JPH08318356A - Method for die-casting half-melted metal - Google Patents

Abstract

PURPOSE: To enable the casting of a product having good quality by bringing an ejection sleeve into close contact with a die after placing half-melted metal on an inner tip and shifting them, ascending the inner tip and a plunger tip and executing pressure-casting. CONSTITUTION: Releasing agent is sprayed onto the cavity surfaces of the dies 4, 8, the inner surface of the injection sleeve 12, etc., from an introducing pipe 36 and a spray nozzle 32 for injection sleeve by descending a rod 21. After placing the half-melted state billet onto the upper surface of the ascended inner tip, the inner tip is descended and the injection device is shifted to bring the injection sleeve 12 into close contact with the dies 4, 8. The inner tip and the plunger tip are integrally ascended at the same speed and the billet is forcedly charged into the cavities in the dies 4, 8, and after cooling the metallic billet, a formed product is taken out of the respective dies 4, 8. By this method, damage of the releasing agent caused by the sliding of the half-melted billet in the injection sleeve 12 hardly occurs and the formed product having good quality can be cast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for die-casting semi-molten metal.

[0002]

2. Description of the Related Art The thixocasting method for pressure-casting semi-molten metal is characterized by less casting defects and segregation, a uniform metallographic structure, longer die life and shorter molding cycle than conventional casting methods. It has advantages and is a technology that has recently been drawing attention. This method is characterized in that a metal material heated to a semi-molten state is press-fitted into a mold cavity and pressure casting is performed.It is important to control the temperature of the metal material in the injection sleeve and a physical external force is applied. However, it is essential to handle a billet made of a metal material that is extremely deformable.

That is, the billet is likely to lose its shape even with a small external force, and the cast product after molding by the billet deformed by the external force is likely to be a product of poor quality. Therefore, when inserting the billet into the injection sleeve, it is necessary to prevent the outer shape from being deformed and to prevent the semi-molten metal from solidifying due to the temperature drop as much as possible, and it is necessary to pay close attention. Therefore, in order to place the billet, which is a semi-molten metal material, on the upper surface, the plunger tip is lifted up to near the upper end of the injection sleeve, then the billet is moved and loaded on the upper surface of the plunger tip, and then the plunger tip is lowered until A method is known in which the tilted injection sleeve is returned to the vertical state, docked with the mold, and the billet is press-molded in the mold cavity by press fitting.

FIG. 8 shows the transition of steps in this method. After the injection is completed, the plunger tip 14 is lowered and then the injection sleeve 12 is tilted (step 1), and then the plunger tip 14 is raised. Then, a mold release agent is spray-coated on the upper surface and the side surface of the chip (step 2), the plunger chip 14 is further lowered, and then the mold release agent is spray-coated on the inner peripheral surface of the injection sleeve 12 (step 3). Then, the plunger tip 14 is again lifted up to near the upper end of the injection sleeve 12 (step 4), and the billet 40 is moved to the plunger tip 14 again.
Plunger tip 1 is mounted on the upper surface of the die and the plunger tip 14 is lowered (step 5), and the injection sleeve 12 is returned from the tilted state to the vertical state and then docked with the die.
4 is lifted and injected into the mold (step 6).

[0005]

However, in the above-mentioned method, the billet 40 is loaded on the upper surface of the plunger tip 14 and the plunger tip 14 is lowered while the injection sleeve 12 is tilted. However, there is a problem that the billet 40 is rubbed against the peripheral wall surface of the injection sleeve 12 and the billet 40 is easily deformed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a die-casting method of semi-molten metal such that the outer shape of the billet is not deformed when the billet is housed in an injection sleeve. .

[0007]

In order to achieve the above object, according to the present invention, a plunger tip which slides in an injection sleeve is fitted into a through hole bored in the axial direction of the central portion of the plunger tip. In a die-casting machine having an upright injection sleeve that is independently slidable in the axial direction and that does not directly contact the inner peripheral surface of the injection sleeve, After applying the release agent to the inner peripheral surface of the injection sleeve, the inner tip is raised while the plunger tip remains under the injection sleeve, and the semi-molten metal heated to the semi-melt temperature range is fixed. The semi-molten metal was grasped from the supply hole of the semi-molten metal opened in the lower area of the fixed plate holding the mold, left to stand on the upper surface of the inner chip, and then the inner chip was lowered and transferred downward. Injection-close contact with the sleeve and the mold,
The inner tip and the plunger tip were integrally raised to press the metal material into the mold cavity for pressure casting.

[0008]

In the present invention, while the injection sleeve is kept upright all the time, the inner tip, which can be raised and lowered independently of the plunger tip, is operated at the center of the plunger tip to cause semi-melting near the upper end of the injection sleeve. After receiving the billet, which is a metallic material heated to the temperature range, and lowering the internal tip to store the billet in the injection sleeve,
The injection sleeve is docked with the die, the inner tip and the plunger tip are integrally raised, and the billet is press-fitted into the die cavity for pressure casting. Therefore, when the billet is stored in the injection sleeve, the inner peripheral surface of the injection sleeve is not rubbed and deformed, and the release agent applied to the inner peripheral surface of the injection sleeve is less likely to be peeled off or damaged. Therefore, the release agent is prevented from being mixed into the molded product, and good molded product quality is secured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for die-casting a semi-molten metal according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic view showing a spraying position of a release agent,
2 is an explanatory view showing a state of supplying the billet to the injection sleeve, FIG. 3 is an explanatory view showing a state where the injection sleeve is docked at a predetermined position of the mold, and FIG. 4 is a side view seen from AA of FIG. FIG. 5 is an explanatory view showing a state where the mold release agent is simultaneously sprayed onto the mold and the injection sleeve, FIG. 6 is a vertical sectional view of the injection sleeve, and FIG. 7 is a process explanatory view of the die-casting method of the semi-molten metal.

FIG. 1 shows a die casting apparatus. In the figure, 2 is a movable platen disposed on a fixed base 3, and the movable platen 2 is slidable in the left and right directions in the figure by a hydraulic piston (not shown).

A movable die 4 is fixed to one side surface of the movable platen 2. Reference numeral 6 denotes a fixed platen fixed on the fixed base 3, and a fixed mold 8 is fixed to the fixed platen 6. Reference numeral 10 indicates a tie bar.

Reference numeral 12 is an injection sleeve, and as shown in FIG. 6, it is fitted in a through hole 14a axially bored in the center of a plunger tip 14 which is slidable inside the injection sleeve 12, An internal tip 16 is provided separately from the plunger tip 14 and independent of the plunger tip 14 so as to be vertically movable. The inner tip 16 is composed of a top portion 16a, which is disposed in the upper portion and has a substantially truncated cone shape, and a rod portion 16b which is connected to the top portion 16a.

The injection sleeve 12 is attached to a main body of an injection device (not shown), and the injection device can be moved back and forth on a linear guide (not shown) in the axial direction of the die cast device 1.

Reference numeral 20 is a spray cylinder body, and a frame 28 having a spray lifting cylinder 26 is fixed to the lower end of this spray rod 21 via a rod 21 which is vertically expandable and contractible.

A vertically movable hollow rod 30 is provided in the spray elevating cylinder 26, and a spray nozzle 32 for an injection sleeve is fixed to the lower end of the hollow rod 30. A plurality of release agent spray holes are formed on the side surface and the lower portion of the injection sleeve spray nozzle 32.

A plurality of conduits 36 are arranged on the same plane as the axis of the hollow rod 30 with a certain distance therebetween, and the lower end of the conduit 36 is separated from the cavity surface 38 of the movable mold 4 and the fixed mold 8. It is alternately bent toward the cavity surface 38 so that the mold agent can be easily sprayed. Reference numeral 40 is a billet (semi-molten metal material), and 42 is a grip portion.

The work steps of the die casting method of the present invention using the stand-up type injection sleeve thus constructed will be described.

After the movable mold 4 and the fixed mold 8 are opened, pressure oil is simultaneously supplied to the spray cylinder main body 20 and the spray lift cylinder 26 to extend the rod 21, and the conduit 36 is shown by a broken line in FIG. The hollow rod 30 is extended and the injection nozzle spray nozzle 32 is lowered to the lower limit (upper end position of the injection sleeve 12) while lowering to a position above the cavity surface 38 of the molds 4 and 8.

Then, from the conduit 36 and the spray nozzle 32 for the injection sleeve, an appropriate amount of a mold release agent is applied to the cavity surfaces 38 of the molds 4 and 8, the inner peripheral surface of the injection sleeve 12, the top 16a of the plunger tip 14 and the inner tip 16, respectively. It is sprayed (FIG. 1, FIG. 5, FIG. 7 (2)).

When the pressure oil is gradually supplied to the spray cylinder body 20 at the same time as the release agent is sprayed, the rod 21 gradually extends and descends, and accordingly, the cavity surface 38 and the injection sleeve 12 are sufficiently sunk from the upper side to the lower side. It is sprayed.

When the spray of the release agent onto the cavity surface 38 and the injection sleeve 12 is completed, the rod 21 and the hollow rod 3 are
While retracting 0, the injection device (not shown) is moved on the linear guide to move the injection sleeve 12 from the position shown by the broken line in FIG. 2 to the fixed platen 6 side shown by the solid line. During this time, the movable platen 2 is moved to the fixed platen 6 side, the movable mold 4 and the fixed mold 8 are closed, and mold clamping is performed.

While the injection sleeve 12 is moving, the inner tip 16 is provided so as to easily receive the billet 40 held by the holding portion 42 while holding the plunger tip 14 in the lowered position.
Only the upper part of the injection sleeve 12 is raised to the vicinity of the upper end (FIG. 2, FIG. 7 (3)). In this case, it is desirable that the upper surface of the internal tip 16 be located slightly below the upper end surface of the injection sleeve 12 so as not to exceed the upper end surface.

Next, the billet 40, which is a semi-molten metal material, is gently loaded on the upper surface of the internal chip 16, the billet 40 held by the holding portion 42 is slowly released, and the internal chip 16 is moved at an extremely low speed. It is lowered (FIG. 7 (4), FIG. 7 (5)).

After that, the injection device is moved again on the linear guide, and the injection sleeve 12 is moved to the molds 4 and 8 shown in FIG.
Then, the injection sleeve 12 is docked to the molds 4 and 8 (broken line position).

Then, the inner tip 16 and the plunger tip 14 are integrated and raised at the same speed to press the billet 40 into the mold cavity (FIGS. 3 and 7 (6)).

After the above steps ((1) to (6) in FIG. 7) are completed, the molds 4 and 8 are opened and the molded product is taken out after waiting for the cooling and solidification of the metal material.

Comparing the process of the present invention with the conventional process, after spray-coating the inner peripheral surface of the injection sleeve 12 with the release agent, the entire inner peripheral surface of the injection sleeve 12 is contacted. In the present invention, the ascending operation of the plunger tip 14 is performed only during the injection shown in FIG. 7 (6), whereas in the conventional process, the process 4 is performed in addition to the process 6 which is the injection process.
Since the number of reciprocations in Step 5 is large, the chances of peeling or damaging the release agent film on the inner peripheral surface of the injection sleeve 12 spray-coated increases, and the released release agent component is mixed into the molded product. The risk of quality deterioration due to
In this embodiment, since the injection device is moved back and forth on the linear guide, it can be applied regardless of the thickness of the fixed mold.

[0029]

As is apparent from the above description, according to the present invention, the plunger tip that slides in the injection sleeve is fitted into the through hole formed in the axial direction of the central portion of the plunger tip and is separated from the plunger tip. In a die-casting machine having an upright injection sleeve that is independently slidable in the axial direction and has an internal tip that does not directly contact the inner peripheral surface of the injection sleeve, After applying the release agent to the inner peripheral surface of the sleeve, the inner tip is raised while the plunger tip remains under the injection sleeve, and the semi-molten metal heated to the semi-melt temperature range is fixed to the mold. After holding the semi-molten metal from the supply hole of the semi-molten metal opened in the lower area of the holding plate to be left still on the upper surface of the inner chip, the inner chip is lowered and transferred to the lower side A semi-molten metal material is obtained by closely adhering the ejection sleeve and the die, raising the inner tip and the plunger tip integrally, and press-fitting the metal material into the die cavity for pressure casting. Since the billet does not slide much even when descending on the inner surface of the injection sleeve, the release agent spray-coated on the inner surface of the injection sleeve is not damaged or peeled off, and the quality of the molded product can be maintained well. Is never transformed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a spraying position of a release agent.

FIG. 2 is an explanatory diagram showing a supply state of a billet to an injection sleeve.

FIG. 3 is an explanatory view showing a state in which the injection sleeve is docked at a predetermined position of the mold.

FIG. 4 is a side view as seen from AA of FIG.

FIG. 5 is an explanatory diagram showing a state where a mold release agent is simultaneously sprayed onto a mold and an injection sleeve.

FIG. 6 is a vertical sectional view of an injection sleeve.

FIG. 7 is a process explanatory diagram of a die-casting method for semi-molten metal.

FIG. 8 is a process explanatory diagram of a conventional die casting method.

[Explanation of symbols]

 1 Die Casting Device 2 Movable Platen 4 Movable Die 6 Fixed Platen 8 Fixed Die 10 Tyber 12 Injection Sleeve 14 Plunger Chip 14a Through Hole 16 Inner Tip 16a Top 16b Rod Part 18 Release Agent Spraying Device 20 Spray Cylinder Body 21 Rod 26 Spray Lifting Cylinder 30 Hollow Rod 32 Spray Nozzle for Injection Sleeve 36 Conduit 38 Cavity Surface 40 Billet (Semi-Melted Metal Material) 42 Gripping Part

Claims (1)

[Claims] 1. A center portion of a plunger tip that slides in an injection sleeve is fitted in a through hole formed in the axial direction of the plunger tip and is slidable in the axial direction independently of the plunger tip, and In a die-casting machine having a stand-up injection sleeve having an internal tip that does not directly contact the inner peripheral surface of the injection sleeve, a release agent is applied to the upper surface of the internal chip and the inner peripheral surface of the injection sleeve. After that, the inner tip is raised while the plunger tip remains under the injection sleeve, and the semi-molten metal heated to the semi-melting temperature range is opened in the lower area of the fixed plate holding the fixed mold. Holding the semi-molten metal from the supply hole, leaving it still on the upper surface of the internal chip, lowering the internal chip and transferring it downward, and then closely contacting the injection sleeve with the mold, A die-casting method for semi-molten metal, in which a nudger chip is integrally lifted to press-fit the metal material into a mold cavity for pressure casting.