JPH09164472A - Method for cooling cast product by sand mold casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling method of a cast product by a sand mold casting which improves the productivity by cooling in a short time without developing surface hardening of the cast product or product cracking and also, prevents the aggravation of working environment and unnecessitates a field for cooling the cast products. SOLUTION: The sand mold 1 completing the pouring of molten metal is carried to cooling pool line 2 and the cast product 4 is cooled to about 600 deg.C or lower and applied to a cast product taking-out device 3 to separate the cast product 4 and the molding sand 5. The cast product 4 is slowly cooled to about 400 deg.C or lower by natural cooling while shifting with a carrying conveyor 6. This slow cooled cast product 4 and the separated molding sand 5 are charged into a drum type mold cooler 7 to rapidly cool the cast product 4.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for cooling a cast product obtained by pouring molten metal into a sand mold.

[0002]

2. Description of the Related Art Among conventional castings obtained by pouring molten metal into a sand mold, there is no problem even if it is rapidly cooled. The castings are buried in the sand, and these are put into a drum type mold cooler to repeat the contact between the castings and the molding sand to rapidly cool the castings and take them out. On the other hand, if it is not preferable that the hardness of the surface of the cast product increases by quenching, or if the cast product causes product cracking by quenching, the molten sand solidifies in the sand mold and the sand mold collapses, casting The products are taken out, stacked in a casting product receiving box, and left to stand for natural cooling.

[0003]

As described above, in the case in which the cast product is slowly cooled in the form of being left unattended, it takes time to cool the cast product, resulting in poor productivity and a cast product receiving box. The area around is exposed to heat for a long time and dries, and dust is scattered around, which deteriorates the work environment. In addition, many castings must be kept in the factory for a long time, which requires a large space for cooling the castings. The present invention has been made in view of the above problems and is intended to improve productivity and prevent deterioration of working environment by cooling within a short time without causing surface hardening or product cracking of cast products and widening for cooling. The aim is to provide a space-free cooling method.

[0004]

As a result of repeating various tests in order to achieve the above-mentioned object, the inventor found that the temperature of the casting was 650 ° C. when the casting was taken out from the sand mold.
Based on the above, it was found that the cast product was in a red-hot state and was deformed due to impact during the removal work. When a high temperature casting is cooled to 100 ° C by stirring contact with the casting sand, the hardness of the surface of the casting increases as described above, and in some cases, product cracking occurs. As a result of a cooling test by stirring contact with sand,
It was confirmed that the surface of the cast product or the product cracking did not occur even if the cast product was rapidly cooled by contact with the molding sand at a temperature of 450 ° C. or lower.

According to the method for cooling a cast product by sand mold casting according to the present invention based on these confirmation tests, the sand mold after pouring the molten metal is put into a cooling pool line to bring the cast product to about 600 ° C. or lower. A step of cooling and solidifying, a step of taking out a casting product that has been cooled and solidifying to about 600 ° C. or less from a sand mold and separating it into a casting product and casting sand, and allowing the casting product to be naturally cooled while being transferred by a conveyor. And gradually cooling to about 400 ° C. or less, and a process of stirring and cooling the cast product cooled to about 400 ° C. or less and the separated molding sand to rapidly cool the cast product. To do.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to FIG. After pouring the molten metal, the pouring completed sand mold 1 is carried into the cooling pool line 2 and the cast product is cooled and solidified to a temperature of about 600 ° C. or less at which the casting can be handled. (The length of the cooling pool line 2 is adjusted in advance). Next, the sand mold in which the cast product is cooled to about 600 ° C. is transferred to a cast product take-out device 3 composed of a vibration type disassembling machine, a cast product take-out robot or the like and separated into a cast product 4 and a casting sand 5.

Next, the separated cast product 4 is gradually cooled in the form of natural cooling while moving to a conveyor 6 composed of a vibration conveyor, a walking beam conveyor or the like, and no defect occurs even if it is rapidly cooled. The temperature is set to 400 ° C. or lower (the length of the conveyor 6 is adjusted in advance). Further, the cast product cooled to a temperature of about 400 ° C. or lower is put into a drum type mold cooler 7 composed of a rotary drum or a vibrating drum together with the separated casting sand 5, and the cast product 4 is a low temperature cast product. By repeated stirring contact with sand 5, it is rapidly cooled to about 100 ° C. and taken out.

On the other hand, the foundry sand 5 charged into the drum type mold cooler 7 is crushed by stirring contact with the cast product, and the cast product is rapidly cooled and separated from the cast product 4 again. It is transferred to a post-treatment process such as the sand reclaimer 8. The cast product cooled in this way is about one-third the size of the conventional one that was left to stand naturally (which took about 4 hours).
It became clear that cooling was possible in about 90 minutes, and there were no casting defects due to cooling.

As is apparent from the above description, the present invention carries the molten metal casting sand mold into a cooling pool line, cools and solidifies the cast product until it reaches about 600 ° C. or lower, and then removes the cast product. It is separated into cast products and foundry sand by the equipment, and about 400 by natural cooling while transferring the cast products by a conveyor.
Since it was gradually cooled to below 0 ° C, the slowly cooled casting and the separated molding sand were put into a drum type mold cooler to rapidly cool the casting by agitating and contacting them. The cooling time can be greatly shortened without any defects in the cast product due to the rapid cooling, and the productivity can be improved. Further, since the cast product is not left in a fixed place for a long time in a high temperature state, there are various effects such as deterioration of the working environment and no need for a special place for cooling the cast product.

[Brief description of the drawings]

FIG. 1 is a flow chart showing an embodiment of the present invention.

[Explanation of reference signs] 1 sand mold for completion of pouring 2 cooling pool line 3 casting product take-out device 4 casting product 5 casting sand 6 transfer conveyor 7 drum type mold cooler

Claims (1)

[Claims] 1. A step of bringing the sand mold after pouring the molten metal into a cooling pool line to cool and solidify the cast product to about 600 ° C. or less, and a sand mold for the cast product cooled and solidified to about 600 ° C. or less. From the casting and separating it into castings and foundry sand;
A method for cooling a cast product by sand mold casting, comprising the step of rapidly cooling the cast product by agitating and contacting the cast product cooled below and the foundry sand.