JP7418838B2 - Stator unit, electric valve, and method for manufacturing the stator unit - Google Patents

Description

The present invention relates to a stator unit, an electric valve having the stator unit, and a method for manufacturing the stator unit.

Patent Document 1 discloses a conventional stator unit for an electric valve. The stator unit of Patent Document 1 includes two yokes having a hollow annular shape and a resin cover integrated with the two yokes. The two yokes are coaxially arranged and in contact with each other. The two yokes are of a claw pole type and have a plurality of pole teeth on the inner peripheral side. Coils are arranged in the inner spaces of the two yokes. The cover houses two yokes. The cover is molded by installing two yokes in a mold cavity and filling the cavity with resin. The shape of the space between the plurality of pole teeth of the two yokes is complex, and the amount of resin flowing into the space tends to vary. Therefore, when forming the cover, a ring-shaped plate is installed on one end surface of one of the yokes. This plate restricts resin from flowing into the space between the plurality of pole teeth. This prevents burrs and filling defects from occurring on the cover.

Japanese Patent Application Publication No. 2013-229994

The above-described stator unit has a plate, which increases manufacturing cost. Furthermore, in the stator unit, there is a risk that moisture may infiltrate into the internal space of the yoke from the space between the plurality of pole teeth. Therefore, in the stator unit, by placing resin in the space before molding the cover, the plate becomes unnecessary and it is possible to suppress moisture from entering the internal spaces of the two yokes. However, it has been difficult to suppress variations in the amount of resin flowing into the space.

Therefore, the present invention provides a stator unit that can suppress variations in the amount of resin disposed in the space between a plurality of pole teeth of a yoke, an electric valve having this stator unit, and a method for manufacturing the stator unit. The purpose is to provide.

In order to achieve the above object, a stator unit according to one aspect of the present invention includes a yoke in the shape of a hollow annular body, a cylindrical bobbin arranged in an internal space of the yoke, and a coil wound around the bobbin. and a resin member integrally molded with the yoke, the bobbin, and the coil, the yoke having a plurality of pole teeth arranged in a circumferential direction on an inner peripheral side, and the resin member has an annular portion disposed on the inner peripheral edge of one end surface of the yoke, and a seal portion disposed in the space between the plurality of pole teeth, and the inner diameter of the annular portion is The inner diameter of the seal portion is the same as the outer diameter of the annular portion, the outer diameter of the annular portion is smaller than the outer diameter of one end surface of the yoke, and the annular portion is connected to the seal portion at a plurality of resin portion connection points arranged in a circumferential direction. and is not connected to the bobbin.

In the present invention, the yoke includes a first plate portion having an annular shape, a second plate portion having an annular shape disposed in parallel with the first plate portion, and an inner portion of the first plate portion. a plurality of first pole teeth connected to the first plate part at right angles to the first plate part on a peripheral edge thereof and having tips facing the second plate part; and a plurality of first pole teeth connected to the second plate part on the inner peripheral edge of the second plate part. a plurality of second pole teeth connected at right angles to the yoke and having a tip facing toward the first plate portion, the first pole tooth and the second pole tooth being connected in a circumferential direction of the yoke. It is preferable that the annular portions are arranged alternately on the inner peripheral edge of the first plate portion.

In the present invention, it is preferable that the stator unit is integrally molded with an assembly including the yoke, the bobbin, the coil, and the resin member, and further includes a resin cover for housing the assembly.
In the present invention, the resin member further includes a yoke filling portion disposed in an internal space of the yoke , and a terminal support portion connected to the yoke filling portion and extending radially outward from the opening of the yoke. The inner circumferential surface of the bobbin is in contact with the plurality of pole teeth, the bobbin and the coil partition the sealing portion and the yoke filling portion , and the annular portion of the resin member and the When a portion including the seal portion is defined as a first resin portion, and a portion of the resin member including the yoke filling portion and the terminal support portion is defined as a second resin portion, the first resin portion and the second resin portion It is preferable that they are separated from each other .
In the present invention, the annular portion includes an annular portion disposed on an inner peripheral edge of one end surface of the yoke, and a protrusion protruding radially outward from the annular portion, and the protrusion Preferably, it is in contact with one end surface of the yoke.
In the present invention, it is preferable that the annular portion is disposed only on one end surface of the yoke.
In the present invention, the stator unit has the two yokes, and the two yokes are arranged coaxially with each other, and the second plate portion of one of the yokes and the second plate portion of the other yoke. It is preferable that they are in contact with each other.

In order to achieve the above object, an electric valve according to another aspect of the present invention includes the stator unit, a cylindrical can disposed inside the stator unit, and a magnet disposed inside the can. It is characterized by having a rotor and a valve body driven by the magnet rotor.

In order to achieve the above object, a method for manufacturing a stator unit according to another aspect of the present invention includes a yoke in the shape of a hollow annular body and a resin member integrally molded with the yoke. The yoke has a plurality of pole teeth aligned in the circumferential direction on the inner circumferential side, and the resin member includes a ring-shaped annular portion disposed on the inner circumferential edge of one end surface of the yoke; a seal portion disposed in a space between a plurality of pole teeth, the annular portion being connected to the seal portion at a plurality of circumferentially aligned resin portion connection points, and the yoke being installed. The cavity of the mold has a first cavity part corresponding to the annular part and a second cavity part corresponding to the seal part, and the first cavity part has a plurality of cavity parts arranged in a circumferential direction. A resin flow path is connected to the second cavity portion at a connection point, a resin flow path is connected to the first cavity portion via a gate, the gate faces one end surface of the yoke, and the resin flow path is connected to the first cavity portion through the gate. The method is characterized in that a resin is injected into the first cavity portion, and the resin is caused to flow from the first cavity portion into the second cavity portion via the plurality of cavity portion connection points.
In order to achieve the above object, a method for manufacturing a stator unit according to another aspect of the present invention includes a yoke in the shape of a hollow annular body, a cylindrical bobbin arranged in an internal space of the yoke, and a bobbin in the bobbin. A method for manufacturing a stator unit including a coil to be wound, and a resin member integrally molded with the yoke, the bobbin, and the coil, wherein the yoke has a plurality of poles arranged in a circumferential direction on an inner circumferential side. a ring-shaped annular portion disposed on the inner peripheral edge of one end surface of the yoke; a seal portion disposed in a space between the plurality of pole teeth; a yoke filling portion disposed in an internal space, and a terminal support portion extending radially outward from the opening of the yoke , the inner diameter of the annular portion being the same as the inner diameter of the sealing portion; an outer diameter of the portion is smaller than an outer diameter of one end surface of the yoke, the annular portion is connected to the seal portion at a plurality of resin portion connection points arranged in a circumferential direction, and the mold in which the yoke is installed; The cavity has a first cavity part corresponding to the annular part, a second cavity part corresponding to the seal part, and a third cavity part corresponding to the terminal support part, and the first cavity part is connected to the second cavity part at a plurality of cavity part connection points lined up in the circumferential direction, the third cavity part is connected to the internal space of the yoke via an opening in the yoke, and the first cavity part A resin flow path is connected to the yoke via a gate, the gate faces one end surface of the yoke, another resin flow path is connected to the third cavity portion via another gate, and the inner circumferential surface of the bobbin is connected to the resin flow path. The bobbin, on which the coil is wound, is arranged so as to be in contact with the plurality of pole teeth and to partition the second cavity portion and the internal space of the yoke, and A resin is injected into a first cavity portion, the resin is caused to flow from the first cavity portion into the second cavity portion via the plurality of cavity portion connection points, and the resin is caused to flow from the other resin flow path through the other gate. The method is characterized in that a resin is injected into the third cavity portion, and the resin is caused to flow into the internal space of the yoke from the third cavity portion through an opening of the yoke.

According to the present invention, the stator unit includes a yoke in the shape of a hollow annular body and a resin member integrally molded with the yoke. The yoke has a plurality of pole teeth aligned in the circumferential direction on the inner peripheral side. The resin member has an annular portion disposed on the inner peripheral edge of one end surface of the yoke, and a seal portion disposed in the space between the plurality of pole teeth. The annular portion is connected to the seal portion at a plurality of resin portion connection locations arranged in the circumferential direction.

The cavity of the mold used for molding the resin member has a first cavity portion corresponding to the annular portion and a second cavity portion corresponding to the seal portion. The first cavity portion is connected to the second cavity portion at a plurality of cavity portion connection points arranged in the circumferential direction corresponding to the plurality of resin portion connection points. Therefore, the resin injected into the first cavity portion flows in the circumferential direction in the first cavity portion. Then, the resin flows from the first cavity portion into the second cavity portion via the plurality of cavity portion connection points. Therefore, the resin flows uniformly into the second cavity portion (that is, the space between the plurality of pole teeth) in the circumferential direction, and flows in the axial direction in the second cavity portion. As a result, the resin quickly spreads into the second cavity, and variations in the amount of resin flowing into the second cavity can be suppressed compared to when the resin flows in the axial and circumferential directions in the second cavity. can. Therefore, the plates used in conventional stator units are no longer necessary, and manufacturing costs can be reduced. Further, the resin can be appropriately placed in the spaces between the plurality of pole teeth, and the intrusion of moisture into the internal space of the yoke can be effectively suppressed.

FIG. 1 is a longitudinal cross-sectional view of an electric valve according to an embodiment of the present invention. FIG. 2 is a perspective view of an assembly including a yoke and a resin member of the stator unit of the electric valve of FIG. 1; 3 is a longitudinal cross-sectional view of the assembly of FIG. 2; FIG. FIG. 3 is a longitudinal cross-sectional view of a yoke, a bobbin, and a coil. FIG. 5 is a cross-sectional view illustrating a method of integrally molding the yoke, bobbin, and coil of FIG. 4 with a resin member. FIG. 6 is a diagram schematically showing the flow of resin in a space between a plurality of pole teeth of a yoke when resin flows into the space from a plurality of locations. FIG. 2 is a diagram schematically showing the flow of resin in a space between a plurality of pole teeth of a yoke when the resin flows from one location.

An electric valve according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 7. The electric valve 1 of this embodiment is used, for example, to adjust the flow rate of refrigerant in a refrigeration cycle or the like.

FIG. 1 is a longitudinal sectional view of an electric valve according to an embodiment of the present invention. FIG. 2 is a perspective view of an assembly including a yoke and a resin member of the stator unit of the electric valve shown in FIG. In FIG. 2, arrows indicate the positions of gates included in the mold used for molding the resin member. 3 is a longitudinal cross-sectional view of the assembly of FIG. 2; FIG. 4 is a longitudinal cross-sectional view of the yoke, bobbin, and coil. FIG. 4 shows the assembly of FIG. 2 in a state before the resin member is molded. FIG. 5 is a sectional view illustrating a method of integrally molding the yoke, bobbin, and coil of FIG. 4 with a resin member. In FIG. 5, a cylindrical portion of the mold located inside the inner circumferential edge of the yoke is not shown, and a plurality of pole teeth facing the cylindrical portion of the yoke are indicated by dotted lines. 6 and 7 are diagrams schematically showing the flow of resin in the space when the resin flows into the space between the plurality of pole teeth of the yoke. FIG. 6 shows a case where resin flows into the space from multiple locations. FIG. 7 shows a case where resin flows into the space from one location. In FIGS. 5 to 7, the flow of resin is schematically shown by arrows.

As shown in FIG. 1, the electric valve 1 according to the present embodiment includes a valve body 10, a holder 20, a valve body support member 25, a can 30, a drive mechanism 40, a valve body 70, and a stator unit 80. It has .

The valve body 10 has a rectangular parallelepiped shape. The valve body 10 has a valve chamber 13 and a valve port 14 connected to the valve chamber 13. The valve body 10 has a first passage 17 and a second passage 18. One end of the first passage 17 is connected to the valve chamber 13, and the other end of the first passage 17 opens to the left side surface 10a of the valve body 10. One end of the second passage 18 is connected to the valve chamber 13 via the valve port 14, and the other end of the second passage 18 opens to the right side surface 10b of the valve body 10. The valve body 10 has a mounting hole 19 . The attachment hole 19 opens on the upper surface 10c of the valve body 10. A female thread is formed on the inner peripheral surface of the mounting hole 19. The valve chamber 13 is open in the bottom surface 19a of the mounting hole 19.

The holder 20 has a cylindrical shape. A male thread is formed at the lower part of the outer peripheral surface of the holder 20. The male thread of the holder 20 is screwed into the female thread of the mounting hole 19 of the valve body 10. The holder 20 is attached to the valve body 10 with a threaded structure.

The valve body support member 25 has a cylindrical shape. The valve body support member 25 is arranged between the valve body 10 and the holder 20 inside the attachment hole 19 . The lower part of the valve element support member 25 is press-fitted into the valve chamber 13 from the attachment hole 19 side. An annular flat surface 25a facing downward is formed on the outer peripheral surface of the valve body support member 25. The annular plane 25a is in contact with the bottom surface 19a of the attachment hole 19. The valve body support member 25 supports the valve body 70 so as to be movable in the vertical direction.

The can 30 has a cylindrical shape with a closed upper end and an open lower end. The lower end portion of the can 30 is joined to the outer peripheral edge of a joining member 35 in the shape of an annular plate. The upper part of the holder 20 is arranged inside the joining member 35. The inner peripheral edge of the joining member 35 is joined to the holder 20.

The drive mechanism 40 moves the valve body 70 in the vertical direction. The drive mechanism 40 includes a magnet rotor 41, a planetary gear mechanism 50, a guide member 60, a drive shaft 65, and a ball 68.

The magnet rotor 41 has a cylindrical shape. On the outer peripheral surface of the magnet rotor 41, N poles and S poles are arranged alternately in the circumferential direction. The outer diameter of the magnet rotor 41 is smaller than the inner diameter of the can 30. The magnet rotor 41 is rotatably arranged inside the can 30. A disc-shaped connecting member 42 is joined to the upper end of the magnet rotor 41 . The connecting member 42 closes the upper end of the magnet rotor 41. A rotor shaft 43 passes through the center of the connecting member 42. The magnet rotor 41 is connected to a rotor shaft 43 via a connecting member 42.

The planetary gear mechanism 50 is arranged inside the magnet rotor 41. The planetary gear mechanism 50 includes a gear case 51, a fixed ring gear 52, a sun gear 53, a plurality of planet gears 54, a carrier 55, an output gear 56, and an output shaft 57. Gear case 51 has a cylindrical shape. The gear case 51 is coaxially joined to the upper end of the holder 20. Fixed ring gear 52 is an internal gear. The fixed ring gear 52 is fixed to the upper end of the gear case 51. The sun gear 53 is arranged coaxially with the connecting member 42 . The sun gear 53 is integrated with the connecting member 42. The rotor shaft 43 passes through the sun gear 53. The sun gear 53 is rotated together with the magnet rotor 41 and the connecting member 42. A plurality of planetary gears 54 are arranged between the fixed ring gear 52 and the sun gear 53. The carrier 55 has a disc shape. The rotor shaft 43 passes through the center of the carrier 55. The carrier 55 is rotatable around the rotor shaft 43. The carrier 55 has a plurality of support shafts 55a. The plurality of support shafts 55a rotatably support the plurality of planetary gears 54. The output gear 56 has a cylindrical shape with a bottom. Output gear 56 is an internal gear. A plurality of planetary gears 54 are arranged between the output gear 56 and the sun gear 53. The output shaft 57 has a cylindrical shape. The upper part of the output shaft 57 is fixed to a hole formed in the bottom of the output gear 56. A slit 57a extending in the vertical direction is formed in the lower part of the output shaft 57. The rotation of the sun gear 53 is reduced in speed by the fixed ring gear 52, the plurality of planetary gears 54, the carrier 55, and the output gear 56, and is transmitted to the output shaft 57.

The guide member 60 has a cylindrical shape. The guide member 60 is arranged inside the upper part of the holder 20. A female thread is formed at the lower part of the inner peripheral surface of the guide member 60. An output shaft 57 is arranged inside the guide member 60. The guide member 60 rotatably supports the output shaft 57.

The drive shaft 65 has a cylindrical portion 66 and a flat plate portion 67. The flat plate part 67 is connected to the upper end of the columnar part 66. The cylindrical portion 66 and the flat plate portion 67 are integrally formed. A male thread is formed on the outer peripheral surface of the cylindrical portion 66. The male thread of the cylindrical portion 66 is screwed into the female thread of the guide member 60. The flat plate portion 67 is arranged in the slit 57a of the output shaft 57 so as to be movable in the vertical direction. The drive shaft 65 is rotated by the output shaft 57 and moved in the vertical direction by screw feeding action. The ball 68 is arranged between the drive shaft 65 and the ball receiving portion 74 of the valve body 70.

The valve body 70 has a stem 71, a valve portion 72, a spring receiving portion 73, and a ball receiving portion 74. Stem 71 has a cylindrical shape. The stem 71 is arranged inside the valve body support member 25. The stem 71 is supported by the valve body support member 25 so as to be movable in the vertical direction. The valve portion 72 is arranged at the lower end of the stem 71. The valve portion 72 has an annular shape. The valve portion 72 projects radially outward from the outer peripheral surface of the stem 71. The valve portion 72 is arranged to face the valve port 14 in the vertical direction. The spring receiving portion 73 has a cylindrical shape. The spring receiver 73 is joined to the upper end of the stem 71. The spring receiving portion 73 has a flange portion 73a that projects radially outward. The ball receiving part 74 has a circular flat plate part and a convex part connected to the lower surface of the flat plate part. The ball receiving part 74 has a flat plate part in contact with the ball 68 and a convex part fitted into a hole formed in the spring receiving part 73 . A valve opening spring 75 is disposed between the flange portion 73a of the spring receiving portion 73 and the valve body support member 25. The valve opening spring 75 is a compression coil spring. The valve opening spring 75 pushes the valve body 70 (flange portion 73a) upward. The valve body 70 changes the opening area of the valve port 14 steplessly by moving the valve portion 72 forward and backward relative to the valve port 14 . The valve body 70 may close the valve port 14 (that is, the opening area may be set to 0).

Stator unit 80 has a fitting hole 80b defined by its inner peripheral surface 80a. The can 30 is fitted into the fitting hole 80b. The can 30 is arranged inside the inner peripheral surface 80a of the stator unit 80. The stator unit 80 and the magnet rotor 41 constitute a stepping motor. The stator unit 80 includes an A-phase yoke 81A, an A-phase bobbin 82A, an A-phase coil 83A, a B-phase yoke 81B, a B-phase bobbin 82B, a B-phase coil 83B, a resin member 85, a cover 95, have.

The A-phase yoke 81A, the A-phase bobbin 82A, the A-phase coil 83A, the B-phase yoke 81B, the B-phase bobbin 82B, the B-phase coil 83B, and the resin member 85 are shown in FIG. 2 in combination with each other. This becomes an assembly 90.

The A-phase yoke 81A has a hollow annular shape with a rectangular cross section in the radial direction. The A-phase yoke 81A is made of metal. The A-phase yoke 81A includes a first plate portion 81a, a second plate portion 81b, an outer plate portion 81c, a plurality of first pole teeth 81d, and a plurality of second pole teeth 81e. The first plate portion 81a has an annular shape. The second plate part 81b has an annular shape and is arranged parallel to the first plate part 81a with an interval in the vertical direction. The inner diameter and outer diameter of the first plate portion 81a and the inner diameter and outer diameter of the second plate portion 81b are the same. The outer plate portion 81c has a cylindrical shape. One end of the outer plate portion 81c is connected to the outer peripheral edge of the first plate portion 81a. The outer plate portion 81c is arranged at right angles to the first plate portion 81a. The other end of the outer plate portion 81c is in contact with the outer peripheral edge of the second plate portion 81b. The outer plate portion 81c connects the outer peripheral edge of the first plate portion 81a and the outer peripheral edge of the second plate portion 81b. The plurality of first pole teeth 81d are connected to the inner peripheral edge of the first plate portion 81a. The plurality of first pole teeth 81d are arranged at right angles to the first plate portion 81a. The plurality of first pole teeth 81d have a tapered shape, and the tips thereof are directed toward the second plate portion 81b. The plurality of first pole teeth 81d are arranged at equal intervals in the circumferential direction. The plurality of second pole teeth 81e are connected to the inner peripheral edge of the second plate portion 81b. The plurality of second pole teeth 81e are arranged at right angles to the second plate portion 81b. The plurality of second pole teeth 81e have a tapered shape, and their tips are directed toward the first plate portion 81a. The plurality of second pole teeth 81e are arranged at equal intervals in the circumferential direction. The plurality of first pole teeth 81d and the plurality of second pole teeth 81e are arranged alternately at intervals in the circumferential direction. The plurality of first pole teeth 81d and the plurality of second pole teeth 81e form an inner peripheral surface 80a of the stator unit 80.

A part having the first plate part 81a, the outer plate part 81c and the first pole tooth 81d, and a part having the second plate part 81b and the second pole tooth 81e are formed by press working, and these parts are combined. Thus, an A-phase yoke 81A is obtained.

The A-phase bobbin 82A has a cylindrical shape. The A-phase bobbin 82A is made of resin. An A-phase coil 83A is wound around the A-phase bobbin 82A. The A-phase bobbin 82A and the A-phase coil 83A are located in the internal space of the A-phase yoke 81A (surrounded by the first plate part 81a, the second plate part 81b, the outer plate part 81c, the first pole tooth 81d, and the second pole tooth 81e). space).

B-phase yoke 81B, B-phase bobbin 82B, and B-phase coil 83B are the same as A-phase yoke 81A, A-phase bobbin 82A, and A-phase coil 83A, except that they are arranged upside down. The A-phase yoke 81A and the B-phase yoke 81B are arranged coaxially with each other. The second plate portion 81b of the A-phase yoke 81A and the second plate portion 81b of the B-phase yoke 81B are in contact with each other. The other end of the outer plate portion 81c of the A-phase yoke 81A is in contact with the other end of the outer plate portion 81c of the B-phase yoke 81B. A plurality of terminals 84 are connected to the A-phase coil 83A and the B-phase coil 83B.

The A-phase yoke 81A and the B-phase yoke 81B have a first opening 81f and a second opening 81g. The first opening 81f is arranged across the outer plate portion 81c of the A-phase yoke 81A and the outer plate portion 81c of the B-phase yoke 81B. The second opening 81g is also arranged across the outer plate portion 81c of the A-phase yoke 81A and the outer plate portion 81c of the B-phase yoke 81B. The center position of the second opening 81g is arranged 180 degrees apart from the center position of the first opening 81f in the circumferential direction of the A-phase yoke 81A. It is preferable that the center position of the second opening 81g is spaced apart from the center position of the first opening 81f by 90 degrees or more in the circumferential direction of the A-phase yoke 81A.

The resin member 85 includes an A-phase yoke filling portion 86A, a B-phase yoke filling portion 86B, a terminal support portion 87, an annular portion 88, and a seal portion 89.

The A-phase yoke filling portion 86A is arranged in the internal space of the A-phase yoke 81A. The A-phase yoke filling portion 86A fills the internal space of the A-phase yoke 81A, and covers the A-phase bobbin 82A and the A-phase coil 83A. The B-phase yoke filling portion 86B is arranged in the internal space of the B-phase yoke 81B. The B-phase yoke filling portion 86B fills the internal space of the B-phase yoke 81B, and covers the B-phase bobbin 82B and the B-phase coil 83B.

The terminal support portion 87 extends radially outward (rightward in FIG. 1) from the first opening 81f. The terminal support portion 87 connects the A-phase yoke filling portion 86A and the B-phase yoke filling portion 86B. A plurality of terminals 84 protrude from the tip of the terminal support portion 87.

The annular portion 88 has a circular ring shape. The annular portion 88 is arranged on the inner peripheral edge of the upper surface (one end surface of the A-phase yoke 81A) of the first plate portion 81a of the A-phase yoke 81A.

The seal portion 89 has a generally cylindrical shape. The seal portion 89 is arranged in a space between a plurality of pole teeth (a plurality of first pole teeth 81d, a plurality of second pole teeth 81e) of the A-phase yoke 81A and the B-phase yoke 81B. The space has a plurality of branched parts, and these parts are connected to each other to form one space. Seal portion 89 fills the space. The seal portion 89 is continuous with the plurality of first pole teeth 81d and the plurality of second pole teeth 81e without any difference in level. The seal portion 89 forms the inner peripheral surface 80a of the stator unit 80 together with the plurality of first pole teeth 81d and the plurality of second pole teeth 81e. A plurality of resin part connection points 88 a arranged in the circumferential direction of the annular part 88 are connected to a seal part 89 . The inner diameter of the sealing portion 89 is the same as the inner diameter of the annular portion 88 . The number of the plurality of resin partial connection points 88a is the sum of the number of the plurality of first pole teeth 81d and the number of the plurality of second pole teeth 81e of the A-phase yoke 81A.

The cover 95 is made of resin. The cover 95 has a cylindrical shape with a closed upper end and an open lower end. Cover 95 houses assembly 90. Cover 95 is integrally molded with assembly 90. The cover 95 has a peripheral wall portion 96, an upper wall portion 97, a connector portion 98, and a cylindrical portion 99. An A-phase yoke 81A, a B-phase yoke 81B, and an annular portion 88 of the resin member 85 are embedded in the inner peripheral surface of the peripheral wall portion 96. The upper wall portion 97 is connected to the upper end of the peripheral wall portion 96. The upper wall portion 97 has a dome shape. The upper end portion of the can 30 is arranged inside the upper wall portion 97. The connector portion 98 has a cylindrical shape that extends radially outward (rightward in FIG. 1). A plurality of terminals 84 are arranged inside the connector portion 98. The cylindrical portion 99 extends downward from the lower end of the peripheral wall portion 96 . A lower end portion of the cylindrical portion 99 is in contact with the upper surface 10c of the valve body 10. Note that the cover 95 may be omitted and only the assembly 90 may be used as the stator unit.

In the electric valve 1, the valve port 14, the holder 20, the valve body support member 25, the can 30, the magnetic rotor 41, the connecting member 42, the rotor shaft 43, the output shaft 57, the guide member 60, the drive shaft 65, the valve body 70, A The center axes of the phase yoke 81A, the B-phase yoke 81B, the annular portion 88, and the seal portion 89 coincide with each other.

Next, the operation of the electric valve 1 will be explained.

In the electric valve 1, current is applied to the A-phase coil 83A and the B-phase coil 83B to rotate the magnet rotor 41 in one direction. The rotation of the magnet rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The screw feeding action between the drive shaft 65 and the guide member 60 causes the drive shaft 65 to move downward. The valve body 70 is pushed downward by the drive shaft 65, and the opening area of the valve port 14 becomes smaller.

In the electric valve 1, current is applied to the A-phase coil 83A and the B-phase coil 83B to rotate the magnet rotor 41 in the other direction. The rotation of the magnet rotor 41 is transmitted to the drive shaft 65 via the planetary gear mechanism 50. The screw feeding action between the drive shaft 65 and the guide member 60 causes the drive shaft 65 to move upward. The valve body 70 is pushed upward by the valve opening spring 75, and the opening area of the valve port 14 becomes larger.

Next, a method for manufacturing the stator unit 80 of the electric valve 1 will be described with reference to FIGS. 4 to 7.

An A-phase yoke 81A and a B-phase yoke 81B are formed by press working. An A-phase bobbin 82A around which an A-phase coil 83A is wound is arranged in the internal space of the A-phase yoke 81A. A B-phase bobbin 82B around which a B-phase coil 83B is wound is arranged in the internal space of the B-phase yoke 81B. The second plate portion 81b of the A-phase yoke 81A and the second plate portion 81b of the B-phase yoke 81B are brought into contact with each other, and the A-phase yoke 81A and the B-phase yoke 81B are arranged coaxially. A plurality of terminals 84 are connected to the A-phase coil 83A and the B-phase coil 83B (FIG. 4).

Then, as shown in FIG. 5, the A-phase yoke 81A and the B-phase yoke 81B are installed in the cavity 285 of the mold 200. The mold 200 is a mold for molding the resin member 85.

The cavity 285 has a shape that corresponds to the outer shape of the A-phase yoke 81A, the B-phase yoke 81B, the terminal support portion 87, the annular portion 88, and the seal portion 89 (inner peripheral surface 80a). Cavity 285 has a first cavity portion 288 , a second cavity portion 289 , and a third cavity portion 287 .

The first cavity portion 288 corresponds to the annular portion 88 of the resin member 85. The second cavity portion 289 corresponds to the seal portion 89 of the resin member 85. The first cavity portion 288 has a plurality of cavity portion connection points 288a corresponding to the plurality of resin portion connection points 88a of the annular portion 88. The first cavity portion 288 is connected to the second cavity portion 289 at a plurality of cavity portion connection points 288a. The third cavity portion 287 corresponds to the terminal support portion 87 of the resin member 85.

In the mold 200, a resin passage 210 is connected to an annular first cavity portion 288 via a plurality of gates G1 to G3. The plurality of gates G1 to G3 are arranged at intervals in the circumferential direction. Another resin passage (not shown) is connected to the third cavity portion 287 via another gate (not shown).

The cavity 285 is filled with resin. Specifically, resin is injected from the resin passage 210 into the first cavity portion 288 via the plurality of gates G1 to G3. Resin flows circumferentially within the first cavity portion 288 . The resin then flows from the first cavity part 288 to the second cavity part 289 via the plurality of cavity part connection points 288a. Resin flows into the second cavity portion 289 from a plurality of locations, and in the second cavity portion 289, the resin flows in the axial direction (downward) as shown in FIG.

Note that FIG. 7 shows the flow of resin in a comparative example. In the comparative example, the cavity 285 of the mold 200 does not have a first cavity part 288 corresponding to the annular part 88, and one gate is connected to a second cavity part 289. In the comparative example, resin flows into the second cavity portion 289 from one location, and in the second cavity portion 289, the resin flows in the circumferential direction (horizontal direction) and the axial direction (vertical direction). Therefore, the distance through which the resin flows from one gate in the second cavity portion 289 is relatively long, and there is a risk that the amount of resin flowing into the second cavity portion 289 may vary due to the influence of changes in viscosity during resin flow. .

Resin is injected into the third cavity portion 287 from another resin passage through another gate. The resin flows from the third cavity portion 287 through the first opening 81f into the internal space of the A-phase yoke 81A and the internal space of the B-phase yoke 81B.

As a result, the first cavity portion 288, the second cavity portion 289, the third cavity portion 287, the internal space of the A-phase yoke 81A, and the internal space of the B-phase yoke 81B are filled with resin. After the resin hardens, it becomes an annular portion 88, a seal portion 89, a terminal support portion 87, an A-phase yoke filling portion 86A, and a B-phase yoke filling portion 86B. As a result, the A-phase yoke 81A, the A-phase bobbin 82A, the A-phase coil 83A, the B-phase yoke 81B, the B-phase bobbin 82B, the B-phase coil 83B, and the resin member 85 are integrated and assembled. It becomes solid 90. Assembly 90 is removed from mold 200.

Assembly 90 is placed in the cavity of another mold (not shown) for forming cover 95. Then, the cavity is filled with resin to form the cover 95. When the resin hardens, the assembly 90 and cover 95 are integrated to form the stator unit 80. The stator unit 80 is taken out from another mold. In this way, stator unit 80 is completed.

The electric valve 1 described above includes a stator unit 80, a cylindrical can 30 disposed inside the stator unit 80, a magnet rotor 41 disposed inside the can 30, and a valve body driven by the magnet rotor 41. 70.

The stator unit 80 includes a hollow annular A-phase yoke 81A and a B-phase yoke 81B, and a resin member 85 integrally molded with the A-phase yoke 81A and the B-phase yoke 81B. The A-phase yoke 81A and the B-phase yoke 81B have a plurality of pole teeth (first pole tooth 81d, second pole tooth 81e) arranged in the circumferential direction on the inner peripheral side. A resin member 85 is disposed in a space between an annular portion 88 disposed on the inner peripheral edge of the upper end surface of the A-phase yoke 81A, and the plurality of first pole teeth 81d and the plurality of second pole teeth 81e. It has a sealed seal portion 89. The annular portion 88 is connected to the seal portion 89 at a plurality of resin portion connection points 88a arranged in the circumferential direction.

The cavity 285 of the mold 200 used for molding the resin member 85 has a first cavity portion 288 corresponding to the annular portion 88 and a second cavity portion 289 corresponding to the seal portion 89. The first cavity portion 288 is connected to the second cavity portion 289 at a plurality of cavity portion connection points 288a arranged in the circumferential direction corresponding to the plurality of resin portion connection points 88a. Therefore, the resin injected into the first cavity portion 288 flows in the circumferential direction in the first cavity portion 288 . Then, the resin flows from the first cavity portion 288 into the second cavity portion 289 via the plurality of cavity portion connection points 288a. Therefore, the resin flows uniformly in the circumferential direction into the second cavity portion 289 (that is, the space between the plurality of pole teeth) and flows in the axial direction in the second cavity portion 289 (FIG. 6). As a result, the resin quickly spreads into the second cavity portion 289, and the amount of resin flowing into the second cavity portion 289 is reduced compared to the case where the resin flows in the axial direction and circumferential direction in the second cavity portion 289 (FIG. 7). It is possible to suppress variations in . Therefore, the plate used in the conventional stator unit becomes unnecessary, and the manufacturing cost of the stator unit 80 can be reduced. Further, the resin can be appropriately placed in the space between the plurality of first pole teeth 81d and the plurality of second pole teeth 81e, and moisture is prevented from entering the internal space of the A-phase yoke 81A and the internal space of the B-phase yoke 81B. The infiltration of can be effectively suppressed.

Further, the A-phase yoke 81A includes a first plate portion 81a having an annular shape, a second plate portion 81b having an annular shape arranged in parallel with the first plate portion 81a with an interval, and a first plate portion 81a. A plurality of first pole teeth 81d are connected to the inner circumferential edge of the second plate part 81b at right angles to the first plate part 81a and the tips thereof are directed toward the second plate part 81b, and a second plate is attached to the inner circumferential edge of the second plate part 81b. It has a plurality of second pole teeth 81e that are connected at right angles to the portion 81b and whose tips are directed toward the first plate portion 81a. A plurality of first pole teeth 81d and a plurality of second pole teeth 81e are alternately arranged in the circumferential direction of the A-phase yoke 81A. B-phase yoke 81B has the same configuration as A-phase yoke 81A. The annular portion 88 is arranged at the inner peripheral edge of the first plate portion 81a of the A-phase yoke 81A. By doing so, the A-phase yoke 81A and the B-phase yoke 81B have a relatively simple configuration, and can be manufactured at low cost by press working.

Further, the stator unit 80 has a resin cover 95 integrally molded with an assembly 90 having an A-phase yoke 81A, a B-phase yoke 81B, and a resin member 85. Cover 95 houses assembly 90. By doing this, the A-phase yoke 81A, the B-phase yoke 81B, and the resin member 85 can be protected from impact and the like. Further, since the seal portion 89 is arranged in the space between the plurality of first pole teeth 81d and the plurality of second pole teeth 81e, the flow of resin into the space is restricted when the cover 95 is molded. Ru. Therefore, burrs and filling defects in the cover 95 can be suppressed.

The electric valve 1 described above slows down the rotation of the magnet rotor 41 and transmits it to the drive shaft 65. The electric valve 1 may have a direct-acting configuration that directly transmits the rotation of the magnet rotor 41 to the drive shaft 65.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments. Additions, deletions, and design changes to the above-mentioned embodiments by those skilled in the art as appropriate, as well as combinations of features of the embodiments as appropriate, are also within the scope of the present invention, as long as they do not go against the spirit of the present invention. included in the range.

DESCRIPTION OF SYMBOLS 1... Electric valve, 10... Valve body, 10a... Left side, 10b... Right side, 10c... Top surface, 13... Valve chamber, 14... Valve port, 17... First passage, 18... Second passage, 19... Mounting hole , 19a... bottom surface, 20... holder, 25... valve body support member, 25a... annular plane, 30... can, 35... joining member, 40... drive mechanism, 41... magnet rotor, 42... connecting member, 43... rotor shaft, 50... Planetary gear mechanism, 51... Gear case, 52... Fixed ring gear, 53... Sun gear, 54... Planetary gear, 55... Carrier, 55a... Support shaft, 56... Output gear, 57... Output shaft, 57a... Slit, 60... Guide member, 65... Drive shaft, 66... Cylindrical part, 67... Flat plate part, 70... Valve body, 71... Stem, 72... Valve part, 73... Spring receiving part, 73a... Flange part, 74... Ball receiving part , 75... Valve opening spring, 80... Stator unit, 80a... Inner peripheral surface, 80b... Fitting hole, 81A... A phase yoke, 82A... A phase bobbin, 83A... A phase coil, 81B... B phase yoke, 82B... B phase bobbin, 83B...B phase coil, 81a...first plate part, 81b...second plate part, 81c...outer plate part, 81d...first pole tooth, 81e...second pole tooth, 81f...first opening, 81g...Second opening, 84...Terminal, 85...Resin member, 86A...A phase yoke filling part, 86B...B phase yoke filling part, 87...Terminal support part, 88...Annular part, 88a...Resin part connection point, 89 ...Seal part, 90... Assembly, 95... Cover, 96... Peripheral wall part, 97... Upper wall part, 98... Connector part, 99... Cylindrical part, 200... Mold, 210... Resin passage, 285... Cavity, 287... Third cavity part, 288... First cavity part, 288a... Cavity part connection point, 289... Second cavity part

Claims (9)

a yoke in the shape of a hollow annular body, a cylindrical bobbin disposed in an internal space of the yoke, a coil wound around the bobbin, and a resin member integrally molded with the yoke, the bobbin, and the coil; A stator unit having:
The yoke has a plurality of pole teeth arranged in the circumferential direction on the inner peripheral side,
The resin member has an annular portion disposed on an inner peripheral edge of one end surface of the yoke, and a seal portion disposed in a space between the plurality of pole teeth,
The inner diameter of the annular portion is the same as the inner diameter of the seal portion,
The outer diameter of the annular portion is smaller than the outer diameter of one end surface of the yoke;
A stator unit characterized in that the annular portion is connected to the seal portion at a plurality of resin portion connection points arranged in a circumferential direction and is not connected to the bobbin. The yoke is
a first plate portion having an annular shape;
an annular second plate portion arranged parallel to and spaced apart from the first plate portion;
a plurality of first pole teeth connected to the inner peripheral edge of the first plate part at right angles to the first plate part and having tips facing the second plate part;
a plurality of second pole teeth connected to the inner circumferential edge of the second plate part at right angles to the second plate part and having tips directed toward the first plate part,
the first pole teeth and the second pole teeth are alternately arranged in the circumferential direction of the yoke;
The stator unit according to claim 1, wherein the annular portion is arranged on an inner peripheral edge of the first plate portion. The stator unit according to claim 1 or 2, further comprising a resin cover that is integrally molded with an assembly including the yoke, the bobbin, the coil, and the resin member, and houses the assembly. The resin member further includes a yoke filling portion disposed in the internal space of the yoke , and a terminal support portion connected to the yoke filling portion and extending radially outward from the opening of the yoke ,
an inner peripheral surface of the bobbin is in contact with the plurality of pole teeth,
the bobbin and the coil partition the seal portion and the yoke filling portion ;
When a portion of the resin member including the annular portion and the seal portion is defined as a first resin portion, and a portion of the resin member including the yoke filling portion and the terminal support portion is defined as a second resin portion; The stator unit according to claim 1, wherein the first resin portion and the second resin portion are separated . The annular portion includes an annular portion disposed on an inner peripheral edge of one end surface of the yoke, and a protrusion projecting radially outward from the annular portion, and the protrusion is a part of the yoke. The stator unit according to claim 1, wherein the stator unit is in contact with an end surface. The stator unit according to claim 1, wherein the annular portion is arranged only on one end surface of the yoke. the stator unit has two of the yokes,
the two yokes are arranged coaxially with each other,
The stator unit according to claim 2, wherein the second plate portion of one of the yokes is in contact with the second plate portion of the other yoke. The stator unit according to any one of claims 1 to 3,
a cylindrical can disposed inside the stator unit;
a magnetic rotor disposed inside the can;
An electric valve comprising: a valve body driven by the magnetic rotor. a yoke in the shape of a hollow annular body, a cylindrical bobbin disposed in an internal space of the yoke, a coil wound around the bobbin, and a resin member integrally molded with the yoke, the bobbin, and the coil; A method for manufacturing a stator unit comprising:
The yoke has a plurality of pole teeth arranged in the circumferential direction on the inner peripheral side,
The resin member is arranged in an annular portion disposed on an inner peripheral edge of one end surface of the yoke, a seal portion disposed in a space between the plurality of pole teeth, and an inner space of the yoke. a yoke filling portion; and a terminal support portion extending radially outward from the opening of the yoke;
The inner diameter of the annular portion is the same as the inner diameter of the seal portion,
The outer diameter of the annular portion is smaller than the outer diameter of one end surface of the yoke;
The annular portion is connected to the seal portion at a plurality of resin portion connection points arranged in the circumferential direction,
The cavity of the mold in which the yoke is installed has a first cavity portion corresponding to the annular portion, a second cavity portion corresponding to the seal portion, and a third cavity portion corresponding to the terminal support portion. have,
The first cavity part is connected to the second cavity part at a plurality of cavity part connection points arranged in the circumferential direction,
the third cavity portion is connected to an internal space of the yoke via an opening in the yoke;
A resin flow path is connected to the first cavity portion via a gate, the gate facing one end surface of the yoke,
Another resin flow path is connected to the third cavity portion via another gate,
arranging the bobbin around which the coil is wound such that an inner circumferential surface of the bobbin is in contact with the plurality of pole teeth and partitions the second cavity portion and the internal space of the yoke;
Injecting a resin from the resin flow path into the first cavity portion via the gate, and causing resin to flow from the first cavity portion into the second cavity portion via the plurality of cavity portion connection points,
Injecting resin from the other resin flow path into the third cavity portion through the other gate, and causing the resin to flow from the third cavity portion into the internal space of the yoke through the opening of the yoke. A method for manufacturing a stator unit characterized by:

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