Armature mold structure

Abstract

Provided is an armature mold structure including: a cylindrical core used in a mold structure of a motor armature; a coil; and a mold resin, the core including a first core piece including first magnetic poles arranged along a circumferential direction of the core, an inner peripheral side tip end portion of the core of adjacent first magnetic poles being formed with a connection portion, and a second core piece including second magnetic poles arranged along the circumferential direction of the core, an inner peripheral side tip end portion of the core of adjacent second magnetic poles being formed with a non-connection portion, the first core piece and the second core piece being laminated along a central axis direction of the core in a manner in which the connection portions, the non-connection portions, and the connection portions and the non-connection portions coincide with each other, the coil being wound around the first and second magnetic poles of the laminated first and second core pieces, the mold resin being mold-formed with the first and second core pieces and the coil, an open window portion being demarcated on an inner peripheral surface of the core by the non-connection portion, and the open window portion being filled with the mold resin.

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to Japanese Patent Application No. 2018-220152, filed with the Japan Patent Office on November 26, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the armature mold structure of a motor. Background Technology

[0004] There are known techniques for forming armature mold structures by resin molding. For example, according to Japanese Patent Publication No. 2016-135022, resin flows into the top of the magnetic pole located on the inner side of the iron core constituting the armature.

[0005] The clearance between the motor's armature and rotor is preferably such that the distance to the inner circumference of the armature core is constant. However, resin flows into the tips of the magnetic poles. Therefore, it is necessary to ensure that the distance to the inscribed circle is constant. As a result, this leads to a problem that reduces torque. Summary of the Invention

[0006] The objective of this invention is to ensure a constant distance to the inscribed circle in the armature mold structure and to improve the resin's filling properties. This ensures strength and also suppresses torque reduction.

[0007] This invention provides an armature mold structure, comprising: a cylindrical iron core used in the mold structure of a motor armature; a coil; and a mold resin. The iron core includes a first iron chip and a second iron chip. The first iron chip includes a first magnetic pole arranged circumferentially along the iron core. A connecting portion is formed at the inner circumferential top end of the iron core of an adjacent first magnetic pole to connect the adjacent first magnetic poles. The second iron chip includes a second magnetic pole arranged circumferentially along the iron core. A connecting portion is formed at the inner circumferential top end of the iron core of an adjacent second magnetic pole to connect the second magnetic poles. The first and second iron chips are laminated along the central axis of the iron core in a manner that overlaps between the connecting parts, between the non-connecting parts, and between the connecting parts and the non-connecting parts. The coil is wound around the first and second magnetic poles of the laminated first and second iron chips. The molding resin is molded through the first and second iron chips and the coil. An opening window is defined on the inner circumferential surface of the iron core through the non-connecting parts, and the opening window is filled by the molding resin.

[0008] The present application also provides an armature mold structure, preferably ring-shaped resin mold end portions are provided at both ends of the core, and a concave-convex structure is formed on the inner peripheral surface of the resin mold end portions, and a flow path for flowing resin into the opening window portion is formed by the concave portions of the concave-convex structure.

[0009] The present application also provides an armature mold structure, preferably the concave-convex structure is discontinuously provided on the inner peripheral surface of the resin mold end portion in the circumferential direction.

[0010] According to the present application, in the armature mold structure, the strength can be ensured, and the torque reduction can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is one example of a core sheet used for a core of a mold structure of a motor armature according to one embodiment of the present application. Figure 1 (a) of FIG. 1 is a plan view showing one configuration example of a first core sheet. Figure 1 (b) of FIG. 1 is a plan view showing one configuration example of a second core sheet.

[0012] Figure 2 is a perspective view showing a configuration example of a core including laminated core sheets.

[0013] Figure 3 is a perspective view showing a state in which a coil is attached to the core shown in Figure 2

[0014] Figure 4 is a perspective view showing a configuration example of a structure (laminated core) after molding of Figure 3

[0015] Figure 5 is the same as Figure 4

[0016] Figure 6 is a sectional view showing one configuration example of the armature mold structure of the present embodiment after molding. In Figure 6 the axial sectional view is shown.

[0017] Figure 7 is a radial sectional view of the armature mold structure of the present embodiment. Figure 7 (b) of FIG. 4 shows the gap shown in (a) of FIG. 4 in an enlarged manner. Figure 7 (c) of FIG. 4 shows a radial sectional view of the laminated second core sheet. Figure 7

[0018] Figure 8 is a perspective view for exemplarily showing the resin flow path in the present embodiment.​​​​ DETAILED DESCRIPTION

[0019] In the following detailed description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments can be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify depiction of the application.

[0020] In the following, a mold structure of a motor armature according to an embodiment of the present application is described in detail with reference to the drawings.

[0021] Figure 1 is an example of a core sheet indicating a core used in the mold structure of a motor armature (stator) according to an embodiment of the present application. Figure 1 (a) of is a plan view indicating one configuration example of a first core sheet. Figure 1 (b) of is a plan view indicating one configuration example of a second core sheet. Figure 2 is a perspective view indicating one configuration example of a core including laminated core sheets. The armature of a motor is, for example, cylindrical. And a rotating rotor (movable element) is arranged at the inner peripheral side thereof.

[0022] As shown in (a) of Figure 1 , the first core sheet 1 includes magnetic poles 1a adjacent to each other in the circumferential direction along the rotation axis thereof. The inner peripheral side top end portions of the adjacent magnetic poles 1a are connected to each other to form a connection portion 1b. The inner peripheral end portion of the cylindrical shape is demarcated by the inner peripheral side end portion of the magnetic pole 1a including the connection portion 1b.

[0023] As shown in (b) of Figure 1 , the second core sheet 3 includes magnetic poles 3a adjacent to each other in the circumferential direction along the rotation axis thereof. The inner peripheral side top end portions of the adjacent magnetic poles 3a are isolated from each other to form a non-connection portion (opening portion) 3b.

[0024] The first core sheet 1 and the second core sheet 3 are positionally aligned in a manner that the position of the connection portion 1b of the first core sheet 1 coincides with the position of the non-connection portion 3b of the second core sheet 3. In this way, the first core sheet 1 and the second core sheet 3 are laminated in the direction of the central axis of the core, and a core 11 as shown in Figure 2 can be formed. That is, the core 11 is configured to have a hollow portion at the inner side thereof by the lamination of the first core sheet 1 and the second core sheet 3 as described above.

[0025] In the lamination process of the first core sheet 1 and the second core sheet 3, the process including the positional alignment and lamination of a prescribed number of one kind of core sheet, and then the positional alignment and lamination of a prescribed number of another kind of core sheet is repeated. By so doing, as shown in Figure 2As shown, the laminated second iron chip 3 has an opening window 15 defined by the continuous lamination of the non-connecting portion (opening) 3b with aligned positions. More specifically, the opening window 15 includes a portion comprising a through hole formed in the shape of a window penetrating the inner peripheral surface 11a and the outer peripheral surface 11b.

[0026] Figure 3 It means to Figure 2 The diagram shows the state of the iron core 11 with the coil 23 installed. Figure 4 It means Figure 3 A three-dimensional diagram of the structure (laminated iron core) after the mold is formed.

[0027] like Figure 3 As shown, a winding tube 25, including a coil 23 wound around a magnetic pole 1a, is inserted into a laminated iron chip. Next, a magnetic yoke 27 is fitted onto the outer periphery. Figure 4 As shown, then through resin mold 33 and Figure 3 The structure shown is integrally formed.

[0028] Figure 5 and Figure 4 The same is a perspective view showing the structure after mold forming. The resin mold 33 is used for insert forming of the armature core. At this time, it is necessary to determine the reference position of the laminated core, as the insert, relative to the resin mold 33 in some way. Therefore, as... Figure 5 As shown, protrusions 33b are discontinuously formed in the circumferential direction on the inner circumferential surface 33a side of the resin mold (end) 33. This allows for a continuous circumferential-convex shape on the inner circumferential surface 33a. By discontinuously providing this circumferential-convex shape, the end of the inner circumferential surface 11a of the iron core 11 is exposed in the recessed portion. Here, by placing the end of the inner circumferential surface 11a of the iron core 11 against the metal mold used during molding, a reference position during molding can be ensured. This facilitates molding.

[0029] Figure 6 This is a cross-sectional view showing an example of the armature mold structure after the mold is formed according to this embodiment. Figure 6 This refers to the cross-section along the axial direction. The first iron chip 1 and the second iron chip 3 are laminated together as described above to form the motor core 11. At this time, only a predetermined number of the first iron chip 1 and the second iron chip 3 are continuously laminated. Therefore, a portion 1 comprising the continuously laminated first iron chip 1 and a portion 3 comprising the continuously laminated second iron chip 3 are formed on the inner circumferential surface 11a of the core 11. An opening window 15, as described above, is formed on this portion 3 as a through hole extending from the inner circumferential surface 11a to the outer circumferential surface 11b.

[0030] like Figure 3As shown, after the coil of the motor is installed, by resin molding, a resin mold 33 is used to obtain an integrally formed body as shown in Figure 5 from the coil end portion to the coil interior. At this time, as shown in Figure 2 , in the center axis direction end portion of the laminated core pieces included in the core 11, a first core piece 1 is laminated on a first end portion. In addition, the first core piece 1 is continuously laminated, for example, at equal intervals and in the same manner from this first end portion. The same is true for a second end portion. Therefore, the connection portion 1b of the connection of the core pieces hinders the flow of the mold resin in the axial direction. As a result, the resin has difficulty spreading to the open window portion 15 shown in Figure 6 . Therefore, complete sealing is not possible.

[0031] Therefore, in order to also fill the resin into the open window portion 15, a protrusion 33b as shown in Figure 6 is provided at the inner diameter end portion. The resin of the coil end portion flows into the end surface of the core 11 from between the protrusions 33b.

[0032] Figure 7 is a radial partial cross-sectional view showing the armature mold structure of the present embodiment. Figure 7 (b) of Figure 7 shows the gap shown in (a) of Figure 7 . (c) of Figure 7 shows a radial partial cross-sectional view of the laminated second core piece. As shown in (a) of Figure 7 to (c) of Figure 6 , the mold resin flows into the open window portion 15 shown in Figure 6 from the gap 51 formed between the magnetic pole 1a and the connection portion 1b and the coil 23 and the bobbin 25 through the protrusions 33b (refer to . Therefore, it becomes easy to fill the open window portion 15 with resin. By filling the open window portion 15 with resin, the strength of the armature mold structure can be improved.

[0033] Figure 8 is a perspective view for exemplarily showing the resin flow path of the present embodiment. As shown by the arrow in Figure 8 , the mold resin is injected from the axial end surface of the armature core 31. Next, it flows in the direction of the laminated core as shown by the flow path LI. Then, as explained above, a portion of the resin flows in the direction (L2) of the protrusions 33b as shown by the flow path L2. As shown in Figure 2 , the end portion of the laminated core 21 is composed of the laminated first core piece 1. Therefore, the mold resin cannot reach the open window portion 15 of the inner periphery. However, the resin that flows along the recesses (inner peripheral surface) 33a by bypassing the protrusions 33b can reach the open window portion 15 through the gap 51 shown in the cross-sectional views of (a) of Figure 7 to (c) of Figure 7 .

[0034] Accordingly, the opening window portion 15 can be filled with resin.

[0035] As described above, the first core piece 1 having the connection portion 1b is mixedly laminated with the second core piece 3 having the non-connection portion 3b. At this time, the core pieces laminated continuously in a prescribed ratio include only the first core piece 1 or the second core piece 3. By so doing, the torque of the motor can be improved. Further, the cogging torque can be reduced. In addition, the problem of the decrease in the rigidity of the core due to the opening window portion 15 can be solved by forming the flow path of resin as described above.

[0036] That is, according to the armature mold structure of the present embodiment, the first core piece is mixedly laminated with at least one or more kinds of the second core piece in the armature structure of the motor. Accordingly, the connection portion formed of the tip end portion of the magnetic pole included in the first core piece connects the adjacent magnetic poles like a bridge. In addition, the second core piece has a non-connection portion (opening portion). Here, the second core piece can include two or more kinds of core pieces having a non-connection portion. Then, the opening window portion is formed on the inner periphery of the laminated core of the motor obtained by the resin mold forming after the coil work by the second core piece having a non-connection portion (opening portion) laminated. Further, in order to cause the resin to flow into the opening window portion, a flow route is provided on the laminated core end surface thereof. By such a mold structure, even the opening window portion can be sufficiently filled with the resin mold. Accordingly, the strength of the mold structure can be improved.

[0037] The present embodiment is not limited to the illustrated configuration and the like. The above-described embodiment can be appropriately changed within a range where the effects of the present application are exerted. In addition, the above-described embodiment can be appropriately changed and implemented within a range not exceeding the object of the present application.

[0038] Further, each of the components described in the above-described embodiment can be appropriately selected and omitted. The embodiment having a configuration including the selected and omitted components is also included in the present embodiment.

[0039] The present application can be used for an armature mold structure.

[0040] The armature mold structure of the embodiment of the present application can be the following first to third armature mold structures.

[0041] The above-described first armature mold structure is a motor armature structure in which a cylindrical core used in a mold structure of a motor armature is formed by laminating core pieces, the core structure has a first core piece having a connection portion connecting inner peripheral side tip end portions of adjacent magnetic poles of the cylinder along a circumferential direction of the cylinder, and a second core piece having a non-connection portion in which inner peripheral side tip end portions of adjacent magnetic poles are not connected, the first core piece and the second core piece are laminated by resin in a manner that the connection portion coincides with the non-connection portion to form a laminated core of the core, and a coil wound on the laminated core is mold formed, and the laminated core has an opening window portion formed by the non-connection portion on an inner peripheral surface of the laminated core, the opening window portion being filled with the resin by laminating a plurality of the second core pieces in a laminating direction.

[0042] The above-described second armature mold structure is the first armature mold structure in which annular resin mold end portions formed by laminating the first core pieces are respectively provided on both ends in the laminating direction of the laminated core, and a concave-convex structure is formed on an inner peripheral surface of the resin mold end portion, and a flow path for allowing resin to flow into the opening window portion is formed by a concave portion of the concave-convex structure.

[0043] The above-described third armature mold structure is the second armature mold structure in which the concave-convex structure is discontinuously provided on the inner peripheral surface of the resin mold end portion along the circumferential direction.

[0044] The detailed description has been presented for the purposes of illustration and description. Many variations and modifications will be possible in light of the above teachings. The detailed description is not intended to be exhaustive or to limit the subject matter described herein to the precise forms disclosed. Although specific features of the subject matter are described above, one of ordinary skill in the art will appreciate that the subject matter defined by the appended claims is not limited to the particular features described above. Rather, the particular features described above are disclosed by way of example and illustration so that one skilled in the art will appreciate that submission within the scope of the claims and their equivalents are intended.

Claims

1. An armature mold structure characterized by comprising: a cylindrical core used in a mold structure of a motor armature; a coil; and a mold resin, the core includes a first core piece and a second core piece, the first core piece includes first magnetic poles arranged along a circumferential direction of the core, inner peripheral side tip end portions of the core of adjacent first magnetic poles are formed with a connecting portion connecting the adjacent first magnetic poles, the second core piece includes second magnetic poles arranged along a circumferential direction of the core, inner peripheral side tip end portions of the core of adjacent second magnetic poles are formed with a non-connecting portion isolating the adjacent second magnetic poles, the first and second core pieces are laminated along a central axis direction of the core in a manner that the connecting portions, the non-connecting portions, and the connecting portions and the non-connecting portions coincide with each other, the coil is wound around the first and second magnetic poles of the laminated first and second core pieces, the mold resin is mold formed with the first and second core pieces and the coil, an open window portion is demarcated on an inner peripheral surface of the core by the non-connecting portion, the open window portion is filled with the mold resin, annular resin mold end portions are provided at both ends of the core, a concave-convex structure is formed on an inner peripheral surface of the resin mold end portion, a flow route for flowing resin into the open window portion is formed by a concave portion of the concave-convex structure and a gap formed between the coil and the first magnetic poles and the connecting portion.

2. The armature die structure of claim 1, wherein the concave-convex structure is discontinuously provided on the inner peripheral surface of the resin mold end portion along a circumferential direction thereof.

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