Gradient magnetic field coil device and magnetic resonance imaging device
View Patent ↗A gradient magnetic field coil device has a main coil arrangement formed by embedding into first resin multiple main coils for generating a gradient magnetic field and a leakage magnetic field, and a shield coil arrangement formed by embedding into second resin multiple shield coils for suppressing the leakage magnetic field, wherein the shield coil arrangement includes a facing area that faces the main coil arrangement and is fixed to the main coil arrangement, and a protruding area that protrudes beyond the main coil arrangement, wherein insulated reinforcing members are embedded into the second resin in the protruding area. Multiple reinforcing members are arranged in a circumferential direction of the shield coil arrangement, and the second resin is preferably filled between the adjacent-to-each-other reinforcing members. The reinforcing members are preferably arranged toward the main coil arrangement with respect to the shield coils.
1. A gradient magnetic field coil device comprising:
a main coil arrangement that is formed by embedding into first resin a plurality of main coils for generating a gradient magnetic field and a leakage magnetic field; and
a shield coil arrangement that is formed by embedding into second resin a plurality of shield coils for suppressing the leakage magnetic field,
wherein the shield coil arrangement includes a facing area that faces the main coil arrangement and is fixed to the main coil arrangement, and a protruding area that protrudes beyond the main coil arrangement,
wherein a reinforcing insulator is embedded in the second resin to straddle between the facing area and the protruding area, and a central position of the reinforcing insulator substantially coincides with an end surface position of the main coil arrangement.
2. The gradient magnetic field coil device according to claim 1 , wherein
the main coil arrangement and the shield coil arrangement are substantially in a disc shape, and
the main coil arrangement and the shield coil arrangement are bonded on respective surfaces which face each other.
3. The gradient magnetic field coil device according to claim 1 , wherein
the main coil arrangement and the shield coil arrangement are substantially in a hollow cylindrical shape, and
the main coil arrangement is arranged inside the shield coil arrangement.
4. The gradient magnetic field coil device according to claim 3 , wherein
the shield coil arrangement is substantially in a hollow cylindrical shape, and
a distance between the main coil arrangement and the shield coil arrangement varies with positions in a circumferential direction.
5. The gradient magnetic field coil device according to claim 3 , wherein
the reinforcing member is one of a plurality of reinforcing members disposed circumferentially around an axial end of the shield coil arrangement,
spacers are embedded into the second resin over the facing area, at positions between adjacent pairs of the reinforcing members, and
each spacer has a surface on which the coil conductor is installed.
6. The gradient magnetic field coil device according to claim 5 , wherein
widths, in the circumferential direction, of the reinforcing members and the spacers fall in a range of 10 mm to 30 mm,
lengths, in the axial direction, of the reinforcing members for a portion in the protruding area fall in a range of 50 mm to 150 mm, and
a distance, in the circumferential direction, between the spacers that are adjacent to each other falls in a range of 50 mm to 150 mm.
7. The gradient magnetic field coil device according to claim 3 , wherein
the main coil arrangement and the shield coil arrangement are bobbinless coils.
8. The gradient magnetic field coil device according to claim 3 , wherein
a plurality of the reinforcing members are arranged in the circumferential direction of the shield coil arrangement, and the second resin is filled between the reinforcing members which are adjacent to each other.
9. The gradient magnetic field coil device according to claim 1 , wherein
one surface of the reinforcing member is along a side surface of the shield coil arrangement.
10. The gradient magnetic field coil device according to claim 1 , wherein
the reinforcing member is arranged toward the main coil arrangement with respect to the shield coil arrangement.
11. The gradient magnetic field coil device according to claim 1 , wherein
the reinforcing member is formed with grooves, and
a coil conductor constituting the shield coil is installed in the groove.
12. The gradient magnetic field coil device according to claim 1 , wherein
the reinforcing member is arranged between windings of the shield coils that are adjacent to each other.
13. The gradient magnetic field coil device according to claim 1 , wherein
the shield coil arrangement is in a hollow cylindrical shape, or in a disc shape.
14. An MRI device comprising:
a gradient magnetic field coil device according to claim 1 ; and
a static magnetic field magnet device that generates a static magnetic field which is uniform in terms of time and space,
wherein a gradient magnetic field and a static magnetic field overlap in an imaging space.