CN117861040A - Core rod, thinning process, pipe body and guide pipe - Google Patents

Abstract

The application discloses a core rod, a thinning process, a pipe body and a guide pipe; the core rod is used for obtaining a pipe body with reduced wall thickness; the mandrel comprises a first section and a second section along the axial direction of the mandrel; the outer diameter of the second section is smaller than that of the first section, and the outer diameter of the first section is smaller than that of the pipe body. The unequal-diameter core rod enables the drawing thinning process of the pipe body to be possible, and optimizes the thinning process of the wall thickness of the pipe body; the first section is used for fixing the part of the original pipe body which does not need to be drawn, and the second section and the part of the original pipe body which needs to be drawn have a gap, so that the contact area of the core rod and the part of the original pipe body which needs to be drawn is effectively reduced, the friction force between the core rod and the original pipe body is small, and the original pipe body is convenient to draw after being heated; after drawing is completed, the core rod is pushed until the first section moves to a drawn heating zone with the inner diameter reduced so as to expand the drawn heating zone to restore the original size, and the drawing device is simple in structure and suitable for various thin-wall thickness thinned pipes.

Description

Core rod, thinning process, pipe body and guide pipe

Technical Field

The application relates to the technical field of medical equipment, in particular to a core rod, a thinning process using the core rod, a pipe body manufactured through the thinning process and a catheter comprising the pipe body.

Background

In the prior art, the commonly used pipe wall thickness thinning process comprises a hot melting thinning process (shown in figure 1), a mechanical cutting thinning process and a polishing thinning process; however, the above-mentioned technique often has a certain problem and defect, and is not suitable for percutaneous delivery into human body in interventional operation.

As shown in fig. 1, when the hot-melting thinning process is used for hot-melting thinning, the pipe body 2' needs to be sleeved on the core rod 1', heated to a molten state, pressure (thrust, negative pressure or high-pressure gas) is applied to enable the molten sizing material to fill the die cavity, and the die cavity is cooled to form a shape basically consistent with the die cavity of the outer film 3 '. The scheme has the advantage of being capable of controlling and thinning the inner diameter and the outer diameter relatively accurately. But also has the obvious disadvantage of: (1) after hot melting, the plastic has higher viscoelasticity, is difficult to fill a space with smaller gaps (such as the wall thickness of 0.05 mm), and has certain technical difficulty in preparing a thinned pipe with a thin wall thickness; (2) the plastic is subjected to secondary hot melting and heating (the first heating is pipe extrusion molding), and the plastic is subjected to repeated heating and melting, so that the thermal fracture of a molecular chain is easily caused, the mechanical strength is reduced, and the ageing is also more easily caused; (3) it is necessary to manufacture relatively precise outer molds.

In some other thinning processes, when the mechanical cutting thinning process is used for mechanical cutting thinning, a relatively precise lathe is needed for cutting the pipe, and the scheme can also be used for preparing the thinning pipe with relatively high precision at the thinning position. But also has the obvious disadvantage of: (1) the cutting cooling liquid is needed to be added in the cutting process (foreign matters are easy to introduce), and the rotating speed cannot be too high in the rotating cutting process (the rotating speed is too high to generate much heat, plastic is easy to be heated and softened, the cutting is affected, and cutting failure is caused); (2) the cutting process can produce debris that affects the environment, (3) is more suitable for hard tubing with relatively high hardness, and medical tubing may not be suitable.

The polishing and thinning process is similar to the mechanical cutting and thinning process, the defects are obvious, more scraps are generated, the scraps are easily attached to the pipe body, the precision is difficult to control, and the plastic with high wear resistance is probably not suitable.

Therefore, how to provide a new thinning mold for optimizing the thinning process, and overcoming the drawbacks caused by several thinning processes in the prior art is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, the present application provides a mandrel, a thinning process using the mandrel, a pipe body manufactured by the thinning process, and a catheter including the pipe body, which solve the problems of the thinning process in the prior art.

In order to achieve the above purpose, the present application provides the following technical solutions:

a mandrel for obtaining a tube body having a reduced wall thickness; the mandrel comprises a first section and a second section along the axial direction of the mandrel; the outer diameter of the second section is smaller than the outer diameter of the first section, and the outer diameter of the first section is smaller than the inner diameter of the pipe body.

Optionally, in the mandrel, an end portion of the second section connected to the first section is formed with an inclined first transition surface.

Optionally, in the above core rod, an included angle between the first transition surface and a central axis of the core rod is 10 ° -80 °.

A thinning process for thinning a wall thickness of a pipe body, comprising:

sleeving an original pipe body outside the core rod of any one of claims 1-3, wherein the original pipe body comprises a first pipe and a second pipe; the first pipe is fixedly sleeved on the first section of the core rod, and a gap is reserved between the second pipe and the first section of the core rod;

a heating zone is formed at one end of the second pipe, which is close to the first pipe, and the length of the heating zone is L1, and the heating zone is heated to reach the glass transition temperature;

a clamping area is formed in the area of the second pipe except the heating area; fixing the first pipe body, clamping the clamping area, and drawing the second pipe in a direction away from the first pipe, wherein the drawing length is delta L, and the length of a heating area after drawing is L2=L1+delta L;

pushing the core rod along the direction of the second pipe away from the first pipe until the first pipe expands the heated area after drawing, so that the inner diameter of the heated area after drawing is the same as the inner diameter of the first pipe, and finally a first thinning section with the outer side wall thinned is formed;

after cooling, removing the core rod to obtain a semi-finished pipe body;

and cutting the semi-finished pipe body along the radial direction of the semi-finished pipe body, and finally obtaining the target pipe body with the first pipe and at least part of the first thinning section.

Optionally, in the thinning process, the heating area is heated by a heating module.

Optionally, in the thinning process described above,

the clamping area is adsorbed and fixed by the sucker, and the sucker drives the clamping area to move so as to realize drawing of the heating area;

or alternatively, the first and second heat exchangers may be,

the clamping zone is located at the end of the second tube remote from the first tube; the clamping area is divided into at least two split clamping areas along the circumferential direction of the clamping area; and a plurality of clamps clamp and fix a plurality of split clamping areas one by one, and the clamps drive the split clamping areas to synchronously move so as to realize drawing of the heating area.

Optionally, in the thinning process described above,

along a direction of the first thinning Duan Yuan from the first tube, the first thinned section includes a second transition surface and a straight curved surface; and the cutting position of the semi-finished pipe body is positioned on the straight curved surface.

Optionally, in the thinning process, an included angle between the second transition surface and the central axis of the pipe body is 10 ° -80 °.

Optionally, in the above thinning process, the inner diameter of the first tube is d2, the outer diameter of the first tube is d3, the outer diameter of the straight curved surface is d4,

a pipe body made by the thinning process described above; the first thinned section of the tube body is used for receiving the developing ring.

A catheter comprising a first tube and a second tube; the first pipe body is the pipe body;

a second thinning section with thinned wall thickness of the inner side wall is formed at the end part of the second pipe body; the second thinning section is sleeved outside the developing ring.

Optionally, in the above catheter, the first thinned section and the second thinned section are fixed by heat shrinkage fusion.

In the core rod, the thinning process, the pipe body and the guide pipe, the core rod is of unequal diameter, and the outer diameter of the first section of the core rod is larger than that of the second section of the core rod; when the original pipe body is sleeved outside the core rod, a gap is reserved between the original pipe body and the second section; the unequal diameter core rod is used for enabling the drawing and thinning process of the pipe body to be possible, and the thinning process of the wall thickness of the pipe body is optimized; when the pipe is thinned, the first section is used for fixing a part of the original pipe body which is not required to be drawn, and the second section has a gap with the part of the original pipe body which is required to be drawn, so that the contact area between the core rod and the part of the original pipe body which is required to be drawn is effectively reduced, the friction force between the core rod and the original pipe body is smaller, and the original pipe body is conveniently drawn after being heated; after the drawing is completed, pushing the core rod until the first section moves to a drawn heating zone with the reduced inner diameter so as to expand the drawn heating zone, and recovering the inner diameter to the original size, thereby finally obtaining a target pipe body with the reduced wall thickness of the outer side wall; the mandrel is simple in structure, convenient and quick to process and manufacture, suitable for various thin-wall thickness thinning pipes, accurate in thinning precision and easy to manage and control, mechanical strength of the thinning section cannot be greatly reduced, and premature aging cannot be caused; the cooling liquid is not needed in the thinning process, the environment is not polluted by the generation of chips and particles, and meanwhile, the hardness of the material of the pipe body is not strictly required.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present application, and that other drawings may be obtained according to the provided drawings without inventive effort to a person skilled in the art.

FIG. 1 is a schematic diagram of a prior art thinning process;

FIG. 2 is a schematic view of the structure of the mandrel and the original tube in the present application;

FIG. 3 is a schematic view of the structure of the original pipe body for heating in the present application;

FIG. 4 is a schematic drawing of the original tube in the present application;

FIG. 5 is a schematic drawing of an original tube according to another embodiment of the present application;

FIG. 6 is a schematic view of the structure of the tube body after being pulled out and expanded in the present application;

fig. 7 is a schematic structural view of a semi-finished pipe body in the present application.

In fig. 1:

1', a core rod; 2', original tube body; 3', an outer mold;

fig. 2-7:

1. a core rod; 2. an original tube body; 3. a heating module; 4. a suction cup; 5. a clamp;

11. a first section; 12. a second section;

21. a first tube; 22. a second tube;

221. heating zone.

Detailed Description

The application provides a core rod, a thinning process using the core rod, a pipe body manufactured through the thinning process, and a catheter comprising the pipe body.

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Referring to fig. 2-6, a mandrel 1 is shown for obtaining a reduced wall thickness tube. Along the axial direction of the mandrel 1, the mandrel 1 comprises a first section 11 and a second section 12; the outer diameter of the second section 12 is smaller than the outer diameter of the first section 11, and the outer diameter of the first section 11 is smaller than or equal to the inner diameter of the pipe body.

The inner diameter of the original pipe body 2 is the same as the inner diameter of the pipe body with the reduced wall thickness.

The core rod 1 of the application is a core rod with unequal diameters, when the original pipe body 2 is sleeved outside the core rod 1, one part of the original pipe body 2 is sleeved and fixed on the first section 11 with larger outer diameter, and a gap is reserved between the other part of the original pipe body 2 and the second section 12 with smaller outer diameter.

The unequal diameter core rod 1 of the application makes the drawing and thinning process of the pipe body possible, and optimizes the thinning process of the wall thickness of the pipe body. When the thickness is reduced, the first section 11 is used for fixing the part of the original pipe body 2 which does not need to be drawn, and the second section 12 is in clearance with the part of the original pipe body 2 which needs to be drawn, so that the contact area between the core rod 1 and the part of the original pipe body 2 which needs to be drawn is effectively reduced, the friction force between the core rod 1 and the original pipe body 2 is smaller, and the original pipe body 2 is conveniently drawn after being heated. After the drawing is completed, the mandrel 1 is pushed until the first section 11 moves to a drawn heating zone with a smaller inner diameter, so that the drawn heating zone is expanded, the inner diameter of the heating zone is restored to the original size, and finally the target pipe body with the reduced wall thickness of the outer side wall is obtained.

Or in the drawing process, when the original pipe body is at the glass transition temperature, the mandrel 1 is pushed to move 5mm towards the drawing direction when being drawn by 5mm, so that the mandrel 1 can timely expand a stretched area, and extrusion and damage of the mandrel 1 to the pipe body in a non-melting state are reduced.

Preferably, the mandrel 1 rotates synchronously during the movement in the drawing direction, so as to realize a smoother heating zone of the expanded original tube body 2. Specifically, the distance of movement of the core rod 1 is matched with one circle of rotation, so that the stress of the inner wall of the pipe body is uniform.

The mandrel is simple in structure, convenient and quick to process and manufacture, suitable for various thin-wall thickness thinning pipes, accurate in thinning precision and easy to manage and control, mechanical strength of the thinning section cannot be greatly reduced, and premature aging cannot be caused; the cooling liquid is not needed in the thinning process, the environment is not polluted by the generation of chips and particles, and meanwhile, the hardness of the material of the pipe body is not strictly required.

In certain embodiments of the present application, the end of the second section 12 that is connected to the first section 11 is formed with an inclined first transition surface.

The transition diameter change from the second section 12 to the first section 11 is realized by arranging the first transition surface, no sharp edges and corners exist, no stress concentration area exists, and the strength of the core rod 1 is ensured; and meanwhile, the original pipe body 2 during drawing cannot be damaged by puncture.

In certain embodiments of the present application, the first transition surface is at an angle of 10 ° -80 ° to the central axis of the mandrel 1. As above, the inclination angle of the first transition surface is controlled, and the manufacturing and the processing are facilitated.

The application also discloses a thinning process for thinning the wall thickness of the pipe body. The thinning process comprises the following steps:

(1) referring to fig. 2, the original pipe body 2 is sleeved outside the mandrel 1 described above, and the original pipe body 2 includes a first pipe 21 opposite to the first section 11 of the mandrel 1, and a second pipe 22 opposite to the second section 12 of the mandrel 1; the first pipe 21 does not need to be drawn, the first pipe 21 is matched with the first section 11, and the first pipe 21 is fixedly sleeved on the first section 11; the second tube 22 needs to be drawn, the second tube 22 is matched with the second section 12, the second tube 22 is sleeved outside the second section 12, and a gap is reserved between the second tube 22 and the second section 12;

(2) referring to fig. 2 to 5, a heating zone 221 is formed at one end of the second tube 22 adjacent to the first tube 21, the heating zone 221 has a length L1, and the heating zone 221 is heated to reach the glass transition temperature;

(3) referring to fig. 4 to 5, a clamping area is formed in the area of the second tube 22 except the heating area 221; fixing the first tube 21, clamping the clamping area, and drawing the second tube 22 in a direction away from the first tube 21, wherein the drawing length is delta L, and the length of the heating area after drawing is L2=L1+delta L;

(4) referring to fig. 6, the mandrel 1 is pushed along the direction of the second tube 22 away from the first tube 21 until the first tube 21 expands the heated region with the reduced inner diameter after drawing, so that the inner diameter of the heated region after drawing is restored to the initial state, that is, to the same inner diameter as the first tube 21, and finally a first thinned section with the thinned wall of the outer side wall is formed;

(5) referring to fig. 7, after cooling, the mandrel 1 is removed to obtain a semi-finished tube;

(6) the semi-finished tube body is cut along the radial direction, and finally the target tube body with the first tube 21 and at least part of the first thinning section is obtained, and the developing ring can be sleeved at the thinning part for fixing so as to be used as a medical tube body to enter the body of a patient through skin, and the developing ring does not excessively protrude out of the tube body, thereby avoiding scratching blood vessels.

The material of the tube body is plastic. Glass transition temperature, the softening temperature of the plastic, is lower than the melting temperature; when the glass transition temperature is reached, the tube can be subjected to tensile deformation under the action of external force.

When pushing the mandrel bar 1 to expand, it is necessary to ensure that the heated region after pulling is in a softened state.

The thinning process can avoid heating the original pipe body 2 to a molten state, avoids the defects that the plastic is subjected to repeated heating and melting, the molecular chain is easy to thermally break, the mechanical strength is reduced, and the aging is easier to cause.

Further, the thickness of the wall of the thinned section can be controlled relatively accurately through the thinning process. The mandrel 1 is inserted into the original pipe body 2, the outer diameter of the second section 12 of the mandrel 1 is reduced to d1 (the inner diameter of the original pipe body 2 is d2, and the outer diameter of the first section 11 of the mandrel 1 is d 2), and the design avoids that friction force is too large and drawing is difficult due to too large contact surface between the inner wall of the second pipe 22 of the target pipe body 2 and the second section 12 of the mandrel 1 during drawing.

Still further, through the thinning process of the present application, the heating zone 221 near the second section 12 of the mandrel 1 can be precisely and quickly heated, and the heating length thereof can be precisely and reliably controlled to L1. The roughness of the depressed part that longer length zone of heating 221 was drawn the back and is presented is superior to the zone of heating 221 of shorter length, and this application can accurate management and control zone of heating 221's length, makes the comparatively level and smooth and better degree of consistency of final result depressed part, and then obtains comparatively level and even first attenuate section.

The portion of the second tube 22 that is not thinned may be trimmed away in the target tubular application, leaving at least a portion of the first thinned segment as the mouth of the target tubular.

In certain embodiments of the present application, the heating zone 221 is heated by the heating module 3.

It should be noted that, the heating module 3 may select a heating metal tube mold with a length L1; when heating is needed, the heating module 3 is sleeved at the position of the second pipe 22 to be heated and drawn in the circumferential direction, namely, outside the heating zone 221, and the second pipe 22 is heated by high-frequency electromagnetic waves; the heating module 3 is removed after the target temperature is reached. As above, the length of the heating zone 221 can be precisely controlled.

Of course, the heating module 3 may also include a heating source that operates in a moving manner, and the heating module 3 performs heating in a moving manner in the circumferential direction on the outer surface of the divided heating area 221.

In some embodiments of the present application, referring to fig. 4, the clamping area is fixed by the suction cup 4, and the suction cup 4 drives the clamping area to move, so as to realize drawing of the heating area 221;

it should be noted that the clamping area is located at the end of the second tube 22 remote from the first tube 21. The suction cup 4 is a negative pressure suction cup.

The sucking disc 4 has good effect of adsorbing and fixing the clamping area, and can not cause abrasion damage to the outer surface of the clamping area.

In some embodiments, referring to fig. 5, the gripping region is located at the end of the second tube remote from the first tube; the clamping area is divided into at least two split clamping areas along the circumferential direction thereof. The plurality of clamps 5 clamp and fix the plurality of split clamping areas one by one, and the plurality of clamps 5 drive the plurality of split clamping areas to synchronously move so as to realize drawing of the heating area 221.

The number of split gripping areas may be two, three, four or more.

The split clamping area provides a stress contact point for the clamp 5, and the split clamping area can provide a larger clamping space for the clamp 5, so that the clamping of the clamping area is convenient to fix.

As above, the form of clamping and fixing the clamping area is further enriched, the clamping area can be selected according to actual requirements, and the flexibility and applicability are extremely strong.

In certain embodiments of the present application, the first thinned segment includes a second transition surface and a straight curved surface along the direction of the first thinned Duan Yuanli first tube 21; the cutting position of the semi-finished pipe body is positioned on the straight curved surface.

The semi-finished pipe body with the second transition surface can be naturally obtained through the thinning process. The cutting position of the semi-finished pipe body is positioned on a straight curved surface, so that the free end of the pipe orifice of the obtained target pipe body can be ensured to be straight, and an inclined second transition surface is formed only at the joint of the first thinning section and the first pipe 21; the developing ring can be supported at the straight curved surface and is abutted against the second transition surface, so that reliable and stable supporting and positioning of the developing ring are realized.

In some embodiments of the application, the second transition surface is at an angle of 10 ° to 80 ° to the central axis of the tube body. As described above, the inclination of the second transition surface can be controlled so that the junction between the first thinned section and the first pipe 21 is smoothly transitioned, and there is no point of stress concentration.

In some embodiments of the present application, the first tube 21 has an inner diameter dimension d2, the first tube 21 has an outer diameter dimension d3, the straight curved surface has an outer diameter dimension d4,

controlling the wall thickness of the first thinned section by controlling the length L1 of the heating zone 221 and the drawing length Δl; based on the principle that the volume of the heating zone 221 is unchanged before and after stretching, the wall thickness of the first thinning section is related to the length L1 of the heating zone 221 and the drawing length Δl.

Before V drawing = after V drawing, then there is the following relationship:

[π*(d3/2) ² -π*(d2/2) ² ]*L1＝[π*(d4/2) ² -π*(d2/2) ² ]* L2, i.e. (d 3) ² -d2 ² )*L1＝(d4 ² -d2 ² )*L2；

The method can obtain:since l2= l1++Δl +.>

Therefore, the pipe body with more accurate thickness at the thinned part can be obtained.

In summary, the present application further provides a tube made by the above thinning process, where the first thinned section of the tube is configured to receive the developing ring.

Because the pipe body of the present application is manufactured by the thinning process described above, the beneficial effects brought by the thinning process of the pipe body of the present application are referred to above, and are not described herein again.

In summary, the present application also provides a catheter, including a first tube and a second tube; the first tube is the tube described above. The end part of the second pipe body is provided with a second thinning section with the inner side wall with thinned wall thickness or a pipe body with the second pipe body with equal diameter and wall thickness in the axial direction; taking the example that the second pipe body is provided with a second thinning section, the developing ring is sleeved on the first thinning section, and the second thinning section is sleeved outside the developing ring. The catheter embedded in the developing ring was obtained as above.

Since the catheter of the present application has the tube body described above, the beneficial effects of the catheter brought by the tube body are referred to above, and will not be described herein.

In some embodiments, the first thinned section and the second thinned section are secured by heat shrink welding.

The heat shrinkage welding step comprises the following steps: (1) sleeving the obtained finished pipe body outside a supporting core rod with the same diameter; (2) sleeving the developing ring on a first thinning section of the finished tube body; (3) sleeving the second pipe body outside the supporting core rod, and ensuring that a second thinning section of the second pipe body is sleeved outside the developing ring; (4) sleeving a heat shrinkage tube at the outer side of the sleeving region of the first thinning section and the second thinning section; (5) heating the heat-shrinkable tube, and tightening the heat-shrinkable tube after heating to ensure that the first thinning section and the second thinning Duan Rongjie after hot melting are together; (6) the heat shrinkage tube and the supporting core rod are removed, so that the catheter with even and smooth inner and outer surfaces can be obtained, the catheter can be used for percutaneous access to the body of a patient, the developing ring does not protrude out of the catheter body too much, and vascular scratches are avoided.

The catheter is used for percutaneous conveying into a patient blood vessel in interventional operation, for example, the catheter is applied to a filter recovery sheath tube, a thrombus taking catheter or a stent conveying catheter, the length of the catheter is long and can reach more than one meter, the mounting position of the developing ring is located at the front end of the catheter, namely, the far end of the operating direction of an operator, so that the position of the catheter entering the blood vessel is convenient to observe, the developing ring is not exposed or excessively protruding to cause vascular scratch with the wall of the catheter or scratch is generated between the developing ring and the recovered filter.

The components, arrangements, etc. referred to in this application are meant to be illustrative examples only and are not intended to require or imply that the connections, arrangements, configurations must be made in the manner shown in the drawings. These components, devices, may be connected, arranged, configured in any manner, as will be appreciated by those skilled in the art. Words such as "including," "comprising," "having," and the like are words of openness and mean "including but not limited to," and are used interchangeably therewith. The terms "or" and "as used herein refer to and are used interchangeably with the term" and/or "unless the context clearly indicates otherwise. The term "such as" as used herein refers to, and is used interchangeably with, the phrase "such as, but not limited to.

It should also be noted that in the device of the present application, the components may be disassembled and/or assembled again. Such decomposition and/or recombination should be considered as equivalent to the present application.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the application to the form disclosed herein. Although a number of example aspects and embodiments have been discussed above, a person of ordinary skill in the art will recognize certain variations, modifications, alterations, additions, and subcombinations thereof.

The foregoing description of the preferred embodiments of the present invention is not intended to limit the invention to the precise form disclosed, and any modifications, equivalents, and alternatives falling within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims (12)

1. A mandrel for obtaining a tube body having a reduced wall thickness; wherein, along the axial direction of the core rod, the core rod comprises a first section and a second section; the outer diameter of the second section is smaller than that of the first section, and the outer diameter of the first section is smaller than or equal to that of the pipe body.

2. The mandrel of claim 1, wherein an end of the second segment that is joined to the first segment is formed with an angled first transition surface.

3. The mandrel of claim 2, wherein the first transition surface is at an angle of 10 ° to 80 ° from the central axis of the mandrel.

4. A thinning process for thinning a wall thickness of a pipe body, comprising:

sleeving an original pipe body outside the core rod of any one of claims 1-3, wherein the original pipe body comprises a first pipe and a second pipe; the first pipe is fixedly sleeved on the first section of the core rod, and a gap is reserved between the second pipe and the first section of the core rod;

a heating zone is formed at one end of the second pipe, which is close to the first pipe, and the length of the heating zone is L1, and the heating zone is heated to reach the glass transition temperature;

a clamping area is formed in the area of the second pipe except the heating area; fixing the first pipe body, clamping the clamping area, and drawing the second pipe in a direction away from the first pipe, wherein the drawing length is delta L, and the length of a heating area after drawing is L2=L1+delta L;

pushing the core rod along the direction of the second pipe away from the first pipe until the first pipe expands the heated area after drawing, so that the inner diameter of the heated area after drawing is the same as the inner diameter of the first pipe, and finally a first thinning section with the outer side wall thinned is formed;

after cooling, removing the core rod to obtain a semi-finished pipe body;

and cutting the semi-finished pipe body along the radial direction of the semi-finished pipe body, and finally obtaining the target pipe body with the first pipe and at least part of the first thinning section.

5. The thinning process of claim 4, wherein the heating region is heated by a heating module.

6. The thinning process according to claim 4, wherein,

the clamping area is adsorbed and fixed by the sucker, and the sucker drives the clamping area to move so as to realize drawing of the heating area;

or alternatively, the first and second heat exchangers may be,

the clamping zone is located at the end of the second tube remote from the first tube; the clamping area is divided into at least two split clamping areas along the circumferential direction of the clamping area; and a plurality of clamps clamp and fix a plurality of split clamping areas one by one, and the clamps drive the split clamping areas to synchronously move so as to realize drawing of the heating area.

7. The thinning process of claim 4, wherein the first thinned segment includes a second transition surface and a straight curved surface along a direction of the first thinning Duan Yuan away from the first tube; and the cutting position of the semi-finished pipe body is positioned on the straight curved surface.

8. The thinning process of claim 7, wherein the second transition surface is at an angle of 10 ° to 80 ° to the central axis of the tube.

9. The thinning process according to claim 7, wherein the first tube has an inner diameter dimension d2, an outer diameter dimension d3, and an outer diameter dimension d4 of the straight curved surface,

10. a pipe body, characterized in that it is produced by the thinning process according to any one of claims 4 to 9; the first thinned section of the tube body is used for receiving the developing ring.

11. A catheter, wherein the catheter comprises a first tube and a second tube; the first pipe body is the pipe body in claim 10;

a second thinning section with thinned wall thickness of the inner side wall is formed at the end part of the second pipe body; the second thinning section is sleeved outside the developing ring.

12. The catheter of claim 11, wherein the first thinned section and the second thinned section are secured by heat shrink welding.