阅读说明：本技术 预制棒的制造工艺 (Preform manufacturing process ) 是由 葛锡良 冯高锋 刘亚萍 赵行军 张其林 包国平 于 2021-03-24 设计创作，主要内容包括：本申请公开了一种预制棒的制造工艺,包括：1)在抽真空管的锥状部上加工出抽气孔；2)将辅助棒的一端内套在抽真空管的小径部,加热熔融,使辅助棒的一端与小径部固定；3)将辅助管外套在抽真空管上,辅助管包括筒状部以及扩口部,扩口部与抽真空管的锥状部相配合,抽气孔位于筒状部内侧,加热熔融,使扩口部与抽真空管的锥状部固定；4)对筒状部进行扩口；5)将芯棒与辅助棒加热熔接在一起；6)将套管外套在芯棒上,使扩口后的筒状部与套管端部熔接在一起；7)对抽真空管进行抽气,将套管与芯棒加热融合在一起。本申请通过抽真空管、辅助管和套管形成真空系统,相对于现有技术而言,芯棒不需要开设凹槽,各管不会开裂。(The application discloses prefabricated excellent manufacturing process includes: 1) processing an air exhaust hole on the conical part of the vacuum exhaust tube; 2) sleeving one end of the auxiliary rod in the small-diameter part of the vacuumizing tube, and heating and melting to fix one end of the auxiliary rod with the small-diameter part; 3) sleeving an auxiliary pipe on the vacuumizing pipe, wherein the auxiliary pipe comprises a cylindrical part and an expansion part, the expansion part is matched with the conical part of the vacuumizing pipe, and the air suction hole is positioned on the inner side of the cylindrical part and is heated and melted to fix the expansion part and the conical part of the vacuumizing pipe; 4) flaring the cylindrical part; 5) heating and welding the core rod and the auxiliary rod together; 6) sleeving the sleeve on the core rod in a sleeved mode, and enabling the flared cylindrical part and the end part of the sleeve to be welded together; 7) and (4) exhausting air from the vacuumizing tube, and heating and fusing the sleeve and the core rod together. This application forms vacuum system through evacuation pipe, auxiliary tube and sleeve pipe, and for prior art, the recess need not be seted up to the plug, and each pipe can not the fracture.)

1. A prefabricated rod manufacturing process, a sleeve and a core rod are fused by MCVD equipment, which is characterized by comprising the following steps:

1) processing an air exhaust hole on an air exhaust tube, wherein the air exhaust tube comprises a large-diameter part, a conical part and a small-diameter part which are sequentially connected, and the air exhaust hole is positioned on the conical part;

2) sleeving one end of the auxiliary rod in the small-diameter part, and heating and melting to fix one end of the auxiliary rod with the small-diameter part;

3) sleeving an auxiliary pipe on the vacuumizing pipe, wherein the auxiliary pipe comprises a cylindrical part and an expansion part, the expansion part is matched with the conical part of the vacuumizing pipe, and the air suction hole is positioned on the inner side of the cylindrical part and is heated and melted to fix the expansion part and the conical part of the vacuumizing pipe;

4) heating one end of the cylindrical part far away from the flaring part to flare the cylindrical part;

5) heating and welding the core rod and the auxiliary rod together;

6) sleeving the sleeve on the core rod, enabling the sleeve to be close to the auxiliary pipe, heating and melting, and enabling the flared cylindrical part and the end part of the sleeve to be welded together;

7) and (4) exhausting air from the vacuumizing tube, moving the blowtorch from one end far away from the vacuumizing tube to one side of the vacuumizing tube, and heating and fusing the sleeve and the core rod together.

2. The preform manufacturing process of claim 1, wherein the end of the auxiliary rod remote from the evacuation tube is located outside the auxiliary tube.

3. The preform manufacturing process of claim 2, wherein the end of the auxiliary rod away from the evacuation tube is 1to 3cm from the end of the auxiliary tube.

4. The preform manufacturing process of claim 1, wherein the number of said pumping holes is at least 3, and is uniformly distributed around the axis of the evacuation tube.

5. The preform manufacturing process of claim 1, wherein the sleeve comprises a deposition portion and a head tube portion fused together, the head tube portion being adapted to be held by a jig, the deposition portion being adapted to be fused together with the core rod to form the preform.

6. The preform manufacturing process of claim 5, wherein in step 7), the hydrogen gas of the torch is controlled at 100-170L/min, the moving speed of the torch is controlled at 5-30mm/min, the surface temperature of the deposition portion is heated by the torch to 1900-2200 ℃, and the pressure in the sleeve is controlled at-1.5 torr to-0.1 torr.

7. The preform manufacturing process of claim 1, wherein said step 4) is performed by a flaring assembly comprising:

a movable base capable of reciprocating left and right;

the first end of the connecting rod is fixed with the movable seat;

and the flaring block is fixed at the second end of the connecting rod and is provided with an arc flaring surface.

8. The preform manufacturing process of claim 7, wherein the first end of the connecting rod is detachably mounted on the moving seat; the connecting rod is a connecting rod with adjustable length.

9. The preform manufacturing process of claim 7, wherein the flare assembly further comprises a guide rail parallel to the auxiliary tube axis, the movable seat being slidably disposed on the guide rail; the movable seat and the blowtorch are arranged in a staggered mode.

10. The preform making process of claim 9, wherein the flaring assembly further comprises a driving element for driving the movable seat to reciprocate.

Technical Field

The invention relates to the field of optical fiber preforms, in particular to a manufacturing process of a preform.

Background

Patent document CN 106242262 a discloses a method for preparing doped optical fiber overcladding layer, which uses MCVD equipment to fuse the deposition tube and core rod of the optical fiber preform, and includes the following steps: 1) carrying out fusion butt joint on the deposition tube and the first tube, and carrying out impurity removal operation on the deposition tube; 2) arranging a groove at one end of the core rod along the length direction of the core rod, extending the end of the core rod with the groove into the negative pressure pumping connecting pipe, heating the negative pressure pumping connecting pipe by using a blast burner to ensure that the negative pressure pumping connecting pipe and the core rod are fused and fixed, and communicating the inner space of the negative pressure pumping connecting pipe with the outer space through the groove; 3) extending the end of the core rod without the groove into the deposition tube towards the first tube until the tube orifice of the negative pressure pumping connecting tube is connected with the tube orifice of the deposition tube, and heating the joint of the negative pressure pumping connecting tube and the deposition tube to ensure that the negative pressure pumping connecting tube is connected with the deposition tube in a melting way; 4) and pumping the deposition tube into negative pressure, moving the blowtorch from the first tube to the negative pressure pumping connecting tube, and heating and fusing the deposition tube and the core rod together.

The method is simple, but problems are easy to occur in the production process, because the core rod is provided with the groove, the core rod cannot be extruded forcefully when the core rod is welded with the negative pressure pumping connecting pipe at high temperature, otherwise the groove of the core rod can be blocked or thinned by extrusion after the auxiliary pipe is extruded at high temperature, and the negative pressure pumping can not meet the requirement; in addition, the core rod is not burnt and burnt completely when the core rod is bonded with the negative pressure suction connecting pipe at high temperature, because if the groove cut by the core rod is burnt and burnt completely, the groove becomes narrow and flat and cannot play a role in ventilation, and the core rod cannot be burnt and burnt also has the reason that if the groove is burnt and burnt, the core rod can droop and bend under the action of gravity, so that the core rod cannot be sleeved on the deposition pipe.

Because of the reasons, certain stress exists at the bonding part of the core rod and the auxiliary tube, when the step 4 is carried out, the deposition tube is fused and combined with the negative pressure pumping connecting tube in the region with larger stress at high temperature, the stress of the region is larger, the region is finally cracked immediately after being cooled by only heating with small fire, and the whole sealing vacuum-pumping system needs to be manufactured again.

Disclosure of Invention

The invention provides a manufacturing process of a prefabricated rod aiming at the problems.

The technical scheme adopted by the invention is as follows:

a preform manufacturing process for fusing a jacket tube with a core rod by using MCVD equipment, comprising the steps of:

1) processing an air exhaust hole on an air exhaust tube, wherein the air exhaust tube comprises a large-diameter part, a conical part and a small-diameter part which are sequentially connected, and the air exhaust hole is positioned on the conical part;

2) sleeving one end of the auxiliary rod in the small-diameter part, and heating and melting to fix one end of the auxiliary rod with the small-diameter part;

3) sleeving an auxiliary pipe on the vacuumizing pipe, wherein the auxiliary pipe comprises a cylindrical part and an expansion part, the expansion part is matched with the conical part of the vacuumizing pipe, and the air suction hole is positioned on the inner side of the cylindrical part and is heated and melted to fix the expansion part and the conical part of the vacuumizing pipe;

4) heating one end of the cylindrical part far away from the flaring part to flare the cylindrical part;

5) heating and welding the core rod and the auxiliary rod together;

6) sleeving the sleeve on the core rod, enabling the sleeve to be close to the auxiliary pipe, heating and melting, and enabling the flared cylindrical part and the end part of the sleeve to be welded together;

7) and (4) exhausting air from the vacuumizing tube, moving the blowtorch from one end far away from the vacuumizing tube to one side of the vacuumizing tube, and heating and fusing the sleeve and the core rod together.

The utility model provides a prefabricated excellent manufacturing process forms vacuum system through evacuation pipe, auxiliary tube and sleeve pipe, and for prior art, the recess need not be seted up to the plug, has overcome prior art's defect through setting up extra auxiliary tube, guarantees that each pipe can not the fracture.

In one embodiment of the present invention, an end of the auxiliary rod away from the evacuation tube is located outside the auxiliary tube.

This arrangement can prevent the cylindrical portion from being heated and melted when step 5) is performed.

In one embodiment of the invention, one end of the auxiliary rod, which is far away from the evacuation tube, is 1-3 cm away from the end of the auxiliary tube.

In one embodiment of the present invention, at least 3 of the pumping holes are uniformly distributed around the axis of the vacuum tube.

At least 3 aspirating holes that evenly set up can guarantee to bleed evenly.

In one embodiment of the present invention, the sleeve includes a deposition portion and a head pipe portion, the deposition portion and the head pipe portion are welded together, the head pipe portion is used for being clamped by a clamp, and the deposition portion and the core rod are fused together to form the preform.

In one embodiment of the present invention, in step 7), the hydrogen gas of the torch is controlled at 100-170L/min, the moving speed of the torch is controlled at 5-30mm/min, the surface temperature of the deposition portion is heated to 1900-2200 ℃ by the torch, and the pressure in the sleeve is controlled at-1.5 torr to-0.1 torr.

In one embodiment of the present invention, the step 4) is performed by a flaring assembly, which includes:

a movable base capable of reciprocating left and right;

the first end of the connecting rod is fixed with the movable seat;

and the flaring block is fixed at the second end of the connecting rod and is provided with an arc flaring surface.

When flaring, the cylindrical part is heated firstly, then the movable seat moves to drive the flaring block to be close to the cylindrical part, so that the arc flaring surface is contacted with the cylindrical part to flare the cylindrical part.

In one embodiment of the present invention, the first end of the connecting rod is detachably mounted on the movable base; the connecting rod is a connecting rod with adjustable length.

The connecting rod can with remove the seat cooperation of pegging graft, this kind of mode can be after the flaring is accomplished, quick remove connecting rod and flaring piece, prevent that connecting rod and flaring piece from producing the influence (for example interfering) to the follow-up process. The connecting rod design of adjustable length can the different auxiliary tubes of adaptation.

In one embodiment of the present invention, the flaring assembly further includes a guide rail parallel to the axis of the auxiliary pipe, and the movable base is slidably disposed on the guide rail; the movable seat and the blowtorch are arranged in a staggered mode.

Remove seat and blowtorch dislocation set, prevent to remove seat and blowtorch interference, during the actual operation, can misplace 90 settings.

In one embodiment of the present invention, the flaring assembly further comprises a driving element for driving the movable base to reciprocate.

In practical application, the driving element may be an existing linear driving structure such as an electric push rod.

The invention has the beneficial effects that: the utility model provides a prefabricated excellent manufacturing process forms vacuum system through evacuation pipe, auxiliary tube and sleeve pipe, and for prior art, the recess need not be seted up to the plug, has overcome prior art's defect through setting up extra auxiliary tube, guarantees that each pipe can not the fracture.

Description of the drawings:

FIG. 1 is a schematic view of an auxiliary rod welded to an evacuation tube;

FIG. 2 is a schematic view of the auxiliary tube being welded to the evacuation tube;

FIG. 3 is a cross-sectional view of the auxiliary tube welded to the evacuation tube;

FIG. 4 is a schematic view of the barrel portion after flaring;

FIG. 5 is a schematic view of the auxiliary rod after welding with the core rod;

FIG. 6 is a schematic view of the sleeve being sheathed over the mandrel;

FIG. 7 is a cross-sectional view of the sleeve after welding with the cylindrical portion;

FIG. 8 is a schematic view of the flaring assembly after flaring.

The figures are numbered:

1. vacuumizing a tube; 2. an air exhaust hole; 3. a large diameter portion; 4. a tapered portion; 5. a small diameter part; 6. an auxiliary rod; 7. an auxiliary tube; 8. a cylindrical portion; 9. a flared part; 10. a sleeve; 11. a blowtorch; 12. a deposition section; 13. a head pipe portion; 14. a movable seat; 15. a connecting rod; 16. a flaring block; 17. an arc-shaped flaring surface; 18. and (4) a core rod.

The specific implementation mode is as follows:

the invention is described in further detail below with reference to specific embodiments and the attached drawing figures. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "circumferential", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., and "several" means one or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all those known to those skilled in the art.

As shown in fig. 1to 7, a preform manufacturing process, in which a sleeve 10 is fused with a mandrel 18 by MCVD equipment, includes the following steps:

1) an air exhaust hole 2 is processed on an air exhaust tube 1, the air exhaust tube 1 comprises a large-diameter part 3, a conical part 4 and a small-diameter part 5 which are sequentially connected, and the air exhaust hole 2 is positioned on the conical part 4;

2) sleeving one end of the auxiliary rod 6 in the small diameter part 5, and heating and melting to fix one end of the auxiliary rod 6 with the small diameter part 5;

3) sleeving an auxiliary pipe 7 on the vacuum tube 1, wherein the auxiliary pipe 7 comprises a cylindrical part 8 and an expanded part 9, the expanded part 9 is matched with the conical part 4 of the vacuum tube 1, and the air exhaust hole 2 is positioned on the inner side of the cylindrical part 8 and is heated and melted to fix the expanded part 9 and the conical part 4 of the vacuum tube 1;

4) heating one end of the cylindrical part 8 far away from the flaring part 9 to flare the cylindrical part;

5) heating and welding the core rod 18 and the auxiliary rod 6 together;

6) sleeving the sleeve 10 on the mandrel 18, making the sleeve 10 close to the auxiliary pipe 7, heating and melting to weld the flared cylindrical part 8 and the end part of the sleeve 10 together;

7) the vacuum tube 1 is evacuated, the blowtorch 11 moves from one end far away from the vacuum tube 1to one side of the vacuum tube 1, and the sleeve 10 and the core rod 18 are heated and fused together.

The prefabricated excellent manufacturing process of this application forms vacuum system through evacuation pipe 1, auxiliary tube 7 and sleeve pipe 10, and for prior art, the recess need not be seted up to plug 18, has overcome prior art's defect through setting up extra auxiliary tube 7, guarantees that each pipe can not ftracture.

As shown in fig. 2 and 3, in the present embodiment, the end of the auxiliary rod 6 remote from the evacuation tube 1 is located outside the auxiliary tube 7. This arrangement can prevent the cylindrical portion 8 from being heated and melted when step 5) is performed.

As shown in FIGS. 2 and 3, in the present embodiment, one end of the auxiliary rod 6 far away from the evacuation tube 1 is 1-3 cm away from the end of the auxiliary tube 7.

As shown in fig. 1, in the present embodiment, at least 3 suction holes 2 are uniformly distributed around the axis of the vacuum tube 1. The 3 at least aspirating holes 2 that evenly set up can guarantee to bleed evenly.

As shown in fig. 6 and 7, in the present embodiment, the jacket tube 10 includes a deposition portion 12 and a head tube portion 13 which are welded together, the head tube portion 13 being used for being held by a jig, and the deposition portion 12 being used for being fused together with the core rod 18 to form a preform.

In this embodiment, in step 7), the hydrogen gas of the torch 11 is controlled at 100-.

As shown in fig. 8, in the present embodiment, step 4) is performed by a flaring assembly, which includes:

a movable base 14 capable of reciprocating left and right;

a connecting rod 15, wherein a first end of the connecting rod 15 is fixed with the movable seat 14;

and a flared block 16 fixed to the second end of the connecting rod 15, the flared block 16 having an arc-shaped flared surface 17.

When flaring, the cylindrical part 8 is heated, then the movable seat 14 moves to drive the flaring block 16 to be close to the cylindrical part 8, so that the arc flaring surface 17 is contacted with the cylindrical part 8 to flare the cylindrical part 8.

In practical use, the first end of the connecting rod 15 is detachably mounted on the moving seat 14; the connecting rod 15 is a connecting rod 15 with adjustable length.

The connecting rod 15 can be inserted and matched with the moving seat 14, and in this way, after the flaring is completed, the connecting rod 15 and the flaring block 16 can be quickly removed, and the connecting rod 15 and the flaring block 16 are prevented from influencing (such as interfering) the subsequent processes. The length-adjustable connecting rod 15 is designed to be adaptable to different auxiliary pipes 7.

In practical use, the flaring assembly further comprises a guide rail parallel to the axis of the auxiliary pipe 7, and the movable seat 14 is arranged on the guide rail in a sliding manner; the movable base 14 is disposed to be offset from the torch 11.

The movable base 14 and the blowtorch 11 are arranged in a staggered mode, interference between the movable base 14 and the blowtorch 11 is avoided, and the movable base can be arranged in a staggered mode by 90 degrees in practical application.

In practice, the flaring assembly also comprises a driving element for driving the mobile seat 14 to reciprocate. The driving element can be an existing linear driving structure such as an electric push rod.

The above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings can be directly or indirectly applied to other related technical fields and are included in the scope of the present invention.