JPH11276929A - centrifuge - Google Patents

Abstract

(57) [Problem] To provide a bucket excellent in corrosion resistance. SOLUTION: A hole 8 for discharging liquid is provided at the bottom of a bucket 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bucket used for a swing rotor for a centrifuge.

[0002]

2. Description of the Related Art In the field of clinical medicine and the like, when a sample such as blood is separated, for example, Japanese Patent Application Laid-Open No. 49-15066 is used.
Gazette, Japanese Utility Model Publication No. 63-2110 and Japanese Utility Model Publication No. 63-
A centrifuge having a swing rotor (hereinafter referred to as a rotor) disclosed in Japanese Patent No. 35797 is used. 3 to 5, the rotor 1 is provided with a through-hole 1a for integrally rotating with a drive shaft rotated by a motor (not shown), and a plurality of radially extending holes are formed in the through-hole 1a. Arm 2 is arranged. A pin 3 is provided near the tip of the arm 2, and a bucket 4 is attached to the pin 3 so as to be swingable. Therefore, the bucket 4 including the square rack 10 having the centrifugal tube 11 by the rotation of the rotor 1 swings by the centrifugal force with the pin 3 as the pivot point.
1 can be centrifuged. In addition, as shown in FIG. 4, the rack 4 is configured such that a rack having a different shape from the rack 10 shown in FIG.

[0003] The rotor 1 is generally formed of stainless steel or an aluminum alloy material, and most of the rotor 1 is manufactured by forging, casting, or machining. The pin 3 is formed of a steel material such as stainless steel, and is manufactured by machining. And bucket 4
Consists of a box shape or a round cup shape shown in FIG. 5, and is formed by pressing a stainless steel plate, machining (milling, lathing) a thick plate or a bar of an aluminum alloy, or by using an aluminum alloy. Manufactured by precision casting.

[0004]

The above-mentioned bucket has a large bottom area because it is configured to accommodate a plurality of racks. Therefore, when the rotor rotates, a centrifugal load according 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. The water is attached to the inner and outer surfaces of the bucket due to the temperature change in the rotating chamber. As a result, the moisture adhering to the inner surface has accumulated at the bottom of the bucket.

[0005] The above-mentioned bucket is made of a corrosion-resistant material such as an aluminum alloy.
As described above, when a liquid such as moisture or a sample adheres to a portion where a large centrifugal load is applied, there is a problem that the portion is gradually corroded (stress corrosion).

An object of the present invention is to solve the above problem and provide a bucket excellent in corrosion resistance.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a centrifuge comprising a bucket having a partition wall forming a plurality of storage chambers capable of individually storing racks for holding samples, and a rotor to which the bucket is mounted. Is achieved by providing a hole for discharging liquid at the bottom of the bucket.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bucket 4 used in a 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 a bucket 4 according to the present invention, and FIG. 2 is a vertical sectional side view of the bucket 4 shown in FIG.

The bucket 4 shown in this embodiment is manufactured by a precision casting method using an aluminum alloy. The precision casting method is generally called a lost wax method, and a “wax model” having the same shape as the actual product is manufactured by an injection molding machine.
The "wax model" is covered with a slurry of a mixture of refractories of fine particles and a binder, dried and fired to melt and burn the wax to create a mold without a parting surface. This is a manufacturing method suitable for an object having a complicated shape irrespective of the size of the object or an object having a high processing cost. The bucket 4 manufactured by this precision casting method is large in the processing step,
A cutting process for adjusting the mass and a corrosion-proofing process for the surface are performed. Further, by manufacturing the bucket 4 by the above-mentioned precision casting method, a partition wall 7 described later can be provided integrally with the bucket 4.

The bucket 4 is swingably attached to a rotor having a plurality of arms via pins.
It has a plurality of storage chambers 6 in which racks for holding centrifuge tubes can be stored. Here, each storage chamber 6 is formed by being partitioned by a partition wall 7 provided integrally with the bucket 4. The provision of the partition wall 7 can improve the strength of the bucket 4. The bucket 4 has a hole 8 at the bottom of the bucket 4 for discharging a liquid such as moisture or a sample, so that moisture attached due to a temperature change in the rotating chamber does not accumulate in the bucket 4. In addition, bucket 4
Has a balance adjustment unit 9.

Next, the stress applied to the bucket 4 will be described with reference to FIGS. FIG. 6 is a stress diagram showing a state viewed from the cross section of the bucket 4, and FIG. 7 is a stress diagram showing a state viewed from the bottom of the bucket 4. 6 and 7 show that the rotation speed of the bucket 4 is 3,000 rpm and the bucket 4 has a weight of 108 rpm.
FIG. 4 is a stress diagram when two sets of racks (including centrifuge tubes) of g are mounted. Numerical values in the diagram indicate respective stress values.
As for this stress value, a plus (+) value indicates a tensile stress acting on the bucket 4, and a minus (−) value indicates a compressive stress acting on the bucket 4. Normally, when the hole 8 is provided in the bucket 4, it is necessary to provide the hole 8 in a place where the stress is as low as possible (near a so-called stress value of 0). This is to prevent the bucket 4 from being broken due to a crack or the like near the hole due to tensile stress or compressive stress. That is, the strength of the bucket 4 is not reduced. In the drawing, the stress value 0 described above is included in (0.50
0 kgf / mm ² ) to (-1.000 kgf / mm ² )
Therefore, it is ideal to provide the hole 8 within this range. However, since this range extends vertically below the hook 4a provided on the bucket 4,
The hole 8 will be provided near the vertical lower part of the hook part 4a. This location is not the location where the liquid is most likely to accumulate due to centrifugal force in the bucket 4 that swings during centrifugation, and as a result, the liquid in the bucket 4 cannot be efficiently discharged. Thus, the optimal range in which the liquid can be efficiently discharged and the hole 8 can be provided so as not to lower the strength of the bucket 4 is (2.000 kgf / mm ² ) to (0.50 kgf / mm ² ).
00 kgf / mm ² ). This is because this range has a place where the liquid is most likely to accumulate due to the centrifugal force, that is, a part surrounded by the partition wall 7 and the bottom and sides of the bucket 4. Therefore, the liquid can be easily discharged from the hole 8 to the outside of the bucket 4, so that the corrosion of the bucket 4 can be prevented.

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 (2.0000 kgf / mm ² ) in the drawing.
(−2.50 kgf / mm ² ), and if it is desired to discharge the liquid to some extent without efficiently discharging the liquid, the above-described partition wall 7 and the bottom and sides of the bucket 4 Any number of holes 8 may be provided in places other than the area surrounded by.

[0013]

According to the present invention, a bucket having excellent corrosion resistance can be provided by providing a hole for discharging liquid at the bottom of the bucket.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an embodiment of a bucket according to the present invention.

FIG. 2 is a vertical sectional side view of the bucket shown in FIG. 1;

FIG. 3 is an external perspective view showing a conventional rectangular rack having a centrifugal tube.

FIG. 4 is an external perspective view showing a conventional bucket.

FIG. 5 is an external perspective view showing a state where a bucket is attached to a conventional rotor.

FIG. 6 is a stress diagram showing a state viewed from a cross section of the bucket according to the present invention.

FIG. 7 is a stress diagram showing a state of the bucket according to the present invention as viewed from the bottom.

[Explanation of symbols]

1 is a rotor, 4 is a bucket, 6 is a storage room, 7 is a partition, 8
Is a hole and 10 is a rack.

Claims (2)

[Claims] 1. A centrifuge comprising: a bucket having a partition wall forming a plurality of storage chambers capable of individually storing racks for holding a sample; and a rotor to which the bucket is mounted. A centrifuge characterized by providing a hole for discharging liquid. 2. The centrifugal separator according to claim 1, wherein the hole is provided in a portion surrounded by the partition wall integrally formed with the bucket and a bottom portion and a side portion of the bucket.