KR101353592B1 - Device and method for pressing amorphous strip - Google Patents

Abstract

Upper and lower dies for forming amorphous strips, chambers surrounding the upper and lower dies, and installed in the chambers to supercool the amorphous strips inside the chambers for easier processing while minimizing damage or defects in the amorphous strips. It provides an amorphous strip forming apparatus comprising a heating unit for heating in a liquid state.

Description

Amorphous Strip Forming Method and Forming Apparatus {DEVICE AND METHOD FOR PRESSING AMORPHOUS STRIP}

The present invention relates to metal strip forming technology. More particularly, the present invention relates to an amorphous strip forming method and a molding apparatus that can more easily form a high hardness amorphous strip.

In general, the electrical steel plate motor core is manufactured through a molding process of stamping the electrical steel sheet into the shape of the motor core by using a press and a process of laminating the formed electrical steel sheet to the required thickness.

The hardness of the electrical steel sheet is a Vickers hardness, and exhibits a relatively low hardness value of about 210 Hv, so that molding can be relatively easy using a press at room temperature. In addition, since the electrical steel sheet has a thickness of 0.2 mm or more, healthy molding is possible without being deformed or destroyed during molding. In addition to excellent formability, electrical steel sheet has been used for a long time because it exhibits a high magnetic flux density of about 1.8T. However, the electrical steel sheet has a disadvantage that the iron loss is as high as 1.72W / kg. Recently, the magnetic flux density is slightly lower than that of electrical steel sheet, but it shows excellent characteristics in iron loss, and an amorphous material that can be applied in the high frequency band has been in the spotlight.

Amorphous materials are produced by rapidly cooling metals in molten state at a high cooling rate of 10 ⁵ K / s. As such, the amorphous material maintains the disordered state of the atomic arrangement of the liquid phase in the solid state without time for atoms to be regularly arranged and crystallized. Unlike conventional crystalline alloys, an amorphous material has a structure similar to a liquid phase in which atoms are irregularly arranged to have no crystallinity. Therefore, amorphous alloys are free from defects such as grain boundaries and dislocations, which are the characteristics of crystalline alloys. It has excellent characteristics such as.

The amorphous material is manufactured in the form of a strip having a thickness of about 25 μm because a fast cooling rate must be maintained.

In order to use the amorphous strip for a motor core or the like, a molding process is required. Since the amorphous strip has a very thin thickness, a high probability of breakage or defects occurs when a plurality of pieces are laminated and molded.

In addition, the amorphous strip has a very high hardness of about 900Hv compared to the electrical steel sheet, there is a disadvantage that the molding is difficult. In addition, there is a high risk of damage to the mold as well as the strip during the molding process.

As described above, the amorphous material is thinner than the electrical steel sheet, and since the fundamental physical properties and mechanical properties of the two materials are different, a different molding process is required.

Accordingly, the present invention provides an amorphous strip molding method and a molding apparatus which can be processed more easily while minimizing damage or defect generation of amorphous strips.

In addition, the present invention provides an amorphous strip molding method and a molding apparatus, which are capable of preventing degradation of quality by maintaining tissue characteristics of the amorphous strip during molding.

In addition, there is provided an amorphous strip forming method and a molding apparatus that can reduce damage of an amorphous strip forming mold.

To this end, the present molding apparatus may include an upper die and a lower die for forming an amorphous strip, a chamber surrounding the upper die and the lower die, and a heating unit installed in the chamber to heat the amorphous strip inside the chamber in a supercooled liquid state.

The heating unit may include at least one halogen lamp disposed inside the chamber.

The halogen lamp may be installed on the bottom surface of the lower die in contact with the amorphous strip.

The halogen lamp may be installed on the inner surface of the chamber.

The apparatus may further include a thermocouple installed inside the chamber to detect a temperature of an amorphous strip.

The upper mold may be further installed inside the heating element.

The chamber or the lower die may have a structure in which cooling water is distributed.

Meanwhile, the present molding method may include a heating step of raising the amorphous strip in a subcooled liquid state, and a processing step of molding the heated amorphous strip.

The heating step may be a structure for heating the amorphous strip with a halogen lamp.

The processing step may be made within the time point of the crystallization of the amorphous strip heated in the heating step.

According to this embodiment as described above, the amorphous strip can be easily and easily molded.

In addition, it is possible to prevent the strip from breaking or defects in the amorphous strip forming process, and to minimize the damage to the mold.

In addition, it is possible to prevent the degradation of tissue properties due to the crystallization of the amorphous strip and to maintain the quality of the product.

In addition, thin amorphous strips can be laminated and molded.

1 is a perspective view schematically showing an outer shape of an amorphous strip forming apparatus according to the present embodiment.
2 is a perspective view schematically showing the internal structure of the amorphous strip forming apparatus according to the present embodiment.
3 is a schematic diagram showing the configuration of an amorphous strip forming apparatus according to the present embodiment.
4 is a flowchart schematically showing an amorphous strip forming process according to the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. 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 or scope of the invention. Wherever possible, the same or similar parts are denoted using the same reference numerals in the drawings.

All terms including technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

FIG. 1 shows the external shape of the amorphous strip forming apparatus according to the present embodiment, and FIGS. 2 and 3 show the internal configuration of the amorphous strip forming apparatus according to the present embodiment.

In the following description, the shaping of the amorphous strip means, for example, pressing a sheet material such as a punching process or a drawing process to process it into a desired shape such as a motor core.

The molding apparatus 10 according to the present embodiment has a structure in which the amorphous strip is heated in a subcooled liquid state to be molded.

To this end, the molding apparatus 10 is, as shown, the upper mold 11 and the lower die 12 for forming an amorphous strip, the chamber 20 surrounding the upper mold 11 and the lower die 12, the It is installed in the chamber 20 includes a heating unit for heating the amorphous strip in the chamber 20 in the subcooled liquid state.

In the present embodiment, the chamber 20 is installed on the upper portion of the lower die 12, and is formed in a rectangular box shape having an upper space, front and rear surfaces, and left and right sides having an internal space.

The inlet 21 and the outlet 22 communicating with the internal space of the chamber 20 are formed between the lower die 12 on the left and right sides of the chamber 20 to allow the amorphous strip of the material to enter and exit. It is.

Accordingly, the chamber 20 may wrap the upper die and the lower die as a whole and block the amorphous strip moved into the chamber 20 from the outside for rapid molding, thereby rapidly increasing the temperature to a predetermined temperature.

The chamber 20 may be formed of a ceramic material on an inner surface of the chamber 20 to sufficiently endure heat generated when the amorphous strip is heated. The chamber 20 is not particularly limited in structure or material thereof.

The upper die 11 and the lower die 12 are for forming an amorphous strip into a desired product shape, and are provided in pairs.

In the present embodiment, the upper die 11 is coupled to the upper and lower movable through the upper end of the chamber 20. The press 14 for driving the upper mold is installed at the upper end of the upper mold 11 extending to the outside of the chamber 20. When the press 14 is driven, the upper die 11 is lowered to press the amorphous strip placed on the lower die 12 to form a desired shape.

The lower die 12 is a flat structure, which is disposed below the chamber 20 and forms an inner bottom surface of the chamber 20. In the center portion of the lower die 12 is formed a mold 13 for amorphous strip processing in accordance with the shape of the product in a position corresponding to the upper mold 11 in the form of recesses. The mold 13 may be variously modified to match the shape of the product to be molded.

The heating unit includes at least one halogen lamp 30 disposed inside the chamber 20 to heat an amorphous strip. The halogen lamp 30 heats the amorphous strip prior to molding so that the amorphous strip is in a subcooled state.

Here, the supercooled liquid phase state indicates a liquid state even at a temperature below the freezing point while the molten metal is quenched, and usually means a state in a temperature section between the glass transition temperature (Tg) and the crystallization temperature (Tx). The intervals vary depending on the composition of the amorphous strip, so that the temperature increases or decreases.However, regardless of the composition, all of the amorphous strips are significantly reduced in viscosity when heated to the respective supercooled liquid state, so that the hardness and strength values are maintained at room temperature. It is much smaller.

Therefore, the present molding apparatus 10, as described above, as the amorphous strip is heated in the subcooled liquid state by the halogen lamp 30, it is possible to form the amorphous strip with less force, and during the molding of the amorphous strip and equipment High speed machining is possible with minimal damage.

In order to use the characteristics exhibited in the subcooled liquid phase region of the amorphous strip, the temperature must be raised to the subcooled liquid phase region as quickly as possible. Otherwise, the amorphous strip may be exposed to heat for a long time to form a crystalline phase therein.

Therefore, the present molding apparatus 10 uses a halogen lamp 30 to rapidly heat the amorphous strip as mentioned. The halogen lamp 30 raises the amorphous strip as quickly as possible in the supercooled liquid state.

Here, in the case of using a general structure such as an electric furnace without using the halogen lamp 30, rapid heating of the amorphous strip is difficult. As a result, the amorphous strip is exposed to heat for a long time while being heated to a temperature lower than the subcooled liquid phase region or heated to the subcooled liquid phase region. Hardness and strength are not reduced when the amorphous strip is at a lower temperature than the subcooled liquid region, making molding difficult. In addition, when the amorphous strip is exposed to heat for a long time in the subcooled liquid phase region, as mentioned, a crystalline phase may be formed inside the amorphous strip, which degrades the soft magnetic properties of the amorphous strip. In terms of mechanical properties, brittleness can be generated and can be easily destroyed with little force. That is, it is difficult to rapidly heat the amorphous strip through the general heating structure, so that the amorphous strip cannot be crystallized.

In this manner, the present molding apparatus 10 can rapidly heat the amorphous strip in the subcooled liquid state by the halogen lamp 30. Therefore, after molding of the amorphous strip, the amorphous strip is rapidly heated during the next molding to avoid exposing the amorphous strip to heat for a long time.

In this embodiment, the halogen lamp 30 is installed on the bottom surface of the lower die 12 through which an amorphous strip passes. Accordingly, the amorphous strip is rapidly heated by the halogen lamp 30 installed in the lower die 12 in the process of entering the chamber 20 and proceeding along the lower die 12. In addition, the halogen lamp 30 may be installed on the inner surface of the chamber 20. The halogen lamp 30 installed on the inner side of the chamber 20 indirectly heats the amorphous strip, while raising the temperature inside the chamber 20 to assist rapid heating of the amorphous strip. The halogen lamps 30 have a structure in which a plurality of halogen lamps 30 are continuously arranged at intervals.

In order to install the halogen lamp 30 on the lower die 12, grooves 32 into which the halogen lamp 30 is inserted are formed on the upper surface of the lower die 12 at intervals. The groove 32 has a size corresponding to that of the halogen lamp 30. The halogen lamp 30 is installed in the groove 32 to be located inside the groove. Accordingly, as shown in FIG. 3, the halogen lamp 30 installed in the groove 32 of the lower die 12 does not protrude upward from the lower die 12, and thus does not interfere with the amorphous strip when the amorphous strip moves.

In addition, the chamber 20 is further provided with a thermocouple 34 for detecting the temperature of the amorphous strip. The thermocouple 34 is disposed close to the molding die of the lower die 12 in which the molding is performed, thereby accurately detecting the amorphous strip temperature during actual molding. The temperature value detected by the thermocouple 34 is applied to, for example, a control unit disposed outside the chamber 20 so that an operator can confirm the action.

In addition, the molding apparatus 10 further includes a heating element 36 installed inside the upper mold 11 to heat the upper mold 11. The heating element 36 may be, for example, a heating wire for converting electrical energy into thermal energy, and is not particularly limited as long as it generates a heat.

The amorphous strip needs to remain in the supercooled liquid state until the end of the molding process. Accordingly, the heating element 36 maintains the temperature of the upper mold 11 appropriately by heating the upper mold 11. Therefore, it is possible to prevent the temperature of the amorphous strip from being lowered by the upper die 11 for pressing the amorphous strip in the forming process.

In addition, the chamber 20 or the lower die 12 has a structure in which cooling water flows. To this end, a cooling flow path 16 for cooling water distribution is formed in the chamber 20 or the lower die 12, and the cooling flow path 16 is connected to the cooling water supply unit 18 to provide cooling water when necessary. Will be cycled. As the coolant flows into the chamber 20 or the lower die 12, the temperatures of the chamber 20 and the lower die 12 can be maintained at optimal conditions for forming an amorphous strip.

Hereinafter, a method of forming an amorphous strip will be described with reference to FIG. 4.

The molding method of the present embodiment includes a heating step (S100) for heating the amorphous strip in the subcooled liquid state, and a processing step (S200) for forming the heated amorphous strip.

The amorphous strip is rapidly heated by the high heat of the halogen lamp 30 installed in the lower die 12 while passing through the lower die 12 in the chamber 20.

In the heating step, the temperature of the amorphous strip is raised to the subcooled liquid phase region through the halogen lamp 30 (S100).

The amorphous strip in the subcooled liquid state is moved to the forming die formed in the lower die 12. And the upper mold | type 11 arrange | positioned at the upper part of a shaping | molding die is shape | molded as it is pressed by a press. (S200)

As such, as the amorphous strip is heated to a supercooled liquid state, the hardness and strength values of the amorphous strip may be lowered, thereby making molding easier.

Here, the processing step is made within the time point of the crystallization start of the amorphous strip heated in the heating step. That is, the present molding method has a structure in which the process time until the temperature of the amorphous strip is raised to the supercooled liquid region and then the process time until the completion of the molding process is shorter than the time at which the crystallization starts after the amorphous strip is heated. Thus, the process time can be avoided longer than the start time of the crystallization of the amorphous strip.

Therefore, the present molding method is capable of forming the amorphous strip in the supercooled liquid state by rapidly heating the amorphous strip without being exposed to heat for a long time, thereby preventing formation of a crystalline phase on the amorphous strip in the forming process.

While the illustrative embodiments of the present invention have been shown and described, various modifications and alternative embodiments may be made by those skilled in the art. Such variations and other embodiments will be considered and included in the appended claims, all without departing from the true spirit and scope of the invention.

10: forming apparatus 11: upper mold
12: lower die 13: molding die
16: cooling passage 20: chamber
30: halogen lamp 32: groove
34: thermocouple 36: heating element

Claims (6)

An upper die and a lower die for forming an amorphous strip, a chamber surrounding the upper die and the lower die, a heating unit installed in the chamber to heat the amorphous strip inside the chamber in a supercooled liquid state, and installed inside the upper die to heat the upper die. An amorphous strip forming apparatus comprising a heating element. The method of claim 1,
And a thermocouple installed inside the chamber to detect a temperature of the amorphous strip. delete 3. The method according to claim 1 or 2,
And the heating unit comprises at least one halogen lamp disposed inside the chamber. delete delete

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