JPH10277720A - Die for die casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the development of cast defect caused by remains remaining moisture in a die. SOLUTION: This die is constituted so as to execute positioning of a slide core 22 at an advancing end part by abutting the tip part of a slide holder 23 for holding the slide core 22 on the outer side surface (stopper surface) 24 of an insert 20 in a movable die 13. In such a case, plural air ejecting holes 40 directed to the stopper surface 24 are arranged in the slide holder 23, and after casting, cooling the die with outer cooling water and executing the coat of releasing agent, the air used to air blowing, is supplied into air passages 43, 44 arranged in the slide holder 23. Then, the air is ejected toward the stopper surface 24 from the air ejecting holes 40 and the moisture which can not be removed with the ordinary air blowing, on the stopper surface 24 is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting mold provided with a slide, and more particularly to a die casting mold suitable for vacuum casting in which casting is performed while reducing the pressure in a cavity.

[0002]

2. Description of the Related Art FIG. 8 shows a general die-casting mold having a slide. In the figure, 1 is a fixed type, 2 is a movable type, 3 is a slide, and a slide 3 is assembled to the movable type 2. The slide 3 includes a slide core 4 and a slide holder 5 for holding the slide core. The slide holder 5 is slidably mounted on the movable mold 2 via a slide key (not shown). The rear end of the slide holder 5 is connected to a piston rod 7a extending from a cylinder 7 supported by a support frame 6 protruding from the side surface of the movable die 2. The slide 3 moves forward by the operation of the cylinder 7. The slide holder 5 is positioned at the forward end by bringing the front end of the slide holder 5 into contact with a stopper surface 8 provided on the movable mold 2. Here, the movable mold 2 includes a movable main mold 2a and a movable nest 2b.
The outer surface of the movable nest 2b is used as the stopper surface 8.

In die casting, usually, after the mold is opened and a cast product is taken out, the mold is cooled by external cooling water, a mold release agent is applied, and water droplets are removed by air blow in order to prepare for the next casting. (For example, see Japanese Patent Application Laid-Open No. 57-72767), when the above-described die casting mold is used, even if the air blow is performed,
The air does not sufficiently reach the stopper surface 8 that regulates the forward end of the slide 3, and water remains on the stopper surface 8, and the remaining water is used in the cavity 9 during the next casting.
(FIG. 8).

[0004]

In the casting performed in the normal atmosphere, the water that has entered the cavity 9 does not cause a significant problem because it escapes from the mold through an air vent or the like during casting. However, in vacuum casting in which the interior of the cavity 9 is vacuumed before casting, the vacuum valve for vacuuming is closed at the same time as the pressure of the molten metal is increased, so that it becomes difficult to discharge water out of the mold. There is a problem that surface defects such as hot lines and hot water boundaries, or internal defects such as casting cavities are easily generated in the cast product due to the moisture remaining in the inside.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and makes it possible to eliminate moisture remaining in a mold, thereby preventing casting defects caused by moisture remaining. It is an object of the present invention to provide a die casting mold that can prevent the die casting.

[0006]

In order to achieve the above object, the present invention comprises a fixed type, a movable type, and a slide, wherein the slide is assembled with a front end of a slide holder for holding a slide core. In a die casting mold adapted to be positioned at the forward end by being brought into contact with a stopper surface provided on one of the dies, a plurality of air jetting air toward the stopper surface to the slide holder. An injection port is provided. In the die casting mold configured as described above, when air is blown in the mold opened state, air is injected from the air injection port of the slide holder toward the stopper surface, so that water does not stay on the stopper surface. .

According to the present invention, the movable mold may have a structure including a main mold and a nest. In this case, an outer surface of the nest can be used as a stopper surface.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 4 shows the overall structure of a die casting mold according to the present invention. In the figure, 11 is
A fixed type 13 fixed to a fixed platen 12; a movable type fixed to a movable platen 14 via a spacer 15;
Reference numeral 16 denotes a slide slidably mounted on the movable mold 13. The movable mold plate 14 can be moved forward and backward with respect to the fixed mold plate 12 by the operation of a cylinder device (not shown).
Mold closed state (FIG. 4) and a mold open state described later (FIGS. 6 and 7) separated from the fixed mold 11.
And are positioned. Each of the fixed mold 11 and the movable mold 13 includes main molds 17 and 18 and nests 19 and 20. A predetermined cavity 21 is provided between the nests 19 and 20 in the mold closed state. It is formed.

On the other hand, the slide 16 is
And a slide holder 23 for holding the slide holder. The slide holder 23 is slidably mounted on the movable mold 13 via a slide key (not shown). The rear end of the slide holder 23 is connected to a piston rod 25a extending from a cylinder 25 supported by a support frame 24 protruding from the side surface of the movable die 13. The slide 15 moves forward by the operation of the cylinder 25.・ They can be retracted. Thus, slide 16
The slide holder 23 is positioned at the forward end by bringing the front end of the slide holder 23 into contact with a stopper surface 27 (here, the outer surface of the movable insert 20) provided on the movable die 13. Thus, the slide core 22 is positioned so that its tip end is inserted into the cavity 21 by a predetermined length.

The fixed mold plate 12 has cavities 21.
An injection device 28 for injecting the molten metal at a high pressure is provided therein. As shown in FIG. 5, the injection device 28 includes a sleeve 29 inserted and fixed from the fixed mold plate 12 into the fixed mold 11, a plunger tip 30 slidably fitted on the sleeve 29, and An injection cylinder (not shown) in which a piston rod 32 is connected to a plunger rod 31 extending from the plunger tip 30. The injection device 28 moves the plunger tip 30 forward from the retracted position by the operation of the injection cylinder, so that a predetermined amount of the molten metal 3 supplied into the sleeve 29 from the hot water supply port 29a.
2 is injected into the cavity 21 at a high pressure.

The movable plate 14 is provided with an extruding mechanism 33 for extruding a cast product. This pushing mechanism 3
Reference numeral 3 denotes an extruding plate 34 disposed in the spacer 15, a base end supported by the extruding plate 34, and a movable main mold 1 connected to the other end.
It comprises a plurality of push pins 35 extending into the cavity 21 through the insert 8 and the insert 20 and a cylinder device (not shown) for moving the push plate 34 forward and backward. The extruding mechanism 33 retracts the extruding plate 34 before casting, thereby connecting the extruding pin 35 with the tip of the cavity 2.
After the casting, the extruding plate 34 is advanced so that the tip of the extruding pin 35 protrudes largely into the cavity 21.

The die casting mold is used for vacuum casting, and the movable mold 13 is provided with a negative pressure passage 36 communicating the inside of the cavity 21 with an external vacuum means. The negative pressure passage 36 is provided with a negative pressure valve 37 which is normally opened by receiving a negative pressure and closed by receiving the molten metal pressure in the cavity 21. This negative pressure passage 36
5, the plunger tip 30 blocks the hot water supply port 29a of the sleeve 29 and the limit switch 38 is actuated, so that the air in the cavity 21 becomes negative pressure as shown in FIG. Air is exhausted through the passage 36.

In order to perform casting using the above-described die casting mold, first, as shown in FIG. 4, after the slide 16 and the movable mold plate 14 are advanced, the movable mold 13 and the slide core 22 are fitted to the fixed mold 11, and then, as shown in FIG. A predetermined amount of molten metal 32 is supplied from the pouring port 29a into the sleeve 29, and the plunger tip 30 is advanced by the operation of the injection cylinder of the injection device 28. Then, during this forward movement, the limit switch 38
Operates to stop the plunger tip 30 from moving forward, and at the same time, the external vacuuming means is conducted to the negative pressure passage 37 in the movable mold 13, and the air in the cavity 21 is released from the negative pressure passage 3.
Exhausted through 6. When the evacuation is performed for a predetermined time, the plunger tip 30 is advanced again by the operation of the injection cylinder of the injection device 28, and the molten metal 32 in the sleeve 29 is injected into the cavity 21 at a high pressure, so-called reduced pressure casting is performed.

When the molten metal in the cavity 21 solidifies, the movable mold plate 14 retreats, and the movable mold 13 separates from the fixed mold 11 as shown in FIG. At this time, the slide 16 is positioned at the forward end as it is, and the casting C is released from the fixed die 11 while sticking to the movable die 13. Upon completion of the mold opening, the work unloading device 38 enters between the fixed mold 11 and the movable mold 13 as shown in FIG.
6, the extruding plate 34 of the extruding mechanism 33 advances, and the extruding pin 35 extrudes the casting C from the movable mold 13.
As a result, the casting C is held by the holding portion 39 of the work unloading device 38, and subsequently, the casting C is unloaded out of the mold by retreating the work unloading device 38.

Thereafter, an integrated device including a cooling means (not shown), a release agent applying means, and an air injection nozzle enters between the fixed mold 11 and the movable mold 13 to cool the mold with external cold water and release the mold. The application of the agent and the air blowing are sequentially performed, and the preparation for the next casting is completed.

Thus, in the present embodiment, FIG.
As shown in FIG. 3 to FIG. 3, a plurality of air injection ports 40 for injecting air toward the stopper surface 24 are provided in a slide holder 23 constituting the slide 16. Inside the slide holder 23, a T-shaped main air including a blind hole-shaped vertical hole 41 extending from the rear end to the front end side, and a horizontal hole 42 extending across the vertical hole 41 at the front end side. A passage 43 is provided, and a side hole 42 of the main air passage 43 is provided.
A plurality of sub air passages 44 are provided to communicate with the respective air injection ports 40. The lateral hole 42 is sealed at both ends by plugs 45.

An air source (not shown) for supplying compressed air to the air injection nozzle through a pipe 46 is provided in the vertical hole 41 of the main air passage 43 provided in the slide holder 23.
Are connected in common. Thereby, after the casting is completed and the mold is opened, when the air is blown using the air injection nozzle as described above, the same air flows from the plurality of air injection ports 40 through the main air passage 43 and the sub air passage 44 in the slide holder 23. Injected toward the stopper surface 24,
Moisture when the mold is cooled by external cold water in advance does not stay on the stopper surface 24. Therefore, at the time of the above-mentioned reduced pressure casting, water does not enter the cast product, and a cast product C excellent in quality without surface defects such as hot lines or hot water boundaries or internal defects such as a casting cavity is obtained. Become.

[0019]

As described above, according to the die casting mold according to the present invention, it is possible to eliminate moisture remaining in the mold, thereby preventing the occurrence of casting defects caused by moisture remaining. It is suitable for vacuum casting.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a main structure of a die casting mold according to the present invention.

FIG. 2 is a perspective view showing a structure of a holder part of a slide used in the die casting mold.

FIG. 3 is a plan view showing a structure of a holder portion of the slide shown in FIG. 2;

FIG. 4 is a cross-sectional view schematically showing the overall structure of the die casting mold.

FIG. 5 is a cross-sectional view schematically showing the structure of an injection device attached to the die casting mold.

FIG. 6 is a cross-sectional view showing a die-open state after casting in the present die-casting die.

FIG. 7 is a cross-sectional view showing a state of carrying out a cast product after casting in the die casting mold.

FIG. 8 is a cross-sectional view schematically showing a main part structure of a conventional die casting mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Fixed type 13 Movable type 16 Slide 17, 18 Main type 19, 20 Nesting 21 Cavity 22 Slide core 23 Slide holder 24 Stopper surface 36 Negative pressure passage 37 Negative pressure valve 40 Air injection port 43 Main air passage 44 Sub air passage

Claims (2)

[Claims] Claims 1. A fixed type, a movable type and a slide,
The slide is positioned at the forward end by bringing the front end of a slide holder holding a slide core into contact with a stopper surface provided on one of the molds to which the slide is attached. 3. The die casting die according to claim 1, wherein the slide holder is provided with a plurality of air injection ports for injecting air toward the stopper surface. 2. The die-casting die according to claim 1, wherein the movable die comprises a main die and a nest, and an outer surface of the nest is used as a stopper surface.