A method for detecting the flatness of micro-intermittent petal-shaped mechanical seals

Abstract

The present invention discloses a method for detecting the flatness of a micro-intermittent petal-shaped mechanical seal, and relates to the field of seal detection. The method for detecting the flatness of a micro-intermittent petal-shaped mechanical seal uses a detection device to detect the flatness of the micro-intermittent petal-shaped mechanical seal, and the detection device includes a solid wood body, a flat crystal tray is provided inside the solid wood body, a plane mirror is provided inside the solid wood body, a computer is provided on the side of the solid wood body, a CCD sensor bracket is provided on the front of the solid wood body, and an industrial CCD imaging camera is provided on the CCD sensor bracket. The method for detecting the flatness of a micro-intermittent petal-shaped mechanical seal greatly improves the efficiency and accuracy of flatness detection of micro-intermittent petal-shaped mechanical seals, and is based on the interference measurement principle, and extracts and amplifies the interference fringe image through a highly economical industrial camera CCD imaging system, and explains and guides the analysis and judgment method of the interference fringe in detail.

Description

Technical Field

[0001] The invention relates to the technical field of seal detection, and in particular to a method for detecting the flatness of a tiny discontinuous petal-shaped mechanical seal. Background Art

[0002] The formation principle of mechanical seal requires at least one pair of end faces perpendicular to the rotation axis to maintain contact and produce relative sliding through the action of external force and the cooperation of auxiliary seals, thus forming an active device to prevent internal liquid and gas leakage during operation.

[0003] At present, the common measurement methods for this type of flatness parameter detection are the flat crystal method and the white light flatness measuring instrument detection method. These two conventional measurement methods cannot meet the flatness detection requirements of tiny intermittent petal-shaped mechanical seal surfaces. The main technical difficulties are that it is difficult to read the flatness value through interference fringes by the flat crystal interference method (the width of this type of part is less than 1mm, and the interference fringes are light and dark, and cannot be clearly distinguished), the white light flatness measuring instrument is expensive (it is an imported device from abroad), and the device's own software needs to filter the image. The filtering process cannot distinguish whether the gross error it recognizes is a burr that actually exists on the edge of the part entity, or air dust. Uniform filtering will affect the judgment of the actual state of the part. In view of the shortcomings of the prior art, the present invention provides a method for detecting the flatness of tiny intermittent petal-shaped mechanical seals to solve the above problems. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a method for detecting the flatness of a tiny intermittent petal-shaped mechanical seal, which solves the problem that two conventional measurement methods cannot meet the flatness detection requirements of a tiny intermittent petal-shaped mechanical seal surface.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for detecting the flatness of a micro-intermittent petal-shaped mechanical seal, using a CCD sensor to extract the flatness of the micro-intermittent petal-shaped mechanical seal detected by a detection device, 1) The detection device includes a solid wood body, a flat crystal tray is provided inside the solid wood body, and a plane mirror is provided inside the solid wood body;

[0008] A computer is provided on the side of the solid wood body, a CCD sensor bracket is provided on the front of the solid wood body, and an industrial CCD imaging camera is provided on the CCD sensor bracket;

[0009] A sodium lamp is arranged inside the solid wood body;

[0010] 2) The detection method includes the following steps:

[0011] During inspection, turn on the sodium lamp placed in the solid wood body, take out the flat crystal within the qualified inspection cycle from the storage box, place it on the flat crystal tray with the working surface facing up, wipe the surface of the part to be tested clean, and gently place it on the flat crystal working surface. Place an industrial CCD imaging camera on the CCD sensor bracket, and the industrial CCD imaging camera records the shape of the reflected interference fringes through a plane mirror at a 45° angle.

[0012] The present invention discloses a method for detecting the flatness of a micro-intermittent petal-shaped mechanical seal, which has the following beneficial effects:

[0013] 1. This method for detecting the flatness of tiny intermittent petal-shaped mechanical seals has greatly improved the detection efficiency and accuracy of the flatness of tiny intermittent petal-shaped mechanical seals. It is based on the interference measurement principle, extracts and amplifies the interference fringe image through a highly economical industrial camera CCD imaging system, and explains and guides the analysis and judgment method of the interference fringe in detail, which makes up for the current situation that the flatness measurement results of tiny intermittent petal-shaped mechanical seals are difficult to read and the measurement results cannot truly reflect the actual state of the measured plane, and can efficiently and accurately quantify the reading of the measurement results.

[0014] 2. The flatness detection method of the tiny intermittent petal-shaped mechanical seal comprises a flat crystal protection cover for protecting the flat crystal tray and the flat crystal inside, and a CCD sensor bracket for supporting the industrial CCD imaging camera, thereby facilitating the flatness detection of the tiny intermittent petal-shaped mechanical seal. The industrial CCD imaging camera is used to amplify the interference fringes and improve the image information. The method has low cost and good use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a diagram of the CCD imaging detection system of the flat crystal interferometry method of the present invention;

[0017] Figure 2 Schematic diagram of monochromatic light interference fringes;

[0018] Figure 3 This is a specific example of the interference fringe pattern of the present invention (0.3um);

[0019] Figure 4 This is a specific example of the interference ring pattern of the present invention (0.6um);

[0020] Figure 5 This is a specific example of the interference ring pattern of the present invention (0.9um);

[0021] Figure 6 This is a typical example of the interference ring pattern of the present invention (2.7um);

[0022] Figure 7 This is a schematic diagram of the conventional interference fringe detection effect of the present invention;

[0023] Figure 8 This is an imaging effect diagram of the interference fringe industrial camera of the present invention;

[0024] Fig. 9 This is a rendering of the actual detection parts of the present invention.

[0025] In the figure: 1. Solid wood body; 2. Flat crystal tray; 3. Flat crystal protection cover; 4. CCD sensor bracket; 5. Computer; 6. Plane mirror. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The embodiment of the present application provides a method for detecting the flatness of a tiny intermittent petal-shaped mechanical seal, thereby solving the problem that two conventional measurement methods cannot meet the flatness detection requirements of a tiny intermittent petal-shaped mechanical seal surface, thereby improving the efficiency and accuracy of flatness detection of a tiny intermittent petal-shaped mechanical seal.

[0028] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] Embodiment 1

[0030] The embodiment of the present invention discloses a method for detecting the flatness of a micro intermittent petal-shaped mechanical seal. Figure 1-6 As shown, the flatness of a tiny intermittent petal-shaped mechanical seal is detected by using a detection device, 1) the detection device comprises a solid wood body 1, a flat crystal tray 2 is arranged inside the solid wood body 1, and a plane mirror 6 is arranged inside the solid wood body 1;

[0031] A computer 5 is provided on the side of the solid wood body 1, and a CCD sensor bracket 4 is provided on the front of the solid wood body 1, and an industrial CCD imaging camera is provided on the CCD sensor bracket 4;

[0032] A sodium lamp is provided inside the solid wood body 1;

[0033] 2) The detection method includes the following steps:

[0034] During the inspection, turn on the sodium light lamp placed in the solid wood body 1, take out the flat crystal within the qualified inspection cycle from the storage box, put it on the flat crystal tray 2 with the working surface facing up, wipe the surface of the part to be tested clean, and gently put it on the flat crystal working surface, and place the industrial CCD imaging camera on the CCD sensor bracket 4. The industrial CCD imaging camera records the shape of the interference fringes reflected by the plane mirror at an angle of 45°. The human eye is about 1 meter away from the actual position of the interference fringes on the surface of the part reflected by the plane mirror, and the human eye can no longer clearly distinguish the actual state of the interference fringes;

[0035] This method greatly improves the efficiency and accuracy of flatness detection of tiny intermittent petal-shaped mechanical seals. Based on the interference measurement principle, the interference fringe image is extracted and amplified through a highly economical industrial camera CCD imaging system, and the analysis and judgment method of the interference fringes is explained and guided in detail. This makes up for the current situation that the flatness measurement results of tiny intermittent petal-shaped mechanical seals are difficult to read and the measurement results cannot truly reflect the actual state of the measured plane, and the measurement results can be quantified and read efficiently and accurately.

[0036] Embodiment 2

[0037] The embodiment of the present invention discloses a method for detecting the flatness of a micro intermittent petal-shaped mechanical seal. Figure 1-6 As shown, the flatness of a tiny intermittent petal-shaped mechanical seal is detected by using a detection device, 1) the detection device comprises a solid wood body 1, a flat crystal tray 2 is arranged inside the solid wood body 1, and a plane mirror 6 is arranged inside the solid wood body 1;

[0038] A computer 5 is provided on the side of the solid wood body 1, and a CCD sensor bracket 4 is provided on the front of the solid wood body 1, and an industrial CCD imaging camera is provided on the CCD sensor bracket 4;

[0039] A sodium lamp is provided inside the solid wood body 1;

[0040] 2) The detection method includes the following steps:

[0041] During inspection, turn on the sodium lamp placed in the solid wood main body 1, take out the flat crystal within the qualified inspection cycle from the storage box, place it on the flat crystal tray 2 with the working surface facing up, wipe the surface of the part to be tested clean, and gently place it on the flat crystal working surface, place an industrial CCD imaging camera on the CCD sensor bracket 4, and record the shape of the reflected interference fringes through a plane mirror at an angle of 45°.

[0042] A flat crystal protection cover 3 is provided on the solid wood main body 1, and the flat crystal protection cover 3 is provided to protect the flat crystal tray 2 and the flat crystal inside. The CCD sensor bracket 4 is provided to support the industrial CCD imaging camera, thereby facilitating the flatness detection of tiny intermittent petal-shaped mechanical seals, amplifying the interference fringes and improving the image information.

[0043] The flatness detection method of tiny intermittent petal-shaped mechanical seal surface is to use the interference method to measure the imaging details, add a specific type of industrial camera to improve the imaging image, and provide detailed analysis guidance for the evaluation process of identifying interference fringes with the naked eye.

[0044] The basic principle of flat crystal detection of flatness error is to use a parallel flat crystal to contact the surface of the workpiece at a certain inclination angle to form a non-angle air medium sandwich or a small angle air medium wedge. At this time, under monochromatic light, continuous light and dark interference fringes can be seen through the flat crystal; under natural light, colorful interference fringes can be seen. Regardless of interference rings or interference bands, they all appear in groups. Under monochromatic light, one black and one white form a group, and under natural light, red, orange, yellow, green, cyan, blue, and purple form a group. Figure 2 Schematic diagram of monochromatic light interference fringes.

[0045] This detection method is widely used in the flatness detection process of high-precision aviation seals. However, in actual work, many companies do not have the ability to clearly interpret the specific numerical values ​​of the flatness presented by the interference fringes, resulting in misjudgments and misdetections in actual work.

[0046] The tolerance requirement of ultra-high precision flatness parameters is usually 0.0003mm, and occasionally there are tolerance requirements of 0.0009mm to 0.0015mm, such as Fig. 9 As shown in the parts diagram of a certain type of valve seat, the shaded area on the left is the location of the tiny intermittent petal-shaped mechanical seal surface on the A surface being measured.

[0047] The theoretical interpretation method is that if there are no more than one interference ring or interference band of the same color, the flatness error is judged to be ≤0.3μm (according to "JJG 21-2008 Micrometer"). In the actual part inspection process, the interference fringe pattern read cannot be as Figure 2 The general standard is summarized as follows, taking the actual interference ring pattern under a monochromatic sodium light source as an example:

[0048] As above Figure 3 The six graphs shown can be analyzed to see their formation principles:

[0049] (a) There is only one uniform stripe, which is formed by the refraction of light in the non-angle air medium interlayer. It is determined that the surface flatness value of the part is ≤0.3μm;

[0050] (b) (c) The interval width of black and white stripes is different. The reason for this is that the thickness of the air medium interlayer formed when the flat crystal contacts the surface of the part is different. If any straight line AB passes through any area in the interference pattern and the straight line AB cannot intersect with two stripes of the same color (such as black) at the same time, it is determined that there is one interference stripe on the surface of the part and the flatness value is ≤0.3μm.

[0051] (d) (e) (f) The interference fringe patterns are all symmetrically distributed. The reason for this is that the surface flatness of the part is high in the middle and low on both sides, or low in the middle and high on both sides, that is, it is symmetrical and uneven. Then the single-sided flatness of the part surface is the overall flatness of the part. At this time, a straight line AB is used to pass through any area in the symmetrical half of the interference pattern. The straight line AB cannot intersect with two stripes of the same color (such as black) at the same time. It is determined that there is one interference fringe on the surface of the part, and the flatness value is ≤0.3μm.

[0052] As above Figure 4 The six graphs shown can be analyzed to see their formation principles:

[0053] (a) There are only two uniform stripes, which are formed by the refraction of light in the non-angle air medium interlayer. It is determined that the surface flatness value of the part is ≤0.6μm;

[0054] (b) (c) The interval width of black and white stripes is different. The reason for this is that the thickness of the air medium interlayer formed when the flat crystal contacts the surface of the part is different. If any two straight lines AB are used to pass through any area in the interference pattern, and the straight lines AB cannot intersect with three stripes of the same color (such as black) at the same time, it is determined that there are two interference stripes on the surface of the part, and the flatness value is ≤0.6μm;

[0055] (d) (e) (f) The interference fringe patterns are all symmetrically distributed. The reason for this is that the surface flatness of the part is high in the middle and low on both sides, or low in the middle and high on both sides, that is, it is symmetrical and uneven. Then the single-sided flatness of the part surface is the overall flatness of the part. At this time, a straight line AB is used to pass through any area in the symmetrical half of the interference pattern. The straight line AB cannot intersect with three stripes of the same color (such as black) at the same time. It is determined that there are two interference fringes on the surface of the part, and the flatness value is ≤0.6μm.

[0056] As above Figure 5 The six graphs shown can be analyzed to see their formation principles:

[0057] (a) There are only three uniform stripes, which are formed by the refraction of light in the non-angled air medium interlayer. It is determined that the surface flatness value of the part is ≤0.9μm;

[0058] (b) (c) The interval widths of black and white stripes are different. The reason for this is that the thickness of the air medium interlayer formed when the flat crystal contacts the surface of the part is different. Using any two straight lines AB to pass through any area in the interference pattern, the straight lines AB cannot intersect with four stripes of the same color (such as black) at the same time. It is determined that there are three interference stripes on the surface of the part, and the flatness value is ≤0.9μm;

[0059] (d) (e) (f) The interference fringe patterns are all symmetrically distributed. The reason for this is that the surface flatness of the part is high in the middle and low on both sides, or low in the middle and high on both sides, that is, it is symmetrical and uneven. Then the single-sided flatness of the part surface is the overall flatness of the part. At this time, a straight line AB is used to pass through any area in the symmetrical half of the interference pattern. The straight line AB cannot intersect with 4 stripes of the same color (such as black) at the same time. It is determined that there are 3 interference fringes on the surface of the part, and the flatness value is ≤0.9μm.

[0060] As above Figure 6 The six graphs shown can be analyzed to see their formation principles:

[0061] (a) There are only 9 uniform stripes, which are formed by the refraction of light in the non-angle air medium interlayer. It is determined that the surface flatness value of the part is ≤ 0.27μm;

[0062] (b) (c) The interval width of black and white stripes is different. The reason for this is that the thickness of the air medium interlayer formed when the flat crystal contacts the surface of the part is different. If any 9 straight lines AB are used to pass through any area in the interference pattern, and the straight line AB cannot intersect with 10 stripes of the same color (such as black) at the same time, it is determined that there are 9 interference stripes on the surface of the part, and the flatness value is ≤0.27μm;

[0063] (d) (e) (f) The interference fringe patterns are all symmetrically distributed. The reason for this is that the surface flatness of the part is high in the middle and low on both sides, or low in the middle and high on both sides, that is, it is symmetrical and uneven. Then the single-sided flatness of the part surface is the overall flatness of the part. At this time, a straight line AB is used to pass through any area in the symmetrical half of the interference pattern. The straight line AB cannot intersect with 10 stripes of the same color (such as black) at the same time. It is determined that there are 9 interference fringes on the surface of the part, and the flatness value is ≤0.27μm.

[0064] When the interference fringe pattern shows multiple interference fringes, we should not simply count the number of interference fringes, but carefully analyze the formation law and reasons of the interference fringes, and count the number of interference fringes that intersect at the same time by intersecting the straight line AB with the interference fringes. That is, the degree of curvature of the interference fringes is the basis for measuring the true flatness of the part.

[0065] As above Figure 7(a) (b) shows a standard gauge block, which is used as a reference standard. When the measured plane area of ​​the part is large enough, the analysis and judgment method summarized in this method can be used to correctly evaluate the flatness parameters of the plane. However, when the measured plane is in the shape of a tiny intermittent petal, the naked eye or through mobile phone magnification cannot accurately and efficiently identify the morphological characteristics of the interference fringes. After consulting multiple sources and conducting experiments, this method selects XX model of industrial camera suitable for reading this type of plane mirror reflection imaging, extracts, amplifies, and improves the resolution of the interference fringes that cannot be identified by the naked eye. The specific imaging effect is as follows: Figure 8 Interference fringe industrial camera imaging effect diagram, in order to clearly present the interference fringe effect, Figure 8 The straight lines AB in the middle are placed in the same direction as the interference fringe contour, but parallel to the blank area next to them. Please zoom in the document to a display ratio of more than 150% for viewing. The interference fringes of the parts in two circles are unclear. They can be extracted separately during actual measurement, wiped and placed again for reading. If they are still unclear, it can be determined that the surface cannot present interference fringes and the flatness parameter test result is unqualified.

[0066] In this method, the flat crystal interferometry detection principle is utilized to build a highly economical industrial camera CCD imaging system to amplify the intermittent tiny stripes, clearly guide the analysis and judgment method of the interference stripes, and achieve highly economical, efficient and accurate detection of the flatness of tiny intermittent petal-shaped mechanical seal surfaces.

[0067] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0068] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for detecting the flatness of a micro-intermittent petal-shaped mechanical seal, using a detection device to detect the flatness of a micro-intermittent petal-shaped mechanical seal, characterized in that: 1) The detection device comprises a solid wood body (1), a flat crystal tray (2) is provided inside the solid wood body (1), and a plane mirror (6) is provided inside the solid wood body (1); A computer (5) is provided on the side of the solid wood body (1), a CCD sensor bracket (4) is provided on the front of the solid wood body (1), and an industrial CCD imaging camera is provided on the CCD sensor bracket (4); A sodium lamp is provided inside the solid wood body (1); 2) The detection method includes the following steps: During the inspection, the sodium light lamp placed in the solid wood body (1) is turned on, and the flat crystal within the qualified inspection cycle is taken out from the storage box, and the working surface is upward, and placed on the flat crystal tray (2). The surface of the part to be tested is wiped clean and gently placed on the flat crystal working surface. An industrial CCD imaging camera is placed on the CCD sensor bracket (4), and the industrial CCD imaging camera records the shape of the interference fringes reflected by the plane mirror at an angle of 45°; 3) The specific analysis method is as follows:

1. There is only one uniform stripe, which is formed by the refraction of light in the non-angle air medium interlayer. It is determined that the surface flatness value of the part is ≤0.3μm; 2. The interval width of black and white stripes is different. The reason for this is that the thickness of the air medium interlayer formed when the flat crystal contacts the surface of the part is different. If any straight line AB passes through any area in the interference pattern, and the straight line AB cannot intersect with two stripes of the same color at the same time, it is determined that there is one interference fringe on the surface of the part, and the flatness value is ≤0.3μm; 3. The interference fringe patterns are all symmetrically distributed. The reason for this is that the surface flatness of the part is high in the middle and low on both sides, or low in the middle and high on both sides, that is, it is symmetrical and uneven. Then the single-sided flatness of the part surface is the overall flatness of the part. At this time, a straight line AB is used to pass through any area in the symmetrical half of the interference pattern. The straight line AB cannot intersect with two stripes of the same color at the same time. It is determined that there is one interference fringe on the surface of the part, and the flatness value is ≤0.3μm; When the interference fringe pattern shows multiple interference fringes, we should not simply count the number of interference fringes, but carefully analyze the formation law and reasons of the interference fringes, and count the number of interference fringes that intersect at the same time by intersecting the straight line AB with the interference fringes. That is, the degree of curvature of the interference fringes is the basis for measuring the true flatness of the part.

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