JPH08132221A - Method for removing core - Google Patents

Abstract

PURPOSE: To perfectly remove the core sand even if the time of chipping treatment is short by executing the sand removal in the core with shot blast using the sand after executing the chipping treatment applying vibration to a casting. CONSTITUTION: In the core sand removal separating and removing the core sand in an intake manifold cast product W, after executing the chipping treatment applying the vibration to the cast product W with a chipping hammer P, the shot blast is executed through nozzles N by using the sand as an injecting material. By this method, the core sand is perfectly removed even from the bending hole 1 and the casting flash is effectively removed, too. Since the chipping can be good in such short time as about 3-10sec, the load of the worker is light, and since the injecting material uses the sand, the treatment without damaging to the casting surface can be executed in the low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core dropping method for casting a cast product using a sand core and then separating and removing the core.

[0002]

2. Description of the Related Art Conventionally, for example, when a cast product having a cavity having a complicated shape in which the internal shape of an intake manifold or a cylinder head is severely bent is cast from an aluminum alloy product using a core, , After casting,
Core dropping is performed in which a core is disintegrated by a chipping process in which vibration is applied to a cast product to separate and remove core sand.

[0003]

However, in the above-mentioned conventional core dropping method, the chipping processing time is 1
It takes about 2 minutes for each piece, and the impact noise due to the chipping hammer is severe, which causes an excessive burden on the worker.

[0004] In the chipping process, a piece of shell (shell shell pieces obtained by breaking the core) may remain in the bent hole without being finely collapsed. In this case, the worker inserts the rod into the hole. Since it is designed to be destroyed with, there is a drawback that it takes time and effort to drop the core.

On the other hand, on the casting surface in contact with the core, the casting and the sand may react with each other to cause sand particles to bite into the casting surface. In the case of, there was a risk that the surface would not be smooth due to the sand of the index.

Therefore, the present invention has been made in order to solve the above-mentioned drawbacks, and an object thereof is to provide a core dropping method capable of completely removing core sand while shortening the chipping treatment time. It is in.

[0007]

In order to achieve the above object, a core removing method according to the present invention is a core removing method for separating and removing core sand from a cast product, wherein vibration is applied to the cast product. After the chipping treatment, shot blasting treatment is performed on the core sand. The chipping processing time is 3 to 10 seconds. The shot blasting shot material is sand. Further, the cast product is a manifold.

[0008]

In the above structure, when the casting product is subjected to a chipping treatment in which vibration is applied for a very short time of 10 seconds or less, the core is separated from the casting, and then the core sand is subjected to the shot blasting treatment. The core sand is discharged from the product and the core sand is removed from the casting surface.

[0009]

Embodiments of the present invention will be described below. FIG. 1 is a front view of an experimental apparatus for carrying out the method of one embodiment, where N is a shot blast nozzle and P is a chipping hammer.

A casting product W (workpiece in Table 1 below) used in the experimental apparatus is provided with bent holes 1, 1 ... Shown by chain lines in an intake manifold made of aluminum alloy. These holes 1, 1 ... Are formed by hollow shell cores.

The experimental conditions are as follows, and the results of the experiment are shown in Table 1. Experimental conditions Shot blasting; Shinto Blator Co., Ltd. MYBLAST
MY-30 Kai Projection; pressurized (air pressure 5 kg / cm ²⁾ shot media; diameter of arc height values 0.08mmA nozzle N;; Ensyu Mikawa sand projection distance; position projected force away 50mm from the hole 1 diameter: 6 mm Chipping hammer (Aa-3SP manufactured by Nippon Pneumatic Mfg. Co., Ltd.) Air pressure; 5 kg / cm @ 2 Chipping method; A part of the cast product W (in the example shown, the feeder section W ') is contacted with a chipping hammer (see FIG. 1). )

[Table 1]

As is clear from the above table, 100% of core sand can be removed by performing shot blasting after chipping for 5 seconds.

In Table 1, the chipping treatment time is 5 seconds, but the chipping treatment according to the present embodiment does not require the core to be completely collapsed as in the conventional chipping treatment, and the inside of the hole 1 does not have to be collapsed. A chipping treatment time of about 3 seconds is sufficient because it is enough to cause the child to crack and peel off at least, and there is no problem if safety is 10 seconds or less in view of safety.

Although sand is used as the shot material, steel balls may be used. However, when steel balls are used, the scale can be removed as in the case of using sand, but sand is preferable because it leaves streaky marks on the casting surface. Is preferred.

In the above-mentioned embodiment, the intake manifold made of aluminum alloy is used as the cast product W, but other materials may be used. Further, the cylinder head may be used instead of the intake manifold, and other cast products may be used. However, the application effect of the present invention is remarkable in the case of a cast product having a bent hole like an intake manifold.

[0016]

According to the core dropping method of the present invention, the shot sand blasting treatment is performed on the core sand after the chipping treatment in which vibration is applied to the casting product. Not only can be completely removed, but also the index can be effectively removed. Moreover, since the chipping treatment time is 3 to 10 seconds, the burden on the worker can be reduced. Furthermore, when the shot blasting shot material is sand, it is inexpensive and does not damage the casting surface. Further, when the cast product is used as a manifold, the core sand can be effectively removed from the bent hole.

[Brief description of drawings]

FIG. 1 is a front view of an experimental device for carrying out an embodiment method of the present invention.

[Explanation of symbols]

 1 hole P Chipping hammer W Cast product (intake manifold) N Nozzle

Claims (4)

[Claims] 1. A core dropping method for separating and removing core sand from a cast product, wherein a shot blasting process is performed on the core sand after a chipping process in which vibration is applied to the cast product. How to drop a child. 2. The core dropping method according to claim 1, wherein the chipping processing time is 3 to 10 seconds. 3. The core dropping method according to claim 1, wherein the shot blasting shot material is sand. 4. The core dropping method according to claim 1, wherein the cast product is a manifold.