JPS59185562A - Forging device for molten metal - Google Patents

Abstract

PURPOSE:To provide a forging device for a molten metal which prevents a solidified part from bein forced into the wall part of a product by providing an expanding part having the diameter increasing gradually toward the cavity in the part, near the cavity, of the plunger sleeve provided inthe casting mold. CONSTITUTION:An expanding part 11 of a plunger sleeve 7 in a casting mold 1 to be held in the upper half part 4 of a bottom mold 3 is formed into a conical shape expanding gradually toward a cavity 6. A heat insulating material 26 is interposed between the cylindrical part 12 and expanding part 11 of the sleeve 7 to prevent transfer of heat and to maintain the part 11 at a desired temp. The cooling and solidifying of the molten metal in the part in a molten metal well 9 in contact with the inside surface of the expanding part 11 is prevented. As a result, the forcing of the solidified part into the wall part of the product and the consequent generation of a fault are prevented and the strength of the product is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the mold is provided with a plunger sleeve that communicates with a cavity of the mold, and a plunger for filling and pressurizing the molten metal toward the cavity is slidably inserted into the plunger sleeve. The present invention relates to a molten metal forging device.

Conventionally, in such a molten metal forging device, the plunger sleeve and the plunger thermally expand due to the heat of the molten metal stored in the cavity, and the molten metal flows into the gap between the plunger sleeve and the plunger caused by the difference in the amount of thermal expansion between them. A galling phenomenon may occur, so approximately 10Q
The mold, plunger sleeve, plunger, etc. had to be replaced every QO time, resulting in a shortened lifespan. Therefore, cooling the plunger sleeve or plunger has been considered as a solution to this problem. However, although such cooling is effective against the galling phenomenon, the molten metal inside the plunger sleeve, especially the molten metal in the portion that is in contact with the inner peripheral surface of the sleeve, is cooled and solidified, and this solidified portion However, when it is press-fitted into the product, faults occur within the product and the product strength decreases.

The present invention was made to eliminate such conventional drawbacks, and an object of the present invention is to provide a molten metal forging device that prevents the solidified portion from being press-fitted into the product.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, a mold 1 is formed by combining an upper mold 2 and a lower mold 3, and the lower mold 3 has an upper half 4. and the lower half part 5 are combined.

A cavity 6 is formed in the upper mold 2 facing the lower mold 3 side, and a plunger sleeve 7 communicating with the plunger cavity 6 is provided in the lower mold 3. A plunger 8 is slid into this plunger sleeve 7 . Molten metal such as aluminum alloy is poured into the hot water storage part 9 formed in the plunger sleeve I and communicated with the cavity 6, and the molten metal is filled into the cavity 6 and pressurized by the suppressing action of the plunger 8, and the pressurized state is maintained. After solidifying by holding for a certain period of time, the upper mold 2 and lower mold 3 are separated, thereby completing the molten metal forging.

A non-kout pin 10 which also serves as a core is provided in the upper mold 2 so as to be slidable up and down in a state of being inserted into the cavity 6.

The plunger sleeve 7 has an expanded portion 11 held in the upper half 4 of the lower mold 3 and a cylindrical portion 12 held in the lower half 5 by integrating the upper half 4 and the lower half 5. Consisting of concentric connections. The expanding portion 11 is formed in a trumpet shape so as to gradually increase in diameter toward the cavity 6, and a flange 13 is integrally provided at its small diameter end. On the other hand, in the upper half 4 of the lower mold 3, a through hole 14 having a slightly larger diameter than the cavity 6 is bored. A large-diameter portion 16 is provided which is enlarged through. The expanded portion 11 has a large diameter end surface 1
1α is flush with the end surface 4a of the upper mold 2 side of the upper half portion 4, the flange 13 is fitted into the large diameter portion 16, and the upper half portion 4 is inserted into the through hole 14. In the inserted state, the end surface 13cL of the flange 13 is flush with the end surface 4b of the upper half 4 on the lower half 5 side. Further, an annular groove 17 is formed in the end surface 13α of the flange 13.

When the expanded portion 11 is inserted into the through hole 14 of the upper half portion 4, an annular gap portion 18 is defined between the outer surface of the expanded portion 11 and the inner surface of the through hole 14. Facing this cavity 18,
An electric heater 1 as a heating means is installed on the outer surface of the expanded portion 11.
9 is wound.

The electric heater 19 has a diameter of 300 to 4,000, for example.
It has the heating ability to heat to about 00℃.

The cylindrical portion 12 of the plunger sleeve 7 has the expanded portion 11
It is formed into a cylindrical shape with a flange 20 corresponding to the flange 13 at one end. On the other hand, in the lower half 5 of the lower mold 3,
A through hole 21 having a smaller diameter than the through hole 14 in the upper half 4 is concentrically bored, and a large diameter hole 21 is enlarged through a step 22 in a portion of the through hole 21 closer to the upper half 4. A section 23 is provided. The cylindrical portion 12 is inserted into the through hole 21 by attaching the flange 20 to the large diameter portion 23, and in this inserted state, the end surface 20a of the flange 20 is aligned with the upper half 4 of the lower half 5 (the end surface 5 of the
The other end of the cylindrical portion 12 projects downward from the lower half 5. Further, on the end surface 20a of the flange 20,
An annular groove 24 corresponding to the groove 17 of the flange 13
is drilled.

A cooling water passage 25 is spirally provided in the cylindrical part 12 over almost its entire length, and cooling water that can maintain the cylindrical part 12 at a temperature of, for example, about 170 to 200° C. is supplied to the cooling water passage 25. be done.

The expanded portion 11 and the cylindrical portion 12 are connected to the end surface 13 (Z and the flange 20 end face 20α of
are brought into close contact and integrated.

Moreover, when integrating the two, the annular space defined by the grooves 17 and 24 of both flanges 13.20 is filled with a heat insulating material 26, and the heat insulating material 26 heats the gap between the expanded portion 11 and the cylindrical portion 12. It functions to prevent movement as much as possible. By integrating the expanded portion 11 and the cylindrical portion 12, the plunger sleeve 7 has the following features:
The hot water storage portion 9 and the sliding hole 27 are formed concentrically.

The plunger 8 consists of a cylindrical plunger body 29 that integrally has a protrusion 28 at its tip, and a bottomed cylindrical plunger tip 30 that is screwed onto the protrusion 28 in a replaceable manner.

The outer diameters of the plunger body 29 and the plunger tip 3o are selected so that they slide into the sliding hole 27 of the plunger sleeve 7.

Further, the plunger tip 3o is made of ceramic, and has the function of preventing as much as possible the high heat from the molten metal stored in the hot water storage section 9 from being transmitted to the plunger body 29, and also preventing seizure with the sliding hole 27. accomplish

The plunger body 29 is provided with a cooling hole 31 that opens on the opposite side of the plunger tip 3°. an outwardly projecting cylindrical rod 32
is screwed and connected to the granger body 29. rod 3
A cooling water supply pipe 33 is inserted through the rod 2 with one end facing the cooling hole 31, so that an annular cooling water is formed between the inner surface of the rod 32 and the outer surface of the cooling water supply pipe 33. A discharge path 34 is formed. Therefore, the cooling water supplied from the cooling water supply pipe 33 cools the plunger body 29 in the cooling hole 31 and is then discharged through the cooling water discharge path 34.

Next, to explain the operation of this embodiment, when forging molten metal, molten metal such as aluminum alloy as a material is poured into the molten metal storage section 9, the electric heater 19 is energized, and the cooling water passage 25 and the cooling water supply are energized. With cooling water being supplied to the pipe 33, the rod 32 is pressed and driven by a driving means such as a hydraulic cylinder (not shown). As a result, the plunger 8 protrudes into the hot water storage section 9 as shown by the chain line, and the molten metal removed by the protrusion of the plunger 8 fills the cavity 6 and is pressurized, and this pressurized state is maintained for a certain period of time. .

In this process, the cylindrical portion 12 of the plunger sleeve 7 and the plunger body 29 of the plunger 8 are
It is cooled to about 170-200'C by cooling water. Further, the expanded portion 11 of the plunger sleeve 7 is heated to about 300 to 400°C by an electric heater 19. Moreover, since the heat insulating material 26 is interposed between the cylindrical portion 12 and the expanded portion 11, the cylindrical portion 12 and the expanded portion 1
Heat transfer between the two is prevented as much as possible. Therefore, the temperature of the expanded portion 11 is maintained at about 300-400C, and the temperature of the cylindrical portion 11 is maintained at about 170-200'C.

By heating the expanded portion 17 in this manner, the molten metal in the portion of the hot water storage portion 9 that is in contact with the inner surface of the expanded portion 11 is prevented from being cooled and solidified by contact with the inner surface. Even if solidification occurs, the expanded portion 11 is formed to gradually become larger in diameter toward the cavity 6, and the grunger 8 will move on the central axis of the expanded portion '11, so the plunger 8 The bath water in the center of the hot water storage section 9 is suppressed and filled toward the cavity 6. Therefore, the solidified matter generated near the inner surface of the expanded portion 11 is absorbed into the cavity 6.
As a result, the solidified part is prevented from being press-fitted inside the product and causing a fault.
Product strength is improved.

On the other hand, by cooling the cylindrical part 12 and the plunger 8 with the cooling water, their temperatures become almost the same, so there is almost no difference in the amount of thermal expansion between the two, and as a result, there is a gap between the cylindrical part 12 and the plunger 80, It is possible to prevent the formation of a gap in which the liquid can flow, and to prevent the galling phenomenon from occurring, thereby making it possible to extend the life of the plunger sleeper 7 and the plunger 8.

After filling the cavity 6 with molten metal for a certain period of time and pressurizing the process, the upper mold 2 and the lower mold 3 are separated,
The product material solidified within the cavity 6 is taken out from the cavity 6 by the extrusion operation of the non-knockout pin 10. Thereafter, the product material is subjected to finishing processing.

In other embodiments of the invention, the cooling means for the plunger 8 may be omitted.

As described above, according to the present invention, the expanded portion that is opened to gradually become larger in diameter toward the cavity is provided in the portion of the plunger sleeve closer to the cavity, so that the plunger can be inserted into the expanded portion. The molten metal in the center is pressed toward the cavity, and even if there is a solidified part in contact with the inner surface of the plunger sleep at the periphery, that solidified part is prevented as much as possible from entering the cavity. Therefore, the formation of faults due to the solidified portion being press-fitted into the product is prevented as much as possible, and the strength of the product is improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall longitudinal sectional view, and FIG. 2 is an end view taken along the line II-If of FIG. 1. DESCRIPTION OF SYMBOLS 1... Mold, 6... Cavity, 7... Plunger sleeve, 8... Plunger, 11... Expanded part,
12...Cylindrical part

Claims (1)

[Claims] In a molten metal forging apparatus, a plunger sleeve communicating with a cavity of the mold is provided in the mold, and a plunger sleeve for filling and pressurizing the molten metal toward the cavity is slidably fitted into the molten metal forging apparatus. A molten metal forging apparatus characterized in that a portion closer to the cavity is provided with an enlarged opening that gradually becomes larger in diameter toward the cavity.