KR20170066720A

KR20170066720A - Apparatus and manufacuring method for diecasting case of vehicle

Info

Publication number: KR20170066720A
Application number: KR1020150171950A
Authority: KR
Inventors: 강동하; 임태성; 인귀승; 이정호
Original assignee: 현대자동차주식회사; 주식회사 코다코
Priority date: 2015-12-04
Filing date: 2015-12-04
Publication date: 2017-06-15
Also published as: US20170157668A1; CN106825488A

Abstract

A method of manufacturing a die casting of a case for a vehicle part according to an embodiment of the present invention includes: a step of preparing an aluminum alloy melt by heating an aluminum alloy; A mold preheating step for preheating the die casting mold; A die casting step of injecting the aluminum alloy melt into the die casting mold to form a case for a vehicle part; A surface treatment step of separating the case for the vehicle part from the die casting mold and trimming the surface; And a finishing step of removing a bur of the vehicle component case.

Description

Technical Field [0001] The present invention relates to a die casting mold apparatus for a vehicle component case, and a method of manufacturing a die casting for a vehicle component case using the same.

The present invention relates to a die casting apparatus for a case, and more particularly, to a die casting mold apparatus for a case for a vehicle part, which uses aluminum to manufacture a case such as a vehicle part and a machine part by a die casting casting method. To a die casting manufacturing method of a case for a vehicle part.

In general, casting refers to a process in which a metal is injected into a metal mold and solidified to form a predetermined shape, and a product molded through such a process is referred to as a cast metal. This casting technology is the most fundamental of the metal processing technology and plays an important role in the development of the metal industry.

As described above, the casting manufactured by the casting method has a close relationship with the automobile industry and has developed along with the automobile industry so that about 50% of the production amount is used for automobiles.

Recently, the automobile industry has been studying aluminum alloy materials that are considered to be environment-friendly, high-functional, light-weighted, and high-sensitive in the material field of body parts in accordance with the recent demand for reduction of exhaust gas and improvement of fuel efficiency, Is progressing actively.

Particularly, as a main component of the vehicle body, there is an urgent need for a production technology for producing a heavy-duty vehicle component case by applying aluminum material. In addition, it is required to reduce the weight of the vehicle component case and to maintain the existing structural rigidity Development of a case is required.

Recently, there has been proposed a method of manufacturing an aluminum alloy having aluminum (Al) as a main component and an aluminum alloy having added thereto copper (Cu), silicon (Si), magnesium (Mg) Research and development for the production of automotive parts cases have been actively carried out through the casting of aluminum alloy for diecastings, in which metal is injected at a high pressure into a metal mold.

However, the conventional aluminum die casting mold has problems in that the dischargeability of the gas contained in the molten aluminum alloy is lowered during the die casting operation of the case for a vehicle part having a complicated shape, and bubbles are generated in the product to lower the structural rigidity and the productivity there was.

It should be understood that the foregoing description of the background art is merely for the purpose of promoting an understanding of the background of the present invention, and is not to be construed as admission that the prior art is known to those skilled in the art.

Published Patent Application No. 10-2009-0010645 (2009. 01. 30.)

Disclosure of the Invention The present invention has been devised to solve the problems as described above, and it is an object of the present invention to provide a die casting mold apparatus for a vehicle component case capable of improving the castability of molten metal in a mold, And a method of manufacturing a die casting of a case for a vehicle part using the same.

The present invention also provides a die casting mold apparatus for a vehicle component case and a die casting manufacturing method for a vehicle component case using the same, which can maintain the die casting conditions according to the flow characteristics of the aluminum alloy to improve the compactness of the product and reduce the defect rate do.

The present invention also provides a die casting mold apparatus for a vehicle component case and a die casting manufacturing method for a vehicle component case using the same, which can reduce the weight of the aluminum alloy and improve the support rigidity.

In addition, the present invention can improve the exhaustiveness of the gas contained in the molten aluminum alloy and reduce the gas remaining in the cavity, thereby reducing bubbles generated in the die casting product, A mold apparatus and a method of manufacturing a die casting of a case for a vehicle part using the same.

According to another aspect of the present invention, there is provided a method of manufacturing a die-casting case for a vehicle component, comprising the steps of: preparing an aluminum alloy melt by heating an aluminum alloy; A mold preheating step for preheating the die casting mold; A die casting step of injecting the aluminum alloy melt into the die casting mold to form a case for a vehicle part; A surface treatment step of separating the case for the vehicle part from the die casting mold and trimming the surface; And a finishing step of removing a bur of the vehicle component case.

The preparation step may be characterized by providing an aluminum alloy melt at a temperature of 645 to 665 ° C.

Preferably, the mold preheating step preheats the die casting mold to 220 to 250 ° C.

The die casting step may include injecting the aluminum alloy melt into the lower portion of the die casting mold.

The die casting step may include injecting the aluminum alloy melt at a pressure of 90 to 110 MPa while maintaining a degree of vacuum in the cavity of the die casting mold at 140 to 160 mbar.

Wherein the aluminum alloy contains 88.2 to 80.3% of aluminum (Al), 9.6 to 12.0% of silicon (Si), 1.5 to 3.5% of copper, 0.1 to 0.5% of manganese (Mn) (Mg): 0.1 to 0.3%, Ni: 0.1 to 0.5%, Fe: 0.1 to 0.9%, Ti: 0.1 to 0.5%, Zn: 0.1 to 1.0% (Sn): 0.1 to 0.3%, lead (Pb): 0.0 to 0.1%, chromium (Cr): 0.0 to 0.1%, and unavoidable impurities.

In the die casting step, the case is preferably formed while evacuating the gas in the molten aluminum alloy by vacuum.

A die casting mold apparatus for a vehicle component case according to an embodiment of the present invention includes: a stationary mold having one side surface of a case formed at an obtuse angle; A movable mold movably installed in the direction of the stationary mold and coupled with the stationary mold to form a case-shaped cavity; And an evacuating unit connected to the cavity to evacuate the inside of the cavity and exhaust gas contained in the molten metal introduced into the cavity.

The movable mold includes a plurality of first gas discharging portions connected to a lower portion of the cavity to form a molten metal flow path through which the molten metal flows and a gas is accommodated in an upper portion of the cavity, A plurality of second gas discharging portions may be formed.

Wherein the movable mold has a first gas flow path and a second gas flow path for communicating the first gas discharging portion and the second gas discharging portion with the tachy bit and the diameter of the second gas flow path is larger than the diameter of the first gas flow path It is preferable that it is formed larger than the diameter.

Preferably, the die casting mold apparatus of the vehicle component case according to an embodiment of the present invention further includes a pressure sensor connected to any one of the first gas discharging units so as to measure the pressure inside the cavity .

The sleeve may further include a sleeve portion connected to the molten metal channel to inject the molten metal therein. The sleeve portion may be formed with a gas outlet so that the gas outlet can be opened and closed to discharge the inner gas.

According to the embodiment of the present invention, by dissolving the aluminum alloy and pre-heating the die and casting it, it is possible to improve the moldability of the molten metal in the die and shorten the cooling time of the product, thereby improving the workability of the product.

In addition, by limiting the temperature of the molten metal, the preheating temperature and the injection pressure of the mold to a certain range of temperatures, and injecting the molten metal from the downward through the optimum designed bath temperature, the die casting conditions according to the flow characteristics of the aluminum alloy are maintained, And reduce the defect rate.

Further, by reducing the content of aluminum and increasing the content of silicon and adding a small amount of nickel, titanium, tin or chromium as the aluminum alloy, the weight of the aluminum alloy can be reduced and the support rigidity can be improved.

Further, by providing the die casting mold as a vacuum die casting mold, the gas exhausted from the aluminum alloy melt can be improved, and the gas remaining in the cavity can be reduced to reduce bubbles generated in the die casting product, have.

1 is a side view showing a die casting mold apparatus of a case for a vehicle part according to an embodiment of the present invention,
FIG. 2 is a view showing a stationary mold according to an embodiment of the present invention,
3 is a view showing a movable mold according to an embodiment of the present invention,
4 is a view for explaining a die casting mold apparatus of a case for a vehicle part according to an embodiment of the present invention,
5 is a view showing a sleeve unit according to an embodiment of the present invention,
6 is a flowchart showing a die casting manufacturing method of a case for a vehicle part according to an embodiment of the present invention,
7 is a view showing the occurrence of defects in the manufacture of a case for a vehicle part by using molten aluminum of less than 645 DEG C,
8 is a view showing the occurrence of defects in the manufacture of a case for a vehicle part by using molten aluminum exceeding 665 DEG C,
9 is a view showing a wavefront of a case for a vehicle part manufactured according to an embodiment of the present invention,
10 is a view showing generation of surface pores in the case of manufacturing a case for a vehicle part by using a die casting mold preheated to a temperature of less than 220 ° C,
11 is a view showing a heat check generated in a die casting mold preheated to more than 250 ° C,
12 is a view showing shrinkage defects when manufacturing a case for a vehicle part using a die casting mold preheated to a temperature exceeding 250 캜.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments. For reference, the same numbers in this description refer to substantially the same elements and can be described with reference to the contents described in the other drawings under these rules, and the contents which are judged to be obvious to the person skilled in the art or repeated can be omitted.

FIG. 1 is a side view showing a die casting mold apparatus of a case for a vehicle part according to an embodiment of the present invention, FIG. 2 is a view showing a stationary mold according to an embodiment of the present invention, and FIG. 4 is a view for explaining a die casting mold apparatus of a case for a vehicle part according to an embodiment of the present invention.

As shown in Claims 1 to 4, the die casting mold apparatus of a case for a vehicle part according to an embodiment of the present invention uses an aluminum alloy melt by using a die casting casting method and car parts such as a differential gear case A movable mold 200 which is moved in the direction of the stationary mold 100 to form a cavity C and an exhaust unit 300 which exhausts the inside of the cavity C to reduce the pressure, ).

The stationary mold 100 is formed with an angular shape of the case and is fixed to the stationary end to be fixed at all times during the die casting operation. In order to remove the die-casted case, a gradient angle is applied to a portion of the movable mold 200, .

The movable mold 200 is detachably mountable to the stationary mold 100 and is formed in a convex shape in the case. The movable mold 200 is coupled to the movable end and is moved toward the stationary mold 100 during the die casting operation, So that a cavity C of a case shape for a vehicle component is formed between the stationary mold 100 and the movable mold 200.

The movable mold 200 is separated from the stationary mold 100 when the die casting operation is completed and the case for a vehicle component molded inside the cavity C is detached from the cavity C and discharged to the outside through the pin.

The movable mold is connected to the cavity C to form a plurality of first and second gas discharge units 220 and 230 for discharging gas contained in the molten aluminum alloy. And communicates with the base 300.

The movable mold 200 includes a first gas passage 221 and a second gas passage 231 for connecting the first and second gas discharging portions 220 and 230 to the cavity C, The diameter of the gas discharging part 230 is preferably larger than the diameter of the first gas discharging part 220.

Accordingly, the amount of gas discharged through the second gas discharging unit 230 connected to the discharging unit 300 may be greater than the amount of gas discharged through the first gas discharging unit 220.

The distance between each adjacent second gas discharge portion 230 is preferably formed to gradually expand from the cavity C. [ Accordingly, there is an effect that the gas discharge performance can be improved by expanding the hot gas flow in the gas discharge direction downstream.

Preferably, the pressure sensing sensor 240 is connected to any one of the plurality of first gas discharging units 220 according to an embodiment of the present invention to check the degree of vacuum in the cavity C.

At this time, the movable mold 200 is formed with a tapered region communicating with the first gas discharging portion 220 to which the pressure detecting sensor 240 is mounted, and the pressure detecting sensor 240 is detachably installed And the sensing aperture may be formed to be openable and closable.

The exhaust part 300 is installed to communicate with the second gas exhaust part 230 downstream in the gas flow direction and forms a vacuum by depressurizing the interior of the cavity C to thereby evacuate gas contained in the molten aluminum alloy For example, a vacuum pump, a vacuum block, a vacuum valve, a vacuum hose, etc., which are mainly used in a high vacuum die casting method.

Particularly, the exhaust part 300 includes a discharge passage formed by bending a plurality of flow paths in a vacuum block, and functions as a cooling block for cooling the molten metal by the bent passage of the vacuum valve. Thus, And at the same time, the casting pressure is reduced, thereby extending the service life of the mold apparatus.

At this time, in the movable mold 200, an exhaust channel connecting the second gas exhaust unit 230 and the exhaust unit 300 is formed. The exhaust gas channel is extended in a bent shape, And exhausts gas from the discharge portion 230.

5 is a view illustrating a sleeve according to an embodiment of the present invention.

5, a die casting mold apparatus of a vehicle component case according to an embodiment of the present invention includes a sleeve unit 400 connected to a melt channel 210 to supply an aluminum alloy melt to a cavity C, And the like.

At this time, the sleeve portion 400 may be formed with a gas discharge port 410 so that the gas inside the sleeve portion 400 can be naturally exhausted at a low speed injection portion upstream in the flow direction of the molten aluminum alloy, and the gas discharge port 410 Can be opened and closed.

Therefore, the quality of the produced automobile parts case can be improved by discharging the gas generated in the sleeve part 400 as needed during the process of injecting the molten aluminum alloy into the cavity C.

The other side of the molten metal channel 210 is connected to the sleeve 400 and the other side is connected to the cavity C. The other side connected to the cavity is branched into a plurality of channels and connected to the cavity C .

6 is a flowchart showing a method of manufacturing a die casting of a case for a vehicle part according to an embodiment of the present invention.

6, the die casting manufacturing method of a vehicle component case includes a preparation step S1, a mold pre-heating step S2, a die casting step S3, a surface treatment step S4 and a finishing step S5 do.

In the preparation step S1, the aluminum alloy is melted by heating to prepare an aluminum alloy melt, and the temperature of the aluminum alloy is maintained at 645 to 665 ° C.

At this time, the aluminum alloy contains, in terms of weight%, 88.2 to 80.3% of aluminum (Al), 9.6 to 12.0% of silicon (Si), 1.5 to 3.5% of copper, 0.1 to 0.5% of manganese (Mn) (Mg): 0.1 to 0.3%, Ni: 0.1 to 0.5%, Fe: 0.1 to 0.9%, Ti: 0.1 to 0.5%, Zn: 0.1 to 1.0% It is preferable that the aluminum alloy contains 0.1 to 0.3% of lead (Sn), 0.0 to 0.1% of lead (Pb), 0.0 to 0.1% of chromium (Cr) and unavoidable impurities. (Ni), titanium (Ti), tin (Sn), chromium (Cr), and the like, while increasing the content of silicon (Si) And the support rigidity can be improved at the same time.

FIG. 7 is a view showing the occurrence of defects in the manufacture of a case for a vehicle component using aluminum melt of less than 645 ° C., and FIG. 8 is a view showing the occurrence of defects in the manufacture of a case for a vehicle component by using aluminum melt exceeding 665 ° C. .

As shown in FIGS. 7 to 8, when the temperature of the molten aluminum alloy is lower than 645 DEG C, the castability of the molten aluminum alloy is lowered, and premature solidification occurs in the process of filling the inside of the cavity C, There is a problem in that the quality of a case for a vehicle component produced by the production of the die is lowered. When the temperature exceeds 665 DEG C, the cost of manufacturing increases as the fuel consumption increases, and local overheating of the die casting mold is caused, And it is preferable to limit the temperature to 645 to 665 ° C.

9 is a view showing a wavefront of a case for a vehicle part manufactured according to an embodiment of the present invention.

As shown in FIG. 9, in an embodiment of the present invention, the aluminum alloy is melted and maintained at 660 ° C. However, when the aluminum alloy melt is maintained at a temperature of 660 ° C., And a case for use could be manufactured.

The mold preheating step S2 is a step of preheating the die casting mold composed of the stationary mold 100 and the movable mold 200 before injection of the molten aluminum alloy, and is preheated to a temperature of 220 to 250 ° C.

10 is a view showing the generation of surface pores in the case of manufacturing a case for a vehicle part by using a die casting mold preheated to a temperature of less than 220 ° C, FIG. 11 is a view showing a heat check generated in a die casting mold preheated to more than 250 ° C 12 is a view showing shrinkage defects when manufacturing a case for a vehicle component using a die casting mold preheated to a temperature exceeding 250 ° C.

As shown in FIGS. 10 and 12, when the temperature of the die casting mold is preheated to be lower than 220 占 폚, a temperature difference of 400 占 폚 or more with the injected aluminum alloy melt is caused to cause premature solidification of the molten aluminum alloy, If the temperature is higher than 250 ° C., it takes a long time to cool the aluminum alloy melt after the injection of the aluminum alloy melt, resulting in an increase in the working time, It is preferable to limit the temperature to 220 to 250 占 폚 because the occurrence of defects and the dimensional accuracy are lowered and the degradation reaction of the die casting mold rapidly proceeds to lower the life of the mold.

In one embodiment of the present invention, the temperature of the die casting mold was preheated to 250 캜.

The die casting step S3 according to the embodiment of the present invention is a step of injecting the molten aluminum alloy into the cavity C and comprises a mold closing process, an aluminum alloy molten metal injection process, a mold opening process, and a mold cleaning process.

The mold closing process is a step of forming a cavity (C) as a flask between the stationary mold (100) and the movable mold (200) provided in a die casting mold apparatus of a case for a vehicle component, Insert the core and slide core.

The process of injecting the aluminum alloy melt is a step of injecting molten aluminum alloy into the cavity C formed between the stationary mold 100 and the movable mold 200. The molten aluminum alloy injected into the sleeve 400 is injected into the cavity C through a plunger So that it is injected into the cavity C.

At this time, the injection tip located at the end of the sleeve unit 400 is advanced at a speed of 0.2 m / s. Since the injection tip of the injection nozzle of the aluminum alloy melt passes the inside of the sleeve unit 400, A gas outlet 410 having a diameter of 30 mm formed within 300 mm from the starting point of the plunger is provided in the upper part of the sleeve 400 to prevent the internal gas from flowing into the cavity C and causing defects of the product. To open it and exhaust it naturally.

The injection pressure of the aluminum alloy melt, that is, the casting pressure, is preferably 90 to 110 MPa, because when the casting pressure is less than 90 MPa, the castability of the aluminum alloy melt drops and it takes a long time, , However, due to the nature of the axially symmetric radial dispenser cup, the initially filled aluminum alloy melt flows backward and causes bubbles to be generated.

Meanwhile, it is desirable to secure a degree of vacuum of 140 to 160 mbar inside the cavity (C) because the inner structure of the aluminum alloy filled in the cavity (C) is dense to increase the density, So as to satisfy the mechanical characteristics required for the case.

In the present invention, while maintaining the casting pressure at 100 MPa, the degree of vacuum in the cavity was maintained at 150 mbar.

The mold opening process is a process of cooling the aluminum alloy melt filled in the cavity C to mold the case for a vehicle component and then separating the stationary mold 100 and the movable mold 200 to take out the case for a vehicle component. Cool the mold, remove the insert core and slide core, and remove the case for the vehicle component.

The mold cleaning process is a process of cleaning the stationary mold 100 and the movable mold 200 for the next operation after taking out the case for a vehicle component. The mold cleaning agent is applied to the interior of the mold after the first cleaning and the second cleaning is performed.

The surface treatment step S4 is a step of trimming the taken-out vehicle component case, which is carried out by attaching a runner or an overflow and a vent hole attached to the exterior of the case for the vehicle component to the trimming die .

When the surface treatment of the vehicle component case is completed, the worker manually removes a fine bur of less than 2 mm remaining on the surface of the vehicle component case in the finishing step (S5) by using a manual tool such as a grinder.

As described above, the case for the vehicle parts from which the burrs have been removed is finally shipped after the appearance inspection.

As described above, according to the present invention, it is possible to improve the injectability of the aluminum alloy melt into the die casting mold and to improve the workability by shortening the cooling time by preheating the die casting die after melting the aluminum alloy, Lt; / RTI >

In addition, by limiting the temperature of the molten aluminum alloy, the preheating temperature of the die casting mold, and the casting pressure to a certain range and injecting the molten aluminum alloy from below, the die casting conditions according to the flow characteristics of the molten aluminum alloy are maintained, It is possible to improve the compactness of the case and reduce the defective rate.

It is also possible to reduce the content of aluminum (Al) by increasing the content of silicon (Si) and by adding a small amount of nickel (Ni), titanium (Ti), tin (Sn) or chromium (Cr) It is possible to reduce the weight of the vehicle component case and to improve the support rigidity.

In addition, by forming the die casting mold from a vacuum die casting mold, it is possible to improve the exhaustiveness of the gas contained in the molten aluminum alloy and reduce the gas remaining in the cavity, thereby reducing bubbles generated in the die casting product, Provides an effect.

Although the present invention has been described with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the following claims. It can be understood that

C: Cavity S1: Preparatory step
S2: mold preheating step S3: die casting step
S4: Surface treatment step S5: Finishing step
100: stationary mold 200: movable mold
210: molten metal channel 220: first gas outlet
221: first gas flow channel 230: second gas discharge section
231: second gas channel 240: pressure sensor
300: exhaust part 400: sleeve part
410: gas outlet

Claims

Preparing a molten aluminum alloy by heating the aluminum alloy;
A mold preheating step for preheating the die casting mold;
A die casting step of injecting the aluminum alloy melt into the die casting mold to form a case for a vehicle part;
A surface treatment step of separating the case for the vehicle part from the die casting mold and trimming the surface; And
And a finishing step of removing a bur of the case for the vehicle part.

The method according to claim 1,
In the preparation step,
Wherein the aluminum alloy melt is heated at a temperature of 645 to 665 占 폚 to provide an aluminum alloy melt.

The method according to claim 1,
In the mold preheating step,
And the die casting mold is preheated to 220 to 250 占 폚.

The method according to claim 1,
Wherein the die-
Casting the aluminum alloy melt into the lower portion of the die casting mold.

The method of claim 4,
Wherein the die-
Wherein the aluminum alloy melt is injected at a pressure of 90 to 110 MPa while maintaining a degree of vacuum within the cavity of the die casting mold at 140 to 160 mbar.

The method according to claim 1,
The above-
(Mg): 0.1 to 0.5%, manganese (Mn): 0.1 to 0.5%, aluminum (Al): 88.2 to 80.3%, silicon (Si): 9.6 to 12.0% 0.1 to 0.5% of iron (Fe), 0.1 to 0.5% of titanium (Ti), 0.1 to 1.0% of zinc, 0.1 to 1.0% of tin (Sn) To 0.3%, Pb: 0.0 to 0.1%, Cr: 0.0 to 0.1%, and unavoidable impurities.

The method according to claim 1,
Wherein the die-
Wherein the case is molded while evacuating the gas in the molten aluminum alloy by vacuum.

A stationary mold having one side surface shape of the case formed at an obtuse angle;
A movable mold movably installed in the direction of the stationary mold and coupled with the stationary mold to form a case-shaped cavity; And
And a discharge unit connected to the cavity to discharge the gas contained in the molten metal introduced into the cavity so as to reduce the pressure inside the cavity.

The method of claim 8,
The movable mold includes:
A plurality of first gas discharging units connected to a lower portion of the cavity to form a molten metal channel into which the molten metal flows and a gas is accommodated in an upper portion of the cavity and a plurality of first gas discharging units connected to the discharging unit, And a second gas discharging portion is formed in the second gas discharging portion.

The method of claim 9,
The movable mold includes:
A first gas flow passage and a second gas flow passage for communicating the first gas discharge portion and the second gas discharge portion with the tachy bit are formed and the diameter of the second gas flow passage is formed larger than the diameter of the first gas flow passage Wherein the die-casting mold apparatus is a die-casting mold apparatus for a vehicle component case.

The method of claim 9,
Further comprising: a pressure sensor connected to one of the first gas discharging units so as to measure the internal pressure of the cavity.

The method of claim 9,
And a sleeve portion connected to the molten metal flow path and into which molten metal is injected,
Wherein the sleeve portion is formed with a gas outlet so as to be capable of opening and closing an upper portion thereof so as to discharge the internal gas.