JPH10311441A - Valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve capable of preventing its sealing performance and operability from being degraded because of fluid pressure or the rotational operation of a valve element. SOLUTION: A valve element housing hole 30 provided with an inlet passage 23 and an outpet passage 25 and a valve seat surface having openings as communication ports for the other sides of the inlet passage 23 and the outlet passage 25 in the fettorn surface are provided in a valve case 26, a valve element 33 provided with a communication passage 34 is housed in the valve element housing hole 30, and is elastically supported by the valve case 26 in a pressed-to-contact state with the valve seat surface side by a pressing spring member 36 and a connecting member 38, a rotation operating means 39 rotationally operating the valve element 33 to a valve opening position or a valve closing position, is provided to a stem 32 at the upper end side of the valve element 33, valve ports at both end sides for the communication passage 34 of the valve element 33, are opened to a bottom surface pressed into contact with the valve set surface, and an intermediate portion mutually communicating the valve ports, is embedded in the inside of the valve element 33. Therefore, by miniaturizing the pressure receiving area of the valve element 33, stable sealing performance is obtained with a comparatively low spring pressure, to smoothly open/close the valve by lowering spring pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve for opening and closing or switching and distributing a flow path of a high-pressure fluid, and for pumping a fluid sample, for example, as a main valve of gas or water or when analyzing a chemical or the like. It is used by mounting it in a pipe flow path. It is small, lightweight, pressure-resistant and chemical-resistant, such as a sample injector (sample injection part) used when performing sample analysis by liquid chromatography. It is very suitable for use as a valve for opening / closing or switching a flow path that requires the above.

[0002]

2. Description of the Related Art As a valve of this type, there is, for example, a valve 1 as shown in FIG. 1 which has already been implemented by the present applicant. This valve 1 communicates with connection ports 2 and 3 of an input / output flow path. Valve holes 6 and 7 communicating with each other through the valve holes 4 and 5 are opened in the upper valve seat surface, and a valve seat member 8 is formed.
A valve body member 10 having a communication groove 9 for communicating or blocking the space between the valve seat member 8 and the valve seat member 8;
Is mounted in the valve case 11 in a state where the bottom surface is in surface contact with the valve seat surface, and a fastening ring 13 is detachably attached to the threaded cylindrical portion 12 formed on the upper end side of the valve case 11, and the fastening is performed. A pressure spring member 1 that presses the valve body member 10 against a valve seat surface between the ring 13 and the valve body member 10.
4 and a washer 15 are provided.
6, the upper end side of the valve stem 16 is inserted into the fastening ring 13 to protrude outward, and the upper end side of the valve stem 16 is fitted with a cap 18 to which an operation handle 17 is attached. A sliding guide groove 19 for regulating the rotation angle of the valve body member 10 rotated by the operation handle 17 is provided on the inner peripheral surface of the screw tube portion 12, and a base portion of the sliding guide groove 19 is attached to the valve body member 10. This is a structure in which the implanted locking pins 20 protrude.

When the operation handle 17 is rotated, the valve body member 10 of the valve 1 is slid on the valve seat surface of the valve seat member 8 via the valve rod 16 in a press-contact state. However, the input / output flow path between the connection ports 2 and 3 communicates with the valve holes 6 and 7 via the communication holes 4 and 5 at the positions aligned with the valve holes 6 and 7, and the flow path is blocked at other mismatched positions.

When the tightening ring 13 is tightened with respect to the valve case 11, the compression state of the pressing spring member 14 is changed to increase or decrease the spring pressure, and the pressure contact state of the valve body member 10 against the valve seat surface is adjusted. Be able to withstand the pressure of the high pressure fluid being handled.

The valve seat member 8, the valve body member 10, and the valve stem 16 of the valve 1 are provided to reduce abrasion due to sliding, to enhance the sealing performance against high-pressure fluid, and to prevent corrosion by the fluid. In addition, a synthetic resin material such as a fluororesin which is relatively flexible and has a small coefficient of friction and excellent in chemical resistance is used, and a synthetic resin material such as a PEEK material or a fluororesin is used for the valve case 11. Etc. are used.

[0006]

However, in the case of the valve 1 having the above-mentioned conventional structure, the pressure receiving area of the valve body member 10 is large due to the horizontally long communication groove 9 formed in the bottom, and the valve body 10 is separated from the valve seat surface. When a strong pressing force by the high-pressure fluid acts on the valve body member 10 from the flow path side and the spring pressure of the pressing spring member 14 due to the adjustment of the tightening ring 13 is weak, the sealing performance against fluid leakage may be impaired. When the pressure is increased, the switching operation of the valve by the operation handle becomes heavier by that amount, so that there is a trouble of making an appropriate adjustment within a range where the spring pressure is not increased more than necessary according to the fluid pressure to be handled.

Further, when the shape and cross-sectional area of the flow path change when the fluid is transferred from the valve holes 6 and 7 to the communication groove 9, the flow velocity and the fluid pressure change, and at the same time, turbulence and stagnation occur. Is likely to occur, and it may not be possible to maintain a constant laminar flow condition.In particular, when transferring a fluid to be used as a sample for analysis, the sample is agitated and the accuracy of analysis is impaired, or part of the sample is It remains in the space between the valve seat member 8 and the valve body member 10 and is not removed even in advance of washing when another sample analysis is performed, and the accuracy of analysis as a contaminant is impaired.

The switching force of the valve is changed by adjusting the pressing force of the high-pressure fluid and the spring pressure of the tightening ring 13, and the locking pin 20 for the sliding guide groove 19 for regulating the rotation angle of the valve is opened and closed. In the case of the structure mounted on the body member 10, the locking pin 20
And the sliding friction force also increases and decreases, so that smooth opening and closing of the valve by rotation of the operation handle 17 may be impaired.

Further, when a relatively flexible synthetic resin material such as fluororesin is used for the valve member 10 to which the locking pin 20 is mounted, the operating handle is used when opening or closing the valve. 17 rotates the locking pin 20 into the sliding guide groove 1.
If an excessive rotational operation force is applied too much when locked at the start end or the end of 9, the valve body member 10 may be deformed and deformed, and the sealing performance to the valve seat surface may be impaired.

Therefore, in the present invention, the communication groove provided on the bottom surface of the valve member for opening and closing the flow path has a structure having a small pressure receiving area, so that a stable sealing performance can be obtained even with a relatively small spring pressure. By reducing the spring pressure, the valve opening / closing operation is facilitated, and by forming a continuous flow path having a substantially constant shape and cross-sectional area, fluid agitation and residue are reduced, and valve opening / closing rotation is performed. By moving the positioning means by the sliding guide groove and the locking pin that regulate the angle to a position that does not affect the valve body member, there is no change in the engagement state due to spring pressure adjustment, and the valve opening / closing operation is smooth. It is another object of the present invention to provide a valve capable of solving the above-mentioned problem in the related art by preventing distortion of the valve body member so that sealing performance is not impaired.

[0011]

According to the present invention, there is provided a valve according to the present invention, which has an inflow passage having one end communicating with an input connection, an outflow passage having one end communicating with an output connection, and an inflow passage having these inflows. The valve case is provided with a valve body receiving hole formed in the bottom surface of a valve seat surface that is opened at the other end side of the channel and the outflow channel as a communication port, and the communication hole is communicated with or blocked by the valve body receiving hole. A valve body having a communication passage for opening and closing or switching is rotatably housed, and the valve body is elastically supported by the valve case in a state where the valve body is pressed against the valve seat surface by a pressing spring member and a connecting member. A valve stem is provided on the upper end side of the valve body, and the valve stem is provided with a rotating operation means for rotating the valve body to the valve opening position or the valve closing position, and the communication passage of the valve body is provided at both ends. While opening the valve port on the bottom surface that is pressed against the valve seat surface, An intermediate portion for communicating the valve opening mutually embedded in the valve body interior.

In the valve, the communication passage of the valve body and the inflow passage and the outflow passage of the valve case have a circular cross-sectional shape, and the valve port of the communication passage and the communication opening of the inflow passage and the outflow passage have a cross-sectional shape and a cross-sectional area. It is preferable that the opening and closing operation means and the valve case are provided so as to set the valve opening position and the valve closing position. Preferably, for example, the opening / closing operation means is constituted by an opening / closing operation knob attached to an upper end of a valve stem protruding from the valve case, and the positioning means is one of the valve case or the opening / closing operation knob. It is preferable to comprise a locking pin protruding from the other, and an arc-shaped sliding guide groove which is recessed in one of the other and is engaged with the locking pin.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 2 is a perspective view of a valve applied to a sample injector, FIG. 3 is a longitudinal sectional view of the valve of FIG. 2, and FIG. 4 is an operation state of the valve of FIG. 5 is a plan view of a fluid switching device using the valve of FIG. 2 as a sample injector, FIG. 6 is a circuit diagram illustrating the operation of the fluid switching device of FIG. 5, and FIG. 7 is an opening / closing valve according to another embodiment. FIG. 8 shows an embodiment in which the present invention is applied to a switching valve.

The valve 21 is, as shown in FIGS.
A valve case 2 having an inflow path 23 communicating with the inflow side connection port 22 and an outflow path 25 communicating with the outflow side connection port 24.
6, a stator portion is formed. In this embodiment applied to a sample injector, in order to press-fit an analysis sample solution into the inflow channel 23 using a syringe, the inflow channel 23 is inclined and a screw is screwed into the inflow-side connection port 22. A hole is formed and an adapter 28 provided with a mounting hole 27 for a syringe is screwed in and connected. An outlet connection port 24 is connected to a fluid switching device described later to transfer a fluid for analysis from an outlet channel 25 to a fluid. A screw shaft 29 which can be screwed and connected directly to the switching device or to a connector for piping is formed so as to protrude.

A valve housing hole 30 is formed in the valve case 26. A communication port 23a, 2 at the end of the inflow passage 23 and the outflow passage 25 is formed in a valve seat surface 31 formed by the bottom surface of the valve housing hole 30.
5a are respectively opened, and a valve body 33 integrally formed with a valve rod 32 at an upper end side is rotatably fitted into the valve body accommodating hole 30. 34a,
34b are respectively opened at the bottom surface, and the valve port 3
A communication passage 34 having an intermediate portion embedded in the valve body 33 is formed in a manner to connect the 4a and 34b to each other. The communication passage 34 has substantially the same cross section as the inflow passage 23 and the outflow passage 25 in cross section. When the valve body 33 is rotated as shown by 4, the valve port and the communication port formed at both open ends are aligned at the valve open position, and are misaligned at the valve closed position. ing.

In the illustrated embodiment, it is assumed that the valve case 26, the valve rod 32 and the valve body 33 are machined.
The inflow passage 23, the outflow passage 25, and the communication passage 34 are formed to have a circular cross-section, and a combination of straight lines so that holes can be formed from the opening side. However, the present invention is not limited to this. It can be implemented in a form suitable for it.

The valve element 33 fitted into the valve element receiving hole 30 is
It is elastically supported by a pressing spring member 36 fitted on the outer periphery of the valve stem 32, and is screwed into a thread groove 37 formed on the upper inner peripheral surface of the valve body receiving hole 30 by being fitted to the valve stem 32. In this embodiment, a plurality of disc springs are used as the pressing spring member 36, and the connecting member 38 is tightened for receiving and rotating a tool. Means (not shown, for example, a slit on the upper surface) is provided to constitute a rotor portion mounted on the stator portion. When the rotor portion is mounted, a connecting member 38 screwed into the screw groove 37 is provided. The compression deformation state of the pressing spring member 36 is changed by tightening, and the pressure contact state of the valve body 33 against the valve seat surface 31 is set as desired.

A switching knob 39 for rotating the valve body 33 to open and close the flow path is mounted on the upper end of the valve rod 32. The switching knob 39 is screwed into a screw hole. An engaging slot 35 provided in the valve stem 32 with the tip of a set screw 40
In order to set the valve opening position and the valve closing position, positioning means for regulating the rotation angle of the switching operation knob 39 is provided by the switching operation knob 39 and the valve case 26.
The switching operation knob 39 is provided in this embodiment.
A sliding guide groove 41 cut out in an arc shape of 60 ° is provided on the outer circumference on the bottom side of the valve case, and a locking pin 42 protruding from the upper surface of the valve case 26 is engaged with the sliding guide groove 41. In some embodiments, the stop pin 41 is implanted on the switching knob 39 side to engage with the sliding guide groove 41 provided on the valve case 26 side.

The valve body 33 and the valve rod 32 of the valve 21 are relatively flexible in order to reduce abrasion due to sliding, to enhance the sealing performance against high-pressure fluid, and to prevent corrosion by the fluid. It is possible to use a synthetic resin material such as a fluororesin, which has a low friction coefficient and excellent chemical resistance, and to use a synthetic resin material such as a PEEK material or a fluororesin for the valve case 26. desirable.

In the illustrated embodiment, the adapter 28
The sample solution was press-fitted by inserting the syringe into the mounting hole 27 of the above. However, instead of the adapter 282, a connector with a piping tube was screwed into the inflow-side connection port 22 and connected to the pumping means such as a syringe or an injection pump. It is also possible to inject the sample solution through a piping tube, and furthermore, make the inflow-side connection port 22 a screw shaft to which a female connector is connected in the same manner as the outflow-side connection port 24, or inject the outflow-side connection port 24 In some embodiments, similarly to the side connection port 22, a screw hole to which a male connector is connected is provided.

The valve 21 according to the above embodiment is provided with a sliding guide groove 41 by rotating the switching operation knob 39 forward or backward.
Is guided by the locking pin 42 while the valve stem 32 and the valve body 3
3 rotates between the valve-opening position and the valve-closing position in FIG. 4, and in the valve-opening position, the valve ports 34 a and 34 b at both ends of the communication passage 34 are valve seat surfaces 31.
The flow path is aligned with the communication port 23a of the inflow path 23 and the communication port 25a of the outflow path 25, and the valve ports 34a and 34b at both ends of the communication path 34 are in the closed position. Since the communication port 23a is not aligned with the communication port 25a of the outflow path 25 and the communication port 23a and the communication port 25a are closed by the flat portion on the bottom surface of the valve body 33, the inflow path 23 and the outflow path 25
The flow path between them is blocked.

When the valve 21 is compared with the valve 1 having a conventional structure, the inflow passage 2 on the valve case 26 side serving as a stator portion is provided.
3 and the communication ports 23a, 25a of the outflow passage 25 and the valve ports 34a, 34b of the communication path 34 on the valve body 33 side serving as the rotor section are formed in substantially the same shape and sectional area. The liquid can be sent in a constant laminar flow state in which the change in pressure is reduced and the occurrence of turbulence and stagnation is reduced.

Further, by reducing the pressure receiving area of the valve body 33 that receives the high-pressure fluid, the sealing performance against fluid leakage is improved, and since the spring pressure of the pressing spring member 36 can be adjusted, the connecting member 38 is excessively large. Since no special tightening is required, the switching operation of the switching knob 39 can be performed smoothly.

Further, positioning means for restricting the rotation angle of the switching operation knob 39 is provided between the switching operation knob 39 which does not affect the valve body 33 and the valve case 26.
The fluid leakage due to the deformation of the valve body 33 during the rotation operation is eliminated, and the engagement of the positioning means is performed by the distortion deformation of the valve body 33 during the rotation operation, the pushing up of the valve body 33 by the fluid pressure, and the spring pressure adjustment. Since the combined state is not changed, the operability of the switching operation knob 39 is impaired, or the communication passage 34 and the valve ports 34a, 34b are opened at the valve open position.
There is no fear that the alignment state is shifted.

The valve 21 is used as a sample injector, for example, as shown in FIG. 5 and as an outline of the operating state in FIG. 5 for switching and transferring an analysis sample solution to a separation column of liquid chromatography. Although it can be used by being attached to the switching device 43, the effects of the present invention can be particularly effectively exhibited in such a case.

The fluid switching device 43 is mounted on a donut-shaped stator portion 44 and an axis of the stator portion 44, and is rotated by a switching operation handle 45 to a predetermined angle (30 ° in the illustrated embodiment). The rotor portion 46 is provided, and the stator portion 44 is provided with through holes 47a to 47f in the radial direction at every predetermined angle (30 ° in the illustrated embodiment). Communication passages 48 a to 48 c formed in an arc shape are provided so as to communicate between the two adjacent through holes provided.
Devices to be switched are connected to the outer peripheral ends of the a to 47f, and the inner peripheral ends of the through holes 47a to 47f are opened so as to be aligned with the communication paths 48a to 48c.

In the fluid switching device 43, for example,
7a is connected to the valve 21 serving as the sample injector via a screw shaft 29, and the other through holes 47b to 47b
As shown in the figure, a separation column 51, a loop (a sample solution accumulation line) is connected to the 7f via a connector 49 and a piping tube 50.
52, the liquid feed pump 53 for the mobile phase, and the waste liquid tank 54, respectively, and the switching operation of the rotor unit 46 by the switching operation handle 45 switches the flow path to the state shown in FIG. 6A or 6B. When the analysis is completed, the old sample solution remaining inside after the analysis is washed and the sample solution to be newly analyzed is pre-filled into the loop 52 having a constant internal volume is used in the state shown in FIG. Then, the analysis is performed in the state shown in FIG.

The sample liquid previously filled in the loop 52 through the valve 21 and the communication path 48a of the fluid switching device 43 in the state of FIG.
3 and the mobile phase fed through the communication passage 48c of the fluid switching device 43 is pressure-fed to the separation column 51 as a carrier, and a predetermined analysis operation is performed in the separation column 51 filled with the stationary phase. 6A is discharged to the waste liquid tank 54 by the cleaning liquid supplied through the valve 21 in the state of FIG. 6A, and the sample liquid to be analyzed next is newly filled in the loop 52. .

The pumping of the mobile phase to the separation column 51
In order to reduce the fluctuation of the pressure, the operation is continuously performed regardless of the switching of the flow path.
When the flow path is switched to the state of (a), the pressure fluid may flow backward from the loop 52 side to the sample liquid injection side via the communication path 48a. Since the used sample injector is mounted, the open / close valve needs to have a high sealing property capable of withstanding the pressure of the high-pressure fluid, and the valve 21 according to the present invention is adapted for such use. .

That is, the use of the valve 21 for improving the sealing property and enabling the fluid supply with little fluctuation in the sample injector enables the sample liquid to be agitated when the fluid to be used as the sample for analysis is transferred, so that the analysis can be performed. There is no possibility that the accuracy is impaired, or that a part of the sample remains as a contaminant in the gap between the valve case 26 and the valve body 33 and the accuracy is impaired when performing another sample analysis. It is possible to prevent the pressure fluid from flowing back to the side, and it can be used effectively for general use, but it is a valve suitable especially for delicate sample analysis by liquid chromatography.

Next, FIG. 7 shows another embodiment of the valve according to the present invention. These embodiments show the inflow side connection port on the stator portion, that is, the valve case side, with respect to the rotor portion having an on-off valve mechanism including a valve body. The configuration of the rotor section and the basic structure of the stator section are the same as those of the previous embodiment, except for the arrangement of the outflow path and the outflow-side connection port, and therefore, the parts that function in the same manner are described above. The following description will be given with the same reference numerals as in the embodiment, and duplicate description will be omitted.

In the valve 21A of FIG. 7 (a), the inflow side connection port 27 and the outflow side connection port 24 are arranged in a direction perpendicular to the axis of the valve body 33, and the inflow side connection port 27 is provided.
And the outflow side connection port 24 are arranged in series, and one end side (valve port 34 a) of the communication path 34 formed in the valve body 33 side and the inflow side connection port 27 are connected by the inflow path 23. The outflow passage 2 is provided between the other end (the valve port 34b) of the passage 34 and the outflow side connection port 24.
A flow path is formed in the valve case 26A so as to be connected at 5.

In the valve 21B shown in FIG. 7B, the inflow-side connection port 27 and the outflow-side connection port 24 are arranged in a direction parallel to the axis of the valve element 33, and the inflow-side connection port 27 is provided.
And an outflow side connection port 24 are arranged in parallel, and one end side (valve port 34 a) of the communication passage 34 formed in the valve body 33 side and the inflow side connection port 27 are connected by the inflow path 23. The outflow passage 2 is provided between the other end (the valve port 34b) of the passage 34 and the outflow side connection port 24.
A flow path is formed in the valve case 26 </ b> B so as to be connected at 5.

In the valve 21C shown in FIG. 7C, the inflow side connection port 27 and the outflow side connection port 24 are arranged in a direction perpendicular to the axis of the valve body 33, and the inflow side connection port 27 is provided.
And the outflow side connection port 24 are arranged in parallel, and the valve port 34a of the communication passage 34 formed in the valve body 33 side and the inflow side connection port 27
Are connected by an inflow path 23, and the valve port 34 b of the communication path 34 and the outflow side connection port 24 are connected by an outflow path 25,
A flow path is formed in the valve case 26C.

In the valve 21D of FIG. 7D, the inflow side connection port 27 is arranged in a direction parallel to the axis of the valve body 33, and the outflow side connection port 24 is arranged in a direction perpendicular to the axis.
The inflow side connection port 27 and the outflow side connection port 24 are arranged orthogonally, and an inflow path is provided between one end side (valve port 34 a) of the communication passage 34 formed in the valve body 33 and the inflow side connection port 27. 23, and the valve case 2 is connected so that the outflow path 25 is connected between the other end side (valve port 34b) of the communication path 34 and the outflow side connection port 24.
A flow path is formed in 6D.

In the valve 21E shown in FIG. 7E, the inflow side connection port 27 is arranged in a direction perpendicular to the axis of the valve body 33 and the outflow side connection port 24 is arranged in a direction parallel to the axis.
The inflow side connection port 27 and the outflow side connection port 24 are arranged orthogonally, and a valve port 34 of a communication hole 34 formed in the valve body 33 side.
a and the inflow side connection port 27 are connected by the inflow path 23, and the connection between the valve port 34 b of the communication hole 34 and the outflow side connection port 24 is the outflow path 2.
A flow path is formed in the valve case 26E so as to be connected at 5.

Furthermore, the valve according to the present invention can be applied not only to the opening and closing of the flow path described in the above embodiment, but also to a flow path switching valve as in the embodiment shown in FIG. 8, for example. In the valve 55, one inflow-side connection port 57 and a plurality of (two in the illustrated example) outflow-side connection ports 58 and 59 are provided in a valve case 56, and a communication port 60 a of an inflow path 60 communicating with the inflow-side connection port 57. The outflow passages 61 and 62 communicating with the outflow side connection ports 58 and 59 constitute a stator portion in which communication ports 61 a and 62 a are opened in a valve seat surface 64 on the bottom surface of the valve body housing hole 63.

The rotor portion is mounted in the valve housing hole 63 of the valve case 56 in the same manner as the embodiment shown in FIGS. When the valve body 33 is rotated, the valve port 34 of the communication passage 34 is
a and 34b are selectively aligned with either the communication port 60a of the inflow path 60 and the communication port 61a of the outflow path 61, or the communication port 60a of the inflow path 60 and the communication port 62a of the outflow path 62. The inflow channel and the outflow channel are configured to communicate with each other via the intermediary.

In this embodiment, a valve for switching two flow paths has been described. However, various modifications such as application to switching of three or more flow paths with a similar structure are possible. The valve case is provided with six communication holes, one end of which is open to the valve seat surface, and the valve body, which is the rotor, is provided with three communication passages, each of which has a communication port opening on the bottom surface. It is also possible to apply to a valve that functions in the same manner as the fluid switching device described based on the above.

[0040]

As is clear from the embodiments described above, in the valve of the present invention, the bottom surface is pressed against the valve seat surface with the communication port between the inflow passage and the outflow passage opened. A communication path for communicating or blocking the communication port between the communication ports is provided on the seated valve element, and the communication ports are opened at the bottom of the valve ports at both ends and an intermediate portion is embedded in the valve element. As the pressure receiving area is reduced, the action of the pressing spring member that seats the valve body on the valve seat surface effectively functions to enhance the sealing effect, and as a leakage between the valve case and the valve body as impurities. The accumulation of the residual liquid is eliminated, and the spring pressure does not need to be excessively increased, so that the operation for rotating the valve body is also facilitated.

The communication passage of the valve body and the inflow passage and the outflow passage of the valve case have a circular cross-sectional shape, and the valve opening of the communication passage and the communication opening of the inflow passage and the outflow passage have substantially the same cross-sectional shape and cross-sectional area. Then, the flow of the fluid becomes smooth, and particularly when used as a sample injector, turbulence, stagnation or stirring of the sample liquid, which may hinder the accuracy of analysis, can be reduced.

Further, if positioning means for regulating the rotation angle of the valve element is provided between the opening / closing operation means which does not affect the valve element and the valve case, the valve element may be distorted when the valve element is rotated. Since there is no possibility of deformation, it is possible to eliminate the possibility of fluid leakage due to reduced sealing performance, accumulation of residual liquid as impurities between the valve case and the valve body, and the like, as well as inflow to the valve port of the communication passage. There is no deviation in the alignment position of the communication port between the path and the outflow path, and the operation for rotating the valve body is not impaired.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a valve having a conventional structure.

FIG. 2 is an external perspective view of a valve according to the embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the valve of FIG. 2;

FIG. 4 is an explanatory diagram of an opening / closing operation state of the valve in FIG. 2;

FIG. 5 is a plan view of a fluid switching device for liquid chromatography using the valve of FIG. 2;

FIG. 6 is a circuit diagram illustrating the operation of the fluid switching device of FIG. 5;

FIG. 7 is a front view of a state in which a part of an on-off valve according to another embodiment of the present invention is broken.

FIG. 8 is a front view of a state in which a part of a switching valve according to another embodiment of the present invention is broken.

[Explanation of symbols]

 21, 21A to 21E, 55 Valve 22, 57 Inflow side connection port 23, 60 Inflow path 23a, 25a Communication port 24, 58, 59 Outflow side connection port 25, 61, 62 Outflow path 26, 56 Valve case 27 Mounting hole 28 Adapter 29 Screw shaft 30, 63 Valve housing hole 31, 64 Valve seat surface 32 Valve rod 33 Valve 34 Communication passage 34a, 34b Valve port 35 Locking groove 36 Pressing spring member 37 Screw groove 38 Connecting member 39 Switching knob Reference Signs List 40 Set screw 41 Sliding guide groove 42 Lock pin 43 Fluid switching device 44 Stator part 45 Switching operation handle 46 Rotor part 47a to 47f Through hole 48a to 48c Communication path 49 Connector 50 Piping tube 51 Separation column 52 Loop 53 Liquid pump 54 Waste liquid tank

Claims (3)

[Claims] An inflow path having one end communicating with an input connection port, an outflow path having one end communicating with an output connection port, and a valve seat having the other end of each of the inflow path and the outflow path opening as a communication port. A valve housing hole with a surface formed on the bottom surface is provided in the valve case, and the valve housing hole is provided with a communication passage for opening or closing or switching the flow path by communicating or blocking the communication port. The valve body is elastically supported by the valve case in a state in which the valve body is pressed against the valve seat surface side by a pressing spring member and a connecting member, and a valve stem is provided on an upper end side of the valve body. The valve body is provided with a rotating operation means for rotating the valve body to a valve opening position or a valve closing position, and the communication passages of the valve body are formed such that valve ports at both end sides are respectively opened to a bottom surface which is pressed against the valve seat surface. In particular, the fact that an intermediate portion that allows the valve port to communicate with each other is buried inside the valve body. Signs of the valve. 2. The communication path of the valve body and the inflow path and the outflow path of the valve case have a circular cross-sectional shape, and the valve port of the communication path and the communication port of the inflow path and the outflow path have substantially the same cross-sectional shape and cross-sectional area. The valve of claim 1, wherein the valve is formed. 3. The valve opening and closing position, wherein a positioning means for regulating a rotation angle of the valve body is provided between the opening / closing operation means and the valve case to set the valve opening position and the valve closing position. 3. The valve according to 2.