Stator for electric valve and electric valve

Abstract

In a stator (21) of an electric valve which constitutes a motor portion together with a magnetic rotor of a valve device, the function of a bracket (1) (a fixing metal member) is ensured so as not to intrude a part of a cast resin portion (21D) into an insertion hole (21H) side of the valve device. In the stator (21), a coil (21b) is wound around a bobbin (21a). The cast resin portion (21D) is cast between the bobbin (21a) and the coil (21b) and an outer cover (21C). A skirt portion (21K) which protrudes toward a lower side of the axis (L) than the cast resin portion (21D) is provided around the axis (L) at an opening portion of the insertion hole (21H) of the bobbin (21a). The valve device is inserted into the insertion hole (21H) of the bobbin (21a) in the axis (L) direction. A base portion (11) of the bracket (1) is installed to a fixing block (21B) formed in a part of the skirt portion (21K). A deep groove (51) (an open space portion) is formed in the fixing block (21B).

Description

[0001] This application is a divisional application; its parent application number is "2020100368447", and its invention title is "Stator for Electric Valve and Electric Valve". Technical Field

[0002] The present invention relates to a stator for an electric valve used in refrigeration cycle systems such as air conditioners, and an electric valve having the stator for the electric valve. Background Technology

[0003] Currently, electric valves of this type utilize the rotation of a magnetic rotor from a motor such as a stepper motor to actuate valve components within the valve body. Such electric valves require a closed fluid flow path, and the magnetic rotor of the motor is housed within a cylindrical housing that forms a sealed structure together with the valve body. Furthermore, the stator of the motor is positioned on the outer periphery of the housing. For example, a similar electric valve is disclosed in Japanese Patent Application Publication No. 2014-52037 (Patent Document 1), in which the stator is constructed such that a spool and coil are covered by a housing body (outer casing), and the housing body is filled with and cured with a molding resin.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-52037 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] As with existing electric valves, when casting resin into the outer casing (outer housing), malfunctions can occur if the molten resin intrudes into unwanted areas during the casting process. For example, in the device of Patent Document 1, a fixing metal part is provided at the lower part of the stator to prevent vibration of the valve body relative to the stator. However, if resin intrudes into the gap between the fixing metal part and the spool, it flows to the inner diameter side of the stator due to capillary action and solidifies, sometimes resulting in poor assembly relative to the valve body, or inability to reliably prevent vibration of the valve body.

[0009] The objective of this invention is to prevent molten resin from penetrating into unnecessary parts during the casting process of an electric valve stator that is formed together with the magnetic rotor of the valve device as a motor unit and sealed in cast resin.

[0010] Solution for solving the problem

[0011] The stator for an electric valve in Scheme 1 is assembled into a valve device that is driven by a motor, and houses a coil. Together with a magnetic rotor on the valve device side, it constitutes the motor unit. The stator is characterized by comprising: a spool on which the coil is wound, and having an insertion hole for embedding the valve device along the axial direction of the coil; an outer cover covering the spool and the coil; a cast resin portion filling the space between the spool, the coil, and the outer cover; an annular wall portion formed around the opening of the insertion hole on the spool along the axial direction; and a fixing metal part, at least a portion of which extends from the cast resin portion side to the insertion hole across the annular wall portion. The configuration facilitates the fixation of the stator of the electric valve to the valve device. The entire circumference of the opening end of the outer cover and the entire circumference of the annular wall portion are formed with the cast resin portion protruding towards the fixing metal part in the axial direction. The fixing metal part includes: an inner plate disposed on the inner side of the annular wall portion; and an outer plate disposed on the outer side of the annular wall portion. The end of the outer plate is disposed in contact with the cast resin portion. An open space portion is formed in the portion of the annular wall portion that is spanned by the fixing metal part. The circumferential width of the open space portion is formed to be equal to or greater than the approximately circumferential width of the fixing metal part around the axis.

[0012] The stator for an electric valve in Scheme 2 is based on the stator for an electric valve described in Scheme 1, characterized in that a gap is formed between the aforementioned fixing metal part and the aforementioned annular wall portion, the gap comprising: a first gap formed by the aforementioned outer plate and the aforementioned annular wall portion, including a portion of the cast resin portion, namely the gap resin portion; and a second gap formed by the aforementioned inner plate and the aforementioned annular wall portion, excluding the cast resin portion, an open space portion being formed between the aforementioned first gap and the aforementioned second gap, the aforementioned first gap and the aforementioned second gap being connected to the aforementioned open space portion.

[0013] The stator for the electric valve in Scheme 3 is based on the stator for the electric valve described in Scheme 1, characterized in that the aforementioned fixing metal part has an elastic sheet that engages with the aforementioned valve device and a base fixed to the fixing block, the aforementioned fixing block is formed on a part of the aforementioned annular wall portion, and the aforementioned open space portion is provided on either or both of the aforementioned fixing block and the aforementioned base portion.

[0014] The stator for an electric valve in Scheme 4 is based on the stator for an electric valve described in Scheme 3, characterized in that a groove is formed on a portion of the end face of the fixed block in the axial direction opposite to the base, and in the approximately circumferential direction around the axial direction, the groove constituting the open space portion.

[0015] The stator for an electric valve in Scheme 5 is based on the stator for an electric valve described in Scheme 3, characterized in that a recess is formed in the portion of the base facing the end face of the fixed block in the direction of the axial direction and in the approximately circumferential direction around the axial direction, and the recess constitutes the open space portion.

[0016] The stator for an electric valve in Scheme 6 is based on the stator for an electric valve described in Scheme 3, characterized in that a groove formed on the fixed block and opposite to the base constitutes the open space portion.

[0017] The stator for an electric valve in Scheme 7 is based on the stator for an electric valve described in Scheme 4, characterized in that the width of the base in the approximately circumferential direction about the axis is included within the width of the groove in the approximately circumferential direction about the axis.

[0018] The electric valve of Scheme 7 is characterized in that the valve device has a stator for an electric valve as described in any one of Schemes 1 to 7.

[0019] The effects of the invention

[0020] According to the stator for electric valves in schemes 1 to 7, since there is an open space between the portion of the fixed metal part that spans the annular wall and the fixed metal part that can store a portion of the cast resin part, even if the molten resin flows in the gap between the annular wall and the fixed metal part due to capillary effect when casting the cast resin part, the flow of the resin will not exceed the open space, so that a portion of the cast resin part will not be formed on the side of the insertion hole into which the valve device is embedded.

[0021] According to the electric valve of scheme 8, the same effect as that of schemes 1 to 7 is obtained. Attached Figure Description

[0022] Figure 1 This is a partial sectional side view of the electric valve according to an embodiment of the present invention.

[0023] Figure 2 (A) and (B) are longitudinal and bottom views of the stator for the electric valve according to the embodiment.

[0024] Figure 3 yes Figure 2 Enlarged view of the main part of (A).

[0025] Figure 4 This is a diagram showing the engagement state of the bracket and the shell in the embodiment.

[0026] Figure 5 This is an enlarged view of the main part of a modified example 1 of the stator for an electric valve, illustrating the embodiment.

[0027] Figure 6 This is an enlarged view of the main part of a modified example 2 of the stator for an electric valve, illustrating the embodiment.

[0028] Figure 7 This is an enlarged view of the main part of a modified example 3 of the stator for an electric valve, illustrating the embodiment.

[0029] Explanation of symbols

[0030] 1—Bracket (metal part for fixing), 11—Base, 11a—Outer side plate, 11b—Inner side plate, 11c—Connecting plate, 12—Elastic sheet, 12a—Protrusion, 41—Slit, 42—Embedded groove, 51—Deep groove (open space part), 52—Inner corner part (open space part), 53—Recess (open space part), 54—Recess (open space part), 20—Stepper motor (motor part), 21—Stator (stator for electric valve), 21a—Spindle, 21b—Coil, 21H—Embedded hole, 21K—Skirt (annular wall part), 21B—Fixing block, 22—Magnetic rotor, 30—Valve body (valve device), 40—Shell (valve device, cylindrical part), 40A—Small diameter part, 40B—Large diameter part, L—Axis. Detailed Implementation

[0031] Next, embodiments of the stator for an electric valve and the electric valve of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a partial sectional side view of the electric valve according to the embodiment. Figure 2 (A) and (B) are a longitudinal sectional view and a bottom view of the stator for the electric valve according to the embodiment. Figure 2 (B) is Figure 1 AA section view before casting, Figure 2 (A) is Figure 2 (B) is a cross-sectional view of BB after casting. Figure 3 yes Figure 2 Enlarged view of the main part of (A), Figure 4 This is a diagram showing the engagement state of the bracket and the housing in the embodiment. Furthermore, the concept of "upper and lower" in the following description is different from... Figure 1 and Figure 2 The top and bottom correspondences in the attached diagram (A).

[0032] like Figure 1 and Figure 2 As shown, the electric valve includes a stator 21 serving as a "stator for the electric valve," a stepper motor 20 serving as a "motor unit," a valve body 30, and a cylindrical housing 40 made of a non-magnetic material. The stepper motor 20 consists of a stator 21 mounted on the outer periphery of the housing 40 and a magnetic rotor 22 rotatably disposed inside the housing 40. Furthermore, a predetermined gap is provided between the outer peripheral surface of the magnetic rotor 22 and the inner peripheral surface of the housing 40.

[0033] The valve body 30 has a housing 310 made of stainless steel or the like, and valve components are built inside the housing 310. Moreover, the valve body 30 is driven by the stepper motor 20 (rotation of the magnetic rotor 22) to control the flow rate of fluid flowing from the first connector pipe 31 to the second connector pipe 32, or the flow rate of fluid flowing from the second connector pipe 32 to the first connector pipe 31.

[0034] A shell 40 is assembled airtightly at the upper end of the housing 310 of the valve body 30 by welding or other means, thereby forming a "valve device" with the valve body 30 and the shell 40.

[0035] The stator 21 includes a resin spool 21a containing coils 21b, 21b, an outer cover 21C covering the spool 21a and coils 21b, 21b, a cast resin portion 21D filling the space between the spool 21a, coils 21b, 21b and the outer cover 21C, and a bracket 1 serving as a "fixed metal part". The spool 21a has a cylindrical insertion hole 21H centered on the axis L for inserting the housing 40 of the aforementioned "valve device" in the direction of the axis L of the coils 21b, 21b. Furthermore, at the bottom of the spool 21a on the valve body 30 side, there is a skirt portion 21K serving as an "annular wall portion" that expands in diameter from the opening 21H1 of the insertion hole 21H towards the valve body 30 side. This skirt portion 21K is formed around the opening of the insertion hole 21H about the axis L, and the skirt portion 21K is formed to protrude downward in the direction of the axis L beyond the cast resin portion 21D. In fact, during the casting of stator 21, Figure 2 In (A), the casting resin flows in an upside-down position, filling the amount of resin that will not overflow from the upper ends of the outer cover 21C and the skirt 21K, and then curing it. The bracket 1 is arranged from the casting resin portion 21D side to the insertion hole 21H, spanning a portion of the skirt 21K (annular wall portion). Furthermore, a magnetic yoke (yoke portion) 21c with magnetic pole teeth 21d is integrally assembled onto the linear shaft 21a by molding, and the magnetic pole teeth 21d of the magnetic yoke 21c are arranged on a portion of the inner circumferential surface of the insertion hole 21H. Moreover, the magnetic pole teeth 21d are arranged facing the outer circumferential surface of the shell 40.

[0036] With the above structure, in the stepper motor 20, applying a pulse output to the coil 21b generates magnetic lines of force in the coil 21b. As a result, the magnetic poles (N and S poles) in the magnetic pole teeth 21d alternate, generating magnetic attraction and repulsion forces on the magnetic rotor 22, thereby causing the magnetic rotor 22 to rotate. Consequently, the valve components inside the valve body 30 actuate to variably control the opening degree of the valve port, thereby controlling the flow rate of refrigerant flowing from the first connector pipe 31 to the second connector pipe 32, or from the second connector pipe 32 to the first connector pipe 31, as described above.

[0037] The housing 40, centered on axis L, is composed of a small-diameter portion 40A opposite to the outer periphery of the magnetic rotor 22 and a large-diameter portion 40B that expands from the small-diameter portion 40A towards the valve body 30. Furthermore, the small-diameter portion 40A of the housing 40 is inserted into the insertion hole 21H of the stator 21, and a portion of the large-diameter portion 40B of the housing 40, when located on the valve body 30 side of the opening 21H1, is housed within the skirt 21K of the linear shaft 21a. Thus, the stator 21 is assembled to the valve assembly. A bracket 1, serving as a "fixed metal part," is mounted at the bottom of the stator 21.

[0038] The bracket 1 is formed by stamping or other processes of a metal sheet, and has a base 11 with a groove structure consisting of three plate-like portions, and an elastic sheet 12 integrally extending from the side of the base 11. The base 11 is composed of an inner plate 11b that is opposite to the outer plate 11a and extends from which the elastic sheet 12 is disposed, and a connecting plate 11c that connects the outer plate 11a and the inner plate 11b. The elastic sheet 12 has a protrusion 12a integrally formed therewith, a pressing portion 12b formed by bending a portion of the elastic sheet 12 on the side opposite to the base 11, and a fulcrum portion 12c.

[0039] A generally rectangular cuboid fixing block 21B is formed on a portion of the skirt 21K of the spool 21a. Specifically, the fixing block 21B is formed on the outer periphery of the opening 21H1 of the insertion hole 21H around the axis L, and is located in the spool 21a at a position lower than the lower end of the coil 21b along the axis L. A slit 41 is formed on the inner side (axis L side) of the fixing block 21B, and an insertion groove 42 is formed on the outer side (opposite to the axis L side) of the fixing block 21B. Furthermore, the inner plate 11b of the bracket 1 is inserted into the slit 41 on the inner side of the fixing block 21B, and the outer plate 11a is inserted into the insertion groove 42 on the outer side of the fixing block 21B. Additionally, the outer plate 11a and the inner plate 11b are equipped with anti-detachment features (not shown) against the insertion groove 42 and the slit 41. Thus, the bracket 1 is fixed to the fixing block 21B. Furthermore, the cast resin portion 21D that fills the space between the spool 21a and coil 21b, and between 21b and the outer cover 21C, penetrates into the embedding groove 42 on the outside of the fixing block 21B.

[0040] like Figure 4As shown, the protrusion 12a of the bracket 1 and the recess 40a of the housing 40 engage when the stator 21 is assembled to the valve device. This positions the stator 21 relative to the housing 40 about the axis L, and the stator 21 is mounted to the housing 40 in a way that prevents it from detaching in the direction of the axis L. Furthermore, regarding the elastic piece 12 of the bracket 1, with the pressing portion 12b abutting against the outer periphery of the housing 40, the fulcrum portion 12c abuts against the inner periphery of the skirt portion 21K. Thus, the elastic piece 12, due to its own elasticity, presses against the housing 40 with the fulcrum portion 12c as the fulcrum. This results in the housing 40 being held by the elastic piece 12 and the opposing inner wall of the opening 21H1 on the side opposite to the elastic piece 12.

[0041] As described above, in this embodiment, the bracket 1, which is a metal part for fixing, has an elastic piece 12 that engages with the valve device and a base 11 that is fixed to the fixing block 21B. The base 11 is constructed by means of a connecting plate 11c that integrates the outer plate 11a and the inner plate 11b that clamp the fixing block 21B in the radial direction of the fitting hole 21H.

[0042] A deep groove 51, serving as an "open space," is formed in the fixing block 21B. This deep groove 51 is a groove that faces the connecting plate 11c of the base 11 of the bracket 1 on the lower end face of the fixing block 21B in the direction of the axis L and runs approximately circumferentially around the axis L. Furthermore, as... Figure 2 As shown in (B), the width (B) of the base 11 (connecting plate 11c) of the bracket 1 in the approximately circumferential direction about the axis L is configured to be contained within the width (A) of the deep groove 51 in the approximately circumferential direction about the axis L. Thus, openings of the deep groove 51 are formed on both sides of the aforementioned width (B) of the base 11, thereby enabling the completion of gap interruptions such as capillary action between the connecting plate 11c of the base 11 and the fixing block 21B.

[0043] As described above, since a deep groove 51 is formed in the fixing block 21B, when casting the molded resin part 21D ( Figure 2 In (A), even if the molten resin flows within the gap between the fixed block 21B (or skirt 21K) and the bracket 1 due to capillary action, a portion of the resin will accumulate in the deep groove 51, and the flow of the resin will not exceed the deep groove 51. Therefore, a portion of the cast resin portion 21D will not form on the side of the elastic sheet 12 of the bracket 1. Furthermore, such a portion of the cast resin portion 21D will not form on the side of the insertion hole 21H. Therefore, the housing 40 (valve device) can be easily inserted into the insertion hole 21H. Furthermore, since a portion of the cast resin portion 21D will not form on the side of the elastic sheet 12, the elastic sheet 12 and the spool portion will not be fixed and thus lose their function as elastic sheets, and the elastic sheet 12 of the bracket 1 will also function reliably.

[0044] Figures 5 to 7 These are figures illustrating variations 1 to 3 of the "open space section". Figure 5 In modified example 1, in the fixing block 21B, an inner corner portion 52, serving as an "open space portion," is formed at the corner of the outer side plate 11a side of the base 11 of the bracket 1. Figure 6 In modified example 2, the connecting plate 11c of the base 11 of the bracket 1 is deformed, and a recess 53 as an "open space" is formed facing the end face of the fixing block 21B in the direction of the axis L. Figure 7 In the modified example 3, the connecting plate 11c of the base 11 of the bracket 1 is deformed, and a recess 54 as an "open space part" is formed on the outer side plate 11a side of the base 11.

[0045] In any of the above variations, when casting the cast resin part 21D ( Figures 5 to 7 In the inverted position, even if the molten resin flows within the gap between the fixed block 21 and the bracket 1 due to capillary action, a portion of the resin will accumulate in the "open space," and the flow of this resin will not exceed the "open space." Therefore, a portion of the cast resin portion 21D will not form on the side of the elastic sheet 12 of the bracket 1 or the side of the insertion hole 21H. Thus, the housing 40 (valve device) can be easily inserted into the insertion hole 21H. Furthermore, as in the embodiment described above, the elastic sheet 12 of the bracket 1 also functions reliably.

[0046] As described above, the "open space" prevents the molten resin from flowing out towards the insertion hole 21H even if capillary action occurs during the casting of the molding resin section 21D. Therefore, the structure is not limited to any particular embodiment or variation; any structure that provides a gap or notch that prevents capillary action is acceptable. For example, a gap of 1 mm or more is preferred to prevent capillary action. Furthermore, the gap can be 0.5 mm or more, or 3 mm or more. Additionally, the shape of the open space, i.e., the groove, is not limited to... Figure 2 The rectangular groove in (B) can also be a square groove, a curved groove, a circular groove, an elliptical groove, an arc-shaped groove, a crescent-shaped groove, etc. Furthermore, the volume of the open space is not limited to the figures shown; it can be larger than the dimensions of the grooves shown, or it can be smaller without departing from the spirit of the invention.

[0047] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes design changes and the like that that do not depart from the spirit of the present invention.

Claims

1. A stator for an electric valve, which is assembled to a valve device that operates by driving of a motor section, and which houses a coil, and which constitutes the motor section together with a magnetic rotor on the valve device side, the stator for an electric valve being characterized by comprising: a bobbin that winds the coil, and that has an insertion hole that is inserted into the valve device in an axial direction of the coil; an outer cover that covers the bobbin and the coil; a cast resin section that is filled between the bobbin and the coil and the outer cover; a ring wall section that is formed around an opening of the insertion hole of the bobbin in the axial direction; and a fixing metal member that is disposed across the ring wall section from the cast resin section side to the insertion hole, and that contributes to fixing of the stator for an electric valve to the valve device, an entire circumference of an opening end of the outer cover and an entire circumference of the ring wall section are formed protrusively toward the fixing metal member side in the axial direction of the cast resin section, an inner side plate that is disposed on an inner side of the ring wall section, and an outer side plate that is disposed on an outer side of the ring wall section, an end portion of the outer side plate is disposed in a state of contacting the cast resin section, an open space section is formed in a portion of the ring wall section that is crossed by the fixing metal member, and a width of the fixing metal member in a substantially circumferential direction around the axis is included in a width of the open space section in a circumferential direction.

2. The stator for an electric valve according to claim 1, characterized in that: a gap is formed between the fixing metal member and the ring wall section, the gap includes a first gap that is a gap formed by the outer side plate and the ring wall section, and that includes a portion of the cast resin section, that is, a gap resin section, and a second gap that is a gap formed by the inner side plate and the ring wall section, and that does not include the cast resin section, an open space section is formed between the first gap and the second gap, and the first gap and the second gap are connected to the open space section.

3. The stator for an electric valve according to claim 1, characterized in that: the fixing metal member has a resilient piece that engages with the valve device, and a base portion that is fixed to a fixing block, and the fixing block is formed in a portion of the ring wall section.

4. The stator for an electric valve according to claim 3, characterized in that: a groove is formed in a portion of the fixing block that is opposite to the base portion, and that is in an end surface in the axial direction, and the groove constitutes the open space section.

5. The stator for an electric valve according to claim 3, characterized in that: the groove that is formed in the portion of the fixing block that is opposite to the base portion constitutes the open space section.

6. The stator for an electric valve according to claim 4, characterized in that: a width of the base portion in the substantially circumferential direction around the axis is included in a width of the groove in the substantially circumferential direction around the axis.

7. A stator for an electric valve, which is assembled to a valve device that operates by driving of a motor section, and which houses a coil, and which constitutes the motor section together with a magnetic rotor on the valve device side, the stator for an electric valve being characterized by comprising: ​ The above-mentioned metal parts for fixation include: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a bobbin which winds the above-mentioned coil and has an insertion hole into which the above-mentioned valve device is inserted in the axial direction of the coil; an outer cover which covers the above-mentioned bobbin and the above-mentioned coil; a cast resin portion which is filled between the above-mentioned bobbin and the above-mentioned coil and the above-mentioned outer cover; a ring wall portion which is formed around the circumference of the opening of the above-mentioned insertion hole of the above-mentioned bobbin in the above-mentioned axial direction; and a fixing metal member which is disposed so as to span the above-mentioned ring wall portion from the side of the above-mentioned cast resin portion to the above-mentioned insertion hole at least in part and which contributes to the fixing of the above-mentioned valve device for electric motor stator to the above-mentioned valve device, the entire circumference of the opening end of the above-mentioned outer cover and the entire circumference of the above-mentioned ring wall portion are formed so as to protrude toward the side of the above-mentioned fixing metal member in the above-mentioned axial direction of the above-mentioned cast resin portion, The above-mentioned metal parts for fixation include: an inner side plate which is disposed on the inner side of the above-mentioned ring wall portion and an outer side plate which is disposed on the outer side of the above-mentioned ring wall portion, the end portion of the above-mentioned outer side plate is disposed in a state of contact with the above-mentioned cast resin portion, the above-mentioned fixing metal member has a base portion which is fixed to a fixing block and an elastic piece which engages with the above-mentioned valve device, and the above-mentioned fixing block is formed in a portion of the above-mentioned ring wall portion, a recessed portion is formed in the above-mentioned base portion at a position which is opposed to the end surface of the above-mentioned fixing block in the above-mentioned axial direction and in the substantially circumferential direction around the above-mentioned axial direction, and the above-mentioned recessed portion constitutes an open space portion.

8. An electric motor valve characterized in that the above-mentioned valve device is provided with the valve device for electric motor stator according to any one of claims 1 to 7.

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