Rotary valve and method for forming a reinforced resin member of a rotary valve

Abstract

To ensure that the sealing performance between the rotor and stator is maintained over a long period of time. [Solution] The device comprises a stator (4), a rotor shaft (8) that rotates axially, and a rotor (6) held at the tip of the rotor shaft (8) and rotating together with the rotor shaft (8) while in surface contact with the stator (4). The stator (4) and the rotor (6) have sliding surfaces that slide against each other due to the rotation of the rotor (6). Either the stator (4) or the rotor (6) is a reinforced resin member made of fiber-reinforced resin containing reinforcing fibers to improve hardness. The reinforcing fibers exposed on the sliding surface of the reinforced resin member are mainly oriented along a direction perpendicular to the sliding surface of the reinforced resin member.

Description

【Technical Field】 【0001】 The present invention relates to a rotary valve used in an analyzer such as a liquid chromatograph, and a method for forming a reinforced resin member of the rotary valve. 【Background Art】 【0002】 A rotary type flow path switching valve (hereinafter referred to as a rotary valve) used in a liquid chromatograph needs to withstand a high liquid feed pressure of several tens of MPa to several hundreds of MPa. Therefore, an elastic member such as a coil spring is used to press the rotor against the stator with a strong force to ensure the sealing performance between the rotor and the stator (see Patent Document 1). 【0003】 Since the rotor and the stator slide while being pressed against each other with a strong force, high sealing performance and wear resistance are required for the sliding surfaces of the rotor and the stator. Therefore, as the material of the stator, hard materials such as ceramics and stainless steel with DLC (diamond-like carbon) coating are generally used (for example, see Patent Document 2), and as the material of the rotor, soft materials such as PEEK (polyether ether ketone) and polyimide are generally used. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent No. 6773233 【Patent Document 2】 U.S. Patent No. 8438910 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 The environment in which rotors and stators are subjected to pressures of 130 MPa or more is so harsh that soft materials such as PEEK undergo plastic deformation. When soft materials are slid against hard materials in such an environment, the soft materials wear out quickly, shortening the lifespan of the parts. Therefore, countermeasures have been taken, such as using fiber-reinforced resins containing reinforcing fibers such as carbon fibers as soft materials. However, even with such wear countermeasures, the sliding surfaces of either the rotor or stator, or both, wear out, and after a certain period of use, the sealing performance between the rotor and stator deteriorates, leading to fluid leakage. 【0006】 This invention has been made in view of the above problems, and aims to maintain the sealing performance between the rotor and stator over a long period of time. [Means for solving the problem] 【0007】 It has been found that when one of the components of a stator or rotor, which slides against each other, is made of a hard material and the other component is made of fiber-reinforced resin, the reinforcing fibers contained in the fiber-reinforced resin cause wear on the component made of the hard material, which accelerates the deterioration of the sealing performance between the stator and the rotor. The inventors have found that the orientation direction of the reinforcing fibers contained in the fiber-reinforced resin on the sliding surface affects the wear of the component made of the hard material, and that by bringing the orientation direction of the reinforcing fibers exposed on the sliding surface closer to a direction perpendicular to the sliding surface, the wear of the component made of the hard material can be suppressed. 【0008】 Based on the above findings, the first rotary valve according to the present invention comprises a stator, a rotor shaft that rotates axially, and a rotor held at the tip of the rotor shaft and rotating together with the rotor shaft while in surface contact with the stator, wherein the stator and the rotor have sliding surfaces that slide against each other due to the rotation of the rotor, and either the stator or the rotor is a reinforced resin member made of a fiber-reinforced resin containing reinforcing fibers to improve hardness, wherein the reinforcing fibers exposed on the sliding surface of the reinforced resin member are mainly oriented along a direction perpendicular to the sliding surface of the reinforced resin member. 【0009】 Furthermore, if the stator is made of a hard material and the rotor is made of a soft material, the rotor is prone to wear, causing the grooves around the rotor to wear down and widen, which can lead to fluid leakage. 【0010】 A second rotary valve according to the present invention, which addresses the above-mentioned problems, comprises a stator, a rotor shaft that rotates axially, and a rotor held at the tip of the rotor shaft and rotating together with the rotor shaft while in surface contact with the stator, wherein the stator is made of resin, and at least the sliding surface of the rotor with respect to the stator is made of a material harder than the stator. 【0011】 Furthermore, if the opposing surfaces of the stator and rotor are not parallel to each other, problems can arise such as uneven contact between the stator and rotor, resulting in a failure to achieve the designed pressure resistance performance, or accelerated wear and reduced durability due to sliding while unevenly contacting each other. To prevent such problems, it is necessary to either form the stator, rotor, and supporting members with high precision, or to provide a separate member that elastically supports the rotor to allow for rotor tilt, which is costly. 【0012】 A third rotary valve according to the present invention, which addresses the above-mentioned problems, comprises a stator, a rotor shaft that rotates axially, and a rotor held at the tip of the rotor shaft and rotating together with the rotor shaft while in surface contact with the stator, wherein a substantially spherical portion, which is a part of either the rotor or the rotor shaft, is provided between the rotor and the rotor shaft, and the sliding surface of the rotor can be tilted from a state perpendicular to the rotation axis of the rotor shaft by the rotor and the rotor shaft directly contacting each other at the substantially spherical portion. 【0013】 Furthermore, when applying a DLC coating to either the rotor or the stator (for example, the stator) to improve the sliding properties and wear resistance of the rotor and stator, the DLC film may peel off from the substrate, causing fluid leakage between the rotor and stator. In particular, it has been found that this problem occurs significantly when one of the rotor or stator is a DLC-forming member with a DLC film formed on it, and the other is a soft member such as resin. This is thought to be because the soft member is pressed against the DLC-forming member with strong force, causing the deformed soft member to enter the opening at the end of the flow path of the DLC-forming member, and when the two slide against each other, the soft member that has entered the opening exerts a force that scrapes away the DLC film at the edge of the opening. Therefore, the inventors focused on the thickness from the surface of the substrate to the surface of the DLC film on the sliding surface of the DLC-forming member. It is known that the thicker the DLC film formed in DLC coating, the higher the wear resistance, and the thickness of the DLC film formed in DLC coating is generally about 1 to 3 μm. However, increasing the thickness of the DLC film increases the residual stress, making the DLC film more prone to peeling from the substrate. Furthermore, if the thickness from the substrate surface to the surface of the DLC film is thick, when the DLC forming member and the soft member slide against each other, the DLC film at the edge of the opening in the DLC forming member is more susceptible to stress in the peeling direction from the soft member that has entered the opening. 【0014】 The inventors conducted sliding experiments with a soft member using multiple DLC-forming members with different thicknesses from the surface of the substrate to the surface of the DLC film. As a result, they confirmed that DLC-forming members with a thinner thickness from the surface of the substrate to the surface of the DLC film were less prone to peeling of the DLC film and had a longer lifespan compared to DLC-forming members with a thicker thickness from the surface of the substrate to the surface of the DLC film, and that this was particularly noticeable when the thickness from the surface of the substrate to the surface of the DLC film was 0.5 μm or less. The fourth rotary valve according to the present invention is based on these findings. 【0015】 In other words, the fourth rotary valve according to the present invention comprises a stator and a rotor that rotates while in surface contact with the stator, wherein each of the stator and the rotor has a sliding surface that slides against each other due to the rotation of the rotor, and either the stator or the rotor is a DLC forming member whose sliding surface is formed of a DLC film, and the thickness from the surface of the substrate to the surface of the DLC film on the sliding surface side of the DLC forming member is 0.5 μm or less. 【0016】 The present invention provides a method for forming one of the rotor and stator, which have sliding surfaces that directly contact and slide against each other in the first rotary valve described above, as a reinforced resin member made of a fiber-reinforced resin containing reinforcing fibers to improve hardness, A flow step in which a liquid fiber-reinforced resin is flowed in one direction perpendicular to the surface that will become the sliding surface when formed as the reinforced resin member, After the flow step, a curing step is performed to cure the fiber-reinforced resin, The process includes a forming step, after the curing step, in which the cured fiber-reinforced resin is used as a base material to form a reinforced resin member in which the reinforced resin exposed on the sliding surface is mainly oriented along a direction perpendicular to the sliding surface. [Effects of the Invention] 【0017】 According to the first rotary valve of the present invention, either the stator or the rotor is a reinforced resin member made of a fiber-reinforced resin containing reinforcing fibers to improve hardness, and the reinforcing fibers exposed on the sliding surface of the reinforced resin member are mainly oriented along a direction perpendicular to the sliding surface of the reinforced resin member, thereby reducing wear on the sliding surfaces of the stator and rotor and maintaining sealing performance between the stator and rotor over a long period of time. 【0018】 According to the second rotary valve of the present invention, the stator is made of resin, and at least the sliding surface of the rotor with respect to the stator is made of a material harder than the stator. This suppresses the widening of the rotor grooves due to wear, and allows the sealing performance between the stator and the rotor to be maintained over a long period of time. 【0019】 According to the third rotary valve of the present invention, a substantially spherical portion, which is a part of either the rotor or the rotor shaft, is provided between the rotor and the rotor shaft, and the rotor and the rotor shaft come into direct contact at the substantially spherical portion, allowing the sliding surface of the rotor to be tilted from a state perpendicular to the rotation axis of the rotor shaft, thereby preventing uneven contact between the stator and the rotor, and maintaining the sealing performance between the stator and the rotor over a long period of time. 【0020】 According to the fourth rotary valve of the present invention, either the stator or the rotor is a DLC forming member whose sliding surface is formed of a DLC film, and the thickness from the surface of the substrate to the surface of the DLC film on the sliding surface side of the DLC forming member is 0.5 μm or less, so that peeling of the DLC film on the DLC forming member is less likely to occur, and the lifespan of the DLC forming member can be extended. 【0021】 According to the method of the present invention, a reinforced resin member can be formed in which the reinforcing fibers exposed on the sliding surface are mainly oriented along a direction perpendicular to the sliding surface. 【Brief Description of the Drawings】 【0022】 [Figure 1] It is a cross-sectional view showing an embodiment of a rotary valve. [Figure 2] It is a conceptual diagram for explaining an example of a method for forming a fiber-reinforced resin. [Figure 3] It is a diagram showing the orientation direction of reinforcing fibers when forming a reinforced resin member by flowing a fiber-reinforced resin in a direction parallel to the direction of the sliding surface. [Figure 4] It is an image showing the state of each sliding surface of a stator and a rotor after using, as a stator, a reinforced resin member in which the reinforcing fibers exposed on the sliding surface are mainly oriented along a direction perpendicular to the sliding surface. [Figure 5] It is an image showing the state of each sliding surface of a stator and a rotor after using, as a stator, a reinforced resin member in which the reinforcing fibers exposed on the sliding surface are mainly oriented along the sliding surface. [Figure 6] It is a diagram showing the structure of the contact portion between a rotor and a rotor shaft. [Figure 7] It is a diagram showing an example of the cross-sectional structure of a DLC forming member. 【Embodiments for Carrying Out the Invention】 【0023】 Hereinafter, an embodiment of a rotary valve according to the present invention will be described with reference to the drawings. 【0024】 As shown in FIG. 1, the rotary valve 1 includes a housing 2, a stator 4, a rotor 6, a rotor shaft 8, a bearing 10, and an elastic member 12. 【0025】 The housing 2 is a single, nearly hollow cylindrical component with an open tip (upper end in the figure). The stator 4 is fixed to the tip of the housing 2 by bolts. The stator 4 is provided with multiple pipe connection points 18 for connecting pipes. Note that only one pipe connection point 18 is shown in the figure. The pipe connection points 18 connect to the internal surface of the housing 2 (lower surface in the figure) via a flow path. When the rotor 6 rotates with the rotor 6 in contact with the lower surface of the stator 4, the interconnection state of the multiple pipes connected to the stator 4 is switched. 【0026】 The rotor shaft 8 is positioned in the internal space of the housing 2 with its tip (upper end in the diagram) facing the stator 4. The rotor shaft 8 is rotated axially by a motor (not shown in the diagram). The rotor 6 is held at the tip of the rotor shaft 8 and rotates in conjunction with the rotation of the rotor shaft 8. 【0027】 The bearing 10 is interposed between the outer circumferential surface of the rotor shaft 8 and the inner circumferential surface of the housing 2, supporting the rotor shaft 8 and stabilizing its rotation. In this embodiment, a retaining ring 16 is attached to the tip of the rotor shaft 8, and the bearing 10 engages with the retaining ring 16. 【0028】 The elastic member 12 is positioned in a compressed state within the internal space of the housing 2, closer to the base end of the rotor shaft 8 than the bearing 10, so as to bias the bearing 10 toward the stator 4. When the bearing 10 is biased toward the stator 4 by the elastic member 12, the rotor shaft 8 is also biased toward the stator 4, and the rotor 6 held at the tip of the rotor shaft 8 is pressed against the stator 4. This ensures a seal between the stator 4 and the rotor 6. In this embodiment, the rotor 6 is in direct contact with the stator 4, but the present invention is not limited to this, and another member fixed to the stator 4 may be interposed between the stator 4 and the rotor 6. 【0029】 The stator 4 can be made of resin. If the stator 4 is made of resin, it can be used in applications where solvents corrosive to metals are used. The resin constituting the stator 4 can be a fiber-reinforced resin such as polyetheretherketone resin or polyimide resin containing reinforcing fibers (e.g., carbon fibers) to improve hardness. By making the stator 4 a reinforced resin component made of fiber-reinforced resin, the hardness of the stator 4 can be improved, and the pressure resistance performance of the rotary valve 1 can be improved. 【0030】 If the stator 4 is made of resin, the rotor 6 can be made of a hard material (for example, ceramic, diamond-like carbon) at least on the sliding surface with the stator 4 (the upper surface in the figure). By making at least the sliding surface of the rotor 6 with the stator 4 from a material harder than the stator 4, the widening of the grooves provided in the rotor 6 due to wear is suppressed. 【0031】 However, the present invention is not limited thereto, and the rotor 6 may be made of fiber-reinforced resin, and at least the sliding surface of the stator 4 with respect to the rotor 6 may be made of a material harder than the rotor 6. 【0032】 If the stator 4 is a reinforced resin member made of fiber-reinforced resin, the reinforcing fibers of the stator 4 exposed on the sliding surface with the rotor 6 are mainly oriented in a direction perpendicular to the sliding surface (bottom surface in the figure) (up and down direction in the figure). If the rotor 6 is a reinforced resin member, the reinforcing fibers of the rotor 6 exposed on the sliding surface with the stator 4 are mainly oriented in a direction perpendicular to the sliding surface with the stator 4 (top surface in the figure). 【0033】 Now, with reference to Figure 2, the method for forming the reinforced resin member in this embodiment will be described. Here, as an example, a method of formation by injection molding will be described. 【0034】 As shown in Figure 2(A), liquid fiber-reinforced resin is poured into the internal space of the mold while flowing it in a direction perpendicular to the surface that will become the sliding surface when formed as a resin-reinforced member. When the fiber-reinforced resin is flowed in this way, in the innermost part of the internal space of the mold, the reinforcing fibers are mainly oriented along the inner surface of the mold, but in the region closer to the gate, the reinforcing fibers are mainly oriented in a direction perpendicular to the surface that will become the sliding surface. Next, as shown in Figure 2(B), after the fiber-reinforced resin filling the internal space of the mold is cured and then demolded, the base material for the reinforced resin member is obtained. Next, as shown in Figure 2(C), by processing the base material of the reinforced resin member, such as shaving (or cutting) off a predetermined thickness from the innermost part of the mold, a reinforced resin member is obtained in which the reinforcing fibers exposed on the sliding surface are mainly oriented in a direction perpendicular to the sliding surface. This method is the same whether the reinforced resin member is a stator 4 or a rotor 6. 【0035】 When forming a cylindrical reinforced resin member by general injection molding, as shown in Figure 3, fiber-reinforced resin is often poured from the side (a direction perpendicular to the surface that will become the sliding surface after formation) into the roughly cylindrical space formed inside the mold, which is the shape of the base material. In this case, at the position that will become the sliding surface, the reinforcing fibers will mainly be oriented along the sliding surface. 【0036】 Here, "the reinforcing fibers exposed on the sliding surface are mainly oriented in a direction perpendicular to the sliding surface" means that the majority (for example, 50% or more) of the reinforcing fibers exposed on the sliding surface of the fiber-reinforced resin are oriented in a direction that intersects (not necessarily perpendicular to) the sliding surface. 【0037】 Although Figure 2 shows an example of injection molding, the method of the present invention is not limited to this. Reinforced resin members can also be formed by methods such as extrusion molding, which includes a step of flowing liquid fiber-reinforced resin in a direction perpendicular to the surface that will become the sliding surface. When a reinforced resin member is formed by injection molding as shown in Figure 2, gate marks may remain on the sliding surface or a surface parallel to the sliding surface of the reinforced resin member. 【0038】 Figure 4 shows images of the sliding surfaces of a stator and rotor when a ceramic rotor is reciprocated 700,000 times against a stator in which the reinforcing fibers exposed on the sliding surface are mainly oriented perpendicular to the sliding surface. Figure 5 shows images of the sliding surfaces of a stator and rotor when a ceramic rotor is reciprocated 700,000 times against a stator in which the reinforcing fibers exposed on the sliding surface are mainly oriented along the sliding surface. 【0039】 Comparing the microscopic images of the stator sliding surface shown in Figure 4 and Figure 5, we see that the proportion of reinforcing fibers exposed as points is high in the sliding surface of the stator in Figure 4, while the proportion of reinforcing fibers exposed as lines is high in the sliding surface of the stator in Figure 5. Due to this difference, the proportion of the area where reinforcing fibers are exposed on the sliding surface of the stator in Figure 4 is smaller than the proportion of the area where reinforcing fibers are exposed on the sliding surface of the stator in Figure 5, and it is thought that the damage inflicted on the rotor by the reinforcing fibers is less in the stator in Figure 4 than in the stator in Figure 5. 【0040】 In fact, comparing the rotor sliding surface shown in Figure 4 with the rotor sliding surface shown in Figure 5, it is clear that the rotor that slid against the stator in Figure 5 is significantly more worn than the rotor that slid against the stator in Figure 4. Conversely, if a reinforced resin member is used in which the reinforcing fibers exposed on the sliding surface are mainly oriented perpendicular to the sliding surface, wear on the member sliding against the reinforced resin member (the rotor in this example) is suppressed compared to using a reinforced resin member in which the reinforcing fibers exposed on the sliding surface are mainly oriented along the sliding surface. 【0041】 Returning to Figure 1 and continuing the explanation, the rotor 6 has a through hole, and a hole is provided on the tip surface of the rotor shaft 8. A pin 14 that passes through the through hole in the rotor 6 is fitted into the hole on the tip surface of the rotor shaft 8, thereby fixing the rotor 6 to the rotor shaft 8 only in the rotational direction. 【0042】 As shown in Figure 6, the rotor 6's rotor shaft 8-side surface (bottom surface in the figure) is provided with a substantially spherical portion 20 that protrudes toward the rotor shaft 8. The rotor 6 contacts the rotor shaft 8 only at the substantially spherical portion 20, and the rotor 6 can oscillate at the tip surface of the rotor shaft 8 so that its sliding surface (top surface in the figure) can be tilted slightly (for example, up to about 0.5°) from a state perpendicular to the rotation axis of the rotor shaft 8. This allows for precise surface contact between the stator 4 and the rotor 6 without uneven contact when the rotor 6 is pressed against the stator 4. 【0043】 The substantially spherical portion 20 does not necessarily have to be provided on the rotor 6, but may be provided on the tip surface of the rotor shaft 8. 【0044】 Furthermore, either the stator 4 or the rotor 6 may be a DLC-forming member whose sliding surface is formed of a DLC film, as shown in Figure 7. In that case, the thickness T from the surface of the substrate to the surface of the DLC film on the sliding surface side (upper side in the figure) of the DLC-forming member is 0.5 μm or less. 【0045】 The inventors used a stator constructed by directly forming DLC ​​films of thicknesses of 2 μm, 1 μm, 0.5 μm, and 0.1 μm on the surface of a stainless steel substrate, and a rotor made of fiber-reinforced resin (polyether ether ketone), as the stator and rotor of an autosampler injection valve (6-port 2-position valve). They conducted a durability test by continuously switching the valves while supplying water as the solvent at a liquid supply pressure of 100 MPa. In the durability test, the injection valve using a stator with a 2 μm thick DLC film experienced liquid leakage due to DLC film peeling after approximately 10,000 switching operations, and the injection valve using a stator with a 1 μm thick DLC film experienced liquid leakage due to DLC film peeling after approximately 15,000 switching operations. On the other hand, in an injection valve using a stator with a DLC film of 0.5 μm thickness, no leakage occurred between the stator and rotor even after more than 20,000 switching operations. In an injection valve using a stator with a DLC film of 0.1 μm thickness, no leakage occurred between the stator and rotor even after more than 150,000 switching operations. These experimental results show that by making the thickness from the surface of the substrate of the DLC-forming member to the surface of the DLC film 0.5 μm or less, the durability of the seal between the stator and rotor can be significantly improved. 【0046】 In the above experiment, the DLC film was formed so as to be in direct contact with the surface of the substrate. However, the present invention is not limited to this, and an adhesive layer or the like may be interposed between the surface of the substrate and the DLC film. In such cases, it is important that the thickness from the surface of the substrate to the surface of the DLC film is 0.5 μm or less. Even if the film thickness of the DLC film is 0.5 μm or less, if the thickness from the surface of the substrate to the surface of the DLC film is greater than 0.5 μm due to the presence of an adhesive layer or the like, the step difference from the edge of the opening in the DLC film of the DLC forming member to the edge of the opening in the substrate becomes larger. In that case, when the DLC forming member (stator in the above experiment) and the soft member (rotor in the above experiment) slide against each other, the stress in the peeling direction that the DLC film receives from the soft member that has entered the opening in the DLC film becomes stronger, making it easier for the DLC film to peel off from the substrate. Conversely, even if an adhesive layer exists between the substrate and the DLC film, if the thickness from the surface of the substrate to the surface of the DLC film is 0.5 μm or less, the stress in the peeling direction that the DLC film experiences when the DLC-forming member and the soft member slide against each other can be reduced, making it less likely for the DLC film to peel off from the substrate. 【0047】 Furthermore, in the above experiment, the stator was made of a DLC-formed material and the rotor was made of a soft material, but the rotor may also be made of a DLC-formed material. 【0048】 Patent Document 2 (U.S. Patent No. 8438910) discloses a DLC-forming member in which a DLC film is formed in the range of 0.2 μm to 3 μm. However, the DLC-forming member disclosed therein has an adhesion-promoting layer having a thickness in the range of 1 μm to 5 μm interposed between the substrate and the DLC film. That is, in the DLC-forming member disclosed in Patent Document 2, the thickness from the surface of the substrate to the surface of the DLC film is 1.2 μm or more. In such a structure, the stress in the peeling direction that the DLC film experiences when the DLC-forming member and the soft member slide against each other is large, and it is not possible to achieve the durability of the sealing performance between the stator and rotor described above according to the present invention. 【0049】 The embodiments described above are merely examples of embodiments of the rotary valve and method according to the present invention. Embodiments of the rotary valve and method according to the present invention are as follows. 【0050】 In a first embodiment of the rotary valve according to the present invention, stator and, A rotor shaft that rotates on an axis, The rotor is held at the tip of the rotor shaft and rotates together with the rotor shaft while making surface contact with the stator, The stator and the rotor have sliding surfaces that slide against each other due to the rotation of the rotor, and either the stator or the rotor is a reinforced resin member made of fiber-reinforced resin containing reinforcing fibers to improve hardness. The reinforcing fibers exposed on the sliding surface of the reinforcing resin member are mainly oriented along a direction perpendicular to the sliding surface of the reinforcing resin member. 【0051】 In the first aspect of the first embodiment described above, the reinforced resin member has gate marks from injection molding on the sliding surface or on a surface parallel to the sliding surface. 【0052】 In the second aspect of the first embodiment described above, the reinforced resin member is the stator. By making the stator a reinforced resin member made of fiber-reinforced resin, the stator can be made resistant to chemicals that corrode metal. This second aspect can be combined with the first aspect described above. 【0053】 In the second phase described above, the sliding surface of the rotor may be made of a non-metallic material that is harder than the stator. This makes it possible to suppress the widening of the rotor grooves due to wear. 【0054】 In the above case, the stator may have multiple pipe connection points for connecting pipes. In this case, since the stator with multiple pipe connection points is made of fiber-reinforced resin and the rotor is made of a non-metallic material that is harder than the stator, a high-pressure rotary valve can be realized while allowing the use of chemicals that corrode metals. 【0055】 In the third aspect of the first embodiment described above, a substantially spherical portion, which is a part of either the rotor or the rotor shaft, is provided between the rotor and the rotor shaft, and the rotor and the rotor shaft come into direct contact at the substantially spherical portion, allowing the sliding surface of the rotor to be tilted from a state perpendicular to the rotation axis of the rotor shaft. As a result, when the rotor is pressed against the stator, it becomes parallel to the sliding surface of the stator so as to follow the sliding surface of the rotor, and the rotor and stator can slide without uneven contact. This third aspect can be combined with the first aspect and / or the second aspect described above. 【0056】 In the third aspect described above, the substantially spherical portion may be provided as a projection on the rotor shaft side of the rotor. It is also possible to provide a substantially spherical projection on the rotor shaft, but providing such a projection on the rotor makes the rotor less prone to cracking. 【0057】 In the fourth aspect of the first embodiment described above, the other of the stator and the rotor is a DLC-forming member whose sliding surface is formed of a diamond-like carbon film, and the thickness from the surface of the substrate to the surface of the diamond-like carbon film on the sliding surface side of the DLC-forming member is 0.5 μm or less. This fourth aspect can be combined with the first, second, and / or third aspects described above. 【0058】 In the fourth phase described above, the diamond-like carbon film of the DLC forming member may be in direct contact with the substrate. 【0059】 In a second embodiment of the rotary valve according to the present invention, stator and, A rotor shaft that rotates on an axis, The rotor is held at the tip of the rotor shaft and rotates together with the rotor shaft while making surface contact with the stator, The stator is made of resin, and at least the sliding surface of the rotor with respect to the stator is formed of a material harder than the stator. 【0060】 In the first aspect of the second embodiment described above, the resin constituting the stator is a fiber-reinforced resin containing reinforcing fibers to improve hardness. By constructing the stator with fiber-reinforced resin, the hardness of the stator is dramatically improved compared to when the stator is constructed of resin, thus improving the pressure resistance performance of the rotary valve. 【0061】 In the second aspect of the second embodiment described above, the stator has a plurality of pipe connection parts for connecting pipes. 【0062】 In the third aspect of the second embodiment described above, the rotor has a sliding surface formed of a diamond-like carbon film, and the thickness from the surface of the substrate on the sliding surface side of the rotor to the surface of the diamond-like carbon film is 0.5 μm or less. This third aspect can be combined with the first and / or second aspects described above. 【0063】 Furthermore, in the third aspect described above, the diamond-like carbon film of the rotor may be in direct contact with the substrate. 【0064】 In a third embodiment of the rotary valve according to the present invention, stator and, A rotor shaft that rotates on an axis, The rotor is held at the tip of the rotor shaft and rotates together with the rotor shaft while making surface contact with the stator, A substantially spherical portion, which is a part of either the rotor or the rotor shaft, is provided between the rotor and the rotor shaft, and the rotor and the rotor shaft come into direct contact at the substantially spherical portion, allowing the sliding surface of the rotor to be tilted from a state perpendicular to the rotation axis of the rotor shaft. 【0065】 In the third embodiment described above, the substantially spherical portion may be provided as a projection on the rotor shaft side of the rotor. It is also possible to provide a substantially spherical projection on the rotor shaft, but providing such a projection on the rotor makes the rotor less prone to cracking. 【0066】 In a fourth embodiment of the rotary valve according to the present invention, stator and, The system comprises a rotor that rotates while in surface contact with the stator, Each of the stator and the rotor has a sliding surface that slides against each other due to the rotation of the rotor, and either the stator or the rotor is a DLC-forming member in which the sliding surface is formed of a diamond-like carbon film. The thickness from the surface of the substrate to the surface of the diamond-like carbon film on the sliding surface side of the DLC-forming member is 0.5 μm or less. 【0067】 In the fourth embodiment described above, the diamond-like carbon film of the DLC forming member may be in direct contact with the substrate. This second surface can be combined with the first surface. 【0068】 One embodiment of the method according to the present invention is a method for forming either the rotor or the stator, which have sliding surfaces that directly contact and slide against each other in a rotary valve, as a reinforced resin member made of a fiber-reinforced resin containing reinforcing fibers to improve hardness, A flow step in which a liquid fiber-reinforced resin is flowed in one direction perpendicular to the surface that will become the sliding surface when formed as the reinforced resin member, After the flow step, a curing step is performed to cure the fiber-reinforced resin, The process includes a forming step, after the curing step, in which the cured fiber-reinforced resin is used as a base material to form a reinforced resin member in which the reinforced resin exposed on the sliding surface is mainly oriented along a direction perpendicular to the sliding surface. [Explanation of symbols] 【0069】 1 Rotary valve 2 Housing 4 stata 6 rotors 8 rotor shafts 10 bearings 12 Elastic members 14 pins 16 Retaining ring 18. Pipe connection section 20 Approximately spherical shaped part

Claims

[Claim 1] stator and, A rotor shaft that rotates on an axis, The rotor is held at the tip of the rotor shaft and rotates together with the rotor shaft while making surface contact with the stator, The stator and the rotor have sliding surfaces that slide against each other due to the rotation of the rotor, and either the stator or the rotor is a reinforced resin member made of fiber-reinforced resin containing reinforcing fibers to improve hardness. A rotary valve in which the reinforcing fibers exposed on the sliding surface of the reinforcing resin member are mainly oriented along a direction perpendicular to the sliding surface of the reinforcing resin member. [Claim 2] The rotary valve according to claim 1, wherein the reinforced resin member has a gate mark from injection molding on the sliding surface or on a surface parallel to the sliding surface. [Claim 3] The rotary valve according to claim 1, wherein the reinforced resin member is the stator. [Claim 4] The rotary valve according to claim 3, wherein the sliding surface of the rotor is made of a non-metallic material that is harder than the stator. [Claim 5] The rotary valve according to claim 4, wherein the stator has a plurality of pipe connection parts for connecting pipes. [Claim 6] A substantially spherical portion, which is a part of either the rotor or the rotor shaft, is provided between the rotor and the rotor shaft, and the rotor and the rotor shaft come into direct contact at the substantially spherical portion, thereby allowing the sliding surface of the rotor to be tilted from a state perpendicular to the rotation axis of the rotor shaft, according to claim 1. [Claim 7] The rotary valve according to claim 6, wherein the substantially spherical portion is provided as a projection on the rotor shaft side surface of the rotor. [Claim 8] The other of the stator and rotor is a DLC forming member whose sliding surface is formed of a diamond-like carbon film. The rotary valve according to claim 1, wherein the thickness from the surface of the substrate to the surface of the diamond-like carbon film on the sliding surface side of the DLC forming member is 0.5 μm or less. [Claim 9] The rotary valve according to claim 8, wherein the diamond-like carbon film of the DLC forming member is in direct contact with the substrate. [Claim 10] stator and, A rotor shaft that rotates on an axis, The rotor is held at the tip of the rotor shaft and rotates together with the rotor shaft while making surface contact with the stator, The stator is made of resin, and at least the sliding surface of the rotor with respect to the stator is formed of a material harder than the stator, in a rotary valve. [Claim 11] The rotary valve according to claim 10, wherein the resin constituting the stator is a fiber-reinforced resin containing reinforcing fibers to improve hardness. [Claim 12] The rotary valve according to claim 10, wherein the stator has a plurality of pipe connection parts for connecting pipes. [Claim 13] The sliding surface of the rotor is formed of a diamond-like carbon film. The rotary valve according to claim 10, wherein the thickness from the surface of the base material to the surface of the diamond-like carbon film on the sliding surface side of the rotor is 0.5 μm or less. [Claim 14] The rotary valve according to claim 13, wherein the diamond-like carbon film of the rotor is in direct contact with the substrate. [Claim 15] stator and, A rotor shaft that rotates on an axis, The rotor is held at the tip of the rotor shaft and rotates together with the rotor shaft while making surface contact with the stator, A rotary valve is provided between the rotor and the rotor shaft, wherein a substantially spherical portion, which is a part of either the rotor or the rotor shaft, is provided between the rotor and the rotor shaft, and the rotor and the rotor shaft come into direct contact at the substantially spherical portion, allowing the sliding surface of the rotor to be tilted from a state perpendicular to the rotation axis of the rotor shaft. [Claim 16] The rotary valve according to claim 15, wherein the substantially spherical portion is provided as a projection on the rotor shaft side surface of the rotor. [Claim 17] stator and, The system comprises a rotor that rotates while in surface contact with the stator, Each of the stator and the rotor has a sliding surface that slides against each other due to the rotation of the rotor, and either the stator or the rotor is a DLC forming member in which the sliding surface is formed of a diamond-like carbon film. A rotary valve in which the thickness from the surface of the substrate to the surface of the diamond-like carbon film on the sliding surface side of the DLC forming member is 0.5 μm or less. [Claim 18] The rotary valve according to claim 17, wherein the diamond-like carbon film of the DLC forming member is in direct contact with the substrate. [Claim 19] A method for forming either the rotor or stator, which have sliding surfaces that directly contact and slide against each other in a rotary valve, as a reinforced resin member made of fiber-reinforced resin containing reinforcing fibers to improve hardness, A flow step in which a liquid fiber-reinforced resin is flowed in one direction perpendicular to the surface that will become the sliding surface when formed as the reinforced resin member, After the flow step, a curing step is performed to cure the fiber-reinforced resin, A method comprising: a forming step, after the curing step, forming a reinforced resin member using the cured fiber-reinforced resin as a base material, wherein the reinforced resin exposed on the sliding surface is mainly oriented along a direction perpendicular to the sliding surface.

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