JPS6359784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a vertical casting machine in which the molten metal in the lower sleeve is filled into the cavity with the lower plunger. The present invention relates to a molten metal filling method that prevents impurities from entering the cavity and obtains a high-quality cast product free of casting defects.

The filling method, in which molten metal is stored in a sleeve below the cavity and filled into the cavity by the upward movement of a lower plunger, does not apply pressure to the molten metal.
It is possible to fill the molten metal quietly and smoothly, and the quality of the cast product can be improved.

By the way, in this molten metal filling method, the fourth
As shown in the figure, the molten metal M is stored on a plunger 51 fitted in the lower part of the sleeve 50, and the plunger 51 is moved upward to fill the molten metal into a cavity (not shown). On the surface in contact with 50, there is a thin shell-like early solidified film _M1
is generated, and impurities M ₂ such as oxides and mixed foreign substances float on the upper surface of the molten metal M. When the plunger 51 is moved upward to fill the cavity with molten metal, such impurities may enter the cavity together with the molten metal, causing casting defects such as deterioration of the external quality, internal quality, strength, etc. of the cast product. There is.

The present inventors have devised the present invention in order to improve the above-mentioned inconveniences in filling molten metal in this type of casting machine. A control valve is provided, and the amount of opening of the control valve is adjusted to suppress the outflow of floating impurities on the upper surface of the molten metal, and to fill the cavity with as clean a molten metal as possible with minimal outflow of the outer shell. The object of the present invention is to provide a method for filling a vertical casting machine with molten metal, which makes it possible to obtain cast products of good quality that do not contain molten metal.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an enlarged vertical cross-sectional view of the molten metal reservoir of a vertical casting machine 1 as an example of implementing the present invention.
consists of an upper mold 2 and a lower mold 3, and a product cavity (not shown) is formed on the mold matching surfaces 2a, 3a of the upper and lower molds 2, 3 in a mated state. A molten metal storage sleeve 4 for injection is installed vertically in a part of the lower mold 3, an upper part 7a of the sleeve 4 extends above the mold mating surface 2a of the upper mold 2, and a ceiling is provided above the sleeve 4 of the upper mold 2. A closed space 5 is formed. A space 5 is formed above the injection sleeve 4 so as to communicate with the inside thereof, and a tip 6a of the pouring sleeve 6 faces on one side above the injection sleeve 4 on the outside of the space 5.
The pouring sleeve 6 extends outward from the upper die 2, and a portion of the extending portion of the pouring sleeve 6 is provided with a pouring port 7, and a plunger 8 is slidably fitted into the pouring sleeve 6. equipped.

A portion of the space 5 on the opposite side of the sleeve 6 extends 9 toward the inside of the upper mold, and the extending portion 9 communicates with the product cavity via a runner 10. A control valve 11, which is a partitioning member, is installed vertically in the boundary part A between the space part 5 and the extension part 9, and the control valve 11 passes vertically through the upper die 2 and faces the boundary part A.
The control valve 11 is driven up and down by a cylinder unit 12 disposed on the upper mold 2, and the control valve 11 has a tapered tip 11a and an end edge 4b facing the boundary A of the sleeve 4.
to face. An injection plunger 13 is fitted into the molten metal storage sleeve 4 so as to be movable up and down.

Next, the function and effect will be explained in detail. The injection plunger 13 is located at the lower limit within the sleeve 4, the plunger 8 is at the retreated position within the pouring sleeve 6, and the pouring port 7 is open. The molten metal M is injected into the sleeve 6 from the pouring port 7, and the molten metal M flows into the sleeve 4 on the plunger 13 and is stored therein. This state is shown in FIG. 1, where a solidified portion _M1 is formed in the portion of the molten metal M that contacts the upper surface of the plunger 13, and a thin shell-like solidified film _M2 is formed in the portion that contacts the inner surface of the sleeve 4.
Furthermore, light impurities M ₃ such as oxides, mixed foreign matter, early solidification components, and sleeve lubricant gather and float on the upper surface of the molten metal M.

After storing the molten metal M, the plunger 8 is advanced, the pouring port 7 is closed, the cylinder unit 12 is driven, the control valve 11 is moved downward, and its tip 11a abuts against the edge 4a of the sleeve 4. Close boundary A. Thus, the space 5 is defined by the valve 11 and the plunger 8, and the space 5 above the sleeve 4 is defined by the extension 9 and the runner 10. In this state, the plunger 13 is moved upward, and the molten metal M in the sleeve 4 rises, and the impurities M ₃
is in contact with the ceiling 5a of the space 5, and a portion of the coagulated film _M2 is in contact with the inside of the control valve 11. This state is shown in FIG.

Next, the control valve 11 is raised to a predetermined height, and its tip 11a and the upper end 4b of the sleeve 4 are
A small opening B is formed at the boundary A between the two and the plunger 13 continues to rise. As the molten metal M rises, the solidified film at the opening B is torn, and the molten metal M moves from this part to the cavity via the extension part 9 and the runner 10 and is filled. Molten metal M is plunger 13
Since the molten metal M is supplied from the opening B to the runner 10 with the rise of the molten metal M, the molten metal M is filled in a moving state and is quietly and smoothly filled into the cavity. During this filling, floating impurities M ₃ on the upper part of the molten metal M are held at the lower part of the control valve 11 forming the upper wall of the opening B, and do not flow out into the extension part 9, especially when the plunger 1
3, the control valve 11 is held in that position by pressure from below, and the control valve 11 functions as a dam. Therefore, the impurity M ₃ will not be mixed into the filled molten metal.

The solidified film _M2 of the molten metal is destroyed at the portion facing the opening B, and the molten metal containing the destroyed part of the solidified film _M4 is supplied and filled into the cavity via the extension part 9 and the runner 10, As the molten metal M continues to rise, a solidified film forms.
M ₂ hits the ceiling and breaks, depositing under the impurities, and only a part of the solidified film is included in the molten metal M filled.

In this way, only clean molten metal is supplied and filled into the cavity.

In the above, the opening amount of the opening B by the control valve 11 is appropriately selected depending on the product and casting conditions.

As is clear from the above, according to the present invention, the control valve functions as a weir for impurities floating on the upper surface of the molten metal to be retained in the space above the storage sleeve, preventing them from entering or flowing into the cavity. Because only the coagulated film is mixed in, clean molten metal is supplied without impurities such as oxides, and the cast product is of high quality with no defects in both appearance and interior, and there are no impurities that cause strength reduction. , pressure resistance,
It is possible to obtain high-quality cast products that require high strength. In addition, the above can be planned by simply attaching a control valve that moves up and down, and it has a simple structure, and the opening amount can be adjusted as desired, supplying clean molten metal according to the casting conditions and the cast product. It has many advantages such as:

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and Figs. 1 to 3 are longitudinal sectional views of the main parts of the casting machine, showing the molten metal injection and filling operation in the order of steps, and Fig. 4 is a similar diagram of the conventional example. This is a diagram. In the drawings, 4 is a sleeve, 5 is an upper part, 9 and 10 are runner communication parts, and 11 is a valve means.

Claims (1)

[Claims] 1. In a vertical casting machine in which the molten metal in the molten metal storage sleeve provided below the product cavity is pushed upward by the upward movement of the lower plunger and moved to fill the cavity, the space above the sleeve is filled with molten metal. A valve means is provided to communicate with the cavity via a passageway communication part, and to open and close the communication part, and the valve means is closed prior to filling the cavity with molten metal, and then, by upward movement of the plunger, impurities on the upper surface of the molten metal are removed. A method for filling molten metal in a vertical casting machine, in which the communication portion is opened by a predetermined amount from below when reaching near the top of a space, and molten metal is filled into a cavity.