KR102324459B1 - Roll flexible forming system of ultrahigh-tensile steel - Google Patents

Abstract

The present invention relates to an ultra-high-strength steel roll forming variable forming system, and more particularly, an uncoiler that unwinds a wound coil-shaped ultra-high-strength steel sheet material and supplies it to the rear end. A strainer that stretches, a plurality of forming roll forming units are arranged in the longitudinal direction, and a forming roll forming unit for sequentially bending and forming the material supplied from the strainer into a forming beam having a predetermined shape, the forming roll forming unit, the forming roll forming Doedoe sliding contact on both side surfaces of the forming beam passing through the part, the side shape fixing rolls installed movably in the left and right directions, respectively, sliding contact with the upper and lower surfaces of the forming beam, installed movably in the left and right directions and up and down directions A plurality of variable roll forming units including upper and lower surface shape fixing rolls are installed along the longitudinal direction to press and fix the outer surface of the bent forming beam to prevent springback, the shape fixing roll forming unit, the shape fixing roll forming An inspection unit that receives the forming beam passing through the unit and inspects the forming state of the forming beam and the shape so that the bending forming amount is adjusted if the forming error rate of the forming beam is greater than or equal to a preset allowable range based on the information measured by the inspection unit By applying a control signal to the fixed roll forming unit, it is provided including a control unit for controlling to move the positions of the side shape fixed roll and the upper and lower surface shape fixed roll.

Description

Ultra high-strength steel roll forming variable forming system {ROLL FLEXIBLE FORMING SYSTEM OF ULTRAHIGH-TENSILE STEEL}

The present invention relates to an ultra-high-strength steel roll forming variable forming system, and more particularly, by controlling the springback phenomenon caused by roll forming forming through shape fixing, and quickly and accurately determining the location of the forming defect, thereby preventing defects from occurring. It relates to an ultra-high-strength steel roll forming variable forming system that can reduce and significantly improve productivity.

In roll-forming, a plurality of roll-forming units are sequentially arranged, and a plate-shaped material (coil) passes through each roll-forming unit and is sequentially molded through a series of forming flows to obtain a desired cross-sectional shape from a flat plate. Eggplant is one of the plastic working methods for forming with a forming beam.

In general, such roll forming is widely used as a cooling roll forming method in related industries such as architecture, automobile, shipbuilding, electronics, machinery, etc. Complex shapes that are difficult to process by bending and pressing can also be formed.

However, this conventional roll forming device is a technique for mass-producing parts with a constant length and a constant cross-section using continuous bending in the width direction, and residual stress is generated in the material. In the case of forming with a forming device, the springback phenomenon due to stress is very large, so shape control is difficult, and the cost of changing equipment to produce a new product is expensive, so it is difficult to use it for multi-vehicle parts.

In addition, even if the product has the same cross-sectional shape, there is a problem that the mechanical properties vary depending on the material or even the same material, depending on the order of production (LOT). There is a problem that

Moreover, when processing products of the same cross-sectional shape with different materials, or when using materials with different quality for each production order (LOT), or when a gap occurs in the roll mold or cassette due to long operation, defects occur. If a defect is found during the inspection of the finished product, a considerable amount of loss occurs.

Therefore, it overcomes the unreasonable points in the conventional roll forming process of ultra-high-strength steel, reduces deformation through the shape correction variable roll forming unit, and removes the stress locally in the part where the internal stress is generated to minimize the springback phenomenon, and to minimize the variable The roll forming unit is movably installed so that it can be applied to various types of vehicles, and the defect inspection is made at the roll forming process stage instead of performing the defect inspection at the finished product stage after cutting, thereby reducing product loss and confirming the exact defect location. Accordingly, there is an increasing demand for an ultra-high-strength steel roll forming variable forming system and forming method that enables rapid response.

Korean Patent No. 1059073

The present invention has been devised to solve the above problems, and an object of the present invention is to minimize the springback phenomenon through a roll forming shape fixing step and a local removal of internal stress in the bent part after roll forming molding, and heating and In addition to promoting tissue stability through the cooling step, the shape fixing roll is made variable to suppress the springback phenomenon, and to induce various widths and curved shapes.

Another object of the present invention is to enable vision inspection in the roll forming process step, so that the precise location of the molding defect can be quickly identified and dealt with, and the bending portion in the narrow space between the forming rolls can be easily inspected. is doing

According to one aspect of the present invention for achieving the above object, an uncoiler that unwinds a wound coil-shaped ultra-high-strength steel sheet material and supplies it to the rear end. A strainer, a plurality of forming roll forming units are arranged in the longitudinal direction, a forming roll forming unit for sequentially bending and forming the material supplied from the strainer into a forming beam having a predetermined shape, the forming roll forming unit passes through the forming roll forming unit A side shape fixing roll that is in sliding contact with both sides of the forming beam, which is installed movably in the left and right directions, and the upper and lower portions that are in sliding contact with the upper and lower surfaces of the forming beam, respectively, are installed movably in the left and right directions and up and down directions A plurality of variable roll forming units including a face fixed roll are installed along the longitudinal direction, and the shape fixed roll forming unit for preventing springback by pressing and fixing the outer surface of the bent forming beam, passing through the shape fixed roll forming unit An inspection unit that receives a forming beam and inspects the forming state of the forming beam, and the shape fixing roll so that the bending molding amount is adjusted if the forming error rate of the forming beam is greater than or equal to a preset allowable range based on the information measured by the inspection unit By applying a control signal to the forming unit, it is provided including a control unit for controlling to move the positions of the side shape fixing roll and the upper and lower surface shape fixing roll.

In addition, at the rear end of the shape-fixing roll forming part, a local thermal stress removing part for irradiating a laser beam to the shaping bending part of the shaping beam so that the shaping bending part is heated within a predetermined temperature range, and the rear end of the local thermal stress removing part A surface heating unit installed at a certain length to surround the outside of the forming beam to heat the forming beam to a predetermined temperature by emitting heat to the surface, and a surface heating unit installed at the rear end of the surface heating unit to supply cooling water to the forming beam It is provided including a surface cooling unit for rapidly cooling the surface by spraying.

Furthermore, a vision inspection unit for inspecting the state of the bent portion of the material is installed in the forming roll forming unit or the shape fixing roll forming unit, and the vision inspection unit has one side on one side of the forming roll forming unit or the shape fixing roll forming unit It is installed rotatably and is installed on one side of the forming roll forming unit or the shape fixing roll forming unit and the reflecting mirror on which the bent part of the material forms an image in the state rotated at a specific angle, and photographing the image formed on the reflector It is provided including a vision camera, and a defect determination control module that analyzes the image captured by the vision camera to determine the molding defect of the material.

In addition, it is installed on the front surface of the reflector, and further comprising a transparent display for outputting a bending inspection boundary line spaced apart from each other by a predetermined interval on both sides of the bending inspection reference line of the material, in the vision camera, the bending inspection boundary line and the material The bent portion is photographed to be overlapped, and the defect determination control module compares and analyzes the image of the region within the bend inspection boundary line with the bending inspection reference line to determine the molding defect.

In addition, the reflector and the vision camera are installed at the rear end of each of the forming roll forming unit and the variable roll forming unit, respectively, and the defect determination control module analyzes the image transmitted from each vision camera to determine when the forming defect occurs let it do

In addition, the surface cooling unit includes a cooling housing having an inlet hole and a through hole through which the forming beam passes so that the forming beam is inserted into one side and the other side thereof, and a plurality of cooling water is installed in a predetermined arrangement on the ceiling surface of the cooling housing. Including a surface cooling nozzle for spraying, and a local cooling nozzle rotatably installed on the ceiling surface and side surface of the cooling housing so that the injection direction is variable, the local cooling nozzle is based on the image taken by the vision camera, The control unit controls the rotation angle of the local cooling nozzle in real time so that the injection direction of the local cooling nozzle is directed toward the bent portion of the shaping beam.

Furthermore, the spacing between the plurality of surface cooling nozzles is narrowed from the inlet hole of the cooling housing toward the through hole.

According to the present invention as described above, the springback phenomenon is minimized through the roll forming shape fixing step and the local removal of internal stress in the bent part after roll forming molding, and the defect rate is reduced by promoting tissue stability through the heating and cooling process after molding. It has the effect of significantly reducing the number of manufacturing processes for forming complex shapes by significantly reducing the number of manufacturing processes for complex shapes by making it possible to induce various widths and curved shapes by making the shape fixing rolls variable, thereby significantly improving product productivity.

In addition, in the roll forming process step, the vision inspection of the bent part of the material can be performed in real time, so that the exact location of the molding defect can be quickly identified and dealt with, thereby improving the production line operation efficiency.

1 is a view schematically showing an ultra-high tensile steel roll forming variable forming system according to the present invention.
2 is a diagram schematically showing the structure of the shape fixing roll forming part according to the present invention.
3 is a view showing a perspective view of a surface cooling unit according to the present invention.
4 is a view showing the side structure of the surface cooling unit according to the present invention.
5 is a diagram schematically illustrating a planar structure of a surface cooling unit according to the present invention.
6 is a diagram schematically illustrating the configuration of the vision inspection unit according to the present invention.
7 is a view showing an image reading process of the vision inspection unit according to the present invention.
8 is a flowchart illustrating a variable forming process of ultra-high tensile steel roll forming according to the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing the ultra-high tensile steel roll forming variable forming system according to the present invention, FIG. 2 is a view schematically showing the structure of the shape-fixing roll forming part according to the present invention, and FIG. 3 is a surface cooling according to the present invention. It is a view showing a perspective view of a part, FIG. 4 is a view showing a side structure of a surface cooling unit according to the present invention, and FIG. 5 is a view schematically showing a planar structure of a surface cooling unit according to the present invention.

Referring to the drawings, the ultra-high tensile steel roll forming variable forming system according to the present invention is an uncoiler 100, a strainer 200, a piercing unit 300, a forming roll forming unit 400, a shape fixing roll forming unit 500. , is configured to include a local thermal stress relief unit 600 , a surface heating unit 700 , a surface cooling unit 800 , a cutting unit 900 , and an inspection unit 1000 .

The uncoiler 100 releases the coil-shaped ultra-high-strength steel sheet material to be supplied to the rear end.

The strainer 200 is released from the uncoiler 100 to flatten the material having the curvature, and the material that has been dried in the form of a coil for a long time is flat due to the stress remaining inside the material even if it is uncoiled by the uncoil part. It may be formed wrinkled without straightening. Accordingly, the plurality of rollers is an uncoiled portion arranged in a zigzag centering on the material, and as the material passes, the residual stress inside the material is relieved, thereby making the material into a flat shape.

The piercing unit 300 uses a press to form a hole for a specific purpose on the surface of the material spread from the strainer 200 .

The forming roll forming unit 400 includes a plurality of forming roll forming units 410 disposed in the longitudinal direction, and sequentially bending and forming the material supplied from the strainer 200 to form a forming beam having a predetermined shape. make it possible

The shape fixing roll forming unit 500 presses and fixes the outer surface of the forming beam that has passed through the forming roll forming unit 400 with a variable roll forming unit 510, and springs back due to internal stress in the portion bent with the forming beam. to prevent the phenomenon. Referring to FIG. 2 , the variable roll forming unit 510 of the shape fixed roll forming unit 500 is configured to include a side shape fixed roll 511 and an upper and lower surface shape fixed roll 512 .

The side shape fixed roll 511 is in sliding contact with both sides of the forming beam that has passed through the forming roll forming unit 400, and is installed movably in the left and right directions, and the upper and lower surface shape fixed roll 512 is the upper and lower portions of the forming beam It is in sliding contact with each surface and is installed to be movable in the left and right and up and down directions at the same time to prevent the springback phenomenon by pressing and fixing the outer surface of the forming beam, and a variable roll forming unit 510 as needed By moving the positions of the side shape fixing roll 511 and the upper and lower surface shape fixing rolls 512, various widths and complex curved shapes can be formed in the longitudinal direction.

The localized thermal stress removal unit 600 is installed at the rear end of the shape fixing roll forming unit 500, and irradiates a laser beam to the molding bending portion of the molding beam supplied to the rear along the longitudinal direction, so that the molding bending portion is at a constant temperature. Heat within the range. The localized thermal stress removing unit 600 applies heat to the edge of the bent portion where the internal stress is generated to remove the internal stress.

The surface heating unit 700 is installed at the rear end of the localized thermal stress relief unit 600 to apply heat as a whole to the outer surface of the forming beam, and the heating surface of the surface heating unit 700 corresponds to the shape of the forming beam. It is formed into a shape and the heat generated by the heating surface is uniformly transmitted to the entire surface of the forming beam through rapid heating method such as high frequency.

The surface cooling unit 800 is installed at the rear end of the surface heating unit 700, and sprays cooling water to the forming beam to cool the surface of the forming beam. Referring to FIGS. 3 to 5 , the surface cooling unit 800 is configured to include a cooling housing 810 , a surface cooling nozzle 820 , and a local cooling nozzle 830 .

In the cooling housing 810, an inlet 811 and a through hole 812 through which the forming beam passes are formed on one side and the other side, and a cooling nozzle is installed inside.

The surface cooling nozzle 820 sprays cooling water over the entire surface of the shaping beam, and a plurality of surface cooling nozzles 820 are installed in a predetermined arrangement on the ceiling surface of the cooling housing 810 so that the cooling water is sprayed downward. In addition, the surface cooling nozzle 820 is formed such that the gap arranged from the inlet 811 of the cooling housing 810 toward the through hole 812 is narrowed, so that the surface of the forming beam can be gradually cooled.

The local cooling nozzle 830 is installed on the ceiling surface and the side surface of the cooling housing 810, and is rotatably installed so that the injection direction of the nozzle is variably deformed. Based on the image captured by the vision camera 840 installed at the front end of the cooling housing 810 in the local cooling nozzle 830, the injection direction of the local cooling nozzle 830 in the control unit 1100 is the bending of the shaping beam. The rotation angle of the local cooling nozzle 830 is controlled in real time to face the part. If the shape of the bent portion is formed in a curved line instead of a straight line along the longitudinal direction, the local cooling nozzle 830 is controlled to rotate along this curved surface.

As described above, in the present invention, in order to remove the internal stress generated in the bent portion of the forming beam as described above, a shape fixing roll forming unit 500 is installed at the rear end of the forming roll forming unit 400 to form a bent portion of the forming beam. In order to reduce the internal stress by forcibly pressing by the roll, and to remove the stress by applying heat locally to the deformed part of the bent part having the greatest internal stress, the entire surface of the forming beam Heat is applied again and cooled to remove the internal stress of the entire surface of the forming beam and improve the tissue stability.

As described above, in order to prevent the springback phenomenon, the forming beam, which has been rough until the cooling process, is cut to a predetermined size by the cutting unit 900 , and the cut forming beam is finally inspected by the inspecting unit 1000 for the forming state of the forming beam.

The inspection unit 1000 is generally made in a vision inspection method, and when it is determined that the forming error rate of the forming beam is greater than or equal to a preset allowable error range based on the information measured by the inspection unit 1000, the variable roll is bent so that the forming amount is adjusted. By applying a control signal to the forming unit 510, the positions of the side shape fixing roll 511 and the upper and lower surface shape fixing rolls 512 are moved. By the movement of the variable roll forming unit 510 as described above, the pressing degree of the forming beam is changed to be formed into a desired shape.

In addition, in the present invention, in order to more accurately determine the point at which the above defects have occurred in the roll forming forming process, the state of the bent part of the material in the forming roll forming unit 400 or the shape fixing roll forming unit 500 can be inspected. so that a separate vision inspection unit 1200 is installed. Preferably, the vision camera 1220 for such a vision inspection is installed individually for each of the forming roll forming unit 410 and the variable roll forming unit 510, so that the image captured by each vision camera 1220 is analyzed. Quickly and accurately determine the location of the molding defect.

6 is a diagram schematically showing the configuration of the vision inspection unit according to the present invention, and FIG. 7 is a view showing the image reading process of the vision inspection unit 1200 according to the present invention. The vision inspection unit 1200 according to the present invention is It is configured to include a reflector 1210 , a transparent display 1230 , a vision camera 1220 , and a failure determination control module 1240 .

The reflector 1210 has one surface rotatably installed on one side of the forming roll forming unit 400 or the shape fixing roll forming unit 500 so that the image of the bent portion of the material is formed in a state rotated at a specific angle. Such a reflector 1210 can advantageously transmit the image of the bent part to the vision camera 1220 in a narrow space, and furthermore, when the molded product is changed, only the angle of the reflector 1210 is adjusted to reflect the bent part and quickly inspected. Enables line setting.

The vision camera 1220 is installed on one side of the forming roll forming unit 400 or the shape fixing roll forming unit 500 to photograph the image formed on the reflector 1210 .

In addition, a transparent display 1230 for setting the vision inspection boundary area is installed on the front of the reflector 1210 , and the image output from the transparent display 1230 is reflected on the reflector 1210 in the vision camera 1220 . It is superimposed on and photographed. Referring to FIG. 7 , the information output to the transparent display 1230 is a bending inspection boundary line L2 spaced apart from each other at regular intervals on both sides of the bending inspection reference line L1 of the material, and overlaps with the bending portion S1 of the material. make it very filmed.

The defect determination control module 1240 analyzes the image captured by the vision camera 1220 to determine the molding defect of the material. By extracting only the image separately, the bending inspection reference line (L1) and the bending part (s1) of the material are compared and analyzed to allow for faster judgment of molding defects.

The reflector 1210 and the vision camera 1220 are installed at the rear end of each of the forming roll forming unit 410 and the variable roll forming unit 510, respectively, so that each vision camera 1220 in the defect determination control module 1240. Through image analysis transmitted from

8 is a flowchart illustrating a variable forming process of ultra-high tensile steel roll forming according to the present invention. Referring to the drawings, the ultra-high tensile steel roll forming variable forming method according to the present invention includes an uncoiling step (S810), a straining step (S820), a piercing step (S830), a roll forming forming step (S840), a roll forming shape fixing step (S850), a bending step local stress relief step (S860), a full heating step (S870), a cooling step (S880), a cutting step (S890) and a finished product inspection step (S900).

In the uncoiling step (S810), the material wound in the coil form is released from the uncoiler 100 to be supplied to the rear end, and in the straining step (S820), the material rolled in the coil form in the strainer 200 is passed through the material inside Relieve the residual stress of

In the piercing step (S830), a hole of a specific shape is formed in the material by using a press.

In the roll forming forming step (S840), the material is sequentially bent while passing through the plurality of forming roll forming units 410 to be processed into a forming beam having a cross-section of a predetermined shape.

In the roll forming shape fixing step (S850), the outer surface of the forming beam bent into a predetermined shape is pressed and fixed with the variable roll forming unit 510 to prevent the springback phenomenon in the bent portion, and the variable roll forming By moving the position of the unit 510 in the longitudinal direction, it is possible to enable detailed molding of various widths and curved shapes.

In the bending part local stress relief step (S860), the laser beam is irradiated locally to the bent part of the bending-molded shaping beam as described above, so as to remove the internal stress in the shaping-bent part.

In the entire heating step (S870), uniform heat transfer is achieved while passing through the surface heating unit 700 on the entire surface of the shaping beam to which heat is locally applied to the bent portion, thereby removing the overall internal stress of the shaping beam.

In the cooling step (S880), the cooling water is supplied to the entire surface of the heated shaping beam to be cooled. In the present invention, the coolant is brought into contact with the entire surface of the shaping beam through the surface cooling nozzle 820, and the local cooling nozzle Through (830), the cooling water is directly sprayed to the correct position of the bent part to more rapidly cool the heated bent part for local stress relief. At this time, by checking the bent portion of the shaping beam through the vision camera 1220 in advance, the control unit 1100 has the local cooling nozzle 830 in real time so that the coolant injection direction of the local cooling nozzle 830 faces the bent portion of the shaping beam. ) to control the rotation angle.

The forming beam from which the internal residual stress is removed through the cooling process as described above is cut to a predetermined length through the cutting step (S890), and the molding error of the finished molded product is determined in the inspection step (S900), and when a defect occurs, the control unit ( 1100) transmits a control signal to the variable roll forming unit 510 to adjust the molding amount so that the position of the side shape fixing roll 511 or the upper and lower surface shape fixing roll 512 is set.

Furthermore, as described above, through the vision inspection unit 1200, the location of the defect occurrence is accurately identified in real time, so that the cause of the defect can be identified before the manufacturing stage of the finished product and quickly dealt with.

Although the present invention has been described with reference to the above-mentioned preferred embodiments, various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the appended claims shall cover such modifications and variations as fall within the scope of the present invention.

100: uncoiler
200: strainer
300: piercing unit
400: forming roll forming unit 410: forming roll forming unit
500: shape fixing roll forming part
510: variable roll forming unit 511: side shape fixed roll
512: upper and lower surface shape fixed roll
600: local thermal stress relief unit
700: surface heating unit
800: surface cooling unit 810: cooling housing
820: surface cooling nozzle 830: local cooling nozzle
900: cutting part
1000: inspection unit
1100: control unit
1200: vision inspection unit 1210: reflector
1220: vision camera 1230: transparent display
1240: bad judgment control module

Claims (3)

An uncoiler that unwinds the wound coil-shaped ultra-high-strength steel sheet and supplies it to the rear end;
a strainer released from the uncoiler to flatten a material having a curvature;
a forming roll forming unit in which a plurality of forming roll forming units are disposed in the longitudinal direction, the material supplied from the strainer is sequentially bent and formed to form a forming beam having a predetermined shape;
Doedoe sliding contact on both sides of the forming beam passing through the forming roll forming unit, a side shape fixed roll installed movably in the left and right directions, and sliding contact with the upper and lower surfaces of the forming beam, respectively, in the left and right directions and up and down directions A plurality of variable roll forming units including upper and lower surface shape fixing rolls that are movably installed are installed along the longitudinal direction, and a shape fixing roll forming unit that presses and fixes the outer surface of the bent forming beam to prevent springback;
an inspection unit receiving the forming beam passing through the shape fixing roll forming unit and inspecting the forming state of the forming beam;
If the forming error rate of the forming beam is greater than or equal to a preset allowable range based on the information measured by the inspection unit, a control signal is applied to the shape fixing roll forming unit so that the bending molding amount is adjusted, and the side shape fixing roll and the upper and lower surface shapes a control unit for controlling the position of the fixed roll to move;
At the rear end of the shape-fixing roll forming unit, a local thermal stress removing unit for irradiating a laser beam to the forming and bending portions of the forming beam so that the forming and bending portions are heated within a predetermined temperature range;
a surface heating unit installed at a rear end of the local thermal stress relief unit to a predetermined length to surround the outside of the forming beam, radiating heat to the surface to heat the forming beam to a predetermined temperature;
A surface cooling unit installed at the rear end of the surface heating unit to rapidly cool the surface by spraying cooling water to the forming beam;
The surface cooling unit
A cooling housing in which an inlet hole and a through hole through which the forming beam passes are formed so that the forming beam is inserted into one side and the other side;
a plurality of surface cooling nozzles installed in a predetermined arrangement on the ceiling surface of the cooling housing to spray cooling water downward;
Including a local cooling nozzle rotatably installed on the ceiling surface and the side surface of the cooling housing so that the injection direction is variable,
The local cooling nozzle is based on an image taken by a vision camera installed at the front end of the cooling housing, the rotation angle of the local cooling nozzle so that the injection direction of the local cooling nozzle in the control unit is toward the bent portion of the shaping beam control in real time,
A vision inspection unit for inspecting the state of the bent part of the material is installed in the forming roll forming unit or the shape fixing roll forming unit,
The vision inspection unit
A reflector with one surface rotatably installed on one side of the forming roll forming part or the shape fixing roll forming part, and the bent portion of the material forms an image when it is rotated at a specific angle;
a vision camera installed on one side of the forming roll forming unit or the shape fixing roll forming unit to photograph the image formed on the reflector;
A defect judgment control module that analyzes the image captured by the vision camera to determine the molding defect of the material;
Doedoe installed on the front side of the reflector, further comprising a transparent display on which the bending inspection boundary lines spaced apart from each other at regular intervals on both sides of the bending inspection reference line of the material are output,
In the vision camera, the bending part inspection boundary line and the bending part of the material are photographed to overlap, and the defect determination control module compares and analyzes the image of the area within the bending part inspection boundary line with the bending inspection reference line to determine the molding defect. Ultra high-strength steel roll forming variable forming system, characterized in that.
The method of claim 1,
The reflector and the vision camera are installed at the rear end of each of the forming roll forming unit and the variable roll forming unit, respectively, so that the defect determination control module analyzes the image transmitted from each vision camera to determine when the forming defect occurs Ultra-high-strength steel roll forming variable forming system, characterized in that.
3. The method of claim 2,
The plurality of surface cooling nozzles are ultra-high-strength steel roll forming variable forming system, characterized in that the arrangement interval is narrowed from the inlet hole of the cooling housing toward the through hole.

Images