JPH09304368A - Syringe injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve drain performance of a droplet from a needle and prevent clogging of the needle hole by connecting the needle tip part and the needle main body part with a tapered face and providing the needle hole for suction/ discharge, for being communicated with a hollow region of the needle main body part in this tapered face. SOLUTION: A needle is constituted of a narrow-diameter and sharp needle tip part 2 and a hollow needle main body part 1 which is larger than the needle tip part, 2. The needle tip part 2 and the needle main body part 1 are connected to each other by a tapered face 3, and a needle hole 4 for suction/discharge which is communicated with the hollow region of the needle main body part 1 is provided in the tapered face 3. Namely, the tip part of the needle connected to a syringe main body 5 has no needle hole and shaped into a narrow diameter and sharp edge. A hollow hole for a liquid sample to flow is provided in the needle main body part 1 and connected to the needle hole 4. The sample is sucked and discharged via this needle hole 4, so that the liquid is injected diagonally to the front and moreover, the needle tip part 2 is a narrow diameter so that if a droplet is generated, it is dropped while it is still in diameter, so as to improve liquid drain characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a syringe injection device used for injecting a liquid sample in a chromatographic device or the like.

[0002]

2. Description of the Related Art When a liquid sample is handled by a chromatographic device or the like, a syringe injection device is sometimes used to perform a pretreatment such as dilution of the liquid or to inject the liquid sample into the chromatographic device or the like. . The syringe injection device uses a syringe for sucking and discharging a liquid sample, and a plunger in the syringe body is slid manually or by driving a motor, so that a sample is drawn from a needle (needle) connected to one end of the syringe. Is sucked and discharged. This syringe injecting device is suitable for injecting a small amount of liquid and the like, because suction and discharge are performed by a needle connected to the syringe. 2. Description of the Related Art Conventionally, various types of needles have been used as needles for injecting a small amount of liquid with a syringe injection device. As the main shape of the needle, there are a blade cutting needle, a right angle cutting needle, and a side hole needle as shown in FIG.

[0003]

Each of these needles has the following disadvantages. When a small amount of a blade-cutting needle or a right-angled needle is ejected, a large droplet is generated on the blade surface at the tip, and a large difference occurs in the injection amount without dropping the droplet (a difference of about 30 to 40 μl occurs for each droplet). ) Is a problem. In addition, since the needle hole is at the tip of the needle in the blade cutting needle and the right angle needle, rubber scraps are generated when the septum rubber or the like provided in the sample introduction part of the chromatograph is pierced,
This causes foreign matter to clog the needle hole.

On the other hand, the side-hole needle has few such drawbacks, but since the liquid is sucked and discharged in the lateral direction, for example, when a liquid sample is discharged into the sample introducing portion of the chromatograph device, A liquid sample will once adhere to the lateral wall surface, and if the amount of the sample is very small, it may not be possible to mix it with another sample in the sample introduction part, or when the sample is aspirated, a very small amount of sample may not be aspirated. There's a problem.

In view of the above, the present invention uses a needle in which the liquid drops from the needle are easily drained, the needle hole is less likely to be clogged due to the generation of rubber scraps, and the liquid is not discharged laterally. The present invention aims to provide a syringe injection device.

[0006]

The syringe injection device of the present invention made to solve the above problems is a syringe injection device for sucking and discharging a sample through a needle connected to a syringe body. It consists of a sharp needle tip with a large diameter and a hollow needle body that is larger in diameter than the needle tip, and the needle tip and the needle body are connected by a tapered surface,
The tapered surface is provided with a needle hole for suction and discharge that communicates with the hollow region of the needle body.

In the syringe injection device of the present invention, the needle connected to the syringe body does not have a needle hole at the tip of the needle, and therefore the tip of the needle has a small diameter and a sharp shape.
The tip of the needle is connected to the needle body having a diameter larger than that of the tip via the tapered surface. A hollow hole through which the liquid sample flows is provided in the needle body, and the hollow hole communicates with the needle hole provided on the tapered surface.
Since the sample is sucked and ejected through the needle hole provided on this tapered surface, the ejection direction of the liquid is not the lateral direction but the oblique forward direction, and the needle tip has a small diameter,
Even if droplets are generated, they fall within a small diameter.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a syringe injection device showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a needle portion thereof. In the figure, 1 is a needle body, 2 is a needle tip, 3 is a tapered surface, and 4 is a needle hole. The needle body 1 has a hollow shape, and this hollow region communicates with the needle hole 4. In this embodiment, two needle holes 4 are provided in the tapered surface 3 to prevent the ejection directions from being biased. The number of holes may be further increased, and by increasing the number of holes, deviation in the ejection direction can be further reduced and the amount of ejected liquid can be increased. Reference numeral 5 is a syringe body to which the terminal side of the needle body 1 is connected. A plunger 6 is slidably mounted in the syringe body 5, and a reciprocating motion of the plunger is performed by a motor drive mechanism (not shown).

When liquid is discharged using the syringe injection device of the present invention, the liquid is discharged not in the lateral direction but in the direction of the inclined surface of the needle. Then, after the liquid sample is ejected, when the droplets adhere to and remain on the needle, the droplets move to the tip of the needle by their own weight. Since the cross-sectional area of the tip of the needle is small, it drops immediately while the droplet is small. That is, as described in FIG. 4, the droplets attached to the tip of the needle depend on the cross-sectional area of the tip portion, and the larger the cross-sectional area, the larger the droplet tends to be. As shown in the figure, the cross-sectional area of the tip of the needle is relatively large in the blade surface cut or right-angled cut, so that large droplets adhere, but as in the present invention, a needle hole is not provided in the needle tip and a small diameter is used. By doing so, the cross-sectional area of the tip portion can be made small, so that the droplets that adhere will drop while they are small, and the liquid cut-off characteristic will be improved.

[0010]

As described above, in the syringe injection device of the present invention, the tip of the needle connected to the syringe has a small diameter, and the needle hole has a tapered surface at the tip which is a connecting portion with the needle body. Since it is provided in the above, the liquid is well drained, and the droplets adhering to the tip of the needle are dropped while they are small, which improves the quantitativeness. Further, the clogging of the needle hole with rubber scrap is also reduced. Further, the discharge direction of the liquid is not the right side but the oblique direction with respect to the needle direction, and is not easily affected by impurities attached to the lateral wall surface of the sample introduction part.

[Brief description of drawings]

FIG. 1 is a sectional view of a syringe injection device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a needle portion of the syringe injection device of FIG.

FIG. 3 is a cross-sectional view of a conventional needle.

FIG. 4 is a diagram showing a state of droplets attached to a needle.

[Explanation of symbols]

 1: Needle body part 2: Needle tip part 3: Tapered surface 4: Needle hole 5: Syringe body 6: Plunger

Claims (1)

[Claims] 1. A syringe injection device for sucking and discharging a sample through a needle connected to a syringe body, wherein the needle has a thin and sharp needle tip, and a needle having a diameter larger than the needle tip and hollow. The needle body is composed of a needle body, and the needle tip and the needle body are connected by a tapered surface, and the tapered surface is provided with a needle hole for suction and discharge that communicates with a hollow region of the needle body. Syringe injection device.