An assembling method of a split combined overlock machine housing

Abstract

The application discloses a kind of assembly methods of split combined overedger cabinet, including split combined overedger cabinet including rear shell and front shell, rear shell and front shell are integrally cast into shape respectively, rear shell is provided with rear assembly surface and rear half hole, front shell is provided with front assembly surface and front half hole, positioning hole is formed on the rear assembly surface of rear shell and the front assembly surface of front shell, positioning pin is inserted in the positioning hole, when rear assembly surface and front assembly surface are completely adhered, rear half hole and front half hole are spliced into main shaft hole, one end of positioning pin is inserted into the positioning hole on rear assembly surface.The overedger cabinet is improved, the traditional integrated cabinet is divided into assembled cabinet, and the roundness of the spliced main shaft hole is detected during assembly, which can improve the assembly yield;It can also ensure that the assembled cabinet can provide effective support for the main shaft, reduce friction when the main shaft rotates, and prolong the service life of the equipment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of overlock machine shell assembly, in particular to an assembly method of a split combined overlock machine shell. BACKGROUND

[0002] An overlock machine (also known as a serging machine or chain stitch sewing machine) is a special sewing equipment mainly used for edge covering treatment on cloth to prevent the cloth edge from unraveling or wearing. The overlock machine is widely used in the clothing manufacturing, home textiles, hats and shoes industries, and can improve production efficiency and product quality.

[0003] The shell of the overlock machine serves as a main support component and needs to provide stable support for the main shaft of the overlock machine. The existing overlock machine shell is manufactured by using an integrated casting process. However, due to the complex internal structure of the overlock machine shell, multiple process machining is often required after pouring, and the construction difficulty is great.

[0004] Therefore, we need to design an assembly method of a split combined overlock machine shell to solve these problems. SUMMARY

[0005] The application aims to provide an assembly method of a split combined overlock machine shell.

[0006] To solve the above technical problems, the technical solution adopted by the application is:

[0007] An assembly method of a split combined overlock machine shell, the split combined overlock machine shell includes a rear shell body and a front shell body, the rear shell body and the front shell body are integrally cast respectively, the rear shell body is provided with a rear assembly surface and a rear half hole, the front shell body is provided with a front assembly surface and a front half hole, a positioning hole is arranged on the rear assembly surface of the rear shell body and the front assembly surface of the front shell body, a positioning pin is inserted into the positioning hole, when the rear assembly surface and the front assembly surface are completely attached, 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 machine shell includes:

[0009] S1, pretreat the rear shell body, the front shell body and the positioning pin before assembly;

[0010] S2, the rear assembly surface on the pre-processed rear shell and the front assembly surface on the front shell are placed opposite, one end of the pre-processed positioning pin is inserted into the positioning hole on the rear assembly surface, and the positioning hole on the front assembly surface is aligned with the other end of the positioning pin and is inserted, the assembly process is completed within 30 seconds, and it is ensured that the rear assembly surface and the front assembly surface are tightly attached after assembly, and remain until the front shell and the rear shell cool to room temperature;

[0011] S3, obtain the front half shaft projection and the front half shaft projection image, obtain the main shaft hole projection image, and pre-process the obtained main shaft hole projection image, rear half shaft projection and front half shaft projection image to obtain a pre-processing result;

[0012] S4, according to the pre-processing result, 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, and the center coordinates and the assembly surface center coordinates of the main shaft hole are obtained by using Hough circle transformation; 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 center coordinates and the opening end point coordinates of the front shell half hole and the center coordinates and the opening end point coordinates of the rear half hole, the shell assembly result is obtained by using the improved fitting algorithm combined with overlapping scanning.

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

[0015] S1.1, obtain the gray value of each pixel point in the main shaft hole projection gray image before assembly, obtain the gray value, and construct a first set;

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

[0017] S1.3, obtain the main shaft hole boundary contour line coordinate point set, and perform gray sum on the pixels in the coordinate point set to obtain a second set;

[0018] S1.4, compare each data in the first set with the number of pixels in the second set, and remove the data different from the number of pixels in the second set;

[0019] S1.5, set the pixel points with the same number of data in the first set and the number of pixels in the second set as seed points;

[0020] S1.6, set the spindle hole boundary contour line coordinate point set as the edge contour point set, perform sliding window traversal on the edge contour point set, and remove the pixel points in the current region whose pixel number is greater than or equal to the average pixel number of the region in the spindle hole orthographic gray scale diagram.

[0021] Preferably, the obtaining of the spindle hole boundary contour line coordinate point set and the gray sum of the 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, obtaining an inner edge line and an outer boundary line of the spindle hole; the inner edge line of the spindle hole is a contour line where the pixel points with non-zero gray values in the spindle hole orthographic gray scale diagram are located, and the outer boundary line is a contour line where the pixel points with zero gray values in the spindle hole orthographic gray scale diagram are located;

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

[0024] S1.3.3, comparing 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, and deleting the coordinates of the 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;

[0025] S1.3.4, repeating the operations of S1.3.2 and S1.3.3 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, superimposing the inner edge line coordinate point set and the outer boundary line coordinate point set of the spindle hole to obtain the spindle hole boundary contour line coordinate point set.

[0027] Preferably, the removing of the data in the first set and the data in the second set includes the following steps:

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

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

[0030] S1.4.3, removing the results obtained in the step S1.4.2.

[0031] 5. The assembly method of the split combined overlock machine housing according to claim 3, wherein the step of setting the pixel points with the same number of pixels in the first set as the number of pixels in the second set as seed points comprises the following steps:

[0032] S1.5.1, setting the spindle hole boundary contour line coordinate point set as the edge contour point set, obtaining the gradient value of each pixel point in the edge contour point set, and drawing the corresponding edge contour point set gray scale diagram according to the gradient value of each pixel point;

[0033] S1.5.2, performing image equalization processing on the edge contour point set gray scale diagram;

[0034] S1.5.3, obtaining the gradient value of all pixel points in the equalized edge contour point set gray scale diagram, constituting a third set, sorting the third set in descending order, obtaining the position of the first 10% pixel points in the third set, and obtaining the coordinates of the pixel points corresponding to the gray value of 255 in the position;

[0035] S1.5.4, setting the pixel points in the window of the pixel points obtained in the step S1.5.3 as seed points.

[0036] Preferably, the step 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 pixel points with the number of pixels in the current region greater than or equal to the average number of pixels in the region and the gray value of 0 in the spindle hole orthographic gray scale diagram as the pixel points with the gray value of 0 in the spindle hole orthographic gray scale diagram comprises the following steps:

[0037] S1.6.1, obtaining the total number of pixel points and the gray value of the neighborhood window of each pixel point in the spindle hole orthographic gray scale diagram;

[0038] S1.6.2, when the total number of pixel points in the neighborhood window is less than the average number of pixels in the region, traversing the coordinates of the pixel points in the neighborhood window, setting a predetermined threshold, traversing the mean value of the neighborhood window of the pixel points, and obtaining the pixel points with the mean value of the neighborhood window of the pixel points less than the gray threshold value, and setting the gray value of the pixel points with the gray value greater than the mean value of the neighborhood window of the pixel points to 0;

[0039] S1.6.3, when the total number of pixel points in the neighborhood window is greater than or equal to the average number of pixels in the region, performing sliding window traversal on the pixel points in the neighborhood window;

[0040] S1.6.4, obtaining the mean value of the pixel window, and setting the gray value of the pixel points to 0 if the mean value of the window is less than the gray threshold value, and setting the gray value of all pixel points in the current region to 0.

[0041] Preferably, when the total number of pixel points in the neighborhood window is greater than or equal to the average number of pixels in the region, the sliding window traversal of the pixel points in the neighborhood window comprises the following steps: obtaining the number of pixel points in the neighborhood window of the current region pixel point, the pixel point gray value, obtaining the average number of pixel points, the average number of pixel points in the main shaft hole, and the difference between the number of pixel points in the neighborhood window of each pixel point, the maximum pixel point gray value and the minimum pixel point gray value and the average number of pixel points, the average number of pixel points in the main shaft hole, if any one of the difference values is greater than or equal to 0, the gray value of the pixel point is set to 0, and if both difference values are less than 0, the gray value of the pixel point is unchanged.

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

[0043] Preferably, according to the preprocessing result, the center coordinates of the front half hole, the opening end point coordinates, the center coordinates of the rear half hole, the opening end point coordinates, the center coordinates of the main shaft hole and the center coordinates of the assembly surface are obtained by using the Hough circle transformation method; the Hough circle transformation method comprises: using the Hough circle transformation method on the second set and the third set respectively to obtain the center coordinates of the front half hole, the opening end point coordinates, the center coordinates of the rear half hole, the opening end point coordinates, the center coordinates of the main shaft hole and the center coordinates of the assembly surface.

[0044] 10. The assembly method of the split combined overlock machine shell according to claim 1, wherein the shell assembly result is obtained by using the improved fitting algorithm in combination with overlapping scanning according to the center coordinates of the front half hole of the front shell and the opening end point coordinates and the center coordinates of the rear half hole and the opening end point coordinates, and comprises the following steps:

[0045] S5.1, obtaining the center coordinates of the main shaft hole of the front shell assembly surface, and overlapping and fitting the front shell assembly surface with the rear shell assembly surface according to the center coordinates of the front shell assembly surface and the opening end point coordinates and the obtained center coordinates of the main shaft hole of the rear shell assembly surface;

[0046] S5.2, obtaining the center coordinates of the rear shell assembly surface as the center coordinates of the front shell assembly surface after overlapping and fitting, and obtaining the center coordinates after overlapping and fitting;

[0047] S5.3, obtaining an inscribed circle with a radius of R, obtaining the polar radius of the inscribed circle, and obtaining a polar coordinate point set according to the radius of the inscribed circle and the polar radius;

[0048] S5.4, obtaining the overlapping of the opening end point of the front shell assembly surface and the opening end point of the rear shell assembly surface, and the overlapping opening end point is the coincidence point; determining whether the length from the center of the front shell assembly surface to the first opening end point is less than the length from the center of the rear shell assembly surface to the first opening end point;

[0049] S5.5、in the front shell assembly surface opening end point and the rear shell assembly surface opening end point are connected with the circle center line, the circle center coordinate is obtained, the operation of S5.2-S5.4 is repeated 1000 times, when the circle center of the front shell assembly surface, the length from the first opening end point to the circle center is always less than the circle center of the rear shell assembly surface, the length from the first opening end point to the circle center is determined to coincide with the rear shell assembly surface, and it is determined that no gap is generated.

[0050] The application has the advantages and positive effects that:

[0051] The application improves the shell of the overlock machine, decomposes the traditional integrated shell into an assembled shell, detects the roundness of the split main shaft hole during assembly, and can improve the assembly yield; and can ensure that the assembled shell can provide effective support for the main shaft, reduce friction when the main shaft rotates, and prolong the service life of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0053] Figure 1 is a disassembled structure diagram of the rear shell and the front shell of the application;

[0054] Figure 2 is a structure diagram of the rear shell of the application;

[0055] Figure 3 is a structure diagram of the front shell of the application;

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

[0057] Figure 5 is a process flow diagram of the assembly and detection process of the rear shell and the front shell of the application.

[0058] The following explains the reference signs:

[0059] 1, rear shell; 2, front shell; 3, positioning pin; 4, positioning hole; 5, shaft 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 application, it is to be understood by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and not indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0061] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood by specific circumstances.

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

[0063] Example 1: reference Figures 1-5 As shown, a kind of split combined overedger shell assembly method, split combined overedger shell includes rear shell 1 and front shell 2, rear shell 1 and front shell 2 are integrally cast into shape respectively, rear shell 1 is provided with rear assembly surface 6 and rear half hole 51, front shell 2 is provided with front assembly surface 7 and front half hole 52, positioning hole 4 is arranged on the rear assembly surface 6 of rear shell 1 and the front assembly surface 7 of shell 2, positioning pin 3 is inserted in positioning hole 4, when rear assembly surface 6 and front assembly surface 7 are completely adhered, rear half hole 51 and front half hole 52 are spliced into main shaft hole 5, one end of positioning pin 3 is inserted into the positioning hole 4 on rear assembly surface 6, and the other end is inserted into the positioning hole 4 on front assembly surface 7;

[0064] The assembly of split combined overedger shell includes:

[0065] S1, pretreatment is carried out on rear shell 1, front shell 2 and positioning pin 3 before assembly;

[0066] S2, the pre-processed rear shell 1 on the rear assembly surface 6 and the front shell 2 on the front assembly surface 7 are placed opposite, the pre-processed positioning pin 3 is inserted into the positioning hole 4 on the rear assembly surface 6, and the positioning hole 4 on the front assembly surface 7 is aligned with the other end of the positioning pin 3 and inserted, the assembly process is completed within 30 seconds, and the assembly process is completed within 30 seconds. Ensure that the rear assembly surface 6 and the front assembly surface 7 are tightly attached after assembly, and remain until the front shell 2 and the rear shell 1 cool to room temperature;

[0067] S3, obtain the front half shaft projection and the front half shaft projection image, obtain the main shaft hole 5 projection image, and obtain the main shaft hole 5 projection image, the rear half shaft projection and the front half shaft projection image are preprocessed to obtain the preprocessing 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, and the center coordinates and the assembly surface center coordinates of the main shaft hole 5 are obtained by using 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 1 assembly surface and the center coordinates and the opening end point coordinates of the front shell 2 assembly surface;

[0069] S5, according to the center coordinates and the opening end point coordinates of the front shell half hole and the center coordinates and the opening end point coordinates of the rear half hole 51, the improved fitting algorithm is used to obtain the shell assembly result.

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

[0071] S1.1, obtain the gray value of each pixel point in the main shaft hole 5 projection gray image before assembly, obtain the gray value, and construct a first set;

[0072] S1.2, the data in the first set are screened, the pixel points corresponding to the gray values greater than or equal to 255 are deleted from the first set, and the remaining elements in the first set are sorted to determine the main shaft hole 5 boundary contour line;

[0073] S1.3, obtain the coordinate point set of the main shaft hole 5 boundary contour line, and perform gray sum on the pixels in the coordinate point set to obtain a second set;

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

[0075] S1.5, the pixel points with the same number of data in the first set and the number of pixels in the second set are set as seed points;

[0076] S1.6, set the spindle hole 5 boundary contour line coordinate point set as the edge contour point set, and perform sliding window traversal on the edge contour point set. The pixel points with the number of pixels in the current region greater than or equal to the average number of pixels in the region and the gray value of 0 in the spindle hole 5 orthographic gray scale diagram are removed.

[0077] Preferably, the spindle hole 5 boundary contour line coordinate point set is obtained, and the gray sum of the pixels in the coordinate point set is obtained to obtain the second set.

[0078] S1.3.1, obtain the inner edge line and the outer boundary line of the spindle hole 5; the inner edge line of the spindle hole 5 is the contour line of the pixel points with non-zero gray value in the spindle hole 5 orthographic gray scale diagram, and the outer boundary line is the contour line of the pixel points with gray value of 0 in the spindle hole 5 orthographic gray scale diagram;

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

[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 the 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 the operations of S1.3.2 and S1.3.3 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 and the outer boundary line coordinate point set of the spindle hole 5 to obtain the spindle hole 5 boundary contour line coordinate point set.

[0083] Preferably, each data in the first set is compared with the number of pixels in the second set, and the data with different number of pixels in the second set is removed.

[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, obtain the pixel points in the edge contour point set, the total number of all pixel points in the neighborhood window of each pixel point is equal to 70% of the total number of all pixel points in the neighborhood window of each pixel point, and the total number of all pixel points in the neighborhood window of each pixel point in the edge contour point set is not equal;

[0086] S1.4.3, remove the results obtained in S1.4.2.

[0087] 5. The method of claim 3, wherein the seed points are set as the pixel points with the same number of pixels in the first set and the second set, and the pixel points with the same number of pixels in the first set and the second set include the following steps:

[0088] S1.5.1, set the coordinate point set of the spindle hole 5 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 gray scale diagram according to the gradient value of each pixel point;

[0089] S1.5.2, perform image equalization processing on the edge contour point set gray scale diagram;

[0090] S1.5.3, obtain the gradient value of all pixel points in the equalized edge contour point set gray scale diagram, form a third set, sort the third set in descending order, obtain the position of the first 10% pixel points in the third set, and obtain the coordinates of the pixel points with a gray value of 255 in the position;

[0091] S1.5.4, set the pixel points in the window of the pixel points obtained in the step S1.5.3 as seed points.

[0092] Preferably, the coordinate point set of the spindle hole 5 boundary contour line is set as the edge contour point set, the edge contour point set is traversed by a sliding window, the pixel points with a number of pixels greater than or equal to the average number of pixels in the current region in the spindle hole 5 orthographic gray scale diagram with a gray value of 0 are set as the pixel points with a gray value of 0 in the spindle hole 5 orthographic gray scale diagram, and the pixel points with a gray value of 0 in the spindle hole 5 orthographic gray scale diagram include the following steps:

[0093] S1.6.1, obtain the total number of pixel points and the gray value of the neighborhood window of each pixel point in the spindle hole 5 orthographic gray scale diagram;

[0094] S1.6.2, when the total number of pixel points in the neighborhood window is less than the average number of pixels in the region, traverse the coordinates of the pixel points in the neighborhood window, set a preset threshold, traverse the mean value of the neighborhood window of the pixel points, obtain the pixel points with a neighborhood window mean value less than the gray threshold value, and set the gray value of the pixel points with a gray value greater than the mean value of the neighborhood window of the pixel points to 0;

[0095] S1.6.3, when the total number of pixel points in the neighborhood window is greater than or equal to the average number of pixels in the region, traverse the pixel points in the neighborhood window by a sliding window;

[0096] S1.6.4, obtain the mean value of the pixel window, and if the window mean value is less than the gray threshold value, set the gray value of the pixel points to 0, and set the gray values of all pixel points in the current region to 0.

[0097] Preferably, when the total number of pixel points in the neighborhood window is greater than or equal to the average number of pixel points in the region, the sliding window traversal of the pixel points in the neighborhood window comprises the following steps: obtaining the number of pixel points in the neighborhood window of the current region pixel point, the pixel point gray value, obtaining the average number of pixel points, the average number of pixel points in the main shaft hole 5, and the number of pixel points in the neighborhood window of each pixel point, the maximum pixel point gray value and the minimum pixel point gray value are respectively subtracted from the average number of pixel points and the average number of pixel points in the main shaft hole 5, if any one of the difference values is greater than or equal to 0, the gray value of the pixel point is set to 0, and if both difference values are less than 0, the gray value of the pixel point is unchanged.

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

[0099] Preferably, according to the preprocessing result, the center coordinates of the front half hole 52, the opening end point coordinates, the center coordinates of the rear half hole 51, the opening end point coordinates, and the center coordinates of the main shaft hole 5 and the center coordinates of the assembly surface are obtained by using the Hough circle transformation method; the Hough circle transformation method comprises: using the Hough circle transformation method on the second set and the third set respectively to obtain the center coordinates of the front half hole 52, the opening end point coordinates, the center coordinates of the rear half hole 51, the opening end point coordinates, and the center coordinates of the main shaft hole 5 and the center coordinates of the assembly surface.

[0100] 10. The assembly method of the split combined overlock machine shell according to claim 1, wherein the shell assembly result is obtained by using the improved fitting algorithm in combination with overlapping scanning according to the center coordinates of the front shell half hole and the opening end point coordinates and the center coordinates of the rear half hole 51 and the opening end point coordinates.

[0101] S5.1, obtaining the center coordinates of the main shaft hole 5 of the front shell assembly surface, and overlapping and fitting the front shell 2 assembly surface with the rear shell 1 assembly surface according to the center coordinates of the front shell 2 assembly surface and the opening end point coordinates and the obtained center coordinates of the main shaft hole 5 of the rear shell 1 assembly surface;

[0102] S5.2, obtaining the center coordinates of the rear shell 1 assembly surface as the center coordinates of the overlapping and fitted front shell 2 assembly surface and rear shell 1 assembly surface, and obtaining the center coordinates after overlapping and fitting;

[0103] S5.3, obtaining an inscribed circle with a radius of R, obtaining the polar radius of the inscribed circle, and obtaining the polar coordinate point set according to the radius of the inscribed circle and the polar radius;

[0104] S5.4, obtaining the overlapping of the opening end point of the front shell 2 assembly surface and the opening end point of the rear shell 1 assembly surface, and the overlapping opening end point is the coincidence point; determining whether the length from the center of the front shell 2 assembly surface to the first opening end point is less than the length from the center of the rear shell 1 assembly surface to the first opening end point;

[0105] S5.5、in the front shell 2 assembly face opening end point and the rear shell 1 assembly face opening end point are connected with the circle center line, the circle center coordinate is obtained, the operation of S5.2-S5.4 is repeated 1000 times, when the circle center of the front shell 2 assembly face, the length from the first opening end point to the circle center is always less than the circle center of the rear shell 1 assembly face, the length from the first opening end point to the circle center is determined, the coincidence point is determined to coincide with the rear shell 1 assembly face, and it is determined that no gap is generated.

[0106] The above describes one embodiment of the present application in detail, but the content is only the preferred embodiment of the present application, and cannot be considered to limit the implementation range of the present application. Any equivalent changes and improvements made according to the scope of the present application should still belong to the patent coverage range of the present application.

Claims

1. A method for assembling a split-type modular overlock sewing machine housing, characterized in that: The split-type combined overlock sewing machine housing includes a rear housing and a front housing, which are integrally cast. The rear housing has a rear assembly surface and a rear half-hole, and the front housing has a front assembly surface and a front half-hole. Positioning holes are provided on both the rear assembly surface of the rear housing and the front assembly surface of the front housing. Positioning pins are inserted into the positioning holes. When the rear assembly surface and the front assembly surface are fully fitted, the rear half-hole and the front half-hole are combined to form 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-type modular overlock sewing machine housing includes: S1. Pre-process the rear housing, front housing, and locating pins before assembly; S2. Place the pre-treated rear assembly surface on the rear housing and the front assembly surface on the front housing opposite each other. Insert one end of the pre-treated positioning pin into the positioning hole on the rear assembly surface, and align the positioning hole on the front assembly surface with the other end of the positioning pin. The assembly process is completed within 30 seconds. Ensure that the assembled rear assembly surface and the front assembly surface fit tightly together and keep them in place until the front housing and the rear housing cool to room temperature. S3. Obtain the orthographic projection images of the front and rear half-axis before and after assembly, and the orthographic projection image of the main spindle hole after assembly. Perform preprocessing on the obtained orthographic projection images of the main spindle hole, the rear half-axis, and the front half-axis to obtain the preprocessing results. S4. Based on the preprocessing results, use the Hough circle transformation method to obtain the center coordinates and opening end coordinates of the front half hole, the center coordinates and opening end coordinates of the rear half hole, the center coordinates of the spindle hole, and the center coordinates of the assembly surface; the center coordinates and opening end coordinates include the center coordinates and opening end coordinates of the rear housing assembly surface and the center coordinates and opening end coordinates of the front housing assembly surface. S5. Based on the center coordinates and opening end coordinates of the front half hole and the center coordinates and opening end coordinates of the rear half hole, the shell assembly result is obtained by using an improved fitting algorithm in conjunction with overlapping scanning.

2. The assembly method of the split-type combined overlock sewing machine housing according to claim 1, characterized in that, The pretreatment process for the rear housing, front housing, and locating pins before assembly includes the following steps: S1.1 Obtain the grayscale value of each pixel in the orthographic projection grayscale image of the spindle hole before assembly, obtain the grayscale value, and construct the first set; S1.2 Filter the data in the first set, delete the pixels corresponding to gray values ​​greater than or equal to 255 from the first set, sort the remaining elements in the first set, and determine the outline of the main shaft hole boundary. S1.3 Obtain the coordinate point set of the main shaft hole boundary contour line, and sum the gray levels of the pixels in the coordinate point set to obtain the second set; S1.4 Compare the number of pixels in each data in the first set with the number of pixels in the second set, and remove data whose number of pixels in the first set is different from that in the second set; S1.

5. Set the pixels in the first set with the same number of data points as the pixels in the second set as seed points; S1.6 Set the coordinate point set of the main shaft hole boundary contour line as the edge contour point set, perform a sliding window traversal on the edge contour point set, and set the gray value of the pixels in the current area that are greater than or equal to the average number of pixels in the area to 0 in the grayscale image of the main shaft hole orthographic projection.

3. The assembly method of a split-type combined overlock sewing machine housing according to claim 2, characterized in that, The process of obtaining the coordinate point set of the main spindle hole boundary contour line and summing the gray levels of the pixels in the coordinate point set to obtain the second set of coordinate point sets of the main spindle hole boundary contour line includes 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 of the pixels with non-zero gray values ​​in the orthographic projection grayscale image of the spindle hole, and the outer boundary line is the contour line of the pixels with zero gray values ​​in the orthographic projection grayscale image of the spindle hole. S1.3.

2. Obtain the contour gradient using the neighborhood pixel averaging method for the coordinate point set of the inner edge line and the outer boundary line of the spindle hole. S1.3.3 Compare the gradient of each pixel on the coordinate point set of the inner edge line of the spindle hole and the coordinate point set of the outer boundary line, and delete the coordinates of the points with different gradient values ​​from the coordinate point set of the inner edge line of the spindle hole and the coordinate point set of the outer boundary line. S1.3.4 Repeat S1.3.2 and S1.3.3 operations at least 1000 times to obtain the coordinate point set of the inner edge line of the spindle hole and the coordinate point set of the outer boundary line. S1.3.

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

4. The assembly method of a split-type combined overlock sewing machine housing according to claim 3, characterized in that, The step of comparing the number of pixels in the first set with the number of pixels in the second set and removing data whose number of pixels differs from the number of pixels in the second set includes the following steps: S1.4.1 Obtain the coordinates of each pixel in the edge contour point set, obtain the neighborhood window of each pixel, and obtain the total number of all pixels of each pixel; S1.4.2 Obtain pixels whose total number of pixels in the edge contour point set is equal to 70% of the total number of pixels in the neighborhood window of each pixel, and whose total number of pixels in the neighborhood window of each pixel in the edge contour point set is not equal. S1.4.3 Remove the results obtained in step S1.4.

2.

5. The assembly method of a split-type combined overlock sewing machine housing according to claim 3, characterized in that, The step of setting the pixels in the first set with the same number of data points as the pixels in the second set as seed points includes the following steps: S1.5.1 Set the coordinate point set of the main shaft hole boundary contour line as the edge contour point set, obtain the gradient value of each pixel in the edge contour point set, and draw the corresponding edge contour point set grayscale image based on the gradient value of each pixel. S1.5.2 Perform 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, form a third set, sort the third set in descending order, obtain the positions of the first 10% of pixels in the third set in order, and obtain the coordinates of the pixel with a grayscale value of 255 at the position of the pixel. S1.5.4 Set the pixel in the window containing the pixel obtained in step S1.5.3 as the seed point.

6. The assembly method of a split-type combined overlock sewing machine housing according to claim 3, characterized in that, The step of setting the coordinate point set of the main shaft hole boundary contour line as the edge contour point set, performing a sliding window traversal on the edge contour point set, and setting the gray value of pixels in the main shaft hole orthographic projection grayscale image that have a number of pixels greater than or equal to the average number of pixels in the current region 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 orthographic projection grayscale image of the spindle hole; 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 average value of the neighborhood window of the pixel is traversed, the pixels whose average value of the neighborhood window of the pixel is less than the grayscale threshold are obtained, and the grayscale value of the pixels whose grayscale value is greater than the average value of the neighborhood window of the pixel is 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 of the pixels in the neighborhood window. S1.6.

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

7. The assembly method of a split-type combined overlock sewing machine housing 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, the sliding window traversal of the pixels in the neighborhood window includes the following steps: obtaining the number of pixels and the gray value of the pixels in the neighborhood window of the current region's pixels; obtaining the average number of pixels and the average number of pixels in the main axis aperture; subtracting the number of pixels, the maximum gray value, and the minimum gray value of each pixel from the average number of pixels and the average number of pixels in the main axis aperture, respectively; if any difference is greater than or equal to 0, the gray value of the pixel is set to 0; if both differences are less than 0, the gray value of the pixel remains unchanged.

8. The assembly method of a split-type combined overlock sewing machine housing according to claim 6, characterized in that: The average number of pixels in the region is the average number of neighboring pixels within each window.

9. The assembly method of a split-type combined overlock sewing machine housing according to claim 1, characterized in that, Based on the preprocessing results, 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. The Hough circle transformation method includes: applying the Hough circle transformation method to 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.

10. The assembly method of a split-type combined overlock sewing machine housing according to claim 1, characterized in that, Based on the center coordinates and opening endpoint coordinates of the front half-hole and the rear half-hole, the housing assembly result is obtained using an improved fitting algorithm combined with overlapping scanning, including the following steps: S5.1 Obtain the center coordinates of the spindle hole on the front housing assembly surface. Based on the center coordinates of the front housing assembly surface and the coordinates of the opening end point, and the obtained center coordinates of the spindle hole on the rear housing assembly surface, overlap and fit the front housing assembly surface and the rear housing assembly surface. S5.

2. Obtain the center coordinates of the rear housing assembly surface; obtain the center coordinates of the front housing assembly surface and the rear housing assembly surface after they overlap and fit together; obtain the center coordinates of the front housing assembly surface and the rear housing assembly surface after they overlap and fit together. S5.3 Obtain the circumcircle with radius r, obtain the polar radius of the circumcircle, and obtain the set of polar coordinate points based on the circumcircle radius and the polar radius; S5.

4. If the opening endpoints of the front housing assembly surface and the rear housing assembly surface coincide, the coincident opening endpoints are the coincident points; determine whether the length from the center of the front housing assembly surface and the first opening endpoint to the center is less than the length from the center of the rear housing assembly surface and the first opening endpoint to the center. S5.5 When both the opening endpoints of the front housing assembly surface and the opening endpoints of the rear housing assembly surface are connected to the center of the circle, obtain the coordinates of the center of the circle. Repeat S5.2-S5.4 1000 times. When the length from the center of the front housing assembly surface and the first opening endpoint to the center of the circle is always less than the length from the center of the rear housing assembly surface and the first opening endpoint to the center of the circle, determine that the coincidence point coincides with the rear housing assembly surface and determine that no gap has been generated.

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