Priority is claimed on Japanese Patent Application No. 2018-079236, filed on Apr. 17, 2018, the contents of which are incorporated herein by reference.
The present invention relates to a molded body and a shaping mold.
In a rotary electric machine, a bus bar unit may be used for electrically connecting an external electric source and a coil of each phase. A plurality of bus bars that are formed of a metal material are molded by a resin material, and the bus bar unit is formed.
In the bus bar unit described above, in order to improve the quality, for example, a configuration described in Japanese Unexamined Patent Application, First Publication No. 2018-23222 is known. The bus bar unit described in Japanese Unexamined Patent Application, First Publication No. 2018-23222 includes a cap that separately supports each of the plurality of bus bars and an outer support part that molds the plurality of bus bars collectively together with the cap.
However, recently, a further improvement of quality is required for a molded body such as the bus bar unit.
An aspect of the present invention provides a molded body and a shaping mold capable of improving a quality.
(1) A molded body according to an aspect of the present invention includes: a first resin part; a metal part that is covered by the first resin part and that has a protrusion portion which protrudes from a first end portion of the first resin part; and a second resin part that has a second end portion which is positioned on an opposite side of the protrusion portion with respect to the first end portion in an extension direction of the protrusion portion and that covers the first resin part in a state where the first resin part protrudes in the extension direction.
(2) In the molded body according to the above aspect (1), a portion of the first resin part that is positioned between the first end portion and the second end portion may be formed in a flat surface.
(3) In the molded body according to the above aspect (1) or (2), the first resin part may cover separately each of a plurality of the metal parts, and the second resin part may cover collectively the first resin part.
(4) In the molded body according to any of the above aspects (1) to (3), the first resin part may be attached to the metal part.
(5) In the molded body according to any of the above aspects (1) to (4), the metal part may be a bus bar that is configured to electrically connect an external electric source and a coil of a rotary electric machine.
(6) Another aspect of the present invention is a shaping mold for molding a molded body described in any of the above aspects (1) to (5), the shaping mold including a mold main body that supports the first resin part and the metal part and that forms a cavity in which the second resin part is molded, wherein the mold main body includes a support part that supports a surface of the first end portion which is directed to a direction that is crossed with the extension direction.
According to the above aspects (1) and (6), the metal part is covered by the first resin part, and thereby, a mold portion of the metal part by the second resin part is able to be reinforced by the first resin part. Thereby, at the time of molding of the second resin part, it is possible to prevent a position displacement and a bend of the metal part in the mold main body due to a molding pressure and the like, and it is possible to perform a positioning of the metal part in the mold main body with high accuracy. Thereby, it becomes possible to simplify a production process, and it is possible to reduce the cost and stabilize the quality.
According to the above aspects (1) and (6), the second resin part covers the first resin part in a state where the first resin part protrudes.
According to this configuration, a boundary section between a first cover portion and a second cover portion is set at a more backward position (position on the opposite side of the protrusion portion with respect to the first end portion) than the first end portion in the extension direction. Therefore, it is possible to allow the mold main body to come into contact with a portion of the first resin part, the portion being a surface that is directed to a direction which is crossed with the extension direction and being positioned between the first end portion and the second end portion, and it is possible to support the first resin part. Accordingly, it is possible to secure a contact area between the first resin part and the support part of the mold main body. Thereby, even when a plane pressure that acts between an outer surface of the first resin part and the support part of the mold main body is low, for example, due to a size dispersion of the first resin part and the like, it is possible to prevent a resin material from flowing into the support part via a space between an outer surface of the first end part and an inner surface of the support part at the time of molding of the second resin part. As a result, it is possible to prevent the resin material from remaining as a burr on the outer surface of the first end portion.
Accordingly, it is possible to provide a molded body having an excellent quality.
According to the above aspect (2), the first end portion is further easily supported by the mold main body at the time of molding of the second resin part.
Therefore, it is possible to further improve the quality of the molded body.
According to the above aspect (3), the first resin part supports separately each metal part, and therefore, each metal part is easily set at a desired position in the mold main body. In this state, by integrating the metal parts by the second resin part, it is possible to provide a molded body in which a relative position of the metal parts is positioned with high accuracy.
According to the above aspect (4), the first resin part that is formed separately from the metal part is attached to the metal part, and therefore, it is possible to further simplify the production process. Further, it is possible to prevent a position displacement of the metal part due to an injection pressure or the like at the time of first molding (at the time of molding of the first resin part) differently from a case in which the first resin part and the second resin part are formed, for example, according to a two-color molding or the like. Thereby, it is possible to further stabilize the quality.
According to the above aspect (5), it is possible to secure a rigidity, for example, compared to a case where a wire material or the like is used for the connection between the rotary electric machine and the external electric source. Further, in the present aspect, it is possible to provide a molded body having an excellent quality as described above, and therefore, it is possible to prevent a twist, a bend, and the like of the metal part in a state where the rotary electric machine and the external electric source are connected together. Thereby, it is possible to reduce stress that acts on the molded body, and it is possible to improve the durability of the molded body.
Hereinafter, an embodiment of the present invention is described with reference to the drawings.
The rotary electric machine 1 shown in
The rotary electric machine 1 includes a case 3, a stator 5, a rotor 7, and an output shaft 9.
The output shaft 9 is supported rotatably by the case 3.
The rotor 7 is externally fitted to the output shaft 9. In the following description, a direction along an axis line O of the output shaft 9 may be simply referred to as an axial direction, a direction orthogonal to the axis line O may be referred to as a radial direction, and a direction around the axis line O may be referred to as a circumferential direction.
As shown in
The stator core 11 is formed in a tube shape that surrounds the rotor 7 (refer to
The back yoke part 19 is fixed to the case 3 (refer to
The teeth part 21 protrudes inward in the radial direction from an inner circumferential surface of the back yoke part 19. A plurality of teeth parts 21 are formed at intervals in a circumferential direction. A slot 23 through which the coil 13 is inserted is formed between the teeth parts 21 that are adjacent in the circumferential direction.
That is, the slot 23 penetrates in an axial direction through the stator core 11.
The coil 13 is a three-phase coil that is constituted of a U-phase, a V-phase, and a W-phase. The coil 13 of each phase of the present embodiment is formed by a plurality of corresponding segment coils 24 being connected to each other. Each of the segment coils 24 is inserted in the slot 23 of the stator core 11 and is attached to the stator core 11. The segment coils 24 of the same phase are joined together by a TIG welding, a laser welding, or the like at a first side in the axial direction with respect to the stator core 11.
The configuration of the coil 13 can be appropriately changed. For example, the coil 13 is not limited to the segment coil 24 and may be attached to the stator core 11 by a method in which the coil 13 is wound around the teeth part 21 or the like. The coil 13 of the present embodiment is attached to the stator core 11 according to a distributed winding; however, the configuration is not limited thereto. The coil 13 may be attached to the stator core 11 according to a concentrated winding.
The bus bar unit 15 includes a plurality of bus bars (metal parts) 31, a first cover portion 32, and a second cover portion 33.
Each of the bus bars 31 is formed in a three-dimensional shape by applying a sheet metal processing to a plate material having conductivity such as a metal (for example, copper). The bus bars 31 are arranged side-by-side in the circumferential direction. The bus bars 31 are formed in a shape that corresponds to each other. Therefore, in the following description, one of the bus bars 31 is described as an example. A part of another of the bus bars 31 which corresponds to a part of the one of the bus bars 31 is given by the same reference sign, and a description of the part is omitted.
As shown in
An external connection terminal 51 is provided on and continue to a +X direction end portion of the first extension part 41. As shown in
As shown in
A +Z direction end portion of the third extension part 43 is connected to a +Y direction end portion in the second extension part 42. The third extension part 43 extends from the +Y direction end portion in the second extension part 42 toward a direction that is crossed with the extension directions of the first extension part 41 and the second extension part 42. Specifically, the third extension part 43 extends toward the +Y direction in a direction directed from the +Z direction to a −Z direction.
As shown in
A coil connection terminal 53 is formed on a −Z direction end portion in the fourth extension part 44. The coil connection terminal 53 extends in a +X direction from the −Z direction end portion in the fourth extension part 44.
As shown in
As shown in
As shown in
As shown in
The cap 61 sandwiches the cover region 31a of the bus bar 31 and holds the cover region 31a inside the cap 61. An insertion opening part 60 in which the bus bar 31 is inserted is formed on the cap 61. The insertion opening part 60 is formed such that the bus bar 31 is able to be inserted in the cap 61 from the +X direction. Specifically, each insertion opening part 60 is formed throughout from a part of the cap 61 that is directed in the +X direction to a part of the cap 61 that is directed in the +Y direction.
The cap 61 has a first accommodation part 63 that accommodates the first extension part 41 and the second extension part 42 and a second accommodation part 64 that accommodates the third extension part 43.
The first accommodation part 63 is formed along the first extension part 41 and the second extension part 42. The first accommodation part 63 covers the −X direction end portion in the first extension part 41 and the entire region of the second extension part 42 from the −X direction and both sides of the Z direction.
The second accommodation part 64 is formed along the third extension part 43. The second accommodation part 64 covers the third extension part 43 from the −X direction and both sides of the Z direction. The insertion opening part 60 described above opens on +X direction end surfaces in the first accommodation part 63 and the second accommodation part 64 and opens on a +Y direction end surface in the second accommodation part 64. It is sufficient that at least part of inner surfaces of the first accommodation part 63 and the second accommodation part 64 are in contact with the bus bar 31.
The outer support part 62 fixes the bus bars 31 integrally in a state of being spaced from each other in the Y direction. In the present embodiment, the outer support part 62 covers the cover region 31a of each of the bus bars 31 together with the cap 61. Specifically, the outer support part 62 includes a cap cover portion 71 that covers each cap 61 and a connection portion 72 that connects the cap cover portions 71 together. That is, in the outer support part 62 of the present embodiment, the cap cover portions 71 that are adjacent to each other in the Y direction are connected together by the connection portion 72. The outer support part 62 is formed of a material that is similar to each cap 61. However, the outer support part 62 may be formed of a material that is different from the cap 61 as long as the material is an insulation material. In the present embodiment, the outer support part 62 covers only the outside of the cap 61; however, part of the outer support part 62 may enter the inside of the cap 61.
The cap cover portion 71 is formed to be larger than the cap 61. The cap cover portion 71 includes a first mold section 81 that covers the first accommodation part 63 and a second mold section (second end portion) 82 that covers the second accommodation part 64.
The first mold section 81 covers the circumference of the first accommodation part 63 in a state of closing the insertion opening part 60. In the present embodiment, a +X direction end portion in the first mold section 81 is directly in contact with the first extension part 41 of the bus bar 31. An exposure hole 84 that externally exposes the cap 61 (first accommodation part 63) is formed on a −X direction end portion of the first mold section 81.
As shown in
In bus bar unit 15 of the present embodiment, the third extension part 43 protrudes through the insertion opening part 60 of the cap 61 (second accommodation part 64) in the extension direction (hereinafter, simply referred to as an extension direction L1) of the third extension part 43. That is, a portion that protrudes from the cap 61 in the third extension part 43 constitutes a protrusion portion of the present embodiment.
The second accommodation part 64 includes a cap protrusion portion (first end portion) 85 that protrudes from the second mold section 82 in the extension direction L1. The cap protrusion portion 85 is externally exposed from the second mold section 82 throughout the entire circumference.
Surfaces (hereinafter, referred to as a front surface 64a and a rear surface 64b) each of which faces each of both sides of a thickness direction (hereinafter, simply referred to as a thickness direction L2) of the third extension part 43 among outer surfaces of the second accommodation part 64 are flat surfaces orthogonal to the thickness direction L2. Accordingly, the front surface 64a and the rear surface 64b of the second accommodation part 64 are flat continuous surfaces throughout a portion that protrudes from the second mold section 82 and an interface with the second mold section 82. It is sufficient that at least a portion that is positioned at the cap protrusion portion 85 of each of the front surface 64a and the rear surface 64b of the second accommodation part 64 is formed to be flat.
Among the outer surfaces of the second accommodation part 64, a corner part that is defined by the front surface 64a and a front end surface 64c (a front end surface of the cap protrusion portion 85) that is directed in the extension direction L1, and a corner part that is defined by the front end surface 64c and the rear surface 64b are formed in a curved surface. The front end surface 64c and the front surface 64a may be orthogonal to each other. The front end surface 64c and the rear surface 64b may be orthogonal to each other. In the present embodiment, among the outer surfaces of the second accommodation part 64, both end surfaces that are directed to a width direction (hereinafter, simply referred to as a width direction L3) of the third extension part 43 are flat surfaces orthogonal to the width direction L3. The end surfaces that are directed to the width direction L3 in the second accommodation part 64 are covered by the second mold section 82 in a state where a front end part in the extension direction L1 protrudes from the second mold section 82.
As shown in
Next, a production method of the above-described bus bar unit 15 is described. In the following description, a production method of the first cover portion 32 is mainly described.
As shown in
Next, as shown in
In the first mold 101, a support part 110 is formed at a further front end side in the extension direction L1 than the second mold part C2. The support part 110 supports the cap protrusion portion 85 at the time of molding of the outer support part 62. The support part 110 is formed along an outer surface shape of the cap protrusion portion 85. The bus bar 31 is set inside the shaping mold 100 in a state where the cap protrusion portion 85 is fitted to (lightly pressed into) the support part 110. In this case, an inner surface of the support part 110 comes into close contact with the front end surface 64c of the cap protrusion portion 85, a section to the front surface 64a from the front end surface 64c, and a section to the rear surface 64b from the front end surface 64c.
Therefore, a boundary section between the second mold part C2 and the support part 110 is set at the front surface 64a and the rear surface 64b (a second side in the extension direction L1 further than the front end surface 64c of the cap protrusion portion 85) of the cap 61.
When the outer support part 62 is molded by using the shaping mold 100 described above, first, the cover region 31a of each bus bar 31 is sandwiched in the width direction L3 by the first mold 101 and the second mold of the shaping mold 100.
Subsequently, a resin material J in a melted state is filled into the shaping mold 100. Thereby, the resin material J is filled into the cavity C inside the shaping mold 100 so as to cover the cap 61. In the present embodiment, the cap protrusion portion 85 is lightly pressed into the support part 110, and therefore, an inner surface of the support part 110 and an outer surface of the cap protrusion portion 85 are in close contact with each other. Therefore, it is prevented that the resin material J which flows inside the second mold part C2 flows into the support part 110.
After the resin material J is filled, the resin material J inside the shaping mold 100 is solidified. Then, by opening the mold, the bus bar unit 15 described above is completed.
In this way, in the present embodiment, by attaching the cap 61 to the bus bar 31, a mold portion of the outer support part 62 in the bus bar 31 is able to be reinforced by the cap 61. Thereby, at the time of molding of the outer support part 62, it is possible to prevent a position displacement and a bend of the bus bar 31 in the shaping mold 100 due to a molding pressure and the like, and it is possible to perform a positioning of the bus bar 31 in the shaping mold 100 with high accuracy. Thereby, it becomes possible to simplify the production process, and it is possible to reduce the cost and stabilize the quality.
In the present embodiment, the outer support part 62 covers the cap 61 in a state where the cap protrusion portion 85 protrudes in the extension direction L1.
According to this configuration, the boundary section between the cap 61 and the outer support part 62 is set at a more backward position than the front end surface 64c of the cap 61 in the extension direction L1. Therefore, it is possible to allow the support part 110 of the shaping mold 100 to come into contact with the front surface 64a and the rear surface 64b of the cap protrusion portion 85, and therefore, it is possible to secure a contact area between the support part 110 and the cap protrusion portion 85. Thereby, even when a plane pressure that acts between the outer surface of the cap 61 and the support part 110 is low, for example, due to a size dispersion of the cap 61 and the like, it is possible to prevent the resin material J from flowing into the support part 110 via a space between the outer surface of the cap protrusion portion 85 and the inner surface of the support part 110 at the time of molding of the outer support part 62. As a result, it is possible to prevent the resin material J from remaining as a burr on the outer surface of the cap protrusion portion 85.
Accordingly, it is possible to provide a bus bar unit 15 having an excellent quality.
In the present embodiment, the front surface 64a and the rear surface 64b of the cap protrusion portion 85 are formed in a flat surface.
According to this configuration, the cap protrusion portion 85 is easily supported at the time of molding of the outer support part 62. Therefore, it is possible to further improve the quality of the bus bar unit 15.
In the present embodiment, each of the caps 61 supports separately each of the bus bars 31, and the outer support part 62 covers collectively the caps 61.
According to this configuration, the cap 61 supports separately each of the bus bars 31, and therefore, each of the bus bars 31 is easily set at a desired position in the shaping mold 100. In this state, by integrating the bus bars 31 by the outer support part 62, it is possible to provide the bus bar unit 15 in which the relative position of the bus bars 31 is positioned with high accuracy.
In the present embodiment, the cap 61 is attached to the bus bar 31.
According to this configuration, the cap 61 that is formed separately from the bus bar 31 is attached to the bus bar 31, and therefore, it is possible to further simplify the production process. Further, it is possible to prevent a position displacement of the bus bar 31 due to an injection pressure or the like at the time of first molding (at the time of molding of the first resin part) differently from a case in which the first resin part and the second resin part are formed, for example, according to a two-color molding or the like. Thereby, it is possible to further stabilize the quality.
In the present embodiment, the metal part is the bus bar 31.
According to this configuration, it is possible to secure a rigidity, for example, compared to a case where a wire material or the like is used for the connection between the rotary electric machine 1 and the external electric source. Further, in the present embodiment, it is possible to provide the bus bar unit 15 having an excellent quality as described above, and therefore, it is possible to prevent a twist, a bend, and the like of the bus bar 31 in a state where the rotary electric machine 1 and the external electric source are connected together. Thereby, it is possible to reduce a stress that acts on the bus bar unit 15, and it is possible to improve the durability of the bus bar unit 15.
Although the preferred embodiment of the invention has been described, the invention is not limited to the above-described embodiment. Addition, omission, and substitution of the configuration, and other changes can be made without departing from the scope of the invention. The invention is not limited by the above description, but is limited only by the appended claims.
For example, the present embodiment is described using an example in which the cap 61 is formed of an insulation material; however, the embodiment is not limited only to this configuration. The cap 61 may be formed of a material having conductivity.
The above embodiment is described using a configuration in which the cap 61 of a separate body is used as the first resin part; however, the embodiment is not limited only to this configuration. The first resin part and the second resin part may be formed according to a two-color molding.
The above embodiment is described using a configuration in which the bus bar 31 includes a plurality of extension parts 41 to 44 that extend in a different direction from one another; however, the embodiment is not limited only to this configuration. The shape of the bus bar 31 can be appropriately changed. For example, the bus bar 31 may be in a linear shape or may be bent in only two directions. Further, the angle formed by the extension parts of the bus bar 31 can also be appropriately changed.
The above embodiment is described using a configuration in which a plurality of bus bars 31 are integrated by the outer support part 62; however, the embodiment is not limited only to this configuration. The bus bars 31 may be covered one by one by the outer support part 62.
The above embodiment is described using an example in which the molded body is employed for the bus bar unit 15 used in the rotary electric machine 1; however, the embodiment is not limited only to this configuration. The molded body may be employed for a bus bar unit used for other applications (for example, an in-vehicle device such as a PCU) other than the rotary electric machine 1. Further, the molded body may be employed for a case in which a coil and an insulator are integrally formed such as a resolver or an integrally molded bobbin. Further, the molded body may be employed for a part that requires a multicolor molding from the viewpoint of a design property or the like.
The configuration element in the embodiment described above can be appropriately replaced by a known configuration element without departing from the scope of the invention. Further, the modified examples described above may be appropriately combined.
Number | Date | Country | Kind |
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2018-079236 | Apr 2018 | JP | national |