JP2005000982A - Device and method for applying flux, and flux used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flux applying device with which a suitable amount of a flux is applied according to the joined part of a work, and to provide a flux applying method by which the efficient application of the flux or efficient brazing is made possible and the flux which is easy to maintain consistency distribution approximately constant. <P>SOLUTION: The flux is supplied to a flux feeder 2 by supplying first compressed air from a controller 12 to a flux storage tank 6 and the flux is supplied to a plurality of syringes 4 by supplying second compressed air from the controller 12 to the flux feeder 2. The flux is applied to the predetermined parts of joining by controlling the opening and closing of a plurality of the syringes 4 by the controller 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flux coating apparatus and a flux coating method used before joining a plurality of metal parts constituting a workpiece, and in particular, using near infrared irradiation heating, an Al (aluminum) part and an Al part The present invention relates to a flux applying apparatus and a flux applying method for applying a flux performed before brazing of a portion to be joined, or a flux used therefor.
[0002]
[Prior art]
The joining of various parts such as heat exchangers constituting the refrigeration cycle is conventionally performed by applying a flux to almost the entire work piece such as a heat exchanger by a roller coating method, a spray coating method, etc. It is carried out using a brazing furnace such as a batch furnace. Recently, we have also proposed that brazing is performed by heating the joint with infrared rays by passing it through an infrared irradiation heating furnace with a brazing material attached to the joint of a metal part such as a heat exchanger. Has been.
[0003]
Further, as described in Patent Document 1, for example, the flux applied to the joint before brazing is made by mixing a synthetic resin binder or an aqueous solution thereof with a flux powder to form a suspension. The thing which apply | coated the liquid to the member which should be brazed and brazed was proposed (for example, refer patent document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-185796 (second page, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, when the work is a heat exchanger that constitutes a refrigeration cycle, the part that requires the most flux is around the header pipe, and the flux does not require much to join the refrigerant pipe and the fin. As described above, in spite of the fact that the required amount of flux varies depending on the part of the workpiece, in the case of the roller coating method, the spray coating method, etc., there is a problem that the flux is applied to the entire workpiece in an approximately equal amount. there were.
[0006]
In addition, in the case of brazing by rapid heating in an oxidizing atmosphere or heating in an inert atmosphere, if the flux is applied more than necessary, the temperature of the base material will be adversely affected, or the amount of heat necessary for melting the flux will be reduced. Variations may occur and flux dissolution may be delayed depending on the location.
[0007]
Furthermore, according to Patent Document 1, a synthetic resin binder is mixed with the flux powder to form a suspension, but there is also a problem that the concentration distribution of the flux is not constant.
[0008]
The present invention has been made in view of the above-described problems of the prior art, and is a flux coating apparatus capable of applying an appropriate amount of flux according to a workpiece joining site, efficient application or efficiency of flux. It is an object of the present invention to provide a flux coating method capable of brazing and a flux that can easily maintain a concentration distribution substantially constant.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 among the present invention is a flux application device that applies a flux to a planned joining portion after assembling a plurality of metal parts constituting a workpiece, The flux supply device connected to the syringe, the flux storage tank for storing the flux supplied to the flux supply device, and the flux supply by reducing the pressure of the air connected to the compressed air source and supplied from the compressed air source And a control device for supplying to the flux storage tank, the first compressed air is supplied from the control device to the flux storage tank, and the flux is supplied to the flux supply device. The second compressed air is supplied to the flux feeder to supply flux to the plurality of syringes, and the control device Characterized by being adapted to apply the flux to the predetermined joining portion by performing the switching control of the plurality of syringes.
[0010]
The invention according to claim 2 further includes a transport table on which the work after assembling the plurality of metal parts is placed, and the transport base is appropriately moved in two directions orthogonal to each other to be joined. It is characterized by applying a flux.
[0011]
Furthermore, the invention described in claim 3 is characterized in that the flux storage tank includes a stirring unit, and the stirring unit stirs the flux in the flux storage tank.
[0012]
According to a fourth aspect of the present invention, the control device controls the air pressure supplied to the syringe and the application time.
[0013]
The invention according to claim 5 is characterized in that the first compressed air has a higher pressure than the second compressed air.
[0014]
The invention of claim 6 is characterized in that so as to apply the flux of 0.001g ^/ mm ² ~100g ^/ mm 2 in the predetermined joining portion.
[0015]
The invention according to claim 7 is characterized in that the plurality of metal parts are made of aluminum.
[0016]
The invention according to claim 8 is characterized in that the work is a heat exchanger constituting a refrigeration cycle.
[0017]
Furthermore, the invention according to claim 9 is a flux application method of applying a flux to a joining scheduled portion before joining a plurality of metal parts constituting a workpiece, and a step of degreasing the plurality of metal parts; It is characterized by comprising a step of assembling the plurality of metal parts, a step of applying a flux to the portion to be joined, and a step of drying the plurality of metal components to which the flux has been applied.
[0018]
The invention described in claim 10 is characterized in that the degreasing step is performed in a temperature range of 100 ° C. to 300 ° C. for 30 seconds to 180 seconds.
[0019]
The invention described in Claim 11, in the coating step, characterized in that so as to apply the flux of 0.001g ^/ mm ² ~100g ^/ mm 2 in the predetermined joining portion.
[0020]
The invention described in claim 12 is characterized in that the drying step is performed in a temperature range of 80 ° C. to 300 ° C. for 10 seconds to 300 seconds.
[0021]
The invention according to claim 13 is characterized in that the plurality of metal parts are made of aluminum.
[0022]
The invention described in claim 14 is characterized in that the work is a heat exchanger constituting a refrigeration cycle.
[0023]
Furthermore, the invention described in claim 15 is a flux characterized in that it contains aluminum fluoride powder and is mixed with a binder composed of a synthetic resin and an organic solvent.
[0024]
The invention described in claim 16 is characterized in that the mixing ratio of the flux and the binder is 25:75 to 50:50 (wt%).
[0025]
The invention described in claim 17 is characterized in that the mixing ratio of the flux and the binder is 30:70 to 35:65 (wt%).
[0026]
The invention described in claim 18 is characterized in that the binder contains one kind each of an organic solvent and a resin solvent.
[0027]
In the invention described in claim 19, the organic solvent is any one of alcohols, aldehydes / ketones, hydrocarbon compounds, chlorine compounds, nitrogen compounds and ethers, and the resin solvent is a thermosetting resin, It is any one of plastic resins.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a flux coating apparatus A according to the present invention, and the flux coating apparatus A includes a flux feeder 2. A plurality of syringes 4 and a flux storage tank 6 are connected to the flux feeder 2 via flux supply pipes 8 and 10, respectively, and a controller 12 is connected via a compressed air pipe 14. Further, the flux storage tank 6 is connected to the control device 12 via a compressed air pipe 16, the control device 12 is connected to a pressure regulator 20 via a compressed air pipe 18, and the pressure regulator 20 is connected to a compressed air pipe. 22 is connected to a compressed air source 24.
[0029]
The compressed air source 24 supplies, for example, 10 kg / cm ² of compressed air to the pressure regulator 20, and the pressure regulator 20 reduces the pressure of 10 kg / cm ² of compressed air to 0.5 kg / cm ² , for example. 12 is supplied. Further, the control device 12 supplies the compressed air decompressed by the pressure regulator 20 to the flux storage tank 6 as necessary, and the compressed air decompressed by the pressure regulator 20 is, for example, 0.2 kg / cm ² . The pressure is reduced and supplied to the flux feeder 2.
[0030]
The flux storage tank 6 is provided with a stirring unit 26 for stirring the flux stored therein (a mixture of flux and binder as will be described later). A nozzle (not shown) for discharging the flux supplied to 4 to the work as needed is attached.
[0031]
Taking a heat exchanger constituting a refrigeration cycle as an example of the work, a case where flux is applied to the heat exchanger using the flux applying apparatus A having the above configuration will be described below.
[0032]
2 and 3 show a heat exchanger 28 constituting a refrigeration cycle, and a pair of headers 30 extending in parallel with each other and both ends of the pair of headers 30 are arranged in parallel with each other at a predetermined interval. A plurality of refrigerant tubes 32 and a plurality of fins 34 formed in a zigzag shape and disposed between the plurality of refrigerant tubes 32 are provided. In addition, caps 36 are attached to both ends of each header 30, and a drawing tube 38 is joined to one end of each cap 36.
[0033]
As shown in FIG. 3C, each header 30 is provided with openings 30a that are slightly larger than the cross-sectional shape of the refrigerant pipe 32 at equal intervals, and the refrigerant pipe 32 is formed in the opening 30a. These end portions are loosely inserted and integrally joined to the header 30.
[0034]
The header 30, the refrigerant pipe 32, the fins 34, and the cap 36 constituting the heat exchanger 28 are all made of Al, and the necessary portions of the flux are the header 30 and the refrigerant pipe 32 that have a large clearance for parts assembly. These are a joint portion between the header 30 and the cap 36, and a close contact portion (point contact portion) between the refrigerant pipe 32 and the fin 34.
[0035]
A process from applying a flux to the heat exchanger having the above-described configuration and joining a predetermined portion to be joined by near infrared heating will be described below with reference to the flowchart of FIG.
[0036]
In step S1, first, in order to uniformize the amount of flux applied to the heat exchanger 28, the header 30, the refrigerant pipe 32, the fin 34, and the cap 36, which are components and components to be joined of the heat exchanger 28, are degreased. Do. Degreasing conditions (heat drying) are as follows.
・ Temperature: 100 ℃ ～ 300 ℃
・ Time: 30 to 180 seconds
Next, in step S <b> 2, the header 30, the refrigerant pipe 32, the fins 34, and the cap 36 are assembled on the heat exchanger 28 having a predetermined shape on the transport table (XY table) 40. Furthermore, an appropriate amount of a previously prepared mixture of flux and binder (this mixture is also referred to as flux in this specification) is used in step S3 by using the flux coating apparatus A shown in FIG. was applied in the range of 0.001g ^/ mm ² ~100g ^/ mm 2 to a predetermined site (joint scheduled portion) of the component provided is, in step S4, drying the component flux has been applied. Drying conditions are as follows.
・ Temperature: 80 ℃ ~ 300 ℃
・ Time: 10 to 300 seconds
Thereafter, in step S5, the predetermined joining portion is heated by heating the portion to be joined by near infrared rays.
[0039]
Here, the flux application process performed in step S3 will be described in more detail with reference to the flux application apparatus A of FIG.
[0040]
The heat exchanger 28 assembled on the transport table 40 is transported along the transport path 42 toward the plurality of syringes 4 fixed at predetermined positions on the transport path 42. When the heat exchanger 28 reaches the lower side of the syringe 4, the control device 12 appropriately moves the transport table 40 in the transport direction (X direction) and the direction orthogonal to the transport direction (Y direction). Apply the required amount of flux to the area.
[0041]
When applying the flux, the flux stored in the flux storage tank 6 is agitated by the agitating unit 26 so that the concentration of the flux particles in the flux storage tank 6 becomes uniform, and as a result, the flux particles in the discharge nozzle attached to the syringe 4. The concentration is made uniform. In addition, since the sedimentation speed of the flux particles in the flux storage tank 6 depends on the stirring speed by the stirring unit 26, it is possible to appropriately control the sedimentation speed of the flux particles by controlling the stirring speed by the control device 12. It is.
[0042]
The graph of FIG. 5 shows changes in the flux concentration at the tip of the discharge nozzle. In the figure, the solid line indicates the case where the stirring unit 26 is provided, and the broken line indicates the case where the stirring unit 26 is not provided.
[0043]
As can be seen from the graph of FIG. 5, the flux particles precipitate over time, but stirring the flux with the stirring unit 26 reduces the precipitation rate, and changes the flux concentration at the tip of the discharge nozzle within ± 10%. Can be controlled.
[0044]
Further, the control device 12 not only performs opening / closing control of the discharge nozzle, but also as shown below, since the flux application amount varies depending on the joining portion, the control device 12 supplies the discharge nozzle with the movement of the transport table 40. The amount of flux applied is controlled in accordance with the joining site by adjusting the air pressure and the application time.
[0045]
That is, the application method according to the present invention can apply the required amount to the required part of the flux by controlling the discharge pressure, time, and the nozzle diameter of the discharge nozzle. Pinpoint application is also possible. In other words,
-It is possible to apply a predetermined amount of flux according to the joint site by controlling the air pressure and the application time.
・ Corresponding to changes in application amount and application area by selecting application nozzles.
・ Quantitative application from high viscosity to low viscosity is possible.
[0046]
FIG. 6 is related to the present invention because a large amount of flux is required for joining the header 30 and the refrigerant pipe 32, but not much flux is required for joining the refrigerant pipe 32 and the fin 34. By using the flux application apparatus A, it is shown that a required amount of flux is applied in accordance with the joining site. On the other hand, according to a conventional spray coating method or the like, the flux is applied substantially uniformly over the entire surface of the heat exchanger 28 regardless of the required amount of flux.
[0047]
Here, the flux used for this invention is demonstrated.
Usually, the flux is scattered when intense energy of near infrared rays is applied, and the effect cannot be sufficiently exhibited. However, since the flux can be suppressed by using a binder, It is extremely effective for this. Further, when the binder is employed in the near-infrared heating method, the flux remains in the bonding portion, acts as an auxiliary material that facilitates bonding, and enables rapid heating in an oxidizing atmosphere.
[0048]
The flux according to the present invention contains aluminum fluoride powder and is used together with a binder composed of a synthetic resin and an organic solvent, and the mixing ratio is as follows.
・ Flux: 25-50wt%
・ Binder: 50-75wt%
Mixing ratio: Flux: Binder = 25: 75-50: 50 (wt%)
[0049]
The optimum mixing ratio is as follows.
・ Flux: 30-35wt%
・ Binder: 65-70wt%
Mixing ratio: Flux: Binder = 30:70 to 35:65 (wt%)
[0050]
Further, the binder contains one type each of an organic solvent and a resin solvent. By using the organic solvent, it is possible to keep the flux concentration distribution constant. In addition, the organic solvent and the resin solvent preferably have the following mixing ratio, but variation within a range of ± 10% is allowed.
Organic solvent: Resin solvent = 80: 20 (wt%)
[0051]
Moreover, as an organic solvent and a resin solvent, the following are preferable.
(Organic solvent)
1. Alcohols 2- (di-n-butylamino) ethanol, 2- (dimethylamino) ethanol, 2-aminoethanol, 2-ethylhexanol, 2-ethoxyethanol, 2-ethoxymethyl acetate, 2-butoxyethanol, 2- 1. Methoxyethanol, 2-methoxymethyl acetate, n-butanol, sec-butanol, tert-butanol, acrylic alcohol, isobutanol, isopropanol, isopropyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, phenethyl alcohol 2. Aldehuman ketones Acetone, Acetaldehyde, Methyl isobutyl ketone, Methyl ethyl ketone 3. Hydrocarbon compounds isopropylbenzene, ethylbenzene, xylene, propylene oxide 4. Chlorine compound 2-dichloroethane, chlorobenzene, dichloromethane, dicyclopetadiene, trichlorometadiene, tetrachloroethylene, trichloroethylene 5. Nitrogen compounds acetonitrile, acrylonitrile, isoprene Ethers Chloromethyl methyl ether [0052]
(Resin solvent)
1. 1. Thermosetting resin: phenol resin, epoxy resin, urea resin, melamine resin, ketone resin, silicon resin, furan resin, diallyl phthalate resin, unsaturated polyester resin Thermoplastic resins granamine, cresol resin, polyimide, trisnonylphenyl phosphite, thermopolyolefin, polyisobutylene, polyphthalamide, ethylene eryl acrylate, ethylene methacrylic acid, ionomer resin, modified silicon, diphenylmethane diisocyanate, melamine formaldehyde, polyethylene oxide ]
In addition, although the said embodiment demonstrated taking the case of the heat exchanger which comprises a refrigeration cycle as a workpiece | work, a workpiece | work is not limited to a heat exchanger.
[0054]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
According to the flux application device according to the present invention, the control device supplies the first compressed air to the flux storage tank to supply the flux to the flux supply device, and the control device supplies the second compressed air to the flux supply device. Since the flux is supplied to the plurality of syringes and the opening and closing control of the plurality of syringes is performed by the control device so that the flux is applied to the joining portion, an appropriate amount of flux is applied according to the joining portion of the workpiece. It is possible to apply.
[0055]
In addition, according to the flux application method of the present invention, since a plurality of metal parts are degreased before assembly, the amount of flux applied becomes uniform and efficient flux application becomes possible. In addition, after applying the flux to the part to be joined, the metal parts coated with the flux are dried, so the organic solvent that constitutes the binder is not separated into moisture, alcohol, etc., and brazed. Can be carried out effectively.
[0056]
Furthermore, since the flux according to the present invention includes aluminum fluoride powder and is used by mixing with a binder composed of a synthetic resin and an organic solvent, the concentration distribution of the flux is caused by the organic solvent contained in the binder. Make uniform.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a flux coating apparatus according to the present invention.
FIG. 2 shows a heat exchanger constituting the refrigeration cycle, where (a) is a front view and (b) is a plan view.
3 shows the heat exchanger of FIG. 2, in which (a) is an exploded front view, (b) is a plan view of a header and a refrigerant pipe, and (c) is a side view of the header.
FIG. 4 is a flowchart showing a flux application method according to the present invention.
FIG. 5 is a graph showing a change in flack concentration at the tip of a discharge nozzle when a flux storage tank is provided with a stirring unit and when it is not provided.
6 is a graph showing the amount of flux applied to a heat exchanger by the flux applying apparatus of FIG. 1 and a conventional apparatus.
[Explanation of symbols]
2 Flux feeder, 4 Syringe, 6 Flux storage tank,
8,10 Flux supply pipe, 12 Control device,
14, 16, 18, 22 Compressed air pipe, 20 Pressure regulator,
24 Compressed air source, 26 Stirring unit, 28 Heat exchanger,
30 header, 32 refrigerant pipe, 34 fin, 36 cap,
38 Drawer tube, 40 Transport stand, 42 Transport path,
A Flux application device.

Claims (19)

After assembling a plurality of metal parts constituting the work, a flux application device that applies a flux to the planned joining portion,
A flux feeder connected to a plurality of syringes, a flux storage tank for storing flux supplied to the flux feeder, and the flux connected to a compressed air source and depressurized air supplied from the compressed air source A supply device and a control device for supplying the flux storage tank, the first compressed air is supplied from the control device to the flux storage tank, and the flux is supplied to the flux supply device. The second compressed air is supplied to the flux supply device to supply the flux to the plurality of syringes, and the control device controls the opening and closing of the plurality of syringes so that the flux is applied to the joining portion. A flux coating apparatus characterized by that. It further comprises a transport table on which the workpieces after assembling the plurality of metal parts are placed, and the flux is applied to the joint portions by appropriately moving the transport table in two orthogonal directions. The flux coating apparatus according to claim 1. The flux coating apparatus according to claim 1 or 2, wherein the flux storage tank includes a stirring unit, and the flux in the flux storage tank is stirred by the stirring unit. The flux coating apparatus according to any one of claims 1 to 3, wherein a supply air pressure to the syringe and a coating time are controlled by the control device. 5. The flux coating apparatus according to claim 1, wherein the first compressed air has a higher pressure than the second compressed air. Flux coating apparatus according to any one of claims 1 to 5, characterized in that so as to apply the flux of 0.001g ^/ mm ² ~100g ^/ mm 2 in the predetermined joining portion. The flux coating apparatus according to claim 1, wherein the plurality of metal parts are made of aluminum. The flux application device according to claim 7, wherein the workpiece is a heat exchanger constituting a refrigeration cycle. A flux application method of applying a flux to a planned joining portion before joining a plurality of metal parts constituting a workpiece,
Degreasing the plurality of metal parts, assembling the plurality of metal parts, applying a flux to a portion to be joined, and drying the plurality of metal parts coated with the flux. A flux coating method characterized by that. The flux application method according to claim 9, wherein the degreasing step is performed in a temperature range of 100 ° C. to 300 ° C. for 30 seconds to 180 seconds. Wherein in the coating step, the flux coating method according to claim 9 or 10, characterized in that so as to apply the flux of 0.001g ^/ mm ² ~100g ^/ mm 2 in the predetermined joining portion. The flux coating method according to claim 9, wherein the drying step is performed in a temperature range of 80 ° C. to 300 ° C. for 10 seconds to 300 seconds. The flux coating method according to any one of claims 9 to 12, wherein the plurality of metal parts are made of aluminum. The flux application method according to claim 13, wherein the workpiece is a heat exchanger constituting a refrigeration cycle. A flux comprising aluminum fluoride powder and being mixed with a binder composed of a synthetic resin and an organic solvent. The flux according to claim 15, wherein a mixing ratio of the flux and the binder is 25:75 to 50:50 (wt%). The flux according to claim 16, wherein a mixing ratio of the flux and the binder is 30:70 to 35:65 (wt%). The flux according to any one of claims 15 to 17, wherein the binder contains one kind each of an organic solvent and a resin solvent. The organic solvent is any one of alcohols, aldehydes / ketones, hydrocarbon compounds, chlorine compounds, nitrogen compounds, ethers, and the resin solvent is any one of thermosetting resins and thermoplastic resins. The flux according to claim 18, which is characterized.

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