Electric valve

Abstract

An electric valve is provided that can adopt a large valve port diameter while ensuring the durability of the electric valve. The electric valve (1) has a valve body (10) having a valve port (14), a valve body (40) facing the valve port (14), a rotor (51) rotatable relative to the valve body (10), and a drive shaft (70) to which the rotation of the rotor (51) is transmitted. When the rotation of the rotor (51) is transmitted to the drive shaft (70), the drive shaft (70) moves downward or upward. When the drive shaft (70) moves downward, it pushes the valve body (40), and when it moves upward, it pulls the valve body (40) and is rotatable relative to the valve body (40).

Description

Technology Field

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

[0002] Patent Document 1 discloses an example of a conventional electric valve. The electric valve disclosed in Patent Document 1 has a valve chamber, a first passage connected to the valve chamber through a valve port, a second passage connected to the valve chamber, and a valve body facing the valve port in an up-and-down direction. The electric valve moves the valve body in an up-and-down direction in response to the rotation of a rotor. The electric valve controls the flow rate of refrigerant flowing from the first passage to the second passage and the flow rate of refrigerant flowing from the second passage to the first passage.

[0003] In an electric valve, the rotation of the rotor is transmitted to the drive shaft. The drive shaft has a male thread. The male thread of the drive shaft is threaded into the female thread of the guide member. When the rotor rotates in one direction, the drive shaft rotates, and the drive shaft moves downward by the action of the screw. The valve body is pushed downward by the drive shaft, and the valve body closes the valve opening. When the rotor rotates in the other direction, the drive shaft rotates, and the drive shaft moves upward by the action of the screw. The valve body is pushed upward by the valve opening spring, and the valve body opens the valve opening. Prior art literature

[0004] Japanese Publication No. 2018-135908 The problem to be solved

[0005] In the above-described electric valve, when the refrigerant pressure in the first passage is higher than the refrigerant pressure in the second passage, an upward force is applied to the valve body. Then, against the upward force and the upward pushing force of the valve opening spring, the drive shaft pushes the valve body downward, thereby closing the valve opening. Additionally, when the refrigerant pressure in the second passage is higher than the refrigerant pressure in the first passage, a downward force is applied to the valve body. Then, against the downward force, the valve opening spring pushes the valve body upward, thereby opening the valve opening.

[0006] To increase the flow rate of the refrigerant flowing through the electric valve, it is effective to increase the diameter of the valve opening. However, increasing the valve opening diameter increases the aforementioned downward force, so it is necessary to increase the force with which the valve opening spring pushes the valve body upward (hereinafter referred to as "spring force"). Furthermore, increasing the valve opening diameter also increases the aforementioned upward force, so it is necessary to increase the force with which the drive shaft pushes the valve body downward to counteract the upward force and spring force. Consequently, the force applied to parts such as the drive shaft increases, accelerating wear on the parts and lowering the durability of the electric valve.

[0007] In the above-described electric valve, by fixing the valve body to the drive shaft, the drive shaft can pull the valve body upward when opening the valve port. As a result, in the electric valve, it is not necessary to increase the spring force even if the diameter of the valve port is increased, and wear on the parts can be suppressed. However, if the valve body is fixed to the drive shaft, the valve body rotates together with the drive shaft, causing the valve body to rub against the valve seat surrounding the valve port in the rotational direction. Consequently, wear on the valve body and the valve seat is accelerated, and the durability of the electric valve is reduced.

[0008] Therefore, the present invention aims to provide an electric valve capable of employing a large valve port diameter while ensuring durability. means of solving the problem

[0009] To achieve the above objective, the electric valve according to the present invention comprises a valve body having a valve opening, a valve body facing the valve opening, a rotor rotatable relative to the valve body, and a drive shaft to which the rotation of the rotor is transmitted, wherein when the rotation of the rotor is transmitted to the drive shaft, the drive shaft moves in a direction toward the valve opening or in a direction away from the valve opening, and when the drive shaft moves in a direction toward the valve opening, it pushes the valve body, and when it moves in a direction away from the valve opening, it pulls the valve body, and is rotatable relative to the valve body.

[0010] In the present invention, it is preferable to have a connecting member attached to the valve body, wherein one side of the drive shaft and the connecting member has a projection, and the other side of the drive shaft and the connecting member has a projection receiving part on which the projection is caught when the drive shaft moves away from the valve opening.

[0011] In the present invention, it is preferable that the projection is rotatably engaged with the projection receiving portion relative to the projection receiving portion.

[0012] In the present invention, it is preferable that the connecting member is attached to the valve body so that the valve body can rotate relative to the connecting member.

[0013] In the present invention, it is preferable that the connecting member has a flat base attached to the valve body, a plurality of elastic pieces extending from the periphery of the base toward the drive shaft and capable of elastic deformation in a direction away from the center of the base, and the plurality of elastic pieces have a projection portion protruding toward the center of the base, the projection receiving portion is disposed at one end of the drive shaft, and the one end of the drive shaft is surrounded by the plurality of elastic pieces.

[0014] In the present invention, it is preferable to have a connecting member attached to the drive shaft, wherein one side of the valve body and the connecting member has a projection, and the other side of the valve body and the connecting member has a projection receiving part that catches the projection when the connecting member moves together with the drive shaft in a direction away from the valve opening. Effects of the invention

[0015] According to the present invention, when the rotation of a rotor is transmitted to a drive shaft, the drive shaft rotates and moves in a direction toward the valve opening or away from the valve opening. Then, when the drive shaft moves in a direction toward the valve opening, it pushes the valve body, and when it moves in a direction away from the valve opening, it pulls the valve body and is rotatable relative to the valve body. By doing so, since the drive shaft pulls the valve body in a direction away from the valve opening, the valve opening can be opened without relying on a valve opening spring that pushes the valve body away from the valve opening. Furthermore, since the drive shaft is rotatable relative to the valve body, when the valve body comes into contact with the valve seat surrounding the valve opening, the drive shaft rotates relative to the valve body, thereby preventing the valve body and the valve seat from rubbing against each other. Therefore, a large valve opening diameter can be adopted while ensuring the durability of the electric valve. Brief explanation of the drawing

[0016] FIG. 1 is a cross-sectional view of an electric valve according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a part of the electric valve of FIG. 1. FIG. 3 is a six-sided view of a connecting member having the electric valve of FIG. 1. FIG. 4 is a diagram illustrating the force applied to the valve body of a conventional electric valve (rectified state). FIG. 5 is a diagram illustrating the force applied to the valve body of a conventional electric valve (reverse flow state). FIG. 6 is a diagram illustrating the force applied to the valve body of the electric valve of FIG. 1 (rectified state). FIG. 7 is a diagram illustrating the force applied to the valve body of the electric valve of FIG. 1 (reverse flow state). FIG. 8 is an enlarged cross-sectional view of a portion of an electric valve according to a second embodiment of the present invention. FIG. 9 is a six-sided view of the connecting member of the electric valve of FIG. 8. Specific details for implementing the invention

[0017] (First embodiment)

[0018] Hereinafter, an electric valve (1) according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The electric valve (1) according to the present embodiment is used, for example, to control the flow rate of a refrigerant in a refrigeration cycle of an air conditioner.

[0019] FIG. 1 is a cross-sectional view of an electric valve according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a part of the electric valve of FIG. 1 (mainly the valve, connecting member, and driving mechanism). In FIG. 2, the description of the stator unit is omitted. FIG. 3 is a six-sided view of the connecting member of the electric valve of FIG. 1. In FIG. 3, the upper drawing is a top view, the lower drawing is a bottom view, and the drawing between the upper drawing and the lower drawing is a front view. In FIG. 3, the left drawing is a left side view, the right drawing is a rear view, and the drawing next to the right drawing is a right side view.

[0020] As illustrated in FIGS. 1 and 2, the electric valve (1) according to the present embodiment has a valve body (10), a holder (20), a valve body support member (25), a can (30), a valve body (40), a connecting member (45), a driving mechanism (50), and a stator unit (80).

[0021] The valve body (10) has a rectangular shape. The valve body (10) has a valve chamber (13) and a valve port (14) connected to the valve chamber (13). The valve port (14) is surrounded by a valve seat (15). The valve body (10) has a first passage (17) and a second passage (18). One end of the first passage (17) is connected to the valve chamber (13) through the valve port (14), and the other end of the first passage (17) is open on the right side (10a) of the valve body (10). One end of the second passage (18) is connected to the valve chamber (13), and the other end of the second passage (18) is open on the left side (10b) of the valve body (10). The valve body (10) has an attachment hole (19). The attachment hole (19) is opened on the upper surface (10c) of the valve body (10). A female screw is formed on the inner surface of the attachment hole (19). A valve chamber (13) is opened on the lower surface (19a) of the attachment hole (19).

[0022] The holder (20) has a cylindrical shape. A male screw is formed on the lower part of the outer surface of the holder (20). The male screw of the holder (20) is screwed into the female screw of the attachment hole (19) of the valve body (10). The holder (20) is attached to the valve body (10) by a screw structure.

[0023] The valve body support member (25) has a cylindrical shape. The valve body support member (25) is positioned between the valve body (10) and the holder (20) inside the attachment hole (19). The lower part of the valve body support member (25) is pressed into the valve chamber (13). On the outer surface of the valve body support member (25), an annular plane (25a) facing downward is formed. The annular plane (25a) is in contact with the bottom surface (19a) of the attachment hole (19). The valve body support member (25) supports the valve body (40) so that it can move in the vertical direction (axis (L) direction).

[0024] The can (30) has a cylindrical shape. The can (30) has a closed upper end and an open lower end. The lower end of the can (30) is joined to the outer circumference of a toroidal joining member (35). The upper end (20a) of the holder (20) is positioned on the inner side of the joining member (35). The inner circumference of the joining member (35) is joined to the holder (20). The can (30) is fixed to the valve body (10) through the joining member (35) and the holder (20).

[0025] The valve body (40) has a stem (41), a valve section (42), and a ball receiving section (43). The stem (41) has a cylindrical shape. The stem (41) is positioned inside the valve body support member (25). The stem (41) is supported by the valve body support member (25) so as to be movable in the vertical direction. The valve section (42) is connected to the lower end of the stem (41). The valve section (42) has a toroidal shape. The valve section (42) protrudes outward in the radial direction from the outer surface of the stem (41). The valve section (42) faces the valve opening (14) in the vertical direction. The ball receiving section (43) has a circular flat section (43a) and a convex section (43b) connected to the lower surface of the flat section (43a). A conical concave portion is formed on the upper surface of the flat portion (43a). The convex portion (43b) is fitted into a hole (41b) provided on the upper surface (41a) of the stem (41). The convex portion (43b) is fixed to the stem (41). The valve body (40) changes the opening area of ​​the valve port (14) steplessly (substantially including stepless) as the valve portion (42) moves back and forth relative to the valve port (14). The minimum area of ​​the valve body (40) is 0 (i.e., the valve port (14) is closed). The minimum area of ​​the valve port (14) may be greater than 0 (i.e., the valve port (14) is slightly open).

[0026] As illustrated in FIG. 3, the connecting member (45) has a base (46) and a plurality of elastic pieces (47). The base (46) has a circular shape. In this embodiment, the connecting member (45) has three elastic pieces (47) arranged at equal intervals along the circumference of the base (46). Each elastic piece (47) extends upward from the periphery of the base (46). Each elastic piece (47) has a main body (48) and a protrusion (49). The main body (48) has a rectangular rim shape. The main body (48) is perpendicular to the base (46). The lower edge of the main body (48) extends to the periphery of the base (46). The protrusion (49) has a thin plate shape extending downward from the upper edge of the main body (48). The protrusion (49) is bent into an S-shape. The lower end of the protrusion (49) protrudes toward the center of the base (46) relative to the main body (48). The shape of the connecting member (45) has rotational symmetry in which the axis of symmetry passes through the center of the base (46). The connecting member (45) is formed by press-forming a metal plate.

[0027] The connecting member (45) is attached to the valve body (40). Specifically, the lower surface of the base (46) of the connecting member (45) is in contact with the upper surface (41a) of the stem (41), and the convex portion (43b) of the ball receiving portion (43) is inserted into the through hole (46a) in the center of the base (46). The base (46) is maintained between the upper surface (41a) of the stem (41) and the flat portion (43a) of the ball receiving portion (43). The ball receiving portion (43) is also a member for attaching the connecting member (45) to the valve body (40). The connecting member (45) may be bonded to the valve body (40) by means of an adhesive or the like.

[0028] The driving mechanism (50) moves the valve body (40) in the up and down direction. The driving mechanism (50) has a rotor (51), a permanent magnet (55), a planetary gear mechanism (60), a guide member (68), a driving shaft (70), a ball (76), and a valve opening spring (77).

[0029] The rotor (51) has a cylindrical shape. The outer diameter of the rotor (51) is smaller than the inner diameter of the can (30). The rotor (51) is rotatably positioned inside the can (30). A circular connecting plate (52) is attached to the upper end of the rotor (51). The connecting plate (52) blocks the upper end of the rotor (51). A rotor shaft (53) passes through the center of the connecting plate (52). The rotor (51) is connected to the rotor shaft (53) through the connecting plate (52). The rotor shaft (53) rotates together with the rotor (51).

[0030] The rotor (51) has multiple N poles and multiple S poles. The multiple N poles and multiple S poles are arranged in a vertical direction. The multiple N poles and multiple S poles are arranged alternately in a circumferential direction on the outer surface of the rotor (51).

[0031] A permanent magnet (55) is positioned above the rotor (51) on the inside of the can (30). The permanent magnet (55) has a disc shape. The permanent magnet (55) is fixed to the upper end of the rotor shaft (53). The permanent magnet (55) is positioned coaxially with the rotor (51) and rotates together with the rotor (51). Between the rotor (51) and the permanent magnet (55), a disc-shaped magnetic shielding member (56) is positioned. The magnetic shielding member (56) is a soft magnetic material with relatively high permeability, such as silicon iron. The magnetic shielding member (56) is fixed to the rotor shaft (53). The magnetic shielding member (56) absorbs the magnetic flux created by the rotor (51). The magnetic shielding member (56) prevents the magnetic field created by the permanent magnet (55) from being distorted by the magnetic field created by the rotor (51).

[0032] The permanent magnet (55) has one N pole and one S pole. One N pole is placed in one part of the permanent magnet (55) divided by its diameter, and one S pole is placed in the other part.

[0033] The planetary gear mechanism (60) is positioned inside the rotor (51). The planetary gear mechanism (60) has a gear case (61), a fixed ring gear (62), a sun gear (63), a plurality of planetary gears (64), a carrier (65), an output gear (66), and an output shaft (67). The gear case (61) has a cylindrical shape. The lower end of the gear case (61) is coaxially joined to the upper end (20a) of the holder (20). The fixed ring gear (62) is an internal gear. The fixed ring gear (62) is fixed to the upper end of the gear case (61). The sun gear (63) is positioned coaxially with the connecting plate (52). The sun gear (63) is integrated with the connecting plate (52). The rotor shaft (53) passes through the sun gear (63). The solar gear (63) rotates together with the rotor (51) and the connecting plate (52). A plurality of planetary gears (64) are positioned between the fixed ring gear (62) and the solar gear (63). The carrier (65) has a disc shape. The rotor shaft (53) passes through the center of the carrier (65). The carrier (65) is rotatable around the rotor shaft (53). The carrier (65) rotatably supports a plurality of planetary gears (64). The output gear (66) has a cylindrical shape with a bottom. The output gear (66) is an internal gear. A plurality of planetary gears (64) are positioned between the output gear (66) and the solar gear (63). The output shaft (67) has a cylindrical shape. The upper part of the output shaft (67) is pressed into a hole formed at the bottom of the output gear (66). A slit (67a) extending in the vertical direction is formed at the lower part of the output shaft (67). The rotation of the solar gear (63) is reduced by the fixed ring gear (62), a plurality of planetary gears (64), a carrier (65), and the output gear (66), and is transmitted to the output shaft (67).

[0034] The guide member (68) has a cylindrical shape. The guide member (68) is positioned on the inner side of the upper part (20a) of the holder (20). A female screw (68c) is formed on the lower part of the inner circumference of the guide member (68). An output shaft (67) is positioned on the inner side of the guide member (68). The guide member (68) rotatably supports the output shaft (67).

[0035] The drive shaft (70) is formed, for example, by cutting a cylindrical metal rod. The drive shaft (70) has a first part (71), a second part (72), a third part (73), and a protrusion support part (74).

[0036] The first part (71) has a rectangular flat plate shape. The thickness of the first part (71) is slightly smaller than the width of the slit (67a) of the output shaft (67). The first part (71) is positioned so as to be movable in the vertical direction on the inner side of the slit (67a) of the output shaft (67). By means of the slit (67a) and the first part (71), the rotation of the output shaft (67) is transmitted to the drive shaft (70), and the vertical movement of the drive shaft (70) relative to the output shaft (67) is made possible.

[0037] The second part (72) has a cylindrical shape. The second part (72) is connected to the lower end of the first part (71). A male screw (72c) is formed on the outer surface of the second part (72). The male screw (72c) is engaged with the female screw (68c) of the guide member (68). Additionally, the guide member (68) may have a male screw and the drive shaft (70) may have a female screw.

[0038] The third part (73) has a disc shape. The third part (73) is connected coaxially to the lower end of the second part (72). The outer diameter of the third part (73) is larger than the outer diameter of the second part (72). On the lower surface of the third part (73), a conical concave portion is formed, and a ball (76) is attached to the concave portion. The ball (76) contacts the concave portion of the flat plate (43a) of the ball receiving portion (43).

[0039] The projection receiving portion (74) has a circular shape. The projection receiving portion (74) protrudes outward in the radial direction from the outer surface of the third portion (73). The outer diameter of the projection receiving portion (74) is smaller than the circle (C1) inscribed in each elastic piece (47) of the connecting member (45) and larger than the circle (C2) inscribed in each projection portion (49) of the connecting member (45) (Fig. 3). The third portion (73) and the projection receiving portion (74) are the end portion (one end portion) on the valve body (40) side of the drive shaft (70). The third portion (73) and the projection receiving portion (74) are arranged inside the plurality of elastic pieces (47) of the connecting member (45) and are surrounded by the plurality of elastic pieces (47). The third part (73) and the base (46) of the connecting member (45) face each other with a gap in the vertical direction. The projection support part (74) is located below each projection part (49) of the plurality of elastic pieces (47), and each projection part (49) is hooked onto the projection support part (74). Specifically, when viewed from above, each projection part (49) and the projection support part (74) overlap, and the lower end of each projection part (49) is lightly in contact with the projection support part (74) in the vertical direction, or is arranged with a slight gap in the vertical direction. As a result, each projection part (49) is hooked onto the projection support part (74) so ​​as to be rotatable relative to the projection support part (74). Accordingly, when the drive shaft (70) moves upward, the protrusion (49) is caught on the protrusion receiving part (74), and the drive shaft (70) becomes rotatable around the axis (L) relative to the connecting member (45).

[0040] The valve opening spring (77) is positioned between the valve body support member (25) and the base (46) of the connecting member (45). The valve opening spring (77) is a compression coil spring. The valve opening spring (77) pushes the valve body (40) upward through the connecting member (45). Additionally, in the electric valve (1), the valve opening spring (77) may be omitted.

[0041] The stator unit (80) has a case (81), a stator (82), and a substrate (83). The case (81) is made of synthetic resin. The case (81) has a box shape. The case (81) accommodates the stator (82) and the substrate (83). The stator (82) and the substrate (83) are screw-fastened to the case (81). The stator (82) has a cylindrical shape. A can (30) is placed inside the stator (82). The stator (82) together with the rotor (51) constitutes a stepping motor.

[0042] An electronic component including an angle sensor (84) is mounted on the substrate (83). The angle sensor (84) is a magnetic angle sensor. The angle sensor (84) is mounted on the lower surface of the substrate (83). The angle sensor (84) is positioned above the can (30). The angle sensor (84) faces the permanent magnet (55) in an up-and-down direction through the can (30). The angle sensor (84) detects the direction and magnitude of the magnetic field passing through the angle sensor (84). Based on the electrical signal output by the angle sensor (84), the rotation angle of the permanent magnet (55) can be obtained.

[0043] In the electric valve (1), the valve port (14), holder (20), valve body support member (25), can (30), valve body (40), connecting member (45) (base (46)), rotor (51), connecting plate (52), rotor shaft (53), permanent magnet (55), output shaft (67), guide member (68), drive shaft (70), and stator (82) each have their center axes aligned with the axis line (L).

[0044] Next, the basic operation of the electric valve (1) will be explained.

[0045] In the electric valve (1), current is passed through the stator (82) to rotate the rotor (51) in one direction. The rotation of the rotor (51) is transmitted to the drive shaft (70) through the planetary gear mechanism (60). When the drive shaft (70) rotates, the drive shaft (70) moves downward due to the screw-feed action between the drive shaft (70) and the guide member (68). The valve body (40) is pushed downward by the drive shaft (70), and as the valve body (40) moves downward, the opening area of ​​the valve port (14) becomes smaller. The electric valve (1) becomes a closed valve state when the valve body (40) comes into contact with the valve seat (15) and the valve port (14) is closed.

[0046] In the electric valve (1), current is passed through the stator (82) to rotate the rotor (51) in the opposite direction. The rotation of the rotor (51) is transmitted to the drive shaft (70) through the planetary gear mechanism (60). When the drive shaft (70) rotates, the drive shaft (70) moves upward due to the screw-feed action between the drive shaft (70) and the guide member (68). The valve body (40) is pushed upward by the valve opening spring (77), and as the valve body (40) moves upward, the opening area of ​​the valve port (14) increases. In addition, if the valve body (40) does not move upward by the force of the valve opening spring (77) alone, when the drive shaft (70) moves upward, the protrusion (49) catches on the protrusion receiving part (74), and the connecting member (45) and the valve body (40) are pulled upward. The electric valve (1) becomes open when the valve body (40) separates from the valve seat and the valve port (14) opens. The electric valve (1) becomes fully open when the valve body (40) is furthest from the valve port (14).

[0047] A method of connecting the valve body (40) and the drive shaft (70) is described. First, the base (46) of the connecting member (45) is placed on the upper surface (41a) of the stem (41) of the valve body (40). The convex portion (43b) of the ball receiving portion (43) is passed through the through hole (46a) of the base (46) and fitted into the hole (41b) of the valve body (40) to attach the connecting member (45) to the valve body (40). One end of the drive shaft (70) (the third part (73) and the protrusion receiving portion (74)) is inserted into the inner side of the plurality of elastic pieces (47) of the connecting member (45), and the protrusion receiving portion (74) is brought into contact with each of the protrusion portions (49) of the plurality of elastic pieces (47). When the insertion of one end of the drive shaft (70) proceeds, the protrusion (49) is pushed against the protrusion receiving part (74), causing the elastic piece (47) to elastically deform in a direction away from the center of the base (46), and when the protrusion receiving part (74) moves over the protrusion (49), the plurality of elastic pieces (47) are restored. As a result, the ball (76) attached to the drive shaft (70) comes into contact with the ball receiving part (43), and the protrusion (49) of each of the plurality of elastic pieces (47) is caught on the protrusion receiving part (74), thereby connecting the valve body (40) and the drive shaft (70) by the connecting member (45). In addition, during the assembly process of the electric valve (1), the stepping motor may be operated to move the drive shaft (70) toward the valve body (40) by means of screw conveying action, thereby allowing one end of the drive shaft (70) to be inserted into the inner side of a plurality of elastic pieces of the connecting member (45).

[0048] Next, with reference to FIGS. 4 to 7, the operation of a conventional electric valve (901) and the operation of an electric valve (1) will be explained.

[0049] FIGS. 4 and 5 are drawings illustrating the force applied to the valve body of a conventional electric valve. FIGS. 6 and 7 are drawings illustrating the force applied to the valve body of the electric valve of FIG. 1. FIGS. 4 and 6 illustrate a rectified state in which refrigerant flows from a first passage to a second passage. In the rectified state, the refrigerant pressure (P1) in the first passage is higher than the refrigerant pressure (P2) in the second passage. FIGS. 5 and 7 illustrate a reversed state in which refrigerant flows from a second passage to a first passage. In the reversed state, the refrigerant pressure (P2) in the second passage is higher than the refrigerant pressure (P1) in the first passage. FIGS. 4A, 5A, 6A, and 7A illustrate the aspect in which the drive shaft pushes the valve body downward. FIGS. 4B, 5B, 6B, and 7B illustrate the aspect in which the drive shaft stops moving. FIG. 7C illustrates the upward movement of the drive shaft. FIGS. 4 to 7 schematically illustrate each component. FIGS. 4 to 7 schematically illustrate the flow of the refrigerant with thin arrows.

[0050] FIG. 4A illustrates an electric valve (901) in a rectified state, and a drive shaft (970) pushes the valve body (940) downward with a force (Fc) through a ball (976). On the valve body (940), a valve opening spring (977) pushes the valve body (940) upward with a force (Fs) and an upward force (Fr) is applied by the refrigerant. In the rectified state, the magnitude of the force (Fr) is the value obtained by multiplying the differential pressure between the refrigerant pressure (P1) of the first passage (917) and the refrigerant pressure (P2) of the second passage (918) by the passage area (S) of the valve port (914) (Fr = (P1 - P2) × S). Therefore, if the following equation (1) holds, the valve body (940) can be moved downward in the electric valve (901) to close the valve opening (914). In addition, in each of the following equations, Fc, Fs, and Fr represent the magnitude of the force. On the left side of each equation, a positive sign (+) or no sign indicates a downward force, and a negative sign (-) indicates an upward force. On the right side of each equation, a positive sign (+) or no sign indicates an upward force, and a negative sign (-) indicates a downward force.

[0051] Fc>Fs+Fr … (1)

[0052] FIG. 4B illustrates an electric valve (901) in a rectified state, with the drive shaft (970) stopped moving. On the valve body (940), a force (Fs) that pushes the valve body (940) upward by the valve opening spring (977) and an upward force (Fr) by the refrigerant are applied. Since the force (Fs) and the force (Fr) are both upward forces, the following equation (2) holds true. Therefore, when the drive shaft (970) stops moving in the electric valve (901), the drive shaft (970) receives the combined force of the force (Fs) and the force (Fr), and when the drive shaft (970) moves upward, the valve body (940) moves upward by the said force and can open the valve opening (914).

[0053] 0 <Fs+Fr …(2)

[0054] FIG. 5A illustrates an electric valve (901) in a reverse flow state, and a drive shaft (970) pushes the valve body (940) downward with a force (Fc) through a ball (976). On the valve body (940), a valve opening spring (977) pushes the valve body (940) upward with a force (Fs) and a downward force (Fr) is applied by the refrigerant. In the reverse flow state, the magnitude of the force (Fr) is the value obtained by multiplying the differential pressure between the refrigerant pressure (P2) of the second passage (918) and the refrigerant pressure (P1) of the first passage (917) by the passage area (S) of the valve port (914) (Fr = (P2 - P1) × S). Therefore, if the following equation (3) holds, the valve body (940) can be moved downward in the electric valve (901) to close the valve port (914).

[0055] Fc>Fs-Fr … (3)

[0056] FIG. 5B illustrates an electric valve (901) in a reverse flow state, with the drive shaft (970) stopped moving. On the valve body (940), a force (Fs) that pushes the valve body (940) upward by the valve opening spring (977) and a downward force (Fr) by the refrigerant are applied. Therefore, when the following equation (4) is satisfied in the electric valve (901), when the drive shaft (970) stops moving, the drive shaft (970) receives a force obtained by subtracting the force (Fr) from the force (Fs), and when the drive shaft (970) moves upward, the valve body (940) moves upward by the said force and can open the valve opening (914).

[0057] 0 <Fs-Fr …(4)

[0058] In the electric valve (901) in a reverse flow state, as indicated by Equation (4), when the force (Fs) of the valve opening spring (977) pushing the valve body (940) upward is greater than the downward force (Fr) caused by the refrigerant, the valve body (940) can be moved upward by the valve opening spring (977). And, since the force (Fr) is proportional to the passage area (S) of the valve opening (914), if the diameter of the valve opening (914) is increased, a valve opening spring (977) capable of applying a force (Fs) greater than the force (Fr) to the valve body (940) is required. Furthermore, as the force (Fs) increases, the force (Fc) of the drive shaft (970) pushing the valve body (940) downward also needs to be increased. Therefore, the force applied to each part increases.

[0059] FIG. 6A illustrates an electric valve (1) in a rectified state, and a drive shaft (70) pushes the valve body (40) downward with a force (Fc) through a ball (76). On the valve body (40), a valve opening spring (77) pushes the valve body (40) upward with a force (Fs) and an upward force (Fr) is applied by the refrigerant. In the rectified state, the magnitude of the force (Fr) is the value obtained by multiplying the differential pressure between the refrigerant pressure (P1) of the first passage (17) and the refrigerant pressure (P2) of the second passage (18) by the passage area (S) of the valve port (14) (Fr = (P1 - P2) × S). Therefore, when the above equation (1) is satisfied, the valve body (40) can be moved downward in the electric valve (1) to close the valve port (14).

[0060] FIG. 6B illustrates an electric valve (1) in a stationary state, with the drive shaft (70) stopped moving. On the valve body (40), a force (Fs) that pushes the valve body (40) upward by the valve opening spring (77) and an upward force (Fr) by the refrigerant are applied. Since the force (Fs) and the force (Fr) are both upward forces, the above equation (2) holds true. Therefore, when the drive shaft (70) stops moving in the electric valve (1), the drive shaft (70) receives the combined force of the force (Fs) and the force (Fr), and when the drive shaft (70) moves upward, the valve body (40) moves upward by the said force and can open the valve opening (14).

[0061] FIG. 7A illustrates an electric valve (1) in a reverse flow state, and a drive shaft (70) pushes the valve body (40) downward with a force (Fc) through a ball (76). On the valve body (40), a valve opening spring (77) pushes the valve body (40) upward with a force (Fs) and a downward force (Fr) is applied by the refrigerant. In the reverse flow state, the magnitude of the force (Fr) is the value obtained by multiplying the differential pressure between the refrigerant pressure (P2) of the second passage (18) and the refrigerant pressure (P1) of the first passage (17) by the passage area (S) of the valve port (14) (Fr = (P2 - P1) × S). Therefore, when the above equation (3) is satisfied, the valve body (40) can be moved downward in the electric valve (1) to close the valve port (14).

[0062] FIG. 7B illustrates an electric valve (1) in a reverse flow state, with the drive shaft (70) stopped moving. On the valve body (40), a force (Fs) that pushes the valve body (40) upward by the valve opening spring (77) and a downward force (Fr) by the refrigerant are applied. Therefore, when the above equation (4) is satisfied in the electric valve (1), when the drive shaft (70) stops moving, the drive shaft (70) receives a force that subtracts the force (Fr) from the force (Fs), and when the drive shaft (70) moves upward, the valve body (40) moves upward by the said force and can open the valve opening (14).

[0063] In the electric valve (1) in a reverse flow state, even if the above equation (4) is not satisfied, as shown in FIG. 7C, when the drive shaft (70) moves upward, the protrusion (49) is caught on the protrusion receiving part (74). By this, a force (Fc) is applied to the connecting member (45) and the valve body (40) by pulling the drive shaft (70) upward. Therefore, when the following equation (5) is satisfied, when the drive shaft (70) moves upward, the valve body (40) can be moved upward to open the valve opening (14). Therefore, in the electric valve (1), even when the diameter of the valve opening (14) is increased, the valve opening (14) can be opened by increasing the force (Fc), and there is no need to increase the force (Fs) of the valve opening spring (77) pushing the valve body (40) upward.

[0064] 0 <Fs-Fr+Fc …(5)

[0065] As described above, the electric valve (1) has a valve body (10) having a valve opening (14), a valve body (40) facing the valve opening (14), a rotor (51) rotatable relative to the valve body (10), and a drive shaft (70) to which the rotation of the rotor (51) is transmitted. When the rotation of the rotor (51) is transmitted to the drive shaft (70), the drive shaft (70) moves downward (in a direction closer to the valve opening (14)) or upward (in a direction away from the valve opening (14). When the drive shaft (70) moves downward, it pushes the valve body (40), and when it moves upward, it pulls the valve body (40), and is rotatable relative to the valve body (40). By doing so, the drive shaft (70) pulls the valve body (40) upward, so the valve opening (14) can be opened without relying on the valve opening spring (77). In addition, since the drive shaft (70) is rotatable relative to the valve body (40), when the valve body (40) comes into contact with the valve seat (15), the drive shaft (70) rotates relative to the valve body (40), thereby preventing the valve body (40) and the valve seat (15) from rubbing against each other. Therefore, the diameter of the valve port (14) can be increased while ensuring the durability of the electric valve (1).

[0066] Additionally, the electric valve (1) has a connecting member (45) attached to the valve body (40). The connecting member (45) has a plurality of protrusions (49). The drive shaft (70) has a protrusion receiving part (74) on which the plurality of protrusions (49) are engaged when the drive shaft (70) moves upward. Then, the protrusions (49) are engaged with the protrusion receiving part (74) so ​​as to be rotatable relative to the protrusion receiving part (74). By doing so, the valve body (40) and the drive shaft (70) can be connected in a relatively simple manner, such that when the drive shaft (70) moves downward, the valve body (40) is pushed, and when it moves upward, the valve body (40) is pulled, and the valve body (40) is rotatable relative to the valve body (40). Additionally, the connecting member (45) may be attached to the valve body (40) so that the valve body (40) can rotate relative to the connecting member (45). In this case, for example, the gap between the upper surface (41a) of the stem (41) of the valve body (40) and the flat plate portion (43a) of the ball receiving portion (43) is made slightly larger than the thickness of the base (46) of the connecting member (45).

[0067] Additionally, the connecting member (45) has a flat base (46) attached to the valve body (40), and a plurality of elastic pieces (47) that extend from the periphery of the base (46) toward the drive shaft (70) and are elastically deformable in a direction away from the center of the base (46). Each elastic piece (47) has a projection (49) that protrudes toward the center of the base (46). A projection receiving part (74) is positioned at the end (one end) of the drive shaft (70) toward the valve body (40). The one end of the drive shaft (70) is surrounded by a plurality of elastic pieces (47). By doing this, the plurality of elastic pieces (47) are elastically deformed in a direction away from the center of the base (46), and one end of the drive shaft (70) (third part (73) and protrusion receiving part (74)) is placed inside the plurality of elastic pieces (47), and the plurality of elastic pieces (47) are restored so that the protrusion (49) can be placed over the protrusion receiving part (74). Therefore, the valve body (40) and the drive shaft (70) can be connected by a connecting member (45) with a relatively simple configuration.

[0068] The above-described electric valve (1) has a connecting member having a protrusion and a driving shaft having a protrusion receiving part, but it may also have a connecting member having a protrusion receiving part and a driving shaft having a protrusion. Additionally, the electric valve (1) has a configuration in which the connecting member is attached to the valve body, but it may also have a configuration in which the connecting member is attached to the driving shaft. In this configuration, one of the valve body and the connecting member has a protrusion, and the other of the valve body and the connecting member has a protrusion receiving part in which the protrusion catches when the connecting member moves away from the valve opening together with the driving shaft.

[0069] (2nd embodiment)

[0070] Hereinafter, an electric valve (2) according to the second embodiment of the present invention will be described with reference to FIGS. 8 and FIGS. 9.

[0071] FIG. 8 is an enlarged cross-sectional view of a part (mainly the valve, connecting member, and driving mechanism) of an electric valve according to a second embodiment of the present invention. In FIG. 8, the description of the stator unit is omitted. FIG. 9 is a six-sided view of the connecting member of the electric valve of FIG. 8. In FIG. 9, the upper drawing is a top view, the lower drawing is a bottom view, and the drawing between the upper drawing and the lower drawing is a front view. In FIG. 9, the left drawing is a left side view, the right drawing is a rear view, and the drawing next to the right drawing is a right side view.

[0072] The electric valve (2) is identical to the electric valve (1) described above (including substantially identical) except that it has a connecting member (145) having a different configuration from the connecting member (45) in place of the connecting member (45). Therefore, in the description of the electric valve (2), the same reference numerals are used for configurations identical to the electric valve (1), and detailed descriptions are omitted.

[0073] The connecting member (145) has a base (146) and a plurality of elastic pieces (147). The base (146) has a disc shape. In this embodiment, the connecting member (145) has three elastic pieces (147) arranged at equal intervals along the circumference of the base (146). Each elastic piece (147) extends upward from the periphery of the base (146). Each elastic piece (147) has a main body (148) and a projection (149). The main body (148) has a rectangular plate shape. The main body (148) is bent into an S shape. The lower end of the main body (148) is connected to the periphery of the base (146). The upper end of the main body (148) is directed away from the center of the base (146). The protrusion (149) has a hemispherical shape. The protrusion (149) protrudes toward the center of the base (146) relative to the main body (148). The shape of the connecting member (145) has rotational symmetry in which the axis of symmetry passes through the center of the base (146). The connecting member (145) is formed by press-forming a metal plate.

[0074] The connecting member (145) is attached to the valve body (40). Specifically, the lower surface of the base (146) of the connecting member (145) is in contact with the upper surface (41a) of the stem (41), and the convex portion (43b) of the ball receiving portion (43) is inserted into the through hole (146a) in the center of the base (146). The base (146) is maintained between the upper surface (41a) of the stem (41) and the flat portion (43a) of the ball receiving portion (43). The ball receiving portion (43) is also a member for attaching the connecting member (145) to the valve body (40).

[0075] One end of the drive shaft (70) (third part (73) and protrusion receiving part (74)) is positioned inside a plurality of elastic pieces (147) of the connecting member (145) and is surrounded by the plurality of elastic pieces (147). The third part (73) and the base (146) face each other with a gap in the vertical direction. The protrusion receiving part (74) is located below each protrusion (149) of the plurality of elastic pieces (147), and each protrusion (149) is hooked onto the protrusion receiving part (74). Specifically, when viewed from above, each protrusion (149) and the protrusion receiving part (74) overlap, and each protrusion (149) is lightly in contact with the protrusion receiving part (74) in the vertical direction, or is positioned with a slight gap in the vertical direction. Accordingly, when the drive shaft (70) moves upward, the protrusion (149) is caught on the protrusion receiving part (74), and the drive shaft (70) becomes rotatable around the axis (L) relative to the connecting member (145).

[0076] In the electric valve (2), the same operational effect as the electric valve (1) described above (including substantially the same) is achieved.

[0077] In this specification, each term indicating a shape, such as "cylinder," "circumference," or "rectangular body," is also used for a member or a part of a member that substantially has the shape of that term. For example, "cylindrical member" includes a cylindrical member and a substantially cylindrical member.

[0078] Although embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments. Any addition, deletion, or design modification of components or appropriate combination of features of the embodiments made by a person skilled in the art with respect to the aforementioned embodiments are also included within the scope of the present invention, provided that such modifications do not contradict the spirit of the present invention. Explanation of the symbols

[0079] 1, 2: Electric valve 10: Valve body 10a: Right side 10b: Left side 10c: Top surface 13: Valve chamber 14: Valve port 15: Valve seat 17: First passage 18: Second passage 19: Attachment hole 19a: Bottom surface 20: Holder 20a: Upper 25: Valve body support member 25a: Annular plane 30: Can 35: Joining member 40: Valve body 41: Stem 41a: Top surface 41b: Hole 42: Valve section 43: Ball receiving section 43a: Flat part 43b: Convex part 45: Lack of connection 46: Donation 46a: Through hole 47: Elastic piece 48: Main body 49: Protrusion 50: Driving mechanism 51: Rotor 52: Connecting plate 53: Rotor shaft 55: Permanent magnet 56: Magnetic shielding member 60: Planetary gear mechanism 61: Gear case 62: Fixed ring gear 63: Solar gear 64: Planetary gear 65: Carrier 66: Output gear 67: Output shaft 67a: Slit 68: Guide element 68c: Female thread 70: Drive shaft 71: Part 1 72: Part 2 72c: Male screw 73: Third part 74: Protrusion receiving part 76: Ball 77: Valve opening spring 80: Stator unit 81: Case 82: Stator 83: Substrate 84: Angle sensor 145: Connection missing 146: Donation 146a: Through hole 147: Elastic piece 148: Main body 149: Protrusion 901: Electric valve 914: Valve port 917: First passage 918: Second passage 940: Valve body 970: Drive shaft 977: Valve opening spring

Claims

Claim 1 An electric valve comprising a valve body having a valve opening, a valve body facing the valve opening, a rotor rotatable relative to the valve body, a drive shaft to which the rotation of the rotor is transmitted, a connecting member attached to the valve body, and an opening valve spring that applies a force to the valve body in a direction away from the valve opening, wherein when the rotation of the rotor is transmitted to the drive shaft, the drive shaft moves in a direction toward the valve opening or away from the valve opening, and one of the drive shaft and the connecting member has a projection, and the other of the drive shaft and the connecting member has a projection receiving part that catches the projection when the drive shaft moves away from the valve opening, and wherein the drive shaft pushes the valve body without passing through the spring when it moves toward the valve opening, pulls the valve body when it moves away from the valve opening, and is rotatable relative to the valve body. Claim 2 An electric valve according to claim 1, characterized in that the projection is rotatably engaged with the projection receiving portion relative to the projection receiving portion. Claim 3 An electric valve according to claim 1, characterized in that the connecting member is attached to the valve body so as to be rotatable relative to the connecting member. Claim 4 An electric valve according to any one of claims 1 to 3, wherein the connecting member has a flat plate-shaped base attached to the valve body, a plurality of elastic pieces extending from the periphery of the base toward the drive shaft and capable of elastic deformation in a direction away from the center of the base, and the plurality of elastic pieces have a projection portion protruding toward the center of the base, the projection receiving portion is disposed at one end of the drive shaft, and the one end of the drive shaft is surrounded by the plurality of elastic pieces. Claim 5 An electric valve according to claim 1, characterized in that when the drive shaft moves in a direction approaching the valve opening, a member joined to the drive shaft contacts the valve body and pushes the valve body through the member. Claim 6 An electric valve characterized in that, in paragraph 5, the above-mentioned member is a ball.

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