JP2008215494A - Flow passage switching valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability of a valve, in the flow passage switching valve used for a liquid chromatograph. <P>SOLUTION: This flow passage switching valve has a stator 11 and a rotor 15 having a mutually contacting contact plane, and has sample flowing ports 19 connected to a plurality of respective flow passages on the contact plane 13 of the stator 11, and has at least one sample groove 21 communicating two in the sample flowing ports 19 on the contact plane 17 of the rotor 15, and rotatably slides the rotor 15 so as to switch the sample flowing ports 19 to be communicated by the sample groove 21. This invention is characterized by having a plurality of cleaning liquid flowing ports 22 for flowing a cleaning liquid on the contact plane 13 of the stator 11, and having at least one cleaning groove 22 communicating two in the cleaning liquid flowing ports 22 on the contact plane 17 of the rotor 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flow path switching valve used in a liquid chromatograph or the like.

In a high performance liquid chromatograph, it is necessary to switch the liquid flow path under high pressure.
Conventionally, as a flow path switching valve in such an application, a disk-shaped rotor having a switching groove is contacted in a plane with a disk-shaped stator (stator) having a through hole connected to the groove. A switching valve that rotates while rotating is used (see Patent Document 1).

The stator is sandwiched between the housing top to which the flow path is connected and the rotor, and the rotor is pressed toward the stator by a predetermined force necessary for airtightness of the switching groove by an elastic member such as a spring. Liquid leakage from the groove is prevented by surface contact with the groove. The stator may be integrated with the housing top.
The rotor is attached to the tip of the rotating shaft, rotates by receiving a rotational driving force, and the flow path is switched by switching the connection state with the through hole on the stator side.

As a material of such a conventional flow path switching valve, a soft material such as resin is used for the rotor, and a material harder than the rotor such as stainless steel is used for the stator.
However, if the valve is used over a long period of time, the contact plane of the rotor made of a material softer than the stator will be worn, which increases rotational torque in the valve, fluid leakage, and cross-contamination due to liquid remaining on the worn part of the rotor. There is a problem of causing an increase.

  In the flow path switching valve, the rotor is pressed against the stator with a constant force in order to prevent liquid leakage. When the rotor rotates in this state, if the rotor material is resin, the rotor is scraped off by friction due to rotation, generating shavings, which causes clogging of the downstream flow path piping and deterioration of the column. . On the other hand, some rotors are made of ceramic, but in such cases, no such shavings are generated. However, in consideration of sealing properties, both the stator and the rotor have a small surface roughness and are flat. It is necessary to finish with high accuracy. However, when such surfaces are pressed against each other with a strong force, there is a problem that a mirror surface adhesion phenomenon called so-called linking occurs, which impairs the rotational operation of the rotor.

JP-A-1-307575

  In addition, the flow path connection part of the conventional flow path switching valve has only a connection part for sample introduction, and when a solvent (for example, a buffer solution) in which salt is precipitated after the organic solvent is volatilized is fed at high pressure. For example, if the flow path is not sufficiently cleaned after the analysis, salt is deposited on the sliding surface between the stator and the rotor. Thereafter, if the operation is continued as it is, scratches are generated on the rotor surface, so that there is a problem that the life of the rotor is remarkably reduced.

  Therefore, an object of the present invention is to improve the durability of the flow path switching valve.

  The flow path switching valve of the present invention includes a stator and a rotor having contact planes that are in contact with each other, the contact plane of the stator has a sample flow port connected to each of a plurality of flow paths, and the contact plane of the rotor includes The rotor has at least one sample groove for communicating two of the sample flow ports, and the rotor rotates and slides so as to switch the sample flow port to be communicated by the sample groove. The contact plane of the stator has a plurality of cleaning liquid flow ports through which the cleaning liquid flows, and the contact plane of the rotor has at least one cleaning groove for communicating two of the cleaning liquid flow ports. .

  As a preferred embodiment, one of the cleaning liquid flow ports is provided on the outer peripheral side of the sample flow port, and one of the cleaning grooves is provided on the outer peripheral side of the sample groove.

  Further, any one of the cleaning liquid circulation ports may be provided on the inner peripheral side with respect to the sample circulation port, and any one of the cleaning grooves may be provided on the inner peripheral side with respect to the sample groove.

  The flow path switching valve of the present invention includes a stator and a rotor having contact planes that are in contact with each other, the contact plane of the stator has a sample flow port connected to each of a plurality of flow paths, and the contact plane of the rotor includes The rotor has at least one sample groove for communicating two of the sample flow ports, and the rotor rotates and slides so as to switch the sample flow port to be communicated by the sample groove. The contact plane of the stator has a plurality of cleaning liquid flow ports through which the cleaning liquid flows and at least one cleaning groove for communicating two of the cleaning liquid flow ports.

  The cleaning groove may be wider and shallower than the sample groove so that liquid leaking from the sample groove can also flow into the cleaning groove. If it does so, the liquid which leaked from the sample groove | channel can be efficiently flowed even with a little washing | cleaning liquid.

  As a preferable example of the shape of the groove, a plurality of sample grooves may be formed in a fan shape on the rotor, and the cleaning groove may be formed in a straight line along the plurality of sample grooves.

In the flow path switching valve according to the present invention, the contact plane of the stator has a plurality of cleaning liquid flow ports, and the contact plane of the rotor includes at least one groove for communicating two of the cleaning liquid flow ports. By constantly feeding a cleaning liquid such as distilled water different from the analytical use from the mouth, the sliding surface of the valve (between the stator and the rotor) can be automatically cleaned even during analysis.
Thus, until now, when a buffer solution was sent to the valve at a high pressure, it was necessary to thoroughly clean the flow path after the end of the analysis. Even if the cleaning is not sufficiently performed, it is possible to prevent the sealing performance of the rotor from being significantly lowered.
Even if the liquid to be fed is not a buffer containing salt, but a commonly used organic solvent or distilled water, the friction between the stator and the rotor can be obtained by constantly feeding the washing liquid to the sliding surface. Since the frictional heat generated by sliding can be suppressed, the life of the sealing performance of the rotor is extended.

  If the cleaning groove is provided on the outer peripheral side of the sample groove, the liquid accumulated on the outer peripheral portion of the sliding surface of the stator and the rotor is discharged together with the cleaning water flowing through the cleaning groove, and abnormal wear can be suppressed.

  If the cleaning groove is provided on the inner peripheral side of the sample groove, the liquid accumulated in the inner peripheral portion between the stator and the rotor is discharged together with the cleaning water flowing through the cleaning groove, and abnormal wear can be suppressed.

  If there is a plurality of cleaning liquid flow ports for flowing the cleaning liquid on the contact plane of the stator and at least one cleaning groove for communicating two of the cleaning liquid flow ports, it is not necessary to form grooves in the rotor. It is easy to configure the valve.

  By making the groove width of the cleaning groove wide and shallowing the groove, the sliding surface can be widely cleaned while keeping the amount of the cleaning liquid small.

  If the cleaning groove is formed in a straight line along the sample groove, only two cleaning liquid circulation ports need be formed regardless of the shape and number of the sample grooves.

An embodiment of the present invention will be described below with reference to the drawings.
1A and 1B are schematic views of a flow path switching valve according to an embodiment. FIG. 1A is a sectional view of the entire valve, FIG. 1B is a plan view of a contact plane side of a stator 11, and FIG. Is shown.
The stator 11 is made of stainless steel and has an integrated housing top to which a flow path is connected. The stator contact plane 13 of the stator 11 is in contact with the rotor contact plane 17 of the rotor 15, and a through hole (sample flow port) 19 provided in the stator 11 is communicated with a sample groove 21 provided in the rotor 15. Yes. The rotor 15 is made of, for example, resin, and a plurality of sample grooves 21 are provided in an arc shape. If it is made of resin, it must be replaced because it wears out. In this embodiment, the rotor side is made of resin because the rotor is easier to process than the stator, but contrary to the above, the stator is made of resin and the rotor is made of stainless steel or resin. It may be made.

The stator 11 is provided with a plurality of sample flow path connection portions 23, and the tips thereof communicate with the through holes 19 of the contact plane 13. The sample groove 21 communicates with the two through holes 19.
The rotor 15 is attached to the tip of the shaft 25 and is urged toward the stator 11 by a spring 29 of an elastic member provided in a body portion 27 that rotatably supports the shaft 25. The body portion 27 is screwed to the outer peripheral portion of the stator 11 with bolts 31.

The stator 11 is provided with two cleaning liquid connection portions 24, and their tips communicate with a through hole (cleaning liquid flow port) 20 of the contact plane 13. A cleaning groove 22 is provided in the contact plane 17 of the rotor 15 and communicates the two through holes 20.
In the above-described embodiment, the cleaning flow path connecting portion 24 and the cleaning groove 22 are provided on the outer peripheral portion than the sample flow path connecting portion 23 and the sample groove 21, respectively, but they may be provided on the inner peripheral portion. Moreover, you may make it provide in both an outer peripheral part and an inner peripheral part.

When the sample is sent to the valve, the target sample is sent from the sample flow path connecting portion 23, and distilled water for cleaning the sliding surfaces of the stator 11 and the rotor 15 is sent from the cleaning flow path connecting portion 24. Liquid.
When a buffer solution is used as a sample, the liquid has leaked from the groove 21 until now and salt has been deposited on the sliding surface. In the present invention, the sliding surface (between the stator and the rotor) is automatically formed. Since it can wash | clean, precipitation of a salt etc. can be prevented. Thereby, the durability of the rotor is improved.

2A and 2B are schematic views of a flow path switching valve according to another embodiment, FIG. 2A is a plan view of the contact plane side of the stator 11, and FIG. 2B is a perspective view of the rotor 15.
In FIG. 1 described above, the cleaning groove 22 is formed on the contact plane 17 of the rotor 15, but in this embodiment, the cleaning groove 32 is formed on the contact plane 13 of the stator 11. In this case, the stainless steel stator 11 is provided with two cleaning liquid flow ports 20 and a cleaning groove 32 communicating with the two cleaning liquid flow ports 20. Since only the stator 11 side needs to be processed to distribute the cleaning water, the step of processing the grooves in the rotor 15 can be omitted. Also in this case, since the sliding surface can be automatically cleaned by flowing the cleaning water into the cleaning groove 32, salt precipitation and the like can be prevented, and the durability of the rotor is improved.

  The present invention can be used for high-performance liquid chromatographs, analytical instruments and other instruments that require switching of flow paths.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic of the flow-path switching valve in one Example is shown, (A) is sectional drawing of the whole valve | bulb, (B) is a top view on the contact plane side of a stator, (C) has shown the perspective view of the rotor. The schematic of the flow-path switching valve in another Example is shown, (A) is a top view on the contact plane side of a stator, (B) has shown the perspective view of the rotor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Stator 13 Contact plane 15 Rotor 17 Contact plane 19, 20 Through-hole 21 Sample groove 22, 32 Cleaning groove 23 Sample flow path connection part 24 Cleaning flow path connection part 25 Shaft 27 Body part 29 Spring 31 Bolt

Claims (6)

A stator and a rotor having contact planes in contact with each other are provided, the contact plane of the stator has a sample flow port connected to each of a plurality of flow paths, and the contact plane of the rotor has 2 of the sample flow ports. A flow path switching valve having at least one sample groove that communicates with each other, and wherein the rotor is rotated and slid so as to switch the sample flow port to be communicated by the sample groove;
The contact plane of the stator has a plurality of cleaning liquid flow ports through which a cleaning liquid flows, and the contact plane of the rotor has at least one cleaning groove for communicating two of the cleaning liquid flow ports. Flow path switching valve.   2. The flow path switching valve according to claim 1, wherein at least one pair of the cleaning liquid flow ports is provided on an outer peripheral side of the sample flow port, and at least one of the cleaning grooves is provided on an outer peripheral side of the sample groove. .   The at least one pair of the said washing | cleaning liquid circulation port is provided in the inner peripheral side rather than the said sample circulation port, At least 1 of the said cleaning groove | channel is provided in the inner peripheral side rather than the said sample groove | channel. Flow path switching valve. A stator and a rotor having contact planes in contact with each other are provided, the contact plane of the stator has a sample flow port connected to each of a plurality of flow paths, and the contact plane of the rotor has 2 of the sample flow ports. A flow path switching valve having at least one sample groove that communicates with each other, and wherein the rotor is rotated and slid so as to switch the sample flow port to be communicated by the sample groove;
A flow path switching valve characterized in that a contact plane of the stator has a plurality of cleaning liquid flow ports for flowing a cleaning liquid and at least one cleaning groove for communicating two of the cleaning liquid flow ports.   The flow path switching valve according to any one of claims 1 to 4, wherein the cleaning groove is wider and shallower than the sample groove.   The flow path switching according to any one of claims 1 to 5, wherein a plurality of the sample grooves are formed in a fan shape on the rotor, and the cleaning grooves are formed in a straight line along the plurality of sample grooves. valve.

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