JP2015075403A - Sample measurement instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently intercept light under a sample measurement chamber in a sample measurement instrument.SOLUTION: An elevating mechanism transports a sample container 36 from a rack to a sample measurement chamber. An inside light-shielding structure is provided over an upper surface of a base frame 181 and a lower surface of a head 44 so as to surround a shaft 43. The inside light-shielding structure comprises a first ring groove 198 and a first ring projection 202. When the head 44 is in a ground state, the upper surface of the base frame 181 and the lower surface of the head 44 are brought into close contact with each other by action of a spring 196. In this case, the first ring groove 198 and the first ring projection 202 are joined together. An outside light-shielding structure is provided around the inside light-shielding structure. A top plate 194 has a laminate structure including a light-shielding sheet and a light reflecting plate.

Description

  The present invention relates to a sample measuring device, and more particularly to a sample measuring device that measures a radioactive substance in a sample using a liquid scintillator.

  The sample measurement device is a device that individually measures a plurality of samples. A typical sample measuring device is a liquid scintillation counter. The liquid scintillation counter includes a rack transport mechanism that transports a rack that holds a plurality of sample containers, a measurement unit that measures light generated by a radioactive substance contained in each sample container, and a sample container between the rack and the measurement chamber unit. A container transport mechanism for transporting In addition to the liquid sample, a liquid scintillator is placed in the sample container. When radiation (for example, β rays) is emitted from the radioactive substance in the sample, the liquid scintillator emits light by the radiation. The light is detected by a pair of photomultiplier tubes constituting the measurement unit.

  In general, it is necessary to provide a shielding structure for shielding extraneous radiation around a measurement chamber that houses a sample container to be measured. Such a shielding structure is made of a very heavy metal. Therefore, it is better to install the shielding structure below the rack placement surface than to install the shielding structure above the rack placement surface. In addition, when adopting a method for transporting the sample container upward from the rack, there is a shaft supporting the sample container in the hoistway during measurement, which makes it difficult to block the hoistway. There is. Therefore, it is desirable to provide a measurement chamber below the rack mounting surface and to pull out the sample container downward from the rack.

  Patent Document 1 discloses a conventional liquid scintillation counter. In the liquid scintillation counter, a measurement chamber is provided above the transport table for transporting the rack. Patent Document 2 discloses a rack transport device that can be used for a liquid scintillation counter or the like.

JP 2007-278969 A JP 2007-176666 A

  When the method of pulling out the sample container from the rack to the lower side is adopted, the sample container raising / lowering shaft usually passes through the sample measurement chamber. Therefore, it is necessary to reliably prevent the entry of extraneous light in the lower part of the sample measurement chamber. In particular, it is desirable to prevent a gap that allows entry of extraneous light from being inadvertently generated even if there are vibrations or processing errors.

  An object of the present invention is to enable reliable light shielding in a lower part of a sample measurement chamber in a sample measurement apparatus.

  A sample processing apparatus according to the present invention includes a transport mechanism that transports a rack on a transport surface, a sample measurement chamber that is provided below the transport surface and that stores a sample container from the rack, and the sample measurement chamber A base frame that constitutes the bottom of the base frame, a shaft that penetrates the base frame up and down, and a head that is provided at an upper end of the shaft and places the sample container thereon, the rack and the sample measurement chamber An elevating mechanism for transporting the sample container between the upper surface of the base frame and the lower surface of the head in a base state in which the shaft is pulled down to the lowest end, and the upper surface of the base frame and the head A light shielding structure is provided so as to surround the shaft across the lower surface of the shaft.

  According to the above configuration, when the shaft is pulled down to the lowest end, a ground state is formed, and the upper surface of the base frame and the lower surface of the head are joined. Since the light shielding structure is formed across these, the light shielding structure prevents the entry of extraneous light into the sample measurement chamber (particularly, the entry of extraneous light along the shaft surface).

  Preferably, the light shielding structure includes an annular protrusion provided on one of the upper surface of the base frame and the lower surface of the head, and an annular protrusion provided on the other of the upper surface of the base frame and the lower surface of the head. A concave portion, and the annular convex portion and the annular concave portion are combined in the ground state. According to this configuration, it is possible to prevent the entry of extraneous light using uneven engagement, that is, using an optical maze.

  Preferably, the head includes an upper end portion of the shaft, a head main body in which the upper end portion of the shaft is inserted so as to be movable up and down, and an elastic body provided between the upper end portion and the head main body. In addition, the elastic body exerts an elastic action in the ground state, whereby the annular convex portion and the annular concave portion are elastically adhered to each other. According to this configuration, the bonding state between the upper surface of the base frame and the lower surface of the head can be strengthened. That is, both surfaces can be brought into close contact with each other, and a good combined state of the annular convex portion and the annular concave portion can be formed. Since the elastic force works, it is possible to prevent a gap from being inadvertently generated due to vibration, and to prevent the entry of extraneous light from around the shaft even if there is a slight processing error or assembly error.

  Preferably, the head body has a well, a stopper member is provided at an upper end portion of the shaft, and the elastic body is a spring provided between a bottom surface of the well and a lower surface of the stopper member, Even after the downward movement of the head body is stopped so that the spring is compressed in the base state, the shaft is pulled down. The degree of adhesion between the two surfaces can be adjusted by the amount of shaft pull-down and the strength of the spring.

  Preferably, a case surrounding the sample measurement chamber is provided, and an outer light shielding structure is provided so as to surround the light shielding structure across the upper surface of the base frame and the lower surface of the case. According to this configuration, the entry of extraneous light along the periphery of the shaft can be prevented, and at the same time, the entry of extraneous light from around the case can be prevented.

  Preferably, the head includes a laminated body that constitutes a mounting surface, and the laminated body includes a lower light shielding sheet and an upper light reflecting layer. According to this configuration, the entry of extraneous light through the head can be prevented, and at the same time, the light generated by the sample can be effectively reflected to increase the light collection efficiency.

  The upper surface of the base frame may be set at a reference level in the elevation control. The concavo-convex light shielding structure formed between the upper surface of the base frame and the lower surface of the head also functions in the horizontal positioning of the head. That is, it is possible to properly position the head and thus the sample container in the sample measurement chamber in the horizontal direction.

  According to the present invention, in the sample measuring apparatus, appropriate light shielding can be performed at the lower part of the sample measuring chamber. Even if there is vibration or formation error, reliable light shielding can be performed.

It is a figure showing the outline of the sample measuring device concerning the present invention. It is a top view of a sample measuring device. It is a perspective view of a sample measuring device. It is a 1st perspective view of a rack. It is a 2nd perspective view of a rack. It is a 1st perspective view of a rack main body. It is a 2nd perspective view of a rack main body. It is a 1st perspective view of an adapter. It is a 2nd perspective view of an adapter. It is a 1st perspective view of an attachment. It is a 2nd perspective view of an attachment. It is operation | movement explanatory drawing of an attachment. It is sectional drawing of a rack. It is a figure which shows the non-operation state of a stopper. It is a figure which shows the operating state of a stopper. It is operation | movement explanatory drawing of a lower end unit. It is a figure which shows the open state of an arm. It is an enlarged top view of a guide block. It is sectional drawing of a guide block. It is a perspective view which shows the rack insertion state to X conveyance path | route. It is a perspective view which shows the delivery state of a sample container. It is an expansion perspective view which shows the delivery state of a sample container. It is sectional drawing which shows the delivery state of a sample container. It is a figure which shows the operation state of a pressing unit. It is a 1st expansion perspective view of a pressing unit. It is a 2nd expansion perspective view of a pressing unit. It is a figure for demonstrating the effect | action of a pressing unit. It is XZ sectional drawing which shows a head raise state. It is XZ sectional drawing which shows the delivery state of a sample container. It is XZ sectional drawing which shows a sample measurement state. It is YZ sectional drawing which shows a head raising state. It is YZ sectional drawing which shows a shutter operation state. It is an expanded sectional view which shows the light-shielding structure of a sample measurement chamber lower part. It is a 1st perspective view of a shutter mechanism. It is a 2nd perspective view of a shutter mechanism. It is sectional drawing of a shutter mechanism. It is a 1st perspective view which shows another adapter. It is a 2nd perspective view which shows another adapter. It is a schematic diagram explaining operation | movement of another adapter. It is sectional drawing explaining operation | movement of another adapter.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

(A) Overview of sample measuring device (Figs. 1-3)
FIG. 1 shows a preferred embodiment of a sample measuring device according to the present invention, and the sample measuring device shown in FIG. 1 is a scintillation counter in this embodiment. The scintillation counter measures a radioactive substance contained in a sample using a liquid scintillator. Of course, the present invention can also be applied to other sample measuring apparatuses.

  FIG. 1 is a schematic diagram showing the overall configuration of the sample measuring apparatus 10. The X direction is the first horizontal direction, the Y direction is the second horizontal direction, and the Z direction is the vertical direction. The sample measuring apparatus 10 includes a transfer table 12 having a transfer surface that extends in the X direction and the Y direction. A plurality of racks 14 are transported on the transport table 12. In the present embodiment, a Y transport path 16, an X transport path 20, a Y transport path 18, and another X transport path are provided on the transport table 12. The transport mechanism 16 </ b> A is a mechanism for transporting the rack 14 in the forward direction in the Y direction on the Y transport path 16. The transport mechanism 18A is a mechanism for transporting the rack 14 in the reverse direction in the Y direction on the Y transport path 18. A mechanism for transporting the rack 14 forward in the X direction on the X transport path 20 is not shown in FIG. Similarly, a mechanism for transporting the rack 14 in the opposite direction in the X direction on another X transport path is not shown in FIG.

  The rack 14 has a longitudinal direction and a short direction. The longitudinal direction is the direction in which the plurality of accommodating portions 24 are arranged. The short direction is a direction orthogonal to the long direction. In each accommodating part 24, the sample container 22 is held. The sample container 22 is, for example, a vial or a test tube. The sample container 22 includes a main body 22A and a cap 22B. A liquid sample 22C is accommodated in the main body 22A. A liquid scintillator for measuring radioactive substances in the liquid sample is also accommodated in the main body 22A. In general, a liquid scintillator is a substance that emits light upon receiving radiation (β rays in this embodiment).

  In the present embodiment, as will be described in detail later, an adapter is attached to each rack 24 with respect to the rack body. An opening / closing mechanism 26 is realized as a function of the adapter. That is, the rack 14 has a plurality of opening / closing mechanisms 26 corresponding to the plurality of accommodating portions 24. Each open / close mechanism 26 takes a closed state and an open state, holds the sample container 22 in the closed state, and releases the sample container 22 by releasing the holding of the sample container 22 in the open state. In the present embodiment, the sample container 22 to be measured is pulled out from the rack 14 downward.

  On the X transport path 20 in the transport table 12, a guide block 30 is fixedly installed at a place where the target container is taken in and out. The guide block 30 is a member that enters the lower portion of the rack 14, and specifically, a member that enters between a pair of legs of the rack 14 and applies an opening force to each opening / closing mechanism 26. . Moreover, it is a member for optimizing the position and posture of the rack in cooperation with the pressing unit 32 described later. The guide block 30 has an opening penetrating in the vertical direction at the center thereof, and the opening corresponds to the upper end portion of the hoistway 28. The hoistway 28 is a passage through which the sample container to be measured moves up and down between the rack 14 and the sample measurement chamber 34. In the present embodiment, the guide block 30 is positioned with high accuracy with respect to such a hoistway 28. In other words, the guide block 30 is physically integrated with the structure constituting the hoistway 28 as will be described later.

  In the present embodiment, a pressing unit 32 is provided in order to optimize the position and posture of the rack 14 when each sample container is taken in and out. The pressing unit 32 exerts a pressing force on the outer surface of one of the pair of legs of the rack 14, and thereby, the one of the legs is against the reference surface of the guide block 30. The inner surface is closely attached. By forming such a close contact state, the position and posture of the rack 14 are optimized.

  At the time of sample measurement, a sample container 36 that is a measurement target is accommodated in the sample measurement chamber 34. An elevating mechanism 40 is provided to elevate and lower the sample container 36. The sample container 36 can be moved up and down in the hoistway 28 by the elevating mechanism 40.

  In the present embodiment, the elevating mechanism 40 includes a shaft 43, a head 44 provided at the upper end portion thereof, a slide mechanism 46 that drives the shaft 43, and the like. As will be described later, when the sample container is transferred between the rack 14 and the head 44, the head 44 is inserted into the opening of the guide block 30. In such a state, the opening / closing mechanism 26 provided in the accommodating portion 24 positioned immediately above the opening is in an open state. Specifically, in the process of transporting the rack 14, the opening / closing mechanism 26 contacts the guide block 30, and the opening / closing mechanism 26 receives a horizontal opening force from the guide block 30, thereby forming the open state of the opening / closing mechanism 26.

  The sample measurement chamber 34 is mounted on the base 48. When light emission occurs in the sample container 36 accommodated in the sample measurement chamber 34, the light is detected by a pair of photomultiplier tubes 38. A pair of photomultiplier tubes 38 are provided to execute a so-called coincidence process. In the present embodiment, a special light shielding structure 50 is provided below the sample measurement chamber 34. The light blocking structure 50 prevents extraneous light from entering the sample measurement chamber 34 through the surface of the shaft 43. The light shielding structure 50 is provided across the lower surface of the head 44 and the upper surface of the base 48 with which the lower surface contacts. A predetermined light shielding structure is also provided in the head 44. These will be described in detail later.

  In the present embodiment, the sample measurement chamber 34 is provided below the transfer table 12. Therefore, there is an advantage that a very heavy shielding member provided around the sample measurement chamber 34 can be arranged below the transfer table 12. Further, as will be described below, when shielding external radiation and external light at a predetermined location on the hoistway 28 during sample measurement, the shaft 43 does not exist at that location. Shielding can be performed easily and reliably.

  More specifically, a shutter mechanism 42 is provided on the hoistway 28 so as to cross it. The shutter mechanism 42 in the present embodiment includes an upper shutter mechanism and a lower shutter mechanism, that is, a double shutter mechanism is realized. The upper shutter mechanism is a mechanism for inserting a radiation shielding member on the upper side of the sample measurement chamber 34 in order to shield extraneous radiation, and the lower shutter mechanism is a hoistway to prevent entry of extraneous light from above. 28 is a mechanism for inserting a light shielding plate so as to cross 28.

  In the sample measuring apparatus 10 according to the present embodiment, the rack 14 is intermittently sent in the X direction on the X transport path 20 with a posture in which the longitudinal direction is aligned with the X direction. In that case, the guide block 30 enters the lower portion of the rack 14, and the opening / closing mechanisms 26 provided in the respective accommodating portions 24 operate in order. The rack 14 is stopped in a state where the center line of each of the accommodating portions 24 and the center line of the hoistway 28 coincide. In this state, the sample container before measurement is sent from the rack 14 into the sample measurement chamber 34. After the measurement is completed, the sample container 36 after the measurement is returned to the original sample container accommodating portion. Thereafter, as the rack 14 is transported, the opening / closing mechanism 26 returns from the open state to the closed state in the storage unit 24 that has received the sample container. Such a series of processes is repeatedly executed for each storage unit 24.

  FIG. 2 is a top view of the sample measuring apparatus shown in FIG. As already described, the rack 14 is transported in the horizontal direction on the transport table 12. In this embodiment, a Y transport path 16, an X transport path 20, a Y transport path 18, and an X transport path 50 are provided as transport paths for the rack 14. A large number of racks 14 are usually arranged on the transport table 12, and each rack 14 is transported in order on each transport path.

  The center position in the X transport path 20 is a reference position for taking in and out the sample container. The guide block 30 is provided so that the center of the guide block 30 coincides with the reference position. In the vicinity of the guide block 30, a pressing unit 32 that exerts a pressing action on the rack 14 is provided. On the X transport path 20, the rack 14 is transported in the X direction by the transport mechanism 52 so that the longitudinal direction of the rack 14 is parallel to the X direction. The transport mechanism 52 has a claw member 54. As will be described later, the claw member 54 is transported in the X direction while the tip of the claw member 54 is hooked on the protruding portion of the rack 14. Thereby, the rack 14 is conveyed in the X direction. The claw member 54 is configured so as not to hinder the operation of each opening / closing mechanism even in a state where the tip end portion is engaged with the rack 14.

  Also in the X transport path 50 on the opposite side, a transport mechanism 56 is provided to transport the rack 14 in the X direction. The transport mechanism 56 has basically the same configuration as the transport mechanism 52. A member corresponding to the guide block 30 is not provided on the X transport path 50, but a pressing unit having the same configuration as the pressing unit 32 is disposed.

  FIG. 3 shows a perspective view of a part of the transfer table. As described above, the rack 14 is transported in the Y direction on the Y transport path 16. In that case, the rack 14 moves in parallel so that the short direction of the rack 14 faces the Y direction. In the X transport path 20, the rack 14 is transported so that the longitudinal direction of the rack 14 faces the X direction. When the sample container is put in and out, in order to make the longitudinal direction of the rack 14 exactly coincide with the X direction, the above-described pressing unit 32 presses one leg portion of the rack 14 toward the guide block 30 side.

  A guide block 30 is provided at a reference position on the X transport path 20. In FIG. 3, the head that forms a part of the lifting mechanism is inserted into the opening of the guide block 30. That is, in FIG. 3, the head is in a floating state. The transport mechanism 52 has the claw member 54 as described above.

(B) Rack and adapter (Figure 4-17)
Next, the rack and adapter will be described in detail.

  FIG. 4 is a perspective view showing the rack 14 as viewed obliquely from above. The rack 14 holds a plurality of sample containers aligned in the longitudinal direction (X direction in FIG. 4). The rack 14 includes a rack body 58 and a plurality of adapters 60 that are detachably attached to the rack body 58. The rack 14 is provided with a plurality of accommodating portions 24, and an adapter 60 is provided for each accommodating portion 24. As will be described in detail later, the adapter 60 includes an annular frame 66 and a pair of arms 70 and 72 extending downward therefrom. The arm 70 and the arm 72 constitute the above-described opening / closing mechanism as a whole.

  The rack 14 has a pair of leg portions 64A and 64B spaced apart in the short direction. The individual leg portions 64A and 84B each extend in the longitudinal direction. Between the pair of leg portions 64A and 64B, a hollow portion for allowing the guide block to pass therethrough is formed. Both the front side and the rear side of the cavity are openings. A protruding portion 58 </ b> A is provided at the front end of the rack 14. The tip of the claw member is inserted into the rack opening of the protruding portion 58A. In addition to the longitudinal direction, it is also possible to use a rack in which a plurality of accommodating portions are arranged in the lateral direction.

  FIG. 5 is a perspective view showing the rack 14 as viewed obliquely from below. As described above, the rack body has a pair of leg portions 64A and 64B. The adapter 60 has an annular frame 66 and a pair of arms 70 and 72 that are spaced apart in the short direction. The pair of arms 70, 72 has a pair of lower end structures 74, 76 that constitute the main part of the opening / closing mechanism 26.

  FIG. 6 shows the rack main body 58 as viewed obliquely from above. The rack body 58 has a plurality of receiving holes 24A aligned in the longitudinal direction. In each accommodation hole 24A, one side structure and the other side structure are provided on both sides in the short direction. Since they have a symmetric form, the form will be described by taking a side structure as a representative. A side plate 78 extending in the vertical direction is provided on one side of the accommodation hole 24A. A rib configured as a wall thickness exists between two adjacent side plates 78 or straddling them. A substantial portion of the side plate 78 is configured as a thin portion. An upper opening 82 is provided in the upper part of the side plate 78, and a lower opening 84 is formed in the lower part of the side plate 78. Each of the upper opening 82 and the lower opening 84 is an opening that penetrates in the lateral direction. FIG. 7 shows the rack main body 58 as viewed obliquely from below.

  Next, the configuration and operation of the adapter will be described with reference to FIGS.

  FIG. 8 shows the adapter 60 viewed from obliquely above. As described above, the adapter 60 includes the annular frame 66 and the pair of arms 70 and 72 extending downward therefrom. The annular frame 66 has a ring shape corresponding to the accommodation hole, and has ribs and the like. The pair of arms 70 and 72 are separated in the short direction (Y direction in FIG. 8), and the sample container is accommodated therebetween. The arm 70 and the arm 72 are symmetrical to each other. Here, attention is paid to the arm 72. It has an upper end portion 86 connected to the annular frame 66, a waved portion 88 as a bent portion provided below the upper end portion 86, and a lower end portion 90 provided below the upper end portion 86. The lower end portion 90 has a hook portion 92 that is bent inward. An attachment, which will be described later, is attached to each hook portion 92 of the two arms 70, 72, thereby forming two lower end structures 74, 76 which will be described in detail later. The wavy portion 88 has a bellows shape. When an opening force outward in the horizontal direction is applied to the hook portion 92, the arm 70 bends around the wavy portion 88 by the force. At the same time, the arm 72 is similarly deformed. As a result, the two arms 70 and 72 are opened in the lateral direction. Since the wave-like portion 88 is configured as an elastic portion, and exhibits an elastic restoring force, when the horizontal opening force does not reach the two arms 70 and 72, the two arms 70 are caused by the elastic restoring force. , 72 return to the original form. That is, the two arms 70 and 72 are closed.

  FIG. 9 shows the adapter viewed from obliquely below. As described above, the adapter 60 has two arms 70 and 72, each having a hook portion 92. In this embodiment, the hook portion 92 has a hook base 92A that is a bent portion and constitutes a pedestal surface. The hook base 92A has a U-shape when viewed from above. The hook base 92A is provided with a contact 92D extending in the vertical direction. The contact 92D has a semi-cylindrical shape or a D-shape when viewed from above. When the contact 92D comes into contact with the slope formed on the guide block during the movement of the rack, an opening force outward in the horizontal direction is generated. A connector 92E is provided below the hook base 92A, and is fixed to the contact 92D. The connector 92D has a rectangular shape, and the attachment is detachably attached using the connector 92D. An L-shaped groove 92 </ b> F having an L-shape when viewed from the X direction is formed at the lower ends of the arms 70 and 72.

  FIG. 10 is a first perspective view of an attachment attached to the main body of the adapter. FIG. 10 shows a state in which the attachment 96 is viewed obliquely from above.

  In FIG. 10, the attachment 96 has a connection structure 98 that is connected to the hook portion shown in FIGS. 8 and 9. The connection structure 98 constitutes a connection end, and specifically, the connection structure 98 includes a lower plate 106 and an upper plate 108. A slit 110 is provided between them, and the connector shown in FIG. 9 is inserted into the slit 110. In FIG. 10, a projection (not shown) is provided in the slit 110, and the projection fits into the opening of the connector. Thereby, the attachment 96 is attached to the main body of the adapter.

  A seat plate 102 as a movable piece is provided above the connection structure 98. The seat plate 102 constitutes a contact end portion, and its upper surface functions as a seat surface. That is, the lower surface of the sample container is placed on the seat plate 102.

  A C-shaped arm 100 having a C-shape is provided between the connection structure 98 and the seat plate 102. The C-shaped arm 100 functions as an elastic deformation portion. In the natural state, the seat plate 102 is inclined. When a pressing force is applied to the seat plate 102 from above via the sample container, the C-shaped arm is elastically deformed so as to absorb the pressing force. In this state, the seat plate 102 is in a horizontal posture.

  At the right end and the left end of the seat plate 102, a pair of stopper pieces 104A and 104B extending downward are provided. As the seat plate 102 moves up and down, the pair of stopper pieces 104A and 104B move up and down. Therefore, when the seat plate 102 sinks downward, the stopper pieces 104A and 104B also move downward, and their lower end positions are further lowered. As a result, as will be described later, even if the lower end structure tries to move outward in the horizontal direction, the stopper pieces 104A and 104B collide with the adapter body, and the lower end structure is prevented from opening.

  FIG. 11 shows a second perspective view of the attachment 96. That is, FIG. 11 shows the attachment 96 as viewed from obliquely below. As described above, the attachment 96 includes the connection structure 98, the C-shaped arm 100, and the seat plate 102. A pair of stopper pieces 104 </ b> A and 104 </ b> B are provided at the right end and the left end of the seat plate 102. It is also possible to integrally form the main body and attachment of the adapter.

  The operation of the adapter will be described with reference to FIGS. FIG. 12 is an explanatory diagram for explaining the operation of the adapter. An adapter is attached to the rack body. The arms 70 and 72 have lower end structures 74 and 76. Each of the lower end structures 74 and 76 includes an attachment 96. In FIG. 12, the attachment in the inclined posture before deformation is indicated by reference numeral 96A, and the attachment in the horizontal posture after deformation is indicated by reference numeral 96B.

  In a state where the sample container is dropped into the housing portion, the seat plates of the pair of attachments abut against the lower surface of the sample container. Thereby, the sample container is supported from below. In this case, as indicated by reference numeral 96A, the seat plate of each attachment is in a floating state, and the two arms are in a closed state.

  In such a closed state, when an excessive pressing force 111 is applied from the upper side to the lower side with respect to the sample container, the attachment is deformed by the pressing force 111 as indicated by reference numeral 96B. Specifically, the seat plate in each attachment sinks downward and assumes a horizontal posture. At the same time, the stopper pieces 104A and 104B attached to the seat plate move downward. On the other hand, the two arms 70 and 72 tend to move away from each other, that is, in the opening direction, by the pressing force from above (see reference numeral 112). However, since the stopper pieces 104A and 104B sink downward together with the seat plate, the lower end structures 74 and 76 pass through the lower opening formed in the rack body and come out to the outside. The stoppers 104A and 104B collide with the inner surface of 64B, and such opening movement 112 is prevented. That is, during the opening movement by the pressing force, the lower end structures 74 and 76 do not come out of the rack body through the lower opening, and the holding of the sample container is maintained. When a liquid sample containing a radioactive substance is stored in the sample container, it is possible to reliably prevent such a sample container from dropping from the rack.

  On the other hand, when the pressing force 111 is not generated, that is, only the force due to the weight of the sample container is applied to the attachment. In this case, as indicated by reference numeral 96A, the seat plate maintains the floating posture in each attachment. In such a case, since the lower end position of the stopper pieces 104A and 104B is at the rising end, when an opening force to the outside in the horizontal direction is applied to the lower end structures 74 and 76, the respective lower end structures 74 are provided. 76 are allowed to go out of the rack body through a lower opening formed in the rack body. That is, the pair of arms is allowed to deform from the closed state to the open state.

  As described above, according to the present embodiment, the lower end structures 74 and 76 are allowed to come out of the rack body only when an appropriate force is applied from the guide block to the outside in the horizontal direction. On the other hand, when an abnormal force is generated in the vertical direction, the pair of arms can be prevented from changing from the closed state to the open state by the action of the stopper pieces 104A and 104B.

  FIG. 13 shows a cross-sectional view of the rack. Specifically, a state where an adapter is attached to the rack body is shown. In the arms 70 and 72, a part of the wave-like portion 88 is accommodated in the upper opening indicated by R1. The entire arms 70 and 72 except for the lower end structures 74 and 76 are substantially within the wall thickness D1 of the rack body. That is, in the state before the arms 70 and 72 are deformed, the arms 70 and 72 do not have a portion protruding outward from the rack body. As a result, even when a specific rack is moved in the longitudinal direction in the aligned state of a plurality of racks, there is no catching that inhibits the movement.

  In a normal closed state where no pressing force is generated from above, when the opening force indicated by reference numeral 114 is applied to the lower end structures 74 and 76 by contact with the guide block, the lower end structures 74 and 76 are separated from each other. Moving in the direction, they project out of the rack through a pair of lower openings.

  In FIG. 13, R3 indicates the vertical size of the lower opening 84. R2 indicates the vertical size of the main area of the lower opening 84, and R4 indicates the vertical size of the subarea of the lower opening. When the opening force 114 is applied in the closed state, the lower end structures 74 and 76 pass through the pair of lower openings. On the other hand, when a pressing force is generated from above, the plurality of stopper pieces are lowered downward, and even if the lower end structures 74 and 76 try to move away from each other, the plurality of stopper pieces collide with the inner surfaces of the pair of leg portions. , Such opening movement is prevented. This operation will be further described with reference to FIGS.

  FIG. 14 shows a state where the stopper piece is not operating. That is, in such a case, in the lower end structure 76, the stopper pieces 104A and 104B are in a floating position, and between the lower side level of the main area in the lower opening 84 and the lower end level of the stopper pieces 104A and 104B. There is a gap h1. Therefore, the lower end structure 76 can go outside through the lower opening 84.

  On the other hand, FIG. 15 shows the operating state of the stopper piece. That is, when the pressing force 114 is applied to the lower end structure 76, the stopper pieces 104A and 104B are lowered downward, and the lower end level is further lower than the lower side level of the main area in the lower opening 84. The overlapping portion at that time is indicated by Δh in FIG. In this state, even if the lower end structure 76 tries to go outside through the lower opening 84, the stopper pieces 104A and 104B collide with the inner side of the leg portion 64B, and the movement is reliably prevented.

  FIG. 16 shows a state in which the sample container 22 is accommodated in the rack. (A) shows a normal state, and (B) shows a state where a pressing force is generated. Reference numerals 74A and 76A indicate lower end structures in a floating state before deformation, and reference numerals 74B and 76B indicate lower end structures in a lowered state after deformation.

  FIG. 17 shows the arm 72 in an open state. As the rack advances in the X direction, a horizontal opening force 116 is applied to the lower end structure by contact with the guide block. Thereby, as described above, the entire arm 72 including the lower end structure performs an opening motion. The lower end structure in the open state is indicated by reference numeral 76C. In this case, the arm 72 is bent and deformed around the wavy portion of the arm 72. A discharge amount from the rack side of the entire arm 72 is indicated by reference numeral 118. In such an open state, since the supporting action on the lower surface of the sample container 22 disappears, if there is no member below the sample container 22, the sample container 22 is naturally lowered downward as indicated by reference numeral 120. Fall. In the present embodiment, the sample container 22 is placed on the head in such an open state.

  When the sample container is transferred from the rack to the head, the pair of lower end structures are moved from the position immediately below the sample container to the retreat position outside in the horizontal direction. Subsequently, after the sample container after the sample measurement is returned into the sample container, the pair of arms returns to the original shape. That is, the pair of lower end structures enter the lower side of the sample container. Thereby, the sample container 22 is supported by the pair of lower end structures, and the sample container 22 is held.

  As described above, according to the present embodiment, the opening / closing mechanism can be shifted from the closed state to the open state at an appropriate timing in each housing portion. Further, when an abnormal pressing force in the vertical direction is generated instead of an appropriate opening force, unnecessary opening movement is reliably prevented by the action of the plurality of stopper pieces described above. Thereby, the sample container can be prevented from falling off. Furthermore, each arm is provided with an elastic deformation portion, and each arm can be returned to its original shape by an elastic restoring force exerted there. Therefore, the transition from the open state to the closed state can be performed by the action of each arm itself. According to this embodiment, a dedicated drive source and a dedicated control unit are not required for opening the pair of arms. Further, a dedicated drive source and a dedicated control unit are not required for the pair of closing operations. Using a part of the rack transport force, the pair of arms can be opened and closed in synchronization with the rack transport.

(C) Guide block (Figs. 18-23)
FIG. 18 shows a part of the transfer table as an enlarged top view. That is, FIG. 18 shows the guide block 30 and the pressing unit 32.

  The guide block 30 is fixedly disposed on the top frame 122. The top frame 122 corresponds to a top plate of a structure including a hoistway. The guide block 30 includes a lower layer 124, an upper layer 126, a front support plate 130 and a rear support plate 132. However, they are integrated. Each of the lower layer 124 and the upper layer 126 has a flat plate shape extending in the horizontal direction. The front support plate 130 and the rear support plate 132 have a form that stands upward. An opening 128 is formed in the center of the guide block 30. The opening 128 has a circular or elliptical shape. The opening 128 constitutes the upper end portion of the hoistway, and the head 44 is inserted into the opening 128 in FIG. The width W1 of the lower layer 124 in the Y direction is substantially the same as the gap between the pair of legs of the rack. Strictly speaking, the width W1 is slightly smaller than the gap. A pair of inclined surfaces 134 are formed at the front end portion (left end portion in FIG. 18) and rear end portion (right end portion in FIG. 18) of the lower layer 124, respectively. That is, the lower layer 124 has a tapered shape in both directions. The width of the front surface and the rear surface of the lower layer 124 in the Y direction is W2, and W1> W2. Since the pair of slopes 134 are formed at the front end portion in this way, even if the position shift in the Y direction occurs on the rack side in the process of the guide block 30 entering between the pair of leg portions, the position shift is eliminated. Is possible. Incidentally, a pair of inclined surfaces is also formed at the rear end portion of the lower layer 124. Thereby, even when it is necessary to return and transport the rack, the guide block 30 can be smoothly inserted into the lower part from the rear side of the rack.

  The upper layer 126 is a portion laminated on the lower layer 124, and a pair of inclined surfaces 136 are formed at a relatively long distance in the front portion of the upper layer 126. The width of the front end surface of the upper layer 126 in the Y direction is W3. Here, W1> W2> W3. The pair of inclined surfaces 136 continuously change the width of the upper layer 126 in the Y direction from W3 to W1 along the X direction.

  When the pair of contacts of the pair of opening / closing mechanisms abut against the pair of slopes 136 and the rack moves forward while maintaining the contact state, the pair of slopes 136 act on the pair of contacts. A horizontal outward opening force is applied. As a result, the adapter changes from the closed state to the open state. In the present embodiment, in the upper layer 126, a pair of inclined surfaces is also formed on the rear portion thereof. With the pair of slopes on the rear side, the return from the open state to the closed state can be performed gently, and a sudden change in the opening / closing mechanism can be prevented.

  In the present embodiment, the pair of front slopes 136 and the pair of rear slopes formed on the upper layer 126 are symmetrical, but they may be configured asymmetrically. .

  The guide block 30 is roughly divided into a front side configuration, an intermediate configuration, and a rear configuration from the upstream side to the downstream side in the X direction. Here, paying attention to the upper layer 126, the front side form of the upper layer 126 exhibits a function of changing the opening / closing mechanism from the closed state to the open state. The intermediate form of the upper layer 126 exhibits the function of maintaining the open state. The rear form of the upper layer 126 exhibits the function of returning the opening / closing mechanism from the open state to the closed state. The guide block 30 as a whole has a symmetrical form with respect to a center line passing through the center position in the Y direction and parallel to the X direction. The rack is centered (positioning in the Y direction) in a state where the guide block 30 is inserted between the pair of legs of the rack. Thereby, it is possible to easily match the center position of the opening 128 with the center position of the sample container to be measured or the sample storage section that stores the sample container in the Y direction.

  In this embodiment, the guide block 30 is fixed on the top frame 122 of the structure including the sample measurement chamber and the lifting mechanism as described above. The guide block 30 is arranged with a certain degree of freedom in the horizontal direction with respect to the transport table. In other words, if the guide block 30 is properly positioned, it is not necessary to strictly position the transport table itself. For example, even if a processing error or assembly error occurs in the transfer table, if the error is within an allowable range, such an error is a problem when the sample container is transferred between the rack and the lifting mechanism. Never become.

  Due to the action of the pair of inclined surfaces 136 formed on the front side of the guide block, the supporting action of the sample container by the opening / closing mechanism disappears in the process of changing the opening / closing mechanism from the closed state to the open state. If the above support function disappears before the bottom surface of the sample container is sufficiently placed on the head 44, the sample container may drop off or change its posture. Therefore, the front support plate 130 is provided in the guide block 30 of the present embodiment. The front support plate 130 has a form protruding upward from the upper surface of the upper layer 126. It exhibits the function of supporting the sample container temporarily and supplementarily in a state where the support function of the sample container by the opening / closing mechanism has disappeared. The front end portion and the rear end portion of the front support plate form a shoulder-decreasing tapered surface, and the corner portion of the sample container is prevented from being caught by the front support plate. Thus, by preparing an auxiliary support on the front side of the opening 128, it is possible to prevent the sample container from dropping off or changing its posture, and the sample container can be smoothly transferred from the rack to the upper surface of the head. Is possible.

  In the present embodiment, a rear support plate 132 is provided on the rear side of the opening 128. The rear support plate 132 has the same form as the front support plate 130. By this rear support plate 132, the support function by the upper surface of the head 44 is partially lost after the measured sample container is returned to the accommodating portion and before the opening / closing mechanism returns from the open state to the closed state. In such a case, it is possible to temporarily and auxiliaryally support the sample container by the upper surface of the rear support plate 132 to prevent the sample container from dropping off or changing its posture.

  As described above, according to the guide block 30 according to the present embodiment, it is possible to apply an opening force outward in the horizontal direction to each opening / closing mechanism using a part of the rack transport force. Therefore, there is no need to provide a dedicated drive source or drive mechanism for generating such an opening force, so that an advantage that the apparatus configuration can be simplified can be obtained. In addition, the operation timing of each opening / closing mechanism can be naturally adjusted with respect to the reference position, and there is an advantage that it is not necessary to perform opening / closing control by the control unit. Further, since the guide block 30 is installed with the reference position itself as a reference, the rack can be centered simply by inserting the guide block 30 into a pair of legs of the rack. That is, it is possible to properly position the sample container or the container having the sample container with respect to the reference position by simply inserting the guide block 30 into the lower portion of the rack.

  In FIG. 18, in addition to the guide block 30, a pressing unit 32 is also shown. Here, the configuration of the pressing unit 32 will be described. The configuration and operation of the pressing unit 32 will be described later with reference to FIGS.

  In FIG. 18, the pressing unit 32 is a unit for optimizing the position and posture of the rack by applying a pressing force to the outside of the rack or to the rack. In this embodiment, the pressing unit 32 has a pair of rollers 138 and 140 that contact the rack and apply a pressing force. The rotation center of the roller 138 is set at a point away from the reference position 143 by a certain distance 144 in the upstream direction, that is, the front side in the X direction. The rotation center of the roller 140 is set at a point away from the reference position 143 by a fixed distance 144 in the X direction.

  As will be described later, the roller 138 is rotatably attached to the end of one movable plate, and the roller 140 is attached to the end of the other movable plate. A common rotation axis of these movable plates is indicated by reference numeral 142. In the Y direction, the rotation centers of the rollers 138 and 140 are set far from the guide block 30 with respect to the rotation center of the common rotation shaft 142. That is, a negative offset is given to the rotation center.

  A reference surface is formed on the guide block 30 in order to optimize the position and posture of the rack in cooperation with the pressing unit 32. Specifically, reference surfaces 124A and 126A are formed. The reference surface 124A is one side surface in the lower layer 124, and the reference surface 126A is one side surface in the upper layer 126. In the present embodiment, these reference surfaces 124A and 126A are surfaces parallel to the X direction, and are each a vertical surface. Of the two reference surfaces 124A and 126A, the reference surface 124A is larger in the X direction. When the guide block enters between the pair of legs of the rack, the pair of rollers 138 and 140 are pressed against the outer surface of one leg (the leg on the pressing unit 32 side) of the pair of legs. . Thereby, the inner surface of one leg part closely_contact | adheres with respect to the reference surfaces 124A and 126A. The reference surface is a vertical surface parallel to the X direction, and the inner surfaces of the pair of leg portions are vertical surfaces parallel to the longitudinal direction. Therefore, when the inner surface is in close contact with the reference surface, the X direction and the longitudinal direction of the rack Become parallel. At the same time, the rack is positioned at a predetermined position in the Y direction. As a result, the position and posture of the rack are optimized.

  In the initial state of the rollers 138, 140, in the present embodiment, a constant gap ΔW is generated between the rollers 138, 140 and the reference surface 124A. Such a gap ΔW is provided as necessary. In the present embodiment, the angle θ1 for receiving the tip portion of one leg is increased by such a gap ΔW and the minus offset of the roller 138. Alternatively, the resistance in accepting it is reduced. Due to the action of the slope 134 and such an opening angle θ1, even if the rack is misaligned in the Y direction, one leg can be smoothly inserted between the reference surface 124A and the roller 138. Is possible.

  As described above, in the state where the guide block 30 is inserted between the pair of legs, a pressing force is applied from the rollers 138 and 140 to the outer surface of one leg. Thereby, the inner surface of one leg part closely_contact | adheres to reference surface 124A, 126A. Therefore, it is possible to optimize the position of the rack (particularly the position in the Y direction) and the posture with a simple mechanism. In the present embodiment, since the rollers 138 and 140 are provided as the pressing members, the sliding resistance can be reduced even when the rack is fed forward.

  In the present embodiment, the pressing unit 32 presses the rack against the guide block 30 arranged in an appropriate position and orientation. Therefore, even if there is a processing error or an assembly error in the transport table, the rack is moved to the reference position. Can be positioned correctly. In this embodiment, since the rollers 138 and 140 are provided at equal intervals in the front and rear direction from the reference position in the X direction, it is possible to apply a force evenly on both sides of the reference position to the rack. Even if the rack is warped, in the present embodiment, since the pressing is performed within the range in the X direction where the guide block 30 exists, the rack is warped regardless of the warp. It is possible to properly position the sample container that is the measurement target.

  The operation of the guide block will be described subsequently with reference to FIGS.

  FIG. 19 shows a cross-sectional view of the guide block 30. As described above, the guide block 30 includes the lower layer 124, the upper layer 126, the front support plate 130, and the rear support plate 132. In FIG. 19, each member is shown as a separate body, but in the present embodiment, they are integrated. The front support plate 130 has an upper surface 130B and slopes 130A and 130C provided in front and rear thereof. The rear support plate 132 has the same form as the front support plate 130.

  An opening 128 penetrating vertically is formed at the center of the guide block 30. In FIG. 19, the head 44 is inserted into the opening 128. The head 44 has a placement surface 44A as its upper surface, and the sample container 22 is placed on the placement surface 44A. As shown in FIG. 19, the sample container 22 is supplementarily supported by the upper surface 130 </ b> B of the front support plate 130 during the transition from the closed state to the open state in the opening / closing mechanism. As a result, the sample container 22 can be smoothly transferred onto the placement surface 44A. At the time of transfer, it is desirable to substantially align the level of the mounting surface 44A of the head 44 with the level of the upper surface 130A. However, one may be slightly higher than the other and slightly lower.

  FIG. 20 shows a state in which the rack 14 is put into the X transport path. As described above, the rack 14 has the protruding portion 58A, and a part of the claw member 54 included in the transport mechanism 52 is inserted into the protruding portion 58A. A guide block 30 is provided in the center of the X conveyance path, and a pressing unit 32 is provided in the vicinity thereof.

  FIG. 21 shows a state in which the rack 14 has advanced on the X transport path. More specifically, FIG. 21 shows a state in which the leading sample container is positioned with respect to the opening of the guide block 30. In this state, the pressing unit 32 functions to optimize the position and posture of the rack 14.

  FIG. 22 shows a part of the contents shown in FIG. 21 as an enlarged view. The rack 14 has a plurality of accommodating portions, and adapters 60 are attached to the respective accommodating portions. The adapter 60 has an opening / closing mechanism 26. In FIG. 22, only one opening / closing mechanism 26 is open. In order to form such an open state, the guide block 30 functions. As described above, the guide block 30 includes the lower layer 124, the upper layer 126, and the like. The guide block 30 is inserted between a pair of legs in the rack 14. In FIG. 22, only the other leg portion 64B is shown. A pair of slopes 134 are formed on the rear side of the lower layer 124, and a pair of slopes 136 are formed on the rear side of the upper layer 126. A pair of slopes are also formed on the front portions of the lower layer 124 and the upper layer 126, respectively. In the state shown in FIG. 22, a pressing force in the Y direction is exerted on the rack by the pressing unit 34, whereby the position and posture of the rack 14 are optimized and stabilized.

  23 is a YZ sectional view of the portion shown in FIG. In FIG. 23, a cross section of the guide block 30 is included. As described above, each storage section in the rack 14 is provided with the adapter 60, and the sample container 22 is stored therein. In the state shown in FIG. 23, the opening / closing mechanism 26 is in an open state, that is, the lower end structures 74 and 76 protrude from the rack body to both sides in the horizontal direction. Such an action is caused by a pair of contacts of the lower end structures 74 and 76 coming into contact with a pair of inclined surfaces in the guide block 30.

  In FIG. 23, a pressing force is applied to the rack 14 from the pressing unit 32, so that the position and posture of the rack 14 are stabilized. A hoistway 28 is formed below the guide block 30. As already described, the lifting mechanism has the shaft 43 and the head 44. They move up and down in the hoistway 28.

  As shown in FIG. 23, a shutter mechanism 42 is provided below the guide block 30 so as to cross the hoistway 28. The shutter mechanism 42 will be briefly described here. The shutter mechanism will be described later with reference to FIGS.

  The shutter mechanism 42 includes an upper shutter mechanism 42A and a lower shutter mechanism 42B. The upper shutter mechanism 42A is a mechanism for shielding extraneous radiation from above, and the lower shutter mechanism is a mechanism for shielding extraneous light entering through the hoistway 28.

  Specifically, the upper shutter mechanism 42A has a lead block 148, and the lead block 148 crosses the hoistway 28 and covers the upper side of the sample measurement chamber, so that external radiation toward the sample measurement chamber through the hoistway 28 ( Especially cosmic rays etc. are shielded. Portions other than the hoistway 28 in the sample measurement chamber are basically covered with a shielding member. However, for the purpose of shielding cosmic rays, it may be possible to omit the arrangement of the shielding member below the sample measurement chamber.

  The upper shutter mechanism 42A has a tube guide 146. The tube guide 146 is positioned in the hoistway 28 when the lead block 148 is in the retracted position, and in this state, guides the head 44 and the sample container 22. Demonstrate. In a state where the lead block 148 has advanced, the tube guide 146 moves to a position where it is retracted from the hoistway 28. The tube guide 146 is a hollow member such as a sleeve, and has a centering function as will be described later.

  The lower shutter mechanism 42 </ b> B includes a light shielding plate 150 and a slit structure 230. When the light shielding plate 150 advances, a part of the light shielding plate 150 is inserted into the slit of the slit structure 230, and thereby the light shielding plate 150 is disposed so as to cross the hoistway 28. In this state, extraneous light from above is blocked by the light shielding plate 150.

  As described above, according to the guide block, the opening / closing mechanism can be opened using a part of the driving force for transporting the rack in the X direction. Therefore, there is an advantage that it is not necessary to provide a dedicated drive source for such an opening operation. Further, when the guide block is inserted between the pair of legs, the position of the rack can be optimized in the Y direction, that is, centering can be naturally performed. Further, since the guide block of the present embodiment has a member that supports the lower side of the sample container in an intermediate state between the open state and the closed state, the guide block in the middle of the operation of the opening / closing mechanism. It is possible to prevent the posture of the sample container from being disturbed. Furthermore, the guide block 30 according to the present embodiment has a reference surface that functions together with the pressing unit, and by their cooperation, the position and posture of the rack can be easily optimized.

(D) Pushing unit (Figs. 24-27)
FIG. 24 is a perspective view showing the operating state of the pressing unit 32. When the rack 14 is transported in the X direction, the pressing unit 32 exerts its function on the left hand side in the traveling direction of the rack 14. The pressing unit 32 includes a pair of rollers 138 and 140 as described above. A first movable plate 154 and a second movable plate 156 are provided to give an elastic biasing force to them.

  FIG. 25 is a first perspective view of the pressing unit. The first movable plate 154 is an upper plate, and the second movable plate 156 is a lower plate. The plates 154 and 156 perform a rotational motion around the common rotational shaft 142. The first movable plate 154 has a crank shape, and the second movable plate 156 also has a crank shape.

  The first movable plate 154 includes a front bent portion 154a, an intermediate portion 154b, and a rear bent portion 154c. A roller 138 is rotatably attached to the end of the front bent portion 154a. The second movable plate 156 includes a front bent portion 156a, an intermediate portion 156b, and a rear bent portion 156c. A roller 140 is rotatably provided at the end of the front bent portion 156a. The pin 160 is a regulating member for preventing the first movable plate 154 from rotating more than necessary in the counterclockwise direction when viewed from above. Similarly, the pin 158 is a regulating member for preventing the second movable plate 156 from rotating more than necessary in the clockwise direction when viewed from above.

  FIG. 26 shows a second perspective view of the pressing unit. As described above, the first movable plate 154 has the rear bent portion 154c, and the motion shaft 164 is provided at the end thereof. The second movable plate 156 has a rear bent portion 156c, and a motion axis 166 is provided at an end thereof. A spring 162 is provided between the motion shaft 164 and the motion shaft 166 in a state of being extended more than the natural state. That is, an elastic restoring force is always generated in the spring 162, and this is transmitted to the pair of rollers 138 and 140 via the first movable plate 154 and the second movable plate 156. This generates a pressing force against the rack. However, as described above, the rotation angle in the initial state of each of the plates 154 and 156 is restricted by the pair of restriction pins. Thereby, the gap ΔW shown in FIG. 18 is set.

  FIG. 27 is a diagram illustrating the operation of the pressing unit. A minus offset 168 is set with respect to the rotation center of each roller 138,140 with respect to the center of the common rotation shaft 142. That is, the rotation center of each roller 138,140 with respect to the center of the rotation shaft 142 is in the Y direction. The shift is far from the guide block. A spring 162 is disposed between the first movable plate 154 and the second movable plate 156. When the rollers 138 and 140 move away from the guide block, the spring 162 is further stretched and the reaction force thereof is increased. As a result, a stronger elastic biasing force is generated. Accordingly, a pressing force 172 that presses the rollers 138 and 140 toward the rack is generated.

  In the present embodiment, since the spring 162 is disposed between the two movable plates, a weak pressing force F1 can be generated in a state where the leg portion enters only between the roller 138 and the reference surface, When the leg portion enters between the two rollers 138 and 140 and the reference surface, it is possible to generate a strong pressing force F2 together with the two rollers 138 and 140. That is, it is possible to exert stepwise power according to the situation of entry. In the initial state where the leg portion does not enter between the roller 138 and the reference surface, a gap ΔW is formed between them, so that compared with the case where the leg portion is not formed, the leg portion is moved to the leg portion when the leg portion enters. The reaching force (reaction force, impact force) can be reduced.

  According to the pressing unit as described above, as described with reference to FIG. 18, the outer surface of one leg portion is in close contact with the reference surface of the guide block so that the inner surface of the one leg portion is in close contact. It is possible to give a pressing force. Further, in this case, since the rollers 138 and 140 are provided so that the minus offset 168 is generated, an advantage that the opening angle for receiving one leg portion can be relatively large as shown in FIG. 18 can be obtained. . In other words, the first movable plate can be smoothly rotated. Further, in the present embodiment, since the spring is disposed between the two movable plates, the pressing force can be increased step by step according to the sandwiched state.

(E) Structure below the conveying surface (FIGS. 28-33)
Next, the structure below the conveyance surface will be described. FIG. 28 shows a state in which the rack 14 is put into the X transport path. In that state, the head 44 is inserted into the opening of the guide block 30, that is, the head 44 is in the uppermost position. A sample measurement chamber 34 is provided immediately below the opening, and a pair of photomultiplier tubes 174 and 176 constituting a measurement unit are provided on both sides thereof. A shield 178 is provided so as to enclose the entire sample measurement chamber 34 and the pair of photomultiplier tubes 174 and 176. The shield 178 is made of lead or the like, and shields radiation coming from the outside. However, shielding in the hoistway is performed by a shutter mechanism described later.

  FIG. 29 shows a state where the top sample container 36 is transferred onto the head 44. In this state, the opening / closing mechanism described above is opened by the action of the guide block.

  FIG. 30 shows a sample measurement state. The sample container 36 to be measured is arranged in the sample measurement chamber 34 by the action of the elevating mechanism 40, that is, in a state of non-contact with the pair of photomultiplier tubes 174 and 176. A sample container 36 is disposed. In the sample measurement state, the shutter mechanism operates so as to cross the hoistway 28. In FIG. 30, a lead block 148 is inserted so as to cross the hoistway 28. At the same time, a light shielding plate described later is inserted across the hoistway 28.

  FIG. 31 shows a YZ section of the sample measuring device. FIG. 31 shows a non-measurement state. In the figure, the head 44 is at the rising end position. The elevating mechanism 40 has a vertical plate 182, and a rail 184 is attached to the vertical plate 182. A slide block 186 is provided to be movable in the vertical direction with respect to the rail 184. The lower end of the shaft 43 is attached to the slide block 186. A head 44 is attached to the upper end of the shaft 43. The driving force of the motor 188 is transmitted to the slide block 186, which is driven in the vertical direction. Accordingly, the shaft 43 and the head 44 move in the vertical direction. The vertical plate 182 is connected to the base frame 181 and the base plate.

  A case described later is fixed on the base frame 181. A shield 178 is provided on the base plate 180 so as to enclose the sample measurement chamber 34 and the case. The shield 178 is made of lead or the like as described above.

  The shutter mechanism 42 includes an upper shutter mechanism 42A and a lower shutter mechanism 42B. The upper shutter mechanism 42 </ b> A includes a lead block 148 that shields extraneous radiation and a tube guide 146. The lower shutter mechanism 42B has a light shielding plate described in detail later.

  FIG. 32 shows an enlarged YZ cross section of the sample measuring device. FIG. 32 shows a sample measurement state. A sample container 36 is disposed in the sample measurement chamber 34. As described above, the shutter mechanism 42 includes the upper shutter mechanism 42A and the lower shutter mechanism 42B. The upper shutter mechanism 42 </ b> A has a lead block 148 and a tube guide 146. In FIG. 32, a lead block 148 is disposed across the hoistway. At the same time, a light shielding plate 150 is inserted across the hoistway. In such a state, extraneous radiation from above is shielded, and at the same time, extraneous light from above is shielded. This makes it possible to realize highly accurate sample measurement.

  FIG. 33 shows an enlarged view of the lower part of the sample measurement chamber. FIG. 33 shows a sample measurement state. The upper surface of the base frame 181 constitutes the reference level 206. That is, in the vertical movement control of the sample container 36, the reference level 206 becomes the origin position in the Z direction.

  A case 190 having a configuration for enclosing the sample container 36 is disposed on the base frame 181. A shield 178 is provided outside the case 190. An opening is formed at the center of the base frame 181, and the shaft 43 is inserted through the opening. The main body of the head 44 is attached to the upper end of the shaft 43. Specifically, a well 192 is formed in the main body of the head 44, and the upper end portion 43 </ b> A of the shaft 43 is inserted into the well 192. A ring-shaped stopper 194 is provided at the upper end portion 43 </ b> A, and a spring 196 is disposed between the stopper 194 and the bottom surface 192 </ b> A of the well 192.

  A top plate 194 is provided so as to cover the well 192. The top plate 194 is configured as a laminated body in the present embodiment, and includes at least a lower elastic sheet and an upper metal reflective layer. Of course, optical reflection may be caused by painting. The lower elastic sheet functions as a light shielding sheet. For example, as shown in FIG. 18 described above, the top plate 194 is attached to the main body of the head 44 using two screw members. Thereby, a favorable light-shielding state is formed.

  Since the spring 196 is provided at the upper end portion 43 </ b> A of the shaft 43, even if the shaft 43 is slightly lowered downward, the excess is absorbed by the spring 196. Therefore, it is easy to pull down the head 44 until the lower surface of the head 44 is firmly attached to the upper surface of the base frame 181, that is, the reference surface. Further, in such a close contact state, it is possible to form a good light shielding state as described below. Incidentally, a stopper 206 is fixedly disposed below the head 44 in the shaft 43, and even when the spring 196 changes from the compressed state to the extended state, the amount of change is regulated by the stopper 206. That is, the extension of the spring 196 is allowed until the stopper 206 contacts the lower surface of the head 44.

  Next, the light shielding structure (inner light shielding structure) will be described. The light shielding structure is a structure constructed across the upper surface of the base frame 181 and the lower surface of the head 44.

  A first ring groove 198 is formed on the upper surface of the base frame 181 so as to surround an opening through which the shaft 43 passes. Correspondingly, a first ring protrusion 202 is formed on the lower surface of the head 44. In a state where the head 44 is positioned at the lowest position, that is, the specified position, the first ring protrusion 202 enters the first ring groove 198, and a state in which both are fitted is formed. In that case, the shaft 43 is slightly lowered below the lowermost position of the head by a control unit (not shown). Thereby, the elastic action by the spring 196 is exhibited. That is, a force that presses the head 44 downward is generated by the spring 196. As a result, a good contact state is formed between the first ring groove 198 and the first ring protrusion 202. That is, a good light shielding state can be formed. In other words, it is possible to reliably prevent extraneous light from entering the sample measurement chamber along the outer surface of the shaft 43 and the upper surface of the base frame 181. Further, the fitting of the first ring groove 198 and the first ring protrusion 202 can provide a horizontal positioning action for the head 44. According to this, the sample container 36 is properly positioned in the sample measurement chamber. It is possible to decide.

  In the present embodiment, the outer light shielding structure is constructed outside the inner light shielding structure described above. Specifically, a second ring groove 200 is formed on the upper surface of the base frame 181 so as to surround the first ring groove 198. On the other hand, a second ring protrusion 204 is formed on the lower surface of the leg of the case 190 so as to surround the first ring protrusion 202. The second ring protrusion 204 enters the second ring groove 200 in an assembled state, and both are in a fitted state. Accordingly, it is possible to reliably prevent extraneous light from entering the sample measurement chamber from the periphery of the base frame 181 along the upper surface of the base frame 181.

  Extraneous light entering the head 44 along the outer surface of the shaft 43 is blocked inside the head 44. That is, the top plate 194 has a light shielding sheet, which is tightly fixed to the main body of the head 44, so that extraneous light is confined in the head 44. That is, the entry of extraneous light through the gap between the top plate 194 and the main body of the head 44 is prevented. In order to perform sufficient light shielding in the head 44, a sheet made of a black elastic body is preferably used as the light shielding sheet. Incidentally, the main body of the head 44 is formed of, for example, a hard resin. The base frame 181 is made of metal or the like. Case 190 is made of metal.

(F) Shading unit (Figs. 34-36)
FIG. 34 shows a first perspective view of the shutter mechanism 42. That is, in FIG. 34, the shutter mechanism 42 viewed from obliquely above is shown.

  As already described, the shutter mechanism 42 includes an upper shutter mechanism 42A and a lower shutter mechanism 42B. They are attached to a stationary structure. Specifically, fixed blocks 208 and 210 are provided in parallel to each other, and a shaft 212 and a guide member 214 are disposed between them. A block is slidably mounted on the shaft 212, and the block constitutes a part of the movable body 220. The guide member 214 constitutes a guide rail, and the roller 224 of the movable body 220 rotates on the guide member.

  A block base 218 extending in the horizontal direction is provided across the fixed block 208 and the fixed block 210. The block base 218 is a member corresponding to the top frame 122 shown in FIG. That is, the guide block 30 is fixed on the block base 218. The motor 226 constitutes a single drive source in the slide mechanism 182, and the feed screw 216 is driven by the motor 226. The feed screw 216 is a trapezoidal screw in this embodiment. A block (not shown) is connected to the trapezoidal screw 216, and the movable body 220 including the block moves in the horizontal direction by the rotation of the feed screw 216. The upper shutter mechanism 42A is attached to the movable frame of the movable body 220, and similarly, the lower shutter mechanism 42B is also attached to the movable frame 222.

  FIG. 35 shows a second perspective view of the shutter mechanism 42. That is, in FIG. 35, the shutter mechanism 42 is shown as viewed from obliquely below. The movable body 220 includes an upper shutter mechanism 42A and a lower shutter mechanism 42B. The lower shutter mechanism 42 </ b> B has a light shielding plate 150. The light shielding plate 150 is made of, for example, a thin metal plate, and examples of a material constituting such a metal plate include zinc and copper. It is desirable that the light shielding plate 150 is made of a metal having a light shielding function and a function of shielding braking radiation. Such bremsstrahlung is secondary radiation that occurs when extraneous radiation is blocked against the lead block.

  The light shielding plate 150 has a main body 150A forming a horizontal portion and a bent portion 150B connected to the main body 150A, and the bent portion 150B constitutes a vertical portion. Further, the bent portion 150B communicates with the attachment portion 150C, and the attachment portion 150C is fixed to the movable frame described above. An elastic block 228 is provided on the base end side of the light shielding plate 150 in the main body 150A. Specifically, the elastic body block 228 has a slit 228A penetratingly formed in the horizontal direction, and a part of the main body 150A, particularly a part of the base end is inserted into the slit 228A. The slit 228A and the main body 150A are not fixed to each other, and relative horizontal movement is allowed. The elastic body block 228 may be fixed to the movable frame, or it may be simply attached to the main body 150A. The elastic body block 228 is made of, for example, a rubber member. In FIG. 35, the slit structure (fixed structure) for receiving the main body 150A of the light shielding plate 150 is not shown.

  FIG. 36 shows a cross-sectional view of the shutter mechanism 42. As described above, the upper shutter mechanism 42 </ b> A includes the lead blocks and the tube guide 146 arranged in the horizontal direction. When the lead block is in the retracted position, the tube guide 146 is positioned on the hoistway, thereby exhibiting a centering action (alignment action) or the like on the sample container.

  Specifically, on the inner surface of the tube guide 146, the upper end portion is a paper surface 146A, and the lower end portion is also a tapered surface 146B. When the sample container moves from the upper side to the lower side due to these slopes, and when the sample container moves from the lower side to the upper side, even if there is a horizontal displacement in the sample container, the sample container is moved horizontally by the action of the slope. It is possible to position at an appropriate position in the direction. Of course, the alignment function for the head may be exhibited.

  Next, the lower shutter mechanism 42B will be described. FIG. 36 shows a slit structure 230. The slit structure 230 constitutes a part of the lower shutter mechanism 42B, and is a fixed structure. The slit structure 230 is roughly divided into an upper plate 232 and a lower plate 234, and a slit is formed therebetween. The periphery of the slit is sealed except for the entrance for receiving the light shielding plate 150, that is, the entrance of light from the outside into the slit is prevented.

  The light shielding plate 150 is in the retracted position in FIG. 36, and in this case, only the front end portion of the light shielding plate 150 enters the slit structure 230. However, the light shielding plate 150 is at a position completely removed from the hoistway.

  An elastic block 228 is attached to the base end side of the light shielding plate 150. The elastic body block 228 has a horizontal slit 228a through which the light shielding plate 150 passes. When the shutter mechanism 42 performs a shutter operation, the movable part in the upper shutter mechanism 42A and the movable part in the lower shutter mechanism 42B move from the retracted position to the front position. Thereby, the lead block is inserted on the upper side of the hoistway, and the light shielding plate 150 is inserted on the lower side thereof. Such a double shutter state shields extraneous radiation and simultaneously shields extraneous light. Incidentally, the slit structure 230 is fixed to the upper end of the case 190 described above.

  When the movable portion in the lower shutter mechanism 42B reaches the advance position, the end of the slit structure 230 is inserted into the recess 228B as a recess formed in the elastic block 228, and the end surface of the end Strongly hits the inner surface of the recess 228B. That is, both are in close contact with each other. Thereby, it is reliably prevented that extraneous light enters the slit through the slit entrance of the slit structure 230. There is a certain slack portion such as a vertical portion on the attachment end side of the light shielding plate 150, and when the light shielding plate 150 protrudes to the forward end, the reaction is absorbed on the base end side of the light shielding plate 150. Is possible.

  According to the shutter mechanism according to the present embodiment, it is possible to simultaneously shield radiation and light by using a single drive source and a single slide mechanism. Therefore, the mechanism can be simplified and the control can be simplified. Is possible. In addition, since the light shielding plate is composed of a member having an action of shielding or attenuating the braking radiation, even if the braking radiation is generated in the lead block, it can be effectively reduced from reaching the sample measurement chamber. Benefits are gained.

  Furthermore, an elastic block is provided on the base side of the light shielding plate, and the slit structure into which the light shielding plate enters and the elastic body block are in close contact with each other, so that intrusion of extraneous light into the slit structure is prevented. In addition to the extraneous light coming from above through the extraneous light, there is an advantage that the extraneous light entering from the surroundings can be effectively shielded. In this embodiment, since the sample measurement chamber is provided below the transfer table, that is, when the shutter mechanism is operated, there is no shaft in the hoistway, so that the configuration of the shutter mechanism can be simplified. Can also be obtained.

(G) Modification of adapter (FIGS. 37-40)
Next, a modified example of the adapter will be described with reference to FIGS.

  FIG. 37 is a first perspective view showing an adapter 236 according to the second embodiment. The adapter 236 has an annular frame 238 and a pair of arms 240 and 242 connected thereto. The arm 240 and the arm 242 have a symmetrical form. Therefore, the arm 242 is represented and described. The arm 242 has an upper part 242A, a wave-like part 242B, and a lower part 242C. A lower end structure 246 is configured in the lower portion 242C. Similarly, the arm 240 has a lower end structure 244.

  The lower end structure 244 and the lower end structure 246 have a symmetric structure. The lower end structure 244 includes a rib 248 protruding in the horizontal direction and a support plate 250 fixed thereto. The upper end portion 250a of the support plate 250 constitutes an inclined portion inclined inward. A reinforcing plate 252 extending from the arm body is connected to an intermediate position of the support plate 250.

  FIG. 38 shows a second perspective view of the adapter 236. As described above, the lower end structures 244 and 246 are formed on the respective arms.

  The operation of the lower end structures 244 and 246 will be described with reference to FIG. When the opening force 258 is applied to the outer side in the horizontal direction by contact with the guide block, the lower end structures 244 and 246 move outward in the horizontal direction. This is indicated by reference numeral 260. On the other hand, when the two arms 240 and 242 are in the closed state, when an excessive pressing force 254 is applied from above through the sample container, the upper end portion of the support plate falls inward as indicated by reference numeral 256. Deform. Such deformation absorbs all or the main part of the pressing force 254 from the upper side. That is, since the pressing force concentrates on the deformed portion of the lower end structures 244 and 246, the above-described opening movement of the two arms 240 and 242 does not occur.

  In the first embodiment described with reference to FIG. 12 and the like, the stopper connected to the deformed portion is used. However, in this embodiment, the pressing force from above using the deformed portion that falls and moves inward. Malfunction due to is prevented. In any embodiment, the deformation is effectively utilized.

  FIG. 40 shows a cross-sectional view of the rack. The adapter 236 is attached to the rack body 262. Reference numerals 240A and 242A indicate a state in which each arm is opened, and reference numerals 240B and 242B indicate a state in which each arm is closed. As described above, even if a pressing force is applied from above in such a closed state, the pressing force is absorbed by a part of the elastic deformation, and the opening movement of the pair of arms is effectively prevented. Even when such an adapter according to the second embodiment is used, the guide block shown in FIG. 18 and the like is used.

  10 sample measurement device (liquid scintillation counter), 12 transport table, 14 racks 22 sample container, 24 sample storage unit, 26 opening / closing mechanism, 28 hoistway, 30 guide block, 32 pressing unit, 34 sample measurement chamber, 38 photomultiplier Tube, 40 Lifting mechanism, 42 Shutter mechanism, 43 Shaft, 44 Head, 60 Adapter, 70, 72 Arm, 74, 76 Lower end structure, 96 Attachment

Claims (6)

A transport mechanism for transporting the rack on the transport surface;
A sample measuring chamber provided below the transport surface and containing a sample container from the rack;
A base frame constituting the bottom of the sample measurement chamber;
A lift that transports the sample container between the rack and the sample measurement chamber, and includes a shaft that vertically penetrates the base frame and a head that is provided at an upper end of the shaft and places the sample container. Mechanism,
Including
In the base state where the shaft is pulled down to the lowest end, the upper surface of the base frame and the lower surface of the head are joined,
A light shielding structure is provided so as to surround the shaft across the upper surface of the base frame and the lower surface of the head,
A sample measuring device characterized by that. The apparatus of claim 1.
The shading structure is
An annular protrusion provided on one of the upper surface of the base frame and the lower surface of the head;
An annular recess provided on the other of the upper surface of the base frame and the lower surface of the head;
Including
In the ground state, the annular convex portion and the annular concave portion are combined,
A sample measuring device characterized by that. The apparatus of claim 2.
The head is
An upper end of the shaft;
A head body into which the upper end of the shaft is inserted so as to be movable up and down;
An elastic body provided between the upper end and the head body;
Including
In the ground state, the elastic body exerts an elastic action, whereby the annular convex portion and the annular concave portion are elastically adhered,
A sample measuring device characterized by that. The apparatus of claim 3.
The head body has a well;
A stopper member is provided at the upper end of the shaft,
The elastic body is a spring provided between the bottom surface of the well and the lower surface of the stopper member,
The shaft is pulled down even after the downward movement of the head body is stopped so that the spring is compressed in the base state.
A sample measuring device characterized by that. The apparatus according to any one of claims 1 to 4,
A case surrounding the sample measurement chamber is provided;
An outer light shielding structure is provided so as to surround the light shielding structure across the upper surface of the base frame and the lower surface of the case.
A sample measuring device characterized by that. The apparatus of claim 1.
The head has a laminated body constituting a mounting surface,
The laminate includes a lower light shielding sheet and an upper light reflection layer,
A sample measuring device characterized by that.

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