JP2000167646A - Structure of feeder head in metallic mold for casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the capacity of a feeder head to the absolute minimum with a simple constitution and to surely replenish molten metal into a cavity by arranging a heat-insulating part having smaller porous ratio than that of a porous metallic mold at the surroundings of the feeder head. SOLUTION: The structure 10 of the feeder head part has the feeder head part 24 having a prescribed capacity as a non-product part communicated with the cavity 20 and in the surroundings, the heat-insulating part 26 is arranged. The heat-insulating part 26 is set to have a porous ratio smaller than that of a sliding mold 18 and e.g. in the case of 17-25 vol.% of the porous ratio of the sliding mold 18, this heat-insulating part has a porous ratio of <=17 vol.%. Thus, the flowing of the air from the heat-insulating part 26 is regulated and the heat-insulation is effectively improved in comparison with the sliding mold 18. Therefore, the solidification of molten metal 28 in the feeder head part 24 can be delayed and the solidify-shrinking part of the molten metal 28 in the cavity 20 can surely be replenished with the molten metal 28 in this feeder head part 24. Further, the heat insulating part, by using a high strength member therefore, can resist the thermal stress caused by the molten metal 28 filled in the feeder heat part 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeder structure of a casting mold provided in a non-product part communicating with a product cavity of a porous mold.

[0002]

2. Description of the Related Art For example, a porous mold is used as a casting mold because of its excellent gas releasing property and heat retaining property. This type of mold uses a gravity casting method (GDC method) in which casting is performed using the gravity of the molten metal itself, or a low pressure method in which casting is performed by applying low pressure to the molten metal surface using air or an inert gas. The casting method (LPD method) or the like may be incorporated in a device to which the method is applied.

[0003] At this time, a mold is provided with a feeder, which controls the solidification balance of the molten metal and replenishes the casting material with respect to the solidification shrinkage of the product part in the cavity. Specifically, as shown in FIG. 4, a mold 1 is provided with a gate system (casting scheme section) 4 connected to the gate 2 from the gate 2.
Is provided, and the product cavity 5 communicates with the runner 3. The cavity 5 is communicated with a feeder 6 which is a non-product part.

[0004]

By the way, the feeder 6 has a function to supply the molten metal to the cavity 5, and the solidification of the molten metal is slower than that of the product 7 in the cavity 5. There is a need to. For this reason, the feeder 6
Is set to a considerably large capacity, and a contrivance for applying a heat insulating coating film on the surface of the feeder unit 6 is made. As a result, it has been pointed out that the retention of the casting in the plan part (product weight / cast weight) is reduced, and that the durability of the coating is reduced due to wear of the coating film.

[0005] The present invention solves this kind of problem and sets the capacity of the feeder to a minimum necessary.
An object of the present invention is to provide a feeder structure of a casting mold that can reliably supply a molten metal to a cavity and has a simple configuration.

[0006]

In the feeder structure of a casting mold according to the present invention, a heat insulating portion having a porosity smaller than that of the mold is provided around the feeder. Thus, the flow of air in the heat insulating portion can be prevented to improve the heat insulating property. Therefore, the capacity of the feeder can be set to the minimum necessary, and the casting yield of the casting can be effectively improved with a simple configuration.

Here, the heat insulating portion has a porous high-strength member formed of a material having higher strength than the material of the mold, and can effectively withstand the thermal stress of the molten metal supplied to the feeder portion. be able to.

The heat insulating portion includes a porous high-density member having a higher density than the mold, a porous high-strength member provided surrounding the porous high-density member, and a porous high-strength member surrounding the porous high-strength member. And a heat-insulating space provided. This makes it possible to delay the solidification of the molten metal in the feeder section under the heat insulating action of the space section, and to reliably supply the molten metal to the product section in the cavity.

In addition, there is no need to provide a coating film on the surface of the riser, and there is no danger of deterioration in durability due to abrasion. Furthermore, by using a porous high-strength member, the entire feeder portion can be made thinner, and the heat capacity of the feeder portion can be reduced to further improve the heat insulating property.

[0010]

FIG. 1 is a schematic longitudinal sectional view of a casting mold 12 provided with a feeder structure 10 according to a first embodiment of the present invention.

The mold 12 includes a plurality of molds, for example, a lower mold 14, an upper mold 16, a slide mold 18, and the like.
The lower mold 14 and the slide mold 18 are, for example, S
It is made of a porous metal material made of US powder.
In the mold 12, a cavity 2 having a predetermined product shape is provided.
0 is formed, and a core (eg, a sand core) 22 is disposed in the cavity 20.

The slide die 18 is provided with a feeder structure 10 according to the first embodiment. Feeder structure 10
As shown in FIGS. 1 and 2, a feeder unit 24 having a predetermined capacity, which is a non-product unit communicating with the cavity 20.
Around the feeder section 24, a heat insulating section 26 is provided.
Is provided. The heat insulating portion 26 is set to have a porosity smaller than the porosity of the slide mold 18. Have.

The heat insulating portion 26 may be made of the same metal material as the slide die 18 or, alternatively, the slide die 1 may be made of the same material.
A porous high-strength member formed of a material having a strength higher than 8, for example, an alumina titanate-based material may be used.

The operation of the feeder structure 10 thus configured will be described below in relation to a mold 12 in which the feeder structure 10 is incorporated.

First, the core 2 is inserted into the cavity 20 of the mold 12.
2 and the cavity 12 is filled with a molten metal (cast material) 28 from a gate (not shown) with the mold 12 clamped. At that time, cavity 2
The molten metal 28 is also filled in the pusher portion 24 communicating with zero.

Next, as the temperature of the molten metal 28 filled in the cavity 20 decreases, solidification progresses, and contraction of the product part is caused. On the other hand, a feeder portion 24 communicates with the cavity 20 corresponding to the non-product portion, and the molten metal 28 in the feeder portion 24 replenishes the shrinkage when the product portion solidifies in the cavity 20. I do.

In this case, in the first embodiment, a heat insulating portion 26 is provided around the feeder portion 24, and the heat insulating portion 26 has a porosity smaller than the porosity of the slide die 18. ing. For this reason, the flow of the air from the heat insulating portion 26 is regulated, and the heat insulating property is effectively improved as compared with the slide die 18. Therefore, the solidification of the molten metal 28 in the feeder 24 can be delayed, and the solidification contraction of the molten metal 28 in the cavity 20 can be reliably replenished by the molten metal 28 in the feeder 24.

As a result, the capacity of the feeder 24 can be set to the minimum necessary, and the yield of the casting can be effectively improved.
There is no need to apply a heat-insulating coating film to the surface, and the effect of easily improving durability can be obtained. In addition, in the feeder portion structure 10, it is only necessary to provide the same material as the slide die 18 or a high-strength member made of alumina titanate so as to surround the feeder portion 24. It has the advantage of being economical.

By using a high-strength member for the heat insulating portion 26, it is possible to withstand the thermal stress caused by the molten metal 28 filled in the feeder portion 24. In addition, the feeder structure 10
May be set to a two-layer structure in which a first layer having a smaller porosity than the slide mold 18 and a second layer made of a porous high-strength member are laminated.

FIG. 3 is an enlarged explanatory view of a main part of a casting mold 42 in which a feeder structure 40 according to a second embodiment of the present invention is incorporated. Note that the same components as those of the feeder structure 10 and the mold 12 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The feeder portion structure 40 has a heat insulating portion 44 provided around the feeder portion 24. The heat insulating portion 44 has a porous high-density member 46 higher in density than the slide die 18 and a porous high-density member 46. A porous high-strength member 48 provided around the high-density member 46 and formed of a material having a higher strength than the material of the slide die 18, and a heat insulating member provided so as to surround the porous high-strength member 48. And a space unit 50.

The porous high-density member 46 may be made of, for example, SUS, which is the same material as the slide die 18. The porous high-strength member 48 is made of a material that can withstand the thermal stress caused by the molten metal 28. For example, it may be made of an alumina titanate-based material. The space 50 is set to have a capacity necessary to maintain the heat insulation of the feeder unit 24.

In the feeder section structure 40 constructed as described above, the space section 50 is provided so as to surround the feeder section 24.
The solidification of the molten metal 28 filled in 4 can be effectively delayed. Therefore, it is possible to reliably supply the molten metal 28 in the feeder portion 24 to the product portion that solidifies and contracts in the cavity 20, and an effect is obtained that the replenishment of the casting material is performed favorably.

Further, since the porous high-strength member 48 is provided inside the space 50, the porous high-strength member 48
In addition, the porous high-density member 46 can be effectively reduced in thickness. For this reason, there is an advantage that the heat retaining property of the molten metal 28 in the pusher part 24 is improved at once.

Thus, in the second embodiment, it is not necessary to set the feeder 24 to a large capacity, and it is not necessary to provide a heat insulating coating on the feeder 24. Therefore, while effectively improving the casting yield of castings,
The same effects as in the first embodiment can be obtained, for example, a decrease in durability can be prevented.

[0026]

According to the feeder structure of the casting mold according to the present invention, a hole smaller than the porosity of the mold is formed around the feeder provided in the non-product portion communicating with the product cavity. Since the heat insulating portion having the ratio is provided, the heat insulating property of the feeder can be effectively improved. As a result, the capacity of the feeder can be set to the minimum necessary. Further, there is no need to provide a heat-insulating coating on the feeder, and the yield of castings can be effectively improved and the coating can be improved. It does not cause a decrease in durability due to the peeling off of the film. Therefore, it is possible to efficiently and economically obtain a high-quality casting with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic vertical cross-sectional explanatory view of a casting mold provided with a feeder structure according to a first embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a main part of the mold including the feeder structure.

FIG. 3 is an enlarged explanatory view of a main part of a casting mold into which a feeder structure according to a second embodiment of the present invention is incorporated.

FIG. 4 is an explanatory view of a casting mold according to the related art.

[Explanation of symbols]

10, 40: Feeder structure 12, 42: Die 18: Slide mold 20: Cavity 24: Feeder 26, 44 ... Heat insulator 28: Melt 46: Porous high-density member 48: Porous high-strength member 50 … Space

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tadashi Okada 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. F-term (reference) 4E093 NB08 PB07 PB12

Claims (3)

[Claims] 1. A feeder structure provided in a non-product part communicating with a product cavity of a porous mold, wherein a space around the feeder is smaller than a porosity of the mold. A feeder structure of a casting mold, wherein a heat insulating portion having a porosity is provided. 2. A casting metal structure according to claim 1, wherein said heat insulating portion has a porous high-strength member formed of a material having a higher strength than said mold material. Type of hot water section structure. 3. The feeder structure according to claim 1, wherein said heat insulating portion is provided surrounding said porous high-density member and a porous high-density member having a higher density than said mold. A casting mold, comprising: a porous high-strength member formed of a material having a higher strength than the material of the mold; and a heat insulating space provided surrounding the porous high-strength member. No hot water section structure.