JPS6293055A - Pressure casting device - Google Patents

Abstract

PURPOSE:To smooth the operation of a plunger and to decrease casting defects by slidably fitting a pressurizing sleeve to a pouring sleeve and freely slidably fitting the plunger pressed toward a counter to the pressurizing sleeve. CONSTITUTION:A molten metal is admitted from a sprue 46a into the hollow part of the pouring sleeve 44 and is poured into a molten metal storage chamber 50. After the sprue 46a is closed by the pressurizing sleeve 36, the counter 26 is moved toward a cope body 14 by a pressing rod 24. The molten metal flows into a cavity 48 and is packed therein. A pressurizing rod 32 is lowered by the effect of a pressurizing cylinder 30, then the plunger 34 moves along the inside peripheral wall of the pressurizing sleeve 34 and the bottom end thereof bulges into the chamber 50. The molten metal in the cavity 48 is thus pressurized and the formed product structure is made denser. Since the sprue 46a is formed to the inside peripheral wall part of the sleeve 36, the plunger 34 is smoothly slidingly moved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure casting apparatus, and more particularly, the present invention relates to a pressure casting apparatus, and more specifically, it is equipped with a plunger and a counter, and pressurizes and fills the molten metal stored between them into a product cavity by the pressing operation of the plunger to form a product. In a pressure casting device for casting and molding, a pressure sleeve for opening and closing the sprue is fitted into a pouring sleeve that has a sprue opening from which the molten metal flows out on the inner peripheral wall, and the plunger is mounted on the inner periphery of the pressurization sleeve. The present invention relates to a pressure casting apparatus configured to manufacture products with fewer casting defects by smoothly moving a plunger by slidably fitting the plunger.

Conventionally, in this type of pressure casting equipment, a counter disposed below fitted into an injection sleeve and a plunger disposed above fitted into a pouring sleeve are disposed vertically opposite each other, and the molten metal is The molten metal is configured to flow from a sprue opened on the inner periphery of the pouring sleeve and to be stored between the plunger and the counter. The stored molten metal is then pressurized by the downward movement of the plunger, and is filled under pressure into the product cavity through the runner. In this case, the sprue opened on the inner periphery of the pouring sleeve is closed by a plunger that moves downward along the inner circumference of the pouring sleeve, thereby preventing the molten metal from flowing out.

By the way, when the molten metal is stored between the plunger and the counter, the molten metal poured from the sprue opened in the inner circumferential wall of the pouring sleeve mainly collides with the inner circumferential wall of the pouring sleeve facing the sprue. After that, it is stored in the injection sleeve located below. In this case, the molten metal adheres to the inner circumferential wall of the pouring sleeve or the peripheral edge of the sprue and solidifies, or the inner circumferential wall is locally pressurized or heated, so that the inner circumferential shape of the pouring sleeve changes over a short period of time. It becomes deformed. Therefore,
The plunger, which slides along the inner circumference of the pouring sleeve, has increased frictional resistance due to the molten metal adhering to the inner peripheral wall and the deformation of the pouring sleeve, making it difficult to move smoothly and in some cases becoming unable to slide. A situation had also arisen.

Therefore, in order to eliminate the above-mentioned situation, it is possible to increase the pressing force to cause the plunger to slide. However, when the pressing force of the plunger is increased, the internal pressure of the molten metal press-fitted into the product cavity increases, and, for example, when casting a cylinder head for an engine, a relatively fragile sand core is When using the sand core, there is a problem that the sand core is damaged by the pressure of the molten metal, resulting in casting defects in the product. Furthermore, increasing the pressing force of the plunger not only places an extra burden on the device, but also causes a reduction in the lifespan of the plunger and members surrounding the plunger.

The present invention has been made to overcome the above-mentioned disadvantages, and includes an upper plunger that is pressed toward a counter disposed below and is slidably fitted into the inner periphery of a pressurizing sleeve. By slidably fitting the pressurizing sleeve into the inner periphery of the pouring sleeve having a sprue, the movement of the plunger becomes smooth, making it possible to manufacture products with fewer casting defects. It is an object of the present invention to provide a pressure casting device that does not increase the burden.

In order to achieve the above object, the present invention provides a pressure casting apparatus that pressurizes and fills a product cavity with molten metal stored between a plunger disposed at an upper part and a counter disposed at a lower part. A pressurizing sleeve is slidably fitted into a pouring sleeve through which a sprue from which the molten metal flows out is opened, and the plunger, which is pressed toward the counter, is slidably fitted into the pressurizing sleeve. It is characterized by being configured to do so.

Next, preferred embodiments of the pressure casting apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 3, reference numeral 10 indicates a main body of a pressure casting apparatus according to the present invention, and this main body 10 includes a lower mold main body 12 and an upper mold main body 14, and these opposing parts A lower mold 16 and an upper mold 18 are respectively attached to the molds. In this case, the upper mold main body 14 is configured to be movable in the vertical direction toward the lower mold main body 12 together with the upper mold 18.

Therefore, a hole 20 passes through the lower mold main body 12 toward the lower mold main body 14, and a cylindrical injection sleeve 22 is fitted and fixed into the hole 20. In addition, the injection sleeve 22
A counter 26 is slidably fitted through a push-up rod 24.

A hole 28 passes through the upper mold body 14 toward the lower mold body 12, and a pressure cylinder 30 is fitted and fixed in the hole 28. The pressure cylinder 30 has a pressure rod 32 that projects toward the lower mold body 12, and a cylindrical plunger 34 is fixed to the lower end of the pressure rod 32. These pressure rods 32 and plungers 34 are connected to the holes 28
It is slidably fitted into a cylindrical pressure sleeve 36 coaxially fixed to the upper mold body 14.

Further, as shown in FIGS. 2 and 3, sliding molds 38 and 40 configured to be movable in the horizontal direction are sandwiched between the lower mold body 12 and the upper mold body 14. . and,
A hole 42 extends vertically through the sliding mold 40, and a cylindrical pouring sleeve 44 is fitted and fixed into the hole 42. In this case, the sprue 46a of the pouring hopper 46 is opened in the inner circumferential wall of the pouring sleeve 44, and the hollow portion of the pouring sleeve 44 is connected to the main body through the pouring hopper 46.
It communicates with the external space of 0.

On the other hand, in the state shown in FIG. 2 or 3, the pressure sleeve 36 is slidably fitted into the pouring sleeve 44. In this case, a cavity 48 is defined in the main body 10 by the lower die 16, the upper die 8, and the sliding die 38, 40. A molten metal storage chamber 50 is defined between the plunger 34 fitted in the pressure sleeve 36 and the counter 26, and the cavity 48 and the molten metal storage chamber 50 are defined between the lower mold 16 and the sliding mold 40. They are communicated by a defined runner 52.

The pressure casting apparatus according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, the sliding molds 38 and 40 are moved horizontally and fixed at predetermined positions on the lower mold body 12 (see FIG. 1). In this case, the upper mold body 14 is arranged above the lower mold main body 12 at a distance, and the pressure sleeve 36 fixed to the upper mold body 14 is not fitted into the pouring sleeve 44. .

Therefore, the sprue 46a of the pouring hopper 46 opens into the inner circumferential wall of the pouring sleeve 44.

Next, in the state shown in FIG. 1, the molten metal A is poured into the pouring hopper 46.
Pour hot water into the water. The poured molten metal A flows into the hollow portion of the pouring sleeve 44 from the sprue 46a, and is received by the counter 26 located below the pouring sleeve 44. In this case, the counter 26 is located at the lower part of the injection sleeve 22, and the molten metal A is stored in the hollow part of the injection sleeve 22.

Next, the upper mold body 14 is lowered toward the lower mold body 12, and the upper mold body 14 and the upper mold 18 are engaged with the sliding mold 38, 40, and the pressurizing sleeve 36 is moved into the pouring sleeve 44.
to fit. As a result, the main body part 10 has a cavity 4 formed by the lower mold 16, the upper mold 18, and the sliding molds 38 and 40.
8 is defined. On the other hand, a sprue 46a opening in the inner wall of the pouring sleeve 44 is closed by the outer periphery of the pressurizing sleeve 36.

Here, the inner peripheral shape of the pouring sleeve 44 is slightly deformed due to the molten metal A flowing out from the sprue 46a adhering to the inner peripheral wall during pouring or being locally heated by the molten metal A. .

Therefore, the pressure sleeve 36 is forced into the pouring sleeve 44 against the frictional resistance caused by the inner circumferential wall.

After pouring the molten metal A into the molten metal storage chamber 50 and closing the sprue 46a with the pressurizing sleeve 36, the counter 26 is moved toward the upper mold body 14 by the push-up rod 24.

As a result, the molten metal A stored in the molten metal storage chamber 50 flows into the cavity 48 through the runner 52, and the molten metal A is filled. The state at this time is shown in FIG.

Then, under the driving action of the pressurizing cylinder 30, the pressurizing rod 3
2 is directed toward the lower mold body 12 and lowered.

As a result, the plunger 34 attached to the lower end of the pressure rod 32 slides along the inner circumferential wall of the pressure sleeve 36, and its lower end gradually bulges into the molten metal storage chamber 50. Therefore, the molten metal A filled in the cavity 48 is pressurized through the molten metal storage chamber 50 and the runner 52, and the product structure formed in the cavity 48 is densified. The state at this time is shown in FIG.

Here, since a sprue 46a is formed on the inner circumferential wall of the pressurizing sleeve 36, the molten metal A may directly collide with the molten metal A, as in the case of the pouring sleeve 44, or the inner periphery may be heated by the molten metal A. A situation where the shape is deformed does not occur.

Therefore, the plunger 34, which slides along the inner periphery of the pressure sleeve 36, slides very smoothly due to the pressure rod 32. As a result, it becomes possible to control the pressure applied to the molten metal A filled in the cavity 48 to a desired value, and a product of extremely good quality can be obtained.

In addition, since the plunger 34 can be slid smoothly, even when casting a product having a sand core that is easily damaged, such as a cylinder head in an engine, the front 3 There is no risk that the sand core will be damaged and casting defects will occur in the product.

The product formed in the cavity 48 in this way is
After the molten metal A has solidified, the upper mold body 1 including the pressurizing sleeve 36
4 upward and horizontally displace the sliding molds 38 and 40 to open the mold, and the mold is ejected from the cavity 48 by an ejector pin (not shown).

As described above, according to the present invention, in the pressure casting apparatus that pressure-fills the molten metal stored between the upper plunger and the lower counter into the product cavity by the pressing operation of the plunger, the molten metal sprue is A pressurizing sleeve for opening and closing the sprue is slidably fitted on the inner periphery of the pouring sleeve that opens, and the plunger is slidably fitted into the pressurizing sleeve.

Therefore, the molten metal flowing out from the sprue does not directly collide with the inner peripheral wall of the pressure sleeve, which is the sliding area of the plunger, and the sliding area is not deformed due to adhesion of molten metal or local heating. . Therefore, the plunger can always move smoothly along the inner periphery of the pressure sleeve, and the internal pressure generated in the product cavity by the plunger can be accurately controlled. As a result, there is no possibility that casting defects will occur in the product due to misalignment of the core within the product cavity, long breakage, or blowholes. Further, since the plunger always operates smoothly, there is no need to apply extra pressure to the plunger, which provides the advantage that the life of the device is improved.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

FIG. 1 is a partially omitted longitudinal cross-sectional view showing the state of molten metal pouring in the pressure casting apparatus according to the present invention, and FIG. 2 is a partially omitted longitudinal cross-sectional view showing the filling state of molten metal in the pressure casting apparatus according to the present invention. The plan view and FIG. 3 are partially omitted vertical cross-sectional views showing the pressurized state of the molten metal in the pressure casting apparatus according to the present invention. 10...Main body part 12...Lower mold main body 14...Upper mold main body 16...Lower mold 18
... Upper mold 22 ... Injection sleeve 26 ... Counter 30 ... Pressure cylinder 34 ... Plunger 36 ... Pressure sleeve 38. 40 ... Sliding mold 44.
...Pouring sleeve 46...Pouring hopper 4
8... Cavity 50... Molten metal storage chamber

Claims (2)

[Claims] (1) In a pressure casting device that pressurizes and fills a product cavity with molten metal stored between a plunger placed at the top and a counter placed at the bottom, a sprue through which the molten metal flows out opens on the inner peripheral wall. A pressure sleeve is slidably fitted into the pouring sleeve, and the plunger, which is pressed toward the counter, is slidably fitted into the pressure sleeve. Pressure casting equipment. (2) The pressure casting device according to claim 1, wherein the pressure sleeve slides along the inner periphery of the pouring sleeve to open and close the sprue.