JP3622490B2 - centrifuge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bucket used in a swing rotor for a centrifuge.
[0002]
[Prior art]
When separating a sample such as blood in the field of clinical medicine or the like, for example, a swing rotor disclosed in Japanese Patent Application Laid-Open Nos. 49-15066, 63-2110, and 63-35797 is disclosed. A centrifuge having (hereinafter referred to as a rotor) is used. 3 to 5, the rotor 1 is provided with through holes 1a for rotating integrally with a drive shaft that is rotated by a motor that is a drive source (not shown), and a plurality of radial holes are radially formed with respect to the through holes. The arm 2 is arranged. A pin 3 is provided near the tip of the arm 2, and a bucket 4 is swingably attached to the pin 3. Therefore, the bucket 4 that accommodates the square rack 10 having the centrifuge tube 11 by the rotation of the rotor 1 is swung by the centrifugal force with the pin 3 as a turning point, so that the sample accommodated in the centrifuge tube 11 is thereby obtained. Can be centrifuged. As shown in FIG. 4, the bucket 4 is configured so that a rack having a shape different from that of the rack 10 shown in FIG. 3 can be arranged.
[0003]
The rotor 1 is generally formed of stainless steel or aluminum alloy material, and many of them are manufactured by forging, casting, or machining. Moreover, the said pin 3 is shape | molded by steel materials, such as stainless steel, and is manufactured by machining. Further, the bucket 4 has a box shape or a round cup shape as shown in FIG. 5, and presses a stainless steel plate, or machines (mills, turns) a thick plate or bar of an aluminum alloy, Manufactured by precision casting with aluminum alloy.
[0004]
[Problems to be solved by the invention]
Since the bucket is configured to accommodate a plurality of racks, it has a large bottom area. For this reason, when the rotor rotates, a centrifugal load related to the mass of the rack and the bottom itself is applied to the bottom of the bucket. (The magnitude of the centrifugal load is 2,000 to 3,000 times the mass of the rack and the bottom itself.) The bucket is cooled by a cooling device provided so as not to impair the activation of the sample. Water is attached to the inner and outer surfaces of the bucket due to a temperature change in the rotating chamber. As a result, water adhering to the inner surface has accumulated at the bottom of the bucket.
[0005]
The bucket is made of a corrosion-resistant material such as an aluminum alloy, but due to repeated use over a long period of time, the bucket bottom is subjected to repeated stress, and as described above, a large centrifugal load is involved. When a liquid such as moisture or a sample adheres to a portion, the portion gradually corrodes (stress corrosion).
[0006]
An object of the present invention is to solve the above-described problems and provide a bucket having excellent corrosion resistance.
[0007]
[Means for solving problems]
The object is to provide a storage chamber composed of a bottom surface and side walls surrounding the four sides, a bucket integrally including a partition wall for partitioning the storage chamber, a rotor for swingably supporting the bucket, and a centrifuge provided with the rotor. In this case, the hole is formed by providing a hole through which the liquid can be discharged at the junction between the bottom surface, the side wall, and the partition wall of the bucket.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The bucket 4 used in the swing rotor for a centrifuge according to the present invention will be described with reference to FIGS. FIG. 1 is an external perspective view showing an embodiment of the bucket 4 according to the present invention, and FIG. 2 is a longitudinal side view of the bucket 4 shown in FIG.
[0009]
The bucket 4 shown in the present embodiment is manufactured by a precision casting method using an aluminum alloy. The precision casting method is generally referred to as the lost wax method, and a “wax model” of the same shape as the actual product is made with an injection molding machine, and the “wax model” is a slurry of a mixture of fine refractory and caking additive. Covering, drying, and firing to melt and burn the wax to create a mold without a split surface, casting it into an object that has a complicated shape regardless of the number of products produced or that is expensive to process It is a suitable manufacturing method. The bucket 4 manufactured by this precision casting method is large in the processing step, and is subjected to cutting for matching the mass and anticorrosion processing to the surface. Moreover, the partition 7 mentioned later can be integrally provided with the bucket 4 by manufacturing the bucket 4 by the said precision casting method.
[0010]
The bucket 4 has a plurality of storage chambers 6 that are swingably attached to a rotor having a plurality of arms via pins, and that can store a rack that holds a centrifuge tube. Here, each storage chamber 6 is formed by being partitioned by a partition wall 7 provided integrally with the bucket 4. In addition, the strength of the bucket 4 can be improved by providing the partition wall 7. Further, the bucket 4 has a hole 8 for discharging liquid such as moisture and a sample at the bottom of the bucket 4 so that moisture adhering to the bucket 4 due to a temperature change does not accumulate in the bucket 4. Further, the bucket 4 has a balance adjusting unit 9.
[0011]
Next, the stress concerning the bucket 4 is demonstrated using FIG.6 and FIG.7. FIG. 6 is a stress diagram showing a state seen from the cross section of the bucket 4, and FIG. 7 is a stress diagram showing a state seen from the bottom of the bucket 4. 6 and 7 are stress diagrams in the case where two sets of racks (centrifuge tubes) having a rotation speed of the bucket 4 of 3,000 rpm and a weight of 108 g are attached to the bucket 4, and the numerical values in the diagrams are the respective stress values. Is shown. As for the stress value, a positive (+) value indicates a tensile stress acting on the bucket 4, and a negative (−) value indicates a compressive stress acting on the bucket 4. Usually, when the hole 8 is provided in the bucket 4, it is necessary to provide it in a place where the stress is as low as possible (so-called stress value 0). This is to prevent the bucket 4 from being broken due to a tensile stress or a compressive stress in the vicinity of the hole. That is, the strength of the bucket 4 is not reduced. In the figure, the stress value 0 described above is included in the range of ( 6 ) (0.500 kgf / mm2) to ( 7 ) (-1.000 kgf / mm2). 8 is ideal. However, since this range is expanded in the vertical lower part of the hook part 4a provided in the bucket 4, the hole 8 is provided in the vicinity of the vertical lower part of the hook part 4a. Since this place is not the place where the liquid is most accumulated by the centrifugal force in the bucket 4 that oscillates during the centrifugal separation, as a result, the liquid in the bucket 4 cannot be discharged efficiently. For this reason, the optimum range in which the hole 8 can be provided so that the liquid can be efficiently discharged and the strength of the bucket 4 is not lowered is ( 5 ) (2.000 kgf / mm @ 2) to ( 6 ). ) (0.500 kgf / mm @ 2). This is because this range has a portion where the liquid is most easily collected by centrifugal force, that is, a portion surrounded by the partition wall 7 and the bottom and side portions of the bucket 4. Therefore, since the liquid can be easily discharged out of the bucket 4 from the hole 8, corrosion of the bucket 4 can be prevented.
[0012]
In the range in which the hole 8 can be provided, the stress level that does not cause a decrease in the strength of the bucket 4 is ( 5 ) (2.000 kgf / mm ² ) to ( 8 ) (−2.500 kgf / mm ² ), and if a certain level of discharge efficiency is desired even if the liquid is not efficiently discharged, a portion other than the portion surrounded by the partition wall 7 and the bottom and side portions of the bucket 4 described above may be used. Any number of holes 8 may be provided in the place.
Therefore, in a centrifuge that includes a bucket having partition walls that form a plurality of storage chambers that can individually store racks that hold samples, and a rotor to which the bucket is attached, a liquid discharge hole is provided at the bottom of the bucket. This is achieved by providing
[0013]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the bucket excellent in corrosion resistance can be provided by providing the hole for liquid discharge in the bottom part of a bucket.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing an embodiment of a bucket according to the present invention.
2 is a longitudinal side view of the bucket shown in FIG. 1. FIG.
FIG. 3 is an external perspective view showing a conventional square rack having a centrifuge tube.
FIG. 4 is an external perspective view showing a conventional bucket.
FIG. 5 is an external perspective view showing a state in which a bucket is attached to a conventional rotor. FIG. 6 is a stress diagram showing a state seen from a cross section of the bucket according to the present invention.
FIG. 7 is a stress diagram showing a state seen from the bottom of the bucket according to the present invention.
[Explanation of symbols]
1 is a rotor, 4 is a bucket, 6 is a storage chamber, 7 is a partition, 8 is a hole, and 10 is a rack.

Claims (1)

In a storage chamber composed of a bottom surface and side walls surrounding the four sides, a bucket integrally including a partition wall that partitions the storage chamber, a rotor that supports the bucket so as to be swingable, and a centrifuge provided with the rotor,
A centrifugal separator characterized in that a hole through which liquid can be discharged is provided at a joint portion between the bottom surface, the side wall, and the partition wall of the bucket.

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