JPH02200349A - Die apparatus for hollow arm wheel - Google Patents

Abstract

PURPOSE:To form the whole range of an arm only with molten metal and to manufacture a wheel having high strength arm and good outward appearance by detaining shaft end parts of upper and lower supporting shafts to axial parts of one side die and the other side die in the upper and lower dies. CONSTITUTION:Lower part of a supporting hole 13 in a core 10 is fitted into a lower supporting shaft 16 fixed to the lower die 18 as standing, and also contracted part in the supporting hole 13 is fitted into non-round shape projection 16a in the lower supporting shaft 16. Successively, the upper supporting shaft 15 is fitted into the upper part of the supporting hole 13 and also the engaging projection 15a thereof is engaged with an engaging hole in the lower supporting shaft 16. By this method, the core 10 is positioned in vertical direction and rotating direction at the same time with the contracted part 14 in the supporting hole 13. Then, the molten Al alloy is filled up in a cavity 20, and by solidifying this, the wheel having hollow arm part can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a mold device for casting a hollow arm wheel having a hollow arm.

(Conventional technology) As a conventional technique, there is a structure shown in FIG.

In FIG. 4, 1 is a core, and a plurality of arm cores 3 are formed radially protruding from the outer periphery of a columnar hub core 2.
A fitting hole 4 is formed through the axial center of the hub core, and each arm 3
A cylindrical keren 5 is protrudingly fixed to the upper and lower surfaces of the outer end of the holder.

The above-mentioned keren 5 is formed from an aluminum alloy material, which is the same material as the molten metal supplied into the cavity 9 described above, and its protrusion amount is slightly larger than the wall thickness of the arm to be formed, and the protrusion portion The axially intermediate portion of the shaft has a small diameter.

Reference numerals 6 and 7 are upper and lower molds that surround the upper and lower surfaces and outer surfaces of the core 1, and the protruding end portion of the keren 5 mentioned above is fitted into the outer periphery of the dividing surface of these upper and lower molds 6 and 7. Recessed portions 6a and 7
form a.

Further, horizontal molds 8 and 8 surrounding the outer peripheral portion of the core 1 are provided.

Then, the core 1 is placed in the lower molds 6 and 7, and the protruding ends of the cores 5 are inserted into the recesses 6a and 7 of the upper and lower molds 6 and 7.
a to position it in the vertical direction and rotational direction. Further, the horizontal molds 8 are brought close to each other, thereby forming a predetermined cavity 9 in the outer peripheral portion of the core 1.

(Problem M to be Solved by the Invention) In the above-mentioned conventional device, the positioning of the core 1 in the vertical direction and rotational direction was performed by the keren 5 protruding and fixed to the arm core of the core 1. The burrs 5 are exposed to the outside from the surface of the molded arm, deteriorating the appearance, and the burrs 5 are separately molded and bonded to the melt supplied into the cavity 9, so the strength of this joint is reduced. There was a drawback.

Furthermore, a separate keren 5 is attached to the core 1 with high precision, and a recess 6a into which the kern 5 fits into the upper and lower molds 6 and 7 is added.
- Since it is necessary to form 7a with high precision, there is a drawback that it requires a lot of work.

SUMMARY OF THE INVENTION An object of the present invention is to obtain a new hollow arm wheel molding device that eliminates the above-mentioned drawbacks.

(Means for solving algg) In order to achieve the above object, the present invention is configured as follows.

That is, a plurality of arm cores are formed radially protruding from the outer periphery of a columnar hub core, a support hole is formed penetratingly through the axial center of the hub core, and a small-diameter, non-standard arm core is formed in the axial center of the support hole. A core with a circular constricted part is provided, and upper and lower support shafts are provided that tightly fit into the support hole and can be engaged and detached at the constricted part of the support hole. A cavity is formed that surrounds the outer periphery of the mold while maintaining a predetermined gap, and the shaft ends of the upper and lower support shafts are locked at the shaft centers of one mold and the other of the upper and lower molds. It is structured as follows.

(Function) Since the present invention has the above structure, the upper and lower support shafts are fitted into the support hole of the core from the upper and lower parts thereof and engaged with each other, so that the shaft ends of the upper and lower support shafts are engaged with each other. When the core is engaged with the shaft center portions of the upper and lower dies, the core is positioned simultaneously in the vertical direction and in the rotational direction by the constricted portion of the support hole.

(Example) Embodiments of the present invention will be described below based on the drawings.

In the drawings, FIG. 1 is a sectional view showing an embodiment of the present invention;
FIG. 2 is an enlarged cross-sectional view of the main part, and FIG. 3 is a cross-sectional view taken along line mm.

In FIG. 1, reference numeral 10 denotes a core formed of casting sand, and a plurality of arm cores 12, for example, three arm cores 12, are formed radially protruding from the outer periphery of a hub core 11 formed in a columnar shape. A support hole 13 is formed through the narrow part of 11.

The support hole 13 is formed in a tapered shape whose diameter decreases from the lower part to the upper end, and has a constricted part 14 in the axial center of the support hole 13, that is, as shown in FIG. It is formed by forming a partition wall 14a that extends out, and an elliptical aperture hole 14b that passes through the center of the partition wall 14a.

15 and 16 are tapered upper and lower support shafts that fit closely into the support hole 13;
As shown in the figure and FIG. 3, they can be engaged with and disengaged from each other.

That is, a non-circular projection 16a having a small diameter and an elliptical column shape that fits into the aperture hole 14b is formed at the upper end of the lower support shaft 16, and the axial center of the non-circular projection 16a has an elongated hole at the top and a large hole at the bottom. An engagement hole 16b serving as a diameter hole is formed.

Further, an inverted T-shaped engagement protrusion 15a is formed at the lower end axis of the upper support shaft 15 to protrude downward.

Then, by fitting the engaging protrusion 15a into the engaging hole 16b and rotating it forward and backward through 90 degrees around its axis, the two can be engaged and disengaged.

Further, the lower support shaft 16 is erected and fixed at the center of the dividing surface of the lower mold 18, and the upper support shaft 15 is removably fitted into the center of the dividing surface of the upper mold 17.

Reference numerals 19 and 19 are horizontal molds that can be attached to and separated from the outer peripheries of the upper and lower molds 15 and 16, and these horizontal molds 19 and 19 and the upper and lower molds 1
7 and 18 form a cavity 20 that surrounds the outer periphery of the core 1° with a predetermined gap.

Next, the manner of use of the above embodiment will be explained.

First, the core 1 is attached to the lower support shaft 16 that is fixed upright on the lower mold 17.
At the same time, the lower part of the support hole 13 of No.
mate.

Then, by fitting the upper support shaft 15 into the upper part of the support hole 13 and engaging the engagement protrusion 15a with the engagement hole 16b of the lower support shaft 16, the core 10 will fit into the support hole. 13 aperture part 14
At this point, positioning is performed simultaneously in the vertical direction and in the rotational direction.

That is, the partition wall 14a of the constricted portion 14 of the support hole 13 is held between the base side step part of the non-circular protrusion 16a and the base side step part of the engagement protrusion 15a, thereby preventing the core 10 from moving in the vertical direction. , the aperture hole 14b of the aperture part 14 fits into the non-circular protrusion 16a, and rotation of the core 10 is prevented.

As a result, when the cavity 20 is filled with molten aluminum alloy and solidified, a wheel with hollow arm portions is formed.

(Effects of the Invention) As is clear from the above description, the present invention forms a small-diameter, non-circular constricted portion in the axial center of the support hole formed in the axial center of the hub core. The removable upper and lower support shafts are fitted to the upper and lower molds, and the shaft ends of these support shafts are locked at the shaft centers of the upper and lower molds, so the entire area of the arm is formed only of molten metal. As a result, it is possible to cast a wheel with a strong arm and a good appearance.
The number of sand molds used for the core is reduced.

In addition, since no separate parts such as a keratin are attached to the core, the molding of the core becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part thereof, and FIG. 3 is a sectional view taken along line III-III.
FIG. 4 is a sectional view showing a conventional example. 10: Core, 11: Hub core, 12: Arm core, 13
: Support hole, 14: Restricted portion, 14a: Partition wall, 14b: Restricted hole, 15: Upper support shaft, 15a: Engagement projection, 16: Lower support shaft, 16a: Non-circular projection, 16b: Engagement hole, 17.
18 Two upper and lower molds, 19: Horizontal type, 20: Cavity. Figure 2 Application agent Hisashi Matsumoto Figure 3

Claims (1)

[Claims] 1. A plurality of arm cores are formed protruding radially on the outer periphery of a columnar hub core, a support hole is formed penetrating through the axial center of the hub core, and a small diameter and non-magnetic arm core is formed in the axial center of the support hole. A core with a circular constricted part is provided, and upper and lower support shafts are provided that tightly fit into the support hole and can be engaged and detached at the constricted part of the support hole. A cavity is formed to surround the outer periphery of the mold while maintaining a predetermined gap, and the shaft ends of the upper and lower support shafts are locked to the shaft centers of one mold and the other of the upper and lower molds. A hollow arm wheel molding device characterized by: