Method for detecting appearance and roughness of inner surface of complex structure

Abstract

The invention discloses a complex structure inner surface morphology and roughness detection method, which comprises the following steps: guiding a magnetic ball in a glue injection pipe to move through an external guide magnetic pole so as to drive a notch of the glue injection pipe to move to a specified position, injecting glue into the glue injection pipe through a glue injection device, the glue is coated at the appointed position of the inner surface of the workpiece through the notch of the glue injection pipe; after the glue is solidified, the glue injection pipe is pulled out for demolding, and a duplicated surface at the designated position is obtained; and detecting the appearance and the roughness of the duplicated surface in an optical detection mode. According to the invention, the glue injection pipe controlled by magnetic force is designed, controllable copying of the local surface in the complex structure is realized, and high-precision accurate copying of the inner surface of the complex structure is realized by using a high-flexibility silicone rubber compound, so that high-precision detection of the morphology and roughness of the inner surface of the complex structure is realized. The solidified colloid and the glue injection pipe form a whole body, and the whole body cannot be broken during demolding; and the glue is mainly formed at the notch, so that the glue injection amount is greatly reduced.

Description

Technical Field

[0001] The present invention relates to deep hole inner surface detection technology, in particular to a method for detecting the inner surface topography and roughness of a complex structure. Background Art

[0002] Inner surfaces with complex structures usually contain areas that are difficult to reach with conventional tools. These structures typically have small apertures, large depth-to-diameter ratios, variable inner diameters, and multiple cross-channels, etc., which pose further challenges to the measurement of the inner surface. Existing high-precision global measurement methods such as confocal microscopes, atomic force microscopes, and scanning electron microscopes are only applicable to the measurement of outer surfaces due to their large equipment size and complex optical circuits.

[0003] For the non-destructive measurement of the inner surface roughness of parts, the touch probe method, the optical interference method, and the replication method are usually adopted. The first two methods are applicable to the measurement of the inner surface of workpieces with large inner diameters. For the measurement of the inner surface of workpieces with small inner diameters, their accessibility is limited. The replication method is to coat a replication material with a certain fluidity on the workpiece surface to ensure that it fills the microstructures of the surface to be measured under the influence of gravity or extrusion pressure. Once the replication material solidifies, the replica of the surface morphology can be demolded. Then, the replica is measured and processed to indirectly obtain the original morphology information.

[0004] Chinese Patent CN 108663012 A discloses a method for detecting the inner wall micro-topography and roughness of a gap. This method shrinks and inserts a flexible mechanism with a measurement film into the gap; the flexible mechanism is controlled by a controller to expand, so that the measurement film is effectively combined with the measured surface, and the measurement film extracts the inner wall micro-topography and surface roughness information by replication; the flexible mechanism is controlled to shrink and exit from the gap entrance, and numerical measurement is carried out through a surface topography measuring instrument. The invention can effectively solve the problem of measuring the inner wall micro-topography and surface roughness of a gap with a narrow entrance size; the method is simple and easy to implement, the operation is simple, the equipment is easy to carry, the cost is low, and the measurement accuracy is relatively high. However, affected by the control of the measurement film and the expansion force of the flexible mechanism, the stability of the replication of the inner surface still needs to be improved, which in turn affects the measurement accuracy.

[0005] Chinese Patent CN 114018662 A discloses a non-destructive testing method for the surface topography and roughness of deep holes. A glue extruder is used to extrude a mixed glue. After the A glue and the B glue are fully mixed and stirred through a mixing glue nozzle, they are extruded onto the surface of the inner cavity of the complex structure at the working temperature and within the working time. The fully stirred mixed glue automatically reacts and cures into an elastic colloid in a short time, replicating the microscopic topography of the inner surface of the workpiece. Subsequently, the cured elastic colloid is peeled off from the surface of the workpiece structure, and a surface topography measuring instrument is used to measure it to accurately observe the surface topography information of the workpiece. This method can observe the change trend of the surface topography; it can quickly and real-time perform high-precision replication and recording of the surface topography of multiple workpieces or different processing stages of the workpiece, ensuring the measurement accuracy. However, when this method encounters a long deep hole, the colloid is easily broken during demoulding, resulting in the need to re-measure. In addition, the entire deep hole is filled with colloid, causing material waste. Summary of the Invention

[0006] To solve the above problems existing in the prior art, the present invention aims to design a detection method for the surface topography and roughness of the inner surface of a complex structure that can not only improve the measurement accuracy but also facilitate demoulding.

[0007] To achieve the above object, the technical solution of the present invention is as follows: A detection method for the surface topography and roughness of the inner surface of a complex structure, comprising the following steps:

[0008] A. Insert a glue injection tube into the workpiece; a magnetic ball is installed at the inner end of the glue injection tube, and a cut is made on the outer side of the glue injection tube.

[0009] B. Guide the magnetic ball in the glue injection tube to move through the external guiding magnetic pole of the workpiece, thereby driving the cut of the glue injection tube to move to a specified position, and inject glue into the glue injection tube through a glue injection device, so that the colloid is coated on the specified position of the inner surface of the workpiece through the cut of the glue injection tube.

[0010] C. After the colloid solidifies, pull out the glue injection tube for demoulding to obtain a replicated surface at the specified position.

[0011] D. Use an optical detection method to detect the topography and roughness of the replicated surface.

[0012] Further, there are multiple cuts, and the positions of the multiple cuts respectively correspond to multiple specified positions inside the workpiece.

[0013] Further, the unfolded shape of the cut is rectangular or circular, and the maximum size of the cut is less than 1 mm.

[0014] Further, the magnetic ball is fixed at the inner end of the glue injection tube, and the distance from the cut to the magnetic ball is less than 10 mm.

[0015] Further, the glue injection tube is a flexible tube.

[0016] Furthermore, the outer dimensions of the glue injection tube match the inner surface dimensions of the workpiece.

[0017] Furthermore, the material of the colloid is a silicone rubber compound, and the silicone rubber compound is formed by mixing glue A and glue B.

[0018] Furthermore, glue A is prepared by mixing 80%-90% by mass of a base polymer, 10%-15% by mass of a reinforcing filler, and 1%-5% by mass of a diluent; the base polymer includes one or more of silicone, epoxy resin, and polyester resin; the reinforcing filler uses nano-fillers, including one or more of fumed silica, carbon black, carbon nanofibers, carbon nanotubes, polyhedral oligomeric silsesquioxane, and graphene; the diluent includes one or more of acetone, methyl ethyl ketone, and cyclohexanone;

[0019] Glue B is prepared by mixing 50%-60% by mass of a catalyst, 25%-30% by mass of a crosslinking agent, and 15%-20% by mass of a demolding agent; the catalyst includes one or more of complex catalysts, metal catalysts, and metal oxide catalysts; the crosslinking agent includes one or more of silicone-based, polyol-based, organic, and organic peroxide-based; the demolding agent includes one or more of high-polymer demolding agents.

[0020] Furthermore, the base polymer is silicone; the reinforcing filler uses fumed silica or carbon black; the catalyst is a complex catalyst; the crosslinking agent is silicone-based.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention designs a glue injection tube controlled by magnetism, realizes the controllable replication of the local surface inside a complex structure, and uses a highly flexible silicone rubber compound to achieve high-precision and accurate replication of the inner surface of the complex structure, thereby realizing the high-precision detection of the inner surface topography and roughness of the complex structure.

[0023] 2. The cured colloid and the glue injection tube of the present invention form an integral body and will not break during demolding; moreover, the colloid is mainly formed at the incision, greatly reducing the amount of injected glue, which not only saves materials but also improves the measurement efficiency. Description of the Drawings

[0024] Figure 1 is the flowchart of the present invention.

[0025] Figure 2 is the surface detection comparison diagram of a certain curved surface and the replicated colloid.

[0026] Figure 3 is the surface detection comparison diagram of the 3D printing surface and the replicated colloid.

[0027] In the figure: 1. magnetic ball, 2. glue injection tube, 3. colloid, 4. workpiece, 5. guiding magnetic pole, 6. incision, 7. replicated surface. Specific implementation mode

[0028] The present invention will be further described below in conjunction with the accompanying drawings. As Figure 1 shown, a method for detecting the surface topography and roughness of a complex structure inner surface includes the following steps:

[0029] A. Insert the glue injection tube 2 into the workpiece 4; a magnetic ball 1 is installed at the inner end of the glue injection tube 2, and an incision 6 is formed on the outer side of the glue injection tube 2;

[0030] B. Guide the movement of the magnetic ball 1 in the glue injection tube 2 through the guiding magnetic pole 5 outside the workpiece 4, and then drive the incision 6 of the glue injection tube 2 to move to a specified position. Inject glue into the glue injection tube 2 through a glue injection device, so that the colloid 3 is coated on the specified position of the inner surface of the workpiece 4 through the incision 6 of the glue injection tube 2;

[0031] C. After the colloid 3 solidifies, pull out the glue injection tube 2 for demoulding to obtain a replicated surface 7 at the specified position;

[0032] D. Use an optical detection method to detect the topography and roughness of the replicated surface 7.

[0033] Furthermore, there are multiple incisions 6, and the positions of the multiple incisions 6 respectively correspond to multiple specified positions inside the workpiece 4.

[0034] Furthermore, the unfolded shape of the incision 6 is rectangular or circular, and the maximum dimension of the incision 6 is less than 1 mm.

[0035] Furthermore, the magnetic ball 1 is fixed at the inner end of the glue injection tube 2, and the distance from the incision 6 to the magnetic ball 1 is less than 10 mm.

[0036] Furthermore, the glue injection tube 2 is a flexible tube.

[0037] Furthermore, the outer dimension of the glue injection tube 2 matches the inner surface dimension of the workpiece 4.

[0038] Furthermore, the material of the colloid 3 is a silicone rubber compound, and the silicone rubber compound is formed by mixing glue A and glue B.

[0039] Further, the adhesive A is prepared by mixing 80%-90% by mass of a base polymer, 10%-15% by mass of a reinforcing filler, and 1%-5% by mass of a diluent; the base polymer includes one or more of silicone, epoxy resin, and polyester resin; the reinforcing filler is a nano-filler, including one or more of fumed silica, carbon black, carbon nanofibers, carbon nanotubes, polyhedral oligomeric silsesquioxane, and graphene; the diluent includes one or more of acetone, methyl ethyl ketone, and cyclohexanone;

[0040] The adhesive B is prepared by mixing 50%-60% by mass of a catalyst, 25%-30% by mass of a crosslinking agent, and 15%-20% by mass of a release agent; the catalyst includes one or more of complex catalysts, metal catalysts, and metal oxide catalysts; the crosslinking agent includes one or more of silicone-based, polyol-based, organic-based, and organic peroxide-based; the release agent includes one or more of high-polymer release agents.

[0041] Further, the base polymer is silicone; the reinforcing filler is fumed silica or carbon black; the catalyst is a complex catalyst; the crosslinking agent is silicone-based.

[0042] Figure 2 This is a comparison of detecting a certain curved surface using the present invention. The three left, middle, and right upper-side figures in the drawing are respectively the three-dimensional morphology diagram, white light interference measurement result, and micrograph of the original curved surface; the three left, middle, and right lower-side figures in the drawing are respectively the three-dimensional morphology diagram, white light interference measurement result, and micrograph of the replicated surface; the detection result is: the roughness of the original curved surface is 0.53 μm, the roughness of the colloidal replicated surface is 0.55 μm, and the difference is only 3.8%.

[0043] Figure 3 This is a comparison of detecting a 3D printing surface using the present invention. The three left, middle, and right upper-side figures in the drawing are respectively the three-dimensional morphology diagram, white light interference measurement result, and micrograph of the original 3D printing surface; the three left, middle, and right lower-side figures in the drawing are respectively the three-dimensional morphology diagram, white light interference measurement result, and micrograph of the replicated surface; the detection result is: the roughness of the original 3D printing body surface is 5.44 μm, the roughness of the colloidal replicated surface is 5.53 μm, and the difference is only 4.5%.

[0044] The present invention is not limited to this embodiment. Any equivalent concept or change within the technical scope disclosed by the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for detecting the internal surface morphology and roughness of a complex structure, characterized by: The following steps are involved: A. Insert the glue injection tube (2) into the workpiece (4); the inner end of the glue injection tube (2) is provided with a magnetic ball (1), and the outer side of the glue injection tube (2) is provided with a cutout (6); B. The magnetic ball (1) in the glue injection tube (2) is guided to move by the external guide magnetic pole (5) of the workpiece (4), thereby driving the cutout (6) of the glue injection tube (2) to move to a specified position, and the glue is injected into the glue injection tube (2) by the glue injection device, so that the glue (3) is coated on the specified position of the inner surface of the workpiece (4) through the cutout (6) of the glue injection tube (2); C. After the colloid (3) solidifies, the injection tube (2) is pulled out to demould, thereby obtaining a replica surface (7) at a designated position; D. Use optical detection methods to detect the morphology and roughness of the replicated surface (7).

2. A method for detecting the internal surface morphology and roughness of a complex structure according to claim 1, characterized in that: There are a plurality of incisions (6), and the positions of the plurality of incisions (6) correspond to a plurality of designated positions inside the workpiece (4).

3. The method for detecting the inner surface morphology and roughness of a complex structure according to claim 1, characterized in that: The unfolded shape of the incision (6) is rectangular or circular, and the maximum size of the incision (6) is less than 1 mm.

4. The method for detecting the inner surface morphology and roughness of a complex structure according to claim 1, characterized in that: The magnetic ball (1) is fixed to the inner end of the glue injection tube (2), and the distance from the incision (6) to the magnetic ball (1) is less than 10 mm.

5. The method for detecting the inner surface morphology and roughness of a complex structure according to claim 1, characterized in that: The glue injection tube (2) is a flexible tube.

6. The method for detecting the inner surface morphology and roughness of a complex structure according to claim 1, characterized in that: The outer dimensions of the glue injection tube (2) match the inner surface dimensions of the workpiece (4).

7. The method for detecting the inner surface morphology and roughness of a complex structure according to claim 1, characterized in that: The material of the colloid (3) is a silicone rubber compound, and the silicone rubber compound is a mixture of A glue and B glue.

8. A method for detecting the internal surface morphology and roughness of a complex structure according to claim 7, characterized in that: The A glue is prepared by mixing 80%-90% by mass of a base polymer, 10%-15% by mass of a reinforcing filler, and 1%-5% by mass of a diluent; the base polymer includes one or more of silicone, epoxy resin, and polyester resin; the reinforcing filler is a nanofiller, including one or more of fumed silica, carbon black, carbon nanofibers, carbon nanotubes, polyhedral oligomeric silsesquioxanes, and graphene; the diluent includes one or more of acetone, butanone, and cyclohexanone; The B glue is prepared by mixing 50%-60% by mass of a catalyst, 25%-30% by mass of a cross-linking agent, and 15%-20% by mass of a release agent; the catalyst includes one or more of a complex catalyst, a metal catalyst, and a metal oxide catalyst; the cross-linking agent includes one or more of silicones, polyols, organics, and organic peroxides; the release agent includes one or more of polymer release agents.

9. A method for detecting the internal surface morphology and roughness of a complex structure according to claim 8, characterized in that: The base polymer is organic silicon; the reinforcing filler is fumed silica or carbon black; the catalyst is a complex catalyst; and the cross-linking agent is organic silicon.

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