Conical surface superconducting magnet coil forming method and forming framework thereof

Abstract

The invention discloses a conical surface superconducting magnet coil forming method and a conical surface superconducting magnet coil forming framework, and relates to the technical field of superconducting magnets. According to the method, a temporary tool which is composed of a split type mandrel, a demolding shaft sleeve, a conical surface demolding framework and the like and can be completely detached is adopted as the forming framework, and introduction of a permanent metal framework is avoided; therefore, the extreme light weight and compactness of the magnet are realized, and the risk of low-temperature thermal stress cracking caused by mismatch of thermal expansion coefficients of metal and a composite material is eradicated; epoxy glue is filled in real time through a wet winding process, and impregnated glass silk threads are accurately filled in gaps of conical surface turns, so that high precision and structural compactness of coil forming are ensured, and the cured coil has high mechanical strength; and after external pre-tightening force is applied through the magnet pre-tightening hoop, controlled overall thermocuring treatment is carried out, so that the coil, the epoxy glass fiber connecting frame and the like are combined into a single self-supporting composite whole, the internal transmission path of electromagnetic force is optimized, and the structural stability is improved.

Description

Technical Field

[0001] This invention relates to the field of superconducting magnet technology, and in particular to a method for forming a conical superconducting magnet coil and its forming skeleton. Background Technology

[0002] High-field superconducting magnets, especially those with special geometries such as conical and hyperboloidal surfaces, occupy a core position in high-tech fields such as strong magnetic field research, nuclear magnetic resonance, particle accelerators, and magnetic confinement fusion. They can precisely generate magnetic fields with specific spatial distributions, meeting the stringent requirements of scientific experiments and engineering applications. In the traditional manufacturing process of superconducting magnets, the core process involves bonding NbTi and N2... Superconducting wires, such as Sn or high-temperature superconducting tapes, are wound onto a pre-processed permanent framework. The framework is then impregnated and cured with adhesives such as epoxy resin to achieve functions such as wire positioning and fixation, mechanical support and reinforcement, improved thermal conductivity, and insulation protection. This permanent framework is typically made of high-strength, non-magnetic metallic materials (such as aluminum alloys or stainless steel) or composite materials, forming an inseparable integrated structure with the coil after curing. This is the mainstream technological approach for manufacturing traditional superconducting magnets.

[0003] However, the aforementioned integrated coil-skeleton structure has many inherent defects, severely restricting the performance improvement and application expansion of medium- and high-field superconducting magnets: First, the permanent skeleton itself has considerable mass and volume, and the additional weight increases the burden on the support structure and cooling system of the entire magnet system; Second, superconducting magnets need to operate at ultra-low temperatures (such as liquid helium at 4.2K). During the cooling process from room temperature to operating temperature, different materials will generate huge thermal stresses due to the difference in their coefficients of thermal expansion. If the thermal shrinkage rates of the coil (composite materials, epoxy resin) and the metal skeleton do not match, microcracks may appear in the cured adhesive layer, or even... Damage to the superconducting wire can, in severe cases, cause the magnet to lose quench during excitation, resulting in equipment damage. Third, high-precision magnetic fields place stringent requirements on the surface tolerances and finish of the permanent framework, especially for complex curved surfaces such as conical surfaces, making processing extremely difficult and costly. Fourth, conductive frameworks are prone to generating eddy currents when the magnetic field changes rapidly (such as pulsed fields or magnet quenching), increasing heat load, consuming cooling capacity, and causing magnetic field distortion, affecting magnetic field quality and stability. Fifth, the enormous Lorentz force generated when the magnet is energized needs to be transmitted through a multi-layered structure of "coil-adhesive layer-framework," resulting in low mechanical transmission efficiency and a tendency to cause localized stress concentration. Therefore, a new superconducting magnet coil forming technology that can eliminate the need for a permanent framework and avoid the aforementioned defects is urgently needed. Summary of the Invention

[0004] This invention provides a method for forming a conical superconducting magnet coil and its forming skeleton, which can solve the problem that the integrated "coil-skeleton" structure in the prior art has many inherent defects, which seriously restricts the performance improvement and application expansion of medium and high field superconducting magnets.

[0005] A method for forming a conical superconducting magnet coil includes the following steps: S1, assembling a split mandrel, a demolding sleeve, and two conical demolding frames, fixing them with a clamping chuck, screwing in a stress support screw to apply radial preload, applying an anti-sticking treatment to the working surfaces of the conical demolding frames and the demolding sleeve, and covering the surface of the demolding sleeve with a PET fiber film; S2, using a wet winding process to wind superconducting wires on the mold surface to form a conical magnet blank, filling with epoxy resin in real time during winding, and filling the coil turn gaps in the conical area with resin-impregnated glass fiber wire; S3, fitting a magnet pre-tightening clamp around the outer periphery of the conical magnet blank and applying a final radial preload, then subjecting the integrated whole to controlled epoxy resin thermosetting treatment; S4, sequentially removing the stress support screw and the clamping chuck, extracting the split mandrel, then removing the demolding sleeve, and finally removing the two conical demolding frames to obtain a self-supporting conical superconducting magnet coil.

[0006] The present invention provides a method for forming a conical superconducting magnet coil, which, compared with the prior art, has the following beneficial effects, but is not limited to: This method for forming conical superconducting magnet coils utilizes a completely removable temporary tooling frame, consisting of a split mandrel, a demolding bushing, and a conical demolding skeleton, as the forming framework. This avoids the introduction of a permanent metal framework, achieving extreme lightweighting and compactness of the magnet and eliminating the risk of low-temperature thermal stress cracking caused by the mismatch in thermal expansion coefficients between metals and composite materials. Real-time filling of epoxy resin through a wet winding process and precise filling of impregnated glass fiber wire into the gaps between the conical turns ensures high precision and structural density in coil forming, giving the cured coil high mechanical strength. Controlled overall thermosetting after applying external pre-tightening force through a magnet pre-tightening clamp combines the coil, epoxy fiberglass connector, and other components into a single self-supporting composite whole, optimizing the internal transmission path of electromagnetic force and improving structural stability. This method simultaneously achieves multiple goals: lightweighting, high reliability, no electromagnetic interference, and low-cost manufacturing.

[0007] Further, in step S1, the demolding process includes uniformly spraying a dry release agent onto all tooling surfaces to form a 5-30 μm coating.

[0008] Furthermore, in step S2, the conical magnet blanks on both sides are connected by an epoxy fiberglass connector with multiple curing channels inside, and the sample observation port core frame is fixed in the middle of the epoxy fiberglass connector.

[0009] Furthermore, in step S4, if excessive resistance is encountered when removing the demolding bushing or conical demolding skeleton, a temperature difference-assisted demolding method is adopted. First, the non-working surface of the tooling is locally cooled at low temperature, and then gently vibrated or tapped axially.

[0010] Furthermore, after step S4 is completed, the inner cavity surface of the conical magnet is subjected to plasma cleaning to remove residual release agent.

[0011] Furthermore, in step S1, the radial preload applied by the stress support screw is 1-2 times the value calculated based on the coil winding stress.

[0012] Furthermore, in step S2, the coil turn gap in the conical area needs to be calculated based on the conical slope, and the corresponding impregnated glass fiber wire is filled to ensure that the cylindricity of each coil surface is uniform.

[0013] A forming frame for a conical superconducting magnet coil, based on the aforementioned forming method for conical superconducting magnet coils, comprises a split mandrel, a demolding sleeve, two conical demolding frames, two clamping chucks, a stress support screw, and several rotating connecting blocks. The split mandrel has a threaded hole inside. The demolding sleeve is coaxially fitted outside the split mandrel, and its inner diameter is larger than the outer diameter of the split mandrel, forming a radial clearance between them. The two conical demolding frames are coaxially fitted at both ends of the demolding sleeve, and the outer surface of each conical demolding frame is... A forming conical surface is used to form the forming inner cavity of the conical magnet. The outer surface of the demolding sleeve exposed between the two conical demolding skeletons is a forming cylindrical surface. Two clamping chucks are coaxially sleeved and locked at both ends of the split mandrel and the ends of the conical demolding skeletons on the corresponding sides, for axially fixing the three. A stress support screw is screwed into the threaded hole of the split mandrel to press the split mandrel and make it expand radially, thereby applying a radial preload to the demolding sleeve. Several rotating connecting blocks are detachably connected at one end to one of the conical demolding skeletons.

[0014] The present invention provides a method for forming a conical superconducting magnet coil, which, compared with the prior art, has the following beneficial effects, but is not limited to: This conical superconducting magnet coil forming frame uses a temporary support system consisting of a split mandrel, a demolding sleeve, and a conical demolding frame, rather than a permanent frame. After forming, the preload can be released by unscrewing the stress support screw, the axial fixation can be released by removing the clamping chuck, and the split mandrel can be pulled out using the radial movement gap between the split mandrel and the demolding sleeve. Then, the demolding sleeve and the conical demolding frame are removed in sequence, ultimately obtaining a pure coil structure without a permanent frame. This completely eliminates the extra weight and volume burden brought by a permanent frame, while avoiding the problem of thermal expansion coefficient differences caused by long-term bonding of dissimilar materials. It also eliminates the risk of adhesive layer cracking and wire damage caused by thermal stress during the cooling process from the root.

[0015] Furthermore, a sample observation port core frame is bonded to the end of the conical magnet, an epoxy fiberglass connecting frame is provided between the sample observation port core frame and the conical magnet, an epoxy fiberglass insulation layer is bonded between the sample observation port core frame and the conical magnet, and a magnet pre-tightening clamp is fitted on the outside of the conical magnet.

[0016] Furthermore, the split mandrel is composed of at least two relatively movable split segments. Attached Figure Description

[0017] Figure 1 This is a flowchart of a method for forming a conical superconducting magnet coil according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a cone-shaped superconducting magnet coil forming frame according to an embodiment of the present invention; Figure 3 This is a cross-sectional view of the forming frame of a conical superconducting magnet coil according to an embodiment of the present invention. Figure 1 ; Figure 4 This is a cross-sectional view of the forming frame of a conical superconducting magnet coil according to an embodiment of the present invention. Figure 2 ; Figure 5 for Figure 3 Schematic diagram of the demolding skeleton with a conical surface; Figure 6 for Figure 3 Schematic diagram of the split-type mandrel; Figure 7 for Figure 3 A schematic diagram of the structure of a conical magnet.

[0018] Explanation of reference numerals in the attached figures: 1. Sample observation port core holder; 2. Conical magnet; 3. Epoxy fiberglass connector; 4. Epoxy fiberglass insulation layer; 5. Magnet pre-tightening clamp; 6. Split mandrel; 7. Conical demolding skeleton; 8. Rotating connecting block; 9. Demolding bushing; 10. Shaft clamping chuck; 11. Stress support screw. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0024] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] like Figure 1 As shown, an embodiment of the present invention provides a method for forming a conical superconducting magnet coil, comprising the following steps: S1, assembling a split mandrel 6, a demolding sleeve 9, and two conical demolding frames 7, and fixing them with a clamping chuck 10, screwing in a stress support screw 11 to apply radial preload, performing anti-stick treatment on the working surfaces of the conical demolding frames 7 and the demolding sleeve 9, and covering the surface of the demolding sleeve 9 with a PET fiber film; S2, using a wet winding process to wind superconducting wires on the mold surface to form a conical magnet blank 2. S3. During the winding process, epoxy resin is filled in real time, and impregnated glass fiber is filled in the coil turn gaps in the conical area; S4. Magnet pre-tightening clamps 5 are fitted around the outer periphery of the conical magnet 2 blank and the final radial pre-tightening force is applied. Then, the integrated whole is subjected to controlled epoxy resin thermosetting treatment; S5. The stress support screws 11 and clamping chucks 10 are removed in sequence, the split mandrel 6 is pulled out, the demolding bushings 9 are removed, and finally the two conical demolding skeletons 7 are removed to obtain the self-supporting conical superconducting magnet coil.

[0026] In this embodiment, a completely removable temporary tooling consisting of a split mandrel 6, a demolding sleeve 9, and a conical demolding frame 7 is used as the molding skeleton, avoiding the introduction of a permanent metal skeleton. This achieves extreme lightweighting and compactness of the magnet and eliminates the risk of low-temperature thermal stress cracking caused by the mismatch in thermal expansion coefficients between metal and composite materials. Real-time filling of epoxy resin through wet winding and precise filling of impregnated glass fiber in the gaps between the conical turns ensures high precision and structural density in coil molding, giving the cured coil high mechanical strength. Controlled overall thermosetting after applying external pre-tightening force through the magnet pre-tightening clamp 5 combines the coil, epoxy fiberglass connector 3, etc., into a single self-supporting composite whole, optimizing the internal transmission path of electromagnetic force and improving structural stability. Sequential demolding and removal of all temporary tooling eliminates the possibility of eddy currents generated by some metal skeletons, avoiding magnetic field distortion and additional heating. This method simultaneously achieves multiple goals: lightweighting, high reliability, no electromagnetic interference, and low-cost manufacturing.

[0027] Specifically, during the process of winding the superconducting wire onto the surface of a temporary mold consisting of a split mandrel 6, a conical demolding skeleton 7, and a demolding bushing 9, low-temperature epoxy adhesive is simultaneously and in real time applied to the surface of the wire. This allows the adhesive to impregnate, initially gel, and cure while winding, thereby instantly fixing the position of each turn of wire and providing a highly intact preform for subsequent overall thermosetting.

[0028] In step S1, the demolding process includes uniformly spraying a dry release agent onto all tooling surfaces to form a 5-30 μm coating.

[0029] In this embodiment, a uniform, continuous and stable physical isolation barrier is constructed between the temporary tooling and the subsequently cured coil composite by a controllable micron-level coating, ensuring that the Teflon conical demolding skeleton 7 and the demolding bushing 9 can achieve low adhesion and non-destructive separation from the epoxy resin with the assistance of the demolding agent coating, thanks to their low surface energy characteristics.

[0030] In step S2, the conical magnet blanks on both sides are connected by an epoxy fiberglass connector 3 with multiple curing channels inside, and the sample observation port core frame 1 is fixed in the middle of the epoxy fiberglass connector 3.

[0031] In this embodiment, the epoxy fiberglass connector 3 with multiple curing channels ensures that the epoxy resin can be fully injected and filled into the interior of the connector and the interface between the connector and the two components. After curing, a three-dimensional continuous high-strength composite material connector is formed, integrating the originally separate coils and functional components into a stable mechanical whole. After curing, the resin columns in the channels are evenly distributed along the axial direction. When subjected to the huge Lorentz force between the coils, they play a role in mechanical interlocking and force transmission, effectively resisting shear and peel stress, and significantly improving the stability of the overall structure under strong electromagnetic loads. The sample observation port core frame 1 acts as the central structural ring connecting and supporting the two conical magnets 2. It forms a physical channel for light, radiation or sample rods to pass through, thus meeting the needs of observation and measurement.

[0032] Preferably, the epoxy fiberglass connector 3 has 10 fiberglass + epoxy curing channels, which can make the separate coils form a whole and resist the Lorentz force between the coils.

[0033] In step S4, if excessive resistance is encountered when removing the demolding bushing 9 or the conical demolding skeleton 7, a temperature difference-assisted demolding method is adopted. First, the non-working surface of the tooling is locally cooled at low temperature, and then gently vibrated or tapped axially.

[0034] In this embodiment, a temperature difference-assisted demolding method is used when removing the demolding bushing 9 or the conical demolding skeleton 7. Taking advantage of the fact that the thermal expansion coefficient of the Teflon material of both is greater than that of epoxy resin, the non-working surface of the tooling is locally cooled at low temperature, causing the demolding bushing 9 and the conical demolding skeleton 7 to undergo slight radial shrinkage, forming a tiny gap with the inner surface of the cured coil. This precisely offsets the excessive demolding resistance, avoids scratching or squeezing damage to the conical cavity or inner cylindrical ring of the coil caused by forced force, and ensures the integrity of the coil surface.

[0035] Specifically, gentle axial vibration or tapping can further break down the residual minor adhesive forces between the tooling and the coil. The vibration / tapping force is controllable and will not be transmitted to the coil body. This solves the jamming problem when demolding large-size densely wound coils and avoids the damage to the superconducting wires and epoxy resin matrix caused by traditional violent demolding, thus improving the success rate of non-destructive demolding. Low-temperature cooling only acts on the non-working surface of the tooling and does not directly contact the coil, so it will not affect the internal material properties of the coil. At the same time, the Teflon material has stable high and low temperature resistance and will not deform or crack after cooling. It can maintain the forming cylindrical surface of the demolding bushing 9 and the forming conical surface of the demolding skeleton 7, and does not affect the reuse of the tooling.

[0036] After step S4 is completed, the inner cavity surface of the conical magnet 2 is subjected to plasma cleaning to remove residual mold release agent.

[0037] In this embodiment, after demolding, the inner surface of the conical magnet 2 may have residual dry fluorine release agent. These residual substances can be precisely removed by plasma cleaning, avoiding the release agent film from affecting the surface adhesion reliability during subsequent insulation treatment or assembly of the coil, ensuring the tight connection between the inner cavity of the coil and other components, and eliminating potential electrical insulation hazards caused by residual release agent, thus adapting to the high voltage operation requirements of medium and high field magnets.

[0038] In step S1, the radial preload applied by the stress support screw 11 is 1-2 times the value calculated based on the coil winding stress.

[0039] In this embodiment, the split mandrel 6 is forced to expand radially by the interference preload, and the supporting force is transmitted to the entire temporary tooling system made of soft materials such as Teflon through the contact surface between it and the demolding bushing 9. This effectively prevents the tooling from elastically deforming or creeping under winding tension. The preload puts the coil in a prestressed state before curing, simulating the huge Lorentz force experienced after actual energization. When the epoxy resin is cured in this state, the coil composite is pre-stressed with favorable compressive stress, which can offset part of the electromagnetic tensile stress when the magnet is actually working, thereby greatly enhancing the overall mechanical strength and anti-quench capability of the coil.

[0040] In step S2, the coil turn gap needs to be calculated based on the cone slope in the conical area, and the corresponding impregnated glass fiber wire is filled in to ensure that the cylindricity of each coil surface is uniform.

[0041] In this embodiment, by actively compensating for the inherent turn gap caused by the conical geometry, each layer of superconducting wire can obtain uniform radial support on the conical surface, thereby ensuring that the outer surface of each layer of coil maintains uniform cylindricity after curing. After the filled glass fiber is epoxy cured, a reinforced support network is formed inside the coil along the generatrix direction of the conical surface, which significantly enhances the coil's resistance to shear and slippage in the mechanically weak direction of the conical surface, effectively resisting the adverse effects of winding tension and subsequent electromagnetic forces.

[0042] like Figure 2-4 As shown in the figure, an embodiment of the present invention provides a conical superconducting magnet coil forming frame, including a split mandrel 6, a demolding sleeve 9, two conical demolding frames 7, two clamping chucks 10, a stress support screw 11, and several rotating connecting blocks 8. The split mandrel 6 has a threaded hole inside; the demolding sleeve 9 is coaxially sleeved on the outside of the split mandrel 6, and its inner diameter is larger than the outer diameter of the split mandrel 6, forming a radial clearance between them; the two conical demolding frames 7 are coaxially sleeved on both ends of the demolding sleeve 9, and the outer surface of each conical demolding frame 7 is formed. A conical surface is used to form the forming inner cavity of the conical magnet 2. The outer surface of the demolding sleeve 9 exposed between the two conical demolding frames 7 is a forming cylindrical surface. Two clamping chucks 10 are coaxially sleeved and locked at both ends of the split mandrel 6 and the ends of the conical demolding frames 7 on the corresponding sides, for axial fixation of the three. The stress support screw 11 is screwed into the threaded hole of the split mandrel 6 to press the split mandrel 6 to make it expand radially, thereby applying radial preload to the demolding sleeve 9. Several rotating connecting blocks 8 are detachably connected at one end to a conical demolding frame 7.

[0043] In this embodiment, a temporary support system is constructed using a split mandrel 6, a demolding sleeve 9, and a conical demolding skeleton 7, instead of a permanent skeleton. After molding, the preload can be released by unscrewing the stress support screw 11, the axial fixation can be released by removing the clamping chuck 10, and the split mandrel 6 can be pulled out using the radial movement gap between the split mandrel 6 and the demolding sleeve 9. Then, the demolding sleeve 9 and the conical demolding skeleton 7 are removed in sequence, ultimately obtaining a pure coil structure without a permanent skeleton. This eliminates the extra weight and volume burden brought by a permanent skeleton, while avoiding the problem of thermal expansion coefficient differences caused by long-term bonding of dissimilar materials, and eliminating the risk of adhesive layer cracking and wire damage caused by thermal stress during the cooling process.

[0044] Specifically, the outer surface of the conical demolding frame 7 is a forming conical surface, which can be directly used as the forming reference for the coil conical cavity. The outer surface of the demolding bushing 9 exposed between the two conical demolding frames 7 is a forming cylindrical surface, which is coaxially locked and fixed with the clamping chuck 10. There is no need to process a high-precision permanent complex curved surface frame, and the processing accuracy requirements of the temporary tooling do not need to meet the long-term service performance requirements. At the same time, the standardized tooling can be reused, which greatly reduces the manufacturing difficulty and cost. The temporary support tooling only plays a role in the forming stage and is completely removed after forming. There are no residual conductive material parts in the coil, avoiding the magnetic properties of traditional partial metal frames. The eddy currents generated during rapid field changes prevent the increase in heat load and magnetic field distortion caused by eddy currents, ensuring the uniformity and stability of the magnetic field. The stress support screw 11 is screwed into the threaded hole of the split mandrel 6, which can tighten the split mandrel 6 to make it expand radially and apply a precise radial preload to the demolding sleeve 9 to ensure the rigid support of the tooling during winding and curing, avoiding surface deformation. After molding, the self-supporting coil formed by removing the tooling allows the electromagnetic force to act directly on the entire coil, solving the problem of indirect mechanical transmission path and easy local stress concentration in traditional multi-layer structures, and comprehensively optimizing the overall performance of the magnet.

[0045] like Figure 4 and Figure 6 As shown, the split mandrel 6 consists of at least two relatively movable split sections.

[0046] In this embodiment, when the stress support screw 11 is screwed into the threaded hole of the split mandrel 6 and tightened, each relatively movable split segment can adaptively expand radially, precisely fitting the inner wall of the demolding sleeve 9, so that the radial preload is evenly transmitted to the demolding sleeve 9, avoiding uneven distribution of preload due to excessive rigidity of the split mandrel 6, thereby ensuring the surface stability of the demolding sleeve 9 and the conical demolding skeleton 7 during winding and curing; during the demolding stage, after unscrewing the stress support screw 11 and removing the clamping chuck 10, each split segment can move relatively, and can shrink radially or slightly misalign, effectively utilizing the radial movement gap between the split mandrel 6 and the demolding sleeve 9, greatly reducing the resistance of the split mandrel 6 being pulled out from the demolding sleeve 9.

[0047] Specifically, the design of multiple relatively movable split sections eliminates the need for a one-piece molded complex conical surface adaptation structure for the split mandrel 6, reducing its own processing difficulty and precision requirements. At the same time, the independent movable characteristics of the split sections can adapt to different radial expansion requirements, improving the mold's adaptability to the molding of conical coils of different specifications, and enhancing the tooling's versatility and reliability for repeated use.

[0048] like Figure 3 and Figure 7 As shown, a sample observation port core frame 1 is bonded to the end of the conical magnet 2, and an epoxy fiberglass connector 3 is provided between the sample observation port core frame 1 and the conical magnet 2.

[0049] In this embodiment, the sample observation port core frame 1 is firmly bonded to the end of the conical magnet 2 through the epoxy fiberglass connector 3 to form an integrated structure. This provides rigid end support for the conical magnet 2, which has no permanent frame, thus compensating for the shortcoming of easy deformation at the end of the pure coil structure. This ensures that the coil as a whole maintains the integrity of its shape during winding, curing and subsequent excitation, and avoids structural damage caused by stress concentration at the end.

[0050] Specifically, the material properties of the epoxy fiberglass connector 3 are similar to the core materials of the conical magnet 2, such as epoxy resin and superconducting wire, in terms of their coefficient of thermal expansion. This effectively reduces the risk of thermal mismatch between different components and minimizes the additional stress caused by thermal expansion and contraction differences during the cooling process from room temperature to the operating low temperature. The epoxy fiberglass connector 3 also functions as an adhesive and structural reinforcement. Its tight integration with the sample observation port core frame 1 and the conical magnet 2 optimizes the mechanical transmission path, allowing the Lorentz force generated during excitation to be evenly distributed to the sample observation port core frame 1 through the connector 3, avoiding local overload and improving the overall mechanical stability of the coil. The sample observation port core frame 1 not only meets the functional requirements of sample observation during magnet use but also ensures the relative positional accuracy between the observation port and the conical magnet 2 through the precise positioning and fixation of the epoxy fiberglass connector 3. At the same time, the epoxy fiberglass material is non-conductive and does not generate eddy currents, avoiding electromagnetic interference and magnetic field distortion caused by traditional metal support components, thus ensuring the uniformity and stability of the magnetic field.

[0051] like Figure 3 and Figure 7 As shown, an epoxy fiberglass insulation layer 4 is bonded between the sample observation port core frame 1 and the conical magnet 2, and a magnet pre-tightening clamp 5 is fitted on the outside of the conical magnet 2.

[0052] In this embodiment, the epoxy fiberglass insulation layer 4, which is bonded between the sample observation port core frame 1 and the conical magnet 2, utilizes the excellent insulation properties of epoxy fiberglass to construct a reliable electrical isolation barrier. This effectively prevents electrical short circuits between the conical magnet 2 and the sample observation port core frame 1, ensuring the insulation requirements of the magnet's 1000V withstand voltage level and adapting to the high-voltage operation scenarios of medium- and high-field magnets. The magnet pre-tightening clamp 5, which is sleeved on the outside of the conical magnet 2, can apply a uniform radial pre-tightening force along the circumference of the coil, counteracting the radial expansion trend generated by the Lorentz force during excitation, preventing surface deformation of the pure coil structure without a permanent frame, and especially ensuring the geometric accuracy at the junction of the conical and cylindrical surfaces.

[0053] Specifically, the epoxy fiberglass insulation layer 4 possesses both flexibility and adhesion. In its bonded state, it enhances the connection between the sample observation core frame 1 and the conical magnet 2, while also buffering minor deformation differences between the two during thermal cycling. The pre-tightening effect of the magnet pre-tightening clamp 5 ensures a tight fit between the coil windings, adhesive layer, and epoxy fiberglass insulation layer 4 of the conical magnet 2, reducing internal gaps. This not only improves the overall mechanical strength and self-supporting stability of the coil but also optimizes the heat conduction path, facilitating heat transfer during low-temperature operation and reducing the risk of localized overheating. The epoxy fiberglass insulation layer 4 and the magnet pre-tightening clamp 5 work synergistically, ensuring electrical safety through the insulation layer and strengthening structural stability through the clamp. Furthermore, since both materials are non-conductive, they do not generate eddy current interference, ensuring that the magnetic field uniformity remains unaffected, thus comprehensively improving the reliability and safety of magnet operation.

[0054] like Figure 2 and Figure 3 As shown, the conical demolding skeleton 7 and the demolding bushing 9 are made of Teflon material.

[0055] In this embodiment, the Teflon material has extremely low surface adhesion and excellent self-lubricating properties, which can significantly reduce the interfacial bonding force between the epoxy resin and the tooling surface, ensuring that the demolding bushing 9 can be smoothly removed axially during sequential demolding and that the conical demolding skeleton 7 can be completely removed from the conical cavity of the coil, avoiding scratches or structural damage to the inner surface of the coil caused by adhesion, and ensuring the integrity of the product molding.

[0056] Specifically, Teflon material has excellent chemical stability. During vacuum impregnation with epoxy resin and temperature curing, it will not react chemically with epoxy resin, nor will it be corroded by the adhesive. It can maintain the forming cone surface accuracy of the cone demolding skeleton 7 and the forming cylindrical surface smoothness of the demolding bushing 9 for a long time, making the tooling reusable and significantly reducing tooling consumption costs.

[0057] like Figure 2 and Figure 3 As shown, the outer surface of the demolding bushing 9 is provided with a PET fiber film, and a Teflon film tape is provided at the joint between the conical demolding skeleton 7 and the demolding bushing 9.

[0058] In this embodiment, the outer surface of the demolding sleeve 9 is the formed cylindrical surface of the conical magnet 2. The PET fiber film covering its outer surface directly contacts the wound superconducting wire and epoxy resin. The PET material has a smooth surface and extremely low adhesion to epoxy resin, which can not only prevent the outer surface of the demolding sleeve 9 from directly rubbing against the inner coil, but also easily peel off during demolding, ensuring that the cylindrical surface of the inner coil is smooth and free of scratches and has a complete structure. At the same time, it further reduces demolding resistance and forms a dual protection of low material adhesion and film anti-sticking with the Teflon demolding sleeve 9, improving the reliability of non-destructive demolding. The Teflon film tape set at the connection gap between the conical demolding skeleton 7 and the demolding sleeve 9 can accurately block the epoxy resin from seeping into the gap during vacuum impregnation by utilizing the density and impermeability of the Teflon material, avoiding the glue from locking the two together after curing and causing demolding difficulties. This ensures that the conical demolding skeleton 7 and the demolding sleeve 9 can be removed independently and smoothly during sequential demolding, structurally solving the problem of glue seepage at the tooling connection.

[0059] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for forming a conical superconducting magnet coil, characterized in that, Includes the following steps: S1. Assemble the split mandrel (6), demolding bushing (9) and two conical demolding skeletons (7), and fix them with a clamping chuck (10). Screw in the stress support screw (11) to apply radial preload. Perform anti-stick treatment on the working surfaces of the conical demolding skeleton (7) and demolding bushing (9), and cover the surface of the demolding bushing (9) with PET fiber film. S2. Use wet winding process to wind superconducting wires on the mold surface to form a conical magnet (2) blank. Epoxy glue is filled in real time during winding, and impregnated glass wire is filled in the coil turn gap in the conical area. S3. A magnet pre-tightening clamp (5) is fitted around the outer periphery of the conical magnet (2) blank and a final radial pre-tightening force is applied. Then, the integrated whole is subjected to controlled epoxy resin thermosetting treatment. S4. Sequentially remove the stress support screw (11) and clamping chuck (10), pull out the split mandrel (6), then remove the demolding bushing (9), and finally remove the two conical demolding skeletons (7) to obtain the self-supporting conical superconducting magnet coil.

2. The method for forming a conical superconducting magnet coil as described in claim 1, characterized in that, In step S1, the demolding process includes uniformly spraying a dry release agent onto all tooling surfaces to form a 5-30 μm coating.

3. The method for forming a conical superconducting magnet coil as described in claim 1, characterized in that, In step S2, the conical magnet (2) blanks on both sides are connected by an epoxy fiberglass connector (3) with multiple curing channels inside, and the sample observation port core frame (1) is fixed in the middle of the epoxy fiberglass connector (3).

4. The method for forming a conical superconducting magnet coil as described in claim 1, characterized in that, In step S4, if excessive resistance is encountered when removing the demolding bushing (9) or the conical demolding skeleton (7), a temperature difference-assisted demolding method is adopted. First, the non-working surface of the tooling is locally cooled at low temperature, and then gently vibrated or tapped along the axis.

5. The method for forming a conical superconducting magnet coil as described in claim 1, characterized in that, After step S4 is completed, the inner cavity surface of the conical magnet (2) is subjected to plasma cleaning to remove residual release agent.

6. The method for forming a conical superconducting magnet coil as described in claim 1, characterized in that, In step S1, the radial preload applied by the stress support screw (11) is 1-2 times the value calculated based on the coil winding stress.

7. The method for forming a conical superconducting magnet coil as described in claim 1, characterized in that, In step S2, the coil turn gap needs to be calculated based on the cone slope in the conical area, and the corresponding impregnated glass fiber wire is filled in to ensure that the cylindricity of each coil surface is uniform.

8. A conical superconducting magnet coil forming frame, characterized in that, The conical superconducting magnet coil forming frame is applied to the method as described in any one of claims 1 to 7, wherein the conical superconducting magnet coil forming frame comprises: The split mandrel (6) has a threaded hole inside; The demolding bushing (9) is coaxially sleeved outside the split mandrel (6), and its inner diameter is larger than the outer diameter of the split mandrel (6), forming a radial clearance between them. Two conical demolding skeletons (7) are coaxially sleeved at both ends of the demolding bushing (9). The outer surface of each conical demolding skeleton (7) is a forming conical surface used to form the forming inner cavity of the conical magnet (2). The outer surface of the demolding bushing (9) exposed between the two conical demolding skeletons (7) is a forming cylindrical surface. Two clamping chucks (10) are coaxially fitted and locked at both ends of the split mandrel (6) and the ends of the conical demolding skeleton (7) on the corresponding side, respectively, to fix the three in the axial direction; The stress support screw (11) is screwed into the threaded hole of the split mandrel (6) to press the split mandrel (6) to make it expand radially, thereby applying a radial preload to the demolding bushing (9); Several rotating connecting blocks (8) are detachably connected at one end to a conical demolding skeleton (7).

9. The conical superconducting magnet coil forming frame as described in claim 8, characterized in that, The sample observation port core frame (1) is bonded to the end of the conical magnet (2), and an epoxy fiberglass connecting frame (3) is provided between the sample observation port core frame (1) and the conical magnet (2). An epoxy fiberglass insulation layer (4) is attached between the sample observation port core frame (1) and the conical magnet (2). A magnet pre-tightening clamp (5) is fitted on the outside of the conical magnet (2).

10. The conical superconducting magnet coil forming frame as described in claim 8, characterized in that, The split mandrel (6) consists of at least two relatively movable split segments.

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