CN114523270A

CN114523270A - Welding processing method for CCT framework of groove-lacking type bent oblique solenoid

Info

Publication number: CN114523270A
Application number: CN202210340724.5A
Authority: CN
Inventors: 魏绍清; 宋云涛; 郑金星; 奚维斌; 赵文龙; 黄兴萌; 倪小军; 韩松博
Original assignee: Hefei Institutes of Physical Science of CAS
Current assignee: Hefei Institutes of Physical Science of CAS
Priority date: 2022-04-02
Filing date: 2022-04-02
Publication date: 2022-05-24
Anticipated expiration: 2042-04-02
Also published as: CN114523270B

Abstract

The invention discloses a welding processing method of a CCT framework of a slot-lacking type bent oblique solenoid, which divides the framework into a plurality of sections along the axial direction, and divides each section into half sections along the radial direction for processing, and the method comprises the following steps: firstly, processing a plurality of bent semi-cylinders on a rectangular aluminum block, processing the inner diameter of each bent semi-cylinder, the required bending radian of each section and a positioning dovetail groove of a contact surface, and milling a trapezoidal notch on the radial contact surface of each bent semi-cylinder, namely missing part of a wire slot at the radial assembly welding position of two semi-bent CCT frameworks; then, every two upper and lower bent semi-cylinders in the radial direction are assembled in a staggered mode through dovetail groove positioning, electron beams are adopted for welding and reinforcing in a notch formed by the notches, a plurality of bent cylinders are positioned through the dovetail grooves, and the bent cylinders are assembled in a staggered mode through an axial cold matching method to form a complete bent semi-cylinder; then, according to the required outer diameter of the framework, the outer wall surface of the bending cylinder is processed; and finally, processing inclined spiral grooves on the outer wall surfaces of the two bent semicylinders. The invention adopts the mode of radial halving and axial segmenting of the framework for processing and assembling, thereby reducing the processing difficulty of the bent CCT framework.

Description

Welding processing method for CCT framework of groove-lacking type bent oblique solenoid

Technical Field

The invention mainly relates to the technical field of processing and manufacturing of special-shaped superconducting magnet frameworks, in particular to a processing and manufacturing method of a bent solenoid (CCT) magnet framework.

Background

The bending CCT coil structure is a novel magnet structure which starts to be researched in recent years, the CCT coil has the advantages of light and novel coil structure, superior magnetic field quality, no accumulated stress of the CCT magnet coil, no need of optimization of coil end parts, outstanding mechanical performance and the like, is suitable for various practical superconducting wires, and meanwhile, the structure can be used for designing a combined functional magnet, so that the magnet has a good application prospect in the fields of large scientific engineering, civil medical treatment and the like.

The CCT coil framework is a caulking groove type framework, the processing quality of the framework directly influences the magnetic field quality of the magnet, and due to the particularity of the structure of the bending type CCT framework, the existing processing method is not suitable for processing the bending CCT magnet framework, so that the development of the technology of the bending CCT magnet is also restricted.

Disclosure of Invention

The invention aims to provide a processing and preparation method suitable for a coil framework of a bent CCT magnet.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a CCT framework welding processing method for a slot-lacking type bent oblique solenoid comprises the following steps:

the method comprises the following steps: milling a plurality of bent semi-circular cylinders on an aluminum alloy material in a mode of combining rough machining and fine machining, wherein every two bent semi-circular cylinders are used as a pair, and annealing stress removal treatment is needed to be carried out on the plurality of bent semi-circular cylinders again before fine machining;

step two: a dovetail groove and a welding notch which can be matched are respectively milled on the contact surfaces of the upper and lower curved semi-cylinders which are taken as a pair, wherein the welding notch is two notches with trapezoidal sections which are milled towards the inner diameter direction and are vertical to the outer diameter surface, the bottom of the notch is tangent to the bottom surface of the spiral line groove, the notch extends along the axial direction of the curved semi-cylinders to form a notch, and a certain welding space is reserved for the electron beam welding of the upper and lower curved semi-cylinders; the upper and lower two curved semi-cylinders are positioned by utilizing dovetail grooves and are assembled together in a staggered mode in the axial direction, electron beam welding is carried out at the trapezoidal notch, the upper and lower two semi-cylinders are assembled and welded, and a section of complete staggered curved cylinder is formed after welding;

step three: processing and assembling a plurality of sections of staggered bent cylinders according to the second step, processing a matched dovetail groove on the contact surface of each section of staggered bent cylinder, respectively matching and assembling the staggered bent cylinders, positioning the plurality of sections of bent cylinders by using the dovetail grooves in the axial direction, and assembling and splicing the staggered bent cylinders by a cold matching method to form a complete bent CCT framework cylinder;

step four: finish machining is carried out on the outer wall surface of the complete CCT cylinder framework, and the bending outer diameter r required by the bending CCT framework is milled_o；

Step five: and continuously processing a spiral wire groove on the outer wall surface of the complete CCT cylinder by utilizing a five-axis numerical control machine tool, and taking a curved oblique spiral curve equation as a driving track.

Furthermore, the upper semicircular ring part and the lower semicircular ring part are respectively used for fixing the upper half framework and the lower half framework and welding, wherein the upper half annular ring part adjusts the height of the upper half framework; the upper circular plate and the lower circular plate are used for being matched with the upper semicircular ring component to fix the whole structure; the bolt is used for connecting and supporting the upper semicircular plate and the lower semicircular plate and can move up and down to adjust the whole structure.

Further, according to the bending radius and the outer diameter of the CCT framework to be bent, a rectangular aluminum alloy block material is selected, and annealing stress removal treatment is carried out on the rectangular aluminum alloy block material.

Further, in the second step, radial up-and-down assembly is carried out, and a staggered assembly mode is adopted in the axial direction.

Further, the bending cylinders in the third step are assembled and spliced in an axis splicing mode by a cold distribution method, wherein one section of the bending cylinder needs to be soaked in liquid nitrogen for cooling, and then is assembled and spliced with one section of the bending cylinder at normal temperature.

Further, in the fifth step, the spiral groove is not processed at the groove-lacking part.

Further, the track equation of the wire grooves is optimized, adjusted and changed according to the magnetic field quality requirement.

Further, after a series of treatment tests are carried out on the processed framework, coil preparation work such as winding and the like is carried out; and the framework of the bent CCT magnet is formed by nesting and combining an inner framework and an outer framework, the second-layer framework is processed according to the method, and when the second-layer framework is welded in a staggered mode in the radial direction, the staggered direction of the second-layer framework is opposite to that of the first-layer inner framework.

The invention has the beneficial effects that:

1. the processing method adopts the way that the bent CCT framework is processed in half along the radial direction and in axial segmentation, and the bent framework with a certain aperture can be processed according to the actual requirement, so that the processing difficulty is reduced, the material is saved, and the cost is reduced;

2. the contact surfaces of the curved semi-cylinder and the curved cylinder section are respectively provided with dovetail grooves which can be matched, so that the joint position can be quickly found during assembly and splicing;

3. the staggered assembly mode is adopted in the upper and lower radial directions of the bent semi-cylinder, the mechanical property of the framework is enhanced, the structure is firmer, and spiral slots can be directly processed at the staggered part of the framework, so that the weight of the framework is reduced;

4. a slot notch is reserved at the welding position of the electron beam for assembling the two bent semi-cylinders, and the two semi-circular bent CCT frameworks are firmly welded together at the slot-lacking position of the bent CCT frameworks in an electron beam welding mode, so that the mechanical strength of the frameworks is enhanced.

The invention has good innovation and strong practicability, can effectively solve the problems of high processing difficulty of the conventional bent CCT framework and multi-layer nesting of bent CCT magnets, and has important reference significance for manufacturing bent CCT dipolar magnets, quadrupole magnets, hexapole magnets and other multipole magnet frameworks and magnets.

Drawings

In order to more clearly illustrate the embodiments or the prior art solutions of the present invention, the drawings used in the description of the embodiments or 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 invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic view of a curved helical line.

FIG. 2 is a schematic view of the upper half of the curved half cylinder of the present invention.

FIG. 3 is a schematic view of the lower half of the curved half cylinder of the present invention.

FIG. 4 is a schematic view of the two curved half cylinders of the present invention assembled vertically.

FIG. 5 is a schematic view of a section of a welded and assembled curved cylinder and an enlarged view of a splice in the present invention.

FIG. 6 is an axial assembling and splicing schematic view of the bending cylinder of the present invention.

FIG. 7 is a schematic view of the assembly and splicing of the curved semi-cylinders according to the present invention.

Fig. 8 is a schematic view of a slotted curved CCT framework in the present invention.

Detailed Description

The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings, and it should be understood that the description and drawings of the embodiments of the present invention are merely illustrative in nature, and not restrictive.

The invention is further described below by taking a bent oblique spiral CCT dipolar magnet framework as an example. The curved CCT framework wire slot track can be determined according to a curved oblique spiral line track equation. Taking a bent CCT dipolar magnet frame as an example, as shown in fig. 1, a track 1 of a certain bent oblique helical coil is established according to a slot track equation. The CCT framework is divided into 5 sections along the axial direction of the curved CCT framework, each section is divided into two semi-curved frameworks along the radial direction, the schematic diagrams of the upper semi-curved framework and the lower semi-curved framework of each section are shown in figures 2 and 3, and the processing method comprises the following steps:

the method comprises the following steps: according to the bending radius and the outer diameter of a certain CCT skeleton to be bent, a proper rectangular aluminum alloy block material is selected, the rectangular aluminum alloy block material is annealed and destressed, a plurality of bent half cylinders, such as an upper half cylinder 201 and a lower half cylinder 301, are milled in a mode of combining rough machining and fine machining on the aluminum alloy material, as shown in figures 2 and 3, the bending radian and the inner diameter r of each section of bent half cylinder_iThe outer diameter r of the bent semi-cylinder should meet the requirement of a bent CCT framework_oSlightly larger than the CCT framework with the outer diameter of 2-5 mm. And annealing and stress relieving treatment are carried out again before the two bent semi-cylinders are subjected to finish machining.

Step two: the mateable dovetail grooves and weld notches 4, as shown in fig. 2 at 401 and fig. 3 at 402, are milled away at the two contact faces of the two curved half-cylinders, respectively, as shown in fig. 4. The welding gap 4 is two gaps with trapezoidal cross sections milled in the direction perpendicular to the outer diameter surface and towards the inner diameter, and the bottom of the gap is tangent to the bottom surface of the spiral groove (namely the inner diameter of the coil). The notch extends along the axial direction, and a certain welding space is reserved for the electron beam welding of the upper and lower bent semi-cylinders. The upper and lower

curved semi-cylinders

201, 301 are positioned by dovetail grooves and assembled together in a staggered manner in the axial direction, as shown in fig. 4, electron beam welding is performed at the trapezoidal notch, the upper and lower semi-cylinders are assembled and welded, and a section of complete curved semi-cylinder as shown in fig. 5 is formed after welding. The up-down staggered welding can ensure that the whole structure of the framework is firmer after the axial welding and assembly, and the staggered part can still process the spiral line groove.

Step three: and 5 sections of offset curved cylinders are machined and assembled according to the second step, and dovetail grooves which can be matched with each other are machined on the contact surface of each section of offset curved cylinder, such as the

upper half cylinders

201, 202, 203, 204 and 205 and the

lower half cylinders

301, 302, 303, 304 and 305, and are respectively matched and assembled into the offset curved cylinders. As shown in fig. 6, the 5 segments of curved cylinders are positioned by dovetail grooves in the axial direction and assembled and spliced by a cold fitting method to form a complete curved CCT skeleton cylinder as shown in fig. 7, an integral upper half cylinder 2 (comprising a plurality of segments of

upper half cylinders

201, 202, 203, 204, 205) and an integral lower half cylinder 3 (comprising a plurality of segments of

lower half cylinders

301, 302, 303, 304, 305). The upper and lower

semi-circular ring parts

6, 5 in fig. 4 and 6 are used to fix the upper and lower half frames, respectively, for welding, wherein the upper semi-circular ring part 6 can adjust the height of the upper half frame. The upper circular plate 7 and the lower circular plate 8 are used for being matched with the upper circular ring component 6 to fix the whole structure, and the bolt 9 is used for connecting and supporting the upper circular plate 7 and the lower circular plate 8 and can move up and down to adjust the whole structure.

Step five: a spiral wire groove is continuously machined on the outer wall surface of a complete CCT cylinder by using a five-axis numerical control machine tool, a curved oblique spiral curve equation is used as a driving track, the spiral wire groove is not machined in a groove-lacking part, a machined framework schematic diagram is shown in figure 8, a spiral wire groove is 10 in figure 8, and a groove-lacking part is 11 in figure 8.

The CCT dipolar magnet is generally formed by nesting an inner layer of framework coil and an outer layer of framework coil, and the second layer of framework nested outside the first layer of framework is processed according to the method, wherein the second layer of framework is radially welded in a vertically staggered manner, and the staggered direction of the second layer of framework is opposite to that of the first layer of inner framework. After a series of treatment tests are carried out on the processed framework, the winding of a coil, the manufacture of joints, epoxy impregnation, magnet assembly and the like can be carried out to finish the manufacture of the magnet, and after the manufacture of the magnet is finished, tests are carried out to verify indexes such as the magnetic field performance, the field quality and the like of the magnet.

The foregoing is only one embodiment of the present invention, and the embodiment is for better explaining the principle and practical application of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention disclosure are included in the spirit and principle of the present invention, and any modifications, equivalents, improvements, etc. that are within the scope of the claims of the present invention.

Claims

1. A CCT framework welding processing method of a slot-lacking type bent oblique solenoid is characterized by comprising the following steps:

Step five: and continuously processing a spiral wire groove on the outer wall surface of the complete CCT cylinder by using a five-axis numerical control machine tool, and taking a curved oblique spiral curve equation as a driving track.

2. The CCT framework welding processing method of the slot-lacking type bending inclined solenoid coil as claimed in claim 1, further comprising:

the upper semi-ring component and the lower semi-ring component are respectively used for fixing the upper framework and the lower framework and welding, wherein the upper semi-ring component adjusts the height of the upper framework; the upper circular plate and the lower circular plate are used for being matched with the upper semicircular ring component to fix the whole structure; the bolt is used for connecting and supporting the upper semicircular plate and the lower semicircular plate and can move up and down to adjust the whole structure.

3. The CCT framework welding processing method of the slot-lacking type bending inclined solenoid coil as claimed in claim 1, further comprising:

according to the bending radius and the outer diameter of the CCT skeleton to be bent, rectangular aluminum alloy block materials are selected and are subjected to annealing stress removal treatment.

4. The CCT framework welding processing method of the slot-lacking type bending inclined solenoid coil as claimed in claim 1, further comprising:

and in the second step, radial up-and-down assembly is carried out, and a staggered assembly mode is adopted in the axial direction.

5. The CCT framework welding processing method for the slot-lacking type bending inclined solenoid according to claim 1, characterized by further comprising the following steps:

and the bent cylinders in the third step are assembled and spliced in an axis splicing manner by adopting a cold distribution method, wherein one section of the bent cylinder needs to be soaked in liquid nitrogen for cooling, and then is assembled and spliced with one section of the bent cylinder at the normal temperature.

6. The CCT framework welding processing method of the slot-lacking type bending inclined solenoid coil as claimed in claim 1, further comprising:

and in the fifth step, the spiral wire grooves are not processed at the groove-lacking part.

7. The CCT framework welding processing method of the slot-lacking type bending inclined solenoid coil as claimed in claim 1, further comprising:

and the track equation of the wire grooves is optimized, adjusted and changed according to the magnetic field quality requirement.

8. The CCT framework welding processing method of the slot-lacking type bending inclined solenoid coil as claimed in claim 1, further comprising:

after a series of treatment tests are carried out on the processed framework, coil preparation work such as winding and the like is carried out; and the framework of the bent CCT magnet is formed by nesting and combining an inner framework and an outer framework, the second-layer framework is processed according to the method, and when the second-layer framework is welded in a staggered mode in the radial direction, the staggered direction of the second-layer framework is opposite to that of the first-layer inner framework.