Valve gear

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 gear provided with galvanic corrosion protection means. [Background technology]

[0002] In some valve devices, when fixing to a housing, etc., a shaft seal type with controlled radial clearance is adopted and flange connection is used.

[0003] For example, Patent Document 1 discloses a valve device 1200 (hereinafter referred to as a "conventional valve device") as shown in Fig. 12, which includes a guide body 1220 made of a metallic 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 portion 1270 that drives the plunger 1240 in the axial direction. The valve device 1200 in Patent Document 1 is of an axial seal type with radial clearance management, and further includes an axial seal member O12 housed in a seal frame portion 1215 made of a metallic material provided on the outer periphery of the lower end of the guide body 1220, and a flange portion 1212 made of a metallic material fixed to the outer periphery of the guide body 1220. In order to mount this valve device 1200 in a sealed state to the valve housing unit H12, the flange portion 1212 is flange-coupled to the valve seat member 1230 via the fastening screw 1212f while the shaft seal member O12 is clamped in the radial direction.

[0004] Here, the valve device is installed, for example, in the engine room or motor room of an automobile, which is not an environment where it is exposed to moisture. However, there is a risk of liquids such as water entering the device for some reason, so there has been a demand for improved pressure resistance (the ability to withstand relatively high pressures, for example, approximately 3 MPa, in order to increase corrosion resistance and versatility.

[0005] Here, since the conventional valve device is of the shaft seal type, if liquid such as water should infiltrate from the external environment through the gap between the flange portion 1212 and the valve seat member 1230, or if condensation water is generated on the outside of the guide body 1220 cooled by the low-temperature internal fluid, the infiltrated liquid will accumulate on the upper part of the shaft seal member O12. If the flange portion 1212, the seal frame portion 1215, and the valve seat member 1230 are made of different metals and are placed in contact with each other in an environment where electricity such as water flows easily, there is a risk of a phenomenon in which the corrosion rate of the metal with a greater ionization tendency increases, that is, bimetallic corrosion (hereinafter referred to as "galvanic corrosion") occurring. Therefore, in the conventional valve device, when a relatively high-pressure fluid is introduced into the valve seat member 1230 or the seal frame member 1215 with which the shaft seal member O12 comes into contact is roughened by galvanic corrosion, there is a risk of leakage into the external environment through the roughened seal portion (hereinafter referred to as "conventional problem (external leakage due to galvanic corrosion)"). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-169795 A Summary of the Invention [Problem to be solved by the invention]

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

[0008] In order to solve the above problems, a valve device accommodated in a housing made of a metal material comprises a valve body having an axial seal portion, a case fixed to the valve body and defining an accommodation space, and galvanic corrosion prevention means, wherein the valve body is made of a resin material, and the galvanic corrosion prevention means seals the accommodation space from the external environment by sandwiching an axial seal member between an axial seal member accommodation groove formed on one of the axial seal portion and the housing, and an annular surface formed on the other of the axial seal portion and the housing, which are arranged radially opposite each other.

[0009] The above valve device may further include a fixing bracket having a circular flange portion, the inner side of the flange portion being insert molded into the valve body, and an axial seal portion reinforcing means for reinforcing the axial seal portion, wherein the axial seal portion reinforcing means is configured so that the case is fixed to the other end face of the flange portion and the axial seal portion is adjacent to one end face of the inner side of the flange portion.

[0010] Moreover, in the above valve device, the shaft seal portion reinforcing means may have a cylindrical portion formed continuously on the inner periphery of the flange portion, extending to one end in the axial direction, and the shaft seal portion may be arranged adjacent to the outer periphery of the cylindrical portion which is insert molded into the valve body.

[0011] In the above valve device, the shaft seal portion reinforcing means may be configured to fix a valve seat member to one end of the cylindrical portion.

[0012] Moreover, in the above valve device, the shaft seal portion reinforcing means may be configured so that, when viewed in the axial direction, a circumferential step is provided in the flange portion adjacent to the outer circumferential side of the shaft seal portion, and the inner circumferential side of the flange portion is offset toward the other end from the outer circumferential side at the step.

[0013] In the above valve device, the shaft seal portion reinforcing means may be provided with at least one through hole in a region of the cylindrical portion where the cylindrical portion is embedded in the valve body.

[0014] In the above valve device, the shaft seal portion reinforcing means may be provided with uneven portions in at least a part of the region of the cylindrical portion and the flange portion that is embedded in the valve body.

[0015] In the above valve device, the resin material may be PPS to which glass fiber or carbon fiber is added as a reinforcing agent.

[0016] In the above valve device, the shaft seal portion reinforcing means may include a fixing plate that holds the flange portion between the housing and the fixing plate.

[0017] In the valve device, the fixing plate may include a bracket fixing mechanism for fixing the coil.

[0018] In the above valve device, the galvanic corrosion prevention means may be configured to include a corrosion prevention member that prevents galvanic corrosion and is disposed between the fixed plate and the housing and between the fixed plate and the flange portion.

[0019] In the above valve device, the galvanic corrosion prevention means may be provided with a surface anticorrosion treatment portion for preventing galvanic corrosion on at least a surface of the fixing plate that faces the housing and the flange portion. Effect of the Invention

[0020] According to the present invention, by adopting a galvanic corrosion prevention means, it is possible to provide a valve device that has improved corrosion resistance, eliminates the conventional problem (external leakage due to galvanic corrosion), and improves sealing performance. [Brief description of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view showing a valve device according to a first embodiment of the present invention. [Diagram 2]2 is a cross-sectional view showing a state in which the valve device shown in FIG. 1 is attached to a housing. [Diagram 3] 3 is an enlarged cross-sectional view taken along line III-III of FIG. 2. [Figure 4] 3 shows a front view of the valve device in the installed state shown in FIG. 2. [Diagram 5] 5A to 5C are explanatory views of modified examples of the shaft seal portion of the first embodiment. [Figure 6] FIG. 4 is a cross-sectional view showing a valve device according to a second embodiment of the present invention. [Figure 7] 7A and 7B are explanatory views of a fixed plate used in the valve device of FIG. 6, where (a) is a top view and (b) is a front view. [Figure 8] 7 is a cross-sectional view showing the valve device shown in FIG. 6 attached to a housing. [Figure 9] FIG. 9 is an enlarged cross-sectional view taken along line IX-IX of FIG. 8 . [Figure 10] 9 shows a front view of the valve device in the installed state shown in FIG. 8. [Figure 11] FIG. 13 is a cross-sectional view showing a valve device according to a third embodiment. [Figure 12] FIG. 1 illustrates a cross-sectional view of a valve device and a valve housing unit before installation according to the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] An embodiment of the present invention will be described in detail with reference to Fig. 1 to Fig. 11. However, the present invention is not limited to the aspects of this embodiment. Although a valve device will be described below, the galvanic corrosion prevention means and shaft seal reinforcing means in the valve device of the present invention can be applied to motor-operated valves, mechanical expansion valves, mechanical pressure regulating valves, manual on-off valves, and solenoid valves.

[0023] <Terminology> In the description of this specification and the claims, the terms "left", "right", "upper", and "lower" refer to the directions shown in Figs. 1-2, 4-6, 7(b), 8, and 10-11. In the description of this specification and the claims, the terms "one end" and "the other end" refer to the "lower end" and "upper end" in the drawings. In the description of this specification and the claims, the term "galvanic corrosion prevention means" refers to "means for preventing galvanic corrosion". In the description of this specification and the claims, the term "shaft seal reinforcing means" refers to "means for reinforcing the shaft seal". In addition, in the description of this specification and the claims, the term "guide body" refers to a device having a guide portion that guides a member (e.g., a drive shaft, a valve body, etc.) that moves in the axial direction. In addition, in the description of this specification and the claims, the term "valve body" refers to a device that constitutes at least a part of the outer shell of the valve device and includes the guide body.

[0024] (First embodiment) <Valve gear configuration> A valve device 100a according to a first embodiment of the present invention will be described with reference to Fig. 1. The valve device 100a is mainly composed of a fixed metal fitting 10, a guide body 20 (valve body), a valve seat member 30, a drive shaft 40, a valve body portion 50, a coil member 60, and a stepping motor 70. Each component of the valve device 100a and a housing H (see Fig. 2) to which the valve device 100a is attached will be described below in order. Here, as will be described in detail later, the valve device 100a of the first embodiment employs a galvanic corrosion prevention means (1) (shaft seal portion made of a resin material) to improve corrosion resistance, 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, and includes a cylindrical portion 11 extending in the direction of the axis L and having a cylindrical shape, and a flange portion 12 formed continuously with the cylindrical portion 11. An opening 12a that defines the side port 1b is formed in the side wall of the cylindrical portion 11. As shown in FIG. 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 direction of the axis L, and a pair of mounting holes 12b is provided in the center of the annular shapes on both ends. A pair of fastening screws 12f are inserted into the pair of mounting holes 12b via fastening washers 12g. Before the stator coil 73 is fixed and disposed on the outer circumferential surface of the case 71, the pair of fastening screws 12f are inserted into the fastening washers 12g and the pair of mounting holes 12b.

[0026] 2, the valve device 100a is attached to the housing H by threading the pair of fastening screws 12f into a pair of screw holes Sh formed in the upper surface H1 of the housing H and moving the flange portion 12 toward one end in the direction of the axis L until the outer periphery of one end of the flange portion 12 abuts against the upper surface H1 of the housing H. This causes the first shaft seal member O1 (shaft seal member) to be sandwiched between the first accommodating groove G1 and the insertion cylinder annular groove 27a (shaft seal member accommodating groove, shaft seal portion), sealing the radial gap between the valve device 100a and the housing H.

[0027] The guide body 20 has a substantially cylindrical shape and is made of a resin material such as polyphenylene sulfide (PPS).

[0028] The guide body 20 is disposed so that its axis overlaps with the axis L. A screw hole 23, a bearing hole 24, and a slide hole 25 are formed concentrically in the center of the guide body 20, aligned in the direction of the axis L so as to penetrate the guide body 20. A female thread portion 23a is formed on the inner peripheral surface of the screw hole 23, and a male thread portion 41a of a drive shaft 40 described later is screwed into the female thread portion 23a. A guide portion 42 of the drive shaft 40 described later is slidably engaged with the inner peripheral surface of the bearing hole 24. The slide hole 25 is disposed on one end side, and is formed to have a larger diameter than the bearing hole 24. A valve body portion 50 described later is slidably engaged with the slide hole 25.

[0029] A guide rail 26 consisting of a helical ridge is integrally formed on the outer circumferential surface of the other end of the guide body 20. Adjacent winding portions of the guide rail 26 are arranged with a gap between them. The guide rail 26 is arranged so that its axis overlaps with the axis L, and guides each winding portion of the coil portion 61 from one side or both sides so that the coil member 60 described below is screwed therewith and can rotate in the circumferential direction.

[0030] An insertion tube 27 is integrally formed at one end of the guide body 20, and can be inserted into a first accommodating groove G1 (see FIG. 2) in an insertion hole extending in the axial direction L of the housing H. The insertion tube 27 is formed in a cylindrical shape with an outer diameter substantially equal to the inner diameter of the first accommodating groove G1. The insertion tube 27 is also formed with an insertion tube annular groove 27a in which the shaft seal member O1 is accommodated.

[0031] The valve seat member 30 is made of a metal material such as stainless steel, and includes a boss portion 31, a valve seat member annular groove 32 in which the second shaft seal member O2 is housed, and an outer circumferential surface 33 provided between the boss portion 31 and the valve seat member annular groove 32. The valve port 1a is opened at the center of the valve seat member 30. The boss portion 31 is formed to have an outer diameter smaller than the outer circumferential 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 a cylindrical rod shape using a metal such as stainless steel. The drive shaft 40 is formed with a threaded portion 41, a guide portion 42, and a flange portion 43 arranged at one end of the guide portion 42, which are aligned in the axial direction L. The threaded portion 41 is formed with a male threaded portion 41a, which is screwed into the female threaded portion 23a of the guide body 20, thereby converting the rotational motion of the drive shaft 40 into a linear motion. The guide portion 42 guides the movement of the drive shaft 40 in the axial direction L by slidably engaging with the inner circumferential surface of the bearing hole 24. The drive shaft 40 is moved in the axial direction L by a screw feed action due to rotation. The flange portion 43 rotatably engages 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-handed threads.

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

[0034] The valve holder 51 is formed in a cylindrical shape with an outer diameter substantially the same as the inner diameter of the slide hole 25 of the guide body 20. The valve holder 51 is engaged with the slide hole 25 so as to be slidable in the axial L direction.

[0035] The valve element 52 has a truncated cone shape on one end, and is fixed to one end 51a of the valve holder 51 so that the tip of the truncated cone faces the valve port 1a. The valve element 52 adjusts the flow rate by adjusting the opening between the valve port 1a and the valve seat between the maximum opening and the minimum opening (or fully closed state) of the valve.

[0036] The flange 43 of the drive shaft 40 is rotatably engaged with 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 the other end 51b of the valve holder 51 is rotatably engaged with the drive shaft 40 by the flange 43. This engagement allows the valve holder 51 to be moved in the axial direction L by the drive shaft 40 and to be supported rotatably about the axial line L. An opening larger than the radial movable range of the drive shaft 40 is formed in the other end 51b of the valve holder 51. A spring receiver 54 is provided in the valve holder 51 so as to be movable in the axial direction L. A compression coil spring 55 is attached between the spring receiver 54 and the valve body 52 in a compressed state to which a predetermined load is applied. As a result, the spring receiver 54 is pressed toward 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 protruding radially outward from one end of the coil portion 61. The coil portion 61 is screwed into the guide rail 26 of the guide body 20 so as to be rotatable in the circumferential direction. The coil member 60 can be easily manufactured by forming a metal wire such as stainless steel.

[0038] The stepping motor 70 includes 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 generally bottomed cylindrical shape with a closed upper end. One open end of the case 71 is airtightly joined to the inner periphery of the flange portion 12 of the fixing bracket 10 via a welded portion W1 by arc welding or the like, thereby defining the accommodation space 3.

[0040] The magnet rotor 72 integrally includes a cylindrical magnet portion 74 whose outer periphery is magnetized to multiple poles, a disk portion 75 that closes the other end, and a protrusion 77. The magnet rotor 72 is fixed to the drive shaft 40 via a metal fitting 76 that is insert-molded in the center of the disk portion 75. As a result, the magnet rotor 72 is provided in the case 71 so as to be rotatable about the axis L of the drive shaft 40. Here, the protrusion 77 of the magnet rotor 72 can abut against the claw portion 62 of the coil member 60. Therefore, the coil member 60 is pushed and rotated in the circumferential direction by the claw portion 62 due to the rotation of the magnet rotor 72. As a result, the coil member 60 hits an upper limit stopper (not shown) or a lower limit stopper (not shown), and the rotation of the coil member 60 is restricted, and the rotation of the magnet rotor 72 is also restricted. Therefore, the valve body portion 50 is restricted from moving beyond the position where the valve body portion 50 is at the maximum opening degree or the position where the valve body portion 50 is at the minimum opening degree (or the valve is closed).

[0041] The stator coil 73 is fixedly disposed on the outer circumferential surface of the case 71, and when a pulse signal is given to the stator coil 73, the magnet rotor 72 is rotated 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 male thread portion 41a and the female thread portion 23a act as a screw feed, causing the drive shaft 40 to move in the direction of the axis L, and the valve body portion 50 to advance and retreat relative to the valve port 1a. This changes the opening of the valve port 1a relative to the valve seat, and controls the flow rate of the fluid flowing from the valve port 1a to the side port 1b (or from the side port 1b to the valve port 1a).

[0043] The shape of the housing H will be described with reference to Figures 2 and 3. Note that Figure 3 is an enlarged cross-sectional view taken along line III-III in Figure 2, and for the sake of convenience, the valve body portion 50 is omitted from the illustration.

[0044] The housing H is made of a metal material such as aluminum, and as shown in Fig. 2, an insertion hole having a plurality of annular stepped portions that are successively reduced in diameter from the other end side to the one end side along the axis L direction is formed. A first housing groove G1 and a second housing groove G2 are formed in the plurality of annular stepped portions in this order. Here, a first flow path Fp1 that communicates with the side (the front side of the paper surface in Fig. 2) is formed in the second housing groove G2, and a second flow path (not shown) that communicates with the side (the rear side of the paper surface of the valve body 52 in Fig. 2) is formed in the first housing groove G1. In addition, a pair of screw holes Sh are formed in the upper surface H1 of the housing H at symmetrical positions across the first housing groove G1.

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

[0046] <About the installation of the valve device> 2 and 4, the operation of mounting the valve device 100a to the housing H will be described. First, as shown in FIG. 2, the valve device 100a is inserted into the first housing groove G1 along the axial line L direction of the housing H. Then, while the pair of fastening screws 12f are screwed into the pair of screw holes Sh, the flange portion 12 is moved toward one end side in the axial line L direction until the outer periphery of one end side of the flange portion 12 abuts against 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 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 tube annular groove 27a, sealing between the first housing groove G1 and the outside environment.

[0047] 4, the stator coil 73 is fixed to the housing H by screwing a fastening screw 73b into a mounting hole (not shown) of a coil bracket 73a made of a metallic material and into a threaded hole (not shown) formed in a side wall of the housing H. In this mounted 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 a fastening bolt Fb, while the side 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] <Previous issues (external leakage due to galvanic corrosion)> As described above, in the conventional valve device shown in Fig. 12, if liquid such as water infiltrates from the external environment through the gap between the flange portion 1212 and the valve seat member 1230, or if condensed water is generated on the outside of the guide body 1220 cooled by the low-temperature internal fluid, the infiltrated liquid will accumulate on the upper part of the shaft seal member O12. If the flange portion 1212, the seal frame portion 1215, and the valve seat member 1230 are made of different metals and are placed in contact with each other in an environment where electricity such as water flows easily, there is a risk of galvanic corrosion occurring. Therefore, in the conventional valve device, if a relatively high-pressure fluid is introduced under the condition that the surface of the seal portion of the seal frame portion 1215 or the valve seat member 1230 with which the shaft seal member O12 comes into contact is roughened by this galvanic corrosion, there is a risk of the sealing performance being reduced due to the conventional problem (external leakage due to galvanic corrosion).

[0049] In contrast, since the valve gear 100a of the first embodiment is accommodated in a housing H made of a metal material such as aluminum, by employing a galvanic corrosion prevention means (1) (shaft seal portion made of a resin material), it is possible to improve corrosion resistance, eliminate the conventional problem (external leakage due to galvanic corrosion), and improve sealing performance.

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

[0051] In the first embodiment, by adopting the galvanic corrosion prevention means (1) (shaft seal portion made of a resin material) and making one of the members clamping the first shaft seal member O1 the guide body 20 made of a resin material, even if liquid such as water infiltrates from the external environment through the gap between the flange portion 12 and the housing H, or, for example, condensation water is generated on the outside of the guide body 1220 cooled by the low-temperature internal fluid and infiltrates and accumulates on the upper part 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 (reduction in strength of shaft seal)> The valve gear 100a of the first embodiment employs galvanic corrosion prevention means (1) (shaft seal portion made of resin material), and one of the members sandwiching the first shaft seal member O1 is the guide body 20 made of resin material. Generally, resin materials have lower pressure resistance and are more easily deformed than metal materials. Therefore, in the unlikely event that the insertion tube 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 will not have the desired crushing allowance, and there is a risk of the sealability being reduced (hereinafter referred to as "concern (reduction in pressure resistance of shaft seal portion)").

[0053] In contrast, the valve gear 100a of the first embodiment employs a shaft seal reinforcing means for reinforcing the insertion tube 27 having the shaft seal in addition to the galvanic corrosion prevention means (1) (shaft seal made of resin material), thereby eliminating the concern (reduction in pressure resistance of the shaft seal) and further improving the sealing performance. Here, the shaft seal reinforcing means in the first embodiment is composed of shaft seal reinforcing means (1) (fixing the case to the flange), shaft seal reinforcing means (2) (cylindrical portion), shaft seal reinforcing means (3) (fixing the valve seat member to the cylindrical portion), shaft seal reinforcing means (4) (step portion of the flange), shaft seal reinforcing means (5) (through hole of the cylindrical portion), shaft seal reinforcing means (6) (uneven portion of the embedded region), and shaft seal reinforcing means (7) (addition of a reinforcing agent to the resin material), which will be described in order below.

[0054] <Means for reinforcing the shaft seal (1) (fixing the case to the flange)> In the shaft seal reinforcing means (1) (fixing of the case to the flange), as shown in Fig. 2, the inner periphery of the annular flange 12 is insert-molded into the guide body 20, and an insertion tube 27 is disposed adjacent to one end face of the inner periphery of the flange 12, while as shown in Fig. 3, the case 71 is fixed to the other end face of the flange 12 as viewed from the axis L direction via a welded part W1 having an annular shape. Here, the flange 12 is formed with a step 12s1 on the other end, and the outer diameter of the step 12s1 on the other end 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 12 via the step 12s1 on the other end, and then fixed.

[0055] In the first embodiment, by employing the shaft seal portion reinforcing means (1) (fixing the case to the flange portion), the flange portion 12 to which the case 71 is fixed has a relatively high structural rigidity, improving the pressure resistance on the inner circumferential side of the flange portion 12. Also, since the insertion tube 27 having the shaft seal portion is disposed adjacent to one end face on the inner circumferential side of the flange portion 12, which has improved pressure resistance, the pressure resistance is mainly improved in the direction of the axis L, thereby eliminating the concern (reduction in the pressure resistance of the shaft seal portion) and further improving the sealing performance.

[0056] <Shaft seal portion reinforcing means (2) (cylindrical portion)> 2 and 3, the shaft seal portion reinforcing means (2) (cylindrical portion) has a cylindrical portion 11 that extends continuously to one end side in the direction of the axis L on the inner peripheral side of the flange portion 12. Here, the other end side 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 disposed adjacent to the outer peripheral side of the embedded region of the cylindrical portion 11.

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

[0058] <Means for reinforcing the shaft seal portion (3) (fixing the valve seat member to the cylindrical portion)> The shaft seal reinforcing means (3) (fixing of the valve seat member to the cylindrical portion) is to fix the valve seat member 30 to one end of the cylindrical portion 11 via a welded portion W2, as shown in Fig. 2. Here, a boss portion 31 is formed on the other end side 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 adopting the shaft seal reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the cylindrical portion 11 to which the valve seat member 30 is fixed has a relatively high structural rigidity and improved pressure resistance. In addition, as with the shaft seal reinforcing means (2) (cylindrical portion), the insertion tube annular groove 27a, which is the shaft seal portion, is disposed adjacent to the outer periphery of the cylindrical portion 11, which has improved pressure resistance, and therefore mainly improves radial pressure resistance, thereby eliminating concerns (reduction in pressure resistance of the shaft seal portion) and further improving sealing performance. Furthermore, by making the valve seat member 30 a separate member from the fixing metal fitting 10, it is not necessary to form the valve port 1a in the fixing metal fitting 10, so that the processing of the fixing metal fitting 10 is simplified, and the valve seat of the valve port 1a can be formed thick, so that stable valve leakage performance can be obtained.

[0060] <Shaft seal portion reinforcing means (4) (step portion of flange portion)> The shaft seal portion reinforcing means (4) (step portion of the flange portion) is, as shown in Fig. 3, a circumferential step portion 12s consisting of an other end side step portion 12s1 (see Fig. 2) and a one end side step portion 12s2 (see Fig. 2) provided at a position adjacent to the outer circumferential side of the insertion tube 27 having the shaft seal portion in the flange portion 12 when viewed from the axial direction. The inner circumferential side of the flange portion 12 is offset toward the other end from the outer circumferential side at the step portion 12s. This step portion 12s can be formed, for example, by subjecting the flange portion 12 to press working or the like.

[0061] In the first embodiment, by employing the shaft seal portion reinforcing means (4) (step portion of the flange portion), the step portion 12s of the flange portion 12 has relatively high rigidity due to work hardening caused by plastic deformation, improving the pressure resistance on the inner peripheral side of the flange portion 12. Also, as with the shaft seal portion reinforcing means (1) (fixing the case to the flange portion), the insertion tube 27 having the shaft seal portion is disposed adjacent to one end face on the inner peripheral side of the flange portion 12, which has improved pressure resistance, and therefore the pressure resistance is mainly improved in the direction of the axis L, thereby eliminating the concern (reduction in the pressure resistance of the shaft seal portion) and further improving the sealing performance.

[0062] <Shaft seal portion reinforcing means (5) (through hole of cylindrical portion)> The shaft seal portion reinforcing means (5) (through hole of cylindrical portion) is provided with at least one (four in this example) through hole 12e in the region of cylindrical portion 11 where it is embedded in guide body 20, as shown in Fig. 3. When fixing bracket 10 is insert molded into guide body 20, resin material solidifies in a state where it is filled in at least one through hole 12e. Note that in the first embodiment, the multiple through holes 12e are evenly arranged in the circumferential direction, but this is not limiting, and for example, the multiple through holes 12e may be unevenly arranged in the circumferential direction.

[0063] In the first embodiment, by adopting the axial seal portion reinforcing means (5) (through hole in the cylindrical portion), the guide body 20 improves the joining strength in the axial L direction and radial direction to the cylindrical portion 11, i.e., the pressure resistance, via the through hole 12e, thereby eliminating the concern (reduction in the pressure resistance of the axial seal portion) and further improving the sealing performance.

[0064] <Shaft seal portion reinforcing means (6) (uneven portion of embedded area)> As shown in FIG. 2, the shaft seal reinforcing means (6) (unevenness in the embedded region) is provided with unevenness (not shown) in at least a part of the embedded region in the guide body 20 in the cylindrical portion 11 and the flange portion 12. Here, in the first embodiment, it is preferable that the embedded region in which the unevenness is provided is a region that continues in the circumferential direction on either the outer peripheral surface on the other end side of the cylindrical portion 11 or the inner end face on the flange portion 12 (see the L-shaped region marked with "x" in FIG. 2). In addition, this unevenness is formed by subjecting a predetermined region of the fixing metal 10 made of a metal material such as stainless steel to a process of forming micron-sized fine unevenness on the surface of the metal material by chemical etching or the like. As a result, when the fixing metal 10 is insert-molded into the guide body 20, the resin material is solidified while being embedded in the unevenness, and the joining strength is further improved by the anchor effect.

[0065] In the first embodiment, by employing the shaft seal reinforcing means (6) (unevenness in the embedded region), the guide body 20 improves the joining strength in the axial L direction and / or radial direction to the fixing metal fitting 10, i.e., the pressure resistance strength, via the unevenness, thereby eliminating the concern (a decrease in the pressure resistance strength of the shaft seal) and further improving the sealing performance. In addition, in the first embodiment, if the embedded region in which the unevenness is provided is a region that is continuous in the circumferential direction of either the outer circumferential surface on the other end side of the cylindrical portion 11 or the inner end face of the flange portion 12 (see the L-shaped region marked with "x" in FIG. 2), no leakage path is formed via the interface between the guide body 20 and the fixing metal fitting 10 on the housing H side, and therefore leakage to the external environment can be reliably suppressed. In the first embodiment, the interface between the guide body 20 and the fixing bracket 10 on the case 71 side is connected to the storage space 3 within the case 71, so even if the bonding strength between the fixing bracket 10 and the guide body 20 decreases, there will be no leakage to the external environment through this interface on the case 71 side.

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

[0067] In the first embodiment, by adopting the axial seal portion reinforcing 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, i.e., the insertion tube 27 having the axial seal portion, is improved, thereby eliminating the concern (reduction in the pressure resistance strength of the axial seal portion) and further improving the sealing performance.

[0068] As described above, the valve device 100a of the first embodiment employs the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) to improve corrosion resistance, 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 employs the shaft seal portion reinforcing means (1) (fixing the case to the flange portion) that reinforces the insertion tube 27 having the shaft seal portion, the shaft seal portion reinforcing means (2) (cylindrical portion), the shaft seal portion reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the shaft seal portion reinforcing means (4) (step portion of the flange portion), the shaft seal portion reinforcing means (5) (through hole of the cylindrical portion), the shaft seal portion reinforcing means (6) (uneven portion of the embedded region), and the shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material), thereby eliminating the concern (reduction in pressure resistance of the shaft seal portion) and further improving sealing performance.

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

[0070] (Modification of shaft seal portion of first embodiment) A valve device 100b according to a modified shaft seal portion of the first embodiment will be described with reference to Fig. 5. The valve device 100b according to the 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 duplicated explanations will be omitted.

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

[0072] In the shaft seal modification of the first embodiment, by adopting the shaft seal reinforcing means (8) (cylindrical insertion tube), it is not necessary to provide the insertion tube annular groove 27a in the insertion tube 27 as in the first embodiment, so the structural rigidity of the insertion tube 27B is relatively high and the pressure resistance is improved, eliminating the concern (reduction in the pressure resistance of the shaft seal) and ensuring further improvement in sealing performance. In addition, the shape of the guide body 20B (particularly the shape of the insertion tube 27B) can be simplified, so that costs can be reduced.

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

[0074] In the shaft seal portion modification of the first embodiment, by adopting the shaft seal portion reinforcing means (9) (cylindrical valve seat member), it is not necessary to provide the valve seat member annular groove 32 in the valve seat member 30 as in the first embodiment, and therefore the rigidity of the valve seat member 30B is relatively high. Therefore, in the shaft seal portion modification of the first embodiment, as with the shaft seal portion reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the pressure resistance strength in the radial direction of the insertion cylinder annular surface 27b, which is the shaft seal portion, is improved mainly through the cylindrical portion 11 to which the valve seat member 30B is fixed, so that the concern (reduction in pressure resistance strength of the shaft seal portion) can be eliminated and the sealing performance can be further improved reliably. In addition, the shape of the valve seat member 30B can be simplified, so that the cost can be reduced.

[0075] As described above, the valve device 100b in the shaft seal portion modification of the first embodiment employs the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) in the same manner as the first embodiment, thereby eliminating the conventional problem (external leakage due to galvanic corrosion) and improving the sealing performance. In addition, the valve device 100b in the shaft seal portion modification of the first embodiment employs the shaft seal portion reinforcing means (1) (fixing the case to the flange portion), the shaft seal portion reinforcing means (2) (cylindrical portion), the shaft seal portion reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the shaft seal portion reinforcing means (4) (step portion of the flange portion), the shaft seal portion reinforcing means (5) (through hole of the cylindrical portion), the shaft seal portion reinforcing means (6) (uneven portion of the embedded region), and the shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material) in the same manner as the first embodiment, thereby eliminating the concern (reduction in pressure resistance strength of the shaft seal portion) and further improving the sealing performance. Furthermore, the valve device 100b in the shaft seal portion modified example 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), thereby eliminating the concern (reduction in pressure resistance of the shaft seal portion) and ensuring further improvement in sealing performance.

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

[0077] Second embodiment A valve device 100c according to a second embodiment will be described with reference to FIG. 6. The valve device 100c according to the second embodiment differs from the valve device 100a according to the first embodiment mainly in the outer shape of the flange portion 12C of the fixing bracket 10C and in the use of a fixing plate 13, but other basic configurations are substantially the same as those of the first embodiment. Here, the same configurations are given the same reference numerals, and duplicated explanations are omitted. Note that the case 71C and the coil bracket 73Ca of the stator coil 73C in the second embodiment (see FIG. 10) are slightly different in length in the axis L direction 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 explanations are omitted.

[0078] The valve device 100c according to the second embodiment is mainly composed of a fixed metal fitting 10C, a fixed plate 13, a guide body 20 (valve body), a valve seat member 30, a drive shaft 40, a valve body portion 50, a coil member 60, and a stepping motor 70C. The following describes the fixed metal fitting 10C, the fixed plate 13, and the housing HC (see FIG. 8) to which the valve device 100c is attached, which are different in configuration from the first embodiment.

[0079] <About the fixing brackets> The fixing bracket 10C is made of a metal material such as stainless steel, extends in the direction of the axis L, and includes a cylindrical portion 11 and a flange portion 12C formed continuously with the cylindrical portion 11. An opening 12a that defines the side port 1b is formed in the side wall of the cylindrical portion 11. Furthermore, as shown in Fig. 9, the flange portion 12C has a circular ring shape when viewed from the direction of the axis L.

[0080] <About the fixing plate> The fixing plate 13 is made of a metal material such as aluminum, stainless steel, or plated steel, or a resin material, and has a rounded, generally rhombic shape as viewed from the axis L direction, as shown in FIG. 7(a). The fixing plate 13 has an insertion hole 13a formed around the axis L and a pair of mounting holes 13b formed at both ends in the longitudinal direction. In addition, the screw hole 13c (bracket fixing mechanism) for the coil bracket in the second embodiment is formed in the side wall of the fixing plate 13, instead of the side wall of the housing H in the first embodiment, as shown in FIG. 7(b). Here, as shown in FIG. 6, before the stator coil 73C is fixed to the outer circumferential surface of the case 71C, the case 71C is inserted into the insertion hole 13a of the fixing plate 13. In addition, 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 the housing HC will be described with reference to Figures 8 and 9. Note that Figure 9 is an enlarged cross-sectional view taken along line IX-IX of Figure 8, and for the sake of convenience, the valve body portion 50 is omitted.

[0082] As shown in Fig. 8, the housing HC is formed with an insertion hole having a plurality of annular stepped portions whose diameters are successively reduced from the other end side to the one end side along the axis L direction. The plurality of annular stepped portions are formed with a flange portion accommodating groove Gf, a first accommodating groove G1, and a second accommodating groove G2, in that order. Here, the second accommodating groove G2 is formed with a first flow path Fp1 communicating with the side (the front side of the paper surface of Fig. 8), and the first accommodating groove G1 is formed with a second flow path (not shown) communicating with the side (the rear side of the paper surface of the valve body 52 in Fig. 8). In addition, a pair of screw holes Sh are formed in the upper surface H1 of the housing HC at symmetrical positions across the first accommodating groove G1.

[0083] In the second embodiment, the shape of the housing HC as shown in Figures 8 and 9 has been described. However, this is merely one example, and the housing HC may have any shape as long as it has an insertion hole and an outer shape that allows the valve device 100c to be inserted into this insertion hole.

[0084] <Installation of the valve device> The operation of mounting the valve device 100c to the housing HC will be described with reference to Fig. 8 and Fig. 10. First, as shown in Fig. 8, the valve device 100c is inserted from the first housing groove G1 along the axis L direction of the housing HC. Then, while the pair of fastening screws 12f are screwed into the pair of screw holes Sh via the fastening washers 12g and the pair of mounting holes 13b, the flange portion 12C is moved toward the one end side in the axis L direction until the one end side outer periphery is accommodated in the flange portion housing groove Gf and abuts against 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 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 tube annular groove 27a, sealing between the first housing groove G1 and the outside environment.

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

[0086] <Regarding concerns (management of pressure resistance of shaft seal)> The valve gear 100a of the first embodiment employs, in addition to the galvanic corrosion prevention means (1) (shaft seal portion made of a resin material), shaft seal portion reinforcing means (shaft seal portion reinforcing means (1) (fixing the case to the flange portion) to shaft seal portion reinforcing means (7) (addition of a reinforcing agent to a resin material), etc., so that even when a relatively high-pressure fluid is introduced, the conventional problem (external leakage due to galvanic corrosion) can be eliminated and the sealing performance can be improved.

[0087] However, in the valve gear 100a of the first embodiment, the pressure resistance of the shaft seal portion and the direction in which it acts (the direction of axis L and / or the radial direction) vary depending on the (combination of) shaft seal portion reinforcing means used. Therefore, in the valve gear 100a of the first embodiment, when it is necessary to handle extremely high-pressure fluids, it is necessary to control the (total) pressure resistance of the shaft seal portion mainly in the direction of axis L so that it is equal to or higher than a required value by the (combination of) shaft seal portion reinforcing means (hereinafter referred to as "concern (control of pressure resistance of shaft seal portion)").

[0088] In contrast, the valve gear 100c of the second embodiment employs a shaft seal reinforcing means (10) (fixing plate) in addition to the galvanic corrosion prevention means (1) (shaft seal made of resin material), so that even if it is necessary to temporarily handle extremely high-pressure fluid, the concern (control of pressure resistance strength of the shaft seal) can be eliminated and the sealability can be reliably improved. Note that, like the valve gear 100a of the first embodiment, the valve gear 100c of the second embodiment also employs a shaft seal reinforcing means (1) (fixing the case to the flange), a shaft seal reinforcing means (2) (cylindrical portion), a shaft seal reinforcing means (3) (fixing the valve seat member to the cylindrical portion), a shaft seal reinforcing means (4) (step portion of the flange), a shaft seal reinforcing means (5) (through hole of the cylindrical portion), a shaft seal reinforcing means (6) (uneven portion of the embedded region), and a shaft seal reinforcing means (7) (addition of a reinforcing agent to the resin material) as shaft seal reinforcing means, but a description thereof will be omitted to avoid duplication.

[0089] <Shaft seal portion reinforcing means (10) (fixed plate)> First, the fixed plate 13 is a relatively thick plate material made of a highly rigid material (for example, a metal material such as aluminum or stainless steel, or a resin material), and as shown in Fig. 7(a), has a rounded, generally rhombus shape when viewed from the direction of the axis L, and includes an insertion hole 13a provided around the axis L and a pair of mounting holes 13b provided at both ends in the longitudinal direction. The case 71C is inserted into this insertion hole 13a. Also, a pair of fastening screws 12f are inserted into the pair of mounting holes 13b via fastening washers 12g.

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

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

[0092] Thus, in the second embodiment, by employing the shaft seal portion reinforcing means (10) (fixed plate), the flange portion 12, which is firmly fixed by the fixed plate 13, has an extremely high structural rigidity, and the pressure resistance of the inner circumference side of the flange portion 12 is dramatically improved. Also, since the insertion tube 27 having the shaft seal portion is disposed adjacent to one end face on the inner circumference side of the flange portion 12, which has improved pressure resistance, the pressure resistance of the shaft seal portion is dramatically improved mainly in the direction of the axis L, thereby eliminating the concern (reduction in the pressure resistance of the shaft seal portion) and further improving the sealing performance. Therefore, in the second embodiment, unlike the first embodiment, the pressure resistance of the shaft seal portion which acts in different directions (axial L direction and / or radial direction) is controlled depending on the shaft seal portion reinforcing means (combination) employed. Instead, the shaft seal portion reinforcing means (10) (fixed plate) is employed and the pressure resistance of the shaft seal portion in the axial L direction is centrally controlled to be equal to or greater than the required value, thereby eliminating the concern (control of the pressure resistance of the shaft seal portion) and making it possible to further improve sealing performance.

[0093] As described above, the valve gear 100c of the second embodiment employs the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) in the same manner as the first embodiment, thereby eliminating the conventional problem (external leakage due to galvanic corrosion) and improving the sealing performance. In addition, the valve gear 100c of the second embodiment employs the shaft seal portion reinforcing means (1) (fixing the case to the flange portion), the shaft seal portion reinforcing means (2) (cylindrical portion), the shaft seal portion reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the shaft seal portion reinforcing means (4) (step portion of the flange portion), the shaft seal portion reinforcing means (5) (through hole of the cylindrical portion), the shaft seal portion reinforcing means (6) (uneven portion of the embedded region), and the shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material) in the same manner as the first embodiment, thereby eliminating the concern (reduction in pressure resistance strength of the shaft seal portion) and further improving the sealing performance. Furthermore, the valve device 100c of the second embodiment employs an axial seal reinforcing means (10) (fixed plate), thereby eliminating concerns (control of the pressure resistance strength of the axial seal) and further improving sealing performance.

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

[0095] (Third embodiment) A valve gear 100d according to a third embodiment will be described with reference to Fig. 11. The valve gear 100d according to the third embodiment differs from the valve gear 100c according to the second embodiment in that a corrosion prevention member 14 for preventing galvanic corrosion is disposed between the fixed plate 13 and the housing HC and the flange portion 12C, but other basic configurations are substantially the same as those of the second embodiment. Here, the same components are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0096] <Regarding concerns (reduction in contact area due to galvanic corrosion)> First, in the valve gear 100a of the first embodiment, as shown in Fig. 2, there is a risk that liquid such as water may infiltrate from the external environment through a 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 placed in contact with each other in an environment where electricity such as water easily flows, there is a risk of galvanic corrosion occurring at the interface between the flange portion 12 and the housing H. However, in the valve gear 100a of the first embodiment, the pressure introduced is not high compared to the second embodiment, so that galvanic corrosion at the interface between the flange portion 12 and the housing H is not a problem, while a galvanic corrosion prevention means (1) (shaft seal portion made of a resin material) is adopted to reliably prevent galvanic corrosion at the shaft seal portion.

[0097] Next, as shown in FIG. 8, the valve gear 100c of the second embodiment employs the shaft seal reinforcing means (10) (fixed plate). However, in the unlikely event that liquid such as water infiltrates from the external environment through a gap between the contact surface 13D on one end side of the fixed plate 13 and the upper surface H1 of the housing HC, galvanic corrosion may occur at the interface between the fixed plate 13 and the housing H. If the galvanic corrosion at the interface between the fixed plate 13 and the housing H is left unattended, rust or the like may occur at the interface between the fixed plate 13 and the flange portion 12C located nearby, reducing the contact area between the fixed plate 13 and the flange portion 12C, that is, reducing the pressure resistance of the shaft seal by the fixed plate 13 (hereinafter referred to as "concern (reduction in contact area due to galvanic corrosion)"). In this case, in the valve gear 100c of the second embodiment, when it is necessary to constantly handle extremely high-pressure fluid, there is a risk of leakage to the external environment due to the reduction in the pressure resistance of the shaft seal by the fixed plate 13.

[0098] In contrast, the valve gear 100d of the third embodiment employs galvanic corrosion prevention means (2) (corrosion-resistant member) in addition to galvanic corrosion prevention means (1) (shaft seal portion made of resin material), thereby eliminating the concern (reduction in contact area due to galvanic corrosion) and reliably improving sealing performance. Note that, like the valve gear 100c of the second embodiment, the valve gear 100d of the third embodiment also employs shaft seal portion reinforcement means (1) (fixing the case to the flange portion), shaft seal portion reinforcement means (2) (cylindrical portion), shaft seal portion reinforcement means (3) (fixing the valve seat member to the cylindrical portion), shaft seal portion reinforcement means (4) (step portion of the flange portion), shaft seal portion reinforcement means (5) (through hole of the cylindrical portion), shaft seal portion reinforcement means (6) (uneven portion of the embedded region), shaft seal portion reinforcement means (7) (addition of a reinforcing agent to the resin material), and shaft seal portion reinforcement means (10) (fixing plate) as shaft seal portion reinforcement means, but the description thereof will be omitted to avoid duplication.

[0099] <Galvanic corrosion prevention means (2) (corrosion prevention materials)> The galvanic corrosion prevention means (2) (corrosion-resistant member) is, as shown in FIG. 11, a corrosion-resistant member 14 (e.g., a member that does not have an inherent potential, such as a sheet-like resin or rubber) that prevents galvanic corrosion, disposed between the fixed plate 13 and the housing HC and flange portion 12C.

[0100] In the third embodiment, by adopting a galvanic corrosion prevention means (2) (corrosion-resistant member), the corrosion-resistant member 14, which does not have an inherent potential, is interposed between the fixed plate 13 and the housing HC and the flange portion 12C, thereby improving corrosion resistance and eliminating the concern (reduction in contact area due to galvanic corrosion), thereby maintaining the pressure resistance strength of the shaft seal portion provided by the fixed plate 13, and as a result, the sealing performance can be further improved.

[0101] <Galvanic corrosion prevention means (3) (surface anticorrosion treatment unit)> In the third embodiment, galvanic corrosion prevention means (2) (corrosion prevention member) is adopted to improve corrosion resistance between the fixed plate 13 and the housing HC and the flange portion 12C, but this is not limited thereto. For example, in the third embodiment, instead of the galvanic corrosion prevention means (2) (corrosion prevention member), galvanic corrosion prevention means (3) (surface corrosion prevention treatment portion) may be adopted, that is, the fixed plate 13 may be made of, for example, a plated steel plate, and at least the surface facing the housing HC and the flange portion 12C may be provided with a surface treatment portion (for example, zinc plating, chrome plating, Ni plating, etc.) that prevents galvanic corrosion.

[0102] As described above, the valve gear 100d of the third embodiment employs the galvanic corrosion prevention means (1) (shaft seal portion made of resin material) in the same manner as the second embodiment, thereby eliminating the conventional problem (external leakage due to galvanic corrosion) and improving the sealing performance. In addition, the valve gear 100d of the third embodiment employs the shaft seal portion reinforcing means (1) (fixing the case to the flange portion), the shaft seal portion reinforcing means (2) (cylindrical portion), the shaft seal portion reinforcing means (3) (fixing the valve seat member to the cylindrical portion), the shaft seal portion reinforcing means (4) (step portion of the flange portion), the shaft seal portion reinforcing means (5) (through hole of the cylindrical portion), the shaft seal portion reinforcing means (6) (uneven portion of the embedded region), and the shaft seal portion reinforcing means (7) (addition of a reinforcing agent to the resin material) in the same manner as the second embodiment, thereby eliminating the concern (reduction in pressure resistance strength of the shaft seal portion) and further improving the sealing performance. Furthermore, the valve gear 100d of the third embodiment employs shaft seal reinforcing means (10) (fixed plate), thereby eliminating the concern (control of pressure resistance strength of the shaft seal) and further improving sealing performance. In addition, the valve gear 100d of the third embodiment employs galvanic corrosion prevention means (2) (corrosion-resistant member) or galvanic corrosion prevention means (3) (surface corrosion prevention treatment part), thereby eliminating the concern (reduction in contact area due to galvanic corrosion) and reliably improving sealing performance.

[0103] The valve gear 100d of the third embodiment employs 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 all of the shaft seal portion reinforcing means (1) (fixing the case to the flange portion) to the shaft seal portion reinforcing means (7) (resin material with added reinforcing agent) and shaft seal portion reinforcing means (10) (fixing plate), but is not limited to this. For example, the valve gear 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 a resin material), at least one of the shaft seal portion reinforcement means (1) (fixing the case to the flange portion) to shaft seal portion reinforcement means (7) (resin material with added reinforcing agent), shaft seal portion reinforcement means (10) (fixing plate), galvanic corrosion prevention means (2) (corrosion-resistant member) (or galvanic corrosion prevention means (3) (surface corrosion prevention treatment portion)) (for example, shaft seal portion reinforcement means (1) (fixing the case to the flange portion) or shaft seal portion reinforcement means (7) (resin material with added reinforcing agent)).

[0104] In the third embodiment only, the galvanic corrosion prevention means (2) (corrosion prevention member) or the galvanic corrosion prevention means (3) (surface corrosion prevention treatment part) is adopted, but this is not limiting. For example, in the first embodiment (see FIG. 2) and the shaft seal part modification of the first embodiment (see FIG. 5), the galvanic corrosion prevention means (2) (corrosion prevention member) or the galvanic corrosion prevention means (3) (surface corrosion prevention treatment part) may be adopted on one end side of the flange part 12 that contacts the housings H, HB.

[0105] Further, although the shaft seal portion reinforcement means (8) (cylindrical insertion tube) and / or shaft seal portion reinforcement means (9) (cylindrical valve seat member) are employed only in the shaft seal portion modification of the first embodiment, the present invention is not limited thereto. For example, the shaft seal portion reinforcement means (8) (cylindrical insertion tube) and / or shaft seal portion reinforcement means (9) (cylindrical valve seat member) may be employed in the insertion tube 27 and / or the valve seat member 30 in the second embodiment (see FIG. 8) and the third embodiment (see FIG. 11).

[0106] <Other> It goes without saying that the valve devices 100a to 100d of the present embodiment are applicable to all fluid devices and fluid circuits, including refrigeration cycles. Furthermore, the present invention is not limited to the above-described embodiments, and appropriate changes and modifications can be made without departing from the technical concept of the present invention. [Explanation of symbols]

[0107] 100a, 100b, 100c, 100d Valve gear 1a Valve port 1b Lateral port 2 Valve chamber 3. Storage space 10,10C Fixing bracket 11 Cylindrical part 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 Insertion hole 13b Pair of mounting holes 13c Screw holes for coil bracket (bracket fixing mechanism) 13D One end contact surface 14 Corrosion-resistant materials 20, 20B Guide body (valve body) 23 Screw hole 23a Female thread 24 Bearing hole 25 Slide hole 26 Guide rail 27,27B Insertion tube 27a Insertion tube annular groove (shaft seal member receiving groove, shaft seal portion) 27b Insertion cylinder annular surface (shaft seal part) 30, 30B Valve seat member 31 Boss section 32 Annular groove in valve seat member 33,33B Outer surface 40 Drive shaft 41 Threaded part 41a Male thread 42 Guide section 43 Flange 50 Valve body 51 Valve holder 51a One end 51b Other end 52 Valve body 53 Washer 54 Spring support 55 Compression coil spring 60 Coil material 61 Coil section 62 Claw part 70,70C stepping motor 71,71C Case 72 Magnet rotor 73,73C Stator coil 73a, 73Ca coil bracket 73b, 73Cb Fastening screw 74 Magnet section 75 Disc Section 76 Metal fittings 77 Protrusion Fb Fastening bolt Fp1 First flow path G1 First Receiving Groove Gs1 First seal member housing groove (shaft seal member housing groove) Gs2 Second seal member receiving groove G2 Second Receiving Groove 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 fitting Pl1 First piping Sh Pair of screw holes W1 weld W2 weld

Claims

1. A valve device accommodated in a housing made of a metal material, A valve body having a shaft seal portion; a case fixed to the valve body and defining an accommodation space; Galvanic corrosion prevention means; 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 accommodation space is sealed from the external environment by sandwiching a shaft seal member between a shaft seal member accommodation groove formed on one of the shaft seal portion and the housing, and an annular surface formed on the other of the shaft seal portion and the housing, which are arranged radially opposite each other.

2. a fixing fitting having an annular flange portion, the inner circumferential side of the flange portion being insert-molded into the valve body; a shaft seal portion reinforcing means for reinforcing the shaft seal portion; Further equipped with 2. The valve device according to claim 1, wherein the shaft seal reinforcing means has the case fixed to the other end face of the flange and the shaft seal disposed adjacent to one inner peripheral end face of the flange.

3. 3. The valve device according to claim 2, wherein the shaft seal portion reinforcing means has a cylindrical portion formed continuously on an inner periphery of the flange portion, extending toward one end in the axial direction, and is insert-molded into the valve body, and the shaft seal portion is disposed adjacent to an outer periphery of the cylindrical portion.

4. 4. The valve device according to claim 3, wherein the shaft seal portion reinforcing means comprises a valve seat member fixed to one end of the cylindrical portion.

5. 3. The valve device according to claim 2, wherein the shaft seal portion reinforcing means is provided with a circumferential step in the flange portion adjacent to the outer circumferential side of the shaft seal portion when viewed from the axial direction, and the inner circumferential side of the flange portion is offset toward the other end from the outer circumferential side at the step.

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

7. 4. The valve device according to claim 3, wherein the shaft seal reinforcing means comprises uneven portions provided in at least a part of the region of the cylindrical portion and the flange portion that is embedded in the valve body.

8. 2. The valve device according to claim 1, wherein the resin material is PPS to which glass fiber or carbon fiber is added as a reinforcing agent.

9. 3. The valve device according to claim 2, wherein the shaft seal portion reinforcing means has a fixing plate for holding the flange portion between the housing and the fixing plate.

10. The valve device according to claim 9, wherein the fixing plate comprises a bracket fixing mechanism for the coil.

11. 10. The valve device according to claim 9, wherein the galvanic corrosion prevention means comprises a corrosion prevention member for preventing galvanic corrosion disposed between the fixed plate and the housing and between the fixed plate and the flange portion.

12. 10. The valve device according to claim 9, wherein the galvanic corrosion prevention means comprises a surface anticorrosion treatment portion for preventing galvanic corrosion provided on at least a surface of the fixing plate facing the housing and the flange portion.

Images