JPH0647517A - Method for casting metal - Google Patents

Abstract

PURPOSE:To cast a fine product having high dimensional precision by directly pressurizing a sprue part after filling molten metal into a cavity with the gravity, thereby increasing pressurizing effect. CONSTITUTION:A sprue part 4 is formed at the mating face part 3 of a fixed die (a) and a movable die and a pressurizing piece 6 is provided at the position just below a gate part 1a in the die mating face part 3 in the cavity 1. At the time of pouring the molten metal (m) from a ladle 12 through the sprue part 4, the molten metal (m) is supplied and filled into the cavity 1 from the gate part 1a through a runner 5. Successively, by working a pressurizing cylinder 8, the pressurizing piece 6 is ascended to the gate part 1a in the cavity 1, and while closing the outlet 5a of the runner 5, the pressure is applied to the molten metal (m) and the molten metal is solidified. In this way, the fine product having higher dimensional precision is obtd., and the yield is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal casting method in which a molten metal is injected and filled into a cavity, and then pressure is applied to the molten metal for casting.

[0002]

2. Description of the Related Art In normal die casting, a molten metal supplied to an injection sleeve is injected and filled into a cavity by an injection plunger to cast a product. In addition to the need to supply a large amount and quickly inject it, there was a problem that a part of the molten metal was cooled and solidified by the time the filling into the cavity was completed, resulting in defective running of the product.

Therefore, in order to solve such a problem, the applicant of the present application first fills the molten metal from the pouring runner into the cavity, and then pressurizes the molten metal while closing the pouring runner. Has proposed a new casting method in which
2869).

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to provide another novel casting method related to the casting method previously proposed by the applicant of the present invention. An object of the present invention is to provide a metal casting method capable of casting a sounder product as compared with the gravity casting method.

[0005]

According to the metal casting method of the present invention for achieving the above object, the molten metal is injected and filled into the cavity from the pouring ports formed in the mating surface portions of both the fixed die and the movable die. This is characterized in that pressure is applied to the molten metal in the cavity by a presser installed on the rear mold mating surface portion.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The mold A used in the metal casting method according to the present invention is composed of a fixed mold a and a movable mold b that form the cavity 1. Reference numeral 2 in the drawing denotes a vent hole for sucking gas in the mold cavity 1.

A pouring spout 4 is formed on both mating surface portions 3 of the fixed die a and the movable die b, and a runner 5 for communicating the pouring spout 4 with the spout 1a of the cavity 1 is formed. In addition, the presser element 6 is installed on the die-matching surface portion 3 directly below the gate 1a of the cavity 1.

The pouring spout 4 is formed at a position higher than the cavity 1, that is, at the uppermost position of the mating surface portions 3 of both the fixed die a and the movable die b, and the pouring spout 4 and the spout portion 1a of the cavity 1 are formed. The runners 5 formed on the two mating surface portions 3 communicate with each other.

The pressurizer 6 is for applying pressure to the molten metal m'supplied and filled in the cavity 1, and moves up and down in the sleeve portion 7 composed of the fixed die a and the movable die b when the die is closed. In order to be able to move, the coupling 9 is attached to the rod 8a of the pressurizing cylinder 8 mounted on the outside of the lower surface of the fixed die a or the movable die b.
The top dead center of the pressurizer 6 is set inside the sprue part 1a of the cavity 1, and the bottom dead center is set just below the outlet 5a of the runner 5.

Reference numeral 10 in the drawing denotes a support plate for supporting the pressurizer 6 so as to be movable up and down, and is detachably attached to the fixed die a by bolts 11 or the like.

When casting a product, after the fixed mold a and the movable mold b are aligned with each other and the mold is closed, the gas in the cavity 1 is sucked from the vent hole 2 and the pressure in the cavity 1 is reduced. , Melted from the pouring port 4 in that state
Is poured with a ladle 12, etc. Then, the molten metal m is injected into the cavity 1 from the spout portion 1a through the runner 5 by gravity, and the molten metal is supplied and filled in the cavity 1.

Next, the pressurizing cylinder 8 is operated to raise the pressurizer 6 to the sprue 1a side of the cavity 1 and block the outlet 51 of the runner 5 while the molten metal in the sprue 1a is passed through the cavity. A pressure is applied to the molten metal m ′ in 1 to wait until the molten metal m ′ is solidified and a product is cast.

When casting a product, boron, talc,
It is preferable to apply a powdery heat insulating agent made of a metal oxide, a metal sulfide, a metal nitride, or a powder obtained by mixing these with resin powder every casting cycle. that way,
There is almost no concern that part of the molten metal will solidify before the molten metal is supplied and filled into the cavity 1 and pressure is applied.

[0014]

As described above, the metal casting method according to the present invention is such that the molten metal is filled in the cavity from the pouring port formed on the mating surface portion of both the fixed die and the movable die in the gravity casting method, and then the two Since the pressurizer installed on the mold matching surface is used to apply pressure to the molten metal in the cavity, a sounder product can be cast as compared with the conventionally known gravity casting method. That is, since the molten metal is gravity-filled into the cavity and then the sprue part is directly pressurized, the pressurizing effect on the cast product is increased, and as a result, a dense product with better dimensional accuracy is cast. In addition, the product defects can be significantly reduced and the product yield can be improved.

In addition, the casting cycle can be increased to the extent that it is almost the same as the die casting method.

Further, since the pressurizer is installed on the mating surface of the fixed mold and the movable mold, even if casting burrs come into the sprue part or the pressurizer part, they can be removed very easily by opening the mold. , The maintenance of the mold itself becomes easy.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention.

FIG. 2 is a side view of the same section.

[Explanation of symbols]

A: Mold a: Fixed type b: Movable type 1: Cavity 1a: Gate part 3: Mold matching surface part 4: Pouring port 5: Runner part 6: Presser

Claims (1)

[Claims] 1. A molten metal is poured into a cavity through a pouring port formed in a mating surface portion of both a fixed mold and a movable mold,
After that, the metal casting method is characterized in that pressure is applied to the molten metal in the cavity with a presser installed on both mating surface parts.