JP2014039379A - Manufacturing method of rotary electric machine housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a rotary electric machine housing capable of improving dimensional accuracy.SOLUTION: A manufacturing method of a housing 14 for rotary electric machines includes a step for producing a core in which a core 104 is formed so that an intermediate part 112 which is a part between adjoining core supporting parts 108a-108d is placed radially farther inward from rotary electric machine 10 than the adjoining core supporting parts 108a-108d.

Description

  The present invention relates to a method for manufacturing a housing for a rotating electrical machine.

  Patent Document 1 discloses a method of manufacturing the housing 20 of the motor 10 using the core 70, the upper mold 90, and the lower mold 93. Specifically, the core 70 is disposed inside the upper mold 90 and the lower mold 93 (FIGS. 4, 6, and [0037]). At this time, the core 70 is supported by the plurality of core support portions 79, thereby forming a space between the core 70 and the upper mold 90 and the lower mold 93. Next, a molten metal 96 such as aluminum flows into the upper mold 90 and the lower mold 93 from an inflow port (not shown). As a result, the molten metal 96 enters the space (FIG. 6 and [0038]). Thereafter, the housing 20 is taken out from the upper mold 90 and the lower mold 93, and the core 70 and the core support portion 79 are removed from the housing 20 ([0040]). Thereby, the housing 20 which is, for example, cylindrical ([0016]) is formed.

  A cooling water passage 52 is formed in a portion of the housing 20 corresponding to the core 70 ([0021], [0042]). Further, the hole 25 formed as a trace of the core support portion 79 in the housing 20 is closed by the lid member 60 (FIG. 7, [0040] and [0041]). In Patent Document 1, six core support portions 79 are arranged at substantially equal intervals (see FIG. 4).

JP 2006-060914 A

  As described above, in Patent Document 1, six core support portions 79 are arranged at substantially equal intervals (see FIG. 4). However, Patent Document 1 does not sufficiently study the position at which the core support 79 is formed so that the housing 20 can be manufactured with high accuracy.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a method for manufacturing a housing for a rotating electrical machine capable of improving dimensional accuracy.

  A method for manufacturing a housing for a rotating electrical machine according to the present invention is a manufacturing method for manufacturing a housing that has an annular or arc-shaped flow path extending along a circumferential direction of a rotating electrical machine and that houses the rotating electrical machine. A core creating step for creating a core having a plurality of core support portions, and a core placing step for placing the core between a first mold and a second mold for forming a space into which molten metal is poured. A molten metal pouring step of pouring the molten metal into the space to form the housing, and a flow path forming step of taking out the core from the housing and forming the flow passage inside the housing, In the core creation step, the core is created such that an intermediate portion, which is a portion between adjacent core support portions, is located radially inward of the rotating electrical machine with respect to the adjacent core support portions. It is characterized by.

  According to the present invention, the core is created such that the intermediate portion, which is a portion between adjacent core support portions, is located radially inward of the adjacent core support portions. As a result, when the molten metal is poured and the core expands radially outward, the core support portion supported by at least one of the first mold and the second mold is moved to either the first mold or the second mold. Even if the intermediate portion that is not supported has a higher degree of expansion, the housing and the annular or arc-shaped flow path inside the housing can be brought closer to, for example, a perfect circle or an arc thereof.

  Further, the longer the arc length between adjacent core support portions, the greater the expansion of the intermediate portion compared to the core support portion. However, according to the present invention, the expansion of the intermediate portion is taken into consideration in advance. It becomes possible. For this reason, it is possible to suppress an increase in the number of core support portions and related parts or parts in order to shorten the arc length between adjacent core support portions, and the presence of the core support portions. Accordingly, it is possible to suppress an increase in the overall size of the housing.

  Further, when the expansion of the intermediate portion is larger than that of the core support portion, the distance between the intermediate portion and the first mold or the second mold may be shortened, and the thickness of the housing may be uneven. is there. According to the present invention, since it becomes possible to take into account the degree of expansion of each of the core support portion and the intermediate portion, the thickness of the housing having an annular or arc-shaped flow path inside is made uniform. Is possible.

  In the core creation step, the core may be created such that a position farthest from the adjacent core support portion among the intermediate portions is located closest to a radial inner side of the rotating electrical machine. The expansion of the core when the molten metal is poured into the core tends to increase as the distance from the core support portion increases, but according to the present invention, the position farthest from the adjacent core support portion is the most radial direction. Try to come inside. This makes it possible to bring the housing and the annular or arcuate flow path inside the housing closer to the perfect circle or the arc.

  In the core creation step, the core may be created such that a position farther from the adjacent core support portion in the intermediate portion is located radially inward of the rotating electrical machine. The expansion of the core when the molten metal is poured into the core tends to increase as the distance from the core support portion increases.According to the present invention, the position farther from the adjacent core support portion increases inward in the radial direction. To come. Thereby, it becomes possible to make the housing and the annular flow path inside the housing closer to a perfect circle or an arc thereof.

  In the core creating step, at least one hole extending in the circumferential direction of the rotating electrical machine is formed in the core, and in the molten metal pouring step, the molten metal is poured into the hole, A rib extending in the circumferential direction of the rotating electrical machine is formed, and a plurality of branch passages are formed by the rib. Further, in the core creating step, the center is formed at a position where the hole is interrupted in the circumferential direction of the rotating electrical machine. A child support portion may be formed, and in the molten metal pouring step, a merge portion where the plurality of branch channels merge at a position where the hole portion is interrupted may be formed.

  Accordingly, since the core support portion is formed at a position where the hole portion is interrupted, it is possible to form a plurality of hole portions with one core. Therefore, since it is not necessary to form a plurality of cores and a plurality of core support portions for each of the plurality of branch flow paths, the housing can be reduced in size.

  In addition, since the branch channel is formed by providing a rib along the circumferential direction of the rotating electrical machine inside the annular or arc-shaped channel, the shape of the annular or arc-shaped channel is simplified. Is possible. Therefore, it is possible to easily remove the core and reduce the man-hours and production costs for that purpose.

  Further, the rib can be formed long in the circumferential direction, and the heat transfer area of the rib can be increased, and the rigidity of the housing can be increased and the vibration of the housing can be reduced accordingly. In addition, by forming the rib in the circumferential direction of the rotating electrical machine, the refrigerant can easily flow in the circumferential direction, and the pressure loss is reduced. As a result, the cooling capacity can be improved.

  When the annular or arcuate channel is a refrigerant channel that guides the refrigerant that cools the rotating electrical machine, the core support portion corresponds to the inlet and the outlet of the refrigerant in the refrigerant channel. The rib may be formed continuously except at a position corresponding to the core support portion. Thereby, it becomes possible to make a rib longer in the circumferential direction, and it becomes possible to further promote an increase in the heat transfer area of the rib, an increase in rigidity of the housing, and a reduction in vibration. The increase in the rigidity of the housing and the reduction in vibration are particularly effective when the number of core support portions is small.

  The rotating electrical machine can be, for example, a rotating electrical machine for driving a vehicle. In general, a rotating electrical machine for driving a vehicle has a relatively large diameter, and as a result, the expansion of the core when molten metal is poured becomes remarkable. However, according to the present invention, the expansion amount of the core is subtracted in advance. By doing so, it is possible to at least one of suppressing the number of core support portions and equalizing the thickness of the housing. As a result, even in the case of a housing used for a rotating electrical machine for driving a vehicle, the shape of the housing and the annular or arcuate flow path inside the housing can be easily approximated to a perfect circle or an arc thereof.

  The manufacturing method of a structure having an annular or arc-shaped flow path according to the present invention includes a core creating step for creating a core having a plurality of core support portions, and a first space for forming a space for pouring molten metal. A core disposing step of disposing the core between the mold and the second mold; a molten metal pouring step of pouring the molten metal into the space to form the structure; and taking out the core from the structure A flow path forming step for forming the annular or arc-shaped flow path inside the structure, and in the core creating step, an intermediate portion that is a portion between adjacent core support portions is provided. The core is formed so as to be located radially inward of the flow path from the adjacent core support portions.

  According to the present invention, the core is created such that the intermediate portion, which is a portion between adjacent core support portions, is located radially inward of the adjacent core support portions. As a result, when the molten metal is poured and the core expands radially outward, the core support portion supported by at least one of the first mold and the second mold is moved to either the first mold or the second mold. Even if the intermediate portion that is not supported is more expanded, the structure and the annular or arcuate flow path inside the structure can be brought close to, for example, a perfect circle or an arc thereof.

  Further, the longer the arc length between adjacent core support portions, the greater the expansion of the intermediate portion compared to the core support portion. However, according to the present invention, the expansion of the intermediate portion is taken into consideration in advance. It becomes possible. For this reason, in order to shorten the arc length between adjacent core support parts, it is possible to suppress an increase in the number of core support parts and parts related thereto, and the presence of the core support part is accompanied. It is possible to suppress an increase in the size of the entire structure.

  Further, when the expansion of the intermediate portion is larger than that of the core support portion, the distance between the intermediate portion and the first mold or the second mold is shortened, and the thickness of the structure may be uneven. There is. According to the present invention, since it is possible to take into account the degree of expansion of each of the core support portion and the intermediate portion, the thickness of the structure having an annular or arc-shaped flow path therein is made uniform. It becomes possible.

  According to the present invention, it becomes possible to bring the housing and the annular or arcuate flow path inside the housing close to, for example, a perfect circle or an arc thereof. Further, it is possible to suppress an increase in the number of core support portions and related parts in order to shorten the arc length between adjacent core support portions, and a housing associated with the presence of the core support portion. It is possible to suppress an increase in overall dimensions. Furthermore, according to the present invention, it is possible to take into account the degree of expansion of each of the core support portion and the intermediate portion, so that the thickness of the housing having an annular or arc-shaped flow path therein can be made uniform. It becomes possible to plan.

It is a perspective view of a part of a motor including a housing manufactured using a manufacturing method according to an embodiment of the present invention. It is the cross-sectional perspective view seen from the same direction as FIG. It is a perspective view which shows a mode that a refrigerant | coolant flows through a refrigerant flow path. It is sectional drawing of the said housing when it sees to the axial direction of the said motor. It is a perspective view containing the cross section of the VV line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is the VII-VII sectional view taken on the line of FIG. It is a perspective view which shows an upper model, a lower model, and a core simply. It is sectional drawing which shows the said upper mold | type, the said lower mold | type, and the said core simply when it sees in the direction of the IX-IX line of FIG. It is a figure which emphasizes and shows the expansion | swelling degree of the said core at the time of pouring a molten metal. It is a figure which emphasizes and shows the outer periphery position (thing before pouring the said molten metal) of the said core in consideration of the expansion degree shown in FIG.

A. Embodiment 1 FIG. Explanation of configuration [1-1. overall structure]
FIG. 1 is a perspective view of a part of a motor 10 including a housing 14 manufactured using a manufacturing method according to an embodiment of the present invention. 2 is a cross-sectional perspective view seen from the same direction as FIG. In addition to the housing 14, the motor 10 as a rotating electrical machine includes a stator 12 disposed inside the housing 14 and a rotor (not shown) disposed inside the stator 12. The motor 10 is a three-phase AC brushless type, and generates driving force based on electric power supplied from a battery (not shown) via an inverter (not shown).

  The motor 10 according to the present embodiment is used for driving a vehicle. Alternatively, the motor 10 can be used for electric power steering, an air conditioner, or an air compressor in a vehicle. Or the motor 10 can also be used for apparatuses, such as an industrial machine and household appliances.

[1-2. Stator 12]
As shown in FIGS. 1 and 2, the stator 12 includes a stator core 20, a slot 22, and a coil 24.

  The stator core 20 is an annular member having a thickness in the axial direction of the motor 10 (X1 and X2 directions in FIG. 1). Each stator core 20 has a slot 22 between teeth 26 formed at equal intervals in the circumferential direction of the motor 10 (C1 and C2 directions in FIG. 1 and the like) and extending in the radial direction (R1 and R2 directions in FIG. 2 and the like). And a coil 24 is wound around the plurality of slots 22. That is, the stator 12 in this embodiment is what is called distributed winding. Alternatively, the stator 12 may be so-called concentrated winding.

  As the stator 12 and the rotor, for example, those described in Japanese Patent Application Laid-Open No. 2012-115099 or International Publication No. 2012/046307 can be used.

[1-3. Housing 14]
(1-3-1. Overview)
The housing 14 is an annular member, and is made of, for example, an aluminum casting. As shown in FIG. 2, the housing 14 includes a stator attachment portion 30 and connecting end portions 32 positioned at both ends of the stator attachment portion 30 in the axial directions X1 and X2 of the motor 10.

  In the stator attachment portion 30, the stator 12 is fixed to the inner side in the radial direction (R1 direction) of the motor 10 by a method such as shrink fitting. In addition, a refrigerant flow path 40 (FIG. 3) through which a refrigerant (water in this embodiment) flows is formed inside the stator attachment portion 30. The refrigerant is used to cool the coil 24 and the stator core 20 that have generated heat by passing a current through the coil 24 of the stator 12. Therefore, the housing 14 also functions as a part of the cooling device for the motor 10 (here, the stator 12).

  When the stator 12 is fixed to the stator attachment portion 30, the outer peripheral surface of the stator 12 and the inner peripheral surface of the stator attachment portion 30 are in surface contact. As a result, the thermal conductivity from the stator 12 to the housing 14 is improved, and the heat on the stator 12 side is easily conducted to the housing 14, thereby improving the cooling performance.

  The connection end 32 is a part for connecting the housing 14 and another member (for example, transmission).

(1-3-2. Refrigerant channel 40)
(1-3-2-1. Entire refrigerant flow path 40)
FIG. 3 is a perspective view showing how the refrigerant flows through the refrigerant flow path 40. FIG. 4 is a cross-sectional view of the housing 14 when viewed in the axial direction X2 of the motor 10. FIG. 5 is a perspective view including a cross section taken along line V-V in FIG. 4. 6 is a sectional view taken along line VI-VI in FIG. 7 is a cross-sectional view taken along line VII-VII in FIG.

  In the housing 14, the refrigerant introduced from the lower right inlet 42 in FIGS. 3 and 4 passes through the refrigerant flow path 40 and is then discharged from the upper left outlet 44 in FIGS. 3 and 4. The axis of the introduction port 42 is parallel to the axial directions X1 and X2 of the motor 10, while the axis of the discharge port 44 is along the radial directions R1 and R2. The introduction port 42 and the discharge port 44 are separated from each other by about 180 degrees in the circumferential directions C1 and C2 of the motor 10.

  Between the introduction port 42 and the discharge port 44, the refrigerant channel 40 is divided into a plurality of branch channels 46a to 46h. That is, in FIG.3 and FIG.4, four branch flow paths 46a-46d which guide a refrigerant | coolant clockwise (C1 direction), and four branch flow paths 46e-46h which guide a refrigerant | coolant counterclockwise (C2 direction). And are provided.

  The height of each of the branch channels 46a to 46h (that is, the wall surface (hereinafter referred to as “inner wall surface 50”) on the radially inner side (R1 direction) of the housing 14 and the wall surface (hereinafter referred to as “R2 direction”) of the housing 14 in the radial direction. As shown in FIGS. 3 and 4, the distance between the outer wall surface 52 and the outer wall 52) is large in the vicinity of the introduction port 42 and the discharge port 44, but is relatively small and the same in other portions. It is the height of.

(1-3-2-2. Ribs 54a to 54c)
As shown in FIGS. 5, 6, etc., each of the branch channels 46 a to 46 h is formed by dividing the coolant channel 40 by a plurality of ribs 54 a to 54 c that connect the inner wall surface 50 and the outer wall surface 52 of the housing 14. Is done. The ribs 54a to 54c extend between the inner wall surface 50 and the outer wall surface 52 in parallel with each other along the circumferential directions C1 and C2.

  As shown in FIGS. 5 and 6, circular through holes 56 a to 56 c are formed at positions corresponding to the introduction port 42 in the ribs 54 a to 54 c. The through holes 56a to 56c are for distributing the refrigerant to the branch channels 46a to 46h. In the present embodiment, the centers of the through holes 56 a to 56 c are located on the axis of the introduction port 42.

  Regarding the size (opening area) of each of the through holes 56a to 56c, the through hole 56a closest to the introduction port 42 is the largest, and the through hole 56c farthest from the introduction port 42 is the smallest. In other words, the opening area decreases as the distance from the introduction port 42 increases. For example, when it is desired to flow a uniform (same flow rate) refrigerant through each of the branch channels 46a to 46h, when the opening area of the inlet 42 is “S”, the opening area of the through hole 56a is “(3/4) S”. The opening area of the through hole 56b can be “(1/2) S”, and the opening area of the through hole 56c can be “(1/4) S”. As described later, the ratio of the opening areas is not limited to this.

  As shown in FIGS. 3 to 5, the ribs 54 a to 54 c are interrupted and an opening 58 is formed at a position corresponding to the discharge port 44.

  3 and 4 and the like, reference numerals 60a and 60b denote core support portions 108c for fixing the core 104 (FIG. 8) used for manufacturing the housing 14 to the upper mold 100 and the lower mold 102, respectively. It is a core support hole caused by the presence of 108d. The axis of the core support hole 60a is separated from the axis of the discharge port 44 by about 68 degrees in the circumferential directions C1 and C2. The axis of the core support hole 60b is separated from the axis of the discharge port 44 by about 100 degrees in the circumferential directions C1 and C2. The core support holes 60a and 60b also serve as sand discharge holes for discharging the sand of the core 104 after casting.

  In the present embodiment, the introduction port 42 and the discharge port 44 also serve as core support holes. From the viewpoint of the function of the refrigerant flow path 40, the core support holes 60a and 60b are unnecessary. For this reason, the core support holes 60a and 60b are closed by the cap 62 as shown in FIG.

  As shown in FIGS. 3 and 4, openings 64 and 66 are formed in the ribs 54 a to 54 c corresponding to the core support holes 60 a and 60 b. Accordingly, the ribs 54 a to 54 c are divided into three in the circumferential directions C 1 and C 2 of the motor 10 by the openings 58, 64 and 66. Further, if it is considered that the ribs 54 a to 54 c are also divided by the through holes 56 a to 56 c, the ribs 54 a to 54 c are divided into four in the circumferential directions C <b> 1 and C <b> 2 of the motor 10. In the space formed by the openings 64 and 66, the refrigerant from each of the branch channels 46a to 46h merges to generate a turbulent flow. For this reason, the cooling effect becomes large in the space.

  The introduction port 42 and the discharge port 44 of the housing 14 are connected to a refrigerant circulation device (for example, a pump (not shown)) for circulating the refrigerant via a pipe (not shown).

  In FIG. 4, the vicinity of each of the introduction port 42, the discharge port 44, and the core support holes 60 a, 60 b shows a cross section at the center in the axial direction X <b> 1, X <b> 2 of the motor 10. It should be noted that the cross section is shown at a position slightly shifted in the axial direction X1 (so that the rib 54b is visible).

2. Manufacturing Method of Housing 14 Next, a manufacturing method of the housing 14 will be described. FIG. 8 is a perspective view schematically showing the upper mold 100, the lower mold 102, and the core 104. 9 is a cross-sectional view schematically showing the upper mold 100, the lower mold 102, and the core 104 when viewed in the direction of the line IX-IX in FIG.

[2-1. Overall flow]
In manufacturing the housing 14, the following steps are mainly performed.
(A) Design of housing 14 (b) Design of upper mold 100, lower mold 102 and core 104 (c) Creation of upper mold 100, lower mold 102 and core 104 (d) Creation of housing 14

[2-2. Design of housing 14]
The designer of the housing 14 designs the housing 14 according to the required specifications of the housing 14. Further, with respect to the relative positions of the introduction port 42 and the discharge port 44, when viewed in the radial directions R1 and R2 of the motor 10, the introduction port 42 and the discharge port 44 are opposite to each other across the rotation axis Ax (FIG. 4) of the motor 10. (Position where the axis of the inlet 42 comes on the extension of the axis of the outlet 44).

  In the present embodiment, the outer peripheral surface of the stator 12 and the inner wall surface 50 of the stator mounting portion 30 of the housing 14 set tolerances based on a perfect circle shape. In other words, the ideal condition is that the outer peripheral surface of the stator 12 and the inner wall surface 50 of the stator mounting portion 30 after manufacture are in a perfect circle.

[2-3. Design of upper mold 100, lower mold 102 and core 104]
(2-3-1. Overview)
The designer of the upper mold 100 (first mold), the lower mold 102 (second mold), and the core 104 designs the upper mold 100, the lower mold 102, and the core 104 according to the material, dimensions, and the like of the housing 14. . In the present embodiment, the upper mold 100 and the lower mold 102 are molds, and the core 104 is a sand mold.

(2-3-2. Design of the core 104)
The core 104 has substantially the same shape as the refrigerant flow path 40 of FIG. However, as shown in FIGS. 8 and 9, the core 104 is provided with core support portions 108 a to 108 d (hereinafter also referred to as “support portions 108 a to 108 d”). Of these, the support portion 108a corresponds to the introduction port 42, the support portion 108b corresponds to the discharge port 44, the support portion 108c corresponds to the core support hole 60a, and the support portion 108d corresponds to the core support hole. This corresponds to 60b. As described above, the space corresponding to the support portions 108c and 108d is closed by the cap 62 (FIG. 1). The support portions 108 b, 108 c and 108 d are fixed between the upper mold 100 and the lower mold 102 by being sandwiched between the upper mold 100 and the lower mold 102. Further, the support portion 108 a is fixed by entering the recess 110 of the upper mold 100.

  FIG. 10 is a diagram that emphasizes the degree of expansion of the core 104 when the molten metal 106 is poured. A two-dot chain line in FIG. 10 indicates that the core 104 expanded by the heat from the molten metal 106 when the core 104 is formed with the same dimensions as the refrigerant flow path 40 (FIG. 4) after the housing 14 is molded. Show contours. It should be noted that the core 104 of the present embodiment is not designed and created so as to be a two-dot chain line in FIG. Further, the arrows in FIG. 10 indicate the degree of expansion of the core 104 due to heat from the molten metal 106.

  FIG. 11 is a diagram that emphasizes and shows the outer peripheral position of the core 104 (before the molten metal 106 is poured) in consideration of the degree of expansion shown in FIG. A two-dot chain line in FIG. 11 highlights and outlines the core 104 before the molten metal 106 is poured. Further, the arrows in FIG. 11 indicate the degree of change in the contour of the core 104 in consideration of the degree of expansion due to heat from the molten metal 106. When molten metal 106 (for example, aluminum) is poured into the space between upper mold 100 and lower mold 102 and core 104, core 104 expands due to the heat of molten metal 106. Therefore, in this embodiment, the dimension of the core 104 is set in consideration of the expansion of the core 104.

  Specifically, when the core 104 is fixed between the upper mold 100 and the lower mold 102, the core support portions 108b, 108c, and 108d are sandwiched between the upper mold 100 and the lower mold 102, and the core support portion 108a is Insert into the recess 110 of the mold 100. In other words, the support portions 108a to 108d are fixed by the force applied to the support portions 108a to 108d from the upper mold 100 and the lower mold 102, and the other part of the core 104 (that is, the portion between the adjacent support portions 108a to 108d). The intermediate part 112 (FIG. 11) is in a non-contact state with the upper mold 100 and the lower mold 102.

  In this state, when heat from the molten metal 106 is applied to the core 104, as shown in FIG. 10, the outer periphery 114 of the core 104 increases as the distance from the support portions 108 a to 108 d increases (from the original position). Change amount) (see arrow in FIG. 10).

  Therefore, as shown in FIG. 11, the outer periphery 114 (design value) of the core 104 before pouring the molten metal 106 is set to be radially inward (R1 direction) as the distance from the support portions 108a to 108d increases. (See arrow in FIG. 11).

  In the present embodiment, ribs 54a to 54c are formed except for positions corresponding to the introduction port 42, the discharge port 44, and the core support holes 60a and 60b (see FIGS. 2 to 4). Therefore, holes 116 (FIGS. 8 and 9) are formed in the core 104 other than the positions corresponding to the introduction port 42, the discharge port 44, and the core support holes 60a and 60b in the core 104. As a result, the molten metal 106 flows into the hole 116, whereby the ribs 54a to 54c are formed.

[2-4. Creation of upper mold 100, lower mold 102 and core 104]
The creator of the upper mold 100, the lower mold 102, and the core 104 creates the upper mold 100, the lower mold 102, and the core 104 based on the design values of the upper mold 100, the lower mold 102, and the core 104. As described above, the outer periphery 114 (design value) of the core 104 is created so as to come radially inward (R1 direction) as the distance from the support portion 108 increases.

[2-5. Creation of housing 14]
As shown in FIGS. 8 and 9, molten metal 106 is poured from an injection port (not shown) with the core 104 fixed between the upper mold 100 and the lower mold 102. As a result, the molten metal 106 enters the space between the upper mold 100 and the lower mold 102 and the core 104.

  Thereafter, the molten metal 106 is cooled to form the housing 14. Thereafter, the housing 14 is removed from the upper mold 100 and the lower mold 102, and the core 104 is removed from the housing 14.

3. Advantages of the present embodiment As described above, according to the present embodiment, the intermediate portion 112 that is a portion between the adjacent core support portions 108a to 108d is more radial than the adjacent core support portions 108a to 108d. The core 104 is created so as to be inside (R1 direction) (FIG. 11). Thereby, when the molten metal 106 is poured and the core 104 expands radially outward (R2 direction) (FIG. 10), the core support portions 108a to 108a supported by at least one of the upper mold 100 and the lower mold 102 are obtained. Even when the intermediate portion 112 that is not supported by either the upper mold 100 or the lower mold 102 has a larger degree of expansion than the upper mold 100d, the housing 14 and the refrigerant flow path 40 inside thereof can be brought closer to a perfect circle. It becomes.

  Further, the longer the arc length between the adjacent core support portions 108a to 108d, the greater the expansion of the intermediate portion 112 compared to the core support portions 108a to 108d. It becomes possible to take into account the expansion of the part 112 in advance. For this reason, in order to shorten the arc length between the adjacent core support portions 108a to 108d, the core support portions 108a to 108d and related components or parts (for example, the cores in the upper mold 100 and the lower mold 102). It is possible to suppress an increase in the groove portions for the support portions 108a to 108d, and to suppress an increase in the overall size of the housing 14 due to the presence of the core support portions 108a to 108d.

  Furthermore, when the expansion of the intermediate portion 112 is larger than that of the core support portions 108a to 108d, the intermediate portion 112 has a shorter distance from the upper mold 100 or the lower mold 102, and the thickness of the housing 14 is increased. May be non-uniform. According to this embodiment, since it becomes possible to take into consideration the degree of expansion of each of the core support portions 108a to 108d and the intermediate portion 112, the thickness of the housing 14 having the refrigerant flow path 40 therein can be made uniform. It becomes possible to plan.

  In the step of creating the core 104 (core creation step) in the present embodiment, the position farthest from the adjacent core support portions 108a to 108d in the intermediate portion 112 is located on the innermost radial direction (R1 direction). The core 104 is created (see FIG. 11). The expansion of the core 104 when the molten metal 106 is poured in tends to increase as the distance from the core support portions 108a to 108d increases. However, according to the present embodiment, adjacent core support portions 108a to 108d. The farther from the position, the more radially inward (R1 direction) is. Thereby, it becomes possible to make the housing 14 and the refrigerant flow path 40 inside thereof closer to a perfect circle.

  In the core creation step of the present embodiment, the core 104 is created so that the position farther from the adjacent core support portions 108a to 108d in the intermediate portion 112 is located radially inward (R1 direction). The expansion of the core 104 when the molten metal 106 is poured in tends to increase as the distance from the core support portions 108a to 108d increases. However, according to the present embodiment, adjacent core support portions 108a to 108d. The farther from the position, the more radially inward (R1 direction) is. Thereby, it becomes possible to make the housing 14 and the refrigerant flow path 40 inside thereof closer to a perfect circle.

  In the core creating process of the present embodiment, the hole 116 extending in the circumferential direction C1 and C2 of the motor 10 is formed in the core 104, and in the process of pouring the molten metal 106 (molten metal pouring process), the hole 116 is formed. The molten metal 106 is poured into the ribs 54a to 54c extending in the circumferential directions C1 and C2, and the plurality of branch channels 46a to 46h are formed by the ribs 54a to 54c. The core support portions 108a to 108d are formed at positions where the holes 116 are interrupted in the circumferential directions C1 and C2, and in the molten metal pouring step, a plurality of branch channels 46a to 46h are merged at the positions where the holes 116 are interrupted. The openings 58, 64 and 66 and the through holes 56a to 56c are formed.

  Accordingly, since the core support portions 108a to 108d are formed at positions where the hole portion 116 is interrupted, it is possible to form a plurality of hole portions 116 with one core 104. Therefore, it is not necessary to form the plurality of cores 104 and the plurality of core support portions 108a to 108d for each of the plurality of branch channels 46a to 46h, so that the housing 14 can be reduced in size.

  Moreover, since the branch channels 46a to 46h are formed by providing the ribs 54a to 54c along the circumferential directions C1 and C2 inside the coolant channel 40, the shape of the coolant channel 40 can be simplified. It becomes. Therefore, it is possible to easily remove the core 104 and reduce man-hours and production costs for that purpose.

  Further, the ribs 54a to 54c can be formed longer in the circumferential directions C1 and C2, and the heat transfer area of the ribs 54a to 54c is increased, and the rigidity of the housing 14 is increased and the vibration of the housing 14 is reduced accordingly. It becomes possible to do. In addition, by forming the ribs 54a to 54c in the circumferential directions C1 and C2, the refrigerant easily flows in the circumferential directions C1 and C2, and pressure loss is reduced. As a result, the cooling capacity can be improved.

  The ribs 54a to 54c are continuously formed except for positions corresponding to the core support portions 108a to 108d in the refrigerant flow path 40 (FIG. 4). As a result, the ribs 54a to 54c can be made longer in the circumferential directions C1 and C2, and the increase in the heat transfer area of the ribs 54a to 54c, the increase in rigidity of the housing 14, and the reduction in vibration can be further promoted. . The rigidity increase and the vibration reduction of the housing 14 are particularly effective when the core support portions 108a to 108d are few.

  In the present embodiment, the motor 10 is for driving a vehicle. In general, a motor for driving a vehicle and other rotating electric machines have a relatively large diameter, and as a result, expansion of the core 104 when the molten metal 106 is poured becomes remarkable. By subtracting the expansion amount of the core 104, it becomes possible to achieve at least one of suppressing the number of core support portions 108a to 108d and making the thickness of the housing 14 uniform. As a result, even if the housing 14 is used for the motor 10 for driving the vehicle, the shape of the housing 14 and the refrigerant flow path 40 inside the housing 14 can be easily approximated to a perfect circle.

B. Modifications It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the contents described in this specification. For example, the following configuration can be adopted.

1. Motor 10 (rotary electric machine)
In the above embodiment, the motor 10 is a brushless type, but may be a brush type. The stator 12 of the above embodiment is disposed radially outward (R2 direction) with respect to a rotor (not shown) (see FIGS. 1 and 2). However, the stator 12 is not limited to this. You may arrange | position to radial inside (R1 direction). In this case, the teeth 26 may be arranged toward the radially outer side (R2 direction). Further, the housing 14 may be arranged on the radially inner side (R1 direction) than the stator 12.

  From the viewpoint of a rotating electrical machine, the present invention can be applied to a generator that generates electric power based on an external driving force instead of the motor 10 that generates an external driving force. Alternatively, from the viewpoint of casting using the core 104, the present invention can be applied to uses other than the rotating electrical machine.

2. Housing 14
In the above embodiment, the housing 14 is for the stator 12. However, from the viewpoint of having an annular or arc-shaped flow path inside, the housing 14 is provided in a portion other than the stator 12 (for example, the rotor not shown). Can also be used.

  In the above embodiment, the housing 14 has a cylindrical shape with no bottom. However, from the viewpoint of a housing for the motor 10 (or rotating electrical machine), the housing 14 has a bottomed cylindrical shape (for example, a connecting end). A shape in which one of the portions 32 is closed in the axial direction X1 or X2 may be used.

  In the embodiment described above, the housing 14 accommodates the stator 12 inside in the radial direction (R1 direction) (in other words, the inside is a cavity), but attention is paid to the configuration (structure) having the refrigerant flow path 40. The housing 14 may be one that is not hollow inside (in other words, a structure having a refrigerant flow path 40 instead of the housing 14).

  In the above embodiment, the through holes 56a to 56c as shown in FIG. 5 and FIG. 6 are used. However, from the viewpoint of guiding or distributing the refrigerant from the inlet 42 to the branch channels 46a to 46h, the present invention is not limited to this. . For example, instead of reducing the opening area of the through holes 56a to 56c as the distance from the introduction port 42 decreases, the opening area of each of the through holes 56a to 56c is made the same or the opening area as the distance from the introduction port 42 increases. You may enlarge it. In the above embodiment, the centers of the through holes 56 a to 56 c are positioned on the axis of the introduction port 42. However, the centers of the through holes 56 a to 56 c may be shifted from the axis of the introduction port 42.

3. Refrigerant flow path 40
In the above embodiment, the coolant channel 40 circulates cooling water. However, from the viewpoint of circulating or guiding the coolant, a coolant other than cooling water (cooling liquid such as cooling oil or cooling of air or the like). (Gas) may be circulated or guided. Alternatively, from the viewpoint of circulating or guiding the fluid, the present invention can be applied to a configuration in which a fluid other than the refrigerant (for example, a heated fluid) is circulated or guided.

  In the above embodiment, the refrigerant flow path 40 has an annular shape (FIG. 4), but the intermediate portion 112 of the core 104 is radially inward (R1 direction) with respect to the adjacent core support portions 108a to 108d. Focusing on the point of creating the core 104 so as to come, the refrigerant flow path 40 may be arcuate. The arc shape here is not limited to a perfect circular arc shape, but may be an arc shape of a circle other than a perfect circle (an ellipse or a distorted circle).

4). Ribs 54a-54c
In the above embodiment, the three ribs 54a to 54c are provided, but the number thereof can be changed as appropriate. If attention is paid to the design and creation of the core 104 in the above embodiment, the ribs 54a to 54c may not necessarily be formed in the circumferential directions C1 and C2, and the ribs 54a to 54c may not be provided. Is possible.

5. Upper mold 100 and lower mold 102
In the above embodiment, the upper mold 100 and the lower mold 102 are molds. However, from the viewpoint of accommodating the core 104 and forming a space for pouring the molten metal 106 (molten metal pouring space), the upper mold 100 is used. And the lower mold | type 102 is not restricted to a metal mold | die.

  In the above-described embodiment, the upper mold 100 and the lower mold 102 are used as the space for accommodating the core 104 and forming the molten metal 106 (melted metal pouring space). However, from the viewpoint of forming the molten metal pouring space. If it does so, arrangement | positioning of a type | mold is not restricted to upper and lower sides, For example, you may be right and left. Further, the number of molds is not limited to two and may be three or more.

6). Core 104
In the above embodiment, the core 104 is a sand core. However, the core 104 is not limited to the sand core from the viewpoint of casting the coolant channel 40 (or the fluid channel).

  In the above embodiment, in the core creating step, the core 104 is created so that the farther from the adjacent core support portions 108a to 108d in the intermediate portion 112, the radially inner side (R1 direction) comes (FIG. 11). From the viewpoint of creating the core 104 so that the intermediate portion 112 is located radially inward (R1 direction) with respect to the adjacent core support portions 108a to 108d, the intermediate portion 112 is far from the core support portions 108a to 108d. It does not have to be so as to be radially inward (R1 direction). For example, the portion of the intermediate portion 112 that is separated from the core support portions 108a to 108d by a predetermined distance or more may have an arc shape with the same radius.

  In the above embodiment, the hole portion 116 is formed in the core 104 in order to form the ribs 54a to 54c that connect the inner wall surface 50 and the outer wall surface 52 (see FIGS. 8 and 9). In order to project from one of the wall surface 50 or the outer wall surface 52 and not connect to the other, a recess may be formed instead of the hole 116 as a through hole.

DESCRIPTION OF SYMBOLS 10 ... Motor (rotary electric machine) 14 ... Housing 40 ... Refrigerant flow path (circular or circular flow path)
42 ... Inlet port 44 ... Discharge port 46a-46h ... Branch channel 54a-54c ... Rib 56a-56c ... Through-hole (merging part) 58, 64, 66 ... Opening part (merging part)
100 ... Upper mold (first mold) 102 ... Lower mold (second mold)
DESCRIPTION OF SYMBOLS 104 ... Core 106 ... Molten metal 108a-108d ... Core support part 112 ... Intermediate | middle part 116 ... Hole C1, C2 ... Circumferential direction R1, R2 ... Radial direction

Claims (6)

A method for manufacturing a housing for a rotating electrical machine that has an annular or arc-shaped flow path extending along a circumferential direction of the rotating electrical machine, and that manufactures a housing that houses the rotating electrical machine,
A core creating step for creating a core having a plurality of core support portions;
A core placement step of placing the core between a first mold and a second mold that form a space for pouring molten metal;
A molten metal pouring step of pouring the molten metal into the space to form the housing;
A flow path forming step of taking out the core from the housing and forming the flow path inside the housing; and
In the core creation step, the core is created such that an intermediate portion that is a portion between adjacent core support portions is positioned radially inward of the rotating electrical machine with respect to the adjacent core support portions. A method of manufacturing a housing for a rotating electrical machine. In the manufacturing method of the housing for rotary electric machines according to claim 1,
In the core creating step, the core is created such that a position farthest from the adjacent core support portion among the intermediate portions is located radially inward of the rotating electrical machine. Manufacturing method for a housing. In the manufacturing method of the housing for rotary electric machines according to claim 1 or 2,
In the core creation step, the core is created so that the position farther from the adjacent core support portion of the intermediate portion is closer to the inner side in the radial direction of the rotary electric machine. Method. In the manufacturing method of the housing for rotary electric machines according to any one of claims 1 to 3,
In the core creating step, at least one hole extending in the circumferential direction of the rotating electrical machine is formed in the core, and in the molten metal pouring step, the molten metal is poured into the hole, A rib extending in the circumferential direction of the rotating electrical machine is formed, and a plurality of branch channels are formed by the rib,
Further, in the core creating step, the core support portion is formed at a position where the hole portion is interrupted in a circumferential direction of the rotating electrical machine, and in the molten metal pouring step, the plurality of tributaries are formed at the position where the hole portion is interrupted. A method for manufacturing a housing for a rotating electrical machine, comprising forming a merge portion where the paths merge. In the manufacturing method of the housing for rotary electric machines according to claim 4,
The annular or arcuate channel is a refrigerant channel that guides a refrigerant that cools the rotating electrical machine,
The core support part is formed including a position corresponding to an inlet and an outlet of the refrigerant in the refrigerant flow path,
The said rib is continuously formed except the position corresponding to the said core support part. The manufacturing method of the housing for rotary electric machines characterized by the above-mentioned. In the manufacturing method of the housing for rotary electric machines according to any one of claims 1 to 5,
The rotating electrical machine is a rotating electrical machine for driving a vehicle. A method for manufacturing a housing for a rotating electrical machine.

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