JP2003053475A - Method and apparatus for manufacturing parts for shielding electromagnetic waves utilizing hot-working method for magnesium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make high-speed production possible by utilizing a magnesium alloy which permits weight reduction and shortening a post working process step to the maximum possible extent in manufacturing of parts for shielding electromagnetic waves. SOLUTION: The method of manufacturing the parts for shielding the electromagnetic waves by using the magnesium alloy includes a material heating process step of cutting the material of the magnesium alloy and homogeneizing the material by relieving stresses so as to be advantageous in molding the products, a process step of hot molding and working for fabricating the products by using the heated material, a trimming process step of neatly trimming the products by cutting off the unnecessary edges, fins, etc., of the fabricated products after undergoing the process step of the hot molding and working, a film treating process step of performing rust preventive work on the finished products after undergoing the trimming process step and a painting work of painting the products after undergoing the film treating process step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing parts such as a case for shielding electromagnetic wave interference generated in various electronic devices, and particularly to hot working using magnesium. The present invention relates to a method and apparatus for manufacturing an electromagnetic wave shielding component that utilizes a magnesium hot working method configured to shorten post-processing steps and realize high-speed production.

[0002]

2. Description of the Related Art Recently, various kinds of home electric appliances, portable communication equipment and the like have appeared due to the development of the electronic industry, and they are becoming smaller and lighter in order to meet the needs of users. Due to the tendency toward miniaturization, lightness and thinness, these electronic products should realize high integration of circuits, so that they are densely arranged on a printed circuit board (PBA: Printed Board Assembly) of an electronic component (electronic function group). The product's outer case and various shielding (s
Hielding parts are becoming thinner, and in the case of portable communication equipment, the user tends to always attach them to the human body.

The components and the outer case, which have been thinned in this way, have various shielding structures for protecting the human body by blocking harmful radio waves generated from electronic components in advance, or It will be manufactured first with a material that can be shut off.

Further, the electromagnetic waves generated in various electronic products are strictly regulated. Among the regulated harmful radio waves, examples of electromagnetic waves include whether the electromagnetic waves are environmentally compatible (electromagnetic wave environmental compatibility). Gender: Electromagnetic Compatibilit
y: There is an environmental compatibility test that tests EMC). Such electromagnetic compatibility is due to electromagnetic interference (EMI: El
ectromagnetic Interference) and electromagnetic sensitivity (EMS: E
lectromagnetic Susceptability), which is harmful to the human body and is therefore strictly regulated.

As described above, as a component for shielding electromagnetic waves, a plastic injection product is manufactured and an electromagnetic shielding paint is applied to the surface thereof, or strip fingers are provided so as to have a predetermined grounding action with a printed circuit board. It may adhere to the above parts. In addition, it may be made of a certain metal alloy during the first production.

In the prior art of the present application, a shield cover applied to a portable wireless terminal among components for shielding electromagnetic waves will be described as an example.

FIG. 1 is a process diagram showing a method of manufacturing an electromagnetic wave shielding component according to the prior art, showing a process of manufacturing a shield cover of a portable radio terminal.

Conventionally, as shown in FIG. 1, a step 100 of melting a material using a magnesium-aluminum alloy (AZ91 series) is performed. After that, since the step 110 of casting a die is performed, the die casting method is used. A component manufactured by the die casting method is subjected to a trimming process step 120, and then an intermediate inspection step 130 for confirming whether or not the product is abnormal. Then, a machining process 140 of tapping or an additional process of a portion not manufactured by the die casting method is performed. Then, after a rust preventive process 150 for preventing rust in advance, a final coating process is performed to complete the product.

However, as described above, the electromagnetic wave shielding parts made of the magnesium-aluminum alloy by the die casting method are not only heavy but also have a gate (gat)
e), there are too many post-processes that must remove barr etc., so it takes a long time during die casting, resulting in poor appearance quality due to unformed and rough surfaces, resulting in poor productivity. And the yield rate deteriorates due to an increase in the defective rate due to many processes. This not only increases capital investment due to the high cost of molding machines, but also
When a magnesium-aluminum alloy ingot is melted and injection-molded, there is a problem that the working environment becomes very bad.

[0010]

SUMMARY OF THE INVENTION Therefore, an object of the present invention for solving the above-mentioned problems is to shorten the post-processing step to the maximum, and to make magnesium capable of high-speed production. An object of the present invention is to provide an electromagnetic wave shielding part manufacturing method and apparatus using a hot working method.

Yet another object of the present invention is the manufacture of electromagnetic shielding components utilizing a magnesium hot working process which is configured to reduce the weight of components manufactured using magnesium alloys which maximize the proportion of magnesium. A method and apparatus are provided.

[0012]

In order to achieve such an object, the present invention provides a method for manufacturing an electromagnetic wave shielding component using a magnesium alloy, which comprises cutting a material of the magnesium alloy to form a product. Sometimes it is advantageous to remove the stress and homogenize the material, a hot forming process for producing a product using the heated material, and a hot forming process. A trimming step for trimming unnecessary edges and fins of the manufactured product to shape the product cleanly, a coating treatment step for performing rust prevention work on the finished product after the trimming step, and the coating treatment step And a painting step of painting after.

Further, the present invention is an apparatus for manufacturing an electromagnetic wave shielding component using a magnesium alloy, which is equipped with a conveyor belt for transferring a large number of materials made of the magnesium alloy, which is advantageous when molding a product. In order to remove stress and homogenize the material, a heating furnace that heats the material at a predetermined temperature, and a plurality of materials discharged from the heating furnace are pressed at a certain level or more before being transferred one by one by a press. A heat insulation furnace that stacks so as to stand by while keeping the temperature,
A press for manufacturing the material transferred one by one in the heating furnace into a product by a hot-molding die, and the press prevents the temperature of the material heated in the heating furnace from decreasing and smoothes the flow during molding. In order to maintain the temperature at a certain level, it is characterized by comprising a predetermined heating device provided so as to heat the material at a certain temperature or higher.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In the present invention, when it is determined that the gist may be unclear, the detailed description thereof will be omitted. The present invention is to manufacture parts using magnesium alloys with an extraordinarily high weight percent specific gravity by a hot working method rather than a die casting method.

FIG. 2 is a view showing a portable wireless terminal that can be formed by hot working magnesium according to a preferred embodiment of the present invention. The present invention is applied to a folder type portable wireless terminal, but it is obvious to those skilled in the art that the present invention is applicable to other devices that generate electromagnetic waves.

As shown in the figure, the portable wireless terminal 30
It is possible to manufacture the upper casing frame A, the lower casing frame B, the LCD guide panel C, which is the folder, and the front panel D, which are the main body of No. 0, by the hot forming process of magnesium according to the present invention. In addition, an electronic component (ele) mounted on the internal RF board of the portable wireless terminal 300 is
A shield cover 310 for preventing electromagnetic waves emitted from the ctronic function group) is provided, which can also be manufactured by the magnesium hot forming method according to the present invention.

FIG. 3 is a process diagram showing a method of manufacturing an electromagnetic wave shielding component according to a preferred embodiment of the present invention. In the figure, a material heating step 200 for cutting the material of the magnesium alloy and homogenizing it by removing stress so as to be advantageous at the time of forming the product, and a hot work for manufacturing the product using this prepared material. A process 210 for processing, a trimming process 220 for trimming unnecessary edges and fins of the manufactured product to shape the product cleanly after the hot working process, and a product finished after the trimming process. It is composed of a coating process 230 for performing rust prevention work and a coating process 240 for performing coating after the coating process.

These steps will be described below with reference to FIG.

In the material preparation step 200, the material 21 is heated in a predetermined heating furnace 23 and a heat-retaining furnace 25 at a temperature higher than a certain temperature to homogenize the material, and the temperature is about 350-.
The temperature is 400 ° C.

Further, in the hot working step 210, the hot forming step is performed by a predetermined press 27 according to the thickness of the finished product. At this time, when a magnesium alloy is used to produce a part having a certain thickness or more, it is formed into an ingot material and undergoes a hot forging process. When producing a thin plate product (for example, an electronic product case), Use hot forming methods.

Further, the press 27 is further provided with a predetermined heating device (not shown) for maintaining the temperature of the charged material and smoothing the flow at the time of molding. The temperature of this heating device is approximately 250 to 300 ° C (for example, approximately 300 ° C).
℃).

The magnesium alloy is preferably composed of 90 to 99% by weight of magnesium and 1 to 10% by weight of aluminum, and particularly preferably 97 of magnesium.
It is composed of 3% by weight of aluminum and 3% by weight of aluminum. By using such a magnesium alloy, the weight of the component can be reduced.

FIG. 4 is a schematic view of a magnesium hot working apparatus 20 according to a preferred embodiment of the present invention. Magnesium hot working apparatus 20 has a large number of materials 2
1. A heating furnace 23 for homogenizing 1; a heat-retaining furnace 25 for maintaining the many homogenized materials 21 at the temperature heated by the heating furnace 23 even in a standby state; and a material 21 supplied from the heat-retaining furnace 25. And a press 27 having a hot forming die for hot working

The heating furnace 23 has a predetermined conveyor belt 22.
Is installed, a large number of materials (for example, 100 to 1
About 50 sheets are heated while being sequentially moved. This heating furnace is a hot air circulation type heating furnace, and the time for heating the material in the heating furnace 23 is about 1 to 1.5 hours. This results in stress relief and homogenization in favor of the molding of the product. The material 21 homogenized in the heating furnace 23 is transferred by the conveyor belt 22 and then transferred into the heat retaining furnace 25 by a predetermined air cylinder 24.

The heat-retaining furnace 25 maintains the molding temperature of the material heated in the heating furnace 23 as it is, and the materials are transferred one by one from the heat-retaining furnace 25 to the press 27 by the material transfer feeder 26. At this time, the time to transfer to the press 27 is 1
About 2 seconds is desirable. Therefore, the heat-retaining furnace 25 must also be maintained at a certain temperature or higher, and a suitable temperature is about 400 ° C. Further, the press 27 is also provided with a predetermined heating device, and preferably, it can be provided on all of the upper and lower molds 28. After all, the heating device is 250-3
It is desirable to maintain a temperature of 00 ° C. A vacuum adsorption type feeder can be used as the transfer feeder 26 for transferring the materials one by one to the press 27 in the heat insulation furnace 25.

The magnesium hot working apparatus 20 is made of the material 21.
Is placed on the conveyor belt 22 of the heating furnace 23, and the press 27 is hot-formed through the heat-retaining furnace 25 to automatically operate until the product is completed. Further, since the heating furnace 23, the heat-retaining furnace 25, and the press 27 are integrally provided, the heating furnace 23, the heat-retaining furnace 25, and the press 27 are configured to operate in a coordinated manner from the time the material is supplied to the time the product is taken out of the press. Therefore, the product is molded at a speed about 2.5 to 3 times faster than the existing die casting method.

FIG. 5 schematically shows a magnesium hot working apparatus 30 according to another embodiment of the present invention. By installing the heating furnace 35 in the portion of the press 31 where the mold 32 is located, the homogenized material 21 is directly transferred to the press 31 in the heating furnace 35 without using a separate heat-retaining furnace to form a product. be able to. At this time, the heating furnace 35 is provided with a material transfer feeder 26 so that the material can be smoothly transferred between the upper and lower molds 32 of the press 31. The material transfer feeder 26 is also a vacuum suction type. The feeder is ready for use.

FIG. 6 is a partial sectional view showing the heating furnace 35 of FIG. 5 in detail. The heating furnace 35 is composed of refractory bricks 36, and a heater coil 37 is provided on the upper portion thereof as a predetermined heating means. become. A pusher 39, which is operated by a cylinder 38 so as to be vertically movable in the vertical direction, is installed under the heating furnace 35, and the material 21 laminated on the upper part of the pusher 39 is supplied to the press and at the same time, the transfer feeder 2 is provided.
It is configured to precisely adjust the distance from 6.

FIG. 7 schematically shows a magnesium hot working apparatus according to another embodiment of the present invention, which is applied when the magnesium base material 42 is used as a square bar or a bar of a constant length. In this case, the magnesium base material 42, which is a square bar or a bar, is heated to a semi-solidified state (a state immediately before melting and flowing) by a predetermined heating device 43 and then supplied to a predetermined die 44 to be desired by a forging method. After forming the product, it is taken out. At this time, the hot working apparatus 40 as shown in FIG. 7 is a layered pallet 41 on which a large number of magnesium base materials 42 of squares or bars are layered, and the layered pallet 41 is transferred by a predetermined transfer device 43 to be semi-solidified. Heating device 43 for heating to a state, and this heating device 43
The mold 44 is used to mold a square or bar material heated in a semi-solidified state into a desired product. At this time, as the transfer device 46, it is possible to use the transfer device 46 in which the pallets 41 are integrated to the mold 44 through the heating device 43, and preferably a predetermined conveyor belt can be used. Also, although not shown, a pusher using hydraulic or pneumatic cylinders for supplying squares or rods from the laminated pallet to the conveyor belt is provided, which is used for high-frequency heating device or mold at desired positions. It can also be used when positioning the material.

On the other hand, as the heating device 43, a coil type high frequency heating device can be used. After inserting a square or rod into the coil type high frequency heating device, the temperature is raised to a certain temperature to heat it to a semi-solidified state. Like This high-frequency heating device has the advantage that it can be rapidly heated to a desired temperature. At this time, the heating temperature is in the range of about 480 ° C to 540 ° C. The use of these square or rod-shaped magnesium base materials has an advantage in forming thick ribs and bosses.

[0031]

As described above, if the magnesium alloy according to the embodiment of the present invention is used to manufacture a component for electromagnetic wave shielding using the hot working method, the post-processing step can be shortened to the maximum, so that high speed production is possible. There is an effect that becomes possible. In addition, it uses magnesium alloys that maximize the ratio of magnesium, so it is possible to reduce the weight of parts to be manufactured, and by using at least one or more heating furnaces and general low-cost manufacturing equipment such as presses. , There is an effect that can realize the minimum capital investment.

[Brief description of drawings]

FIG. 1 is a process drawing showing a method of manufacturing an electromagnetic wave shielding component according to a conventional technique.

FIG. 2 is a view showing a portable wireless terminal that can be formed by hot working magnesium according to the present invention.

FIG. 3 is a process drawing showing a method for manufacturing an electromagnetic wave shielding component according to the present invention.

FIG. 4 is a diagram schematically showing a magnesium hot working apparatus according to the present invention.

FIG. 5 is a diagram schematically showing a magnesium hot working apparatus according to another embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing the heating furnace of FIG. 5 in detail.

FIG. 7 is a view schematically showing a magnesium hot working apparatus according to still another embodiment of the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B21J 5/02 B21J 5/02 D 13/02 13/02 A 17/00 17/00 Z (72) Invention Investor Republic of Korea Gorgeous Republic of Korea Gyeonggi-do Suwon-si, Batada, Baidan 1-dong, 5th main apartment, 521-605 F term (reference) 4E087 AA08 AA10 BA03 CA11 CB01 CB04 DB02 DB15 DB18 DB22 DB24 ED12 FB05 GA09 HB06

Claims (11)

[Claims] 1. A method for manufacturing an electromagnetic wave shielding component using a magnesium alloy, the material heating step of cutting a material of a magnesium alloy to remove stress so as to be advantageous in molding a product, and homogenizing the material. A step of hot forming for producing a product using the heated material; and a step of cutting the unnecessary edge or fins of the produced product after the step of hot forming A trimming step for shaping the material cleanly, a coating treatment step for performing rust prevention work on the finished product after the trimming step, and a painting step for painting after the coating treatment step. A method of manufacturing an electromagnetic wave shielding part using a hot working method of magnesium. 2. The method according to claim 1, wherein in the material heating step, the material is heated in a predetermined heating furnace at a temperature higher than or equal to a certain temperature to homogenize the material, and then hot forming is performed immediately. A method of manufacturing an electromagnetic wave shielding part using a hot working method of magnesium. 3. In the material heating step, the material is heated in a predetermined heating furnace at a temperature higher than or equal to a certain temperature to homogenize, and then heated in a predetermined heat-retaining furnace at a temperature higher than or equal to a predetermined temperature to perform hot forming. A constant temperature is maintained before starting.
A method for producing an electromagnetic wave shielding part, which utilizes the described magnesium hot working method. 4. The temperature of the heating furnace and the heat insulating furnace is 350 to
It is 400 degreeC, The manufacturing method of the components for electromagnetic wave shielding using the magnesium hot working method of Claim 2 or Claim 3. 5. The hot forming process is carried out by a predetermined press equipped with a hot forming die, and the predetermined temperature is maintained in the press to maintain the temperature of the material and smooth the flow at the time of forming. The method for producing an electromagnetic wave shielding component using the magnesium hot working method according to claim 1, further comprising a heating device. 6. The temperature of the heating device is 250 to 300 ° C.
The method for producing an electromagnetic wave shielding component using the magnesium hot working method according to claim 5. 7. The magnesium alloy is magnesium 9
The method for producing an electromagnetic wave shielding component using the magnesium hot working method according to claim 1, wherein the method is composed of 0 to 99% by weight and 1 to 10% by weight of aluminum. 8. An apparatus for manufacturing an electromagnetic wave shielding component using a magnesium alloy, comprising a conveyor belt for transferring a large number of materials made of the magnesium alloy, which is advantageous when molding a product. A heating furnace that heats the material at a predetermined temperature to remove stress and homogenize it, and maintain a temperature above a certain level before transferring a large number of materials discharged from the preheating furnace one by one with a press. While holding a heat-retaining furnace that stacks so as to stand by, a press for manufacturing the material transferred one by one in the heating furnace into a product by a hot-molding die, and the press includes a material heated in the heating furnace. In order to prevent the temperature from decreasing and to maintain a smooth flow during molding, the magnesi is configured by a predetermined heating device provided to heat the material at a certain temperature or higher. Electromagnetic wave shielding component manufacturing apparatus utilizing a beam hot working method. 9. The temperature of the heating furnace and the heat insulation furnace is 350 to
An electromagnetic wave shielding component manufacturing apparatus utilizing the magnesium hot working method according to claim 8 at 400 ° C. 10. The apparatus for manufacturing an electromagnetic wave shielding component using a magnesium hot working method according to claim 8, wherein a temperature of a heating device provided in the press is 250 to 300 ° C. 11. The electromagnetic wave shielding part manufacturing apparatus using the magnesium hot working method according to claim 8, wherein the magnesium alloy is 90 to 99% by weight of magnesium and 1 to 10% by weight of aluminum.