JP5412406B2 - Core support bracket and method for manufacturing the same - Google Patents

Description

  The present invention relates to a core support fitting for supporting a core in a cavity during casting and a method for manufacturing the same.

  When molding a cast product having a hollow portion, a core may be arranged in a mold cavity. In this case, a core support bracket (chaplet) is used as a means for positioning the core in the cavity.

  For example, keren applied to the casting apparatus of Patent Document 1 has four support pieces (hereinafter referred to as legs) on the outer periphery of a sleeve into which a sand core (hereinafter simply referred to as core) is inserted. The core is supported at an axial center position in the product part space (hereinafter referred to as a cavity) of the mold by the kelen having the legs. Then, in a state where the core is supported by keren, the molten metal is filled in the cavity, and the molten metal is solidified to form a cast product having a hollow portion.

Japanese Patent Laid-Open No. 04-288934

  When the molten metal flows into the cavity, the legs supporting the core are deformed or deformed by the influence of the pressing force (molten pressure) from the molten metal or heat. Failure to melt occurs. Thereby, keren easily changes the support state of the core in the cavity. And when Keren breaks the support state of the core, a casting defect such as uneven thickness occurs, and a cast product is cast, resulting in a problem that the yield during casting is reduced.

  The present invention has been made to solve the above-described problems, and when molten metal flows into the cavity, the influence of the molten metal on the leg portion can be reduced with a simple configuration, and thereby, a cast product can be obtained. It is an object of the present invention to provide a core support metal fitting that can stabilize the casting accuracy and improve the yield during casting, and a method for manufacturing the same.

  In order to achieve the above object, the present invention provides a main body part mounted on a core disposed in a cavity, and a connecting part extending radially outward from a root part connected to the main body part. A plurality of legs that abuts against the wall surface of the cavity, and a core support fitting that supports the core when molten metal flows into the cavity, wherein the legs are the root parts. The connecting portion has a shape in which the width in the short direction of the surface viewed from the direction of the molten metal in the vicinity of the tip is viewed from a direction orthogonal to the direction of the entrance. It is characterized by being smaller than the width in the short direction.

  According to the above configuration, the leg portion has a shape twisted from the root portion to the tip portion, and the width in the short direction of the surface viewed from the approach direction of the molten metal in the vicinity of the tip portion of the connecting portion is the approach direction. Since the width of the surface viewed from the direction orthogonal to the width is smaller than the width of the surface, the plane area of the surface facing the molten metal entering direction is reduced. Therefore, even when the molten metal flows into the cavity, even if the leg is subjected to a pressing force associated with the flow of the molten metal, the plane area of the opposing surface is small, so that it can be easily received. It is possible to reduce the deformation or melting of the leg due to the influence of the above.

  Further, since the leg portion of the core support fitting has a twisted shape, the strength of the leg portion against falling or bending can be improved. That is, the core support fitting is disposed in the cavity, so that the leg portion receives a pressing force from the wall surface of the cavity. In this case, the leg may be tilted or bent depending on the direction of the pressing force, but the bending strength against the pressing force is increased because the leg portion of the core support fitting is twisted. Therefore, the core can be stably supported.

  Thus, the core support fitting can reduce the influence of the molten metal when the molten metal flows into the cavity with a simple configuration in which the legs are twisted. Thereby, the casting precision of a cast product can be stabilized and the yield at the time of casting can be improved.

  Moreover, the said structure can be formed only by twisting a leg part with respect to the conventional core support metal fitting. For this reason, it is not necessary to make a design change to the conventional core support metal fitting, and the core support metal fitting according to the present invention can be easily manufactured.

  In this case, it is preferable that the leg portion is twisted by approximately 90 ° from the root portion to the tip portion.

  As described above, since the leg portion is twisted by approximately 90 °, the surface facing the side surface direction with respect to the molten metal entering direction can be made to face the molten metal entering direction. Therefore, for example, by forming flat leg portions, the flat plate thickness surface can be opposed to the molten metal entering direction.

  Here, the main body portion and the leg portion are integrally formed of a flat plate material, and the leg portion has a configuration in which the connecting portion extending in a flat plate shape from the root portion to the tip end portion is twisted. It can be.

  By integrally forming the main body portion and the leg portion with a plate material, for example, a joining step by welding can be omitted, so that the manufacturing process of the core support fitting can be made efficient. Moreover, the leg part which consists of a board | plate material is formed so that the area of the flat surface of the connection part seen from the approach direction of a molten metal may be large, and the area of the board thickness face seen from the direction orthogonal to this approach direction may be small. Therefore, when the legs are twisted, the plate thickness surface of the plate material can be directed in the direction of the molten metal, and the molten metal can be more easily passed when the molten metal flows into the cavity.

  Moreover, it is preferable that the said leg part is twisted in the said base part vicinity of the said connection part.

  By twisting in the vicinity of the base portion of the connecting portion, the width in the short direction of the surface viewed from the direction of the molten metal can be reduced as a whole from the vicinity of the base portion to the tip portion. The plane area of the leg part which opposes a direction becomes still smaller. Thereby, when a molten metal flows in into a cavity, a molten metal can be received more easily.

  Furthermore, the leg part may be formed in a tapered shape that tapers from the root part to the tip part.

  Thus, since the leg portion is formed in a tapered shape, the tip portion contacting the wall surface of the cavity can be reduced, and the exposure of the core to the peripheral surface of the cast product to be cast is reduced. be able to. In addition, when the leg portion is twisted in the vicinity of the base portion of the connecting portion, the vicinity of the base portion of the connecting portion has a cross-sectional area that can sufficiently cope with the torsional stress, so that the torsion can be performed without breaking the leg portion. Can be tolerated.

  Furthermore, only the leg part that abuts on the lower wall surface of the cavity may be twisted in the plurality of leg parts.

  Here, the plurality of legs of the core support metal fitting may be subjected to a large load (pressing force) from the wall surface due to cavity clamping or the like. In particular, the legs that contact the lower wall surface of the cavity, together with this load, are most affected by the pressure and heat of the molten metal as it enters, so they deform more than the legs that contact the upper wall surface. Cheap. Therefore, the influence of the molten metal can be surely reduced by twisting the leg portion that contacts the lower wall surface of the cavity. Moreover, it is only necessary to twist only the leg part that contacts the lower wall surface of the cavity among the plurality of leg parts, so that the leg part having a twisted shape can be easily formed, and the work efficiency at the time of manufacturing is improved. Can do.

  In order to achieve the above-described object, the present invention includes a main body portion attached to a core disposed in the cavity, and a connecting portion extending radially outward from a root portion connected to the main body portion. And a plurality of leg portions abutting against the wall surface of the cavity, and a manufacturing method of a core support fitting for supporting the core when molten metal flows into the cavity, A first step of forming a disk-shaped precursor member from a plate material; a second step of pressing the precursor member to form the body portion and a flange portion extending radially outward from the body portion; The method includes a step, a third step of forming the leg portion by cutting out the flange portion, and a fourth step of twisting the leg portion.

  According to such a configuration, by performing the first to fourth steps, it is possible to easily form the core support fitting with the leg portion twisted from the plate material.

  According to the present invention, when the molten metal flows into the cavity, the influence of the molten metal on the leg portion can be reduced with a simple configuration, thereby stabilizing the casting accuracy of the cast product, and the yield during casting. Can be improved.

It is a partial cross section explanatory drawing which shows roughly the casting_mold | template using the core support metal fitting which concerns on 1st Embodiment. It is a perspective view which shows the core support metal fitting of FIG. 1, and the front-end | tip of a core. 3A and 3B are views showing the core support fitting of FIG. 2, FIG. 3A is a view seen from the direction of arrow A in FIG. 2, and FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. FIG. 4A is an enlarged explanatory view of the leg portion of the core support fitting of FIG. 3, FIG. 4A is a view before twisting the leg portion, FIG. 4B is a view of the leg portion of FIG. 4A being twisted, and FIG. FIG. 4D is a view of the leg portion of FIG. 5A and 5B are explanatory diagrams showing a manufacturing process of the core support metal fitting, FIG. 5A is a diagram showing the first process, FIG. 5B is a diagram showing the second process, and FIG. 5C is a diagram showing the third process; FIG. 5D is a diagram showing a fourth step. FIG. 6A is a first explanatory view of a casting method using the core support fitting of FIG. 2, FIG. 6A is a view showing the attachment of the core support fitting and the core, FIG. 6B is a view showing the arrangement of the core, and FIG. It is a VIC-VIC sectional view taken on the line of 6B. FIG. 7A is a second explanatory view of a casting method using the core support fitting of FIG. 2, FIG. 7A is a diagram showing a clamped state of a movable mold and a fixed mold, and FIG. . It is a VIII-VIII line sectional view of Drawing 7A. It is a figure which shows the cast product cast in FIG. 7B, FIG. 9A is side surface sectional drawing, FIG. 9B is IXB-IXB sectional view taken on the line of FIG. 9A. 10A is a perspective view showing a core support fitting according to the second embodiment, FIG. 10B is an explanatory view showing a support state of the core support fitting shown in FIG. 10A, and FIG. 10C is a core according to a modification of the second embodiment. FIG. 10D is an explanatory view showing a support state of the core support fitting of FIG. 10C.

  Hereinafter, preferred embodiments (first and second embodiments) of the core support fitting and the manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a partial cross-sectional explanatory view schematically showing a mold 12 using the core support fitting 10 according to the first embodiment. As shown in FIG. 1, the core support metal fitting 10 is applied as a metal fitting for supporting a rod-shaped core 16 disposed in the cavity 14 when the molten metal flows into the cavity 14 of the mold 12.

  The mold 12 according to the first embodiment is a sand mold in which the fixed mold 18 and the movable mold 20 are formed of mold sand (for example, silica sand), and the movable mold 20 is moved up and down to perform mold opening and mold clamping. A wall surface 14 a of the cavity 14 is formed as a depression on the contact surface of the fixed mold 18 and the movable mold 20, and these depressions are formed in the cavity 14 having a predetermined shape by clamping the fixed mold 18 and the movable mold 20. Is done.

  The core 16 disposed in the cavity 14 is formed in a long cylindrical body made of mold sand like the mold 12. Since the core 16 needs to be removed after casting of the cast product, the core 16 is manufactured using sand containing a binder, wax that melts and disappears by heat, and the like. The core support fitting 10 is put on the tip of the core 16. On the other hand, a skirting board (not shown) that prevents the core 16 from rotating is formed at the rear end of the core 16. That is, the core 16 is arranged at the axial center position in the cavity 14 by supporting the tip end thereof by the core support fitting 10 and supporting the rear end (baseboard) thereof by the mold 12.

  FIG. 2 is a perspective view showing the tips of the core support fitting 10 and the core 16 of FIG. The core support fitting 10 according to the first embodiment includes a main body portion 22 attached to the tip of the core 16 and a plurality of (three in the first embodiment) leg portions extending radially from the main body portion 22. 24. In addition, the core support fitting 10 is subjected to tin (Sn) plating treatment or surface treatment for improving adhesion to a cast product.

  3 is a view showing the core support fitting 10 of FIG. 2, FIG. 3A is a view seen from the direction of arrow A in FIG. 2 (the axial direction of the main body 22), and FIG. 3B is IIIB- of FIG. It is a IIIB line sectional view. As shown in FIG. 3B, the main body portion 22 of the core support fitting 10 is formed in a bottomed cylindrical shape, and the inner diameter of the peripheral wall 22 a of the core 16 is such that it can be put on the tip of the core 16. It is set larger than the outer diameter. In addition, the main-body part 22 can also add the function as a cooling metal.

  As shown in FIG. 3A, the three leg portions 24 of the core support fitting 10 are formed at equal intervals (that is, 120 ° intervals) at the opening ends 22b of the main body portion 22 (the peripheral wall 22a). Each leg portion 24 has the same length in the longitudinal direction and extends from the main body portion 22 in the radially outward direction (the normal direction of the opening end 22b). The core support fitting 10 is arranged so that the main body portion 22 is coaxially arranged with the axial center of the cavity 14 by abutting the tip end portion 30 of each leg portion 24 with the wall surface 14a of the cavity 14 having a circular cross section. (See FIG. 8 etc.). Moreover, the core support metal fitting 10 can press-mold the main-body part 22 and the leg part 24 integrally using the flat plate-shaped board | plate material 40 by forming the leg part 24 in the opening end 22b of the surrounding wall 22a. This is possible (see FIG. 5).

  4 is an enlarged explanatory view showing the leg 24 of the core support fitting 10 of FIG. 3, FIG. 4A is a view before the leg 24 is twisted, and FIG. 4B is a twist of the leg 24 of FIG. 4A. FIG. 4C is a view before twisting the relatively wide leg 24, and FIG. 4D is a view of the leg 24 of FIG. 4C being twisted. As shown in FIG. 4A, the leg portion 24 extends from the plate member 40 through press molding, and extends in a flat plate shape. The leg portion 26 is connected to the main body portion 22, the leg portion 24 is connected to the root portion 26, and extends radially outward. The connection part 28 to come out, and the front-end | tip part 30 which followed the connection part 28 and was formed in the circular arc shape are provided. In this case, the width W1 in the short direction of the surface (flat plate surface 32) viewed from the axial direction of the main body 22 is the width of the plate thickness (plate thick surface 34) of the leg 24 viewed from the axial side surface (not shown). Z)).

  The core support fitting 10 according to the first embodiment is configured such that the leg portion 24 is twisted by approximately 90 ° from the root portion 26 to the distal end portion 30 as shown in FIGS. 2, 3A, 3B, and 4B. Has been. That is, when viewed from the axial direction of the main body 22, the leg 24 is twisted by approximately 90 ° as shown in FIG. 4B from the flat plate surface 32 formed with a relatively large width W1 in the lateral direction shown in FIG. 4A. Thus, the plate is deformed so that the plate thickness surface 34 in which the width W2 in the short-side direction is reduced faces.

  The leg portion 24 will be described in more detail. As shown in FIG. 4A, the plate-like leg portion 24 after pressing is formed in a tapered shape that tapers from the root portion 26 to the tip portion 30. By forming the taper shape in this manner, the leg portion 24 becomes thin in a state where the strength of the leg portion 24 is ensured, and the tip portion 30 that contacts the wall surface 14a of the cavity 14 becomes small. When manufacturing, it can prevent reliably that the front-end | tip part 30 is exposed from the surrounding surface of this casting.

  Then, the leg 24 shown in FIG. 4A is deformed into the leg 24 shown in FIG. 4B by twisting approximately 90 °. That is, the leg portion 24 shown in FIG. 4B has a flat surface 32 near the base portion 26 and a twisted portion X that is twisted approximately 90 ° in the vicinity of the root portion 26 of the connecting portion 28. The plate thickness surface 34 faces the distal end portion 30 (therefore, as viewed from the axial side surface of the main body portion 22, as shown in FIG. 3B, the plate thickness surface 34 faces in the vicinity of the root portion 26, A flat plate surface 32 faces from the twisted portion X to the tip portion 30).

  Here, the twisted portion X of the connecting portion 28 is provided in the vicinity of the root portion 26, and the leg portion 24 of the core support fitting 10 has a tapered shape, so that the cross-sectional area can sufficiently cope with torsional stress. have. Therefore, even if a twisting stress is applied at the twisted portion X, twisting of approximately 90 ° can be easily permitted without breaking the leg portion 24. Since the leg portion 24 is twisted by approximately 90 ° at the twisted portion X in this manner, the core support fitting 10 has a support function of the core 16 and the plane area viewed from the axial direction is greatly reduced. As a result (see FIGS. 4A and 4B), it becomes possible to easily receive the pressing force of the molten metal. Specific effects of the legs 24 will be described later.

  As shown in FIG. 4C, the leg portion 24 may be formed such that the width W1 'in the short direction of the flat plate surface 32 is wider than the width W1 shown in FIG. 4A. In this case, if the width W2 ′ of the plate thickness surface 34 is the same as the width W2 of the plate thickness surface 34 of the leg portion 24 in FIGS. 4A and 4B, the leg portion 24 is twisted by approximately 90 °, as shown in FIG. Thus, since the planar area seen from the axial direction of the main body portion 22 coincides with the planar area shown in FIG. 4B, the reduction rate of the planar area increases.

  Next, a method for manufacturing the core support fitting 10 according to the first embodiment will be described. FIG. 5 is an explanatory view showing a manufacturing process of the core support fitting 10 of FIG. 2, FIG. 5A is a view showing the first step, FIG. 5B is a view showing the second step, and FIG. FIG. 5D is a diagram showing a fourth process. In the case where the core support fitting 10 is formed, a disk-shaped precursor member 42 is formed from the flat plate material 40 in the first step (see FIG. 5A). That is, in the first step, the precursor member 42 in the previous stage that is press-formed on the core support fitting 10 is prepared.

  In the second step, the precursor member 42 is pressed to integrally form a bottomed cylindrical main body 22 and a flange 44 extending radially outward from the main body 22 (see FIG. 5B). . The outer diameter of the flange 44 is formed so as to coincide with the inner diameter of the wall surface 14a of the cavity 14 in which the core support fitting 10 is disposed.

  In the third step, a part of the collar portion 44 (area shown by hatching) is cut out to form the three leg portions 24 (see FIG. 5C). As a result, the leg portion 24 is formed such that the width W1 of the flat plate surface 32 viewed from the axial direction is sufficiently larger than the width (plate thickness) of the plate thickness surface 34 (see FIG. 4A).

  In the fourth step, a predetermined position of the leg 24 is gripped by a dedicated gripping device or pliers or the like, and the leg 24 is twisted approximately 90 ° (see FIG. 5D). As a result, the core support fitting 10 is deformed into a shape in which the leg portion 24 is twisted by approximately 90 ° from the root portion 26 to the tip portion 30.

  Thus, by performing the first to fourth steps, the core support fitting 10 in which the leg portion 24 is twisted by approximately 90 ° can be easily formed from the plate member 40. Moreover, since the main body part 22 and the leg part 24 of the core support metal fitting 10 are integrally formed, for example, a joining process by welding can be omitted, so that the manufacturing process of the core support metal fitting 10 can be made efficient. After the first to fourth steps, tin plating is applied to the surface (including the inner surface of the main body 22), and the core support fitting 10 suitable for casting can be obtained.

  Next, the casting method using the core support metal fitting 10 according to the first embodiment and the effects of the core support metal fitting 10 will be described. 6 is a first explanatory view of a casting method using the core support fitting 10 of FIG. 2, FIG. 6A is a view showing attachment of the core support fitting 10 and the core 16, and FIG. 6B is an arrangement of the core 16 FIG. 6C is a cross-sectional view taken along the line VIC-VIC in FIG. 6B. FIG. 7 is a second explanatory view of the casting method using the core support fitting 10 of FIG. 2, FIG. 7A is a diagram showing a clamping state of the movable mold 20 and the fixed mold 18, and FIG. It is a figure which shows the state filled. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7A.

  When casting using the core support fitting 10, the main body portion 22 of the core support fitting 10 is placed on the tip of the core 16 as shown in FIG. 6A. As described above, since the inner diameter of the main body portion 22 is formed larger than the outer diameter of the tip of the core 16, the core support fitting 10 can be easily attached to the core 16.

  Next, as shown in FIGS. 6B and 6C, the core 16 to which the core support fitting 10 is attached is disposed on the fixed mold 18. In the present embodiment, after one leg portion 24 is in a posture of extending downward, the rear end of the core 16 is positioned at a predetermined position of the fixed mold 18, and the tip portion 30 of the leg portion 24 is cavityd. 14 wall surfaces 14a. Since the base 16 is supported by the mold 12 at the rear end, the core 16 is stably supported by the depression on the upper surface of the fixed mold 18 even with one leg portion 24 at the front end. Of course, the core 16 may be supported in a posture in which the two leg portions 24 extend obliquely downward. In the state in which the leg portion 24 is in contact, the tip portion 30 is formed in an arc shape, so that the leg portion 24 can be brought into point contact with the wall surface 14 a of the cavity 14.

  Next, as shown in FIG. 7A, the movable mold 20 is lowered and the mold 12 is clamped. When the mold 12 is clamped, the two legs 24 abut on the wall surface 14 a of the cavity 14 of the movable mold 20. Thereby, the core support fitting 10 reliably supports the core 16 in the cavity 14 in which the mold clamping is performed. Here, in the core support fitting 10, the leg 24 receives a pressing force from the wall surface 14 a of the cavity 14 as the movable mold 20 is clamped. In this case, the leg portion 24 may be tilted or bent depending on the direction of the pressing force. However, the core support metal fitting 10 according to the first embodiment has a strong bending strength with respect to the pressing force because the leg portion 24 is twisted by approximately 90 °, and thus stably supports the core 16. Is possible.

  Next, the molten metal obtained by melting cast iron or the like is filled in the cavity 14. The molten metal flows into the cavity 14 through the runner 12a, and further flows from the front end side of the core 16 toward the rear end side (in the direction of the arrow in FIG. 7A). That is, the molten metal enters the core support fitting 10 shown in FIG.

  As shown in FIG. 8, in the core support fitting 10 according to the first embodiment, the leg portion 24 is twisted by approximately 90 ° at the twisted portion X of the connecting portion 28. For this reason, from the twisted part X of the leg part 24, the plate | board thickness surface 34 has faced the approach direction of a molten metal, and the width | variety of the surface seen from the approach direction of the molten metal is toward the front-end | tip part 30 from the root part 26 whole. It is getting smaller. As a result, the planar area of the leg portion 24 facing the molten metal entering direction is greatly reduced, so that when the molten metal flows into the cavity 14, the leg portion 24 can be easily received even if it receives a pressing force of the molten metal. The deformation and melting of the leg portion 24 can be reduced.

  Here, for example, by simply increasing the width of the flat plate surface 32 and the plate thickness surface 34 of the leg portion 24, the deformation rate and melting rate of the leg portion 24 when affected by the pressing force or heat of the molten metal are reduced. Thus, a means for maintaining the support of the core 16 is also conceivable. However, when the width of the flat plate surface 32 or the plate thickness surface 34 of the leg portion 24 is large, the leg portion 24 prevents the flow of the molten metal flowing into the cavity 14, so that the turbulent flow is caused in the molten metal injected into the cavity 14. Will occur, causing nests and cavities. On the other hand, the core support fitting 10 of the present embodiment has an effect of reducing the deformation and melting of the leg 24 while smoothing the flow of the molten metal by the structure in which the leg 24 is twisted by approximately 90 °. be able to.

  Even if buoyancy acts on the core 16 due to the inflow of molten metal, the leg portion 24 is in contact with the wall surface 14 a of the cavity 14 of the movable mold 20, so that the core 16 can be prevented from moving. As described above, the core support fitting 10 can stably support the tip of the core 16 when the molten metal flows into the cavity 14. Further, since the molten metal is filled in the cavity 14 without being disturbed by the legs 24 of the core support fitting 10, the occurrence of casting defects such as nests and cavities can be reduced during solidification.

  The core support fitting 10 according to the present embodiment has a plurality of leg portions 24 formed in a twisted shape, but only one leg portion 24 is twisted, and the leg portion having this twisted shape. 24 may be brought into contact with the lower wall surface 14 a of the cavity 14. The leg portion 24 that abuts the lower wall surface 14a of the cavity 14 abuts against the upper wall surface 14a at the same time as the pressing force from the wall surface 14a is affected by the pressing force and heat of the molten metal when entering the molten metal. It is easier to deform than the legs 24. Therefore, the influence of the molten metal can be surely reduced even if only one leg portion 24 that contacts the lower wall surface 14a of the cavity 14 has a twisted shape. In addition, since only one leg portion 24 among the plurality of leg portions 24 has to be twisted, the torsion-shaped leg portions 24 can be easily formed, and the working efficiency during manufacturing can be improved.

  As shown in FIG. 7B, after the molten metal is filled in the cavity 14, the molten metal is solidified after waiting for a certain time. In addition, the main-body part 22 of the core support metal fitting 10 can prevent that the front-end | tip of the core 16 is seized and sand adheres to a cast product at the time of solidification of a molten metal. Furthermore, since the main body portion 22 functions as a cooling metal, solidification is smoothly promoted, and it is possible to prevent a cast hole from being generated in a cast product.

  After the molten metal in the cavity 14 is solidified, the movable mold 20 is raised and the mold 12 is opened. Here, since the surface of the core support fitting 10 is tin-plated, a cast product in which the molten metal is securely adhered to the core support fitting 10 is formed. Therefore, the quality of the cast product can be improved.

  9A and 9B are diagrams showing the cast product 50 cast in FIG. 7B, FIG. 9A is a side sectional view, and FIG. 9B is a sectional view taken along line IXB-IXB in FIG. 9A. After the cast product 50 is cast by the above-described casting method, the cast product 50 is taken out from the mold 12 and the core 16 is removed from the cast product 50. As shown in FIG. 9A, the cast product 50 has a hollow portion 52 formed in the shaft center, and the core support fitting 10 is integrally cast in the hollow portion 52 on the distal end side.

  Further, as shown in FIG. 9B, even if the core support fitting 10 is cast in the cast product 50, the tip portion 30 of the leg portion 24 does not protrude outward from the outer periphery of the cast product 50. For this reason, the operation | work which cuts off the leg part 24 which protruded from the casting 50 becomes unnecessary.

  As described above, the core support fitting 10 has an influence of the molten metal when the molten metal flows into the cavity 14 by a simple configuration in which the leg portion 24 is twisted by approximately 90 ° from the root portion 26 to the distal end portion 30. Can be reduced. Thereby, the casting precision of the casting 50 can be stabilized and the yield at the time of casting can be improved. Moreover, this structure can be formed only by twisting the leg part 24 of the conventional core support metal fitting 10. For this reason, it is not necessary to make a design change to the conventional core support fitting 10, and the core support fitting 10 according to the present invention can be easily manufactured.

  Next, a second embodiment of the present invention will be described. 10A is a perspective view showing the core support fitting 100 according to the second embodiment, FIG. 10B is an explanatory view showing a support state of the core support fitting 100 in FIG. 10A, and FIG. 10C is according to a modification of the second embodiment. FIG. 10D is an explanatory view showing a support state of the core support fitting 100A of FIG. 10C. In addition, in 2nd Embodiment, the structure which has the same structure or 1st Embodiment as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description.

  The core support fitting 100 according to the second embodiment is attached to an intermediate portion (not shown) of the rod-shaped core 16 in the cavity 14, as shown in FIGS. 10A and 10B. That is, when casting a long object such as a camshaft, the core 16 becomes long, so that it is necessary to support an intermediate portion of the core 16. The core support metal fitting 100 according to the second embodiment is configured as a metal fitting that supports an intermediate portion of the core 16 formed in such a long shape.

  As shown in FIG. 10A, the core support fitting 100 has a main body portion 102 formed in a ring shape. By inserting the core 16 into the ring, the core support fitting 100 is placed on the outer periphery of the core 16. Can be arranged. Legs 104 extending radially outward are formed on the side surfaces of the main body 102 (see FIG. 10B). The leg portion 104 of the core support fitting 100 is twisted by approximately 90 ° from the root portion 26 to the tip end portion 30 in the same manner as the core support fitting 10 according to the first embodiment. Therefore, the leg 104 of the core support fitting 100 can also easily receive the molten metal when the molten metal flows into the cavity 14, and can reduce deformation and melting of the leg 104. . As a result, the core support fitting 100 can reliably support the intermediate portion of the core 16, stabilize the casting accuracy of the casting 50, and improve the yield during casting.

  As shown in FIGS. 10C and 10D, as a modification of the second embodiment, the core support fitting 100 </ b> A is formed in a substantially C shape by cutting out a part of the ring-shaped main body 102. You can also. By having the notch 106 in the main body 102 as described above, the core support fitting 100A can be mounted from the side surface direction of the core 16 through the notch 106. Therefore, for example, even if the core 16 has an outer peripheral surface formed in an uneven shape, the core support fitting 100A can be mounted. In addition, since the leg portion 104 of the core support fitting 100A is also twisted by approximately 90 °, the pressing force of the molten metal can be easily received as in the case of the core support fitting 100 of FIG. 10A. 104 deformation and melting can be reduced.

  Of course, the core support fittings 10, 100, 100A according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. For example, in the core support fittings 10, 100, and 100A according to the first and second embodiments, the configuration in which the legs 24 and 104 are twisted by approximately 90 ° has been described, but the twist angle of the legs 24 and 104 is It is not limited to this angle. That is, of course, the angle may be adjusted to an appropriate angle so that the plate thickness surfaces 34 of the legs 24 and 104 are opposed to the molten metal ingress direction in accordance with the molten metal inflow path or the like flowing into the cavity 14. is there. In addition, the legs 24 and 104 are likely to run out of molten metal in the cavity 14 by slightly shifting the twist angle from approximately 90 ° with respect to the molten metal ingress direction (for example, setting the twist angle to about 80 °). It is also possible to guide the molten metal to a location.

DESCRIPTION OF SYMBOLS 10,100,100A ... Core support metal 12 ... Mold 14 ... Cavity 14a ... Wall surface 16 ... Core 22, 102 ... Main-body part 24, 104 ... Leg part 26 ... Root part 28 ... Connection part 30 ... Tip part 32 ... Flat plate Surface 34 ... Thick plate surface 40 ... Plate material 42 ... Precursor member 44 ... Butt 50

Claims (7)

A plurality of legs whose tip is in contact with the wall surface of the cavity via a main body portion mounted on a core disposed in the cavity and a connecting portion extending radially outward from a base portion connected to the main body portion A core support fitting that supports the core when molten metal flows into the cavity,
The leg part is a shape twisted from the root part to the tip part,
The connecting portion is characterized in that the width in the short direction of the surface viewed from the molten metal entering direction in the vicinity of the tip is smaller than the width in the short direction of the surface viewed from the direction orthogonal to the entering direction. The core support bracket. In the core support metal fitting according to claim 1,
The core support fitting according to claim 1, wherein the leg portion is twisted by approximately 90 ° from the base portion to the tip portion. In the core support metal fitting according to claim 1 or 2,
The main body and the leg are integrally formed of a flat plate material,
The core support bracket according to claim 1, wherein the leg portion is twisted in the connecting portion extending in a flat plate shape from the root portion to the tip end portion. In the core support metal fitting according to any one of claims 1 to 3,
The core support metal fitting, wherein the leg portion is twisted in the vicinity of the root portion of the connecting portion. In the core support metal fitting according to any one of claims 1 to 4,
The core support fitting according to claim 1, wherein the leg portion is formed in a tapered shape that tapers from the root portion to the tip portion. In the core support metal fitting according to any one of claims 1 to 5,
The core support metal fitting, wherein the plurality of leg portions are twisted only in the leg portions that contact the lower wall surface of the cavity. A plurality of legs whose tip is in contact with the wall surface of the cavity via a main body portion mounted on a core disposed in the cavity and a connecting portion extending radially outward from a base portion connected to the main body portion A core support fitting for supporting the core when molten metal flows into the cavity,
A first step of forming a disk-shaped precursor member from a flat plate material;
A second step of pressing the precursor member to form the main body and a flange extending radially outward from the main body;
A third step of notching the collar and forming the leg;
A fourth step of twisting the legs;
A method for manufacturing a core support metal fitting, comprising:

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