JPH0243577B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous precision casting method using an investment precision casting method using a disappearing model (pattern) made of wax, water-soluble urea resin, or other plastic.

In the conventional investment precision casting method, each process of making a pattern (model), assembling the pattern, forming a shell mold, demolding, firing, and casting are performed independently, and the casting process is performed by moving for each process. goods were being produced. Moreover, in the above-mentioned process, forming the shell mold requires a drying process for each layer, which takes a long time, making it difficult to automate and continuousize the entire process, which poses problems in terms of economy and productivity.

The present invention was developed in view of these circumstances, and is based on the rapid shell molding method (Japanese Patent No. 613423,
A rapid continuous shell automatic molding machine based on the Shubtrad method is used to continuously mold shell molds, significantly shortening the time required. At the same time, by using an assembly pattern in which a pattern tree is attached to a vertical sprue, the above-mentioned Enabling automation and continuity of the molding process to the casting process, improving productivity and
The object of the present invention is to provide a continuous precision casting system that can greatly improve economic efficiency.

Embodiments of the present invention will be described below based on the drawings. FIG. 1 shows a layout diagram of the continuous precision casting method according to the present invention, in which 1 is a pattern assembly table, 2 is a pattern assembly table;
3 is a rapid continuous shell molding machine, 3 is a microwave demolding furnace, 4 is a firing furnace, 5 is a firing conveyor that moves inside the firing furnace 4, 6 is a reheating furnace, and 7 is a casting conveyor that moves inside the reheating furnace 6. , 8 is a rapid high-frequency melting furnace, 9 is a shaking conveyor, 10 is a turnplast, 11 is a finishing and inspection table, 12 to 14
is a handling robot.

First, on a pattern assembly table, as shown in FIGS. 2 to 4, a plurality of pattern trees 21 are placed in a ceramic sprue 20 formed in a vertically long tub shape.
Attach and assemble the pattern. The pattern tree 21 has a large number of patterns 2 on a sprue 22 made of urea resin or other plastic or a paper tube.
3 or by connecting a large number of assembly patterns 24 with sprue. In addition, the sprue 20 is configured to be vertically long so as to enable pouring by the rapid high-frequency melting furnace 8 without stopping the casting conveyor 7, and by adopting such a configuration, it is possible to attach a plurality of pattern trees 21. I have to.

Next, in order to facilitate handling in the rapid continuous shell molding machine 2 and increase the efficiency of molding work, the pattern assembly 2 assembled as described above is
5 is a mounting plate 26 equipped with a handle 27 as shown in FIG.
Attach several pieces in parallel. The group of pattern assemblies 25 thus attached is held by the handling robot 12, and the rapid continuous shell molding machine 2 repeats dipping and sanding a certain number of times to create a shell having a desired thickness. When the shell is completed, it is immediately loaded into the micro web demolding furnace 3 by the handling robot 13 and demolded.
The demolded shell is attached to the mounting plate 26 together with the sprue 20.
The mold is removed from the mold, placed on the firing conveyor 5, and fed into the firing furnace 4 to complete the shell mold. This shell mold is transferred to the casting conveyor 7 by the handling robot 14, heated in the reheating furnace 6, and then poured directly into the sprue 20 from the rapid high-frequency furnace 8 without stopping the casting conveyor 7, and placed on the conveyor. The shell is then poured into a moving shell mold.

After casting, the shell mold is transferred to a shaking conveyor 9 to destroy the shell, cleaned by a turn blast 10, and then transferred to a finishing inspection table 11 to complete the entire process.

The working speed (required time) of each step described above is set based on the molding time of a predetermined layer of shell formed by the rapid continuous shell molding machine 2.

That is, during the processing time of the shell in the demolding furnace 3, the shell is transported from the firing furnace 4 to the firing conveyor 5.
The carrying out time during which the shell is placed on the casting conveyor 7 and carried out and the pouring time during which the shell is placed on the casting conveyor 7 and passes in front of the rapid high frequency melting furnace 8 are controlled by a program so that they are the same as the molding time. , each of the above steps can be performed continuously.
By adopting the assembly pattern 25 in which the pattern tree 21 is attached to the vertically elongated sprue 20, metal can be poured from each rapid high-frequency melting furnace 8 into the sprue 20 of the shell mold that is placed on the casting conveyor 7 and is being moved. Can be cast.

Additionally, the entire process is automated under computer control.

EXAMPLE The time required to form a desired shell layer by the rapid continuous shell molding machine 2 varies depending on the number of shell layers. For example, when forming an 8-layer shell, the molding is completed in 8 minutes and 15 seconds. Based on this molding time, the mold removal processing time of the shell in the microwave demolding furnace 3 was set to 8 minutes and 15 seconds. Further, the speed of the firing conveyor was adjusted so that the shells were transported from the firing furnace 4 by the firing conveyor 5 for a time of 8 minutes and 15 seconds. Specifically, if the length of the firing furnace 4 is 15000mm, the conveyor speed should be set to 3.
mm/sec, and the residence time in the furnace was 83 minutes and 33 seconds. In the pouring line consisting of four rapid high-frequency melting furnaces 8, the time for the shell to be placed on the casting conveyor 7 and passing in front of each rapid high-frequency melting furnace 8 is 2 minutes, and the time between each melting furnace 8 is 2 minutes. The total pouring time for the shell, including transfer time, is 8 minutes.
The speed of casting conveyor 7 was adjusted so that the time was 15 seconds.

As described in detail above, according to the present invention, the time required to make a shell mold is significantly shortened by using a rapid continuous shell making machine, and the pattern tree can be assembled by attaching it to a vertical sprue without stopping the casting conveyor. Since it has become possible to pour metal while moving the shell mold, the entire process can be continuously automated, greatly improving productivity and saving labor. Furthermore, the system of the present invention has the advantage that it can be applied to a wide range of precision castings, from mass-produced products to small-volume products of a wide variety.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the arrangement of the continuous precision casting system according to the present invention, Fig. 2 is a partially vertical front view of the pattern assembly, Fig. 3 is a sectional view taken along line 3-3' in Fig. 2, and Fig. This figure is a plan view of the same, and FIG. 5 is a plan view of the handling robot mounting plate. 1...Pattern assembly table, 2...Rapid continuous shell molding machine, 3...Microwave demolding furnace, 4...
Firing furnace, 5... Firing conveyor, 6... Reheating furnace,
7... Casting conveyor, 8... Rapid high frequency melting furnace, 9... Shaking conveyor, 10... Turn blasting, 11... Finishing/inspection table, 12-1
4... Handling robot, 20... Sprue, 2
1...Pattern tree, 25...Pattern assembly, 26...Mounting plate.

Claims (1)

[Scope of Claims] 1. A pattern assembly step of attaching a pattern tree to a vertical sprue; A molding step of grasping the assembled pattern with a handling robot and continuously manufacturing shell molds with a rapid continuous shell molding machine; and the shell molds. There is a demolding process in which the mold is sent to a microwave demolding furnace using a handling robot, and a firing process in which the demolded shell mold is placed on a firing conveyor that moves through the firing furnace and fired continuously. While the shell mold is placed on a casting conveyor that moves inside the heating furnace and is continuously moved,
a casting step of pouring the metal through the vertically elongated sprue using a rapid melting furnace, and the processing time of the shell in the demolding step and the firing step based on the molding time of a predetermined layer of shells by the rapid continuous shell molding machine; The method is characterized in that the unloading time of the shell in the step and the pouring time for the shell in the casting step are each controlled by a program so as to be the same as the molding time, so that each of the steps can be performed continuously. Continuous precision manufacturing method.