JP5276478B2 - X-ray CT system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gantry for X-ray CT scanners which permits rotating actions to be safely braked without involving the scattering of the rotary frame and a rotary mounted object even when the cylinder portion of the rotary frame rotating at high speed is damaged. <P>SOLUTION: The gantry for X-ray CT scanners includes the rotary frame 30 rotatably supported on a main frame 23, a ring 40 closely arranged in a state of wrapping the outside and a ring frame 50 rotatably supporting a ring 40 through a slip plane, and fixed to the main frame 23. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an X-ray CT apparatus, and more particularly to a rotating body safety mechanism in an X-ray CT apparatus capable of high-speed scanning.

  In a conventional X-ray CT apparatus, in particular, an X-ray CT apparatus having a rotation speed of 1 second / rotation or higher, as described in Patent Documents 1 and 2, for example, improvement in safety during rotation There are some rotating frames that are made cylindrical. This is to improve the safety against scattering of the rotationally mounted object by mounting the rotationally mounted object such as the X-ray tube device on the inner peripheral surface of the cylindrical rotating frame.

  Furthermore, in Patent Documents 3 and 4, when a rotating load is scattered, a circular detection sensor is arranged outside the rotating body to automatically detect and brake the phenomenon. An X-ray CT apparatus is disclosed in which this sensor is turned on to automatically apply braking.

JP-A-9-56710 JP 2000-116641 A Japanese Utility Model Publication No. 4-120706 Japanese Utility Model Publication No. 6-38917

  However, in Patent Documents 1 and 2, no consideration is given to the case where the cylindrical rotary frame itself is broken by a high centrifugal force. That is, the cylindrical rotary frame is manufactured from an aluminum alloy casting for weight reduction or the like, but if there is a defect such as a nest inside due to a defective casting method, the cylindrical rotating frame cannot have a predetermined strength and is consequently broken. there is a possibility. If the cylindrical rotating frame breaks, the mounted rotating object will be scattered, resulting in equipment damage and human damage.

  Further, in Patent Documents 3 and 4, it is possible to detect the scattering of the rotationally mounted object and automatically stop the rotation operation, but the device by which the scattered object until it stops collides with the stationary part. No consideration is given to preventing damage to humans or preventing human damage.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to safely brake a rotating operation without scattering of a cylindrical rotating frame or a rotating load even when a cylindrical portion of a cylindrical rotating frame rotating at a high speed is damaged.

  In order to solve the above problems, an X-ray CT apparatus according to the present invention includes an X-ray tube apparatus that generates X-rays, an X-ray detector that detects the X-rays and outputs a transmitted X-ray signal, An X-ray tube device and the X-ray detector are mounted facing each other, and a reconstruction image is generated based on a gantry rotating around the subject and the transmitted X-ray signal, and generating a reconstructed image of the subject An gantry having a cylindrical rotating frame having an opening, and the X-ray tube apparatus on an inner peripheral surface facing the opening. And at least one of a rotating frame mounted with the X-ray detector, a support that rotatably supports the rotating frame without interlocking with a rotating operation of the rotating frame, and an outer peripheral surface of the rotating frame. A ring that covers the width of the rotating wheel When the rotating frame does not come into contact during normal rotation and an abnormality accompanied by deformation of the rotating frame occurs during the rotating operation, the spatial distance of the rotating frame is set so that the rotating frame after the deformation contacts. A ring provided between the outer peripheral surface and a ring frame fixed to the support body and covering the outer peripheral surface of the ring, the ring frame supporting the ring rotatably via a sliding surface And.

  According to the present invention, when an abnormality accompanied by deformation occurs during the rotating operation of the rotating frame, the deformed rotating frame is pressed against and contacted with the ring by centrifugal force, and the inner peripheral surface of the ring frame is integrated with the ring. Slide. At this time, a frictional force generated by multiplying the centrifugal force by the friction coefficient is generated between the ring and the ring frame, so that the rotational operation can be braked. Therefore, even when the cylindrical portion of the rotating frame that rotates at high speed is damaged, the rotating operation can be safely braked without scattering of the rotating frame and the rotating load.

1 is an overall configuration diagram of an X-ray CT apparatus according to the present invention. Front view of gantry 20 according to the first embodiment Front perspective view of gantry 20 according to the first embodiment Rear perspective view of gantry 20 according to the first embodiment FIG. 5A is a schematic diagram illustrating a configuration of the gantry 20 according to the first embodiment, and FIG. 5A is a schematic diagram for explaining a cross-sectional shape of a cylindrical rotary frame 30 in the gantry 20; FIG. FIG. 5A is a partially enlarged view within a one-dot chain line in FIG. 5A, and is a partially enlarged view for explaining the cross-sectional shapes of the ring 40 and the ring frame 50 provided outside the gantry 20. Exploded view of the ring 40 and the ring frame 50 according to the first embodiment. A-A 'sectional view of FIG. Sectional drawing of the ring 40 and the ring frame 50 which concern on 2nd embodiment. Sectional drawing of the ring 40 and ring frame 50 concerning 3rd embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of an X-ray CT apparatus according to the present invention. The X-ray CT apparatus 10 in FIG. 1 is equipped with an X-ray tube apparatus and an X-ray detector, rotates around the subject 2, detects X-rays transmitted through the subject 2, and transmits a transmitted X-ray signal. A gantry housing 1 having a built-in gantry 20, a bed 3 on which a subject 2 is placed on a top board and transported to an opening 33 of the gantry 20, and a transmitted X-ray signal transmitted from the gantry 20 is received. An image processing device 4 that generates a reconstructed image, a display device 5 that displays the reconstructed image, and an operation device 6 for inputting shooting conditions and various instructions to the image processing device 4.

<First embodiment>
In the first embodiment, in the gantry 20, the ring 40 and the ring frame 50 are connected to the front and rear end portions outside the cylindrical rotary frame 30 (of the end portions along the rotation axis direction, the direction into which the subject is inserted). This is an embodiment in which two rows are arranged at the front end. Hereinafter, the schematic configuration of the gantry 20 of the X-ray CT apparatus 10 according to the first embodiment will be described with reference to FIGS. 2 is a front view of the gantry 20, FIG. 3 is a front perspective view of the gantry 20, FIG. 4 is a rear perspective view of the gantry 20, and FIG. FIG. 5B is a schematic diagram for explaining the cross-sectional shape, and FIG. 5B is a partially enlarged view within the one-dot chain line in FIG. 5A, and the cross-sectional shapes of the ring 40 and the ring frame 50 provided outside the gantry 20. It is the elements on larger scale for demonstrating.

  The gantry 20 includes a stand 21, a bearing 22, a main frame 23, a cylindrical rotary frame 30, a ring 40, and a ring frame 50.

  The main frame 23 is supported by the stand 21 via a bearing 22 so as to be tiltable in the front-rear direction.

  Inside the main frame 23, a cylindrical rotary frame 30, a ring 40, and a ring frame 50 are provided in order from the inside toward the outside. The cylindrical rotary frame 30 is equipped with an X-ray tube device 31, an X-ray detector 32, and devices (not shown) necessary for CT inspection such as a high-voltage generating device and a control device, and opens these devices. It is rotated around the subject 2 placed on the bed 3 conveyed to the unit 33. Although not shown, the cylindrical rotary frame 30 is supported by a main frame 23 so as to be rotatable about a direction perpendicular to the paper surface as a central axis.

  Further, the outer space of the cylindrical rotary frame 30 wraps around the outer periphery of the cylindrical rotary frame 30 and has a limit spatial distance d (for example, thermal expansion of the cylindrical rotary frame 30 that does not come into contact with the normal rotary operation). The ring 40 is arranged at a position separated by an amount or a deformation amount due to centrifugal force. As shown in FIGS. 5A and 5B, a ring frame 50 is disposed on the outer side of the ring 40. The ring 40 and the ring frame 50 are in contact with each other via a sliding surface. The ring frame 50 is rotatably supported. The ring frame 50 is fixedly supported on the main frame 23.

  Next, the structure of the ring 40 and the ring frame 50 will be described with reference to FIGS. 6 is an exploded view of the ring 40 and the ring frame 50, and FIG. 7 is a cross-sectional view taken along the line A-A 'in FIG.

  As shown in FIG. 6A, the ring 40 includes a ring body 41 and a sliding material 42, and the sliding material 42 is fixed to the ring body 41. The material of the sliding material 42 is, for example, a tetrafluoroethylene resin, and a material generally used for a sliding bearing may be used. Further, as shown in FIG. 6B, the sliding material may be fixed to the ring frame 50, that is, the ring frame 50 may be constituted by a ring frame 51 main body and a sliding material 52 fixed to the main body. FIG. 6C shows a case where the material of the ring body 41 is, for example, gun metal or brass. In this case, a lubricant such as grease is applied to the contact surface with the ring frame body 51. As described above, the ring 40 is rotatably attached to the ring frame 50 via a sliding surface formed by the outer surface of the sliding material 42 or 52 or a sliding surface constituted by a contact surface coated with a lubricant.

  Next, a mounting structure for the cylindrical rotary frame 30, the ring 40, and the ring frame 50 will be described with reference to FIG.

The ring 40 is provided apart from the outer peripheral surface 30a of the cylindrical rotary frame 30 by a spatial distance d. Ring 40, the convex outer flange portion 40a is attached to the outer, ring 40 is rotatable along the inner peripheral surface of the ring frame 5 0 without derailing.

  Next, the operation of this embodiment will be described. If the cylindrical rotating frame 30 does not have a predetermined strength due to defects such as defective casting production as described above, the cylindrical rotating frame 30 may not be able to withstand centrifugal force due to rotation, and the cylindrical rotating frame 30 may crack and spread outward. is there. In this case, the cylindrical rotary frame 30 is pressed against the ring 40 to prevent the cylindrical rotary frame 30 from scattering, and the deformed cylindrical rotary frame 30 is pressed against the ring 40 by centrifugal force, so that the cylindrical rotary frame 30 and the ring 40 are integrated. Thus, the inner peripheral surface of the ring frame 50 is slid. At this time, a frictional force generated by multiplying the centrifugal force by the friction coefficient is generated between the ring 40 and the ring frame 50, so that the rotational operation can be braked.

  In the first embodiment, the ring 40 and the ring frame 50 are connected to the front and rear end portions on the outer side of the cylindrical rotary frame 30 (the end portion along the rotation axis direction is the direction where the subject 2 is inserted as the front end portion. However, the ring 40 may be provided only at the end portion closer to the point where the load of the X-ray tube device 31 is applied in the cylindrical rotary frame 30. For example, in the first embodiment, since the X-ray tube device 31 is located on the front side of the center of the full width of the cylindrical rotary frame, the ring 40 may be provided only at the front end. And when adding the ring 40 further, it comprises not only a rear-end part but the arbitrary number according to the width | variety of the ring 40 in arbitrary positions facing the outer peripheral surface of the cylindrical rotary frame 30. May be.

<Other embodiments>
Next, a second embodiment will be described based on FIG. FIG. 8 is a cross-sectional view of the ring 40 and the ring frame 50 according to the second embodiment. In the second embodiment, the ring 40 is provided so as to cover the entire width of the outer peripheral surface of the cylindrical rotary frame 30 (the width from the front end portion to the rear end portion along the rotation axis direction of the rotation operation). In addition, the front end portion and the rear end portion of the ring 40 are provided with outward outward flange portions 40a that are convex outward, and the outward flange portion 40a is configured to restrict movement of the ring frame 50 in the rotation axis direction. Is done. A sliding material 42 is provided on the surface of the ring body 41 facing the ring frame 50 and the surface of the ring body 41 facing the ring frame 50 of the outward flange 40a.

  Next, a third embodiment will be described based on FIG. FIG. 9 is a cross-sectional view of the ring 40 and the ring frame 50 according to the third embodiment. In the third embodiment, the ring 40 is provided so as to cover the entire width of the outer peripheral surface of the cylindrical rotary frame 30 (the width from the front end portion to the rear end portion along the rotation axis direction of the rotation operation). Further, the front end portion and the rear end portion of the ring 40 are provided with an inward flange portion 40b that is convex inward, and the inward flange portion 40b regulates the movement of the cylindrical rotary frame 30 in the rotation axis direction. Configured.

  Compared with the third embodiment, the second embodiment can further increase the contact area between the ring 40 and the ring frame 50, and therefore can be more strongly braked by the rotating operation of the cylindrical rotating frame 30 at the time of breakage. . Further, when grease is used as the sliding material, grease leakage can be suppressed by the outward flange portion 40a.

In addition, since the third embodiment can cover the cylindrical frame 30 more widely by the inward flange portion 40b compared to the second embodiment, the scattering range can be further increased even when the components are scattered. It can be narrowed. On the other hand, in the second embodiment is provided with a sliding member 42 with the facing surface of the ring frame 50 in the outward collar portion 40 a, the sliding member 42 corresponding thereto becomes unnecessary.

  In the above embodiment, the sliding material is partially provided on the opposing surfaces of the ring 40 or the ring frame 50, but may be provided on the entire opposing surfaces of the ring 40 or the ring frame 50.

1: gantry housing, 2: subject, 3: bed, 4: image processing device, 5: display device, 6: operation device, 10: X-ray CT device, 20: gantry, 21: stand, 22: bearing, 23: main frame, 30: cylindrical rotary frame, 30a: outer peripheral surface, 31: X-ray tube device, 32: X-ray detector, 33: opening, 40: ring, 40a: outward flange, 40b: inside Orientation collar part, 41: ring main body, 42: sliding material, 50: ring frame, 51: ring frame main body, 52: sliding material.

Claims (3)

An X-ray tube device for generating X-rays;
An X-ray detector that detects the X-ray and outputs a transmitted X-ray signal;
A gantry that mounts the X-ray tube device and the X-ray detector facing each other, and rotates around the subject;
An image reconstruction unit that performs a reconstruction operation based on the transmitted X-ray signal and generates a reconstructed image of the subject;
An X-ray CT apparatus comprising:
The gantry is
A cylindrical rotating frame having an opening, wherein the rotating frame is rotated by mounting the X-ray tube device and the X-ray detector on an inner peripheral surface facing the opening;
A support that rotatably supports the rotating frame without interlocking with the rotating operation of the rotating frame;
A ring that covers at least a part of the width of the outer peripheral surface of the rotating frame, and does not come into contact with the rotating frame in a normal rotating operation, and an abnormality accompanied by deformation of the rotating frame occurs during the rotating operation. In addition, a ring provided with a space distance between the outer peripheral surface of the rotating frame and a space distance to which the rotating frame after the deformation comes into contact,
A ring frame fixed to the support and covering an outer peripheral surface of the ring, the ring frame supporting the ring rotatably via a sliding surface;
An X-ray CT apparatus comprising: The ring is a ring that covers a partial width of the outer peripheral surface of the rotating frame,
The X-ray CT apparatus is based on a point at which the load of the X-ray tube apparatus is applied to the rotating frame among both ends of the rotating frame along the rotation axis direction of the rotating operation, and an end closer to this point Provided with the ring,
The X-ray CT apparatus according to claim 1. The ring is a ring that covers the entire width of the outer peripheral surface.
The X-ray CT apparatus according to claim 1.

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