Flow path switching valve, method for operating same, and liquid chromatograph provided with said flow path switching valve
The flow path switching valve efficiently removes wear particles through integrated discharge grooves, addressing friction-related issues and extending service life without additional cleaning mechanisms.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- HITACHI HIGH TECH CORP
- Filing Date
- 2025-08-07
- Publication Date
- 2026-06-18
Smart Images
Figure JP2025028078_18062026_PF_FP_ABST
Abstract
Description
Flow path switching valve, method of operating the same, and liquid chromatograph including the flow path switching valve 【0001】 The present invention relates to a flow path switching valve, a method of operating the same, and a liquid chromatograph including the flow path switching valve. 【0002】 Conventionally, a flow path switching valve having a stator and a rotor in which a sample groove and a cleaning groove are formed on a contact surface with respect to the stator is known (see, for example, Patent Document 1). Specifically, this flow path switching valve has a pair of sample grooves that extend in an arc shape in the circumferential direction on the contact surface on the rotor side with respect to the stator, and an arc-shaped cleaning groove that extends in the circumferential direction on the outer peripheral side of these sample grooves and surrounds the pair of sample grooves. Further, a sample flow port is formed in the stator so as to face the sample groove of the rotor, and a cleaning liquid flow port is formed so as to face the cleaning groove of the rotor. 【0003】 In this flow path switching valve, when the rotor rotates with respect to the stator at a predetermined angle, the flow path on the stator side of the sample flowing through the sample groove on the rotor side is switched. Further, in this flow path switching valve, the contact surface between the sliding stator and rotor is cleaned by a cleaning liquid such as distilled water that constantly flows through the cleaning groove on the rotor side. According to such a flow path switching valve, the space between the stator and the rotor is automatically cleaned even during the analysis of a sample by a predetermined apparatus to which the flow path switching valve is applied. As a result, the flow path switching valve can prevent salts and the like contained in the sample from being deposited as dried solids between the stator and the rotor without separately performing a cleaning operation after use. 【0004】 Japanese Patent Application Laid-Open No. 2008-215494 【0005】Incidentally, in flow path switching valves, which generally switch the flow path of a sample by the rotation of a rotor, fine wear particles can be generated due to friction between the rotor and the stator. These wear particles further accelerate wear at the contact surface between the rotor and the stator, and gradually accumulate on the contact surface. This wear at the contact surface between the rotor and the stator hinders the adhesion between the rotor and the stator. Furthermore, the accumulated wear particles increase the frictional resistance of the rotor against the stator, hindering the smooth flow path switching operation of the flow path switching valve. Ultimately, the generation of wear particles reduces the service life of the flow path switching valve. 【0006】 Therefore, it is conceivable to use a conventional flow path switching valve (see, for example, Patent Document 1) that has a cleaning function between the stator and the rotor, for the purpose of removing wear particles generated on the contact surface (sliding surface) between the rotor and the stator. However, conventional flow path switching valves (see, for example, Patent Document 1) are configured to clean the liquid sample remaining between the stator and the rotor, and have the problem of not being able to efficiently remove the solid wear particles that are generated. In addition, conventional flow path switching valves require an additional liquid supply mechanism such as a liquid supply device for the cleaning liquid, which has the problem of making the predetermined device using this flow path switching valve larger. 【0007】 The object of the present invention is to provide a flow path switching valve and a method for operating the same, as well as a liquid chromatograph equipped with this flow path switching valve, which can efficiently remove wear particles generated on the sliding surface between the stator and rotor without requiring an additional liquid supply mechanism, efficiently prevent the accumulation of wear particles on the sliding surface, and ultimately achieve a longer service life. 【0008】The flow path switching valve of the present invention, which solves the above problems, comprises a stator and a rotor that rotates while sliding in contact with the stator, wherein the stator has a plurality of through holes, the rotor has flow path grooves that communicate with the through holes, and at least one of the sliding surfaces of the rotor and the stator has a wear particle discharge groove, one end of the wear particle discharge groove is located within the sliding surface, and the other end of the wear particle discharge groove faces the outside of the sliding surface. Furthermore, the operation method of the flow path switching valve of the present invention, which solves the above problems, is an operation method of the flow path switching valve, comprising a flow path switching step by the rotor that switches the communication between the through holes of the stator and the flow path grooves of the rotor, and a wear particle discharge step by the rotor that discharges wear particles from the sliding surface through the wear particle discharge groove. Furthermore, the liquid chromatograph of the present invention, which solves the above problems, comprises the flow path switching valve. 【0009】 According to the present invention, it is possible to provide a flow path switching valve and a method for operating the same, as well as a liquid chromatograph equipped with this flow path switching valve, which do not require an additional liquid supply mechanism, efficiently remove wear particles generated on the sliding surface between the stator and rotor, efficiently prevent the accumulation of wear particles on the sliding surface, and consequently achieve a longer service life. 【0010】This is an explanatory diagram of the configuration of a flow path switching valve according to an embodiment of the present invention. This is a partial top view of the rotor constituting the flow path switching valve according to an embodiment of the present invention. This is a partial bottom view of the stator constituting the flow path switching valve according to an embodiment of the present invention. This diagram shows the positional relationship between the stator and the rotor in contact with the stator at a first position in a flow path switching valve according to an embodiment of the present invention. This diagram shows the positional relationship between the stator and the rotor in contact with the stator at a second position in a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a liquid chromatograph equipped with a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a first modified example of a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a second modified example of a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a third modified example of a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a fourth modified example of a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a fifth modified example of a flow path switching valve according to an embodiment of the present invention. This is an explanatory diagram of the configuration of a sixth modified example of a flow path switching valve according to an embodiment of the present invention. This is a partial top view of the rotor in a seventh modified example of a flow path switching valve according to an embodiment of the present invention. This is a partial bottom view of the stator in a seventh modified example of a flow path switching valve according to an embodiment of the present invention. This is a partial top view of the rotor in an eighth modified example of a flow path switching valve according to an embodiment of the present invention. This is a partial bottom view of the stator in an eighth modified example of a flow path switching valve according to an embodiment of the present invention. This is a diagram illustrating the configuration of a ninth modified example of a flow path switching valve according to an embodiment of the present invention. This is a diagram illustrating the configuration of a tenth modified example of a flow path switching valve according to an embodiment of the present invention. This is a flowchart showing the procedure executed by the control unit constituting the flow path switching valve shown in Figure 15. 【0011】The flow path switching valve of the present invention and embodiments for implementing a liquid chromatograph equipped therewith will be described in detail with reference to the drawings as appropriate. Below, the flow path switching valve applicable to a liquid chromatograph will be described. However, the flow path switching valve of the present invention is not limited to this and can be used in various chemical analysis devices other than liquid chromatographs. Furthermore, the flow path switching valve of the present invention can also be applied to flow path switching valves in liquid-liquid contact devices such as microreactors. 【0012】 (Flow path switching valve) Figure 1 is an explanatory diagram of the configuration of the flow path switching valve 1 according to this embodiment. Figure 1 is a longitudinal cross-sectional view of the flow path switching valve 1 corresponding to the I-I section of Figure 4A which will be described later. In the following description, the vertical direction is based on the vertical direction indicated by the arrow in Figure 1. As shown in Figure 1, the flow path switching valve 1 mainly comprises a stator 11 and a rotor 12 that rotates while sliding in contact with the stator 11. 【0013】 In this embodiment, the stator 11 is assumed to be made of a metal such as stainless steel or a ceramic. Alternatively, a stator 11 with a diamond-like carbon coating on its surface can also be used. The stator 11 has a stator body 11a, a rotor contact portion 11b that is integrally provided with the stator body 11a and contacts the rotor 12, and a flange portion 11c that is integrally provided with the stator body 11a and supported by a support portion 14. 【0014】 The stator body 11a is formed to occupy most of the stator 11 and has a substantially cylindrical outer shape. The rotor contact portion 11b is formed to have a smaller diameter than the stator body 11a and is formed in a circular, trapezoidal shape that protrudes downward from the lower surface of the stator body 11a. The rotor contact portion 11b has a circular lower surface in a plan view that is perpendicular to the axis of the stator body 11a and coaxial with it. This lower surface forms the sliding surface S1 of the stator 11 with respect to the rotor 12 (see Figure 3). 【0015】The flange portion 11c is formed to partially protrude outward from the circumferential surface of the lower end of the stator body 11a. The flange portion 11c is fixed to the support portion 14 with screws (not shown). As a result, the stator body 11a is supported by the support portion 14 via the flange portion 11c. In this embodiment, the support portion 14 can utilize a part of the housing (not shown) that houses the stator 11 and rotor 12, or it can be constructed from a separate component from the housing. 【0016】 The stator 11 has a plurality of through-holes 31 through which a liquid sample flows. The through-holes 31 are formed to penetrate vertically through the stator body 11a and the rotor contact portion 11b. The liquid flow port 31a formed at the lower end of the through-hole 31 faces the flow channel groove 32 of the rotor 12, which will be described later, when the rotor 12 rotates relative to the stator 11 to a predetermined rotation angle. In other words, the through-hole 31 communicates (conducts) with the flow channel groove 32. Furthermore, the piping P (see Figure 5) of an analytical device (for example, the liquid chromatograph 100 (see Figure 5) described later) will be connected to the upper end of the through-hole 31. The arrangement of the through-holes 31 will be described in detail later. 【0017】 Next, the rotor 12 (see Figure 1) will be described. As shown in Figure 1, the rotor 12 comprises a rotor body 12a and a rotor seal 12b. In this embodiment, the rotor body 12a is assumed to be made of a metal such as stainless steel and has a substantially cylindrical outer shape. A disc-shaped rotor seal 12b is attached to the upper surface of the rotor body 12a by pins (not shown) so as to be coaxial with the rotor body 12a. 【0018】 In this embodiment, the rotor seal 12b is assumed to be made of a material such as stainless steel, ceramic, or resin. Furthermore, for rotor seals 12b made of metal or ceramic, a surface coated with diamond-like carbon can also be used. A flow channel groove 32 and a wear chip discharge groove 33, which will be described in detail later, are formed on the upper surface of the rotor seal 12b. 【0019】The rotor 12 is positioned coaxially with the stator 11, and the rotor seal 12b is in contact with the rotor contact portion 11b of the stator 11. The rotor 12 is also rotatable around its axis at a predetermined angle, as described later, by a shaft 15 extending from a motor 17 with an encoder connected to the rotor body 12a. 【0020】 Furthermore, the rotor 12 is configured such that the rotor seal 12b is pressed against the rotor contact portion 11b with a predetermined load by a biasing means 16 such as a spring. As a result, the flow channel groove 32 formed in the rotor seal 12b is sealed liquid-tight by the rotor contact portion 11b. 【0021】 Next, the flow channel groove 32 and the wear chip discharge groove 33 formed in the rotor seal 12b will be described. Figure 2 is a partial top view of the rotor 12, showing only the rotor seal 12b portion of the rotor 12. In Figure 2, reference numeral S2 denotes the sliding surface of the rotor 12 that slides against the rotor contact portion 11b of the stator 11, indicated by the dashed line (two-dot dashed line). For ease of drawing, the sliding surface S2 of the rotor 12 is shown with shading. 【0022】 As shown in Figure 2, the flow channel grooves 32 in this embodiment are formed as grooves that extend in an arc shape along the upper surface of the rotor seal 12b. Specifically, the flow channel grooves 32 extend in the circumferential direction around the axis of the rotor seal 12b with a predetermined circumference, and are formed so that multiple grooves are arranged in the circumferential direction at predetermined intervals. The circumference, number, and position of each flow channel groove 32 can be set to correspond to the circumferential arrangement angle, number, and position of the liquid flow port 31a (see Figure 1) of the stator 11 (rotor contact portion 11b), and the rotation angle of the rotor 12. In this embodiment, as shown in Figure 2, it is assumed that there are three flow channel grooves 32 arranged at equal intervals in the circumferential direction with a predetermined circumference, but the positional relationship between the flow channel grooves 32 and the liquid flow port 31a (see Figure 1) of the rotor contact portion 11b (see Figure 1), and the rotation angle of the rotor 12 will be explained in detail later. 【0023】As shown in Figure 2, the wear debris discharge groove 33 is formed as a groove extending radially from the inside to the outside of the rotor seal 12b. In this embodiment, the wear debris discharge groove 33 has an oval shape (running track shape) with arc portions at both ends in the longitudinal direction when viewed from above. Furthermore, one end of the wear debris discharge groove 33 formed radially inward is located within the sliding surface S2 of the rotor 12, and the other end of the wear debris discharge groove 33 formed radially outward faces the outside of the sliding surface S2. More specifically, in this embodiment, one end of the wear debris discharge groove 33 radially inward (inner circumference end) is located outside the flow channel groove 32, and the other end radially outward (outer circumference end) is located outside the sliding surface S2. That is, the other end (outer circumference end) of the wear debris discharge groove 33 communicates with the gap between the stator 11 and the rotor 12 formed outside the sliding surface S2. 【0024】 In this embodiment, the wear debris discharge grooves 33 are assumed to be arranged in multiple rows at equal intervals in the circumferential direction of the rotor seal 12b. Specifically, the wear debris discharge grooves 33 are assumed to be arranged at intervals less than or equal to a predetermined rotation angle of the rotor 12. Incidentally, the predetermined rotation angle of the rotor 12 in this embodiment is assumed to be 60 degrees, as will be described later. Therefore, in this embodiment, the wear debris discharge grooves 33 are arranged at equal intervals in the circumferential direction with an interval of 60 degrees or less between adjacent grooves. 【0025】 In other words, in the example shown in Figure 2, the wear debris discharge grooves 33 are arranged in a circumferential direction with seven grooves spaced 51.4 degrees apart. The number of wear debris discharge grooves 33 will be explained in detail later, but it can be set to one or more grooves as appropriate depending on the rotation angle of the rotor 12, which is set in advance. Furthermore, in the configuration in which multiple wear debris discharge grooves 33 are arranged in a circumferential direction, the spacing between adjacent grooves is not limited to being equal. 【0026】Next, the multiple through holes 31 (see Figure 1) that penetrate the stator 11 (see Figure 1) in the axial direction will be described. Figure 3 is a partial bottom view of the stator 11, showing only the rotor contact portion 11b (see Figure 1). As shown in Figure 3, the lower surface of the rotor contact portion 11b forms the sliding surface S1 of the stator 11 that slides against the sliding surface S2 (see Figure 2) of the rotor seal 12b (see Figure 2). As shown in Figure 3, in this embodiment, the through holes 31 are formed in a circular direction around the axis of the rotor contact portion 11b, with six holes arranged at equal intervals (60-degree intervals). Each of the six through holes 31 has a circular cross-section of the same diameter and forms a liquid flow port 31a that opens to the sliding surface S1. 【0027】 Next, the positional relationship between the liquid flow port 31a of the through hole 31 formed in the stator 11 (rotor contact portion 11b) and the flow channel groove 32 formed in the rotor 12 (rotor seal 12b) will be explained. Figure 4A shows the positional relationship between the stator 11 and the rotor 12 in contact with the stator 11 at a first position. Figure 4B shows the positional relationship between the stator 11 and the rotor 12 in contact with the stator 11 at a second position. Figures 4A and 4B correspond to the IV-IV cross section in Figure 1. 【0028】 As shown in Figure 4A, the rotor 12 in the first position connects the through-hole 31 indicated by A and the through-hole 31 indicated by B of the stator 11 by the flow channel groove 32 indicated by X. The rotor 12 in the first position also connects the through-hole 31 indicated by C and the through-hole 31 indicated by D of the stator 11 by the flow channel groove 32 indicated by Y. The rotor 12 in the first position also connects the through-hole 31 indicated by E and the through-hole 31 indicated by F of the stator 11 by the flow channel groove 32 indicated by Z. 【0029】In this configuration, each of the six through-holes 31 has a liquid flow port 31a located at the circumferential end of each of the three flow grooves 32. That is, the circumference of the arc-shaped flow groove 32 is set to correspond to the distance between liquid flow ports 31a arranged on a predetermined circumference. Specifically, the circumference of the flow groove 32 is set so that, when viewed from above the rotor 12, each of the adjacent liquid flow ports 31a fits within the respective ends of the flow groove 32. Furthermore, the distance of the flow groove 32 from the axis of the rotor 12 is set to match the distance of the liquid flow port 31a from the axis of the stator 11. 【0030】 Next, the rotor 12 in the second position will be described. As shown in Figure 4B, the second position of the rotor 12 is set by rotating the rotor 12 in the first position shown in Figure 4A at a predetermined rotation angle θ1 (60 degrees). The rotation angle θ1 of the rotor 12 is set to match the angle (60 degrees) of the fluid flow port 31a centered on the axis of the stator 11. That is, the rotation angle θ1 of the rotor 12 is 2π / M [radians], where M is the number of fluid flow ports 31a arranged at equal intervals. 【0031】 As the rotor 12 changes from the first position to the second position, the flow channel groove 32 indicated by X, which connects the through hole 31 indicated by A in Figure 4A and the through hole 31 indicated by B, switches its flow channel so that it connects the through hole 31 indicated by B and the through hole 31 indicated by C, as shown in Figure 4B. 【0032】 Furthermore, the flow channel groove 32 indicated by Y, which connects the through hole 31 indicated by C in Figure 4A and the through hole 31 indicated by D, switches its flow path so that it connects the through hole 31 indicated by D and the through hole 31 indicated by E, as shown in Figure 4B. Also, the flow channel groove 32 indicated by Z, which connects the through hole 31 indicated by E in Figure 4A and the through hole 31 indicated by F, switches its flow path so that it connects the through hole 31 indicated by F and the through hole 31 indicated by A, as shown in Figure 4B. 【0033】Next, the displacement of the wear debris discharge groove 33 relative to the stator 11 (rotor contact portion 11b) when the rotor 12 changes from the first position to the second position will be described. As shown in Figure 4B, for example, the wear debris discharge groove indicated by the dotted line 33X and the adjacent dotted line indicated by the dotted line 33Y are separated by an interval of θ2 (51.4 degrees), as described above. 【0034】 Then, when the rotor 12 rotates at a predetermined rotation angle θ1 (60 degrees), the wear debris discharge groove indicated by the dotted line 33X in Figure 4B (the wear debris discharge groove at the first position in Figure 4A) moves to the position of the wear debris discharge groove 33X indicated by the solid line (the wear debris discharge groove at the second position in Figure 4B) so as to open at an angle of θ1 (60 degrees). Meanwhile, the wear debris discharge groove indicated by the dotted line 33Y in Figure 4B (the wear debris discharge groove at the first position in Figure 4A) moves to the position of the wear debris discharge groove 33Y indicated by the solid line (the wear debris discharge groove at the second position in Figure 4B) so as to open at an angle of θ1 (60 degrees). 【0035】 Therefore, in this flow path switching valve, when the rotor 12 rotates at a predetermined rotation angle θ1 (60 degrees) to switch the through-holes 31 that communicate with each other via the flow path grooves 32, the range in which one wear debris discharge groove 33X rotates and the range in which the adjacent wear debris discharge groove 33Y rotates overlap. In other words, in this flow path switching valve 1, when the rotor 12 rotates at a predetermined rotation angle θ1 (60 degrees), each wear debris discharge groove 33 (see Figure 4A) works together to set the range of movement of the wear debris discharge grooves 33 without interruption in the circumferential direction of the sliding surface S1 (see Figure 3) of the stator 11. 【0036】(Liquid Chromatograph) Next, a liquid chromatograph equipped with a flow path switching valve 1 (see Figures 4A and 4B) according to this embodiment will be described. Figure 5 is an explanatory diagram of the configuration of a liquid chromatograph 100 equipped with a flow path switching valve 1. In the flow path switching valve 1 shown in Figure 5, the flow path grooves 32 indicated by X (see Figure 4A), Y (see Figure 4A), and Z (see Figure 4A) of the rotor 12 at the first position are each represented by solid lines. In addition, the flow path grooves 32 indicated by X (see Figure 4B), Y (see Figure 4B), and Z (see Figure 4B) at the second position, which is obtained by rotating the rotor 12 clockwise from the first position at an angle θ1 (see Figure 4B) toward the plane of the paper in Figure 5, are each represented by dotted lines. 【0037】 As shown in Figure 5, the liquid chromatograph 100 includes a needle 109 for supplying the sample 108 to be analyzed to the flow path switching valve 1, a suction pump 106, a liquid transfer pump 102 for supplying the eluent 101, which serves as a carrier for the sample 108, to the flow path switching valve 1, a separation column 103, a detector 104, and piping P connecting these to the flow path switching valve 1. 【0038】 Specifically, the needle 109 of the liquid chromatograph 100 is connected to the aforementioned upper end of the through-hole 31 indicated by E via piping P1. The suction pump 106 is connected to the aforementioned upper end of the through-hole 31 indicated by D via piping P2. The liquid transfer pump 102 is connected to the aforementioned upper end of the through-hole 31 indicated by A via piping P3. The separation column 103 and the detector 104 are connected to the aforementioned upper end of the through-hole 31 indicated by B via piping P4. The aforementioned upper end of the through-hole 31 indicated by F of the liquid chromatograph 100 and the aforementioned upper end of the through-hole 31 indicated by C are connected by a sample loop P5 (for example, a hollow tube). 【0039】In such a liquid chromatograph 100, when the rotor 12 is in the first position and the liquid transfer pump 102 is driven, the eluent 101 is sent to pipe P4 via pipe P3, through hole 31 indicated by A, flow channel groove 32 indicated by X, and through hole 31 indicated by B. The eluent 101 flowing through pipe P4 passes through separation column 103 and detector 104 before being collected in waste liquid tank 105. 【0040】 Furthermore, when the rotor 12 is in the first position and the suction pump 106 is driven, the sample 108 flows into the pipe P2 via the needle 109, the pipe P1, the through hole 31 indicated by E, the flow channel groove 32 indicated by Z, the through hole 31 indicated by F, the sample loop P5, the through hole 31 indicated by C, the flow channel groove 32 indicated by Y, and the through hole 31 indicated by D. When the sample 108 begins to be discharged from the pipe P2 into the waste liquid tank 107, the liquid transfer pump 102 and the suction pump 106 stop. 【0041】 Next, when the rotor 12 rotates to the predetermined rotation angle θ1 (see Figure 4B) and is set to the second position, the flow channel groove 32 indicated by Y switches to connect the through hole 31 indicated by D and the through hole 31 indicated by E. Also, the flow channel groove 32 indicated by Z switches to connect the through hole 31 indicated by F and the through hole 31 indicated by A. As a result, the sample loop P5 is disconnected from the pipes P1 and P2 and filled with a predetermined amount of sample 108. 【0042】 Furthermore, when the rotor 12 is set to the second position and the liquid transfer pump 102 starts to operate, the eluent 101 is sent to the sample loop P5 via the piping P3, the through hole 31 indicated by A, the flow channel groove 32 indicated by Z, and the through hole 31 indicated by F. The eluent 101 sent to the sample loop P5 then flows into the through hole 31 indicated by C, together with the sample 108 that was filling the sample loop P5. 【0043】The eluent 101 and the sample 108 that flow into the through-hole 31 indicated by C are sent out to the pipe P4 through the flow path groove 32 indicated by X and the through-hole 31 indicated by B. The separation column 103 separates the analysis species contained in the sample 108 by the interaction between the stationary phase and the mobile phase. The detector 104 outputs the detection signal of the separated analysis species to a display device (not shown) or the like. The sample 108 and the eluent 101 that have passed through the separation column 103 and the detector 104 are collected in the waste liquid tank 105. 【0044】 For the flow path switching valve 1 of the liquid chromatograph 100 as described above, every time the rotor 12 rotates at a rotation angle θ1 (60 degrees) to switch the flow path between the sample 108 and the eluent 101, the wear powder discharge groove 33 moves along the sliding surface S1 (see FIG. 3) of the stator 11, thereby collecting and discharging the wear powder from between the stator 11 and the rotor 12. 【0045】 ≪Function and Effect≫ Next, the function and effect of the flow path switching valve 1 according to the present embodiment and the liquid chromatograph 100 provided with this flow path switching valve 1 will be described. The flow path switching valve 1 according to the present embodiment includes a stator 11 and a rotor 12 that rotates while being in sliding contact with the stator 11. The stator 11 has a plurality of through-holes 31, the rotor 12 has a flow path groove 32 that communicates with the through-holes 31, the wear powder discharge groove 33 is provided in the sliding surface S2 of the rotor 12, one end of the wear powder discharge groove 33 is located within the sliding surface S2, and the other end of the wear powder discharge groove 33 faces the outside of the sliding surface S2. 【0046】In this flow path switching valve 1, every time the rotor 12 rotates to switch the flow path, the wear powder discharge groove 33 moves in the circumferential direction to collect the wear powder generated on the sliding surfaces S1 and S2 between the stator 11 and the rotor 12. Then, the collected wear powder is discharged from the other end of the wear powder discharge groove 33 to the outside of the sliding surfaces S1 and S2. According to this flow path switching valve 1 and the liquid chromatograph 100, different from the conventional flow path switching valve (for example, see Patent Document 1), no additional liquid feeding mechanism is required, and the wear powder generated on the sliding surfaces S1 and S2 between the stator 11 and the rotor 12 is efficiently removed. The flow path switching valve 1 can efficiently prevent the wear powder from depositing on the sliding surfaces S1 and S2, and thus achieve an extended service life. 【0047】 Also, in such a flow path switching valve 1, a plurality of wear powder discharge grooves 33 are formed side by side in the circumferential direction of the rotor 12 and arranged at intervals of a predetermined rotation angle θ1 or less of the rotor 12. According to this flow path switching valve 1 and the liquid chromatograph 100, when the rotor 12 rotates at the rotation angle θ1 to switch the flow path, each of the plurality of wear powder discharge grooves 33 cooperates to form a movement locus across the entire circumference without interruption in the circumferential direction of the sliding surface S1 (see FIG. 3) of the stator 11. Thereby, the wear powder discharge groove 33 efficiently collects and discharges the wear powder. 【0048】 Also, in such a flow path switching valve 1, the wear powder discharge groove 33 is arranged on the outer peripheral side of the flow path groove 32. Thereby, the wear powder discharge groove 33 can efficiently collect and discharge the wear powder generated more on the outer peripheral side than on the inner peripheral side of the sliding surfaces S1 and S2. Incidentally, on the outer peripheral side of the sliding surfaces S1 and S2, the amount of displacement in the circumferential direction due to rotation is larger than that on the inner peripheral side, and the amount of generated wear powder tends to increase due to the uneven surface pressure caused by the uneven pressure applied to each flow path. 【0049】 Also, since the wear powder discharge groove 33 is arranged on the outer peripheral side of the flow path groove 32, when the rotor 12 rotates, it does not interfere with the flow path groove 32 or the through hole 31 of the stator 11. Thereby, the liquid tightness of the flow path formed by the flow path groove 32 and the through hole 31 is ensured. 【0050】Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. The first to tenth modified examples of the flow path switching valve 1 of the above embodiment will be described with reference to Figures 6 to 16. In these modified examples, the same reference numerals are used for the same components as in the above embodiment, and their detailed descriptions are omitted. 【0051】 In the flow path switching valve 1 of the above embodiment (see Figure 4B), when the predetermined rotation angle θ1 of the rotor 12 is set to 60 degrees, the wear chip discharge grooves 33 are arranged at intervals of θ2 (in the example shown in Figure 4B, θ2 is 51.4 degrees) that are less than or equal to the rotation angle of the rotor 12. That is, the interval θ2 of the wear chip discharge grooves 33 can also be set to be equal to the rotation angle θ1 of the rotor 12 (θ2 = θ1). 【0052】 Figure 6 is an explanatory diagram of the configuration of a first modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. As shown in Figure 6, in the flow path switching valve 1 of the first modified example, when the predetermined rotation angle θ1 of the rotor 12 is set to 60 degrees, six wear debris discharge grooves 33 are arranged at equal intervals in the circumferential direction. That is, in the example shown in Figure 6, the interval θ2 of the wear debris discharge grooves 33 is set to 60 degrees, which is equal to the rotation angle θ1 (60 degrees) of the rotor 12. With this first modified example of the flow path switching valve 1, when the rotation angle θ1 of the rotor 12 is set to 60 degrees, the minimum number of wear debris discharge grooves 33 is used to form a continuous movement trajectory of the wear debris discharge grooves 33 in the circumferential direction of the sliding surface S1 with the stator 11. 【0053】Furthermore, although the wear debris discharge groove 33 (see Figure 4A) in the above embodiment has an oval shape (running track shape) in plan view, the planar shape of the wear debris discharge groove 33 is not limited to this. Figure 7 is an explanatory diagram of the configuration of a second modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. Figure 8 is an explanatory diagram of the configuration of a third modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. In these second and third modified examples, six wear debris discharge grooves 33 are arranged at equal intervals in the circumferential direction, similar to the first modified example (see Figure 6). 【0054】 As shown in Figure 7, the wear debris discharge groove 33 in the second modified example has a rectangular planar shape, unlike the wear debris discharge groove 33 in the above embodiment (see Figure 4A). With this wear debris discharge groove 33 in the second modified example, a larger opening area can be secured on the upper surface compared to the wear debris discharge groove 33 of the above embodiment, which has the same groove width and length, resulting in superior wear debris recovery efficiency. 【0055】 Furthermore, as shown in Figure 8, the wear debris discharge groove 33 in the third modified example differs from the wear debris discharge groove 33 in the above embodiment (see Figure 4A) in that it has a fan-shaped planar shape that widens from the radially inward (inner circumference) side of the rotor seal 12b to the radially outward (outer circumference) side. Also, unlike the wear debris discharge groove 33 in the above embodiment (see Figure 4A), the wear debris discharge groove 33 in the third modified example extends to the outer peripheral edge of the rotor seal 12b and opens to the circumferential surface of the rotor seal 12b. 【0056】 In the second modified example, the wear particle discharge groove 33 has a fan-shaped planar shape that widens radially outward (outer circumference side) and extends to the outer edge of the rotor seal 12b, thus providing excellent wear particle recovery efficiency on the outer circumference side, where more wear particles tend to be generated compared to the inner circumference side of the stator 11. Furthermore, in the second modified example, the wear particle discharge groove 33 opens to the circumferential surface of the rotor seal 12b, resulting in excellent wear particle discharge efficiency by discharging the collected wear particles from the wear particle discharge groove 33 toward the outside of the rotor seal 12b. 【0057】Figure 9 is an explanatory diagram of the configuration of a fourth modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. As shown in Figure 9, in the flow path switching valve 1 of the fourth modified example, only one flow path groove 32 is formed so as to extend radially outward from the center of the rotor seal 12b in a plan view. In addition, the through holes 31 of the stator 11 in the fourth modified example consist of one through hole 31α located in the center and five through holes 31β arranged at equal intervals on the circumference centered on this through hole 31α. Note that in Figure 9, the four through holes 31β other than the one through hole 31β facing the front side of the paper in Figure 9 via the flow path groove 32 of the rotor seal 12b are shown as hidden lines (dotted lines). 【0058】 The flow channel groove 32 is positioned to connect the central through hole 31α and the through holes 31β arranged on the circumference. That is, in the fourth modified example, the flow channel switching valve 1 is configured to connect the central through hole 31α and the through holes 31β arranged on the circumference each time the rotor 12 rotates 72 degrees. In addition, as shown in Figure 9, only one wear debris discharge groove 33 is formed on the outer circumference side of the through hole 31β in the fourth modified example. This wear debris discharge groove 33 is formed in the rotor seal 12b such that one end is located within the sliding surface S1 of the stator 11 and the other end faces the outside of the sliding surface S1. 【0059】 With this fourth modified flow path switching valve 1, one of the two through holes 31 connected by the flow path groove 32 can be limited to the central through hole 31α, so the number of through holes 31β to which the other end of the flow path groove 32 is connected can be freely increased or decreased, not limited to the aforementioned five. This fourth modified flow path switching valve 1 assumes that the rotor 12 rotates at least 360 degrees in order for the wear particle discharge groove 33 to collect and discharge wear particles generated between the stator 11 and the rotor 12. In other words, this fourth modified flow path switching valve 1 assumes that the rotation process of the rotor 12 that performs flow path switching and the rotation process of the rotor 12 that discharges wear particles are performed at different timings. 【0060】Figure 10 is an explanatory diagram of the configuration of a fifth modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. In this fifth modified example, as with the first modified example (see Figure 6), six wear debris discharge grooves 33 are arranged at equal intervals in the circumferential direction. As shown in Figure 10, in the flow path switching valve 1 of the fifth modified example, the rotor seal 12b further has a wear debris discharge groove (inner circumferential wear debris discharge groove) 33a that extends radially from the rotor 12 on the inner circumferential side of the flow path groove 32. 【0061】 In this fifth modified example, the wear particle discharge groove 33a of the flow path switching valve 1 is located on the inner circumference side, where the amount of wear particle generation is less than on the outer circumference side, and is configured to retain the wear particle discharged from the sliding surface S1 within the wear particle discharge groove 33a. With this fifth modified example of the flow path switching valve 1, in addition to the wear particle discharge groove 33 located on the outer circumference side of the flow path groove 32, there is also a wear particle discharge groove 33a on the inner circumference side of the flow path groove 32, which further improves the efficiency of wear particle recovery between the stator 11 and the rotor 12. 【0062】 Figure 11 is an explanatory diagram of the configuration of a sixth modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. As shown in Figure 11, the flow path switching valve 1 of the sixth modified example has six wear debris discharge grooves 33 spaced equally apart in the circumferential direction of the rotor seal 12b. In the sixth modified example, one of the six wear debris discharge grooves 33b extends from the center of the rotor seal 12b to the outside of the sliding surface S1 of the stator 11, such that one of the wear debris discharge grooves 33b passes between two adjacent flow path grooves 32. 【0063】 In other words, in the sixth modified flow path switching valve 1, at least one of the plurality of wear particle discharge grooves 33 has one end of the wear particle discharge groove 33 located on the inner circumference side of the flow path groove 32. With this sixth modified flow path switching valve 1, by having a wear particle discharge groove 33b that is radially longer than the wear particle discharge groove 33, the efficiency of wear particle recovery between the stator 11 and the rotor 12 can be further improved. 【0064】Furthermore, in the sixth modified example, as shown in Figure 11, when the rotor 12 rotates and switches the flow path, the wear particle discharge groove 33b moves to the position of the wear particle discharge groove 33b indicated by the dotted line in Figure 11, and intersects with the through hole 31b and through hole 31c of the stator 11. Note that in the sixth modified example, the through hole 31b and through hole 31c are assumed to be, for example, waste liquid flow paths that do not affect the analysis. The through hole 31b and through hole 31c are intended to be used as discharge paths for the wear particle collected by the wear particle discharge groove 33b. 【0065】 In other words, in this sixth modified flow path switching valve 1, the wear particle discharge groove 33b formed inside the flow path groove 32 intersects and conducts only with specific through holes 31b and 31c of the stator 11 due to the rotation of the rotor 12. With this sixth modified flow path switching valve 1, the specific through holes 31b and 31c can be used as a discharge path for wear particles collected by the wear particle discharge groove 33b. 【0066】 Next, a seventh modified example of the flow path switching valve 1 according to the above embodiment (see Figure 4A) will be described. Figure 12A is a partial top view of the rotor 12 in the seventh modified example. Figure 12B is a partial bottom view of the stator 11 in the seventh modified example. As shown in Figure 2, the wear debris discharge groove 33 of the flow path switching valve 1 according to the above embodiment is formed only on the rotor seal 12b of the rotor 12, and as shown in Figure 3, the wear debris discharge groove 33 is not formed on the stator 11 side. 【0067】In contrast, the rotor seal 12b of the seventh modification does not have a wear debris discharge groove 33, as shown in Figure 12A. Furthermore, in the seventh modification, the wear debris discharge groove 33 is formed only on the stator 11, as shown in Figure 12B. In this seventh modification, as with the first modification (see Figure 6), six wear debris discharge grooves 33 are arranged at equal intervals in the circumferential direction. Specifically, the wear debris discharge groove 33 of the stator 11 extends radially from the sliding surface S1 with the rotor seal 12b on the outer circumference side of the through hole 31, facing the outside of this sliding surface S1. With this seventh modification of the flow path switching valve 1, since the wear debris discharge groove 33 is formed on the fixed stator 11 side, the wear debris collected in the wear debris discharge groove 33 can be stably discharged to the outside of the sliding surface S1. 【0068】 Next, an eighth modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment will be described. Figure 13A is a partial top view of the rotor 12 in the eighth modified example. Figure 14B is a partial bottom view of the stator 11 in the eighth modified example. As shown in Figure 13A, the rotor seal 12b in the eighth modified example has the same configuration as the rotor seal 12b in the first modified example shown in Figure 6. That is, as shown in Figure 13A, the wear chip discharge grooves 33 are arranged at equal intervals in the circumferential direction on the outer circumference side of the flow path groove 32, extending from the sliding surface S2 to the outside of this sliding surface S2. 【0069】 Furthermore, in the eighth modified example, the stator 11 is arranged in a circumferential direction with six equally spaced grooves extending from the sliding surface S1 to the outer edge of the sliding surface S1 on the outer circumference side of the through hole 31. In other words, the flow path switching valve 1 of the eighth modified example has wear particle discharge grooves 33 formed on both the stator 11 and the rotor 12. With this eighth modified example of the flow path switching valve 1, since wear particle discharge grooves 33 are formed on both the stator 11 and the rotor 12, the efficiency of wear particle recovery between the stator 11 and the rotor 12 can be further increased. 【0070】Figure 14 is an explanatory diagram of the configuration of a ninth modified example of the flow path switching valve 1 (see Figure 4A) according to the above embodiment. In this ninth modified example, as with the first modified example (see Figure 6), six wear particle discharge grooves 33 are arranged at equal intervals in the circumferential direction. As shown in Figure 14, in the flow path switching valve 1 of the ninth modified example, both ends of the flow path groove 32 are in a position to communicate with the through hole 31, but the middle part has a shape that bends inward. The flow path groove 32 is curved so as to be convex inward when viewed in plan. That is, in the flow path switching valve 1 according to the ninth modified example, the middle part of the flow path groove 32 of the rotor 12 is bent inward more than the ends that communicate with the through hole 31, and the wear particle discharge groove 33 is arranged close to the bent middle part of the flow path groove 32. As a result, even if the flow path switching valve 1 extends the wear debris discharge groove 33 further inward than the flow path switching valve 1 according to the first modified example (see Figure 6), it is possible to expand the range over which the wear debris discharge groove 33 collects wear debris while maintaining a distance that prevents electrical contact between the wear debris discharge groove 33 and the flow path groove 32. 【0071】 Figure 15 is an explanatory diagram of the configuration of a tenth modified example of the flow path switching valve 1 (see Figure 1) according to the above embodiment. As shown in Figure 15, the flow path switching valve 1 of the tenth modified example has a control unit 18 that controls the driving timing of the motor 17. Specifically, the control unit 18 is configured to control the timing of the execution of the flow path switching operation of the rotor 12, which switches the electrical connection between the through hole 31 of the stator 11 and the flow path groove 32 of the rotor 12, and the wear powder discharge operation of the rotor 12, which discharges wear powder from the sliding surfaces S1 and S2 using the wear powder discharge groove 33. Note that the wear powder discharge operation here is set separately from the flow path switching operation and does not include the wear powder discharge operation by the rotor 12 that is performed together with the flow path switching operation as described above. 【0072】In the tenth modified example, the wear particle discharge operation may include, for example, the case when a wear particle discharge groove 33 formed at a predetermined position is rotated 360 degrees by the rotor 12 from its initial position (reference position). However, the wear particle discharge operation is not limited to an operation solely for the purpose of collecting and discharging wear particles, but can also serve as an operation of the rotor 12 for other purposes, such as the rotor 12 returning to its home position. Such a control unit 18 can be configured to include a ROM (Read Only Memory) for storing a predetermined program, a RAM (Random Access Memory) for reading and expanding the program stored in the ROM, and a CPU (Central Processing Unit) for executing the expanded program and outputting commands to the motor 17. 【0073】 Figure 16 is a flowchart showing the specific steps performed by the control unit 18 (see Figure 15). For example, when the analysis of sample 108 by the liquid chromatograph 100 (see Figure 5) begins, the control unit 18 (see Figure 15) outputs a wear particle discharge operation command as shown in Figure 15 (step S101). Specifically, the control unit 18 (see Figure 15) outputs a command to the motor 17 (see Figure 15) to rotate the rotor 12 (see Figure 15) by at least 360 degrees. As a result, the area between the sliding surface S1 of the stator 11 (see Figure 15) and the sliding surface S of the rotor 12 (see Figure 15) becomes clean and free of wear particles. 【0074】 Next, the control unit 18 (see Figure 15) outputs a flow path switching operation command as shown in Figure 16 (step S102). Specifically, the control unit 18 (see Figure 15) outputs a command to the motor 17 (see Figure 15) so that the rotor 12 rotates and performs the necessary multiple flow path switching operations during the analysis process of the sample 108 (see Figure 5) by the liquid chromatograph 100 (see Figure 5). 【0075】Next, the control unit 18 determines whether a predetermined number of flow path switching operations have been performed since the previous wear particle discharge operation (step S103). If the control unit 18 determines that the predetermined number of flow path switching operations have been performed (Yes in step S103), it outputs a wear particle discharge operation command (step S104), and then executes the next step S105. If the control unit 18 determines in step S103 that the predetermined number of flow path switching operations have not been performed (No in step S103), it executes the next step S105 without going through step S104. 【0076】 In step S105, the control unit 18 determines whether the sample analysis by an analytical device, such as a liquid chromatograph 100 (see Figure 5), has been completed. If the control unit 18 determines that the sample analysis by the analytical device has not been completed (No in step S105), it returns to step S102 and repeats the procedure from step S102 to step S105. Then, in step S105, if the control unit 18 determines that the sample analysis by the analytical device has been completed (Yes in step S105), it outputs a wear particle discharge operation command (step S106), and then terminates this control process. 【0077】 In addition, in step S103 of the procedure executed by the control unit 18, the condition for judgment can be changed from "whether a predetermined number of flow path switching operations have been performed since the previous wear particle discharge operation" to "whether a predetermined time has elapsed since the previous wear particle discharge operation was performed." 【0078】 The operation of the flow path switching valve 1 can be achieved not only by the control method of the control unit 18 shown in Figure 15, but also by manual operation by the user. Specifically, the operation method of the flow path switching valve 1 includes a flow path switching step by the rotor 12 that switches the conductivity between the through hole 31 of the stator 11 and the flow path groove 32 of the rotor 12, and a wear powder discharge step by the rotor 12 that discharges wear powder from the sliding surfaces S1 and S2 through the wear powder discharge groove 33. 【0079】Furthermore, in the operation method of this flow path switching valve, the timing for performing the wear particle discharge process is at least one of the following: at the start of the analysis work by the analytical device equipped with the flow path switching valve, at the end of the analysis work, at any time the user of the flow path switching valve performs the operation, after a predetermined number of flow path switching processes have been performed since the previous wear particle discharge process in the case of multiple wear particle discharge processes, and after a certain period of time has elapsed since the previous wear particle discharge process in the case of multiple wear particle discharge processes. 【0080】 This method of operating the flow path switching valve 1 does not require an additional fluid supply mechanism, efficiently removes wear particles generated on the sliding surface between the stator and rotor, effectively prevents wear particles from accumulating on the sliding surface, and ultimately achieves a longer service life. 【0081】 1 Flow path switching valve 11 Stator 12 Rotor 18 Control unit 31 Through hole 32 Flow path groove 33 Wear particle discharge groove 100 Liquid chromatograph S1 Sliding surface S2 Sliding surface
Claims
1. A flow path switching valve comprising a stator and a rotor that rotates while sliding in contact with the stator, wherein the stator has a plurality of through holes, the rotor has flow path grooves that communicate with the through holes, and at least one of the sliding surfaces of the rotor and the stator has a wear debris discharge groove, one end of the wear debris discharge groove is located within the sliding surface, and the other end of the wear debris discharge groove faces the outside of the sliding surface.
2. The flow path switching valve according to claim 1, characterized in that the wear chip discharge grooves are formed in a plurality of arrangements in the circumferential direction of the rotor and are arranged at intervals less than or equal to the rotation angle of the rotor.
3. The flow path switching valve according to claim 2, characterized in that at least one of the wear debris discharge grooves has one end located on the inner circumference side of the flow path groove.
4. The flow path switching valve according to claim 3, characterized in that the wear debris discharge groove, one end of which is located on the inner circumference side of the flow path groove, is formed to intersect and conduct electricity only with a specific through hole of the stator due to the rotation of the rotor.
5. The flow path switching valve according to claim 1, characterized in that it has a control unit that controls the timing of the execution of a flow path switching operation of the rotor, which switches electrical contact between the through hole of the stator and the flow path groove of the rotor, and a wear particle discharge operation of the rotor, which discharges wear particles from the sliding surface through the wear particle discharge groove.
6. The flow path switching valve according to claim 1, characterized in that the flow path groove of the rotor is bent inward in the middle portion than the ends that communicate with the through hole, and the wear chip discharge groove is positioned close to the bent middle portion of the flow path groove.
7. A method for operating a flow path switching valve according to claim 1, comprising: a flow path switching step by the rotor that switches the conductivity between the through hole of the stator and the flow path groove of the rotor; and a wear powder discharge step by the rotor that discharges wear powder from the sliding surface through the wear powder discharge groove.
8. The method for operating a flow path switching valve according to claim 7, characterized in that the timing of the wear particle discharge process is at least one of the following timings: at the start of the analysis work by the analytical device equipped with the flow path switching valve, at the end of the analysis work, at any time the user of the flow path switching valve performs an arbitrary operation, after a predetermined number of flow path switching processes have been performed since the execution of the previous wear particle discharge process in the case of multiple wear particle discharge processes, and after a certain period of time has elapsed since the execution of the previous wear particle discharge process in the case of multiple wear particle discharge processes.
9. A liquid chromatograph comprising a flow path switching valve according to any one of claims 1 to 6.