JP4972021B2 - Method for manufacturing cast-in products - Google Patents

Description

  The present invention relates to a manufacturing method that aims to reduce the influence of a core material from a mold when the core material is cast with another material to manufacture a cast product (cast product).

The other mold is aligned with one mold for holding the core material, a space is formed between the mold and the core material, and the core material is casted by filling the space with a predetermined amount of metal. A method for casting a product is known (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 7-21246

  However, the conventional method has a problem that the physical properties of the core differ before and after the molten metal is filled in the mold.

  As a result of testing and research, the inventor of the present application has found that one of the causes of such physical property changes is heat transfer from the mold.

  Here, FIG. 4 is a cross-sectional view of an essential part schematically showing the structure in the molds 1 and 2 when casting is performed by a conventional method using the sleeve member 3 holding the rotating shaft inside as a core material. .

  In the conventional casting, as shown in FIG. 4, the inner peripheral surface 31 of the sleeve member 3 is held by the mold convex portion 1p over the entire circumference, so that the influence of heat transfer from the mold 1 is influenced by the inner peripheral surface. 31 The whole thing was received and baked.

  That is, when the inner peripheral surface 31 of the sleeve member 3 is held by the mold convex portion 1p over the entire circumference, the inventor of the present application has a physical property around the inner peripheral surface 31 of the sleeve member 3 before casting. And later changed, resulting in a decrease in wear resistance.

  The problem to be solved by the present invention is that the physical properties of the core material change due to heat transfer from the mold, and the manufacture of a cast product that hardly changes in the physical properties of the core material due to such heat transfer. It is to provide a method.

A present invention, a method of manufacturing a casting-products is arranged automatic transmission, the core material of the sleeve member for holding the sliding member is a rotary member held in the die, the one mold The other mold is combined, a space is formed between the mold and the core material, and the core material is cast by filling the space with molten metal, A mold for holding the core material by providing the core material with a holding part where the core material is locally held with respect to the mold and forming a gap between the core material and the mold. When holding the core material in the mold by locally holding the core material with respect to the mold and providing a holding portion that forms a gap between the mold and the core material , The contact area between the core material and the mold is reduced.

  In the present specification, the expression “casting” is used, but a specific casting method includes die casting.

  In addition, various materials can be adopted as the core material and the molten metal filled in the mold according to the present invention, for example, using an aluminum alloy as the core material according to the present invention, A case where a magnesium alloy is used as the molten metal filled in the mold is mentioned.

  Further, the manufacturing method of the present invention can be used for various products, but as the cast product, a sleeve member whose main purpose is to hold a sliding member represented by a rotating shaft is a core material. The automatic transmission case used as

As in the present invention, the core material is provided with a holding portion where the core material is locally held with respect to the mold to form a gap between the core material and the mold , or the core By providing a holding part for locally holding the core material with respect to the mold and forming a gap between the mold and the core material in the mold for holding the material, If the contact area between the core material and the mold is reduced when held in, the heat transfer from the mold to the core material is reduced, so that changes in physical properties of the core material due to heat can be suppressed. .

  Further, since the holding portion is provided, a gap is formed between the core material and the mold, so that the gap forms a heat insulating space and further reduces heat transfer from the mold to the core material.

  That is, by using the manufacturing method of the present invention, it is possible to provide a cast product that hardly changes in the physical properties of the core material.

  In particular, when the core material is an aluminum alloy, and the molten metal filled in the mold is a magnesium alloy, the aluminum alloy is annealed as heat is transferred from the mold to the core material. Therefore, it is possible to suppress a decrease in wear resistance accompanying the softening of the core material. For this reason, it is possible to manufacture a cast-out product with high durability.

  By the way, since the sleeve member disposed in the automatic transmission case is generally intended to hold a sliding member represented by a rotating shaft, high wear resistance is an important requirement. is there. For this reason, according to this invention, if an automatic transmission case is manufactured by casting a sleeve member, the effect can be exhibited effectively.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of an automatic transmission case 100 that can be cast according to the present invention. FIG. 2 is a schematic cross-sectional view schematically showing the structure in the molds 1 and 2 when the sleeve member 3 is cast in the first embodiment of the present invention.

  Reference numerals 1 and 2 respectively denote molds for forming a known automatic transmission case 100 using the sleeve member 3 as a core material.

  The mold 1 is a convex mold having a convex portion (hereinafter referred to as “mold convex portion”) 1 p protruding in a cylindrical shape from the mating surface 11 with the mold 2. The mold 1 holds the sleeve member 3 on the outer peripheral surface 12 of the mold convex portion 1p, and positions the sleeve member 3 by abutting one end of the sleeve member 3 against the mating surface 11 thereof.

  The mold 2 has a concave portion (hereinafter referred to as “mold concave portion”) 2n with which the tip surface 13 of the mold convex portion 1p comes into contact with the mating surface 21 with the mold 1 when the die 1 is brought together. It is a concave mold. In this mold 2, a cavity C that forms the external shape of the automatic transmission case 100 together with the sleeve member 3 is formed between the inner surface 22 of the mold recess 2 n (hereinafter referred to as “recess inner surface”) 22 and the mold 1. At the same time, the other end of the sleeve member 3 is abutted against the inner surface 22 to position the sleeve member 3.

  Inside the sleeve member 3, two annular portions 3 r that protrude radially inward toward the central axis O are provided integrally with the sleeve member 3. As a result, when the sleeve member 3 is attached to the mold 1, the two parts (hereinafter referred to as “holding parts”) 3 r are respectively formed over the entire outer peripheral surface 12 of the mold convex part 1 p as shown in the figure. The member 3 is held locally with respect to the mold 1.

  In manufacturing the automatic transmission case 100, the sleeve member 3 is held by the mold convex portion 1 p, and then the mold 2 is aligned with the mold 1, and the mold 1, 2 and the sleeve member 3 are placed between the mold 1 and the sleeve member 3. The space S is formed, and the sleeve member 3 is cast by filling the space S with molten metal. Thereby, the automatic transmission case 100 integrally provided with the sleeve member 3 is cast.

  According to the present embodiment, the sleeve member 3 is provided with the holding portion 3r that locally holds the sleeve member 3 with respect to the mold 1, so that the sleeve member 3 is held when the sleeve member 3 is held by the mold 1. Since the heat transfer from the mold 1 to the sleeve member 3 is reduced by reducing the contact area between the mold 3 and the mold 1, changes in physical properties of the sleeve member 3 due to heat can be suppressed.

  Further, since the holding portion 3r is provided in the sleeve member 3, an annular gap A is formed between the sleeve member 3 and the mold 1, so that the gap A forms a heat insulating space, and the mold 1 The heat transfer from to the sleeve member 3 is further reduced.

  That is, if the manufacturing method of the present embodiment is used, it is possible to provide the automatic transmission case 100 as a cast product in which the physical properties of the sleeve member 3 hardly change.

  In addition, according to the present invention, as shown in FIG. 2B, the holding portion 3r can be removed as post-processing after casting. In this case, the portion appearing as the inner peripheral surface of the sleeve member 3 is the most excellent in wear resistance without being affected by heat.

  Furthermore, according to the present invention, as a modification of the same form, the two holding portions 3r provided on the sleeve member 3 can be only one of them. In addition, the position where the holding member 3r is provided on the axis O can be changed as appropriate.

  FIG. 3 is a schematic cross-sectional view schematically showing the structure in the molds 1 and 2 when casting the sleeve member 3 in the second embodiment of the present invention. The same parts as those in FIGS.

  In this embodiment, one annular portion 1r that protrudes radially outward toward the central axis O is provided integrally with the mold 1 on the outer peripheral surface 12 of the mold protrusion 1p. As a result, when the sleeve member 3 is attached to the mold 1, one portion (hereinafter referred to as “holding portion”) 1 r extends over the entire outer peripheral surface 12 of the mold convex portion 1 p as shown in the figure. 3 is retained locally.

  In this embodiment, in manufacturing the automatic transmission case 100, as in the first embodiment, after holding the sleeve member 3 with the mold convex portion 1p, the concave mold 2 is aligned with the mold 1, and the mold A space S is formed between the molds 1 and 2 and the sleeve member 3, and the sleeve member 3 is cast by filling the space S with molten metal. As a result, the automatic transmission case 100 integrally including the sleeve member 3 is manufactured.

  Even if the holding part 1r for holding the sleeve member 3 locally with respect to the mold 1 is provided in the mold 1 that holds the sleeve member 3 as in this embodiment, the sleeve member 3 is held by the mold 1 When this is done, the contact area between the sleeve member 3 and the mold 1 is reduced, and heat transfer from the mold 1 to the sleeve member 3 is reduced, so that changes in physical properties of the sleeve member 3 due to heat are suppressed. Can do.

  Also in this embodiment, since the holding part 1r is provided in the mold 1, an annular gap A is formed between the sleeve member 3 and the mold 1, so that the gap A serves as a heat insulating space. The heat transfer from the mold 1 to the sleeve member 3 is further reduced.

  That is, it is possible to provide the automatic transmission case 100 as a cast product that hardly changes in the physical properties of the sleeve member 3 even if the manufacturing method of this embodiment is used.

  According to the present invention, the sleeve member 3 can be left in the state after casting, but the inner peripheral surface 31 of the sleeve member 3 is used as post-processing after casting as in the first embodiment. It can be removed by a method such as polishing. In this case, the portion appearing as the inner peripheral surface of the sleeve member 3 is the most excellent in wear resistance without being affected by heat. As a modification of this embodiment, a plurality of holding portions 3r provided in the mold 1 can be provided. In addition, the position where the holding member 1r is provided on the axis O can be changed as appropriate.

  Further, according to the present invention, various materials can be adopted as the material of the sleeve member 3 and the molten metal filled in the mold 1. In this embodiment, an aluminum alloy is used as the material of the sleeve member 3. In addition, a magnesium alloy is used as the molten metal filled in the mold 1. In this case, the aluminum alloy is not annealed with heat transfer from the mold 1 to the sleeve member 3, and a decrease in wear resistance due to softening of the inner peripheral surface of the sleeve member 3 can be suppressed. . Therefore, the highly durable automatic transmission case 100 can be manufactured.

  Further, since the sleeve member 3 disposed in the automatic transmission case 100 is generally intended to hold a sliding member represented by a rotating shaft, it is important that the wear resistance is high. It is a requirement. Therefore, if the automatic transmission case 100 is manufactured by casting the sleeve member 3 in accordance with the present invention, the effect can be effectively exhibited.

  In particular, when an aluminum alloy is used as the material of the sleeve member 3 and a magnesium alloy is used as the molten metal filled in the mold 1 as in the present embodiment, the wear resistance is lower than the aluminum alloy but the weight is relatively light. By forming the appearance shape of the case 100 with a magnesium alloy, it is possible to reduce the weight of the entire case 100 while ensuring the same wear resistance as that of a conventional automatic transmission case manufactured only with an aluminum alloy.

  In this embodiment, the inner peripheral surface 31 of the sleeve member 3 is held by the holding portion 1r. However, compared with the conventional cast-in method that holds the entire inner peripheral surface 31 over the entire circumference, the influence of heat. It is clear that it is effective for improving the wear resistance because the size of the film is small.

  In each of the above embodiments, both ends of the sleeve member 3 are in contact with the mating surface 11 of the mold 1 and the concave inner surface 22 of the mold 2. In this case, the sleeve member 3 is transmitted from the mating surface 11 and the concave inner surface 22. Heat does not directly affect the target portion (inner peripheral surface 31) that requires wear resistance.

  The above description shows preferred forms of the present invention, but various modifications can be made within the scope of the claims. For example, FIG. 1 shows a secondary pulley shaft via a bearing B as an example of a sleeve member 3 cast as an automatic transmission case (actually, a converter housing that is a part of the automatic transmission case 100) 100. (Output shaft) 10 is shown to rotatably support the sleeve member 3, but the sleeve member 3 is cast also in a portion for holding other rotating elements, and the application location is shown in FIG. It is not limited to the illustrated part.

  Further, the member used as the core material according to the present invention is not limited to the sleeve member. Furthermore, the product cast by the cast hole according to the present invention is not limited to the automatic transmission case. Moreover, each component of the form mentioned above can be combined suitably according to a use etc.

It is a schematic cross section of the automatic transmission case cast according to the present invention. It is a schematic cross section which shows typically the structure in the metal mold | die at the time of casting a core material with the 1st form of this invention. It is a schematic cross section which shows typically the structure in the metal mold | die at the time of casting a core material with the 2nd form of this invention. It is principal part sectional drawing which shows typically the structure in a metal mold | die at the time of casting a core material with the conventional method.

Explanation of symbols

1 Mold (Convex mold)
1p Mold convex part
1r Holding part 2 Mold (concave mold)
3 Sleeve member (core material)
3r retention site
10 Secondary pulley shaft
11 Convex mold mating surface
21 Indented die mating surface
31 Inner circumferential surface of sleeve member
100 Automatic transmission case A Clearance (insulation space)
B Bearing C Cavity S Filling space

Claims (2)

A core member as a sleeve member that is arranged in an automatic transmission and holds a sliding member that is a rotating member is held in one mold ,
Matching the other mold to the one mold, forming a space between the mold and the core,
It is a manufacturing method of a cast product made by casting a core material by filling the space with molten metal,
In the core material, by providing a holding portion where the core material is locally held with respect to the mold to form a gap between the core material and the mold , or
By providing a holding part that locally holds the core material with respect to the mold and forms a gap between the mold and the core material in the mold that holds the core material ,
A method for manufacturing a cast product, characterized in that when the core material is held by a mold, the contact area between the core material and the mold is reduced.   2. The method of manufacturing a cast product according to claim 1, wherein an aluminum alloy is used as a material of the core material, and a magnesium alloy is used as a molten metal filled in the mold.

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