JPH073844U - Hollow core for mold - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] To provide a hollow core for a mold that can prevent the occurrence of casting defects and can significantly improve the quality without impairing the molding efficiency of the mold. A hollow core 4 arranged in a cavity 3 of a mold formed by an upper mold 1 and a lower mold 2 is provided with a suction part 7 having an intake port 6 communicating with a hollow part 5 of the hollow core. A hollow core for a mold, which has a structure protruding from the upper surface 8 of the upper mold.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hollow mold core that is disposed in a mold cavity.

[0002]

[Prior art]

 The vacuum suction casting method, which has been developed as one of the casting manufacturing techniques, is disclosed in JP-A-55-77968. It is designed such that a predetermined molten metal is sucked and filled in the cavity to be cast. That is, a shell mold consisting of an upper mold and a lower mold or a general sand mold is held in a chamber, and the suction holes provided in the lower mold portion are immersed in molten metal, while the pressure inside the chamber is reduced to lower the mold. This is a method of filling the molten metal into the mold cavity by sucking the molten metal through the suction holes to produce the desired casting, which is difficult to manufacture with the conventional sand mold process. It has a feature that a casting having a complicated shape can be manufactured relatively easily.

However, in such a vacuum suction casting method, if the casting conditions and the molding used are improper, it often happens that a small cavity defect occurs in the obtained casting. is there. It is considered that this defect is largely caused by the inclusion of air during casting, and it is also presumed that the inclusion of combustion gas of the organic binder when using an organic self-hardening mold.

[0004]

[Problems to be solved by the device]

 To solve such a problem, Japanese Patent Laid-Open No. 3-5060 has been disclosed. This technology sucks the gas in the mold cavity through the core during vacuum suction casting, so that the molten metal flows into the mold cavity along the core surface and suppresses the entrainment of gas in the casting product. Is what you are trying to do. However, in order to improve the decompression suction effect of the chamber that holds the mold and decompresses it, it is necessary to form a vent hole in the mold that communicates with the hollow portion of the core. Therefore, the number of man-hours for molding a mold increases, which hinders the improvement of molding efficiency and causes a cost increase, which leads to unfavorable results. By the way

[0005] Therefore, as a result of diligent research, the inventors of the present invention have completed the present invention by developing a new technique capable of effectively sucking the main part of the casting mold with an extremely compact decompression facility. The present invention has been made in view of such problems, and an object thereof is to prevent the occurrence of casting defects and significantly improve the quality without impairing the molding efficiency of the mold. A hollow core for a mold is provided.

[0006]

[Means for Solving the Problems]

 The mold hollow core of the present invention is a hollow core disposed in the cavity of a mold formed by an upper mold and a lower mold, and has an intake port communicating with the hollow portion of the hollow core. It is characterized in that the suction part has a structure protruding from the upper surface of the upper mold.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view of a mold in which a hollow core is placed. A hollow core 4 arranged in the cavity 3 of the mold formed by the upper mold 1 and the lower mold 2, the suction part 7 having an intake port 6 communicating with the hollow part 5 of the hollow core 4. Is projected from the upper surface 8 of the upper mold 1.

Next, the operation and effect of the above configuration will be described. When the molten metal is poured into the mold through the sprue 9 of the upper mold 1, the suction part 7 having the suction port 6 and protruding from the upper surface 8 of the upper mold 1 is connected to a decompression suction source (not shown) so that the mold cavity The air inside is discharged from the intake port 6 through the core 4, and even when an organic self-hardening mold is used, the combustion gas of the organic binder is also discharged from the intake port 6. Therefore, air, gas, etc. do not remain in the cavity of the mold, and a good casting can be manufactured without causing void defects in the casting.

[0009]

[Effect of device]

 As is clear from the above description, the hollow core for a mold of the present invention is capable of preventing the occurrence of casting defects and significantly improving the quality without impairing the molding work efficiency of the mold and is industrially excellent. It brings about the effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold in which a hollow core is placed.

[Explanation of Codes] 1 Upper mold 2 Lower mold 3 Cavity 4 Hollow core 5 Hollow part 6 Intake port 7 Suction part 8 Top surface 9 Gate

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Takehisa Nishimata 35 Nagahama-cho, Kanda-cho, Kyoto-gun, Fukuoka Prefecture Hitachi Metals Co., Ltd. Kyushu Plant

Claims (1)

[Scope of utility model registration request] 1. In a hollow core disposed in a cavity of a mold formed by an upper mold and a lower mold, a suction part having an intake port communicating with the hollow part of the hollow core is provided from the upper surface of the upper mold. A hollow core for a mold, which has a protruding structure.