Assembling method of split type combined overlock machine shell

Abstract

The invention discloses an assembly method of a split combined type overedger shell, which comprises a rear shell and a front shell, the rear shell and the front shell are respectively integrally cast and formed, the rear shell is provided with a rear assembly surface and a rear half hole, the front shell is provided with a front assembly surface and a front half hole, and the front assembly surface is provided with a rear half hole and a rear half hole. Positioning holes are formed in the rear assembling face of the rear shell and the front assembling face of the front shell, positioning pins are inserted into the positioning holes, when the rear assembling face and the front assembling face are completely attached, the rear half hole and the front half hole are spliced into a main shaft hole, and one end of each positioning pin is inserted into the corresponding positioning hole in the rear assembling face. The machine shell of the overlock machine is improved, a traditional integrated machine shell is decomposed into the assembled machine shell, the roundness of a spliced main shaft hole is detected in the assembling process, and the assembling yield can be increased; and it can be ensured that the assembled machine shell can effectively support the main shaft, friction can be reduced when the main shaft rotates, and the service life of equipment is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of overlock machine casing assembly, and in particular relates to an assembly method of a split combined overlock machine casing. Background Art

[0002] Overlock sewing machine (also called overlock machine or chain stitch sewing machine) is a special sewing equipment, mainly used for overlocking the edge of fabric to prevent the edge of fabric from unthreading or fraying. Overlock sewing machine is widely used in clothing manufacturing, home textile, shoes and hats and other industries, which can improve production efficiency and product quality.

[0003] The casing of the overlock sewing machine is the main supporting component and needs to provide stable support for the main shaft of the overlock sewing machine. Existing overlock sewing machine casings are all manufactured using an integrated casting process. However, due to the complex internal structure of the overlock sewing machine casing, multiple processing steps are often required after casting, and the construction is difficult.

[0004] Therefore need us to design a kind of assembling method of split combined type overlock sewing machine casing to solve these problems. Summary of the invention

[0005] The problem to be solved by the present invention is to provide an assembly method for a split combined overlock sewing machine casing.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A method for assembling a split-type combined overlock sewing machine casing, the split-type combined overlock sewing machine casing comprising a rear casing and a front casing, the rear casing and the front casing are respectively integrally cast, the rear casing is provided with a rear assembly surface and a rear half hole, the front casing is provided with a front assembly surface and a front half hole, both the rear assembly surface of the rear casing and the front assembly surface of the front casing are provided with positioning holes, positioning pins are inserted in the positioning holes, when the rear assembly surface and the front assembly surface are completely fitted, the rear half hole and the front half hole are combined into a main shaft hole, one end of the positioning pin is inserted into the positioning hole on the rear assembly surface, and the other end is inserted into the positioning hole on the front assembly surface;

[0008] The assembly of the split combined overlock sewing machine casing includes:

[0009] S1. Pre-process the rear housing, front housing and positioning pins before assembly;

[0010] S2. Place the pretreated rear assembly surface on the rear shell and the front assembly surface on the front shell opposite to each other, insert one end of the pretreated positioning pin into the positioning hole on the rear assembly surface, align the positioning hole on the front assembly surface with the other end of the positioning pin and insert it. The assembly process is completed within 30 seconds, ensuring that the assembled rear assembly surface is tightly fitted with the front assembly surface, and the front shell and the rear shell are kept until they cool to room temperature;

[0011] S3, obtaining the orthographic projection images of the front and rear semi-axes and the front semi-axes, obtaining the orthographic projection image of the main shaft hole after assembly, and preprocessing the obtained orthographic projection images of the main shaft hole, the rear semi-axes and the front semi-axes to obtain preprocessing results;

[0012] S4. According to the preprocessing results, the center coordinates and the opening end point coordinates of the front half hole, the center coordinates and the opening end point coordinates of the rear half hole, the center coordinates and the opening end point coordinates of the spindle hole, and the center coordinates of the assembly surface are obtained by using the Hough circle transformation method; the center coordinates and the opening end point coordinates include the center coordinates and the opening end point coordinates of the rear shell assembly surface and the center coordinates and the opening end point coordinates of the front shell assembly surface;

[0013] S5. According to the coordinates of the center of the front shell half hole and the coordinates of the opening end point, and the coordinates of the center of the rear shell half hole and the coordinates of the opening end point, an improved fitting algorithm is used in conjunction with overlapping scanning to obtain the shell assembly result.

[0014] Preferably, the pre-processing of the rear housing, the front housing and the positioning pins before assembly includes the following steps:

[0015] S1.1. Obtain the grayscale value of each pixel in the grayscale image of the orthographic projection of the spindle hole before assembly, obtain the grayscale value, and construct a first set;

[0016] S1.2, filter the data in the first set, delete the pixel points corresponding to the grayscale value greater than or equal to 255 from the first set, sort the remaining elements in the first set, and determine the boundary contour line of the spindle hole;

[0017] S1.3, obtaining a set of coordinate points of the boundary contour line of the spindle hole, and summing the grayscales of the pixels in the set of coordinate points to obtain a second set;

[0018] S1.4, comparing the number of pixels of each data in the first set with that in the second set, and removing the data whose number of pixels of each data in the set is different from that in the second set;

[0019] S1.5, setting the pixel points whose data number in the first set is the same as the pixel number in the second set as seed points;

[0020] S1.6. Set the coordinate point set of the spindle hole boundary contour line as the edge contour point set, perform sliding window traversal on the edge contour point set, and set the grayscale value of the pixel points whose number of pixels in the current area is greater than or equal to the average number of pixels in the area to 0 in the spindle hole orthographic projection grayscale image.

[0021] Preferably, the step of obtaining the spindle hole boundary contour line coordinate point set and summing the grayscale of pixels in the coordinate point set to obtain the spindle hole boundary contour line coordinate point set in the second set comprises the following steps:

[0022] S1.3.1. Obtain the inner edge line and outer boundary line of the spindle hole; the inner edge line of the spindle hole is the contour line where the pixel points with non-zero grayscale values ​​in the grayscale image of the orthographic projection of the spindle hole are located, and the outer boundary line is the contour line where the pixel points with zero grayscale values ​​in the grayscale image of the orthographic projection of the spindle hole are located;

[0023] S1.3.2. For the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole, the contour line gradient is obtained by using the neighborhood pixel averaging method;

[0024] S1.3.3. Compare the gradients of each pixel point on the spindle hole inner edge line coordinate point set and the outer boundary line coordinate point set, and delete the coordinates of points with different gradient values ​​from the spindle hole inner edge line coordinate point set and the outer boundary line coordinate point set;

[0025] S1.3.4. Repeat S1.3.2 and S1.3.3 for at least 1000 times to obtain the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole;

[0026] S1.3.5. Superimpose the inner edge line coordinate point set of the spindle hole and the outer boundary line coordinate point set to obtain the spindle hole boundary contour line coordinate point set.

[0027] Preferably, comparing the number of pixels of each data in the first set with that in the second set, and removing the data in which the number of pixels of each data in the set is different from that in the second set comprises the following steps:

[0028] S1.4.1. Obtain the coordinates of each pixel point in the edge contour point set, obtain the neighborhood window of each pixel point, and obtain the total number of all pixel points of each pixel point;

[0029] S1.4.2, obtaining pixel points where the total number of pixels of each pixel point in the edge contour point set is equal to 70% of the total number of pixels in the neighborhood window of each pixel point, and the total number of pixels in the neighborhood window of the pixel point in the edge contour point set is not equal;

[0030] S1.4.3. Remove the result obtained in step S1.4.2.

[0031] 5. The assembly method of a split combined overlock machine casing according to claim 3, characterized in that the step of setting the pixel points having the same number of data in the first set as the number of pixels in the second set as the seed points, and setting the pixel points having the same number of pixels as the number of pixels in the second set as the seed points comprises the following steps:

[0032] S1.5.1. Set the coordinate point set of the spindle hole boundary contour line as the edge contour point set, obtain the gradient value of each pixel point in the edge contour point set, and draw the corresponding edge contour point set grayscale image according to the gradient value of each pixel point;

[0033] S1.5.2, performing image equalization processing on the grayscale image of the edge contour point set;

[0034] S1.5.3. Obtain the gradient values ​​of all pixels in the grayscale image of the edge contour point set after equalization to form a third set, sort the third set in descending order, obtain the positions of the first 10% of the pixels in the third set in order, and obtain the coordinates of the pixel corresponding to the grayscale value of 255 in the pixel position;

[0035] S1.5.4. Set the pixel point in the window where the pixel point obtained in step S1.5.3 is located as the seed point.

[0036] Preferably, the method of setting the spindle hole boundary contour line coordinate point set as an edge contour point set, performing a sliding window traversal on the edge contour point set, and setting the grayscale value of the pixel points in the spindle hole orthographic projection grayscale image to 0, wherein the number of pixels in the current region is greater than or equal to the average number of pixels in the region, and setting the grayscale value of the spindle hole orthographic projection grayscale image to 0 comprises the following steps:

[0037] S1.6.1. Obtain the total number of pixels and grayscale value of the neighborhood window of each pixel in the spindle hole orthographic projection grayscale image;

[0038] S1.6.2. When the total number of pixels in the neighborhood window is less than the average number of pixels in the region, the coordinates of the pixels in the neighborhood window are traversed, a preset threshold is set, the mean of the neighborhood window of the pixels is traversed, and the pixels whose neighborhood window mean is less than the grayscale threshold are obtained, and the grayscale values ​​of the pixels whose grayscale values ​​are greater than the neighborhood window mean of the pixels are set to 0;

[0039] S1.6.3. When the total number of pixels in the neighborhood window is greater than or equal to the average number of pixels in the region, perform a sliding window traversal on the pixels in the neighborhood window;

[0040] S1.6.4. Get the mean of the pixel window. If the window mean is less than the grayscale threshold, the grayscale value of the pixel is set to 0, and the grayscale values ​​of all pixels in the current area are set to 0.

[0041] Preferably, when the total number of pixels in the neighborhood window is greater than or equal to the average number of pixels in the region, the sliding window traversal of the pixels in the neighborhood window includes the following steps: obtaining the number of pixels and the grayscale value of the pixels in the neighborhood window of the pixel points in the current region, obtaining the average number of pixels and the average number of pixels in the spindle hole, and subtracting the number of pixels in the neighborhood window of each pixel point, the maximum grayscale value of the pixels and the minimum grayscale value of the pixels from the average number of pixels and the average number of pixels in the spindle hole, respectively; if any difference is greater than or equal to 0, the grayscale value of the pixel is set to 0; if both differences are less than 0, the grayscale value of the pixel remains unchanged.

[0042] Preferably, the average number of pixels in the region is the average number of neighborhood pixels in each window.

[0043] Preferably, the Hough circle transformation method is used to obtain the center coordinates and opening endpoint coordinates of the front half hole, the center coordinates and opening endpoint coordinates of the rear half hole, the center coordinates of the spindle hole, and the center coordinates of the assembly surface according to the preprocessing results; the Hough circle transformation method includes: using the Hough circle transformation method on the second set and the third set respectively to obtain the center coordinates and opening endpoint coordinates of the front half hole, the center coordinates and opening endpoint coordinates of the rear half hole, the center coordinates of the spindle hole, and the center coordinates of the assembly surface.

[0044] 10. The assembly method of a split combined overlock sewing machine casing according to claim 1 is characterized in that the casing assembly result is obtained by using an improved fitting algorithm and overlapping scanning according to the center coordinates and opening end point coordinates of the front casing half hole and the center coordinates and opening end point coordinates of the rear casing half hole, including the following steps:

[0045] S5.1. Obtain the center coordinates of the spindle hole of the front shell assembly surface, and overlap the front shell assembly surface with the rear shell assembly surface according to the center coordinates and the opening end coordinates of the front shell assembly surface and the center coordinates of the spindle hole of the rear shell assembly surface;

[0046] S5.2. Obtain the coordinates of the center of the rear shell assembly surface: obtain the coordinates of the center of the front shell assembly surface and the rear shell assembly surface after overlapping and matching; obtain the coordinates of the center of the circle after overlapping and matching;

[0047] S5.3, obtain a circumscribed circle with a radius of , obtain the polar radius of the circumscribed circle, and obtain a polar coordinate point set according to the circumscribed circle radius and the polar radius;

[0048] S5.4. Obtain the coincidence of the opening endpoint of the front shell assembly surface and the opening endpoint of the rear shell assembly surface, and the coincident opening endpoints are the coincidence points; determine whether the length from the center of the front shell assembly surface and the first opening endpoint to the center of the circle is less than the length from the center of the rear shell assembly surface and the first opening endpoint to the center of the circle;

[0049] S5.5. When the opening endpoints of the front shell assembly surface and the opening endpoints of the rear shell assembly surface are both connected to the center of the circle, obtain the coordinates of the center of the circle, repeat S5.2-S5.4 operations 1000 times, and when the length from the center of the front shell assembly surface and the first opening endpoint to the center of the circle is always smaller than the length from the center of the rear shell assembly surface and the first opening endpoint to the center of the circle, determine that the coincidence point coincides with the rear shell assembly surface, and determine that no gap is generated.

[0050] The advantages and positive effects of the present invention are:

[0051] The present invention improves the casing of the overlock sewing machine, decomposes the traditional integrated casing into an assembled casing, and detects the roundness of the assembled spindle hole during the assembly process, thereby improving the assembly yield rate; it can also ensure that the assembled casing can provide effective support for the spindle and reduce friction when the spindle rotates, thereby extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0053] Figure 1 It is a schematic diagram of the exploded structure of the rear housing and the front housing of the present invention;

[0054] Figure 2 It is a schematic diagram of the rear housing structure of the present invention;

[0055] Figure 3 It is a schematic diagram of the front housing structure of the present invention;

[0056] Figure 4 It is a schematic diagram of the position of the axle hole after the rear housing and the front housing are assembled;

[0057] Figure 5 It is a process flow chart of assembling and testing the rear housing and the front housing of the present invention.

[0058] The following are the descriptions of the reference numerals:

[0059] 1. Rear housing; 2. Front housing; 3. Positioning pin; 4. Positioning hole; 5. Axis hole; 51. Rear half hole; 52. Front half hole; 6. Rear assembly surface; 7. Front assembly surface. DETAILED DESCRIPTION

[0060] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0061] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0062] The present invention will be further described below in conjunction with the accompanying drawings:

[0063] Example 1: Reference Figure 1-Figure 5 As shown, a method for assembling a split-type combined overlock machine casing, the split-type combined overlock machine casing comprises a rear casing 1 and a front casing 2, the rear casing 1 and the front casing 2 are respectively integrally cast, a rear assembly surface 6 and a rear half hole 51 are provided on the rear casing 1, a front assembly surface 7 and a front half hole 52 are provided on the front casing 2, positioning holes 4 are provided on the rear assembly surface 6 of the rear casing 1 and the front assembly surface 7 of the casing 2, positioning pins 3 are inserted in the positioning holes 4, when the rear assembly surface 6 and the front assembly surface 7 are completely fitted, the rear half hole 51 and the front half hole 52 are combined into a main shaft hole 5, one end of the positioning pin 3 is inserted into the positioning hole 4 on the rear assembly surface 6, and the other end is inserted into the positioning hole 4 on the front assembly surface 7;

[0064] The assembly of the split combined overlock sewing machine casing includes:

[0065] S1, pre-processing the rear housing 1, the front housing 2 and the positioning pin 3 before assembly;

[0066] S2, place the pre-treated rear assembly surface 6 on the rear shell 1 and the front assembly surface 7 on the front shell 2 opposite to each other, insert one end of the pre-treated positioning pin 3 into the positioning hole 4 on the rear assembly surface 6, align the positioning hole 4 on the front assembly surface 7 with the other end of the positioning pin 3 and insert, the assembly process is completed within 30 seconds, ensure that the assembled rear assembly surface 6 and the front assembly surface 7 are tightly fitted, and keep it until the front shell 2 and the rear shell 1 cool to room temperature;

[0067] S3, obtaining the orthographic projection images of the front and rear semi-axes and the front semi-axes, obtaining the orthographic projection image of the main shaft hole 5 after assembly, and pre-processing the obtained orthographic projection images of the main shaft hole 5, the rear semi-axes and the front semi-axes to obtain a pre-processing result;

[0068] S4. According to the preprocessing result, the center coordinates and the opening end point coordinates of the front half hole 52, the center coordinates and the opening end point coordinates of the rear half hole 51, the center coordinates and the opening end point coordinates of the spindle hole 5, and the center coordinates and the assembly surface center coordinates are obtained by using the Hough circle transformation method; the center coordinates and the opening end point coordinates include the center coordinates and the opening end point coordinates of the assembly surface of the rear shell 1 and the center coordinates and the opening end point coordinates of the assembly surface of the front shell 2;

[0069] S5. Obtain the shell assembly result by using an improved fitting algorithm and overlapping scanning according to the center coordinates and opening end point coordinates of the front shell half hole and the center coordinates and opening end point coordinates of the rear shell half hole 51.

[0070] Preferably, the pre-treatment of the rear housing 1, the front housing 2 and the positioning pin 3 before assembly includes the following steps:

[0071] S1.1, obtaining the gray value of each pixel in the grayscale image of the orthographic projection of the spindle hole 5 before assembly, obtaining the grayscale value, and constructing a first set;

[0072] S1.2, filter the data in the first set, delete the pixel points corresponding to the grayscale values ​​greater than or equal to 255 from the first set, sort the remaining elements in the first set, and determine the boundary contour line of the spindle hole 5;

[0073] S1.3, obtaining a set of coordinate points of the boundary contour line of the spindle hole 5, and performing grayscale summation on the pixels in the set of coordinate points to obtain a second set;

[0074] S1.4, comparing the number of pixels of each data in the first set with that in the second set, and removing the data whose number of pixels of each data in the set is different from that in the second set;

[0075] S1.5, setting the pixel points whose data number in the first set is the same as the pixel number in the second set as seed points;

[0076] S1.6. Set the coordinate point set of the boundary contour line of the spindle hole 5 as the edge contour point set, perform a sliding window traversal on the edge contour point set, and set the grayscale value of the pixel points whose number of pixels in the current area is greater than or equal to the average number of pixels in the area to 0 in the grayscale image of the orthographic projection of the spindle hole 5.

[0077] Preferably, obtaining the coordinate point set of the boundary contour line of the spindle hole 5, and summing the grayscale of the pixels in the coordinate point set to obtain the coordinate point set of the boundary contour line of the spindle hole 5 in the second set comprises the following steps:

[0078] S1.3.1. Obtain the inner edge line and outer boundary line of the spindle hole 5; the inner edge line of the spindle hole 5 is the contour line where the pixel points with non-zero grayscale values ​​in the grayscale image of the orthographic projection of the spindle hole 5 are located, and the outer boundary line is the contour line where the pixel points with zero grayscale values ​​in the grayscale image of the orthographic projection of the spindle hole 5 are located;

[0079] S1.3.2, for the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole 5, the contour line gradient is obtained by using the neighborhood pixel averaging method;

[0080] S1.3.3. Compare the gradients of each pixel point on the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole 5, and delete the coordinates of points with different gradient values ​​from the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole 5;

[0081] S1.3.4. Repeat S1.3.2 and S1.3.3 for at least 1000 times to obtain the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole 5;

[0082] S1.3.5. Superimpose the inner edge line coordinate point set of the spindle hole 5 and the outer boundary line coordinate point set to obtain the boundary contour line coordinate point set of the spindle hole 5.

[0083] Preferably, comparing the number of pixels of each data in the first set with that in the second set, and removing the data in which the number of pixels of each data in the set is different from that in the second set comprises the following steps:

[0084] S1.4.1. Obtain the coordinates of each pixel point in the edge contour point set, obtain the neighborhood window of each pixel point, and obtain the total number of all pixel points of each pixel point;

[0085] S1.4.2, obtaining pixel points where the total number of pixels of each pixel point in the edge contour point set is equal to 70% of the total number of pixels in the neighborhood window of each pixel point, and the total number of pixels in the neighborhood window of the pixel point in the edge contour point set is not equal;

[0086] S1.4.3. Remove the result obtained in step S1.4.2.

[0087] 5. A method for assembling a split combined overlock machine casing according to claim 3, characterized in that setting the pixel points having the same number of data in the first set as the number of pixels in the second set as the seed points, and setting the pixel points having the same number of pixels as the number of pixels in the second set as the seed points comprises the following steps:

[0088] S1.5.1. Set the coordinate point set of the boundary contour line of the spindle hole 5 as the edge contour point set, obtain the gradient value of each pixel point in the edge contour point set, and draw the corresponding grayscale image of the edge contour point set according to the gradient value of each pixel point;

[0089] S1.5.2, performing image equalization processing on the grayscale image of the edge contour point set;

[0090] S1.5.3. Obtain the gradient values ​​of all pixels in the grayscale image of the edge contour point set after equalization to form a third set, sort the third set in descending order, obtain the positions of the first 10% of the pixels in the third set in order, and obtain the coordinates of the pixel corresponding to the grayscale value of 255 in the pixel position;

[0091] S1.5.4. Set the pixel point in the window where the pixel point obtained in step S1.5.3 is located as the seed point.

[0092] Preferably, the coordinate point set of the boundary contour line of the spindle hole 5 is set as the edge contour point set, and the edge contour point set is traversed by sliding window, and the pixel points whose number of pixels in the current area is greater than or equal to the average number of pixels in the area are set to 0 in the grayscale value of the spindle hole 5 orthographic projection grayscale image, and the grayscale value of the spindle hole 5 in the orthographic projection grayscale image is set to 0 includes the following steps:

[0093] S1.6.1. Obtain the total number of pixels and grayscale value of the neighborhood window of each pixel in the grayscale image of the orthographic projection of the spindle hole 5;

[0094] S1.6.2. When the total number of pixels in the neighborhood window is less than the average number of pixels in the region, the coordinates of the pixels in the neighborhood window are traversed, a preset threshold is set, the mean of the neighborhood window of the pixels is traversed, and the pixels whose neighborhood window mean is less than the grayscale threshold are obtained, and the grayscale values ​​of the pixels whose grayscale values ​​are greater than the neighborhood window mean of the pixels are set to 0;

[0095] S1.6.3. When the total number of pixels in the neighborhood window is greater than or equal to the average number of pixels in the region, perform a sliding window traversal on the pixels in the neighborhood window;

[0096] S1.6.4. Get the mean of the pixel window. If the window mean is less than the grayscale threshold, the grayscale value of the pixel is set to 0, and the grayscale values ​​of all pixels in the current area are set to 0.

[0097] Preferably, when the total number of pixels in the neighborhood window is greater than or equal to the average number of pixels in the region, sliding window traversal of the pixels in the neighborhood window includes the following steps: obtaining the number of pixels and the grayscale value of the pixels in the neighborhood window of the pixel points in the current region, obtaining the average number of pixels and the average number of pixels in the spindle hole 5, and subtracting the number of pixels in the neighborhood window of each pixel point, the maximum grayscale value of the pixels and the average number of pixels in the spindle hole 5, respectively; if any difference is greater than or equal to 0, the grayscale value of the pixel is set to 0; if both differences are less than 0, the grayscale value of the pixel remains unchanged.

[0098] Preferably, the average number of pixels in the region is the average number of neighborhood pixels in each window.

[0099] Preferably, the Hough circle transform method is used to obtain the center coordinates and opening endpoint coordinates of the front half hole 52, the center coordinates and opening endpoint coordinates of the rear half hole 51, the center coordinates of the spindle hole 5, and the center coordinates of the assembly surface according to the preprocessing results; the Hough circle transform method includes: using the Hough circle transform method on the second set and the third set respectively to obtain the center coordinates and opening endpoint coordinates of the front half hole 52, the center coordinates and opening endpoint coordinates of the rear half hole 51, the center coordinates of the spindle hole 5, and the center coordinates of the assembly surface.

[0100] 10. According to claim 1, a method for assembling a split-type combined overlock machine casing is characterized in that the casing assembly result is obtained by using an improved fitting algorithm and overlapping scanning according to the center coordinates and opening end point coordinates of the front casing half hole and the center coordinates and opening end point coordinates of the rear casing half hole 51, including the following steps:

[0101] S5.1. Obtain the center coordinates of the spindle hole 5 of the assembly surface of the front housing 2, and overlap the assembly surface of the front housing 2 with the assembly surface of the rear housing 1 according to the center coordinates and the opening end coordinates of the assembly surface of the front housing 2 and the center coordinates of the spindle hole 5 of the assembly surface of the rear housing 1;

[0102] S5.2, obtaining the coordinates of the center of the assembly surface of the rear housing 1, obtaining the coordinates of the center of the assembly surface of the front housing 2 and the assembly surface of the rear housing 1 after overlapping and matching ...;

[0103] S5.3, obtain a circumscribed circle with a radius of , obtain the polar radius of the circumscribed circle, and obtain a polar coordinate point set according to the circumscribed circle radius and the polar radius;

[0104] S5.4. Obtain the coincidence of the opening endpoint of the assembly surface of the front shell 2 and the opening endpoint of the assembly surface of the rear shell 1, and the coincident opening endpoints are the coincidence points; determine whether the length from the center of the assembly surface of the front shell 2 and the first opening endpoint to the center of the circle is less than the length from the center of the assembly surface of the rear shell 1 and the first opening endpoint to the center of the circle;

[0105] S5.5. When the opening end points of the assembly surface of the front shell 2 and the assembly surface of the rear shell 1 are both connected to the center of the circle, obtain the coordinates of the center of the circle, repeat S5.2-S5.4 operations 1000 times, and when the length from the center of the assembly surface of the front shell 2 and the first opening end point to the center of the circle is always smaller than the length from the center of the assembly surface of the rear shell 1 and the first opening end point to the center of the circle, determine that the coincidence point coincides with the assembly surface of the rear shell 1, and determine that no gap is generated.

[0106] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for assembling a split combined overlock sewing machine casing, characterized in that: The split combined overlock sewing machine casing comprises a rear shell and a front shell, the rear shell and the front shell are respectively integrally cast, a rear assembly surface and a rear half hole are arranged on the rear shell, a front assembly surface and a front half hole are arranged on the front shell, positioning holes are arranged on the rear assembly surface of the rear shell and the front assembly surface of the shell, positioning pins are inserted in the positioning holes, when the rear assembly surface and the front assembly surface are completely fitted, the rear half hole and the front half hole are combined into a main shaft hole, one end of the positioning pin is inserted into the positioning hole on the rear assembly surface, and the other end is inserted into the positioning hole on the front assembly surface; The assembly of the split combined overlock sewing machine casing includes: S1. Pre-process the rear housing, front housing and positioning pins before assembly; S2. Place the pretreated rear assembly surface on the rear shell and the front assembly surface on the front shell opposite to each other, insert one end of the pretreated positioning pin into the positioning hole on the rear assembly surface, align the positioning hole on the front assembly surface with the other end of the positioning pin and insert it. The assembly process is completed within 30 seconds, ensuring that the assembled rear assembly surface is tightly fitted with the front assembly surface, and the front shell and the rear shell are kept until they cool to room temperature; S3, obtaining the orthographic projection images of the front and rear semi-axes and the front semi-axes, obtaining the orthographic projection image of the main shaft hole after assembly, and preprocessing the obtained orthographic projection images of the main shaft hole, the rear semi-axes and the front semi-axes to obtain preprocessing results; S4. According to the preprocessing results, the center coordinates and the opening end point coordinates of the front half hole, the center coordinates and the opening end point coordinates of the rear half hole, the center coordinates and the opening end point coordinates of the spindle hole, and the center coordinates of the assembly surface are obtained by using the Hough circle transformation method; the center coordinates and the opening end point coordinates include the center coordinates and the opening end point coordinates of the rear shell assembly surface and the center coordinates and the opening end point coordinates of the front shell assembly surface; S5. According to the coordinates of the center of the front shell half hole and the coordinates of the opening end point, and the coordinates of the center of the rear shell half hole and the coordinates of the opening end point, an improved fitting algorithm is used in conjunction with overlapping scanning to obtain the shell assembly result.

2. The method for assembling a split combined overlock sewing machine casing according to claim 1, characterized in that: The pre-treatment of the rear housing, the front housing and the positioning pins before assembly includes the following steps: S1.

1. Obtain the grayscale value of each pixel in the grayscale image of the orthographic projection of the spindle hole before assembly, obtain the grayscale value, and construct a first set; S1.2, filter the data in the first set, delete the pixel points corresponding to the grayscale value greater than or equal to 255 from the first set, sort the remaining elements in the first set, and determine the boundary contour line of the spindle hole; S1.3, obtaining a set of coordinate points of the boundary contour line of the spindle hole, and summing the grayscales of the pixels in the set of coordinate points to obtain a second set; S1.4, comparing the number of pixels of each data in the first set with that in the second set, and removing the data whose number of pixels of each data in the set is different from that in the second set; S1.5, setting the pixel points whose data number in the first set is the same as the pixel number in the second set as seed points; S1.

6. Set the coordinate point set of the spindle hole boundary contour line as the edge contour point set, perform sliding window traversal on the edge contour point set, and set the grayscale value of the pixel points whose number of pixels in the current area is greater than or equal to the average number of pixels in the area to 0 in the spindle hole orthographic projection grayscale image.

3. The method for assembling a split combined overlock sewing machine casing according to claim 2, characterized in that: The step of obtaining the spindle hole boundary contour line coordinate point set and summing the grayscale of pixels in the coordinate point set to obtain the spindle hole boundary contour line coordinate point set in the second set comprises the following steps: S1.3.

1. Obtain the inner edge line and outer boundary line of the spindle hole; the inner edge line of the spindle hole is the contour line where the pixel points with non-zero grayscale values ​​in the grayscale image of the orthographic projection of the spindle hole are located, and the outer boundary line is the contour line where the pixel points with zero grayscale values ​​in the grayscale image of the orthographic projection of the spindle hole are located; S1.3.

2. For the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole, the contour line gradient is obtained by using the neighborhood pixel averaging method; S1.3.

3. Compare the gradients of each pixel point on the spindle hole inner edge line coordinate point set and the outer boundary line coordinate point set, and delete the coordinates of points with different gradient values ​​from the spindle hole inner edge line coordinate point set and the outer boundary line coordinate point set; S1.3.

4. Repeat S1.3.2 and S1.3.3 for at least 1000 times to obtain the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole; S1.3.

5. Superimpose the inner edge line coordinate point set of the spindle hole and the outer boundary line coordinate point set to obtain the spindle hole boundary contour line coordinate point set.

4. The method for assembling a split combined overlock sewing machine casing according to claim 3, characterized in that: The step of comparing the number of pixels of each data in the first set with the number of pixels in the second set and removing the data in which the number of pixels of each data in the set is different from that in the second set comprises the following steps: S1.4.

1. Obtain the coordinates of each pixel point in the edge contour point set, obtain the neighborhood window of each pixel point, and obtain the total number of all pixel points of each pixel point; S1.4.2, obtaining pixel points where the total number of pixels of each pixel point in the edge contour point set is equal to 70% of the total number of pixels in the neighborhood window of each pixel point, and the total number of pixels in the neighborhood window of the pixel point in the edge contour point set is not equal; S1.4.

3. Remove the result obtained in step S1.4.

2.

5. The method for assembling a split combined overlock sewing machine casing according to claim 3, characterized in that: The step of setting the pixel points having the same number of data in the first set as the number of pixels in the second set as the seed points, and setting the pixel points having the same number of pixels as the number of pixels in the second set as the seed points comprises the following steps: S1.5.

1. Set the coordinate point set of the spindle hole boundary contour line as the edge contour point set, obtain the gradient value of each pixel point in the edge contour point set, and draw the corresponding edge contour point set grayscale image according to the gradient value of each pixel point; S1.5.2, performing image equalization processing on the grayscale image of the edge contour point set; S1.5.

3. Obtain the gradient values ​​of all pixels in the grayscale image of the edge contour point set after equalization to form a third set, sort the third set in descending order, obtain the positions of the first 10% of the pixels in the third set in order, and obtain the coordinates of the pixel corresponding to the grayscale value of 255 in the pixel position; S1.5.

4. Set the pixel point in the window where the pixel point obtained in step S1.5.3 is located as the seed point.

6. The method for assembling a split combined overlock sewing machine casing according to claim 3, characterized in that: The method of setting the spindle hole boundary contour line coordinate point set as the edge contour point set, performing sliding window traversal on the edge contour point set, and setting the grayscale value of the pixel points whose number of pixels in the current region is greater than or equal to the average number of pixels in the region to 0 in the spindle hole orthographic projection grayscale image, and setting the grayscale value of the spindle hole orthographic projection grayscale image to 0 includes the following steps: S1.6.

1. Obtain the total number of pixels and grayscale value of the neighborhood window of each pixel in the spindle hole orthographic projection grayscale image; S1.6.

2. When the total number of pixels in the neighborhood window is less than the average number of pixels in the region, the coordinates of the pixels in the neighborhood window are traversed, a preset threshold is set, the mean of the neighborhood window of the pixels is traversed, and the pixels whose neighborhood window mean is less than the grayscale threshold are obtained, and the grayscale values ​​of the pixels whose grayscale values ​​are greater than the neighborhood window mean of the pixels are set to 0; S1.6.

3. When the total number of pixels in the neighborhood window is greater than or equal to the average number of pixels in the region, perform a sliding window traversal on the pixels in the neighborhood window; S1.6.

4. Get the mean of the pixel window. If the window mean is less than the grayscale threshold, the grayscale value of the pixel is set to 0, and the grayscale values ​​of all pixels in the current area are set to 0.

7. The method for assembling a split combined overlock sewing machine casing according to claim 6, characterized in that: When the total number of pixels in the neighborhood window is greater than or equal to the average number of pixels in the region, sliding window traversal of the pixels in the neighborhood window includes the following steps: obtaining the number of pixels and the grayscale value of the pixels in the neighborhood window of the pixel points in the current region, obtaining the average number of pixels and the average number of pixels in the spindle holes, and subtracting the number of pixels in the neighborhood window of each pixel point, the maximum grayscale value of the pixels and the minimum grayscale value of the pixels from the average number of pixels and the average number of pixels in the spindle holes respectively; if any difference is greater than or equal to 0, the grayscale value of the pixel point is set to 0; if both differences are less than 0, the grayscale value of the pixel point remains unchanged.

8. The method for assembling a split combined overlock sewing machine casing according to claim 6, characterized in that: The average number of pixels in the region is the average number of neighborhood pixels in each window.

9. The method for assembling a split combined overlock sewing machine casing according to claim 1, characterized in that: According to the preprocessing results, the center coordinates and opening endpoint coordinates of the front half hole, the center coordinates and opening endpoint coordinates of the back half hole, the center coordinates of the spindle hole, and the center coordinates of the assembly surface are obtained by using the Hough circle transformation method; the Hough circle transformation method includes: using the Hough circle transformation method on the second set and the third set respectively to obtain the center coordinates and opening endpoint coordinates of the front half hole, the center coordinates and opening endpoint coordinates of the back half hole, the center coordinates of the spindle hole, and the center coordinates of the assembly surface.

10. The method for assembling a split combined overlock sewing machine casing according to claim 1, characterized in that: The shell assembly result is obtained by using the improved fitting algorithm and overlapping scanning according to the center coordinates and opening end point coordinates of the front shell half hole and the center coordinates and opening end point coordinates of the rear shell half hole, including the following steps: S5.

1. Obtain the center coordinates of the spindle hole of the front shell assembly surface, and overlap the front shell assembly surface with the rear shell assembly surface according to the center coordinates and the opening end coordinates of the front shell assembly surface and the center coordinates of the spindle hole of the rear shell assembly surface; S5.

2. Obtain the coordinates of the center of the rear shell assembly surface: obtain the coordinates of the center of the front shell assembly surface and the rear shell assembly surface after overlapping and matching; obtain the coordinates of the center of the circle after overlapping and matching; S5.3, obtain a circumscribed circle with a radius of , obtain the polar radius of the circumscribed circle, and obtain a polar coordinate point set according to the circumscribed circle radius and the polar radius; S5.

4. Obtain the coincidence of the opening endpoint of the front shell assembly surface and the opening endpoint of the rear shell assembly surface, and the coincident opening endpoints are the coincidence points; determine whether the length from the center of the front shell assembly surface and the first opening endpoint to the center of the circle is less than the length from the center of the rear shell assembly surface and the first opening endpoint to the center of the circle; S5.

5. When the opening endpoints of the front shell assembly surface and the opening endpoints of the rear shell assembly surface are both connected to the center of the circle, obtain the coordinates of the center of the circle, repeat S5.2-S5.4 operations 1000 times, and when the length from the center of the front shell assembly surface and the first opening endpoint to the center of the circle is always smaller than the length from the center of the rear shell assembly surface and the first opening endpoint to the center of the circle, determine that the coincidence point coincides with the rear shell assembly surface, and determine that no gap is generated.

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