JP2022020206A - Method for casting article stock, cast and method for producing cast - Google Patents

Abstract

To provide a method for casting an article stock capable of effectively suppressing the effusion of a fluid, a cast and a method for producing a cast.SOLUTION: A method is used for casting an article stock 1 comprising a cast hole 10 which has a size expanded to the side of a first edge part 1a and which is formed into a size-fixed storage hole storing the object to be stored by subjecting a wall face to machine working, and a flow passage scheduled part 32 provided radially outside of the cast hole 10, in which, an escaping recessed part 41 recessed radially outside is formed radially inside of the flow passage scheduled part 32 in the wall face of the cast hole 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method of casting an article material, a cast product, and a method of manufacturing a cast product.

In Patent Document 1 below, a method of reducing the area for machining a cast motor case material is proposed in order to prevent oil and cooling water from entering the inside of the motor case. In this method, at the time of casting, a plurality of protrusions are formed on the inner peripheral surface of the motor case material, and after casting, only the protrusions on the inner peripheral surface of the motor case material are machined. However, the only finding is that the area of machining is reduced.

Japanese Unexamined Patent Publication No. 2002-10562

An object of the present invention is to provide a method for casting an article material, a cast product, and a method for manufacturing a cast product, which can effectively suppress the exudation of a fluid.

The method for casting an article material according to the present invention includes a cast hole whose diameter is expanded toward the first end portion, which is a storage hole having a constant diameter for accommodating an object to be contained by machining a wall surface, and casting. A method of casting an article material having a planned flow path portion provided on the radial outer side of the hole, which is recessed radially on the inner side of the planned flow path portion on the wall surface of the cast hole. Form a relief recess.

According to this method, a relief recess is formed on the wall surface of the cast hole. When machining the wall surface of the cast hole, it becomes difficult to machine the portion where the relief recess is formed. For example, even if the portion where the relief recess is formed remains without being machined, or even when the portion where the relief recess is formed is machined, the cutting allowance is smaller than that of other parts of the wall surface. The surface of the article material is the material surface in the cast state. Casting may have created cavities inside the article material. If cavities are generated, it is unlikely that the cavities will be exposed on the material surface. On the other hand, when the surface of the article material is machined to remove the material surface to become the processed surface, the possibility that the cavities are exposed is higher than that of the material surface. The planned flow path portion is, for example, machined to become a flow path. Alternatively, if a cast hole for the flow path is formed in the planned flow path portion, the cast hole for the flow path can be used as it is without machining, or the flow path can be used as it is. A separate tube or the like is inserted into the cast hole for use, and the tube is used as a flow path. As a typical example, the case where the planned flow path portion is machined will be described. The wall surface of the flow path will be a machined surface. Therefore, there is a possibility that the cavities will be exposed on the wall surface of the flow path. When the cavities are exposed on the wall surface of the flow path, the fluid flowing through the flow path penetrates into the article through the cavities exposed on the wall surface of the flow path. On the other hand, if the portion where the relief recess is formed remains without being machined, the portion where the relief recess is formed remains as a material surface. Therefore, it is difficult for the cavities to be exposed at the locations where the relief recesses are formed. Further, even when the portion where the relief recess is formed is machined, the cutting allowance is small. Therefore, it is difficult for the cavities to be exposed at the locations where the relief recesses are formed. Therefore, by forming the relief recesses in the article material, it is possible to suppress the possibility that the fluid flowing through the flow path seeps out from the wall surface of the accommodating hole through the cavities.

In particular, the second draft of the wall surface of the relief recess is set smaller than the first draft of the wall surface of the cast hole, and the depth gradually increases outward toward the second end side of the cast hole. It is preferable to form a relief recess. According to this method, the relief recess can be easily formed by the gradient difference between the first draft and the second draft.

Further, on the peripheral surface of the hole forming portion of the die for forming the cast hole, the tapered portion of the first punching gradient and the tapered portion are gradually radially outward toward the tip end side of the hole forming portion. It is preferable to provide a protrusion having a protruding end surface having a second draft. According to this method, the main surface portion can be formed by the tapered portion, and the relief concave portion can be formed by the convex portion.

Further, the cast product according to the present invention is a cast product having a wall surface machined and having a storage hole having a constant diameter for accommodating an object to be contained and a flow path provided on the radial outer side of the accommodation hole. Therefore, the material surface left unmachined is provided on the inner side of the wall surface of the accommodating hole in the radial direction of the flow path.

Further, the method for manufacturing a cast product according to the present invention is a method for manufacturing a cast product having a storage hole having a constant diameter for accommodating an object to be contained and a flow path provided on the radial outer side of the accommodation hole. A cast hole that expands in diameter toward the first end, a planned flow path portion provided on the radial outside of the cast hole, and a planned flow path inside the wall surface of the cast hole. The first step of casting the article material, which has an escape recess recessed outward in the radial direction, and the wall surface of the cast hole of the article material is machined to form an accommodating hole and flow of the article material. Includes a second step of forming a flow path by machining the planned path.

As described above, it is possible to suppress the exudation of the fluid from the radial inner part of the flow path in the wall surface of the accommodating hole, and the impregnation treatment as a measure against leakage becomes unnecessary.

The perspective view of the motor case material in one Embodiment of this invention seen from the 1st end side. A perspective view of the motor case material as seen from the first end side. The figure which looked at the motor case material from the 1st end side in the axial direction. FIG. 3A is a cross-sectional view taken along the line AA of FIG. BB sectional view of FIG. FIG. 3 is a sectional view taken along the line CC of FIG. The schematic diagram which shows the casting method of the motor case material. The schematic diagram which shows the main part of the mold for casting the motor case material. The perspective view of the motor case in one Embodiment of this invention seen from the 1st end side. A perspective view of the motor case as seen from the first end side. The figure which looked at the motor case material from the 1st end side in the axial direction. FIG. 11 is a sectional view taken along the line DD of FIG. FIG. 11 is a sectional view taken along the line EE of FIG. FIG. 11 is a cross-sectional view taken along the line FF. The perspective view of the motor case in another embodiment of this invention seen from the 1st end side. FIG. 3 is a cross-sectional view showing an article material according to another embodiment of the present invention.

Hereinafter, the motor case material 1 and the casting method thereof according to the embodiment of the present invention, and the motor case 5 formed by machining the motor case material 1 will be described with reference to FIGS. 1 to 14. 1 to 6 show the motor case material 1 according to the present embodiment. The motor case material 1 is manufactured by casting, specifically, by die casting. The motor case material 1 is in a cast state and is in a state before being machined. The motor case material 1 is a semi-finished product, and is machined to become a finished motor case 5.

The motor case material 1 has a cylindrical shape. Hereinafter, the direction of the center line of the motor case material 1 is simply referred to as the axis direction. Further, the side of the first end portion 1a of the motor case material 1 is referred to as the front side, and the side of the second end portion 1b of the motor case material 1 is referred to as the rear side. 1 and 2 are perspective views of the motor case material 1 as viewed from the front side.

The motor case material 1 includes a main cast hole 10, a front shaft cast hole 11, a front annular cast hole 12, a front flow path cast hole 13, a front screw cast hole 14, and a rear. It has a shaft cast hole 20, a rear annular cast hole 21, a rear flow path cast hole 22, a rear screw cast hole (not shown), and a cooling horizontal hole 23. The main cast hole 10, the front shaft cast hole 11, the front annular cast hole 12, the front flow path cast hole 13, and the front screw cast hole 14 are the first of the motor case material 1. It is open to the end 1a side, that is, the front side, and is cast to the front side. The rear shaft cast hole 20, the rear annular cast hole 21, the rear flow path cast hole 22, and the rear screw cast hole are on the second end 1b side of the motor case material 1, that is, the rear. It has an opening on the side and is cast on the rear side.

The main cast hole 10 is formed coaxially with the center line of the motor case material 1. The main cast hole 10 is a main hole of the motor case material 1, and the main cast hole 10 makes the motor case material 1 cylindrical. The main cast hole 10 is open to the first end portion 1a of the motor case material 1. The front shaft cast hole 11 is formed coaxially with the main cast hole 10. The front shaft cast hole 11 and the front annular cast hole 12 are continuous on the rear side of the main cast hole 10. The front annular cast hole 12 is located on the radial outside of the front shaft cast hole 11 and orbits the radial outside of the front shaft cast hole 11. The front flow path cast hole 13 and the front thread cast hole 14 are located on the radial outer side of the main cast hole 10. A plurality of cast holes 13 for the front flow path are formed at intervals in the circumferential direction. In this embodiment, two cast holes 13 for the front flow path are formed. However, the number and arrangement of the cast holes 13 for the front flow path are arbitrary. A plurality of cast holes 14 for front screws are formed at intervals in the circumferential direction. The number and arrangement of the front screw cast holes 14 are arbitrary, but in the present embodiment, six front screw cast holes 14 are formed.

The cooling horizontal hole 23 communicates with the main cast hole 10. A plurality of cooling lateral holes 23 are formed at intervals from each other, and two are formed in the present embodiment. One cooling horizontal hole 23 is an insertion path through which a refrigerant such as water enters, and the other cooling horizontal hole 23 is an discharge path through which the refrigerant exits.

The rear shaft cast hole 20 communicates with the front shaft cast hole 11. The front shaft cast hole 11 and the rear shaft cast hole 20 are coaxial. The rear annular cast hole 21 is located on the radial outer side of the rear shaft cast hole 20 and orbits the radial outer side of the rear shaft cast hole 20. The rear flow path cast hole 22 is continuous with the front side of the rear annular cast hole 21. A plurality of cast holes 22 for the rear flow path are formed at intervals in the circumferential direction. In this embodiment, two cast holes 22 for the rear flow path are formed. The front flow path cast hole 13 and the rear flow path cast hole 22 are located coaxially with each other. A plurality of cast holes for the rear screw are formed at intervals in the circumferential direction. The number and arrangement of the cast holes for the rear screw are arbitrary, but in the present embodiment, six are formed. The cast hole 14 for the front screw and the cast hole for the rear screw are located coaxially.

On the outer peripheral surface of the motor case material 1, a plurality of front screw bosses 30, rear screw bosses 31, and flow path bosses 32 as planned flow path portions are provided so as to project outward in the radial direction and extend along the axial direction. The front screw boss 30 is locally formed on the front side portion of the total length of the motor case material 1 in the axial direction. The rear screw boss 31 is locally formed on the rear side portion of the total length of the motor case material 1 in the axial direction. The front screw boss 30 and the rear screw boss 31 face each other in the axial direction. A plurality of front screw bosses 30 and rear screw bosses 31 are formed at intervals in the circumferential direction. A cast hole 14 for a front screw is formed in the front screw boss 30, and a cast hole for a rear screw is formed in the rear screw boss 31. The flow path boss 32 is formed over the entire length of the motor case material 1 in the axial direction. Two flow path bosses 32 are formed so as to be spaced apart from each other in the circumferential direction. A cast hole 13 for the front flow path is formed in the front portion of the flow path boss 32, and a cast hole 22 for the rear flow path is formed in the rear portion of the flow path boss 32. The front flow path cast hole 13 and the rear flow path cast hole 22 are both non-penetrating holes and do not communicate with each other. However, the cast hole 13 for the front flow path and the cast hole 22 for the rear flow path may communicate with each other. Further, the cast hole 13 for the front flow path may not be formed in the flow path boss 32, and the cast hole 22 for the rear flow path may not be formed.

<Escape recess 41>
The wall surface of the main cast hole 10 constitutes the inner peripheral surface of the motor case material 1. The main cast hole 10 has a circular cross section and has a diameter increasing toward the front side. The wall surface of the main cast hole 10 has a main surface portion 40. The main surface portion 40 has a first draft. Due to the first draft, the diameter of the main cast hole 10 is expanded toward the front side.

On the wall surface of the main cast hole 10 facing the inner side of the flow path boss 32 in the radial direction, a relief recess 41 recessed outward in the radial direction is formed. Two escape recesses 41 are formed corresponding to the two flow path bosses 32. The relief recess 41 extends in a streak shape along the axial direction. The width (dimension in the circumferential direction) of the relief recess 41 gradually widens toward the front side. The width of the relief recess 41 is preferably larger than the diameter of the cast hole 13 for the front flow path and the diameter of the cast hole 22 for the rear flow path, and is preferably larger than the width of the flow path boss 32. The relief recess 41 is gradually deepened radially outward toward the rear side. That is, the amount of the relief recess 41 dented outward in the radial direction gradually increases toward the rear side.

The wall surface of the relief recess 41 is behind the recess main surface 41a facing radially outward with respect to the relief recess 41, a pair of recess side surfaces 41b continuous on both sides of the recess main surface 41a in the circumferential direction, and the recess main surface 41a. It has a recessed bottom surface 41c that is continuous on the side. The recess main surface 41a has a second draft that is smaller than the first draft. The second draft is preferably 1 degree or less. The second draft may be 0 degrees.

The change in the depth of the relief recess 41 is caused by the gradient difference between the first draft and the second draft. The rear end portion (recessed bottom surface 41c) of the relief recess 41 is located in the vicinity of the rear end portion of the main cast hole 10. The relief recess 41 reaches up to the first end portion 1a of the motor case material 1. That is, the front end portion of the relief recess 41 is located at the first end portion 1a of the motor case material 1. The depth at the front end of the relief recess 41 may be zero. Further, the relief recess 41 does not have to reach the first end portion 1a of the motor case material 1, and the front end portion of the relief recess 41 is located behind the first end portion 1a of the motor case material 1. May be good.

<Casting method>
FIG. 7 is a schematic view showing a main part of a mold for casting the motor case material 1. At the time of casting, the axial direction of the motor case material 1 is, for example, the horizontal direction. The mold opening direction of the main mold (not shown) is, for example, the left-right direction with respect to the center line of the motor case 5. The main type includes a fixed type and a movable type.

The mold forms a main hole forming portion 100 for forming the main cast hole 10, a front shaft hole forming portion 101 for forming the front shaft punched hole 11, and a front annular cast hole 12. Front annular hole forming portion 102 for forming a front channel hole forming portion 102, a front flow path hole forming portion (not shown) for forming a front flow path cast hole 13, and a front thread hole (not shown) for forming a front thread cast hole 14. A forming portion, a rear axle hole forming portion 200 for forming a rear axle hole 20, a rear annular hole forming portion 201 for forming a rear annular cast hole 21, and a rear flow path cast hole. It has a rear flow path hole forming portion (not shown) for forming 22 and a rear screw hole forming portion (not shown) for forming a cast hole for rear screw. In FIG. 7, for the sake of simplification of the drawings, the front flow path hole forming portion, the front thread hole forming portion, the rear flow path hole forming portion, and the rear threaded hole forming portion are not shown. The main hole forming portion 100 is driven along the axial direction. The moving direction of the main hole forming portion 100 is a direction orthogonal to the mold opening direction of the main mold.

A tapered portion 110 and two convex portions 120 are formed on the peripheral surface of the main hole forming portion 100. The tapered portion 110 is a portion for forming the main surface portion 40 of the wall surface of the main cast hole 10. The tapered portion 110 has a first draft and expands in diameter toward the proximal end side of the main hole forming portion 100. The convex portion 120 is a portion that forms a relief recess 41 on the wall surface of the main cast hole 10. The convex portion 120 projects radially outward with respect to the tapered portion 110. The amount of protrusion of the convex portion 120 to the outside in the radial direction gradually increases toward the tip end side of the main hole forming portion 100. The protruding end surface 121, which is the radial outer end surface of the convex portion 120, has a second draft. The protruding end surface 121 of the convex portion 120 forms the concave main surface 41a of the relief concave portion 41. In FIG. 8, the main hole forming portion 100 is exaggerated and schematically shown. For the sake of simplification of the explanation, only one convex portion 120 is shown.

The motor case material 1 is machined into a finished motor case 5. 9 to 14 show the motor case 5. 9 to 14 correspond to FIGS. 1 to 6, respectively. The motor case 5 has an accommodating hole 50, a flow path 51, a front screw hole 52, and a rear screw hole. The wall surface of the main cast hole 10 is machined to form an accommodating hole 50. The flow path boss 32 is drilled so as to communicate the front flow path cast hole 13 and the rear flow path cast hole 22 in the front-rear direction to form the flow path 51. The flow path 51 penetrates the flow path boss 32 back and forth. The front screw hole 14 and the rear screw cast hole are respectively drilled and threaded to form a front screw hole 52 and a rear screw hole (not shown). The first end portion 1a and the second end portion 1b of the motor case material 1 are preferably machined, and the first end portion 5a and the second end portion 5b of the motor case 5 are both machined surfaces. Is preferable.

The accommodation hole 50 has a constant diameter. Of the wall surface of the main cast hole 10, at least the entire main surface portion 40 is machined. The wall surface of the main cast hole 10 is a material surface in a cast state, but in the present embodiment, the entire wall surface of the main cast hole 10 is machined. The relief recess 41 has disappeared by cutting. In FIGS. 9 to 14, the disappeared relief recess 41 is shown by a two-dot chain line. The concave main surface 41a of the relief recess 41 is also machined. As described above, in the present embodiment, the entire wall surface of the accommodating hole 50 is a machined surface that has been machined. The front end portion of the relief recess 41 is located in the vicinity of the front end portion of the accommodating hole 50.

Inside the motor case 5, a motor (not shown) and a cylindrical cooling sleeve 6 are housed. FIG. 12 shows the cooling sleeve 6 as a chain double-dashed line. The cooling sleeve 6 is fitted into the accommodating hole 50 from the first end portion 5a side. The rear end portion 6a of the cooling sleeve 6 is located in the vicinity of the rear end portion of the accommodating hole 50. The outer peripheral surface of the cooling sleeve 6 is in close contact with the wall surface of the accommodating hole 50. A cooling groove (not shown) is formed on the outer peripheral surface of the cooling sleeve 6. Refrigerant flows through the cooling groove. Refrigerant is put into the cooling groove through one of the cooling lateral holes 23 of the motor case 5. After flowing through the cooling groove, the refrigerant is discharged from the other cooling lateral hole 23. The motor is housed inside the cooling sleeve 6. The stator of the motor fits on the inner peripheral surface of the cooling sleeve 6. The motor is cooled by the refrigerant flowing through the cooling groove. The rear end portion of the relief recess 41 is located in the vicinity of the rear end portion 6a of the cooling sleeve 6.

Other members (not shown), for example, a front cover, are screwed to the first end portion 5a of the motor case 5. The front cover is screwed by the front screw hole 52. Other members (not shown), for example, a rear cover, are screwed to the second end portion 5b of the motor case 5. The rear cover is screwed in by the rear screw holes. Various fluids such as oil flow through the flow path 51.

As described above, the relief recess 41 is formed on the wall surface of the main cast hole 10 of the motor case material 1. Therefore, when cutting the wall surface of the main casting hole 10, the cutting allowance (machining allowance) in the relief recess 41 is smaller than the cutting allowance of the main surface portion 40. Since the material on the concave main surface 41a of the relief recess 41 is not scraped off thickly, it is difficult for the cavities to be exposed on the facing portion of the wall surface of the accommodating hole 50 facing the inside of the flow path 51 in the radial direction. Therefore, it becomes difficult for a fluid such as oil flowing through the flow path 51 to seep out from the facing portion through the cavities. Therefore, it is possible to prevent the fluid in the flow path 51 from being mixed with the refrigerant in the cooling groove. Further, it is not necessary to impregnate the wall surface of the accommodating hole 50 as a measure against leakage. Since the relief recess 41 is formed in substantially the entire length in the axial direction of the portion of the main cast hole 10 that becomes the accommodating hole 50, it is possible to effectively suppress the seepage of the fluid in the flow path 51. Further, the relief recess 41 can be easily formed by providing a gradient difference between the first draft of the main surface portion 40 and the second draft of the recess main surface 41a. By providing the convex portion 120 on the peripheral surface of the main hole forming portion 100 of the mold, the relief recess 41 can be formed by a simple mold structure.

In the above-mentioned motor case 5, the case where the entire wall surface of the main cast hole 10 is machined is illustrated, but only the main surface portion 40 of the wall surface of the main cast hole 10 is machined and escapes. The concave main surface 41a of the concave portion 41 may be left uncut. FIG. 15 shows a form in which the concave main surface 41a of the relief recess 41 is left without being cut. In FIG. 15, a large number of dots are attached to the concave main surface 41a. Of the wall surface of the main cast hole 10 of the motor case material 1, the entire main surface portion 40 is machined, and the relief recess 41 disappears, but the recess main surface 41a is left as it is without being machined. In the motor case 5, only the concave main surface 41a of the wall surface of the accommodating hole 50 is left uncut. The concave main surface 41a is a material surface (unprocessed surface) as cast. The portion of the wall surface of the accommodating hole 50 other than the concave main surface 41a is a machined surface. Therefore, the wall surface of the accommodating hole 50 has a processed portion which is a processed surface and an unprocessed portion which is a material surface. There may or may not be a step between the material surface and the machined surface. The material surface and the processed surface may be substantially flush with each other. Further, the cooling sleeve 6 may not be fitted in the accommodating hole 50 of the motor case 5, and the motor may be directly mounted in the accommodating hole 50, for example.

The article is not limited to the motor case 5, and may be various articles, and the shape of the article may be various. For example, the block-shaped article material 7 as shown in FIG. 16 may be used. In this case, the portion where the cast hole 13 for the front flow path and the cast hole 22 for the rear flow path are formed becomes the planned flow path portion. The accommodating hole 50 may be a non-penetrating hole or may be a recess.

1 Motor case material 1a 1st end 1b 2nd end 5 Motor case 5a 1st end 5b 2nd end 6 Cooling sleeve 6a Rear end 7 Article 10 Main cast hole 11 Front shaft cast hole 12 Front Circular cast hole 13 Front flow path cast hole 14 Front thread cast hole 20 Rear shaft cast hole 21 Rear annular cast hole 22 Rear flow path cast hole 23 Cooling side hole 30 Front screw boss 31 After Screw boss 32 Flow path boss (planned flow path)
40 Main surface 41 Relief recess 41a Recess main surface 41b Recess side surface 41c Recess bottom surface 50 Containing hole 51 Flow path 52 Front screw hole 100 Main hole forming portion 101 Front shaft hole forming portion 102 Front annular hole forming portion 110 Tapered portion 120 Convex portion 121 Protrusion surface 200 Rear shaft hole forming portion 201 Rear annular hole forming portion

Claims (5)

A cast hole that expands in diameter to the first end side, which becomes a storage hole with a constant diameter by machining the wall surface, and a flow path provided on the radial outside of the cast hole. A method of casting an article material that has a planned portion.
A method for casting an article material, in which a relief recess recessed outward in the radial direction is formed on the inner side of the wall surface of the cast hole in the radial direction of the planned flow path. The second draft of the wall surface of the relief recess is set smaller than the first draft of the wall surface of the cast hole, and the relief recess gradually becomes deeper radially outward toward the second end side of the cast hole. The method for casting an article material according to claim 1. On the peripheral surface of the hole forming portion of the die for forming the cast hole, the tapered portion of the first draft gradient and the tapered portion gradually project radially outward toward the tip end side of the hole forming portion. The method for casting an article material according to claim 2, wherein a convex portion having a protruding end surface having a second draft is provided. A cast product having a wall surface machined and having a storage hole having a constant diameter for accommodating an object to be contained and a flow path provided on the radial outside of the accommodation hole.
A cast product having a material surface left unmachined inside the wall surface of the accommodating hole in the radial direction of the flow path. A method for manufacturing a cast product having a storage hole having a constant diameter in which an object to be stored is stored and a flow path provided on the radial outer side of the storage hole.
A cast hole that expands in diameter on the first end side, a planned flow path portion provided on the radial outside of the cast hole, and a planned flow path portion on the wall surface of the cast hole provided on the radial inside of the planned flow path portion. The first step in casting an article material, which has a radial outer recessed relief recess.
A second step of forming a flow path by machining the planned flow path portion of the article material as well as forming a storage hole by machining the wall surface of the cast hole of the article material. Production method.

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