JP6063316B2 - Brazing equipment - Google Patents

Description

The present invention relates to a brazing apparatus for brazing an aluminum member constituting a workpiece.

  Conventionally, heat exchangers used in, for example, vehicles and cooling devices are composed of aluminum header parts and tube parts, but in this type of heat exchangers in recent years due to demands for energy saving and higher efficiency. However, the trend of weight reduction and thinning is remarkable. In addition, when brazing such a heat exchanger (work), a high-speed brazing method has been developed by forcibly convection of a high-temperature inert gas into a brazing chamber (for example, Patent Documents). 1).

  FIG. 23 shows a structure of a brazing chamber 100 of such a conventional brazing furnace, and FIG. 25 shows a front view of a general heat exchanger (work) W brazed by the conventional brazing furnace. Yes. The heat exchanger W as a work to be brazed is composed of aluminum header parts 1 and 1 at both ends and a tube part 2 formed between them. The tube portion 2 is composed of a plurality of aluminum microtubes 3 brazed in parallel between the header portions 1 and 1, and aluminum fins 4 brazed between the microtubes 3. Yes.

  In FIG. 25, the heat exchanger W as a work is generally thinner and lighter than the conventional product, but the header portion 1 is more than the microtube 3 and the fins 4 constituting the tube portion 2. Has a large thickness and a large heat capacity. Therefore, when similarly heated, the temperature of the header part 1 is difficult to rise, the rate of temperature rise is slow, the temperature of the tube part 2 is likely to rise, and the rate of temperature rise is fast.

  Next, an electric heater 101 and an in-furnace fan 102 are provided in the brazing chamber 100 of FIG. 23, and nitrogen gas (inert gas) heated to a high temperature by the electric heater 101 is in-furnace fan 102. Therefore, forced convection is performed in the brazing chamber 100. At this time, a hood 103 is provided below the in-furnace fan 102, the lower end of the hood 103 is opened above the conveying means 104 (roller or mesh belt), and the upper end is directly below the in-furnace fan 102. It is set as the structure opened by.

  As a result, the high-temperature nitrogen gas is once blown up by the in-furnace fan 102, hits the upper surface of the brazing chamber 100, goes outward, descends the outside of the hood 103, hits the bottom and goes inward again, and then rises Then, it passes through the tray 106 on which the conveying means 104 and the heat exchanger W are placed, and is blown onto the heat exchanger W from below. Then, after passing through the heat exchanger W, the inside of the hood 103 was further raised and sucked into the furnace fan 102 again (forced convection indicated by arrows in FIG. 23).

  FIG. 24 shows the temperature transition of each part of the heat exchanger W that is brazed in the conventional brazing chamber 100. In the figure, the broken line indicates the ideal temperature transition, the alternate long and short dash line indicates the temperature transition of the part where the heating rate is fast (the tube part 2), and the solid line shows the temperature transition of the part where the heating rate is slow (the header part 1). Yes. The front chamber is a chamber that replaces the atmosphere with nitrogen gas at the front stage of the brazing chamber 100, and the cooling chamber and the rear chamber are chambers that gradually cool the heat exchanger W after being heated in the brazing chamber 100. It is.

  As described above, when the heat exchanger W is brazed, the temperature of the header portion 1 having a large heat capacity is difficult to increase, and the temperature of the tube portion 2 having a small heat capacity is likely to increase. Therefore, when the heat exchanger (work) W in the brazing chamber 100 is heated, the rate of temperature rise of the header section 1 is slow (solid line) as shown in FIG. The temperature is lowered, the temperature raising rate of the tube portion 2 is fast (dashed line), and is higher than the ideal temperature transition (dashed line).

  As described above, since the heating rate of the header portion 1 and the tube portion 2 is different, the heat capacity is small in the method in which high-temperature nitrogen gas is forced to convection in the brazing chamber 100 as in a conventional brazing furnace. The tube portion 2 is heated first, and the temperature rise of the header portion 1 having a large heat capacity is delayed. Therefore, the header part 1 and the tube part 2 cannot be heated uniformly, and deformation or generation of excessive corrosion allowance occurs in the excessively heated place P1 (tube part 2 shown in FIG. 25). On the contrary, in the place P2 where the heating is insufficient (header portion 1 shown in FIG. 25), defective brazing or insufficient generation of corrosion allowance occurs.

  In particular, in the case of the heat exchanger W having a reduced thickness, an excessive amount of decay is generated when the temperature increase rate of the tube portion 2 is increased. Further, if the heating temperature and time are limited in order to prevent this, a sufficient amount of corrosion is not generated in the header portion 1 and the corrosion resistance is deteriorated. For this reason, brazing of this kind of heat exchanger W requires higher speed heating and uniform temperature rise than before.

  Therefore, when the temperature of the tube part 2 rises to a predetermined value, a method of placing a cover thereon to increase the heat capacity and suppressing the temperature rise of the tube part 2 to match the temperature rise rate of the header part 1 has been developed. (For example, refer to Patent Document 2). In addition to the forced convection of high-temperature gas, brazing involves irradiating the entire workpiece with near infrared rays (see, for example, Patent Document 3 and Patent Document 4).

Japanese Patent No. 4592645 JP 2010-196931 A JP 2004-358484 A JP 2004-35883 A

  However, as described in Patent Document 2, a method in which a cover having a large heat capacity is brought into contact with the tube portion 2 having a high temperature increase rate to delay the temperature increase and the temperature increase is matched with the header portion 1 having a low temperature increase rate is a high speed. It would be against brazing. Further, as in Patent Documents 3 and 4, if the entire heat exchanger (workpiece) W is heated with near infrared rays, brazing at an extremely high speed is possible. However, since the infrared irradiation area is very narrow, In order to achieve a uniform temperature increase of the tube portion 2, a large number of near infrared irradiation devices must be arranged at a high density, resulting in poor cost feasibility.

The present invention has been made in order to solve the conventional technical problem, and can braze at a high temperature by using a simple configuration to achieve uniform temperature rise in each part of the workpiece and realize high-speed brazing. A device is provided.

The brazing apparatus according to the first aspect of the present invention heats and brazes an aluminum member constituting a workpiece in the brazing chamber by causing convection of a high-temperature inert gas into the brazing chamber. by controlling the flow of hot inert gas convection in the chamber, provided with air distribution means for blowing preferentially the hot inert gas into the site heating rate is slow work, the air distribution means, a plurality of vent The wind direction plate has a louver adjacent to the ventilation portion, and the flow of the high temperature inert gas is controlled by the angle and / or shape of the louver .

  In the brazing device according to the second aspect of the present invention, in the above invention, the air distribution means is configured such that the temperature of the workpiece heated in the brazing chamber is at least + 450 ° C. and less than + 500 ° C. The temperature difference of a part with a high speed is within 20 deg, and the temperature difference between a part with a slow temperature rise rate and a part with a fast temperature rise rate is within 10 deg when the temperature of the workpiece is + 500 ° C. or more.

  The brazing device according to a third aspect of the present invention is characterized in that, in the above invention, the work is a heat exchanger comprising a header portion and a tube portion, and the air distribution means preferentially blows a high-temperature inert gas onto the header portion. And

According to a fourth aspect of the present invention, there is provided a brazing apparatus according to each of the above-mentioned inventions , comprising air-permeable conveying means for conveying a work in the brazing chamber, and a tray that holds the work and is placed on the conveying means. While the active gas is sprayed onto the work from below, a wind direction plate is constituted by the tray.

A brazing device according to a fifth aspect of the present invention is the brazing apparatus according to any of the first to third aspects, further comprising air-permeable conveying means for conveying the work in the brazing chamber, and spraying high-temperature inert gas onto the work from below. A wind direction plate is disposed below the conveying means.

A brazing device according to a sixth aspect of the present invention is characterized in that in each of the above-mentioned inventions , there is provided an auxiliary heating means for heating a portion where the rate of temperature rise of the workpiece is slow.

According to a seventh aspect of the present invention, there is provided a brazing apparatus according to the above invention, wherein the auxiliary heating means heats a portion where the temperature rise rate of the workpiece is low by irradiating near infrared rays.

The brazing apparatus according to an eighth aspect of the present invention includes the front chamber located in the front stage of the heating furnace in the sixth or seventh aspect of the present invention to replace the atmosphere with an inert gas, and provided with auxiliary heating means in the front chamber. It is characterized by that .

According to the present invention, a high-temperature inert gas that convects in the brazing chamber when the aluminum member constituting the workpiece is heated and brazed by convection of the high-temperature inert gas in the brazing chamber. Since the high-temperature inert gas is preferentially blown to the part where the workpiece heating rate is slow, the flow of the workpiece is controlled by the air distribution means. By combining the temperature increase with the temperature increase at the part where the temperature increase rate is slow, it becomes possible to uniformly increase the temperature of the entire workpiece during brazing, and comprises a header portion and a tube portion as in the invention of claim 3. It is possible to avoid the occurrence of excessive corrosion allowance and a decrease in corrosion resistance when brazing the heat exchanger.

  In particular, it does not match the part where the temperature rise rate is fast with the temperature rise of the part where the temperature rise rate is slow as in the conventional case, and the temperature rise of the part is preferentially blown to the part where the temperature rise rate is slow. Because it promotes, it can meet the demand for higher speed. Another advantage of the present invention is that it can be realized with a relatively simple configuration of adding air distribution means.

Further, the air distribution means is composed of a wind direction plate in which a plurality of ventilation portions are formed, and a louver adjacent to the ventilation portion of the wind direction plate is provided. Depending on the angle and / or shape of the louver, the high temperature inert gas Since the flow is controlled, the structure can be further simplified, and the flow of the high-temperature inert gas in the brazing chamber can be more accurately controlled.

In particular, when the temperature of the workpiece heated in the brazing chamber is at least + 450 ° C. or more and less than + 500 ° C. by the air distribution means as in the invention of claim 2, the temperature rising rate is low and the temperature rising rate is high. When the temperature difference is within 20 deg and the workpiece temperature is in the range of + 500 ° C. or more, the temperature difference between the part where the heating rate is slow and the part where the heating rate is fast is within 10 deg. And good brazing can be realized.

Furthermore, as in the invention of claim 4 , there is provided a breathable transfer means for transferring the work in the brazing chamber, and a tray for holding the work and being placed on the transfer means, and supplying the hot inert gas from below to the work. If the wind direction plate is configured with a tray, the number of parts can be further reduced, and the flow of high-temperature inert gas can be controlled in accordance with each workpiece transferred by the transfer means. As a result, the temperature rise of the workpiece can be made more accurate and uniform.

In this case, as in the fifth aspect of the invention, there is provided air-permeable conveying means for conveying the work in the brazing chamber, and when high-temperature inert gas is blown onto the work from below, a wind direction plate is disposed below the conveying means. May be.

Furthermore, if an auxiliary heating means for heating a part where the temperature rise rate of the workpiece is slow as in the invention of claim 6 is provided, in addition to the flow control of the high temperature inert gas by the air distribution means, the temperature rise rate by the auxiliary heating means. Therefore, it is possible to further promote the temperature rise in the part where S is slow.

In this case, as in the inventions of claim 7 and claim 8 , the near-infrared rays are irradiated by the auxiliary heating means to heat the portion where the workpiece heating rate is low, and further, the atmosphere is not located in the front stage of the heating furnace. In the front chamber that replaces the active gas, before heating in the brazing chamber, if the near-infrared ray is irradiated and heated by the auxiliary heating means to the part where the workpiece heating rate is slow, the heating rate is slow. The temperature of the part can be more accurately promoted, and the temperature of the part where the rate of temperature rise is low in the previous step in the front chamber can be increased in advance, so that it is possible to further increase the speed. . In this case, since the temperature rise by the auxiliary heating means in the front chamber is still low, the adverse effect of oxygen can be ignored even in the front chamber in which the atmosphere is replaced with an inert gas.

It is a figure which shows the whole structure of the brazing apparatus of one Example to which this invention is applied. It is a front view of the heat exchanger as a workpiece | work brazed with the brazing apparatus of FIG. (Example 1) which is the perspective view of the workpiece | work hold | maintained on the tray of the brazing apparatus of FIG. FIG. 4 is a plan view of FIG. 3. It is CC sectional view taken on the line of FIG. It is a figure which shows the structure of the brazing chamber of the brazing apparatus of FIG. It is a figure which shows the temperature transition of each part when a heat exchanger is brazed with the brazing apparatus of FIG. FIG. 8 is a detailed view of FIG. 7. FIG. 8 is another detailed view of FIG. 7. It is a front view of the heat exchanger brazed with the brazing apparatus of FIG. It is a perspective view of the workpiece | work hold | maintained on the tray of the other Example of the brazing apparatus of FIG. 1 (Example 2). It is a top view of FIG. It is the DD sectional view taken on the line of FIG. It is a perspective view of the workpiece | work hold | maintained on the tray of another another Example of the brazing apparatus of FIG. 1 (Example 3). FIG. 15 is a plan view of FIG. 14. It is the EE sectional view taken on the line of FIG. It is a principal part enlarged view of FIG. FIG. 10 is a perspective view of a workpiece held on a tray of still another embodiment of the brazing apparatus of FIG. 1 (embodiment 4). It is a top view of FIG. It is the FF sectional view taken on the line of FIG. It is a figure which shows the whole structure of the brazing apparatus of the other Example to which this invention is applied (Example 5). It is a figure which shows the whole structure of the brazing apparatus of another another Example to which this invention is applied (Example 6). It is a figure which shows the structure of the brazing chamber of the conventional brazing furnace. It is a figure which shows the temperature transition of each part when a heat exchanger is brazed in the brazing chamber of FIG. It is a front view of the heat exchanger brazed in the brazing chamber of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an overall configuration of a brazing apparatus SB as an embodiment to which the present invention is applied, and FIG. 2 shows a front view of a heat exchanger W as an embodiment of a workpiece to be brazed. The heat exchanger W as a work to be brazed is used as a radiator or an evaporator in a vehicle, a cooling device or the like, and its structure is the same as that in the case of FIG. That is, the heat exchanger W is composed of aluminum header parts 1 and 1 at both ends and a tube part 2 formed between them, and the tube part 2 is parallel between the header parts 1 and 1. A plurality of aluminum microtubes 3 brazed to each other, and aluminum fins 4 brazed between the microtubes 3.

  In FIG. 2, the heat exchanger W as a work of the embodiment is generally thinner and lighter than the conventional product as described above, and the header portion 1 actually flows into the header portion 1. The inlet pipe and the outlet pipe (not shown) that flow out are connected. Further, the header portion 1 has a thickness dimension larger than that of the microtube 3 and the fin 4 constituting the tube portion 2, and has a large heat capacity. Therefore, when similarly heated, the temperature of the header part 1 is difficult to rise, the rate of temperature rise is slow, the temperature of the tube part 2 is likely to rise, and the rate of temperature rise is fast.

  Next, the brazing apparatus SB of FIG. 1 as an embodiment of the brazing apparatus of the present invention is a so-called high-speed brazing furnace, and includes a drying furnace 12 in which a drying chamber 11 is configured, a front chamber 13, It is composed of a heating furnace 17 in which a brazing chamber 14 is configured, a cooling furnace 21 in which a cooling chamber 19 is configured, and a rear chamber 22, which are sequentially arranged and are air permeable. The heat exchanger W placed and held on the tray 23 is dried by an air-permeable conveying means (roller or mesh belt) 24 by a drying chamber 11, a front chamber 13, a brazing chamber 14, a cooling chamber 19, and a rear chamber. It is set as the structure conveyed in order of 22.

  In the drying chamber 11, processing oil such as isopropylene alcohol (IPA) applied to the heat exchanger W is evaporated. A metal curtain 26 is provided between the drying chamber 11 and the front chamber 13. Nitrogen gas as an inert gas is introduced into the front chamber 13, the brazing chamber 14 and the cooling chamber 19 through a nitrogen gas introduction pipe 27.

  The atmosphere is replaced with nitrogen gas in the front chamber 13, but the metal curtain 26 separates the interior of the front chamber 13 from the drying chamber 11, and plays a role in helping to replace the atmosphere in the front chamber 13 with nitrogen gas. In the brazing chamber 14 of the heating furnace 17, an electric heater 28 as a main heating means and an in-furnace fan 29 as a forced convection means are provided as shown in FIG. The nitrogen gas is forcedly convected into the brazing chamber 14 by the furnace fan 29. At this time, a hood 32 is provided below the furnace fan 29, and the lower end of the hood 32 is opened above the conveying means 24, and there is an interval between the inner wall surface of the heating furnace 17. Then, the upper end gradually closes as it goes upward, and then the upper end opens directly below the in-furnace fan 29.

  As a result, the high-temperature nitrogen gas is once blown up by the furnace fan 29, hits the upper wall of the heating furnace 17, travels outward, falls outside the hood 32 (inside the side wall of the heating furnace 17), and hits the bottom wall. After going inward again, it rises, passes through the conveying means 24 and the tray 23, and is blown onto the heat exchanger W from below. Then, after passing through the heat exchanger W, the inside of the hood 32 is further raised and sucked into the furnace fan 29 again (forced convection indicated by thin arrows in FIG. 6).

  Next, the configuration of one embodiment of the tray 23 used in the brazing apparatus SB of the present invention and the holding of the heat exchanger (work) W will be described with reference to FIGS. The tray 23 of the embodiment is made of a rectangular metal plate, and a plurality of through holes 33 are formed as vents on the entire upper surface 23A. A heat exchanger (work) W is placed on the tray 23 via a receiving member 34 and held (FIG. 3).

  In this case, the heat exchanger (work) W is set in a predetermined jig, and the header portions 1 and 1 and the tube portion 2 are arranged in the state shown in FIG. Further, the receiving member 34 is interposed between the header portions 1 and 1 at both ends and the tray 23 to prevent the inconvenience that the heat exchanger (workpiece) W is fixed to the tray 23 (FIG. 5).

  Further, a shielding plate 36 is attached to the upper surface 23A of the tray 23 so as to correspond to the lower part of the center portion of the tube portion 2 that is a portion where the temperature rise rate of the heat exchanger (workpiece) W is fast (FIGS. 4 and 5). In FIG. 4, the heat exchanger W is seen through). As a result, the through-hole 33 positioned below the tube portion 2 is closed in the range where the shielding plate 36 exists, and thereby the flow of the high-temperature nitrogen gas blown to the heat exchanger (workpiece) W is controlled. Therefore, the tray 23 constitutes the air distribution means of the present invention, and the tray 23 (the upper surface 23A) and the shielding plate 36 constitute the wind direction plate.

  Next, the brazing operation of the heat exchanger W by the brazing apparatus SB of the embodiment having the above configuration will be described. First, as described above, the heat exchanger (work) W is set on a predetermined jig, and the header portions 1 and 1 and the tube portion 2 are arranged in a state as shown in FIG. The heat exchanger (work) W in this state is placed on the tray 23 via the receiving member 34, and the entire tray 23 is placed on the transport unit 24.

  In this case, the tray 23 is mounted on the transport unit 24 so that the header portions 1 and 1 of the heat exchanger (work) W are on both sides (the rear side and the front side in FIG. 1) with respect to the traveling direction of the transport unit 24. To do. The tray 23 and the heat exchanger (workpiece) W held on the tray 23 are transported at a predetermined speed by the transport means 24 while moving from the left to the right in FIG. The processing oil is evaporated (evaporation process). Thereafter, the heat exchanger W is transferred to the front chamber 13 through the metal curtain 26, and the atmosphere around the heat exchanger W is changed to a nitrogen gas atmosphere in the process of passing therethrough (pre-process).

  The heat exchanger (workpiece) W is sequentially transferred from the front chamber 13 to the brazing chamber 14 of the heating furnace 17, and forced convection of high-temperature nitrogen gas by the in-furnace fan 29 as described above and direct radiant heat from the electric heater 28. Thus, preheating and heating steps are performed. At that time, the high-temperature nitrogen gas rises from below the conveying means 24, passes through the through holes 33 of the tray 23, and is blown to the heat exchanger (workpiece) W from below. At this time, the tube portion 2 Since the through-hole 33 of the tray 23 corresponding to the lower side is closed by the shielding plate 36, the high-temperature nitrogen gas toward the tube portion 2 cannot pass through the through-hole 33 of this portion, and both sides thereof. The outer header portion 1 is directed in one direction (indicated by an arrow in FIG. 6).

  As a result, a large amount of high-temperature nitrogen gas is preferentially blown to the header portions 1 and 1 (parts where the temperature increase rate is slow). The tube portion 2 is also sprayed with high-temperature nitrogen gas that has passed through the shielding plate 36. After the header part 1 and the tube part 2 (microtube 3 and fin 4) are brazed in the heating process from preheating to heating in the brazing chamber 14, the heat exchanger W is transferred to the cooling chamber 19, and this After slow cooling in a nitrogen gas atmosphere is performed in the cooling chamber 19 (cooling step), the final chamber 22 is reached and brazing is completed.

  The control of the brazing device SB, that is, the conveying speed of the heat exchanger (work) W by the conveying means 24, the amount of heat generated by the electric heater 28 in the brazing chamber 14, the operation of the in-furnace fan 29, etc. 14 is executed by the controller C based on the output of the temperature of the nitrogen gas in the temperature detector 14 and / or the temperature of the heat exchanger (work) W and the temperature detection device (thermocouple or the like) K1. The controller C is constituted by a microcomputer, and a control program for realizing temperature transition of each part of the heat exchanger (work) W described below is incorporated in advance.

  Next, the temperature transition of each part of the heat exchanger (work) W brazed by the brazing apparatus SB will be described with reference to the temperature graphs shown in FIGS. 7 shows the temperature transition from the front chamber 13 to the rear chamber 22, FIG. 8 shows an enlarged view of circle A and circle B in FIG. 7, and FIG. 9 shows the temperature transition in the brazing chamber 14, respectively. The broken lines in the graphs shown in each figure indicate the temperature of the tube part 2 that is a part where the temperature rise rate is fast in the heat exchanger W, the solid line indicates the temperature transition of the header part 1 that is the part where the temperature rise rate is slow, and the one-dot chain line is ideal. The temperature transition of each is shown.

  As described above, in this embodiment, the through hole 33 of the tray 23 corresponding to the lower part of the tube portion 2 of the heat exchanger (work) W is closed by the shielding plate 36, and high-temperature nitrogen gas is preferentially used for the header portions 1 and 1. Therefore, in the heating process in the brazing chamber 14, the temperature rise of the header part 1 having a slow temperature rise rate is promoted from the preheating stage to the heating stage, and the temperature of the header part 1 (solid line). And the temperature (broken line) of the tube part 2 with a high temperature rising rate rises in substantially the same way, and they change at the approximate temperature (FIG. 7).

  The heat exchanger (work) W is finally heated to + 570 ° C. or higher and + 600 ° C. or lower by a heating process (preheating and heating) for a predetermined time in the brazing chamber 14, but during the heating process in the brazing chamber 14 (cooling) In the range where the temperature of the heat exchanger (workpiece) W is at least + 450 ° C. or higher (in the embodiment, + 440 ° C. or higher) + 500 ° C. or lower, the temperature difference between the header portion 1 and the tube portion 2 (varies). Is kept within 5 degrees in the embodiment. In the range of + 500 ° C. or higher, the temperature difference (variation) between the header portion 1 and the tube portion 2 is kept within 2.5 deg in the embodiment (FIGS. 8 and 9). In the embodiment, the temperature difference between the header portion 1 and the tube portion 2 is kept within 5 deg when the temperature of the heat exchanger (workpiece) W is + 440 ° C. or more and less than + 500 ° C., and when the temperature is + 500 ° C. or more, the temperature difference is kept. Although kept within 2.5 deg, the temperature difference between the header part 1 and the tube part 2 is kept within 20 deg at least when the temperature of the heat exchanger (workpiece) W is + 440 ° C. or higher and less than + 500 ° C., and + 500 ° C. or higher. In this range, if the temperature difference is kept within 10 deg, it is considered that the amount of zinc diffusion and distortion can be within the allowable range. Even during the heating control by the controller C, the high-temperature nitrogen gas passing through the tray 23 is preferentially blown to the header portion 1, so that the temperature of the header portion 1 having a large heat capacity and the tube portion 2 having a small heat capacity are accurately increased. It becomes possible to match. Thereby, the header part 1 and the tube part 2 (the microtube 3 and the fin 4) are brazed.

  As described above, in the present invention, a high-temperature nitrogen gas (inert gas) is convected in the brazing chamber 14 so that the header portion which is an aluminum member constituting the heat exchanger (work) W in the brazing chamber 14. In heating and brazing the tubes 1 and 1 and the tube portion 2, the circulation of the hot nitrogen gas convection in the brazing chamber 14 is controlled by the tray 23 (air distribution means), and the hot nitrogen gas is transferred to the heat exchanger (workpiece). ) Since the header portion 1 with a slow W temperature rise rate is preferentially blown to the header portion 1, the temperature of the tube portion 2 with a fast heat exchanger (workpiece) W rise rate is increased during heating in the brazing chamber 14. In addition, the temperature of the header portion 1 with a slow temperature rise rate is matched, and the entire region (header portion 1 and tube portion 2) in which brazing of the heat exchanger (workpiece) W indicated by the broken line X in FIG. Joint with Range) over Luo tube portion 2 whole it is possible to uniformly heated. Therefore, it is possible to avoid the occurrence of excessive corrosion allowance and a decrease in corrosion resistance when the heat exchanger W composed of the header portion 1 and the tube portion 2 is brazed.

  In particular, the tube portion 2 having a high temperature rise rate is not matched with the temperature rise of the header portion 1 having a slow temperature rise rate as in the prior art, and high temperature nitrogen gas is preferentially blown to the header portion 1 having a slow temperature rise rate. Since the temperature rise of the header part 1 is promoted, the demand for high speed can be satisfied. Further, since the air distribution means is configured with a simple configuration in which the shielding plate 36 is simply attached to the tray 23, the number of parts can be reduced, and the heat exchanger ( The flow of the high-temperature nitrogen gas can be controlled corresponding to each of the workpieces W, and the temperature rise of the heat exchanger (work) W can be made more uniform.

  Particularly, when the temperature of the workpiece heated in the heating process in the brazing chamber 14 is at least + 450 ° C. or more and less than + 500 ° C. due to the air distribution by the tray 23, the header portion 1 and the temperature rising rate are slow. When the temperature difference of the tube portion 2 is within 20 deg, preferably within 5 deg, and the temperature of the heat exchanger (workpiece) W is + 500 ° C. or more, the header portion 1 with a slow temperature rise rate and the tube portion 2 with a fast temperature rise rate By making the temperature difference within 10 deg, preferably within 2.5 deg, it becomes possible to raise the temperature of the entire heat exchanger (workpiece) W more uniformly and to achieve good brazing.

  Next, FIGS. 11 to 13 show another embodiment to which the present invention is applied. In addition, in each figure, what is shown with the same code | symbol as FIGS. 3-5 shall show | play the same or the same function. In the first embodiment, the shielding plate 36 attached to the tray 23 completely blocks the through hole 33 corresponding to the lower part of the tube portion 2 of the heat exchanger (work) W. When the difference in heat capacity, that is, the difference in the heating rate is smaller than that in the first embodiment, the higher the temperature of the header portion 1 is, the more the high-temperature nitrogen gas is distributed in the tube portion 2 than in the first embodiment. And the temperature rise of the tube part 2 are matched.

  Therefore, in the second embodiment, a plurality of through holes (ventilating portions) 37 having a smaller size (smaller diameter) than the through holes 33 are formed in the shielding plate 36. As a result, the high-temperature nitrogen gas passes through the through-holes 33 of the tray 23 and the through-holes 37 of the shielding plate 36 and is directly blown to the central part of the tube part 1, so that the amount is higher than in the first embodiment. The high-temperature nitrogen gas is blown to the tube portion 2, whereby the temperature rise of the header portion 1 of the heat exchanger (work) W and the temperature rise of the tube portion 2 in this case can be matched. .

  In addition, adjustment of the air distribution amount to the header part 1 and the tube part 2 by the flow control of the high-temperature nitrogen gas by the tray 23 is not limited to the dimension change of such a through hole (ventilation part), its shape and position, those It may be done in combination.

  14 to 17 show another embodiment to which the present invention is applied. In addition, in each figure, what is shown with the same code | symbol as FIGS. 3-5 shall show | play the same or the same function. In the first and second embodiments described above, the through hole 33 is formed in the tray 23, and the through hole 33 below the tube portion 2 is closed by the shielding plate 36, or the size of the vent portion is substantially reduced by the through hole 37. However, in the third embodiment, a plurality of slits 38 are formed as ventilation portions in the tray 23 corresponding to the vicinity of the lower portion of the header portions 1 and 1 of the heat exchanger (work) W.

  In this case, no slit is formed at a position corresponding to the lower portion of the center portion of the tube portion 2. In addition, louvers 39 directed in the direction of the header portion 1 are formed by cutting and raising on the inner edges of the slits 38 (in the central direction of the tray 23), adjacent to the slits 38 (FIG. 17). In this case, the receiving member 34 is formed in a substantially gate shape in order to avoid the louver 39. Thereby, the high-temperature nitrogen gas rising from below can be more effectively directed toward the header portion 1 and can be preferentially blown.

  In this case as well, the angle and shape of the louver 39 may be determined in accordance with the difference in heat capacity between the header portion 1 and the tube portion 2, that is, the difference in temperature increase rate, and the proportion of air distribution may be adjusted.

  Furthermore, in addition to that, as shown in FIGS. 18 to 20, a plurality of through holes 41 may be formed between the groups of slits 38 corresponding to the vicinity of the lower portion of each header portion 1, 1. As a result, the high-temperature nitrogen gas passes through the through hole 41 of the tray 23 and is directly blown to the central portion of the tube portion 2. 2, so that the temperature rise of the header portion 1 and the temperature rise of the tube portion 2 of the heat exchanger (work) W having a smaller difference in heat capacity between the header portion 1 and the tube portion 2 can be combined. become able to.

  Thus, the dimension of the through holes 33 and 37 (ventilation part) of the tray 23 constituting the wind direction plate of the air distribution means (any of the shape, dimension, and position as described above, or a combination thereof) By controlling the flow of the high-temperature nitrogen gas, it is possible to further simplify the structure. Further, a slit 38 is formed and a louver 39 adjacent to the slit 38 is provided, and the flow of the high-temperature nitrogen gas is controlled by the angle and / or shape of the louver 39, so that the high-temperature nitrogen in the brazing chamber 14 can be controlled. It becomes possible to control the distribution of gas more accurately.

  Here, in each of the above-described embodiments, the wind direction plate of the air distribution means is configured by the tray 23. However, the tray 23 is not limited thereto, and the tray 23 has a large number of through holes 33 formed on the entire upper surface 23A. Further, as shown in FIG. 21, a wind direction plate 42 may be separately provided on the lower side of the conveying means 24 (the lower side of the forward path of the conveying means 24 on which the tray 23 is placed).

  The wind direction plate 42 in this case is also provided with a through hole 33 of the tray 23 shown in FIGS. 4, 12, 15, and 19, a shielding plate 36 (through hole 37), a slit 38, a louver 39, and a through hole 41. Or, it is formed. 4, 12, 15, and 19, the left and right ends of each figure are the back side and the near side (positions on both sides with respect to the traveling direction of the conveying means 24) in FIG. 21. An airflow direction plate 42 is disposed in the brazing chamber 14 and arranged in parallel over substantially the entire area.

  Even with such a configuration, the high-temperature nitrogen gas can be preferentially sprayed onto the header portions 1 and 1 of the heat exchanger (work) W located on the back side and the near side in FIG.

  Further, a near-infrared irradiation device 44 as auxiliary heating means may be disposed in the anterior chamber 13 described above as shown in FIG. The near-infrared irradiation device 44 includes a near-infrared lamp that generates near-infrared light and a reflecting mirror that collects the near-infrared light generated by the near-infrared lamp toward an irradiation target. It is provided to irradiate near-infrared rays to the header portions 1 and 1 at both ends where the heat capacity is large and the temperature rising rate is slow.

  In this case as well, the tray 23 is configured as in the first to fourth embodiments. In this case, a temperature detection device (thermocouple or the like) K2 for detecting the ambient temperature in the front chamber 13 and / or the temperature of each part of the heat exchanger (work) W is provided, and the output of this temperature detection device “K2”. The near infrared irradiation device 44 is controlled by the controller C based on the above. In addition, the position of the near infrared irradiation device 44 and / or the irradiation direction of the near infrared radiation can be changed according to the size and shape of the workpiece (heat exchanger) and the position of the part where the heating rate is slow.

  When the pre-process in the front chamber 13 is completed by the irradiation of the near infrared rays, the temperature of the header portion 1 of the heat exchanger (work) W is + 420 ° C. or approximately + 420 ° C., and the temperature of the tube portion 2 is + 400 ° C. C. or rise to about + 400.degree. As described above, when the temperature of the header portion 1 is around + 420 ° C. and the temperature of the tube portion 2 is around + 400 ° C., the heat exchanger (workpiece) W is transferred to the brazing chamber 14 and enters the heating process. To do.

  In this way, the near-infrared irradiation device 44 is provided in the front chamber 13, and the header portion 1, which is a portion where the temperature rise rate of the heat exchanger (work) W is slow in the previous process in the front chamber 13, is heated by the near-infrared irradiation device 44. By doing so, before heating the heat exchanger (workpiece) W in the brazing chambers 14, 16, the temperature of the header portion 1 having a slow heating rate may be raised in the previous step in the front chamber 13 in advance. become able to.

  Thus, in combination with the above-described high-temperature nitrogen gas distribution, during the heating in the brazing chamber 14, the temperature rise rate of the heat exchanger (workpiece) W is increased in the temperature of the tube portion 2, which is high. It becomes possible to adjust the temperature increase of the slow header portion 1 more effectively. In particular, the temperature (solid line) of the header portion 1 having a slow temperature rise rate is raised first in the previous step in the front chamber 13, and the temperature rise rate is increased in the temperature rise of the portion where the temperature rise rate is slow as in the prior art. Since it does not match the fast parts, it results in higher speed.

  In this case, since the temperature rise by the near-infrared irradiation device 44 in the front chamber 13 is still low (+ 400 ° C. to + 420 ° C.), the adverse effect of oxygen should be ignored even in the previous step of replacing the atmosphere with nitrogen gas. Can do. Moreover, since it can implement | achieve by the comparatively simple structure of providing the near-infrared irradiation apparatus 44 in the front chamber 13, since it is the heating in the front chamber 13, a heating means (implementation) whose heat-resistant temperature is comparatively low as auxiliary heating means It is also possible to employ the example of the near infrared irradiation device 44).

  That is, as in this embodiment, the near-infrared irradiation device 44 irradiates near-infrared rays in the previous process and heats the header portion 1 with a slow temperature increase rate of the heat exchanger (workpiece) W. It becomes possible to raise the temperature of the slow header part 1 more accurately than the temperature of the tube part 2 having a fast temperature rising rate.

  In the previous step, the temperature of the header portion 1 with a slow temperature rise rate of the heat exchanger (work) W is + 420 ° C. or about + 420 ° C., and the temperature of the tube portion 2 with a high temperature rise rate is + 400 ° C. or about + 400 ° C. If the heat exchanger (workpiece) W is transferred to the brazing chamber 14 at this point and the process proceeds to the heating step, the influence of oxygen in the previous step in the front chamber 13 is not a problem, and the subsequent brazing In the heating process in the chambers 14 and 16, the temperature of the entire heat exchanger (workpiece) W can be quickly and uniformly increased from + 570 ° C. to 600 ° C.

  In each of the embodiments, the heat exchanger has been described as a workpiece. However, the invention is not limited thereto, and the invention is effective for all aluminum members manufactured by brazing except for the invention of claim 3.

SB Brazing device W Heat exchanger (workpiece)
1 Header (part where temperature rise rate is slow)
2 Tube part (part with high heating rate)
3 Microtube 4 Fin 13 Front chamber 14 Brazing chamber 17 Heating furnace 23 Tray (air distribution means, wind direction plate)
24 Conveying means 28 Electric heater 29 In-furnace fan 33, 37, 41 Through hole (vent)
36 Shielding plate 38 Slit (vent)
39 Louver 42 Wind direction plate (air distribution means)
44 Near-infrared irradiation device (auxiliary heating means)

Claims (8)

In a brazing apparatus that heats and brazes an aluminum member constituting a workpiece in the brazing chamber by convection of a high-temperature inert gas into the brazing chamber,
By controlling the flow of the high-temperature inert gas that convects in the brazing chamber, air distribution means that preferentially blows the high-temperature inert gas to a portion where the temperature rise rate of the workpiece is slow ,
The air distribution means comprises a wind direction plate in which a plurality of ventilation portions are formed,
The wind direction plate has a louver adjacent to the ventilation portion, and controls the flow of the hot inert gas according to the angle and / or shape of the louver .   When the temperature of the workpiece heated in the brazing chamber is at least + 450 ° C. or more and less than + 500 ° C., the air distribution means has a temperature difference of 20 deg or less between the portion where the heating rate is slow and the portion where the heating rate is fast. 2. The brazing according to claim 1, wherein a temperature difference between the portion where the heating rate is slow and the portion where the heating rate is fast is within 10 deg within a range where the temperature of the workpiece is + 500 ° C. or more. apparatus.   The said work is a heat exchanger which consists of a header part and a tube part, The said air distribution means sprays the said high temperature inert gas preferentially to the said header part, The Claim 1 or Claim 2 characterized by the above-mentioned. The brazing device described. A breathable transfer means for transferring the work in the brazing chamber; and a tray that holds the work and is placed on the transfer means, and blows the high-temperature inert gas from below onto the work. The brazing device according to any one of claims 1 to 3, wherein the wind direction plate is configured by the tray . The apparatus further comprises an air permeable conveying means for conveying the work in the brazing chamber, the high temperature inert gas is sprayed onto the work from below, and the wind direction plate is disposed below the conveying means. The brazing apparatus according to any one of claims 1 to 3 . The brazing apparatus according to any one of claims 1 to 5, further comprising auxiliary heating means for heating a part of the workpiece that has a slow temperature increase rate . The brazing apparatus according to claim 6 , wherein the auxiliary heating unit heats a portion of the workpiece having a low temperature rising rate by irradiating near infrared rays . The brazing according to claim 6 or 7, further comprising a front chamber that is positioned in front of the heating furnace to replace the atmosphere with an inert gas, and wherein the auxiliary heating means is provided in the front chamber. apparatus.

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