JPH0423290Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a magnet device, and more particularly to a superconducting magnet device having an electromagnetic winding housed in a cryostat.

Conventionally, in an electromagnet that generates a strong magnetic field of 0.5 Tesla or more, the electromagnet winding was attached to an aluminum former placed in a liquid helium container of a cryostat. The liquid helium container is usually surrounded by a radiant heat shield, a liquid nitrogen container, and an outer vacuum jacket to minimize heat flow to the magnet.

However, such have the disadvantage that the materials of their construction are relatively expensive.

The magnet device of this invention has at least one liquid refrigerant container formed of a cylindrical inner wall, a cylindrical outer wall, and both end walls interconnecting these inner and outer walls, and has at least one liquid refrigerant container on the inner surface of the inner wall opposite to the outer wall. An electric coil installation groove is provided, the groove is formed in a fibrous material bonded with a cured resin, and an electromagnet winding is disposed within the groove.

According to this invention, since the coil grooves are formed in a material made by bonding fibers such as glass fibers with a cured resin, the grooves can be determined much more accurately during manufacturing than the above-mentioned conventional method. A separate winding form is not required, and a significant cost reduction can be achieved.

Moreover, since the diameter of the coil groove can be made smaller than the diameter of conventional formers, the amount of electrical conductor can be significantly reduced.

Furthermore, if the fiber material is a wound fiber composite material, it can withstand large forces acting on the winding wire during use. In a magnet device that generates a strong magnetic field, at least one reinforcing wall that engages with the groove forming material is provided on the inner surface of the inner wall of the cooling medium container. This reinforcing wall is preferably made of a strong metal such as stainless steel.

To manufacture the magnet device of this invention, at least one block of resin-bonded fibrous material is provided on the radially outer surface of the cylindrical inner wall, and the fibrous material block is cured to fix the block to the inner wall. The block is machined to form at least one electrical coil mounting groove, the windings of the electrical coil are disposed within the groove, and the inner wall is connected to the cylindrical outer wall and the end walls to form a liquid coolant container. Form.

Apart from the above, in this invention, at least one block of resin-bonded fibrous material having at least one electric coil installation groove formed by molding is provided on the radially outer surface of the cylindrical inner wall, and the fibrous material block is A magnetic device is manufactured by hardening and fixing the block to the inner wall, placing the windings of the electrical coil in the groove, and connecting the inner wall to the cylindrical outer wall and the end walls to form a liquid medium container. do.

This invention will be explained in detail below using examples.

A typical magnet system for a nuclear magnetic resonance apparatus has a cryostat with a series of concentric shields and a series of concentric liquid coolant vessels. The inner container is a liquid helium container formed by a cylindrical inner wall, a cylindrical outer wall, and a pair of annular end walls.
Figure 1 shows a part of the liquid helium container.
Only one end of a pair of annular end walls 2 connecting the cylindrical inner wall 1 and the cylindrical outer wall (not shown) is shown. Each wall is made of stainless steel.

A large number of stainless steel rings are formed on the inner surface 3 of the inner wall 1, six of which are shown in FIG. 1 as rings 4, 5, 6, 7, 8, and 9. Also, the partially shown liquid helium container is symmetrical with respect to plane 10. The rings 4-9 are fixed to the inner wall 1, for example by welding.

Each stainless steel ring pair 4, 5; 6, 7; 8, 9
In this case, the gaps are filled with coarsely twisted glass fibers. By mixing resin with this glass fiber material and curing the resin, a solid block of the above material is formed between the pair of stainless steel rings fixed to the inner surface 3. If the inner surface 3 is cleaned in advance, the fixing efficiency will be increased. The solid block is then machined to form grooves 11, 12, 13 with U-shaped sections 14, 15, 16 of hardening material, respectively. Because precision machining can be performed, multiple grooves can be formed in close proximity.

As you can see from Figure 1, stainless steel ring 4
-9 have the function of reinforcing the corresponding U-shaped parts 14-16.

Alternatively, the grooves may be formed by molding a glass fiber composite material into the respective ring pairs 4, 5; 6, 7; 8, 9. The composite material is cured as in the previous example to form a groove similar to that shown in FIG.

Figure 2 shows a model with a significantly reduced number of stainless steel rings. 1 having a coating 18 made by hardening and machining a glass-epoxy resin composite material on one end in the axial direction of the inner surface of the inner wall 1 of the liquid helium container;
stainless steel rings 17 are provided to form one axially outer groove 19. A similar axial outer groove is formed at the other axial end (not shown) of the inner wall 1, and a member 27 made of hardened and machined glass-epoxy resin composite material is provided at the center of the inner wall 1, and a pair of grooves 20 and 21 are formed. The glass-epoxy resin member 27 is not reinforced with a stainless steel ring because it can resist the forces that act during use on the electromagnet winding located in the center of the magnet device. However, reinforcement is required to prevent movement of the end windings of the magnet.

For larger devices, the cost can be further reduced by replacing the composite coated grooves with resin-injected molded fibers.

FIG. 3 shows a machined wound fiber composite material 25, 26 which is fixed to the inner wall 1 and coil grooves 22, 23, 24 formed therein. Even with such a structure, reinforcement of the stainless steel ring can be made unnecessary. When a wound fiber tube containing 55% glass by volume is used as a wound fiber material, its mechanical properties are as follows:
UTS is 1100MPa, compressive strength is 400MPa, Et is
It is preferable to set the pressure to 55 GPa and the density to 2.0 g/cm ³ .

The need for reinforcement depends on the strength of the generated magnetic field and the volume of liquid coolant in the coolant container. FIG. 3 is used, for example, for magnetic fields up to 1 Tesla, and FIG. 2 is used, for example, for magnetic field strengths of 1 Tesla or more.

[Brief explanation of the drawing]

1 to 3 are sectional views of main parts showing different embodiments of this invention. 1... Cylindrical inner wall, 2... End wall, 3... Inner wall inner surface, 11, 12, 13, 19, 20, 21, 2
2, 23, 24...groove, 14, 15, 16, 1
8, 25, 26, 27... fiber material.

Claims (1)

[Claims for Utility Model Registration] 1. At least one liquid refrigerant container formed of a cylindrical inner wall, a cylindrical outer wall, and both end walls interconnecting these inner and outer walls, and an inner wall inner surface facing the outer wall. 1. A magnet device, characterized in that the groove is provided with at least one electric coil installation groove, the groove is formed in a fibrous material bonded with a cured resin, and an electromagnetic winding is disposed within the groove. 2. The magnet device according to claim 1 of the utility model registration claim, characterized in that the fiber material is a wound fiber composite material. 3. The magnet device according to claim 1 of the utility model registration, characterized in that the fiber material is coated with glass and epoxy resin. 4. The magnet device according to any one of claims 1 to 3 of the claims for utility model registration, characterized in that at least one reinforcing wall that engages with the groove forming material is provided on the inner surface of the cooling medium container. . 5. The magnet device according to claim 4 of the utility model registration, characterized in that the reinforcing wall is integrally formed with the inner wall of the liquid cooling medium container. 6. A magnet device according to any one of claims 1 to 5 as a utility model, characterized in that the grooves are formed by machining a cured resin fiber material.