the threshold α, where α = 50% to 70%, then the mounting surface should be re-examined in a targeted manner (5). b) If the residual Δguideway of the guide rail body > the threshold β, β = the vertical straightness of the guide rail × the detection length L / 1000, then the guide rail (9) body is oriented and repaired; the vertical straightness of the guide rail is in mm / m, and the detection length L is in m; In step 3, the repair and adjustment include: repairing or replacing the upper surface of the mounting surface (5) and the guide rail (9); the horizontal parallelism adjustment is achieved by fine adjustment of the adjusting block screw (14); In step 1, the number of segments n in "segmented measurement" satisfies: n = guide rail length × 24, and the spacing between equal measurement points (2) is ≤ 500mm. The number of equal measurement points (2) is n+1. The first and last measurement points can be arranged inward according to the size of the measuring tool to avoid the end of the guide rail and adapt to the width of the tool. All of these meet the requirements of GB / T11336-2004 pitch method. In step 2, the number of measuring points (8) for vertical straightness detection is greater than or equal to the length of the guide rail × 2, and the first and last measuring points (8) must be located at both ends of the guide rail and ≤ 50 mm from the end face to ensure full stroke error coverage.

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