CN109604367B - Roll bending forming device and method for variable-thickness folding type micro-channel flat tube - Google Patents
Roll bending forming device and method for variable-thickness folding type micro-channel flat tube Download PDFInfo
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- CN109604367B CN109604367B CN201811584930.0A CN201811584930A CN109604367B CN 109604367 B CN109604367 B CN 109604367B CN 201811584930 A CN201811584930 A CN 201811584930A CN 109604367 B CN109604367 B CN 109604367B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
- B23P15/26—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass heat exchangers or the like
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Abstract
The invention provides a variable-thickness folding type roller bending forming device and method for a microchannel flat tube, which comprises an uncoiler, a straightener, a rolling mill, a brazing flux coating device and a roller bending forming machine which are sequentially arranged, wherein the uncoiler is used for releasing a coiled metal plate; the straightening machine is used for straightening the metal plate; the rolling machine is used for cold rolling the metal plate, locally thinning the metal plate, quantitatively increasing the width of the metal plate and feeding the metal plate into the roll bending forming machine; the brazing flux coating device is used for coating brazing flux on the folding overlapped part of the metal plate and brazing the metal plate after the metal plate is formed; the roll bending forming machine is used for gradually bending the rolled metal plate into the porous micro-channel flat tube. The invention has the characteristics of obvious energy saving, low manufacturing cost, high yield, high product quality, high pipe making speed, increased micro-channel hole area ratio and the like.
Description
Technical Field
The invention relates to the technical field of manufacturing methods and equipment for processing a micro-channel flat tube for an air-conditioning heat exchanger, in particular to a forming device and a forming method for a variable-thickness folding type micro-channel flat tube.
Background
Air conditioner heat exchangers used in the heating, ventilating and refrigerating industry traditionally use round copper light tubes or efficient internal threaded tubes and external fin aluminum tubes. Because of the requirement of light weight of automobiles and the limitation on refrigerants, at present, copper tube-fin type heat exchangers are no longer adopted in condensers and evaporators of automobile air conditioners, almost all automobiles adopt aluminum material parallel flow micro-channel type heat exchangers, and the condensers and the evaporators have the advantages of light weight, compact structure, high heat exchange efficiency and the like. The parallel flow micro-channel heat exchanger adopts a porous micro-channel flat tube as a refrigerant circulation pipeline, the channel size is about 0.5mm, and the more the number of micro-channels is, the smaller the size is, the stronger the pressure resistance is, and the better the heat exchange capacity is.
At present, a porous micro-channel flat tube is mainly produced by adopting an aluminum material continuous hot extrusion mode, and the continuous extrusion technology is to adopt a round bar aluminum material as a blank, heat the blank to over 500 ℃, extrude the blank into a shunting die cavity through a large-scale extruder, weld the blank at high temperature and high pressure, and further extrude a product through a die core working belt. This extrusion process has the following limitations:
1. the production process has high cost: in the extrusion process, the working condition of an extrusion die is severe, the friction between the aluminum metal flow and the surface of a core die with a needle-shaped structure is strong, the abrasion speed of a working belt of the die is high, and the service life of the die is short.
2. The energy consumption in the production process is large: firstly, a hot extrusion process needs to heat a cylindrical aluminum ingot to over 500 ℃; secondly, the extrusion ratio of the micro-channel flat tubes is large, so that the requirement on extrusion force is high, and the energy consumption in the production process is high.
3. The product quality is unstable: the technological parameters of temperature, speed, running clearance of the extrusion wheel and the like in the continuous extrusion process are interdependent dynamic adjustment parameters, the continuous extrusion can generate overstock, and pollutants such as an oxide film, oil stain, water vapor and the like on the surface layer of a blank are easily and directly extruded into a product, so that the traditional manufacturing method of the porous microchannel flat tube seriously influences the product quality.
4. The utilization rate of raw materials is low: firstly, because the requirements on extrusion quality and product precision are high, the extrusion flat tube with a thinner wall thickness is easy to have product defects, so that the wall thickness of the extrusion type microchannel tube is larger and generally larger than 0.3mm, and the flat tube has high linear density and low material utilization rate; secondly, after the round bar aluminum ingot is extruded, the material properties of the two end parts of the round bar aluminum ingot are changed greatly, a large amount of excess pressure is generated, and the material waste is caused.
5. The product has poor corrosion resistance: the single material of the extruded flat tube is unfavorable in corrosion resistance, so that the extruded micro-channel flat tube is poor in corrosion resistance, the performance of the heat exchanger is seriously reduced along with the use, the service life is short, and the problem of leakage in the tube is aggravated.
The folding type micro-channel flat tube formed by roll bending of the composite aluminum strip can avoid the limitation of the extrusion type flat tube. Through search, the following U.S. patents are found: a Folded tube for heat exchange and method of making same, patent No.: US6209202B 1; U.S. patents: folded tube for a heat exchange and method of making same, patent No.: US2005/0092476A 1; european patent No.: fabric, woven metal exchange tube manufacture, patent No.: EP1712862a 2; the invention has the following patent: roll bending forming device and forming method of ten-hole microchannel flat tubes, patent number: 201410021043.8, respectively; the microchannel flat tubes invented by the patents are all processed in a mode of folding composite aluminum strips with equal thickness, although the defects generated by the extrusion process can be avoided, because the strips with equal thickness are used as blanks, the inner holes of the folding microchannel flat tubes have the condition of overlapped wall thickness, the wall thickness at the folded overlapped part is twice of that at the non-overlapped part, so that not only is material waste caused, but also the heat exchange efficiency is influenced.
Through retrieval, the invention with application number 201110073278.8 discloses a roll bending forming manufacturing method and equipment of a porous microchannel flat tube: firstly, a metal strip coil is uncoiled, straightened and cleaned on line, and then is sent to a roller press to be pressed into a microgroove; then the metal plate enters a multi-pass forming roller which is configured in sequence, and the roller bends the conveyed strip material gradually into two symmetrical sides from a straight state; and finally, connecting the two symmetrical sides to form the porous micro-channel flat tube. "while this invention avoids the problems associated with continuous extrusion processes, it has the following limitations in its practice: firstly, the belt needs to be pressed with micro-grooves before being bent by a roller, so that the belt has strict requirements; secondly, the welding of the two symmetrical sides requires an additional pressure welding process, which severely hinders the tube-making speed.
Through retrieval, the invention patent with the application number of 201280026539.3 discloses a preparation method of a porous microchannel flat tube and related manufacturing equipment: the method comprises the steps of locally thinning a metal belt, bending the metal belt into a B-shaped channel pipe, assembling a wavy bent plate into the B-shaped channel pipe, and then brazing the B-shaped channel pipe and the wavy bent plate together through a brazing furnace to form the porous micro-channel flat pipe. Although the defect that the hole walls of the folding micro-channel flat tubes with the same wall thickness are uneven can be overcome, the tube type relates to the assembly of two parts, the assembly error of the tube type affects the product quality, welding leakage is easily caused, the leakage of a refrigerant in the flat tubes is caused, and the yield of the micro-channel flat tubes manufactured by the method is low.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a roll bending forming device and a roll bending forming method for a variable-thickness folding type microchannel flat tube.
The invention provides a roll bending forming device of a variable-thickness folding type microchannel flat tube, which comprises an uncoiler, a straightener, a rolling mill, a brazing flux coating device and a roll bending forming machine which are sequentially arranged, wherein:
the uncoiler is used for releasing the coiled metal plate;
the straightening machine is used for straightening the metal plate;
the rolling machine is used for cold rolling the metal plate, locally thinning the metal plate, quantitatively increasing the width of the metal plate and feeding the metal plate into the roll bending forming machine;
the brazing flux coating device is used for coating brazing flux on the folding overlapped part of the metal plate and brazing the metal plate after the metal plate is formed;
the roll bending forming machine is used for gradually bending the rolled metal plate into the porous micro-channel flat tube.
Preferably, the cutting machine is further used for cutting out the metal plate material with a specific length.
Preferably, the rolling mill comprises two pairs of rollers, the first pair of rollers locally thins the folded and overlapped part of the metal plate, and the width of the plate is increased; and the second pair of rollers rolls the two sides of the edge of the metal plate to be thin, and the width of the plate is further lengthened to a set width.
Preferably, the rolls have a precision profile configuration, the profile shape being designed according to the sheet metal shape and the microchannel tube shape.
Preferably, the roll bending machine comprises a multi-pass roll bending forming roll pair comprising a pre-forming roll, a wire forming roll and a finish forming roll.
The invention also provides a roll bending forming method of the variable-thickness folding type microchannel flat tube, which adopts the roll bending forming device of the variable-thickness folding type microchannel flat tube and comprises the following steps:
step 1: the metal plate rolled passes through an uncoiler, a straightener and a rolling mill in sequence to form a metal plate which is locally thinned and has a specific width, and the metal plate is sent into a roll bending forming machine;
step 2: the metal plate is bent for multiple times through a plurality of sequentially configured roll bending forming rollers with symmetrical specific profile sections;
and step 3: the flux coating device comprises a first flux coating device and a second flux coating device, the first flux coating device and the second flux coating device are respectively arranged between the pre-forming roller pair and the wire forming roller pair and between the wire forming roller pair and the fine forming pair, and flux is coated on the folding overlapped part of the metal plate for brazing after forming.
Preferably, the porous microchannel flat tube has a symmetrical structure along a central line, and the two sides of the central line have the same channel number.
Preferably, the cross-sectional shape of the microchannel hole of the porous microchannel flat tube is rectangular.
Preferably, the metal plate adopts a composite aluminum plate strip foil with heat transfer performance, the composite aluminum plate strip foil comprises three layers, wherein the middle layer is made of Al-Mn alloy, and Al-Si alloy brazing filler metal with the thickness of 10% of that of the composite aluminum plate strip foil is coated on two surfaces of the middle layer.
Preferably, the locally thinned metal plate has a symmetrical structure, and the contact parts of the inner wall and the outer wall of the microchannel tube are thinned.
Compared with the prior art, the invention has the following beneficial effects:
1. the micro-channel flat tube provided by the invention does not need a more precise die in production, a series of problems in continuous extrusion are avoided, and the quality of the produced flat tube is more stable;
2. when the invention adopts the extrusion mode for production, the extrusion speed is usually 2-3 m/min, the production speed of the roll bending process is more than 80 m/min, and the production efficiency is improved by more than 20 times compared with the traditional extrusion mode;
3. the invention avoids adding extra welding process in the roll bending forming process, and can realize the production of the whole heat exchanger only by the brazing process;
4. according to the invention, the rolling procedure is added, so that the metal plate is locally thinned, and the plate with a special shape is obtained. Compared with the micro-channel flat tube obtained by the traditional roll bending forming mode, most materials are saved, and the micro-channel flat tube with more excellent performance is obtained.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic structural view of a roll bending forming device for sixteen-hole microchannel flat tubes according to the present invention;
FIG. 2 is a sectional view of a sixteen-hole microchannel flat tube prepared by the method of the present invention;
FIG. 3 is a simplified schematic diagram of a roll bending forming process of a sixteen-hole microchannel flat tube;
FIG. 4 is a schematic diagram showing the pattern change in the roll bending forming process of a sixteen-hole microchannel flat tube;
in the figure: 1-uncoiler
2-straightening machine
3-Rolling Mill
4-preforming roll-bending forming unit
5-first flux coating device
6-first straightening device for products
7-line forming roll bending forming unit
8-second flux coating device
9-second straightening device for products
10-precision forming roll bending forming unit
11-third straightening device for products
12-sixteen-hole micro-channel flat tube
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
The following description will be made in detail of the respective parts of the roll-bending apparatus for forming sixteen-hole microchannel flat tubes as a preferred embodiment. The invention is not limited to manufacturing sixteen-hole micro-channel flat tubes, and the invention comprises a forming device and a forming method of the micro-channel flat tubes with 8-30 holes and the thickness range of tube walls of 1% -50%. Referring to fig. 1 to 4, a roll bending apparatus and a roll bending method for forming sixteen-hole microchannel flat tubes are shown.
The embodiment provides a roll bending forming device for a sixteen-hole variable-thickness folding type micro-channel flat tube, which comprises an uncoiler, a straightener, a rolling mill, a brazing flux coating device, a cutting machine, a material collecting and collecting device and a roll bending forming unit which are sequentially arranged. The rolling machine comprises two pairs of rollers with precise outline shapes, the rollers are vertically assembled on a base, the outline shapes are designed according to the shapes of metal plates and the shapes of the microchannel tubes, the first pair of rollers are used for folding and overlapping the metal plates to locally thin the metal plates, and the width of the metal plates is increased; and the second pair of rollers rolls the two sides of the edge of the metal plate to be thin, and the width of the plate is further lengthened to a specific width. The roll bending forming unit comprises an upper row of rollers and a lower row of rollers which are sequentially formed by 36-pass roll bending forming roller pairs, and a brazing flux coating device and a product straightening device which are arranged between the roll bending forming roller pairs, wherein a gap matched with the shape and the size of the micro-channel flat tube is arranged between the upper row of rollers and the lower row of rollers; the roll-forming roll pair is of symmetrical construction and has a precision profile configuration.
The uncoiler releases the coiled metal plate, and the metal plate is fed into the straightening machine at a constant speed; the straightening machine tensions and straightens the metal plate, so that the metal plate is more flat and is sent into the rolling machine; and (3) cold rolling the metal plate by using a rolling machine, locally thinning the metal plate, quantitatively increasing the width of the metal plate, and then feeding the metal plate into a roll bending forming device. The upper row of rollers and the lower row of rollers of the roll bending forming unit are used for gradually bending a straight metal plate into a porous variable-thickness folding type microchannel flat tube; the brazing flux coating device coats a certain amount of brazing flux on the folded overlapped part of the metal plate, so that brazing is carried out after forming.
The product straightening device is used for ensuring that the fed metal plate is kept straight, preventing the plate from sliding and shaking laterally during feeding, and tensioning the metal plate.
Further, the rolling mill rolls the metal plate into a partially thinned metal plate, and the width of the plate is increased. Wherein, the sheet metal all has the attenuate at microchannel flat tube inner wall board and outer wall board contact position.
Furthermore, the rear end of the roll bending forming unit is also provided with a high-speed cutting device, and the high-speed cutting device cuts the produced micro-channel flat tubes according to the length requirement.
Further, the flux coating device comprises a first flux coating device and a second flux coating device, wherein the first flux coating device and the second flux coating device are respectively arranged between the pre-forming roller pair and the wire forming roller pair and between the wire forming roller pair and the fine forming roller pair. The first flux coating device is arranged at the 15 th roller bending forming roller pair, and the second flux coating device is arranged at the 28 th roller bending forming roller pair. The first brazing flux coating device is provided with 8 point rubber heads, and the second brazing flux coating device is provided with 7 point rubber heads. The 36 pass roll bending forming roll pair consists of a series of pre-forming rolls, wire forming rolls and fine forming rolls.
Further, the sixteen-hole microchannel flat tube is provided with 16 microchannels, as shown in fig. 2. Overall having a symmetrical structure formed by a left outer wall portion 13, a left inner channel tube wall 14, a right outer wall portion 15, a right inner channel tube wall 16 forming the overall outline thereof. Wherein the left-hand inner channel tube wall 14 and the right-hand inner channel tube wall portion are embedded in the outer wall portions 13 and 15, respectively. The pipe wall of the inner channel is embedded with the horizontal part of the outer wall part, and no protruding part exists, so that the material of the embedded part is saved, the manufacturing cost is reduced, and the quality of a finished product is stable.
The left side bending round hole and the right side bending round hole of the sixteen-hole micro-channel flat tube are used as 90-degree bending guide holes of the plate, and the plate has a good stress state after being bent.
Hereinafter, a typical apparatus and method for roll bending a multi-hole variable thickness folding type microchannel flat tube will be described in detail.
The forming method of the roll bending forming device for the sixteen-hole micro-channel flat tube comprises the following steps:
step 1, a metal strip coil sequentially passes through an uncoiler, a straightener and a rolling mill to form a metal plate, and the metal plate is fed into a roll bending forming unit;
step 2, sequentially bending the metal plate by a plurality of symmetrical roll bending forming rollers with specific profile sections in sequence;
step 3, coating a certain amount of brazing flux on the folded overlapped part of the metal plate at the 15 th-pass roll bending forming roller pair and the 28 th-pass roll bending forming roller pair respectively by the first brazing flux coating device and the second brazing flux coating device for brazing after forming;
and 4, sequentially passing the bent metal plate through a product straightening device and a high-speed cutting device, and cutting to form the sixteen-hole micro-channel flat tube with any length.
Furthermore, sixteen-hole micro-channel flat tubes have a symmetrical structure along a center line, and eight channels are respectively arranged on two sides of the center line. The eight microchannels may be substantially rectangular in cross-sectional shape.
Further, the microchannel flat tube is embedded in the outer wall plate at the horizontal portion inner wall plate, and at the flat portion, the sum of the thicknesses of the microchannel flat tube outer wall plate and the inner wall plate is one unit thickness.
Furthermore, the 90-degree bent transition round hole near the middle part of the micro-channel flat tube prevents the plate from generating the phenomenon of breaking stress when the plate is vertically bent.
Furthermore, the metal strip coil adopts a composite aluminum plate strip foil with heat transmission performance, the composite aluminum plate strip foil comprises three layers, wherein the middle layer is made of Al-Mn alloy, and Al-Si alloy brazing filler metal with the thickness of 10% of that of the composite aluminum plate strip foil is coated on two surfaces of the middle layer.
The embodiment specifically includes:
as shown in fig. 1, the forming method of the roll bending forming device for sixteen-hole microchannel flat tubes provided in this embodiment includes the following steps:
firstly, the original strip material is a strip-shaped metal strip coil, and the material of the strip-shaped metal strip coil is a composite material consisting of three layers of aluminum alloys with different components; the metal strip is uncoiled by an uncoiler 1 and straightened by a straightener 2 and then is sent to a rolling mill 3 for rolling;
then, the sheet metal with the original width enters a rolling machine to be rolled into the shape as shown in fig. 2, the width of the sheet metal after rolling is increased relative to the original width, the metal sheet metal is thinned at the contact position of the inner wall plate and the outer wall plate of the micro-channel flat tube, and the thinned metal sheet metal is sent into a roll bending forming device.
Then, the metal plate enters a multi-pass roll bending forming roller pair which is sequentially configured to gradually form, and the forming process is shown in fig. 3; during the process, the sheet materials need to be turned over for 180 degrees twice, and the sheet materials can be overlapped with each other to form a closed hole each time the sheet materials are turned over, so that a certain amount of brazing flux needs to be coated on the corresponding position on the metal strip material for brazing before the two times of turning over, and the brazing flux coating device 5 is arranged before the #15 roll bending forming procedure and the #28 roll bending forming procedure; forming the sixteen-hole micro-channel flat tube after coming out of the roll bending forming unit;
and finally, conveying the product to a high-speed cutting device through a product straightening device for on-line cutting to obtain a sixteen-hole micro-channel flat tube product meeting the requirements.
As shown in fig. 2, the product produced by applying the above method is a folded flat tube with sixteen micro-channels, that is, a sixteen-hole micro-channel flat tube, wherein the sixteen-hole micro-channel flat tube has a left outer wall portion, a left inner wall portion, a right outer wall portion and a right inner wall portion, and the left outer wall portion is an outer left upper and lower straight portion and a left circular arc portion of the micro-channel flat tube; the right side outer wall part is an upper and lower right side straight part and a right side circular arc part outside the micro-channel flat tube; the left inner wall part is a part for embedding the upper half part of the inner side of the micro-channel flat tube with the outer wall and a left bent semi-circular arc part; the right inner wall part is a part for embedding the upper half part of the inner side of the micro-channel flat tube with the outer wall and a right-side bent semi-circular arc part.
As shown in fig. 4, the rolling process and the roll bending process of the sixteen-hole microchannel flat tube consist of the following 38 passes:
the original strip 19 is rolled for the first time after rolling the # 0' rolling procedure to form a partially thinned metal plate material 20, and the width of the plate material is lengthened;
after the 0 th rolling bending forming procedure, the original thick parts on the two sides of the plate are rolled to be thin, the width of the plate is further lengthened to form the plate 21 with a special shape, and the plate 21 is sent into a rolling bending forming device.
After the sheet 21 is straightened and rolled, the sheet enters a roll bending forming process, and after the sheet is subjected to the #1-14 roll bending forming processes, the sheet 23 with 8 arched bulges on two sides is formed. The arch 22 has a depth Hs. After the working procedure, the flatness of the plate is high; the folding angle is moderate, and the folding fillet is excessively smooth; the left side forms a transition circular arc, the angle of the circular arc is about 90 degrees, and the circular arc rebounds less.
And forming an arc part to present a 30-degree upward-turning-over shaped sheet material 25 after the #15-21 roll bending forming procedure, wherein the turning-over angle of the arc part sheet material 24 is 30 degrees, the resilience is small, and the stress state is good.
After the #22-27 roll bending forming procedure, the bending angle of the arc part 26 is 90 degrees to form a plate material 27, after the plate material is subjected to the procedure, the arc part faces downwards, and the arc top is embedded with the thinned part of the plate material; the 90-degree bending part has no cracking phenomenon, the stress state is good, and the resilience is small;
after the #28-32 roller bending forming process, the arch part and the part 28 which is embedded with the arch part start to turn inwards to form a shape 29, and the turning angle is 60 degrees. After the folding is finished, the stress state of the bending part is good, and the cracking phenomenon does not occur; the resilience of the plate is small.
After the #33-36 roll bending forming procedure, the arched parts on the two sides of the sheet and the embedded part 29 of the arched parts are turned inwards by 90 degrees, the bent edges are attached to the bottom of the sheet, the circular arcs of the arched parts on the two sides are attached to each other, and the shape of the turned sheet is approximately rectangular. There are 16 channels 31.
In this embodiment:
the roll bending forming process of the sixteen-hole micro-channel flat tube comprises the following steps:
firstly, uncoiling and straightening a metal strip coil, and then sending the metal strip coil into a rolling machine;
then, rolling the metal strip coil to form a plate material with a locally thinned part and a lengthened width, and sending the plate material into a roll bending forming unit;
then, sequentially bending the metal strip by a plurality of forming rollers which are sequentially configured and have symmetrical specific profile sections for a plurality of times to form the sixteen-hole micro-channel flat tubes;
finally, the microchannel flat tube with any length is formed by straightening and cutting.
The obtained sixteen-hole micro-channel flat tube is symmetrical along the central line, and each side of the micro-channel flat tube is provided with eight channels.
The rolling machine is used for respectively performing local thinning and width rolling on the plate by two pairs of rollers and sending the cold-rolled plate into a roll bending forming unit.
The roller of the rolling machine has a precise contour structure.
The rolling process can save metal plates, improve the utilization rate of the plates, and optimize the forming performance and the mechanical property of the micro-channel flat tubes
The roll bending forming process is to gradually bend a coiled material or a single sheet material transversely through a plurality of sequentially arranged forming rolls with specific profile profiles so as to manufacture a metal profile with a specific end face.
The roll bending forming process has the advantages of high production efficiency, good product surface quality, high dimensional precision and no limit on length.
The roll bending forming process can be used for manufacturing the pipe at a high speed, and the production speed is more than 80 m/min.
The roll bending forming process can be fully automatic, mainly adopts the row roll bending forming, has clean working environment, no pollution, low noise and energy conservation.
The roll bending forming process belongs to a flexible forming process, and different embossing pass rollers can be replaced to produce channels with circular sections, square sections and variable sections.
The roll bending forming Ti craft product has stable quality, the aluminum strip is in a better stress state in the roll bending process, the microchannel can be ensured to have higher dimensional precision, and the service life of each row of rolls is longer.
The high-quality heat transfer composite aluminum plate strip foil adopted by the roll bending forming process takes Al-Mn alloy as a core material, and the Al-Si alloy brazing filler metal with the thickness of 10% is coated on two sides, so that the roll bending forming process has the advantages of excellent surface quality, accurate size and flat plate shape, uniform tissue, good forming performance, and particularly excellent coating uniformity and weldability.
The embodiment provides a roll bending forming device of porous variable thickness folding microchannel flat tube, includes:
an uncoiler for releasing the coiled metal sheet;
the straightening device is used for enabling the metal plate to be more flat and sending the metal plate into a forming stage;
the rolling machine is used for cold rolling the metal plate, locally thinning the metal plate and increasing the width of the metal plate.
The roll bending forming unit is used for gradually bending a flat metal plate into a microchannel flat tube;
and the flux coating device is used for coating a certain amount of flux on the folded overlapped part of the metal plate so as to braze after forming.
The high-speed cutting device is used for limiting and cutting the porous microchannel pipe which is continuously formed in the length direction, the high-speed cutting machine can be matched with the forming speed, and the porous variable-thickness folding type microchannel flat pipe which is produced can be cut according to the required length.
The product straightening device keeps the fed metal plate straight and avoids lateral sliding and shaking during feeding.
The rolling machine is used for cold rolling the metal plate, locally thinning the metal plate, increasing the width of the metal plate and then sending the metal plate into the roll bending forming device.
The roll bending forming unit consists of a series of pre-forming rolls and fine forming rolls, wherein the shape and the clearance of the upper and lower rolls are determined by the size of the flat tubes to be produced.
The flux coating device is respectively arranged between the pre-forming roller pair and the wire forming roller pair and between the wire forming roller pair and the fine forming pair.
The brazing flux coating device is provided with two different sets, and each set is provided with a different number of dispensing heads.
And a cutting machine is arranged behind the roll bending forming unit and is used for cutting the produced micro-channel flat tubes according to the required length.
The roll bending forming unit is provided with a series of roll pairs with precise profile sections, the profile surfaces of the roll pairs are all in symmetrical shapes, and the metal strip advances along the roll pairs and is gradually bent and formed.
In the roll bending forming process, two sides of the metal plate are bent into a roughly rectangular sawtooth shape, and then the metal plate is turned over for 180 degrees twice to form the porous variable-thickness folding type microchannel flat tube.
The microchannel flat tubes are connected at the overlapped part of the tube walls by a brazing method.
The brazing process requires that a certain amount of flux is applied to the corresponding location of the metal strip during the forming process.
In summary, the invention provides a roll bending forming device and a forming method for variable thickness folding type microchannel flat tubes, which are characterized in that a metal plate is guided into a rolling mill to obtain a partially thinned metal plate with a specific shape, and a coiled material or a single plate is gradually and transversely bent by a plurality of sequentially configured roll bending forming rolls with specific profile profiles to prepare a metal section with a specific end surface shape; the forming method belongs to a flexible forming process, and can replace different embossing pass roll bending forming roll pairs to produce channels with circular sections, square sections and variable sections.
The roll bending forming device and the roll bending forming method for the variable-thickness folding type microchannel flat tube have the advantages of high production efficiency, good product surface quality, high material utilization rate, high dimensional precision and unlimited length; the pipe can be made at high speed, and the production speed is more than 80 m/min; on the basis of saving materials, the mechanical property of the micro-channel flat tube is optimized; the automatic bending machine can be fully automated, is formed by bending the row rollers, has clean working environment, no pollution, low noise, energy conservation and material conservation; the variable-thickness folding type microchannel flat tube produced by the invention has stable product quality, and the aluminum strip is in a better stress state in the roll bending process, so that the microchannel has higher dimensional precision and the service life of each row of rollers is longer; the adopted high-quality heat transmission composite aluminum plate strip foil takes Al-Mn alloy as a core material, and the Al-Si alloy brazing filler metal with the thickness of 10 percent of the composite aluminum plate strip foil is coated on two sides, so that the high-quality heat transmission composite aluminum plate strip foil has excellent surface quality, accurate size and flat plate shape, uniform tissue, good forming performance, and particularly excellent coating layer uniformity and weldability.
The metal coil adopted by the invention is an aluminum alloy coil similar to the fins, so that the corrosion resistance control is easy, the welding process of the flat tubes and the welding of the flat tubes are the same as the brazing process, only a certain amount of brazing flux is coated during tube manufacturing, and the tube manufactured and the assembled fins are brazed in a brazing furnace without an additional special welding process; the produced flat tube has stable quality, and has the characteristics of obvious energy conservation, low manufacturing cost, high yield, high tube manufacturing speed and the like.
The invention provides a metal plate cold rolling forming device, which can cold roll a plate with a shorter width to obtain a metal plate with a large width, wherein the metal plate is thinned at the contact position of an inner wall plate and an outer wall plate of a micro-channel flat tube, the inner wall plate is embedded into the outer wall plate, the plate is gradually formed into a variable-thickness folding type micro-channel flat tube through a roll bending forming process, all mechanical properties of the micro-channel flat tube are enhanced to a certain extent, a large amount of raw materials are saved, and the metal plate cold rolling forming device has the characteristics of obvious energy conservation, high material utilization rate, high product quality, high micro-channel hole area occupation ratio and the like.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (8)
1. The utility model provides a become roll bending forming device of thickness folding microchannel flat tube which characterized in that, includes decoiler, straightener, rolling mill, scribbles brazing flux device and roll bending forming machine, wherein:
the uncoiler is used for releasing the coiled metal plate;
the straightening machine is used for straightening the metal plate;
the rolling machine is used for cold rolling the metal plate, locally thinning the metal plate, quantitatively increasing the width of the metal plate and feeding the metal plate into the roll bending forming machine;
the brazing flux coating device is used for coating brazing flux on the folded and overlapped part of the metal plate and brazing the formed metal plate;
the roll bending forming machine is used for gradually bending the rolled metal plate into a porous micro-channel flat tube;
the rolling machine comprises two pairs of rollers, the first pair of rollers locally thins the folded and overlapped part of the metal plate, and the width of the plate is increased; and the second pair of rollers rolls the two sides of the edge of the metal plate to be thin, and the width of the plate is further lengthened to a set width.
2. A roll bending apparatus for forming folded micro channel flat tubes with varying thickness as claimed in claim 1, further comprising a cutting machine for cutting a metal plate of a specific length.
3. A roll bending apparatus for forming variable thickness folding microchannel flat tubes as claimed in claim 1, wherein the roll has a precision profile configuration, the profile configuration being designed according to sheet metal shape and microchannel tube shape.
4. A variable thickness folding microchannel flat tube roll forming apparatus as claimed in claim 1, wherein the roll forming machine comprises a multi-pass roll forming roll pair comprising a pre-forming roll pair, a wire forming roll pair and a finish forming roll pair.
5. The roll bending forming method of the variable-thickness folding type microchannel flat tube adopts the roll bending forming device of the variable-thickness folding type microchannel flat tube as claimed in claim 4, and is characterized by comprising the following steps:
step 1: the rolled metal plate sequentially passes through an uncoiler, a straightener and a rolling mill to form a metal plate which is locally thinned and has a specific width, and the metal plate is sent into a roll bending forming machine;
step 2: the metal plate is bent for multiple times through a plurality of sequentially configured roll bending forming rollers with symmetrical specific profile sections;
and step 3: the brazing flux coating device comprises a first brazing flux coating device and a second brazing flux coating device, the first brazing flux coating device and the second brazing flux coating device are respectively arranged between the pre-forming roller pair and the wire forming roller pair and between the wire forming roller pair and the fine forming pair, and brazing flux is coated on the folded and overlapped part of the metal plate for brazing after forming;
the locally thinned metal plate has a symmetrical structure, and the contact part of the inner wall and the outer wall of the micro-channel tube is thinned.
6. The roll bending method for forming variable thickness folding microchannel flat tubes of claim 5, wherein the porous microchannel flat tubes have a symmetrical structure along a center line, and the same number of channels are arranged on both sides of the center line.
7. The roll bending forming method for the variable thickness folding type microchannel flat tube as claimed in claim 5, wherein the section shape of the microchannel hole of the porous microchannel flat tube is rectangular.
8. The roll bending forming method for the variable-thickness folding type microchannel flat tube as claimed in claim 5, wherein the metal plate adopts a composite aluminum plate strip foil with heat transmission performance, the composite aluminum plate strip foil comprises three layers, wherein the middle layer is made of Al-Mn alloy, and Al-Si alloy brazing filler metal with the thickness of 10% of that of the composite aluminum plate strip foil is coated on two sides of the middle layer.
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| CN110732845B (en) * | 2019-10-26 | 2021-01-15 | 赣州宇辉金属有限公司 | Flexible metal sheet cutting processing method |
| CN111922642A (en) * | 2020-08-05 | 2020-11-13 | 江西安维尔智能设备有限公司 | Power battery shell forming method |
| CN113732103B (en) * | 2021-08-05 | 2023-05-02 | 湖南湘投金天新材料有限公司 | Heat exchange tube manufacturing method and device and heat exchange tube |
| CN113634614A (en) * | 2021-08-13 | 2021-11-12 | 广州科技职业技术大学 | Forming method for harmonica tube of heat exchanger and extrusion die thereof |
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| US3676910A (en) * | 1970-11-19 | 1972-07-18 | F R Gross Co Inc | Machine for forming heat-exchanger fins |
| JPS63174827A (en) * | 1987-01-09 | 1988-07-19 | Calsonic Corp | Manufacture of fin |
| FR2973490B1 (en) * | 2011-03-31 | 2018-05-18 | Valeo Systemes Thermiques | THERMAL EXCHANGER TUBE, HEAT EXCHANGER AND CORRESPONDING PROCESSING METHOD |
| CN103486877B (en) * | 2013-09-23 | 2015-11-04 | 上海交通大学 | The micro-channel flat coiled heat exchanger of variable-flow-path |
| CN103753162B (en) * | 2014-01-17 | 2016-05-04 | 上海交通大学 | The roll forming device of ten hole micro-channel flat and manufacturing process |
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