A method of assembling a multi-layer nested curved superconducting magnet

Abstract

This invention discloses a multi-layer nested bending superconducting magnet assembly method, belonging to the field of heavy ion therapy equipment manufacturing technology. Specifically, it includes the following steps: 1) Coil frame pre-assembly: After machining the grooves on each coil frame, burrs and chips are cleaned from the surface; the coil frames are sequentially nested and connected on the beam center tube from the inside out, with both ends of the coil frames aligned to complete the pre-assembly; 2) Concentricity adjustment: The gaps between adjacent coil frames are adjusted sequentially from the inside out to ensure concentricity; after adjustment, G10 shims are placed between each coil frame for support; 3) Drilling fixing screw holes; 4) Winding the coil; 5) Installing the end plate; 6) Wiring. In this invention, when machining the grooves on each layer of the coil frame, process planes are machined in the four directions (up, down, left, and right) at both ends of the coil frame. These process planes serve as reference planes, providing assembly and measurement benchmarks for concentricity alignment of each layer of the coil frames during assembly.

Description

Technical Field

[0001] This invention belongs to the field of heavy ion therapy equipment manufacturing technology, specifically relating to a multi-layer nested bending superconducting magnet assembly method. Background Technology

[0002] Heavy ion therapy devices are technologically complex, large in size, and expensive to build and operate, which has become a major problem restricting their development and promotion. Therefore, miniaturizing and lightening the large treatment devices is the development direction of radiotherapy devices.

[0003] In the miniaturization of heavy ion therapy devices, the use of superconducting magnets is an inevitable choice. Compared with conventional magnets, superconducting magnets have two significant advantages: First, superconducting magnets use a pure coil structure, eliminating the need for a bulky iron core. When necessary, the iron core only serves to shield leakage fields and improve magnetic field quality, resulting in a much smaller size and weight. To generate the same magnetic field, the weight of a superconducting magnet is significantly reduced compared to a conventional magnet. Second, at liquid helium temperatures, superconducting magnets can generate higher magnetic fields. While maintaining magnetic stiffness, the deflection radius is reduced, effectively decreasing the overall size of the magnet.

[0004] A multi-layered nested curved superconducting magnet, its external structure is as follows: Figure 1 As shown, it includes a junction box 1, a left end plate 2, a coil assembly 3, and a right end plate 4; its cross-sectional structure is as follows. Figure 2 As shown, from the inside out, the coils are arranged as follows: beam center tube 1, first layer coil frame 2, first layer aluminum ring 3, second layer coil frame 4, second layer aluminum ring 5, third layer coil frame 6, third layer aluminum ring 7, fourth layer coil frame 8, and fourth layer aluminum ring 9. The end plates 3 and 4 and the beam center tube 1 are made of 304 stainless steel, the coil frames are made of G10, and the aluminum rings are made of 1060 aluminum alloy. Because the coil structure is a multi-layered nested structure, the concentricity of each layer of coils must be ensured during assembly. The higher the concentricity of each layer of coils, the stronger the magnetic field that the magnet can generate. Summary of the Invention

[0005] This invention provides a multi-layer nested bending superconducting magnet assembly method, the purpose of which is to ensure the concentricity of each layer of coil skeleton during superconducting magnet assembly, so as to produce a high-performance superconducting magnet.

[0006] Therefore, the present invention adopts the following technical solution:

[0007] A method for assembling a multi-layer nested bent superconducting magnet includes the following steps:

[0008] 1) Coil frame pre-assembly: After the wire grooves of each coil frame are machined, the burrs and chips on the surface are cleaned; each coil frame is nested and connected from the inside to the outside on the beam center tube, and the two ends of the coil frames are aligned to complete the pre-assembly.

[0009] 2) Concentric Adjustment: Adjust the gap between adjacent coil frames from the inside out to make the coil frames concentric. After adjustment, install shims between each coil frame for support.

[0010] 3) Drilling fixing screw holes: Install end plates on the left and right end faces of the coil frame respectively, with the end plates concentric with the coil frame; drill through holes along the circumferential direction on the end plates to connect each coil frame, and drill fixing screw holes corresponding to the through holes on the end faces of each coil frame through the through holes, with at least three fixing screw holes drilled on each coil frame.

[0011] Remove the end plate, then remove each coil frame and pad layer by layer, and mark the pads for easy assembly later.

[0012] 4) Winding the coil: Place the first layer of coil skeleton on the support fixture, and wind the superconducting wire in the wire groove processed in step 1). After the first layer of coil skeleton is completed, nest the second layer of coil skeleton, install the shim removed in step 2), and continue winding the second layer of coil skeleton. Wind each coil skeleton in turn until each coil skeleton is completed, and adjust each coil skeleton to be concentric.

[0013] 5) Install the end plate: Connect the end plate prepared in step 2) to the left and right ends of the coil frame, and connect the screw to the through hole of the end plate and the fixing screw hole of the coil frame;

[0014] 6) Wiring: Install a junction box on the left end plate on the left side of the coil frame, connect the superconducting wire inside the junction box to complete the assembly of the coil frame.

[0015] Furthermore, after the wire groove is processed in step 1), multiple process planes are processed on the circumferential surfaces at both ends of the coil frame, and the processing depth of each process plane is equal.

[0016] Furthermore, each end of the coil frame has four process planes, and adjacent process planes are perpendicular to each other; when the coil frame is laid flat, two process planes are in a horizontal state, and the other two process planes are in a vertical state.

[0017] Further, in step 1), after the first layer of coil skeleton is nested on the beam center tube, the process planes at both ends of the coil skeleton in four directions are used as reference planes. The distance from the reference planes to the outer surface of the beam center tube is measured with a depth gauge. The process planes are adjusted to be equidistant from the outer surface of the beam center tube, that is, the first layer of coil skeleton is concentric with the beam center tube. The same method is used to adjust the concentricity of each layer of coil skeleton.

[0018] Further, in step 1), after adjusting the coil frames of each layer to be concentric, G10 pads are placed between the coil frames, and each pad is marked.

[0019] Furthermore, each coil frame has an outer layer of nested aluminum rings. The inner diameter of the aluminum rings is larger than the outer diameter of the corresponding coil frame, and the length and curvature of the aluminum rings are adapted to the coil frame.

[0020] Furthermore, in step 3), the coils on each coil frame are wound with the same superconducting cable.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. In this invention, when machining grooves on each layer of coil skeleton, process planes are machined in the four directions of up, down, left, and right at both ends of the coil skeleton. The process planes serve as reference planes, providing assembly and measurement references for finding the concentricity of each layer of coil skeleton during assembly.

[0023] 2. During the pre-assembly of this invention, after adjusting each layer of coil frame to be concentric, G10 pads are placed between the coil frames, and the pads are marked to facilitate subsequent assembly.

[0024] 3. When winding superconducting wire on the coil frame of the present invention, the coil frame is fixed on the winding machine with a tooling to ensure the tension of the wire during winding and improve the winding efficiency. After winding one layer, when winding the second layer, only the positioning block on the winding tooling needs to be replaced. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the external structure of the superconducting magnet of the present invention;

[0026] Figure 2 This is a schematic diagram of the cross-sectional structure of the superconducting magnet of the present invention;

[0027] Figure 3 This is a schematic diagram of the superconducting magnet endplate of the present invention;

[0028] Figure 4 This is a schematic diagram of the superconducting magnet coil winding of the present invention;

[0029] Figure 5 This is a schematic diagram of the superconducting magnet winding fixture of the present invention;

[0030] Figure 6 This is a schematic diagram of the assembly and measurement reference of the superconducting magnet coil skeleton of the present invention;

[0031] In the diagram: 1-Wire box, 2-Left end plate, 3-Coil assembly, 4-Right end plate, 5-Current center tube, 6-First layer coil skeleton, 7-First layer aluminum ring, 8-Second layer coil skeleton, 9-Second layer aluminum ring, 10-Third layer coil skeleton, 11-Third layer aluminum ring, 12-Fourth layer coil skeleton, 13-Fourth layer aluminum ring, 14-Coil skeleton, 15-Positioning block, 16-Support fixture, 17-Process plane. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings:

[0033] A multi-layered nested curved superconducting magnet, its external structure is as follows: Figure 1 As shown, it includes junction box 1, left end plate 2, coil assembly, and right end plate 4; its cross-sectional structure is as follows. Figure 2 As shown, from the inside out, the layers are: beam center tube 5, first layer coil frame 6, first layer aluminum ring 7, second layer coil frame 8, second layer aluminum ring 9, third layer coil frame 10, third layer aluminum ring 11, fourth layer coil frame 12, and fourth layer aluminum ring 13. The two end plates and beam center tube 5 are made of 304 stainless steel, each layer of coil frame 14 is made of G10, and each layer of aluminum ring is made of 1060 aluminum alloy.

[0034] A method for assembling a multi-layer nested bent superconducting magnet, the assembly method comprising the following steps:

[0035] 1) Coil frame pre-assembly: After the wire grooves are machined for each coil frame 14, four process planes 17 are machined on the circumferential surfaces at both ends of the coil frame 14. Adjacent process planes 17 are perpendicular to each other. When the coil frame 14 is laid flat, two process planes 17 are in a horizontal state and two process planes 17 are in a vertical state. The distances of the process planes 17 of each coil frame 14 from the circumferential surface of the coil frame 14 are relative. The process planes 17 serve as the reference for alignment and concentricity adjustment during pre-assembly.

[0036] After the processing is completed, the burrs and chips on the surface are cleaned, and the parts are nested from the inside out for pre-assembly.

[0037] 2) Concentricity Adjustment: After the first layer of coil skeleton 6 is nested on the beam center tube 5, the process planes 17 of the four directions at both ends of the coil skeleton 14 are used as reference planes. The distance from the reference planes to the outer surface of the beam center tube 5 is measured with a depth gauge and adjusted to be equidistant in the four directions, that is, the first layer of coil skeleton 6 and the beam center tube 5 are concentric. G10 shims are placed between the first layer of coil skeleton 6 and the beam center tube 5. The concentricity of each layer of coil skeleton 14 is adjusted in the same way, and G10 shims are placed. The shims are marked to facilitate subsequent assembly.

[0038] 3) Drilling and fixing screw holes: The left end plate 2 and the right end plate 4 are installed at both ends of the coil frame 14. Figure 3 This is a schematic diagram of the end plates. Adjust the outer circles of the left end plate 2 and right end plate 4 to be concentric with the outer circle of the fourth layer coil frame 12. Place G10 shims between the left end plate 2 and right end plate 4 and the beam center tube 5. Using the mounting holes on the left end plate 2 and right end plate 4 as a reference, drill fixing screw holes on each coil frame 14.

[0039] Take the left end plate 2 and the right end plate 4, remove the coil skeleton 14 and the gaskets layer by layer and mark the gaskets to facilitate subsequent assembly. Tap the fixed screw holes drilled on the end face of the coil skeleton 14 and install wire thread inserts.

[0040] 4) Wind the coil: Figure 4 is a schematic diagram of coil winding. The coils on each layer of the skeleton are divided into upper and lower poles. Figure 4 The upper pole wire grooves shown in are for the upper pole. The lower pole wire grooves are opposite to the upper pole wire grooves. The shape of the coil for each pole is a loop shape. The coils on the four-layer skeleton are wound with 1 superconducting wire.

[0041] Figure 5 is a schematic diagram of the winding tooling. Place the first-layer coil skeleton 6 in the positioning block 15 of the tooling, and fix the tooling body on the winding machine. When winding, first wind the outermost coil of the upper pole. After winding one circle, jump to the second outermost circle until winding to the innermost circle. Then, start from the innermost circle and wind to the outermost circle in sequence. Then, jump from the ring groove at the end of the skeleton to the lower pole. Take out the coil skeleton 14 from the positioning block 15, turn it over 180 degrees, and wind the coil of the lower pole according to the above steps. After winding, lead out the superconducting wire from the jump wire groove and fix the wire head on the coil skeleton 14 with fiberglass tape. Take down the first-layer coil skeleton 6 and press on Figure 2 Put the first-layer aluminum ring 7 and the second-layer coil skeleton 8 outside the first-layer coil skeleton 6, and pad the G10 gaskets taken down in step 2) at both ends. Adjust to be concentric. After the aluminum ring shrinks at low temperature, it has a certain binding force on the superconducting wire. Replace the positioning block 152 on the winding tooling, place the nested coil skeleton 14 on the winding tooling, and wind and assemble the coils of each layer in sequence according to the above steps until the last layer is wound.

[0042] 5) Install the end plates; install the left end plate 2 and the right end plate 4 at both ends of the coil skeleton 14 respectively. Nest the beam center tube 5 inside the coil skeleton 14 and adjust so that the lengths of the beam center tube 5 extending from both ends of the coil skeleton 14 are the same. Pad the gasket taken down in step 2) between the beam center tube 5 and the first-layer coil skeleton 6 and adjust to be concentric. Spot weld the left end plate 2 and the beam center tube 5 to prevent the whole coil skeleton 14 from moving up and down on the beam center tube 5, and connect the screw to the through hole of the end plate and the fixed screw hole of the coil skeleton 14.

[0043] 6) Wiring: Install the junction box 1 on the left end plate 2 and connect the superconducting wire inside the junction box 1 to complete the assembly of the coil skeleton 14.

Claims

1. A method for assembling a multi-layer nested bent superconducting magnet, characterized in that, Includes the following steps: 1) Coil frame pre-assembly: After the wire grooves of each coil frame (14) are processed, multiple process planes (17) are processed on the circumferential surfaces of the left and right ends of the coil frame (14), and the processing depth of each process plane (17) is equal; each end of the coil frame (14) is provided with four process planes (17), and adjacent process planes (17) are perpendicular to each other; when the coil frame (14) is laid flat, two process planes (17) are in a horizontal state, and the other two process planes (17) are in a vertical state; clean the burrs and chips on the surface; connect each coil frame (14) in sequence from the inside to the outside on the beam center tube (5), and align the two ends of the coil frame (14) to complete the pre-assembly; 2) Concentricity Adjustment: Adjust the gap between adjacent coil frames (14) sequentially from the inside out to make the coil frames (14) concentric. After adjustment, install shims between each coil frame (14) for support. Concentricity adjustment includes: After the first layer coil frame (6) is nested on the beam center tube (5), take the process planes (17) at both ends of the coil frame (14) as reference planes, measure the distance from the reference plane to the outer surface of the beam center tube (5) with a depth gauge, and adjust it to be equidistant from the four process planes (17) to the outer surface of the beam center tube (5), that is, the first layer coil frame (6) is concentric with the beam center tube (5); adjust the concentricity of each layer of coil frames (14) in the same way. 3) Drilling fixing screw holes: Install end plates on the left and right end faces of the coil frame (14), with the end plates concentric with the coil frame (14); drill through holes along the circumferential direction on the end plates to connect each coil frame (14), and drill fixing screw holes corresponding to the through holes on the end faces of each coil frame (14) through the through holes, with at least three fixing screw holes drilled on each coil frame (14); Remove the end plate, remove each coil frame (14) and gasket layer by layer, and mark the gaskets for easy subsequent assembly; 4) Winding the coil: Place the first layer coil skeleton (6) on the support fixture (16), and wind the superconducting wire in the groove processed in step 1). After the first layer coil skeleton (6) is completed, nest the second layer coil skeleton (8), install the shim removed in step 2), and continue winding the second layer coil skeleton (8). Wind each coil skeleton (14) in turn until each coil skeleton (14) is completed. Adjust each coil skeleton (14) to be concentric. 5) Install the end plate: Connect the end plate prepared in step 2) to the left and right ends of the coil frame (14), and connect the screw to the through hole of the end plate and the fixing screw hole of the coil frame (14); 6) Wiring: Install junction box (1) on the left end plate (2) on the left side of the coil frame (14), connect super wire in junction box (1) to complete the assembly of coil frame (14).

2. The multi-layer nested bent superconducting magnet assembly method according to claim 1, characterized in that, In step 2), after adjusting the coil frames (14) of each layer to be concentric, G10 pads are placed between the coil frames (14), and each pad is marked.

3. The multi-layer nested bent superconducting magnet assembly method according to claim 1, characterized in that, Each coil frame (14) has an outer layer of nested aluminum rings. The inner diameter of the aluminum rings is larger than the outer diameter of the corresponding coil frame (14). The length and curvature of the aluminum rings are adapted to the coil frame (14).

4. The multi-layer nested bent superconducting magnet assembly method according to claim 1, characterized in that, In step 3), the coils on each coil frame (14) are wound with the same superconducting cable.

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