KR102683386B1 - Method for manufacturing parts with differential strength - Google Patents

Abstract

The present invention relates to a method of manufacturing parts with differential strengths that can produce parts with locally different strengths from one part, which includes a forming step of press forming a metal sheet to produce a molded product having a predetermined shape; , a softening step of softening at least a portion of the molded product through heat treatment to form a locally softened area in the molded product, and forming a reinforcing member by three-dimensional printing in at least a portion of the area excluding the softened area of the molded product, A reinforcing step of forming a locally reinforced area in the molded product may be included.

Description

Method for manufacturing parts with differential strength}

The present invention relates to a method of manufacturing parts with differential strengths, and relates to a method of manufacturing parts with differential strengths that can manufacture parts with locally different strengths from one part.

Components with various strengths are used in vehicles. For example, when a vehicle crashes or rolls over, parts that need to absorb energy may require relatively low strength, while parts that need to maintain their shape to secure survival space for the occupants may require relatively strong strength. When a vehicle crashes, if the strength of the part that must absorb energy is too high, the impact energy cannot be absorbed properly and is transmitted to other parts, which can cause the problem of transmitting excessive shock to passengers and other parts of the vehicle. Because you can.

In addition, in recent years, there has been a demand for both lightweighting and high strength of parts to reduce fuel efficiency of vehicles, and it has become increasingly necessary for one part to have partially different strengths in order to satisfy both requirements such as light weight and high strength. .

In general, a method of forming parts with differential strengths is a method of individually press forming parts made of two different materials and then welding or fastening them to form parts, and a cut-welded steel sheet (Tailor) made by welding two materials with different strengths. A method of forming parts by pressing Welded Blanks (TWB) or Tailor Rolled Blanks (TRB), which are rolled to different thicknesses depending on the location of the material, is being used.

However, the conventional method of manufacturing parts with differential strengths has the problem of excessively consuming process time and cost due to complicated manufacturing processes such as separately preparing a plurality of parts or undergoing separate processing processes. In addition, there was a problem that it was difficult to selectively apply softening and reinforcement treatment to precise areas of the part.

The present invention is intended to solve various problems including the problems described above. Compared to conventional two-part forming and part forming using cut-welded steel sheets or cut-rolled steel sheets, it is possible to reduce the number of parts and the number of processes, thereby reducing the number of parts. The purpose is to provide a method for manufacturing parts with differential strengths that can reduce manufacturing process time and process costs, and can selectively apply softening and reinforcement treatment to precise areas. However, these tasks are illustrative and do not limit the scope of the present invention.

According to one embodiment of the present invention, a method for manufacturing parts having differential strengths is provided. The method of manufacturing parts having the above-described differential strengths includes a molding step of press forming a metal plate to produce a molded product having a predetermined shape; A softening step of softening at least a portion of the molded product through heat treatment to form a localized softened area in the molded product; and a reinforcing step of forming a reinforcement area locally in the molded product by forming a reinforcement member through three-dimensional printing in at least a portion of the area excluding the softened area of the molded product.

According to one embodiment of the present invention, in the softening step, the softened region of the molded product can be softened by locally heating and heat treating the softened region by using a first laser beam.

According to an embodiment of the present invention, in the reinforcement step, a three-dimensional printing device of the LMD (Laser Melting Deposition) method is used to melt metal powder or metal wire by a second laser beam to form the reinforcement area of the molded product. The reinforcing member may be formed in .

According to one embodiment of the present invention, the first laser beam in the softening step and the second laser beam in the reinforcement step may be laser beams that are emitted from the same laser source and have different output energies.

According to one embodiment of the present invention, in the reinforcement step, the three-dimensional printing device includes: a laser head assembly emitting the first laser beam or the second laser beam; and a head transporter that moves the laser head assembly in at least one of the width direction, length direction, and height direction of the molded product with respect to the molded product.

According to one embodiment of the present invention, the laser head assembly includes: a laser nozzle portion formed at the center of the laser head assembly and emitting the first laser beam or the second laser beam; and a material nozzle portion formed to surround the laser nozzle portion in the laser head assembly and discharging the metal powder or the metal wire.

According to one embodiment of the present invention, in the reinforcement step, the material nozzle part of the laser head assembly discharges the metal powder or the metal wire into the reinforcement area of the molded product, and the laser nozzle of the laser head assembly The unit emits the second laser beam so that the metal powder or the metal wire discharged on the reinforcement area of the molded product can be melted, and the portion of the reinforcement area where the metal powder or the metal wire is discharged is 1,400 degrees Celsius. It can be heated to a temperature range of 1,600 degrees to 1,600 degrees.

According to one embodiment of the present invention, in the softening step, the material nozzle part of the laser head assembly does not eject the metal powder or the metal wire, and the laser nozzle part of the laser head assembly does not eject the metal powder or the metal wire. In order for the softened area to be softened by heat treatment, the first laser beam having a lower output energy than the second laser beam may be emitted to heat the softened area to a temperature range of 600 to 800 degrees.

According to one embodiment of the present invention, the laser head assembly may further include a gas nozzle portion formed to surround the material nozzle portion in the laser head assembly and discharging shield gas.

According to an embodiment of the present invention made as described above, a metal sheet is press-molded to manufacture a molded product having a predetermined shape, and then, using the same laser source, the molded product is locally heat treated using a laser or By forming reinforcing members using 3D printing, such as laser cladding, parts with locally differential strength can be manufactured.

In this way, after pre-forming a part with a predetermined shape, softening and reinforcement are selectively implemented in a single process in one device, compared to conventional two-part forming and part forming using cut-welded steel sheets or cut-rolled steel sheets. It is possible to reduce the number of parts and processes, thereby reducing the manufacturing process time and cost of parts, and having the effect of selectively performing softening and reinforcement treatment on precise areas.

In addition, as a softening and reinforcing method using a laser, it can be used in combination with existing laser trimming or laser welding process systems, providing differential strength that can have the effect of simplifying the overall part manufacturing process and reducing additional process costs. Branches can implement manufacturing methods for parts. Of course, the scope of the present invention is not limited by this effect.

1 is a flow chart sequentially showing a method of manufacturing parts with differential strength according to an embodiment of the present invention.
Figures 2 to 6 are schematic diagrams schematically showing each step of the manufacturing method of the component having differential strength of Figure 1.
Figures 7 and 8 are cross-sectional views schematically showing embodiments of molded products in which softened areas and reinforced areas are formed locally using the method of manufacturing parts with differential strengths of Figure 1.

Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified into various other forms, and the scope of the present invention is as follows. It is not limited to the examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete and to fully convey the spirit of the present invention to those skilled in the art. Additionally, the thickness and size of each layer in the drawings are exaggerated for convenience and clarity of explanation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will now be described with reference to drawings that schematically show ideal embodiments of the present invention. In the drawings, variations of the depicted shape may be expected, for example, depending on manufacturing technology and/or tolerances. Accordingly, embodiments of the present invention should not be construed as being limited to the specific shape of the area shown in this specification, but should include, for example, changes in shape resulting from manufacturing.

1 is a flowchart sequentially showing a method of manufacturing parts having differential strengths according to an embodiment of the present invention, and FIGS. 2 to 6 schematically show each step of the manufacturing method of parts having differential strengths of FIG. 1. These are schematic diagrams, and FIGS. 7 and 8 are cross-sectional views schematically showing embodiments of molded products in which softened regions and reinforced regions are formed locally using the method of manufacturing parts with differential strengths of FIG. 1.

First, as shown in FIG. 1, the method of manufacturing parts with differential strength according to an embodiment of the present invention largely includes a forming step (S10), a softening step (S20), and a reinforcing step (S30). can do.

As shown in FIG. 2, in the forming step (S10), a molded product 1 having a predetermined shape can be manufactured by press forming a metal plate. Here, the press molding uses all types of press molding methods that can produce a molded product (1) having a predetermined shape by mounting a male and a female mold on a press molding device and inserting the metal plate between them. You can.

Subsequently, as shown in FIG. 3, in the softening step (S20), at least a portion of the molded product 1 is softened through heat treatment to form a softened area A1 locally in the molded product 1.

More specifically, as shown in FIG. 4, in the softening step (S20), the softened area (A1) of the molded product (1) is locally heated and heat treated by the first laser beam (L1), thereby softening the area (A1). ) can be softened.

Subsequently, as shown in FIG. 5, in the reinforcement step (S30), a reinforcement member 2 is formed by three-dimensional printing in at least a portion of the area excluding the softened area A1 of the molded article 1, thereby forming the molded article ( A reinforcement area (A2) can be formed locally in 1).

More specifically, as shown in FIG. 6, in the reinforcement step (S30), a three-dimensional printing device of the LMD (Laser Melting Deposition) method is used to form the reinforcement member 2 by laser cladding (Laser Cladding) Using 100), the reinforcing member 2 can be formed in the reinforcing area A2 of the molded product 1 by melting the metal powder M or the metal wire with the second laser beam L2.

At this time, as shown in FIGS. 4 and 6, the first laser beam (L1) in the above-described softening step (S20) and the second laser beam (L2) in the strengthening step (S30) are used in a three-dimensional printing device. (100) can be emitted from the same laser source. At this time, the first laser beam (L1) and the second laser beam (L2) have different output energies according to their characteristics so that different treatments, such as softening treatment or reinforcement treatment, can be performed on the molded article (1). It could be a laser beam.

A three-dimensional printing device ( 100) is a laser head assembly 10 that emits the first laser beam L1 or the second laser beam L2 and the laser head assembly 10 is positioned in the width direction of the molded product 1 with respect to the molded product 1. , may include a head transport body 20 that moves in at least one of the longitudinal direction and the height direction.

Here, the head transporter 20 moves the laser head assembly 10 in at least one of the width direction, longitudinal direction, and height direction of the molded product 1 with respect to the molded product 1, thereby forming the laser head assembly 10. (10) can selectively diverge the first laser beam (L1) or the second laser beam (L2) to the part set as the softening area (A1) and the part set as the reinforcement area (A2) of the molded product (1), A multi-axis joint robot or machining center can be used.

In addition, the head transporter 20 is capable of moving the laser head assembly 10 in at least one of the width direction, longitudinal direction, and height direction of the molded product 1 with respect to the molded product 1, that is, , any driving device capable of moving the laser head assembly 10 in three axes, such as the X-axis direction, Y-axis direction, and Z-axis direction, can be used.

In addition, as shown in FIGS. 4 and 6, the laser head assembly 10 is formed at the center of the laser head assembly 10 to selectively use the first laser beam L1 or the second laser beam L2. a laser nozzle unit 11 that emits light, a material nozzle unit 12 and a laser head formed to surround the laser nozzle unit 11 in the laser head assembly 10 and ejecting metal powder (M) or metal wire. The assembly 10 may include a gas nozzle unit 13 that is formed to surround the material nozzle unit 12 and discharges shield gas.

Therefore, as shown in FIGS. 3 and 4, in the softening step (S20), the material nozzle portion 12 of the laser head assembly 10 does not eject the metal powder M or the metal wire, but the laser head The laser nozzle portion 11 of the assembly 10 uses a first laser beam (L1) having a lower output energy than the second laser beam (L2) so that the softened area (A1) of the molded product (1) can be softened by heat treatment. ) can be emitted.

More specifically, while the laser head assembly 10 of the three-dimensional printing device 100 is passing through the portion set as the softening area A1 of the molded product 1 by the head transporter 20, the material nozzle portion 12 Only the first laser beam L1 can be emitted through the laser nozzle unit 11 without ejecting the metal powder M or the metal wire.

At this time, the first laser beam L1 is directed to the softened area A1 of the molded product 1 so that the softened area A1 of the molded product 1 is not heated to the point of melting but heated to the point where heat treatment can be performed. It may be desirable to have a level of output energy capable of heating within a temperature range of 600 to 800 degrees.

In addition, as shown in FIGS. 5 and 6, in the reinforcement step (S30), the material nozzle portion 12 of the laser head assembly 10 injects metal powder (M) into the reinforcement area A2 of the molded product 1. ) or a metal wire is discharged, and the laser nozzle portion 11 of the laser head assembly 10 is configured to melt the metal powder M or the metal wire discharged on the reinforcement area A2 of the molded product 1. , it is possible to emit a second laser beam (L2) having higher output energy than the first laser beam (L1).

At this time, so that the metal powder (M) or metal wire discharged on the reinforcement area (A2) of the molded product (1) can be melted, the second laser beam (L2) is emitted to melt the metal powder (M) in the reinforcement area (A2). ) Alternatively, it may be desirable to have output energy sufficient to heat the portion where the metal wire is discharged to a temperature range of 1,400 to 1,600 degrees, most preferably 1,500 degrees.

More specifically, while the laser head assembly 10 of the three-dimensional printing device 100 is passing through the portion set as the reinforcement area A2 of the molded product 1 by the head transporter 20, the material nozzle portion 12 While the metal powder (M) or metal wire is being discharged onto the reinforcement area (A2), the second laser beam (L2) can be emitted together through the laser nozzle unit (11).

Accordingly, the metal powder (M) or metal wire discharged onto the reinforcement area (A2) of the molded product (1) is melted together with at least a portion of the surface of the molded product (1) by the second laser beam (L2), thereby forming the molded product (1). A melt pool (3) is formed on (1), and after the laser head assembly (10) passes by, the melt pool (3) solidifies to form a reinforcing member (2) on the molded product (1).

The reinforcing member 2 is formed by melting the metal powder M or metal wire together with at least a portion of the surface of the molded article 1 and then solidifying it again, and may be formed substantially as one body with the molded article 1. there is.

In addition, the laser head assembly 10 has a melt pool 3 formed by melting the metal powder M or the metal wire together with at least a portion of the surface of the molded product 1 by the second laser beam L2 in the air. As shown in FIG. 6, shield gas (G) is discharged around the melt pool (3) through the gas nozzle unit (13) to prevent defective parts from occurring in the reinforcing member (2) due to contact with oxygen or foreign substances. can do.

As described above, the method of manufacturing parts with differential strength according to an embodiment of the present invention by the three-dimensional printing device 100 including the laser head assembly 10 and the head transport body 20 is one. As a method of locally forming a softened area (A1) and a reinforced area (A2) in a molded product (1) using a laser source (laser head assembly), the laser head assembly (10) is formed by the head transporter (20). When passing over the area set as the softening area A1, only the first laser beam L1 is emitted, and when the laser head assembly 10 passes over the area set as the reinforcement area A2 by the head transporter 20, the laser head assembly 10 emits only the first laser beam L1. The second laser beam (L2) may be emitted along with the discharge of the metal powder (M) or metal wire.

This process of forming the softened area (A1) and the reinforced area (A2) in the molded product 1 includes a softening step (S20) and The reinforcing step (S30) may be performed alternately regularly or irregularly, and the softening step (S20) and the reinforcing step (S30) are substantially one process (the head transporter 20 performs the laser head assembly 10 ), it may be reasonable to view it as taking place within the process of moving the entire area of the molded product 1 along a predetermined path.

Accordingly, using the manufacturing method of parts having differential strength of the present invention, the softened area A1 and the reinforced area A2 are locally formed in various patterns as needed in the molded article 1 press-molded into a predetermined shape. It can be formed as

For example, the molded product 1 is a vehicle part, and as shown in FIGS. 7 and 8, depending on the area where the vehicle part is applied to the vehicle, various types of buckling occur to effectively absorb shock and protect occupants in the event of a vehicle collision. Form may be required. Therefore, by using the manufacturing method of parts with differential strength of the present invention according to the required buckling form of the molded product 1, the softened area A1 and the reinforced area are selectively localized to the molded product 1, which is a vehicle part. By forming (A2), the buckling form of the molded product (1), which may occur during a vehicle collision, can be freely adjusted.

The above-mentioned example is an example in which the molded product 1 is applied as a vehicle part to aid understanding of the present invention, and of course, the present invention is not limited by the above-described embodiments.

Therefore, according to the method of manufacturing parts with differential strength according to an embodiment of the present invention, one metal plate is press-molded to produce a molded product 1 having a predetermined shape, and then using the same laser source, By locally forming a reinforcing member 2 on the molded product 1 using heat treatment using a laser or 3D printing such as laser cladding, parts with locally differential strength can be manufactured.

Therefore, by pre-forming parts with a predetermined shape and then selectively implementing softening and reinforcement in a single process in one device, compared to conventional two-part forming, part forming using cut-welded steel sheets or cut-rolled steel sheets. It is possible to reduce the number and number of processes, thereby reducing the manufacturing process time and cost of parts, and having the effect of selectively performing softening and reinforcement treatment on precise areas.

In addition, as a softening and reinforcement method using a laser, it can be used in combination with systems in existing laser trimming or laser welding processes, which can have the effect of simplifying the overall part manufacturing process and reducing additional process costs.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

1: Molded product
2: Reinforcement member
3: Melt Pool
10: Laser head assembly
11: Laser nozzle part
12: Material nozzle part
13: Gas nozzle part
20: Head transport body
100: 3D printing device
A1: softening zone
A2: Reinforcement area
L1: 1st laser beam
L2: Second laser beam
M: metal powder
S: shield gas

Claims (9)

A forming step of press forming a metal plate to produce a molded product having a predetermined shape;
A softening step of softening at least a portion of the molded product through heat treatment to form a localized softened area in the molded product; and
A reinforcement step of forming a reinforcement area locally in the molded product by forming a reinforcement member by three-dimensional printing in at least a portion of the area excluding the softened area of the molded product,
In the softening step,
Softening the softened region by locally heating and heat-treating the softened region of the molded product with a first laser beam,
In the reinforcement step,
Using a three-dimensional printing device of the LMD (Laser Melting Deposition) method, the reinforcing member is formed in the reinforcing area of the molded product by melting metal powder or metal wire with a second laser beam,
The 3D printing device,
a laser head assembly emitting the first laser beam or the second laser beam; and
Including a head transporter that moves the laser head assembly in at least one of the width direction, length direction, and height direction of the molded product with respect to the molded product,
The first laser beam in the softening step and the second laser beam in the strengthening step are emitted with different output energies from the laser head assembly, which is the same laser source,
The softening step and the reinforcing step are,
During the process of the head transporter moving the laser head assembly along a predetermined path to pass through the softening area and the reinforcement area on the molded product, the laser head assembly sends the first laser beam or the second laser beam to the softening area. A method of manufacturing parts with differential strength, which is carried out selectively according to the passing area, and is carried out alternately in one process, so as to selectively radiate it to the part set as the area and the part set to the reinforcement area. delete delete delete delete According to claim 1,
The laser head assembly,
a laser nozzle unit formed at the center of the laser head assembly to emit the first laser beam or the second laser beam; and
a material nozzle portion formed to surround the laser nozzle portion in the laser head assembly and discharging the metal powder or the metal wire;
A method of manufacturing a part having differential strength, comprising: According to claim 6,
In the reinforcement step,
The material nozzle portion of the laser head assembly,
Discharging the metal powder or the metal wire into the reinforcement area of the molded product,
The laser nozzle portion of the laser head assembly,
The second laser beam is emitted so that the metal powder or the metal wire discharged on the reinforcement area of the molded product is melted, and the portion of the reinforcement area where the metal powder or the metal wire is discharged is heated at 1,400 degrees to 1,400 degrees. A method of manufacturing parts with differential strengths that involves heating to a temperature range of 1,600 degrees. According to claim 6,
In the softening step,
The material nozzle portion of the laser head assembly,
Without discharging the metal powder or the metal wire,
The laser nozzle portion of the laser head assembly,
Differential intensity of heating the softened area to a temperature range of 600 to 800 degrees by emitting the first laser beam having a lower output energy than the second laser beam so that the softened area of the molded product can be softened by heat treatment. A method of manufacturing a part having a. According to claim 6,
The laser head assembly,
a gas nozzle portion formed to surround the material nozzle portion in the laser head assembly and discharging shield gas;
A method of manufacturing a part having differential strength, further comprising:

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