CN114523263B - Method for processing internal structure of composite tube shell - Google Patents

Abstract

The invention discloses a method for processing the internal structure of a composite shell, comprising: using a mold having the shape of the composite shell to support and fix the composite shell; drilling a bottom hole inside the composite shell; reaming the bottom hole; and broaching the inner wall of the composite shell by using a broach having at least one set of blades through the reamed bottom hole to form at least one flat groove on the inner wall, wherein the bottom of the flat groove protrudes radially outward of the composite shell relative to other parts of the inner wall.

Description

Method for Machining Internal Structure of Composite Shell

technical field

The invention relates to the field of microwave electric vacuum devices, in particular to a method for processing the internal structure of a composite shell.

Background technique

As a vacuum microwave core device for aerospace, the space traveling wave tube can play the role of microwave power amplification and has the advantages of high power and so on. In the space traveling wave tube, the composite shell, as a slow wave component, belongs to the core component of the space traveling wave tube, which can play the role of support and heat dissipation. The dimensional consistency of the internal structure of the composite shell affects the heat dissipation performance of the space traveling wave tube. Generally, the process of processing the internal structure of the composite shell can easily cause the size of the internal structure of the composite shell to be inconsistent. The processed internal structure is different from the composite shell, and there is an oxide layer on the surface of the internal structure, which leads to a high outgassing rate of the internal structure and reduces the stability and reliability of the space traveling wave tube.

Contents of the invention

In view of the above problems, the present invention can solve the problems of inconsistency in size of the internal structure of the processed composite tube and high surface outgassing rate by providing a method for processing the internal structure of the composite tube shell.

In order to achieve the above object, the present invention provides a method for processing the internal structure of the composite shell, comprising: using a mold having the shape of the composite shell to hold and fix the composite shell; drilling a bottom hole inside the composite shell; reaming the bottom hole; and broaching the inner wall of the composite shell with a broach having at least one set of blades through the reamed bottom hole to form at least one flat groove on the inner wall, wherein the bottom of the flat groove is opposite to other parts of the inner wall. The composite shell is convex in a radially outward direction.

According to an embodiment of the present invention, it is characterized in that, using a broach having at least one set of blades to broach the inner wall of the composite shell after reaming the bottom hole includes: using a broach matching the inner diameter of the bottom hole, driving the broach to make a main movement in a direction perpendicular to the plane where the bottom hole is located by a broaching machine, and performing a feed motion by the blades on the broach to complete the broaching process on the inner wall of the composite shell.

According to an embodiment of the present invention, it is characterized in that, after the broaching process, it further includes: putting the composite casing having at least one flat groove into a mixed solution of diamond yarn powder and acetone for ultrasonic cleaning to remove burrs.

According to an embodiment of the present invention, it is characterized in that after the ultrasonic cleaning, it further includes: putting the deburred composite shell into an acetone solution for ultrasonic degreasing and cleaning to obtain a processed composite shell.

According to an embodiment of the present invention, it is characterized in that, after putting the composite tube shell into the mold, the composite tube shell is pressed and fixed by screws.

According to an embodiment of the present invention, it is characterized in that it further includes: broaching the inner wall of the composite shell with a broach having three sets of blades through the bottom hole after reaming, so as to form three flat grooves on the inner wall, wherein the bottom of the flat grooves protrudes in the radially outward direction of the composite shell relative to other parts of the inner wall.

According to an embodiment of the present invention, it is characterized in that the drilling of the bottom hole and the reaming are all processed based on the outer diameter of the composite shell.

According to an embodiment of the present invention, it is characterized in that the broaching process is performed based on the bottom hole.

According to the method for processing the internal structure of the composite shell of a space traveling wave tube according to the above-mentioned embodiments of the present invention, the bottom hole is processed by drilling and reaming, and then broached by a forming broach with a blade to realize the processing of the internal structure of the composite shell; the size of the center of the bottom hole of each flat groove in the processed internal structure is determined by the broach, and the processed size has good consistency; through mechanical processing, the surface of the processed internal structure is bright and free of oxide layers, which reduces the surface outgassing rate.

Description of drawings

Figure 1A schematically shows a front view of a composite shell according to an embodiment of the present invention;

Figure 1B schematically shows a cross-sectional view of the internal structure of the composite shell according to an embodiment of the present invention;

Fig. 1C schematically shows an enlarged cross-sectional view of the bottom hole in the internal structure of the composite shell according to an embodiment of the present invention;

Fig. 2 schematically shows a flow chart of a method for processing the internal structure of a composite shell according to an embodiment of the present invention;

Fig. 3 schematically shows a cross-sectional view of the internal structure of the composite shell during processing according to an embodiment of the present invention;

Fig. 4 schematically shows a perspective view of a broach according to an embodiment of the present invention;

Fig. 5 schematically shows a schematic cross-sectional view of the internal structure of the broach according to the embodiment of the present invention in the composite shell;

Fig. 6 schematically shows a cross-sectional view of the internal structure of the composite shell during application according to an embodiment of the present invention.

[Description of the above reference signs]:

1: Composite shell

2: Pole shoe;

3: connecting ring;

4: Internal structure;

5: Bottom hole;

6: The first flat slot;

7: The second flat slot;

8: The third flat slot;

9: broach;

10: chip flat groove

11: Composite shell outer diameter;

12: Composite shell end face;

13: fillet;

14: clamping rod;

15: helix;

16: The first set of blades;

17: The second set of blades;

18: The third set of blades;

19: leading part;

20: Rear guide.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be understood, however, that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It may be evident, however, that one or more embodiments may be practiced without these specific details. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the invention. The terms "comprising", "comprising", etc. used herein indicate the presence of stated features, steps, operations and/or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

All terms (including technical and scientific terms) used herein have the meaning commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted to have a meaning consistent with the context of this specification, and not be interpreted in an idealized or overly rigid manner.

Where an expression similar to "at least one of A, B, and C, etc." is used, generally speaking, it should be interpreted according to the meaning that those skilled in the art usually understand the expression (for example, "a system having at least one of A, B, and C" shall include, but not limited to, a system having A alone, B alone, C alone, A and B, A and C, B and C, and/or A, B, C, etc.).

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

Fig. 1A schematically shows a front view of a composite shell according to an embodiment of the present invention; Fig. 1B schematically shows a cross-sectional view of an internal structure of a composite shell according to an embodiment of the present invention; Fig. 1C schematically shows a cross-sectional enlarged view of a bottom hole in a composite shell internal structure according to an embodiment of the present invention.

As shown in FIG. 1A and FIG. 1B , the composite casing 1 includes: multiple sets of pole shoes 2 , multiple sets of connecting rings 3 and an internal structure 4 . The internal structure 4 may include: a bottom hole 5 penetrating through the center of the composite shell 1; at least one flat groove disposed on the inner wall of the bottom hole 5, and the bottom of the flat groove protrudes radially outward of the composite shell 1 relative to other parts of the inner wall.

As shown in FIG. 1B and FIG. 1C , the outer diameter 11 of the composite shell, the end surface 12 of the composite shell, the bottom hole 5 , the first flat groove 6 , the second flat groove 7 and the third flat groove 8 can also be seen. The outer diameter 11 of the composite shell is the outer diameter of the end surface 12 of the composite shell. The bottom hole 5 is located at the center of the end face 12 of the composite shell. The first flat groove 6, the second flat groove 7, and the third flat groove 8 are evenly and equidistantly distributed on the edge of the bottom hole 5; there are rounded corners 13 at both ends of each flat groove.

According to the embodiment of the present invention, the internal structure of the composite shell is made as a bottom hole plus three flat grooves. The plane contact of the three flat grooves can increase the heat dissipation path and improve the heat dissipation performance of the space traveling wave tube.

Fig. 2 schematically shows a flowchart of a method for processing the internal structure of a composite shell according to an embodiment of the present invention.

As shown in FIG. 2, the method includes steps S201-S204.

In step S201, a mold having the shape of the composite casing is used to hold and fix the composite casing.

In step S202, a bottom hole is drilled inside the composite shell.

In step S203, reaming is performed on the bottom hole.

In step S204, by reaming the processed bottom hole, the inner wall of the composite shell is broached with a broach having at least one set of cutting edges, so as to form at least one flat groove on the inner wall, wherein the bottom of the flat groove protrudes in the radially outward direction of the composite shell relative to other parts of the inner wall.

According to an embodiment of the present invention, the mold for clamping the composite shell can be processed on the processing equipment to form a semicircular shape that matches the composite shell. Specifically, two semicircular clamping molds can be selected. When the composite shell is put into one of the semicircular molds, the other semicircular mold can be connected by screws or other flexible connections. The composite shell can be pressed and fixed in the mold to ensure the concentricity between the center of the bottom hole and the center of the composite shell during the process of processing the bottom hole.

Fig. 3 schematically shows a cross-sectional view of the internal structure of the composite shell during processing according to an embodiment of the present invention.

According to the embodiment of the present invention, after fixing the composite shell, the outer diameter of the composite shell can be used as a reference to select the position of the deep slot, and the deep slot can be located in the center of the composite shell. As shown in FIG. 3 , conforming to A means that when machining the bottom hole 5 , the outer diameter 11 of the composite shell is used as the reference for machining. When drilling the bottom hole 5, a gun drill can be used to drill deep and long holes from the bottom of the composite shell along the extension direction of the composite shell to complete the rough machining of the internal structure. A machining allowance of 0.1 to 0.3 mm can be reserved during the process of gun drilling the bottom hole. According to an alternative embodiment of the present invention, the method of drilling the hole can also adopt a drilling method suitable for processing deep and long holes such as end milling to drill deep and long holes.

According to the embodiment of the present invention, when reaming the bottom hole, the same reference and fixing method as drilling the bottom hole can be used. For example, the outer diameter of the composite shell can be used as the reference to carry out precise reaming on the drilled bottom hole to realize the precision machining of the bottom hole, and the size of the hole can be processed to the required size. According to an alternative embodiment of the present invention, the way of precision machining the bottom hole may also be precision machining by means of honing or the like. The size of the bottom hole before processing and the bottom hole after processing can be adaptively adjusted according to actual needs.

According to the embodiment of the present invention, both the drilling of the bottom hole and the reaming process are performed based on the outer diameter of the composite shell. During processing, the position of the composite shell is pressed and fixed by the external equipment, and the drilling and reaming of the bottom hole can be realized without changing the position of the composite shell by changing the processing tool, which can ensure that the center of the bottom hole of the internal structure is the same as that of the composite shell.

Fig. 4 schematically shows a three-dimensional view of a broach according to an embodiment of the present invention; Fig. 5 schematically shows a cross-sectional view of a broach inside a composite shell according to an embodiment of the present invention.

As shown in FIGS. 4-5 , the formed broach 9 may be a broach 9 with three sets of blades, and the broach 9 may include a first set of blades 16 , a second set of blades 17 , and a third set of blades 18 . The broach 9 also includes a leading part 19 and a trailing part 20 . The three groups of blades are evenly and equidistantly distributed on the broach 9. Taking the bottom hole 5 after the reaming process as a reference, the internal structure of the first flat groove 6, the second flat groove 7 and the third flat groove 8 respectively corresponding to the first group of blades 16, the second group of blades 17, and the third group of blades 18 are broached through the reamed bottom hole 5 in the internal structure, and the broaching process of the internal structure of the composite shell is completed.

According to an embodiment of the present disclosure, each group of blades may also include multiple sub-blades (not shown in the figure), there may be more than 5 sub-blades, and the multiple sub-blades are arranged in steps. Specifically, during broaching, a broach 9 matching the inner diameter of the bottom hole 5 can be used, and the broach 9 is driven by the broaching machine to make a main movement in a direction perpendicular to the plane where the bottom hole 5 is located, and the sub-blade on the broach 9 performs a feed motion to complete the broaching of the composite shell. A chip flute 10 can also be provided next to each group of cutting edges, which can prevent the burrs after broaching from scratching the processed surface.

According to an embodiment of the present invention, the forming broach can also be a broach with a set of blades. Taking the reamed bottom hole as a reference, the internal structure with three flat grooves is broached three times through the reamed bottom hole in the internal structure to complete the processing of the internal structure of the composite shell.

According to the embodiment of the present invention, the broaching process is carried out on the basis of the reamed bottom hole, and the concentricity between the bottom hole and the three flat grooves can be guaranteed without clamping the composite shell.

According to the embodiment of the present invention, the processing of the three flat groove structures inside the composite shell is realized by using a forming broach for broaching. The distance between the flat grooves and the center of the bottom hole is determined by the broach. In the internal structure of the processed composite shell, the distance between each flat groove and the center of the bottom hole has good consistency.

According to the embodiment of the present invention, the bottom hole is processed by drilling and reaming, and then broached by a forming broach with a blade to realize the processing of the internal structure of the composite shell; the distance between each flat groove and the center of the bottom hole is determined by the broach, and the processed size has good consistency; through mechanical processing, the surface of the processed internal structure is bright and free of oxide layers, which reduces the surface outgassing rate; improves the stability and reliability of the space traveling wave tube. The processing method provided by the embodiment of the present invention is not only easy to realize and complete, but also convenient to popularize and apply the processing method.

According to an embodiment of the present invention, the broached composite shell can also be ultrasonically cleaned in a mixed solution of corundum powder and acetone to remove burrs generated after broaching. By this method, not only large-sized burrs can be removed, but also small-sized burrs can be removed. Not only the burrs are removed relatively cleanly, but also the surface of the inner structure will not be damaged.

According to an embodiment of the present invention, the deburred composite shell can also be put into an acetone solution for ultrasonic cleaning again, so as to achieve the purpose of degreasing and cleaning the composite shell. By degreasing and cleaning the processed composite shell, the oil stains that may remain on the surface during processing are removed, the surface finish is improved, and the application performance of the composite shell is improved.

According to the embodiment of the present invention, the airtightness test can also be performed on the composite shell after degreasing and cleaning. Before testing the air tightness, the composite shell can also be placed in a hydrogen atmosphere and kept at 800°C for 15 minutes to perform high-temperature cleaning treatment on the composite shell. It should be noted that the type of atmosphere, temperature and holding time involved in the high-temperature cleaning process can also be adjusted according to actual needs. After the high-temperature cleaning treatment, the air leakage rate of the composite shell can be checked by a helium mass spectrometer leak detector. When the air leakage rate is less than or equal to 5×10 ^-10 Pa·m ³ /s, it can be confirmed as a qualified part. However, the standard of air leakage rate is not limited to 5×10 ^-10 Pa·m ³ /s, and the specific standard value can be determined according to actual needs.

According to the embodiment of the present invention, the appearance inspection of the internal structure of the composite shell can also be carried out. Specifically, the surface of the internal structure can be observed through industrial endoscopes such as electronic endoscopes and optical fiber endoscopes, and the inner surface can be observed to be bright and free of oxidation.

According to the embodiments of the present invention, the internal structure prepared by a mechanical method has no oxide layer on the surface of the internal structure, which can reduce the outgassing rate of the surface of the internal structure and improve the stability and reliability of the space traveling wave tube.

According to the embodiment of the present invention, it is also possible to carry out dimensional inspection on the processed composite shell.

As shown in Figure 3, R1 represents the distance of the circle center of the first flat groove 6 bottom hole 5, R2 represents the distance of the circle center of the bottom hole 5 of the second flat groove 7, R3 represents the distance of the circle center of the bottom hole 5 of the 3rd flat groove 8. Through the method provided by the embodiment of the present invention, any one of the dimensions of R1, R2, and R3 of the processed internal structure is less than or equal to 0.005 mm, and the corresponding size differences between R1 and R2, R2 and R3, and the size difference between R1 and R3 among R1, R2, and R3 are also less than or equal to 0.005 mm, that is, R1, R2, and R3 have good dimensional consistency. The processing is performed based on the outer diameter 11 of the composite shell, and the concentricity between the processed bottom hole 5 and the end face 12 of the composite shell can be less than or equal to 0.05 mm.

As shown in Figure 1C, it can be seen from the enlarged bottom hole 5 that there are rounded corners 13 at both ends of each flat groove in the first flat groove 6, the second flat groove 7 and the third flat groove 8, and the rounded corners 13 after processing can be less than or equal to 0.05 through the method provided by the embodiment of the present invention.

Fig. 6 schematically shows a cross-sectional view of the internal structure of the composite shell during application according to an embodiment of the present invention.

As shown in FIG. 6 , during application of the composite shell 1 , the internal structure is used to accommodate the clamping rod 14 and the helical wire 15 . The helix 15 is located at the center of the bottom hole 5, and one end of each of the three clamping rods 14 is respectively located in the first flat groove 6, the second flat groove 7 and the third flat groove 8, and the other end of each clamping rod is connected to the helix 15 respectively. The rounded corners prepared by the traditional process are about 0.1mm. When assembling the product, due to the large rounded corners, the two ends of the flat groove have no guides, causing the side of the clamping rod 14 to press on the rounded corners 13, which is easy to cause splitting at the contact between the clamping rod 14 and the rounded corners 13. However, in the internal structure of the composite shell provided by the embodiment of the present invention, the rounded corner after processing is less than or equal to 0.05, which can reduce the possibility of splitting of the clamping rod and improve the yield of the space traveling wave tube.

It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "rear", "left", "right", "protrusion", etc., are only referring to the directions of the drawings, and are not used to limit the protection scope of the present invention. Throughout the drawings, the same elements are indicated by the same or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present invention.

And the shape and size of each component in the figure do not reflect the actual size and proportion, but only illustrate the content of the embodiment of the present invention. Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Similarly, it is to be understood that in the above description of exemplary embodiments of the invention, in order to streamline the invention and to facilitate understanding of one or more of the various inventive aspects, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. This method of invention, however, is not to be interpreted as reflecting an intention that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing invention. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. A method for processing an internal structure of a composite tubular housing, comprising:

using a die having a composite tube shell shape to receive and secure the composite tube shell, wherein the composite tube shell is used for a space traveling wave tube;

drilling deep and long bottom holes in the composite tube shell by adopting a gun drill;

performing precise reaming on the deep and long bottom hole, wherein the precision of the precise reaming is between-0.01 mm and 0.01mm, the machined inner surface is bright and has no oxide layer, and the air release rate of the surface is reduced; and

broaching the inner wall of the deep and long bottom hole of the composite pipe shell by using a broach with three groups of cutting edges through the reamed deep and long bottom hole, so as to form three flat grooves on the inner wall of the deep and long bottom hole, wherein the bottoms of the flat grooves are raised in the radial outward direction of the composite pipe shell relative to other parts of the inner wall;

wherein, the method further comprises the following steps: carrying out primary broaching on the inner wall of the deep and long bottom hole of the composite pipe shell by using a broach with three groups of blades to form three flat grooves on the inner wall of the deep and long bottom hole, wherein the bottoms of the flat grooves are raised in the radial outward direction of the composite pipe shell relative to other parts of the inner wall, the distance from each flat groove in the three flat grooves to the center of the deep and long bottom hole is less than or equal to 0.005mm, each group of blades in the three groups of blades is provided with more than 5 sub-blades, the sub-blades are arranged in a step-like manner, and chip-containing grooves are formed beside each group of blades to prevent scratching the processed surface;

the gun drill is adopted to drill a bottom hole, the reaming processing is carried out by taking the outer diameter of the composite pipe shell as a reference, the position of the composite pipe shell is not changed, and the concentricity of the deep and long bottom hole after processing and the end surface of the composite pipe shell is less than or equal to 0.05mm;

and the broaching processing is carried out by taking the bottom hole as a reference, and the distance from each of the three flat grooves to the center of the bottom hole is determined by the broach, so that the distances from each of the three flat grooves to the center of the bottom hole are consistent.

2. The method of claim 1, wherein broaching the inner wall of the composite pipe shell with a broach having three sets of cutting edges through the reamed bottom hole comprises:

and (3) driving the broaching tool to perform main movement along the direction perpendicular to the plane of the bottom hole by adopting the broaching tool matched with the inner diameter of the bottom hole, and performing feeding movement by a cutting edge on the broaching tool to finish broaching the inner wall of the composite pipe shell.

3. The method of claim 1, further comprising, after the broaching:

the composite tube shell with three flat grooves is put into a mixed solution of diamond yarn powder and acetone for ultrasonic cleaning to remove burrs.

4. A method according to claim 3, further comprising, after the ultrasonic cleaning:

and (3) placing the composite tube shell after the deburring into an acetone solution for ultrasonic degreasing and cleaning to obtain the finished composite tube shell.

5. The method of claim 1, wherein the composite shell is compressed and secured by screws after the composite shell is placed in the mold.