JPS60152343A - Casting mold - Google Patents

Abstract

PURPOSE:To abolish the operation of closing through-holes prior to casting and to simplify the operation by providing a space in the place for escaping wax by using a suitable material. CONSTITUTION:A wax pattern is prepared and the wax surface thereof is coated by a mold coating material to produce a casting mold. Semicircular paper is embedded in the wax mold in this case to provide a space 4. The wax expands and fills the space 4 in the case of heating the mold by using steam in an autoclave and discharging the wax from the inside of the mold and therefore the pressure exerted on the casting mold is correspondingly decreased. The mold is calcined at a prescribed temp. and the paper burns in this stage. No problems arise in the stage of pouring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention is applied to the manufacture of precision cast products by completely manufacturing molds by the cost wax method.

[Background of the invention]

Conventionally, when pouring wax out of a mold, the wax material is selected and the casting method is considered to prevent the wax from expanding and causing cracks in the mold, and through holes are generally installed in the mold. It is true.

In this case, in order to prevent the molten metal from flowing out of the mold during pouring, it is customary to close all through holes before pouring.

In this case, the problem is that the casting is defective due to the plugging operation or forgetting to blow it.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned through holes and completely eliminate the work of blocking the through holes before casting, thereby simplifying the work. For this reason, the object of the present invention is to create a complete mold in which all expansion escape areas are provided at appropriate locations during wax assembly, and in addition, there are no parts that penetrate the outside air as a mold.

[Summary of the invention]

In order to achieve the above, a suitable material is used to create a space in the area where the wrinkles are allowed to expand and escape. In this case, the material is a problem, so why not use something like paper, which burns in the open mold firing afterward, and also leaves little residue? It is necessary to select.

[Embodiments of the invention]

Examples are shown for all automotive turbochargers. This mold is the first. As shown in Figure 2, the sprue, the runner 2', the weir 5,
Product 1 is composed of p. First, a wax model is made in the shape shown in the figure, and then the wax surface is completely coated with mold coating material to manufacture the entire mold. Next, the wax is heated in an autoclave using steam to completely flush out the wax in the mold.

At this time, the wax may expand and crack the mold.

To prevent this, a space 4 is provided by filling a semicircular piece of paper into the wax model and making a groove. During dewaxing, the wax expands to fill the space, which reduces the pressure on the mold. The mold is then fired at about 1100C, but the paper is burned off and no problems occur during pouring. According to this method, there is no need to worry about plugging holes during the diameter process.

〔Effect of the invention〕

According to this method, the work of completely closing the hole in the diameter process can be omitted, and at the same time, when closing the hole, there is a possibility that some sand may get mixed into the mold and cause sand stains on the product, but this can be completely eliminated. . This eliminates the possibility of hot water leaking due to forgetting to cover the reeds.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the @-type, and FIG. 2 is a cross-sectional view. 1...product, 2...runner, dam...weir. N ) 14' Zu 4

Claims (1)

[Claims] 1. To prevent the mold from cracking due to the expansion of wax during dewaxing, create a space in an appropriate place. This space should not be connected to the outside air, and should be used before pouring the molten metal into the mold in the subsequent process. A mold that is designed so that it does not need to be plugged.