Stop valve

Abstract

The invention provides a stop valve, which adopts a thread feeding mechanism as a driving mechanism of the stop valve, can improve durability and sealing performance of a valve core sealing surface and a valve seat sealing surface, and improves reliability. The shut-off valve is provided with: a drive shaft (30) that can be moved by a screw feed mechanism; a valve seat part (10a); a valve body section (40) having a valve body (42), a valve support body (41), a spring seat section (45), and a compression spring (46); a rotation suppression mechanism that suppresses transmission of rotation of the drive shaft to the valve body (42); and a pressing force adjusting / blocking mechanism for adjusting the pressing force of the valve body (42) against the valve seat part and blocking the flow path, the rotation suppressing mechanism having a structure in which the valve body (42) is supported by the valve support body (41) in a clearance fit manner when the valve body (42) is seated on the valve seat part. When the valve body is seated on the valve seat part, the pressing force adjusting and cutting mechanism is in a self-weight seated state in which the valve body sealing surface (42a) is flush with the valve seat sealing surface (10aa) due to the self weight of the valve body.

Description

Technical Field

[0001] The present invention relates to a stop valve provided with a rotation restraining mechanism and a pressing force regulating and shutting mechanism. Background Art

[0002] A solenoid is sometimes used as a drive mechanism for shutoff valves to improve the responsiveness of the valve's opening and closing movements. However, to maintain either the open or closed state, the solenoid must be energized. Consequently, operating costs are relatively high when using such shutoff valves, and there is a concern that the valve may temporarily lose functionality in the event of a power outage. To address this issue, a screw feed mechanism is sometimes used as a drive mechanism for shutoff valves.

[0003] For example, in Patent Document 1, Figure 11 , describes a stop valve 1100 (hereinafter referred to as a "conventional stop valve") comprising: a manifold 1110; a support member 1120 fitted and fixed to the manifold 1110; a drive shaft 1130 supported by the support member 1120 so as to be rotatable and movable in the direction of an axis L; a valve core 1140 fixed to one end of the drive shaft 1130; a gear motor 1160 that rotates the drive shaft 1130 via a drive sleeve 1131; and a housing 1161 fixed to the manifold 1110 and accommodating the gear motor 1160. The manifold 1110 includes an inlet flow path 1101, an outlet flow path 1102, a valve chamber 1112, and a valve seat 1110aa provided at the boundary between the valve chamber 1112 and the outlet flow path 1102. The valve core portion 1140 includes a valve support portion 1141 that holds one end portion of the drive shaft 1130 in the direction of the axis L, and a valve core 1142 having a disc-shaped valve core sealing surface.

[0004] Furthermore, although Patent Document 1 does not describe a specific drive mechanism between the support member 1120 and the drive shaft 1130, a screw feed mechanism is conceivable as an example. This screw feed mechanism screws together internal threads and external threads formed on the inner circumferential surface of the other end of the support member 1120 and the outer circumferential surface of the other end of the drive shaft 1130, thereby enabling the drive shaft 1130 to move along the axis L while rotating together with the valve core 1140.

[0005] In such an existing stop valve 1100, when the valve core 1142 is seated on the valve seat 1110aa, the valve core 1142, which rotates together with the drive shaft 1130, is pressed while rotating relative to the valve seat 1110aa, thereby causing a problem of great wear on the sealing surfaces of the valve core 1142 and the valve seat 1110aa (hereinafter referred to as "existing problem 1 (wear caused by the rotation and pressing of the valve core when seating)").

[0006] Furthermore, like conventional stop valves, conventional stop valve 1100 is subject to significant assembly errors because the drive shaft 1130 and valve core 1140 are connected to manifold 1110 via support member 1120. Consequently, when valve core 1142 is seated on valve seat 1110aa, the valve core sealing surface and the valve seat sealing surface are not completely flush but rather tilted relative to each other, resulting in reduced sealing performance (hereinafter referred to as "Conventional Problem 2 (Reduced Sealing Performance Due to the Tilt of the Valve Core Sealing Surface and the Valve Seat Sealing Surface)").

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Chinese Patent Application Publication No. 114233914 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] The object of the present invention is to provide a stop valve, which adopts a threaded feed mechanism as the drive mechanism of the stop valve, wherein special attention is paid to improving the durability and sealing of the valve core sealing surface and the valve seat sealing surface when seating, thereby improving reliability.

[0012] Solutions to Problems

[0013] In order to solve the above-mentioned problems, a stop valve is provided, which comprises: a drive shaft, which can be rotated and moved in the axial direction by a screw feed mechanism; a valve seat, which has an annular valve seat sealing surface on the other end side; a valve core part, which has a valve core, a valve support body, a spring seat part and a compression spring, wherein the valve core has a disc-shaped valve core sealing surface on one end side, the valve support body has a cylindrical guide part and a support part that supports the above-mentioned valve core, the spring seat part is accommodated in the above-mentioned guide part and can abut against one end part of the above-mentioned drive shaft, and the compression spring is clamped in the above-mentioned spring seat part and the above-mentioned support part; a rotation inhibiting mechanism, which inhibits the rotation of the above-mentioned drive shaft from being transmitted to the above-mentioned valve core; and a pressing force adjusting and cutting mechanism, which adjusts the pressing force of the above-mentioned valve core on the above-mentioned valve seat and cuts off the flow path. The above-mentioned rotation inhibiting mechanism has a structure in which the above-mentioned valve core is loosely fitted and supported on the above-mentioned support part of the above-mentioned valve support body when the above-mentioned valve core is seated on the above-mentioned valve seat. The above-mentioned pressing force adjusting and cutting mechanism has a structure in which, when the above-mentioned valve core is seated on the above-mentioned valve seat, the above-mentioned valve core is seated in a self-weight seating state in which the sealing surface of the above-mentioned valve core is flush with the sealing surface of the above-mentioned valve seat by utilizing the self-weight of the above-mentioned valve core.

[0014] In addition, in the above-mentioned stop valve, the above-mentioned pressing force adjustment cutting mechanism may also have a structure that becomes a force-applied seating state, and the force-applied seating state is a state in which the above-mentioned valve core sealing surface is seated flush with the above-mentioned valve seat sealing surface, and one end portion of the above-mentioned drive shaft overcomes the force of the above-mentioned compression spring and presses the above-mentioned spring seat portion, thereby pressing the above-mentioned valve core sealing surface against the above-mentioned valve seat sealing surface via the abutment portion in the axial direction of the above-mentioned valve core and the above-mentioned support portion of the above-mentioned valve support body.

[0015] In addition, in the above-mentioned stop valve, the above-mentioned pressing force adjustment cutting mechanism may also have a structure that becomes an additional self-weight seating state simultaneously with the above-mentioned force seating state, or between the above-mentioned self-weight seating state and the above-mentioned force seating state. The additional self-weight seating state utilizes the self-weight of the above-mentioned valve core and the above-mentioned valve support body, and the seating is such that the sealing surface of the above-mentioned valve core is flush with the sealing surface of the above-mentioned valve seat.

[0016] Furthermore, in the above-mentioned stop valve, the rotation restraining mechanism may further have a structure for preventing the one end portion of the drive shaft from being clamped by the valve element in the axial direction in the biased seating state.

[0017] In the stop valve, the rotation restraining mechanism may further have a structure in which the valve support body is loosely fitted and supported on one end portion of the drive shaft when the valve element is seated on the valve seat.

[0018] In addition, in the above-mentioned stop valve, it can also be set that when the above-mentioned valve core is in a suspended state in which the above-mentioned support part is supported by the above-mentioned valve support body with clearance, the axial direction gap between the above-mentioned valve core and the above-mentioned support part on one side is larger than the axial direction thread pitch of the above-mentioned drive shaft.

[0019] In addition, in the above-mentioned stop valve, it can also be set that when the above-mentioned valve support body is supported by a clearance fit on one end part of the above-mentioned drive shaft, and the above-mentioned valve core is supported by a clearance fit on the above-mentioned support part of the above-mentioned valve support body, the axial direction gap on one side of the above-mentioned valve core and the above-mentioned support part is larger than the axial direction gap on the other side of the above-mentioned valve support body and the above-mentioned one end part of the above-mentioned drive shaft.

[0020] Furthermore, in the stop valve, one of the valve element sealing surface and the valve seat sealing surface may be made of a resin material, and the other may be made of a metal material.

[0021] In the above-mentioned stop valve, the valve element sealing surface may further include a flow regulating mechanism including a protrusion or a recess extending along the axis.

[0022] Effects of the Invention

[0023] According to the present invention, a stop valve can be provided, which adopts a threaded feed mechanism as a drive mechanism of the stop valve, wherein, with particular attention paid to the seating, the durability and sealing performance of the valve core sealing surface and the valve seat sealing surface can be improved, thereby improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a longitudinal sectional view showing the electric stop valve according to the first embodiment of the present invention.

[0025] Figure 2 yes Figure 1 A local enlarged view of the area surrounded by the dotted line II is shown.

[0026] Figure 3 yes Figure 2 The diagrams for explaining the closing action of the electric stop valve shown in the figure show (a) a suspended state, (b) a self-weight seated state, (c) a transitional state, and (d) an additional self-weight seated state and a force-applied seated state.

[0027] Figure 4 yes Figure 3 The diagrams illustrate the valve closing operation of the electric stop valve in a state where the valve support is tilted relative to the axis. (a) shows a partially seated state, and (b) shows a deadweight seated state.

[0028] Figure 5 These are explanatory diagrams of valve core deformation examples 1 to 4 of the first embodiment (suspended state), (a) represents valve core deformation example 1 (conical cone-shaped protrusion), (b) represents valve core deformation example 2 (cylindrical protrusion), (c) represents valve core deformation example 3 (conical recess), and (d) represents valve core deformation example 4 (cylindrical recess).

[0029] Figure 6 A longitudinal sectional view showing an electric stop valve according to a second embodiment (with Figure 2 correspond).

[0030] Figure 7 yes Figure 6 The diagrams for explaining the valve closing action of the electric stop valve shown in the figure show (a) a suspended state, (b) a self-weight seated state, (c) a self-weight-applied seated state, and (d) a force-applied seated state.

[0031] Figure 8 yes Figure 7 The diagrams illustrate the valve closing operation of the electric stop valve in a state where the valve support is tilted relative to the axis. (a) shows the deadweight seating state, and (b) shows the additional deadweight seating state.

[0032] Figure 9 A longitudinal sectional view showing an electric stop valve according to a third embodiment (with Figure 6 correspond).

[0033] Figure 10 yes Figure 9 The diagrams for explaining the valve closing action of the electric stop valve shown in the figure show (a) a suspended state, (b) a self-weight seated state, (c) a self-weight-applied seated state, and (d) a force-applied seated state.

[0034] Figure 11 It is a longitudinal sectional view showing a conventional stop valve. DETAILED DESCRIPTION

[0035] Reference Figures 1 to 10 In addition, the following describes the electric stop valve, but the rotation suppression mechanism and the pressing force adjustment and shutoff mechanism of the present invention are not limited to the electric stop valve, for example, it can also be applied to all stop valves such as manual stop valves.

[0036] About Terminology

[0037] In this specification and claims, “left”, “right”, “upper” and “lower” mean Figures 1 to 10In the direction shown. In this specification and the claims, "one end" and "the other end" mean the "lower end" and "upper end" in the drawings. In this specification and the claims, "rotation suppression mechanism" means suppressing the transmission of the rotation of the drive shaft to the valve core. In this specification and the claims, "pressing force adjustment and shutoff mechanism" means adjusting the pressing force of the valve core on the valve seat to cut off the flow path. In this specification and the claims, "clearance fit support" means that two components are fit together in a state with clearance, and there is a gap between the two components that can move relative to each other in the radial direction and the axial direction. In this specification and the claims, "suspended state" means that the valve core is arranged in a suspended state relative to the support portion of the valve support body, or the valve support body is arranged relative to one end of the drive shaft. In this specification and the claims, "self-weight seating state" means that when the valve core is seated on the valve seat, the valve core is supported by the clearance fit and, using the self-weight of the valve core, is seated so that the valve core sealing surface is flush with the valve seat sealing surface. In the description of this specification and claims, "additional deadweight seating state" means that the valve support body is supported by a clearance fit, and the deadweight of the valve core and the valve support body is utilized to seat the valve core sealing surface flush with the valve seat sealing surface. In the description of this specification and claims, "forced seating state" means that when the valve core sealing surface is seated flush with the valve seat sealing surface, the valve core sealing surface is pressed against the valve seat sealing surface by the force of the compression coil spring. In the description of this specification and claims, "disc-shaped valve core sealing surface" means that when viewed along the axial direction, the valve core sealing surface has a disc-shaped surface, indicating that in addition to the flat disc-shaped valve core sealing surface, a disc-shaped valve core sealing surface is also included with a protrusion or recessed portion extending along the axis.

[0038] (First embodiment)

[0039] <Structure of electric stop valve>

[0040] use Figure 1 and Figure 2 , an electric stop valve 100a according to a first embodiment of the present invention is described. The electric stop valve 100a is mainly composed of a valve body 10, a support part 20, a drive shaft 30, a valve core part 40, a coil part 50, and a stepping motor 60. Below, each structure of the electric stop valve 100a is described in sequence. Here, the details will be described later, but the electric stop valve 100a according to the first embodiment can simultaneously eliminate the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seating) and the existing problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface) by simultaneously adopting a rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support part) and a pressing force adjustment and cutting mechanism (1) (self-weight seating state), thereby improving reliability.

[0041] The valve body 10 is formed into a cylindrical shape using a metal material such as stainless steel, or a resin material. The valve body 10 is provided with a valve seat portion 10a extending vertically in an annular shape toward the other side of the axis L. A valve port 10b is formed in the center of the valve seat portion 10a, and an annular valve seat sealing surface 10aa is formed at the other end. Furthermore, a valve chamber 12 is formed within the valve seat portion 10a.

[0042] A first joint pipe 1, serving as a fluid flow path, is connected to the outer circumference of the valve body 10. This first joint pipe 1 communicates with the valve chamber 12. Furthermore, a second joint pipe 2 is connected to the bottom surface of the valve body 10. This second joint pipe 2 communicates with the valve chamber 12 via the valve port 10b. The first and second joint pipes 1 and 2 are made of materials such as copper and stainless steel and are fixed to the valve body 10.

[0043] The support member 20 includes a generally cylindrical bracket portion 21 made of a resin material such as polyphenylene sulfide (PPS), and a stainless steel fixing portion 22 integrally formed by insert molding at the end of the bracket portion 21 adjacent to the valve body 10. The support member 20 is fixed to the valve body 10 by welding via the fixing portion 22.

[0044] The bracket portion 21 is configured so that its axis coincides with the axis L of the shaft passing through the valve port 10b. A threaded hole 23, a bearing connection hole 24, and a sliding hole 25 are formed in the center of the bracket portion 21, arranged concentrically along the axis L so as to penetrate the bracket portion 21. An internal threaded portion 23a is formed on the inner circumference of the threaded hole 23, which is threadedly engaged with an external threaded portion 31a of the drive shaft 30, which will be described later. A guide portion 32 of the drive shaft 30, which will be described later, is slidably engaged with the inner circumference of the bearing connection hole 24. The sliding hole 25 is configured to be closer to the valve port 10b and is formed to have a larger diameter than the bearing connection hole 24. The valve core portion 40, which will be described later, is slidably engaged with the sliding hole 25.

[0045] A guide rail 26 composed of spiral protrusions is integrally formed on the outer circumference of the bracket portion 21. Adjacent winding portions of the guide rail 26 are spaced apart. The guide rail 26 is arranged so that its axis coincides with the axis L, and is threadedly engaged with the coil portion 51 of the coil component 50 described later. The guide rail 26 guides the winding portions of the coil portion 51 from one or both sides so that the coil component 50 can rotate circumferentially.

[0046] The drive shaft 30 is made of a metal such as stainless steel and is formed into a cylindrical rod shape. The drive shaft 30 has a threaded portion 31, a guide portion 32, a contraction portion 33 and a flange portion 34 arranged in sequence along the axis L. An external threaded portion 31a is formed on the threaded portion 31, and the external threaded portion 31a is threadedly engaged with the internal threaded portion 23a of the bracket portion 21, thereby forming a thread feed mechanism, and the rotational motion of the drive shaft 30 is converted into linear motion. The guide portion 32 is slidably engaged with the inner circumference of the bearing connection hole 24, guiding the movement of the drive shaft 30 in the direction of the axis L. As a result, the drive shaft 30 moves along the axis L direction as it rotates through the thread feed action of the thread feed mechanism. The flange portion 34 rotatably hooks the valve core portion 40 described later. In the first embodiment, the internal threaded portion 23a and the external threaded portion 31a are right-handed threads.

[0047] The valve body portion 40 includes a valve support body 41 , a valve body 42 , an engaging portion 43 , a spacer 44 , a spring seat portion 45 , a compression coil spring 46 , and a cover portion 47 .

[0048] The valve support body 41 is engaged along the sliding hole 25 so as to be slidable along the axis L, and comprises a guide portion 41a and a support portion 41b. The guide portion 41a is formed into a cylindrical shape with an outer diameter substantially the same as the inner diameter of the sliding hole 25 of the bracket portion 21. Furthermore, the support portion 41b is provided at one end of the guide portion 41a and has a skirt shape that expands radially outward and extends toward one end.

[0049] The valve core 42 is made of, for example, a resin material or a metal material such as stainless steel, and has: a disc-shaped valve core sealing surface 42a provided on one end side; a disc-shaped pressed surface 42b provided on the other end side; and a valve core flange portion 42c extending radially outward from the pressed surface 42b.

[0050] The engaging portion 43 has an L-shaped ring shape and is fixedly fitted in the support portion 41b of the valve support body 41. The valve element 42 is loosely fitted and supported between the engaging portion 43 and the support portion 41b of the valve support body 41 with clearance in the radial direction and the axial direction L.

[0051] The flange portion 34 of the drive shaft 30 is rotatably hooked on the other end side of the valve support body 41. Specifically, in the hanging state, a ring-shaped cover portion 47 is embedded and fixed to the other end of the valve support body 41, and a gasket 44 is sandwiched between the cover portion 47 and the flange portion 34 of the drive shaft 30 (see Figure 3(a)). The cover portion 47 is arranged at a position opposite to the contraction portion 33 of the drive shaft 30. Thus, the drive shaft 30 is hooked on the valve support body 41 via the flange portion 34, so that it can rotate around the axis L of the valve support body 41 and move in the direction of the axis L. In addition, the inner diameter of the cover portion 47 is set to be larger than the outer diameter of the contraction portion 33 of the drive shaft 30. In addition, a spring seat portion 45 is provided in the guide portion 41a of the valve support body 41 so as to be movable in the direction of the axis L. A compression coil spring 46 is installed between the spring seat portion 45 and the support portion 41b of the valve support body 41 in a compressed state with a predetermined load applied. As a result, the spring seat portion 45 is urged toward the other end side and abuts against one end portion 30a of the drive shaft 30.

[0052] The coil component 50 integrally includes a coil portion 51 in the shape of a spiral spring and a claw portion 52 protruding radially outward from one end of the coil portion 51. The coil portion 51 can be screwed to the guide rail 26 of the bracket portion 21 so as to be rotatable in the circumferential direction. The claw portion 52 can abut against the protrusion 67 of the magnetic rotor 62 described later, and the coil component 50 is pushed in the circumferential direction via the claw portion 52 by the rotation of the magnetic rotor 62. As a result, the coil component 50 abuts against the upper limit stopper (not shown) or the lower limit stopper (not shown), and the rotation of the coil component 50 is restricted, and the rotation of the magnetic rotor 62 is also restricted. Therefore, the movement of the valve core portion 40 beyond the position where the valve is fully opened or the position where the valve is closed is restricted. The coil component 50 can be easily manufactured by forming a metal wire such as stainless steel.

[0053] The stepping motor 60 includes a housing 61 , a magnetic rotor 62 , and a stator coil (not shown).

[0054] The housing 61 is made of metal such as stainless steel and has a substantially cylindrical shape with its upper end closed. The lower open end of the housing 61 is airtightly fixed to the upper end of the valve body 10 by welding or the like.

[0055] The magnetic rotor 62 integrally comprises a cylindrical magnet portion 64, whose outer periphery is magnetized to multiple poles, and a disk portion 65, which closes one end of the magnet portion 64. The magnetic rotor 62 is secured to the drive shaft 30 via a metal fitting 66 integrally formed in the center of the disk portion 65. This allows the magnetic rotor 62 to rotate within the housing 61 about the axis of the drive shaft 30. The drive shaft 30 serves as the rotation axis of the magnetic rotor 62.

[0056] The stator coil is disposed on the outer peripheral surface of the housing 61 . When a pulse signal is applied to the stator coil, the magnetic rotor 62 rotates according to the number of pulses. The stator coil corresponds to the stepping motor 60 .

[0057] When the magnetic rotor 62 rotates, the drive shaft 30 rotates along with it. The threaded action of the external threaded portion 31a and the internal threaded portion 23a (threaded feed mechanism) causes the drive shaft 30 to move along the axis L, causing the valve core 40 to advance and retreat relative to the valve seat 10a. This controls the flow of fluid from the first joint pipe 1 to the second joint pipe 2 by causing the valve core sealing surface 42a and the valve seat sealing surface 10aa to separate and contact.

[0058] <Existing Problem 1 and Existing Problem 2>

[0059] As mentioned above, in Figure 11 The conventional stop valve 1100 shown utilizes a threaded feed mechanism. Consequently, when the valve core 1142 seats on the valve seat 1110aa, the valve core 1142, which rotates along with the drive shaft 1130, is pressed against the valve seat 1110aa while rotating. This presents conventional problem 1 (wear caused by the rotation and pressure of the valve core during seating). Furthermore, conventional stop valve 1100 has assembly errors, so when the valve core 1142 seats on the valve seat 1110aa, the valve core sealing surface and the valve seat sealing surface are not completely flush, presenting conventional problem 2 (reduced sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface).

[0060] Therefore, the existing stop valve 1100 has both existing problem 1 (wear caused by the rotation and pressure of the valve core when seating) and existing problem 2 (reduced sealing due to the inclination of the valve core sealing surface and the valve seat sealing surface), so there is concern about reduced reliability.

[0061] In contrast, in the electric stop valve 100a of the first embodiment, a rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion) and a pressing force adjustment cut-off mechanism (1) (self-weight seating state) are simultaneously adopted, thereby simultaneously eliminating the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seating) and the existing problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface).

[0062] <Details of valve closing operation>

[0063] Since then, use Figure 3 , the valve closing action of the electric stop valve 100a (suspended state, self-weight seated state, transition state, additional seated state and force seated state) is described in sequence. The rotation suppression mechanism (1) and (2) for suppressing the rotation of the drive shaft 30 from being transmitted to the valve core 42 and the pressure adjustment and cutting mechanism (1) to (3) for adjusting the pressure of the valve core 42 on the valve seat portion 10a to cut off the flow path are shown in the valve closing action. In addition, Figure 3In the figure, the closing action of the electric stop valve 100a is bilaterally symmetrical, so only the left side will be used for the description. Furthermore, since the opening action is the opposite of the closing action, only the closing action will be described here. Furthermore, when viewed from the axis L, the valve seat sealing surface 10aa is completely covered by the valve core sealing surface 42a.

[0064] <Hanging state>

[0065] use Figure 3 (a) of FIG. 1 illustrates the suspended state. In the suspended state, the valve core 40 clamps one end of the drive shaft 30 between the gasket 44 and the spring seat 45 with the compression coil spring 46 acting on it, thereby being integrally connected to the drive shaft 30. As a result, the valve core 40 rotates together with the drive shaft 30 in the direction of the axis L (see FIG. 1 ). Figure 3 Furthermore, the valve element sealing surface 42a of the valve element 42 is separated from the valve seat sealing surface 10aa of the valve seat portion 10a.

[0066] At this point, the valve core 42 is placed on the engaging portion 43 via the valve core flange 42c, with a first radial gap tra1 between the engaging portion 43 and the valve core. Furthermore, a one-side axial gap tla1 and a second radial gap tra2 are defined between the valve core 42 and the support portion 41b of the valve support body 41. The second radial gap tra2 is set larger than the first radial gap tra1 (tra2>tra1). Furthermore, a gap region Ga is formed between the pressing portion 41ba at the bottom of the support portion 41b and the pressed surface 42b at the other end of the valve core 42, thereby allowing the valve core 42 to be suspended relative to the valve support body 41.

[0067] <Seated under own weight>

[0068] use Figure 3 (b) of FIG. 1 illustrates the self-weight seated state. In the self-weight seated state, the valve core 40 clamps one end of the drive shaft 30 in the same manner as in the suspended state, thereby being integrally connected to the drive shaft 30. As a result, the valve core 40 rotates along the axis L direction (refer to FIG. 1 ) together with the drive shaft 30. Figure 3 The valve body 42 moves as indicated by the arrow M2 in (b), and the valve body sealing surface 42a of the valve body 42 abuts against the valve seat sealing surface 10aa of the valve seat portion 10a.

[0069] Rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion)

[0070] The rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion) has the following structure: when the valve core 42 is seated on the valve seat portion 10a, the valve core 42 is in a non-contact state relative to the support portion 41b and the locking portion 43 of the valve support body 41, and is supported by a clearance fit so as to be movable in the radial direction and the direction of the axis L.

[0071] Specifically, the valve core flange portion 42c of the valve core 42 is separated from the engaging portion 43, and a gap tla1' is still present on one side in the axial direction between the pressing portion 41ba of the support portion 41b and the pressed surface 42b of the valve core 42, forming a gap area Ga. Therefore, when the valve core 42 is seated on the valve seat portion 10a, the rotation suppression mechanism (1) (the valve core is loosely fitted with the support portion) causes the valve core 42 to be in a non-contact state with respect to the valve support body 41 and the engaging portion 43, and is loosely fitted so as to be movable in the radial direction and the direction of the axis L. Therefore, the rotation suppression mechanism (1) (the valve core is loosely fitted with the support portion) operates like a clutch, completely cutting off the connection between the valve core 42 and the valve support body 41 and the engaging portion 43, that is, the connection with the drive shaft 30. This eliminates the conventional problem 1 (wear caused by the accompanying rotation and pressure on the valve core when seated).

[0072] · Press pressure to adjust the cutting mechanism (1) (seated by self-weight)

[0073] The pressure regulating cut-off mechanism (1) (self-weight seating state) has the following structure: when the valve core 42 is seated on the valve seat portion 10a, it becomes a self-weight seating state in which the valve core sealing surface 42a is flush with the valve seat sealing surface 10aa by utilizing the self-weight of the valve core 42.

[0074] Specifically, in the suspended state of the electric stop valve 100a (see Figure 3 In the case of (a), due to assembly errors, the valve core sealing surface 42a and the valve seat sealing surface 10aa are not arranged parallel to each other, but have a significant inclination relative to each other. In this case, by pressing the pressure adjustment cut-off mechanism (1) (self-weight seating state), when the valve core 42 is seated on the valve seat portion 10a, the valve core sealing surface 42a is seated by the self-weight of the valve core 42, following the valve seat sealing surface 10aa, thereby automatically becoming flush with each other, thereby eliminating the existing problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface).

[0075] Based on the above, in the electric stop valve 100a of the first embodiment, by simultaneously adopting the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion) and the pressing force adjustment cut-off mechanism (1) (self-weight seating state), it is possible to simultaneously eliminate the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seating) and the existing problem 2 (reduced sealing due to the inclination of the valve core sealing surface and the valve seat sealing surface), thereby improving reliability.

[0076] <Transitional state>

[0077] use Figure 3 (c) of the present invention will explain the transient state. The transient state represents the instantaneous state in which the valve core 40 rotates along the axis L (refer to FIG. Figure 3 ) moves as indicated by the arrow M3 in (c), whereby the pressing portion 41ba of the support portion 41b abuts against the pressed surface 42b of the valve core 42. Therefore, in the transition state, the valve core portion 40 clamps one end side of the drive shaft 30 in the same manner as in the self-weight seating state, thereby being integrally connected relative to the drive shaft 30. As a result, the valve core 42 is not supported by the clearance fit, but is clamped by the valve support body 41 and the valve seat portion 10a along the axis L direction. At this time, the valve support body 41 is supported on the drive shaft 30, so that the self-weight of the valve support body 41 is not applied to the valve core sealing surface 42a. Therefore, in the transition state, as in the self-weight seating state (refer to Figure 3 Similarly to (b)), the valve element sealing surface 42a is pressed against the valve seat sealing surface 10aa by the dead weight of the valve element 42.

[0078] In addition, the transition state is when the drive shaft 30 moves in the direction of the axis L (refer to Figure 3 Since the arrow M3 in (c) is in the momentary state of movement, the discussion of the rotation suppression mechanism and the pressing force adjustment and cutting mechanism is omitted.

[0079] <Seating with added deadweight and seating with applied force>

[0080] use Figure 3 (d) of FIG. 1 illustrates the additional self-weight seating state and the force-applied seating state. Here, the additional self-weight seating state and the force-applied seating state occur simultaneously. First, the drive shaft 30 rotates while moving along the axis L direction (refer to FIG. 1 ). Figure 3 The valve support 41 is in contact with the valve seat 10a via the valve core 42, and thus cannot move along the axis L direction together with the drive shaft 30. As a result, the drive shaft 30 overcomes the force of the compression coil spring 46, presses the spring seat 45, and rotates along the axis L direction (refer to FIG. Figure 3As a result, the valve core 40 releases its grip on one end of the drive shaft 30. Furthermore, the valve core sealing surface 42a of the valve core 42 is pressed against the valve seat sealing surface 10aa of the valve seat 10a by the weight of the valve support 41 in addition to the weight of the valve core 42. Furthermore, the valve core 42 is in a force-seated state, pressed by the biasing force of the compression coil spring 46.

[0081] Rotation suppression mechanism (2) (the drive shaft is not clamped by the valve core)

[0082] The rotation suppression mechanism (2) (the drive shaft is not held by the valve core portion) has a structure in which one end side of the drive shaft 30 is not held by the valve core portion 40 in the axis L direction.

[0083] Specifically, the drive shaft 30 overcomes the urging force of the compression coil spring 46 and presses the spring seat 45, rotating in the direction of the axis L (see FIG. Figure 3 When the valve core 40 moves (as indicated by the arrow M4 in (d), the grip of the valve core 40 on one end of the drive shaft 30 is released like a clutch. Due to this rotation suppression mechanism (2) (the drive shaft is not gripped by the valve core), the transmission path of the rotational force from the drive shaft 30 to the valve core 42 must pass through the spring seat 45, the compression coil spring 46, and the support portion 41b, thereby generating sliding friction caused by the relative rotation between these components. As a result, the rotational force from the drive shaft 30 to the valve core 42 is effectively dissipated.

[0084] Therefore, in the electric stop valve 100a of the first embodiment, in addition to adopting the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion), a rotation suppression mechanism (2) (the drive shaft is not clamped by the valve core portion) is also adopted, thereby more reliably suppressing the rotation of the drive shaft 30 from being transmitted to the valve core 42.

[0085] Pressing force adjustment and cutting mechanism (2) (additional self-weight seating state) and pressing force adjustment and cutting mechanism (3) (forced seating state)

[0086] The pressure-adjusting shutoff mechanism (2) (additional deadweight seating state) has a structure in which the valve support body 41 is supported by a loose fit and is in an addition deadweight seating state in which the valve core 42 and the valve support body 41 are seated so that the valve core sealing surface 42a is flush with the valve seat sealing surface 10aa. Furthermore, the pressure-adjusting shutoff mechanism (3) (forced seating state) has a structure in which, when the valve core sealing surface 42a is seated so that the valve core sealing surface 42a is flush with the valve seat sealing surface 10aa, the valve core sealing surface 42a is pressed against the valve seat sealing surface 10aa by the force of the compression coil spring 46.

[0087] Specifically, in the electric stop valve 100a, from the self-weight seated state (see Figure 3 (b)) through the transient state (refer to Figure 3 (c)) transition to the additional deadweight seating state and the force-applied seating state (refer to Figure 3 (d)). Here, in the self-weight seated state (refer to Figure 3 In (b), the valve core sealing surface 42a is pressed against the valve seat sealing surface 10aa in a completely stationary state by the deadweight of the valve core 42. After that, the valve core sealing surface 42a is pressed against the valve seat sealing surface 10aa in a completely stationary state by the deadweight of the valve core 42. Figure 3 At (d), the clamping of the valve core portion 40 on one end side of the drive shaft 30 is released like a clutch. At this time, the valve core sealing surface 42a is pressed against the valve seat sealing surface 10aa by the pressing force adjustment cut-off mechanism (2) (additional self-weight seating state), and the self-weight of the valve core 42 and the valve support body 41 acts, and the force of the compression coil spring 46 acts to press the valve core sealing surface 42a against the valve seat sealing surface 10aa by the pressing force adjustment cut-off mechanism (3) (forced seating state).

[0088] Therefore, in the electric stop valve 100a of the first embodiment, in addition to adopting the pressing force adjustment cut-off mechanism (1) (self-weight seating state), the pressing force adjustment cut-off mechanism (2) (additional self-weight seating state) and the pressing force adjustment cut-off mechanism (3) (forced seating state) are also adopted, thereby adjusting the pressing force of the valve core 42 on the valve seat portion 10a and more reliably cutting off the flow path.

[0089] <Investigation of Maximum Static Friction>

[0090] In the electric stop valve 100a of the first embodiment, in the self-weight seated state (see Figure 3 In (b)), the valve core 42 is in a completely stationary state relative to the valve seat portion 10a. Figure 3 Under (d), in order to keep the valve core 42 in a completely stationary state relative to the valve seat portion 10a, the force in the rotational direction applied by the drive shaft 30 to the valve core 42 needs to be less than the maximum static friction force of the valve core 42 relative to the valve seat portion 10a (fmax = μN: static friction coefficient μ, normal force N).

[0091] Here, especially from becoming Figure 3 From the moment of the forced seating state shown in (d), the force (normal force N) of the compression coil spring 46 clamped between the spring seat portion 45 and the support portion 41b is applied to the valve core 42 by the pressing force adjustment cut-off mechanism (3) (forced seating state). Figure 3The force (normal force N) exerted by the compression coil spring 46 on the valve core 42 increases rapidly, resulting in a larger maximum static friction force (fmax = μN). As a result, even if the valve core 42 or the valve seat portion 10a is made of a resin material with a low static friction coefficient μ and high sliding properties, the valve core 42 and the valve seat portion 10a can be seated in the state of added deadweight and the state of applied force (see FIG. Figure 3 Even in the case of (d)), the valve element 42 can be kept completely stationary relative to the valve seat portion 10a.

[0092] Therefore, in the first embodiment, it is possible to make one of the valve core 42 (that is, the valve core sealing surface 42a) and the valve seat portion 10a (that is, the valve seat sealing surface 10aa) be composed of a resin material, and the other be composed of a metal material. In addition, the resin material of the first embodiment can be made of, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), nylon, acetal, polyimide (PI), polyester, etc., considering high sliding properties. Furthermore, the resin material of the first embodiment can also be made of polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), etc., or polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyamide (PA), nylon, etc. to which additives (graphite, molybdenum, carbon fiber, etc.) are added, considering wear resistance, processability, etc.

[0093] <Axial clearance on one side of the absorption valve support body's inclination>

[0094] Next, use Figure 4 The details of the axial clearance tla1 on one side for absorbing the inclination of the valve core portion 40 in the electric stop valve 100a of the first embodiment will be described. Figure 4 In the description, the case where the valve core portion 40 has an inclination relative to the axis L is taken as an example, but the same description can be made even when the drive shaft 30 has an inclination relative to the axis L, or when both the valve support body 41 and the drive shaft 30 have an inclination relative to the axis L.

[0095] first, Figure 4 (a) indicates that the drive shaft 30 rotates along the axis L direction (refer to Figure 4 The moment when the valve core 40 moves from the suspended state to the partially seated state (as indicated by the arrow M1 in (a)). Here, the valve core 40 has an inclination θ1 relative to the axis L. Furthermore, the valve core 42 is mounted on the engaging portion 43 via the valve core flange 42c, and has a one-side axial gap tla1 between it and the support portion 41b of the valve support body 41, forming a gap area Ga.

[0096] Here, if Figure 4As shown in (a), the guide length L1 formed by the guide portion 41a of the valve support body 41 and the sliding hole 25, and the radial gap a between the guide portion 41a of the valve support body 41 and the sliding hole 25 are set. If the inclination θ1 of the valve core portion 40 is calculated, it is the following (Formula 1).

[0097] tanθ1=a / L1 (Equation 1)

[0098] In addition, the inner diameter D1 of the valve seat sealing surface 10aa at the seating position and the axial opening gap T1 between the valve seat sealing surface 10aa and the valve core 42 are set. If the inclination θ1 of the valve core sealing surface 42a relative to the valve seat sealing surface 10aa is calculated, it is the following (Formula 2).

[0099] tanθ1=T1 / D1 (Equation 2)

[0100] In addition, Figure 4 In (a), as shown in the following (Formula 3), the axial clearance tla1 on one side between the support portion 41b and the valve core 42 is set to be larger than the axial opening clearance T1 between the valve seat sealing surface 10aa and the valve core 42, thereby reliably generating the rotational movement caused by the clearance fitting support until the valve core 42 is seated on the valve seat portion 10a (refer to Figure 4 M2m in (b).

[0101] tla1>T1(Formula 3)

[0102] Here, when (Formula 1) and (Formula 2) are substituted into (Formula 3), it can be organized into the following (Formula 4).

[0103] tla1>a×D1 / L1(Equation 4)

[0104] Therefore, in the electric stop valve 100a of the first embodiment, in order to absorb the inclination θ1 of the valve core portion 40, the one-side axial clearance tla1 is set to satisfy the relationship (Formula 4), thereby reliably generating the rotation action of the valve core 42 (see Figure 4 M2m in (b)). In addition, the upper limit of the one-side axial clearance tla1 is not limited, but if it is too large, the responsiveness of the valve closing action and the valve opening action will be significantly reduced. Therefore, it is preferably set to satisfy 0.05mm≤tla1≤0.4mm, for example.

[0105] then, Figure 4 In (b), the drive shaft 30 rotates along the axis L direction (refer to Figure 4The valve core flange portion 42c of the valve core 42 is separated from the valve support body 41 and the engaging portion 43 in the direction of the axis L. At this time, as described above, the one-side axial direction gap tla1 is set to be larger than the axial direction opening gap T1 (refer to Figure 4 (a) and (Formula 3)), the valve core 42 is supported by the clearance fitting so that it can move in the radial direction and the axis L direction relative to the valve support body 41 and the engaging portion 43 (refer to Figure 4 Thus, the valve core 42 can reliably generate a rotational movement based on the clearance fitting support until the valve core 42 is seated on the valve seat portion 10a by its own weight (see Figure 4 M2m in (b).

[0106] In addition, if Figure 3 As shown in (a), the valve core 42 has a first radial clearance tra1 between the engaging portion 43 and a second radial clearance tra2 between the valve core 42 and the supporting portion 41b of the valve support body 41. Here, the second radial clearance tra2 is set to be larger than the first radial clearance tra1 (tra2>tra1), thereby enabling the valve core 42 to more reliably generate a rotational action based on the clearance engagement support until it is seated on the valve seat portion 10a (see Figure 4 M2m in (b).

[0107] <Axial clearance on one side absorbing the axial thread pitch>

[0108] Next, use Figure 3 (a) of the first embodiment describes the details of the one-side axial clearance tla1 of the thread pitch C (not shown) in the direction of the absorption axis L in the electric stop valve 100a. Here, the outer thread portion 31a of the drive shaft 30 and the inner thread portion 23a (see Figure 1 ) is described as an example in which the thread feed mechanism formed has a thread pitch C in the direction of the axis L, but the same description can be made even if the drive shaft 30 is offset from the desired installation position in the direction of the axis L due to assembly error.

[0109] <Concerns (Variation in Valve Opening and Closing Operations)>

[0110] By moving in the direction of the axis L of the drive shaft 30, the valve core portion 40 advances and retreats relative to the valve seat portion 10a, performing valve opening and closing operations. However, when the thread pitch C in the axial direction of the drive shaft 30 is large, there is a concern that the valve closing operation may be performed earlier than the desired valve closing timing, and the valve opening operation may be performed later than the desired valve opening timing (hereinafter referred to as "concerns (deviations in valve opening and closing operations)").

[0111] For this, Figure 3 As shown in (a), when the valve core 42 is suspended relative to the support portion 41b of the valve support body 41, the one-side axial clearance tla1 between the support portion 41b and the valve core 42 is set to be larger than the thread pitch C in the direction of the axis L of the thread feed mechanism (tla1>C). This allows the timing of the valve opening and closing operation to be determined by the one-side axial clearance tla1, regardless of the thread pitch C in the direction of the axis L, thereby eliminating concerns (variation in the valve opening and closing operation).

[0112] (Example of valve core deformation)

[0113] Here, use Figure 5 , valve core modifications 1 to 4 of the first embodiment are described. First, valve core modifications 1 and 2 differ from the first embodiment in that protrusions 42Aa and 42Ba extending along the axis L are provided on the valve core sealing surface 42a. The rest of the basic structure is the same as the first embodiment. Furthermore, valve core modifications 3 and 4 differ from the first embodiment in that recessed portions 42Ca and 42Da extending along the axis L are provided on the valve core sealing surface 42a. The rest of the basic structure is the same as the first embodiment.

[0114] <Concerns (Valve core vibration caused by turbulent flow when the valve is open)>

[0115] like Figure 3 As shown in (a), in the open state, the valve core 42 is suspended relative to the support portion 41b of the valve support body 41. At this time, fluid flows radially inward from the outer side of the valve core sealing surface 42a of the valve core 42, violently colliding and merging at the center portion on the axis L. This generates turbulent flow near the valve core 42, raising concerns about vibration of the valve core 42 relative to the support portion 41b (hereinafter referred to as "Concern (Valve Core Vibration Due to Turbulent Flow in the Open State)").

[0116] In contrast, in valve element modifications 1 to 4 of the first embodiment, a rectifying mechanism including protrusions 42Aa and 42Ba or recesses 42Ca and 42Da extending along the axis L is provided on the valve element sealing surface 42a of the valve elements 42A to 42D.

[0117] (Valve core modification examples 1 to 4)

[0118] use Figure 5(a) to (d) of the first embodiment describe the valve cores 42A to 42D of the valve core modification examples 1 to 4 of the first embodiment. First, in the valve core modification example 1, a rectification mechanism consisting of a truncated cone-shaped protrusion 42Aa extending along the axis L is provided on the valve core sealing surface 42a of the valve core 42A. In addition, in the valve core modification example 2, a rectification mechanism consisting of a cylindrical protrusion 42Ba extending along the axis L is provided on the valve core sealing surface 42a of the valve core 42B. Furthermore, in the valve core modification example 3, a rectification mechanism consisting of a conical recess 42Ca extending along the axis L is provided on the valve core sealing surface 42a of the valve core 42C. Moreover, in the valve core modification example 4, a rectification mechanism consisting of a cylindrical recess 42Da extending along the axis L is provided on the valve core sealing surface 42a of the valve core 42D.

[0119] Thus, the valve cores 42A to 42D of the valve core modifications 1 to 4 of the first embodiment are provided with protrusions 42Aa and 42Ba and recesses 42Ca and 42Da extending along the axis L as a rectifying mechanism. This rectifying mechanism smoothly deflects the flow of fluid from the radially outer side to the inner side of each valve core sealing surface 42a toward one side in the direction of the axis L, thereby eliminating concerns about vibration of the valve core caused by turbulent flow generated in the valve open state.

[0120] As described above, in the electric stop valve 100a of the first embodiment, by simultaneously adopting the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion) and the pressing force adjustment and shutoff mechanism (1) (the deadweight seated state), it is possible to simultaneously eliminate the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core during seating) and the existing problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface), thereby improving reliability. In addition, in the electric stop valve 100a of the first embodiment, by adopting the pressing force adjustment and shutoff mechanism (2) (the deadweight seated state) and the pressing force adjustment and shutoff mechanism (3) (the force seated state), it is possible to adjust the pressing force of the valve core 42 on the valve seat portion 10a, thereby more reliably shutting off the flow path. Furthermore, in the electric stop valve 100a of the first embodiment, by adopting the rotation suppression mechanism (2) (the drive shaft is not clamped by the valve core portion), it is possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42. Furthermore, in the electric stop valve 100a of the first embodiment, by setting the one-side axial clearance tla1 between the support portion 41b and the valve core 42 to be larger than the thread pitch C in the direction of the axis L of the thread feed mechanism (tla1>C), it is possible to eliminate concerns (variation in the valve opening and closing operation). In addition, in the electric stop valve 100a of the first embodiment, the maximum static friction force can be increased by the pressure adjustment cutoff mechanism (3) (forced seating state), so that it is possible to adopt a solution in which either the valve core sealing surface 42a or the valve seat sealing surface 10aa is made of a resin material and the other is made of a metal material.

[0121] In addition, in the first embodiment, all of the rotation suppression mechanisms (1) and (2) and the pressing force adjustment and cutting mechanisms (1) to (3) are adopted, but the present invention is not limited to this. For example, as long as at least the rotation suppression mechanism (1) and the pressing force adjustment and cutting mechanism (1) are adopted simultaneously, none of the rotation suppression mechanism (2) and the pressing force adjustment and cutting mechanism (2) and (3) may be adopted, or a combination including at least one of them may be adopted.

[0122] Furthermore, in the valve element modifications 1 to 4 of the electric stop valve 100a of the first embodiment, a rectifying mechanism is employed for the valve elements 42A to 42D, thereby eliminating concerns (vibration of the valve element due to turbulent flow generated in the valve open state).

[0123] (Second embodiment)

[0124] use Figures 6 to 8Next, a second embodiment of the electric stop valve 100b will be described. The electric stop valve 100b of the second embodiment differs from the electric stop valve 100a of the first embodiment in that an extension 45a' is provided on the spring seat 45'. The remaining basic structure is the same as that of the first embodiment. Identical components are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0125] <Structure of electric stop valve>

[0126] use Figure 6 The electric stop valve 100b according to the second embodiment of the present invention is described. The electric stop valve 100b mainly comprises a valve body 10, a support member 20 (see Figure 1 ), drive shaft 30, valve core part 40 ', coil component 50 (refer to Figure 1 )、Stepping motor 60 (refer to Figure 1 Hereinafter, the spring seat portion 45 ′ of the valve body portion 40 ′ which is different from the electric stop valve 100 a of the first embodiment will be described.

[0127] <Spring seat>

[0128] The spring seat portion 45' further includes a protruding portion 45a' having a circular ring shape on the other side. The protruding portion 45a' abuts against the gasket 44. In addition, as described in detail later, the length of the protruding portion 45a' in the direction of the axis L is set to be larger than the length in the direction of the axis L from the one end 30a of the drive shaft 30 to the other end of the flange portion 34. Therefore, as a rotation suppression mechanism (2'), it has the following structure: when the valve core 42 is seated on the valve seat portion 10a, the valve support body 41 is supported by the one end 30a of the drive shaft 30 so as to be movable in the radial direction and the axial direction.

[0129] <Details of valve closing operation>

[0130] Next, use Figure 7 The valve closing operation of the electric stop valve 100b (suspended state, self-weight seated state, transition state, additional seated state, and force seated state) is described in sequence. The description is provided while showing the rotation suppression mechanisms (1) and (2') that suppress the transmission of the rotation of the drive shaft 30 to the valve core 42d, and the pressure adjustment and shutoff mechanisms (1) to (3) that adjust the pressure of the valve core 42 against the valve seat portion 10a to shut off the flow path. Furthermore, in the second embodiment, a rotation suppression mechanism (2') is employed instead of the rotation suppression mechanism (2) of the first embodiment.

[0131] <Hanging state>

[0132] use Figure 7(a) of the embodiment will now be described regarding the suspended state. In the suspended state, the valve core 40' is clamped between the spring seat 45' and the cover 47 with the force of the compression coil spring 46 applied thereto, while the valve core 40' is supported by a clearance fit so as to be movable in the radial direction and the direction of the axis L relative to one end 30a of the drive shaft 30. As a result, the valve core 40' rotates together with the drive shaft 30 and moves in the direction of the axis L (see FIG. Figure 7 Furthermore, the valve core sealing surface 42a of the valve core 42 is separated from the valve seat sealing surface 10aa of the valve seat portion 10a.

[0133] At this time, the valve core 42 is placed on the engaging portion 43 via the valve core flange 42c, with a first radial gap trb1 between the engaging portion 43 and the valve core. Furthermore, a first axial gap tlb1 and a second radial gap trb2 are defined between the valve core 42 and the support portion 41b of the valve support body 41. Furthermore, a second axial gap tlb2 is defined between the spring seat 45' and the one end portion 30a of the drive shaft 30. Here, the first axial gap tlb1 is set larger than the second axial gap tlb2 (tlb1>tlb2). Similarly to the first embodiment, the second radial gap trb2 is set larger than the first radial gap trb1 (trb2>trb1).

[0134] <Seated under own weight>

[0135] use Figure 7 (b) of FIG. 1 illustrates the self-weight seated state. In the self-weight seated state, the valve core 40' is supported by a clearance fit relative to one end 30a of the drive shaft 30 so as to be movable in the radial direction and the axis L direction, as in the suspended state. As a result, the valve core 40' rotates together with the drive shaft 30 while moving in the axis L direction (see FIG. Figure 7 The valve core 42 moves as indicated by arrow M2' in (b), and the valve core sealing surface 42a of the valve core 42 abuts the valve seat sealing surface 10aa of the valve seat portion 10a. At this point, a one-side axial gap tlb1' still exists between the pressing portion 41ba of the support portion 41b and the pressed surface 42b of the valve core 42, forming a gap area Ga.

[0136] Rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion)

[0137] The rotation suppression mechanism (1) (the valve core is supported by a loose fitting relative to the support portion) has the following structure, similar to the first embodiment: when the valve core 42 is seated on the valve seat portion 10a, the valve core 42 is in a non-contact state relative to the support portion 41b of the valve support body 41, and is loosely fitted and supported so as to be movable in the radial direction and the direction of the axis L. By adopting this rotation suppression mechanism (1) (the valve core is supported by a loose fitting relative to the support portion), the conventional problem 1 (wear caused by the accompanying rotation and pressure on the valve core when seated) can be eliminated.

[0138] Rotation suppression mechanism (2') (the valve core is supported by a clearance fit relative to the drive shaft)

[0139] The rotation restraining mechanism (2') (the valve core is loosely fitted and supported relative to the drive shaft) has a structure in which the valve core 40' is loosely fitted and supported relative to one end portion 30a of the drive shaft 30 so as to be movable in the radial direction and the axis L direction.

[0140] Therefore, in the electric stop valve 100b of the second embodiment, in addition to the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion), a rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) is also adopted, thereby making it possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42.

[0141] · Press pressure to adjust the cutting mechanism (1) (seated by self-weight)

[0142] The pressure-adjusting shutoff mechanism (1) (self-weight seated state) has the following structure, similar to the first embodiment: when the valve element 42 is seated on the valve seat portion 10a, the valve element 42 is seated in a self-weight seated state in which the valve element sealing surface 42a is flush with the valve seat sealing surface 10aa by the self-weight of the valve element 42. By adopting this pressure-adjusting shutoff mechanism (1) (self-weight seated state), the existing problem 2 (reduction in sealing performance due to the inclination of the valve element sealing surface and the valve seat sealing surface) can be eliminated.

[0143] As described above, in the electric stop valve 100b of the second embodiment, by adopting the rotation suppression mechanism (1) (the valve core is supported by a loose fitting relative to the support portion) and the pressing force adjustment and cut-off mechanism (1) (seated state by its own weight), similarly to the first embodiment, it is possible to simultaneously eliminate the conventional problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seated) and the conventional problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface), thereby improving reliability. In addition, in the electric stop valve 100b of the second embodiment, by adopting the rotation suppression mechanism (2') (the valve core portion is supported by a loose fitting relative to the drive shaft), it is possible to more reliably suppress the transmission of the rotation of the drive shaft 30 to the valve core 42.

[0144] <Seated with attached deadweight>

[0145] use Figure 7 (c) of the invention will explain the state of the additional deadweight seat. First, the valve core 40' rotates with the drive shaft 30 along the axis L direction (refer to Figure 7 The driving shaft 30 further rotates while moving along the axis L direction (see arrow M3' in (c)). Figure 7 3' in (c), the drive shaft 30 and the valve core 40' are in a non-contact state. At this point, a gap tlb2' exists in the other axial direction between the spring seat 45' and the one end 30a of the drive shaft 30. Consequently, the valve core sealing surface 42a of the valve core 42 is seated against the valve seat sealing surface 10aa of the valve seat 10a, pressed by the additional weight of the valve support 41 in addition to the weight of the valve core 42.

[0146] Rotation suppression mechanism (2') (the valve core is supported by a clearance fit relative to the drive shaft)

[0147] The rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) has the following structure, similar to the deadweight seating state: the valve core portion 40' is in a non-contact state relative to one end portion 30a of the drive shaft 30, and is supported by a clearance fit so as to be movable in the radial direction and the axial direction L.

[0148] Therefore, in the electric stop valve 100b of the second embodiment, in addition to the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion), a rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) is also adopted, thereby making it possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42.

[0149] · Pressing pressure to adjust the cutting mechanism (2) (additional deadweight seating state)

[0150] The pressure adjustment cut-off mechanism (2) (additional self-weight seating state) has the following structure in the same manner as the first embodiment: the valve support body 41 is supported by a clearance fit, and is in an addition self-weight seating state in which the valve core 42 and the valve support body 41 are seated so that the valve core sealing surface 42a is flush with the valve seat sealing surface 10aa by utilizing the self-weight of the valve core 42 and the valve support body 41.

[0151] Therefore, in the electric stop valve 100b of the second embodiment, in addition to adopting the pressing force adjustment cut-off mechanism (1) (self-weight seating state), the pressing force adjustment cut-off mechanism (2) (additional self-weight seating state) is also adopted, thereby being able to adjust the pressing force of the valve core 42 on the valve seat portion 10a and more reliably cut off the flow path.

[0152] <Forced seating state>

[0153] use Figure 7 (d) of the present invention describes the state of the seated position. Here, the drive shaft 30 rotates along the axis L direction (refer to Figure 7 The valve core 42 moves as shown by the arrow M4' in (d), abuts against the spring seat 45', and overcomes the force of the compression coil spring 46 to press the spring seat 45', thereby causing the valve core sealing surface 42a of the valve core 42 to be forced to sit on the valve seat sealing surface 10aa of the valve seat portion 10a by the force of the compression coil spring 46.

[0154] Rotation suppression mechanism (2') (the valve core is supported by a clearance fit relative to the drive shaft)

[0155] The rotation suppression mechanism (2') (the valve core part is loosely fitted and supported relative to the drive shaft) has the following structure, similar to the deadweight seated state: the valve core part 40' is loosely fitted and supported relative to one end part 30a of the drive shaft 30 so as to be movable in the radial direction and the axis L direction.

[0156] Therefore, in the electric stop valve 100b of the second embodiment, in addition to adopting the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion), a rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) is also adopted, thereby being able to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42.

[0157] Pressing force adjustment and cutting mechanism (2) (additional self-weight seating state) and pressing force adjustment and cutting mechanism (3) (forced seating state)

[0158] The pressing force adjustment shutoff mechanism (2) (additional deadweight seating state) has the following structure, similar to the first embodiment: the valve support body 41 is supported by a loose fit, and is in the addition deadweight seating state in which the valve core 42 and the valve support body 41 are seated so that the valve core sealing surface 42a is flush with the valve seat sealing surface 10aa. In addition, the pressing force adjustment shutoff mechanism (3) (forced seating state) has the following structure, similar to the first embodiment: in the state in which the valve core sealing surface 42a is seated so that the valve core sealing surface 42a is flush with the valve seat sealing surface 10aa, the valve core sealing surface 42a is pressed against the valve seat sealing surface 10aa by the biasing force of the compression coil spring 46.

[0159] Therefore, in the electric stop valve 100b of the second embodiment, in addition to adopting the pressing force adjustment cut-off mechanism (1) (self-weight seating state), the pressing force adjustment cut-off mechanism (2) (additional self-weight seating state) and the pressing force adjustment cut-off mechanism (3) (forced seating state) are also adopted, thereby adjusting the pressing force of the valve core 42 on the valve seat portion 10a and more reliably cutting off the flow path.

[0160] In addition, in the second embodiment, as in the first embodiment, the maximum static friction force can be increased by adjusting the pressure to adjust the cut-off mechanism (3) (forced seating state), so that one of the valve core 42 (i.e., the valve core sealing surface 42a) and the valve seat portion 10a (i.e., the valve seat sealing surface 10aa) can be made of a resin material, and the other can be made of a metal material. In addition, as in the first embodiment, the resin material of the second embodiment can be made of, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), nylon, acetal, polyimide (PI), polyester, etc., considering high sliding properties. Furthermore, as in the first embodiment, the resin material of the second embodiment can be made of, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), etc., or polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyamide (PA), nylon, etc., to which additives (graphite, molybdenum, carbon fiber, etc.) are added, as in the first embodiment.

[0161] <Axial clearance on the other side of the inclination of the absorption valve support>

[0162] Next, use Figure 8 The details of the other side axial clearance tlb1 for absorbing the inclination of the valve core portion 40' in the electric stop valve 100b of the second embodiment will be described. Figure 8 In the description, the case where the valve core portion 40' has an inclination relative to the axis L is used as an example, but the same description can be made even when the drive shaft 30 has an inclination relative to the axis L, or when both the valve support body 41 and the drive shaft 30 have an inclination relative to the axis L.

[0163] Here, if Figure 7As shown in (a), the electric stop valve 100b of the second embodiment has an axial gap tlb1 on one side and an axial gap tlb2 on the other side. During the period from the self-weight seating state to the additional self-weight seating state, the inclination of the valve support body 41' is first absorbed by the axial gap tlb1 on one side, and then the inclination of the valve support body 41' is further absorbed by the axial gap tlb2 on the other side. However, the description of absorbing the inclination of the valve support body 41' by the axial gap tlb1 on one side is omitted because it is repeated with the above-mentioned <Axial gap on one side that absorbs the inclination of the valve support body>. Here, the focus is on the description of absorbing the inclination of the valve support body 41' by the axial gap tlb2 on the other side. Therefore, Figure 8 (a) is the same as Figure 4 (b) corresponds to the figure.

[0164] first, Figure 8 (a) represents the self-weight seated state, that is, the drive shaft 30 rotates while moving along the axis L direction (refer to Figure 8 The valve body 40' moves as indicated by the arrow M2' in (a), and the valve body 42 is seated on the valve seat portion 10a by the weight of the valve body 42. Here, the valve body portion 40' has an inclination θ1 with respect to the axis L.

[0165] like Figure 8 As shown in (a), the guide length L1 formed by the guide portion 41a of the valve support body 41 and the sliding hole 25, and the radial gap a between the guide portion 41a of the valve support body 41 and the sliding hole 25 are set. When the inclination θ1 of the valve core portion 40' is calculated, it is the above-mentioned (Formula 1).

[0166] tanθ1=a / L1 (Equation 1)

[0167] Furthermore, when the outer diameter D2 of the flange 34 at the contact position and the axial gap T2 between the flange 34 and the gasket 44 are set and the inclination θ1 of the gasket 44 relative to the flange 34 is calculated, the following (Formula 5) is obtained.

[0168] tanθ1=T2 / D2(Formula 5)

[0169] In addition, Figure 8 In (a), as shown in the following (Equation 6), the other side axial gap tlb2 between the spring seat portion 45' and the one end portion 30a of the drive shaft 30 is set to be larger than the axial gap T2 between the flange portion 34 and the gasket 44, thereby making it possible to reliably generate the rotational movement caused by the clearance fitting support until the pressing portion 41ba of the valve support body 41 abuts against the pressed surface 42b of the valve core 42 (see Figure 8 M3m' in (b).

[0170] tlb2>T2 (Equation 6)

[0171] Here, when (Formula 1) and (Formula 5) are substituted into (Formula 6), the following (Formula 7) can be obtained.

[0172] tlb2>a×D2 / L1(Equation 7)

[0173] Therefore, in the electric stop valve 100b of the second embodiment, in order to absorb the inclination θ1 of the valve core portion 40', the other side axial direction gap tlb2 is set to satisfy the relationship of (Formula 7), thereby reliably generating the rotation action of the valve core portion 40' (refer to Figure 8 M3m' in (b)). In addition, in the other side axial direction gap tlb2, the upper limit value is not limited, but if it is too large, the responsiveness of the valve closing action and the valve opening action will be significantly reduced. Therefore, it is preferably set to satisfy, for example, 0.01mm≤tlb2≤0.1mm.

[0174] then, Figure 8 In (b), the drive shaft 30 is rotated along the axis L direction (refer to Figure 8 The driving shaft 30 becomes non-contact with the valve core portion 40' (see arrow M3' in (b)). Figure 8 At this time, as described above, the other side axial gap tlb2 is set to be larger than the axial gap T2 (refer to Figure 8 (a) and (Formula 6)), the valve core portion 40 'is supported by a clearance fit relative to the drive shaft 30 so as to be movable in the radial direction and the axis L direction (see Figure 8 Thus, the valve core 40' is subjected to its own weight until the pressing portion 41ba of the valve support 41 contacts the pressed surface 42b of the valve core 42, and a rotational movement based on the clearance fitting support can be reliably generated (see Figure 8 M3m' in (b).

[0175] In addition, if Figure 7 As shown in (a), the second radial clearance trb2 is set larger than the first radial clearance trb1 (trb2>trb1), thereby more reliably generating the rotational action based on the clearance fitting support until the valve core 42 is seated on the valve seat portion 10a (refer to Figure 8 M3m' in (b).

[0176] In addition, in the second embodiment, Figure 7The axial clearance tlb1 on one side shown in (a) is set larger than the axial clearance tlb2 on the other side. This allows the valve core 42 to take a longer time from seating on the valve seat 10a to entering the self-weight seating state than from the self-weight-added seating state to the force-applied seating state. This prolongs the time required to reach the self-weight-added seating state, allowing the valve core 42's own weight to more reliably seat the valve core sealing surface 42a flush with the valve seat sealing surface 10aa. Furthermore, the time required to transition from the self-weight-added seating state to the force-applied seating state is shortened, allowing the sealing performance between the valve seat sealing surface 10aa and the valve core sealing surface 42a to be improved more quickly.

[0177] As described above, in the electric stop valve 100b of the second embodiment, by simultaneously adopting the rotation suppression mechanism (1) (the valve core is supported by a clearance fit relative to the support portion) and the pressing force adjustment shutoff mechanism (1) (self-weight seated state), similarly to the first embodiment, it is possible to simultaneously eliminate the conventional problem 1 (wear caused by the accompanying rotation and pressing of the valve core during seating) and the conventional problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface), thereby improving reliability. In addition, in the electric stop valve 100b of the second embodiment, by adopting the pressing force adjustment shutoff mechanism (2) (self-weight seated state) and the pressing force adjustment shutoff mechanism (3) (forced seated state), similarly to the first embodiment, it is possible to adjust the pressing force of the valve core 42 against the valve seat portion 10a, thereby more reliably shutting off the flow path. Furthermore, in the electric stop valve 100b of the second embodiment, by adopting the rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft), the transmission of the rotation of the drive shaft 30 to the valve core 42 can be more reliably suppressed. Moreover, in the electric stop valve 100b of the second embodiment, as in the first embodiment, the one-side axial clearance tla1 between the support portion 41b and the valve core 42 is set to be larger than the thread pitch C in the direction of the axis L of the thread feed mechanism (tla1>C), thereby eliminating the concern (variation in the opening and closing valve operation). In addition, in the electric stop valve 100b of the second embodiment, the one-side axial clearance tlb1 is set larger than the other-side axial clearance tlb2, thereby extending the time until the valve core 42 reaches the self-weight seated state. Therefore, the valve core sealing surface 42a can be more reliably seated flush with the valve seat sealing surface 10aa by utilizing the self-weight of the valve core 42. Moreover, the time from the self-weight seated state to the force seated state can be shortened, thereby more quickly improving the sealing performance between the valve seat sealing surface 10aa and the valve core sealing surface 42a. Furthermore, in the electric stop valve 100b of the second embodiment, the maximum static friction force can be increased by the pressure adjustment cutoff mechanism (3) (force seated state). Therefore, it is possible to adopt a solution in which one of the valve core sealing surface 42a and the valve seat sealing surface 10aa is made of a resin material and the other is made of a metal material.

[0178] In addition, in the second embodiment, the rotation suppression mechanism (1), (2') and the pressing force adjustment and cutting mechanism (1) to (3) are all adopted, but the present invention is not limited to this. For example, as long as at least the rotation suppression mechanism (1) and the pressing force adjustment and cutting mechanism (1) are adopted simultaneously, any one of the rotation suppression mechanism (2') and the pressing force adjustment and cutting mechanism (2) and (3) may not be adopted, or a combination including at least one of them may be adopted.

[0179] In the electric stop valve 100b of the second embodiment, similarly to the first embodiment, the rectifying mechanism of the valve element modifications 1 to 4 is adopted, thereby eliminating concerns (vibration of the valve element due to turbulent flow generated in the valve open state).

[0180] (Third embodiment)

[0181] use Figures 9 and 10 Next, the electric stop valve 100c of the third embodiment will be described. The electric stop valve 100c of the third embodiment differs from the electric stop valve 100b of the second embodiment in that the support portion 41b" of the valve support body 41" is loosely engaged and supported within the valve core 42". The remaining basic structure is the same as that of the second embodiment. Identical components are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0182] <Structure of electric stop valve>

[0183] use Figure 9 The electric stop valve 100c according to the third embodiment of the present invention is described. The electric stop valve 100c mainly comprises a valve body 10, a support member 20 (see Figure 1 ), drive shaft 30, valve core part 40", coil component 50 (refer to Figure 1 )、Stepping motor 60 (refer to Figure 1 ) structure. Hereinafter, the valve support body 41 ″ and the valve body 42 ″ of the valve body portion 40 ″ which are different from the electric stop valve 100 b of the second embodiment will be described.

[0184] <Valve support>

[0185] The valve support body 41" is engaged along the sliding hole 25 so as to be slidable along the axis L, and has a guide portion 41a and a support portion 41b" provided at one side end of the guide portion 41a. The guide portion 41a is formed into a cylindrical shape having an outer diameter substantially the same as the inner diameter of the sliding hole 25 of the bracket portion 21. In addition, the support portion 41b" has: a necked portion 41bc" that is necked down compared to the guide portion 41a; an engaging portion 41bb" that is provided at one end side of the necked portion 41bc" and has a disc shape; and a pressing portion 41ba" provided at the step portion between the guide portion 41a and the necked portion 41bc".

[0186] The valve core 42" is made of, for example, a resin material or a metal material such as stainless steel, and has an upward C-shaped cross-sectional shape that defines an accommodating space As. The valve core 42" has: a disc-shaped valve core sealing surface 42a" provided on one end side; a C-shaped pressed surface 42b" provided on the other end side; and a lip 42c" provided on the other end side and extending radially inward. Here, the valve core 42" is supported by a clearance fit by having a gap in the radial direction and the axial line L direction between the accommodating space As and the support portion 41b".

[0187] <Details of valve closing operation>

[0188] Below, use Figure 10 , the valve closing action of the electric stop valve 100c (suspended state, self-weight seating state, transition state, additional seating state, and force seating state) is described in sequence. The rotation suppression mechanism (1'), (2') for suppressing the rotation of the drive shaft 30 from being transmitted to the valve core 42" in the valve closing action, and the pressing force adjustment and cutting mechanism (1') to (3') for adjusting the pressing force of the valve core 42" on the valve seat portion 10a to cut off the flow path are shown and described. In addition, compared with the second embodiment, the third embodiment is different only in the clearance fitting support structure between the valve support body 41" and the valve core 42". Therefore, the rotation suppression mechanism (1'), (2') and the pressing force adjustment and cutting mechanism (1') to (3') are the same as the rotation suppression mechanism (1), (2') and the pressing force adjustment and cutting mechanism (1) to (3) of the second embodiment.

[0189] <Hanging state>

[0190] use Figure 10 (a) of the embodiment will now be described regarding the suspended state. Similarly to the second embodiment, in the suspended state, the valve core portion 40" clamps the gasket 44 between the spring seat portion 45' and the cover portion 47 in a state where the force of the compression coil spring 46 is applied, thereby being supported by a clearance fit so as to be movable in the radial direction and the direction of the axis L relative to one end portion 30a of the drive shaft 30. Thus, the valve core portion 40" rotates together with the drive shaft 30 while moving in the direction of the axis L (see FIG. Figure 10 In addition, the valve core sealing surface 42a" of the valve core 42" is separated from the valve seat sealing surface 10aa of the valve seat portion 10a.

[0191] At this time, the valve core 42″ is placed on the engaging portion 41bb″ via the lip piece 42c″, and has a first radial gap trc1 between the engaging portion 41bb″, a second radial gap trc2 between the constricted portion 41bc″, and a one-side axial gap tlc1 between the valve core 42″ and the pressing portion 41ba″ of the support portion 41b″. In addition, there is a second-side axial gap tlc2 between the spring seat portion 45′ and the one end portion 30a of the drive shaft 30. Here, the one-side axial gap tlc1 is set to be larger than the other-side axial gap tlc2 (tlc1>tlc2). In addition, the second radial gap trc2 is set to be larger than the first radial gap trc1 (trc2>trc1) similarly to the second embodiment. As a result, in the self-weight seated state, the rotational movement until the valve core 42″ is completely seated on the valve seat portion 10a can be more reliably generated.

[0192] <Seated under own weight>

[0193] use Figure 10 (b) of FIG. 1 illustrates the self-weight seated state. In the self-weight seated state, the valve core portion 40 ″ is supported by a clearance fit so that it can move in the radial direction and the axis L direction relative to one end portion 30a of the drive shaft 30, as in the suspended state. As a result, the valve core portion 40 ″ rotates together with the drive shaft 30 and moves in the axis L direction (see FIG. Figure 10 The valve core 42” moves as shown by the arrow M2” in (b), and the valve core sealing surface 42a” of the valve core 42” abuts against the valve seat sealing surface 10aa of the valve seat portion 10a. At this time, there is still a one-side axial gap tlc1' between the pressing portion 41ba” of the support portion 41b” and the pressed surface 42b” of the valve core 42”.

[0194] Rotation suppression mechanism (1') (the valve core is supported by the clearance between the valve core and the support portion)

[0195] The rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion) has the following structure, similar to the second embodiment: when the valve core 42" is seated on the valve seat portion 10a, the valve core 42" is in a non-contact state relative to the support portion 41b" of the valve support body 41", and is supported by a clearance fit so as to be movable in the radial direction and the direction of the axis L. By adopting this rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion), the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seating) can be eliminated.

[0196] Rotation suppression mechanism (2') (the valve core is supported by a clearance fit relative to the drive shaft)

[0197] The rotation suppression mechanism (2') (the valve core portion is loosely fitted and supported relative to the drive shaft) has the following structure, similar to the second embodiment: the valve core portion 40" is loosely fitted and supported relative to one end portion 30a of the drive shaft 30 so as to be movable in the radial direction and the axis L direction.

[0198] Thus, in the electric stop valve 100c of the third embodiment, in addition to adopting the rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion), the rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) is also adopted as in the second embodiment, thereby making it possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42".

[0199] · Press pressure to adjust the cutting mechanism (1') (seated by self-weight)

[0200] The pressure-adjusting and cutting mechanism (1') (self-weight seating state) has the following structure in the same manner as the second embodiment: when the valve core 42" is seated on the valve seat portion 10a, the valve core 42" is seated in a self-weight seating state in which the valve core sealing surface 42a" is flush with the valve seat sealing surface 10aa by utilizing its own weight. By adopting this pressure-adjusting and cutting mechanism (1') (self-weight seating state), the existing problem 2 (reduced sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface) can be eliminated.

[0201] Based on the above, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, by adopting the rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion) and the pressing force adjustment and cut-off mechanism (1) (seated state due to its own weight), it is possible to simultaneously eliminate the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seated) and the existing problem 2 (reduction in sealing performance due to the inclination of the valve core sealing surface and the valve seat sealing surface), thereby improving reliability. In addition, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, by adopting the rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft), it is possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42".

[0202] <Seated with attached deadweight>

[0203] use Figure 10 (c) of the invention describes the state of the additional deadweight seat. First, the valve core 40" rotates with the drive shaft 30 along the axis L direction (refer to Figure 10 The arrow M3 in (c) moves, whereby the pressing portion 41ba" of the support portion 41b" abuts against the pressed surface 42b" of the valve core 42". Then, the drive shaft 30 further rotates while moving in the direction of the axis L (refer to FIG. Figure 10” in (c)), thereby achieving a non-contact state between the drive shaft 30 and the valve core portion 40”. At this time, there is a gap tlc2’ in the other side axial direction between the spring seat portion 45’ and the one end portion 30a of the drive shaft 30. Therefore, the valve core sealing surface 42a” of the valve core 42” is pressed against the valve seat sealing surface 10aa of the valve seat portion 10a by the additional deadweight of the valve support body 41” in addition to the deadweight of the valve core 42”.

[0204] Rotation suppression mechanism (2') (the valve core is supported by a clearance fit relative to the drive shaft)

[0205] The rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) has the following structure, similar to the second embodiment: the valve core portion 40" is in a non-contact state relative to the one end portion 30a of the drive shaft 30, and is supported by a clearance fit so as to be movable in the radial direction and the direction of the axis L.

[0206] Thus, in the electric stop valve 100c of the third embodiment, in addition to the rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion), the rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) is also adopted, thereby making it possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42".

[0207] · Pressing pressure to adjust the cutting mechanism (2') (additional deadweight seating state)

[0208] The pressure-adjustable cut-off mechanism (2') (additional self-weight seating state) has the following structure in the same manner as the second embodiment: the valve support body 41" is supported by a clearance fit, and is seated in an addition self-weight seating state in which the valve core sealing surface 42a" is flush with the valve seat sealing surface 10aa by utilizing the self-weight of the valve core 42" and the valve support body 41".

[0209] Therefore, in the electric stop valve 100c of the third embodiment, in addition to adopting the pressing force adjustment cut-off mechanism (1') (self-weight seating state), a pressing force adjustment cut-off mechanism (2') (additional self-weight seating state) is also adopted, thereby being able to adjust the pressing force of the valve core 42" on the valve seat portion 10a", thereby more reliably cutting off the flow path.

[0210] <Forced seating state>

[0211] use Figure 10 (d) of the present invention describes the state of the seated position. Here, the drive shaft 30 rotates along the axis L direction (refer to Figure 10The valve core 42" moves as shown by the arrow M4" in (d), abuts against the spring seat 45', and overcomes the force of the compression coil spring 46 to press the spring seat 45', thereby causing the valve core sealing surface 42a" of the valve core 42" to be forced into a seated state by the force of the compression coil spring 46 against the valve seat sealing surface 10aa of the valve seat portion 10a.

[0212] Rotation suppression mechanism (2') (the valve core is supported by a clearance fit relative to the drive shaft)

[0213] The rotation suppression mechanism (2') (the valve core portion is loosely fitted and supported relative to the drive shaft) has the following structure, similar to the second embodiment: the valve core portion 40" is loosely fitted and supported relative to one end portion 30a of the drive shaft 30 so as to be movable in the radial direction and the axis L direction.

[0214] Thus, in the electric stop valve 100cb of the third embodiment, in addition to the rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion), the rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft) is also adopted, thereby making it possible to more reliably suppress the rotation of the drive shaft 30 from being transmitted to the valve core 42".

[0215] Pressing force adjustment and cutting mechanism (2') (additional self-weight seating state) and pressing force adjustment and cutting mechanism (3') (forced seating state)

[0216] The pressure-adjusting and cutting mechanism (2') (additional self-weight seating state) has the following structure, similar to the second embodiment: the valve support body 41" is supported by a clearance fit, and is in an addition self-weight seating state in which the valve core 42" and the valve support body 41" are seated so that the valve core sealing surface 42a" is flush with the valve seat sealing surface 10aa by utilizing the self-weight of the valve core 42". In addition, the pressure-adjusting and cutting mechanism (3') (forced seating state) has the following structure, similar to the second embodiment: in a state in which the valve core sealing surface 42a" is seated so that it is flush with the valve seat sealing surface 10aa, the valve core sealing surface 42a" is pressed against the valve seat sealing surface 10aa by the force of the compression coil spring 46.

[0217] Therefore, in the electric stop valve 100c of the third embodiment, in addition to the pressing force adjustment cutoff mechanism (1') (self-weight seating state), the pressing force adjustment cutoff mechanism (2') (additional self-weight seating state) and the pressing force adjustment cutoff mechanism (3') (forced seating state) are also adopted, thereby adjusting the pressing force of the valve core 42" on the valve seat portion 10a, thereby more reliably cutting off the flow path.

[0218] In addition, in the third embodiment, as in the second embodiment, the maximum static friction force can be increased by adjusting the pressure of the cut-off mechanism (3') (forced seating state), so that one of the valve core 42" (that is, the valve core sealing surface 42a") and the valve seat portion 10a (that is, the valve seat sealing surface 10aa) can be made of a resin material, and the other can be made of a metal material. In addition, as in the second embodiment, the resin material of the third embodiment can be made of, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), nylon, acetal, polyimide (PI), polyester, etc., considering high sliding properties. Furthermore, as in the first embodiment, the resin material of the second embodiment can be made of polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), etc., or polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyamide (PA), nylon, etc. to which additives (graphite, molybdenum, carbon fiber, etc.) are added, considering wear resistance, processability, etc.

[0219] Based on the above, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, by simultaneously adopting a rotation suppression mechanism (1') (the valve core is supported by a clearance fit relative to the support portion) and a pressing force adjustment cut-off mechanism (1') (self-weight seating state), it is possible to simultaneously eliminate the existing problem 1 (wear caused by the accompanying rotation and pressing of the valve core when seating) and the existing problem 2 (reduced sealing due to the inclination of the valve core sealing surface and the valve seat sealing surface), thereby improving reliability. In addition, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, by adopting a pressing force adjustment cut-off mechanism (2') (additional self-weight seating state) and a pressing force adjustment cut-off mechanism (3') (force seating state), the pressing force of the valve core 42" on the valve seat portion 10a can be adjusted, thereby more reliably cutting off the flow path. Furthermore, in the electric stop valve 100c of the third embodiment, by adopting a rotation suppression mechanism (2') (the valve core portion is supported by a clearance fit relative to the drive shaft), the rotation of the drive shaft 30 can be more reliably suppressed from being transmitted to the valve core 42". Furthermore, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, the one-side axial clearance tlc1 between the pressing portion 41ba" of the support portion 41b" and the valve element 42" is set to be larger than the thread pitch C in the direction of the axis L of the thread feed mechanism (tlc1>C), thereby eliminating concerns (variation in valve opening and closing operations). Furthermore, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, the one-side axial clearance tlc1 is set to be larger than the other-side axial clearance tlc2. This prolongs the time required to achieve the self-weight seating state. Therefore, the self-weight of the valve element 42" can be utilized to more reliably seat the valve element sealing surface 42a" flush with the valve seat sealing surface 10aa. Furthermore, the time required to transition from the self-weight seating state to the force-application seating state can be shortened, thereby more quickly improving the sealing performance between the valve seat sealing surface 10aa and the valve element sealing surface 42a". Furthermore, in the electric stop valve 100c of the third embodiment, similarly to the second embodiment, the maximum static friction force can be increased by adjusting the shutoff mechanism (3') (forced seating state), so that it is possible to adopt a solution in which either one of the valve core sealing surface 42a" and the valve seat sealing surface 10aa is made of a resin material and the other is made of a metal material.

[0220] Furthermore, in the third embodiment, all of the rotation suppression mechanisms (1'), (2') and the pressing force adjustment and cutting mechanisms (1') to (3') are employed, but the present invention is not limited thereto. For example, as long as at least the rotation suppression mechanism (1') and the pressing force adjustment and cutting mechanism (1') are employed simultaneously, none of the rotation suppression mechanism (2') and the pressing force adjustment and cutting mechanism (2'), (3') may be employed, or a combination including at least one of them may be employed.

[0221] In the electric stop valve 100c of the third embodiment, similarly to the first embodiment, the rectifying mechanism of the valve element modifications 1 to 4 is adopted, thereby eliminating concerns (vibration of the valve element due to turbulent flow generated in the valve open state).

[0222] <Other>

[0223] It goes without saying that the electric stop valves 100a to 100c of this embodiment are applicable to all fluid devices and fluid circuits. Furthermore, the present invention is not limited to the above-described embodiments, embodiments, and variations described herein, and appropriate changes and modifications are possible without departing from the technical spirit of the present invention.

[0224] Explanation of symbols

[0225] 100a-100c—Electric stop valve; 1—First connecting pipe; 2—Second connecting pipe; 10—Valve body; 10a—Valve seat portion (valve seat); 10aa—Valve seat sealing surface; 10b—Valve port; 12—Valve chamber; 20—Support member; 21—Bracket portion; 22—Fixed portion; 23—Threaded hole; 23a—Internal threaded portion (thread feed mechanism); 24—Bearing connection hole; 25—Sliding hole; 26—Guide rail; 30—Drive shaft; 30a—One end portion of the drive shaft; 31—Threaded portion; 31a—External threaded portion (thread feed mechanism); 32—Guide portion; 33—Constricted portion; 34—Flange portion; 40, 40′, 41′ 0"—valve core; 41, 41', 41"—valve support; 41a—guide; 41b, 41b"—support; 41ba, 41ba"—pressing portion (abutment); 41bb"—engaging portion; 41bc"—retracted portion; 42, 42", 42A~42D—valve core; 42a, 42a"—valve core sealing surface; 42b, 42b"—pressed surface (abutment); 42Aa, 42Ba—protrusion; 42Ca, 42Da—recess; 42c—valve core flange; 42c"—lip; 43—engaging portion; 44—gasket; 45, 45'—spring seat; 45a'—protrusion ; 46—compression coil spring (compression spring); 47—cover; 50—coil component; 60—stepping motor; a—radial gap; As—accommodation space; C—axial thread pitch; D1—inner diameter of the valve seat sealing surface at the seating position; D2—outer diameter of the flange at the abutment position; Ga—gap area; L—axis; L1—guide length of the guide portion and the sliding hole; Nc—non-contact portion; tla1, tla1', tlb1, tlb1'—one-side axial gap between the valve core and the support portion; tlb2, tlb2', tlc2, tlc2'—between the spring seat portion and one end portion of the drive shaft The other side axial direction gap; tlc1, tlc1'—one side axial direction gap between the valve core and the pressing part of the support part; tra1, trb1, trc1—the first radial direction gap between the valve core and the engaging part; tra2, trb2—the second radial direction gap between the valve core and the support part; trc2—the second radial direction gap between the valve core and the constricted part; T1—the axial direction opening gap between the valve seat sealing surface and the valve core; T2—the axial direction gap between the flange part and the gasket; θ1—the inclination of the valve core part relative to the axis L, the inclination of the valve core sealing surface relative to the valve seat sealing surface, and the inclination of the gasket relative to the flange part.

Claims

1. A stop valve, characterized in that: have: A drive shaft that is capable of rotating and moving along the axial direction by a screw feed mechanism; a valve seat having an annular valve seat sealing surface at the other end side; a valve core portion comprising a valve core, a valve support body, a spring seat portion, and a compression spring, wherein the valve core has a disc-shaped valve core sealing surface on one end side, the valve support body includes a cylindrical guide portion and a support portion for supporting the valve core, the spring seat portion is accommodated in the guide portion and can abut against one end portion of the drive shaft, and the compression spring is clamped between the spring seat portion and the support portion; a rotation suppressing mechanism that suppresses the transmission of the rotation of the drive shaft to the valve element; and The pressure regulating and cutting mechanism adjusts the pressing force of the valve core against the valve seat to cut off the flow path. The rotation restraining mechanism has a structure in which the valve element is loosely fitted and supported by the support portion of the valve support body when the valve element is seated on the valve seat. The pressing force regulating cutoff mechanism has a structure in which, when the valve element is seated on the valve seat, the valve element is seated in a self-weight seated state in which the valve element sealing surface is flush with the valve seat sealing surface by its own weight.

2. The stop valve according to claim 1, characterized in that The above-mentioned pressing force adjustment and cutting mechanism also has a structure that becomes a force-applied seating state, and in this force-applied seating state, when the above-mentioned valve core sealing surface is seated flush with the above-mentioned valve seat sealing surface, one end portion of the above-mentioned drive shaft overcomes the action force of the above-mentioned compression spring and presses the above-mentioned spring seat portion, thereby pressing the above-mentioned valve core sealing surface against the above-mentioned valve seat sealing surface via the abutment portion in the axial direction of the above-mentioned valve core and the above-mentioned support portion of the above-mentioned valve support body.

3. The stop valve according to claim 2, characterized in that The above-mentioned pressing force adjustment cutting mechanism also has a structure that becomes an additional self-weight seating state simultaneously with the above-mentioned force seating state, or between the above-mentioned self-weight seating state and the above-mentioned force seating state. The additional self-weight seating state utilizes the self-weight of the above-mentioned valve core and the above-mentioned valve support body, and the seating is such that the sealing surface of the above-mentioned valve core is flush with the sealing surface of the above-mentioned valve seat.

4. The stop valve according to claim 2, characterized in that The rotation restraining mechanism further has a structure in which the one end portion of the drive shaft is not clamped by the valve element in the axial direction in the biased seating state.

5. The stop valve according to claim 1, characterized in that The rotation restraining mechanism may further have a structure in which the valve support body is supported by the one end portion of the drive shaft in a loosely fitted manner when the valve element is seated on the valve seat.

6. The stop valve according to claim 1, characterized in that When the valve element is in a suspended state with a loose fit supported by the support portion of the valve support body, an axial clearance between the valve element and the support portion is set to be larger than an axial thread pitch of the drive shaft.

7. The stop valve according to claim 6, characterized in that It is set that when the above-mentioned valve support body is supported by a clearance fit on one end part of the above-mentioned drive shaft, and the above-mentioned valve core is supported by a clearance fit on the above-mentioned support part of the above-mentioned valve support body in a suspended state, the axial direction gap on one side of the above-mentioned valve core and the above-mentioned support part is larger than the axial direction gap on the other side of the above-mentioned valve support body and one end part of the above-mentioned drive shaft.

8. The stop valve according to claim 2, characterized in that One of the valve element sealing surface and the valve seat sealing surface is made of a resin material, and the other is made of a metal material.

9. The stop valve according to claim 1, characterized in that The valve element sealing surface is further provided with a flow regulating mechanism composed of a protrusion or a recess extending along the axis.

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