CN216688312U

CN216688312U - Pipe forming die

Info

Publication number: CN216688312U
Application number: CN202123267811.2U
Authority: CN
Inventors: 廖寄乔; 刘学文; 石磊; 李丙菊; 李军; 王跃军; 龚玉良
Original assignee: Hunan Jinbo Carbon Co ltd
Current assignee: Hunan Jinbo Carbon Co ltd
Priority date: 2021-12-23
Filing date: 2021-12-23
Publication date: 2022-06-07
Anticipated expiration: 2031-12-23

Abstract

The utility model relates to a pipe forming die, comprising: the supporting rod comprises a rod main body and a limiting convex strip arranged along the axial direction of the rod main body; the supporting plate is provided with a mounting hole and a limiting hole communicated with the mounting hole, the supporting plate is used for being mounted on the supporting rod, the mounting hole is used for being matched with the rod main body, and the limiting hole is used for being matched with the limiting convex strip; the supporting plate comprises a plurality of arc-shaped plates, and the arc-shaped plates are sequentially arranged on the supporting plate along the circumferential direction of the rod main body so as to be spliced to form an outer pipe for coating the supporting rod; and the two cover plates are respectively sleeved at two ends of the outer pipe. The pipe forming die can be used for forming a pipe material, when the pipe is formed on the outer pipe formed by the arc-shaped plate, the cover plate is firstly removed, the supporting rod is then pulled out, the supporting plate is then taken out, and the arc-shaped plate is pulled out, so that the roundness and the straightness of the formed pipe can be improved.

Description

Pipe forming die

Technical Field

The utility model relates to the technical field of carbon composite materials, in particular to a pipe forming die.

Background

The application field of the pipe is wide. For example, the exhaust pipe inside the heat treatment equipment is long (for example, more than 1000 mm), small (for example, less than 100 mm) in diameter, and the length-diameter ratio of the pipe is large (greater than 10) and thin (less than 5 mm). If the graphite material is adopted to prepare the pipe with larger major diameter, the graphite has the defects of high processing rejection rate and short service life due to the large brittleness. The carbon/carbon composite material has a long service life, so that the carbon/carbon composite material is popular in the pipe market.

The common carbon/carbon composite pipe is produced through several circulations including making prefabricated blank with foamed pipe and stainless steel rod as mold, needle punching, chemical vapor deposition, machining, etc. Because the products of the pipes are long and have small inner diameters, needling is needed, the preparation of the prefabricated body needs to be operated by full manpower, and the efficiency is low. Taking a pipe product with an outer diameter of 81 mm, an inner diameter of 75 mm and a length of 1000 mm as an example, the manufacturing method comprises the following steps: a stainless steel rod with the diameter of 20-25 mm is used as a mould, a foam tube with the outer diameter of 75 mm and the length of 1050 mm is sleeved on the stainless steel rod, two ends of the stainless steel rod are supported, so that carbon cloth can be wound on the foam tube, a net tire can be laid, and needling can be performed manually. After the needle had been punched to the appropriate outside diameter, the stainless steel rod was removed, the foam removed, and chemical vapor deposition was carried out. When the die is used for production, the die is difficult to take out, so that the tubular product is easy to deform in the length direction in the preparation process.

In order to ensure the smooth production of the pipe, enough allowance must be reserved for the inner diameter and the outer diameter of the prefabricated body, so that the blank must be made thicker, the raw material cost and the labor cost are increased, in addition, the machining times are more, the furnace feeding times are more, and the machining cost is increased.

SUMMERY OF THE UTILITY MODEL

Based on the technical scheme, the utility model provides the pipe forming die which is used for pipe forming, is easy to demould and cannot cause deformation of pipes.

The technical scheme of the utility model is as follows:

one aspect of the present invention provides a pipe molding die, including:

the supporting rod comprises a rod main body and a limiting convex strip arranged along the axial direction of the rod main body;

the supporting plate is provided with a mounting hole and a limiting hole communicated with the mounting hole, the supporting plate is used for being mounted on the supporting rod, the mounting hole is used for being matched with the rod main body, and the limiting hole is used for being matched with the limiting convex strip;

the supporting plate comprises a plurality of arc-shaped plates, and the arc-shaped plates are sequentially arranged on the supporting plate along the circumferential direction of the rod main body so as to be spliced to form an outer pipe wrapping the supporting rod; and

the cover plate, the apron is two, two the apron is used for the cover respectively to be established the both ends of outer tube.

In some embodiments, at least a part of the outer contour of the support plate is arc-shaped, and the support plate is abutted against the inner wall of the arc-shaped plate through the arc-shaped outer contour.

In some of these embodiments, at least a portion of the outer contour of the support plate is a straight line;

the outer contour of the supporting plate comprises a first arc line, a first straight line, a second arc line and a second straight line which are sequentially connected, the first arc line is opposite to the second arc line, and the first straight line is opposite to the second straight line.

In some embodiments, the number of the supporting plates is multiple, and the supporting plates are sequentially arranged on the same limiting convex strip on the supporting rod; in any two adjacent support plates, one of the support rods corresponds to the first arc line or the second arc line in the position where the limit hole matched with the limit convex strip corresponds to the support rod, and the other support rod corresponds to the first straight line or the second straight line in the position where the limit hole matched with the limit convex strip corresponds to the support rod.

In some embodiments, the number of the limiting holes on the supporting plate is at least two, wherein two limiting holes are a first limiting hole and a second limiting hole respectively, the first limiting hole is arranged corresponding to the first arc line or the second arc line, and the second limiting hole is arranged corresponding to the first straight line or the second straight line;

one of the supporting plates is matched with the limiting convex strip through the first limiting hole, and the other supporting plate is matched with the limiting convex strip through the second limiting hole.

In some embodiments, the supporting plate is further provided with a positioning hole; the pipe forming die further comprises a pull rod, and the pull rod sequentially penetrates through the plurality of positioning holes of the supporting plates.

In some embodiments, the number of the positioning holes on the support plate is at least four, wherein four positioning holes are a first positioning hole, a second positioning hole, a third positioning hole and a fourth positioning hole which are respectively arranged corresponding to the first arc line, the first straight line, the second arc line and the second straight line;

the number of the pull rods is at least four, and each pull rod sequentially penetrates through one positioning hole of the plurality of the supporting plates, so that the four pull rods penetrate through each supporting plate and are arranged in parallel.

In some embodiments, each pull rod is further provided with a positioning part;

in the four pull rods corresponding to each support plate, at least two opposite positioning parts on the pull rods are respectively positioned on two sides of the support plate and used for positioning the support plate.

In some embodiments, in the four pull rods corresponding to each support plate, positioning portions on two opposite pull rods are respectively located on two sides of the support plate and used for positioning the support plate;

the two opposite pull rods are respectively matched with the first positioning holes and the second positioning holes of the supporting plates.

In some of these embodiments, the cover plate is provided with a through hole for the end of the rod body to pass through; and/or

The inner wall of the cover plate is provided with an annular step, and the annular step is used for abutting against the end part of the outer pipe.

Advantageous effects

Above-mentioned tubular product forming die can be used to form the tubular product material, after tubular product shaping on the outer tube that the arc formed, demolishs the apron earlier, takes out the support rod again, then takes out the backup pad, take out the arc again can, so this tubular product forming die's drawing of patterns is easy, has avoided traditional mould to cause the problem of the deformation of tubular product easily, can improve the circularity and the straightness accuracy of shaping tubular product.

Drawings

Fig. 1 is a schematic structural view of a pipe forming mold according to an embodiment of the present invention;

FIG. 2 is an exploded view of the pipe forming die shown in FIG. 1;

FIG. 3 is a schematic structural view of a support plate in the pipe forming mold shown in FIG. 2;

FIG. 4 is a schematic view of the structure of the tie bar and the support plate of the tube forming mold according to another embodiment of the present invention;

fig. 5 is a schematic structural view of a cover plate in the pipe forming mold shown in fig. 2.

Detailed Description

To facilitate an understanding of the utility model, the utility model will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the utility model herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, an embodiment of the utility model provides a pipe forming mold 100, including: support rod 110, support plate 120, arc plate 130 and cover plate 140.

The support rod 110 includes a rod main body 111 and a limit protrusion 112 provided along an axial direction of the rod main body 111.

Referring to fig. 3, the supporting plate 120 is provided with a mounting hole 121 and a limiting hole communicated with the mounting hole 121, the supporting plate 120 is configured to be mounted on the supporting rod 110, the mounting hole 121 is configured to be matched with the rod main body 111, and the limiting hole is configured to be matched with the limiting convex strip 112.

The number of the arc-shaped plates 130 is plural, and the plural arc-shaped plates 130 are sequentially arranged on the support plate 120 along the circumferential direction of the rod main body 111 to form an outer tube covering the support rod 110 by splicing.

The number of the cover plates 140 is two, and the two cover plates 140 are respectively used for being sleeved at two ends of the outer pipe.

When the pipe forming mold 100 is assembled, the support plate 120 is mounted on the support rod 110, the mounting hole 121 is engaged with the rod body 111, and the limiting hole is engaged with the limiting protrusion 112, so that the support plate 120 is fixed. Then, the arc-shaped plates 130 are sequentially arranged on the supporting plate 120 along the circumferential direction of the rod main body 111 and spliced to form an outer tube for coating the supporting rod 110; then, two cover plates 140 are sleeved on two ends of the outer tube to fix the arc-shaped plate 130.

Above-mentioned tubular product forming die 100 can be used to form the tubular product material, and after tubular product shaping on the outer tube that arc 130 formed, demolish apron 140 earlier, take out support rod 110 again, then take out backup pad 120, take out arc 130 again can, so this tubular product forming die 100's drawing of patterns is easy, has avoided traditional mould to cause the problem of the deformation of tubular product easily, can improve the circularity and the straightness accuracy of shaping tubular product.

In some embodiments, the number of arcuate plates 130 may be 2, 3, and more. In this embodiment, the number of the arc plates 130 is 4, and the corresponding radian of each arc plate 130 is 90 degrees.

In some embodiments, at least a portion of the outer contour of the support plate 120 is arc-shaped, and the support plate 120 abuts against the inner wall of the arc-shaped plate 130 through the arc-shaped outer contour.

Further, at least a part of the outer contour of the support plate 120 is a straight line; the outer contour of the support plate 120 includes a first arc line, a first straight line, a second arc line and a second straight line which are connected in sequence, the first arc line is opposite to the second arc line, and the first straight line is opposite to the second straight line. The first straight line and the second straight line are not used for abutting against the inner wall of the arc plate 130, and a gap exists between the first straight line and the inner wall of the arc plate 130, so that the support plate 120 can be conveniently taken out.

Further, the first straight line and the second straight line are parallel to each other.

Further, the number of the support plates 120 is plural. In this particular example, the number of support plates 120 is 6; it is understood that the number of the supporting plates 120 may be set as desired.

As shown in fig. 2, the plurality of support plates 120 are sequentially disposed on the same position-limiting protruding strip 112 of the support rod 110. In any two adjacent support plates 120, the limiting hole of one support rod 110 engaged with the limiting convex strip 112 corresponds to the first arc line or the second arc line, and the limiting hole of the other support rod 110 engaged with the limiting convex strip 112 corresponds to the first straight line or the second straight line. In other words, the arrangement directions of any two adjacent support plates 120 are different; in some specific examples, the rotation angle of any one support plate 120 and another adjacent support plate 120 is 90 degrees.

In some embodiments, the retaining ribs 112 extend from one end of the rod body 111 to the other end, and the plurality of support plates 120 are sequentially distributed along one end of the support plates 120 at the other end. Further, the plurality of support plates 120 are uniformly distributed along the support plates 120. This may be done to better provide support for the arcuate plate 130.

Referring to fig. 3, in some embodiments, at least two limiting holes are formed in the supporting plate 120. Wherein, two spacing holes are respectively the first spacing hole 1221 and the second spacing hole 1222. The first limiting hole 1221 corresponds to a first arc line or a second arc line, and the second limiting hole 1222 corresponds to a first straight line or a second straight line.

Referring to fig. 2 and 3, one of any two adjacent support plates 120 is engaged with the limiting protrusion 112 through the first limiting hole 1221, and the other is engaged with the limiting protrusion 112 through the second limiting hole 1222.

Referring to fig. 3 and 4, in some embodiments, the supporting plate 120 further has positioning holes; the tube forming mold 100 further includes a pull rod 150, and the pull rod 150 sequentially passes through the positioning holes of the plurality of support plates 120. Thus, the pull rod 150 is arranged to facilitate the taking out of the support plate 120; specifically, the pull rod 150 can be pulled to further pull the support plate 120 away.

Referring to fig. 3, further, at least four positioning holes are disposed on the supporting plate 120; the four positioning holes are respectively a first positioning hole 1231, a second positioning hole 1232, a third positioning hole 1233 and a fourth positioning hole 1234 which are arranged corresponding to the first arc line, the first straight line, the second arc line and the second straight line.

Further, the pipe forming mold 100 includes at least four tie bars 150, and each tie bar 150 sequentially passes through one positioning hole of the plurality of support plates 120, so that the four tie bars 150 pass through each support plate 120 and are arranged in parallel. Thus, the four pull rods 150 are arranged, so that the support plate 120 can be taken out smoothly.

Furthermore, each tie bar 150 is further provided with a positioning portion 151. Thus, the positioning portion 151 of the pull rod 150 facilitates the fixing of the support plate 120 on the pull rod 150, so that the support plate 120 will not be separated from or displaced from the pull rod 150 when being drawn out.

Furthermore, in the four tie rods 150 corresponding to each support plate 120, at least two positioning portions 151 of the two tie rods 150 opposite to each other are respectively located at two sides of the support plate 120 and are used for positioning the support plate 120. By pulling the two opposite pull rods 150 in opposite directions, the support plate 120 can be rotated, and the support plate 120 and the arc plate 130 can be easily separated from each other, so that the support plate 120 can be smoothly taken out.

Furthermore, in the four tie rods 150 corresponding to each support plate 120, the positioning portions 151 on two opposite tie rods 150 are respectively located at two sides of the support plate 120 and are used for positioning the support plate 120; the two opposite pull rods 150 provided with the positioning portions 151 are respectively engaged with the first positioning holes 1231 and the second positioning holes 1232 of the respective support plates 120. In other words, the tie bars 150 of two adjacent support plates 120 provided with the positioning portions 151 are different. That is, the rotation of the odd number of support plates 120 can be controlled by pulling any two opposite tie rods 150, and the rotation of the even number of support plates 120 can be controlled by pulling the other two opposite tie rods 150.

Referring to fig. 5, in some embodiments, the cover plate 140 is provided with a through hole 141, and the through hole 141 is used for the end of the rod main body 111 to pass through. Further, the inner wall of the cover plate 140 is provided with an annular step 142, and the annular step 142 is used for abutting against the end of the outer tube.

In some embodiments, the components of the tube forming mold 100 are made of steel, such as stainless steel; in other words, the tube forming mold 100 is a steel mold. The tube forming die 100 can be used repeatedly. In a particular example, the tie rod 150 may be a steel wire rope. Further, the positioning portion 151 of the pull rod 150 may be made of steel or aluminum, and the positioning portion 151 may be disposed at a corresponding position of the pull rod 150 after the support plate 120 and the pull rod 150 are mounted.

An embodiment of the present invention further provides a method for manufacturing a carbon/carbon composite pipe, using any one of the pipe forming molds 100, the method including the following steps (1) to (4):

and (1) assembling all parts of the pipe forming die 100 to obtain the assembled pipe forming die 100.

Specifically, the method of assembly is as described above, with the pipe forming die 100 assembled, with the arcuate plate 130 forming the outer tube.

And (2) wrapping at least one carbon fiber layer on the outer pipe of the assembled pipe forming die 100, winding long carbon fibers on the carbon fiber layer to enable the long carbon fibers to be spiral, and wrapping at least one carbon fiber layer on the spiral long carbon fibers to obtain a first carbon/carbon prefabricated blank.

Wherein, each carbon fiber layer is independently selected from carbon fiber unidirectional cloth or carbon fiber net tire, and adjacent two screw threads in the long carbon fiber of heliciform have the interval between.

It is understood that the carbon fiber layer wrapped on the outer tube and the helical long carbon fiber of the assembled tube forming mold 100 may be one or more layers. In addition, in the outer tube of the assembled tube forming mold 100 and the carbon fiber layers wrapped on the helical long carbon fibers, the material of each carbon fiber layer may be the same or different. For example, the carbon fiber unidirectional cloth or the carbon fiber net tire or the carbon fiber unidirectional cloth and the carbon fiber net tire are used.

In some specific examples, the carbon fiber layer wrapped on the outer tube of the assembled tube forming mold 100 is two layers, and the carbon fiber layer wrapped on the helical long carbon fiber is one layer.

Further, when the carbon fiber layer is carbon fiber unidirectional cloth, the warp direction of the carbon fibers in the carbon fiber unidirectional cloth is parallel to or intersects with the axial direction of the support rod. Wherein the angle of intersection is not limited, including but not limited to perpendicular. In some specific examples, when the carbon fiber layer is carbon fiber unidirectional cloth, the warp direction of the carbon fibers in the carbon fiber unidirectional cloth is parallel or perpendicular to the axial direction of the support rod.

The long carbon fibers are wound on the carbon fiber net tire in the step (2) to enable the long carbon fibers to be in a spiral shape, so that the fibers in the carbon fiber unidirectional cloth are tightly wound, the effect of improving the strength of the material is achieved, and meanwhile, the risk that the carbon fibers in the carbon fiber unidirectional cloth fall off in the using process is greatly reduced; and a space is arranged between two adjacent threads in the spiral long carbon fiber, so that an inlet channel of deposition gas is provided for a carbon deposition step in the subsequent step.

(3) Repeating the wrapping and winding steps in the step (2) on the first carbon/carbon prefabricated blank for n times, and after baking, sequentially taking out the cover plate 140, the support rod 110, the support plate 120 and the arc-shaped plate 130 of the pipe forming die 100 to obtain a second carbon/carbon prefabricated blank; wherein n is an integer greater than or equal to 1; wherein, the projections of the spiral long carbon fiber formed by any two adjacent winding steps on the pipe forming die 100 are arranged in a staggered manner.

The projections of the spiral long carbon fibers formed in the two adjacent winding steps on the pipe forming die 100 are arranged in a staggered manner, so that the strength of the material is improved;

it can be understood that the projections of the spiral long carbon fibers formed in any two adjacent winding steps on the pipe forming mold 100 are "staggered" in the staggered arrangement, and since the spiral long carbon fibers formed in any two adjacent winding steps are not in the same layer and are not in direct contact, this refers to the positional relationship of the projections on the pipe forming mold 100, for example, the projections on the outer pipe of the pipe forming mold 100.

And (4) performing carbon deposition on the second carbon/carbon prefabricated blank by adopting a chemical vapor deposition method to obtain the carbon/carbon composite pipe.

According to the preparation method of the carbon/carbon composite pipe, the pipe forming die 100 is adopted for manufacturing the carbon/carbon composite pipe, the demoulding of the pipe forming die 100 is easy, the problem that the traditional die is easy to cause the deformation of the pipe is solved, the roundness and the straightness of the formed pipe can be improved, needling is not carried out in the manufacturing process of the prefabricated part of the formed pipe, and the roundness and the straightness of the manufactured pipe are excellent; the preparation method of the carbon/carbon composite pipe is optimized, and needling is not performed in the process of manufacturing the prefabricated body, so that the raw material cost and the labor cost can be reduced.

In the preparation method, the pipe forming die 100 is adopted, tension is generated when carbon fibers are wound, so that the density of the prepared carbon/carbon prefabricated blank can reach the density of the blank prepared by the traditional needling process, the steel pipe forming die 100 is further adopted, the thermal expansion coefficient of the carbon/carbon prefabricated blank is larger than that of the carbon fibers, and in the calcining process, the long carbon fibers are extruded due to the thermal expansion of the pipe forming die 100, so that the carbon fiber net tire and the carbon fiber unidirectional cloth are pulled to be tighter, and the density and the strength of the prepared carbon/carbon prefabricated blank are further improved; when the pipe material is cooled, the pipe material forming mold 100 and the carbon fiber have larger difference of thermal expansion coefficients, so that the demolding can be further facilitated.

In some embodiments, in any two adjacent winding steps, the same end of the assembled pipe forming mold 100 is taken as a winding starting point, and the winding directions of the two adjacent winding steps are controlled to be opposite; so that the projections of the spiral long carbon fibers formed in any two adjacent winding steps on the pipe forming mold 100 are staggered.

It can be understood that if the winding directions of the adjacent two winding steps are controlled to be opposite, the long carbon fiber with the spiral direction opposite to the spiral direction is formed. For example, the same end of the pipe forming mold 100 is taken as a winding starting point, the winding direction of the winding step in step (1) is from left to right, and when the winding step in step (2) is repeated, the winding direction of the winding step is from right to left, and the winding direction of the winding step is from left to right next time, the operation is repeated, so that the long carbon fibers in the carbon fiber unidirectional cloth are further tightly wound, and a space is reserved between two adjacent threads in the spiral long carbon fibers, so that the high-strength carbon/carbon preform is obtained.

When no space is left between two adjacent threads in the spiral long carbon fiber, namely the carbon fiber net tire is covered and wrapped tightly, so that the chemical vapor deposition is reduced, the entry channel of deposition gas is reduced, and the densification effect is reduced; however, if the distance between two adjacent threads in the helical long carbon fiber is too large, it is difficult to ensure the tensile strength of the carbon/carbon composite pipe.

In some of these embodiments, the distance controlling the spacing between two adjacent threads in the helical long carbon fiber is 0.5 mm to 6 mm in each winding step.

In some of these embodiments, the long carbon fibers are selected from at least one of 1K carbon fiber bundle, 3K carbon fiber bundle, 6K carbon fiber bundle, and 12K carbon fiber bundle. The carbon fiber bundle is unfolded like a carbon fiber cloth strip with a certain width, and the carbon fiber bundle is wound on the carbon fiber net tire to enable the carbon fiber bundle to be in a spiral shape, so that the fibers in the carbon fiber unidirectional cloth are tightly wound, the strength of the material is improved, and the risk of falling off of the carbon fibers in the carbon fiber unidirectional cloth in the using process is greatly reduced; however, if no space is left between the carbon fiber bundles, which is equivalent to tight covering and wrapping, the chemical vapor deposition is reduced, which is an access channel for deposition gas, thereby reducing the densification effect; however, if the distance between two adjacent threads in the spiral carbon fiber bundle is too large, it is difficult to ensure the tensile strength of the carbon/carbon composite pipe.

In some of these embodiments, n is 1 to 10. It can be understood that the number of repetitions n is selected according to actual needs, specifically according to the requirements of the thickness and the outer diameter of the pipe to be prepared.

It should be noted that, in the step of wrapping the carbon fiber unidirectional cloth and the carbon fiber mesh tire, a small amount of water can be sprayed on the carbon fiber unidirectional cloth and/or the carbon fiber mesh tire, so that the viscosity of the carbon fiber unidirectional cloth and the carbon fiber mesh tire is increased, and the carbon fiber unidirectional cloth and the carbon fiber mesh tire are not easy to fall off in the preparation process.

In some of these embodiments, the conditions of the baking in step (3) are: baking for 2-8 h at 200-500 ℃; in one specific example, the incubation is carried out at 300 ℃ for 3 hours.

In some embodiments, the number of carbon deposition in step (4) may be performed as many times as required, and the time for each carbon deposition is 50 to 200 hours.

In one specific example, in step (4), the second carbon/carbon preform is first subjected to chemical vapor deposition to perform carbon deposition for 100 hours, the outer diameter is processed to be 81 mm, the inner diameter is processed to be 75 mm, the length is processed to be 1000 mm, and then the chemical vapor deposition is performed for about 100 hours, wherein the density reaches 1.4g/cm³And the strength of the pipe prepared in the way meets the requirement.

Further, the deposition gas is a carbon source gas, and the carbon source gas is a hydrocarbon gas, and may be at least one of methane, propylene and natural gas.

The utility model also provides a carbon/carbon composite pipe which is prepared by adopting any one of the preparation methods of the carbon/carbon composite pipe.

The following are specific examples.

Example 1

(1) Providing a pipe forming die as shown in fig. 1, and assembling each part of the pipe forming die to obtain the assembled pipe forming die.

(2) Wrapping the outer pipe of the assembled pipe forming die with carbon fiber unidirectional cloth, wrapping the carbon fiber unidirectional cloth with a carbon fiber net tire, winding long carbon fibers on the carbon fiber net tire to enable the long carbon fibers to be spiral, and wrapping the spiral long carbon fibers with the carbon fiber net tire to obtain a first carbon/carbon prefabricated blank; the warp direction of the carbon fiber in the carbon fiber unidirectional cloth is the same as the axial direction of the support rod, and a space is reserved between two adjacent threads in the spiral long carbon fiber. Wherein, spout a small amount of water to carbon fiber unidirectional cloth and carbon fiber net child to increase its viscosity, the warp direction of carbon fiber in the carbon fiber unidirectional cloth keeps unanimous with the axial of support stick. And then taking one end point of the carbon fiber net tire as a starting point, and uniformly and spirally winding a 12K long fiber tow from one end of the outer pipe to the other end of the outer pipe. In the winding process, the spacing distance between two adjacent threads in the spiral long carbon fiber is about 5 mm, and then a layer of carbon fiber net tire is wrapped to prepare a first carbon/carbon prefabricated blank.

(3) Sequentially wrapping carbon fiber unidirectional cloth and a carbon fiber net tire on the first carbon/carbon prefabricated blank obtained in the step (2), wherein the warp direction of carbon fibers in the carbon fiber unidirectional cloth is consistent with the axial direction of the support rod; and (3) continuing to uniformly and spirally wind the 12K long fiber tows from one end of the outer pipe to the other end of the outer pipe by taking the same end point of the carbon fiber net tire in the step (2) as a starting point. The spacing distance between two adjacent threads in the spiral long carbon fiber formed in the winding process is about 5 mm, the winding direction is opposite to the previous winding direction, and a layer of carbon fiber net tire is wrapped.

(4) And then repeating the steps of wrapping the carbon fiber unidirectional cloth and the carbon fiber net tire and winding for 3 times until the outer diameter is about 85 mm, carrying out heat preservation baking for 3 hours at 300 ℃, then cooling to room temperature, and sequentially taking out the cover plate, the support rod, the support plate and the arc-shaped plate of the pipe forming die to obtain a second carbon/carbon prefabricated blank.

(5) And (4) performing carbon deposition on the second carbon/carbon precast blank obtained in the step (4) by adopting chemical vapor deposition, machining, and repeating the operation for 2 times. Wherein the deposition time of each carbon deposition step is 100h, and the deposition gas is natural gas. The carbon/carbon composite pipe with the external diameter phi 81, the internal diameter 75 mm and the length 1000 mm is prepared. The detection shows that the density of the carbon/carbon composite pipe is 1.4g/cm, and the roundness and the straightness are excellent.

All possible combinations of the technical features of the above embodiments may not be described for the sake of brevity, but should be considered as within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A pipe forming die, comprising:

2. The tube forming die of claim 1, wherein at least a portion of the outer contour of the support plate is arcuate, and the support plate abuts against the inner wall of the arcuate plate through the arcuate outer contour.

3. The tube forming die of claim 2, wherein at least a portion of the outer profile of the support plate is rectilinear;

4. The tube forming die of claim 3, wherein the number of the support plates is multiple, and the support plates are sequentially arranged on the same limiting convex strip on the support rod;

in any two adjacent support plates, the limiting hole of one of the support rods, which is matched with the limiting convex strip, corresponds to the first arc line or the second arc line, and the limiting hole of the other support rod, which is matched with the limiting convex strip, corresponds to the first straight line or the second straight line.

5. The tube forming die of claim 4, wherein the number of the limiting holes on the supporting plate is at least two, wherein the two limiting holes are a first limiting hole and a second limiting hole, the first limiting hole is arranged corresponding to the first arc or the second arc, and the second limiting hole is arranged corresponding to the first straight line or the second straight line;

6. The tube forming die of claim 4, wherein the support plate is further provided with a positioning hole; the pipe forming die further comprises a pull rod, and the pull rod sequentially penetrates through the plurality of positioning holes of the supporting plates.

7. The tube forming die of claim 6, wherein the support plate has at least four positioning holes, and wherein four of the positioning holes are a first positioning hole, a second positioning hole, a third positioning hole and a fourth positioning hole, which are respectively arranged corresponding to the first arc line, the first straight line, the second arc line and the second straight line;

8. The tube forming die of claim 7, wherein each tie bar is further provided with a positioning portion;

9. The tube forming die of claim 8, wherein the positioning portions of two opposite pull rods of the four pull rods corresponding to each support plate are respectively positioned at two sides of the support plate and used for positioning the support plate;

10. The tube forming die of any one of claims 1 to 9, wherein the cover plate is provided with a through hole for passing an end of the rod body therethrough; and/or