Segmented slide rail flatness assembly and detection process method

Abstract

The application provides a segmented slide rail flatness assembling and detecting process method, processes a box base, guarantees that the flatness of the bottom surface of the base meets the requirements, places the box base and the box in rigid connection on an assembling platform after the box base and the box are in rigid connection, guarantees that the flatness of the assembling platform meets the requirements, sets at least 5 groups of sampling points on the center line positions of the left and right sides of the inner wall of the box from the front end to the back, collects data, obtains a theoretical center surface after data fitting, takes at least 8 points on the two sides of the sliding surface of the front and back slide rails for sampling, calculates the distance difference of each point from the theoretical center surface, takes the maximum distance difference as the symmetry of the slide rail, arranges a laser tracker in a cross type at 4 stations at both ends of the box in sequence, measures in sequence by using the 4 stations, fits data of the measurement results, and the maximum height difference of each point on the slide rail is the flatness of the slide rail. The application reduces the operation difficulty of the slide rail assembling, shortens the reference locking time, and can obtain high-precision point three-dimensional data.

Description

Technical Field

[0001] This invention belongs to the field of assembly and inspection, and relates to a flatness assembly and inspection process. Background Technology

[0002] The segmented slide rail consists of two parts: a front slide rail and a rear slide rail. The length of a single slide rail exceeds 4m, and during assembly, it is placed within a 1.2×1.2m square cross-section space, which restricts the use of tooling and equipment. Because the length of the box body is greater than 9m, the square box body has a slight curvature after welding. In addition, the deflection caused by its own weight has an effect, and the flatness of the bottom surface of the box body is about 4mm, which cannot be used as the assembly datum for the slide rail. Moreover, the flatness accuracy of the slide rail is 0.04mm. The extremely high measurement accuracy and the structure of the object being measured pose new challenges to the flatness measurement of the slide rail inside the box body.

[0003] To address the issue of slight taper in the housing, current assembly methods compensate for this by machining the entire housing surface after welding. However, the machining allowance for the bottom skin of the housing is insufficient; direct machining would compromise the structural strength. Machining the base after assembly results in excessive machining allowance, causing deformation that affects axial positioning dimensions. Existing segmented slide rail assembly uses scribing for positioning, with the two ends of the housing and the inner wall as references. Due to the excessive length of the housing, the used positioning references are coarse and cannot guarantee the symmetry of the entire slide rail length. While coordinate measuring machines (CMMs) can achieve high accuracy and a relatively large measurement range for slide rail flatness measurement, this method is only suitable for movable workpieces and is clearly impractical for large housings.

[0004] Currently, the flatness of workpieces inside the box is measured using an electronic level and a slider. This method achieves a flatness accuracy of only 0.2mm, with unclear measurement uncertainty and is time-consuming and labor-intensive, failing to meet the accuracy requirements for slide rail flatness measurement. Flatness measurement using a laser tracker can be divided into single-station and multi-station methods. Single-station measurement is relatively simple, but its accuracy depends entirely on the instrument's precision. Commonly used laser trackers have a ranging error of up to 15μm / m, with significant errors occurring at lengths of up to 9m. Multi-station measurement includes two-station and four-station or higher methods. Two-station measurement requires one station to be located on the measured plane, but this condition cannot be met for slide rails that are too small. A four-station arrangement is the most efficient for multi-station measurement. Currently, for large parts, a four-station arrangement requires all four points to be on the same spherical surface; this method is not suitable for flatness measurement of large-size strip slide rails.

[0005] Therefore, for measuring the flatness of slide rails inside large boxes, it is necessary to determine new assembly datums and flatness assembly and inspection processes. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a process for assembling and inspecting the flatness of segmented slide rails. This involves determining the assembly reference plane of the segmented slide rail, adjusting the external dimensions of the base and housing, and compensating for the housing's tilt and deflection. Data fitting is performed on the inner wall of the housing to obtain a precise positioning reference, ensuring the accuracy of the assembly reference and thus guaranteeing the symmetry of the two sides of the slide rail relative to the center of the housing. Four-station measurements are performed using a laser tracker, and data fitting is performed on the slide rail surface using a shuttle-shaped sampling method to obtain high-precision slide rail flatness.

[0007] The technical solution adopted by this invention to solve its technical problem includes the following steps:

[0008] Step 1: Process the two bases of the box body to ensure that the flatness of the bottom surface of the base meets the requirements;

[0009] Step 2: Rigidly connect the two bases of the box to the box and then place the whole box on the assembly platform, ensuring that the flatness of the assembly platform meets the requirements.

[0010] Step 3: Set at least 5 sampling points on the left and right sides of the inner wall of the box from the front to the back to collect data. After data fitting, obtain the theoretical center plane.

[0011] Step 4: Take at least 8 samples on both sides of the sliding surface of the front and rear slide rails, calculate the distance difference between each point and the theoretical center plane, and take the maximum distance difference as the symmetry of the slide rail.

[0012] Step 5: Arrange the laser tracker at four stations in a cross pattern at both ends of the box. After taking measurements at the four stations, fit the measurement results to obtain the maximum height difference between each point on the slide rail, which is the flatness of the slide rail.

[0013] Step one ensures that the height of the base is less than or equal to the minimum required height for the slide rail assembly.

[0014] In step one, the two bases are kept at the same height and the flatness of the bases is ≤0.25mm.

[0015] In step two, the flatness of the assembly platform is ≤0.228mm.

[0016] In step three, the laser tracker host is placed at the center of the rear end face of the box. At least five sets of sampling points are set on the center lines of the left and right sides of the inner wall of the box from front to back. The sampling points are located at the center of each solid part of the box, and the distance between adjacent sampling points is 1.2 to 1.6m.

[0017] In step four, an L-shaped slider is embedded in the groove of the slide rail, and the target reflector SMR is placed on the side of the slider to collect data at the corresponding point.

[0018] In step five, the laser trackers are positioned at opposite ends of the housing, with the Z-axis height higher than the rear slide rail height.

[0019] In step five, the laser trackers are arranged sequentially at both ends of the housing. Station 1 is located near the rear end of the rear slide rail, with a height equal to the sum of the rear slide rail height H and the side height H1 / 3 of the slide groove. Station 2 is located on the extension line connecting the front end of the front slide rail and the center point of the rear slide rail, and is arranged on the left and right sides respectively. Stations 3 and 4 are located near the front slide rail end and are arranged symmetrically with stations 1 and 2. During measurement, station 1 is used as the initial point, and samples are taken from the bottom surface of the sliding surfaces of the front and rear slide rails respectively.

[0020] The beneficial effects of this invention are as follows: By adopting the above-mentioned segmented slide rail flatness assembly and inspection process, the operational difficulty of slide rail assembly is reduced. A high-precision slide rail assembly benchmark can be determined in one go using a laser tracker, shortening the benchmark locking time. Using a laser tracker to measure flatness according to a four-station cross-layout method, high-precision three-dimensional point data can be obtained. Based on the data fitted by the measurement points, the slide rail can be finely adjusted point-to-point, with clear target guidance, improving production efficiency by up to 30%. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the assembly positions of the front and rear slide rails;

[0022] Figure 2 This is a schematic diagram illustrating the principle of symmetry measurement.

[0023] Figure 3 This is a schematic diagram of a 4-station measurement layout for a laser tracker;

[0024] Figure 4 This is a schematic diagram of the rear slide rail flatness measurement;

[0025] In the diagram, 1-box body, 2-rear slide rail, 3-rear slide rail support, 4-front slide rail, 5-slider, 6-target reflector, 7-laser tracker host, 8-base, 9-solid component. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention includes, but is not limited to, the following embodiments.

[0027] Assembling and inspecting the flatness of guide rails in narrow, confined spaces limits the use of large tooling. Due to the precision requirements for the flatness and symmetry of the guide rails, coordinate measuring machines (CMMs) face numerous limitations related to workpiece structure and measurement space. Digital levels with sliders offer only 0.2mm of accuracy, resulting in low measurement efficiency. Measuring a 9m long box requires extremely high distance and angle measurement accuracy from a single laser tracker, increasing equipment costs. Two-station setups require two sets of equipment, one of which must be in direct contact with the measurement plane, making them unsuitable for slender parts. Multi-station setups are only suitable for large, circular parts with spherical multi-point arrangements, making it difficult to guarantee accuracy for slender guide rails in narrow spaces. Increasing the number of stations significantly extends the assembly and debugging time. All of these methods fail to achieve accurate guide rail symmetry and flatness while maintaining production efficiency.

[0028] Therefore, the present invention provides a process for assembling and inspecting the flatness of a segmented slide rail, wherein the slide rail assembly and flatness inspection steps include:

[0029] Step 1: Process the two bases of the box body so that the height of the base is less than or equal to the minimum value required for the assembly of the slide rail, while ensuring that the flatness of the bottom surface of the base meets the requirements.

[0030] Step 2: Rigidly connect the two bases of the box to the box body, and then place the whole box on the assembly platform, ensuring that the flatness of the assembly platform meets the requirements.

[0031] Step 3: Starting from the front end and moving backward, set at least 5 sets of sampling points on the left and right sides of the inner wall of the box (especially near the welded parts) to collect data. After IFM processing and data fitting, obtain the theoretical center plane.

[0032] Step 4: Take at least 8 samples on both sides of the sliding surface of the front and rear slide rails, calculate the distance difference between each point and the center plane, and take the maximum distance difference as the symmetry of the slide rail. When the symmetry of the slide rail relative to the center of the box meets the requirements, the assembly accuracy is qualified.

[0033] Step 5: Arrange the laser tracker at both ends of the housing in a crisscross pattern with four stations. The height of station 1 near the rear slide rail is equal to the sum of the rear slide rail height H and the side height H of the slide groove. Station 2 is located on the extension line between one end of the front slide rail and the center of the rear slide rail, arranged on the left and right sides respectively. Stations 3 and 4 near the front slide rail are arranged symmetrically with stations 1 and 2. During measurement, station 1 is used as the initial point. Samples are taken from the bottom surface of the sliding surfaces of both the front and rear slide rails. Since the rear slide rail consists of two sliding surfaces (left and right), the distance between each measurement point should not exceed 300mm, and the distance between each point on the front slide rail should not exceed 800mm. After four measurements are performed using the four stations, the measurement results are fitted. The maximum height difference between points on the slide rail is the slide rail flatness. If the flatness of both the front and rear slide rails meets the requirements, the slide rail assembly is complete.

[0034] In the above-mentioned assembly and inspection process of segmented slide rail flatness, in step one, the height of the two bases must be consistent, the depth of the groove from the bottom surface is 52mm, and the flatness of the base is ≤0.25mm;

[0035] In the above-mentioned process for assembling and inspecting the flatness of a segmented slide rail, in step two, the flatness of the assembly platform is ≤0.228mm;

[0036] In the above-mentioned process for assembling and inspecting the flatness of a segmented slide rail, in step three, the laser tracker host is placed at the center of the rear end of the box, and at least 5 sets of sampling points are set on the center lines of the left and right sides of the inner wall of the box from the front to the rear of the target reflector (SMR). The sampling points are located at the center of each solid part of the box, with a spacing of 1.2 to 1.6m.

[0037] In the above-mentioned process for assembling and inspecting the flatness of a segmented slide rail, in step four, since the width of the groove on the side of the sliding surface is small, the SMR cannot directly collect the points. Therefore, it is necessary to perform point coordinate transformation, embed an L-shaped slider on the groove, place the SMR on the side of the slider to collect data at the corresponding points, and measure the maximum difference relative to the theoretical center plane, which is the symmetry of the slide rail side. The symmetry does not exceed 0.4mm.

[0038] In the above-mentioned segmented slide rail flatness assembly and inspection process, in step five, the laser tracker is cross-stationed at both ends of the housing, with the Z-axis height higher than the rear slide rail height. The flatness requirement for the front and rear slide rails is 0.04mm. The front slide rail is a single slide rail with a pitch not exceeding 800mm, and the rear slide rail is a double slide rail with an appropriately shortened pitch. When taking points on the rear slide rail, points are taken alternately from the front end to the back end, with the distance between the points at both ends widened and the points in the middle section concentrated.

[0039] An embodiment of the present invention unifies the assembly datum to the surface of the assembly platform, enabling the slide rail assembly work to be completed in one alignment. A stable planar datum is obtained by repairing the bottom base. A theoretical datum plane is established by taking the center of the inner contour of the box using a laser tracker. The symmetry of the slide rail is obtained by controlling the distance from the side of the slide rail to the datum plane. One laser tracker station is used as the initial station, and four stations are arranged in a cross pattern at both ends of the box. The front and rear slide rails are measured four times using the shuttle method. The measured data are fitted to the plane, and the flatness is controlled by fine-tuning the slide rail plane point by point.

[0040] Figure 1 This is a schematic diagram of the slide rail installation. The internal cavity of the housing is 9000×1200×1200mm. As shown in the diagram, the assembly and inspection steps for the flatness of the segmented slide rail include:

[0041] Step (1) Process the two bases 8 of the box body 1 so that the height of the base is less than or equal to the minimum value required for the slide rail height assembly (the bottom surface of the base is the reference for the assembly of the front and rear slide rails. Due to the limitation of the total height of the box body and the vehicle after assembly, the height difference between the slide rail surface and the bottom surface of the base needs to be kept in a certain range. Therefore, the height of the base itself must be less than or equal to the minimum value required for the slide rail height assembly). At the same time, ensure that the flatness of the bottom surface of the base meets the requirements, the height of the two bases must be consistent, the depth of the groove from the bottom surface is 52mm, and the flatness of the base is ≤0.25mm.

[0042] Step (II) Rigidly connect the two bases 8 of the box 1 to the box 1 and then place the whole box on the assembly platform, ensuring that the flatness of the assembly platform meets the requirements, and the flatness of the assembly platform is ≤0.228mm;

[0043] Step (3) Place the laser tracker host 7 at the center of the rear end of the box, 1m away from the end face of the box. Set 5 sets of sampling points on the center line of the left and right sides of the inner wall of the box 1 from the front to the back of the target reflector 6. The sampling points are located at the center of each solid part 9 of the box, and the distance between adjacent sampling points is 1.2 to 1.6m to obtain the theoretical center plane.

[0044] Step (IV) Since the width of the groove on the side of the sliding surface is small, the SMR cannot directly collect the points. Therefore, it is necessary to perform point coordinate transformation. An L-shaped slider is embedded in the groove, and the target reflector 6 is placed on the side of the slider to collect data at the corresponding points. The target reflector 6 is rigidly connected to the slider 5. The slider 5 is L-shaped, and the flatness of the contact surface with the side of the rear slide rail 2 and the target reflector is ≤0.2mm, and the surface roughness is 0.3μm. The slider is sampled at 500mm intervals from the rear end to the front, for a total of 5 points. The distance difference from each point to the center surface is calculated as a1, a2, a3, a4, a5. Points are taken at the corresponding positions on the other side of the slide rail to measure the point values ​​b1, b2, b3, b4, b5. The ai-bi is calculated, and the maximum distance difference is taken as the symmetry of the slide rail. The front slide rail 4 can be tested in the same way as above. When the symmetry of the slide rail relative to the center of the box meets the requirements, the assembly accuracy is qualified.

[0045] Step (5) Position the laser tracker on the near-rear slide rail 1, at a height of 370mm and in the center of the left rear slide rail in the width direction. Take points on the target reflector 6 sequentially from the rear to the front on one side of slide rail 2, as follows: Figure 4 As shown, the distance from the rear end a ≥ 200mm, the spacing between points at both ends is widened, and the point distances g and f are 400-500mm. Points in the middle section are concentrated, with a point distance of 300-350mm. The height differences H1, H2, ... Hn at each point are recorded. The station is moved to position 2 (e.g., ...). Figure 3As shown), the height is 391mm, and the width is located at the center of the right rear slide rail. Take points and record them in sequence; repeat the above point taking and recording at positions 3 and 4. Fit the slide rail of the component to the plane. At this time, Hmax-Hmin is the flatness of the slide rail. Perform point-to-point assembly adjustment according to the distance difference between the theoretical reference plane and each point. The flatness requirement of the front and rear slide rails is 0.04mm. Slide rail 4 is a single slide rail with a pitch of 800mm. Refer to the above detection method.

Claims

1. A segmented slide rail flatness assembly and inspection process method, characterized in that, It comprises the following steps: Step one, process the two bases of the box, ensure that the flatness of the base bottom surface meets the requirements; Step two, rigidly connect the two bases of the box with the box, and then place the whole on the assembly platform, ensure that the flatness of the assembly platform meets the requirements; Step three, set at least 5 groups of sampling points on the centerline positions of the left and right sides of the inner wall of the box from the front end to the back, collect data, and obtain the theoretical center surface after data fitting; In step three, place the laser tracker host at the center position of the rear end surface of the box, and set at least 5 groups of sampling points on the centerline positions of the left and right sides of the inner wall of the box from the front to the back, the sampling points are located at the center positions of each solid piece of the box, and the distance between adjacent sampling points is 1.2-1.6m; Step four, take at least 8 points on both sides of the sliding surface of the front and rear slides for sampling, calculate the distance difference of each point from the theoretical center surface, and take the maximum distance difference as the symmetry of the slide; Step five, arrange the laser tracker in a cross arrangement of 4 stations at both ends of the box, measure in turn with the 4 stations, and then fit the measurement results to obtain the maximum height difference of each point on the slide, which is the flatness of the slide; In step five, the laser tracker is arranged in a cross arrangement of 4 stations at both ends of the box, and the Z-direction height is higher than the height of the rear slide; In step five, the laser tracker is arranged in turn at both ends of the box, wherein station 1 is close to the rear end of the rear slide, the height is equal to the sum of the height H of the rear slide and the height H1 / 3 of the side surface of the chute, station 2 is located on the extension line of the connecting line between the front end surface of the front slide and the center point of the rear slide, and is arranged on the left and right sides respectively; station 3 and station 4 are close to the front end of the front slide, and are symmetrically arranged with station 1 and station 2; during measurement, station 1 is taken as the initial point, and sampling is performed on the bottom surfaces of the front and rear slide sliding surfaces.

2. The segmented slide rail flatness assembly and inspection process method of claim 1, wherein, In step one, the height of the base is less than or equal to the minimum value of the assembly requirement of the slide height.

3. The segmented slide rail flatness assembly and inspection process method of claim 1, wherein, In step one, the heights of the two bases are consistent, and the flatness of the base is ≤0.25mm.

4. The segmented slide rail flatness assembly and inspection process method of claim 1, wherein, In step two, the flatness of the assembly platform is ≤0.228mm.

5. The segmented slide rail flatness assembly and inspection process of claim 1, wherein, In step four, embed an L-shaped sliding block on the chute of the slide, and place the target mirror SMR on the side surface of the sliding block to collect data at the corresponding point.

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