Honing belt quality testing method and device

Abstract

This invention relates to a method and apparatus for quality inspection of honing belts. The honing belt quality inspection apparatus is used to automatically inspect the quality of the honing belts on the workpiece, which can improve the accuracy and efficiency of inspection, and also significantly save the production costs of enterprises.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically to a method and apparatus for detecting the quality of honing belts. Background Technology

[0002] The EV14 is a ball valve type electromagnetic fuel injector. Its core components include a needle valve assembly and a valve seat. The fit between the needle valve assembly and the valve seat directly affects the injector's spray characteristics, such as atomization particle size, mist distribution, fuel jet direction, range, and diffusion cone. These indicators, in turn, affect vehicle emissions. Currently, in injector manufacturing, injector characteristics can be improved by tightening the tolerance for injector leakage. Injector leakage is caused by a gap between the sealing surface of the valve seat and the valve ball sealing surface of the needle valve assembly. To reduce this gap, the valve seat is typically honed. The honed band, when fitted with the valve ball sealing surface, significantly reduces leakage, allowing for further improvements in leakage standards.

[0003] After honing the valve seat, it is necessary to check whether the honing belt meets the requirements. The standard procedure for inspecting the honing belt in the existing technology is: first, clean and dry the valve seat, then conduct a visual inspection. However, in actual production, to reduce processes, production line workers generally do not clean the valve seat before visual inspection. The oil and metal particles present on the valve seat reduce the accuracy of the visual inspection. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for automating the quality inspection of honing belts, thereby improving inspection efficiency and accuracy and reducing labor costs.

[0005] To achieve the above objectives, the present invention provides a method for detecting the quality of honing belts, based on a honing belt quality detection device, the honing belt quality detection device comprising an imaging element and a control unit, comprising the following steps:

[0006] The imaging element acquires an image of the workpiece and sends the image to the control unit, wherein a honing belt is formed on the workpiece and the image displays the honing belt; the control unit determines whether the honing belt is qualified based on the image.

[0007] Optionally, before determining whether the honing belt is qualified, the method further includes: the control unit positioning the workpiece on the image and calculating the area where the honing belt is located;

[0008] The control unit first performs coarse positioning on the workpiece, and then performs fine positioning on the workpiece.

[0009] Optionally, the workpiece has an axis, and along the axis, the workpiece has a circular region, and the honing belt is a ring-shaped structure surrounding the circular region; the image shows the circular region and the honing belt with the ring-shaped structure.

[0010] The method for coarsely positioning the workpiece includes:

[0011] Step S111: Binarize the image;

[0012] Step S112: Locate the characteristic arc of the circular region in the image processed by step S111;

[0013] Step S113: Calculate the center of the characteristic arc to obtain the reference center; and / or,

[0014] The method for precisely positioning the workpiece includes:

[0015] Step S121: Determine a reference circle with the reference center as the center, the reference circle surrounding the circular area;

[0016] Step S122: Locate the edge of the circular area within the reference circle;

[0017] Step S123: Calculate the center of the circular region.

[0018] Optionally, the method by which the control unit calculates the region where the honing belt is located includes:

[0019] Step S210: Perform gradient processing on the image;

[0020] Step S220: Binarize the image processed in step S210;

[0021] Step S230: Search for the edge line of the honing belt in the image obtained after processing in step S220. If the edge line cannot be found, determine that the edge line of the honing belt is a preset edge line. If the edge line can be found, store the found edge line of the honing belt.

[0022] Optionally, the method by which the control unit determines whether the honing belt is qualified includes:

[0023] Step S310: Binarize the image after gradient processing. The parameter values ​​for binarization in this step are smaller than the parameter values ​​for binarization in step S220.

[0024] Step S320: In the image processed by step S310, determine whether there is a linear defect within the edge line of the honing belt. If not, proceed to step S330. If yes, determine that the honing belt is unqualified.

[0025] Step S330: In the image processed by step S310, check whether the honing belt is complete. If not, determine that the honing belt is unqualified.

[0026] Optionally, if the honing belt is intact, after step S330 is completed, the process further includes...

[0027] Step S340: Output the width value of the honing belt;

[0028] Step S350: Determine whether the width of the honing belt is greater than the preset width. If yes, the honing belt is deemed unqualified; otherwise, the honing belt is deemed qualified.

[0029] Optionally, step S320 specifically includes:

[0030] Step S321: Identify the defective region and calculate the area of ​​the defective region;

[0031] Step S322: Determine whether the area of ​​the defective region is greater than a preset area. If yes, determine that the honing belt has a linear defect; if no, determine that the honing belt does not have a linear defect; and / or, step S330 specifically includes:

[0032] Step S331: Divide the honing belt into several sub-honing belts;

[0033] Step S332: Determine whether each of the sub-honing belts is complete. If it is, the honing belt is determined to be complete. If at least one of the sub-honing belts is incomplete, the honing belt is determined to be incomplete.

[0034] The method for determining whether the sub-honing belt is complete is as follows: calculate the edge pairs and gray values ​​of the sub-honing belt; determine whether the edge pairs and gray values ​​of the sub-honing belt are both zero. If so, the sub-honing belt is incomplete; if not, the sub-honing belt is complete.

[0035] To achieve the above objectives, the present invention also provides a honing belt quality inspection device, comprising a workpiece stage, a light source, an imaging element, and a control unit; wherein,

[0036] The workpiece stage is used to place the workpiece to be inspected, and the workpiece has a honing belt formed on it;

[0037] The light source is used to provide an illumination beam to the workpiece to be inspected;

[0038] The imaging element is used to acquire an image of the workpiece and send the image to the control unit, wherein the honing belt is displayed on the image; and

[0039] The control unit determines whether the honing belt on the workpiece is qualified based on the image.

[0040] Optionally, the control unit is configured to: locate the workpiece on the image, calculate the area where the honing belt is located, and determine whether the honing belt is qualified;

[0041] In the process of positioning the workpiece, the control unit is configured to: first perform coarse positioning of the workpiece, and then perform fine positioning of the workpiece.

[0042] Optionally, the workpiece has a circular region, and along the axial direction of the circular region, the honing belt is an annular structure surrounding the circular region; the image shows the circular region and the honing belt with the annular structure;

[0043] The control unit is configured to: perform binarization processing on the image, find the characteristic arc of the circular area, calculate the center of the characteristic arc to obtain a reference center to achieve the coarse positioning; determine a reference circle around the circular area with the reference center as the center, find the edge of the circular area within the reference circle, and calculate the center of the circular area to achieve the fine positioning.

[0044] Optionally, the control unit is configured to: sequentially perform gradient processing and binarization processing on the image, and calculate the edge line of the honing strip based on the binarized image to determine the region where the honing strip is located.

[0045] Optionally, the control unit is configured to: perform binarization processing on the image after gradient processing, wherein the parameter value of the current binarization processing is less than the parameter value of the binarization processing when searching for the edge line of the honing belt; identify a defect region within the edge line of the honing line and calculate the area of ​​the defect region; and determine whether the honing belt has a linear defect based on the area of ​​the defect region.

[0046] If the honing belt does not have the linear defect, the control unit is further configured to: divide the honing belt into several sub-honing belts, calculate the edge pairs and gray values ​​of each sub-honing belt, and determine whether the honing belt is complete based on the edge pairs and gray values ​​of each sub-honing belt.

[0047] If the honing belt is intact, the control unit is further configured to: output the width value of the honing belt and determine whether the width of the honing belt is qualified.

[0048] Optionally, the workpiece is an injector valve seat, the light source is a ring-shaped structure, the imaging element is a camera, the light source is disposed between the camera and the workpiece stage, and the light source and the camera are arranged coaxially; the light source is used to generate an illumination beam, and the illumination beam forms an angle with the surface of the workpiece stage, the angle being in the range of 45°-60°.

[0049] Compared with the prior art, the honing belt quality detection method and apparatus of the present invention have the following advantages:

[0050] The honing belt quality inspection device includes an imaging element and a control unit. The honing belt quality inspection method includes: the imaging element acquiring an image of the workpiece and sending it to the control unit; the workpiece having a honing belt; and the control unit determining whether the honing belt is qualified based on the image. This honing belt quality inspection method can achieve automated inspection of honing belt quality, not only replacing manual visual inspection and saving labor costs, but also improving inspection accuracy and efficiency. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the honing belt quality detection device provided by the present invention in one direction according to an embodiment;

[0052] Figure 2 This is a schematic diagram of the honing belt quality detection device provided by the present invention according to one embodiment, in another direction;

[0053] Figure 3 This is an overall flowchart of the honing belt quality detection device provided by the present invention for detecting the honing belt on a workpiece according to an embodiment;

[0054] Figure 4 This is a schematic diagram of the injector valve seat according to an embodiment of the present invention;

[0055] Figure 5 This is a schematic diagram showing the positional relationship between the imaging element, the light source, and the injector valve seat in the honing belt quality detection method provided according to an embodiment of the present invention;

[0056] Figure 6 This is a schematic diagram of the structure of the light source in the honing belt quality detection method provided by an embodiment of the present invention;

[0057] Figure 7 This is a schematic diagram showing the angular relationship between the illumination beam incident on the honing belt of the injector valve seat in the honing belt quality detection method provided by an embodiment of the present invention.

[0058] Figure 8 This is a schematic diagram of an image of an injector valve seat acquired by an imaging element in a honing belt quality detection method provided in an embodiment of the present invention.

[0059] Figure 9 This is a flowchart illustrating the positioning of the injector valve seat by the control unit in the honing belt quality detection method provided by an embodiment of the present invention.

[0060] Figure 10a This is a schematic diagram of the control unit finding a feature arc on an image in the honing belt quality detection method according to an embodiment of the present invention;

[0061] Figure 10b This is a schematic diagram of the control unit finding the rounded edge on the image in the honing belt quality detection method according to an embodiment of the present invention;

[0062] Figure 11 This is a schematic diagram of the incident and reflected light when an illumination beam shines on the honing belt and its surrounding area of ​​the injector valve seat in a honing belt quality detection method according to an embodiment of the present invention.

[0063] Figure 12 This is a flowchart illustrating the calculation of the honing belt edge line by the control unit in the honing belt quality detection method according to an embodiment of the present invention;

[0064] Figure 13 This is a schematic diagram of the image after gradient processing and binarization processing when searching for edge lines in the honing belt quality detection method provided by an embodiment of the present invention;

[0065] Figure 14 This is a flowchart of the control unit detecting whether the honing belt is qualified in the honing belt quality detection method according to an embodiment of the present invention;

[0066] Figure 15 This is a schematic diagram of the control unit detecting linear defects on an image in the honing belt quality detection method provided by an embodiment of the present invention, wherein (a) is a schematic diagram of the image after gradient processing and binarization processing, and (b) is a schematic diagram of the defect area being identified on the image;

[0067] Figure 16 This is a schematic diagram of the control unit dividing the honing belt into several sub-honing belts when detecting the integrity of the honing belt in the honing belt quality detection method provided by an embodiment of the present invention.

[0068] [The annotations in the attached figures are explained below]:

[0069] 100 - Workpiece stage;

[0070] 200 - Light source;

[0071] 210-Visor;

[0072] 300 - Imaging element;

[0073] 400 - Feeding mechanism;

[0074] 500 - Unloading mechanism;

[0075] 600 - Alarm;

[0076] 700 - Control Panel;

[0077] 800-Electrical cabinet;

[0078] 10-Injector valve seat;

[0079] 11-Honing belt;

[0080] 11a-serial honing belt;

[0081] 12-Cone surface;

[0082] 13-Circular area; Detailed Implementation

[0083] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the objectives of the embodiments of the present invention.

[0084] As used herein, the singular forms “a,” “an,” and “the” include plural objects unless otherwise expressly indicated. As used herein, the term “or” is generally used to include the meaning of “and / or” unless otherwise expressly indicated, and the terms “installed,” “connected,” and “linked” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Connections can be mechanical or electrical. Connections can be direct or indirect through an intermediate medium, and can represent internal communication between two elements or an interaction between two elements. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances. The same or similar reference numerals in the drawings represent the same or similar parts.

[0085] This invention provides a method and apparatus for detecting the quality of honing belts, so as to achieve automated detection of the quality of honing belts. Figure 1 and Figure 2 A schematic diagram of the honing belt quality inspection device is shown, as follows: Figure 1 and Figure 2 As shown, the honing belt quality inspection device includes a workpiece stage 100 and a light source 200 (see...). Figure 5The system includes an imaging element 300 and a control unit. The workpiece stage 100 is used to place the workpiece to be inspected, and a honing strip is formed on the workpiece. The light source 200 provides an illumination beam to the workpiece. The imaging element 300 acquires an image of the workpiece, and the image displays the honing strip. The imaging element 300 also transmits the image to the control unit. The control unit determines whether the honing strip is qualified based on the image. The method by which the control unit determines whether the honing strip is qualified will be described in detail below.

[0086] The honing belt quality inspection method and apparatus provided in this invention can be applied to various workpieces that have undergone honing. In a typical embodiment, the workpiece can be an injector valve seat. By using the imaging element 300 to acquire an image of the workpiece and displaying the honing belt on the image, the control unit determines whether the honing belt is qualified based on the image, thereby achieving automated inspection of the honing belt quality. This not only standardizes inspection criteria and improves inspection accuracy but also greatly improves inspection efficiency and reduces production costs for manufacturing enterprises.

[0087] Furthermore, the honing belt quality inspection device also includes a feeding mechanism 400 and an unloading mechanism 500. The feeding mechanism 400 is used to automatically provide the workpiece to be inspected to the workpiece table 100, and the unloading mechanism 500 is used to automatically collect the workpiece that has been inspected on the workpiece table 100, thereby making the honing belt quality inspection device have a higher degree of automation.

[0088] Preferably, the honing belt quality inspection device has four stations: a loading station, an inspection station, a unloading station, and a cleaning station. The workpiece table 100 is connected to a drive mechanism, which can drive the workpiece table 100 to switch between the loading station, the inspection station, the unloading station, and the cleaning station. Preferably, the loading station, the inspection station, the unloading station, and the cleaning station are evenly arranged along the same circumference, the workpiece table 100 is a four-section frustum, and the drive mechanism is a rotating mechanism that drives the workpiece table 100 to rotate.

[0089] Furthermore, the honing belt quality detection device also includes an alarm 600, which is communicatively connected to the control unit. The control unit also controls the operation of components such as the imaging element 300, the feeding mechanism 400, the unloading mechanism 500, and the rotating mechanism. Please refer to [reference needed]. Figure 3 The honing belt quality inspection device can inspect the quality of the honing belt according to the following procedure:

[0090] Step S1: The control unit detects whether there is a workpiece at the loading station. If yes, step S2 is executed. If no, the control unit controls the loading mechanism 400 to transport the workpiece to the loading station.

[0091] Step S2: The control unit controls the drive mechanism to drive the workpiece stage 100 to move, so as to transport the workpiece to the inspection station.

[0092] Step S4: The imaging element 300 acquires an image of the workpiece and transmits the image to the control unit.

[0093] Step S5: The control unit determines whether the image has been received. If yes, it executes step S6. If no, it determines that the camera is faulty and controls the alarm 600 to sound an alarm.

[0094] Step S6: The control unit detects whether the honing belt is qualified.

[0095] Step S7: The control unit controls the drive mechanism to drive the workpiece stage 100 to move, so as to transport the workpiece to the unloading station.

[0096] Step S8: The unloading mechanism 400 unloads the material.

[0097] Step S9: The control unit controls the drive mechanism to drive the workpiece stage 100 to move, and the workpiece stage 100 is cleaned at the cleaning station.

[0098] Furthermore, after step S2 and before step S4, the method includes step S3, where the control unit detects whether there is a workpiece at the detection station. This is because a workpiece may fall off during the rotation of the workpiece stage 100. In this step, if the control unit detects a workpiece at the detection station, it executes step S4; if the control unit detects no workpiece at the detection station, it returns to step S1.

[0099] Furthermore, in step S8, if the unloading mechanism 500 unloads normally, the workpiece table 100 is cleaned after unloading is completed, and the honing belt quality detection device repeats steps S1 to S9 to continuously detect the workpiece. If the unloading mechanism 500 malfunctions and cannot unload normally, the control unit also controls the alarm 600 to sound an alarm.

[0100] In addition, the honing belt quality inspection device also includes components such as a control panel 700 and an electrical cabinet 800. The electrical cabinet 800 is equipped with various electronic components, and the control panel 700 is equipped with control buttons, a display screen, and other components for the operator to operate the honing belt quality inspection device so that the honing belt quality inspection device can operate normally.

[0101] The following description uses the inspection of the honing strip 11 on the injector valve seat 10 as an example to illustrate the process by which the control unit detects whether the honing strip is qualified. Furthermore, all processing steps in this embodiment are performed using the graphical software Insight. Those skilled in the art can modify the following description to make the honing strip quality inspection device and method applicable to the honing strip quality inspection of other workpieces.

[0102] Figure 4 A schematic diagram of the injector valve seat 10 is shown. Figure 4 As shown, the injector valve seat 10 includes a housing with an inner cavity. Axially, the inner cavity has a first end and a second end opposite to each other, wherein the first end is an open end, and the inner wall of the second end is formed into a tapered surface 12. The tapered surface 12 forms an angle of approximately 120° with the end face of the second end, and the honing band 11 is disposed on the tapered surface 12.

[0103] In this embodiment, the workpiece stage 100 is placed horizontally, and a workpiece seat is provided on the upper surface of the workpiece stage 100. When the honing belt is inspected using the honing belt quality inspection device, the injector valve seat 10 is placed inside the workpiece seat. Figure 5 The positional relationship of the imaging element 300, the light source 200, and the injector valve seat 10 during detection is shown. Figure 5 As shown, from bottom to top, the injector valve seat 10, the light source 200, and the imaging element 300 are arranged sequentially, with the first end of the inner cavity facing the imaging element 300. In this embodiment, the light source 200 is a ring-shaped LED lamp, and the imaging element 300 is a camera equipped with an image-side telecentric lens, with the lens and the light source 200 arranged coaxially.

[0104] When the imaging element 300 acquires an image of the injector valve seat 10, the honing band 11 should be fully displayed in the image, and the honing band 11 should be clearly distinguishable from other non-honed areas. Therefore, in this embodiment, based on the structure and size characteristics of the injector valve seat 10, a camera with a pixel size of less than 5µm and a resolution of less than 2.5µm (e.g., a 300,000-pixel industrial camera, specifically a Cognex 8402) is selected as the imaging element 300. Its lens magnification is 1.5x, and the final image magnification is 57.15x (the camera magnification can be calculated using the formula: magnification = objective lens magnification × interface magnification × image diagonal length / camera sensor block diagonal length). Furthermore, in actual testing, based on the structure of the light source 200, a light shield 210 can be set on the light source 200 (e.g., a light shield 210). Figure 6 As shown), the incident light of the illumination beam entering the inner cavity forms an angle λ with the upper surface of the workpiece stage 100, and the angle λ ranges from 45° to 60° (e.g., Figure 7 (As shown). In addition, the diameter of the light source 200 should be greater than 50 mm, and the distance between the lower surface of the light source 200 and the end face of the first end of the injector valve seat 10 should be less than or equal to 15 mm.

[0105] Figure 8 A schematic diagram of an image of the injector valve seat 10 acquired by the imaging element 300 is shown. In the image, the second end of the inner cavity is formed as a black circular area 13, and the honing belt 11 has a ring-shaped structure and surrounds the circular area 13. The area of ​​the workpiece that has undergone honing (i.e., the honing belt 11) is smoother than the non-honed belt area. Therefore, when the illumination beam shines on the honing belt, the light reflected by the honing belt 11 has a uniform density, while the light reflected by the non-honed belt area is chaotic (e.g., ...). Figure 11 (As shown). In this way, the brightness of the honed band 11 in the image is higher than the brightness of the non-honed band area; visually, the honed band 11 appears whiter than the non-honed area. The control unit will analyze the image to determine whether the honed band on the injector valve seat 10 is up to standard.

[0106] When the imaging element 300 acquires an image of the injector valve seat 10, the injector valve seat 10 is preferably arranged coaxially with the lens of the imaging element 300, so that the control unit can determine the position of the honing belt 11 on the image and thus judge the quality of the honing belt 11. However, in actual operation, the injector valve seat 10 has a certain positional offset (up / down, left / right offset ±500µm) within the workpiece seat, which causes the center of the honing belt 11 to shift. Therefore, the control unit also needs to compensate for the center offset of the honing belt 11 on the image. Thus, before judging whether the honing belt 11 is qualified, the control unit also includes: locating the injector valve seat 10 on the image and calculating the area where the honing belt 11 is located.

[0107] The control unit performs coarse positioning and then fine positioning on the workpiece. Please refer to [the relevant documentation / reference]. Figure 9 and combined Figure 10a The method by which the control unit performs coarse positioning of the workpiece is as follows:

[0108] Step S111: Binarize the image.

[0109] Step S112: Locate the characteristic arc of the circular region in the image after processing in step S112.

[0110] Step S113: Calculate the center of the feature arc to obtain the reference center.

[0111] The circular area 13 has numerous arcs along its edge. After binarization of the image, it is very easy to find the characteristic arcs along the edge of the circular area 13. By searching for the characteristic arcs of the circular area 13 instead of searching the entire circular edge, the injector valve seat 10 can be coarsely located, avoiding situations where pixel differences within and around the entire circular area 13 prevent its location. This method is fast and has a high success rate. In this embodiment, at least one characteristic arc can be searched, and its center can be calculated as a reference center. When searching for multiple characteristic arcs, their centers usually coincide. In this case, the coincident center can be used as the reference center. If the centers of multiple characteristic arcs do not coincide, an average value can be calculated based on the multiple centers, and this average value can be used as the reference center.

[0112] Then, the control unit performs precise positioning of the workpiece based on the reference center. Please refer to [link / reference] for details. Figure 9 and combined Figure 10b ,include:

[0113] Step S121: Determine a reference circle L1 with the reference circle center as the center, and the reference circle L1 surrounds the circular area 13.

[0114] Step S122: Locate the entire edge of the black-and-white junction within the reference circle L1. This edge is the edge of the circular area 13.

[0115] Step S123: Calculate the center of the circular area 13, which is the center of the injector valve seat 10, thereby achieving precise positioning of the injector valve seat 10.

[0116] It is understandable that for other workpieces, as long as they have the same characteristics as the injector valve seat 10, i.e., the workpiece has an axis, and when viewed along the axis, the workpiece has a circular area, and the honing strip presents a ring-shaped structure surrounding the circular area, the control unit can use the same method to position the workpiece on the image. However, it should be noted that when acquiring the image of the workpiece, it is necessary to adjust the incident angle of the irradiation beam onto the workpiece according to the actual situation of the workpiece, so that the honing strip and the non-honed area present a clear distinction.

[0117] Next, please refer to Figure 12 and Figure 13 The control unit calculates the area where the honing belt 11 is located using the center of the injector valve seat 10 (i.e. the center of the circular area) as a reference coordinate, and the control unit stores preset edge lines in advance.

[0118] As mentioned earlier, on the injector valve seat 10, the density of the reflected light from the illumination beam at the honing strip 11 is uniform. Therefore, the brightness value of the honing strip 11 in the image varies as a vector value according to the depth of the reflected light, resulting in the grayscale value change of the honing strip 11 exhibiting the characteristic of a first-order continuous partial derivative. Based on this characteristic, the control unit can calculate the area where the honing strip 11 is located using the following method:

[0119] Step S210: Perform gradient processing on the image.

[0120] Step S220: The image processed in step S210 is binarized. At this time, the workpiece displayed in the image is as follows: Figure 13 As shown, in the image, the grayscale value of the honing belt 11 is relatively dark.

[0121] Step S230: In Figure 13The edge line of the honing belt 11 is located in the image to determine the area where the honing belt 11 is located. If the control unit finds the edge line in the image, the control unit stores the edge line. However, since the injector valve seat 10 was not cleaned before the detection, if there is too much oil or particulate matter on the injector valve seat 10, the control unit may be unable to find the edge line. In this case, the control unit determines that the edge line of the honing belt 11 is the preset edge line.

[0122] Next, the control unit detects whether the honing belt 11 is qualified within the edge line. Figure 14 This illustration shows a process by which the control unit in an exemplary embodiment detects whether the honing belt 11 is qualified. Specifically, it includes the following steps:

[0123] Step S310: Binarize the image after gradient processing. It can be understood that "the image after gradient processing" in this step can be the image processed in step S210. Furthermore, the parameter value set when binarizing the image here is smaller than the parameter value set when binarizing in step S220. For example, the binarization parameter in step S220 can be 27, while the binarization parameter in this step can be 24. The image obtained after this step is as follows: Figure 15 As shown in (a)

[0124] Step S320: In Figure 15 (a) If the honing belt 11 is found to have linear defects, step S330 is executed if no defects are found. If so, the honing belt is deemed unqualified.

[0125] Step S330: In Figure 15 (a) Check whether the honing belt 11 is intact. If it is, proceed to step S340. If not, determine that the honing belt is unqualified.

[0126] Step S340: The control unit outputs the width value of the honing belt 11.

[0127] Step S350: Determine whether the width of the honing belt is greater than the preset width. If yes, the honing belt is deemed unqualified; otherwise, the honing belt is deemed qualified.

[0128] Specifically, step S320 includes:

[0129] Step S321: Identify the defect region L2 and calculate the area of ​​the defect region L2. For those skilled in the art, after gradient processing and binarization, the continuous honing band should be a continuous pixel region without discontinuity, but please refer to... Figure 15In (a) and (b) of the above, there is a white bubble-like region within the edge line of the honing belt 11. This white bubble-like region is the defect region L2, and the area of ​​the defect region L2 is the area of ​​the white bubble-like region.

[0130] Step S322: Determine whether the area of ​​the defect region L2 is greater than a preset area. If yes, determine that the honing belt 11 has a linear defect; otherwise, determine that the honing belt portion has a linear defect. The preset area refers to the allowable defect area of ​​the honing belt that is pre-stored in the control unit.

[0131] Step S330 specifically includes:

[0132] Step S331: Divide the honing belt 11 into several sub-honing belts 11a, for example, the number of sub-honing belts 11a is 19 (e.g. Figure 16 (As shown).

[0133] Step S332: Determine whether each of the sub-honing belts 11a is complete. If it is, the honing belt 11 is determined to be complete. If at least one of the sub-honing belts 11a is incomplete, the honing belt is determined to be incomplete.

[0134] The method for determining whether the sub-honing belt 11a is complete is as follows: calculate the edge pairs and gray values ​​of the sub-honing belt 11a, and determine whether the edge pairs and gray values ​​of the sub-honing belt 11a are both zero. If so, the sub-honing belt 11a is determined to be incomplete; otherwise, the sub-honing belt 11a is determined to be complete.

[0135] In this embodiment, a segmented method is used to determine the integrity of the honing strip 11 because the Insight software determines the integrity of the honing strip by calculating the number of pixels or the area of ​​the region using a histogram. The width of the honing strip 11 is generally between 20um and 100um, and the area ratio between the widest and narrowest regions of the honing strip 11 can reach 25 times. For an injector valve seat 10 with an incomplete honing strip, its pixel count will be much higher than that of an injector valve seat 10 with a complete honing strip, making it difficult to determine the overall integrity of the honing strip using a single histogram by calculating the number of pixels or the area of ​​the region.

[0136] Furthermore, in step S340, the width value output by the control unit is actually a pixel value. When determining whether the width of the honing tape 11 is greater than the preset width, the preset width can also be set to a pixel value. That is, before performing honing tape quality inspection, the operator can pre-determine the width of a qualified honing tape, then convert the width of the honing tape into a pixel value and store it in the control unit.

[0137] Furthermore, it should be understood that steps S340 and S350 are determined to be executed based on actual needs. That is, if the detection standard does not require a specific width for the honing band 11 of the injector valve seat 10, then the control unit can determine that the honing band 11 is qualified when it detects that the honing band 11 is intact.

[0138] This invention provides a method and apparatus for inspecting the quality of honing belts. The honing belt quality inspection apparatus includes an imaging element and a control unit. The imaging element acquires an image of the workpiece to be inspected, and the image fully displays the honing belt on the workpiece. The control unit determines whether the honing belt is qualified based on the image. Thus, the honing belt quality inspection apparatus replaces manual inspection of the honing belt quality, achieving automated honing belt quality inspection. Compared with traditional manual visual inspection, automated inspection can save manufacturing companies nearly 300,000 RMB in labor costs annually. Simultaneously, the detection rate of defective honing belts is improved. Taking injector valve seats as an example, after using the automatic honing belt inspection apparatus provided in this invention, the detection rate of injector valve seats with defective honing belts increases by approximately 0.3%. A higher rate of defective product detection can reduce the risk of injector leaks. Based on a monthly demand of 500,000 injector valve seats, the number of defective injectors can be reduced by 20,000 annually, resulting in a quality cost saving of 400,000. That is, annual production costs can be reduced by 700,000.

[0139] While the present invention has been disclosed above, it is not limited thereto. Those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention also intends to include such modifications and variations.

Claims

1. A method for detecting the quality of honing belts, based on a honing belt quality detection device, the honing belt quality detection device comprising an imaging element and a control unit, characterized in that, Includes the following steps: The imaging element acquires an image of the workpiece and sends the image to the control unit, wherein a honing strip is formed on the workpiece and the image displays the honing strip; the control unit calculates the area where the honing strip is located on the image and determines whether the honing strip is qualified based on the image; The method by which the control unit calculates the region where the honing belt is located includes: Step S210: Perform gradient processing on the image; Step S220: Binarize the image processed in step S210; Step S230: Search for the edge line of the honing belt in the image obtained after processing in step S220. If the edge line cannot be found, determine that the edge line of the honing belt is a preset edge line. If the edge line can be found, store the found edge line of the honing belt. The method by which the control unit determines whether the honing belt is qualified includes: Step S310: Binarize the image after gradient processing. The parameter values ​​for binarization in this step are smaller than the parameter values ​​for binarization in step S220. Step S320: In the image processed by step S310, determine whether there is a linear defect within the edge line of the honing belt. If not, proceed to step S330. If yes, determine that the honing belt is unqualified. Step S330: In the image processed by step S310, check whether the honing belt is complete. If not, determine that the honing belt is unqualified.

2. The method for detecting the quality of honing belts according to claim 1, characterized in that, Before determining whether the honing belt is qualified, the method further includes: the control unit positioning the workpiece on the image; The control unit first performs coarse positioning on the workpiece, and then performs fine positioning on the workpiece.

3. The method for detecting the quality of honing belts according to claim 2, characterized in that, The workpiece has an axis, and along the axis, the workpiece has a circular area. The honing belt is a ring-shaped structure surrounding the circular area. The image shows the circular area and the honing belt with the ring-shaped structure. The method for coarsely positioning the workpiece includes: Step S111: Binarize the image; Step S112: Locate the characteristic arc of the circular region in the image processed by step S111; Step S113: Calculate the center of the characteristic arc to obtain the reference center; and / or, The method for precisely positioning the workpiece includes: Step S121: Determine a reference circle with the reference center as the center, the reference circle surrounding the circular area; Step S122: Locate the edge of the circular area within the reference circle; Step S123: Calculate the center of the circular region.

4. The method for detecting the quality of honing belts according to claim 1, characterized in that, If the honing belt is intact, after step S330 is completed, the following steps are also included: Step S340: Output the width value of the honing belt; Step S350: Determine whether the width of the honing belt is greater than the preset width. If yes, the honing belt is deemed unqualified; otherwise, the honing belt is deemed qualified.

5. The method for detecting the quality of honing belts according to claim 4, characterized in that, Step S320 specifically includes: Step S321: Identify the defective region and calculate the area of ​​the defective region; Step S322: Determine whether the area of ​​the defective region is greater than a preset area. If yes, determine that the honing belt has a linear defect; if no, determine that the honing belt does not have a linear defect; and / or, step S330 specifically includes: Step S331: Divide the honing belt into several sub-honing belts; Step S332: Determine whether each of the sub-honing belts is complete. If it is, the honing belt is determined to be complete. If at least one of the sub-honing belts is incomplete, the honing belt is determined to be incomplete. The method for determining whether the sub-honing belt is complete is as follows: calculate the edge pairs and gray values ​​of the sub-honing belt; determine whether the edge pairs and gray values ​​of the sub-honing belt are both zero. If so, the sub-honing belt is incomplete; if not, the sub-honing belt is complete.

6. A honing belt quality inspection device, characterized in that, It includes a workpiece stage, a light source, an imaging element, and a control unit; among which, The workpiece stage is used to place the workpiece to be inspected, and the workpiece has a honing belt formed on it; The light source is used to provide an illumination beam to the workpiece to be inspected; The imaging element is used to acquire an image of the workpiece and send the image to the control unit, wherein the honing belt is displayed on the image; and The control unit calculates the area where the honing belt is located based on the image, and determines whether the honing belt on the workpiece is qualified; The control unit is configured to perform the following steps to calculate the region where the honing belt is located: Step S210: Perform gradient processing on the image; Step S220: Binarize the image processed in step S210; Step S230: Search for the edge line of the honing belt in the image obtained after processing in step S220. If the edge line cannot be found, determine that the edge line of the honing belt is a preset edge line. If the edge line can be found, store the found edge line of the honing belt. The control unit is configured to perform the following steps to determine whether the honing belt is qualified: Step S310: Binarize the image after gradient processing. The parameter values ​​for binarization in this step are smaller than the parameter values ​​for binarization in step S220. Step S320: In the image processed by step S310, determine whether there is a linear defect within the edge line of the honing belt. If not, proceed to step S330. If yes, determine that the honing belt is unqualified. Step S330: In the image processed by step S310, check whether the honing belt is complete. If not, determine that the honing belt is unqualified.

7. The honing belt quality detection device according to claim 6, characterized in that, The control unit is configured to: position the workpiece on the image; when positioning the workpiece, the control unit is configured to: first perform coarse positioning of the workpiece, and then perform fine positioning of the workpiece.

8. The honing belt quality detection device according to claim 7, characterized in that, The workpiece has a circular area, and along the axial direction of the circular area, the honing belt is a ring-shaped structure surrounding the circular area; the image shows the circular area and the honing belt with the ring-shaped structure; The control unit is configured to: perform binarization processing on the image, find the characteristic arc of the circular area, calculate the center of the characteristic arc to obtain a reference center to achieve the coarse positioning; determine a reference circle around the circular area with the reference center as the center, find the edge of the circular area within the reference circle, and calculate the center of the circular area to achieve the fine positioning.

9. The honing belt quality detection device according to claim 6, characterized in that, When performing step S320, the control unit is configured to: identify a defect area within the edge line of the honing belt and calculate the area of ​​the defect area, and determine whether the honing belt has a linear defect based on the area of ​​the defect area; When performing step S330, the control unit is further configured to: divide the honing strip into several sub-honing strips, calculate the edge pairs and gray values ​​of each sub-honing strip, and determine whether the honing strip is complete based on the edge pairs and gray values ​​of each sub-honing strip; If the honing belt is intact, the control unit is further configured to: output the width value of the honing belt and determine whether the width of the honing belt is qualified.

10. The honing belt quality detection device according to any one of claims 6-9, characterized in that, The workpiece is an injector valve seat, the light source is a ring-shaped structure, the imaging element is a camera, the light source is disposed between the camera and the workpiece stage, and the light source and the camera are arranged coaxially; the light source is used to generate an illumination beam, and the illumination beam forms an angle with the surface of the workpiece stage, the angle being 45°-60°.

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