JPH07224B2 - Casting cooling method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a casting cooling method capable of solidifying a molten metal while cooling it under arbitrary conditions.

(Prior Art) In general, in order to obtain a good quality casting by casting, hot metal is poured and filled in a preheated mold. In order to remove the gas generated at the time of pouring without being caught in the molten metal, a suction unit was previously provided below the mold, and casting was performed while discharging the gas generated by the suction unit. In the cooling in this case, the gas generated together with the heat of the metal hot water is also discharged by the suction means, but after a certain period of time, most of the air in the mold is discharged and the state becomes close to a vacuum state, after which the heat of the metal hot water Is not discharged and remains in the mold, and the cooling effect is almost lost. Therefore, pinholes generated by external factors such as gas entrapment can be prevented,
When a coarse metal structure, which is an internal factor, solidifies during cooling, the pinhole is generated by contraction of the structure, especially where the molten metal solidifies from the surroundings to finally solidify the inside, for example, shown in FIG. Pinholes were likely to occur when the shaded area in the figure solidified. As a method of preventing this, there is also a method in which the cooling rate is controlled using a chill, but if the chill is rusty or has moisture attached, it will come into contact with metal water and generate water vapor or gas, There is a possibility that defective products will be produced, and if the chill is too large, the material will tend to be non-uniform, and if it is applied in the wrong place, it may crack. In addition, since the unevenness appears on the casting surface at the place where the chill is applied,
There was a problem that post-processing was required.

Therefore, in recent years, as shown in FIG. 5, a cooling pipe member (2) is embedded in a mold (1) made of foundry sand or the like, and a cooling medium is placed in the cooling pipe member (2). A casting cooling method for circulation is disclosed in JP-A-57-85636, "Cooling Method for Vacuum Molding Mold".

(Problems to be Solved by the Invention) However, in the above-mentioned Japanese Patent Laid-Open No. 57-85636, when the molten metal is cooled while solidifying, the heat of the molten metal is discharged by the suction means (4) together with the generated gas. , The metal water begins to solidify from the lower mold (1b) side, but after a certain period of time, most of the air in the mold (1) is exhausted and becomes close to a vacuum state, after which the air that transfers heat is between the casting sands. Almost disappears. At this point, the cooling effect due to the suction of air is almost lost, and heat is trapped in the mold (1). Even if a large amount of this heat is circulated by the supply means (3) from the supply port (2d) into the cooling pipe member (2) and discharged from the discharge port (2e), the cooling pipe Since there is almost no air contacting the member (2), the cooling effect can hardly be expected. Therefore, there has been no method in the prior art for controlling the effective cooling conditions in the mold (1).

The present invention is to provide a casting cooling method capable of forming a casting with an optimum structure and almost eliminating the occurrence of pinholes by arbitrarily controlling the optimum cooling conditions of the molten metal.

(Means for Solving Problems) The present invention is for cooling by continuously ejecting a cooling gas body from a jet pipe tip of a cooling pipe member embedded in a mold into a casting sand to absorb heat of a metal hot water. The gas body continues to be discharged together with air through the sand between the molding sands, and further, by detecting the temperature sensor in the mold, by adjusting the amount of the cooling gas body supplied into the cooling pipe member, the metal This is a cooling method in which the molten metal is solidified while cooling under arbitrary cooling conditions, and the structure of the casting can be controlled.

(Operation) Next, the operation of the present invention will be described with reference to FIG. 1. A mold (1) is made in advance by using molding sand or the like, and a cooling pipe member (2) and a temperature sensor are provided in the mold (1). (6)
And the cooling pipe member (2) and the supply means (3) are connected, and the suction means (4) is provided below the mold (1). Further, the mold (1) is heated. First, the suction means (4) is actuated and the molten metal is poured into the mold (1). The gas generated during the pouring is discharged from the mold (1) by the suction means (4). Simultaneously with the pouring, the supply of the cooling gas body is started by the supply means (3). Then, the cooling gas body is jetted from the jet hole (2c) at the tip of the jet pipe (2a) of the cooling pipe member (2) embedded in the mold (1) and is discharged between the casting sands. For this reason, the heat of the metal hot water contained in the mold (1) is absorbed by the cooling gas body, passes through between the molding sands as shown by the arrow in the figure, and is continuously discharged to the outside of the mold (1). At this time, the cooling gas body ejected from the supply means (3) on the upper die (1a) side absorbs heat while passing through the outside of the mold (1) from above the upper die (1a) and sucking means (4). And the cooling gas body ejected from the supply means (3) on the lower die (1b) side is also discharged from the lower side of the mold (1) while absorbing the heat of the metal hot water, and the temperature sensor (6) The amount of cooling gas supplied to the cooling pipe member (2) may be adjusted to increase or decrease while observing the detected temperature. Therefore, the surface of the casting surface is continuously cooled by the cooling gas body which is continuously ejected from the ejection hole (2c), so that the surface is rapidly cooled to form a dense casting surface and become beautiful. In addition, the internal structure of the casting (5) is such that the amount of the cooling gas body supplied can be adjusted variably with time and the temperature at the time of supplying the cooling gas body can be arbitrarily controlled, so that the molten metal can be melted under the best cooling conditions. Once coagulated, the tissue can be preset.

FIG. 2 is an explanatory view showing a casting cooling method of the present invention used in the case of open casting, and this method will be described.
A casting mold (1) is made in advance by using foundry sand or the like, and a cooling pipe member (2) and a temperature sensor (6) are attached to the casting mold (1).
Is embedded, and the cooling pipe member (2) is connected to the supply means (3) as in the above case, and the suction means (4) is provided below the mold (1). Also mold (1)
Do not heat. First, the suction means (4) is operated to prepare for discharging the gas generated during pouring. Next, the molten metal is poured from above the mold (1) and filled. Other operations are the same as above. Then, the metallic hot water is always ejected from the injection hole (2c) without approaching the vacuum state in the mold (1) as in the conventional case.
Cooling is performed by continuously ejecting the cooling gas body. As a result, since the molten metal is forcibly solidified upward from the casting surface side, it is possible to obtain a good quality casting (5) with a dense casting surface and few pinholes.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
(1) is a mold consisting of an upper mold (1a), a lower mold 1b) and a metal frame (1c). The upper mold (1a) and the lower mold (1b) are made of molding sand, ceramic particles and the like. To use. (2) is a cooling pipe member to be embedded in the mold (1), and the cooling pipe member (2) includes a large number of ejection pipes (2a) standing in the mold (1), It is composed of a cooling pipe (2b) connected so as to communicate with the lower end side of the jet pipe (2a) (see FIG. 3). The upper ends of the ejection pipes (2a) are closed, and a large number of ejection holes (2c) are formed in the upper portion of each ejection pipe (2a). The arrangement of this ejection pipe (2a) is
As shown in Fig. 1, the upper die (1a) and the lower die (1b) are provided with cooling pipe members (2) having a shape suitable for each, and when the open casting is performed as shown in Fig. 2. Mold (1b)
In some cases, the casting surface side can be cooled evenly. In addition, each ejection pipe (2a) has an ejection hole (2
Cover c) with a cloth (not shown) to prevent sand from entering. One end of the cooling pipe (2b) projects outward from the side surface of the metal frame (1c) to form a supply port (2d).
The arrangement shape of the cooling pipe member (2) is erected in accordance with the casting shape. (3) is a supply means connected to each supply port (2d). This supply means (3) uses a compression device such as a general compressor to supply a cooling gas body such as air or nitrogen gas. To do. The amount of the cooling gas body supplied from the supply port (2d) is determined in consideration of the size and shape of the mold (1), the type of metal hot water, and the temperature of the cooling gas body supplied is also metal. It is decided in consideration of the type of hot water. Further, the one having a structure capable of adjusting the supply amount and temperature of the cooling gas body is used. (4) is a suction means provided below the mold (1), and the suction means (4) is provided with a suction port (4a) provided on the upper mold (1a) side and a suction port (4b) provided on the lower mold (1b) side. A suction port (4b), a compressor or a vacuum pump is used as the suction means (4), and the suction capacity thereof is larger than the supply capacity of the supply means (3). Further, a structure is used in which this suction force can be changed according to the supply amount of the cooling gas body. (6) is a mold (1)
It is a temperature sensor for detecting the internal temperature, and may be a general one used in the mold (1).

FIG. 4 is an explanatory view showing a copper casting cast by the casting cooling method of the present invention, and this cooling method will be described in detail. The mold (1) is heated in advance, and first the suction means (4) is operated to prepare for discharging the gas generated during pouring. In this case, if the suction means (4) is operated in advance, the bathing of the metallic hot water becomes good. Next, the molten copper is started to be poured into the mold (1), and the gas generated at the time of pouring is discharged to the outside of the mold (1) by the suction means (4). At the same time as pouring, the supply of cooling gas is started, and the ejection hole (2c)
The cooling gas body is ejected from and is continuously discharged between the foundry sands, so that the cooling gas body absorbs the heat of the molten metal.
The cooling gas body passes between the molding sands on the outer side and absorbs the heat accumulated in the mold (1) as well as the suction ports (4a), (4
After passing through b), it is discharged to the outside of the mold (1) by the suction means (4). The supply amount of the cooling gas body at this time is adjusted by increasing or decreasing the supply amount in the cooling pipe member (2) by the detection of the temperature sensor (6), and under the optimal cooling condition, the casting surface side is rapidly cooled to be dense. Form a casting surface. In other words, the above amount of supply should be about 20 to 30 minutes at the beginning, and then about 20 to 30%.
It is possible to solidify the molten metal while cooling it under appropriate cooling conditions toward the casting surface side or inward by setting the amount so that the molten metal is gradually cooled.

(Effects of the Invention) Since the present invention is configured as described above, it has the effects described below.

When the casting cooling method of the present invention is used, the cooling gas is discharged from the jet pipe (2a) into the foundry sand without the air in the mold (1) being exhausted as in the conventional case and approaching the vacuum state. Continuously, the heat of the metal hot water can always be efficiently absorbed and cooled, so that a casting (5) that solidifies into a dense structure toward the inside is obtained.

Unlike the conventional solidification of natural hot water, it is possible to arbitrarily control the best cooling conditions, so that the occurrence of pinholes is almost eliminated.

In addition, since the cooling conditions of the hot metal can be controlled arbitrarily, it is possible to make the structure dense and to make the casting surface beautiful, and in particular, it is possible to form a product with a skin pattern or wood pattern on the surface and no finishing work is required. is there.

Since the structure is densified, the hardness, tensile strength, etc. of the casting (5) are improved by about 30% as compared with the conventional one.

Since the cooling time is about half that of the conventional case, the efficiency of the casting operation is improved.

Since the chill money used in the past is not required, the number of defective products is drastically reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing an embodiment according to the casting cooling method of the present invention, FIG. 2 is a cross-sectional view of an essential part showing a casting cooling method in the case of performing open casting, and FIG. 3 is a cooling of the present embodiment. FIG. 4 is an explanatory view showing a main part of a pipe member, FIG. 4 is an explanatory view showing a casting cast by the cooling method of the present invention, FIG. 5 is a cross-sectional view of a main part for explaining a conventional casting cooling method, and FIG. FIG. 4 is an explanatory view showing a casting cast by a conventional cooling method. (1) …… Mold (2) …… Cooling pipe member (2a) …… Spout pipe, (2b) …… Cooling pipe (2c) …… Spout hole, (2d) …… Supply port (3) …… Supply means, (4) ... Suction means (6) ... Temperature sensor

Claims (1)

[Claims] 1. A casting mold (1) is made from foundry sand or the like, a cooling pipe member (2) is embedded in the casting mold (1), and a cooling medium is circulated in the cooling pipe member (2). In the casting cooling method, the molten metal is solidified while being cooled under any cooling condition as described below. B) The cooling pipe member (2) has a large number of ejection pipes (2a) standing up in the mold (1) having ejection holes (2c) on the tip side, and the ejection pipes (2a). 2a) comprises a cooling pipe (2b) connected so as to communicate with the rear end side, and the cooling pipe member (2) supplies a cooling gas body such as air or nitrogen gas therein. And a suction means (4) having a suction amount larger than the supply amount of the cooling gas body from the supply means (3) is provided below the mold (1). A temperature sensor (6) for detecting the temperature in the mold (1) was embedded and preset. B) First, at the same time as pouring metal hot water into the mold (1), the suction means (4) is operated, and by the supply means (3), a cooling gas body is discharged from the cooling pipe (2b) to the jet pipe (2). 2a) and the ejection hole (2
From c), the water was continuously jetted directly between the molding sands in the mold (1) to absorb the temperature of the molten metal with the cooling gas body to cool it. C) The cooling gas body that has absorbed the temperature of the metal hot water has passed through the space between the molding sands and has been continuously discharged to the outside of the mold (1) by the suction means (4). D) The temperature inside the mold (1) is controlled by the temperature sensor (6).
And the amount of the cooling gas body supplied by the supply means (3) is adjusted based on the detection by the solid state, and the solidified metal is solidified while being cooled under the optimum cooling conditions.