Stator unit and motor-operated valve using the same

Abstract

To provide a stator unit capable of improving reliability while securing waterproofness, and a motor operated valve using the same.SOLUTION: The stator unit includes a yoke, a stator coil, a first resin portion formed of a first resin material, and a second resin portion formed of a second resin material and covering the first resin portion, one end of a wire extending from the stator coil is soldered to a power supply pin, the first resin portion covers the wire at least from the stator coil to a soldered portion, and a linear expansion coefficient of the first resin material is smaller than a linear expansion coefficient of the second resin material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stator unit and a motor-operated valve using the same. [Background technology]

[0002] For example, a stator unit equipped with a stator coil is used to drive an electric valve that is placed in a fluid piping system and opens and closes the fluid flow path or controls the flow rate of the fluid. In some cases, it is necessary to ensure waterproofing to prevent moisture from reaching the stator coil in the stator unit.

[0003] Patent Document 1 discloses a stator unit in which stator coils are stacked one on top of the other and set in a mold in which a cover has been placed in advance, and a thermosetting resin such as urethane resin is poured into the mold as a molding resin by vacuum casting, and then hardened in a drying oven, and then removed from the mold, thereby covering and filling the entire stator coil with molding resin. According to the motor-operated valve of Patent Document 1, waterproofing can be achieved by surrounding the entire stator coil with molding resin such as urethane resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-146299 Summary of the Invention [Problem to be solved by the invention]

[0005] A wire is wound around the stator coil, and one end of the wire is pulled out to supply power to the stator coil. Therefore, if the entire stator coil is enclosed in a molding resin, a portion of the pulled wire will be in close contact with the molding resin. In this state, if the ambient temperature around the motor-operated valve changes, the difference in linear expansion between the metal part and the molding resin may place a relatively large load on the wire.

[0006] An object of the present invention is to provide a stator unit that can improve reliability while ensuring waterproofing, and a motor-operated valve using the same. [Means for solving the problem]

[0007] The stator unit according to the present invention comprises: York and A stator coil; a first resin portion formed from a first resin material; a second resin portion formed from a second resin material and covering the first resin portion; One end of a wire extending from the stator coil is soldered to a power supply pin, the first resin portion covers the wire at least from the stator coil to a soldered portion, The linear expansion coefficient of the first resin material is smaller than the linear expansion coefficient of the second resin material. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a stator unit that can improve reliability while ensuring waterproofing, and a motor-operated valve using the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a stator unit according to a first embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view of an annular intermediate obtained in the manufacturing process of the stator unit. [Figure 3] FIG. 3 is a vertical cross-sectional view showing a state in which the second resin portion is filled into the intermediate body shown in FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view showing a stator unit according to the second embodiment. [Figure 5]FIG. 5 is a vertical cross-sectional view showing a state in which the intermediate body shown in FIG. 2 is filled with a second resin portion to form a stator unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The stator unit of the present invention can be used to drive an electric valve, for example, but is not limited to this.

[0011] (First embodiment) FIG. 1 is a longitudinal cross-sectional view showing a stator unit 10 according to a first embodiment. FIG. 2 is a longitudinal cross-sectional view of an annular intermediate 1 obtained in the manufacturing process of the stator unit 10. When the stator unit 10 is attached to an electric valve, it is turned upside down from the state shown in FIG. 1 and fitted onto the outside of a can containing a rotor unit, and is covered with a cylindrical resin cover with a top. The rotor unit inside the can and the stator unit form a stepping motor.

[0012] Stator unit 10 has A-phase yoke 11a, A-phase bobbin 12a, A-phase coil 13a, B-phase yoke 11b, B-phase bobbin 12b, B-phase coil 13b, first resin part 14, and second resin part 15 (shown by dotted lines in FIG. 1). Here, A-phase yoke 11a and B-phase yoke 11b are referred to as yokes, A-phase bobbin 12a and B-phase bobbin 12b are referred to as bobbins, and A-phase coil 13a and B-phase coil 13b are referred to as stator coils.

[0013] The A-phase yoke 11a, the A-phase bobbin 12a, the A-phase coil 13a, the B-phase yoke 11b, the B-phase bobbin 12b, the B-phase coil 13b, and the first resin part 14 are combined with each other to form the intermediate body 1 shown in Figure 2.

[0014] The A-phase yoke 11a has a hollow annular shape with a rectangular radial cross section. The A-phase yoke 11a is made of metal and has a first plate portion 11d, a second plate portion 11e, an outer plate portion 11f, a plurality of first pole teeth 11g, and a plurality of second pole teeth 11h. The first plate portion 11d has an annular shape. The second plate portion 11e also has an annular shape and is arranged parallel to and spaced apart from the first plate portion 11d in the axial direction of the stator unit.

[0015] The outer plate portion 11f has a cylindrical shape. One end of the outer plate portion 11f is connected to the outer peripheral edge of the first plate portion 11d, and the outer plate portion 11f is disposed at a right angle to the first plate portion 11d.

[0016] The first pole teeth 11g are connected to the inner peripheral edge of the first plate portion 11d and are arranged perpendicular to the first plate portion 11d. The first pole teeth 11g are tapered, with their tips pointing toward the second plate portion 11e. The first pole teeth 11g are arranged at equal intervals in the circumferential direction.

[0017] The second pole teeth 11h are connected to the inner peripheral edge of the second plate portion 11e and are arranged perpendicular to the second plate portion 11e. The second pole teeth 11h are tapered, with their tips pointing toward the first plate portion 11d. The second pole teeth 11h are arranged at equal intervals in the circumferential direction.

[0018] The first pole teeth 11g and the second pole teeth 11h are alternately arranged at intervals in the circumferential direction. The first pole teeth 11g and the second pole teeth 11h form the inner circumferential surface of the stator unit 10 (and the intermediate body 1).

[0019] By press processing, a part having the first plate portion 11d, the outer plate portion 11f and the first pole tooth 11g, and a part having the second plate portion 11e and the second pole tooth 11h are formed, and by combining these parts, the A-phase yoke 11a is obtained.

[0020] The A-phase bobbin 12a has a cylindrical shape and is made of resin. The A-phase bobbin 12a has a first flange portion 12c, a second flange portion 12d, and a cylindrical portion 12e. The first flange portion 12c and the second flange portion 12d have an annular flat plate shape and are arranged parallel to and spaced apart from the first flange portion 12c in the axial direction. The cylindrical portion 12e connects the inner peripheral edge of the first flange portion 12c and the inner peripheral edge of the second flange portion 12d.

[0021] An A-phase coil 13a is wound around the A-phase bobbin 12a. The A-phase bobbin 12a and the A-phase coil 13a are disposed in the internal space of the A-phase yoke 11a (the space surrounded by the first plate portion 11d, the second plate portion 11e, the outer plate portion 11f, the first pole tooth 11g, and the second pole tooth 11h). The first flange portion 12c contacts the first plate portion 11d of the A-phase yoke 11a. The second flange portion 12d contacts the second plate portion 11e of the A-phase yoke 11a. The cylindrical portion 12e contacts the multiple first pole teeth 11g and multiple second pole teeth 11h of the A-phase yoke 11a. The A-phase bobbin 12a separates the internal space of the A-phase yoke 11a from the spaces between the multiple first pole teeth 11g and multiple second pole teeth 11h of the A-phase yoke 11a.

[0022] The B-phase yoke 11b, B-phase bobbin 12b, and B-phase coil 13b are the same as the A-phase yoke 11a, A-phase bobbin 12a, and A-phase coil 13a except that they are arranged inverted with respect to the axial direction, and therefore the same reference numerals are used for each part and redundant explanations will be omitted. A plurality of power supply pins 21 are implanted in each of the A-phase bobbin 12a and the B-phase bobbin 12b and extend in the radial direction.

[0023] The A-phase yoke 11a and the B-phase yoke 11b are arranged coaxially. The second plate portion 11e of the A-phase yoke 11a and the second plate portion 11e of the B-phase yoke 11b are in contact with each other. An end of the outer plate portion 11f of the A-phase yoke 11a is in contact with an end of the opposing outer plate portion 11f of the B-phase yoke 11b. A wire 16 is wound around the A-phase bobbin 12a and the B-phase bobbin 12b to form the A-phase coil 13a and the B-phase coil 13b. The wire 16 drawn from the A-phase coil 13a and the B-phase coil 13b extends radially outward along the second flange portion 12d, and its end W is wrapped around and soldered to the pin 21. The wire 16, except for the portion to be soldered, is coated with polyimide resin.

[0024] The first resin portion 14 is made of a first resin material and is molded integrally with the A-phase yoke 11a and the B-phase yoke 11b on the inner side thereof.

[0025] The first resin portion 14 covers the entire periphery of the A-phase bobbin 12a and the A-phase coil 13a, and also covers the entire periphery of the B-phase bobbin 12b and the B-phase coil 13b.

[0026] However, it is sufficient that the first resin portion 14 covers at least the wires 16 from the A-phase coil 13a and the B-phase coil 13b to the portions soldered to the power supply pins 21.

[0027] The second resin portion 15 shown in FIG. 1 is formed from a second resin material different from the first resin material, and covers the outer periphery of the first resin portion 14. The linear expansion coefficient of the second resin material is greater than the linear expansion coefficient of the first resin material. Wires 16 extending from the A-phase coil 13a and the B-phase coil 13b are not in contact with the second resin portion 15. The first resin material has a linear expansion coefficient of, for example, 10 -5 / °C, and does not adhere to polyimide. The second resin material has a linear expansion coefficient of, for example, 1.6 × 10 -4 The second resin portion 15 is made of a urethane resin having a temperature of / ° C. and adheres to polyimide. The outer shape of the second resin portion 15 matches the inner shape of the cover (not shown).

[0028] The second resin portion 15 has a seal portion 15a. The seal portion 15a has a roughly cylindrical shape and is disposed to fill the space between the plurality of pole teeth (the plurality of first pole teeth 11g and the plurality of second pole teeth 11h) of the A-phase yoke 11a and the B-phase yoke 11b. The space has a plurality of branched portions that are connected to each other to form a single space. The seal portion 15a fills the space and is seamlessly connected to the plurality of first pole teeth 11g and the plurality of second pole teeth 11h. The seal portion 15a, together with the plurality of first pole teeth 11g and the plurality of second pole teeth 11h, forms the inner periphery of the stator unit 10.

[0029] The pins 21 are soldered to the circuit of the relay board 22, and a connector 23 is connected to the circuit of the relay board 22. Wiring 24 extending from the connector 23 extends to the outside and is connected to a control device (not shown). When the stator unit 10 of this embodiment is assembled to an electric valve, power is supplied from an external control device to the A-phase coil 13a and the B-phase coil 13b via the wiring 24, relay board 22, and pins 21, generating a magnetic force that drives the rotor unit.

[0030] The second resin portion 15 covers the pins 21, the relay board 22, the connector 23, and the wiring 24 except for the soldered portions.

[0031] It is preferable to attach a rotation prevention member 25 to the first plate portion 11d of the A-phase yoke 11a by welding. The rotation prevention member 25 is a member that prevents rotation of the stator unit 10 by being fixed to the can side when the stator unit 10 is assembled to the motor-operated valve.

[0032] Fig. 3 is a vertical cross-sectional view showing a state in which the intermediate 1 shown in Fig. 2 is filled with the second resin portion 15. The process of filling the intermediate 1 with the second resin portion 15 will be described below.

[0033] As shown in Fig. 3, a mold 30 is prepared. The mold 30 is composed of an outer peripheral wall 31, a bottom wall 32 that closes the bottom of the outer peripheral wall 31, a short cylindrical portion 33 formed on the bottom wall 32, and a central cylindrical portion 34 formed in the center of the short cylindrical portion 33, all of which are connected together.

[0034] With the relay board 22, connector 23, and wiring 24 attached to the pins 21 of the intermediate body 1, the intermediate body 1 is brought close from above to the mold 30, and the inner periphery of the intermediate body 1 is fitted onto the outer periphery of the central cylindrical portion 34. Then, the first plate portion 11d of the B-phase yoke 11b abuts against the upper surface of the short cylindrical portion 33, and a gap is created between the first plate portion 11d and the bottom wall 32.

[0035] From this state, molten urethane resin is poured into the mold 30 from position X in FIG. 3 until the liquid level is above the welded portion of the anti-rotation member 25. When a vacuum is applied, the urethane resin enters the gap between the first plate portion 11d and the bottom wall 32, and also enters between the multiple first pole teeth 11g and the multiple second pole teeth 11h, conforming to the outer circumferential surface of the central cylindrical portion 34 to form the seal portion 15a. The mold 30 is then heated, causing the urethane resin to harden and form the second resin portion 15. After the urethane resin has hardened, it is removed from the mold 30, completing the stator unit 10.

[0036] According to the present embodiment, wire 16 extending from A-phase coil 13a and B-phase coil 13b is in contact with first resin portion 14 but not with second resin portion 15. In particular, the radially inner sides of A-phase coil 13a and B-phase coil 13b are separated from second resin portion 15 by A-phase bobbin 12a and B-phase bobbin 12b, and the radially outer sides of A-phase coil 13a and B-phase coil 13b, including end W of soldered wire 16, are separated from second resin portion 15 by first resin portion 14. This has the advantage that even if the environmental temperature of the motor-operated valve to which stator unit 10 is assembled changes and second resin portion 15 shrinks relatively significantly, shrinkage of first resin portion 14 is suppressed, and therefore load is less likely to be applied to wire 16.

[0037] In addition, the second resin part 15 covers the entire A-phase yoke 11a, the A-phase bobbin 12a, the A-phase coil 13a, the B-phase yoke 11b, the B-phase bobbin 12b, and the B-phase coil 13b, including the first resin part 14, thereby achieving waterproofing.

[0038] (Second embodiment) 4 is a vertical cross-sectional view showing a stator unit 10A according to the second embodiment. In this embodiment, the intermediate body 1 shown in FIG. 2 is also used, and a resin cover 40 is also used. The other configurations are the same as those in the first embodiment, so a duplicated description will be omitted.

[0039] FIG. 5 is a vertical cross-sectional view showing a state in which the intermediate body 1 shown in FIG. 2 is filled with the second resin portion 15 to form the stator unit 10A.

[0040] When forming the stator unit 10A of this embodiment, a cover 40 and a core 50 are used instead of the mold used to mold the second resin portion 15. The cover 40 is made up of an outer peripheral wall 41, a bottom wall 42 that closes the bottom of the outer peripheral wall 41, and a cylindrical recess 43 formed in the bottom wall 42, which are connected together. An annular portion 44 that protrudes in the axial direction is formed on the edge of the cylindrical recess 43. The annular portion 44 is fitted onto the inner periphery of the first plate portion 11d of the B-phase yoke 11b, thereby positioning the intermediate body 1 and the cover 40.

[0041] The core 50 has a large-diameter cylindrical portion 51 and a support portion 52 coaxial with the large-diameter cylindrical portion 51. The outer diameter of the large-diameter cylindrical portion 51 is approximately equal to the inner diameter of the intermediate body 1 and the inner diameter of the cylindrical recess 43. A cylindrical retainer 55 that holds the anti-rotation member 25 is arranged around the upper periphery of the core 50.

[0042] With the relay board 22, connector 23, and wiring 24 attached to the pins 21 of the intermediate 1, the cover 40 is brought closer from above, and the inner periphery of the first plate portion 11d is fitted onto the outer periphery of the annular portion 44. This connects the inner periphery of the intermediate 1 with the inner periphery of the cylindrical recess 43 without any steps. Thereafter, the core 50 is brought closer from above the cover 40, and fitted onto the inner periphery of the intermediate 1 and the inner periphery of the cylindrical recess 43. At this time, the inner periphery of the cylindrical recess 43 is in close contact with the outer periphery of the large-diameter cylindrical portion 51 over the entire circumference, thereby preventing the urethane resin from entering the inside of the cylindrical recess 43.

[0043] From this state, molten urethane resin is poured into the cover 40 from a position similar to position X shown in FIG. 3 until the liquid level is above the welded portion of the anti-rotation member 25. The urethane resin penetrates between the first pole teeth 11g and the second pole teeth 11h, conforming to the outer peripheral surface of the large-diameter cylindrical portion 51 of the core 50 to form the seal portion 15a. The mold 30 is then heated, causing the urethane resin to harden and form the second resin portion 15. After the urethane resin has hardened, it is integrated with the cover 40 to complete the stator unit 10A.

[0044] It should be noted that the present invention is not limited to the above-described embodiments. Any of the components of the above-described embodiments may be modified within the scope of the present invention. Furthermore, any of the components of the above-described embodiments may be added or omitted.

[0045] This specification includes the disclosure of the following inventions. (First aspect) York and A stator coil; a first resin portion formed from a first resin material; a second resin portion formed from a second resin material and covering the first resin portion; One end of a wire extending from the stator coil is soldered to a power supply pin, the first resin portion covers the wire at least from the stator coil to a soldered portion, The linear expansion coefficient of the first resin material is smaller than the linear expansion coefficient of the second resin material; A stator unit characterized by:

[0046] (Second aspect) a bobbin disposed radially inside the stator coil contacts the second resin portion; The first resin portion disposed radially outside the stator coil is in contact with the second resin portion. 10. The stator unit of claim 1, wherein:

[0047] (Third aspect) The yoke has a plurality of pole teeth spaced apart in the circumferential direction, the second resin portion is interposed between the pole teeth, The stator unit according to the first or second aspect, characterized in that:

[0048] (Fourth aspect) the first resin material is an epoxy resin, The second resin material is a urethane resin. The stator unit according to any one of the first to third aspects, characterized in that:

[0049] (Fifth aspect) A stator unit according to any one of the first to fourth aspects is included. A motor-operated valve characterized by: [Explanation of symbols]

[0050] 10, 10A stator unit 11a A phase yoke 11b B phase yoke 12a A phase bobbin 12b B phase bobbin 13a A-phase coil 13b B-phase coil 14 First resin part 15 Second resin part 16 wires 40 Cover

Claims

1. York and A stator coil; a first resin portion formed from a first resin material; a second resin portion formed from a second resin material and covering the first resin portion; One end of a wire extending from the stator coil is soldered to a power supply pin, the first resin portion covers the wire at least from the stator coil to a soldered portion, The linear expansion coefficient of the first resin material is smaller than the linear expansion coefficient of the second resin material. A stator unit characterized by:

2. a bobbin disposed radially inside the stator coil contacts the second resin portion; the first resin portion disposed radially outside the stator coil is in contact with the second resin portion; 2. The stator unit according to claim 1.

3. The yoke has a plurality of pole teeth spaced apart in the circumferential direction, the second resin portion is interposed between the pole teeth, 2. The stator unit according to claim 1.

4. the first resin material is an epoxy resin, The second resin material is a urethane resin.

2. The stator unit according to claim 1.

5. A stator unit according to any one of claims 1 to 4, A motor-operated valve characterized by:

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