Electric valve

Abstract

Provided is an electrically operated valve which suppresses wear of a sealing member. An electric valve (10) is provided with: a valve seat (24A) having a first opening (24A1); a drive shaft (22) extending in a direction orthogonal to the valve seat and rotating about a shaft center offset from the first opening; a valve body (24D) that has a seal (50), is provided to the drive shaft, and opens and closes the first opening by means of the seal by rotating along the valve seat as a result of the rotation of the drive shaft; a spring member (26) that urges the valve body toward the valve seat; and a conversion mechanism (60) that converts at least a rotational motion of the valve body from a state in which the seal closes the first opening to a state in which the seal opens the first opening into a linear motion of the seal toward the valve body on a side away from the valve seat.

Description

Technical Field

[0001] The present invention relates to an electric valve. Background Art

[0002] Conventionally, as in Patent Document 1, a needle valve type electric valve (hereinafter, an electric needle valve) that adjusts the flow rate by moving a valve element up and down through a feed screw mechanism is known. The electric needle valve includes: a valve body; a cylindrical housing that is attached to the valve body; a rotor that is provided inside the housing; and a stator that is disposed outside the housing and rotates the rotor.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-219059

[0006] Technical Problem to be Solved by the Invention

[0007] In an electric valve that closes an opening by rotating a valve element having a seal along a formation surface of the opening of a housing, in the conventional electric valve, the seal is always pressed against the formation surface of the opening by a biasing portion, and thus the seal is worn. Summary of the Invention

[0008] The present invention provides an electric valve that suppresses wear of a seal accompanying opening and closing of an opening as compared with a structure that always presses a seal of a valve element against a formation surface of the opening.

[0009] Technical Means for Solving the Technical Problem

[0010] The electric valve according to the first aspect includes: a housing having an opening; a shaft body that extends in a direction orthogonal to a formation surface of the opening and rotates about a shaft center offset from the opening; a valve element having a seal and provided on the shaft body, and that rotates along the formation surface by rotation of the shaft body, thereby opening and closing the opening with the seal; a biasing portion that biases the valve element toward the formation surface; and a conversion mechanism that converts at least a rotational movement of the valve element from a state where the seal closes the opening to a state where the opening is opened into a linear movement of the valve element that causes the seal to move toward a side away from the formation surface.

[0011] In the electric valve according to the first aspect, when the valve element rotates from a state where the opening is closed to the open side, the conversion mechanism converts the rotational movement of the valve element into a linear movement and the seal acts on a side away from the formation surface of the opening. Thus, in the present electric valve, wear of the seal is suppressed as compared with a structure that always presses the seal of the valve element against the formation surface of the opening.

[0012] In the electric valve of the second mode, based on the electric valve of the first mode, the conversion mechanism has: a convex portion that is disposed on the housing and protrudes in a direction away from the formation surface of the opening; and a plate portion that is disposed on a side of the valve element opposite to the convex portion and has an inclined surface that is inclined with respect to the formation surface of the opening, and the convex portion moves along the inclined surface as the shaft body rotates.

[0013] In the electric valve of the second mode, due to the acting force of the biasing portion, the convex portion on the housing side contacts the plate portion on the valve element side. If the inclined surface moves along the convex portion by rotating the valve element, the rotational motion of the valve element is converted into a linear motion. In this electric valve, since the plate portion has an inclined surface with a complex shape, compared with the structure in which the inclined surface is disposed on the housing, the direction of the motion of the valve element is changed by a simple structure.

[0014] In the electric valve of the third mode, based on the electric valve of the second mode, when viewed from the direction along the axis center, the inclined surfaces of the convex portion and the plate portion are disposed outside the valve element.

[0015] In the electric valve of the third mode, compared with the structure in which the inclined surfaces of the convex portion and the plate portion are disposed between the axis center of the shaft body and the outer edge of the valve element, the seal moves away from the formation surface with a smaller load.

[0016] In the electric valve of the fourth mode, based on the electric valve of any one of the second mode or the third mode, the plate portion has a base surface that extends from the inclined surface in a direction opposite to the rotation direction of the shaft body and is formed to be flat.

[0017] In the electric valve of the fourth mode, during the period when the base surface passes through the convex portion, the interval between the seal of the valve element and the formation surface of the opening is maintained, and thus, compared with the structure in which the plate portion only has an inclined surface, the power to overcome the acting force of the biasing portion is reduced.

[0018] In the electric valve of the fifth mode, based on the electric valve of the fourth mode, the plate portion has a reference surface that is formed by extending from the base surface in a direction away from the formation surface of the opening and in a direction opposite to the rotation direction of the shaft body, and the convex portion moves along this reference surface when the seal transfers from the state of opening the opening to the state of closing the opening.

[0019] In the electric valve of the fifth embodiment, when the contact surface of the convex portion in the plate portion reaches the reference surface from the base surface as the shaft body rotates, the seal contacts the surface formed by the opening. Furthermore, when the convex portion moves along the reference surface as the shaft body rotates, the seal is shifted from a state in which the opening is opened to a state in which the opening is closed. Thus, in the electric valve, compared with a structure in which the contact surface of the convex portion reaches the reference surface from the base surface when the seal overlaps the opening, the seal is prevented from being broken or damaged by the edge of the opening.

[0020] In a sixth aspect, according to the electric valve of any one of the first to fifth aspects, the pair of conversion mechanisms are symmetrically arranged with respect to the axial center of the shaft body.

[0021] In the electric valve of the sixth aspect, compared with a case where there is only one conversion mechanism, the inclination of the conversion mechanism generated when the rotational motion of the valve body is converted into the linear motion of the valve body that moves the seal toward the side away from the opening forming surface is suppressed.

[0022] Effects of the Invention

[0023] According to the electric valve of the present invention, compared with a structure in which the seal of the valve body is always pressed against the surface forming the opening, wear of the seal is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a cross-sectional view for explaining the electric valve according to the present embodiment.

[0025] Figure 2 It is a bottom side perspective view of the second disk portion of this embodiment.

[0026] Figure 3 (a) is a side view of the second disc portion of this embodiment, Figure 3 (b) is a bottom view of the second circular plate portion.

[0027] Figure 4 (a) is a front view of the valve core of the electric valve of this embodiment. Figure 4 (b) is a bottom view of the valve element as viewed from the second adjustment portion side.

[0028] Figure 5 (a1) to (f1) are bottom views showing the position of the pin of the electric valve of this embodiment relative to the second disc portion. Figure 5 (a2)~(f2) represent Figure 5 A partial cross-sectional view of the opening and closing state of the first opening caused by the seal member corresponding to each state (a1) to (f1) as viewed from the top surface, Figure 5 (a3) to (f3) are viewed from a direction perpendicular to the valve core. Figure 5Partial sectional views showing the open / closed states respectively represented by (a2) to (f2).

[0029] Figure 6 It is a sectional view for explaining an electric valve of a modified example.

[0030] Symbol Explanation

[0031] 10 Electric valve

[0032] 12 Housing

[0033] 14 Stator

[0034] 16 Support member

[0035] 18 Transmission shaft

[0036] 20 Rotor

[0037] 21 Reduction gear

[0038] 22 Drive shaft (an example of a shaft body)

[0039] 24 Valve body

[0040] 24A1 First opening (an example of an opening)

[0041] 24A Valve seat (an example of a housing and a forming surface)

[0042] 24B Side wall (an example of a housing)

[0043] 24C Valve chamber

[0044] 24D Valve core

[0045] 26 Spring member (an example of a biasing portion)

[0046] 50 Seal

[0047] 60 Conversion mechanism

[0048] 62 Pin (an example of a convex portion)

[0049] 64 Second circular plate portion (an example of a plate portion)

[0050] 64D Valve core

[0051] 66A, 66A1 First inclined surface (an example of an inclined surface)

[0052] 66B, 66B1 Base surface

[0053] 66C, 66C1, 66C2 Reference surface. Detailed Description of the Invention

[0054] The following describes this embodiment. In the descriptions of the following drawings, the same or similar parts are labeled with the same or similar reference numerals. However, the drawings are schematic, and the relationships between thickness and planar dimensions, the ratios of the thicknesses of various devices and components, etc. are different from the actual situation. Therefore, specific thicknesses and dimensions should be determined with reference to the following descriptions. Additionally, there are also parts with different relationships and ratios of dimensions between the drawings. For convenience, the H direction refers to the vertically downward direction.

[0055] <Structure of Electric Valve>

[0056] Refer to Figures 1 to 6 This describes the electric valve 10 of this embodiment. As Figure 1 shown, the electric valve 10 includes a housing 12, a stator 14, a support member 16, a transmission shaft 18, a rotor 20, a drive shaft 22, a valve body 24, a spring member 26, and a conversion mechanism 60. In addition, Figure 1 This is a cross-sectional view of the electric valve 10 cut along a vertical plane including the axis center C.

[0057] (Housing)

[0058] The housing 12 is a cylindrical member. Regarding the material of the housing 12, any material can be used as long as the rotor 20 described later can rotate inside and the desired resistance to the fluid flowing inside can be obtained. The housing 12 has a bottom 12A and a side wall portion 12B. The bottom 12A of the housing 12 is located on the upper side (opposite to the H direction) in Figure 1 , and the opening of the cylindrical housing 12 is located on the lower side (H direction) opposite to the bottom 12A. In Figure 1 , the following state is exemplified, and the housing 12 is joined to the valve body 24 by fitting the upper part of the valve body 24 into the opening of the housing 12.

[0059] (Stator)

[0060] The stator 14 is provided outside the housing 12 and has a drive coil (not shown). The rotor 20 described later rotates through the drive coil. In Figure 1 , for ease of observation, the details of the stator 14 are omitted.

[0061] (Support Member)

[0062] The support member 16 is provided inside the housing 12 on one side of the bottom 12A ( Figure 1above). A gap is formed between the support member 16 and the bottom 12A. The support member 16 has a circular plate-like member, i.e., a first circular plate portion 16A, in a plan view, and a pressing portion 16B provided at the center of the first circular plate portion 16A. The material of the support member 16 is resin, metal, etc., and is arbitrary.

[0063] The outer diameter of the first circular plate portion 16A is substantially equal to the inner diameter of the cylinder of the housing 12. The end surface of the outer periphery of the first circular plate portion 16A is fitted to the inner surface of the side wall portion 12B of the housing 12. The support member 16 can slide a certain distance along the axial direction (H direction, Figure 1 the up-and-down direction in) in a state where the first circular plate portion 16A is in contact with the inner surface of the side wall portion 12B of the housing 12.

[0064] The pressing portion 16B is cylindrical. The opening of the cylindrical pressing portion 16B faces Figure 1 a rotor 20, which will be described later, located below the pressing portion 16B. The inner diameter of the cylindrical pressing portion 16B is substantially the same as the outer diameter of a transmission shaft 18, which will be described later. By inserting one end ( Figure 1 the upper end in) of the transmission shaft 18 into the inside of the cylindrical pressing portion 16B, the inner surface of the bottom of the cylindrical pressing portion 16B comes into contact with the end surface ( Figure 1 the upper surface in) of one end of the transmission shaft 18.

[0065] As Figure 1 shown, a guide groove 16C is provided on the surface of the support member 16 on the side of the bottom 12A of the housing 12 ( Figure 1 the upper side in), at the boundary between the first circular plate portion 16A and the pressing portion 16B. The guide groove 16C is annular in a plan view. The annular guide groove 16C circles around the side wall of the pressing portion 16B. The bottom surface of the guide groove 16C is lower than Figure 1 the upper surface of the first circular plate portion 16A in.

[0066] A spiral spring-like spring member 26, which will be described later, is disposed inside the guide groove 16C. The groove width of the guide groove 16C is substantially the same as the width of the spring material of the spring member 26. Figure 1 The lower part of the spring member 26 in contacts the bottom surface of the guide groove 16C. In addition, Figure 1 the upper part of the spring member 26 in contacts the inner surface of the bottom 12A of the housing 12.

[0067] (transmission shaft)

[0068] The transmission shaft 18 is a rod-like member. The transmission shaft 18 extends along the axial direction of the housing 12, that is, along Figure 1extends from the shaft center C therein and transmits the force of a later-described spring member 26 to the valve element 24D. The material of the transmission shaft 18 is resin, metal, etc., and is arbitrary. One end of the transmission shaft 18 is supported by the support member 16. In the present embodiment, one end of the transmission shaft 18 is rotatably supported by the shaft center C by the pressing portion 16B of the support member 16. That is, one end of the transmission shaft 18 is gently fitted inside the cylindrical pressing portion 16B so as to be rotatable. Further, the other end of the transmission shaft 18 ( Figure 1 (the lower end therein) has a hemispherical shape. The other end of the transmission shaft 18 is supported by a later-described drive shaft 22.

[0069] (rotor)

[0070] The rotor 20 has a cylindrical support body 20A, a sun gear 20B, a planetary gear 20C, a fixed gear 20D, and an output gear 20E. The sun gear 20B, the planetary gear 20C, the fixed gear 20D, and the output gear 20E are arranged inside the support body 20A.

[0071] The support body 20A is provided inside the housing 12. A through hole is formed at the center of the bottom of the cylindrical support body 20A, and the transmission shaft 18 is rotatably inserted into the through hole. The sun gear 20B is rotatably mounted on the transmission shaft 18. The planetary gear 20C meshes with the sun gear 20B, and the fixed gear 20D meshes with the planetary gear 20C. The output gear 20E is connected to the planetary gear 20C.

[0072] The sun gear 20B, the planetary gear 20C, the fixed gear 20D, and the output gear 20E integrally formed with the support body 20A constitute a reduction gear 21. The reduction gear 21 of the present embodiment is a reduction gear having a differential planetary gear mechanism that decelerates the rotation of the rotor 20 and outputs it to a later-described drive shaft 22.

[0073] In the reduction gear 21 having a differential planetary gear mechanism, by inputting the output rotation of an unillustrated drive coil from the stator 14, the sun gear 20B rotates self-rotationally. Along with the self-rotational rotation of the sun gear 20B, the planetary gear 20C that meshes with the sun gear 20B and the fixed gear 20D rotates around the sun gear 20B while rotating self-rotationally.

[0074] Further, the planetary gear 20C meshes with the output gear 20E, and the output gear 20E is in a transposed relationship with respect to the fixed gear 20D. Therefore, by the rotation of the planetary gear 20C, the output gear 20E can rotate relative to the fixed gear 20D at a relatively very high reduction ratio, for example, a reduction ratio of about 50 to 1, according to the degree of transposition (that is, the difference in the number of teeth).

[0075] In the present embodiment, the rotor 20 and the support member 16 are separately arranged, so that a gap is formed between the rotor 20 and the support member 16. In addition, since the transmission shaft 18 is rotatably supported by the pressing portion 16B at the shaft center C, even if the transmission shaft 18 rotates in conjunction with the rotation of the rotor 20, the support member 16 does not rotate.

[0076] (Drive shaft)

[0077] The drive shaft 22 is a cylindrical member whose axis is along the shaft center C. The material of the drive shaft 22 can be resin, metal, etc., and is arbitrary. One end of the drive shaft 22 on the side of the transmission shaft 18 ( Figure 1 the upper end in) is connected to the output gear 20E and rotates in conjunction with the output gear 20E. As Figure 1 shown, a support hole 22A is formed at one end of the drive shaft 22. The drive shaft 22 rotationally drives a spool 24D described later. The drive shaft 22 is an example of a shaft body.

[0078] The support hole 22A opens on the side of the transmission shaft 18. In the present embodiment, the shape of the support hole 22A is a hemispherical depression corresponding to the shape (hemispherical) of the other end of the transmission shaft 18.

[0079] The diameter of the support hole 22A is substantially the same as the diameter of the other end of the transmission shaft 18. By inserting the other end of the transmission shaft 18 into the support hole 22A, the transmission shaft 18 is supported to be rotatable. That is, in the rotating state, the drive shaft 22 supports the other end in the axial direction of the transmission shaft 18 on one end side. In the present embodiment, the drive shaft 22 and the spool 24D described later are integrally formed of the same component.

[0080] (Valve body)

[0081] The valve body 24 is configured to accommodate a cylindrical member including a spool inside a bottomed cylindrical member serving as a valve box, and is the main part that functions as a valve in the electric valve 10. Specifically, the valve body 24 has a valve seat 24A, a side wall 24B, a valve chamber 24C, a spool 24D, a flow path 24E, and a pin hole 24F. The valve seat 24A and the side wall 24B are the main parts of the above-mentioned cylindrical member having the valve chamber 24C, the flow path 24E, and the pin hole 24F. That is, the valve seat 24A and the side wall 24B are examples of the housing. The spool 24D of the valve body 24 can rotate inside the cylindrical member. The material of the valve body 24 can be any material as long as it can obtain the desired resistance to the flowing fluid.

[0082] (Valve seat and side wall)

[0083] The valve seat 24A is formed as the bottom of the cylindrical member and is provided on the other end side of the drive shaft 22 along the orthogonal plane to the axis of the drive shaft 22 (Figure 1 The lower side in). A circular first opening 24A1 that communicates the inside and the outside of a valve chamber 24C described later is formed in the valve seat 24A. The first opening 24A1 penetrates the valve seat 24A in the thickness (up and down in the figure) direction. Further, the entire first opening 24A1 is formed so as to be offset from the axis of the drive shaft 22 in the valve seat 24A. The surface on the drive shaft 22 side in the valve seat 24A is an example of a forming surface. One end of a first pipe 30 having a diameter larger than the inner diameter of the first opening 24A1 is inserted into the valve seat 24A. The first opening 24A1 communicates with the inside of the first pipe 30. The material of the first pipe 30 is resin, metal, etc., and is arbitrary.

[0084] The side wall 24B stands up from the peripheral edge of the valve seat 24A and extends toward the rotor 20 side ( Figure 1 The upper side in). The side wall 24B has a second opening 24B1 and a third opening 24B2. One end of a second pipe 32 is inserted into the side wall 24B.

[0085] The second opening 24B1 communicates the inside and the outside of the valve chamber 24C described later. The second opening 24B1 communicates with the inside of the second pipe 32. The material of the second pipe 32 is resin, metal, etc., and is arbitrary. Through the first opening 24A1 and the second opening 24B1, a flow path for a fluid, which is an object of flow control, is formed between the first pipe 30 and the second pipe 32.

[0086] The third opening 24B2 communicates the inside and the outside of the valve body 24 in order to equalize the pressure inside and outside the valve body 24.

[0087] (Hole for pin)

[0088] The pin hole 24F is a hole formed in the upper part of the side wall 24B and opens on the support member 16 side parallel to the axis center C. A pin 62 described later is buried in the pin hole 24F. The pin hole 24F fixes the pin 62. In the present embodiment, two pin holes 24F are formed symmetrically with respect to the axis center C. Further, the pin hole 24F is formed such that a part of the pin 62 is located outside the outer edge of a second disk portion 64 described later.

[0089] (Valve chamber)

[0090] The valve chamber 24C is a space surrounded by the valve seat 24A and the side wall 24B, and is the internal space of the valve body 24 of the cylindrical member. The bottom of the valve chamber 24C is the valve seat 24A. The shape inside the valve chamber 24C changes according to the position of a valve element 24D described later, and allows the fluid to flow through the first pipe 30 and the second pipe 32.

[0091] (Valve element)

[0092] The valve core 24D is cylindrical with a seal 50 and a flow path 24E, and is integrally formed on the other end side of the drive shaft 22 ( Figure 1 the lower side in). The valve core 24D can rotate according to the rotation of the drive shaft 22. By rotating the valve core 24D, the opening and closing state of the flow path between the first opening 24A1 and the second opening 24B1 is controlled. That is, by the rotation of the drive shaft 22 rotating around the axis center C offset from the first opening 24A1, a rotational movement is performed along the upper surface of the valve seat 24A, and thus the first opening 24A1 is opened and closed by the seal 50 as described later.

[0093] Specifically, as shown in Figure 4 (a) of, the valve core 24D of the present embodiment has: a disk-shaped base portion 34; and a facing portion 36 provided on the base portion 34 and having a fan-shaped bottom surface 36B1. The facing portion 36 protrudes from the base portion 34 toward the valve seat 24A side ( Figure 4 the lower side in (a)), and faces the upper surface of the valve seat 24A. The facing portion 36 has: a first adjustment portion 36A mounted on Figure 4 the lower surface of the base portion 34 in (a); and a second adjustment portion 36B mounted on the lower surface of the first adjustment portion 36A.

[0094] As shown in Figure 4 (a) and Figure 4 (b) of, the first adjustment portion 36A is a short column type (block shape) having a substantially semi-circular fan-shaped bottom surface 36A1. More specifically, as shown in Figure 4 (b) of, the central angle of the arc portion of the bottom surface 36A1 of the first adjustment portion 36A with respect to the axis center C of the drive shaft 22 is about 200 degrees. In addition, in the present invention, the central angle of the arc portion of the bottom surface of the first adjustment portion 36A can be appropriately changed.

[0095] In addition, as shown in Figure 4 (a) and Figure 4 (b) of, the second adjustment portion 36B is a short column type (block shape) having a fan-shaped bottom surface 36B1 with a central angle of about 90 degrees. In the present invention, the central angle of the bottom surface 36B1 of the second adjustment portion 36B can be appropriately changed.

[0096] The bottom surface 36B1 of the second adjustment portion 36B faces the first opening 24A1. In Figure 4 (b), for ease of explanation, the outer edge of the first opening 24A1 is shown by a single-dot chain line inside the bottom surface 36B1 of the second adjustment portion 36B. As shown in Figure 4As shown in (b), according to the rotational position of the valve element 24D connected to the drive shaft 22, the area of the first opening 24A1 covered by the bottom surface 36B1 of the second adjustment portion 36B changes. That is, a throttle hole serving as a throttle structure is formed by the first opening 24A1 of the valve seat 24A and the valve element 24D. Therefore, according to the rotation of the valve element 24D, the flow rate of the fluid flowing in the flow path is controlled.

[0097] As Figure 4 As shown in (b), the position of the vertex where the two radius portions intersect in the bottom surface 36B1 of the second adjustment portion 36B is outside the axis center C. That is, the axis center C of the rotation axis of the valve element 24D is located inside the fan-shaped bottom surface 36B1 of the second adjustment portion 36B. In this embodiment, the support shaft portion protruding from the bottom surface 36B1 is supported by a support hole formed in the valve seat 24A so as to be rotatable about the axis center C.

[0098] The side surface 36A2 of the first adjustment portion 36A and the side surface 36B2 of the second adjustment portion 36B face the second opening 24B1.

[0099] In Figure 4 (a), for the sake of easy explanation, the opening range of the second opening 24B1 is illustrated by a two-way arrow extending in the vertical direction. As Figure 4 (a) and Figure 4 (b) shown, by the rotation of the valve element 24D connected to the drive shaft 22, the degree of covering the second opening 24B1 changes.

[0100] Specifically, in a state where the first opening 24A1 is at least partially open, the first opening 24A1 and the second opening 24B1 are at least partially communicated to form a flow path, and in a state where the first opening 24A1 is open, the flow path is opened. On the other hand, in a state where the first opening 24A1 is entirely closed, the flow path is closed. In addition, in this specification, the change from the open state to the closed state is not limited to the change from the fully open state to the fully closed state, but also includes the change from a partially open state to the fully closed state.

[0101] As Figure 1 shown, in the second adjustment portion 36B of the valve element 24D, a cylindrical seal member 50 for improving the sealing performance of the first opening 24A1 is press-fitted from the bottom surface 36B1 side. The seal member 50 has a diameter slightly larger than the inner diameter of the first opening 24A1. The seal member 50 can be made of a known material. For example, the material of the seal member 50 is fluororesin.

[0102] As Figure 1As shown, the flow path 24E is a through hole formed in the valve element 24D along the axial center C with a uniform hole diameter on the side wall 24B side compared to the drive shaft 22, connecting the valve chamber 24C and the third opening 24B2. The flow path 24E equalizes the internal pressure of the valve body 24.

[0103] (Spring member)

[0104] The spring member 26 applies a load toward the valve seat 24A to the valve element 24D along the axial direction of the drive shaft 22. The spring member 26 is an example of a biasing portion. In the present embodiment, the spring member 26 is disposed between the bottom 12A of the housing 12 and the support member 16. The spring member 26 applies an acting force as a load to the valve element 24D via the transmission shaft 18 and the drive shaft 22 supported by the support member 16. In the present embodiment, the spring member 26 is a metal compression coil spring. In the present invention, the shape and material of the spring member 26 can be arbitrarily changed.

[0105] (Conversion mechanism)

[0106] The conversion mechanism 60 has a pin 62 and a second circular plate portion 64. The conversion mechanism 60 converts the rotational motion of the valve element 24D into a linear motion of the valve element 24D. In the present embodiment, it is a mechanism that converts the rotational motion around the axial center C of the drive shaft 22 into a linear motion along the axial center C of the drive shaft 22 in the direction away from the valve seat 24A by the valve element 24D. The conversion mechanism 60 is fixed to the valve body 24. The material of the conversion mechanism 60 is resin, metal, etc., and is arbitrary.

[0107] (Pin)

[0108] The pin 62 is a rod-shaped member and is an example of a convex portion. In the present embodiment, two are symmetrically arranged with respect to the axial center C of the drive shaft 22. The lower part of the pin 62 is buried Figure 1 in the pin hole 24F in the upper part of the side wall 24B of the valve body 24, and the pin 62 is fixed to the valve body 24. In addition, the upper part of the pin 62 is exposed on the upper side of the valve body 24 in Figure 1 . One end of the pin 62 is formed in an arc shape. The material of the pin 62 is, for example, SUS.

[0109] (Second circular plate portion)

[0110] As Figure 2 and Figure 3As shown, the second circular plate portion 64 is a circular plate having a through hole in the center and concavities and convexities on one surface side. The second circular plate portion 64 is an example of a plate portion. The second circular plate portion 64 includes a front (positive) surface 64H having concavities and convexities and a flat back surface 64T. The second circular plate portion 64 is fixed to the drive shaft 22 by a fixing unit (not shown) in a state where the surface 64H faces the pin 62 side and the back surface 64T is along the orthogonal plane with the axis center C, and rotates about the axis center C together with the valve element 24D. In this embodiment, the second circular plate portion 64 has a larger diameter than the valve element 24D (base portion 34) housed in the side wall 24B, and the outer edge side portion covers the pin 62 buried in the upper end of the side wall 24B from above. In addition, in this embodiment, a part of the pin 62 is located at a position outside the outer edge of the second circular plate portion 64. The position where the second circular plate portion 64 contacts the pin 62 changes as the valve element 24D rotates, thereby converting the rotational motion of the valve element 24D into a linear motion. Hereinafter, a more specific description will be given.

[0111] In the second circular plate portion 64, concavo-convex portions are continuously formed from the surface 64H toward the back surface 64T side within a constant range W from the outer edge of the second circular plate portion 64. The concavo-convex portions are sequentially composed of a reference surface 66C, a first inclined surface 66A, a base surface 66B, a second inclined surface 66D, and an adjustment surface 66E in a direction opposite to the rotation direction of the drive shaft 22. In this embodiment, the ranges occupied by the reference surface 66C, the first inclined surface 66A, the base surface 66B, the second inclined surface 66D, and the adjustment surface 66E are semi-circular (180°), and this range constitutes two cycles in the above range W. Here, the rotation direction of the drive shaft 22 refers to the direction that becomes clockwise when observing from the inside near the front in the figure of (b) of Figure 3 and the direction opposite to this rotation direction refers to the direction that becomes counterclockwise when observing from the inside near the front in the figure of (b) of Figure 3 (the direction indicated by the arrow R).

[0112] The reference surface 66C is an arc-shaped flat surface formed parallel to the back surface 64T of the second circular plate portion 64. The reference surface 66C is arranged on the back surface 64T side compared to the surface 64H in the plate thickness direction (H direction) of the second circular plate portion 64. During the period when the reference surface 66C is located on the pin 62, the seal 50 of the valve element 24D described later applies a force to the valve seat 24A.

[0113] The first inclined surface 66A is an arcuate inclined surface that extends from the reference surface 66C and is arranged along the outer edge of the second circular plate portion 64, having a constant slope with respect to the reference surface 66C toward the surface 64H. In the present embodiment, the central angle of the arc of the first inclined surface 66A is about 140°. While the first inclined surface 66A is located on the pin 62, the seal 50 of the valve element 24D receives a force from the conversion mechanism 60 toward the side away from the valve seat 24A. For example, while the middle portion of the first inclined surface 66A is located on the pin, the seal 50 of the valve element 24D moves away from the valve seat 24A.

[0114] The base surface 66B is an arcuate flat surface that extends from the first inclined surface 66A and is arranged along the outer edge of the second circular plate portion 64. While the base surface 66B is located on the pin 62, the seal 50 of the valve element 24D is farthest from the valve seat 24A. The distance between the reference surface 66C and the base surface 66B in the plate thickness direction of the second circular plate portion 64 is, for example, 0.1 mm.

[0115] The second inclined surface 66D is an arcuate inclined surface that extends from the base surface 66B and is arranged along the outer edge of the second circular plate portion 64, having a constant slope toward the reference surface 66C. The direction of the slope of the second inclined surface 66D is opposite to the direction of the slope of the first inclined surface 66A, and the absolute value of the slope of the second inclined surface 66D (the inclination angle with respect to the reference surface) is larger than the absolute value of the slope of the first inclined surface 66A. In the present embodiment, the central angle of the arc of the second inclined surface 66D is about 10°. While the second inclined surface 66D is located on the pin 62, the seal 50 of the valve element 24D is closer to the valve seat 24A than when the seal 50 is located on the base surface 66B.

[0116] The adjustment surface 66E is a step arranged between the second inclined surface 66D and the reference surface 66C. The adjustment surface 66E can also be said to be a wall surface that mainly extends from the second inclined surface 66D and is along the axis center C, and the portion below this wall surface and extending toward the reference surface 66C is chamfered corresponding to the shape of one end of the pin 62.

[0117] Through the reference surface 66C, the first inclined surface 66A, the base surface 66B, the second inclined surface 66D, and the adjustment surface 66E described above, it can be understood that in the second circular plate portion 64, a cam surface that contacts the pin 62 is formed on the surface 64H and on the side of the back surface 64T closer to the surface 64H. This cam surface is pressed against the pin 62 by the acting force of the spring member 26, causing the pin 62 to function as a cam follower. That is, the conversion mechanism 60 has the following structure: the contact positions in the circumferential and axial directions of the surface 64H and the surface on the side of the back surface 64T closer to the surface 64H with respect to the pin 62 change as the valve element 24D rotates, thereby converting the rotational motion of the valve element 24D into a linear motion.

[0118] As shown Figure 5 in (a1) to (f1) of FIG. Figure 5 , in the electric valve 10 of the present embodiment, according to the position of each surface of the second circular plate portion 64 with respect to the pin 62, the opening / closing state of the first opening 24A1 caused by the seal 50 changes. Specifically, when the rotor 20 is rotated by the stator 14, the drive shaft 22, the transmission shaft 18, and the valve element 24D rotate integrally in conjunction with the rotation of the rotor 20. When the valve element 24D rotates, the second circular plate portion 64 rotates relative to the pin 62, and the seal 50 of the valve element 24D opens or closes the first opening 24A1. In addition, for ease of explanation, in FIGS. (a1) to (f1), the operation of one pin 62 is focused on, and the description and illustration of the other pins 62 are omitted.

[0119] In Figure 5 (a1) of FIG. Figure 5 , the reference surface 66C1 of the second circular plate portion 64 is located on the pin 62. The position of the seal 50 corresponding to this position is as shown Figure 5 in (a2) of FIG. Figure 5 , which is a position overlapping the first opening 24A1, and as shown Figure 5 in (a3) of FIG. Figure 5 , which is a position closing the first opening 24A1. That is, the seal 50 is in a state of applying force to the valve seat 24A.

[0120] Figure 5 (b1) of FIG. Figure 5 is a state where the valve element 24D rotates from the state of Figure 5 (a1) of FIG. Figure 5 in the rotation direction of the drive shaft 22. Specifically, in Figure 5 (b1) of FIG. Figure 5 , the boundary between the reference surface 66C1 of the second circular plate portion 64 and the first inclined surface 66A1 is located on the pin 62. As shown Figure 5 in (b2) of FIG. Figure 5 , the position of the seal 50 corresponding to this position is a position offset from the first opening 24A1, opening the first opening 24A1. In this state, the load caused by the spring member 26 of the seal 50, which is accompanied by the contact between the seal 50 and the valve seat 24A, is released. In other words, through the rotational movement of the valve element 24D from Figure 5 (a1) of FIG. Figure 5 to Figure 5 (b1) of FIG. Figure 5 , the valve element 24D starts linear movement along the axis center C.

[0121] Figure 5 (c1) of FIG. Figure 5 is a state where the valve element 24D rotates from the state of Figure 5 (b1) of FIG. Figure 5 in the rotation direction of the drive shaft 22. Specifically, in Figure 5 (c1) of FIG. Figure 5 , the first inclined surface 66A1 of the second circular plate portion 64 is located on the pin 62. As shown Figure 5 in (c2) of FIG. Figure 5 , the position of the seal 50 corresponding to this position is a position separated from the first opening 24A1. And, as shown Figure 5As shown in (c3), the first opening 24A1 is open and the seal 50 is separated from the valve seat 24A. In this state, no load caused by the spring member 26 of the seal 50 due to the contact between the seal 50 and the valve seat 24A is generated. In other words, from Figure 5 of (b1) to Figure 5 of (c1), the rotational movement of the valve element 24D is converted into a linear movement in the direction opposite to the H direction along the axis center C of the valve element 24D to overcome the acting force of the spring member 26.

[0122] Figure 5 In (d1), the valve element 24D rotates in the rotational direction of the drive shaft 22 from the state of Figure 5 of (c1). Specifically, in Figure 5 of (d1), the reference plane 66C2 of the second disc portion 64 is located on the pin 62. As Figure 5 shown in (d2) of, the position of the seal 50 corresponding to this position is a position separated from the first opening 24A1. And, as Figure 5 shown in (d3) of, the seal 50 applies a force to the valve seat 24A on the opposite side of the first opening 24A1 with respect to the axis center C.

[0123] Figure 5 In (e1), the valve element 24D rotates about 150° in the rotational direction of the drive shaft 22 from the state of Figure 5 of (d1). Specifically, in Figure 5 of (e1), the base surface 66B1 of the second disc portion 64 is located on the pin 62. As Figure 5 shown in (e2) of, the position of the seal 50 corresponding to this position is a position where a part overlaps with the first opening 24A1. However, as Figure 5 shown in (e3) of, the seal 50 is in a state of being separated from the valve seat 24A (open state). That is, no load caused by the spring member 26 of the seal 50 due to the contact between the seal 50 and the valve seat 24A is generated.

[0124] Figure 5 In (f1), the valve element 24D rotates in the rotational direction of the drive shaft 22 from the state of Figure 5 of (e1). Specifically, in Figure 5 of (f1), the reference plane 66C1 of the second disc portion 64 is located on the pin 62. More specifically, in a state where the second inclined surface 66D is detached from the pin 62 and the side surface of the pin 62 is along the adjustment surface 66E as a wall surface, the reference plane 66C is located on the pin 62. As Figure 5 shown in (f2) of, the position of the seal 50 corresponding to this position is compared to Figure 5The position where the state of (e2) further overlaps with the first opening 24A1, but the first opening 24A1 is slightly open.

[0125] If the valve core 24D rotates from Figure 5 the state of (f1) in the rotational direction of the drive shaft 22, it returns to Figure 5 the state of (a1).

[0126] As described above, the opening and closing state of the flow path is controlled by the rotation of the valve core 24D. That is, flow rate control is performed.

[0127] <Effect>

[0128] The electric valve 10 of the present embodiment includes: a valve seat 24A having a first opening 24A1; a drive shaft 22 extending in a direction orthogonal to the valve seat 24A and rotating about an axis center offset from the first opening 24A1; a valve core 24D having a seal 50 provided on the drive shaft 22 and rotating along the valve seat 24A by the rotation of the drive shaft 22, thereby opening and closing the first opening 24A1 by the seal 50; a spring member 26 that biases the valve core 24D toward the valve seat 24A; and a conversion mechanism 60 that converts at least the rotational movement of the valve core 24D from the state where the seal 50 closes the first opening 24A1 to the state where the first opening 24A1 is opened into a linear movement of the valve core 24D in which the seal 50 moves toward the side away from the valve seat 24A. In this electric valve 10, if the valve core 24D rotates from the closed state of the first opening 24A1 toward the open side, the conversion mechanism 60 converts the rotational movement of the valve core 24D into a linear movement and the seal 50 acts toward the side away from the valve seat 24A. Accordingly, in the electric valve 10, compared with the structure in which the seal 50 of the valve core 24D always presses against the valve seat 24A, wear of the seal 50 is suppressed.

[0129] In addition, in the electric valve 10 of the present embodiment, the conversion mechanism 60 includes: a pin 62 disposed on the side wall 24B and protruding in a direction away from the valve seat 24A; and a second circular plate portion 64 disposed on the side of the valve element 24D opposite to the pin 62 and having a first inclined surface 66A inclined with respect to the valve seat 24A. The pin 62 moves along the first inclined surface 66A as the drive shaft 22 rotates. In this electric valve 10, due to the acting force of the spring member 26, the pin 62 on the side wall 24B side contacts the valve element 24D side, that is, the second circular plate portion 64. If the first inclined surface 66A moves along the pin 62 by the rotation of the valve element 24D, the rotational motion of the valve element 24D is converted into a linear motion. In this electric valve 10, since the second circular plate portion 64 has the first inclined surface 66A with a complex shape, compared with the structure in which an inclined surface is disposed on the side wall 24B or the base portion 34 of the valve element 24D, the direction of the motion of the valve element 24D is changed with a simple structure.

[0130] In addition, in the electric valve 10 of the present embodiment, when viewed from the direction along the axis center C, both the pin 62 and the first inclined surface 66A of the second circular plate portion 64 are disposed outside the valve element 24D. In this electric valve 10, compared with the structure in which the pin 62 and the first inclined surface 66A of the second circular plate portion 64 are disposed between the axis center C of the drive shaft 22 and the outer edge of the valve element 24D, the seal member 50 moves to the side away from the valve seat 24A with a smaller load.

[0131] In addition, in the electric valve 10 of the present embodiment, the second circular plate portion 64 has a base surface 66B that extends from the first inclined surface 66A in a direction opposite to the rotation direction of the drive shaft 22 and is formed flat. In this electric valve 10, during the period when the base surface 66B passes through the pin 62, the interval between the seal member 50 of the valve element 24D and the valve seat 24A is maintained, so that compared with the structure in which the second circular plate portion 64 only has an inclined surface, the power to overcome the acting force of the spring member 26 is reduced.

[0132] In addition, in the electric valve 10 of the present embodiment, the second disc portion 64 has a reference surface 66C, which is formed by continuing from the base surface 66B in a direction away from the valve seat 24A and in a direction opposite to the rotation direction of the drive shaft 22, and the pin 62 moves along the reference surface when the seal 50 is transferred from the state of opening the first opening 24A1 to the state of closing the first opening 24A1. In the electric valve 10, if the contact surface of the pin 62 in the second disc portion 64 reaches the reference surface 66C from the base surface 66B as the drive shaft 22 rotates, the seal 50 contacts the valve seat 24A. And, if the reference surface 66C moves along the pin 62 as the drive shaft 22 rotates, the seal 50 is transferred from the state of opening the first opening 24A1 to the state of closing the first opening 24A1. Therefore, in the electric valve 10, compared with a structure in which the contact surface of the pin 62 reaches the reference surface 66C from the base surface 66B to close the first opening 24A1 when the seal 50 overlaps the first opening 24A1, the seal 50 is prevented from being broken or damaged by the edge of the first opening 24A1.

[0133] Moreover, in the electric valve 10 of the present embodiment, the conversion mechanism 60 is symmetrically arranged in a pair with respect to the axial center of the drive shaft 22. In the electric valve 10, compared with the case where there is only one conversion mechanism 60, the inclination of the second disc portion 64 in the conversion mechanism 60 when the rotational motion of the valve core 24D is converted into the linear motion of the valve core 24D that causes the seal 50 to move toward the side away from the valve seat 24A is suppressed.

[0134] The present invention has been described through the above disclosed embodiments, but the discussion and drawings constituting a part of the present invention should not be understood as limiting the present invention. Figures 1 to 6 The present invention is constituted by partially combining the structures shown in the above. The present invention includes various embodiments and the like not described above, and the technical scope of the present invention is determined only by the invention specific matters of the appropriate claims from the above description.

[0135] <Modification>

[0136] (Electric valve)

[0137] This modification example is different from the above-mentioned embodiment in that the second disc portion 64 is integrated with the output gear 20E, and the other structures are the same. Figure 6 As shown, in this modification, the surface of the output gear 120E on the valve seat 24A side is formed with projections and depressions. This modification does not add the second disc portion 64 in the above embodiment but changes the shape of the output gear 120E, so the number of components is reduced compared to the structure in which the second disc portion 64 is added.

[0138] In addition, in the above-described embodiment, the drive shaft 22 rotates in a constant rotational direction, but it is not limited thereto. For example, the drive shaft 22 may also be rotated in a direction opposite to this rotational direction. In this case, by bringing the side surface of the pin 62 into contact with the adjustment surface 66E in the second disc portion 64, the initialization operation (home position reset) can be performed.

[0139] (Transfer shaft)

[0140] One end of the transfer shaft 18 is gently fitted inside the cylindrical pressing portion 16B so as to be rotatable, but it is not limited thereto. For example, one end of the transfer shaft 18 may also be fixed inside the cylindrical pressing portion 16B. In addition, although the shape of the other end of the transfer shaft 18 is hemispherical, it is not limited thereto. For example, the other end of the transfer shaft 18 can be appropriately changed to a conical shape that tapers toward the drive shaft 22.

[0141] (Reduction gear)

[0142] The reduction gear 21 is an unusual planetary gear mechanism, but it is not limited thereto. For example, the reduction gear 21 may also be a reduction gear having a gear structure other than the unusual planetary gear mechanism, such as a 2K-H multi-stage reduction gear having two sun gears and one output gear. In addition, in the above-described embodiment, a planetary gear mechanism is used as the rotor 20, but it is not limited thereto. As long as the drive shaft 22 can be rotated, a rotational transmission structure other than the planetary gear mechanism may also be used.

[0143] (Drive shaft)

[0144] In the drive shaft 22, the shape of the support hole 22A is a hemispherical depression corresponding to the shape of the other end of the hemispherical transfer shaft 18, but it is not limited thereto. For example, as long as the shape of the support hole 22A is formed according to the shape of the other end of the transfer shaft 18, it may also be conical or the like. In addition, the drive shaft 22 and the valve element 24D are integrally formed of the same component, but it is not limited thereto. For example, the drive shaft 22 and the valve body 24 may be manufactured as independent components and integrated by connecting them to each other.

[0145] (Valve body)

[0146] Through the first opening 24A1 and the second opening 24B1, a flow path for the fluid, which is the object of flow control, is formed between the first pipe 30 and the second pipe 32, but it is not limited thereto. For example, at least one of the first pipe 30 and the second pipe 32 may also be included in the flow path. In addition, the first opening 24A1 is circular, but it is not limited thereto.

[0147] Moreover, in the present embodiment, the seal member 50 is separated from the valve seat 24A, but is not limited thereto. In a state where the seal member 50 applies a force to the valve seat 24A, the acting force of the spring member 26 is also changed to the extent of elastic deformation of the seal member 50, whereby wear of the seal member 50 is suppressed as compared with a structure in which the acting force does not change.

[0148] (Spring member)

[0149] The spring member 26 is a helical spring made of metal, but is not limited thereto. For example, the spring member 26 may be other spring members such as leaf springs. In addition, the number of turns of the helical spring of the spring member is about several turns, but is not limited thereto. For example, the number of turns can be appropriately set according to the magnitude of the desired load.

[0150] (Conversion mechanism)

[0151] The pin 62 is a rod-shaped member, but is not limited thereto. For example, the pin 62 may also be other columnar members such as an elliptical cylinder or a prism, or other convex members such as a hemisphere, a cone, a pyramid, or a frustum formed integrally or independently on the side wall 24B.

[0152] A reference surface 66C, a first inclined surface 66A, a base surface 66B, a second inclined surface 66D, and an adjustment surface 66E are arranged on the second circular plate portion 64, but are not limited thereto. For example, the second circular plate portion 64 may be provided with only a single first inclined surface 66A.

[0153] In addition, in the second circular plate portion 64, two cycles of the reference surface 66C, the first inclined surface 66A, the base surface 66B, the second inclined surface 66D, and the adjustment surface 66E are arranged in this order in a direction opposite to the rotation direction of the drive shaft 22, but are not limited thereto. For example, in the second circular plate portion 64, these respective surfaces may be arranged in one cycle or three or more cycles.

[0154] In addition, in the second circular plate portion 64, each surface is arranged continuously in a constant range W from the outer edge of the second circular plate portion 64, but is not limited thereto. For example, each surface may be arranged in a constant range from a position away from the axis center C side of the outer edge of the second circular plate portion 64 toward the axis center C, or a chamfered portion may be provided at the outer edge of the second circular plate portion 64, and each surface may be arranged in this portion. In the case of adopting these exemplified structures, the pin 62 is formed at a position corresponding to each surface of the second circular plate portion 64.

[0155] In addition, as a part of the conversion mechanism 60, as long as the rotational movement of the valve element 24D is converted into a linear movement of the valve element 24D together with the pin 62, it is not limited thereto. For example, the second circular plate portion 64 may be an elastic body that is elastically deformed at least in the direction along the axis center C, such as a leaf spring.

[0156] In addition, a plurality of first inclined surfaces 66A are arranged at intervals of 180° within a specified range from the outer edge of the second disc portion, but it is not limited thereto. The first inclined surfaces 66A may also be arranged offset from each other in the radial direction of the second disc portion 64, or a single first inclined surface 66A may be arranged in each of the plurality of second disc portions 64, and they may be stacked axially in a state where the phases of the respective second disc portions 64 are shifted. In the case of adopting these exemplified structures, pins 62 are formed at positions corresponding to the respective surfaces of the second disc portion 64.

[0157] The first inclined surface 66A is an inclined surface having a constant slope, but it is not limited thereto. For example, the first inclined surface 66A may also be an inclined surface whose slope changes each time according to the position.

Claims

1. An electric valve, characterized in that: have: a housing having an opening; An axis body extending in a direction orthogonal to a surface forming the opening and rotating around an axis center offset from the opening; a valve core having a seal and disposed on the shaft body, and rotating along the forming surface by the rotation of the shaft body, thereby opening and closing the opening through the seal; A force applying portion, the force applying portion applying force to the valve core toward the formed surface; as well as A conversion mechanism converts at least the rotational motion of the valve element from a state in which the sealing member closes the opening to a state in which the opening is opened into a linear motion of the valve element that moves the sealing member away from the forming surface.

2. The electric valve according to claim 1, characterized in that: The conversion mechanism has: a convex portion disposed on the housing and protruding in a direction away from a surface on which the opening is formed; and A plate portion is arranged on a side of the valve element opposite to the convex portion and has an inclined surface inclined with respect to a surface forming the opening, wherein the convex portion moves along the inclined surface as the shaft body rotates.

3. The electric valve according to claim 2, characterized in that: When viewed from a direction along the center of the axis, the convex portion and the inclined surface of the plate portion are both arranged outside the valve element.

4. The electric valve according to claim 3, characterized in that: The plate portion has a base surface that is continued from the inclined surface in a direction opposite to a rotation direction of the shaft body and is formed flat.

5. The electric valve according to claim 4, characterized in that: The plate portion has a reference surface that is formed to continue with the base surface in a direction away from the forming surface of the opening compared to the base surface and in a direction opposite to the rotation direction of the shaft body. The protrusion moves along the reference surface when the seal is transferred from a state of opening the opening to a state of closing the opening.

6. The electric valve according to any one of claims 1 to 5, characterized in that: A pair of the conversion mechanisms are arranged symmetrically with respect to the axial center of the shaft body.

Images