Patent ID: 12234923

DESCRIPTION OF EMBODIMENTS

First Embodiment

An electric valve1according to a first embodiment of the present invention is illustrated below with reference toFIG.1toFIG.9.

FIG.1is a sectional view of an electric valve according to the first embodiment of the present invention.FIG.2is a sectional view of a stator unit of the electric valve inFIG.1.FIG.3is a perspective view of a main circuit board of the electric valve inFIG.1.FIG.4is a perspective view of a sub circuit board of the electric valve inFIG.1.FIG.5is a sectional view taken along line V-V ofFIG.1. InFIG.5, members disposed in an inner space of the stator unit are omitted.FIG.6is a perspective view of the stator unit inFIG.2during assembly.FIG.7is an enlarged perspective view of a part ofFIG.6.FIG.6andFIG.7illustrate the stator unit before the sub circuit board is located in a sub circuit board space of the housing.FIG.8is another perspective view of the stator unit inFIG.2during assembly.FIG.9is an enlarged perspective view of a part ofFIG.8.FIG.8andFIG.9illustrate the stator unit after the sub circuit board is located in the sub circuit board space of the housing. In each figure, an X direction indicated by the arrow X is a left-and-right direction (a lateral direction), a Y direction indicated by the arrow Y is a front-and-back direction, and a Z direction indicated by the arrow Z is an up-and-down direction. A direction with the letter “X” on the arrow X is a right direction, a direction with the letter “Y” on the arrow Y is a front direction, and a direction with the letter “Z” on the arrow Z is an upward direction.

As illustrated in the figures, an electric valve1includes a valve body10, a can20, a driving section30, a valve member40, and a stator unit50.

The valve body10is made of a metal such as an aluminum alloy. The valve body10includes a main body portion11, a circular cylindrical portion12, and a flange portion13. The main body portion11has a rectangular parallelepiped shape. The circular cylindrical portion12projects from the upper surface of the main body portion11. The circular cylindrical portion12is mounted on the main body portion11by a screw structure. A valve chamber14and flow channels15and16are provided in the main body portion11. The flow channel15is connected to the valve chamber14. The flow channel16is connected to the valve chamber14via a port17. The flange portion13has an annular plate-like shape. The inner peripheral edge of the flange portion13is bonded to the upper portion of the circular cylindrical portion12.

The can20is made of a metal such as stainless steel. The can20has a circular cylindrical shape that is closed at the upper end. The lower end of the can20is bonded to the outer peripheral edge of the flange portion13.

The driving section30moves the valve member40in the up-and-down direction (a direction of an axis L). The driving section30includes a magnet rotor31, a valve stem holder32, a guide bush33, a valve stem34, and a permanent magnet38.

The magnet rotor31has a circular cylindrical shape. The outer diameter of the magnet rotor31is slightly smaller than the inner diameter of the can20. Multiple N poles and multiple S poles are provided on the outer circumferential surface of the magnet rotor31. The multiple N poles and multiple S poles extend in the up-and-down direction and are arranged alternately and circumferentially at equal intervals. In the present embodiment, the magnet rotor31includes 12 N poles and 12 S poles.

The valve stem holder32has a circular cylindrical shape that is closed at the upper end. A supporting ring35is fixed to the upper portion of the valve stem holder32. The magnet rotor31and the valve stem holder32are coupled together by the supporting ring35. The inner circumferential surface of the valve stem holder32has an internal thread32c.

The guide bush33integrally includes a first circular cylindrical portion33aand a second circular cylindrical portion33b. The outer diameter of the second circular cylindrical portion33bis smaller than the outer diameter of the first circular cylindrical portion33a. The second circular cylindrical portion33bis provided coaxially and continuously with the upper end of the first circular cylindrical portion33a. The outer circumferential surface of the second circular cylindrical portion33bhas an external thread33c. The external thread33cis screwed into the internal thread32cof the valve stem holder32. The first circular cylindrical portion33ais press-fitted into a fitting hole12athat is provided in the circular cylindrical portion12of the valve body10. The guide bush33is coupled to the valve body10.

The valve stem34has a circular columnar shape. The valve stem34includes an upper portion34athat extends through the valve stem holder32. A push nut36as a retainer is attached to the upper portion34aof the valve stem34. The valve stem34is disposed in the guide bush33and the circular cylindrical portion12. The lower portion of the valve stem34is disposed in the valve chamber14. The valve stem34has a step portion34b. The step portion34bis an annular plane facing upward. A valve closing spring37is disposed between the valve stem holder32and the step portion34bof the valve stem34. The valve closing spring37is a compression coil spring. The valve closing spring37pushes the valve stem34downward.

The permanent magnet38is located above the magnet rotor31inside the can20. The permanent magnet38has an annular flat plate-like shape. The permanent magnet38includes one N pole and one S pole that are disposed so as to face radially each other. The permanent magnet38is fixed to the supporting ring35via a fixing member39. The permanent magnet38rotates together with the magnet rotor31.

The valve member40is provided integrally and continuously with the lower end of the valve stem34. The valve member40is disposed in the valve chamber14. The driving section30moves the valve member40in the up-and-down direction. The movement of the valve member40opens and closes the port17.

The stator unit50includes a stator60, a housing70, and a case80, a main circuit board90, a sub circuit board100, and a magnetic sensor110.

The stator60has a circular cylindrical shape. The stator60and the magnet rotor31are members of a stepping motor. The stator60includes an upper stator61, a lower stator62, and a mold63that is made of synthetic resin.

The upper stator61is disposed coaxially on the lower stator62. The upper stator61includes multiple claw-pole-type pole teeth61aand61bthat are arranged circumferentially at equal intervals. The lower stator62includes multiple claw-pole-type pole teeth62aand62bthat are arranged circumferentially at equal intervals. In this embodiment, the upper stator61includes 12 pole teeth61aand 12 pole teeth61b. The lower stator62includes 12 pole teeth62aand 12 pole teeth62b. The tip ends of the pole teeth61aand62apoint downward, and the tip ends of the pole teeth61band62bpoint upward. One pole tooth62ais located in the center position between the pole teeth61aand61badjacent to each other when viewed in the direction of the axis L. One pole tooth62bis located in the center position between the pole teeth61aand61badjacent to each other when viewed in the direction of the axis L. When the upper stator61is energized, the pole teeth61aand the pole teeth61bhave mutually opposite polarities. When the lower stator62is energized, the pole teeth62aand the pole teeth62bhave mutually opposite polarities. The mold63fills the upper stator61and the lower stator62. The mold63and the pole teeth61a,61b,62a, and62bform an inner circumferential surface60aof the stator60. The diameter of the inner circumferential surface60aof the stator60is equal to the diameter of the outer circumferential surface of the can20. The mold63includes a terminal supporting portion64.

The terminal supporting portion64extends from the upper stator61and the lower stator62in the lateral direction. The terminal supporting portion64supports multiple terminals65. The terminals65extend from the tip end of the terminal supporting portion64in the lateral direction. The terminals65are connected to a coil of the upper stator61and a coil of the lower stator62.

The housing70is made of synthetic resin. The housing70is formed by injection molding. The housing70houses the stator60. The housing70may be formed by integrally molding (insert molding) with the stator60. The stator60and the housing70may be manufactured separately, and the stator60may be fitted inside the housing70. The housing70integrally includes a peripheral wall portion71, a dome portion72, and a tubular portion73.

The peripheral wall portion71has a circular cylindrical shape. The stator60is disposed inside the peripheral wall portion71. The dome portion72has a circular cylindrical shape that is closed at the upper end. The outer diameter of the dome portion72is smaller than the outer diameter of the peripheral wall portion71. The dome portion72is provided continuously with the upper end of the peripheral wall portion71. The dome portion72has an inner circumferential surface72a(that is, the inner circumferential surface of the housing70) that has a diameter equal to the diameter of the inner circumferential surface60aof the stator60. The inner circumferential surface72aof the dome portion72continues to the inner circumferential surface60aof the stator60. The inner circumferential surface72aof the dome portion72and the inner circumferential surface60aof the stator60form an inner space74of the stator unit50. The can20is inserted into the inner space74, and the stator60is disposed on the outer circumferential surface of the can20. The tubular portion73has a circular cylindrical shape. The outer diameter of the tubular portion73is smaller than the outer diameter of the peripheral wall portion71. The tubular portion73is provided continuously with the lower end of the peripheral wall portion71. The tubular portion73is disposed such that the tubular portion73encloses the circular cylindrical portion12of the valve body10. The tubular portion73and the circular cylindrical portion12form a gap in which a seal18in an annular shape is disposed. The seal18is made of an elastic material such as a rubber material. The seal18inhibits water from entering the inner space74.

The housing70includes a sub circuit board space75. The sub circuit board space75extends in the lateral direction and opens to the side surface of the housing70. The sub circuit board space75is located adjacent to the inner space74. A partition wall76is disposed between the inner space74and the sub circuit board space75. The partition wall76separates the sub circuit board space75from the inner space74. As illustrated inFIG.5, the cross section of the partition wall76has an arc shape along the outer circumferential surface of the can20.

Two press-fit grooves77are provided on the inner surface of the sub circuit board space75. The press-fit grooves77extend in the lateral direction. The press-fit grooves77are disposed so as to face each other in the front-and-back direction. Multiple projections78are provided on each of the inner surfaces of the press-fit grooves77. Some projections78of the multiple projections78(projections78ainFIG.7) are disposed so as to face each other in the up-and-down direction. Other projections78of the multiple projections78(projections78bof one press-fit groove77inFIG.7and projections78bof the other press-fit groove77not illustrated) are disposed so as to face each other in the front-and-back direction. The projections78are compressed and elastically deformed when the sub circuit board100is press-fitted into the press-fit grooves77. The multiple projections78press the sub circuit board100, which is press-fitted into the press-fit grooves77, in the up-and-down direction and the front-and-back direction and support the sub circuit board100.

The case80is made of synthetic resin. The case80is formed by injection molding. The case80is located laterally adjacent to the housing70. The case80includes a case body81, a lid body82, and a connector83. The case body81has a rectangular parallelepiped box shape with an opening on the side. The lid body82has a flat plate-like shape. The lid body82is disposed so as to close the opening on the side of the case body81. The connector83has an elliptical cylindrical shape. The connector portion83extends from the case body81in the lateral direction (right direction). The case body81and the connector83are integrally formed.

The case body81includes a side wall portion84. The side wall portion84has a flat plate-like shape. The side wall portion84is disposed so as to face the lid body82in the lateral direction. The side wall portion84has a case opening84ain a quadrangular shape. The case opening84ais connected to the sub circuit board space75of the housing70. The peripheral edge portion of the case opening84aon the side wall portion84is bonded to the housing70. In addition, the case body81includes multiple supporting columns85. The supporting columns85have a circular columnar shape. The supporting columns85extend from the side wall portion84in the lateral direction (right direction). Tip ends85aof the supporting columns85point in a direction away from the inner space74.

The main circuit board90is a printed circuit board on which electronic components are mounted. The main circuit board90has a flat plate-like shape. The main circuit board90is housed in the case80. The main circuit board90is disposed parallel to the front-and-back direction and the up-and-down direction. The main circuit board90includes a surface facing the inner space74on which a circuit board connector91is disposed. A microcomputer, not illustrated, is mounted on the main circuit board90. The microcomputer functions as a calculation device that calculates a signal output from the magnetic sensor110. The main circuit board90has penetrating holes92corresponding to each of the multiple supporting columns85. The tip ends85aof the supporting columns85are inserted into the penetrating holes92. Then, the tip ends85aof the supporting columns85are deformed to enlarge the diameters thereof beyond the diameters of the penetrating holes92by infrared caulking or the like. The main circuit board90is supported by the supporting columns85. The terminals65of the stator60are connected to the main circuit board90.

The sub circuit board100is a printed circuit board on which electronic components are mounted. The sub circuit board100has a flat plate-like shape. The sub circuit board100is disposed in the sub circuit board space75of the housing70. The sub circuit board100is disposed parallel to the lateral direction and the front-and-back direction. Both edges of the sub circuit board100that are opposite to each other in the front-and-back direction are press-fitted into the press-fit grooves77. The sub circuit board100is interposed by the projections78of the press-fit grooves77in the up-and-down direction and the front-and-back direction. The sub circuit board100is disposed at a right angle (including generally a right angle) to the main circuit board90. The sub circuit board100includes a first end100athat is located near the main circuit board90. The sub circuit board100includes a second end100bthat is located near the partition wall76of the housing70(that is, near the inner space74). The first end100aand the second end100bare opposite to each other in the left-and-right direction. The sub circuit board100extends from near the main circuit board90to near the inner space74. A portion in the second end100bfacing the partition wall76has an arc shape along the partition wall76. As a result, the sub circuit board100can be located closer to the partition wall76, and the distance between the magnet rotor31and the magnetic sensor110that is mounted on the sub circuit board100can be shortened.

Circuit board terminals101are located at the first end100aof the sub circuit board100. The circuit board terminals101are connected to the circuit board connector91of the main circuit board90. The sub circuit board100is connected to the main circuit board90via the circuit board terminals101and the circuit board connector91. The circuit board terminals101may be disposed on the main circuit board90, and the circuit board connector91may be disposed on the sub circuit board100.

The magnetic sensor110is a rotational angle sensor. The magnetic sensor110has a surface-mount package. The magnetic sensor110is located at the second end100bof the sub circuit board100. The magnetic sensor110is located closer to the inner space74than the circuit board terminals101is. The magnetic sensor110is located so as to face the permanent magnet38in the lateral direction with the can20and the partition wall76in between. The magnetic sensor110senses a magnetic field generated by the permanent magnet38and outputs the signal corresponding to a rotational angle of the permanent magnet38.

In the electric valve1, the respective axes of the circular cylindrical portion12of the valve body10, the port17, the can20, the magnet rotor31, the valve stem holder32, the guide bush33, the valve stem34, the valve member40, the inner space74of the stator unit50, the stator60(the upper stator61and the lower stator62), and the housing70(the peripheral wall portion71and the tubular portion73) are aligned with the axis L.

The operation of the electric valve1is described below.

In the electric valve1, the upper stator61and the lower stator62are energized to rotate the magnet rotor31in one direction. The valve stem holder32rotates together with the magnet rotor31. A screw-feed action between the internal thread32cof the valve stem holder32and the external thread33cof the guide bush33moves the valve stem holder32downward. The valve stem34moves downward together with the valve stem holder32, and the valve member40closes the port17(a valve-closing state).

In the electric valve1, the upper stator61and the lower stator62are energized to rotate the magnet rotor31in the other direction. The valve stem holder32rotates together with the magnet rotor31. The screw-feed action between the internal thread32cof the valve stem holder32and the external thread33cof the guide bush33moves the valve stem holder32upward. The valve stem34moves upward together with the valve stem holder32, and the valve member40opens the port17(a valve-opening state).

The permanent magnet38rotates together with the magnet rotor31inside the can20. The magnetic sensor110is located near the inner space74in which the can20is disposed. The magnetic sensor110outputs the signal corresponding to the rotational angle of the permanent magnet38. The signal output from the magnetic sensor110is sent from the sub circuit board100to the main circuit board90via the circuit board terminals101and the circuit board connector91. The microcomputer mounted on the main circuit board90calculates an opening degree of the port17or the like based on the signal output from the magnetic sensor110.

A method for assembling the electric valve1is described below.

The stator unit50is assembled. First, the stator60is installed in a housing mold, and the housing70is formed by injection molding such that the stator60and the housing70are integrated. A terminal component of the connector83is installed in a case mold, and the case body81and the connector83are formed by injection molding such that the case body81, the connector83and the terminal component are integrated. The lid body82is formed by injection molding. As illustrated inFIG.6, the side wall portion84of the case body81is bonded to the housing70by ultrasonic welding or infrared welding, and the sub circuit board space75and the case opening84aare connected. As illustrated inFIG.8, the sub circuit board100is inserted into the sub circuit board space75through the case opening84a. At this time, both the edges of the sub circuit board100that are opposite to each other in the front-and-back direction are press-fitted into the press-fit grooves77. As a result, the sub circuit board100is supported by the press-fit grooves77. The sub circuit board100is disposed across the case80and the sub circuit board space75. As the circuit board terminals101of the sub circuit board100are connected to the circuit board connector91of the main circuit board90, the tip ends85aof the supporting columns85are inserted into the penetrating holes92of the main circuit board90. The tip ends85aof the supporting columns85are deformed and enlarged by infrared caulking. As a result, the main circuit board90is supported by the supporting columns85. The terminals65of the stator60are soldered to the main circuit board90. The lid body82is bonded to the case body81, and the stator unit50is completed.

A valve body assembly is manufactured by combining the valve body10, the can20, the driving section30, and the valve member40in a process separate from the assembling process for the stator unit50. Then, the can20is inserted into the inner space74of the stator unit50, the stator unit50is fixed to the valve body10, and the electric valve1is completed.

As described above, the electric valve1includes the valve body10, the can20that is bonded to the valve body10, the magnet rotor31that is disposed inside the can20, and the stator unit50that includes the inner space74in which the can20is disposed. The stator unit50includes the housing70, the stator60in the circular cylindrical shape that is housed in the housing70, the main circuit board90in the flat plate-like shape that is disposed parallel to the up-and-down direction, the sub circuit board100in the flat plate-like shape that is disposed at a right angle to the main circuit board90, and the magnetic sensor110that is mounted on the sub circuit board100. The housing70includes the sub circuit board space75that is located adjacent to the inner space74. The first end100aof the sub circuit board100is connected to the main circuit board90via the circuit board terminals101. The second end100bof the sub circuit board100is located near the inner space74in the sub circuit board space75. The magnetic sensor110is located at the second end100bof the sub circuit board100.

In the electric valve1, the sub circuit board100is disposed at a right angle to the main circuit board90, and the second end100bof the sub circuit board100is located near the inner space74. The magnetic sensor110is located at the second end100bof the sub circuit board100. Therefore, the magnetic sensor110can be located near the can20. The main circuit board90is disposed parallel to the up-and-down direction, which reduces both the shape in plan view and the height dimension of the electric valve1. The electronic components are shared by and mounted on the main circuit board90and the sub circuit board100, allowing the main circuit board90to be decreased in size. Therefore, the magnetic sensor110can be located near the can20, and the electric valve1can be decreased in size.

In addition, the housing70includes the partition wall76that separates the sub circuit board space75from the inner space74. This configuration inhibits electrostatic discharge from the can20to the sub circuit board100. This configuration prevents water entered into the inner space74from entering the sub circuit board space75.

In addition, the housing70includes the press-fit grooves77into which the sub circuit board100is press-fitted. With this configuration, the sub circuit board100can be supported by the housing70. As a result, a separate member to support the sub circuit board100can be omitted.

In addition, the press-fit grooves77have the inner surface on which the projections78are provided, and the projections78are in the elastically deformed shape when the sub circuit board100is press-fitted into the press-fit grooves77. With this configuration, the projections78press the sub circuit board100, and the sub circuit board100can be more securely supported.

In addition, the electric valve1includes the permanent magnet38that rotates together with the magnet rotor31. The magnetic sensor110is located so as to sense the magnetic field generated by the permanent magnet38. With this configuration, the permanent magnet38generates a stronger magnetic field than the magnet rotor31, allowing the sensing range of the magnetic sensor110for the magnetic field to be further extended. As a result, a limitation on a location of the magnetic sensor110can be relaxed.

The electric valve1has a configuration in which the sub circuit board100is disposed perpendicular to the up-and-down direction, but may also have a configuration in which the sub circuit board100is disposed parallel to the up-and-down direction. Among various surface-mount package type magnetic sensors, a magnetic sensor with a magneto-sensitive surface on the upper surface of the package (a surface of the package of the magnetic sensor parallel to a circuit board on which the magnetic sensor is mounted) is relatively inexpensive. The sub circuit board100is disposed parallel to the up-and-down direction, allowing the upper surface of the package of the magnetic sensor110mounted on the sub circuit board100to face the outer circumferential surface of the can20. As a result, the relatively inexpensive magnetic sensor110can be employed in the electric valve1, and the component cost of the electric valve1can be reduced.

Second Embodiment

An electric valve1A according to a second embodiment of the present invention is illustrated below with reference toFIG.10toFIG.14.

FIG.10is a sectional view of an electric valve according to the second embodiment of the present invention.FIG.11is a sectional view of a stator unit of the electric valve inFIG.10.FIG.12is a perspective view of a main circuit board of the electric valve inFIG.10.FIG.13is a perspective view of a sub circuit board and a sub circuit board supporting member of the electric valve inFIG.10.FIG.14is a sectional view taken along line XIV-XIV ofFIG.10. InFIG.14, members disposed in an inner space of the stator unit are omitted. In the description below, elements having the same (including substantially the same) configurations as those of the electric valve1according to the first embodiment are denoted by the same reference signs as those of the electric valve1, and detailed descriptions of these elements are omitted.

As illustrated in the figures, an electric valve1A includes a valve body10, a can20, a driving section30, a valve member40, and a stator unit50A. The stator unit50A includes a stator60, a housing70, and a case80, a main circuit board90, a sub circuit board100, a sub circuit board supporting member105, and a magnetic sensor110. The main circuit board90has, instead of the circuit board connector91, through holes93into which circuit board terminals101are inserted.

The sub circuit board supporting member105includes a flat plate portion106and two mounting portions107. The flat plate portion106is fixed to the sub circuit board100. The flat plate portion106is disposed on and overlaps the upper surface of the sub circuit board100. The flat plate portion106is disposed across the case80and a sub circuit board space75together with the sub circuit board100. The mounting portions107have a circular cylindrical shape. The inner diameters of the mounting portions107are equal to the diameters of supporting columns85of the case80. One mounting portion107is provided continuously with one of two edges of the flat plate portion106in a front-and-back direction, while the other mounting portion is provided continuously with the other of the two edges. Two mounting portions107are interposed between a side wall portion84of a case body81and the main circuit board90. The sub circuit board supporting member105supports the sub circuit board100. The stator unit50A includes the sub circuit board supporting member105, allowing the sub circuit board100to be more securely supported.

A method for assembling the stator unit50A is described below.

The method for assembling the stator unit50A includes the same processes as those of the method for assembling the stator unit50of the first embodiment, from forming the housing70by injection molding to bonding the case body81to the housing70. The flat plate portion106of the sub circuit board supporting member105is fixed to the sub circuit board100. As the supporting columns85are inserted into the mounting portions107, the sub circuit board100and the flat plate portion106are inserted into the sub circuit board space75through a case opening84a. At this time, both edges of the sub circuit board100that are opposite to each other in the front-and-back direction are press-fitted into press-fit grooves77. In the present embodiment, only tips of both the edges in a second end100bof the sub circuit board100are press-fitted into the press-fit grooves77. As a result, the sub circuit board100is supported by the press-fit grooves77. As the circuit board terminals101of the sub circuit board100are inserted into the through holes93of the main circuit board90, tip ends85aof the supporting columns85are inserted into penetrating holes92of the main circuit board90. The tip ends85aof the supporting columns85are deformed and enlarged by infrared caulking. As a result, the main circuit board90is supported by the supporting columns85, and the mounting portions107are interposed between the side wall portion84and the main circuit board90. The sub circuit board100is supported by the sub circuit board supporting member105. Multiple terminals65of the stator60and the circuit board terminals101of the sub circuit board100are soldered to the main circuit board90. A lid body82is bonded to the case body81, and the stator unit50A is completed.

The electric valve1A has the effects similar to or the same as those of the electric valve1according to the first embodiment.

Third Embodiment

An electric valve1B according to a third embodiment of the present invention is illustrated below with reference toFIG.15toFIG.20.

FIG.15is a sectional view of an electric valve according to the third embodiment of the present invention.FIG.16is a sectional view of a stator unit of the electric valve inFIG.15.FIG.17andFIG.18are perspective views of a sub circuit board and a sub circuit board supporting member of the electric valve inFIG.15.FIG.19andFIG.20are diagrams illustrating the positional relationship between pole teeth of a stator and two magnetic sensors of the electric valve inFIG.15.FIG.19is a diagram viewed in a direction of an axis of the stator.FIG.19schematically illustrates magnetic poles of a magnet rotor in a semi-elliptical shape. InFIG.19, members inside the magnet rotor and a mold of the stator are omitted.FIG.20is a diagram viewed in a radial direction of the stator.FIG.20schematically illustrates the magnetic sensors and pole teeth of the stator. In the description below, elements having the same (including substantially the same) configurations as those of the electric valve1A according to the second embodiment are denoted by the same reference signs as those of the electric valve1A, and detailed descriptions of these elements are omitted.

As illustrated in the figures, an electric valve1B includes a valve body10, a can20a driving section30B, a valve member40, and a stator unit50B. The driving section30B has the same configuration as that of the driving section30of the electric valve1A except that the permanent magnet38and the fixing member39are omitted. The stator unit50B includes a stator60, a housing70, a case80, a main circuit board90, a sub circuit board100, a sub circuit board supporting member105, and two magnetic sensors110B.

The magnetic sensors110B are Hall ICs. The magnetic sensors110B have a surface-mount package. The magnetic sensors110B are located at a second end100bof the sub circuit board100. The magnetic sensors110B are arranged side by side in a front-and-back direction. Specifically, the two magnetic sensors110B are positioned at equal distances from an axis L and arranged around the axis L with a gap between them. The magnetic sensors110B are arranged along an outer surface of a partition wall76when viewed in a direction of the axis L. The magnetic sensors110B face a magnet rotor31in the lateral direction with the can20and the partition wall76in between. The magnetic sensors110B sense the density of the magnetic flux generated by the magnetic pole of the magnet rotor31. The magnetic sensors110B output signals corresponding to the density of the magnetic flux sensed by them. A rotational angle (rotational amount) and a rotational direction of the magnet rotor31can be detected based on the signals from the magnetic sensors110B.

In the electric valve1B, circuit board terminals101are mounted on the upper surface of the sub circuit board100, and a flat plate portion106of the sub circuit board supporting member105is mounted on the lower surface of the sub circuit board100.

As illustrated inFIG.20, one of the two magnetic sensors110B is located on a center line C1 of one of multiple pole teeth61aof an upper stator61, while the other of the two magnetic sensors110B is not located on a center line of any of the multiple pole teeth61a. Each center line is parallel to the axis L. With this configuration, the phase of the signal waveform of one of the two magnetic sensors110B is shifted from that of the other of the two magnetic sensors110B. As a result, the rotational direction of the magnet rotor31can be detected based on the waveforms. In particular, in the present embodiment, the other of the two magnetic sensors110B is located on a center line C2 of a pole tooth62bof a lower stator62. In other words, the center line C2 passes through the center position between the pole tooth61aand the pole tooth61badjacent to each other. As a result, the overlap period of the signal waveforms of the two magnetic sensors110B can be shortened. Specifically, a configuration that utilizes two Hall ICs as the two magnetic sensors110B, for example, the Hall IC outputting an H-signal when an N pole is nearby and outputting an L-signal when an N pole is not nearby, allows for a shorter overlap period of H-signal parts of the signal waveforms of the two magnetic sensors110B as the magnet rotor31rotates. Therefore, the detection accuracy of the rotational angle of the magnet rotor31can be improved.

In this specification, terms indicating shapes of members, such as “circular cylindrical” and “circular columnar”, are also used for members substantially having the shapes indicated by the terms. For example, “a circular cylindrical member” includes a circular cylindrical member and a substantially circular cylindrical member.

The embodiments of the present invention are described above. The present invention, however, is not limited to these embodiments. Embodiments obtained by a person skilled in the art appropriately adding, removing, or modifying components according to the embodiments described above, and an embodiment obtained by appropriately combining features of the embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

REFERENCE SIGNS LIST

1. . . electric valve,1A . . . electric valve,1B . . . electric valve,10, . . . valve body,11. . . main body portion,12. . . circular cylindrical portion,12a. . . fitting hole,13. . . flange portion,14. . . valve chamber,15. . . flow channel,16. . . flow channel,17. . . port,20. . . can,30. . . driving section,30B . . . driving section,31. . . magnet rotor,32. . . valve stem holder,32c. . . internal thread,33. . . guide bush,33a. . . first circular cylindrical portion,33b. . . second circular cylindrical portion,33c. . . external thread,34. . . valve stem,34a. . . upper portion,34b. . . step portion,35. . . supporting ring,36. . . push nut,37. . . valve closing spring,38. . . permanent magnet,39. . . fixing member,40. . . valve member,50. . . stator unit,50A . . . stator unit,50B . . . stator unit,60. . . stator,60a. . . inner circumferential surface,61. . . upper stator,61a,61b. . . pole teeth,62. . . lower stator,62a,62b. . . pole teeth,63. . . mold,64. . . terminal supporting portion,65. . . terminal,70. . . housing,71. . . peripheral wall portion,72. . . dome portion,72a. . . inner circumferential surface,73. . . tubular portion,74. . . inner space,75. . . sub circuit board space,76. . . partition wall,77. . . press-fit groove,78. . . projection,78a. . . projection,78b. . . projection,80. . . case,81. . . case body,82. . . lid body,83. . . connector,84. . . side wall portion,84a. . . case opening,85. . . supporting column,85a. . . tip end,90. . . main circuit board,91. . . circuit board connector,92. . . penetrating hole,93. . . through hole,100. . . sub circuit board,100a. . . first end,100b. . . second end,101. . . circuit board terminal,105. . . sub circuit board supporting member,106. . . flat plate portion,107. . . mounting portion,110. . . magnetic sensor,110B . . . magnetic sensor, L . . . axis