JPH0943400A - Radioactive isotope irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely connect a radiation source holder to an operation wire for a radioactive isotope irradiation device and provide a simple structure. SOLUTION: A female screw 11f is engraved in a radiation source holder side connection part 11, an operation wire side connection part 20 comprises a shaft 16 which has the first male screw 16m for threadly engaged with the female screw, and a hollow shaft 17 which has the second male screw 17m for threadly engaged with the female screw continuously therewith and has a shaft column 16s rotatably inserted therein, a spring 18 is tensioned between a shaft fixing part 19 for fixing the shaft column and the hollow shaft, the hollow shaft has a recessed part for storing the spring and a spring fixing part 17b for fixing one end 18a of the spring, a shaft fixing part has a recessed part 19a for storing the spring and a spring fixing part 19b for fixing the other end 18b of the spring, and the first and the second male screws are always subjected to a force in the direction tar deviating a pitch so that the screws are hardly to be detached and safety of the device is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioisotope irradiation apparatus, and more particularly to a radioisotope irradiation apparatus which is effective in preventing the equipped radiation source holder from falling off.

[0002]

2. Description of the Related Art Conventionally, in order to ensure the reliability of welded parts of various plants and equipment, a radiation transmission test has been widely applied. Among them, a radioisotope irradiation apparatus using a radioisotope is often used for a field welding test of various plants because of its small size.

As shown in FIG. 3, the radioactive isotope irradiation apparatus is connected to the radioactive isotope storage container 12 for shielding and storing the radioactive source holder H (FIG. 4) equipped with the radioactive isotope 1, and the radioactive source holder H. Sending out the source holder H-
An operation wire 21 for remotely operating rewinding, an operation tube 15 in which the operation wire 21 is housed, an operation device 13 connected to the operation wire 21 for sending and rewinding the radiation source holder H, and a container 12. The transmission tube 14 that guides the radiation source holder H from above, and a cylindrical tip jig 14a provided at the tip of the transmission tube 14.

The radioactive isotope storage container 12 has a sufficient shielding effect against radiation, and in order to shield the radiation, the radiation source holder H is used only when a radiation transmission test is performed.
Is connected to the operation wire 21 and is sent out from the storage container 12 through the inside of the transmission pipe 14 to a required place by the operation of the operation device 13 for use. After use, the radiation source holder H is stored in the storage container 12 by the reverse operation and then the operation wire 2
The connection between 1 and the radiation source holder H is released.

The connection between the radiation source holder H and the operation wire 21, which is only attached and detached when performing the radiation transmission test, is easy to attach and detach, and has a structure and method in which the detachment during use never occurs after the connection from the viewpoint of safety. Although it is desirable that
Only screwing with screws and meshing with unevenness were performed.

[0006]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention
The connection between the radiation source holder H and the operation wire 21 by meshing is
All of them use friction to prevent disengagement, and are not perfect. At present, there is no other suitable method, and in order to prevent the detachment during use, the connection between the radiation source holder H and the operation wire 21 is checked every predetermined number of times of feeding back. However, since the confirmation is performed by a person, it may be forgotten, and a more reliable connection structure and connection method between the radiation source holder H and the operation wire 21 have been demanded.

[0007]

[PROBLEMS] The present invention has been made to solve such a problem, and provides a radioisotope irradiation apparatus having a reliable and simple connection structure between a source holder and an operation wire, which is used for human confirmation work. The purpose is to ensure extremely safe radiation transmission test work in combination.

[0008]

In order to achieve this object, a radioisotope irradiation apparatus of the present invention comprises a source holder equipped with a radioisotope, and a source holder that is connected to the source holder and sends and winds the source holder. A radioisotope irradiation device comprising an operation wire for remote control of return, a radioisotope storage container for accommodating a radiation source holder, and an operation device for sending and rewinding the operation wire, which is connected to the operation wire A female screw is engraved on the radiation source holder-side connecting portion, and the operation wire-side connecting portion connected to the radiation source holder-side connecting portion has a shaft having a first male screw to be screwed into the female screw and a first male screw. The hollow shaft has a second male screw threaded continuously with the male thread and screwed into the female thread, and the shaft column of the shaft is rotatably inserted.

Further, in the radioisotope irradiation apparatus of the present invention, a spring is stretched between the shaft fixing portion to which the shaft column is fixed and the hollow shaft, and the hollow shaft has a recess for accommodating the spring and one end of the spring. The shaft fixing portion has a recess for accommodating the spring and a spring fixing portion for fixing the other end of the spring, and the first male screw and the second male screw have a constant pitch due to the spring. It receives force in the direction of deviation.

In the connection portion between the radiation source holder and the operation wire in the radioisotope irradiation apparatus of the present invention, the radiation source holder side connection portion is a female thread, the operation wire side connection portion is two male threads, and one male thread is the other. It is configured so that it can be rotated about the axis of the male screw to shift the positional relationship in minute amounts. By shifting the positional relationship between these two male screws, the pitch of the two male screws has continuity, has a function as one male screw, and can be screwed with the female screw on the side of the radiation source holder.

Further, when the two male screws are aligned so that the pitches thereof are continuous, a force is applied to the two male screws by the spring in the direction of shifting the positions. Therefore, if the pitches of the two male threads on the operation wire side are matched and fitted to the female threads on the source holder side, the force of the spring will
Since a force in the direction of shifting the pitch is always acting between the two male screws, even if some force acts to disengage the screws, it becomes very difficult to come off.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A radioisotope irradiation apparatus according to the present invention will be described below in detail with reference to the drawings. As shown in FIG. 3, the radioactive isotope irradiation apparatus is a radioactive isotope 1
A radiation source holder H (see FIG. 4) equipped with is stored in a radioactive isotope storage container 12, and is connected to the radiation source holder H and includes an operation wire 21 for remotely controlling the sending and rewinding of the radiation source holder H. The pipe 15 is connected to one of the storage containers 12 and is provided with an operating device 13 for sending and rewinding the operation wire 21, and the other of the storage containers 12 is guided by including a radiation source holder H therein. The transmission tube 14 is connected to the transmission tube 14, and a cylindrical tip jig 14a is provided at the tip of the transmission tube 14, and the operator can operate the radiation source holder remotely and safely.

The radiation source holder H is housed in a radioactive isotope storage container 12 having a radiation shielding ability, a safety device and the like, which are stipulated by law, and only the radiation source holder side connecting portion 11 described below is allowed to be exposed to the outside. Has been done. In the radiation source holder H, as shown in FIG. 4, the radioactive isotope 1 in which iridium 192 is adopted in this embodiment is sealed in the radioactive isotope sealed portion 2, and the radioactive isotope sealed portion 2 is connected to the connection fitting 3 It is fixed by caulking. The spring 5 contains tungsten having a function as the radiation shield 4 inside, and is screwed into the connection fitting 3 and the spring stopper 6 to be fixed. The wire 7 serving as the core is protected by the ring 8, the spring stopper 6 and the wire 7 are fixed by silver brazing, and the wire stopper 9 on the side of the source holder side connecting portion 11 is fixed.
The wire 7 is also fixed by silver brazing. Further, the wire stopper 9 and the radiation source holder-side connecting portion 11 are fixed with screws 10.

The source holder side connecting portion 11 fixed to the wire stopper 9 with a screw 10 is hollow, and an internal thread 11f is engraved on the inner periphery of the side to which the operation wire 21 is connected (FIG. 4, FIG. 4). 1, FIG. 2). As shown in FIG. 2, the operation wire side connection portion 20 connected to the radiation source holder side connection portion 11 has a shaft 16 having a first male screw 16m screwed into the female screw 11f of the radiation source holder side connection portion 11. A shaft column 16s extending from the shaft 16 is composed of a hollow shaft 17 that is rotatably inserted, and the hollow shaft 17 is a second screw that is screwed into a female screw 11f continuously with the first male screw 16m. It has a male screw 17m.

The male screw 16m of the shaft 16 and the male screw 17m of the shaft 17 are constructed so that the pitch is continuous only when the shaft 17 is rotated by a predetermined amount with respect to the shaft 16. The shaft column 16s of the shaft 16 is joined by overlay welding 22 to the hollow shaft fixing portion 19 into which the shaft column 16s is inserted. Further, a spring 18 is stretched between the shaft fixing portion 19 to which the shaft 16 having the first male screw 16m is fixed and the hollow shaft 17 having the second male screw 17m as described later.

The hollow shaft 17 has a recess 17a for accommodating the spring 18 and a hole 17b as a spring fixing part for fixing one end 18a of the spring 18, and the shaft fixing part 19 is a recess 19a for accommodating the spring 18. And the other end 18b of the spring 18
Has a hole 19b as a spring fixing portion for fixing the. A shaft column 16s extending from the shaft 16 is inserted into the spring 18, and the spring 18 includes a recess 17a of the hollow shaft 17 and a shaft fixing portion 19a.
Is housed in the concave portion 19a of the hollow shaft 17 and one end 18a of the hollow shaft 17
Is fixed to the hole 17b of the shaft and the other end is a recess 19 of the shaft fixing portion 19.
It is fixed to a and has a function of suppressing rotation of the hollow shaft 17 with respect to the shaft 16.

On the end surface A where the hollow shaft 17 and the shaft fixing portion 19 are in contact with each other, the hollow shaft 17 is provided with a notch 17h, and the shaft fixing portion 19 is provided with a convex portion 19p smaller than the notch 17h. , And can rotate by engaging with each other with a gap g (17h = 19p + g), but the rotation angle is limited within the gap g. It is also preferable that the notch and the protrusion are formed by notching the shaft fixing portion 19 and projecting a protrusion smaller than the notch on the hollow shaft 17 (not shown).

A hole 22a for inserting the outer surface of the overlay welding 22 for joining the shaft 16s of the shaft 16 and the hollow shaft fixing portion 19 into which the shaft 16s is inserted and the end 21a of the operating wire 21.
After the overlay welding, the wire is finished by machining, and the wire end portion 21a and the machined overlay welding 22 are brazed with silver. The operation wire 21 having the end portion 21 a brazed to the overlay welding 22 by silver brazing is housed inside the transmission pipe 15,
It is connected to the operating device 13.

As described above, the male screw 16m of the shaft 16 and the male screw 17m of the hollow shaft 17 are constructed so that the pitch is continuous only when the hollow shaft 17 is rotated with respect to the shaft 16 by a predetermined amount. When the operation wire side connecting portion 20 is not connected to the side connecting portion 11, the tension of the spring 18 is
And the screw pitch of the hollow shaft 17 is displaced. That is, as shown in FIG. 1, when connecting to the female screw 11f of the radiation source holder-side connecting portion 11 of the radiation source holder H, the male screw 16m of the shaft 16 and the male screw 17m of the hollow shaft 17 are connected.
If the hollow shaft 17 is rotated and connected so that the pitches of the two screws are continuous, after the connection, the tension of the spring 18 causes a force to constantly shift the pitches of these screws, and therefore, the connection portion on the source holder side. It is very difficult for the female screw 11f of 11 and the male screws 16m and 17m of the operation wire side connecting portion 20 to be disengaged from each other.

Only when used in the radiation transmission test, the radiation source holder H is connected to the operation wire 21 and is connected to the operation wire 21 to perform the sending / rewinding operation.
By this operation, the radiation source holder H can be safely sent from the storage container 12 to the necessary place through the inside of the transmission pipe 14 and used safely. After use, the radiation source holder H is stored in the storage container 12 by the reverse operation, and then the connection between the operation wire 21 and the radiation source holder H is released.

[0021]

As described above, according to the radioisotope irradiation apparatus of the present invention, the connection between the radiation source holder and the operation wire in the radioisotope irradiation apparatus is performed by using a female screw at the connection portion on the radiation source holder side. The wire-side connecting portion has two male screws, and one male screw is configured to rotate about the axis of the other male screw so that the minute positional relationship can be shifted. By shifting the positional relationship between these two male screws, the pitch of the two male screws has continuity, has a function as one male screw, and can be screwed with the female screw on the side of the radiation source holder.

Further, when the two male screws are aligned so that the pitches thereof are continuous, a force is applied to the two male screws by the spring in the direction of shifting the positions. Therefore, if the pitches of the two male threads on the operation wire side are matched and fitted to the female threads on the source holder side, the force of the spring will
Since a force for shifting the pitch is constantly applied between the two male screws, even if some force acts to remove the screw, it is very difficult to remove the screw and the detachment during use does not occur.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the relationship between a source holder side connection part and an operation wire side connection part in a radioisotope irradiation device of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is an overall schematic view of a radioisotope irradiation device.

FIG. 4 is a schematic view of a radiation source holder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Radioisotope 2 ... Radioisotope enclosure part 3 ... Connection metal fitting 4 ... Radiation shielding body 5 ... Spring 6 ... Spring stop 7 ... Wire 8 ... Ring 9 ... Wire stop 10 ... Screw 11 ... Connection of the source holder side Part 11f ... Female screw 12 ... Radioisotope storage container 13 ... Manipulator 14 ... Source holder transmission pipe 14a ... Tip jig 15 ... Manipulation pipe 16 ... Shaft 16m ... First male screw 16s ... Shaft pillar 17 ... Hollow shaft 17a ... Recessed portion 17b ... Spring fixing portion (hole) 17h ... Notch 17m ... Second male screw 18 ... Spring 18a ... One end of spring 18b ... Other end of spring 19 ... Shaft fixing portion 19a ... Recessed portion 19b ... Spring fixing portion (hole) 19p ... Projection portion 20 ... Operation wire side connection portion 21 ... Operation wire 21a ... Operation wire end portion 22 ... Overlay welding 22a ... Hole A ... End surface H between hollow shaft and shaft fixing portion H ... Radiation source holder g Gap

Claims (2)

[Claims] 1. A radiation source holder (H) equipped with a radioactive isotope (1), an operation wire (21) connected to the radiation source holder for remotely controlling the sending and rewinding of the radiation source holder, and A radioisotope irradiating device comprising a radioisotope storage container (12) for accommodating a radiation source holder and an operation device (13) for feeding and rewinding the operation wire, which is connected to the operation wire. Source side holder connection (1
A female screw (11f) is engraved in 1), and an operation wire side connecting portion (20) connected to the source holder side connecting portion has a first male screw (16m) screwed into the female screw. (16) and a second male screw (17 m) which is screwed into the female screw continuously with the first male screw.
And a hollow shaft (17) in which a shaft column (16s) of the shaft is rotatably inserted. 2. A spring (18) is stretched between a shaft fixing portion (19) to which the shaft column is fixed and the hollow shaft, and the hollow shaft has a recess (17a) for accommodating the spring and the hollow shaft. A spring fixing portion (1) for fixing one end (18a) of the spring.
7b), the shaft fixing portion has a recess (19a) for accommodating the spring and a spring fixing portion (19b) for fixing the other end (18b) of the spring, the first male screw and the The radioisotope irradiating device according to claim 1, wherein the second male screw receives a force in a direction in which the pitch is always displaced by the spring.