Electric valve

Abstract

Provided is an electric valve capable of reliably detecting magnetic flux generated from a magnetic rotor with a structure having a small number of parts. The electric valve (1) has a magnetic rotor (41) arranged inside a housing (30). On the outer peripheral surface (41a) of the magnetic rotor (41), a plurality of N poles and a plurality of S poles are arranged in a manner alternately arranged in the circumferential direction. Magnetic sensors (35a) and (35b) are arranged on the outer peripheral surface (30a) of the housing (30) and are radially opposite to the magnetic rotor (41) with the housing (30) interposed therebetween. Furthermore, when viewed from the direction of the rotation axis, the magnetic sensor (35a) is arranged on a straight line (F1) passing through the rotation axis of the magnetic rotor (41) and the center of a lower pole tooth (63a) among a plurality of pole teeth of an upper stator (61).

Description

Technical Field

[0001] The present invention relates to an electric valve, and more particularly to an electric valve having a magnetic rotor disposed inside a housing. Background Art

[0002] Patent Documents 1 and 2 describe an example of a conventional electric valve. The electric valve of Patent Document 1 includes a magnetic rotor for driving a valve core and a permanent magnet that rotates together with the magnetic rotor. The magnetic rotor and the permanent magnet are arranged inside a housing. A magnetic sensor is provided on a substrate arranged above the housing. The electric valve detects the magnetic force of the permanent magnet through the magnetic sensor, thereby obtaining the rotation angle of the magnetic rotor.

[0003] The electric valve of Patent Document 2 has a magnetic rotor for driving a valve core, a magnetic drum fixed to a rotating shaft of the magnetic rotor, and a magnet provided at the upper end of the rotating shaft. The magnetic rotor, the magnetic drum, and the magnet are arranged on the inner side of a housing. A magnetic sensor for detecting a rotation angle and a magnetic sensor for detecting an upper and lower position are arranged on the outer side of the housing. The electric valve detects the magnetic force of the magnetic drum and the magnet by the magnetic sensor for detecting a rotation angle and the magnetic sensor for detecting an upper and lower position, thereby calculating the valve opening.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-179133

[0007] Patent Document 2: Japanese Patent Application Publication No. 2001-12633

[0008] Technical problem to be solved by the invention

[0009] The above-mentioned electric valve has a permanent magnet and a magnetic drum which are different parts from the magnetic rotor. Therefore, the above-mentioned electric valve has a technical problem that the number of parts increases and the structure becomes complicated, thereby increasing the manufacturing cost. In order to suppress the increase in the number of parts, for example, the electric valve of Patent Document 1 can have a structure that detects the magnetic force of the magnetic rotor by a magnetic sensor on a substrate. However, in this structure, the substrate and the magnetic rotor are far apart. Therefore, the magnetic force of the magnetic rotor cannot be correctly detected by the magnetic sensor on the substrate. Summary of the invention

[0010] Therefore, an object of the present invention is to provide an electric valve that can reliably detect a magnetic flux generated from a magnetic rotor with a structure having a small number of parts.

[0011] Technical means for solving technical problems

[0012] In order to achieve the above-mentioned purpose, the electric valve of the present invention comprises: a valve body; a cylindrical shell, which is installed on the valve body; a cylindrical magnetic rotor, which is arranged on the inner side of the shell; a valve core, which is driven to open and close the port in the valve body by the rotation of the magnetic rotor; and a stator, which is arranged on the outer side of the shell, and on the outer peripheral surface of the magnetic rotor, one or more N poles and S poles extending in the direction of the rotation axis of the magnetic rotor are arranged alternately in the circumferential direction, and the magnetic sensor is arranged to be radially opposite to the magnetic rotor across the shell, and when viewed from the direction of the rotation axis, the magnetic sensor is arranged on a straight line passing through the rotation axis of the magnetic rotor and the center of one of the multiple pole teeth of the stator.

[0013] According to the present invention, a magnetic rotor is arranged inside a housing. On the outer peripheral surface of the magnetic rotor, one or more N poles and S poles extending in the direction of the rotation axis of the magnetic rotor are arranged alternately in the circumferential direction. In addition, the magnetic sensor is arranged to be radially opposite to the magnetic rotor via the housing. The magnetic flux generated from the magnetic poles (N pole, S pole) of the magnetic rotor is easily transmitted in the radial direction. Therefore, by arranging the magnetic sensor closely to be radially opposite to the magnetic rotor, the magnetic flux can be effectively transmitted to the magnetic sensor. Therefore, the present invention can reliably detect the magnetic flux generated from the magnetic rotor with a structure having a small number of parts.

[0014] In addition, when viewed from the direction of the rotation axis, the magnetic sensor is arranged on a straight line passing through the rotation axis of the magnetic rotor and the center (including the approximate center) of one of the plurality of pole teeth of the stator. In a structure in which the stator has a plurality of pole teeth, when the magnetic rotor stops rotating, it becomes any of the following states: (i) a state in which the pole teeth face the magnetic poles of the magnetic rotor; (ii) a state in which the pole teeth face the portion between adjacent magnetic poles on the outer peripheral surface of the magnetic rotor. In the state (i) above, at the position of the pole teeth viewed from the direction of the rotation axis, the radial component contained in the magnetic flux from the N pole toward the S pole is the largest, and the magnetic flux transmitted to the magnetic sensor is the largest. In the state (ii) above, at the position of the pole teeth viewed from the direction of the rotation axis, the radial component contained in the magnetic flux from the N pole toward the S pole is the smallest, and the magnetic flux transmitted to the magnetic sensor is the smallest. Therefore, the state (i) above and the state (ii) above can be clearly distinguished, so that the stop position of the magnetic rotor can be obtained with high accuracy. In addition, based on the waveform of the detected magnetic flux, the rotation direction of the magnetic rotor can be obtained.

[0015] In the present invention, it is preferable that a positioning recess is provided on the inner peripheral surface of the stator, and the positioning recess accommodates the magnetic sensor. Thereby, the magnetic sensor can be appropriately positioned relative to the stator.

[0016] In the present invention, it is preferred that the magnetic rotor moves to one side in the direction of the rotation axis when the port is closed, and moves to the other side in the direction of the rotation axis when the port is opened, and the magnetic sensor is arranged on the one side compared to the end face of the other side of the magnetic rotor in the state of closing the port, and the magnetic sensor is arranged on the other side compared to the end face of the one side of the magnetic rotor in the state of fully opening the port. Thus, in any state from the state of closing the port (valve closed state) to the state of fully opening the port (valve open state), the magnetic rotor moving in the direction of the rotation axis and the magnetic sensor are radially opposite. Therefore, the magnetic flux of the magnetic rotor can be reliably detected, so that the rotation angle of the magnetic rotor can be obtained with high accuracy.

[0017] In the present invention, it is preferred that the magnetic rotor moves to one side in the direction of the rotation axis when the port is closed, and moves to the other side in the direction of the rotation axis when the port is opened, and the magnetic sensor is arranged on the other side compared to the plurality of pole teeth of the stator, and is arranged to be radially opposite to the magnetic rotor across the housing in the state of closing the port. Thus, in any state from the state of closing the port (valve closed state) to the state of fully opening the port (valve open state), the magnetic rotor moving in the direction of the rotation axis and the magnetic sensor are radially opposite. Therefore, the magnetic flux of the magnetic rotor can be reliably detected, so that the rotation angle and rotation direction of the magnetic rotor can be obtained with high accuracy.

[0018] In the present invention, it is preferred that in any state from the state of closing the port to the state of fully opening the port, the position of the magnetic sensor in the direction of the rotation axis is within the range of the full length of the magnetic rotor. Thus, in any state from the state of closing the port (valve closed state) to the state of fully opening the port (valve open state), the magnetic rotor and the magnetic sensor are radially opposite. Therefore, the magnetic flux of the magnetic rotor can be reliably detected, so that the rotation angle and rotation direction of the magnetic rotor can be obtained with high accuracy.

[0019] In the present invention, it is preferred that in any state from the state of closing the port to the state of fully opening the port, the position of the stator in the direction of the rotation axis is within the full length of the magnetic rotor. Thus, in any state from the state of closing the port (valve closed state) to the state of fully opening the port (valve open state), the magnetic force of the stator can effectively act on the magnetic rotor, thereby enabling the magnetic rotor to effectively rotate.

[0020] In the present invention, it is preferred that a box is further provided, the box accommodating the housing and the stator, the box also accommodating a substrate, and the magnetic sensor is connected to the substrate via a wire. Thus, the magnetic sensor can be arranged at a position away from the substrate. Therefore, the position and posture of the substrate can be set relatively freely.

[0021] Effects of the Invention

[0022] According to the present invention, it is possible to reliably detect the magnetic flux generated from the magnetic rotor with a structure having a small number of parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a longitudinal sectional view showing a closed valve state of the electric valve according to the first embodiment of the present invention.

[0024] Figure 2 Yes means Figure 1 A longitudinal sectional view of the electric valve in the open state.

[0025] Figure 3 Yes Description Figure 1 Diagram of the magnetic rotor and stator of an electric valve.

[0026] Figure 4 yes Figure 1 A longitudinal sectional view of a stator of an electric valve.

[0027] Figure 5 It is a longitudinal sectional view showing a valve-closed state of an electric valve according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0028] (First embodiment)

[0029] Below, refer to Figure 1 to Figure 4 The electric valve according to the first embodiment of the present invention will be described. The electric valve 1 according to the present embodiment is used, for example, to adjust the flow rate of a refrigerant in a refrigeration cycle, etc. The same is true for the electric valve according to the second embodiment.

[0030] Figure 1 , Figure 2 It is a cross-sectional view (longitudinal cross-sectional view) along the axis L of the electric valve according to the first embodiment of the present invention. Figure 1 Indicates the closed state of the electric valve. Figure 2 Indicates the open state of the electric valve. Figure 3 Yes Description Figure 1 Diagram of the magnetic rotor and stator of an electric valve. Figure 3 (a) is along Figure 2 The sectional view of line XX. Figure 3 In (a), only the housing, the magnetic rotor, and the yoke of the upper stator of the stator are shown. Figure 3In (a), the position of the magnetic sensor is indicated by a dotted line. Figure 3 (b) is a three-dimensional diagram of the magnetic rotor. Figure 3 In (a) and (b), the magnetic poles (N pole and S pole) of the magnetic rotor are schematically shown. Figure 4 yes Figure 1 A longitudinal sectional view of a stator of an electric valve. Figure 4 Indicates along Figure 3 A cross section of straight line F1 and straight line F2 in (a).

[0031] like Figure 1 , Figure 2 As shown, the electric valve 1 includes a valve body 10 , a housing 30 , magnetic sensors 35 a and 35 b , a drive mechanism 40 , a valve element 50 , a stator 60 , and a case 70 .

[0032] The valve body 10 is made of a metal material such as aluminum alloy. The valve body 10 includes a main body 11 and a cylindrical portion 12. The main body 11 is formed in a rectangular parallelepiped shape. The cylindrical portion 12 protrudes upward from the upper surface 11a of the main body 11. A valve chamber 13 is provided inside the main body 11. Figure 1 The flow path 17 extending to the left side and to Figure 1 The flow path 18 extends to the right side of the valve chamber 13. The flow path 17 is connected to the valve chamber 13. The flow path 18 is connected to the valve chamber 13 via a port 19 opened to the valve chamber 13.

[0033] An external thread portion 12b is provided on a portion of the outer circumferential surface of the cylindrical portion 12. An internal thread portion 11b opened on the upper surface 11a is provided on the main body 11. The main body 11 and the cylindrical portion 12 are integrally combined by screwing the external thread portion 12b and the internal thread portion 11b. The inner space of the cylindrical portion 12 is connected to the valve chamber 13.

[0034] The valve body 10 further includes a flange 20. The flange 20 is made of a metal material such as stainless steel. The flange 20 is formed in a circular ring plate shape. An inner peripheral edge 20a of the flange 20 is joined to the upper end of the cylindrical portion 12 by brazing or the like.

[0035] The housing 30 is made of a metal material such as stainless steel. The housing 30 is formed into a cylindrical shape with a closed upper end. The lower end of the housing 30 is joined to the outer peripheral edge 20b of the flange 20 by welding or the like. A drive mechanism 40 is arranged inside the housing 30.

[0036] The magnetic sensors 35a and 35b are composed of, for example, Hall ICs. The Hall ICs have Hall elements and output signals corresponding to the direction and magnitude of the magnetic flux density passing through the magnetically sensitive surface. The magnetic sensors 35a and 35b may also be composed of magnetic sensors of a type other than Hall ICs. The rotation angle and rotation direction of the magnetic rotor 41 can be obtained based on the signals output by the magnetic sensors 35a and 35b. In the present embodiment, although the structure has two magnetic sensors 35a and 35b, it may also be a structure having only one magnetic sensor.

[0037] The magnetic sensors 35a and 35b are accommodated in the positioning recesses 66a and 66b of the stator 60. The magnetic sensors 35a and 35b are arranged on the outer peripheral surface 30a of the housing 30. Preferably, the magnetic sensors 35a and 35b are arranged in contact with the outer peripheral surface 30a of the housing 30. The magnetic sensors 35a and 35b may be arranged at a distance from the outer peripheral surface 30a of the housing 30 as long as they can detect the magnetic force of the magnetic rotor 41. That is, the magnetic sensors 35a and 35b may be arranged close to the outer peripheral surface 30a of the housing 30. The magnetic sensors 35a and 35b are arranged so that their respective magnetic sensing surfaces are along the outer peripheral surface 30a of the housing 30.

[0038] The drive mechanism 40 drives the valve body 50 in the up-down direction. The drive mechanism 40 includes a magnetic rotor 41 , a valve shaft holder 42 , a guide bushing 43 , and a valve shaft 44 .

[0039] The magnetic rotor 41 is formed in a substantially cylindrical shape. The outer diameter of the magnetic rotor 41 is slightly smaller than the inner diameter of the housing 30. A plurality of N poles and a plurality of S poles are provided on the outer peripheral surface 41a of the magnetic rotor 41. The plurality of N poles and the plurality of S poles extend in the direction of the axis L and are arranged alternately and at equal intervals in the circumferential direction. One N pole and one S pole may be provided. In the present embodiment, 12 N poles and 12 S poles are arranged alternately at intervals of 15 degrees. The magnetic rotor 41 is configured to be rotatable inside the housing 30. Figure 3 (a) and (b) are schematic diagrams showing the configuration of the N pole and the S pole of the magnetic rotor 41. Figure 3 In (a) and (b) of FIG. 1 , the shaded area schematically represents the N pole, and the dotted area schematically represents the S pole. The rotation axis of the magnetic rotor 41 coincides with the axis L.

[0040] The valve shaft holder 42 is formed into a cylindrical shape with a closed upper end. The support ring 45 is fixed to the upper end of the valve shaft holder 42 by caulking. The magnetic rotor 41 is integrally connected to the valve shaft holder 42 via the support ring 45. The inner peripheral surface of the valve shaft holder 42 is provided with an internal thread portion 42c.

[0041] The guide bushing 43 includes a large diameter cylindrical portion 43a and a small diameter cylindrical portion 43b. The outer diameter of the large diameter cylindrical portion 43a is larger than the outer diameter of the small diameter cylindrical portion 43b. The small diameter cylindrical portion 43b is coaxially connected to the upper end of the large diameter cylindrical portion 43a. An external threaded portion 43c is provided on the outer peripheral surface of the small diameter cylindrical portion 43b. The external threaded portion 43c is screwed into the internal threaded portion 42c of the valve shaft retainer 42. The large diameter cylindrical portion 43a is pressed into the inner side of the cylindrical portion 12 of the valve body 10. The guide bushing 43 is integrally combined with the valve body 10.

[0042] The valve shaft 44 has a cylindrical trunk 44a and a cylindrical upper small diameter portion 44b. The diameter of the upper small diameter portion 44b is smaller than the diameter of the trunk 44a. The upper small diameter portion 44b is coaxially connected to the upper end of the trunk 44a. The upper small diameter portion 44b is arranged to pass through the valve shaft retainer 42. A push nut 46 is installed on the upper small diameter portion 44b to prevent it from falling off. The valve shaft 44 has a step portion between the trunk 44a and the upper small diameter portion 44b. A compression coil spring 47 is arranged between the step portion and the valve shaft retainer 42. The valve shaft 44 is pressed downward by the compression coil spring 47.

[0043] An upper stopper 48 is mounted on the valve shaft holder 42. A lower stopper 49 is mounted on the large diameter cylindrical portion 43a of the guide bush 43. When the valve shaft holder 42 reaches the lower limit position by rotation, the upper stopper 48 abuts against the lower stopper 49 to restrict further rotation of the valve shaft holder 42.

[0044] The valve element 50 is provided integrally with the lower end portion of the valve shaft 44. The valve element 50 is driven to move in the up-down direction by the driving mechanism 40. The valve element 50 opens and closes the port 19 opened in the valve chamber 13.

[0045] The stator 60 is formed in a substantially cylindrical shape. The stator 60 has a fitting hole 60b defined by an inner peripheral surface 60a. The inner diameter of the fitting hole 60b is substantially the same as the outer diameter of the housing 30. The fitting hole 60b of the stator 60 is fitted into the housing 30. The stator 60 is arranged outside the housing 30. The stator 60 has an upper stator 61, a lower stator 62, and a molded part 65 made of synthetic resin.

[0046] The upper stator 61 and the lower stator 62 are arranged to overlap each other. Figure 4As shown, the upper stator 61 has a yoke 61a and a coil 61c wound on the yoke 61a via a coil frame 61b. The yoke 61a has a plurality of claw-pole type pole teeth 63. The plurality of pole teeth 63 are arranged at equal intervals in the circumferential direction. In the present embodiment, the yoke 61a has 24 pole teeth 63. The plurality of pole teeth 63 have downward pole teeth 63a with the top end (thinner end) facing downward and upward pole teeth 63b with the top end facing upward. The plurality of downward pole teeth 63a and the plurality of upward pole teeth 63b are arranged alternately in the circumferential direction.

[0047] The upper stator 61 and the lower stator 62 are arranged to overlap each other. Figure 4 As shown, the upper stator 61 has a yoke 61a and a coil 61c wound on the yoke 61a via a coil frame 61b. The yoke 61a has a plurality of claw-pole type pole teeth 63. The plurality of pole teeth 63 are arranged at equal intervals in the circumferential direction. In the present embodiment, the yoke 61a has 24 pole teeth 63. The plurality of pole teeth 63 have downward pole teeth 63a with the top end (thinner end) facing downward and upward pole teeth 63b with the top end facing upward. The plurality of downward pole teeth 63a and the plurality of upward pole teeth 63b are arranged alternately in the circumferential direction.

[0048] The lower stator 62 has the same structure as the upper stator 61. The lower stator 62 has a yoke 62a, a coil frame 62b, a coil 61c, and a plurality of claw-pole type pole teeth 64 (a downward pole tooth 64a and an upward pole tooth 64b). The lower stator 62 is arranged to be offset in the circumferential direction by half the interval between the plurality of pole teeth 63 relative to the upper stator 61. In the present embodiment, the interval between the plurality of pole teeth 63 and the interval between the plurality of pole teeth 64 are 15 degrees (360 degrees / 24), respectively, and the lower stator 62 is arranged to be offset in the circumferential direction by 7.5 degrees (15 degrees / 2) relative to the upper stator 61. The upper stator 61, the lower stator 62, and the magnetic rotor 41 constitute a stepping motor. In addition, although the present embodiment describes a structure in which the stator 60 has claw-pole type pole teeth, a structure having other types of pole teeth may also be adopted.

[0049] The molded material 65 is filled in the upper stage stator 61 and the lower stage stator 62. The molded material 65, together with the plurality of pole teeth 63 and the plurality of pole teeth 64, constitute the inner peripheral surface 60a of the stator 60. The molded material 65 has an annular portion 66 and a terminal support portion 67.

[0050] The annular portion 66 is formed in a circular ring shape. The annular portion 66 has an inner diameter that is the same as the outer diameter of the housing 30. The annular portion 66 is arranged on the upper surface of the upper stator 61. Positioning recesses 66a and 66b are provided on the inner circumferential surface of the annular portion 66 (i.e., the upper part of the inner circumferential surface 60a). The positioning recesses 66a and 66b are recesses for accommodating the magnetic sensors 35a and 35b. The positioning recesses 66a and 66b are open upward. The magnetic sensor 35a is accommodated in the positioning recess 66a on one side. The magnetic sensor 35b is accommodated in the positioning recess 66b on the other side.

[0051] The magnetic sensors 35a and 35b are arranged to face the outer peripheral surface 41a of the magnetic rotor 41 in the radial direction of the magnetic rotor 41 via the housing 30 in any state from the state of closing the port 19 (valve closing state) to the state of fully opening the port 19 (valve opening state). In addition, the magnetic sensors 35a and 35b are arranged on the lower side than the end surface on the upper side of the magnetic rotor 41 in the valve closing state, and are arranged on the upper side than the end surface on the lower end side of the magnetic rotor 41 in the valve opening state. The magnetic sensors 35a and 35b are arranged on the upper side than the plurality of pole teeth 63.

[0052] When viewed from the rotation axis direction of the magnetic rotor 41, the magnetic sensor 35a is arranged on a straight line F1 passing through the rotation axis (axis L) and the center of one pole tooth 63 of the upper stator 61. The "center" of the pole tooth 63 includes not only the center but also the approximate center, and the same applies to the following description. In the structure having the yoke 61a with a plurality of claw-pole type pole teeth 63, when the magnetic rotor 41 stops rotating, it becomes any of the following states: (i) a state in which the pole teeth 63 face the magnetic poles of the magnetic rotor 41; (ii) a state in which the pole teeth 63 face the adjacent magnetic poles on the outer peripheral surface 41a of the magnetic rotor 41. In the above state (i), at the position of the pole tooth 63 viewed from the rotation axis direction, the radial component included in the magnetic flux from the N pole to the S pole is the largest, and the magnetic flux transmitted to the magnetic sensor 35a is the largest. In the state (ii) above, at the position of the pole tooth 63 observed from the rotation axis direction, the radial component contained in the magnetic flux from the N pole to the S pole is the smallest, and the magnetic flux transmitted to the magnetic sensor 35a is the smallest. Therefore, the state (i) above and the state (ii) above can be clearly distinguished, so that the stop position of the magnetic rotor can be obtained with high accuracy. In addition, based on the waveform of the detected magnetic flux, the rotation direction of the magnetic rotor 41 can be obtained.

[0053] When viewed from the rotation axis direction of the magnetic rotor 41, the magnetic sensor 35b is arranged on a straight line F2 passing through the rotation axis and the center of one pole tooth 64 of the lower stator 62. In the magnetic sensor 35b, the state (i) and the state (ii) can be clearly distinguished in the same manner as described above, so that the stop position of the magnetic rotor can be obtained with high accuracy.

[0054] In addition, it is preferable that the magnetic sensor 35a and the magnetic sensor 35b are arranged at a distance θ [degrees] expressed by the following formula (1).

[0055] θ=(90 / n)+(360×m) / n…(1)

[0056] Here, n is a value that is 1 / 2 of the number of pole teeth of a stator, m is an arbitrary integer, and θ<360 degrees.

[0057] When the magnetic sensors 35a and 35b are arranged to satisfy the above formula (1), one of the magnetic sensors 35a and 35b faces the magnetic pole of the magnetic rotor 41, and the other faces the portion between the adjacent magnetic poles in the outer peripheral surface 41a of the magnetic rotor 41. Thus, when the magnetic flux detected by one of the magnetic sensors 35a and 35b is maximum, the magnetic flux detected by the other is minimum. Therefore, the rotation angle of the magnetic rotor 41 can be obtained with higher accuracy. In addition, the rotation direction of the magnetic rotor 41 can be obtained based on the waveform of the detected magnetic flux.

[0058] The terminal support portion 67 is arranged to extend from the upper stator 61 and the lower stator 62 to the side ( Figure 1 The terminal support portion 67 has a plurality of terminals 68 embedded therein. The plurality of terminals 68 are connected to the coil 61c of the upper stator 61 and the coil 62c of the lower stator 62. The plurality of terminals 68 protrude from the top end 67a of the terminal support portion 67 and are connected to a substrate 75 described later through a flexible substrate or the like.

[0059] The box 70 is formed in a substantially rectangular box shape. The box 70 is configured to accommodate the housing 30 and the stator 60. The box 70 has a cylindrical barrel portion 73 protruding toward the valve body 10 side. The barrel portion 73 is configured to surround the cylindrical portion 12 of the valve body 10. A sealing member 100 is arranged in a compressed state between the barrel portion 73 and the cylindrical portion 12. The sealing member 100 is an annular O-ring made of an elastic material such as a rubber material.

[0060] In addition, the box 70 accommodates a substrate 75. The substrate 75 is a printed circuit board for mounting electronic components. The substrate 75 is arranged above the housing 30 in a posture perpendicular to the axis L. In addition, the position and posture of the substrate 75 are arbitrary. The substrate 75 is connected to the magnetic sensors 35a and 35b through the wire 77. The wire 77 is, for example, a lead wire, a flexible substrate, etc. that can be bent and stretched freely and can maintain a shape to a degree that can be independent. A computing device composed of a computer or the like can also be installed on the substrate 75. The computing device is a structure that calculates the rotation angle of the magnetic rotor 41 and the valve opening (opening of the port 19) based on the signal output by the magnetic sensors 35a and 35b.

[0061] In the electric valve 1, the cylindrical portion 12 of the valve body 10, the port 19, the housing 30, the magnetic rotor 41, the valve shaft holder 42, the guide bushing 43, the valve shaft 44, the valve core 50, the stator 60 (the upper stator 61, the lower stator 62, the annular portion of the molded part 65), and the cylindrical portion 73 of the box 70 have their respective axes aligned with the axial direction L. In other words, all of these components are coaxially arranged. The axial direction L is aligned with the up-down direction.

[0062] Next, the operation of the electric valve 1 will be described.

[0063] In the electric valve 1, the upper stator 61 and the lower stator 62 are energized to rotate the magnetic rotor 41 in one direction. The valve shaft holder 42 rotates together with the magnetic rotor 41. The magnetic rotor 41 and the valve shaft holder 42 move downward (i.e., one side in the direction of the rotation axis) by the thread feed action of the internal thread 42c of the valve shaft holder 42 and the external thread 43c of the guide bushing 43. The valve shaft 44 also moves downward together with the valve shaft holder 42, so that the valve core 50 closes the port 19 (valve closed state).

[0064] In addition, in the electric valve 1, the upper stator 61 and the lower stator 62 are energized to rotate the magnetic rotor 41 in the other direction. The valve shaft holder 42 rotates together with the magnetic rotor 41. The magnetic rotor 41 and the valve shaft holder 42 move upward (i.e., the other side of the rotation axis direction) by the thread feed action of the internal thread 42c of the valve shaft holder 42 and the external thread 43c of the guide bushing 43. The valve shaft 44 also moves upward together with the valve shaft holder 42, so that the valve core 50 opens the port 19 (valve opening state).

[0065] Furthermore, when the magnetic rotor 41 rotates, the positional relationship between each N pole and each S pole provided on the outer peripheral surface 41a and the magnetic sensors 35a and 35b changes, so that the direction and magnitude of the magnetic flux density detected by the magnetic sensors 35a and 35b change. Thus, the signal output from the magnetic sensors 35a and 35b changes according to the rotation angle of the magnetic rotor 41, and the rotation angle and rotation direction of the magnetic rotor 41 can be obtained based on the signal.

[0066] As described above, according to the electric valve 1 of this embodiment, on the outer surface 41a of the magnetic rotor 41 arranged on the inner side of the housing 30, a plurality of N poles and a plurality of S poles extending in the direction of the rotation axis of the magnetic rotor 41 are arranged in a manner alternately arranged in the circumferential direction. In addition, on the outer peripheral surface 30a of the housing 30, magnetic sensors 35a and 35b are arranged to face the magnetic rotor 41 in the radial direction via the housing. The magnetic flux generated by the magnetic poles (N poles and S poles) of the magnetic rotor 41 is easily transmitted in the radial direction. Therefore, by arranging the magnetic sensors 35a and 35b in a manner close to the magnetic rotor 41 in the radial direction, the magnetic flux can be effectively transmitted to the magnetic sensors 35a and 35b. As a result, the magnetic flux generated from the magnetic rotor 41 can be reliably detected by a structure with a small number of parts.

[0067] Furthermore, positioning recesses 66a and 66b for accommodating the magnetic sensors 35a and 35b are provided on the inner peripheral surface 60a of the stator 60. Thus, the magnetic sensors 35a and 35b can be appropriately positioned relative to the pole teeth 63 and 64 of the stator 60.

[0068] In addition, the magnetic rotor 41 moves downward when the port 19 is closed, and moves upward when the port 19 is opened. The magnetic sensors 35a and 35b are arranged above the plurality of pole teeth 63 of the upper stator 61 of the stator 60. Furthermore, the magnetic sensors 35a and 35b are arranged to be radially opposite to the magnetic rotor 41 via the housing 30 in the state of closing the port. Thus, the magnetic rotor 41 and the magnetic sensors 35a and 35b are radially opposite to each other from the closed valve state to the open valve state. Therefore, in any state from the closed valve state to the open valve state, the magnetic flux of the magnetic rotor 41 can be reliably detected, so that the rotation angle and rotation direction of the magnetic rotor 41 can be obtained with high accuracy.

[0069] In addition, the electric valve 1 has a box 70 that accommodates the housing 30 and the stator 60. The box 70 accommodates a substrate 75. The magnetic sensors 35a and 35b are connected to the substrate 75 through the wires 77. Thus, the magnetic sensors 35a and 35b can be arranged at a position away from the substrate 75. Therefore, the position and posture of the substrate 75 can be set relatively freely.

[0070] (Second embodiment)

[0071] Below, refer to Figure 5 An electric valve according to a second embodiment of the present invention will be described. Figure 5 is a longitudinal sectional view of an electric valve according to a second embodiment of the present invention,

[0072] like Figure 5As shown, the electric valve 2 of the second embodiment includes a valve body 10 , a housing 30 , magnetic sensors 35 a and 35 b , a drive mechanism 80 , a valve element 55 , a stator 60 , and a case 70 .

[0073] The electric valve 2 has the same (including substantially the same) structure as the electric valve 1 except that it has a drive mechanism 80 and a valve core 55 which are different in structure from the electric valve 1 of the first embodiment. In the following description, the same reference numerals are given to the same structures as those of the first embodiment and the description thereof is omitted.

[0074] The drive mechanism 80 drives the valve body 55 in the up-down direction. The drive mechanism 80 includes a magnetic rotor 81 , a planetary gear mechanism 85 , a guide member 95 , a lifting shaft 96 , a ball 97 , and a valve opening spring 98 .

[0075] The magnetic rotor 81 is formed in a substantially cylindrical shape. The outer diameter of the magnetic rotor 81 is slightly smaller than the inner diameter of the housing 30. A plurality of N poles and a plurality of S poles are provided on the outer peripheral surface of the magnetic rotor 81, similarly to the magnetic rotor 41 of the first embodiment described above. The rotation axis of the magnetic rotor 81 coincides with the axis L. Even if the magnetic rotor 81 rotates, it does not move in the rotation axis direction. The upper end portion of the magnetic rotor 81 is integrally connected to the rotor shaft 83 via the rotor support member 82. The stepping motor is composed of the upper rotor 61, the lower stator 62, and the magnetic rotor 81.

[0076] In this embodiment, in any state from the closed valve state to the open valve state, the positions of the magnetic sensors 35a and 35b in the rotation axis direction are all located within the full length of the magnetic rotor 81 (i.e., from the lower end to the upper end of the magnetic rotor 81). Therefore, in any state from the closed valve state to the open valve state, the magnetic rotor 81 and the magnetic sensors 35a and 35b are all opposite to each other in the radial direction. Therefore, the magnetic flux of the magnetic rotor 81 can be reliably detected, and the rotation angle and rotation direction of the magnetic rotor 81 can be obtained with high accuracy.

[0077] In addition, in the present embodiment, the positions of the upper stator 61 and the lower stator 62 of the stator 60 in the direction of the rotation axis are always within the range of the full length of the magnetic rotor 81. Thus, from the closed valve state to the open valve state, the magnetic forces of the upper stator 61 and the lower stator 62 can effectively act on the magnetic rotor 81, so that the magnetic rotor 81 can be effectively rotated.

[0078] The planetary gear mechanism 85 is arranged inside the magnetic rotor 81. The planetary gear mechanism 85 includes a sun gear 86, a fixed ring gear 87, a plurality of planetary gears 88, a planetary gear carrier 89, an output gear 90, an output shaft 91, and a gear box 92. The sun gear 86 is provided integrally with the rotor support member 82. The fixed ring gear 87 is an internal gear. The fixed ring gear 87 is fixed to the upper end of the cylindrical gear box 92. The planetary gears 88 are arranged between the sun gear 86 and the fixed ring gear 87. The planetary gears 88 mesh with the sun gear 86 and the fixed ring gear 87. The planetary gear carrier 89 supports the plurality of planetary gears 88 so as to be rotatable. The output gear 90 is formed in a bottomed cylindrical shape. The output gear 90 is an internal gear. The output gear 90 meshes with the plurality of planetary gears 88 from the outside. The upper portion of the output shaft 91 is fixed to a hole formed at the bottom of the output gear 90 by press-fitting or the like. The gear box 92 is mounted on the upper end portion of the cylindrical portion 12 of the valve body 10.

[0079] The guide member 95 is formed in a cylindrical shape and is arranged inside the upper end portion of the cylindrical portion 12 of the valve body 10. The guide member 95 has an internal thread portion 95a formed on its inner peripheral surface.

[0080] The lifting shaft 96 is formed in a cylindrical shape. An external thread portion 96a is provided on the outer peripheral surface of the lifting shaft 96. The external thread portion 96a is screwed with the internal thread portion 95a of the guide member 95. The lifting shaft 96 is provided with a flat plate portion 96b protruding upward from the upper end surface. The flat plate portion 96b is inserted into the slit 91a provided in the output shaft 91 of the planetary gear mechanism 85 in a manner that can move in the up-down direction. The lifting shaft 96 rotates along with the rotation of the output shaft 91, and moves in the up-down direction by the thread feeding action of the external thread portion 96a and the internal thread portion 95a.

[0081] The ball 97 is disposed between the lifting shaft 96 and the valve body 55. The valve opening spring 98 is composed of a compression coil spring. The valve opening spring 98 is disposed between the valve body 55 and the valve body 10.

[0082] The valve element 55 is formed in a substantially cylindrical shape. The lower end of the valve element 55 is disposed facing the port 19 in the vertical direction. The upper end of the valve element 55 is connected to the lifting shaft 96 via the ball 97. The valve element 55 is pressed upward by the valve opening spring 98.

[0083] Next, the operation of the electric valve 2 will be described.

[0084] In the electric valve 2, the upper stator 61 and the lower stator 62 are energized to rotate the magnetic rotor 81 in one direction. When the magnetic rotor 81 rotates, the lifting shaft 96 rotates together with the output shaft 91 of the planetary gear mechanism 85. The lifting shaft 96 moves downward (i.e., one side in the direction of the rotation axis) by the thread feeding action of the external thread portion 96a of the lifting shaft 96 and the internal thread portion 95a of the guide member 95. The valve core 55 is pressed downward by the lifting shaft 96, so that the valve core 55 closes the port 19 (valve closed state).

[0085] In addition, in the electric valve 2, the upper stator 61 and the lower stator 62 are energized to rotate the magnetic rotor 81 in the other direction. When the magnetic rotor 81 rotates, the lifting shaft 96 rotates together with the output shaft 91 of the planetary gear mechanism 85. The lifting shaft 96 moves upward (that is, the other side of the rotation axis direction) by the thread feeding action of the external thread portion 96a of the lifting shaft 96 and the internal thread portion 95a of the guide member 95. When the lifting shaft 96 moves upward, the valve core 55 is pressed upward by the valve opening spring 98, so that the valve core 55 opens the port 19 (valve opening state).

[0086] Furthermore, when the magnetic rotor 81 rotates, the positional relationship between each N pole and each S pole provided on the outer peripheral surface and the magnetic sensors 35a, 35b changes, so that the direction and magnitude of the magnetic flux density detected by the magnetic sensors 35a, 35b change. That is, the signal output from the magnetic sensors 35a, 35b changes according to the rotation angle of the magnetic rotor 81, and the rotation angle of the magnetic rotor 81 can be obtained based on the signal.

[0087] The electric valve 2 of this embodiment also achieves the same operational effects as the electric valve of the first embodiment described above.

[0088] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. As long as it does not violate the gist of the present invention, the structures obtained by adding, deleting, and designing the structural elements of the above-mentioned embodiments by those skilled in the art, and the structures obtained by appropriately combining the features of the embodiments are also included in the scope of the present invention.

[0089] Explanation of symbols

[0090] (First embodiment)

[0091] 1...electric valve, 10...valve body, 11...body, 11a...upper surface, 11b...internal thread, 12...cylindrical portion, 12b...external thread, 13...valve chamber, 17, 18...flow path, 19...port, 20...flange, 30...housing, 30a...outer peripheral surface, 35a, 35b...magnetic sensor, 40...driving mechanism, 41...magnetic rotor, 41a...outer peripheral surface, 42...valve shaft holder, 42c...internal thread, 43...guide bushing, 43a...large diameter cylindrical portion, 43b...small diameter cylindrical portion, 43c...external thread, 44...valve shaft, 44a...trunk, 44b...upper small diameter portion, 45...support ring , 46...thrust nut, 47...compression coil spring, 48...upper stopper, 49...lower stopper, 50...valve core, 60...stator, 60a...inner circumferential surface, 60b...fitting hole, 61...upper stator, 61a...yoke, 61b...coil frame, 61c...coil, 62...lower stator, 62a yoke, 62b...coil frame, 62c...coil, 63, 64...pole teeth, 63a, 64a...downward pole teeth, 63b, 64b...upward pole teeth, 65...molded part, 66...annular part, 66a, 66b...positioning recess, 67...terminal support part, 67a...top end, 68...terminal, 70...box, 100...sealing member

[0092] (Second embodiment)

[0093] 2...electric valve, 55...valve core, 80...driving mechanism, 81...magnetic rotor, 82...rotor support member, 83...rotor shaft, 85...planetary gear mechanism, 86...sun gear, 87...fixed ring gear, 88...planetary gear, 89...planetary gear carrier, 90...output gear, 91...output shaft, 91a...slit, 92...gear box, 95...guide member, 95a...internal thread portion, 96...lifting shaft, 96a...external thread portion, 96b...flat plate portion, 97...ball, 98...valve opening spring

Claims

1. An electric valve, comprising: a valve body; a cylindrical shell, the shell being mounted on the valve body; a cylindrical magnetic rotor, the magnetic rotor being arranged inside the shell; a valve core, the valve core being driven to open and close a port in the valve body by the rotation of the magnetic rotor; and a stator, the stator being arranged outside the shell, wherein the electric valve is characterized in that: On the outer peripheral surface of the magnetic rotor, one or more N poles and S poles extending in the direction of the rotation axis of the magnetic rotor are arranged alternately in the circumferential direction. The magnetic sensor is arranged to be opposite to the magnetic rotor in the radial direction via the housing. The magnetic sensor is arranged on a straight line passing through the rotation axis of the magnetic rotor and the center of one of a plurality of pole teeth included in the stator when viewed in the rotation axis direction.

2. The electric valve according to claim 1, characterized in that: A positioning recess is provided on the inner circumferential surface of the stator, and the magnetic sensor is accommodated in the positioning recess.

3. The electric valve according to claim 1 or 2, characterized in that: When the port is closed, the magnetic rotor moves to one side of the rotation axis direction, and when the port is opened, the magnetic rotor moves to the other side of the rotation axis direction. The magnetic sensor is arranged on the one side relative to the other end surface of the magnetic rotor when the port is closed, and is arranged on the other side relative to the one end surface of the magnetic rotor when the port is fully opened.

4. The electric valve according to claim 1 or 2, characterized in that: When the port is closed, the magnetic rotor moves to one side of the rotation axis direction, and when the port is opened, the magnetic rotor moves to the other side of the rotation axis direction. The magnetic sensor is disposed on the other side of the plurality of pole teeth of the stator, and is disposed to face the magnetic rotor in a radial direction via the housing in a state where the port is closed.

5. The electric valve according to claim 1 or 2, characterized in that: In any state from a state in which the port is closed to a state in which the port is fully opened, the position of the magnetic sensor in the rotation axis direction is within the range of the entire length of the magnetic rotor.

6. The electric valve according to claim 5, characterized in that: In any state from a state in which the port is closed to a state in which the port is fully opened, the position of the stator in the rotation axis direction is within the range of the full length of the magnetic rotor.

7. The electric valve according to claim 1 or 2, characterized in that: A box is also provided, the box accommodating the housing and the stator, The box also contains a substrate. The magnetic sensor is connected to the substrate through a wire.

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