Electric valve

Abstract

The invention provides an electrically operated valve capable of easily setting initial valve opening characteristics. The magnetic rotor (62) has an arc-shaped guide portion (623) capable of guiding the insertion portion (652) of the rotation restricting member (65). When manufacturing an electrically operated valve (1A), a magnetic rotor (62) and a rotation restricting member (65) are rotated relative to each other so that an insertion portion (652) moves from a valve-opening end portion (623B) to a valve-closing end portion (623A) of a guide portion (623), and then the magnetic rotor (62) and the rotation restricting member (65) are fixed, whereby desired initial valve-opening characteristics can be obtained without using other devices, and the initial valve-opening characteristics can be easily set.

Description

Technical Field

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

[0002] Generally, an electric valve is known that can adjust the valve opening degree by rotating a magnetic rotor and a rotor shaft and converting the rotational motion into a linear motion. In such an electric valve, with the rotor shaft restricted from rotating on the most valve-closed side, it is set to have a predetermined (greater than 0) valve opening degree, or it is set to open the valve when the valve element seats on the valve seat and the rotor shaft rotates a predetermined angle (hereinafter, the setting of such an initial valve-opening characteristic will be referred to as "initial valve-opening characteristic"). Therefore, a method for manufacturing an electric valve for setting the initial valve-opening characteristic using a pressing jig for pressing the magnetic rotor and a clamping jig for rotating the rotor shaft has been proposed (for example, refer to Patent Document 1). In the manufacturing method described in Patent Document 1, the magnetic rotor is pressed by the pressing jig so that it cannot rotate, and at the same time, only the rotor shaft is rotated by the clamping jig, thereby obtaining the desired initial valve-opening characteristic.

[0003] Prior Art Documents

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2024-147241

[0005] However, in the manufacturing method described in Patent Document 1, when rotating the rotor shaft by the clamping jig, a dedicated device is required to manage the rotation angle. That is, it is necessary to store a predetermined rotation angle in a dedicated device or install a dedicated device, and there is a possibility of a decrease in productivity if the desired initial valve-opening characteristic is to be obtained. Summary of the Invention

[0006] An object of the present invention is to provide an electric valve capable of easily setting the initial valve-opening characteristic.

[0007] The electric valve of the present invention includes: a valve body that constitutes a valve chamber; a valve element that adjusts the opening area between the valve element and a valve seat where a valve port is provided inside the valve body; a rotor shaft that is provided so as to be rotatable about a predetermined axis and drives the valve element to advance and retreat in the axial direction; a screw feed mechanism that converts the rotational motion of the rotor shaft into a linear motion at a predetermined ratio; a magnetic rotor that rotates together with the rotor shaft; and a movable region determination mechanism that determines a movable region in the axial direction by restricting the rotation of the rotor shaft. The electric valve is characterized in that the movable region determination mechanism has a rotation restricting member that can rotate together with the magnetic rotor and restricts rotation by abutting from the circumferential direction. One of the magnetic rotor and the rotation restricting member has a guiding portion that is formed in an arc shape around the axis and can guide the other. The guided portion guided by the guiding portion among the other is disposed at one end of the arc of the guiding portion.

[0008] According to the present invention as described above, when manufacturing the electric valve, the magnetic rotor and the rotation restricting member can be relatively moved, and the relative movement can be made into a relative rotation at a predetermined angle by the arc-shaped guiding portion. That is, after disposing the guided portion at the other end of the arc of the guiding portion, the guided portion is moved to one end, whereby the central angle of the guiding portion can be relatively rotated. Thus, the guided portion is disposed at the other end of the arc. In a state where the magnetic rotor and the rotor shaft are located on the most valve-closed side and the rotation is restricted, by moving the guided portion to one end and then fixing the magnetic rotor and the rotation restricting member, the desired initial valve-opening characteristics can be obtained without using other devices, and the initial valve-opening characteristics can be easily set.

[0009] At this time, in the electric valve of the present invention, it is preferable that one end of the arc is an end on the side where the rotor shaft moves toward the valve-closed side through the screw feed mechanism and is away from the guided portion during rotation. The value obtained by converting the central angle of the arc-shaped guiding portion into a dimension in the axial direction at the predetermined ratio corresponds to the axial interval between the valve seat and the valve element when the minimum valve opening is achieved. According to such a structure, the minimum valve opening can be set to a predetermined size greater than 0.

[0010] In addition, in the electric valve of the present invention, it is also possible that one end of the arc is the end on the side that is intended to move away from the guided portion during the rotation when the rotor moves axially toward the valve opening side by the screw feed mechanism, and the central angle of the arc-shaped guided portion corresponds to the rotation angle from the state where the rotation of the rotor shaft is restricted on the most valve closing side until the valve element separates from the valve seat when rotating in the valve opening rotation direction. According to such a structure, the minimum valve opening can be made 0, and valve opening can start when a predetermined angle of rotation is made from the state where the magnetic rotor and the rotor shaft are located on the most valve closing side and the rotation is restricted.

[0011] In addition, in the electric valve of the present invention, it is preferable that the magnetic rotor has a cylindrical portion centered on the axis and a rotor plate portion provided inside the cylindrical portion and formed with the guided portion, and the rotation restricting member has a valve closing side plate portion that extends along a plane orthogonal to the axis and is disposed on the valve closing side with respect to the rotor plate portion. The valve closing side plate portion abuts against the rotor plate portion and has a through hole through which the rotor shaft is inserted and fitted. According to such a structure, relative rotation of the magnetic rotor and the rotation restricting member can be performed in a state where the rotor plate portion and the valve closing side plate portion overlap and abut against each other, and tilting during relative rotation can be suppressed. In addition, by fitting the rotor shaft into the through hole of the valve closing side plate portion, relative movement of the rotor shaft and the rotation restricting member in the radial direction with respect to the axis can be suppressed. In this way, deviation in an undesired direction during relative rotation can be suppressed, and workability can be improved.

[0012] In addition, in the electric valve of the present invention, it is also possible that the magnetic rotor has a cylindrical portion centered on the axis and a rotor plate portion provided inside the cylindrical portion and formed with the guided portion, and the rotation restricting member has a valve opening side abutting portion that abuts against the rotor plate portion from the valve opening side. According to such a structure, relative rotation of the magnetic rotor and the rotation restricting member can be performed in a state where the rotor plate portion and the valve opening side abutting portion abut against each other, and tilting during relative rotation can be suppressed, improving workability. In addition, the rotation restricting member and the rotor plate portion can be connected by an operation from the valve opening side, and the area of the connecting portion can be easily ensured, improving workability.

[0013] The effects of the present invention are as follows.

[0014] According to the electric valve of the present invention, the initial valve opening characteristics can be easily set. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional view showing an electric valve according to a first embodiment as an example of the present invention.

[0016] Figure 2 is along Figure 1Cross-sectional view of line A1-A1.

[0017] Figure 3 is a cross-sectional view of the same position in the first manufacturing stage of the electric valve Figure 2 as shown.

[0018] Figure 4 is a cross-sectional view of a different position in the first manufacturing stage of the electric valve Figure 3 as shown.

[0019] Figure 5 is a cross-sectional view of the same position in the second manufacturing stage of the electric valve Figure 2 as shown.

[0020] Figure 6 is a cross-sectional view of the same position in the second manufacturing stage of the electric valve Figure 4 as shown.

[0021] Figure 7 is a cross-sectional view of the same position in the third manufacturing stage of the electric valve Figure 2 as shown.

[0022] Figure 8 is a graph showing the flow characteristics of the electric valve.

[0023] Figure 9 is a cross-sectional view showing the electric valve according to the second embodiment as an example of the present invention.

[0024] Figure 10 is a cross-sectional view of the same position of the electric valve Figure 2 as shown.

[0025] Figure 11 is a cross-sectional view of the same position of the electric valve Figure 4 as shown.

[0026] Figure 12 is a graph showing the flow characteristics of the electric valve.

[0027] Figure 13 is a cross-sectional view showing the electric valve according to the third embodiment as an example of the present invention.

[0028] In the figures: 1A, 1B, 1C - electric valve; 2 - valve body; 2R - main valve chamber (valve chamber); 5 - sub-valve core (valve core); 41a - sub-valve port (valve port); 61 - rotor shaft; 62 - magnetic rotor; 621 - cylindrical portion; 622 - rotor plate portion; 623 - guide portion; 623A - valve closing end portion; 623B - valve opening end portion; 65 - rotation limiting member; 652, 654 - insertion portion (guided portion); 653 - valve closing side plate portion; 655 - flange portion (valve opening side abutting portion); 6B - screw feed mechanism; 6C - movable region determining mechanism. DETAILED DESCRIPTION

[0029] [First embodiment]

[0030] The first embodiment of the present invention will be described with reference to the accompanying drawings. The electric valve 1A of the first embodiment is used in a refrigeration cycle system of an air conditioner such as a combined air conditioner or a room air conditioner. Figure 1 As shown in FIG. 1 , a valve body 2, a guide member 3, a main valve core 4, a sub-valve core 5, and a drive unit 6 are provided. The main valve core 4 and the sub-valve core 5 are arranged to move along a predetermined axial direction. Hereinafter, the axial direction is referred to as the Z direction, and two directions orthogonal to the Z direction are referred to as the X direction and the Y direction. The up and down directions in the Z direction are referred to as Figure 1 In addition, the lower side in the Z direction becomes the valve closing side, and the upper side becomes the valve opening side. In addition, the circumferential direction around the axis of movement of the main valve core 4 and the auxiliary valve core 5 is sometimes referred to as the circumferential direction, and the radial direction centered on the axis is sometimes referred to as the radial direction, and the side close to the axis in the radial direction is set as the inner circumference, and the side away from the axis is set as the outer circumference.

[0031] The valve body 2 is a valve housing formed into a substantially cylindrical shape by, for example, brass, stainless steel, etc., and has a main valve chamber 2R inside thereof. The valve body 2 has a first port 21 opened on one side of the side surface in the X direction and a second port 22 opened on the lower side in the Z direction. The first joint pipe 11 extending in the X direction is connected to the first port 21, and the second joint pipe 12 extending in the Z direction is connected to the second port 22, and the first joint pipe 11 and the second joint pipe 12 are connected to the main valve chamber 2R. The first joint pipe 11 and the second joint pipe 12 can be fixed to the valve body 2 by, for example, brazing.

[0032] A cylindrical main valve seat 23 is formed at the lower end of the valve body 2, which protrudes toward the main valve chamber 2R side (toward the upper side) with the Z direction as the axial direction, and the inner side of the main valve seat 23 becomes a main valve port 23a, and the main valve port 23a is connected to the second port 22. That is, the second joint pipe 12 is connected to the main valve chamber 2R via the main valve port 23a. In the first embodiment, the electric valve 1A is used in a manner that the fluid (refrigerant) flowing into the main valve chamber 2R from the first joint pipe 11 flows out from the second joint pipe 12, with the first port 21 as the primary side and the second port 22 as the secondary side, but the electric valve 1A can also be assembled in a cycle in which the fluid can flow in both directions. In addition, in this embodiment, the main valve seat 23 is formed as a part of the valve body 2, but the valve seat component having the main valve seat can also be set as a component different from the cylindrical valve housing, and the valve seat component can be fixed to the lower end of the valve housing by brazing or the like.

[0033] The guide member 3 is installed in the opening at the upper end of the valve body 2 and has: a press-fitting portion 31 that is press-fitted into the inner peripheral surface of the valve body 2; a substantially cylindrical guide portion 32 that is located inside the press-fitting portion 31; a bracket portion 33 that extends upward from the guide portion 32; and an annular flange portion 35 that is located on the outer periphery of the guide portion 32. The press-fitting portion 31, the guide portion 32, and the bracket portion 33 are formed as an integral resin member. In addition, the flange portion 35 is a metal plate made of, for example, brass or stainless steel, and the flange portion 35 is integrally provided together with the resin press-fitting portion 31 and the bracket portion 33 by insert molding.

[0034] The guide member 3 is assembled to the valve body 2, and the flange portion 35 is fixed to the upper end portion of the valve body 2 by welding. In addition, in the guide member 3, a cylindrical guide hole 32a having the Z direction as its axis is formed in the guide portion 32. In addition, an internal thread portion (thread hole) 34a that is coaxial with the guide hole 32a and the insertion hole 33a is formed at the center of the bracket portion 33.

[0035] The main spool 4 is disposed in the guide hole 32a of the bracket portion 33 and is integrally formed in a cylindrical shape with the Z direction as its axis. The main valve body 4 integrally has: a partition portion 41 that extends along the XY plane and to which the sub-spool 5 approaches or separates; a cylindrical portion 42 that extends from the partition portion 41 to the side opposite to the main valve port 23a (upper side); and a main valve portion 43 that approaches or separates from the main valve seat 23.

[0036] The partition portion 41 is a sub-valve seat portion provided at the lower end portion of the cylindrical portion 42 and is formed in a plate shape having a predetermined plate thickness (Z direction dimension). A bottomed cylindrical portion is formed by the partition portion 41 and the cylindrical portion 42, and the inside of the bottomed cylindrical portion becomes the sub-valve chamber 4R. A sub-valve port 41a serving as a through hole is formed at the center of the partition portion 41. The cylindrical portion 42 is formed in a cylindrical shape, and a pressing member 7 described later is provided inside it. The inner peripheral surface of the pressing member 7 functions as a needle guide hole. A guiding boss portion 53 mounted on a valve shaft 51 described later is inserted through the needle guide hole, and an annular retainer 44 is fixed to the upper end of the cylindrical portion 42 by fitting or welding. In addition, a main valve spring 4a is disposed between the retainer 44 and the upper end portion of the guide hole 32a, and the main spool 4 is biased toward the main valve seat 23 (closing valve side) by the main valve spring 4a.

[0037] A plurality of communication paths 421 that communicate the inside and outside of the cylindrical portion 42 are formed in the cylindrical portion 42. The plurality of communication paths 421 are arranged at equal intervals in the circumferential direction centered on the Z direction. By forming the communication paths 421 in the cylindrical portion 42, the main valve chamber 2R, the sub-valve chamber 4R, the sub-valve port 41a, and the main valve port 23a communicate with each other.

[0038] The main valve portion 43 is formed in a substantially cylindrical shape such that the cylindrical portion 42 extends downward from the partition portion 41. The main valve portion 43 is arranged to seat (abut) on the main valve seat 23 in the fully closed state.

[0039] The sub-valve element 5 is a needle valve, which is provided at the lower end of a rotor shaft 61 described later, and integrally has a valve shaft 51 connected to the rotor shaft 61 side and a needle portion 52 connected to the lower end of the valve shaft 51. The sub-valve element 5 further has a guide boss portion 53 fixed to the valve shaft 51. The guide boss portion 53 is fixed separately from the valve shaft 51, but the guide boss portion 53 may also be integrally formed with the valve shaft 51. The guide boss portion 53 is slidably inserted into a needle guide hole formed by a pressing member 7.

[0040] The drive portion 6 is provided inside and outside a housing 24 fixed to the upper end of the valve body 2, and includes: a stepping motor 6A; a screw feed mechanism 6B, which converts the rotational motion of the rotor shaft 61 into a linear motion at a predetermined ratio and makes the sub-valve element 5 advance and retreat by the rotation of the stepping motor 6A; and a movable region determination mechanism 6C, which limits the rotation of the stepping motor 6A. The housing 24 is hermetically fixed to the valve body 2 by welding or the like, for example.

[0041] The stepping motor 6A is composed of a rotor shaft 61, a magnetic rotor 62 rotatably disposed inside the housing 24, a stator coil 63 disposed opposite to the magnetic rotor 62 on the outer periphery of the housing 24, a rotation restricting member 65, and other yokes, exterior components, etc. not shown. The rotor shaft 61 is mounted on the center of the magnetic rotor 62 via a bushing 64, and an external thread portion 61a is formed on the outer periphery of the rotor shaft 61 on the guide member 3 side. The external thread portion 61a is screwed with an internal thread portion 34a of the guide member 3, whereby the guide member 3 supports the rotor shaft 61 on the axis along the Z direction. And, the internal thread portion 34a of the guide member 3 and the external thread portion 61a of the rotor shaft 61 constitute the screw feed mechanism 6B. In the present embodiment, when viewed from the valve opening side, by clockwise rotation, the rotor shaft 61 and the magnetic rotor 62 move in the valve closing direction, so this rotation direction is taken as the valve closing rotation direction, and when viewed from the valve opening side, by counterclockwise rotation, the rotor shaft 61 and the magnetic rotor 62 move in the valve opening direction, so this rotation direction is taken as the valve opening rotation direction. In addition, in the present embodiment, the internal thread portion 34a and the external thread portion 61a are right-handed threads.

[0042] The magnetic rotor 62 is formed in a bottomed cylindrical shape opening toward the valve closing side, and has a cylindrical portion 621 and a disk-shaped rotor plate portion 622 provided inside the cylindrical portion. On the rotor plate portion 622, there is also formed as Figure 2The arc-shaped opening (through hole) shown is the guiding portion 623. The guiding portion 623 is formed in an arc shape extending in the circumferential direction around the axis of the rotor shaft 61, and has a closing valve end portion 623A which is the end portion on the closing valve rotation direction side and an opening valve end portion 623B which is the end portion on the opening valve rotation direction side.

[0043] The rotation restricting member 65 is formed as a member different from the magnetic rotor 62 and is fixed to the magnetic rotor 62, whereby it can rotate together with the magnetic rotor 62. The magnetic rotor 62 needs to be made of a magnetic material, but the rotation restricting member 65 does not need to be made of a magnetic material, and it is preferable that their materials are different.

[0044] The rotation restricting member 65 has: a protruding portion 651 which extends in the Z direction and is disposed inside the cylindrical portion 621; an insertion portion 652 as a guided portion which extends from the protruding portion 651 toward the opening valve side in the Z direction and is inserted into the guiding portion 623; and a closing valve side plate portion 653 which extends in the XY plane and is disposed on the closing valve side with respect to the rotor plate portion 622 and abuts (i.e., overlaps). The insertion portion 652 protrudes from the rotor plate portion 622 toward the opening valve side, and in the electric valve 1A in the manufactured state, it is disposed at the closing valve end portion 623A in the arc-shaped guiding portion 623. A through hole 653A for inserting and fitting the rotor shaft 61 is formed at the central portion of the closing valve side plate portion 653.

[0045] On the outer peripheral surface of the support portion 33 of the guiding member 3, an externally threaded guiding groove 34b is formed, and a slider 66 is provided in the guiding groove 34b. The slider 66 abuts against the protruding portion 651 of the rotation restricting member 65, and rotates and moves up and down along the guiding groove 34b as the magnetic rotor 62 rotates. Further, the slider 66 abuts against the upper end or the lower end of the guiding groove 34b, thereby constituting a movable region determining mechanism 6C for restricting the rotation of the magnetic rotor 62. In addition, the rotation restricting member 65 abutting against the slider 66 also constitutes a part of the movable region determining mechanism 6C. By this movable region determining mechanism 6C, the lowermost position and the uppermost position of the rotor shaft 61 and the magnetic rotor 62 are restricted. That is, the movable region determining mechanism 6C determines the movable region of the rotor shaft 61 in the Z direction.

[0046] In the first embodiment, a first sound absorbing member 8 and a second sound absorbing member 9 are provided. The first sound absorbing member 8 is integrally formed in an annular shape so that the valve shaft 51 and the needle portion 52 can pass through, and is disposed in the flow path from the communication path 421 to the sub-valve port 41a. In order to dispose the first sound absorbing member 8 inside the cylindrical portion 42, a pressing member 7 is provided. That is, the pressing member 7 and the first sound absorbing member 8 are clamped from the Z direction by the partition portion 41 and the retainer 44. The second sound absorbing member 9 is disposed in the flow path from the sub-valve port 41a to the main valve port 23a.

[0047] The first silencing component 8 and the second silencing component 9 are filters formed into a three-dimensional mesh by randomly bending linear components, and can be any demister, for example. The silencing components 8 and 9 formed into a mesh can subdivide the flow path and subdivide the bubbles in the fluid to obtain a silencing effect, thereby fully suppressing the sound of the fluid passing through.

[0048] Here, the details of the opening and closing actions of the main valve core 4 and the auxiliary valve core 5 in the electric valve 1A are described. When the rotor shaft 61 and the magnetic rotor 62 are rotated by the drive of the stepping motor 6A, the rotor shaft 61 moves in the Z direction through the thread feed mechanism 6B of the external thread portion 61a of the rotor shaft 61 and the internal thread portion 34a of the guide member 3. As a result, the auxiliary valve core 5 moves forward and backward in the Z direction and approaches or separates relative to the auxiliary valve port 41a, thereby controlling the valve opening of the auxiliary valve port 41a (small flow control). In addition, the guide boss portion 53 of the auxiliary valve core 5 engages with the pressing member 7, and the main valve core 4 moves together with the auxiliary valve core 5, and approaches or separates relative to the main valve seat 23 (large flow control). As a result, the flow rate of the refrigerant flowing from the first joint pipe 11 to the second joint pipe 12 is controlled. In addition, in the first embodiment, even when the auxiliary valve core 5 moves forward and backward in the Z direction and is closest to the auxiliary valve seat portion having the auxiliary valve port 41a, the auxiliary valve core 5 does not abut against the auxiliary valve seat portion (does not sit on it), and a gap is formed between the auxiliary valve core 5 and the auxiliary valve seat portion, so that the fluid can pass through the auxiliary valve port 41a.

[0049] In the electric valve 1A of the first embodiment, the sub-valve core 5 as the valve core adjusts the opening area between the sub-valve core 5 and the valve seat where the sub-valve port 41a as the valve port provided on the inner side of the valve body 2 is located. At this time, as described above, even when the sub-valve core 5 is closest to the valve seat, it does not abut against the valve seat and a gap is formed. Therefore, the electric valve 1A needs to be manufactured in such a way that the sub-valve port 41a becomes a predetermined valve opening when the slider 66 abuts against the stopper 36 at the lower end of the guide groove 34b. The manufacturing method of such an electric valve 1A is described below.

[0050] First, the electric valve 1A is assembled except for the housing 24, the stator coil 63, the magnetic rotor 62, and the rotation restricting member 65. In this state, the slider 66 is rotated in the valve closing rotation direction to abut against the stopper 36, and the rotor shaft 61 is rotated in the valve closing rotation direction to seat the auxiliary valve core 5 on the auxiliary valve seat.

[0051] Next, the magnetic rotor 62 and the rotation limiting member 65 are installed. Figure 3 The insertion portion 652 is separated from both ends of the guide portion 623 and is as shown in FIG. Figure 4 When the protrusion 651 and the slider 66 are arranged in the separated position, only the magnetic rotor 62 and the magnetic rotor 62 in the rotation limiting member 65 rotate in the valve closing rotation direction.Figure 5 As shown, within the guide portion 623, the insertion portion 652 relatively faces the valve-opening rotation direction and reaches the valve-opening end portion 623B. Further, when the magnetic rotor 62 is rotated in the valve-closing rotation direction, the rotation restricting member 65 rotates in the valve-closing rotation direction as the magnetic rotor 62 rotates. As Figure 6 shown, the protruding portion 651 abuts against the slider 66 to restrict further rotation in the valve-closing rotation direction.

[0052] In this state, the magnetic rotor 62 and the rotor shaft 61 are fixed via the bushing 64 by welding or the like to be in a state where they cannot move relative to each other. Next, the rotation restricting member 65 is pressed so as not to rotate, and only the magnetic rotor 62 is rotated in the valve-opening rotation direction. Thus, as Figure 7 shown, within the guide portion 623, the insertion portion 652 relatively faces the valve-closing rotation direction and reaches the valve-closing end portion 623A. In this state, the rotation restricting member 65 is fixed to the magnetic rotor 62. Additionally, the method of fixing the rotation restricting member 65 to the magnetic rotor 62 is not particularly limited, and methods such as welding, cladding, bonding, and fixing using a fitting groove that can obtain the desired fixing strength can be used. When the magnetic rotor 62 is rotated in the valve-opening rotation direction as described above, the rotor shaft 61 is fixed to the magnetic rotor 62, so the rotor shaft 61 also rotates in the valve-opening rotation direction, and the sub-valve element 5 is separated from the sub-valve seat portion. That is, in a state where rotation in the valve-closing rotation direction is restricted, a predetermined valve opening that is not 0 can be obtained. The lift amount of the sub-valve element 5 at this time (the interval in the Z direction relative to the sub-valve seat) is determined by the central angle of the arc-shaped guide portion 623 and the conversion ratio from rotational motion to linear motion in the screw feed mechanism 6B.

[0053] After that, by assembling the housing 24 and the stator coil 63, the manufacture of the electric valve 1A is completed. The electric valve 1A manufactured in this way, as Figure 8 shown, has a flow characteristic such that even when the drive pulse of the stator coil 63 is 0 (the lift amount of the sub-valve element 5 is 0), a predetermined minimum flow rate FL1 that is not 0 can be obtained.

[0054] The minimum flow rate FL1 is determined by the central angle of the arc-shaped guide portion 623. That is, the value obtained by converting the central angle of the arc-shaped guide portion 623 into a dimension value in the Z direction at the conversion ratio of the screw feed mechanism 6B corresponds to the interval in the Z direction between the sub-valve element 5 and the sub-valve seat when the minimum valve opening is achieved, and the minimum flow rate FL1 is determined by this interval.

[0055] According to the above first embodiment, the magnetic rotor 62 has an arc-shaped guiding portion 623 capable of guiding the insertion portion 652 of the rotation restricting member 65. When manufacturing the electric valve 1A, the magnetic rotor 62 and the rotation restricting member 65 are relatively rotated such that the insertion portion 652 moves from the valve opening end portion 623B of the guiding portion 623 to the valve closing end portion 623A, and then they are fixed. Thus, the desired initial valve opening characteristics can be obtained without using other devices, and the initial valve opening characteristics can be easily set.

[0056] In addition, the magnetic rotor 62 has a rotor plate portion 622, and the rotation restricting member 65 has a valve closing side plate portion 653, so that the magnetic rotor 62 and the rotation restricting member 65 can be relatively rotated in a state where the rotor plate portion 622 and the valve closing side plate portion 653 overlap and abut against each other, and tilting during relative rotation can be suppressed. Further, by forming a through hole 653A in the valve closing side plate portion 653 for the rotor shaft 61 to be inserted and fitted, relative movement of the rotor shaft 61 and the rotation restricting member 65 in the radial direction can be suppressed. In this way, deviation in an undesired direction during relative rotation can be suppressed, and workability can be improved.

[0057] [Second Embodiment]

[0058] After the second embodiment, the same reference numerals are assigned to the structures common to the first embodiment, and the description will focus on the differences from the first embodiment. For the structures not specifically described, they have the same shape and function as those in the first embodiment.

[0059] The electric valve 1A of the first embodiment includes a main valve element 4 and a sub-valve element 5 to perform two-stage flow control. In contrast, as Figure 9 shown, the electric valve 1B of the second embodiment includes a valve body 2, a guiding member 3, a valve element 13, and a driving portion 6 to perform flow control in one stage. The valve element 13 has a valve element main body 14, a valve bracket 15, and a compression coil spring 16. That is, the valve element main body 14 having a needle valve is connected to the rotor shaft 61 by being suspended by the valve bracket 15. At this time, by providing a compression coil spring 16 inside the valve bracket 15, the valve element main body 14 can move relative to the rotor shaft 61 in the Z direction.

[0060] In the electric valve 1B of the second embodiment, a valve seat member 20 formed separately from the valve body 2 is fixed to the valve body 2. The valve seat member 20 has a valve seat 201 and a valve port 202 inside the valve seat 201.

[0061] In the first embodiment, the minimum valve opening is not 0 but has a minimum flow rate FL1. However, in the second embodiment, a compression coil spring 16 is provided between the rotor shaft 61 and the valve element main body 14, so that there can be the following two forms: the same form as in the first embodiment where the minimum valve opening is not 0, and a form in which the valve starts to open after rotating a predetermined angle from the state where the rotor shaft 61 is located on the fully closed side and the rotation of the magnetic rotor 62 in the fully closed rotation direction is restricted. Hereinafter, the latter form will be described. In addition, in the case of the former form, the relationship between the guide portion 623 and the insertion portion 652 is the same as in the first embodiment.

[0062] As Figure 10 shown, the insertion portion 652 is located at the valve opening end portion 623B, and the rotation restricting member 65 is fixed to the magnetic rotor 62. That is, when manufacturing the electric valve 1B, while rotating the slider 66 in the fully closed rotation direction to abut against the stopper 36 and rotating the rotor shaft 61 in the fully closed rotation direction to seat the valve element main body 14 on the valve seat 201, the protruding portion 651 of the rotation restricting member 65 is made to abut against the slider 66, and at the same time, the magnetic rotor 62 is rotated in the valve opening rotation direction, whereby the insertion portion 652 is positioned at the fully closed end portion 623A. The magnetic rotor 62 and the rotor shaft 61 are fixed, the rotation restricting member 65 is pressed so as not to rotate, and only the magnetic rotor 62 is rotated in the fully closed rotation direction, whereby the insertion portion 652 reaches the valve opening end portion 623B.

[0063] Thereby, the rotor shaft 61 and the magnetic rotor 62 can further rotate a predetermined angle in the fully closed rotation direction from the state where the valve element main body 14 is seated on the valve seat 201 and the valve opening (flow rate) is 0. As Figure 12 shown, the electric valve 1B manufactured in this way has a flow rate characteristic such that the valve starts to open when the drive pulse of the stator coil 63 reaches a predetermined value PL0.

[0064] The predetermined value PL0 of this drive pulse is equal to the pulse difference ΔPL obtained by moving the insertion portion 652 in the guide portion 623, and the value obtained by converting the pulse difference ΔPL into a rotation angle value is equal to the central angle of the arc-shaped guide portion 623.

[0065] According to the above second embodiment, similarly to the first embodiment, the initial valve opening characteristics can be easily set.

[0066] [Third Embodiment]

[0067] As Figure 13As shown, the shape of the rotation restricting member 65 of the electric valve 1C in the third embodiment is different from that of the electric valve 1A in the first embodiment. In the third embodiment, the rotation restricting member 65 has a protrusion 651, an insertion portion 654, a flange portion 655 as an open valve side abutting portion, and a cylindrical standing portion 656. In addition, in the first embodiment, in the magnetic rotor 62, the rotor plate portion 622 is disposed at the end of the cylindrical portion 621 on the open valve side, but in the third embodiment, the rotor plate portion 622 is located at a position slightly closer to the closed valve side than the end of the cylindrical portion 621 on the open valve side, and the magnetic rotor 62 has a recess on the open valve side.

[0068] The insertion portion 652 of the first embodiment penetrates through the guiding portion 623 and protrudes from the rotor plate portion 622, but the insertion portion 654 of the third embodiment does not protrude from the rotor plate portion 622 and is continuous with the flange portion 655 that overlaps the rotor plate portion 622 on the open valve side. The flange portion 655 is formed in a plate shape extending along the XY plane, and a cylindrical standing portion 656 protruding toward the open valve side is provided at the center thereof. The cylindrical standing portion 656 is formed in a cylindrical shape, and a part of the rotor shaft 61 and the bushing 64 is inserted through the opening 657 thereof. The rotor shaft 61, the bushing 64, and the cylindrical standing portion 656 are fixed by welding. That is, the rotation restricting member 65 is indirectly fixed to the magnetic rotor 62 via the bushing 64, and the fixing within the guiding portion 623 as in the first embodiment is not required.

[0069] In addition, the electric valve 1C in the third embodiment has the same flow rate characteristics as those in the first embodiment. In an electric valve having the flow rate characteristics as in the second embodiment, the rotation restricting member 65 as in the third embodiment can also be adopted.

[0070] According to the above third embodiment, similarly to the first embodiment, the initial opening characteristics can be easily set.

[0071] In addition, since the magnetic rotor 62 has the rotor plate portion 622 and the rotation restricting member 65 has the flange portion 655, the magnetic rotor 62 and the rotation restricting member 65 can be relatively rotated in a state where the rotor plate portion 622 abuts against the flange portion 655, the inclination during the relative rotation can be suppressed, and the workability can be improved. In addition, the rotation restricting member 65 and the rotor plate portion 622 can be connected by operating from the open valve side. In addition, the cylindrical standing portion 656 standing up from the flange portion 655 can be used as a connecting portion, and the connecting area can be easily ensured, thereby improving the workability.

[0072] In addition, the present invention is not limited to the first to third embodiments, and includes other structures and the like that can achieve the object of the present invention. Modifications and the like shown below are also included in the present invention. For example, in the first embodiment, among the magnetic rotor 62 and the rotation restricting member 65 that can rotate relative to each other during manufacturing, the magnetic rotor 62 has an arc-shaped guiding portion 623, and the rotation restricting member 65 has an insertion portion 652 as the guided portion. However, it is also possible that the rotation restricting member has an arc-shaped guiding portion and the magnetic rotor has a guided portion. Even with such a structure, it is possible to easily set the initial valve-opening characteristics by relatively rotating the magnetic rotor and the rotation restricting member at an appropriate timing during manufacturing, similarly to the first embodiment.

[0073] Further, in the first embodiment, the guiding portion 623 is an opening (through-hole), and the insertion portion 652 passing through the opening functions as the guided portion. However, the shapes of the guiding portion and the guided portion are not limited to this. That is, the guiding portion may be a non-through groove shape (rail shape), or it may be a form in which the guided portion is inserted into the groove of the guiding portion and guided.

[0074] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific structure is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention.

Claims

1. An electric valve, comprising: a valve body constituting a valve chamber; a valve core for adjusting an opening area between the valve core and a valve seat provided inside the valve body where a valve port is located; and a rotor shaft provided in a manner rotatable around a predetermined axis and driving the valve core forward and backward along the axis direction; a screw feed mechanism that converts the rotary motion of the rotor shaft into a linear motion at a predetermined ratio; a magnetic rotor that rotates together with the rotor shaft; and The movable region determining mechanism determines the movable region in the axial direction by limiting the rotation of the rotor shaft, wherein the electric valve is characterized in that: The movable region determining mechanism includes a rotation restricting member that is rotatable together with the magnetic rotor and restricts rotation by abutting against the magnetic rotor in the circumferential direction. One of the magnetic rotor and the rotation restricting member has a guide portion which is formed in an arc shape around the axis and can guide the other. The guided portion of the other portion that is guided by the guide portion is disposed at one end of an arc of the guide portion.

2. The electric valve according to claim 1, characterized in that: One end of the arc is an end portion of the side that is intended to be away from the guided portion when the rotor shaft is rotated by the screw feeding mechanism to move to the valve closing side. A value obtained by converting the central angle of the arc-shaped guide portion into a dimension in the axial direction at the predetermined ratio corresponds to a distance in the axial direction between the valve seat and the valve element when the valve opening is the minimum.

3. The electric valve according to claim 1, characterized in that: One end of the arc is an end portion of the side that is intended to be away from the guided portion when the rotor shaft is rotated by the screw feeding mechanism to move toward the valve opening side. The central angle of the arc-shaped guide portion corresponds to a rotation angle from a state in which the rotor shaft is restricted from rotating at the valve closing side to a state in which the valve element rotates in the valve opening rotation direction and starts to leave the valve seat.

4. The electric valve according to any one of claims 1 to 3, characterized in that: The magnetic rotor includes: a cylindrical portion centered on the axis; and a rotor plate portion provided inside the cylindrical portion and having the guide portion formed thereon. The rotation restricting member includes a valve closing side plate portion extending along a plane orthogonal to the axis and arranged on the valve closing side relative to the rotor plate portion. The valve closing side plate portion is in contact with the rotor plate portion and has a through hole into which the rotor shaft is inserted and fitted.

5. The electric valve according to any one of claims 1 to 3, characterized in that: The magnetic rotor includes: a cylindrical portion centered on the axis; and a rotor plate portion provided inside the cylindrical portion and having the guide portion formed thereon. The rotation restricting member includes a valve opening side contact portion that contacts the rotor plate portion from a valve opening side.

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