Valve device

Abstract

To provide a valve gear which adopts galvanic corrosion prevention means to improve corrosion resistance, resolve a conventional problem (leakage to the outside by galvanic corrosion), and improve sealability.SOLUTION: A valve gear 100a housed in a housing H made of a metal material includes: a valve body 20 having a shaft seal part; a case 71 fixed to the valve body 20 and defining a housing space 3; and galvanic corrosion prevention means. In the galvanic corrosion prevention means, the valve body 20 is made of a resin material. Further, a shaft seal member O1 is sandwiched between a shaft seal member housing groove 27a formed at the shaft seal part and an annular surface G1 formed at the housing H, which are disposed facing each other in a radius direction, to seal the housing space 3 and thereby separate the housing space 3 from an external environment.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a valve device provided with a means for preventing galvanic corrosion.

Background Art

[0002] In a valve device, when fixing to a housing or the like, there is a type that adopts an axial seal type with clearance management in the radial direction and is flange-coupled.

[0003] For example, in Patent Document 1, as shown in FIG. 12, there is described a valve device 1200 (hereinafter referred to as "conventional valve device"), which includes a guide body 1220 made of a metal material, a plunger 1240 movable within the guide body 1220, a valve body portion 1250 fixed to the tip of the plunger 1240, and a drive unit 1270 for driving the plunger 1240 in the axial direction. Further, the valve device 1200 in Patent Document 1 is of an axial seal type with clearance management in the radial direction, and further includes a shaft seal member O12 housed in a seal frame portion 1215 made of a metal material provided on the outer peripheral portion of the lower end of the guide body 1220, and a flange portion 1212 made of a metal material fixed to the outer peripheral portion of the guide body 1220. In order to attach this valve device 1200 to the valve housing unit H12 in a sealed state, while sandwiching the shaft seal member O12 in the radial direction, the flange portion 1212 is flange-coupled to the valve seat member 1230 via a fastening screw 1212f.

[0004] Here, the valve device is installed, for example, in an engine room or a motor room of an automobile, which is not an environment exposed to moisture. However, due to some reasons, there is a possibility that a liquid such as water may penetrate. Therefore, in order to enhance corrosion resistance and versatility, an improvement in pressure resistance (being able to withstand relatively high pressure, for example, usage conditions of about 3 MPa) has been desired.

[0005] In conventional valve devices, since they are of the shaft seal type, if a liquid such as water were to enter from the external environment through the gap between the flange portion 1212 and the valve seat member 1230, or if condensation water formed on the outside of the guide body 1220 cooled by, for example, a low-temperature internal fluid and entered, the entered liquid would accumulate on top of the shaft seal member O12. When the flange portion 1212, the seal frame portion 1215, and the valve seat member 1230 are made of different metals and are in contact with each other in an environment where electricity easily flows, such as water, there was a risk of a phenomenon occurring where the corrosion rate of the metal with the higher ionization tendency increases, that is, galvanic corrosion (hereinafter referred to as "galvanic corrosion"). Therefore, in conventional valve devices, if a relatively high-pressure fluid is introduced while the surface of the seal portion of the seal frame portion 1215 or the valve seat portion 1230, which the shaft seal member O12 contacts, is roughened by this galvanic corrosion, there is a risk of leakage to the external environment through this roughened seal portion (hereinafter referred to as "conventional problem (external leakage due to galvanic corrosion)"). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-169795 [Overview of the project] [Problems that the invention aims to solve]

[0007] The objective of the present invention is to provide a valve device that can improve corrosion resistance by employing a galvanic corrosion prevention means, eliminate conventional problems (external leakage due to galvanic corrosion), and improve sealing performance. [Means for solving the problem]

[0008] To solve the above problems, a valve device housed in a metal housing comprises a valve body having a shaft seal portion, a case fixed to the valve body and defining a housing space, and a galvanic corrosion prevention means, wherein the valve body is made of a resin material, and the housing space is sealed from the external environment by sandwiching a shaft seal member between a shaft seal member housing groove formed in one of the shaft seal portion and the housing, which are radially opposed to each other, and an annular surface formed in the other of the shaft seal portion and the housing.

[0009] Furthermore, the valve device may further include a fixing fitting having an annular flange portion, the inner circumference of which the flange portion is insert-molded into the valve body, and a shaft seal portion reinforcing means for reinforcing the shaft seal portion, wherein the shaft seal portion reinforcing means has the case fixed to the other end face of the flange portion, and the shaft seal portion is adjacent to one end face on the inner circumference of the flange portion.

[0010] Furthermore, in the valve device described above, the shaft seal portion reinforcing means may have a cylindrical portion that extends continuously from the inner circumference side of the flange portion toward one end in the axial direction and is insert-molded into the valve body, with the shaft seal portion positioned adjacent to the outer circumference side of the cylindrical portion.

[0011] Furthermore, in the valve device described above, the shaft seal portion reinforcing means may be such that a valve seat member is fixed to one end of the cylindrical portion.

[0012] Furthermore, in the valve device described above, the shaft seal portion reinforcing means may be provided with a circumferentially shaped step portion on the flange portion adjacent to the outer circumference side of the shaft seal portion when viewed from the axial direction, and the inner circumference side of the flange portion may be offset to the other end side from the outer circumference side with respect to the step portion.

[0013] Furthermore, in the valve device described above, the shaft seal portion reinforcing means may be provided with at least one through hole in the area of ​​the cylindrical portion embedded in the valve body.

[0014] Furthermore, in the valve device described above, the shaft seal portion reinforcing means may be provided with uneven surfaces in at least a portion of the area embedded in the valve body in the cylindrical portion and the flange portion.

[0015] Furthermore, in the valve device described above, the resin material may be PPS to which glass fibers or carbon fibers have been added as a reinforcing agent.

[0016] Furthermore, in the valve device described above, the shaft seal portion reinforcing means may have a fixing plate between itself and the housing that sandwiches the flange portion.

[0017] Furthermore, in the valve device described above, the fixing plate may be equipped with a coil bracket fixing mechanism.

[0018] Furthermore, in the valve device described above, the galvanic corrosion prevention means may include a corrosion-preventive member that prevents galvanic corrosion, which is positioned between the fixing plate, the housing, and the flange portion.

[0019] Furthermore, in the valve device described above, the galvanic corrosion prevention means may be provided with a surface corrosion prevention treatment that prevents galvanic corrosion on at least the surface of the fixing plate facing the housing and the flange portion. [Effects of the Invention]

[0020] According to the present invention, by employing a galvanic corrosion prevention means, it is possible to provide a valve device that can improve corrosion resistance, eliminate conventional problems (external leakage due to galvanic corrosion), and improve sealing performance. [Brief explanation of the drawing]

[0021] [Figure 1] This diagram shows a cross-sectional view of a valve device according to the first embodiment of the present invention. [Figure 2]It represents a cross-sectional view showing the state where the valve device shown in FIG. 1 is attached to the housing. [Figure 3] It represents an enlarged cross-sectional view taken along line III-III shown in FIG. 2. [Figure 4] It represents a front view of the valve device in the attached state shown in FIG. 2. [Figure 5] It represents an explanatory view of a modification example of the shaft seal portion of the first embodiment. [Figure 6] It represents a cross-sectional view showing the valve device according to the second embodiment of the present invention. [Figure 7] It is an explanatory view of the fixing plate used in the valve device of FIG. 6, where (a) represents a top view and (b) represents a front view. [Figure 8] It represents a cross-sectional view showing the state where the valve device shown in FIG. 6 is attached to the housing. [Figure 9] It represents an enlarged cross-sectional view taken along line IX-IX shown in FIG. 8. [Figure 10] It represents a front view of the valve device in the attached state shown in FIG. 8. [Figure 11] It represents a cross-sectional view showing the valve device according to the third embodiment. [Figure 12] It represents a cross-sectional view showing the valve device and the valve housing unit before attachment according to the prior art.

Embodiments for Carrying out the Invention

[0022] Embodiments of the present invention will be described in detail with reference to FIGS. 1 to FIG. 11. However, the present invention is not limited to the aspects of this embodiment. Hereinafter, the valve device will be described, but the galvanic corrosion prevention means and the shaft seal portion reinforcement means in the valve device of the present invention can be applied to electric valves, mechanical expansion valves, mechanical pressure regulating valves, manual on-off valves, and solenoid valves.

[0023] <Regarding Terms> In this specification and the claims, “left,” “right,” “up,” and “down” refer to the directions shown in Figures 1-2, 4-6, 7(b), 8, and 10-11. In this specification and the claims, “one end” and “the other end” refer to the “lower end” and “upper end” in the drawings. In this specification and the claims, “galvanic corrosion prevention means” refers to “means for preventing galvanic corrosion.” In this specification and the claims, “shaft seal reinforcement means” refers to “means for reinforcing the shaft seal.” In this specification and the claims, “guide body” refers to a guide body having a guide portion that guides a member that moves in the axial direction (e.g., a drive shaft or a valve body). Furthermore, in this specification and the claims, “valve body” refers to a valve body that constitutes at least a part of the outer casing of a valve device and includes a guide body.

[0024] (First Embodiment) <Regarding the configuration of the valve device> A valve device 100a according to the first embodiment of the present invention will be described using Figure 1. The valve device 100a mainly consists of a fixing bracket 10, a guide body 20 (valve body), a valve seat member 30, a drive shaft 40, a valve body 50, a coil member 60, and a stepping motor 70. The respective components of the valve device 100a and the housing H (see Figure 2) to which the valve device 100a is mounted will be described in order below. Hereinafter, although the details will be described later, the valve device 100a of the first embodiment can improve corrosion resistance by employing a galvanic corrosion prevention means (1) (shaft seal part made of resin material), thereby eliminating the conventional problem (external leakage due to galvanic corrosion) and improving sealing performance.

[0025] The fixing bracket 10 is made of a metal material such as stainless steel, extends in the axial direction L, and comprises a cylindrical portion 11 having a cylindrical shape, and a flange portion 12 continuously formed on the cylindrical portion 11. An opening 12a defining a lateral port 1b is formed in the side wall of the cylindrical portion 11. As shown in Figure 3, the flange portion 12 has a shape in which approximately three annular shapes are connected in parallel in the longitudinal direction when viewed from the axial direction L, and a pair of mounting holes 12b are provided in the center of the annular shapes at both ends. A pair of fastening screws 12f are inserted into this pair of mounting holes 12b via fastening washers 12g. Here, the pair of fastening screws 12f are inserted into the fastening washers 12g and the pair of mounting holes 12b before the stator coil 73 is fixedly arranged on the outer circumferential surface of the case 71.

[0026] As will be described in detail later, as shown in Figure 2, the operation to attach the valve device 100a to the housing H involves screwing the pair of fastening screws 12f into the pair of screw holes Sh formed on the upper surface H1 of the housing H, while moving the flange portion 12 toward one end in the axial direction L until the outer circumference of one end of the flange portion 12 contacts the upper surface H1 of the housing H. As a result, the first shaft seal member O1 (shaft seal member) is sandwiched between the first housing groove G1 and the insertion cylinder annular groove 27a (shaft seal member housing groove, shaft seal portion), and the radial gap between the valve device 100a and the housing H is sealed.

[0027] The guide body 20 has a roughly cylindrical shape and is made of a resin material such as polyphenylene sulfide (PPS), and a fixing fitting 10 is integrally insert-molded into one end of the guide body 20.

[0028] The guide body 20 is positioned so that its axis aligns with axis L. At the center of the guide body 20, a screw hole 23, a bearing hole 24, and a slide hole 25 are formed concentrically, passing through the guide body 20 in the direction of axis L. A female threaded portion 23a is formed on the inner circumferential surface of the screw hole 23, into which the male threaded portion 41a of the drive shaft 40 (described later) is screwed. The guide portion 42 of the drive shaft 40 (described later) is slidably engaged with the inner circumferential surface of the bearing hole 24. The slide hole 25 is located at one end and is formed to be larger in diameter than the bearing hole 24. The valve body portion 50 (described later) is slidably engaged with the slide hole 25.

[0029] A guide rail 26, consisting of spiral projections, is integrally formed on the outer circumferential surface of the other end of the guide body 20. The guide rails 26 are arranged with adjacent winding portions spaced apart. The guide rails 26 are positioned so that their axes coincide with the axis L, and the coil portion 61 of the coil member 60 (described later) is screwed onto them, guiding each winding portion of the coil portion 61 from one or both sides so that the coil member 60 can rotate in the circumferential direction.

[0030] Furthermore, an insertion tube 27 is integrally formed at one end of the guide body 20, which can be inserted into a first housing groove G1 (see Figure 2) in an insertion hole extending in the axial direction L of the housing H. This insertion tube 27 is formed in a cylindrical shape with an outer diameter approximately the same as the inner diameter of the first housing groove G1. In addition, an annular insertion tube groove 27a is formed in the insertion tube 27, which accommodates the shaft seal member O1.

[0031] The valve seat member 30 is made of a metal material such as stainless steel and comprises a boss portion 31, an annular groove 32 for housing the second shaft seal member O2, and an outer peripheral surface 33 provided between the boss portion 31 and the annular groove 32. A valve port 1a is opened in the center of the valve seat member 30. The boss portion 31 is formed to have a smaller outer diameter than the outer peripheral surface 33, and after being fitted into the cylindrical portion 11 of the fixing bracket 10, the valve seat member 30 is joined to the fixing bracket 10 via a welded portion W2 formed by arc welding or the like. This defines a valve chamber 2 inside the cylindrical portion 11.

[0032] The drive shaft 40 is formed in the shape of a cylindrical rod using a metal such as stainless steel as the material. The drive shaft 40 has a threaded portion 41, a guide portion 42, and a flange portion 43 positioned at one end of the guide portion 42, all aligned in the direction of the axis L. The threaded portion 41 has a male threaded portion 41a, and when this male threaded portion 41a is screwed into the female threaded portion 23a of the guide body 20, the rotational motion of the drive shaft 40 is converted into linear motion. The guide portion 42 is slidably engaged with the inner circumferential surface of the bearing hole 24, thereby guiding the movement of the drive shaft 40 in the direction of the axis L. The drive shaft 40 is moved in the direction of the axis L by a screw-feeding action caused by rotation. The flange portion 43 rotatably engages with the valve body portion 50, which will be described later. In the first embodiment, the female threaded portion 23a and the male threaded portion 41a are right-hand threads.

[0033] The valve body 50 comprises a valve holder 51, a valve body 52, a washer 53, a spring retainer 54, and a compression coil spring 55.

[0034] The valve holder 51 is formed in a cylindrical shape with an outer diameter that is approximately the same as the inner diameter of the slide hole 25 of the guide body 20. The valve holder 51 is slidably engaged along the slide hole 25 in the axial direction L.

[0035] The valve body 52 has a frustoconical shape at one end, and is fixed to one end 51a of the valve holder 51 such that the tip of this frustoconical shape faces the valve port 1a. The valve body 52 adjusts the flow rate by adjusting the opening between the valve seat of the valve port 1a and the valve body, ranging from the maximum opening of the valve to the minimum opening of the valve (or a fully closed state).

[0036] The flange 43 of the drive shaft 40 is rotatably hooked onto the other end 51b of the valve holder 51. Specifically, a washer 53 is sandwiched between the flange 43 of the drive shaft 40 and the other end 51b of the valve holder 51, and this flange 43 rotatably hooks the other end 51b of the valve holder 51 onto the drive shaft 40. This engagement allows the valve holder 51 to be supported by the drive shaft 40 so as to be movable in the direction of axis L and rotatable about axis L. An opening larger than the radial range of motion of the drive shaft 40 is formed at the other end 51b of the valve holder 51. A spring retainer 54 is also provided inside the valve holder 51 so as to be movable in the direction of axis L. A compression coil spring 55 is mounted between this spring retainer 54 and the valve body 52 in a compressed state with a predetermined load applied. As a result, the spring retainer 54 is pressed against the other end and comes into contact with the washer 53 and one end of the drive shaft 40.

[0037] The coil member 60 integrally comprises a coil spring-shaped coil portion 61 and a claw portion 62 that protrudes radially outward from one end of the coil portion 61. The coil portion 61 is screwed onto the guide rail 26 of the guide body 20 so as to be rotatable in the circumferential direction. This coil member 60 can be easily manufactured by shaping a metal wire such as stainless steel.

[0038] The stepping motor 70 comprises a case 71, a magnet rotor 72, and a stator coil 73.

[0039] The case 71 is made of a metal material such as stainless steel and has a roughly bottomed cylindrical shape with its upper end closed. The open end of one end of the case 71 is airtightly joined to the inner circumference of the flange portion 12 of the fixing bracket 10 via a welded portion W1 formed by arc welding or the like, thereby defining the housing space 3.

[0040] The magnet rotor 72 integrally comprises a cylindrical magnet portion 74 with a multi-pole magnetized outer circumference, a disc portion 75 that closes the other end, and a ridge 77. The magnet rotor 72 is fixed to the drive shaft 40 via a fitting 76 that is insert-molded into the center of the disc portion 75. As a result, the magnet rotor 72 is rotatably mounted within the case 71 around the axis L of the drive shaft 40. Here, the ridge 77 of the magnet rotor 72 can contact the claw portion 62 of the coil member 60. Therefore, the rotation of the magnet rotor 72 pushes the coil member 60 in the circumferential direction via the claw portion 62. As a result, the coil member 60 abuts against an upper limit stopper (not shown) or a lower limit stopper (not shown), restricting the rotation of the coil member 60 and also restricting the rotation of the magnet rotor 72. Thus, the valve body portion 50 is prevented from moving beyond the position of maximum opening or minimum opening (or valve closed state).

[0041] The stator coil 73 is fixedly mounted on the outer surface of the case 71, and when a pulse signal is applied to the stator coil 73, the magnet rotor 72 rotates according to the number of pulses.

[0042] When the magnet rotor 72 rotates, the drive shaft 40 rotates together with the magnet rotor 72, and the screw-feeding action of the male threaded portion 41a and the female threaded portion 23a causes the drive shaft 40 to move in the direction of the axis L, causing the valve body 50 to move forward and backward relative to the valve port 1a. This changes the opening degree of the valve port 1a with respect to the valve seat, and controls the flow rate of the fluid flowing from the valve port 1a to the lateral port 1b (or from the lateral port 1b to the valve port 1a).

[0043] The shape of the housing H will be explained using Figures 2 and 3. Note that Figure 3 is an enlarged view of the III-III cross-section shown in Figure 2, and for the sake of clarity, the valve body 50 is not shown.

[0044] The housing H is made of a metal material such as aluminum, and as shown in Figure 2, it has a through hole with a plurality of annular stepped sections that sequentially decrease in diameter from one end to the other along the axis L. A first housing groove G1 and a second housing groove G2 are formed in these plurality of annular stepped sections, in order. Here, a first flow path Fp1 communicating to the side (the front side of the paper in Figure 2) is formed in the second housing groove G2, and a second flow path (not shown) communicating to the side (the back side of the paper in Figure 2) is formed in the first housing groove G1. In addition, a pair of screw holes Sh are formed on the upper surface H1 of the housing H at symmetrical positions on either side of the first housing groove G1.

[0045] In the first embodiment, the shape of the housing H was described as shown in Figures 2 and 3, but this is merely an example, and any shape is acceptable as long as the housing H has an insertion hole and an outer shape that allows the valve device 100a to be inserted into this insertion hole.

[0046] <Regarding the installation and operation of valve devices> The installation operation of the valve device 100a to the housing H will be explained using Figures 2 and 4. First, as shown in Figure 2, the valve device 100a is inserted through the first housing groove G1 along the axis L of the housing H. Then, while screwing the pair of fastening screws 12f into the pair of screw holes Sh, it is moved toward one end in the axis L direction until the outer circumference of one end of the flange portion 12 contacts the upper surface H1 of the housing H. At this time, the second shaft seal member O2 is sandwiched between the second housing groove G2 and the valve seat member annular groove 32 of the valve seat member 30, sealing the space between the first housing groove G1 and the second housing groove G2, and the first shaft seal member O1 is sandwiched between the first housing groove G1 and the insertion cylinder annular groove 27a, sealing the space between the first housing groove G1 and the external environment.

[0047] Next, as shown in Figure 4, the stator coil 73 is fixed to the housing H by screwing fastening screws 73b into mounting holes (not shown) in the coil bracket 73a made of metal material and screw holes (not shown) formed in the side wall of the housing H. In this installed state of the valve device 100a, the valve port 1a defined by the valve seat member 30 communicates with the first piping Pl1 via the first flow path Fp1 and a seal joint Pf fixed to the housing H by fastening bolts Fb, while the lateral port 1b defined by the opening 12a of the cylindrical portion 11 communicates with the second piping (not shown) via the second flow path.

[0048] <Regarding conventional problems (external leakage due to galvanic corrosion)> As mentioned above, in the conventional valve device shown in Figure 12, if a liquid such as water were to enter from the external environment through the gap between the flange portion 1212 and the valve seat member 1230, or if condensation water formed on the outside of the guide body 1220 cooled by, for example, a low-temperature internal fluid and entered, the infiltrated liquid would accumulate on the upper part of the shaft seal member O12. When the flange portion 1212, the seal frame portion 1215, and the valve seat member 1230 are made of different metals and are in contact with each other in an environment where electricity easily flows, such as water, there was a risk of galvanic corrosion occurring. Therefore, in the conventional valve device, if a relatively high-pressure fluid is introduced while the surface of the seal portion of the seal frame portion 1215 or the valve seat member 1230 in contact with the shaft seal member O12 is roughened by this galvanic corrosion, there was a risk of reduced sealing performance due to the conventional problem (external leakage due to galvanic corrosion).

[0049] In contrast, since the valve device 100a of the first embodiment is housed in a housing H made of a metal material such as aluminum, by employing a galvanic corrosion prevention means (1) (shaft seal part made of resin material), corrosion resistance can be improved, conventional problems (external leakage due to galvanic corrosion) can be resolved, and sealing performance can be improved.

[0050] <Galvanic corrosion prevention means (1) (shaft seal part made of resin material)> The galvanic corrosion prevention means (1) (shaft seal portion made of resin material) is made of a resin material for the guide body 20, and the first shaft seal member O1 is sandwiched between the insertion tube annular groove 27a of the insertion tube 27 of the guide body 20 and the annular surface of the first housing groove G1 of the housing H which is arranged radially opposite to it, thereby sealing the housing space 3 from the external environment.

[0051] In the first embodiment, by employing a galvanic corrosion prevention means (1) (shaft seal portion made of resin material) and making one of the members that sandwiches the first shaft seal member O1 a guide body 20 made of resin material, even if a liquid such as water penetrates from the external environment through the gap between the flange portion 12 and the housing H, or if condensation water forms on the outside of the guide body 1220 cooled by, for example, a low-temperature internal fluid and penetrates and accumulates on top of the first shaft seal member O1, the conventional problem (external leakage due to galvanic corrosion) can be eliminated and the sealing performance can be improved.

[0052] <Regarding concerns (reduced strength of the shaft seal)> The valve device 100a of the first embodiment employs a galvanic corrosion prevention means (1) (a shaft seal portion made of resin material), and one of the members that sandwiches the first shaft seal member O1 is a guide body 20 made of resin material. Generally, resin materials have lower pressure resistance and are more easily deformed than metal materials. Therefore, if the insertion cylinder 27 of the guide body 20 having the shaft seal portion is significantly deformed in the axial L direction or radial direction, the first shaft seal member O1 may not have the desired compression allowance, and there is a risk that the sealing performance will decrease (hereinafter referred to as "concern (reduction in pressure resistance of the shaft seal portion)").

[0053] In contrast, the valve device 100a of the first embodiment employs a shaft seal reinforcement means that reinforces the insertion cylinder 27 having the shaft seal, in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of resin material), thereby eliminating concerns (reduction in pressure resistance strength of the shaft seal portion) and further improving sealing performance. Here, the shaft seal reinforcement means in the first embodiment consists of a shaft seal reinforcement means (1) (case fixing to the flange portion), a shaft seal reinforcement means (2) (cylindrical portion), a shaft seal reinforcement means (3) (valve seat member fixing to the cylindrical portion), a shaft seal reinforcement means (4) (step portion of the flange portion), a shaft seal reinforcement means (5) (through hole of the cylindrical portion), a shaft seal reinforcement means (6) (uneven portion of the buried area), and a shaft seal reinforcement means (7) (addition of a reinforcing agent to the resin material), and will be described in order below.

[0054] <Means for reinforcing the shaft seal portion (1) (Case fixing to the flange portion)> The shaft seal reinforcement means (1) (case fixing to flange portion) is as shown in Figure 2, in which the inner circumference of the annular flange portion 12 is insert-molded into the guide body 20, and an insertion cylinder 27 is positioned adjacent to one end face of the inner circumference of the flange portion 12, while as shown in Figure 3, the case 71 is fixed to the other end face of the flange portion 12 via an annular welded portion W1 when viewed from the direction of the axis L. Here, a stepped portion 12s1 is formed on the other end of the flange portion 12, and the outer diameter of this stepped portion 12s1 is set to be equal to or slightly smaller than the inner diameter of one end of the case 71. As a result, the case 71 is positioned on the flange portion 12 via this stepped portion 12s1 and then fixed.

[0055] In the first embodiment, by employing the shaft seal reinforcement means (1) (case fixing to the flange portion), the flange portion 12 to which the case 71 is fixed becomes structurally rigid, and the pressure resistance strength on the inner circumference side of the flange portion 12 is improved. Furthermore, since the insertion cylinder 27 having the shaft seal portion is positioned adjacent to one end face on the inner circumference side of the flange portion 12, which has improved pressure resistance strength, the pressure resistance strength in the axial direction L is mainly improved, thus eliminating concerns (reduction in the pressure resistance strength of the shaft seal portion) and further improving sealing performance.

[0056] <Shaft seal reinforcement means (2) (cylindrical section)> As shown in Figures 2 and 3, the shaft seal reinforcement means (2) (cylindrical portion) has a cylindrical portion 11 that extends continuously from the inner circumference side of the flange portion 12 to one end in the direction of the axis L. Here, the other end of the cylindrical portion 11 is insert-molded into the guide body 20, and an insertion cylinder annular groove 27a, which is the shaft seal portion, is positioned adjacent to the outer circumference side of the embedded area of ​​the cylindrical portion 11.

[0057] In the first embodiment, by employing the shaft seal reinforcement means (2) (cylindrical portion), the cylindrical portion 11, which is continuously formed on the inner circumference side of the flange portion 12, has relatively high structural rigidity and improved pressure resistance. Furthermore, since the insertion cylinder annular groove 27a, which is the shaft seal portion, is located adjacent to the outer circumference side of the cylindrical portion 11, which has improved pressure resistance, the pressure resistance is mainly improved in the radial direction, thus eliminating concerns (reduction in the pressure resistance of the shaft seal portion) and further improving sealing performance.

[0058] <Means for reinforcing the shaft seal portion (3) (fixing the valve seat member to the cylindrical portion)> The shaft seal reinforcement means (3) (fixing the valve seat member to the cylindrical portion) is, as shown in Figure 2, a valve seat member 30 is fixed to one end of the cylindrical portion 11 via a welded portion W2. Here, a boss portion 31 is formed on the other end of the valve seat member 30, and the outer diameter of this boss portion 31 is set to be equal to or slightly smaller than the inner diameter of one end of the cylindrical portion 11. As a result, the valve seat member 30 is positioned on the cylindrical portion 11 via this boss portion 31 and then fixed.

[0059] In the first embodiment, by employing the shaft seal reinforcement means (3) (fixing the valve seat member to the cylindrical portion), the cylindrical portion 11 to which the valve seat member 30 is fixed becomes structurally relatively rigid, and the pressure resistance strength is improved. Also, similar to the shaft seal reinforcement means (2) (cylindrical portion), since the insertion cylinder annular groove 27a, which is the shaft seal portion, is located adjacent to the outer circumference of the cylindrical portion 11, which has improved pressure resistance strength, the pressure resistance strength in the radial direction is mainly improved, thus eliminating concerns (reduction in the pressure resistance strength of the shaft seal portion) and further improving the sealing performance. Furthermore, by making the valve seat member 30 a separate component from the fixing bracket 10, the formation of the valve port 1a on the fixing bracket 10 becomes unnecessary, simplifying the processing of the fixing bracket 10, and allowing the valve seat of the valve port 1a to be formed with a thicker wall, thus providing stable valve leakage performance.

[0060] <Reinforcement means for shaft seal portion (4) (Step portion of flange portion)> The shaft seal reinforcement means (4) (step portion of flange portion) is provided as shown in Figure 3, with a circumferential step portion 12s consisting of a step portion 12s1 on the other end (see Figure 2) and a step portion 12s2 on the one end (see Figure 2) at a position adjacent to the outer circumference of the insertion cylinder 27 having the shaft seal portion, when viewed from the axial direction on the flange portion 12. The flange portion 12 is offset from the outer circumference by the other end, with the step portion 12s as the boundary. This step portion 12s can be formed, for example, by press working on the flange portion 12.

[0061] In the first embodiment, by employing the shaft seal reinforcement means (4) (step portion of the flange portion), the rigidity of the step portion 12s of the flange portion 12 becomes relatively high due to work hardening caused by plastic deformation, and the pressure resistance strength on the inner circumference side of the flange portion 12 is improved. Furthermore, similar to the shaft seal reinforcement means (1) (case fixing to the flange portion), since the insertion cylinder 27 having the shaft seal portion is arranged adjacent to one end face on the inner circumference side of the flange portion 12, which has improved pressure resistance strength, the pressure resistance strength in the axial L direction is mainly improved, thus eliminating concerns (reduction in the pressure resistance strength of the shaft seal portion) and further improving sealing performance.

[0062] <Shaft seal reinforcement means (5) (through hole in cylindrical part)> The shaft seal reinforcement means (5) (through holes in the cylindrical portion) is provided with at least one (four in this example) through holes 12e in the embedded area of ​​the cylindrical portion 11 in the guide body 20, as shown in Figure 3. Here, when the fixing fitting 10 is insert-molded into the guide body 20, the resin material solidifies with at least one through hole 12e filled in. In the first embodiment, the multiple through holes 12e are evenly arranged in the circumferential direction, but this is not limited to this, and for example, the multiple through holes 12e may be unevenly arranged in the circumferential direction.

[0063] In the first embodiment, by employing the shaft seal reinforcement means (5) (through hole in the cylindrical portion), the guide body 20 has improved joint strength in the axial L direction and radial direction with respect to the cylindrical portion 11 via the through hole 12e, i.e., pressure resistance strength. This eliminates the concern (reduction in pressure resistance strength of the shaft seal portion) and further improves sealing performance.

[0064] <Shaft seal reinforcement means (6) (Uneven portion of buried area)> The shaft seal reinforcement means (6) (uneven portion of the embedded area) is provided with an uneven portion (not shown) in at least a part of the area of ​​the cylindrical portion 11 and flange portion 12 that is embedded in the guide body 20, as shown in Figure 2. In the first embodiment, it is preferable that the embedded area where the uneven portion is provided is a region that is continuous in the circumferential direction of either the outer peripheral surface of the other end of the cylindrical portion 11 or the inner end surface of the flange portion 12 (see the L-shaped area marked with "x" in Figure 2). Furthermore, this uneven portion is formed by applying a treatment to a predetermined area of ​​the fixing fitting 10 made of a metal material such as stainless steel, by chemical etching or the like, to form micron-sized fine uneven portions on the surface of the metal material. As a result, when the fixing fitting 10 is insert-molded into the guide body 20, the resin material solidifies while embedded in this uneven portion, further improving the bonding strength through an anchoring effect.

[0065] In the first embodiment, by employing the shaft seal reinforcement means (6) (uneven portion of the buried area), the guide body 20 has improved joint strength in the axial L direction and / or radial direction with respect to the fixing fitting 10 via the uneven portion, i.e., the pressure resistance strength is improved, thus eliminating the concern (reduction in the pressure resistance strength of the shaft seal) and further improving the sealing performance. In addition, in the first embodiment, if the buried area where the uneven portion is provided is a region continuous in the circumferential direction of either the outer peripheral surface of the other end of the cylindrical portion 11 or the inner end surface of the flange portion 12 (see the L-shaped area marked "x" in Figure 2), then no leakage path is formed through the interface between the guide body 20 and the fixing fitting 10 on the housing H side, thus reliably suppressing leakage to the external environment. In the first embodiment, the interface between the guide body 20 and the fixing bracket 10 on the case 71 side is in communication with the housing space 3 inside the case 71. Therefore, even if the bonding strength between the fixing bracket 10 and the guide body 20 decreases, leakage to the external environment will not occur through this interface on the case 71 side.

[0066] <Method for reinforcing the shaft seal (7) (addition of reinforcing agent to resin material)> The shaft seal reinforcement means (7) (addition of a reinforcing agent to the resin material) is to use PPS to which glass fiber or carbon fiber has been added as a reinforcing agent for the resin material of the guide body 20. This PPS with added reinforcing agent has a very high tensile strength (for example, 150 MPa). The guide body 20 may also be made of PPS to which polytetrafluoroethylene (PTFE) has been added. Since this PPS with added PTFE has good sliding properties, the durability of the guide body 20 can be improved.

[0067] In the first embodiment, by employing the shaft seal reinforcement means (7) (adding a reinforcing agent to the resin material), the pressure resistance strength in the axial L direction and radial direction of the guide body 20 itself, that is, the insertion cylinder 27 having the shaft seal, is improved, thereby eliminating the concern (reduction in the pressure resistance strength of the shaft seal) and further improving the sealing performance.

[0068] As described above, the valve device 100a of the first embodiment can improve corrosion resistance by employing a galvanic corrosion prevention means (1) (shaft seal portion made of resin material), thereby eliminating the conventional problem (external leakage due to galvanic corrosion) and improving sealing performance. In addition, the valve device 100a of the first embodiment can further improve sealing performance by employing a shaft seal portion reinforcing means (1) (case fixing to flange portion), shaft seal portion reinforcing means (2) (cylindrical portion), shaft seal portion reinforcing means (3) (valve seat member fixing to cylindrical portion), shaft seal portion reinforcing means (4) (step portion of flange portion), shaft seal portion reinforcing means (5) (through hole of cylindrical portion), shaft seal portion reinforcing means (6) (uneven portion of buried area), and shaft seal portion reinforcing means (7) (addition of reinforcing agent to resin material), thereby eliminating concerns (reduction in pressure resistance strength of shaft seal portion).

[0069] The valve device 100a of the first embodiment employs all of the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) and the shaft seal portion reinforcing means (1) (case fixing to flange portion) to the shaft seal portion reinforcing means (7) (addition of reinforcing agent to resin material), but is not limited to this. For example, the valve device 100a of the first embodiment may employ only the galvanic corrosion prevention means (1) (shaft seal portion made of resin material). Alternatively, for example, the valve device 100a of the first embodiment may employ at least one of the shaft seal portion reinforcing means (1) (case fixing to flange portion) to the shaft seal portion reinforcing means (7) (addition of reinforcing agent to resin material) in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of resin material).

[0070] (Modified example of the shaft seal portion of the first embodiment) Using Figure 5, a valve device 100b relating to a modified shaft seal portion of the first embodiment will be described. The valve device 100b relating to a modified shaft seal portion of the first embodiment employs shaft seal portion reinforcing means (8) (cylindrical insertion tube) and shaft seal portion reinforcing means (9) (cylindrical valve seat member), and therefore differs from the valve device 100a of the first embodiment in the clamping means for the first shaft seal member O1 and the clamping means for the second shaft seal member O2, but the other configurations are the same as those of the first embodiment. Here, the same components are denoted by the same reference numerals, and redundant explanations are omitted.

[0071] <Shaft seal reinforcement means (8) (cylindrical insertion tube)> The shaft seal reinforcement means (8) (cylindrical insertion tube) uses the insertion tube annular surface 27b (shaft seal portion) of the insertion tube 27B of the guide body 20B as the shaft seal portion, and sandwiches the first shaft seal member O1 between it and the first seal member housing groove Gs1 (shaft seal member housing groove) formed in the first housing groove G1 of the housing HB.

[0072] In the modified version of the shaft seal portion of the first embodiment, by employing the shaft seal portion reinforcing means (8) (cylindrical insertion tube), it is not necessary to provide an insertion tube annular groove 27a in the insertion tube 27 as in the first embodiment. As a result, the structural rigidity of the insertion tube 27B is relatively high, and the pressure resistance strength is improved. This eliminates the concern (reduction in the pressure resistance strength of the shaft seal portion) and ensures further improvement in sealing performance. In addition, the shape of the guide body 20B (especially the shape of the insertion tube 27B) can be simplified, thus reducing costs.

[0073] <Shaft seal reinforcement means (9) (cylindrical valve seat member)> The shaft seal reinforcement means (9) (cylindrical valve seat member) sandwiches the second shaft seal member O2 between the outer circumferential surface 33B of the valve seat member 30B and the second seal member housing groove Gs2 formed in the second housing groove G2 of the housing HB.

[0074] In the modified shaft seal portion of the first embodiment, by employing the shaft seal portion reinforcing means (9) (cylindrical valve seat member), it is not necessary to provide the valve seat member annular groove 32 on the valve seat member 30 as in the first embodiment, thus the rigidity of the valve seat member 30B becomes relatively high. Therefore, in the modified shaft seal portion of the first embodiment, similar to the shaft seal portion reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the pressure resistance strength of the insertion cylinder annular surface 27b, which is the shaft seal portion, is mainly improved in the radial direction via the cylindrical portion 11 to which the valve seat member 30B is fixed, thus eliminating concerns (reduction in the pressure resistance strength of the shaft seal portion) and ensuring further improvement in sealing performance. In addition, the shape of the valve seat member 30B can be simplified, thus reducing costs.

[0075] As described above, the valve device 100b in the modified shaft seal portion of the first embodiment, like the first embodiment, can eliminate the conventional problem (external leakage due to galvanic corrosion) and improve sealing performance by employing galvanic corrosion prevention means (1) (shaft seal portion made of resin material). In addition, the valve device 100b in the modified shaft seal portion of the first embodiment, like the first embodiment, can eliminate concerns (reduction in pressure resistance of the shaft seal portion) and further improve sealing performance by employing shaft seal portion reinforcing means (1) (case fixing to flange portion), shaft seal portion reinforcing means (2) (cylindrical portion), shaft seal portion reinforcing means (3) (valve seat member fixing to cylindrical portion), shaft seal portion reinforcing means (4) (step portion of flange portion), shaft seal portion reinforcing means (5) (through hole of cylindrical portion), shaft seal portion reinforcing means (6) (uneven portion of buried area), and shaft seal portion reinforcing means (7) (addition of reinforcing agent to resin material). Furthermore, in the modified example of the shaft seal portion of the first embodiment, the valve device 100b employs shaft seal portion reinforcing means (8) (cylindrical insertion tube) and shaft seal portion reinforcing means (9) (cylindrical valve seat member), thereby eliminating concerns (reduction in pressure resistance strength of the shaft seal portion) and ensuring further improvement in sealing performance.

[0076] The valve device 100b in the modified shaft seal portion of the first embodiment employs all of the shaft seal portion reinforcing means (9) (cylindrical valve seat member) from the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) and the shaft seal portion reinforcing means (9) (cylindrical valve seat member) from the shaft seal portion reinforcing means (1) (case fixing to flange portion), but is not limited thereto. For example, the valve device 100b in the modified shaft seal portion of the first embodiment may employ only the galvanic corrosion prevention means (1) (shaft seal portion made of resin material). Alternatively, for example, the valve device 100b in the modified shaft seal portion of the first embodiment may employ at least one of the shaft seal portion reinforcing means (9) (cylindrical valve seat member) from the shaft seal portion reinforcing means (1) (case fixing to flange portion) to the shaft seal portion reinforcing means (9) (cylindrical valve seat member) in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) (for example, shaft seal portion reinforcing means (1) (case fixing to flange portion) or shaft seal portion reinforcing means (7) (addition of reinforcing agent to resin material)).

[0077] (Second embodiment) The valve device 100c according to the second embodiment will be described using Figure 6. The valve device 100c according to the second embodiment differs from the valve device 100a of the first embodiment mainly in the outer shape of the flange portion 12C of the fixing bracket 10C and the adoption of the fixing plate 13, but the other basic configurations are substantially the same as those of the first embodiment. Here, the same reference numerals are used for identical components, and redundant explanations are omitted. In the second embodiment, the case 71C and the coil bracket 73Ca of the stator coil 73C (see Figure 10) differ slightly in length in the axial direction L from the case 71 and the coil bracket 73a of the stator coil 73 in the first embodiment, but the configurations are the same, so the explanation is omitted.

[0078] The valve device 100c according to the second embodiment mainly consists of a fixing bracket 10C, a fixing plate 13, a guide body 20 (valve body), a valve seat member 30, a drive shaft 40, a valve body 50, a coil member 60, and a stepping motor 70C. Below, the fixing bracket 10C, the fixing plate 13, and the housing HC (see Figure 8) to which the valve device 100c is attached, which have different configurations from the first embodiment, will be described in order.

[0079] <Regarding mounting hardware> The fixing bracket 10C is made of a metal material such as stainless steel, extends in the axial direction L, and comprises a cylindrical portion 11 having a cylindrical shape and a flange portion 12C formed continuously with the cylindrical portion 11. An opening 12a defining the lateral port 1b is formed in the side wall of the cylindrical portion 11. The flange portion 12C has a single annular shape when viewed from the axial direction L, as shown in Figure 9.

[0080] <About the fixing plate> The fixing plate 13 is made of a metal material such as aluminum, stainless steel, or plated steel sheet, or a resin material, and as shown in Figure 7(a), it has a rounded, roughly rhombic shape when viewed from the direction of the axis L. The fixing plate 13 is provided with an insertion hole 13a provided in the center of the axis L, and a pair of mounting holes 13b provided on both ends in the longitudinal direction. In addition, the screw holes 13c for the coil bracket (bracket fixing mechanism) in the second embodiment are formed on the side wall of the fixing plate 13 instead of the side wall of the housing H in the first embodiment, as shown in Figure 7(b). Here, as shown in Figure 6, the case 71C is inserted into the insertion hole 13a of the fixing plate 13 before the stator coil 73C is fixedly arranged on the outer circumferential surface of the case 71C. Also, a pair of fastening screws 12f are inserted into the pair of mounting holes 13b via fastening washers 12g.

[0081] The housing HC is made of a metal material such as aluminum. The shape of this housing HC will be explained using Figures 8 and 9. Note that Figure 9 is an enlarged view of the IX-IX cross-section shown in Figure 8, and for the sake of explanation, the valve body 50 is not shown.

[0082] As shown in Figure 8, the housing HC has an insertion hole with multiple annular stepped sections that sequentially decrease in diameter from one end to the other along the axis L. These multiple annular stepped sections are, in order, formed a flange portion accommodating groove Gf, a first accommodating groove G1, and a second accommodating groove G2. Here, the second accommodating groove G2 has a first flow path Fp1 that communicates to the side (the front side of the paper in Figure 8), and the first accommodating groove G1 has a second flow path (not shown) that communicates to the side (the back side of the paper in Figure 8, where the valve body 52 is located). In addition, a pair of screw holes Sh are formed on the upper surface H1 of the housing HC at symmetrical positions on either side of the first accommodating groove G1.

[0083] In the second embodiment, the shape of the housing HC as shown in Figures 8 and 9 was described, but this is merely an example. Any shape is acceptable as long as the housing HC has an insertion hole and an outer shape through which the valve device 100c can be inserted.

[0084] <Regarding the installation and operation of valve devices> The installation operation of the valve device 100c to the housing HC will be explained using Figures 8 and 10. First, as shown in Figure 8, the valve device 100c is inserted through the first housing groove G1 along the axial direction L of the housing HC. Then, while screwing the pair of fastening screws 12f into the pair of screw holes Sh via the fastening washer 12g and the pair of mounting holes 13b, the flange portion 12C is moved toward the one end in the axial direction L until the outer circumference of one end is housed in the flange portion housing groove Gf and contacts the upper surface H1 of the housing HC. At this time, the second shaft seal member O2 is sandwiched between the second housing groove G2 and the valve seat member annular groove 32 of the valve seat member 30, sealing the space between the first housing groove G1 and the second housing groove G2, and the first shaft seal member O1 is sandwiched between the first housing groove G1 and the insertion cylinder annular groove 27a, sealing the space between the first housing groove G1 and the external environment.

[0085] Next, as shown in Figure 10, the stator coil 73C is fixed to the housing HC by screwing fastening screws 73Cb into the mounting holes (not shown) of the coil bracket 73Ca, which is made of metal, and into the screw holes 13c (see Figure 7(b)) formed in the side wall of the fixing plate 13 for the coil bracket. This ensures that the stator coil 73C is securely fixed to the housing HC via the fixing plate 13. Furthermore, since there is no need to provide screw holes, which are the bracket fixing mechanism, in the housing HC, the design freedom of the housing HC is increased. In this installed state of the valve device 100c, the valve port 1a defined by the valve seat member 30 communicates with the first piping Pl1 via the first flow path Fp1 and the seal joint Pf fixed to the housing HC by fastening bolts Fb, while the lateral port 1b defined by the opening 12a of the cylindrical portion 11 communicates with the second piping (not shown) via the second flow path.

[0086] <Regarding concerns (management of pressure resistance strength of the shaft seal)> The valve device 100a of the first embodiment employs galvanic corrosion prevention means (1) (shaft seal portion made of resin material) as well as shaft seal portion reinforcement means (shaft seal portion reinforcement means (1) (case fixing to flange portion) and shaft seal portion reinforcement means (7) (addition of reinforcing agent to resin material), so that even when a relatively high-pressure fluid is introduced, it is possible to eliminate the conventional problem (external leakage due to galvanic corrosion) and improve sealing performance.

[0087] However, in the valve device 100a of the first embodiment, the pressure resistance strength and direction of action (axial L direction and / or radial direction) of the shaft seal differ depending on the shaft seal reinforcement means (combination) used. Therefore, in the valve device 100a of the first embodiment, when it is necessary to handle extremely high-pressure fluids, it was necessary to manage the shaft seal reinforcement means (combination) so that the total pressure resistance strength of the shaft seal, mainly in the axial L direction, is equal to or greater than the required value (hereinafter referred to as "concern (management of shaft seal pressure resistance)").

[0088] In contrast, the valve device 100c of the second embodiment employs a galvanic corrosion prevention means (1) (shaft seal portion made of resin material) in addition to a shaft seal portion reinforcing means (10) (fixing plate), thereby eliminating concerns (management of the pressure resistance strength of the shaft seal portion) and ensuring improved sealing performance, even when it is necessary to temporarily handle extremely high-pressure fluids. Note that, similar to the valve device 100a of the first embodiment, the valve device 100c of the second embodiment also employs a shaft seal portion reinforcing means (1) (case fixing to the flange portion), a shaft seal portion reinforcing means (2) (cylindrical portion), a shaft seal portion reinforcing means (3) (valve seat member fixing to the cylindrical portion), a shaft seal portion reinforcing means (4) (step portion of the flange portion), a shaft seal portion reinforcing means (5) (through hole of the cylindrical portion), a shaft seal portion reinforcing means (6) (uneven portion of the buried area), and a shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material), but the explanation is omitted due to repetition.

[0089] <Shaft seal reinforcement means (10) (fixing plate)> First, the fixing plate 13 is a relatively thick plate made of a high-rigidity material (for example, a metal material such as aluminum or stainless steel, or a resin material), and as shown in Figure 7(a), it has a rounded, roughly rhombic shape when viewed from the direction of the axis L, and is provided with an insertion hole 13a centered on the axis L and a pair of mounting holes 13b provided on both ends in the longitudinal direction. The case 71C is inserted into this insertion hole 13a. A pair of fastening screws 12f are inserted into the pair of mounting holes 13b via fastening washers 12g.

[0090] In the case where the fixing plate 13 in the second embodiment is made of a resin material, PPS or the like is used. Furthermore, by using PPS to which glass fibers or carbon fibers have been added as a reinforcing agent, the fixing plate 13 can have a very high tensile strength (for example, 150 MPa).

[0091] As shown in Figure 8, the shaft seal reinforcement means (10) (fixing plate) has a fixing plate 13 that sandwiches the flange portion 12C between itself and the housing HC, and as shown in Figure 9, when viewed from the direction of the axis L, the fixing plate 13 and the outer circumference of the flange portion 12C overlap.

[0092] Thus, in the second embodiment, by employing the shaft seal reinforcement means (10) (fixing plate), the flange portion 12, which is firmly fixed by the fixing plate 13, becomes structurally extremely rigid, and the pressure resistance strength on the inner circumference side of the flange portion 12 is dramatically improved. Furthermore, since the insertion cylinder 27 having the shaft seal portion is positioned adjacent to one end face on the inner circumference side of the flange portion 12, which has improved pressure resistance strength, the pressure resistance strength of the shaft seal portion is dramatically improved mainly in the axial L direction, thus eliminating concerns (reduction in the pressure resistance strength of the shaft seal portion) and further improving sealing performance. Therefore, in the second embodiment, instead of managing the pressure resistance strength of the shaft seal portion in different directions (axial L direction and / or radial direction) by using a combination of shaft seal portion reinforcing means, as in the first embodiment, a shaft seal portion reinforcing means (10) (fixing plate) is employed, and the pressure resistance strength of the shaft seal portion in the axial L direction is centrally managed to be greater than or equal to the required value. This eliminates the concern (management of the pressure resistance strength of the shaft seal portion) and further improves sealing performance.

[0093] As described above, the valve device 100c of the second embodiment, like the first embodiment, can eliminate the conventional problem (external leakage due to galvanic corrosion) and improve sealing performance by employing galvanic corrosion prevention means (1) (shaft seal portion made of resin material). In addition, the valve device 100c of the second embodiment, like the first embodiment, can eliminate concerns (reduction in pressure resistance of the shaft seal portion) and further improve sealing performance by employing shaft seal portion reinforcement means (1) (case fixing to flange portion), shaft seal portion reinforcement means (2) (cylindrical portion), shaft seal portion reinforcement means (3) (valve seat member fixing to cylindrical portion), shaft seal portion reinforcement means (4) (step portion of flange portion), shaft seal portion reinforcement means (5) (through hole of cylindrical portion), shaft seal portion reinforcement means (6) (uneven portion of buried area), and shaft seal portion reinforcement means (7) (addition of reinforcing agent to resin material). Furthermore, the valve device 100c of the second embodiment can eliminate concerns (management of pressure resistance strength of the shaft seal) and further improve sealing performance by employing a shaft seal reinforcement means (10) (fixing plate).

[0094] The valve device 100c of the second embodiment employs all of the galvanic corrosion prevention means (1) (shaft seal portion made of resin material), shaft seal portion reinforcement means (1) (case fixing to flange portion), shaft seal portion reinforcement means (7) (addition of reinforcing agent to resin material), and shaft seal portion reinforcement means (10) (fixing plate), but is not limited to this. For example, the valve device 100c of the second embodiment may employ only the galvanic corrosion prevention means (1) (shaft seal portion made of resin material). Furthermore, for example, the valve device 100c of the second embodiment may employ, in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of resin material), at least one of the shaft seal portion reinforcing means (1) (case fixing to flange portion), shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material), and shaft seal portion reinforcing means (10) (fixing plate) (for example, shaft seal portion reinforcing means (1) (case fixing to flange portion) or shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material)).

[0095] (Third embodiment) The valve device 100d according to the third embodiment will be described using Figure 11. The valve device 100d according to the third embodiment differs from the valve device 100c of the second embodiment in that a corrosion-preventive member 14 is placed between the fixing plate 13 and the housing HC and flange portion 12C to prevent galvanic corrosion, but the other basic configurations are substantially the same as those of the second embodiment. Here, the same reference numerals are used for the same components, and redundant explanations are omitted.

[0096] <Regarding concerns (reduction in contact area due to galvanic corrosion)> First, in the valve device 100a of the first embodiment, as shown in Figure 2, there is a risk that liquid such as water may enter from the external environment through the gap between the flange portion 12 and the housing H. In this case, if the flange portion 12 and the housing H are made of different metals and are in contact with each other in an environment where electricity easily flows, such as water, there is a risk of galvanic corrosion occurring at the interface between the flange portion 12 and the housing H. However, in the valve device 100a of the first embodiment, the introduced pressure is not as high as in the second embodiment, so galvanic corrosion at the interface between the flange portion 12 and the housing H is not a problem. On the other hand, in order to reliably prevent galvanic corrosion in the shaft seal portion, a galvanic corrosion prevention means (1) (shaft seal portion made of resin material) is adopted.

[0097] Next, the valve device 100c of the second embodiment employs a shaft seal reinforcement means (10) (fixing plate) as shown in Figure 8. However, there was a risk that liquid such as water could seep in from the external environment through the gap between the contact surface 13D on one end of the fixing plate 13 and the upper surface H1 of the housing HC, causing galvanic corrosion at the interface between the fixing plate 13 and the housing H. If this galvanic corrosion at the interface between the fixing plate 13 and the housing H is left untreated, galvanic corrosion may occur at the interface between the fixing plate 13 and the flange portion 12C located nearby, reducing the contact area between the fixing plate 13 and the flange portion 12C, which could lead to a decrease in the pressure resistance strength of the shaft seal portion provided by the fixing plate 13 (hereinafter referred to as "concern (reduction in contact area due to galvanic corrosion)"). In this case, if the valve device 100c of the second embodiment needs to constantly handle extremely high-pressure fluids, there was a risk that leakage to the external environment could occur due to the decrease in the pressure resistance strength of the shaft seal portion provided by the fixing plate 13.

[0098] In contrast, the valve device 100d of the third embodiment employs a galvanic corrosion prevention means (2) (corrosion-preventive member) in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of resin material), thereby eliminating concerns (reduction in contact area due to galvanic corrosion) and ensuring improved sealing performance. It should be noted that, similar to the valve device 100c of the second embodiment, the valve device 100d of the third embodiment also employs a shaft seal portion reinforcement means (1) (case fixing to flange portion), a shaft seal portion reinforcement means (2) (cylindrical portion), a shaft seal portion reinforcement means (3) (valve seat member fixing to cylindrical portion), a shaft seal portion reinforcement means (4) (step portion of flange portion), a shaft seal portion reinforcement means (5) (through hole of cylindrical portion), a shaft seal portion reinforcement means (6) (uneven portion of buried area), a shaft seal portion reinforcement means (7) (addition of reinforcing agent to resin material), and a shaft seal portion reinforcement means (10) (fixing plate) as shaft seal portion reinforcement means, but their explanations are omitted due to repetition.

[0099] <Galvanic corrosion prevention means (2) (corrosion prevention member)> As shown in Figure 11, the galvanic corrosion prevention means (2) (corrosion prevention member) involves placing a corrosion prevention member 14 (for example, a sheet-like resin or rubber, or any other material that does not have a specific potential) between the fixing plate 13 and the housing HC and flange portion 12C to prevent galvanic corrosion.

[0100] In the third embodiment, by employing the galvanic corrosion prevention means (2) (corrosion-preventive member), the corrosion-preventive member 14, which does not have an inherent potential, is interposed between the fixing plate 13 and the housing HC and flange portion 12C. This improves corrosion resistance and eliminates concerns (reduction in contact area due to galvanic corrosion), thereby maintaining the pressure resistance strength of the shaft seal portion by the fixing plate 13, and as a result, further improvement in sealing performance can be achieved.

[0101] <Galvanic corrosion prevention method (3) (Surface corrosion protection treatment)> In the third embodiment, a galvanic corrosion prevention means (2) (corrosion-preventive member) is employed to improve corrosion resistance between the fixing plate 13 and the housing HC and flange portion 12C, but the embodiment is not limited to this. For example, in the third embodiment, instead of the galvanic corrosion prevention means (2) (corrosion-preventive member), a galvanic corrosion prevention means (3) (surface corrosion prevention treatment) may be employed, that is, the fixing plate 13 may be made of, for example, plated steel plate, and at least the surface facing the housing HC and flange portion 12C may be provided with a surface treatment (for example, zinc plating, chromium plating, Ni plating, etc.) to prevent galvanic corrosion.

[0102] As described above, the valve device 100d of the third embodiment, like the second embodiment, can eliminate the conventional problem (external leakage due to galvanic corrosion) and improve sealing performance by employing galvanic corrosion prevention means (1) (shaft seal portion made of resin material). In addition, the valve device 100d of the third embodiment, like the second embodiment, can eliminate concerns (reduction in pressure resistance of the shaft seal portion) and further improve sealing performance by employing shaft seal portion reinforcement means (1) (case fixing to flange portion), shaft seal portion reinforcement means (2) (cylindrical portion), shaft seal portion reinforcement means (3) (valve seat member fixing to cylindrical portion), shaft seal portion reinforcement means (4) (step portion of flange portion), shaft seal portion reinforcement means (5) (through hole of cylindrical portion), shaft seal portion reinforcement means (6) (uneven portion of buried area), and shaft seal portion reinforcement means (7) (addition of reinforcing agent to resin material). Furthermore, the valve device 100d of the third embodiment can eliminate concerns (management of pressure resistance strength of the shaft seal) and further improve sealing performance by employing a shaft seal reinforcement means (10) (fixing plate). In addition, the valve device 100d of the third embodiment can eliminate concerns (reduction of contact area due to galvanic corrosion) and reliably improve sealing performance by employing a galvanic corrosion prevention means (2) (corrosion prevention member) or a galvanic corrosion prevention means (3) (surface corrosion prevention treatment).

[0103] The valve device 100d of the third embodiment employs, but is not limited to, all of the galvanic corrosion prevention means (1) (shaft seal portion made of resin material), galvanic corrosion prevention means (2) (corrosion prevention member) (or galvanic corrosion prevention means (3) (surface corrosion prevention treatment portion)), and shaft seal portion reinforcement means (1) (case fixing to flange portion), shaft seal portion reinforcement means (7) (addition of reinforcing agent to resin material), and shaft seal portion reinforcement means (10) (fixing plate). For example, the valve device 100d of the third embodiment may employ only the galvanic corrosion prevention means (1) (shaft seal portion made of resin material). Furthermore, for example, the valve device 100d of the third embodiment may employ, in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of resin material), at least one of the shaft seal portion reinforcing means (1) (case fixing to flange portion), shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material), shaft seal portion reinforcing means (10) (fixing plate), and galvanic corrosion prevention means (2) (corrosion prevention member) (or galvanic corrosion prevention means (3) (surface corrosion prevention treatment portion)) (for example, shaft seal portion reinforcing means (1) (case fixing to flange portion) or shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material)).

[0104] In the third embodiment, only the use of galvanic corrosion prevention means (2) (corrosion-preventive member) or galvanic corrosion prevention means (3) (surface corrosion prevention treatment) has been described, but the invention is not limited to this. For example, in the first embodiment (see Figure 2) and the modified shaft seal portion of the first embodiment (see Figure 5), galvanic corrosion prevention means (2) (corrosion-preventive member) or galvanic corrosion prevention means (3) (surface corrosion prevention treatment) may be used on one end of the flange portion 12 that contacts the housing H, HB.

[0105] Furthermore, while only a modified example of the shaft seal portion of the first embodiment has been described in which the shaft seal portion reinforcing means (8) (cylindrical insertion tube) and / or shaft seal portion reinforcing means (9) (cylindrical valve seat member) are employed, the invention is not limited to this. For example, in the second embodiment (see Figure 8) and the third embodiment (see Figure 11), the shaft seal portion reinforcing means (8) (cylindrical insertion tube) and / or shaft seal portion reinforcing means (9) (cylindrical valve seat member) may be employed in the insertion tube 27 and / or valve seat member 30.

[0106] <Other> It goes without saying that the valve devices 100a to 100d of this embodiment are applicable to all fluid devices and fluid circuits, including refrigeration cycles. Furthermore, the present invention is not limited to the embodiments described above, and can be appropriately modified or altered without departing from the technical spirit of the present invention. [Explanation of Symbols]

[0107] 100a, 100b, 100c, 100d Valve device 1a Valve port 1b Side port 2 valve chambers 3. Containment space 10,10C Fixing Bracket 11 Cylindrical section 12,12C Flange section 12a opening 12b Pair of mounting holes 12s stepped section 12s1 Step part on other end side 12s2 Stepped part on one end 12e through hole 12f Pair of fastening screws 12g fastening washer 13 Fixed plate 13a Through hole 13b A pair of mounting holes 13c coil bracket screw holes (bracket fixing mechanism) 13D One end contact surface 14. Corrosion-resistant material 20,20B Guide body (valve body) 23 screw holes 23a Female thread section 24 bearing holes 25 slide holes 26 Guide rails 27,27B Insertion tube 27a Insertion tube annular groove (shaft seal member housing groove, shaft seal portion) 27b Insertion tube annular surface (shaft seal portion) 30,30B Valve seat member 31 Boss Section 32 Valve seat member annular groove 33,33B Outer surface 40 Drive shaft 41 Threaded part 41a Male threaded portion 42 Guide section 43 Guard section 50 Valve body 51 Valve holder 51a One end 51b Other end 52 Valve body 53 Washer 54 Spring receiver 55 Compression coil spring 60 Coil components 61 Coil section 62 Nail part 70,70C Stepping Motor 71, 71C Case 72 Magnet Rotor 73,73C Stator Coil 73a, 73Ca coil bracket 73b, 73Cb fastening screws 74 Magnet section 75 Disc section 76 Metal fittings 77 Protrusion Fb fastening bolts Fp1 First channel G1 First storage trench Gs1 First seal member housing groove (shaft seal member housing groove) Gs2 Second seal member housing groove G2 Second storage trench Gf flange housing groove H, HB, HC Housing H1 top L axis O1 First shaft seal member (shaft seal member) O2 Second shaft seal member Pf seal fittings Pl1 First Piping Sh Pair of screw holes W1 Weld W2 weld

Claims

1. A valve device housed in a housing made of a metal material, A case for defining a housing space for accommodating a component that moves axially within the interior, A valve body joined to the case and having a shaft seal portion that seals the external environment and the housing space, A fixing bracket having an annular flange portion, the inner circumference of the flange portion being insert-molded into the valve body, and the outer circumference of one end of the flange portion being housed in direct contact with the housing, Galvanic corrosion prevention measures, Equipped with, The galvanic corrosion prevention means is a valve device characterized in that the valve body is made of a resin material, and the axial seal member is sandwiched between a shaft seal member housing groove formed in one of the shaft seal portion and the housing, which are radially opposed to each other, and an annular surface formed in the other of the shaft seal portion and the housing, thereby sealing the housing space from the external environment.

2. A means for reinforcing the shaft seal portion, Furthermore, The valve device according to claim 1, characterized in that the shaft seal portion reinforcing means is such that the case is fixed to the other end face of the flange portion, and the shaft seal portion is adjacent to one end face on the inner circumference side of the flange portion.

3. The valve device according to claim 2, characterized in that the shaft seal portion reinforcing means has a cylindrical portion that extends continuously from the inner circumference side of the flange portion toward one end in the axial direction, and is insert-molded into the valve body, with the shaft seal portion being adjacent to the outer circumference side of the cylindrical portion.

4. The valve device according to claim 3, characterized in that the shaft seal portion reinforcing means fixes a valve seat member to one end of the cylindrical portion.

5. The valve device according to claim 2, characterized in that the shaft seal portion reinforcing means is provided with a circumferentially shaped step portion on the flange portion adjacent to the outer circumference side of the shaft seal portion when viewed from the axial direction, and the inner circumference side of the flange portion is offset to the other end side from the outer circumference side with respect to the step portion.

6. The valve device according to claim 3, characterized in that the shaft seal portion reinforcing means is provided with at least one through hole in the embedded region of the cylindrical portion within the valve body.

7. The valve device according to claim 3, characterized in that the shaft seal portion reinforcing means is provided with an uneven portion in at least a part of the area embedded in the valve body in the cylindrical portion and the flange portion.

8. The valve device according to claim 1, characterized in that the resin material is PPS to which glass fibers or carbon fibers have been added as a reinforcing agent.

9. The valve device according to claim 2, characterized in that the shaft seal portion reinforcing means has a fixing plate between itself and the housing that sandwiches the flange portion.

10. The valve device according to claim 9, characterized in that the fixing plate is provided with a coil bracket fixing mechanism.

11. The valve device according to claim 9, characterized in that the galvanic corrosion prevention means includes a corrosion-preventive member for preventing galvanic corrosion, which is disposed between the fixing plate, the housing, and the flange portion.

12. The valve device according to claim 9, characterized in that the galvanic corrosion prevention means is provided with a surface corrosion prevention treatment that prevents galvanic corrosion on at least the surface of the fixing plate facing the housing and the flange portion.

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