Molded article, motor, device and method for manufacturing molded article

Abstract

The present invention relates to a molded article, an electric motor, and an apparatus and method for manufacturing the molded article. The molded article can arrange a parting line at a position that is not conspicuous in the appearance of the product. The molded article has a cylindrical main body, a hole that penetrates the main body in the radial direction, or a convex portion that protrudes radially from the main body, and a parting line corresponding to a mold mating surface of a mold is formed on the molded article, and the parting line has a first line extending from the hole or the convex portion to one direction of the circumference of the main body, and a second line extending from an end point of the first line in one direction of the circumference to an axial end of the main body.

Description

Technical Field

[0001] The invention relates to a shaped object, an electric motor, a device for producing a shaped object and a method. Background Art

[0002] There is known a molded product in which a parting line formed at a position corresponding to a mold mating surface is arranged at a predetermined position (Japanese Patent Application Laid-Open No. 7-243028).

[0003] In the past, for a molded product having a hole or a convex portion, a parting line was arranged at the position of the hole or the convex portion from the viewpoint of being able to take the molded product out of the mold. For such a molded product, it is desirable to arrange the parting line at a position that is not conspicuous in the appearance of the product. Summary of the invention

[0004] In one technical solution disclosed herein, the molded object comprises a cylindrical main body portion and a hole radially penetrating the main body portion, or a convex portion radially protruding from the main body portion, and a parting line corresponding to a mold joining surface is formed on the molded object, the parting line comprising a first line extending from the hole or the convex portion in one circumferential direction of the main body portion and a second line extending from an end point of the first line in one circumferential direction to an axial end of the main body portion.

[0005] In another technical solution of the present disclosure, the electric motor has the above-mentioned molded object as a motor housing. In another technical solution of the present disclosure, the device for manufacturing the above-mentioned molded object has a pair of molds, which are a pair of molds that can be opened and closed to each other, and when closed to each other, a space for forming the molded object is defined inside.

[0006] A pair of molds have mating surfaces that contact each other when the pair of molds are closed, and the mating surfaces have: a first mating surface that extends from a position corresponding to a hole or a convex portion in one circumferential direction and forms a first line; and a second mating surface that extends from an end edge in one circumferential direction of the first mating surface in one axial direction and forms a second line. In another technical solution of the present disclosure, a method for manufacturing a molded object using the above-mentioned device includes injecting a liquid material into a space while closing a pair of molds so that the pair of molds are in contact with each other with the mating surfaces, and after the material is solidified to form a molded object, opening the pair of molds and taking out the molded object.

[0007] According to the present disclosure, a mold hole or a convex portion can be used for molding, and a parting line can be arranged at a relatively inconspicuous position in appearance. Thus, the aesthetics of the molded product can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a side view of a motor according to one embodiment.

[0009] Figure 2 is from Figure 1 Observe in the direction of arrow B Figure 1 Figure of the molded object shown.

[0010] Figure 3 is from Figure 2 Observe in the direction of arrow D Figure 2 Figure of the molded object shown.

[0011] Figure 4 This is a diagram of an apparatus for manufacturing a molded product according to one embodiment.

[0012] Figure 5 is from Figure 4 Observe in the direction of arrow G Figure 4 A diagram of a pair of dies shown.

[0013] Figure 6 This is an enlarged view of a main part of a molded product according to another embodiment.

[0014] Figure 7 is a diagram of a molded product according to another embodiment, and Figure 2 Corresponding.

[0015] Figure 8 This is a diagram of an apparatus for producing a molded product according to another embodiment.

[0016] Fig. 9 is to use Figure 8 The molded product formed by the mold shown in the figure is Figure 7 Corresponding.

[0017] Fig.10 is a diagram of a molded product according to another embodiment, and Figure 2 Corresponding.

[0018] Fig.11 is a diagram of a molded product according to another embodiment, and Figure 2 Corresponding.

[0019] Fig.12 is a diagram of a molded product according to another embodiment, and Figure 2 Corresponding.

[0020] Fig.13 is a diagram of a molded product according to another embodiment, and Figure 2 Corresponding.

[0021] Fig.14 is from Fig.13 Observe the arrow H in Fig.13 Figure of the molded object shown. DETAILED DESCRIPTION

[0022] Hereinafter, the embodiments of the present disclosure will be described in detail based on the accompanying drawings. In addition, in the various embodiments described below, the same elements are marked with the same reference numerals, and repeated descriptions are omitted. Figure 1 , an electric motor 10 according to an embodiment is described. In the following description, the axial direction refers to the direction along the rotation axis A1 of the rotor of the electric motor 10, the circumferential direction refers to the direction around the axis A1, and the radial direction refers to the radius direction of a circle centered on the axis A1. In addition, for convenience, the direction of the arrow C in the figure is referred to as the axial front, the direction of the arrow E in the figure is referred to as one circumferential direction, and the direction of the arrow F is referred to as the other circumferential direction.

[0023] The motor 10 includes a rotor 12, a stator 14, and molded objects 16 and 18. The rotor 12 is supported by the molded objects 16 and 18 so as to be rotatable around an axis A1, and includes a rotating shaft 20 and a rotor core (not shown) fixedly provided on the outer peripheral surface of the rotating shaft 20. The rotating shaft 20 extends straight along the axis A1. The rotor core is arranged inside the stator 14 so as to be slightly separated from the stator 14 in the radial direction inward, and has a plurality of magnets (not shown) built in.

[0024] The stator 14 is a cylindrical member having an octagonal outer shape and is composed of a plurality of magnetic steel plates stacked in the axial direction. A coil (not shown) is wound around the inner periphery of the stator 14. The molded object 16 is a motor housing fixed to the axial front end of the stator 14. The molded object 16 is a cylindrical member having a shape substantially the same as that of the stator 14 (i.e., an octagonal shape) and is molded using a mold (e.g., an aluminum die casting).

[0025] On the other hand, the molded product 18 is a motor housing fixed to the axial rear end of the stator 14. The molded product 18 is molded by a die (for example, aluminum die casting) in the same manner as the molded product 16. Figure 2 and Figure 3 , the details of the molded article 18 will be described.

[0026] The molded article 18 includes a main body 22, a through hole 24, and a convex portion 26. The main body 22 is a cylindrical member having an outer shape (i.e., an octagon) substantially the same as that of the stator 14. The main body 22 is arranged substantially concentrically with the stator 14 with respect to the axis A1. The main body 22 has an axially forward end face 23 and an axially rearward end face 25. At least one of these end faces 23 and 25 is molded into a plane substantially orthogonal to the axial direction by post-processing (e.g., cutting).

[0027] The convex portion 26 is provided on the main body 22 in a manner protruding radially outward from the main body 22. The convex portion 26 has a quadrilateral shape when viewed from the radial direction, and is integrally formed on an outer surface 22a of one side of the octagonal shape defining the main body 22. The through hole 24 is provided in a manner penetrating the main body 22 and the convex portion 26 in the radial direction. In the present embodiment, the through hole 24 is a circular hole having a central axis A2, extending from the outer surface 26a of the convex portion 26 to the inner peripheral surface 22b ( Figure 3 ) penetrates the main body 22 and the convex portion 26. In the present embodiment, the through hole 24 and the convex portion 26 are arranged substantially concentrically.

[0028] Lead wires from the coil wound on the stator 14 or signal wires from electronic devices (not shown) such as encoders provided inside the molded article 18 are led out to the outside of the motor 10 through the through hole 24. A chamfered portion 30 is formed at the axially rear end of the main body 22. The chamfered portion 30 is provided at the radial outer edge of the end face 25 so as to extend circumferentially over the entire circumference of the main body 22.

[0029] like Figure 2 As shown, a parting line 32 is formed on the molded object 18. The parting line 32 is a small protrusion formed at a position corresponding to the mating surface of the pair of molds when the molded object 18 is molded using a pair of molds described later. In this embodiment, the parting line 32 includes a line 32a, a line 32b, a line 32c, a line 32d, and a line 32e.

[0030] The line 32a (first line) is arranged at the substantially same axial position as the center of the through hole 24 and the convex portion 26 (i.e., the axis A2), and extends straight from the through hole 24 in one circumferential direction to the end point P1. In addition, in the present embodiment, the end point P1 is located on the one circumferential direction side of the end surface 26b of the convex portion 26 in one circumferential direction, and is arranged on the end edge 22c of the outer surface 22a in one circumferential direction (i.e., one side of the octagonal outer shape of the main body 22).

[0031] The line 32b (second line) extends from the end point P1 to the axially rear end of the main body portion 22. Specifically, the line 32b extends straightly from the end point P1 at an angle relative to the axial direction to the end point P2 of the edge portion 30a disposed on the axially front side of the chamfered portion 30. The angle θ1 between the lines 32a and 32b is set to an obtuse angle (e.g., 120°).

[0032] The line 32c (third line) extends from the end point P2 to the end point P3 in one direction of the circumferential direction along the edge 30a of the chamfered portion 30. In the present embodiment, the end point P3 is arranged at the edge 30a of the chamfered portion 30, and the line 32c extends in the circumferential direction in such a manner that its entire area is arranged at the edge 30a of the chamfered portion 30.

[0033] On the other hand, the line 32e (first line) is arranged at substantially the same axial position as the center (axis line A2) of the through hole 24 and the protrusion 26, similarly to the line 32a, and extends straightly from the through hole 24 in the other circumferential direction to the end point P4. In the present embodiment, the end point P4 is located on the other circumferential direction side of the end surface 26c of the protrusion 26 in the other circumferential direction, and is arranged on the end edge 22d of the outer surface 22a in the other circumferential direction (that is, one side of the octagonal outer shape of the main body 22).

[0034] The line 32d (second line) extends from the end point P4 to the axial rear end of the main body 22. Specifically, the line 32d extends straightly from the end point P4 to the end point P3 while being inclined relative to the axial direction. The angle θ2 between the lines 32e and 32d is set to an obtuse angle (e.g., 120°). In addition, the angles θ1 and θ2 may be the same as each other or different from each other.

[0035] Next, refer to Figure 4 and Figure 5 , the device 50 for manufacturing the above-mentioned molded product 18 is described. The device 50 includes a pair of molds 52 and 54, a pin 56, a driving unit 57, a material supply device 63, and an ejection device 61. The pair of molds 52 and 54 are arranged in a manner that can be opened and closed with respect to each other. More specifically, the mold 54 is fixed, and on the other hand, the mold 52 is arranged to be movable in a manner that can approach and separate from the mold 54. In addition, Figure 4 This shows a state where the molds 52 and 54 are closed to each other.

[0036] A pair of molds 52 and 54 are formed in a Figure 4 When closed as shown, a cylindrical space 58 for forming the main body 22 and a space 59 for forming the convex portion 26 are defined inside. A cylindrical inclined surface 55 for forming the chamfered portion 30 is formed at the radial outer edge of the bottom surface 53 of the mold 54 defining the space 58.

[0037] The pair of molds 52 and 54 has a mold hole 60 and a mold surface 62. The mold hole 60 is a circular hole having a central axis A2 corresponding to the through hole 24, and is defined between the molds 52 and 54 when the molds 52 and 54 are closed. The mold hole 60 is connected to the space 59 and is concentrically arranged relative to the space 59 with the axis A2 as a reference.

[0038] The die mating surface 62 is composed of the surface of the die 52 and the surface of the die 54 that are in contact with each other when the pair of dies 52 and 54 are closed, and has die mating surfaces 62a, 62b, 62c, 62d, and 62e. The die mating surface 62a (first die mating surface) is arranged at the same axial position as the center of the die hole 60 (i.e., the axis A2), and extends from the die hole 60 in one direction in the circumferential direction. The die mating surface 62a is a plane that is substantially orthogonal to the axial direction. The die mating surface 62a forms the above-mentioned line 32a.

[0039] The mold mating surface 62b (second mold mating surface) extends from the end edge Q1 in one direction of the circumferential direction of the mold mating surface 62a to the axial rear side. Specifically, the mold mating surface 62b is a plane and extends from the end edge Q1 to the end edge Q2 on the opposite side of the end edge Q1 in a manner inclined relative to the axial direction. The mold mating surface 62b forms the above-mentioned line 32b.

[0040] The die-matching surface 62c (third die-matching surface) is an annular plane extending from the end edge Q2 to the end edge Q3 in one direction in the circumferential direction and is substantially orthogonal to the axial direction. The die-matching surface 62c forms the above-mentioned line 32c. The end edges Q2, Q3 and the die-matching surface 62c are arranged at the same axial position as the axial front end of the above-mentioned inclined surface 55.

[0041] On the other hand, the die-matching surface 62e (first die-matching surface) is arranged at substantially the same axial position as the center (axis line A2) of the die hole 60, similarly to the die-matching surface 62a, and extends from the die hole 60 to the end edge Q4 in the other circumferential direction. The die-matching surface 62e is a plane substantially orthogonal to the axial direction, and forms the above-mentioned line 32e.

[0042] The mold surface 62d (second mold surface) extends axially rearward from the other circumferential edge Q4 of the mold surface 62e. Specifically, the mold surface 62e is a plane and extends from the edge Q4 to the edge Q3 in a manner inclined relative to the axial direction. The mold surface 62d forms the above-mentioned line 32d.

[0043] The pin 56 is a cylindrical member that is arranged concentrically with the die hole 60 and has the same outer shape as the die hole 60. The pin 56 is inserted into the die hole 60 so as to be able to move forward and backward in the radial direction relative to the spaces 58 and 59. The pin 56 can be moved forward and backward manually by an operator, or the device 50 can further include a second driving unit (cylinder or motor, etc.) that automatically moves the pin 56. The pin 56 forms the through hole 24.

[0044] The driving unit 57 has, for example, a cylinder or a motor, and moves the mold 52 relative to the mold 54, and opens and closes the molds 52 and 54. The material supply device 63 injects and fills the liquid material of the molded object 18 into the spaces 58 and 59 inside the pair of molds 52 and 54 through the sprue 64, the runner 66, and the gate 68. In the present embodiment, the sprue 64, the runner 66, and the gate 68 are provided in the mold 54. However, the sprue 64, the runner 66, and the gate 68 may also be provided in the mold 52.

[0045] After the molded object 18 is molded by the molds 52 and 54 and the molds 52 and 54 are opened, the ejection device 61 applies force to the molded object 18 bonded to one mold 52 to separate the molded object 18 from the mold 52. Specifically, the ejection device 61 includes an ejection pin provided on the mold 52 so as to be able to advance and retreat in the axial direction, and a third driving unit (both not shown) that drives the ejection pin, and uses the ejection pin to push the molded object 18 bonded to the mold 52 axially backward. Thus, the molded object 18 can be separated from the mold 52, and the molded object 18 can be taken out from the molds 52 and 54.

[0046] Next, a method for manufacturing the molded product 18 using the device 50 is described. First, the driving unit 57 closes the pair of molds 52 and 54 so that the pair of molds 52 and 54 are in contact with each other at the mold surface 62 (so-called mold closing). At this time, the pin 56 is inserted into the spaces 58 and 59 through the mold hole 60 and is arranged at an advanced position that crosses the spaces 58 and 59 in the radial direction. Next, the material supply device 63 injects and fills the liquid material of the molded product 18 into the spaces 58 and 59.

[0047] Next, the operator cools the material filled in the spaces 58 and 59 and solidifies the material. Thus, the molded object 18 is molded in the spaces 58 and 59. Next, the operator (or the second drive unit) moves the pin 56 radially outward to a retracted position where the pin 56 is pulled out of the spaces 58 and 59. Next, the drive unit 57 moves the mold 52 axially forward to separate it from the mold 54, thereby opening the molds 52 and 54.

[0048] At this time, the molded object 18 is adhered to the mold 52 and moves axially forward together with the mold 52. Next, the ejection device 61 uses the third drive unit to move the ejection pin axially backward and use the ejection pin to push the molded object 18 adhered to the mold 52. As a result, the molded object 18 is separated from the mold 52 and taken out from the molds 52 and 54.

[0049] In this way, the molded product 18 is manufactured in which the parting line 32 is formed at a position corresponding to the mold surface 62. As described above, the parting line 32 includes the lines 32a and 32e extending from the through hole 24 and the convex portion 26, and the lines 32b and 32d extending from the lines 32a and 32e to the axially rear end of the main body 22.

[0050] According to this structure, the through hole 24 and the protrusion 26 can be molded by using the molds 52 and 54, and the parting line 32 can be arranged at the axial end of the main body 22 in a circumferential section other than the lines 32a, 32b, 32d, and 32e (in this embodiment, the line 32b).

[0051] Therefore, the parting line 32 can be arranged at a relatively inconspicuous position in the local circumferential section (line 32b), thereby improving the aesthetics of the molded product 18. In addition, assuming that the parting line 32 is removed by post-processing (for example, cutting) in the circumferential section other than the lines 32a, 32b, 32d, and 32e, the parting line 32 is arranged at the axial end of the main body 22 in the circumferential section, so it is easy to process the parting line 32 in the circumferential section.

[0052] In addition, in the present embodiment, the parting line 32 has a line 32b disposed on the chamfered portion 30. According to this structure, the line 32b can be made less noticeable in appearance more effectively. In addition, in the present embodiment, the line 32b is disposed on the edge 30a of the chamfered portion 30. According to this structure, the line 32b can be made less noticeable more effectively, so the processing of the parting line 32 by post-processing can also be omitted. In addition, the line 32b is not limited to the edge 30a of the chamfered portion 30, and can also be formed on the flat portion of the chamfered portion 30.

[0053] In addition, the main body 22 may be formed with a rounded corner instead of the chamfered portion 30. Figure 6 This method is expressed in Figure 6 In the embodiment shown, a rounded corner 30' (so-called R portion) is formed at the axial rear end of the main body 22. The line 32c extends along the edge 30a' of the rounded corner 30'. The rounded corner 30' can be formed by a pair of dies or by post-processing (cutting).

[0054] Next, refer to Figure 7 , another embodiment of the molded product 18' is described. The molded product 18' can be applied to the motor 10 instead of the above-mentioned molded product 18. The molded product 18' is different from the above-mentioned molded product 18 in the parting line 32'. Specifically, the parting line 32' has lines 32a, 32b, 32d, and line 32e, and does not have line 32c.

[0055] Next, refer to Figure 8 , the device 50' for manufacturing the molded product 18' is described. The device 50' is different from the above-mentioned device 50 in terms of a pair of molds 52' and 54'. Specifically, the pair of molds 52' and 54' have a mold hole 60 and a mating surface 62', and the mating surface 62' has mating surfaces 62a, 62b', 62c', 62d', and 62e.

[0056] The mold mating surface 62b' (second mold mating surface) is a plane and extends from the end edge Q1 to the rear in the axial direction and extends to the end edge Q2' on the side opposite to the end edge Q1 in a manner inclined relative to the axial direction. The mold mating surface 62c' (third mold mating surface) is an annular plane extending from the end edge Q2' to the end edge Q3' in one direction of the circumferential direction and is substantially orthogonal to the axial direction. Here, the end edges Q2', Q3' and the mold mating surface 62c' are arranged at the same axial position as the bottom surface 53 of the mold 54'.

[0057] The mold surface 62d' (second mold surface) is a plane extending axially rearward from the end edge Q4 and extending from the end edge Q4 to the end edge Q3' in a manner inclined relative to the axial direction. The above-mentioned inclined surface 55 is not formed in the mold 54', and when the pair of molds 52' and 54' are closed to each other, a space 58' is defined inside.

[0058] Next, a method for manufacturing the molded product 18' using the device 50' is described. First, the driving unit 57 closes the pair of molds 52' and 54' so that the pair of molds 52' and 54' contact each other at the mold surface 62' (so-called mold closing). At this time, the pin 56 passes through the mold hole 60 and is arranged at an advanced position crossing the spaces 58' and 59. Next, the material supply device 63 injects and fills the liquid material into the spaces 58' and 59.

[0059] Next, the operator cools the material filled in the spaces 58' and 59 and solidifies the material. Next, the operator (or the second driving unit) moves the pin 56 radially outward so that the pin 56 is disposed in the retracted position. Next, the driving unit 57 opens the molds 52' and 54', and the ejection device 61 drives the ejection pin to remove the molded product from the molds 52' and 54'.

[0060] exist Fig. 9 The molded product formed at this time is shown in FIG. Fig. 9 The molded product 18 ″ shown is different from the molded product 18 ′ described above in the following structure. Specifically, a parting line 32 ″ is formed in the molded product 18 ″, and the parting line 32 ″ includes lines 32 a , 32 b ′, 32 c ′, 32 d ′, and a line 32 e .

[0061] The line 32b' is formed at a position corresponding to the mating surface 62b' of the pair of molds 52' and 54'. The line 32b' is inclined with respect to the axial direction and extends straightly from the end point P1 to the end point P2'. The line 32c' is formed at a position corresponding to the mating surface 62c' of the pair of molds 52' and 54'. The line 32c' extends from the end point P2' to one direction of the circumferential direction to the end point P3'.

[0062] Here, the end points P2' and P3' are arranged at the position of the end face 25 axially rearward of the main body 22'. Therefore, the line 32c' is formed at the radial outer edge of the end face 25. The line 32d' is formed at a position corresponding to the mating surface 62d' of the pair of molds 52' and 54'. The line 32d' is inclined relative to the axial direction and extends straightly from the end point P4 to the end point P3'. In this way, the molded object 18" is molded using the pair of molds 52' and 54'.

[0063] After the molding 18 ″ is formed, the operator uses a processing machine or the like to chamfer the axial rear end of the main body 22 ′ of the molding 18 ″, thereby forming a chamfered portion 30 at the end. As a result, Figure 7 As shown in FIG. 1 , a molded article 18 ′ having a main body 22 formed with a chamfered portion 30 is manufactured. By this chamfering process, the chamfered portion 30 is formed, and the Fig. 9 The axial rear ends of the lines 32b' and 32d' shown and the line 32c' form a Figure 7 Parting line 32' is shown.

[0064] According to the molded product 18', the through hole 24 and the protrusion 26 can be molded by the molds 52' and 54', and the parting line 32' can be made less noticeable by removing a portion of the parting line 32' (ie, the axial rear ends of the lines 32b' and 32d' and the line 32c').

[0065] Furthermore, the through hole 24 can be omitted from the molded articles 18 and 18'. Fig.10 This method is expressed in Fig.10 The molded article 70 shown is different from the molded article 18 described above in the following structure: That is, in the molded article 70 , the through hole 24 is not formed in the convex portion 26 and the main body portion 22 .

[0066] The molded product 70 is provided with a parting line 72 having lines 73, 32b, 32c, and 32d. The line 73 (first line) passes through the center (axis A2) of the convex portion 26 and extends straight in the circumferential direction between the end points P1 and P4.

[0067] The through hole 24 can be formed in the convex portion 26 of the molded object 70, for example, by post-processing. Alternatively, a screw hole can be formed in the convex portion 26 of the molded object 70, and a handle (for example, an eye bolt) for lifting the motor 10 can be fastened to the screw hole. In this case, the handle can be lifted by a crane or the like, so that the motor 10 can be transported.

[0068] In addition, the line 73 does not necessarily need to pass through the center of the protrusion 26, and may be offset from the center of the protrusion 26 in the axial direction within the axial section of the protrusion 26. Fig.11 In the way like this. Fig.11 The molded article 70 ′ shown is formed with a parting line 74 having lines 73 ′, 32 b ″, 32 c , and 32 d ″. Line 73 ′ extends straightly in the circumferential direction between end points P1 ′ and P4 ′ at a position offset axially rearward from the center (axis A2 ) of the protrusion 26 .

[0069] In addition, the line 32b" extends obliquely with respect to the axial direction between the end points P1' and P2, and the line 32d" extends obliquely with respect to the axial direction between the end points P4' and P3. The molded products 70, 70' as described above can also be molded using a pair of molds. In this case, the pin 56 is omitted, and the pair of molds has a mating surface that forms the lines 73, 73'.

[0070] In addition, when the through hole 24 has the same shape as the protrusion 26, the lines 32a and 32e do not need to be arranged at the same axial position as the center of the through hole, and may be axially offset from the center of the through hole within the axial section of the through hole. Fig.12 In the way like this.

[0071] Fig.12 The molded article 76 shown is different from the molded article 70' in the following structure. That is, the molded article 76 does not have the convex portion 26, but has a through hole 78 that penetrates the main body 22 in the radial direction. The through hole 78 has a quadrilateral shape when viewed from the radial direction, and the end face 78a in one circumferential direction and the end face 78b in the other circumferential direction that define the through hole 78 are parallel to the axial direction.

[0072] In addition, a parting line 79 is formed in the molded product 76, and the parting line 79 has lines 32a', 32b", 32c, 32d", and 32e'. Line 32a' extends straightly from the through hole 78 in one direction in the circumferential direction to an end point P1' at a position offset axially rearward from the center (axis A2) of the through hole 78.

[0073] On the other hand, the line 32e' extends straight from the through hole 78 to the other circumferential direction to the end point P4' at a position offset axially rearward from the center (axis A2) of the through hole 78. The molded object 76 can also be molded using a pair of molds. In this case, the pin 56 has the same outer shape as the through hole 78, and the through hole 78 is formed using the pin 56.

[0074] In addition, the molded object 16 has the same shape as the molded object 18, 18' (18"), 70, 70' or 76, and can also be manufactured using the above-mentioned device 50 or 50'. In addition, the end point P1 (or P4) can also be located at a position offset from the end edge 22c (or 22d) of the outer surface 22a in the circumferential direction.

[0075] The outer shape of the stator 14, the molded article 18, 18', 18", 70, 70' or 76 may be a polygon other than an octagon, or may be any shape such as a circle or an ellipse. In addition, the line 32a, 32a', 32b, 32b', 32b", 32c, 32c', 32d, 32d', 32d", 32e, 32e', or 73' may be a curve. In addition, the line 32b, 32b', or 32b" (second line) may extend parallel to the axial direction (axis A1).

[0076] In addition, a plurality of through holes 24, 78 or convex portions 26 may be provided in a manner arranged in the circumferential direction. Fig.13 and Fig.14 Such an implementation method is shown in FIG. Fig.13 and Fig.14 The molded article 80 shown is different from the molded article 18 described above in the following structure. That is, the molded article 80 further includes a convex portion 82. The convex portion 82 is arranged at a position offset from the through hole 24 and the convex portion 26 in one direction in the circumferential direction, and is integrally formed on the outer surface 22e of the main body 22 in a manner protruding radially outward from the outer surface 22e.

[0077] The molded product 80 is provided with a parting line 84, which includes a line 32a, a line 32b, a line 32c1, a line 32f, a line 32g, a line 32h, a line 32c2, a line 32d, and a line 32e. The line 32c1 (third line) extends from the end point P2 along the edge 30a of the chamfered portion 30 in one direction of the circumferential direction to the end point P5. The end point P5 is arranged at the edge 30a of the chamfered portion 30 on the one direction side of the circumferential direction relative to the end point P2.

[0078] On the other hand, the line 32g (first line) passes through the convex portion 82 and extends straightly in the circumferential direction between the end point P6 and the end point P7. The line 32f (second line) extends straightly from the end point P6 to the end point P5 while being inclined relative to the axial direction. The line 32h (second line) extends straightly from the end point P7 to the end point P8 while being inclined relative to the axial direction. The end point P8 is arranged at the edge 30a of the chamfered portion 30.

[0079] The line 32c2 (third line) extends from the end point P8 to the end point P3 along the edge 30a of the chamfered portion 30 in one direction in the circumferential direction. The convex portion 82 can be used as an element for forming the screw hole for fastening the handle. It can be understood that the pair of molds used to mold the molded object 80 has a mold surface forming the parting line 84.

[0080] In addition, the circumferential end faces 26b and 26c of the convex portion 26 are substantially parallel to the axial direction, but in fact, the end faces 26b and 26c are tapered surfaces that are inclined relative to the axial direction so that the circumferential width between the end faces 26b and 26c is maximized at the position of the lines 32a, 32e, 73, and 73'. Similarly, the circumferential end faces of the convex portion 82 are substantially parallel to the axial direction, but in fact, the end faces are tapered surfaces that are inclined relative to the axial direction so that the circumferential width between the end faces is maximized at the position of the line 32g.

[0081] In addition, in the above-mentioned embodiment, the molded object 18, 18', 70, 70', 76 or 80 is described as a case where the motor housing of the electric motor 10 is used, but the present invention is not limited thereto and may be any component of any device. For example, the molded object 18, 18', 70, 70', 76 or 80 may be a joint member connecting two pipes, or a restraint member that allows pipes to communicate with each other and fixes the pipes to other members. The present disclosure is described above by using the embodiment, but the above-mentioned embodiment does not limit the invention of the claims.

Claims

1. A molded article, wherein The molded article has: a cylindrical main body; and a hole that penetrates the main body in the radial direction, or a protrusion that protrudes from the main body in the radial direction, A parting line corresponding to the mold surface of the mold is formed on the molded product. The parting line has: A first line extending from the hole or the protrusion toward a direction of the circumference of the main body; as well as A second line extends from an end point of the first line in one direction of the circumferential direction to an end portion of the main body portion in an axial direction.

2. The molded article according to claim 1, wherein The parting line further includes a third line extending from an end point of the second line on the opposite side to the end point of the first line in one direction of the circumferential direction and arranged at the end portion of the main body portion.

3. The molded article according to claim 2, wherein A chamfered portion or a rounded corner is formed at the end of the main body. The third line is disposed at the chamfered portion or the rounded corner portion.

4. The molded article according to any one of claims 1 to 3, wherein The second line extends obliquely with respect to the axial direction.

5. The molded article according to any one of claims 1 to 3, wherein The molded object is a motor housing of an electric motor.

6. The molded article according to claim 4, wherein The molded object is a motor housing of an electric motor.

7. An electric motor, wherein: This electric motor includes the molded article according to claim 5 or 6 as the motor case.

8. An apparatus for producing a molded product, which is an apparatus for producing the molded product according to any one of claims 1 to 6, wherein: The device includes a pair of molds that can be opened and closed to each other, and define a space for forming the molded object inside when the molds are closed to each other. The pair of molds has the mating surfaces that contact each other when the pair of molds are closed, The die surface has: a first mating surface extending from a position corresponding to the hole or the convex portion in one direction of the circumference and forming the first line; as well as The second mold-matching surface extends from an end edge of the first mold-matching surface in one direction of the circumferential direction toward one direction of the axial direction and forms the second line.

9. The device for producing a shaped object according to claim 8, wherein: The parting line further includes a third line extending from an end point of the second line on the opposite side to the end point of the first line in one direction of the circumferential direction and arranged at the end of the main body. The mold-matching surface further includes a third mold-matching surface that extends from an end edge of the second mold-matching surface on the opposite side to the end edge of the first mold-matching surface toward one direction of the circumferential direction and forms the third line.

10. A method for producing a molded object, which is a method for producing the molded object using the apparatus for producing a molded object according to claim 8 or 9, wherein: In this method, a liquid material is injected into the space while the pair of molds are closed so that the pair of molds are in contact with each other on the mold mating surfaces. After the material is solidified to form the molded object, the pair of molds are opened and the molded object is taken out.

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