JP2017136610A - Fluxless brazing method of aluminum material and processing device for brazing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new brazing method of an aluminum material and a processing unit for brazing where the vaporization of Mg and Zn contained in a base material and the like can be suppressed by bringing the degree of vacuum in a furnace closer to atmospheric pressure and the flowability of a brazing material can be improved.SOLUTION: Work-pieces P, B are heated to a prescribed temperature at the inside and outside of a vacuum drying chamber, the inside of the vacuum drying chamber is made vacuum to a high vacuum region and then brazing treatment is performed by increasing the temperature of a brazing chamber in a low vacuum region to the melting temperature of a brazing material while flowing a high purity inert gas into the brazing chamber and exhausting the gas in the brazing chamber.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of brazing aluminum materials (base materials) using a brazing material without using a flux, and a brazing processing apparatus used for brazing an aluminum material by this brazing method. Is.

  In recent years, equipment such as heat exchangers and radiators for automobiles is often made of aluminum alloy for the purpose of weight reduction, etc., and in the manufacturing process of equipment made of such aluminum alloy, the production cost Many are due to brazing methods. By the way, as a brazing method of such an aluminum material, there have been a method performed in a high vacuum and a method performed using a flux in the atmosphere. However, in the method performed in the high vacuum, Mg and Zn contained in the aluminum alloy and the brazing material are evaporated and scattered in the vacuum at the time of brazing, and the strength and corrosion resistance are deteriorated. In the method performed in the air, there are various problems such as the need for a flux application operation, the flux remaining after brazing, and the additional cleaning operation. In recent years, a non-corrosion flux has been developed, which makes it possible to braze in a nitrogen gas atmosphere under atmospheric pressure, making improvements such as no need for cleaning in the subsequent process, and using such a non-corrosion flux. Although brazing methods are generally widespread, there are problems in that the flux and the coating process are costly and that flux remains on the joint and other surfaces after brazing. Therefore, a brazing method under a low vacuum is being developed without using the above-mentioned flack.

  As a brazing method under such a low vacuum, for example, a method disclosed in Japanese Patent Laid-Open No. 2013-39586 (Patent Document 1) (a method for manufacturing a high-strength, high-corrosion-resistant aluminum heat exchanger) has been proposed. ing. In the method disclosed in Patent Document 1, a base material made of an aluminum alloy containing a predetermined amount of Zn or the like is coated with a brazing material containing Mg, and the inside of the furnace is evacuated to a vacuum degree of 10 to 500 Pa. Thereafter, an inert gas is introduced into the furnace, the furnace pressure is maintained at a low vacuum of 100 to 3000 Pa, and the furnace is maintained at the melting temperature of the brazing material. In addition, in the said patent document 1, while introducing the said inert gas, size reduction of a vacuum pump and shortening of operation time were possible, and it was contained in the brazing material by setting it as the said vacuum degree. It is described that the evaporation of Mg can be suppressed and the strength of the brazed portion can be improved.

  Further, a method (aluminum brazing method) disclosed in Japanese Patent Laid-Open No. 2013-91066 (Patent Document 2) has also been proposed. The method disclosed in Patent Document 2 uses a brazing material containing a predetermined amount of Mg and heats it in an argon gas atmosphere or a helium gas atmosphere with a nitrogen purity of 1% or less. The temperature raising rate is a method of setting in the range of 30 to 200 ° C. per minute, preferably in the range of 40 to 180 ° C. per minute. According to the method disclosed in Patent Document 2, it is described that a vacuum furnace is not required by setting the pressure during heating to be close to atmospheric pressure.

JP 2013-39586 A JP2013-91066A

  However, in the brazing method disclosed in Patent Document 1, when brazing, that is, when the brazing material melts and reaches between the base material and the base material, Mg or Zn contained in the base material or the like The amount of evaporation is not small and does not meet the strength and corrosion resistance required for products. In particular, in the field of equipment such as automotive heat exchangers and radiators that are becoming thinner for the purpose of weight reduction, the brazing method disclosed in Patent Literature 1 described above is a residual material such as Mg contained in the base material. The amount is small and the strength and corrosion resistance required for F are not satisfied. Moreover, in the brazing method disclosed in Patent Document 2, there is a description that a vacuum furnace is not required by setting the pressure during heating to be close to atmospheric pressure, but this includes a viewpoint of fluidity of the brazing material. There is suspicion, and the uneasiness to the reliability with respect to mechanical strength cannot be dispelled.

  Therefore, the present invention is proposed in order to solve the problems of the above-described conventional brazing methods, and is a brazing method that does not use a flux, and includes Mg contained in a base material and a brazing material. A new aluminum brazing method capable of maintaining the strength and corrosion resistance of the base material by suppressing evaporation of Zn and Zn, and at the same time, enhancing the fluidity of the brazing material and satisfying the mechanical strength, and It aims at providing the processing apparatus for brazing.

  The present invention has been proposed in order to solve the above-mentioned problems, and is a first invention (the invention according to claim 1 is a method of brazing an aluminum material performed in a brazing processing apparatus, A brazing material in which at least one of Mg and Zn is contained in one base material and the other base material each made of an aluminum alloy containing at least one of Mg and Zn without using a flux. A brazing method of aluminum materials (hereinafter, the one base material and a combination of the other base material and the brazing material are referred to as a workpiece), wherein the brazing processing apparatus includes: A vacuum drying chamber and a brazing chamber that communicate with each other through an opening opened and closed by a shield door, and the workpiece is heated to a predetermined temperature in advance and carried into the vacuum drying chamber. A heating / carrying-in process, a vacuuming process in which the vacuum drying chamber is evacuated to a high-vacuum region after the heating / carrying-in process, and a high purity of 99.999% or more after the high-vacuing process A return pressure step for returning the atmospheric pressure in the vacuum drying chamber to a low vacuum region while allowing an inert gas to flow into the vacuum drying chamber, a vacuum drying step provided, and the brazing in the vacuum drying step The atmospheric pressure in the brazing chamber is reduced to a low vacuum by evacuating the atmospheric pressure in the chamber to a medium vacuum region and then exhausting the gas in the brazing chamber while allowing the high-purity inert gas to flow into the brazing chamber. A brazing chamber preparatory step for returning the pressure within the region, a repressure step in the vacuum drying chamber, and a brazing chamber preparatory step after the brazing chamber preparatory step while the shield door is being opened and closed. The brazing chamber is caused to flow in the brazing chamber in a predetermined low vacuum region while the high purity inert gas is allowed to flow into the brazing chamber and the gas in the brazing chamber is exhausted. And a brazing treatment step of brazing the workpiece by raising the temperature to the melting temperature of the material.

  In the brazing method for an aluminum material according to the first invention, a vacuum drying step is performed in the vacuum drying chamber, and then a brazing chamber preparation step and a brazing treatment step are performed in the brazing chamber. In the vacuum drying process, first, a heating / carrying process is performed in which the work is heated to a predetermined temperature in advance and carried into the vacuum drying chamber. Then, when the workpiece heated to the predetermined temperature is carried into the vacuum drying chamber, a high vacuuming step is then performed in which the vacuum drying chamber is evacuated to a high vacuum region. By this high evacuation step, not only the oxygen content but also the evaporation of the water adhering to the workpiece is further promoted, and the water evaporated together with the oxygen content is exhausted outside the vacuum drying chamber. In the brazing treatment step performed in the brazing chamber, the high-purity inert gas is allowed to flow into the brazing chamber and the gas in the brazing chamber is exhausted, while the brazing chamber is subjected to a predetermined amount. The temperature of the brazing chamber is raised to the melting temperature of the brazing material in a low vacuum region. Therefore, the brazing chamber becomes an atmosphere in the furnace in which a large amount of the high-purity inert gas occupies, and in the high-purity inert gas atmosphere, the brazing material is melted, and one base material which is the workpiece and the other The base material is brazed.

Therefore, according to the brazing method of the aluminum material according to the first aspect of the present invention, the brazing preparation step performed in the vacuum drying chamber causes the work of the vacuum drying chamber, the oxygen content and moisture present in the vacuum drying chamber, etc. The oxidation promoting component is almost completely discharged out of the vacuum drying chamber, and in the brazing treatment step, the temperature of the brazing material is set in the low vacuum region in the high purity inert gas atmosphere. Since the temperature is raised to the melting temperature, the oxide film (Al ₂ O ₃ ) formed on the surface of the workpiece reacts with Mg when Mg is contained in the brazing material to produce oxidized Mg (MgO ) in order to peel off from the surface of the next workpiece, the fluidity of the brazing material is promoted, will be deposited directly on the base material without interposing between the oxide film (Al 2 _{O 3),} the upper Since the brazing treatment process is performed in a low vacuum region, the amount of Mg and Zn contained in the workpiece and brazing material can be significantly reduced (see the examples described later), and the base material described above. Strength and corrosion resistance can be maintained, and as a result, the mechanical strength of the workpiece can be sufficiently satisfied.

  The heating performed on the workpiece outside the vacuum drying chamber can use, for example, a heating device equipped with an electric heater or the like, and the heating temperature for heating the workpiece in advance is set at It is preferable that the temperature is equal to or higher than the temperature at which water attached to the work carried into the preparation chamber evaporates, and 150 ° C. or lower. In addition, when the said heating temperature exceeds 150 degreeC, since a workpiece | work will re-oxidize, it is unpreferable. Further, as the high purity inert gas used in the brazing treatment step, any one of nitrogen gas, helium gas, argon gas, or a plurality of high purity inert gases may be mixed and used.

  Moreover, the brazing method of the aluminum material which concerns on 2nd invention (invention of Claim 2) replaces with the said heating and carrying-in process in the said 1st invention, and carries in the said workpiece | work in the said vacuum-drying chamber. At the same time, a heating step of heating to a predetermined temperature in the vacuum drying chamber is performed in a stage prior to the high vacuuming step.

  That is, the brazing method of the aluminum material according to the present invention is a timing for heating the workpiece, as in the brazing method of the aluminum material of the first invention described above, even if it is preheated outside the vacuum capable chamber, As in the method of brazing the aluminum material of the second invention, heating may be performed after the work in the vacuum drying chamber is carried in, and any method can be used to contain Mg contained in the base material or the brazing material. By suppressing the evaporation of Zn and Zn, the strength and corrosion resistance of the base material can be maintained, and at the same time, the fluidity of the brazing material can be increased and the mechanical strength can be satisfied.

  An aluminum material brazing method according to a third invention (invention of claim 3) is the predetermined low vacuum region in the brazing treatment step according to any one of the first and second inventions. Is characterized by being an atmospheric pressure in the range of 3 kPa to 68 kPa.

  In the brazing method for an aluminum material according to the third aspect of the present invention, even in the low vacuum region, the pressure in the brazing chamber is set to a pressure in the range of 3 kPa to 68 kPa. Thus, the strength and corrosion resistance of the base material are maintained by suppressing the evaporation of Mg and Zn contained in the base material and the brazing material by performing the brazing treatment step at a pressure in the range of 3 kPa to 68 kPa. As can be seen from the examples described later, the fluidity of the brazing material can be further enhanced.

  Moreover, the brazing method of the aluminum material which concerns on 4th invention (invention of Claim 4) WHEREIN: In the brazing method of the aluminum material which concerns on the said 2nd invention, in the process before performing the said heating process, A first evacuation step of evacuating the air pressure in the vacuum drying chamber to a medium vacuum region, and after the primary evacuation step, the high-purity inert gas is allowed to flow into the vacuum drying chamber. And a first repressure step of returning the pressure in the vacuum drying chamber within the range of the low vacuum region by exhausting gas to the outside, and in the heating step, Heating is performed until a predetermined temperature not lower than 150 degrees Celsius and higher than a temperature at which moisture in the workpiece or the vacuum drying chamber evaporates is characterized.

  In the brazing method for an aluminum material according to the fourth aspect of the invention, since the first decompression step is performed, the high-purity inert gas is contained in the vacuum drying chamber even before the heating step is performed. In addition to being able to be in a gas atmosphere, in the heating step, the vacuum drying chamber is heated to a temperature not lower than a temperature at which the work or moisture in the vacuum drying chamber evaporates to a predetermined temperature of 150 degrees Celsius or less. The fluidity of the brazing material can be further increased.

  An aluminum material brazing method according to a fifth invention (invention of claim 5) is the aluminum material brazing method according to any one of the first to fourth inventions, wherein the workpiece is formed of a heat-resistant material and the upper part is opened. The bottom plate is disposed in a gas inflow box in which a plurality of gas discharge openings are formed, or the workpiece is disposed on the tray in which the plurality of gas discharge openings are formed and In the brazing process, the high-purity inert gas is dispersed from above the gas inflow box into the gas inflow box, and the gas inflow box is surrounded by a gas inflow box having an open side plate. The gas in the brazing chamber to the outside from the lower side of the plurality of gas discharge openings formed in the bottom plate or tray of the gas inflow box. It is an able and features to care.

  In the brazing method for an aluminum material according to the fifth invention, the high-purity inert gas uniformly flows into the gas inflow box from above the gas inflow box in which the work is disposed. It passes through the gas discharge opening formed in the bottom plate or tray of the gas inflow box and is discharged to the outside from the vacuum drying chamber or the brazing chamber. Therefore, the high-purity inert gas is not diffused in the vacuum drying chamber or the entire brazing chamber, and the high-purity state can be maintained in the gas inflow box surrounding the workpiece and used. The flow rate of the high purity inert gas can be suppressed, and the brazing treatment cost can be reduced. In addition, according to the method of brazing an aluminum material according to the fifth aspect of the invention, oxidation promoting components such as oxygen and moisture in the vacuum drying chamber or brazing chamber are diffused in the vacuum drying chamber or brazing chamber. Therefore, the fluidity of the brazing material can be further improved, and the workpiece can be firmly joined via the brazing material.

  An aluminum material brazing method according to a sixth invention (invention of claim 6) is the high purity inert gas flowing into the vacuum drying chamber in the vacuum drying step in the fifth invention. Is a nitrogen gas, and in the brazing treatment step, the high-purity inert gas flowing from above the gas inflow box into the gas inflow box is an argon gas.

  According to the brazing method for an aluminum material according to the sixth aspect of the present invention, the high-purity inert gas flowing from above the gas inflow box into the gas inflow box is argon gas, and the argon gas is a gas Since it occupies most of the inflow box and thus the brazing treatment process is performed in an atmosphere occupying a large amount of argon gas, it is possible to further improve the fluidity of the brazing material.

  An aluminum material brazing method according to a seventh invention (invention of claim 7) is the aluminum material brazing method according to the sixth invention, wherein the gas inflow is performed in the brazing treatment step. Argon gas as a high purity inert gas that flows into the gas inflow box from above the box is caused to flow, and nitrogen gas as the high purity inert gas is allowed to flow into the brazing chamber. The flow rate ratio between nitrogen gas and argon gas is characterized in that the argon gas flow rate is higher than 5: 4.

  According to the brazing method for an aluminum material according to the seventh aspect of the present invention, since the flow rate ratio of the nitrogen gas and the argon gas is higher than 5: 4, the flow rate of the brazing material is further improved. The mechanical strength of the workpiece can be sufficiently satisfied.

  An eighth invention (invention according to claim 8) is a brazing treatment apparatus used for carrying out the brazing method for an aluminum material according to the first invention, and includes a shield door therebetween. A vacuum drying chamber and a brazing chamber communicated with each other through an opening opened and closed by a high vacuum evacuation means for evacuating the vacuum drying chamber to a high vacuum region; A first pressure detecting means for detecting a pressure in the vacuum drying chamber; a first gas introduction pipe connected to the vacuum drying chamber for introducing a high purity inert gas having a purity of 99.999% or more into the vacuum drying chamber; A first gas introduction valve disposed in the middle of the first gas introduction pipe, and the brazing chamber includes a medium vacuuming means for evacuating the brazing chamber to a medium vacuum region; A second for detecting the pressure in the brazing chamber; A force detection means; a second gas introduction pipe connected to the brazing chamber for introducing the high purity inert gas into the brazing chamber; and a second gas introduction pipe disposed in the middle of the second gas introduction pipe A valve, a heating means for heating the temperature in the brazing chamber, a temperature detection means for detecting the temperature in the brazing chamber, and a gas discharge means for discharging the gas in the brazing chamber, respectively, The high evacuation means, the first pressure detection means, the first gas introduction valve, the medium evacuation means, the second pressure detection means, the heating means, the temperature detection means and the gas discharge means are each connected to the control means, After the vacuum drying chamber is evacuated to a high vacuum region by the control of the high evacuation means and the first pressure detection means by the control means, the control of the first gas introduction valve and the gas discharge means Vacuum drying room While the high purity inert gas having a purity of 99.999% or more is allowed to flow into the vacuum drying chamber, the pressure in the vacuum drying chamber is returned to the low vacuum region, and the second gas introduction valve, the gas discharge means, 2 By controlling the pressure detecting means, the heating means, and the temperature detecting means, the high-purity inert gas is allowed to flow into the brazing chamber and the gas in the brazing chamber is exhausted. The workpiece is brazed by raising the temperature of the brazing chamber to the melting temperature of the brazing material in a vacuum region.

  A ninth invention (invention according to claim 9) is an aluminum material brazing treatment apparatus used for carrying out the aluminum material brazing method according to the invention according to claim 2. A vacuum drying chamber and a brazing chamber that communicate with each other through an opening that is opened and closed by a shield door, and the vacuum drying chamber includes a first heating unit that heats the vacuum drying chamber; A first temperature detecting means for detecting the temperature in the vacuum drying chamber; a high vacuuming means for evacuating the vacuum drying chamber to a high vacuum region; and a first pressure detecting means for detecting the pressure in the vacuum drying chamber; A first gas introduction pipe connected to the vacuum drying chamber for introducing a high purity inert gas having a purity of 99.999% or more into the vacuum drying chamber, and a first gas introduction pipe disposed in the middle of the first gas introduction pipe 1 gas introduction valve and air in the vacuum drying chamber A first gas exhausting means for exhausting gas, and the brazing chamber includes medium vacuuming means for evacuating the brazing chamber to a medium vacuum region, and first pressure detecting means for detecting the pressure in the brazing chamber. 2 pressure detection means; a second gas introduction pipe connected to the brazing chamber for introducing the high purity inert gas into the brazing chamber; and a second gas disposed in the middle of the second gas introduction pipe An introduction valve, a second heating means for heating the temperature in the brazing chamber, a second temperature detection means for detecting the temperature in the brazing chamber, and a second gas exhaust for discharging the gas in the brazing chamber Each of the first heating means, the first temperature detection means, the high vacuum suction means, the first pressure detection means, the first gas introduction valve, the first gas discharge means, the medium vacuum suction means, Second pressure detection means, second heating means, second temperature detection The stage and the second gas discharge means are respectively connected to the control means, and the vacuum drying chamber is heated to a predetermined temperature by the control of the first heating means and the first temperature detection means by the control means. Then, after the vacuum drying chamber is evacuated to a high vacuum region by the control of the high vacuum suction means and the first pressure detection means, the first gas introduction valve, the first gas discharge means, and the first By controlling with the pressure detection means, the pressure in the vacuum drying chamber is returned to the low vacuum region while flowing a high purity inert gas having a purity of 99.999% or more into the vacuum drying chamber, and the control means The high purity inert gas is caused to flow into the brazing chamber under the control of the second gas introduction valve, the second gas discharge means, the second pressure detection means, the second heating means, and the second temperature detection means. And And brazing the workpiece by raising the temperature of the brazing chamber to the melting temperature of the brazing material in a predetermined low vacuum region while exhausting the gas in the brazing chamber. It is characterized by performing.

  According to the brazing apparatus for brazing aluminum material according to the eighth invention, the same effect as the brazing method for aluminum material according to the first invention can be realized, and the aluminum material according to the ninth invention. According to the brazing processing apparatus, the same effect as the brazing method of the aluminum material according to the second invention can be realized.

  According to a tenth aspect of the present invention (invention of the tenth aspect), in the brazing apparatus for aluminum material, the high purity inert gas is dispersed in the vacuum drying chamber from above the work carried in the vacuum drying chamber. And a first gas discharge nozzle connected to the first gas introduction pipe is disposed, and the first gas discharge means discharges the gas in the vacuum drying chamber from below the workpiece. An exhaust pipe is provided, and in the brazing chamber, the high-purity inert gas is dispersed and discharged from above the work carried into the brazing chamber and is connected to the second gas introduction pipe. Two gas discharge nozzles are arranged, and the second gas discharge means includes a second exhaust pipe for discharging the gas in the brazing chamber from below the workpiece.

  According to the brazing processing apparatus according to the tenth aspect of the present invention, the same effects as those of the aluminum material brazing method according to the fourth aspect of the present invention can be realized.

  An aluminum material brazing apparatus according to an eleventh invention (invention of claim 11) is the high purity inert gas released from the first gas discharge nozzle in the tenth invention. Nitrogen gas, and the high-purity inert gas discharged from the second gas discharge nozzle is argon gas, and the twelfth invention (the invention according to claim 12) The brazing apparatus for aluminum material according to the eleventh aspect of the invention is characterized in that, in the eleventh aspect of the invention, the brazing chamber measures the flow rate of argon gas discharged from the second gas discharge nozzle and is connected to the control means. An argon gas flow meter, a nitrogen gas introduction pipe for flowing nitrogen gas into the brazing chamber, and an intermediate part of the nitrogen gas introduction pipe and connected to the control means A nitrogen gas introduction valve controlled by the control means and a nitrogen gas flow meter for measuring the flow rate of the nitrogen gas, the nitrogen gas flowing into the brazing chamber from the nitrogen gas introduction pipe and the second gas The flow rate ratio with respect to the argon gas discharged from the discharge nozzle is characterized in that the flow rate of the argon gas is higher than 5: 4.

  According to the brazing apparatus for brazing aluminum material according to the eleventh aspect of the invention, the same effect as the brazing method for aluminum material according to the sixth aspect of the invention can be realized, and the aluminum according to the twelfth aspect of the invention. According to the brazing apparatus for material, it is possible to achieve the same effect as the brazing method for aluminum material according to the seventh aspect of the present invention.

According to the brazing method for an aluminum material according to the first invention (the invention described in claim 1) and the second invention (the invention described in claim 2), the brazing preparation step performed in the vacuum drying chamber is performed. In addition, the oxidation promoting components such as oxygen and moisture present in the vacuum drying chamber and the work in the vacuum drying chamber are almost completely discharged out of the vacuum drying chamber. In the atmosphere, the temperature of the brazing chamber is raised to the melting temperature of the brazing material in the low vacuum region, so that the oxide film (Al ₂ O ₃ ) formed on the surface of the workpiece is the brazing material. When Mg contains Mg, it reacts with Mg to become oxidized Mg (MgO) and peels off from the surface of the workpiece, so that the fluidity of the brazing material is promoted, and the oxide film (Al ₂ O ₃ ) Between In addition, since the brazing process is performed in a low vacuum region, the amount of Mg and Zn contained in the work and brazing material is greatly reduced. The strength and corrosion resistance of the base material can be maintained, and as a result, the mechanical strength of the workpiece can be sufficiently satisfied. Even in the case of using the brazing apparatus for an aluminum material according to the above and the eighth invention (the invention according to the eighth aspect) and the ninth invention (the invention according to the ninth aspect), the above-described effects can be obtained. Can be realized.

  Further, by the brazing method of the aluminum material according to the third invention (invention of claim 3), the strength and corrosion resistance of the base material are reduced by suppressing the evaporation of Mg and Zn contained in the base material and the brazing material. In addition to being able to be maintained, the fluidity of the brazing material can be further enhanced as will be apparent from the examples described later.

  Further, according to the brazing method for aluminum material according to the fourth invention (invention of claim 4) and the brazing apparatus for aluminum material according to the tenth invention (invention of claim 10), respectively. The fluidity of the brazing material can be further enhanced, and the fluidity of the brazing material can be further enhanced by the brazing method for an aluminum material according to the fifth invention (invention of claim 5). .

  Further, according to the brazing method for aluminum material according to the sixth invention (invention of claim 6) and the brazing apparatus for aluminum material according to the eleventh invention (invention of claim 11), argon gas is used. Occupies most of the gas inflow box, it is possible to further improve the fluidity of the brazing material. Furthermore, the method of brazing aluminum material according to the seventh invention (the invention according to claim 7) and the According to the brazing apparatus for brazing aluminum material according to the twelfth invention (the invention according to claim 12), the fluidity of the brazing material can be further improved and the mechanical strength of the workpiece can be sufficiently satisfied. .

It is a side view which shows typically a brazing processing apparatus, a carrying-in side trolley, and a carrying-out side trolley, respectively. It is sectional drawing which expands from the side surface side and shows typically the internal structure of the vacuum-drying chamber shown in FIG. It is sectional drawing which expands from the front side and shows typically the internal structure of the vacuum-drying chamber shown in FIG. It is sectional drawing which expands from the side surface side and shows typically the internal structure of the brazing chamber shown in FIG. It is sectional drawing which expands from the front side and shows typically the internal structure of the brazing chamber shown in FIG. It is a block diagram of each apparatus etc. which comprise a brazing processing apparatus, a carrying-in side trolley, and a carrying-out side trolley. It is a front view which shows the structure of a control panel typically. It is a perspective view which shows an example of a tray and a gas inflow box. It is a flowchart which shows operation | movement of a brazing processing apparatus. It is a flowchart following the flowchart shown in FIG. It is a flowchart following the flowchart shown in FIG. It is a flowchart following the flowchart shown in FIG. It is a side view which shows the test method of a gap filling test. It is an experimental result table | surface which described the gap filling length based on a gap filling test. It is an experimental result table | surface which shows the residual amount of Mg and Zn.

  Hereinafter, a brazing processing apparatus according to the best mode for carrying out the present invention will be described in detail with reference to the drawings, and then an aluminum brazing method using the brazing processing apparatus will be described.

  As shown in FIG. 1, the brazing processing apparatus 1 according to this embodiment includes a vacuum drying chamber 2, a brazing chamber 3 disposed on the downstream side of the vacuum drying chamber 2, and the brazing chamber 3. A vacuum cooling chamber 4 disposed on the downstream side is provided inside. The entire brazing processing apparatus 1 including the vacuum drying chamber 2, the brazing chamber 3, and the vacuum cooling chamber 4 is formed in a cylindrical shape whose outer shape has a length in the horizontal direction. The vacuum drying chamber 2 is formed with a loading-side opening (not shown), and this loading-side opening is closed by a loading-side shield door 5. The loading-side shield door 5 opens and closes the loading-side opening by driving a loading-side shielding door opening / closing device described later, and the workpiece described later is opened by driving the loading-side shielding door opening / closing device. It is comprised so that a workpiece | work can be carried in in this vacuum-drying chamber 2 from the carrying-in side opening. Further, the vacuum drying chamber 2 and the brazing chamber 3 are partitioned by a partition plate 7 formed in a disc shape, and an opening (not shown) is formed in the partition plate 7. 1 is closed by the intermediate shield door 8. The first intermediate shield door 8 opens and closes the opening by driving a first intermediate shield door opening / closing device described later. The brazing chamber 3 and the vacuum cooling chamber 4 are partitioned by a partition plate 9 formed in a disc shape, and an opening (not shown) is formed in the partition plate 9. Is closed by the second intermediate shield door 11. The second intermediate shield door 11 opens and closes the respective openings by driving a second intermediate shield door opening / closing device described later. Further, an unillustrated unloading side opening is formed on the downstream side of the vacuum cooling chamber 4, and the unloading side opening is closed by the unloading side shield door 12. The carry-out side shield door 12 opens and closes the carry-out side opening by driving a carry-out side shield door opening / closing device described later.

  Hereinafter, the structure of the vacuum drying chamber 2 will be described. As shown in FIG. 2 or FIG. 3, the vacuum drying chamber 2 is provided with an upstream heat insulating chamber 13 formed of a graphite heat insulating material. As shown in FIG. 3, the upstream heat insulation chamber 13 is supported by support members 14 and 14 formed on the inner periphery of the furnace cylindrical plate 2a that forms the vacuum drying chamber 2 inside. Further, an upstream internal opening 13a is formed on the upstream side of the upstream heat insulating chamber 13, and the upstream internal opening 13a is closed by a first internal heat insulating door 16 shown in FIG. The first internal heat insulating door 16 opens and closes the first internal opening by a first internal heat insulating door opening / closing device described later. Further, a downstream internal opening 13b is formed on the downstream side of the upstream heat insulating chamber 13, and the downstream internal opening 13b is closed by a second internal heat insulating door 17 shown in FIG. This 2nd internal heat insulation door 17 opens and closes the said 2nd internal opening by the 2nd internal heat insulation door opening / closing apparatus mentioned later.

  In the upstream heat insulation chamber 13, left and right roller rails 22 and 23 for supporting the tray 20 on which the workpiece is placed and the gas inflow box 21 surrounding the workpiece from the lower side are arranged. These left and right roller rails 22 and 23 are supported by left and right rail support members 24 and 25 which are erected with their lower ends fixed to the inner peripheral surface of the furnace shell cylindrical plate 2a. The tray 20 is formed of a heat-resistant material into a flat plate shape, and has six through holes 20d described later. The tray 20 and the gas inflow box 21 supported on the left and right roller rails 22 and 23 will be described later in detail. In addition, a first internal transfer motor is disposed outside the upstream heat insulation chamber 13, and the tray 20 that supports the workpieces and the like is configured such that the left and right roller rails driven by the first internal transfer motor are provided. By the rotational drive of 22 and 23, while being carried in in the upstream heat insulation chamber 13, it is carried out to the downstream heat insulation chamber side mentioned later provided in the said brazing chamber 3. FIG.

  Further, as shown in FIG. 2, the vacuum drying chamber 2 is formed with a first vacuum exhaust port 26 for evacuating the vacuum drying chamber 2. The first vacuum exhaust port 26 is a part through which the gas in the vacuum drying chamber 2 is discharged to the outside by driving a first high vacuum exhaust system (not shown). The first high vacuum evacuation system is a high vacuum evacuation means constituting the present invention. The first high vacuum exhaust system includes an oil rotary vacuum pump (RP) that evacuates from atmospheric pressure to an initial stage, a mechanical booster vacuum pump (MBP) that evacuates from the initial stage to an intermediate stage, and an intermediate stage An oil diffusion pump (DP) that evacuates to a high vacuum and a holding pump (HP) that preliminarily evacuates the oil diffusion pump are configured. The vacuum drying chamber 2 is provided with a first vacuum gauge (or pressure gauge) 27 for measuring the pressure in the vacuum drying chamber 2. The first vacuum gauge 27 is a first pressure detecting means constituting the present invention. The first vacuum gauge (or pressure gauge) 27 includes a Bourdon tube vacuum gauge that measures low vacuum, a Pirani vacuum gauge that measures medium vacuum, and a Penning vacuum gauge that measures high vacuum. Further, as will be described later, the vacuum drying chamber 2 is provided with the present invention when the pressure in the vacuum drying chamber 2 is restored to a predetermined low vacuum region after the vacuum drying chamber 2 is evacuated to a high vacuum. A gas introduction pipe 33 for introducing a high purity nitrogen gas of 99.999% or more, which is an inert gas, into the vacuum drying chamber 2 is arranged. The gas introduction pipe 33 is a first gas introduction pipe constituting the present invention. The base end of the gas introduction pipe 33 is connected to a nitrogen gas supply tank (not shown). A first nitrogen gas introduction valve 35 that opens and closes the flow path of the gas introduction pipe 33 is disposed in the middle of the gas introduction pipe 33. The first nitrogen gas introduction valve 35 is a first gas introduction valve constituting the present invention. The middle part of the gas introduction pipe 33 is branched by branch pipes 33a and 33b. The middle part of the branch pipes 33a and 33b is inserted into the vacuum drying chamber 2, and The front end faces the upstream heat insulation chamber 13 and is connected to a nitrogen gas discharge nozzle 36 that discharges the nitrogen gas from above the workpiece. A large number of openings (not shown) are formed on the lower surface of the nitrogen gas discharge nozzle 36, and nitrogen gas is discharged from the large numbers of openings toward a work described later. The nitrogen gas discharge nozzle is a first gas discharge nozzle constituting the present invention.

  Further, an upper first heater 39 is disposed in the upstream heat insulation chamber 13 above the work carried into the interior, and a lower first heater 40 is disposed below the work. Yes. In this embodiment, the upper first heater 39 and the lower first heater 40 are important elements of the first heating means constituting the present invention, and are each composed of a special metal heater. The upper first heater 39 is supported by left and right electrode rods 41 and 42 inserted from the vacuum drying chamber 2 to the upstream heat insulating chamber 13, as shown in FIG. The lower first heater 40 is supported by left and right electrode rods 43 and 44 inserted from the vacuum drying chamber 2 to the upstream heat insulating chamber 13. Each of the electrode rods 41... 44 serves as a support rod that combines external heater electrical wiring (not shown) and a heater in the vacuum heating chamber, and also serves as an energization. The upper first heater 39 and the lower first heater 40 generate heat by electricity passing through the electrode rods 41... 44, respectively, and the temperature in the upstream heat insulation chamber 13 is increased. The vacuum drying chamber 2 is provided with a first thermometer (thermocouple) 45 for measuring the temperature in the upstream heat insulation chamber 13. The first thermometer 45 is a first temperature detecting means constituting the present invention.

  Further, as shown in FIG. 3, the vacuum drying chamber 2 is provided with an upstream gas discharge mechanism 48 for discharging gas from the upstream heat insulation chamber 13 to the outside. The upstream gas discharge mechanism 48 is a first gas discharge means constituting the present invention. The upper end of the upstream gas discharge mechanism 48 is located immediately below the tray 20, and each through-hole 20d formed in the tray 20 is provided. The lower end side of the exhaust pipe 49 is located outside the vacuum drying chamber 2, the horizontal pipe 50 to which the lower ends of the exhaust pipes 49 are respectively connected, and the And a first pump 54 connected to the horizontal pipe 50 via a pipe line 53 and serving as an exhaust vacuum pump. Each exhaust pipe 49 is a first exhaust pipe constituting the present invention. A first exhaust valve 55 that opens and closes the flow path of the exhausted gas is disposed in the middle of the pipe line 53. Accordingly, when the first pump 54 is driven, the gas existing on the tray 20 and in the gas inflow box 21 in which the work is disposed is moved to the exhaust pipe 49, the horizontal pipe 50, and the pipe line 53. Are exhausted to the outside.

  Next, the structure of the brazing chamber 3 will be described. As will be described later, the brazing chamber 3 is for brazing the work transferred from the vacuum drying chamber 2. The brazing chamber 3 is provided with a downstream heat insulating chamber 63 having substantially the same structure as the upstream heat insulating chamber 13 described above, and the downstream heat insulating chamber 63 is formed as shown in FIG. These are supported by support members 61 and 61. Further, an upstream internal opening 63a is formed on the upstream side of the upstream heat insulating chamber 13, and the upstream internal opening 63a is closed by a third internal heat insulating door 64 shown in FIG. The third internal heat insulating door 64 opens and closes the upstream internal opening 63a by a third internal heat insulating door opening / closing device described later. A downstream internal opening 63 b is formed on the downstream side of the downstream heat insulating chamber 63, and the downstream internal opening 63 b is closed by a fourth internal heat insulating door 65. The fourth internal heat insulating door 65 opens and closes the downstream internal opening 63b by a fourth internal heat insulating door opening / closing device which will be described later. In the downstream heat insulating chamber 63, left and right roller rails 66 and 67 for supporting the tray 20 on which the work is placed, the gas inflow box 21 and the like from below are disposed. In addition, a second internal transfer motor (not shown) is disposed outside the downstream heat insulation chamber 63, and the tray 20 that supports the workpieces and the like is driven by the second internal transfer motor. As the roller rails 66 and 67 are driven to rotate, they are carried into the downstream heat insulation chamber 63 and carried out in the direction of the vacuum cooling chamber 4 described later. Further, as shown in FIG. 4, the brazing chamber 3 is provided with a second evacuation port 68, and the gas in the brazing chamber 3 is discharged to the outside by driving a middle evacuation system (not shown). Is done. This middle vacuum exhaust system is a middle vacuuming means constituting the present invention, and is composed of the oil rotary vacuum pump (RP) and the mechanical booster vacuum pump (MBP). The brazing chamber 3 is provided with a second vacuum gauge (or pressure gauge) 69 for measuring the pressure in the brazing chamber 3. The second vacuum gauge (or pressure gauge) 69 is composed of a Pirani vacuum gauge and a Bourdon tube vacuum gauge for measuring medium and low vacuum. The second vacuum gauge 69 is a second pressure detecting means constituting the present invention.

  The brazing chamber 3 is provided with a second nitrogen gas introduction pipe 70 for introducing 99.999% or more high-purity nitrogen gas, which is an inert gas, into the brazing 3 as will be described later. Yes. The second nitrogen gas introduction pipe 70 is a nitrogen gas introduction pipe constituting the present invention. The base end of the second nitrogen gas introduction pipe 70 is connected to a nitrogen gas supply tank (not shown) similarly to the gas introduction pipe 33. A second nitrogen gas introduction valve 71 that opens and closes the flow path and a nitrogen gas flow meter 72 that measures the flow rate of the nitrogen gas are disposed in the flow path of the nitrogen gas introduction pipe 70. The second nitrogen gas introduction valve 71 is a nitrogen gas introduction valve constituting the present invention. The brazing chamber 3 is provided with an argon gas introduction pipe 73 that introduces 99.999% or more high-purity argon gas, which is an inert gas, into the brazing chamber 3. The argon gas introduction pipe 73 is a second gas introduction pipe constituting the present invention. The base end of the argon gas introduction pipe 73 is connected to an argon gas supply tank (not shown). An argon gas flow meter 74 that measures the flow rate of argon gas and an argon gas introduction valve 75 that opens and closes the flow path of the argon gas introduction tube 73 are disposed in the middle of the argon gas introduction tube 73. . The argon gas introduction valve 75 is a second gas introduction valve constituting the present invention. The middle part of the argon gas introduction pipe 73 is branched by branch pipes 73a and 73b. The middle parts of the branch pipes 73a and 73b are inserted into the brazing chamber 3, respectively. The front end of the head faces the downstream heat insulation chamber 63 and is connected to an argon gas discharge nozzle 76 that discharges the argon gas from above the workpiece. A large number of small-diameter holes (not shown) are formed on the lower surface of the argon gas discharge nozzle 76, and argon gas is discharged from the numerous small-diameter holes toward a work described later.

  Further, an upper second heater 79 is disposed in the downstream heat insulating chamber 63 above the work carried into the interior, and a lower second heater 80 is disposed below the work. Yes. In this embodiment, the upper second heater 79 and the lower second heater 80 are important elements of the second heating means constituting the present invention. In this embodiment, the upper second heater 79 and the lower second heater 80 are composed of special metal heaters. Yes. The upper second heater 79 is supported by left and right electrode rods 81 and 82 inserted from the brazing chamber 3 to the downstream heat insulating chamber 63, as shown in FIG. The lower second heater 80 is supported by left and right electrode rods 83 and 84 inserted from the brazing chamber 3 to the downstream heat insulation chamber 63. Each of the electrode rods 81... 84 serves as a support rod that combines an external heater electric wiring (not shown) and a heater in the vacuum heating chamber 2 and also serves as an energization. The upper second heater 79 and the lower second heater 80 generate heat by electricity passing through the electrode rods 81... 84, respectively, and the temperature in the downstream heat insulation chamber 63 is raised. The brazing chamber 3 is provided with a second thermometer (thermocouple) 85 for measuring the temperature in the downstream heat insulating chamber 63. The second thermometer 85 is a second temperature detecting means constituting the present invention.

  Further, as shown in FIG. 5, the brazing chamber 3 is provided with a downstream gas discharge mechanism 88 for discharging gas from the downstream heat insulating chamber 63 to the outside. The downstream gas discharge mechanism 88 is a second gas discharge means constituting the present invention. The downstream gas discharge mechanism 88 has an upper end located immediately below the tray 20 and a portion corresponding to each through-hole 20d formed in the tray 20, and has a lower end side. Are respectively an exhaust pipe 89 located outside the brazing chamber 3, a horizontal pipe 90 to which the lower ends of these exhaust pipes 89 are respectively connected, and an exhaust into which the gas flowing into the horizontal pipe 90 flows. A duct 91, a capturing device 92 that captures Mg and Zn (described later) contained in the gas, and a second pump 94 that is connected to the capturing device 92 via a conduit 93 and serves as an exhaust vacuum pump. I have. Each exhaust pipe 89 is a second exhaust pipe constituting the present invention. Trap filters 91a and 92a for capturing the Mg and Zn are accommodated in the exhaust duct 91 and the capturing device 92, and the flow of the exhausted gas flows in the middle of the conduit 93. A second exhaust valve 95 that opens and closes the path is disposed. Accordingly, when the second pump 94 is driven, the gas present on the tray 20 and in the gas inflow box 21 in which the work is disposed is transferred to the exhaust pipe 89, the horizontal pipe 90, and the exhaust duct 91, respectively. The trap device 92 and the pipe line 93 are exhausted to the outside, and when passing through the exhaust duct 91 and the trap device 92, Mg and Zn contained in the gas are trapped by the trap filters 91a and 92a. Is done.

  Next, the structure of the vacuum cooling chamber 4 will be described. As will be described later, the vacuum cooling chamber 4 cools the work brazed in the brazing chamber 3, and the tray 20 moved by opening the second intermediate shield door 11 is provided. Left and right roller rails (reference numerals are omitted) are provided. In addition, a third internal transfer motor (not shown) is disposed in the vacuum cooling chamber 4, and the tray 20 that supports a workpiece or the like is provided with the left and right roller rails driven by the third internal transfer motor. Is driven into the vacuum cooling chamber 4 and is carried out from the brazing processing apparatus 1 to the outside. As shown in FIG. 1, the vacuum cooling chamber 4 is formed with a second vacuum exhaust port 106 for evacuating the vacuum cooling chamber 4. The second vacuum exhaust port 106 is a part through which the gas in the vacuum cooling chamber 4 is discharged to the outside by driving a second high vacuum exhaust system (not shown). The second high vacuum evacuation system includes an oil rotary vacuum pump (RP), a mechanical booster vacuum pump (MBP), an oil diffusion pump (DP), and a holding pump (HP). The vacuum cooling chamber 4 is provided with a third vacuum gauge (or pressure gauge) (not shown) that measures the pressure in the vacuum cooling chamber 4. This third vacuum gauge (or pressure gauge) is composed of the above Bourdon tube vacuum gauge, Pirani vacuum gauge, and Penning vacuum gauge. Further, as will be described later, the vacuum cooling chamber 4 has a gas introduction pipe 107 for introducing nitrogen gas when the pressure in the vacuum cooling chamber 4 is restored after high vacuum is drawn inside the vacuum cooling chamber 4. A third nitrogen gas introduction valve (not shown) is arranged in the flow path of the gas introduction pipe 107.

  Further, a cooling fan 110 is disposed in the vacuum cooling chamber 4, and this cooling fan 110 is connected to a fan motor 111 having a rotational drive shaft 110 a disposed on the vacuum cooling chamber 4. A heat exchanger 112 for cooling the workpiece is provided in the vicinity of the cooling fan 110. The heat exchanger 112 is connected to a cooling medium (not shown) such as water provided outside the vacuum cooling chamber 4, and is introduced into the vacuum cooling chamber 4 and heated against the work as will be described later. The workpiece is cooled by cooling the nitrogen gas by contacting the workpiece.

  As shown in FIG. 1, a carry-in carriage 120 is disposed on the upstream side of the brazing treatment apparatus 1 described above, and a carry-out carriage 121 is disposed on the downstream side of the brazing treatment apparatus 1. Is arranged. The carry-out side carriage 120 is provided with a hearth roller (reference numeral is omitted) on which the tray 20 is placed on the upper surface, and is not shown for carrying the tray 20 into the vacuum drying chamber 2. Carry-in cylinders are provided. Further, the carry-out side carriage 121 includes a hearth roller (reference numeral is omitted) on which the work on the tray 20 cooled in the vacuum cooling chamber 4 is placed, and the vacuum cooling chamber 4. An unillustrated cart unloading cylinder for pulling out the tray 20 unloaded from the inside onto the hearth roller is provided.

  The brazing processing device 1 described above includes a central processing unit (CPU) 125 connected to each device, meter, valve, or the like described below, as shown in FIG. This central processing unit (CPU) is a control means constituting the present invention. The central processing unit 125 is connected to a ROM 126 that stores various programs such as calculation, input, and display, and a ROM 127 that stores numerical values such as set pressure, temperature, and time. In addition, they are connected to a first timer 128a, a second timer 128b, a third timer 128c, a fourth timer 128d, and a fifth timer 128e. The central processing unit 125 can be input with numerical values such as vacuum gauges and thermometers, which will be described later, and is connected to a control panel (display / operation unit) 131 for displaying a pressure state and a temperature state. Has been. That is, as shown in FIG. 7, the control panel 131 includes a first pressure display unit 131a for displaying the pressure in the vacuum drying chamber 2 measured by the first vacuum gauge 27 described above, and the vacuum. A first pressure input portion 131b that is pressed when the pressure in the drying chamber 2 is set to a predetermined pressure, and a first temperature that displays the temperature in the upstream heat insulation chamber 13 measured by the first thermometer 45. Temperature display part 131c and a first temperature input part 131d for setting the temperature in the upstream heat insulation chamber 13 to a predetermined temperature. A first timer input unit 131e for inputting the set time of the first timer 128a is provided below the first temperature display unit 131c. Further, below the first timer input part 131e, the pressure in the vacuum drying chamber 2 measured by the first vacuum gauge 27 and the upstream heat insulating chamber 13 measured by the first thermometer 45 are provided. A first recording unit 131f that records each of the temperatures is arranged. The first pressure input unit 131b, the first temperature input unit 131d, and the first timer input unit 131e are not shown by a predetermined program stored in the ROM 126 when pressed by an operator. An input screen is displayed together with the numeric keypad, and each numerical value can be set. The input numerical values are stored in the RAM 127. The control panel 131 includes a second pressure display unit 131g for displaying the pressure in the brazing chamber 3 measured by the second vacuum gauge 69 described above, and the pressure in the brazing chamber 3. The second pressure input portion 131h that is pressed when the pressure is set to a predetermined pressure, and the second temperature display portion 131i that displays the temperature in the downstream heat insulation chamber 63 measured by the second thermometer 85. And a second temperature input portion 131j for setting the temperature in the downstream heat insulation chamber 63 to a predetermined temperature. A third timer input unit 131k for inputting the set time of the third timer 128c is provided below the second temperature input unit 131j. A fourth timer input unit 131l for inputting the set time of the fourth timer 128d is provided below the second temperature display unit 131i. When the operator presses the third timer input unit 131k and the fourth timer input unit 131l, an input screen (not shown) is displayed together with a numeric keypad according to a predetermined program stored in the ROM 126. The input numerical values are configured to be stored in the RAM 127. Further, below the fourth timer input portion 131l, the pressure in the brazing chamber 3 measured by the second vacuum gauge 69 and the downstream heat insulating chamber 63 measured by the second thermometer 85 are provided. A second recording unit 131m that records each of the temperature and temperature is arranged. The second pressure input unit 131h and the second temperature input unit 131j are each pressed by an operator so that an input screen (not shown) is displayed together with a numeric keypad by a predetermined program stored in the ROM 126. Each numerical value can be set, and each input numerical value is stored in the RAM 127. The control panel 131 includes a third pressure display unit 131n that displays a pressure measured by a third vacuum gauge (not shown) that measures the atmospheric pressure or the pressure in the vacuum cooling chamber 4, and the inside of the vacuum cooling chamber 4 A third pressure input portion 131o that is pressed when the pressure of the second timer 128b is set to a predetermined pressure, a second timer input portion 131p that inputs a set time of the second timer 128b, and a setting of the fifth timer 128e. A fifth timer input unit 131q for inputting time is provided. The third pressure input unit 131o, the second timer input unit 131p, and the fifth timer input unit 131q are not shown by a predetermined program stored in the ROM 126 when pressed by an operator. An input screen is displayed together with the numeric keypad, and each numerical value can be set. The input numerical values are stored in the RAM 127. A third recording unit 131r that records the pressure in the vacuum cooling chamber 4 measured by the third vacuum gauge is disposed below the fifth timer input unit 131q.

  Further, as shown in FIG. 6, the central processing unit (CPU) 125 includes a carry-in shield door opening / closing device, a first internal heat insulating door opening / closing device, 1 vacuum gauge, first thermometer, first high vacuum exhaust system, (upper and lower) first heater, first nitrogen gas introduction valve, first pump, first exhaust valve, first internal transfer motor, and first Two internal heat insulating door opening / closing devices (reference numerals are omitted) are connected. The central processing unit (CPU) 125 includes a third internal heat insulating door opening / closing device, a second vacuum gauge, a second thermometer, a medium vacuum exhaust system, which are arranged or connected to the brazing chamber 3. (Upper and lower) Second heater, second nitrogen gas introduction valve, second pump, argon gas introduction valve, second exhaust valve, second internal transfer motor, and fourth internal heat insulation door opening / closing device Is omitted). The central processing unit (CPU) 125 includes a third vacuum gauge, a second high vacuum exhaust system, a third nitrogen gas introduction valve, a fan motor, a third motor, which are arranged or connected to the vacuum cooling chamber 4. The internal transfer motor and the carry-out side shield door opening / closing device (the respective symbols are omitted) are connected. In this embodiment, the central processing unit (CPU) 125 includes a carriage carrying cylinder (not shown) provided on the carry-in carriage 120 and a carriage (not shown) provided on the carry-out carriage 121. A carry-out cylinder is also connected.

  Further, the tray 20, the gas inflow box 21 and the like on which the work to be brazed by the brazing processing apparatus 1 according to the above-described embodiment is placed will be described. Both the tray 20 and the gas inflow box 21 are made of C / C graphite, which is a heat-resistant material. As shown in FIG. 8, the tray 20 includes a main plate portion 20a formed into a rectangular shape, one small plate portion 20b formed at the center of the left end of the main plate portion 20a, and the main plate portion 20a. And the other small plate portion 20c formed at the center of the right end. The main plate portion 20a has the six through holes 20d described above. The through hole 20d is a gas discharge opening constituting the present invention. The one small plate portion 20b and the other small plate portion 20c are respectively formed with rectangular locking holes 20e and 20f. These locking holes 20e and 20f are portions through which fingers are inserted when an operator places the tray 20 on the carry-in side carriage 120 or the carry-out side carriage 121, as described above. This is a portion where the leading end of the truck carry-in cylinder or the truck carry-out cylinder is locked. The gas inflow box 21 is placed on the tray 20 and surrounds a work placed on the tray 20. That is, the gas inflow box 21 includes a front plate 21a and a back plate 21b, a left plate 21c and a right plate 21d, which are formed in a rectangular shape and face each other, and the front plate 21a, the back plate 21b, the left plate 21c, and A frame-shaped inner flange portion 21e protruding inward is formed at the upper end of the right side plate 21d. In addition, when brazing a workpiece using the brazing processing apparatus 1, as described above, in addition to the method of placing each workpiece directly on the tray 20, the workpiece is placed on the tray 20. Work baskets (not shown) made of C / C graphite and having a mounting plate to be mounted may be stacked in a vertical direction and used. This work basket is composed of a rectangular placing plate on which each work is placed, and side plates standing up from four sides of the placing plate, and a plurality of openings are formed in these placing plates and the side plates. It will be. When such a work basket is used, a large number of works can be brazed at a time.

  Hereinafter, the process (brazing method) of brazing a workpiece by the brazing processing apparatus 1 according to the present embodiment described above will be described in detail in the order of each process with reference to the flowcharts shown in FIGS. To do. In these flowcharts, the cart carry-in cylinder and the cart carry-out cylinder, the carry-in shield door opening / closing device, the first and second intermediate shield door opening / closing devices, and the first to fourth internal heat insulation doors described above. The operation timings of the switchgear and the first to fourth internal transfer motors are not included in the flowcharts shown in FIGS. 9 to 12, respectively. In the brazing processing apparatus 1, predetermined processes are simultaneously performed in the vacuum drying chamber 2, the brazing chamber 3, and the vacuum cooling chamber 4, respectively. That is, when a workpiece is carried into the vacuum drying chamber 2 and various processes are performed in the vacuum drying chamber 2, predetermined steps are also performed in the brazing chamber 3 and the vacuum cooling chamber 4, and the workpiece is Sequentially passes through the vacuum drying chamber 2, the brazing chamber 3, and the vacuum cooling chamber 4 and is carried out to the outside.

  First, the process of bringing the workpiece into the vacuum drying chamber 2 will be described. As for the work, an operator places the tray 20 on the carry-in carriage 120 and places a plurality of works to be brazed on the tray 20, and the gas inflow box on the tray 20. 21 is placed, and the work is surrounded by the gas inflow box 21. It should be noted that the workpiece placed on the tray 20 is left in an atmosphere of high humidity, whether or not foreign matter such as oil, powder brazing material, dust or adhesive adhesive remains or remains. Check that each is not a bad thing. And while opening the said carrying-in side shield door 5 by the drive of the said opening side shield door opening / closing apparatus, the 1st internal heat insulation door opening / closing device is opened, the 1st internal heat insulation door 16 is opened, By driving the carry-in cylinder, the tray 20, the gas inflow box 21 and the work (hereinafter simply referred to as work) are carried into the vacuum drying chamber 2, and again the first internal heat insulating door. The first internal heat insulating door 16 is closed by driving the opening / closing device, and the loading-side shield door 5 is closed by driving the opening / closing device for the loading-side shield door. That is, the central processing unit (CPU) 125 serving as a control unit drives the carry-in shield door opening / closing device and the first internal heat insulation door, so that the carry-in shield door 5 and the first internal heat insulation door 16 are driven. Are opened and closed (step St1). As described above, when the carry-in shield door 5 is opened, the first intermediate shield door 8 is closed and the atmospheric pressure in the vacuum drying chamber 2 is set to 5 kPa (described later). Steps St17 to 19). When such step St1 is executed, the pressure in the brazing chamber 3 is also 5 kPa (step St42). In addition, the already cooled work is carried out from the vacuum cooling chamber 4, and the second intermediate shield door 11 and the carry-out side shield door 12 are closed (see Steps St44 and St53, which will be described later). The inside of the cooling chamber 4 is at atmospheric pressure. The processes of the brazing chamber 3 and the vacuum cooling chamber 4 will be described later.

  When step St1 is completed, the central processing unit (CPU) 125 starts driving the first high vacuum exhaust system (step St2), and the gas in the vacuum drying chamber 2 is 1 is discharged from the vacuum exhaust port 26 to the outside. With the start of driving of the first high vacuum evacuation system, the atmospheric pressure in the vacuum drying chamber 2 gradually decreases. Next, whether the atmospheric pressure in the vacuum drying chamber 2 has reached the middle vacuum region (for example, 5 Pa) by the central processing unit (CPU) 125 (the first evacuation step constituting the present invention has been performed). If it is determined that the pressure has reached the atmospheric pressure (step St3), the driving of the first high vacuum evacuation system that has been driven is stopped and the first heater (upper first heater) is stopped. 39 and the lower second heater 40) are turned ON, while the first nitrogen gas introduction valve 35 is opened, the driving of the first pump 54 is started, and the first exhaust valve 55 is opened. (Step St4). That is, by the operation of step St4, high-purity nitrogen gas flows into the vacuum drying chamber 2 from the nitrogen gas discharge nozzle 36 connected to a nitrogen gas supply tank (not shown), and the first pump 54 Since driving is started and the first exhaust valve 55 is opened, the nitrogen gas flowing in from the nitrogen gas discharge nozzle 36 flows downward from above the workpiece toward the workpiece. In step St4, the flow rate of the first nitrogen gas introduction valve 35 and the first exhaust valve 55 or the first pump 54 by the central processing unit (CPU) 125 is controlled from the nitrogen gas discharge nozzle 36, respectively. An amount of gas smaller than the inflow amount of the inflowing nitrogen gas is started to be exhausted by driving the first pump 54. Therefore, the pressure in the vacuum drying chamber 2 which has been set to 5 Pa until then is gradually restored. (First decompression step constituting the present invention).

  In step St5, the central processing unit (CPU) 125 determines whether or not the atmospheric pressure in the vacuum drying chamber 2 gradually restored in step St4 has been restored to a predetermined atmospheric pressure (for example, 15 kPa). When it is determined that the pressure has been restored (for example, to 15 kPa), the first nitrogen gas introduction valve 35 and the first exhaust valve 55 or the first pump 54 by the central processing unit (CPU) 125 are determined. Is maintained at 15 kPa (step St6). While the atmospheric pressure is maintained, the central processing unit (CPU) 125 then causes the temperature in the upstream heat insulation chamber 13 to be set to a predetermined temperature (for example, 100 degrees Celsius) by the first thermometer 45. (Step St7), and if it is determined that the predetermined temperature (100 degrees Celsius) has been reached, the first timer 128a is turned on, and the first thermometer 45 and the above By controlling the temperature of the first heater (the upper first heater 39 and the lower first heater 40), the temperature in the upstream heat insulation chamber 13 is maintained in step St8 (heating step constituting the present invention). While the temperature is maintained, in the upstream heat insulating chamber 13, as described above, high-purity nitrogen gas is continuously flowing into the gas inflow box 21 from above the workpiece and into the tray 20. Since the gas passes through the formed through-holes 20a and continues to be exhausted out of the vacuum drying chamber 2, the oxidative impurities such as oxygen and water adhering to the inside of the upstream heat insulating chamber 13 and the work are removed by the vacuum It is discharged from the drying chamber 2 to the outside. Next, the central processing unit (CPU) 125 determines whether or not a predetermined time has elapsed by the first timer 128a (step St9). If it is determined that the predetermined time has elapsed, the process goes to step St10. Transition. In step St10, the first timer 128a is turned off, the first nitrogen gas introduction valve 35 is closed, the drive of the first pump 54 is stopped, and the first exhaust valve 55 is closed. . Further, the driving of the first high vacuum exhaust system is resumed. Then, the central processing unit (CPU) 125 determines whether or not the pressure in the vacuum drying chamber 2 has reached a high vacuum (for example, 0.01 Pa) by the first vacuum gauge 27 (step St11). If it is determined that the atmospheric pressure has been reached, then, in step St12, the atmospheric pressure is maintained under the control of the first high vacuum evacuation system (the high evacuation step constituting the present invention is executed), and then The first timer 128a is turned on (step St13).

Then, the central processing unit (CPU) 125 determines whether or not a predetermined time has passed by the first timer 128a (step St14), and if it is determined that the predetermined time has passed, step St15. Then, the first timer 128a is turned off, the driving of the first high vacuum exhaust system is stopped, and the process proceeds to Step St16. That is, in step St14, the inside of the vacuum drying chamber 2 is maintained at the high vacuum (for example, 0.01 Pa of atmospheric pressure) for a predetermined time, so that the oxygen content in the surface of the workpiece and the vacuum drying chamber 2 is increased. In addition, oxidizing impurities such as moisture are completely discharged out of the vacuum drying chamber 2 and the work is sufficiently dried. In Step St16, the central processing unit (CPU) 125 opens the first nitrogen gas introduction valve 35, starts driving the first pump 54, and sets the first exhaust valve 55 to Opened. Therefore, in this step St16, the inside of the vacuum drying chamber 2 is again decompressed by the high-purity nitrogen gas (a brazing preparation step constituting the present invention). Next, in step St17, it is determined whether or not the atmospheric pressure in the vacuum drying chamber 2 has reached 5 kPa, and if it is determined that the pressure has been restored to the atmospheric pressure (recompression step constituting the present invention). Then, the process proceeds to step St18. In Step St18, the first nitrogen gas introduction valve 35 is closed, and the driving of the first pump 54 is stopped.
The first exhaust valve 55 is closed, the brazing preparation process in the vacuum drying chamber 2 is completed, and the process proceeds to step St19.

  In this step St19, the second internal heat insulation door 17 and the first intermediate shield door 8 are opened, and the third internal heat insulation door 64 arranged in the brazing chamber 3 is opened. When the first internal transfer motor and the second internal transfer motor are driven, the work dried in the vacuum drying chamber 2 moves into the brazing chamber 3, and the work When the movement is completed, the second internal heat insulating door 17 and the first intermediate shield door 8 are closed, and the third internal heat insulating door 64 disposed in the brazing chamber 3 is also closed. That is, in step St19, the central processing unit (CPU) 125 opens and closes the second internal heat insulation door 17, the first intermediate shield door 8, and the third internal heat insulation door 64, respectively. The workpiece is moved and transported during operation. The first intermediate shield door 8 is opened in order to transport the workpiece from the vacuum drying chamber 2 to the brazing chamber 3, and the atmospheric pressure in the vacuum drying chamber 2 at this time is 5 kPa. (Steps St17 to 19) In addition, the atmospheric pressure in the brazing chamber 3 is set to 5 kPa (see Step St42 described later). On the other hand, the atmospheric pressure in the vacuum cooling chamber 4 is set to atmospheric pressure by the opening / closing operation of the carry-out side shield door 12 accompanying the carrying-out of the workpiece described later. Therefore, prior to step St20 (see FIG. 10) described below, the central processing unit (CPU) 125 controls the second high vacuum evacuation system and the third vacuum gauge, so that the vacuum cooling chamber is controlled. 4 is evacuated to a high vacuum region, and this state is maintained for a predetermined time. Thereafter, nitrogen gas is introduced into the vacuum cooling chamber 4 from the gas introduction pipe 107, whereby the atmospheric pressure in the brazing chamber 3 is increased. When the pressure is restored to 5 kPa, which is the same atmospheric pressure, and it is determined that the pressure has been restored to this atmospheric pressure, the operations after Step St20 described below are performed.

  In step St20, the central processing unit (CPU) 125 opens the fourth internal heat insulating door 65 and the second intermediate shield door 11, respectively, and the brazing chamber 3 and the vacuum cooling chamber 4 communicate with each other. Is done. At this time, the first intermediate shield door 8, the third internal heat insulation door 64, and the carry-out side shield door 12 are all closed. When the fourth inner heat insulating door 65 and the second intermediate shield door 11 are opened, the central processing unit (CPU) 125 then performs the second high vacuum exhaust system and the middle vacuum exhaust. System drive is started (step St21). Therefore, the internal pressure in the brazing chamber 3 and the vacuum cooling chamber 4 gradually decreases. Next, in step St22, the central processing unit (CPU) 125 determines whether or not the internal atmospheric pressure has reached a predetermined high vacuum region (for example, 0.01 kPa). If it is determined that the second timer 128b has been reached, the second timer 128b is turned on (step St23), and then it is determined whether or not a predetermined time has elapsed (step St24). If the central processing unit (CPU) 125 determines in step St24 that the predetermined time has elapsed, then the second timer 128b is turned off, and the fourth internal heat insulating door 65 and the The two intermediate shield doors 11 are closed, and the process proceeds to step St26. In step St26, the control in the brazing chamber 3 is started, and in the vacuum cooling chamber 4, step St43 shown in FIG. 12 is started. In step St26, as shown in FIG. 10, the central processing unit (CPU) 125 stops the driving of the middle vacuum exhaust system, the second nitrogen gas introduction valve 71 is opened, and the second The drive of the pump 94 is started. By opening the second nitrogen gas introduction valve 71 and starting driving the second pump 94, the pressure in the brazing chamber 3 is gradually restored. In step St27, it is determined whether or not the atmospheric pressure in the brazing chamber 3 has reached 5 kPa. If it is determined that it has reached 5 kPa, in step St28, the holding control of the atmospheric pressure is performed. At the same time, the second internal heat insulation door 17, the first intermediate shield door 8, and the third internal heat insulation door 64 are opened and closed. During the opening / closing operation of the second internal heat insulation door 17, the first intermediate shield door 8, and the third internal heat insulation door 64, the first internal conveyance motor and the second internal conveyance motor are respectively driven. The workpiece that has been in the vacuum preparation chamber 2 (upstream heat insulation chamber 13) is transferred to the downstream heat insulation chamber 63.

  And as above-mentioned, if a workpiece | work is conveyed to the brazing chamber 3 (inside the downstream heat insulation chamber 63), next, the drive of the 2nd pump 94 will be stopped by the said central processing unit (CPU) 125. At the same time, the second exhaust valve 95 is closed, while the argon gas introduction valve 75 is opened. As a result, the air pressure in the brazing chamber 3 which has been 5 kPa until then is gradually restored. Then, in step St30, it is determined whether or not the atmospheric pressure in the brazing chamber 3 has reached a predetermined low vacuum region (for example, 30 kPa). If it is determined that the atmospheric pressure has been reached, step St31 is determined. Migrate to In this step St31, the driving of the second pump 94 that has been stopped is restarted, the second exhaust valve 95 is opened, and the nitrogen gas flow meter 72, the argon gas flow meter 74 described above, Is adjusted so that the flow rate ratio of nitrogen gas to argon gas becomes a predetermined ratio. In step St31, the atmospheric pressure of 30 kPa is maintained and the second heater (the upper second heater 79 and the lower second heater 80) is turned on. By the ON operation of the second heater, the temperature in the downstream heat insulation chamber 63 is gradually increased, and in step St32, the central processing unit (CPU) 125 performs a preheating temperature (for example, 400 degrees Celsius to 550 degrees Celsius). When it is determined that the preheat temperature has been reached, the third timer 128c is turned on (step St33). Next, the central processing unit (CPU) determines whether or not a predetermined time has elapsed (step St34). If it is determined that the predetermined time has elapsed, the third timer 128c is determined in step St35. Is turned off and the temperature rise is controlled by increasing the output of the second heater (the upper second heater 79 and the lower second heater 80). Next, in step St36, the central processing unit (CPU) 125 determines whether or not the temperature in the downstream heat insulation chamber 63 has reached the melting temperature (brazing temperature) of the used brazing material. If it is determined through the measurement result of the total 85 and it is determined that the brazing temperature has been reached, then the process proceeds to step St37 where the fourth timer 128d is turned on and the brazing temperature is reached. The holding control is performed (the brazing process step constituting the present invention). That is, the work in the brazing chamber 3 (downstream heat insulating chamber 63) is brazed at the atmospheric pressure in the low vacuum region.

  Next, in step St38, the central processing unit (CPU) 125 turns off the fourth timer 128d and turns off the second heater (the upper second heater 79 and the lower second heater 80). . By the OFF operation of the second heater, the temperature in the brazing chamber 3 (downstream heat insulating chamber 63) gradually decreases and the temperature of the workpiece also decreases. Next, in step St40, the central processing unit (CPU) 125 determines whether or not the temperature in the brazing chamber 3 has decreased to a predetermined temperature, and if it is determined that the temperature has decreased to a predetermined temperature. In step St41, the second nitrogen gas introduction valve 71 and the argon gas introduction valve 75 are closed. Thus, when the second nitrogen gas introduction valve 71 and the argon gas introduction valve 75 are closed, the second pump 94 is still driven and the second exhaust valve 95 is opened. Therefore, the air pressure in the brazing chamber 3 gradually decreases. Next, in step St42, it is determined whether or not the atmospheric pressure in the brazing chamber 3 has reached a predetermined medium vacuum region (for example, 5 kPa), and if it is determined that this predetermined atmospheric pressure has been reached, The operation in the brazing chamber 3 ends.

  Next, the operation of the vacuum cooling chamber 4 will be described with reference to the flowchart shown in FIG. In the vacuum cooling chamber 4, as described above, the second intermediate shield door 11 is closed by the execution of step St25, and the carry-out side shield door 12 is also closed. Since the second high vacuum evacuation system continues to be driven, the pressure in the vacuum cooling chamber 4 is set to a high vacuum region (0.01 Pa). Therefore, in step St43, the central processing unit (CPU) 125 stops the driving of the second high vacuum exhaust system and opens a third nitrogen gas introduction valve (not shown). By opening the third nitrogen gas introduction valve, nitrogen gas flows from the gas introduction pipe 107 into the vacuum cooling chamber 4. Therefore, the atmospheric pressure in the vacuum cooling chamber 4 is gradually restored from the high vacuum region. Next, in step St44, the central processing unit (CPU) 125 causes the atmospheric pressure in the vacuum cooling chamber 4 to be changed to the atmospheric pressure (5 kPa) in the brazing chamber 3 at the time when the brazing process is completed (see step St42). ) Is determined based on the measurement result of the third vacuum gauge. When it is determined that the atmospheric pressure in the vacuum cooling chamber 4 is the same as the atmospheric pressure (5 kPa) in the brazing chamber 3, the central processing unit (CPU) 125 performs the third nitrogen gas. The introduction valve is closed and the holding control of the atmospheric pressure (5 kPa) is performed (step St45). When such control is performed, the fourth internal heat insulating door 65 and the second intermediate shield door 11 are then opened and closed (step St46), and the workpiece in the brazing chamber 3 is moved during the opening and closing operation. It is transferred into the vacuum cooling chamber 4. That is, first, each opening is opened by driving both the fourth internal heat insulating door 65 and the second intermediate shield door 11, and the second internal transfer motor disposed in the brazing chamber 3. And the third internal transfer motor disposed in the vacuum cooling chamber 4 are respectively driven, and the work in the brazing chamber 3 is transferred into the vacuum cooling chamber 4, then, the second internal transfer motor The driving of the motor and the third internal transfer motor disposed in the vacuum cooling chamber 4 is stopped, and the opening of the fourth internal heat insulating door 65 is closed by the driving of the fourth internal heat insulating door opening / closing device, The opening of the second intermediate shield door 11 is closed by driving the second intermediate shield door opening / closing device.

  Then, when the work is transferred into the vacuum cooling chamber 4 through the above-described steps, in step St47, the third nitrogen gas introduction valve is opened again by the central processing unit (CPU) 125, High purity nitrogen gas is introduced into the vacuum cooling chamber 4 from the gas introduction pipe 107. Next, the central processing unit (CPU) 125 determines whether or not the atmospheric pressure in the vacuum cooling chamber 4 has reached a predetermined atmospheric pressure (for example, 68 kPa) (step St48), and has reached the predetermined atmospheric pressure. If it is determined, the process proceeds to step St49. In step St49, the third nitrogen gas introduction valve is closed, the drive of the fan motor 111 is started, and the fifth timer 128e is turned on. By driving the fan motor 111, the nitrogen gas introduced inside is diffused in the vacuum cooling chamber 4 and comes into contact with the workpiece, and the diffused nitrogen gas comes into contact with the heat exchanger 112 and is cooled. Is done. By such an action, the work is gradually cooled within a set time (cooling time) by the fifth timer 128e. Next, in step St50, when the central processing unit (CPU) 125 determines that a predetermined time has elapsed by the fifth timer 128e, the fifth timer 128e is turned off and the fan motor 110 is turned off. Is stopped (step St51), and then, in step St52, the third nitrogen gas introduction valve is opened (step St52). By opening the third nitrogen gas introduction valve, the air pressure in the vacuum cooling chamber 4 gradually increases, and in step St53, it is determined whether or not the air pressure in the vacuum cooling chamber 4 has reached atmospheric pressure. When the central processing unit (CPU) 125 determines that the atmospheric pressure in the vacuum cooling chamber 4 has reached atmospheric pressure, the third nitrogen gas introduction valve is closed (step St54), and then The carry-out side shield door 12 is opened and closed (step St55). That is, the carry-out shield door 12 is opened by driving the carry-out shield door opening / closing device, and the work is moved downstream (outside the vacuum cooling chamber 4) by driving the third internal transfer motor. Be transported. At this time, the central processing unit (CPU) 125 also starts to drive a cart carry-out cylinder provided in the carry-out cart 121, and drives the third internal transfer motor and the cart carry-out. By driving with the cylinder, the work in the vacuum cooling chamber 4 is carried out onto the carrying-out side carriage 121 while being cooled to a predetermined temperature. When the unloading of the workpiece is completed, the unloading shield door 12 that has been released is closed by the unloading shield door opening / closing device.

  In the above-described process, the vacuum drying chamber 2 is once evacuated to a medium vacuum region (for example, 5 Pa) (step St3), and then returned to a predetermined atmospheric pressure (for example, 15 kPa) (step St5). Although the temperature in the upstream heat insulation chamber 13 has been raised to a predetermined temperature (for example, 100 degrees Celsius) (step St7), in the present invention, the vacuum drying chamber 2 is evacuated to the middle vacuum region in this way, Without returning the pressure to the atmospheric pressure, the workpiece is heated in advance to a predetermined temperature (for example, around 80 degrees Celsius) outside the brazing treatment apparatus 1, and the heated workpiece is carried into the vacuum drying chamber 2. (The heating / carrying-in process constituting the present invention is executed), and then step St10 and subsequent steps may be executed. In this case, step St10 starts driving only the first high vacuum evacuation system, and the first timer OFF operation and the like are not performed. Then, outside the brazing processing apparatus 1 as described above, the work is heated to a predetermined temperature in advance, and the heated work is carried into the vacuum drying chamber 2 (the heating and carrying-in process constituting the present invention is executed). In addition, even when the pressure in the vacuum drying chamber 2 is evacuated to a high vacuum region and then the respective steps described above are performed and brazed, The same effect can be realized.

  The present inventors conducted a gap filling test by the method described above. This gap filling test is a method standardized as LWS T8801 of the Light Metal Welding Structure Association. As shown in FIG. 13, the inventors have a rectangular base base material (horizontal material) formed into 75 mm × 50 mm. A stainless steel spacer S having a diameter of 2 mm at a position 5 mm from the right end of FIG. Is set between the upper surface of the base base material P and the lower surface of the brazing sheet B, and the brazing sheet B is separated from the base base material P and the brazing sheet B by two fixing thin wires (not shown). By maintaining the standing state of the sheet B, the brazing method described above is carried out to form the brazing sheet B Was measured for the length filled in the gap (gap filling length). The base base material P is one base material constituting the present invention, and the brazing sheet B is the other base material and brazing material constituting the present invention. In this gap filling test, the base base material P was classified into two types, “1050” and “3003” based on JIS standards (planning of aluminum brazing material: JIS H 4000-1999). The brazing sheet used was “BAS-231” based on the JIS standard. In the brazing condition in the gap filling test, the brazing temperature (corresponding to Step St36 described above) is 595 degrees Celsius, and the brazing temperature is maintained (corresponding to Steps St37 to 39 described above). The time was 3 minutes. Then, under the brazing conditions, the pressure (atmospheric pressure) in the low vacuum region (as pressure corresponding to step St30) was set to four types of conditions of 68 kPa, 51 kPa, 22 kPa, and 3 kPa. Further, as the high purity inert gas constituting the present invention, the ratio of the flow rates of argon gas (corresponding to step St31) and nitrogen gas (corresponding to step St26) is 1: 0, 4: 5, 1 respectively. : 2 respectively, and the above gap filling test was conducted.

  FIG. 14 is an experimental result table describing the gap filling length based on the gap filling test. As is clear from this experimental result table, in the above experiment, the good gap filling length (fluidity of the brazing material) becomes better as the flow rate ratio of the argon gas to the flow rate of the nitrogen gas becomes higher. Was confirmed. For example, when the ratio of the respective flow rates of argon gas and nitrogen gas is 1: 2, the pressure in the brazing chamber 3 is 68 kPa, 51 Pa, 3 kPa, In each case, the gap filling length was less than 35 m. On the contrary, when the flow rate ratio of argon gas to the flow rate of nitrogen gas is increased, each of the above pressures is generally good, and only argon gas is used without using nitrogen gas. When brazing was carried out while flowing, an extremely good gap length (fluidity of brazing material) could be obtained.

  Furthermore, the present inventors used the aluminum alloy “A7075” based on the JIS standard (planning of aluminum brazing material: JIS H 4000-1999) as a sample, and heat treatment similar to the brazing method described above (see step St36 above). ) For a predetermined time (see steps St37 to 39), and the atmospheric pressure (see step St30) in the brazing chamber 3 when the heat treatment is performed is 8 kPa, 22 kPa, 30 kPa, 36 kPa, 51 kPa, and 68 kPa. The total was changed to six types, and the Mg component and Zn component contained in each sample were measured. The heating temperature was the same as the brazing temperature, and the heating time was 3 minutes. In addition, the concentration distribution measurement by EPMA of the Mg component and the Zn component contained in each of the above samples is within a range of a depth of 150 μm from the sample surface to a width of 200 μm and a depth of 1,000 μm from the sample surface. In the range of 900 μm in width and in the two ranges.

  FIG. 15 is an experimental result table showing residual amounts of Mg and Zn. Note that “component%” shown in FIG. 15 is an average value of the concentrations of Mg and Zn within the above measurement ranges. As is clear from this experimental result table, according to the brazing method, although the processing pressure is in the range of 8 kPa to 68 kPa, the residual amount of Mg and Zn is generally good by heating in a low vacuum region. Met. In particular, when the processing pressure is in the range of 22 kPa to 68 kPa, the residual amounts of Mg and Zn are found to be even better, and the mechanical strength and corrosion resistance of the workpiece can be improved. confirmed.

As is clear from the description of the above examples, according to the aluminum material brazing method and the aluminum material brazing processing apparatus 1 according to the above-described embodiment, a workpiece (above) is predetermined. Even when the heating step of heating to a temperature is performed in the vacuum drying chamber 2 or outside the vacuum drying chamber 2, the brazing preparation step performed in the vacuum drying chamber 2 Workpieces in the vacuum drying chamber 2 and oxidation promoting components such as oxygen and moisture present in the vacuum drying chamber 2 are almost completely discharged out of the vacuum drying chamber, and in the brazing treatment process, In the active gas atmosphere, the temperature of the brazing chamber is raised to the melting temperature of the brazing material in the low vacuum region, so that the oxide film (Al ₂ O ₃ ) formed on the surface of the workpiece is Mg in brazing material When it is contained, it reacts with this Mg to become Mg oxide (MgO) and peels off from the surface of the workpiece. Therefore, the fluidity of the brazing material is promoted compared to the conventional invention, and the oxide film (Al ₂ O ₃ ) is directly attached to each base material without any intervening, and the brazing treatment step is performed in a low vacuum region as is apparent from the description of the above embodiment. In addition, the amount of Mg and Zn contained in the workpiece and brazing material can be reduced, the strength and corrosion resistance of the base material can be maintained, and the mechanical strength of the workpiece can be sufficiently satisfied. it can.

  In particular, as described above, the brazing treatment process performed in the brazing chamber 3 (downstream heat insulating chamber 63) is, for example, at a low vacuum region pressure of 30 kPa or the like (3 kPa to 68 kPa in the embodiment). As a result, the strength and corrosion resistance of the base metal can be maintained by suppressing the evaporation of Mg and Zn contained in the base material and the brazing material, which are workpieces. It becomes possible to raise. In the brazing method for an aluminum material, as described above, after the primary evacuation process is performed in step St3, the high-purity inert gas is allowed to flow into the vacuum drying chamber 2 in step St4. A primary decompression pressure for restoring the pressure in the vacuum drying chamber 2 within the range of the low vacuum region (for example, 15 kPa: see steps St5 and 6) by exhausting the gas in the vacuum drying chamber 2 to the outside. While the process is executed, in the heating process (steps St7, St8), the vacuum drying chamber 2 has a predetermined temperature (for example, 150 degrees Celsius or higher above the temperature at which the work or moisture in the vacuum drying chamber evaporates). Since it is heated to 100 degrees Celsius), the fluidity of the brazing material can be further enhanced.

  Further, the workpiece to be brazed is placed on the tray 20 shown in FIG. 8 and is surrounded by the gas inflow box 21. In the brazing process, the workpiece is placed above the gas inflow box 21. The high-purity inert gas is dispersed toward the gas inflow box 21 to flow uniformly into the gas inflow box 21, and a plurality of gas discharge openings formed in the tray 20. Since the gas in the brazing chamber 3 is exhausted to the outside from the lower side of the through hole 20d, the high purity inert gas is not diffused in the entire brazing chamber 3, and the gas inflow surrounding the workpiece It is possible to maintain a high purity state in the box 21 and to suppress the flow rate of the high purity inert gas to be used. It is possible to reduce the door. In addition, according to the brazing method of the aluminum material (and the brazing treatment apparatus 1) according to the above-described embodiment, oxidation promoting components such as oxygen content and moisture in the vacuum drying chamber 2 or the brazing chamber 3 are Since it can be effectively discharged outside without diffusing inside the vacuum drying chamber 2 or the brazing chamber 3, the fluidity of the brazing material can be further improved, It becomes possible to join workpieces to each other.

  Furthermore, according to the brazing method for an aluminum material (and the brazing treatment apparatus 1) according to the above-described embodiment, the height of the gas flowing in from the upper side of the gas inflow box 21 toward the gas inflow box 21 is increased. The purity inert gas is argon gas, and the brazing process is performed in an atmosphere in which the argon gas occupies most of the gas inflow box 21. Therefore, the fluidity of the brazing material can be further improved. In particular, in the brazing method and the brazing processing apparatus 1, argon as a high-purity inert gas that flows into the gas inflow box 21 from above the gas inflow box 21 in the brazing processing step. Gas is allowed to flow in and nitrogen gas is allowed to flow into the brazing chamber 3. Since the flow rate ratio of the nitrogen gas and the argon gas is high, the flowability of the brazing material is further increased. It becomes possible.

  In the aluminum material brazing method and the aluminum material brazing processing apparatus 1 according to the above-described embodiment, a workpiece is placed on the tray 20 in which a plurality of through holes 20d are formed, and the workpiece is allowed to flow into the gas. Although what was brazed in the state enclosed by the box 21 was demonstrated, in this invention, without using the said tray 20, the bottom plate part in which the said through-hole was formed was provided and the upper part was open | released and the gas which is not illustrated An inflow box may be used. In addition to the method of placing or placing the workpiece directly on the tray 20 or the bottom plate portion, the method of brazing by placing the workpiece on a basket (not shown) formed with a plurality of openings. Further, the above brazing method may be carried out by stacking such baskets in a plurality of stages. In this way, the baskets are stacked in a plurality of stages, and the workpieces are placed on the baskets, and the above-described method of brazing the aluminum material is performed, so that a large number of workpieces are brazed at once. can do.

1 Brazing processing equipment
2 Vacuum drying chamber 3 Brazing chamber 7, 9 Partition plate 8 First intermediate shield door 27 First vacuum gauge 35 First nitrogen gas introduction valve 39 Upper first heater 40 Lower first heater 45 First thermometer 54 First Pump 55 First exhaust valve 69 Second vacuum gauge 71 Second nitrogen gas introduction valve 72 Nitrogen gas flow meter 74 Argon gas flow meter 75 Argon gas introduction valve 79 Upper second heater 80 Lower second heater 85 Second thermometer 94 First 2 pump 95 2nd exhaust valve 125 Central processing unit (CPU)
B Brazing sheet P Base base material

Claims (12)

A brazing method for an aluminum material that is performed in a brazing processing apparatus, wherein one base material made of an aluminum alloy containing at least one of Mg and Zn, and the other base material, use a flux. Without being made, an aluminum material joined together by a brazing material containing at least one of Mg and Zn (hereinafter, the one base material and the combination of the other base material and the brazing material are called workpieces). .) Brazing method,
The brazing processing apparatus includes a vacuum drying chamber and a brazing chamber that are communicated with each other via an opening that is opened and closed by a shield door.
A heating / carrying-in process in which the workpiece is heated in advance to a predetermined temperature and carried into a vacuum drying chamber;
After the heating / carrying-in process, a high vacuuming process for evacuating the vacuum drying chamber to a high vacuum region;
A return pressure step for returning the pressure in the vacuum drying chamber to a low vacuum region while allowing a high purity inert gas having a purity of 99.999% or more to flow into the vacuum drying chamber after the high vacuuming step;
A vacuum drying process comprising:
During the vacuum drying step, the atmospheric pressure in the brazing chamber is evacuated to a medium vacuum region, and then the gas in the brazing chamber is exhausted while flowing the high-purity inert gas into the brazing chamber. A brazing chamber preparation step of restoring the pressure in the brazing chamber within a low vacuum region;
After the decompression step in the vacuum drying chamber and the brazing chamber preparation step, the workpiece is transferred into the brazing chamber during opening and closing of the shield door,
While the high purity inert gas is allowed to flow into the brazing chamber and the gas in the brazing chamber is exhausted, the temperature of the brazing chamber is melted in the brazing chamber in a predetermined low vacuum region. A brazing method for an aluminum material, comprising: a brazing process step of brazing the workpiece by raising the temperature to a temperature.   Instead of the heating / carrying-in step, the heating step of carrying the workpiece into the vacuum-drying chamber and heating it to a predetermined temperature in the vacuum-drying chamber is performed before the high vacuuming step. The method for brazing an aluminum material according to claim 1.   The method for brazing an aluminum material according to claim 1 or 2, wherein the predetermined low vacuum region in the brazing treatment step is an atmospheric pressure within a range of 3 kPa to 68 kPa. In the previous step of performing the heating step,
A first evacuation step of evacuating the air pressure in the vacuum drying chamber to a medium vacuum region;
After the first evacuation step, the gas in the vacuum drying chamber is exhausted to the outside while the high-purity inert gas is allowed to flow into the vacuum drying chamber, thereby reducing the pressure in the vacuum drying chamber within the range of the low vacuum region. A first decompression step for restoring pressure in the interior, and
3. The aluminum material according to claim 2, wherein in the heating step, the vacuum drying chamber is heated to a predetermined temperature not lower than a temperature at which the work or moisture in the vacuum drying chamber evaporates and not higher than 150 degrees Celsius. Brazing method. The workpiece is formed in a gas inflow box formed of a heat-resistant material and opened at the top and a plurality of gas discharge openings are formed in the bottom plate, or the workpiece is used for the plurality of gas discharges. It is placed on a tray in which an opening is formed and surrounded by a gas inflow box with a side plate that is open at the top,
In the brazing treatment step, the high-purity inert gas is dispersed from above the gas inflow box into the gas inflow box and uniformly flows into the gas inflow box, and the bottom plate of the gas inflow box 5. The brazing of an aluminum material according to claim 1, wherein the gas in the brazing chamber is exhausted to the outside from the lower side of the plurality of gas discharge openings formed in the tray. Method. In the vacuum drying step, the high purity inert gas flowing into the vacuum drying chamber is nitrogen gas,
6. The brazing of an aluminum material according to claim 5, wherein in the brazing treatment step, the high-purity inert gas that flows into the gas inflow box from above the gas inflow box is argon gas. Method.   In the brazing treatment step, argon gas as a high purity inert gas that flows into the gas inflow box from above the gas inflow box is caused to flow, and the high purity inert gas is introduced into the brazing chamber. 7. The method of brazing an aluminum material according to claim 6, wherein nitrogen gas as a gas is introduced, and the flow rate ratio of the nitrogen gas and the argon gas is 5: 4 or higher. A processing apparatus for brazing an aluminum material used for carrying out the brazing method of an aluminum material according to the invention of claim 1,
A vacuum drying chamber and a brazing chamber that communicate with each other through an opening that is opened and closed by a shield door in between,
In the vacuum drying chamber,
High vacuuming means for evacuating the vacuum drying chamber to a high vacuum region, first pressure detecting means for detecting the pressure in the vacuum drying chamber, and high purity of 99.999% or more connected to the vacuum drying chamber A first gas introduction pipe for introducing a pure inert gas into the vacuum drying chamber, and a first gas introduction valve arranged in the middle of the first gas introduction pipe,
In the brazing room,
Medium vacuuming means for evacuating the brazing chamber to a medium vacuum region, second pressure detecting means for detecting the pressure in the brazing chamber, and the high purity inert gas connected to the brazing chamber A second gas introduction pipe to be introduced into the brazing chamber; a second gas introduction valve disposed in the middle of the second gas introduction pipe; a heating means for heating the temperature in the brazing chamber; A temperature detecting means for detecting the temperature and a gas discharging means for discharging the gas in the brazing chamber are arranged, respectively.
The high evacuation means, the first pressure detection means, the first gas introduction valve, the medium evacuation means, the second pressure detection means, the heating means, the temperature detection means and the gas discharge means are each connected to a control means. ,
After evacuating the vacuum drying chamber to a high vacuum region by controlling the high vacuuming means and the first pressure detecting means by the control means,
By controlling the first gas introduction valve and the gas discharge means, the atmospheric pressure in the vacuum drying chamber is restored to the low vacuum region while flowing a high purity inert gas having a purity of 99.999% or more into the vacuum drying chamber. As well as
The high purity inert gas is caused to flow into the brazing chamber and the brazing chamber by the control of the second gas introduction valve, the gas discharge unit, the second pressure detection unit, the heating unit, and the temperature detection unit by the control unit. And brazing the workpiece by raising the temperature of the brazing chamber to a melting temperature of the brazing material in a predetermined low vacuum region while exhausting the gas. Aluminum brazing equipment. A processing apparatus for brazing an aluminum material used for carrying out the brazing method of an aluminum material according to the invention of claim 2,
A vacuum drying chamber and a brazing chamber that communicate with each other through an opening that is opened and closed by a shield door in between,
In the vacuum drying chamber,
A first heating means for heating the vacuum drying chamber; a first temperature detecting means for detecting a temperature in the vacuum drying chamber; a high vacuum pulling means for evacuating the vacuum drying chamber to a high vacuum region; A first pressure detecting means for detecting a pressure in the vacuum drying chamber; a first gas introduction pipe connected to the vacuum drying chamber for introducing a high purity inert gas having a purity of 99.999% or more into the vacuum drying chamber; A first gas introduction valve arranged in the middle of the first gas introduction pipe, and a first gas discharge means for discharging the gas in the vacuum drying chamber, are respectively arranged;
In the brazing room,
Medium vacuuming means for evacuating the brazing chamber to a medium vacuum region, second pressure detecting means for detecting the pressure in the brazing chamber, and the high purity inert gas connected to the brazing chamber A second gas introduction pipe to be introduced into the brazing chamber; a second gas introduction valve disposed in the middle of the second gas introduction pipe; a second heating means for heating the temperature in the brazing chamber; A second temperature detecting means for detecting the temperature in the brazing chamber, and a second gas discharging means for discharging the gas in the brazing chamber, respectively,
The first heating means, the first temperature detection means, the high vacuum suction means, the first pressure detection means, the first gas introduction valve, the first gas discharge means, the medium vacuum suction means, the second pressure detection means, the second The heating means, the second temperature detection means and the second gas discharge means are respectively connected to the control means,
The vacuum drying chamber is heated to a predetermined temperature by the control of the first heating means and the first temperature detection means by the control means, and then the control of the high vacuum suction means and the first pressure detection means. After evacuating the vacuum drying chamber to a high vacuum region,
By controlling the first gas introduction valve, the first gas discharge means, and the first pressure detection means, a high purity inert gas having a purity of 99.999% or more is allowed to flow into the vacuum drying chamber, and While returning the atmospheric pressure to the low vacuum range,
By the control of the second gas introduction valve, the second gas discharge means, the second pressure detection means, the second heating means and the second temperature detection means by the control means, the high purity inert gas is introduced into the brazing chamber. The brazing chamber is heated to the melting temperature of the brazing material in a predetermined low vacuum region while the brazing chamber is exhausted and the gas in the brazing chamber is exhausted. A brazing apparatus for aluminum material, characterized by performing brazing. In the vacuum drying chamber, a first gas discharge nozzle that disperses and discharges the high-purity inert gas from above the work carried into the vacuum drying chamber and is connected to the first gas introduction pipe is disposed. And the first gas discharge means comprises a first exhaust pipe for discharging the gas in the vacuum drying chamber from below the workpiece,
Disposed in the brazing chamber is a second gas discharge nozzle that disperses and discharges the high-purity inert gas from above the work carried into the brazing chamber and is connected to the second gas introduction pipe. 10. The aluminum material according to claim 8, wherein the second gas discharge means includes a second exhaust pipe for discharging the gas in the brazing chamber from below the work. Brazing processing equipment.   The high purity inert gas discharged from the first gas discharge nozzle is nitrogen gas, and the high purity inert gas discharged from the second gas discharge nozzle is argon gas. The brazing apparatus for aluminum material according to claim 10. In the brazing chamber, an argon gas flowmeter that measures the flow rate of the argon gas discharged from the second gas discharge nozzle and is connected to the control means;
A nitrogen gas introduction pipe for flowing nitrogen gas into the brazing chamber, a nitrogen gas introduction valve disposed in the middle of the nitrogen gas introduction pipe and connected to the control means and controlled by the control means, and the nitrogen A nitrogen gas flow meter for measuring the gas flow rate,
The flow rate ratio between the nitrogen gas flowing into the brazing chamber from the nitrogen gas introduction pipe and the argon gas discharged from the second gas discharge nozzle is higher than 5: 4. The aluminum material brazing apparatus according to claim 11.