JPH03188349A - Fluorescent x-ray analyzer - Google Patents

Abstract

PURPOSE:To make it possible to preform efficient analysis by constituting an analyzer with the main body case of the analyzer, a vacuum chamber for projecting X rays, a sample inserting hole, a turntable, a receiving stage which is also used for sealing the sample inserting hole and a lift mechanism. CONSTITUTION:A sample 12 is loaded in a recess part 11 of a turntable 5 which is exposed from a main body case 1 of an analyzer. The sample 12 is brought into the main body case of the analyzer by rotating the turntable 5. The sample 12 which has reached the specified taking-out position is lifted up with a lift mechanism 14. The sample is loaded into a sample inserting hole 6 of a vacuum chamber 4. At the same time, the sample inserting hole 6 is sealed with a receiving stage 15. The inside of the vacuum chamber 4 is evacuated, and X rays are applied. The sample 12 whose analysis is completed is returned to the turntable 5 again. A new sample is sent into the taking-out position by one-pitch turn of the turntable 5. The sample loading and the X-ray projection are performed by the same procedure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fluorescent X-ray analyzer that irradiates a sample with X-rays and spectrally analyzes fluorescent X-rays excited by the X-rays and emitted from the sample.

(Prior Art) In general, an X-ray fluorescence analyzer is sometimes used to analyze elements of various types of samples online. In order to efficiently analyze such a large number of samples, conventional methods load a large number of samples onto a turntable exposed outside the device body, and swing the samples at a predetermined phase of the turntable. There are models that are carried into the equipment body by an arm and loaded into the internal vacuum chamber for X-ray irradiation, and there are also models that have a turntable installed in the vacuum chamber installed inside the equipment body, and are loaded onto the turntable inside the vacuum chamber. A type is provided in which each sample at a predetermined position is lifted to the X-ray irradiation site.

(Problem to be Solved by the Invention) However, in the former swing arm transport type, only one sample is loaded into the vacuum chamber within the apparatus main body, so the volume of the vacuum chamber can be reduced, and therefore a predetermined vacuum can be achieved. Although it has the advantage of being able to evacuate in a short period of time until reaching the desired temperature, the swing arm mechanism itself for loading and unloading the sample is complex, requires a large operating space, and is large in size. Moreover, since the sample has to be transported over a long distance, it takes time to transport the sample.

Furthermore, if the swing speed is increased to shorten the transport time, the sample will fall off during the swing, so there is a natural limit to increasing the transport speed.

In addition, although the latter model with a turntable installed inside the vacuum chamber does not have the above-mentioned problems when loading and unloading the sample, the vacuum chamber is large and requires evacuation until the required degree of vacuum is reached. In addition, even when analyzing a small number of samples that are less than the predetermined number of samples loaded on the turntable, the entire vacuum chamber must be evacuated, which is wasteful. There were some problems such as not being able to add files easily.

The present invention solves the above-mentioned problems found in the conventional type, and enables efficient analysis regardless of the number of samples.
The purpose is to provide a line analysis device.

(Means for solving problems) In order to achieve the above object, the present invention adopts the following configuration.

That is, the fluorescent X-ray analyzer of the present invention includes a vacuum chamber for X-ray irradiation installed in the device main body case, a sample insertion hole is formed in the lower surface of the vacuum chamber, and a sample insertion hole is formed in the lower surface of the vacuum chamber. is equipped with a rotatable turntable, sample insertion holes are formed at a predetermined pitch on the outer periphery of the turntable, and a fixed circular table with a larger diameter than the turntable is installed below the turntable. is provided concentrically with the turntable, and a circular hole having a size that approximately matches the size of the sample insertion hole is formed at the intersection of the fixed circular table with the vertical axis. Directly below, a lift mechanism including a pedestal having a diameter smaller than the circular hole and also serving as a seal for the sample insertion hole was provided so as to be movable up and down along the axial direction of the vertical axis.

(Function) According to the above configuration, the sample is loaded into the recess of the turntable exposed to the outside from the device main body case, and the sample is brought into the device main body case by rotation of the turntable.
The sample that has reached a predetermined extraction site is lifted by a lift mechanism and loaded into the sample insertion hole of the vacuum chamber, the sample insertion hole is sealed with a pedestal, the vacuum chamber is evacuated, and then X-ray irradiation is performed.

The analyzed sample is returned to the turntable, and a new sample is sent to the extraction site by one pitch rotation of the turntable, and sample loading and X-ray irradiation are performed in the same manner.

This operation is performed every time the turntable rotates at a fixed pitch, and the samples are analyzed one by one and collected on the turntable.The samples that have been sent out of the device body are taken out from the turntable and replaced with new ones as necessary. Supply the sample.

(Example) FIG. 1 is a longitudinal sectional view of an example of the fluorescent X-ray analyzer according to the present invention.

The fluorescent X-ray analyzer of this embodiment is provided with a vacuum chamber 4 equipped with analysis equipment such as an X-ray tube 2 and a spectrometer 3 in the upper half of the device main body case L, which has a box-like structure. A sample insertion hole 6 that penetrates vertically is formed in the lower center of the vacuum chamber 4, and a shutter 7 is provided between the sample insertion hole 6 and the vacuum chamber 4 to communicate with and block the two. ing.

The lower end of the sample insertion hole 6 is opened in a tapered shape that widens downward, and a sealing O-ring 8 is attached to the inner surface of the opening.

On the other hand, in the lower half of the apparatus main body case 1, a turntable 5 for loading and unloading the sample is provided so as to be rotatable about the vertical axis P. Approximately half of this turntable 5 is inserted into the apparatus main body case 1 to a position where it intersects the vertical axis passing vertically through the sample insertion hole 6, and the other approximately half of the turntable 5 is inside the apparatus main body case 1. It is placed so that it is exposed to the outside. Further, a fixed circular table 9 having a larger diameter than the turntable 5 is provided below the turntable 5, and the fixed circular table 9 is fixed to the lower half of the device main body case 1. Further, a stepping motor 10 is attached to the lower part of the fixed circular table 9, and the rotating shaft of this stepping motor 10 is arranged concentrically with the vertical axis P, and is fixed to the turntable 5 through the fixed circular table 9. has been done. At the outer peripheral edge of the turntable 5, approximately semicircular recesses 11 for transporting the sample are formed at partial pitches along the circumferential direction. A short cylindrical sample 12 is loaded into the recess 11 and placed on the fixed circular table 9. Further, the sample insertion hole 6 of the vacuum chamber 4 of the fixed circular table 9
A circular hole 1 having a size that matches the curve of the recess 11 with the center at the position intersecting the vertical axis passing vertically.
3 is formed.

A lift mechanism 1 for lifting the sample is provided below this circular hole 13.
4 are provided. The lift mechanism 14 includes the circular hole 1
It consists of a disc-shaped pedestal 15 having a diameter smaller than that of 3 and arranged concentrically with the circular hole 13, a rack shaft 16 that supports the pedestal 15, and a motor 17 that drives the rack shaft 16 up and down.

In addition, 22 is a detection piece provided at the lower end of the rack shaft I6, and 23
．． Reference numeral 24 designates an upper and lower pair of photointerrupters, and the vertical stroke of the pedestal 15 is controlled by the photointerrupters 23 and 24 detecting the detection piece 22.

Next, the operation of filling the sample 12 in the X-ray fluorescence analyzer having the above configuration will be described.

During analysis, the fixed circular table 9 is inserted through the recess 11 of the turntable 5 exposed outside the device main body case l.
With the sample 12 placed on top, the turntable 5 is rotated one pitch at a time by the stepping motor IO, and the sample 12 is fed into the apparatus main body case 1.

The pedestal 15 where the required sample I2 was waiting inside the circular hole 13
When you sit on the top, the motor 17 is started and the rack shaft 1
6 rotates, which causes the pedestal 15 to rise through the circular hole 13. Along with this, the sample I2 is inserted into the sample insertion hole 6, and the expanding tapered outer peripheral surface of the pedestal 15 is pressed against the tapered opening of the sample insertion hole 6. is sealed from below via an O-ring 8. At this time, the shutter 7 is closed.

The area above the shutter 7 has already been kept in a vacuum state in the previous operation, so the air inside the sample insertion hole 6 is evacuated using a vacuum pump (not shown) to create a vacuum inside the shutter 7. Open it, irradiate X-rays from X-ray tube 2,
Fluorescent X-rays emitted from the sample 12 are guided to a spectrometer 3 for spectroscopy.

When the analysis is completed, the shutter 7 is closed to cut off the communication between the inside of the vacuum chamber 4 and the sample insertion hole 6, and after the sample insertion hole 6 is leaked and returned to the atmosphere, the pedestal 15 is lowered to the original height of the turntable. do.

The analysis operation for one sample 12 is completed with the above operations, and henceforth, the above operations are sequentially repeated as the turntable 5 rotates one pitch.

In addition, in the above operation, by closing the shutter 7 after the analysis to maintain the vacuum in the vacuum chamber 4, the time required for the next analysis is shortened.

By the way, since the radius of the sample 12 is smaller than the radius of curvature of the recess 11 of the turntable 5, when the turntable 5 rotates, the sample 12 is rotated in the opposite direction than the center of curvature of the recess 11. It will be sent in a state where it is deviated by an angle θ. Therefore, when the sample 12 is sent to the circular hole I3 formed in the fixed circular table 9 and the center of the sample 12 coincides with the center of the circular hole 13 as shown in FIG. The center of curvature of the recess 11 overruns the center of the circular hole I3 by a predetermined angle θ in the rotational direction. Therefore, if the pedestal 15 rises in this state, the turntable 5
It comes into contact with and becomes unable to rise. Therefore, this overrun of the turntable 5 is corrected as follows.

That is, on the lower surface of the turntable 5, an index pin 18a for returning the sample 12 is located on the inside on a line connecting the center of curvature of each recess 11 and the vertical axis P, and an index pin 18b for feeding the sample 12 is located on the outside. They each protrude downward, and on a line connecting the center of curvature of the recess 11 and the vertical axis P, an origin pin 19 for determining the reference amount of rotation of the turntable 5 protrudes downward. has been done. on the other hand,
On the fixed circular table 9, there is a photointerrupter 2 for detecting the return of the sample 12 at the intersection of the return indexing pin 18a on the line connecting the center of the circular hole 13 and the vertical axis P.
0 is provided, and the sample 12 is placed at a position ahead in the sample feeding direction by a predetermined angle θ from the line connecting the center of the circular hole 13 and the vertical axis P, and at an intersection point crossed by the feeding index pin 18b. A photointerrupter 21 for detecting feed is provided, and furthermore, a photointerrupter 21 is provided for detecting feed, and further, a photointerrupter 21 is provided at a position that is returned by a predetermined angle θ in the opposite direction to the sample feed direction from the line connecting the center of the circular hole 13 and the vertical axis P, and is located at the origin. A photointerrupter 22 for detecting the origin is provided at the intersection point where the output pins 19 cross.

Therefore, when the turntable 5 is rotated until the feed detection photo interrupter 21 detects the feed index pin tab, the sample 12 is fed onto the center of the pedestal 15 as shown in FIG. The center of curvature of the recess 11 of No. 5 overruns the center of the circular hole 13 by a predetermined angle θ in the sample feeding direction. Therefore, when the feed index pin 18b is detected by the feed detection photo interrupter 21, the turntable 5 is kept in the state shown in FIG. 3 until the return detection photo interrupter 20 detects the return index pin 18a. 2, the concave portion 11 becomes the circular hole 13 as shown in FIG.
, the pedestal 15 in the lift mechanism 14 can be raised and lowered.

As shown in FIG. 4, if each sample 12 is placed on a dish-shaped pedestal 15 and the radius of this pedestal 15 is matched with the radius of curvature of the recess 11 of the turntable 5, the above There is no need to reversely correct the turntable 5 as in
It is sufficient to simply perform constant pitch feeding. Also, in this case,
The recess 11 formed in the circumference of the turntable 5 can also be implemented as a circular hole.

(Effect of the invention) According to the present invention, the following effects can be obtained.

(1) Since samples can be fed and loaded into the vacuum chamber one by one, the volume of the vacuum chamber can be small, similar to the swing arm method. The time required can be shortened. Also,
Since the sample is transported in and out of the vacuum chamber by short-distance locked transport using a turntable, there is no risk of the sample falling off during transport, the transport speed can be sufficiently high, and the evacuation time is short. Combined with this, it is possible to perform efficient analysis with a short processing cycle.

(2) Since a part of the turntable is exposed outside the main body of the apparatus, it is easy to take out and add samples.

[Brief explanation of drawings]

FIG. 1 is a longitudinal side view of the fluorescent X-ray analyzer according to the present invention;
FIG. 2 is a plan view of the turntable section, FIG. 3 is a plan view at the time when feeding of the sample at a fixed pitch is completed, and FIG. 4 is a longitudinal sectional view of a modified example. DESCRIPTION OF SYMBOLS 1... Apparatus main body, 4... Vacuum chamber, 5... Turntable, 6... Sample insertion hole, 9... Fixed circular table, ll... Recessed part, 12... Sample, 13 ...Circular hole, 14... foot mechanism.

Claims (1)

[Claims] (1) A vacuum chamber for X-ray irradiation is installed inside the main body case of the device, and a sample insertion hole is formed on the bottom surface of this vacuum chamber.
Further, a turntable is rotatably provided below the vacuum chamber, and sample insertion holes are formed at a predetermined pitch on the outer peripheral edge of the turntable. A fixed circular table with a large diameter is provided concentrically with the turntable, and a circular hole having a size that approximately matches the size of the sample insertion hole is formed at the intersection of the fixed circular table with the vertical axis. On the other hand, directly below the circular hole, a lift mechanism is provided that is movable up and down along the axial direction of the vertical axis and includes a pedestal that has a smaller diameter than the circular hole and also serves as a seal for the sample insertion hole. A fluorescent X-ray analyzer characterized by: