JP3809433B2 - Shielding door with clearance shielding structure - Google Patents

Description

  The present invention relates to a shielding door having a clearance shielding structure in a shielding door installed in a facility that stores or handles a high radiation source such as a nuclear power plant or a large-scale hospital.

  The shielding door is a door provided for entrances and exits of people and objects installed in radiation shielding facilities such as buildings that contain radiation sources, but when the shielding door is closed, a shielding wall that forms the shielding facility and It is provided in such a structure that the radiation is not released to the outside from the radiation shielding area including the shielding door.

  The entrance / exit formed on the shielding wall as described above and the shielding door installed therein form the inner peripheral surface of the opening forming the entrance / exit on a stepped inner peripheral surface by a stepped portion such as unevenness, and also shield it. On the outer peripheral surface of the door, there is provided a step portion that fits into the stepped inner peripheral surface of the opening. This is because, if the inner peripheral surface of the opening and the outer peripheral surface of the shielding door are opposed to each other on a flat surface, radiation leaks from a straight gap formed between them. Is to prevent.

  For example, in the known horizontal shielding door SD shown in FIG. 9, a step W1 formed on the door-to-door side of the wall SW with respect to the opening EX for entrance and exit provided in the shielding wall SW and the door SD. By providing the front part d1 and rear part d2 of the shielding door SD facing the step W2 formed facing the rear side, the opening EX of the shielding wall SW and the facing part of the shielding door SD are arranged inside and outside. In order to prevent the radiation from going straight and to attenuate any radiation that enters the gap, the gap forms a zigzag or staircase. It is formed like this.

  This also applies to the step-back type shielding door SD shown in FIGS. 10 and 11, or the hinge opening / closing type shielding door (not shown). 10 and 11, the same parts and members as those in FIG. 9 are denoted by the same reference numerals. However, in the shielding door SD illustrated in FIGS. 10 and 11, the inner periphery located at the middle part in the front-rear direction of the opening / closing part EX. A step e1 is provided on the surface, and a step d3 corresponding to the step e1 is provided on the outer surface of the door SD. 9 to 11, F is a floor.

  In places where the shielding door SD is installed as described above, there may be a step on the floor F of the entrance EX for the purpose of preventing radiation leakage from the gap. Since there are many inconveniences in the entry and exit of articles, especially heavy items, the floor F is flat without any steps, and the front or back of the shielding door SD is installed in the form of a soil or block. Placing the shield SG is performed (see FIG. 11).

  However, the installation of an auxiliary shield such as a block shape can be expected to have a certain effect in shielding a straight gap formed between the flat bottom surface (lower surface) of the shielding door and the flat surface of the floor, Not only does it require extra work to move the auxiliary shield every time the shielding door is opened or closed, or return it to its original position, but even the auxiliary shield has considerable weight, Many aspects are not reasonable, such as requiring manpower and mechanical power.

  Therefore, in the present invention, in view of the problems of the conventional auxiliary shield in the shield door installed at the place where the floor is formed flat, a clearance shielding structure that replaces the conventional auxiliary shield that does not need to be moved manually or by mechanical force It is an object of the present invention to provide a shielding door including

  The configuration of the shielding door having the clearance shielding structure of the present invention made for the purpose of solving the above problems is a closed state of the shielding door that is installed at the entrance formed in the radiation shielding wall and is opened and closed by sliding. A concave groove having a width smaller than the front and rear width (thickness) of the door and having a length at least approximately equal to the opening width of the doorway is formed on the floor facing the bottom surface of the door. A rod-shaped shield having a cross-section formed on a part of a flat or substantially flat surface in the length direction is rotatably supported so that the flat surface is substantially flush with the floor surface when rotated. On the other hand, a concave portion having a cross-sectional shape in which a portion other than the flat surface of the rotated rod-shaped shield is formed on the bottom surface of the door facing the concave groove.

  The shielding door of the present invention can be configured such that, in the above-described configuration, the sliding opening / closing operation of the shielding door and the rotation operation of the rod-shaped shielding body are synchronized with each other at the beginning and end of the sliding opening and closing operations of the door. . That is, in order to rotate the rod-shaped shield at the beginning and end of the sliding opening and closing operations of the shielding door, a direction changing mechanism for changing the direction of the sliding operation is provided on the door side, and the changing mechanism includes While providing a rack-like drive body, a pinion-like follower that is rotated by the drive body is provided on the rotating shaft on the rod-like shield side, so that when the shielding door is all closed, the part other than the flat surface is the door. The rod-shaped shield that has been housed in the concave portion of the door is rotated in a direction to make the flat surface the upper surface at the start of the opening operation of the door, and the flat surface is formed into a surface continuous with the floor surface, When closing this shielding door, the rod-shaped shielding body whose flat surface faces the upper surface at the end of the closing operation is rotated so that the portion other than the flat surface is accommodated in the recess formed on the bottom surface of this door. .

  In a shielding door that is slidably opened and closed installed at an entrance formed on the radiation shielding wall, the bottom surface of the closed shielding door and the opposite surface of the floor are formed in a concave shape over at least the same length as the opening width of the entrance. A rod-shaped shield having a part in the length direction formed on a flat or substantially flat surface is rotatably accommodated in the opposed concave portions, and the shield is placed on the shield in the opened state of the door. Since the flat surface is located on the top surface and the flat surface rotates to a position other than the top surface when the door is closed, the clearance on the bottom and floor surfaces of the sliding-type shielding door can be shielded only when the door is closed. Can be formed.

  Next, an embodiment of the shielding door provided with the clearance shielding structure of the present invention will be described with reference to the drawings. FIG. 1 is a plan sectional view of an essential part of an example in which the clearance shielding structure of the present invention is applied to the horizontally pulling type shielding door of FIG. 9, FIG. 2 is a side sectional view of the apparatus of FIG. 1, and FIG. 2 is a left side view of the apparatus of FIG. 2, FIG. 4 is a view taken along line AA of FIG. 2, and FIGS. 5 and 6 are a drive cam body and a passive block body at the closing operation end of the shielding door in the shielding structure of the present invention. 7 and FIG. 8 show the relationship between the rack and pinion on the back surface of the passive block body in FIG. 5 and FIG. 6, and the rotation operation of the bar-shaped shield and the bottom of the door. It is the perspective view seen from the back surface side in order to demonstrate the relationship with the recessed part provided in FIG. 9 is a cross-sectional plan view showing the main part of a conventional horizontal-type shielding door, FIG. 10 is a cross-sectional plan view showing the main part of a conventional step-back type shielding door, and FIG. It is a sectional side view.

  1 to 4, reference numeral 1 denotes a horizontal-type shielding door (hereinafter simply referred to as a door 1) installed in an opening 3 provided in the shielding wall 2, and FIG. 1 is a plan view of the front end side of the door 1. The state seen from.

  In the present invention, as illustrated in the cross-sectional view of FIG. 4, the cross section of the flat floor F in the opening 3 is almost directly below the door 1 when the door 1 is fully closed. A concave groove 4 that forms most of the shape is provided, and an arc-shaped concave portion 5 that forms a substantially circular shape in combination with the cross-sectional shape of the concave groove 4 is formed on the bottom surface 1B of the door 1 facing the concave groove 4. Yes. In the example of FIG. 4, the concave groove 4 is formed by filling a floor F with a stainless steel pipe material partially cut in the length direction, and the concave portion 5 provided on the bottom surface 1B of the door 1 is also formed. Although formed by a pipe material formed by the same method, in the present invention, the material and configuration of the recessed groove 4 and the recessed portion 5 are not limited to those illustrated. In the present invention, the length of the concave groove 4 or the concave portion 5 is substantially the same length as the opening width (front width) of the doorway where the door 1 is installed or the front width of the door 1.

  The concave groove 4 has an auxiliary shield 6 (hereinafter referred to as a rod-shaped auxiliary shield 6) having a size that can rotate within the cross section of the concave groove 4, that is, a cross-sectional rod shape that is closely inserted into the cross sectional shape of the concave groove 4. A rod-shaped shielding body 6 or a shielding body 6) is housed so as to be rotatable about an axis 6a passing through the center.

  The shielding body 6 is filled with a shielding material 6b formed of a plastic material, iron, or the like in a member having a cross section obtained by partially cutting a stainless steel pipe material in the length direction in the same manner as the concave groove 4. And a flat surface (hereinafter referred to as a flat surface 6c) in which the cover plate 6c is flush with the upper surface of the floor F of the shield 6. It is formed to become.

  Reference numeral 7 denotes a bearing portion (see FIG. 2, the right side is omitted) for supporting the rod-shaped shield 6 at both left and right ends thereof. The left bearing portion 7 shown in FIG. 2 is disposed outside the bearing plate. A support box 8 for slidably supporting a drive plate 9 having a rack 10 described below on its lower surface is formed from a plate material.

  On the other hand, a pinion 11 that meshes with the rack 10 is attached to the shaft 6a at a position corresponding to the rack 10 on the left end side of the rod-shaped shield 6 (see FIGS. 2 and 3). The rack 10 and the pinion 11 may be, for example, a linear chain and a sprocket that meshes with it as long as they perform the same function.

  5 and 6, a cam follower member 13 that slides the drive plate 9 forward and backward by being pushed by the inclined cam 12 provided at the lower left portion of the door 1 is provided on the upper surface of the drive plate 9. The drive plate 9, the cam 12, and the cam follower member 13 form a direction changing mechanism that changes the slide direction of the drive plate 9 by 90 degrees with respect to the sliding opening / closing direction of the door 1. The rack 10 provided in the above constitutes a driving body.

  Here, the drive plate 9 is always biased to the lower side of FIG. 1 (the right side of FIG. 3) by a spring or the like (not shown) and is not subjected to the action of the inclined cam 12 (ie, When the door 1 is opened), it is located at the stroke end (downward in FIG. 1, rightward in FIG. 3) due to the urging force. At this time, the stroke amount of the drive plate 9, the position of the stroke end, and the meshing state of the rack 10 and the pinion 11 are adjusted in advance so that the flat shield 6c faces the same upper surface as the floor F. Shall be set.

  Therefore, the state in which the flat surface 6c of the rod-shaped shield 6 shown by the solid line in FIGS. 2 to 4 and 7 is facing directly above is the state in which the door 1 is opened, and the flat surface of the shield 6 By forming a flat surface in which the upper surface of 6c and the floor F are connected, a state in which there is no hindrance to loading and unloading of heavy articles at the doorway 3 is realized.

  Now, the door 1 is closed from the above-described open state (moving leftward in FIGS. 1 and 2), and the leading end on the closed side is in the state shown in FIG. 1, that is, as illustrated in FIGS. At the end of the closing operation of the door 1, when the inclined cam 12 provided on the end of the door 1 pushes the cam follower member 13 on the upper surface of the drive plate 9, the follower member 13 is positioned at the position of the imaginary line in FIG. 1), the drive plate 9 integrated with the cam follower member 13 is slid upward in the example of FIG.

  By the slide of the drive plate 9, the pinion 11 is rotated counterclockwise in FIG. By this rotation, the flat surface 6c of the rod-shaped shield 6 rotates counterclockwise, and the right-half cross-sectional circular portion of the shield 6 enters the recess 5 formed on the lower surface of the door 1. The operation mode of the rod-shaped shield 6 can be understood with reference to perspective views from below in FIGS. Therefore, when the door 1 is opened (slid) from this state (closed door), the pinion 11 and the rack 10 are operated in the opposite direction by the spring force pulling the drive plate 9, and the rod-shaped shield 6 The non-flat part is deviated from the recessed part 5 of the door 1 and the flat part 6c is rotated to the same surface as the floor F.

  As described above, the clearance shielding structure of the present invention is embedded in the floor F of the opening 3 at the start / end of the sliding opening / closing operation of the door 1 and a part of the circumference along the length direction. When the door 1 is opened, the flat surface 6c has a flat shield 6c having a flat surface 6c that is flush with the floor F so as to rotate in conjunction with the sliding motion of the door 1. When it is rotated to the same surface as the floor F and the door 1 is closed, the non-flat surface portion of the shield 6 is rotated and inserted into the recess 5 provided on the bottom 1B of the door 1. As in the case of a conventional shielding door, the operation of moving the auxiliary shielding body every time the door is opened or closed by input or external mechanical force is completely unnecessary.

  In the embodiment of the present invention described above, the cross section of the concave groove 4 provided on the floor F or the concave portion 5 of the bottom surface 1B of the door 1 does not necessarily have to be cylindrical (cylindrical), for example, a polygonal cross section having a square shape or more It may be. Further, the rod-shaped shield 6 is not limited to the circular arc shape obtained by cutting a part of the circular cross section of the embodiment, and may be a polygonal cross section, a door shape, or other cross sectional shapes.

  In short, the relationship between the rotating rod-shaped shield 6 and the concave groove 4 and the concave portion 5 that accommodates it realizes an interlocking operation and a rotational position with the above operation at the start and end of the opening and closing operation of the door 1 in the above embodiment. It is only necessary to form a non-linear step or curved gap between the lower surface of the door 1 and the floor F by the rod-shaped shield 6 that has entered the recess 5 of the door 1.

  Furthermore, the clearance shielding structure of the present invention can further improve the shielding property by providing two or more sets in parallel in the thickness direction of the door in view of the thickness of this type of shielding door. become.

  More specifically, the above-described clearance shielding structure of the present invention is implemented in the form having the lock mechanism shown in FIGS. 12 to 14, and will be described below with reference to FIGS. 12 to 14, the same members and parts as those in FIGS. 1 to 8 use the same reference numerals.

  FIG. 12 is a plan view of the cam 12 provided with a cam groove 12a provided at the lower part of the front end surface of the door 1. The solid line indicates the position of the cam 12 in the closed state, and the imaginary line indicates the position of the cam 12 that starts to open. Is shown. Near the rear end of the groove 12a of the cam 12 indicated by a solid line, a roller-like cam follower 13 provided on the upper surface of the drive plate 9 provided with the rack 10 is located.

  FIG. 14 is an end view taken along the line AA in FIG. 13 and shows a state in which the rack 10 is moved leftward by the support box 8 by the action of the cam 12 when the door 1 shown in FIG. . In FIG. 13, the cam 12 in the closed state of the door 1 is shown by a solid line. However, when the door 1 is opened, the cam 12 is integrated with the door 1, so that it is separated from this position.

  The cam 12 in FIG. 12 is provided with a cam slope 14 formed in a downward slope with the upper surface facing forward (toward the tip of the cam 12) in a direction parallel to the moving direction of the cam 12 (left-right direction in the figure). ing. When the door 1 is opened, the cam slope 14 acts to start opening the door 1 so that the shield 6 rotated so that the flat surface 6c becomes the upper surface cannot be rotated at that position. This is for releasing the lock state of the lock rod 15 near the end of the door 1 closing operation.

  In the position of the cam 12 with the door 1 in the closed state in FIG. 14, the lock rod 15 is unlocked by the action of the cam inclined surface 14, but in the open state in FIG. When the surface 6c is positioned on the upper surface, the lock rod 15 is positioned coaxially with the cam follower 13, and is locked to the center of the upper surface of the cam follower 13 by the pressing action of the spring 15a. The operating body 9 having 10 is held stationary.

  In the present invention, when the flat surface 6c of the shield 6 is positioned on the upper surface and becomes the same surface as the front and rear floor surfaces F, the rotation of the shield 6 is locked on the flat surface 6c. This is to prevent the shield 6 from tilting or rotating due to the weight of the article or vehicle passing therethrough.

  When the flat surface 6c of the shield 6 comes to the upper surface, that is, the lock mode for preventing rotation when the door 1 is in the open state, the mode schematically shown in FIGS. it can. FIG. 15 shows an embodiment in which a locking arm 15 is provided on the side surface of the shield 6, and when the flat surface 6c comes to the upper surface, a lock pin 16 is applied to the arm 15 so as to be rotatably constrained. FIG. 17 shows a configuration in which a lock pin 16 protruding and retracting in a lock hole 17 provided on a side surface of the shield 6 is put in and out so as to be unrotatable. FIG. 17 shows a lock plate (or rod) 18 on a flat surface 6c of the shield 6. It is a form which restrains so that rotation is impossible.

  Since the shielding effect of the clearance shielding structure of the present invention described above has been evaluated by simulation analysis verified by experiments, this point will be described next with reference to FIGS.

  Fig. 18 shows a concrete wall W1, W2 180cm thick, wall W3 245cm thick, wall W4 230cm thick, surrounded by a boundary of the wall W1 and W4, 230cm thick and 330cm long. FIG. 3 is a plan view of a model shielding room IR having an inner dimension of 500 × 395 cm formed by providing the shielding door 1.

  In this shielding room IR, it was set that EP = 30 MeV, Cu target T was placed at a height of about 1.8 m at the center. Further, a clearance of 1 cm was set between the shielding door 1 and the floor F, and a clearance between the shielding body 6 according to the present invention and the concave portion 5 and the concave groove 4 of the door 1 in which the shielding member 6 is accommodated was also set to 1 cm. Further, the shield 6 is provided at a position indicated by a two-dot chain line at the approximate center of the door 1 in FIG. Here, the evaluation points for the door 1 in FIG. 18 were set at the positions of 7 locations # 1 to # 7 shown in FIG. 18 at intervals of 50 cm at a height of 0.5 cm from the floor of the door 1.

  In the simulation analysis, the conventional case in which the shield 6 is not provided at all in the door 1 of the shielding room IR in FIG. 18, the case in which the shield 6 having a diameter of 10 cm is provided in parallel with the door sliding direction at the center of the bottom of the door 1 is the same. 5 cases were provided: a case provided with a shield 6 having a diameter of 20 cm, a case provided with a shield 6 having a diameter of 30 cm, and a case in which two shields 6 having a diameter of 20 cm were provided in parallel and at approximately equal intervals. .

  The result of the analysis was as shown in the diagram of FIG. In the diagram of FIG. 19, the horizontal axis indicates seven evaluation points # 1 to # 7 in the door 1, and the vertical axis indicates the unit of shielding energy (Sv / h). As can be seen from this diagram, the radiation dose that can be shielded is high in the door 1 without the shield 6, but the radiation dose that can be shielded decreases as the diameter of the shield 6 increases in the door 1 with the shield 6. It can be seen that the shielding effect is enhanced. Incidentally, the ratio of the shielding performance between the door 1 without the shield 6 and the door 1 with the double 20 cm diameter shield 6 is about 1/100 to 1/700 at each of the evaluation points # 1 to # 7. It was.

  The present invention is as described above, and a clearance shielding structure that replaces the conventional auxiliary shielding body is provided on the floor of the doorway facing the bottom surface of the closed door so that it does not need to be moved manually or by mechanical force. A concave groove having a width smaller than the front-rear width (thickness) of the door and having a length at least approximately equal to the opening width of the doorway is formed, and a part of the outer periphery is flat in the longitudinal direction in the concave groove. A bar-shaped shield having a cross-section formed on the surface is rotatably supported on the axis, and a portion other than the flat surface of the rotated bar-shaped shield is provided on the bottom surface of the door facing the concave groove. By forming a recess having a cross-sectional shape that can be accommodated, when the shielding door is all closed, the bar-shaped shielding body in which the portion other than the flat surface is accommodated in the recess of the door can be opened. At the start, the flat The flat shield is formed in a plane continuous with the floor by rotating in a direction to face the upper surface, and when the shielding door is closed, the flat shield faces the upper surface at the end of the closing operation. It is possible to place the part other than the flat surface in the recess formed on the bottom surface of the door by rotating the auxiliary shield for clearance shielding, and automatically perform the necessary function. And can be very effective.

  In addition, since the clearance shielding structure of the present invention does not use any external power or drive source, it is not only simple in structure but also simple in mechanical structure, so that it can be applied to a new shielding door. Also, there is an advantage that it can be easily applied to existing doors with some modifications.

Plan sectional view of the main part of an example in which the clearance shielding structure of the present invention is applied to a horizontal pulling type shielding door Side sectional view of the shielding structure of FIG. 1 and 2 left side view of the shielding structure AA line arrow view of FIG. The perspective view seen from the upper surface in order to explain the relationship between the drive cam body and the passive block body at the closing operation end of the shielding door in the shielding structure of the present invention The perspective view seen from the upper surface in order to explain the relationship between the drive cam body and the passive block body at the closing operation end of the shielding door in the shielding structure of the present invention The perspective view seen from the back side in order to explain the relationship between the rack and pinion on the back surface of the passive block body in FIG. 5 and FIG. 6 and the rotation operation of the bar-shaped shield and the recesses provided on the door bottom surface. The perspective view seen from the back side in order to explain the relationship between the rack and pinion on the back surface of the passive block body in FIG. 5 and FIG. 6 and the rotation operation of the bar-shaped shield and the recesses provided on the door bottom surface. A cross-sectional view showing the main parts of a conventional horizontal-type shielding door Plan sectional view showing the main part of a conventional step-back type shielding door 10 is a side sectional view of FIG. The top view of the cam 12 used for the specific example of this invention clearance shielding structure Front sectional view of main part of specific example of clearance shielding structure of present invention AA sectional view taken along line AA in FIG. The perspective view which shows the outline | summary of the 2nd example of the locking mechanism of the shield 6 The perspective view which shows the outline | summary of the 3rd example of the locking mechanism of the shield 6 The perspective view which shows the outline | summary of the 4th example of the locking mechanism of the shield 6 Plan view of model shielding room used for simulation analysis of clearance shielding effect of the present invention FIG. 18 is a diagram comparing the shielding performance between each example of the clearance shielding structure of the present invention applied to the model shielding room of FIG. 18 and a conventional example that does not employ the shielding structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield door 2 Shield wall 3 Opening part 4 Concave groove 5 Concave part 6 Bar-shaped shielding body 7 Bearing plate 8 Support box 9 Drive plate
10 racks
11 Pinion
12 Slope cam
13 Cam follower member F Floor

Claims (6)

  In a shielding door that is slidably opened and closed installed at an entrance formed on the radiation shielding wall, the bottom surface of the closed shielding door and the opposite surface of the floor are formed in a concave shape over at least the same length as the opening width of the entrance. A rod-shaped shield having a part in the length direction formed on a flat or substantially flat surface is rotatably accommodated in the opposed concave portions, and the shield is placed on the shield in the opened state of the door. A shielding door provided with a clearance shielding structure, wherein the flat surface is located on the upper surface, and the flat surface is rotated to a position other than the upper surface in the closed state.   In a shielding door that is opened and closed by sliding and is installed at an entrance formed in a radiation shielding wall, the entrance has a width smaller than the front-rear width (thickness) of the door on the floor facing the bottom of the closed door A rod-shaped shield having a cross section in which a groove having at least approximately the same length as the opening width of the groove is formed, and a part of the outer periphery is formed in a flat or substantially flat surface in the length direction in the groove. While rotating, the flat surface is rotatably supported so as to be substantially flush with the floor surface, while the bottom surface of the door facing the concave groove is other than the flat surface of the rotated rod-shaped shield. The shielding door provided with the clearance shielding structure characterized by forming the recessed part which has the cross-sectional shape which the site | part of this fits.   The shielding door according to claim 1 or 2, wherein the sliding opening / closing operation of the shielding door and the rotation operation of the rod-shaped shielding body are synchronously linked at the beginning and end of the sliding opening and closing operations of the door.   In order to rotate the rod-shaped shield at the beginning and end of sliding opening and closing operations of the shielding door, a direction changing mechanism for changing the direction of the sliding operation is provided on the door side, and the changing mechanism is rack-shaped. The shield door according to claim 3, wherein a pinion-like driven body that is rotated by the drive body is provided on a rotating shaft on the rod-shaped shield side.   The shielding door according to any one of claims 1 to 4, wherein at least two sets of the clearance shielding structure according to any one of claims 1 to 4 are arranged in parallel in the thickness direction of the shielding door. The shielding door according to any one of claims 1 to 5, wherein the bar-like shield is provided with stopper means for restraining the position when the flat surface is located on the upper surface aligned with the floor.

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