JP2002126863A - Manufacturing method for large and thin aluminum die- cast product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a large and thin aluminum die-cast product. SOLUTION: To a die used for the die-cast manufacturing capable of providing a gate on the arbitrary position, a mechanism of conducting temperature raising and holding up to 300-350 deg.C is added, and while keeping this condition, molten aluminum is filled into a mold cavity to manufacture the large and thin aluminum die-cast product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to the manufacture of large thin aluminum die cast products. More specifically, the present invention relates to the production of an aluminum die-cast product having an area of 0.16 square meters or more and an average thickness of 1.5 mm or less.

[0002]

2. Description of the Related Art As a technique related to a method of manufacturing an aluminum die-cast product, generally, a cavity of a mold provided with a circulation path of a cooling medium is filled with molten aluminum, and then the cooling medium is passed through the circulation path. There is a method of rapidly solidifying molten aluminum in a mold cavity to obtain a product.

However, when molding a thin aluminum die-cast product, the cavity must be filled with molten aluminum in 0.06 to 0.1 seconds, so that the flow distance of the molten aluminum is limited to 300 mm or less. It has been difficult to make large products thinner.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a mold structure capable of suppressing the attenuation of the flow energy of molten aluminum and allowing a gate to be installed at an arbitrary position. It is an object of the present invention to provide a manufacturing method capable of manufacturing a large-sized thin aluminum die-cast product.

[0005]

In order to achieve the above object, in the method for manufacturing a thin aluminum die-cast product according to the present invention, the mold temperature is maintained at 300 to 350 ° C., and the mold is maintained in this state. Molten aluminum was injected into the mold cavity from a gate placed at an arbitrary position and filled to obtain a molded product.

[0006]

According to the above structure, the mold structure in which the sprue is installed at an arbitrary position makes it possible to optimally fill the thin portion with the molten aluminum, for example, the energy required for the flow. The gate is installed at the shortest distance between the gate with the least attenuation and the thin-walled part, and before the molten aluminum is filled into the mold, the mold temperature becomes 300 to 3
It is kept at 50 ° C, and by completing the filling of the mold cavity with molten aluminum in 0.03 seconds or less, the attenuation of the flow energy of the molten aluminum can be suppressed. Can be reached. After that, the molten aluminum starts to solidify and is shaped into a product during the solidification process.
The thin portion of the mold cavity can be formed into a thin product by the same action.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a large thin aluminum die-cast product of the present invention will be described below with reference to an embodiment shown in the drawings.

In the method for producing a large-sized thin-walled aluminum die-cast product of the present invention, a casting aluminum alloy containing aluminum as a main component, such as A
DC10, ADC12, etc. are used, but fluidity in a mold cavity in a mold for manufacturing a large thin aluminum die-cast molded product in a molten state can be secured.
i: 9 to 13.5% by weight, Zn: 1 to 3% by weight, Be:
Aluminum alloy containing 0.01 to 0.05% by weight, or Si: 9 to 13.5% by weight, Mn: 1.0 to 4.
Aluminum alloy containing 0% by weight, and further, low density of molten and solidified Si: 9-13.5% by weight, L
i: It is desirable to use any of aluminum alloys containing 1.0 to 7.0% by weight.

The fixed mold and the movable mold are each composed of a main mold and a nest, and a mold cavity is formed when a part of their mating surfaces is in contact with each other. An injection sleeve is fixed to the fixed mold. A plunger tip is disposed in the injection sleeve so that the plunger tip can reciprocate inside the injection sleeve.

The injection sleeve and the plunger tip include:
In order not to disturb the reciprocating operation of the plunger tip due to thermal expansion caused by contact with the molten aluminum, the circulation path of the circulating medium that maintains each at a constant temperature and a temperature sensor are embedded, and the outside of the casting machine The temperature is adjusted to maintain an appropriate temperature in accordance with the temperature of the injection sleeve and the plunger tip at each time. A hot oil bath or hot water is used as the circulation medium.

[0011] The fixed mold is provided with a fixed mold gate that communicates with the inside of the injection sleeve. Further, it is configured so that it can be divided into one or many pieces in a horizontal direction or an arbitrary direction with respect to the mold opening direction. The divided divided fixed mold is constituted by a fixed mold and a hydraulic drive or an inclined pin in a horizontal or arbitrary direction with respect to a mold opening direction, and further connected to the fixed mold by a movable mold closing operation. It is arranged as follows. Also, in the split fixed mold, in the mold cavity,
1 so that molten aluminum can be injected from any position
Alternatively, a plurality of split fixed mold gates are provided. Furthermore, a runner is engraved on the split fixed mold so that each gate and the fixed mold gate communicate with each other, and can be mounted on the peripheral portion of the mold at an arbitrary angle with respect to the axis in the mold opening direction. After the die cast molded product is formed in the mold cavity, the runner remaining in the mold can be discharged from the mold from any direction by the hydraulically driven runner discharging mechanism.

The movable mold is also configured to be dividable like the fixed mold. Also, after nesting the movable mold, penetrating the main mold of the movable mold, and forming the molten aluminum into a die-cast molded product in the mold cavity, the pressure per unit area is reduced from the mold to reduce the burden on the product. 12 to extrude
A 20 mm extrusion pin is slidably mounted from the opposite side of the mold cavity. The base end of the extrusion pin is fixed to an extruding plate which is close to the movable mold by the pushing force of the die casting caster and which is separated from the movable mold by the pullback force of the die casting caster. In addition, the movable mold is not included in the product shape of the movable mold because molten aluminum is injected into the mold cavity from a large number of gates, and a place where the tip of each molten aluminum collides occurs. In the case of engraving a basin in a nest, a hydraulically driven basin discharging mechanism capable of discharging the basin to the outside of the mold after opening the mold is provided.

A material that insulates the space between the mold and the atmosphere and suppresses the dissipation of the heat of the mold is adhered to the contact surface between the fixed mold and the movable mold with the atmosphere. A urethane resin or a silver powder paint is adhered to the heat insulating material. A radiant tube gas burner, an electric heater and a temperature sensor are embedded in the nest of the fixed mold and the nest of the movable mold.In addition, a path for circulating a hot oil bath or hot water inside the nest is inscribed. Each is connected to a temperature control mechanism provided outside the casting machine, and is adjusted so as to maintain an appropriate temperature in accordance with the mold temperature at each time.

A heat insulating material that suppresses the release of heat of the respective molds into the atmosphere is fused to the surfaces forming the mold cavities of the nest of the fixed mold and the nest of the movable mold. As the heat insulating material, for example, TiO, TiC, or the like is used.

The main mold and the nest of the fixed mold, and the main mold and the nest of the movable mold, respectively, have a minimum value of the area required for coupling, for example, the nest, in order to suppress heat conduction from the nest to the main mold. The area ratio between the mating surface and the contact surface of the main mold is 40 to 50%, and the nested or held heat is arranged so that the amount of heat released to the main mold is minimized. .

The cavity pressure reducing mechanism suppresses a decrease in the flow distance of the molten aluminum caused by friction between the molten aluminum and residual air in the mold cavity in a mold cavity formed by the fixed mold and the movable mold. Therefore, before the molten aluminum is filled, the residual air in the mold cavity is suctioned and discharged to the outside of the mold cavity, and is arranged outside the casting machine so as to communicate with the inside of the mold cavity and the decompression path. ing.

Next, embodiments of the present invention using the large-sized thin-walled aluminum die-casting mold having the above-described structure and its accompanying equipment will be described. However, the present invention is not limited by these examples.

[0018]

Embodiment 1 FIG. 1 is an explanatory view schematically showing a method for manufacturing a large-sized thin-walled aluminum die-cast molded product according to Embodiment 1 of the present invention. First, the temperature control mechanism measures the temperature of each of the temperature sensors 3 embedded in the nest 1a of the fixed mold 1 and the nest 2a of the movable mold 2, and detects a temperature of 300 to 350 ° C.
On the other hand, a portion having a large difference in temperature is transmitted by a radiant tube gas burner 4, and a portion having a small difference in temperature is transmitted by an electric heater 5 and a hot oil bath circulating in a mold circulation path 6. At the same time, the temperature of the injection sleeve 7 and the temperature of the plunger tip 8 are measured by the temperature sensor 7a of the injection sleeve 7 and the temperature sensor 8a of the plunger tip 8.
The temperature is raised to 50 ° C. by passing a hot oil bath through the injection sleeve circulation path 7b and the plunger tip circulation path 8b. During or after the temperature increase, the amount of heat applied to the mold depends on the urethane resin 9 on the atmosphere contact surface of the mold, TiC on the nest cavity surface, and the bonding between the nest and the main mold with the minimum contact area. The heat is efficiently nested in the nest, and the temperature can be raised to the set temperature in a short time.

The temperature of the fixed mold 1 and the movable mold 2 is 300 to
When the temperature of the injection sleeve 7 and the plunger tip 8 reaches 250 ° C. within the range of 350 ° C., the mold closing operation of the movable mold 2 is started by a command from a casting machine control mechanism (not shown), and the fixed mold 1 The movable mold 2 is closed. After the mold closing is completed, a signal of the mold closing completion is transmitted from the casting machine control mechanism to the cavity depressurizing mechanism (not shown), and the cavity depressurizing mechanism that has received the signal transmits the signal from the depressurizing path 11 leading to the mold cavity 10. 27000 to 40000 in the mold cavity
Reduce pressure to the range of Pascal.

After the completion of the decompression, the molten aluminum M prepared in the above component range is pumped up with the ladle 12 and poured into the injection sleeve 7 to be filled. Thereafter, by moving the plunger tip 8 in the direction of the mold at a high speed, the molten aluminum M is injected and filled into the mold cavity 10 through the fixed mold gate 13.

The molten aluminum M injected into the mold cavity 10 receives the energy flowing in the mold cavity 10 and the protection of the attenuation thereof, while protecting the inside of the mold cavity 10 including the thin portion. Fill sequentially. After the filling is completed, the time required for solidification of the molten aluminum M elapses, the mold opening operation is performed on the movable mold 2, and the mold is opened. Thereafter, the casting machine operates the extrusion plate 14 toward the mold cavity 10, and releases the product from the mold cavity 10 via the extrusion pin 15. Then, the casting cycle is repeatedly executed.

According to the present embodiment, since the flow energy is protected by heating and maintaining the temperature of the mold and keeping the temperature and reducing the atmospheric friction, the molten aluminum M can be filled up to the thin portion of the mold cavity 10. Can be. Therefore, it is possible to produce a large thin aluminum die-cast product, for example, a product having an area of 0.16 square meters or more and an average thickness of 1.5 mm or less.

[0023]

[Embodiment 2] The mold dividing lines L1 to L2 of FIG.
The dividing line connecting the mold dividing line L3 indicates a dividing line that divides into the fixed mold 1 and the divided fixed mold 1A in the method for manufacturing a large thin aluminum die-cast molded product according to the second embodiment of the present invention. In the present embodiment, the fixed mold 1 is divided so that the split fixed mold gate 13A
An example used in the case of performing injection and filling from a theoretical optimum gate with the least attenuation of flow energy from 13B to a thin portion is shown. Other methods are the same as in the first embodiment.

After controlling the temperatures of the divided fixed mold 1A, the movable mold 2, the injection sleeve 7, and the plunger tip 8 as in the first embodiment, the divided fixed mold 1A, the fixed mold 1, and the movable mold are controlled. The mold 2 is closed. After the mold closing is completed, the pressure is reduced to the range of 27000 to 40000 Pascal by the cavity pressure reducing mechanism.

After the completion of the decompression, the molten aluminum M is pumped up with the ladle 12, poured into the injection sleeve 7, and the molten aluminum M is supplied through the fixed mold gate 13 to the optimum position for filling the thin portion of the mold cavity. Reach the divided fixed mold gates 13A and 13B through the runner 16 and are injected into the mold cavity 10 from the divided fixed mold gates 13A and 13B.

The molten aluminum M injected into the mold cavity 10 protects and suppresses the energy flowing through the mold cavity 10 and the attenuation thereof,
The inside of the mold cavity 10 including the thin portion is sequentially filled. After the filling is completed, the time required for solidification of the molten aluminum M elapses, the mold opening operation is performed on the movable mold 2, and the mold is opened. Thereafter, the casting machine sets the extruded plate 14
Is actuated in the direction of the mold cavity 10 and the extrusion pin 15
, The product is released from the mold cavity 10, and at the same time, the dispensing mechanism 17 of the runner 16 is operated,
The runner 16 remaining in the split fixed mold 1A is discharged out of the mold. Further, the hot-hole discharge mechanism 18 of the movable mold is also operated to discharge the hot-water pool remaining inside the nest out of the mold, thereby completing the molding cycle of the die-cast molded product. Then, the above molding cycle is repeatedly executed.

Here, the filling of the molten aluminum M into the thin portion of a large-sized aluminum die-cast molded product will be considered. In order to completely fill the thin portion, the volume of the molten aluminum M filling the thin portion must have flow energy required for filling before solidification and solidification. Factors attenuating the flow energy of the molten aluminum M include the flow distance of the molten aluminum M, the shape of the product, friction with air, and the like.
In order to fill the gas, it is necessary to protect the flow energy from the above-mentioned damping factor to the complete filling. In addition, in order to obtain a die-cast molded product, it is necessary to solidify the molten aluminum M after filling the molten aluminum M into a thin portion. Must be reduced to Therefore, in order to continuously produce a large thin aluminum die-cast product, it is necessary to suppress the flow energy attenuation to a range where the thin wall portion can be filled, and repeat a system in which the molten aluminum M quickly absorbs heat to a temperature below the freezing point. Is essential.

According to this embodiment, the flow energy is suppressed by the injection from the theoretically optimal gate of the split fixed die to the thin portion, and the flow of the die is increased by heating and maintaining the temperature and reducing the friction in the atmosphere. Since the energy is protected, the molten aluminum M can be filled up to the thin portion of the mold cavity 10. In addition, the mechanism 18 for discharging the hot pool formed inside the movable mold to the outside of the mold after forming the die-cast molded product can normally form the hot pool in a difficult place such as the center of the mold cavity 10. When the molten aluminum M is filled into the mold cavity 10 from a plurality of gates, the molten aluminum M is caused to collide with the molten aluminum M, and the molten aluminum M is transferred to a non-product-shaped basin engraved inside the nest. Since it can be guided, the quality of the die-cast molded product can be improved. Therefore, a high-quality large-sized thin aluminum die-cast molded product can be manufactured.

[0029]

Embodiment 3 Mold dividing lines L1 to L2 in FIG.
The parting line connecting the mold parting line L4 indicates the parting line for dividing into the fixed mold 1 and the divided fixed mold 1A in the method for manufacturing a large thin aluminum die-cast molded product according to the third embodiment of the present invention. This embodiment is used in a case where the fixed mold 1 has a complicated product shape in which the flow energy is attenuated due to friction with the residual air even after the pressure in the mold cavity 10 is reduced. An example of using a mold that performs more partially will be described. Other methods are the same as in the second embodiment.

According to the present embodiment, the flow energy is protected by heating and keeping the temperature of the mold and keeping the temperature low, and the friction between the molds is reduced. The injection suppresses the flow energy attenuation, and furthermore, the residual air after decompression can be extruded from the split surface to the outside of the mold cavity 10 without attenuation of the flow energy. 10 thin-walled portions can be filled. Therefore, similarly to the second embodiment, it is possible to manufacture a high-quality large-sized thin-walled aluminum die-cast product.

[0031]

Embodiment 4 The dividing line connecting the mold dividing line L1 to the mold dividing line L5 in FIG. 2 is the same as the movable mold 2 in the method for manufacturing a large thin aluminum die-cast molded product according to Embodiment 4 of the present invention. A dividing line for dividing into the mold 2A is shown. This embodiment is used, for example, when it is desired to secure uniform flow energy from the gate to a thin portion scattered around the outer periphery or the like depending on the product shape, and the movable mold 1 is perpendicular to the mold opening direction. An example using a mold that divides in the direction is shown. In this embodiment, the split fixed mold gate 13A is not provided, the split fixed mold gate 13B is a split movable mold gate 13B, and the runner dispensing mechanism is not used. Other methods are the same as in the second embodiment.

According to the present embodiment, for a product shape in which many thin portions are scattered around the outer periphery of the product, uniform flow energy can be ensured for any thin portion, and the sprue is located at the center of the flow distance. Can be installed, the molten aluminum M
Can be uniformly filled in any thin portion of the mold cavity 10. Therefore, similarly to the second embodiment, a large-sized thin aluminum die-cast product can be manufactured.

According to the present invention, when manufacturing a large-sized thin-walled aluminum die-cast product, the flow required for the molten aluminum to reach the thin-walled portion is controlled by the mold of 300 to 350.
It is ensured by heating and keeping the temperature controlled at ℃, and the mold structure in which the sprue is installed at an arbitrary position makes it possible to inject and fill molten aluminum from an optimum position for filling the thin portion. Therefore, the filling of the molten aluminum into the thin portion of the large-sized aluminum die-cast product can be completely performed, and a molded product can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a die casting machine used for carrying out a first embodiment of the present invention.

FIG. 2 is an explanatory view of a die casting machine used for carrying out Embodiments 2, 3, and 4 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Movable mold 6 Mold circulation path 7 Injection sleeve 8 Plunger tip 10 Mold cavity 12 Ladle 13 Fixed mold spout 14 Extruded plate 15 Extrusion pin 16 Runner 17 Runner dispensing mechanism 18 Hot water discharge mechanism L Gold Mold split surface

Claims (2)

[Claims] In a die casting method of aluminum and an aluminum alloy, a temperature of a die casting mold is maintained at 300 to 350 ° C., and molten aluminum is injected into a mold cavity to be filled to obtain a molded product. Production method of large thin aluminum die-cast products. 2. A large thin wall according to claim 1, wherein in a die casting method of aluminum and an aluminum alloy, a gate for injecting molten aluminum of a die casting die into a die cavity is installed at an arbitrary position. Manufacturing method of aluminum die-cast products.