JPH08303600A - Lip packing for rotary valve - Google Patents

Abstract

PURPOSE: To improve the form of a lip packing so that air bubbles are not mixed therein. CONSTITUTION: For interposing no gap between optional two adjoining openings 82 of a lip packing 60, the adjoining openings 82 are partitioned off with a common lip 86A. Even if a rotor is rotated, air bubbles are not taken in a port.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lip packing of a rotary valve used for switching a flow path of an analyzer.

[0002]

2. Description of the Related Art Japanese Utility Model Publication No. 3-55098 discloses a rotary valve lip packing formed by integrally molding a plurality of O-ring portions on one annular sheet.

[0003]

As will be described later with reference to the drawings, in this integral type packing, adjacent O
Since the ring portions are isolated from each other and a gap is present between the adjacent O-ring portions, when the rotor of the rotary valve is rotated to switch the flow passage, the port of the rotor has a space where air is present. Will pass through. As a result, there is a risk that air will be taken into the flow path of the analyzer, which causes an analysis error.

It is an object of the present invention to improve the shape of the lip packing so as to provide a lip packing free from air bubbles.

[0005]

Configuration of the Invention

SUMMARY OF THE INVENTION According to the present invention, in a lip packing arranged between a stationary member of a rotary valve and a rotor, adjacent openings of the lip packing are partitioned by a common lip. It is characterized in that it constitutes a lip packing.

As described above, by sharing the lip separating the adjacent openings of the lip packing, the space in which air may exist between the adjacent openings is eliminated, so that the rotor can be rotated while the rotor is rotated. The port never touches the air. Therefore, it is possible to prevent bubbles from being mixed in the flow path of the analyzer and improve the analysis accuracy.

In a preferred embodiment, the opening of the lip packing is formed in a fan shape in plan view. By doing so, even if some error occurs in the positioning of the rotor, the flow path can be surely connected.

The above features and effects of the present invention, as well as other features and effects, will be described in more detail according to the description of the following embodiments.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The attached drawings show an application example of the lip packing of the present invention. 1 and 2, a syringe pump rotary valve module 1 in which a rotary valve 14 is integrally incorporated in the head of a micro syringe pump 12
0 is shown, and the lip packing of the present invention is used for this rotary valve 14.

The syringe pump 12 has a main body 18 having a cylinder hole 16 formed therein. A piston 20 is slidably fitted in this cylinder hole to form a variable volume pump chamber 22. An O-ring 24 is arranged on the outer circumference of the piston 20 so that the piston 20 can fit into the cylinder hole 16
It is designed to slide in a liquid-tight manner.

The piston 20 is reciprocally driven by a motor 32 such as a stepping motor fixed to the base 30 of the main body 18 and a lead screw 34 which converts the rotation of the motor into a linear motion. The lead screw 34 is connected to the output shaft of the motor 32, and a nut 36 is engaged with the lead screw.

A pair of diametrically opposed detent pins 38 penetrate through the skirt of the piston 20, and the tips of these pins 38 are screwed into the nut 36.
The detent pin 38 is slidably guided in a pair of axial slots 40 formed in the body 18. Therefore, if the motor 32 is rotated in either direction, the nut 36
At the same time, the piston 20 is driven up and down to suck the liquid into the pump chamber 22 or deliver the liquid from the pump chamber.
The syringe pump 12 includes a central port 42 that communicates with the pump chamber 22 through which liquid enters and exits the rotary valve 14.

In the illustrated embodiment, the rotary valve 14
Is configured to switch the pump chamber 22 of the syringe pump 12 to six flow paths. Rotary valve 14
Has a stepping motor 50 with a reduction gear and a disk-shaped rotor 52 that is rotationally driven by this motor. The rotor 52 is rotatably fitted in a cylindrical recess 56 formed in the head portion 54 of the main body 18. Therefore, the head portion 54 of the main body 18 also serves as the stationary member of the rotary valve 14.

A lip packing 60 of the present invention is disposed between the bottom surface 58 of the recess 56 and the rotor 52. The rotor 52 and the lip packing 60 are biased toward the bottom surface 58 of the recess 56 by the coil spring 62, so that the lip packing 60 is sandwiched between the rotor 52 and the bottom surface 58 of the recess 56 with an appropriate sealing pressure. It has become.

The rotor 52 is provided with a central port 64 that is aligned and opposed to the central port 42 of the syringe pump 12, and an outer port 66 that is offset radially outward from the central port 64. The ports 64 and 66 are connected to each other by a horizontal internal passage 68.

As can be seen clearly in FIG. 5, the bottom surface 58 of the recess 56 has, for example, six circumferentially equally spaced ports 70 open at the same radial offset distance as the outer port 66 of the rotor 52. Each of these ports 70 communicates with a nipple 74 by a corresponding internal passage 72 formed in the body head 54. To these nipples 74 can be connected hoses or lines extending from the components of the analyzer.

Since the rotary valve 14 has such a structure, by driving the motor 50, the rotor 52 can be rotated until the outer port 66 of the rotor 52 is aligned with any one of the ports 70 of the bottom surface 58. Twelve pump chambers 22 are connected to either nipple 74. If the syringe pump 12 is operated at this position,
Liquid can be aspirated from the port 70 communicating with either nipple 74 or delivered to either port.

Referring to FIGS. 3 and 4, the lip packing 60 of the present invention has a disk-shaped body 80 made of an elastic material such as an elastomer. In the illustrated embodiment, the body 80 is provided with a rotary body. Formed are six outer openings 82 that communicate with the six outer ports 70 of the valve 14, respectively, and one central opening 84 that communicates with the central ports 42 and 64 of the rotary valve. Respective openings 82 and 84
Is surrounded by a lip 86 protruding upward from the main body 80 of the lip packing 60, and the lip 86 is elastically engaged with the lower surface of the rotor 52.

The lip 86 is fan-shaped and any two circumferentially adjacent outer openings 82 are partitioned from each other by a radial portion 86A of the lip 86. Inner lip portion 86 surrounding the central opening 84
B and the outer portion 86C of the lip 86 are formed in a circular shape. A similar lip 88 is also formed on the back surface of the body 80 so as to elastically engage with the bottom surface 58 of the recess 56.

Referring to FIG. 6, which is an exploded view of the section taken along line 6-6 of FIG. 3, the rotor 52 is used to switch the port 70.
The rotation of the rotor causes the outer port 66 of the rotor to transition from one opening 82 to the adjacent opening 82 over the radial portion 86A of the lip. Each opening 82 communicates with port 70 and is therefore filled with the liquid used for analysis so that rotor outer port 66 does not come into contact with air during rotation of rotor 52.

On the other hand, as shown in FIG. 7, when the packing of Japanese Utility Model Publication No. 3-55098 described above is used, the respective O-ring portions 90 are isolated from each other and adjacent O-rings are provided. Since there is a gap 92 in which air may exist between the portions 90 and 90, the outer port 66 of the rotor may come into contact with air as the rotor 52 rotates, and air bubbles may be taken into the port 66. is there. When the amount of the liquid measured and transferred by the microsyringe pump 12 in the analysis is on the order of microliter (μl), even if a minute amount of air bubbles is mixed in the fluid transfer system, the analysis accuracy is adversely affected.

In the lip packing 60 of the present invention,
Since the lip portions 86A that partition the adjacent openings 82 are made common, and there is no space in which air may exist between the adjacent openings 82, the port 66 of the rotor is exposed to air while rotating the rotor. There is no touch.

Further, since the lip portion defining each opening 82 is formed in a fan shape and has a certain length in the circumferential direction, the outer port 66 of the rotor 52 does not have to be precisely aligned with the port 70. However, the ports 66 and 70 can be communicated with each other. Therefore, the assembly accuracy of the parts and the control of the motor 50 can be simplified.

Although a specific embodiment of the present invention has been described above, the present invention is not limited to this, and various design changes can be made. For example, the number of ports of the rotary valve can be appropriately increased or decreased, and the port arrangement can be appropriately changed. The arrangement of the opening of the lip packing can be changed accordingly.

[0025]

As described above, according to the lip packing of the present invention, it is possible to prevent air bubbles from being taken into the port of the rotary valve and improve the analysis accuracy.

When the lip of the lip packing is formed in a fan shape, it is possible to simplify assembly accuracy of parts and control of the motor.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a syringe pump rotary valve module to which the lip packing of the present invention can be applied.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a plan view of the lip packing of the present invention.

4 is a cross-sectional view of the lip packing taken along line 4-4 of FIG.

5 is a plan view taken along line 5-5 of FIG.

6 is a development view of a cross section taken along line 6-6 of FIG.

FIG. 7 is a development view similar to FIG. 5 and shows a case where a packing of the related art is used.

[Explanation of reference symbols] 14: Rotary valve 52: Rotary valve rotor 54: Rotary valve stationary member 60: Lip packing 82: Lip packing opening 86: Lip packing lip

Claims (3)

[Claims] 1. Used for sealing between a rotor static member and a rotor having a plurality of ports arranged circumferentially, and engaging the rotor with an opening corresponding to each port of the static member. A lip packing for a rotary valve, characterized in that, in a lip packing having a lip, adjacent openings are partitioned by a common lip. 2. The lip packing according to claim 1, wherein the lip defining the opening is fan-shaped in a plan view. 3. A lip packing according to claim 1 or 2 having a lip which engages said stationary member.