JPH10246690A - Sample-introducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent air from being sucked by detecting the presence or absence of a sample container and at the same time prevent a needle from being bent by detecting that a foreign object exists at the position of the sample container. SOLUTION: When a vial detection plate 28 collides with a foreign object and a needle 8 also collides with the foreign object, a needle mount 2 cannot descend any further since the tip of the needle 8 is in contact with the foreign object even if a screw 14 rotates and a screw support 16 is lowered. As a result, the screw support 16 descends while compressing the spring 18 and pushes down an actuator 24, thus turning off a sensor 10 and hence detecting that the needle 8 is in contact with the foreign object. Since the screw support 16 pushes down the needle mount 2 via the spring 18, only the spring force is applied to the needle 8 even if the needle 8 contacts the foreign object. And, when it is detected that the needle 8 is in contact with the foreign object, the descent of the needle mount 2 is stopped, thus preventing the needle 8 from being bent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for analyzing a liquid chromatograph or the like, in which a sample contained in a sample container is sucked by a sampling needle and introduced into the analyzer.

[0002]

2. Description of the Related Art In a sample introduction device equipped with a sampling needle, the needle is moved from a home position by a set value and lowered into a sample container, then the sample is sucked, and the needle is sent to an injection port of an analyzer. The sample is transferred and introduced.

[0003]

The sampling operation of lowering the needle by a set distance to the sample container containing the sample is performed even if the sample container is not at a predetermined position. The problem of suction occurs. Also, if there is foreign matter instead of the sample container where the needle descends, or if the needle hits the edge of the sample container, the conventional device cannot distinguish it as a foreign object. An accident occurs in which the needle bends while trying to lower by the value. An object of the present invention is to detect the presence or absence of a sample container to prevent air from being sucked, and to detect the presence of a foreign substance at the position of the sample container to prevent the needle from bending.

[0004]

According to the present invention, two sensors are provided, one for detecting the presence or absence of a sample container and the other for detecting foreign matter. The sample introduction device of the present invention includes a downward needle for aspirating and discharging a liquid sample, a first sensor A for detecting a foreign substance, and an actuator for a second sensor B for detecting the presence or absence of a sample container, and moves vertically. A needle mount supported as possible, a feed screw provided in the vertical direction and driven by a motor, and screwed with the feed screw, directly contacting the needle mount in the upward direction and pushing up, and the spring in the downward direction A screw receiver that pushes down the needle mount through the screw receiver is attached to a shaft supported to be vertically movable with respect to the screw receiver, and is urged upward through a spring between the screw receiver and the screw receiver. An actuator for the first sensor A, which is depressed by the lowering of the receiver, and a container having a second sensor B supported movably up and down with respect to the needle mount. And a detection unit.

[0005] When the feed screw is driven by a motor to aspirate the sample and the needle mount is lowered via the spring by the screw receiver being lowered, the container detector also starts to move down together with the needle mount. When a sample container is present at a predetermined position, the container detector hits the sample container and stops descending, but the needle mount continues to descend, whereby the second sensor B and its actuator detect that the sample container is present. .

On the other hand, when foreign matter is present at the position of the sample container, when the needle mount is lowered and the needle hits the foreign matter, the lowering of the needle mount stops. When the feed screw is further driven by the motor, the needle mount does not lower but the screw receiver continues to lower, and the first sensor A stops because the needle mount is provided on the needle mount. It is detected that the needle is hitting a foreign substance by being pushed down by the descent.

At this time, since the screw receiver pushes down the needle mount via the spring, even if the needle hits a foreign matter, only the spring force is applied to the needle. By setting so that the lowering of the needle mount is stopped when it is detected that the needle has hit a foreign object, it is possible to prevent a strong force from acting on the needle.

[0008]

FIG. 1 shows an embodiment in a state of a home position. Needle mount 2 supports 4
Are guided by a guide shaft 6 provided in a vertical direction, and are movably supported in a vertical direction. A needle 8 for sucking and discharging a liquid sample is provided on the needle mount 2.
The first sensor 10 for detecting that the needle 8 has hit foreign matter is provided on the upper surface of the needle mount 2. A second sensor actuator 12 for detecting the presence or absence of a sample container is provided on the upper surface of the needle mount 2.

A vertically extending feed screw 14 is rotatably supported by the support table 4, and the feed screw 14 is provided to penetrate the needle mount 2 in the vertical direction. The feed screw 14 is connected to a motor 15 and is driven to rotate by the motor 15. The needle mount 2 is provided with an opening at a portion where the feed screw 14 penetrates,
A screw receiver 16 screwed with the feed screw 14 is provided in the opening. Within the opening of the needle mount 2, the upper side of the screw receiver 16 can directly contact the needle mount 2 so as to push the needle mount 2 upward,
A coil spring 18 for pressing the needle mount 2 downward is provided between the lower side of the screw receiver 16 and the needle mount 2.

The shaft 20 is attached to the screw receiver 16 so as to be movable in the vertical direction. The shaft 20 is urged upward by a spring 22 between the screw receiver 16 and the screw receiver 1.
An actuator 24 for the first sensor, which is pushed down by the screw receiver 16 with the lowering of the actuator 6, is provided integrally with the shaft 20. When the shaft 20 is in the home position shown in FIG.
Is in contact with

A shaft 26 is supported on the needle mount 2 movably in the vertical direction, and a vial detecting plate 28 as a container detecting portion is attached to a lower end of the shaft 26.
At the upper end of the shaft 26, a second sensor 32 for detecting the presence or absence of a sample container via a sensor base 30 is provided. The sensors 10 and 32 are, for example, photo interrupters. 36 is a vial of a sample container, and 37 is an upper surface of a rack in which the vial 36 is stored.

Next, the operation of this embodiment will be described. In FIG. 1 showing the home position, the spring 1
8, 22, and 34 are all contracted, and the position of the actuator 24 is determined by the upper end of the shaft 20 being in contact with the support base 4;
As a result, the actuator of the sensor 10 for the first sensor comes off and is turned off. Sensor 32
Is turned on across the actuator.

FIG. 2 shows a normal operation when a vial exists at a predetermined position. (A) From the state of the home position in FIG. 1, the motor 15 rotates to aspirate the sample, the screw receiver 16 starts descending by the feed screw 14, and the needle mount 2
8 is pushed down. When the screw receiver 16 is lowered, the spring 22 is extended, and when the actuator 24 is pushed up, the sensor 10 is turned on. The spring 18 remains, but the spring 34 is expanding.

(B) When the feed screw 14 further rotates and the screw receiver 16 continues to descend, the springs 18 and 22 remain as they are, but the spring 34 further extends, and the state of the sensors 10 and 32 does not change. Eventually, the vial detection plate 28 contacts the vial 36.

(C) When the feed screw 14 is further rotated and the screw receiver 16 is lowered, the lowering of the shaft 26 and the lowering of the sensor 32 are stopped because the vial detecting plate 28 is in contact with the vial 36. However, the needle mount 2 continues to descend further, and the needle 8 moves to the vial 36.
By entering the inside, the actuator 12 is separated from the sensor 32 and the sensor 32 is turned off. This allows
Vial 36 is present and it is detected that needle 8 has been inserted into vial 36.

FIG. 3 shows the operation when the vial is not placed at a predetermined position. Since the needle mount 2 further descends from the position shown in FIG. 2 (B) and the spring 34 further extends, even if the vial detecting plate 28 descends to the position corresponding to the vial, the lowering of the vial detecting plate 28 does not stop. The sensor 12 does not come off the sensor 32 and keeps the sensor 32 on. As a result, even when the needle mount 2 is lowered to a preset position, the sensor 32 is not turned off, and thus it is detected that no vial is placed.

FIG. 4 shows the operation when a foreign substance is present at the position of the vial. In the state of FIG. 2B, when the vial detecting plate 28 hits the foreign matter 38 and the needle 8 also hits the foreign matter 38, the tip of the needle 8 is moved to the foreign matter 38 even if the feed screw 14 is further rotated to lower the screw receiver 16.
Therefore, the needle mount 2 cannot descend further. As a result, the screw receiver 16 descends while compressing the spring 18 to push down the actuator 24, thereby turning off the sensor 10. Thereby, it is detected that the needle 8 is in contact with the foreign matter. At this time, the screw receiver 16 pushes down the needle mount 2 via the spring 18 so that the needle 8
, Only the spring force is applied to the needle 8. By setting so that the lowering of the needle mount 2 is stopped when it is detected that the needle 8 hits the foreign matter 38, a strong force can be prevented from acting on the needle 8, and the needle 8 is bent. Can be prevented.

In the embodiment, the case where the sample is sucked from the vial is shown as an example, but the present invention can be similarly applied to the case where the sample is discharged from the sample introduction device to the injection port. In this case, the presence of the injection port can be detected, and the needle can be prevented from hitting a foreign substance at the injection port or bending against a portion other than the suction hole of the injection port.

In FIG. 2C, when the needle 8 is lowered until the tip of the needle 8 reaches the bottom of the vial, the lowering of the needle 8 stops and the sensor 10 is turned off as described in FIG. Alternatively, the vial depth can be detected. As a result, it becomes possible to use a sample container having an arbitrary depth. become.

[0020]

According to the sample introduction apparatus of the present invention, two sensors, one for detecting the presence or absence of a sample container and the other for detecting foreign matter, are provided, and the mechanism for pushing down the needle acts on the needle via a spring. So,
This can prevent the air from being sucked or the needle from being bent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment.

FIG. 2 is a process sectional view showing a normal operation of the embodiment.

FIG. 3 is a cross-sectional view showing an operation in a case where there is no sample container at a predetermined position in the embodiment.

FIG. 4 is a cross-sectional view showing an operation when a foreign substance is present at a position of a sample container in the embodiment.

[Explanation of symbols]

 2 needle mount 4 support base 6 shaft 8 needle 10 first sensor 12 second sensor actuator 14 feed screw 16 screw receiver 18 coil spring 24 first sensor actuator 28 vial detection plate 32 second sensor 32

Claims (1)

[Claims] 1. An apparatus according to claim 1, further comprising a downward needle for sucking and discharging the liquid sample, a first sensor for detecting foreign matter, and an actuator for a second sensor for detecting the presence or absence of a sample container. Needle mount, a feed screw provided in the vertical direction and driven by a motor, and screwed with the feed screw, directly contacting and pushing up the needle mount in the upward direction, and through the spring in the downward direction. A screw receiver that presses down the needle mount to attach the shaft to a shaft supported to be vertically movable with respect to the screw receiver, and is urged upward by a spring between the screw receiver and the screw receiver. An actuator for the first sensor A that is depressed by the lowering of the needle mount; Sample introduction apparatus characterized by comprising: a container detecting unit, the.