Metal founding – Process – Shaping liquid metal against a forming surface
Patent
1983-12-13
1985-02-05
Lin, Kuang Y.
Metal founding
Process
Shaping liquid metal against a forming surface
164315, B22D 1802
Patent
active
044973594
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to die-casting and, more particularly, to a die-casting method employing apparatus having a runner through which a molten metal is injected into a die cavity for die-casting an article, a squeeze passage communicating with the die cavity at a portion other than the portion where the runner communicates with the die cavity, and a squeeze plunger snugly and slidably disposed in the squeeze passage, the squeeze plunger being adapted to forcibly displace the molten metal from the squeeze passage back to the die cavity to effect a squeeze on the molten metal in the die cavity.
BACKGROUND ART
Japanese Laid-open Patent Publication No. 51-129817 (129817/76) discloses a die-casting apparatus similar to one having a squeeze passage communicating with a die cavity at a portion of the latter other than the portion where the die cavity communicates with a runner, and a squeeze plunger snugly and slidably disposed in the squeeze passage, the squeeze plunger being adapted to be moved, before the runner is closed, to forcibly displace the molten metal from the squeeze passage back to the die cavity to effect a squeeze on the molten metal in the die cavity. Such a die-casting apparatus as referred to above has not been practically used. In fact, Japanese Laid-open Patent Publication No. 51-129817 merely discloses the provision of the squeeze passage and the squeeze plunger and does not suggest at all various practical factors such as the relationship between the cross-sectional area and axial length of the squeeze passage.
DISCLOSURE OF THE INVENTION
With a die-casting apparatus having a squeeze passage communicating with the die cavity at a portion of the latter other than the portion in communication with the runner, and a squeeze plunger snugly and slidably displaced in the squeeze passage, the present inventors have attempted to obtain a good die-cast article by starting the squeeze by the squeeze plunger before the runner is closed by solidification of the metal therein, but failed to obtain a successful result.
The present inventors then made various studies and researches so as to clarify the reason and cause of the failure and reached a conclusion that the die-casting is largely affected by the relationship between the cross-sectional area of the squeeze passage and the stroke or travel of the squeeze sleeve.
In designing a die-cast apparatus having a squeeze passage provided at a location other than the location of the runner, it has been a general tendency that the squeeze passage is designed to have as small cross-sectional area as possible from various points of views such as reduction of the size of the squeezing device and so forth. With a small cross-sectional area of the squeeze passage, however, the squeeze plunger is required to have a sufficiently large stroke or travel to displace the required amount of molten metal back to the die cavity.
The present inventors have prepared a number of die-casting apparatus with a variety of the relations between the cross-sectional areas of the squeeze passages and the strokes or travels of the squeeze plungers and conducted a test with these die-casting apparatus. As a result of the test, it has been discovered that, in order to obtain a satisfactory die-casting, it is essential that the cross-sectional area of the squeeze passage is not smaller than 0.35 times the square of length of the squeeze plunger passage. The present invention is based upon the above-stated discovery.
Namely, according to the invention, there is provided a die-casting method using apparatus comprising a die cavity defined by the cooperation of a fixed die and a movable die for die-casting an article; a runner being open at its one end to the die cavity and adapted to introduce the molten metal into the die cavity; a squeeze passage communicating with the die cavity at a portion of the latter other than the portion at which the runner is open to the die cavity, the squeeze passage having a uniform cross-sectional area over its entire length;
REFERENCES:
patent: 3106002 (1963-10-01), Bauer
Hashimoto Shigeyoshi
Suzuki Haruo
Lin Kuang Y.
Nippondenso Co. Ltd.
LandOfFree
Die-casting method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Die-casting method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Die-casting method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2079059