JPS59153566A - Casting mold for vacuum casting and mounting method thereof - Google Patents

Abstract

PURPOSE:To mount easily a casting mold which can produce a thin-walled casting good dimensional accuracy without generating gas holes by providing a groove part and a notch above the same on the side face of a sand mold opened with runner from the cavity formed of top and bottom molds toward the lower side. CONSTITUTION:A top mold having a cavity and bottom mold 3 penetrated with a runner from the cavity to the lower part are combined and stuck to form a casting mold 5 which is a sand mold. A flask 6 for mounting the casting mold is cylindrical and is provided with a pawl 7 in the lower part on the inside of the lower opening thereof. An elastic material 7a is fixed below the pawl. A suspended pipe 8 is attached to the upper part of the flask 6 and, an evacuating port 9 for venting air is provided to said part. A groove part 3a is provided on the side face of the mold 3 and a notch 3b is provided on the projection above the same. The pawl 7 of the mold 5 is first passed in the notch 3b under the flask 6 and the mold 5 or the flask 6 is rotated along the groove part 3a. Then, the pawl fits into the groove part 3a to stop the rotation and the mold 5 is held by the flask 6 and is sealed by the elastic material 7a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a casting mold used for pressure reduction and a method for installing the same.

Conventionally, in the casting method using a sand mold or a stack mold, the sand mold is made by molding and is held down by a formwork from the top and sides, and the metal is poured from the top sprue.

Also, in shell stack molds, there was a presser from the top, even if there was no side presser, and the metal was poured from the sprue in the same way. Moreover, since it is a cast product, a riser is also required to remove gas generated from the sand mold and shell, and the proportion of these parts is high compared to the runner and riser and the cast product, and the yield is low. It is something.

An alternative method is low-pressure casting, but since the mold is made of metal, it is cold and cannot be used for casting unless the mold is preheated. Thin parts are not filled. In addition, since the mold is a metal mold, it has good airtightness, but since the gas in the cavity of the mold is not removed, there are many problems such as gas defects easily occurring in the product due to the entrainment of this gas.

The present invention eliminates these drawbacks, and provides a simple mold installation method for the vacuum casting method that eliminates the occurrence of gas defects and allows the production of thin-walled castings with good dimensional accuracy. The purpose is to provide the following.

The present invention is a sand mold in which an upper mold and a lower mold form a cavity and a runner is opened below the cavity. After passing the pawl portion through the notch, the mold is rotated while the pawl portion is aligned with the groove portion on the side of the mold, so that the mold can be attached neatly and easily.

Embodiments of the present invention will be partially explained below with reference to the drawings.
The figure is a cross-sectional view of the upper and lower molds, Figure 2 is a cross-sectional view of the combined mold mounting frame of the upper and lower molds, Figure 3 is a diagram of the state during casting, and Figure 4 is a part of the lower mold. In the enlarged view, (a) is a cross-sectional view at 1, (b) is a plan view.

In the figure, 1 is the upper mold, 2 is the cavity, 3 is the lower mold, and 38 is the side face runner 4 penetrating from the cavity to the lower part.
These are combined and covered with the mold 5.

Reference numeral 6 denotes a mold mounting frame, which is cylindrical in shape and has an opening at the bottom, and a claw portion 7 is provided at the inner bottom of the frame.

Further, an elastic material 7a is fixed below the claw portion 7.

A suspended vibrator 8 is attached to the upper part of the mold mounting frame 6, and there is a decompression port 9 for air release, and a vacuum pump (not shown).
It is connected to the.

In such a configuration, first the upper mold and the lower mold are formed with the necessary cavities 2 and sprues 4, respectively, and then the upper mold and the lower mold are glued together with an adhesive, or unevenness, fitting holes, or protrusions are formed. The mold 5 is fixed by positioning and seams etc., and a predetermined mold 5 is obtained. The mold shall be a sand mold with air passage. Further, the lower mold 3 may be made of semi-permanent mold instead of being made of sand every time. Place the completed mold 5 under the mold mounting frame 6, first by passing the claw 7 through the notch 3b on the side of the lower mold, and then rotating the mold 5 along the groove 3a or by rotating the mold mounting frame. The inner claw part 7 fits into the groove and rotation is stopped, and the mold 5 is held in the mold mounting frame 6. The rotation of the claw portion 7 may be such that the claw portion 7 is no longer visible from the notch 3b. Further, an elastic vJ7a is used at the lower end of the claw portion 7 to seal the side surface of the downward protrusion of the vortex portion 3a of the lower die in order to reduce the pressure in the void portion 10 within the frame 6. Next, the mold 5 of the mold mounting frame 6 is rotated by the rotation of the vacuum pump.
When the cavity 10 between the mold 5 and the runner 4 gradually becomes vacuum, the mold 5 is placed on a crucible or melting furnace (not shown) filled with molten metal 11. (
Move the mold mounting frame 6 and immerse the runner 4 to pour the molten metal 1.
1 into the cavity.

The mold mounting frame 6 is attached to the mold mounting frame 6 by using the side surface of the mold. As shown in FIG. stomach·"
It is possible to narrow the gap 10 within the frame and shorten the cycle time.

In the drawings and explanations of application A, the sand mold is also provided with unevenness on the side surface of the mold due to the elevation of the frame l\ (by doing so, the installation to the frame can be carried out smoothly and the collapse of the mold can be avoided. It is possible.

As explained above, by providing unevenness in advance on the mold side surface of the mold of the present invention, and by rotating the claw part along the groove part during installation, the installation to the mold flask can be carried out smoothly. This has the effect of being able to improve immediate vacuum performance at the same time.

[Brief explanation of drawings]

Figure 1 is a sectional view of the upper and lower molds, Figure 2 is a sectional view of the combination of molds and the mold mounting frame, Figure 3 is a diagram of the state during casting after mold removal (=l), and Figure 4 is a diagram of the other molds. It is a sectional view of an example. 5: Mold, 6: Mold mounting frame, 7: Claw part

Claims (1)

[Claims] 1. A mold consisting of a sand mold in which a cavity is formed by an upper mold and a lower mold, and a runner is opened in the lower blade of the cavity, and a groove part on the side surface of the mold and a protrusion above the vortex part. A mold for vacuum casting characterized by having a notch. 2. Claim 1, wherein the lower mold of the mold is a metal mold.
Method for removing a mold for vacuum casting described in Section 1. 3. After passing the claws on the inside of the mold mounting frame through the notches on the side of the mold, rotate the mold while inserting the claws into the grooves on the side of the mold to easily attach the mold to the mold mounting frame. A method for removing a mold for vacuum casting, which is characterized by: