JPH0224518Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention is equipped with a die casting machine,
The present invention relates to a pouring device that feeds molten metal under pressure into a mold cavity.

(Prior art) Cast products that are required to have a precise shape and a smooth casting surface are usually manufactured by feeding molten metal at low speed into a cavity formed in a mold. It is cast using a die casting machine that solidifies the molten metal in the mold cavity under high pressure to obtain a molded product.

When casting is performed using such a die casting machine, the molten metal is retained in the injection sleeve, and then is pressed by a plunger tip that slides along the inner circumferential surface of the injection sleeve and is fed under pressure into the mold cavity. At this time, the molten metal enters the minute gap between the inner circumferential surface of the injection sleeve and the outer circumferential surface of the plunger tip and solidifies, causing flash to adhere to the plunger tip. The problem is that flash adhering to the tip prevents the plunger tip from working properly as it slides within the injection sleeve to deliver molten metal into the mold cavity.

For this reason, as a measure to remove flash attached to the plunger tip inside the injection sleeve, for example,
Japanese Unexamined Patent Publication No. 56-6768 describes a vertical die casting machine having an upper mold and a lower mold forming a mold cavity, in which molten metal injected into an injection sleeve provided in the upper mold is poured into the mold cavity. In order to pressurize the injection, the plunger tip (referred to as the injection tip in the above publication) attached to the tip of the lifting rod is slid to the lower limit position of the injection sleeve and held still, and then only the upper mold and injection sleeve are removed. The plunger tip is raised to open the mold, and then the elevating rod is operated to raise the plunger tip and house it in the injection sleeve.The end edge of the injection sleeve removes the flash that adheres to the plunger tip when feeding the molten metal. A method of peeling and removing it has been proposed.

However, in such a method, an extra process for removing flash is added to the original casting process, which not only reduces the productivity of casting work using a die casting machine, but also reduces the productivity of the plunger. Since the flash that has peeled off from the plunger chip will fall onto the surface of the molded product or the mold (lower mold), there is the inconvenience of having to remove the flash that has peeled off and fallen from the plunger chip. be.

(Purpose of the invention) In view of the above, the present invention has developed a special work process to remove flash attached to the plunger tip that sends molten metal from the injection sleeve to the mold cavity during casting using a die casting machine. The purpose of the present invention is to provide a pouring device for a die casting machine that can perform pouring without adding any cast flash and eliminates the inconvenience of the removed flash remaining in the cast molded product or mold. .

(Structure of the invention) The pouring device in the die casting machine according to the present invention includes an injection sleeve that is moved toward and away from the pouring port of the mold, a plunger tip that slides inside the injection sleeve, and a plunger tip that is connected to the plunger tip. and causes it to take a retracted position within the injection sleeve in order to retain the molten metal within the injection sleeve,
a drive rod for moving the injection sleeve from a retracted position to an advanced position to deliver molten metal from the injection sleeve to the mold cavity;
An annular groove is formed in the inner peripheral surface of the injection sleeve at a position around the plunger tip that assumes the above-mentioned retracted position, and an air supply means is provided at a position opposite to the annular groove when the plunger tip assumes the above-mentioned forward position in the drive rod. is arranged and configured. After the flash attached to the plunger tip is deposited in the annular groove as the plunger tip moves from the above-mentioned retracted position to the forward position in the injection sleeve, air is blown into the annular groove by the air supply means. and removed.

By doing this, the flash attached to the plunger tip inside the injection sleeve can be removed when the plunger tip slides inside the injection sleeve to deliver the molten metal to the mold cavity. There is no need to set up a separate work process for removing flash, and therefore, the inconvenience of reducing productivity in casting with a die casting machine associated with the removal of flash adhering to the plunger tip is avoided. There is no possibility of this occurring.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a pouring device in a die casting machine according to the present invention. In this example, a lower mold 10, which is a fixed mold having a recess 10a constituting a mold cavity, is placed on a fixed base 12. The upper end of a tie rod 14 is fixed to the lower surface of the fixed base 12, and the lower end of this tie rod 14 is attached to the upper surface of the injection cylinder support frame 16. An injection cylinder 18 is disposed in the center of the injection cylinder support frame 16, and is supported by a swing center shaft 17 with both ends attached to opposite side surfaces thereof, and this injection cylinder 18 is not shown. A known tilting means is used to perform a tilting operation about the pivot axis 17. An injection piston 20 is fitted into the injection cylinder 18, and the injection piston 20 is connected to a plunger rod 24 via an annular member 22. A plunger tip 26 is fixed to the tip of the plunger rod 24. The injection piston 20 is moved up and down along the inner peripheral surface of the injection cylinder 18 by hydraulic pressure supplied into the injection cylinder 18.

An air passage 28 is formed in the plunger rod 24 along its longitudinal direction, and the air passage 28 extends radially from the center of the plunger rod 24 at a predetermined position of the plunger rod 24.
A plurality of nozzles 29 are drilled toward the outer peripheral surface of the
It is assumed that it communicates with The air passage 28 is connected to an air supply source 32 via a directional control valve 30 which switches its valve configuration when the solenoid is energized to connect the air supply source 32 to the air supply source 32.
and the air passage 28. It is considered to be a normally closed solenoid valve.

On the other hand, on the upper surface side of the injection cylinder support frame 16, an engagement ram 34 extending from the injection cylinder 18 is provided.
In addition, a sleeve coupling frame 38 in which a cylinder 36 is fitted into the engagement ram 34 is disposed, and an injection sleeve 42 is attached to the upper end of the sleeve coupling frame 38 via a joining member 40.
is fixed. The sleeve coupling frame 38 moves up and down along the engagement ram 34 by the operation of the cylinder 36, and at its upper limit position, the injection sleeve 42 moves toward the positioning ring member provided on the lower surface of the lower die 10. 44 to the pouring port 10b of the lower mold 10,
In addition, at the lower limit position, the injection sleeve 4
2 assumes a lower position away from the pouring port 10b of the lower mold 10.

A plunger tip 26 is located within the injection sleeve 42.
The plunger tip 26 is slidably inserted into the injection piston 20 in the injection cylinder 18.
The plunger rod 24 is driven by a plunger rod 24 that moves up and down as the robot moves up and down, and is moved between a retreat position shown by a solid line in FIG. 1 and a forward position shown by a dashed line in FIG. It is assumed that The retracted position of the plunger tip 26 corresponds to the injection piston 20.
The lower end surface of the annular member 22 disposed in the sleeve connection frame 38 is set by coming into contact with and being locked therein. An annular groove 46 is formed in the inner peripheral surface of the injection sleeve 42 at a position facing near the upper end of the outer peripheral surface of the plunger tip 26 in the retracted position.

Further, the forward position of the plunger tip 26 is set by a limit switch 48 attached to a predetermined position of the sleeve coupling frame 38 being brought into contact with an engaging portion 50 provided on the plunger rod 24. When the plunger tip 26 assumes this forward position, the nozzle 29 bored in the plunger rod 24
Its position on the plunger rod 24 is set so as to face an annular groove 46 formed on the inner peripheral surface of the injection sleeve 42. When the limit switch 48 is brought into contact operation by the engaging portion 50 provided on the plunger rod 24,
It defines the forward position of the plunger tip 26 and supplies current to the solenoid of the directional control valve 30.

When casting is performed by a die casting machine with this configuration, first, the plunger tip 26 in the injection sleeve 42 is placed in a retracted position, and the sleeve coupling frame 38 is
is at the lower limit position, and the injection sleeve 42 is in the lower mold 1
0, the injection cylinder 18 is tilted about the pivot axis 17 together with the sleeve coupling frame 38 by a tilting means (not shown), and then tilted. Molten metal is injected into the injection sleeve 42 supported by the rolled sleeve coupling frame 38. At this time, plunger tip 26
is in a retracted position within the injection sleeve 42,
The injected molten metal is retained in the injection sleeve 42 above the plunger tip 26.

When the injection of the molten metal into the injection sleeve 42 is completed, the injection cylinder 18 together with the sleeve coupling frame 38 is brought into an upright position as shown in FIG. 1 by the tilting means. Then, when the sleeve coupling frame 38 is at its upper limit position along the engagement ram 34, that is, as shown in FIG.
It is raised to a position where it is connected to pouring port 10b of No. 0.

On the other hand, at this time, a movable mold (upper mold) (not shown) is placed on the upper surface of the lower mold 10, which is a fixed mold, on which the concave portion 10a is provided, and the mold is clamped to form a mold cavity. has been done.

In this state, when the injection sleeve 42 is connected to the pouring port 10b of the lower mold 10, the injection cylinder 18 is activated and the injection piston 20 is raised, and the plunger rod 24 is moved upward and moved to the retracted position. The plunger tip 26, which was intended to be used as a stopper, is driven to slide upwardly within the injection sleeve 42, causing the plunger tip 26 to assume an advanced position as shown by the dashed line in FIG. As a result, the plunger tip 26 pressurizes and delivers the molten metal retained in the injection sleeve 42 to a mold cavity formed inside the lower mold 10, which is a fixed mold, and the movable mold.

Thereafter, when the molten metal sent into the mold cavity is cooled and solidified in the mold cavity under high pressure, the injection piston 20 is lowered by the operation of the injection cylinder 18, and the plunger rod 24 is moved downward accordingly. Then, the plunger tip 26, which was supposed to take the forward position, is driven to slide downward within the injection sleeve 42, and the plunger tip 26 is again made to take the retracted position as shown by the solid line in FIG. . Then, the lower end surface of the annular member 22 fixed to the injection piston 20 contacts and presses the sleeve coupling frame 38, so that the sleeve coupling frame 38 connects the injection sleeve 42 and the pouring port 10b of the lower die 10. It is lowered to the lower limit position where the engagement is released, and a series of casting work steps is completed.

In addition, in the lower mold 10, which is a solid metal mold, and the movable mold, after the molten metal is cooled and solidified in the mold cavity, the mold is opened and the cast molded product is taken out, and the molded product is removed on the surface of both molds. A mold release accelerator is sprayed on the mold and the mold is clamped for the next casting.

In the series of casting work steps as described above, when the plunger tip 26 slides inside the injection sleeve 42 from its retracted position to its forward position in order to pressurize and send molten metal into the mold cavity, the outer circumferential surface of the plunger tip 26 The molten metal that has entered the minute gap between the mold cavity and the inner circumferential surface of the injection sleeve 42 solidifies and forms a flash when the molten metal in the mold cavity is cooled. Such flashing may adhere to the outer circumferential surface of the plunger tip 26 and prevent the plunger tip 26 from sliding smoothly within the injection sleeve 42. In this case, as shown in FIG. Plunger tip 26 sliding within sleeve 42
The flash W attached to the outer peripheral surface of the plunger tip 26 passes through the annular groove 46 provided on the inner peripheral surface of the injection sleeve 42 when the plunger tip 26 slides inside the injection sleeve 42 from its retracted position to its forward position. At this time, it is peeled off from the outer peripheral surface of the plunger tip 26 by the peripheral edge of the annular groove 46, and a portion thereof is deposited within the annular groove 46. This prevents the plunger tip 26 from interfering with smooth sliding within the injection sleeve 42 due to the flash W attached to the outer circumferential surface of the plunger tip 26.

Furthermore, when the plunger tip 26 assumes the forward position as shown in FIG.
9 faces the annular groove 46, and the limit switch 48 attached to the sleeve coupling frame 38 is actuated by the engaging portion 50 provided on the plunger rod 24.
Current is supplied to the solenoid of the directional control valve 30. As a result, the valve arrangement of the directional control valve 30 is switched to the open state, and the air supply source 3
Air from the plunger rod 24 is introduced into the air passage 28 of the plunger rod 24, and as shown by arrow B in FIG. The flash W deposited on 46 is removed.

In the above-described example, the annular groove 46 provided on the inner peripheral surface of the injection sleeve 42 allows the plunger tip 26 to slide inside the injection sleeve 42 in order to pressurize and send the molten metal from the injection sleeve 42 to the mold cavity. During the moving process, the flash attached to the outer circumferential surface of the plunger tip 26 is peeled off and removed, so there is no need to add a separate process for removing flash, and therefore production in casting with a die-casting machine is reduced. There is no risk of deterioration in performance. Moreover, since the flash is peeled off and removed from the outer peripheral surface of the plunger tip 26 under the lower mold 10, which is a fixed mold, the flash flash peeled off from the outer peripheral surface of the plunger tip 26 is removed from the cast molded product or There is no risk of remaining in the mold cavity.

In the above example, the air passage 28 and nozzle 29 are formed in the plunger rod 24 as air supply means, but an air supply hose and a nozzle member may be provided around the outer circumference of the plunger rod 24. Further, the air supply time may be controlled by a timer or the like.

(Effects of the invention) As is clear from the above description, the pouring device for a die casting machine according to the invention prevents flash from sticking to the plunger tip sliding inside the injection sleeve connected to the mold cavity. During the process in which the plunger tip slides within the injection sleeve to deliver molten metal to the mold cavity, it can be separated and removed from the plunger tip. Therefore, the flash attached to the plunger tip during casting with a die casting machine can be removed without adding a separate process to the casting process, and the flash from the plunger tip can be removed. It is possible to avoid the inconvenience of reducing productivity in casting with a die-casting machine due to removal.

Furthermore, since the flash attached to the plunger tip is removed below the mold cavity, the removed flash may adhere to the cast product or enter the mold cavity. There is no risk that it will happen.

[Brief explanation of the drawing]

FIG. 1 is a side view including a partial cross section showing an example of a pouring device in a die casting machine according to the present invention, and FIGS. 2 and 3 show the configuration and operation of the main parts of the example shown in FIG. 1. It is a partially enlarged view provided for explanation. In the figure, 10 is a lower mold, 10b is a spout, 18 is an injection cylinder, 20 is an injection piston, 24 is a plunger rod, 26 is a plunger tip, 28 is an air passage, 29 is a nozzle, 32 is an air supply source, 42
is an injection sleeve, and 46 is an annular groove.

Claims (1)

[Scope of utility model registration request] an injection sleeve that is moved toward and away from the pouring port of the mold;
a plunger tip that slides within the injection sleeve; and a plunger tip connected to the plunger tip that allows the plunger tip to take a retracted position within the injection sleeve so as to retain the molten metal within the injection sleeve, and to remove the mold from the injection sleeve. a drive rod that moves the plunger tip from the retracted position to the forward position in the injection sleeve to deliver molten metal to the cavity, and the plunger tip is positioned around the plunger tip in the retracted position on the inner peripheral surface of the injection sleeve. an annular groove is formed in which flash burrs attached to the plunger tip are deposited as the plunger tip moves within the injection sleeve; and when the plunger tip of the drive rod assumes the forward position, the annular groove 1. A pouring device for a die casting machine, characterized in that an air supply means for blowing air into the annular groove is disposed at a position facing the groove.