JPH0292434A - Feeder casting method - Google Patents

Abstract

PURPOSE:To make crystal grains finely and to obtain a casting having high strength and toughness by pouring molten metal into lost foam pattern in a molding flask, filling up part corresponding to the lost foam pattern with the molten metal and continuously applying vibration to the molding flask just after completing the pouring of molten metal till the solidification completes. CONSTITUTION:The lost foam pattern 2 for product and the lost foam pattern 3 for gate part are set at the prescribed position in the molding flask 4, and backup material 5 is packed around the lost foam patterns 2, 3. The molten metal 8 is poured from top sprue cup 7 by the quantity corresponding to the quantity of the product and the parts of the lost foam patterns 2, 3 for the product and the gate part are perfectly filled up with the molten metal 8. At the same time, by driving the vibrating table 6 just after completing the pouring of molten metal 8, the vibration under the prescribed condition is started to apply to the whole molding flask 4 toward the arrow direction, and continuously executed till the molten metal 8 filled up into the part of the lost foam pattern 2 for the product perfectly solidifies. By this method, the crystal grains are made to fine and the casting having high strength and toughness can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a riser casting method, and more particularly to a riser casting method using a vanishing model.

b. Conventional Technology In casting methods using vanishing models, non-caking dry sand is usually used as a back-up material for the model. However, the thermal conductivity of sand is poorer than that of molds such as Guicast, so the cooling rate of the casting is slow, and the metal structure and weave of the manufactured casting become coarse, which is disadvantageous in terms of strength, toughness, etc. Therefore, a casting method using iron particles as a backup material has been proposed. In this casting method, a vanishing model 52 is placed in a casting flask 51 as shown in FIG.
The molten metal is poured while fixing the iron grains 53 by the electromagnetic force generated in step 4. Since the iron grains 53 have better thermal conductivity than sand, a casting with a fine metal structure equivalent to mold casting can be obtained.

Problems to be Solved by the C0 Invention However, in the conventional casting method described above, iron particles 53, which have a higher specific gravity than sand, are used, so ancillary equipment for transporting the heavier mold is required. At the same time, an electromagnetic force generating device 54 for fixing the iron grains 53 becomes indispensable, which has the disadvantage of increasing equipment costs. In addition, the weight of the resin-made vanishing model 5 and the iron particles 53 caused deformation and breakage, and as a result, there was a risk that a cast product with an appropriate shape could not be obtained.

On the other hand, in the normal casting method using the disappearing model 52, as shown in FIG.
In order to sufficiently fill the vanishing model 52 with 5 to the smallest detail, the flask 51 is placed on a vibrating table 56, and the entire flask 51 is vibrated in this state.

The present invention has been made in view of these circumstances, and its purpose is to provide a riser casting method that can eliminate the above-mentioned drawbacks.

d. Means for Solving the Problems In order to solve the problems of the prior art described above, in the present invention, a vanishing model is placed in a casting flask, and a non-caking backup material is provided around the vanishing model. is poured into the mold, and then molten metal is poured into the vanishing model to completely fill the part corresponding to the vanishing model with the molten metal, while the flask is vibrated from immediately after the pouring of the molten metal is completed until the end of solidification. are added continuously.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

Figures 1 and 2 show an embodiment of the feeder casting method according to the present invention. In the figures, 1 is a casting that will become a product, and 2 is a disappearing model for the product formed in almost the same shape as the casting 1. A base disappearing model 3 made of the same material is integrally joined to the upper part of this product disappearing model 2. These vanishing models 2.3 are arranged in a casting flask 4 so that the base vanishing model 3 is located above the product vanishing model 2, and a non-caking backup is provided around it. A material (normal non-caking sand) 5 is placed in the mold. Note that 6 is a vibration table that is driven by a drive device (not shown) to vibrate the cast flask 4 placed thereon, and 7 is a sprue cup that is installed on the top surface of the backup material 5 that has been molded. It is arranged so as to surround the upper part of the vanishing model 3.

The feeder casting method for the above casting I is as follows.

First, the vanishing model 2 for the product and the vanishing model 3 for the base are placed in the casting flask 4.
These disappearing models 2.3
The backup material 5 is molded around the . To insert the backup material 5 into the mold, place the flask 4 on the vibration table 6,
This is done by vibrating the entire flask 4 on the vibration table 6 in this state. Then, a sprue cup 7 is installed on the upper surface of the backup material 5 located above the disappearing model 3 for the base, and the casting flask 4 is placed on the vibrating table 6.

Next, an amount of molten metal 8 approximately equivalent to the volume of the product is poured over from the sprue cup 7 to completely fill the parts of the vanishing model 2 for the product and the vanishing model 3 for the base with the molten metal 8. At the same time, as shown in FIG. 2, immediately after the pouring of the molten metal 8 is completed, the vibration table 6 is driven to begin applying vibrations under predetermined conditions to the entire flask 4 in the direction of the arrow. The vibration conditions at this time include, for example, in the case of At-4.5% Cu alloy, the frequency is 60 to 150.
The vibration frequency is preferably 0 Hz and the amplitude is in the range of 70 to 250 μm, and the flask 4 is vibrated continuously until the molten metal 8 filled in the vanishable product model 2 is completely solidified. In addition,
If the vibration is applied before the molten metal 8 fills the disappearing product model 2 and the base disappearing model 3, there is a risk that the casting 1 will collapse.

According to the feeder casting method of the above embodiment, since the flask 4 is vibrated on the vibration table 6 from immediately after the completion of pouring the molten metal 8 until the end of solidification, the average of the casting l under the above-mentioned vibration conditions is The crystal grain size is about 273 to 1/10 when no vibration is applied. Moreover, since the vibrating table 6 for filling the backup material 5 is used as the vibration device for the flask 4, no special device is required.

Although one embodiment of the present invention has been described above, the present invention is not limited to the embodiment described above, and various modifications and changes can be made based on the technical idea of the present invention.

For example, in the previously described embodiment, the flask 4 was placed on the vibrating table 6 for filling the backup material 5 and the molten metal 8 was poured. Of course, the casting flask 4 may be vibrated by pouring the metal on a vibrator.

e. Effects of the Invention As mentioned above, the riser casting method according to the present invention is characterized by pouring molten metal into the disappearing model in the flask, completely filling the part corresponding to the disappearing model with the molten metal, and pouring the molten metal into the disappearing model in the flask. Since we continued to apply vibration to the flask from immediately after the pouring was completed until the end of solidification, the vibration energy increased the frequency of nucleation during solidification, resulting in finer grains and a casting with high strength and toughness. It will be done. Furthermore, in the casting method of the present invention, a backup material made of ordinary non-caking sand can be used.
It is economically advantageous because the product cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a casting manufactured by a riser casting method according to an embodiment of the present invention, FIG. 2 is a conceptual cross-sectional view showing the state in which the casting is manufactured, and FIG. 3 is a conventional FIG. 4 is a conceptual cross-sectional view showing a state in which a casting is manufactured by the casting method of FIG. 5... Backup material, 6... Vibration table,
7... Sprue cup, 8... Molten metal. Suzuki Automobile Industry Co., Ltd. (and 2 others) 1...Casting, 2...Disappearance model for products,
3... Vanishing model for the base, 4... Casting flask, Fig. 1 Fig. 3 Fig. 2 Fig. 4

Claims (1)

[Claims] A vanishing model is placed in a casting flask, and a non-caking backup material is molded around the vanishing model, and then molten metal is poured into the vanishing model so that the portion corresponding to the vanishing model becomes molten metal. 1. A feeder casting method characterized in that, while the molten metal is completely filled, vibration is continuously applied to the flask from immediately after the completion of pouring the molten metal until the end of solidification.