JPH0481256A - Casting apparatus in die casting - Google Patents

Abstract

PURPOSE:To cut and remove gate and sprue in only one process with press by arranging a movable type pressurizing piece for pressurizing toward direction, where cross sectional area of the gate is reduced as less than the cross sectional area at the time of starting filling-up of molten metal, before completing solidification of the molten metal in cavity, in part of the gate connecting the sprue and a product part. CONSTITUTION:Before completing the solidification of molten metal in the cavity 4 in a die 1, by descending the pressurizing piece 8 to the lower limit position P2 to reduce the cross sectional area of gate 52, thickness of the gate 52 after casting is made to gap C. Therefore, as after-treatment after casting, the gate 52 and the sprue 53 can be cut and removed in only one process with gate cutting press without depending on a metal saw or a band saw.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a die-casting apparatus, and more specifically, a die-casting apparatus that takes into consideration the ease of separating non-product parts such as sprues and weirs attached to the product part after casting. Regarding.

Conventional technology and its issues In the die-casting method, after casting, non-product parts such as sprues and weirs attached to the product part are cut and removed from the base of the weir using press equipment generally called a weir folding press as a post-processing process. be done. On the other hand, in casting plans, the cross-sectional area of the weir, especially the wall thickness of the weir, may be made larger than normal dimensions in order to improve the running properties of the weir. Because the wall thickness is large, it is difficult to cut and remove using a weir folding press, so instead of the weir folding press, a cutting method using a metal saw or a band saw is used.

For example, when the product 50 shown in FIG. 5 is cast using a multi-cavity (two-cavity) method using a vertical die-casting machine as shown in FIGS. 6 and 7, both product parts that become the final product are Between 51 and 51 are relatively thick weirs 52 and 5.
A sprue 53 that is even thicker than the sprue 2 is attached.

Here, 1 in FIG. 6 is a mold consisting of an upper mold 2 and a lower mold 3;
4 is a cavity formed by the upper and lower dies 2 and 3; 5 is a plunger for filling the cavity 4 with the molten metal supplied to the sleeve 6 under pressure; and 7 is an extrusion bottle.

When attempting to cut and remove the weir 52 and sprue 53 along the product shape with a metal saw or a band saw, the connection between the weir 52 and the product part 51 or the product part 51 is removed.
Because it is a part of the corner of The cutting operation must be performed in at least two steps along the cutting line C7, which is undesirable as it results in an increase in the number of processing steps.

The present invention was made in view of the above problems.
Even if the casting plan requires a relatively thick weir, the weir and sprue can be shaped according to the shape of the product using the weir folding press method instead of using a metal saw or band saw for post-casting processing. The object of the present invention is to provide a casting device that can be cut and removed by cutting.

Means for Solving the Problems The present invention provides a tie-casting device that performs casting by pressurizing and filling a mold cavity with molten metal. In addition, a movable pressurizing piece is provided which pressurizes the weir in a direction that reduces the cross-sectional area of the weir along the external shape of the product part compared to when filling the molten metal starts, before the solidification of the molten metal in the cavity is completed. It is a feature.

Function According to the above structure, the cross-sectional area of the weir is reduced by the pressurizing piece before the solidification of the molten metal in the cavity is completed, thereby achieving the original function of the weir while reducing the cross-sectional area of the weir after casting. The wall thickness is relatively small. Therefore, as post-processing after casting, the weir and sprue can be cut and removed in one step by weir folding press without using a metal saw or Pantone.

Embodiment FIGS. 2 and 3 are diagrams showing an embodiment of the present invention, and show an example in which the product 50 shown in FIG. 5 is cast using a two-cavity method as shown in FIG. 7. .

As shown in FIGS. 2 and 3, the weir 52 of the upper mold 2
This structure is different from the conventional structure in that a pressure piece 8 having a substantially V-block shape corresponding to the shape of a part of the corner of the product part 51 is provided at a portion corresponding to the root part of the product part 51.

The pressure piece 8 is connected to an actuator provided on the upper mold 2, for example, a piston rod 10 of a hydraulic cylinder 9, and when the hydraulic cylinder 9 is actuated, it moves to the upper limit position P shown in FIG. 2 and to the lower limit position P shown in FIG. It will move downward between the limit position P and the end position P.

As the upper limit position P1 of the pressure piece 8, the second
As shown in the figure, the tip end surface of the pressure piece 8 is set at a position flush with the horizontal wall surface on the upper mold 2 side forming the cavity 4, while the lower limit position P2 of the pressure piece 8
As shown in FIG. 1, the position is such that a minute gap C is secured between the horizontal wall surface on the side of the lower die 3 and the tip end surface of the pressure piece 8.

Therefore, according to the above structure, as shown in FIG. 2, the upper and lower molds 2,
3 is clamped, and the plunger 5 pushes up the molten metal previously supplied into the sleeve 6. As a result, the molten metal passes through the sprue 53 and the weir 52, fills the entire cavity 4 under pressure, and gradually solidifies and contracts.

Then, before the molten metal in the cavity 4 is completely solidified, the hydraulic cylinder 9 is operated to lower the pressurizing piece 8 to the lowering limit position P2 as shown in FIG. 1 in order to reduce the cross-sectional area of the weir 52. As a result, weir 52 where solidification is progressing.
The root portion is pressurized by the pressure piece 8, leaving only a minute gap C as its wall thickness, and solidification is completed in this state.

After the solidification is completed, the product is extruded by the extrusion pin 7 while opening the lower molds 2 and 3 to obtain an intermediate product 54 as shown in FIG.

This intermediate product 54 is divided into two product parts 51 that will become the final product.
．． 51 are connected by a weir 52 and a sprue 53, but as mentioned above, the thin wall portion 55 pressurized by the pressure piece 8 is formed at the base of the weir 52, so post-processing is not required. From the product section 51 to the weir 52 and sprue 53
Cutting and removing can be done with a highly productive weir folding press instead of using a metal saw or band saw.

Effects of the Invention As described above, according to the present invention, the part of the mold corresponding to the weir connecting the sprue and the product part is heated along the outer shape of the product part before the molten metal in the cavity completes solidification. Since the structure is equipped with a movable pressurizing piece that applies pressure in a direction that reduces the cross-sectional area of the weir compared to when filling the molten metal starts, the weir attached to the product part after casting has a cross-sectional area smaller than when filling the molten metal starts. Because the area is reduced and the wall thickness is reduced, for example, even if a thick weir is required in the casting plan, the weir can be formed in one step using a highly productive weir folding press as post-processing after casting. And the sprue can be cut and removed. As a result, the number of processing steps can be reduced compared to the conventional method using a metal saw or Pantone, and since the molten metal is pressurized with a pressurizing piece before it solidifies, the structure is as dense as that of the local pressure casting method. is obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a mold showing an embodiment of the present invention, FIG. 2 is a sectional view of the mold similarly showing a state in which the pressure piece is raised, and FIG. 3 is a plan view of FIG. 4. Figure 4 is a perspective view of an intermediate product cast by the molds shown in Figures 1 and 2, Figure 5 is a perspective view of a final product obtained from the intermediate product, and Figure 6 is an example of a conventional mold. 7 is a perspective view of an intermediate product cast by the mold shown in FIG. 6, and FIG. 8 is an explanatory plan view of the product shown in FIG. 7. 1...Mold, 2...Upper die, 3...Lower die, 4...
Cavity, 5...Plunger, 50...Product, 5
1... Product department, 52... Weir, 53... Sprue, 54
...Intermediate product, 55...Thin wall part.

Claims (1)

[Claims] (1) In die-casting equipment that performs casting by pressurizing and filling the cavity of the mold with molten metal, a part of the mold corresponding to the weir connecting the sprue and the product part is
A movable pressurizing piece is provided which pressurizes the weir in a direction that reduces the cross-sectional area of the weir along the external shape of the product part compared to when filling the molten metal starts before the solidification of the molten metal in the cavity is completed. die casting equipment.