JP2965179B2 - Mold casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold casting apparatus, and more particularly to a mold casting apparatus having an improved hot water supply mechanism suitable for magnesium alloy die casting.

[0002]

2. Description of the Related Art Conventionally, a casting cavity communicated with a casting port through a casting port at a lower portion of a mold in which a casting sleeve is engaged and a hot water supply passage (runner portion) extending vertically. In order to perform casting by a mold casting apparatus having a mold apparatus having a mold and a hot water supply apparatus for supplying hot water into the casting sleeve, a molten metal is put into the casting sleeve, and the casting sleeve is placed at the bottom of the mold. Then, the injection plunger is raised, and the molten metal in the casting sleeve is fed into the cavity and injected.

[0003] As a method of pouring a molten metal into the casting sleeve, the casting sleeve is separated from a mold and poured with a ladle. In order to make it easier to pour the molten metal with a ladle, the casting sleeve is tilted (for example, FIG. 3 of Japanese Patent Publication No. 57-21414), or the casting sleeve is retracted from below the mold while keeping the casting sleeve in a vertical posture (see the same publication). (Fig. 4). Fig. 2 shows the method of lowering the lower mold while keeping the casting sleeve attached to the lower mold, and pouring the molten metal into the casting sleeve from the ladle from above the lower mold through the hot water supply passage. It is shown.

[0004]

In the method in which the casting sleeve is separated from the mold and the molten metal is poured with a ladle, the time from the pouring of the molten metal into the casting sleeve to the actual injection into the cavity is taken. become longer. In addition, foreign matter is easily mixed in the molten metal. Further, when the casting sleeve is inclined, the molten metal cannot be filled to the full upper edge of the casting sleeve, so that the casting sleeve needs to be lengthened accordingly. Even in the method of pouring the molten metal from above the lower mold with the lower mold and the casting sleeve attached, it is necessary to wait only while the upper mold and the lower mold are clamped. Become. Further, there is a problem that molten metal spilled on the upper surface of the lower mold is likely to be applied.

Further, in any of the above methods, the molten metal is exposed to the atmosphere when the molten metal is transferred to the casting sleeve or until the casting sleeve is engaged with the casting port. For this reason, the molten metal is easily oxidized, which is not suitable for casting of easily oxidizable metals (for example, magnesium, aluminum and alloys thereof), and there is a possibility that casting defects may occur due to mixing of oxides.

[0006]

SUMMARY OF THE INVENTION A mold casting apparatus according to the present invention has a movable mold and a fixed mold in which a casting cavity is formed on a mating surface. A mold casting apparatus comprising: a mold device connected to the casting cavity through a casting port and a hot water supply passage extending vertically, and a hot water supply device for supplying hot water into the casting sleeve. A horizontal hot water supply passage, which is provided on a fixed mold and is provided on the inner wall surface of the casting port or the hot water supply passage, has a tapered shape expanding toward the movable mold.
To the front end of the hot water supply passage on the movable side.
Before the hot water is filled into the cavity.
Air in cavity casting sleeve can be replaced with inert gas
A rod having a passage for an inert gas, a conduit for communicating a rear lower surface of the hot water supply passage with the hot water supply device, a heater for heating molten metal provided in the conduit, and the casting port of the hot water supply passage. Or, in the vicinity of the hot water supply passage, a valve seat provided in a tapered shape that expands toward the movable mold, and is held by the movable mold, and is advanced and retreated in a seating direction with respect to the valve seat by a driving device. And a valve element of an on-off valve for opening and closing the hot water supply passage.

[0007]

In the mold casting apparatus of the present invention, the casting sleeve is attached to the casting opening of the clamped mold.
The on-off valve is opened, and molten metal is supplied from a hot water supply device to a casting port or a hot water supply passage in a mold. This melt accumulates in the casting sleeve. After supplying the required amount of molten metal, close the on-off valve,
Immediately raise the injection plunger and inject the molten metal into the cavity. As described above, in the mold casting apparatus of the present invention, the molten metal is supplied into the casting sleeve, and can be injected immediately.
Also, there is no spilling of molten metal during hot water supply. Further, the casting sleeve can be always in a vertical position, a large amount of molten metal can be poured into the casting sleeve, and the length of the casting sleeve can be reduced.

In the mold casting apparatus of the present invention, the molten metal is not exposed to the atmosphere at all until it is injected from the hot water supply apparatus into the cavity. Therefore, it is suitable for casting a metal that is easily oxidized, and also prevents casting defects due to oxides. It is extremely useful for die casting magnesium alloys that are easy to explode when exposed to the atmosphere. Since a heater is provided in the conduit, the molten metal remaining in the conduit does not solidify and can be used as it is for the next hot water supply. Therefore, the pouring time can be extremely shortened.

In the mold casting apparatus of the present invention, the hot water supply passage is opened and closed when the valve body held by the movable mold is seated on or separated from the valve seat provided on the fixed mold. In this case, the fixed type does not require a sliding holding member that slidably supports the valve element, and the sliding surface of the sliding holding member does not face the hot water supply passage. As a result, the sealing performance of the hot water supply passage is improved.

The present applicant has proposed a casting apparatus similar to the present invention in Japanese Patent Application No. 3-9945. However, in the casting apparatus of the prior application, a valve body is inserted into the molten metal passage from the side opposite to the fixed mold cavity, so that the molten metal is continuously supplied from the molten metal passage. In the casting apparatus of the prior application, since the sliding surface between the valve element and the fixed mold faces the molten metal passage, the molten metal may leak from the sliding surface. The present invention has been improved to reliably prevent such molten metal leakage.

[0011]

Embodiments will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a mold casting apparatus according to an embodiment of the present invention, and FIG. 2 and subsequent figures are enlarged sectional views of the vicinity of a hot water supply passage and an on-off valve. The mold apparatus 1 includes a fixed mold 3 mounted on a fixed platen 2.
And a movable mold 5 attached to a movable platen 4 which is moved forward and backward with respect to the fixed mold 3 by a toggle mechanism (not shown) in the left-right direction in the figure. This fixed mold 3
A casting port 6 is provided on the bottom surface of the mold composed of the movable mold 5 and the movable mold 5 so that molten metal can be supplied to the cavity 8 via a runner portion 7 as a hot water supply passage. The upper end of a casting sleeve 9 can be engaged with the casting port 6. The casting sleeve 9 is provided at an upper end portion of the injection device 10, and the injection plunger 11 is slidably disposed in the casting sleeve 9. The injection plunger 11 is connected to an injection cylinder (not shown) via a rod 12 and is moved up and down by the injection cylinder. After the casting sleeve 9 is slightly lowered from the state shown in FIG. 1 and separated from the molds 2 and 3, it is swung laterally or moved horizontally to move the opening to a position away from the mold position. The inside of the injection sleeve 9 can be cleaned by spraying or a lubricant can be applied.

The casting hole 6 extends from the opening in the inner peripheral wall of the runner 7.
The pouring port 6 and the outside of the mold are
They are communicated via a horizontal hot water supply passage 13 provided in the fixed mold 3. However, the inner peripheral surface of the hot water supply passage 13 which is provided in a horizontal state has a tapered shape that gradually expands toward the movable mold 5, and all the molten metal in the hot water supply passage 13 is on the casting port 6 side. To run down. In the hot water supply passage 13, the on-off valve 1 is located near the casting port 6.
4 are provided. The on-off valve 14 includes a tapered valve seat 15 that opens toward the movable mold 5 and a valve body 16 that is held by the movable mold 5 so as to be able to advance and retreat, and that can be seated on the valve seat 15. Have. The valve body 16 includes an opening / closing cylinder (valve body driving device) 1 fixed to a part of the movable mold 5.
7 are connected by screwing. 19 is a guide bush for sliding the valve element. In addition,
A solenoid or the like may be used instead of the cylinder.

The hot water supply passage 13 also serves as a molten metal reservoir, and a conduit 20 that is inclined obliquely rearward is attached to the rear lower surface of the horizontal hot water supply passage 13. Conduit 2
Reference numeral 0 denotes an inner liner 21 made of ceramic or heat-resistant metal (for example, SKD61) at the inner surface in contact with the molten metal, and an induction heating coil (induction heater) 21a and a heat insulating material 21b are provided on the outer peripheral side of the inner liner 21. . Note that an inner liner or an induction heating coil made of ceramic or heat-resistant metal may be used around the hot water supply passage 13 in the fixed mold 3.

A hot water supply device 23 is installed via a horizontal conduit 22 provided following a conduit 20 inclined to supply hot water to the hot water supply passage 13. This water heater 2
3 is provided with a molten metal storage tank 24 and a pump device 25 for pumping hot water in the storage tank 24. This pump device 25
Has a cylinder barrel 27 with a piston 26 inserted therein,
A cylinder 28 for vertically moving the piston 26 is provided, and the inside of the cylinder barrel 27 is communicated with the inside of the storage tank 24 via a passage 29 and a suction port 30. A valve stem 31 is provided so as to open and close the suction port 30, and the valve stem 31 is moved up and down by a valve cylinder 32. Barrel 27
The molten metal therein can be supplied to the conduit 22 through a passage 33 and a check valve 34. 35 is the conduit 22
The heater is provided in the.

In the fixed mold 3, a rod 36 is slidably provided on the fixed plate 2 side of the hot water supply passage 13 in a horizontal state. Reference numeral 37 denotes a cylinder fixed to a part of the fixed platen 2, and the rod 36 can be moved in and out of the hot water supply passage 13 and retracted by the operation of the cylinder 37. A passage 38 as shown in FIG. 1 is provided in the rod 36, and the rear of the passage 38 is connected to an inert gas supply source (not shown) via a connecting member 39. 38 is opened at the outer peripheral surface near the tip of the rod 36, and the rod 36 is connected to the hot water supply passage 13.
When it advances to the portion, the inert gas can be supplied into the cavity 8 through a narrow passage between the opening of the passage 38 and the inner peripheral surface of the hot water supply passage 13 which has a divergent taper shape. It has become. In addition, a passage 46 communicating with the outside air is provided on a sliding surface of the rod 36 behind the hot water supply passage 13 of the fixed mold 3, and when the rod 36 retreats,
Hot water supply passage 13 communicates with outside air via passage 46.

Reference numeral 40 denotes a feeder pin. The pin 40 is moved forward and backward by a cylinder 41 attached to a part of the fixed mold 3. Reference numeral 42 denotes a product extrusion device including an extrusion pin 43. Reference numeral 44 denotes a known mold degassing device.
It is communicated with the cavity 8 via a gas vent passage 45 provided on the separation surface of the molds 3 and 5.

In the thus-configured die casting apparatus, when the valve rod 31 is raised and the piston 26 is raised in this state, the molten metal M in the storage tank 24 is removed from the cylinder barrel 27.
It is sucked in. At this time, since the check valve 34 is provided in the passage 33 and the conduit 22, the molten metal M in the conduits 20 and 22
Does not flow backward and is sucked into the cylinder barrel 27. Next, with the valve body 16, the feeder pin 40, and the product push-out pin 43 retracted to predetermined positions, the mold is clamped as shown in FIG. In the state of being docked to the lower surfaces of the molds 3 and 5, the cylinder 37 is operated to advance the rod 36 in FIG. 1, and the outlet of the passage 38 in the rod 36 reaches a position facing the tapered inner peripheral surface of the hot water supply passage 13. By moving it, an on-off valve (not shown) or the like is operated, an inert gas is introduced from the outlet of the passage 38, and the air in the cavity 8 and the casting sleeve 9 is expelled and filled with the inert gas.

Next, the suction port 30 is closed by the valve rod 31 and, as shown in FIG. 2, the piston 26 is lowered in a state in which the on-off valve 14 with the valve body 16 retracted and the on-off valve 14 kept open. And the molten metal M in the cylinder barrel 27
Is poured into the casting sleeve 9 through the casting port 6 through the passage 33, the check valve 34, the conduits 22, 20, the hot water supply passage 13, and the runner portion 7. The injection plunger 11
Is preferably raised to the upper limit and gradually lowered as the molten metal M is poured, in order to suppress the extreme flow and scattering of the molten metal as much as possible, to prevent air from being entrained, and to prevent the temperature of the molten metal from lowering. At this time, the casting sleeve 9 is filled with the inert gas. However, as the molten metal falls into the casting sleeve 9 and is supplied, the inert gas in the casting sleeve 9 becomes the upper cavity. It is driven in eight directions and escapes from the open mold degasser 44. When the pump device 25 is stopped, all the molten metal M in the hot water supply passage 13 whose inner surface is slightly tapered falls into the casting sleeve 9, and the molten metal in the conduit 20 is seen to the top of the conduit 20. It remains in the state. Then, the next pouring is performed efficiently in a shorter time.

After a sufficient amount of the molten metal M is stored in the casting sleeve 9, the operation of the pump device 25 is stopped. In addition,
Since the inner peripheral surface of hot water supply passage 13 is inclined toward runner portion 7, all molten metal in hot water supply passage 13 enters casting sleeve 9. The molten metal in the conduit 20 remains in a state of entering the upper end surface. Next, as shown in FIG. 4, the on-off valve 14 is closed by seating the valve body 16 on the valve seal 15,
Further, the rod 36 is retracted to the position shown in FIG. 4, the injection plunger 11 is raised, and the molten metal M is injected into the cavity 8. At this time, the cavity 8 is filled with an inert gas, but the molten gas M is cast into the cavity 8 so that the inert gas in the cavity 8 is removed from the gas vent passage 45,
It is discharged to the atmosphere via the mold degassing device 44. Of course, when the molten metal reaches the mold degassing device 44, the valve of the mold degassing device 44 is closed by the inertia force of the molten metal or an electric command, and the molten metal enters the mold degassing device 44,
It does not blow out. In addition, since there is no air in the cavity 8 and only inert gas, even if a small amount of inert gas that has not been discharged outside during casting remains in the molten metal,
The inert gas reacts and disappears due to the high heat, and the space in which the inert gas remains is crushed by the high-pressure molten metal, so that no cavities are generated in the molten metal and thus in the cast product. In this embodiment, since the on-off valve 14 is provided, the injection pressure surely prevents the molten metal M from flowing back toward the hot water supply passage 13 and the storage tank 24. In addition, since the rod 36 is retracted to allow the passage 46 to communicate with the hot water supply passage 13, as in the case where a small burr adheres to the on-off valve 14 that should have been completely closed during high-pressure casting. However, when the on-off valve 14 is not completely closed for some reason and there is a slight gap, a part of the molten metal blows out into the hot water supply passage 13. The applied force is dissipated outside through the passage 46 and does not adversely affect the remaining molten metal in the conduit 20.

At the time of injection, the cylinder 41 is operated while the molten metal M is substantially filled in the cavity 8, and the pin 40 for the feeder is advanced to perform the feeder operation. The injection is over,
When the molten metal in the cavity 7 and the like solidifies and cools after a predetermined time, the mold is opened. At this time, the cylinder 37 is actuated to advance the rod 36 at the same time, and after covering the upper end of the conduit 20 with the rod 36, the inert gas or air or lubricant is sprayed into the hot water supply passage 13 from the passage 38 to supply hot water. The inside of the passage 13 is cleaned. This state is shown in FIG.
Thereafter, after the removal of the product is completed, the mold is clamped again, and the molten metal is supplied into the casting sleeve 9 by the same procedure as described above to perform casting. In this case, the molten metal remaining in the conduits 20, 22 and the like is maintained at a required temperature by the induction heating coil 21a, the heater 35, and the like, and is immediately supplied into the casting port 6 by the pump pressure. Supply is extremely quick.

After the molten metal M is poured into the casting sleeve 9, the on-off valve 14 is closed, and the injection process can be started immediately. Therefore, the casting time can be shortened, and the temperature of the molten metal in the casting sleeve 9 can be reliably prevented from lowering and thereby partially solidifying. Products can be obtained.

Further, as is apparent from FIG.
The molten metal in the casting sleeve 9
Since it is supplied to the inside, even a molten metal such as aluminum or magnesium which is easily oxidized can be cast without causing any oxidation. Therefore, casting of easily oxidizable metals can be performed without any trouble, and casting defects due to oxides can be reliably prevented, so that extremely high quality cast products can be obtained.

In this embodiment, a cooling mechanism such as water cooling can be incorporated in the valve body 16. Thereby, the valve body 16 can be protected from high heat. As is clear from the figure,
In the present embodiment, the inner peripheral surface of the hot water supply passage 13 has a tapered shape that expands. For this reason, there is no portion like a weir that obstructs the flow of the molten metal, the flow of the molten metal in the hot water supply passage 13 is smooth, and the molten metal does not remain in this portion.

In the above-described embodiment, a horizontal clamping vertical casting mold apparatus is shown in which the movable mold 5 is clamped to the fixed mold 3 from the lateral direction and cast from below. After the molten metal in the cavity 8 has solidified, the movable mold 5 is fixed to the fixed mold 3.
When the solidified product is taken out from the opening, the biscuit portion on the casting port 6 side with respect to the on-off valve 14 can also be taken out integrally with the cast product. As is clear from the figure, since the casting sleeve 9 of this embodiment is in the vertical position connected to the casting port 6 at the time of casting, a large amount of molten metal M can be poured into the casting sleeve 9 and casting is performed. The length of the sleeve 9 is also short and sufficient. In addition, the casting sleeve 9 may be slightly lowered to separate it from the molds 3 and 5 other than at the time of casting, and tilted around the lower portion of the injection device 10 to clean the inside of the casting sleeve 9. In the present invention, the mold may be a vertical clamp mold in which the movable mold moves up and down.

[0025]

As described above, in the mold casting apparatus of the present invention, the molten metal in the hot water supply apparatus is supplied to the casting sleeve through the conduit, the hot water supply passage, and the casting port in the mold. No spilling of molten metal during hot water supply. Furthermore, since the molten metal does not come into contact with the atmosphere during pouring, it can be cast even if the molten metal is extremely easily oxidized, such as magnesium.
Casting defects caused by voids due to oxides can also be prevented. If a non-porous die casting method of casting under an atmosphere of oxygen or the like is used together, a cast product of good quality without burrs can be obtained easily and reliably. In addition, the pouring time is remarkably short, and the casting cycle can be shortened. In addition, the temperature of the molten metal to be cast is sufficiently high, so that a high quality cast product can be obtained.

According to the present invention, the sealing property of the hot water supply passage provided in the fixed mold is good, and the leak of the molten metal from the hot water supply passage is reliably prevented. In the present invention, the casting sleeve can always be in the vertical position, and a large amount of molten metal can be poured into the casting sleeve to shorten the length of the casting sleeve. If a check valve is provided at the conduit connection of the hot water supply device, the backflow of the molten metal is reliably prevented. Since the molten metal remaining in the conduit is heated by a heater provided in the conduit and maintained at a required temperature, it can be used as it is for the next pouring.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mold casting apparatus according to one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state at the time of pouring of an embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a longitudinal sectional view showing a state at the time of injection according to the embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a state when the mold is opened according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold apparatus 3 Fixed mold 5 Movable mold 6 Casting port 7 Runner part 8 Cavity 9 Casting sleeve 11 Injection plunger 13 Hot water supply passage 14 Open / close valve 15 Valve seat 16 Valve element 17 Opening / closing cylinder 20,22 Pipe 23 Hot water supply device Reference Signs List 25 pump device 26 piston 30 suction port 34 check valve 35 heater 36 rod 37 cylinder 38 passage 45 mold degassing device

Claims (1)

(57) [Claims] 1. A casting die in which a casting cavity is formed in a mating surface and a fixed die, and a casting hole at a lower part of a mold in which a casting sleeve is engaged and a hot water supply passage extending in a vertical direction. And a hot water supply device for supplying hot water into the casting sleeve, the mold casting device being provided in the fixed mold, the casting port being provided in the fixed mold. Alternatively, a horizontal hot water supply passage provided in the inner wall surface of the hot water supply passage is provided, and the hot water supply passage having a tapered shape expanding toward the movable mold is provided .
The hot water passage is movable forward and backward to the movable mold side front end, and
Cavity casting before the hot water is filled into the cavity
Inert gas that can replace the air inside the
A rod having a water passage, a conduit connecting a rear lower surface of the hot water supply passage to the hot water supply device, a heater for heating the molten metal provided in the conduit, and the pouring port or the hot water supply passage of the hot water supply passage And a valve seat provided in a tapered shape that expands toward the movable mold, and a hot water supply passage opening and closing that is held by the movable mold and is advanced and retracted in a seating direction with respect to the valve seat by a driving device. And a valve element for an on-off valve for use in a mold.