JPH07115168B2 - Brazing furnace - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing heating furnace for heating and melting a brazing material placed on a brazed portion of a welding base material. Generally, this type of heating furnace welds a brazing filler metal by directly heating the welding base metal by conduction heat of a heater composed of a non-metallic heating element such as silicon carbide or a metallic heating element such as nichrome wire. Alternatively, the welding base material is indirectly heated by radiant heat from the heated furnace wall or the like to melt the brazing material. By the way, in the conventional brazing heating furnace, since the brazing material is heated to a predetermined temperature necessary for melting, the welding base material is carried out of the furnace. When the carry-out means such as the chain conveyor or the heat-resistant belt conveyor fails, the temperature inside the furnace does not fall immediately even if the power supply to the heater is stopped. Therefore, there is a problem that the welding base metal remaining in the furnace is overheated and becomes a defective product. Further, since the temperature inside the furnace is lowered after the failure of the carry-out means is repaired, the maximum heating temperature for the welding base metal is lowered immediately after the energization of the heater is resumed, and the temperature inside the furnace once lowered is raised to a predetermined temperature. Takes a long time. For this reason,
If the delivery means such as the conveyor fails, there is a problem that the operating rate of the heating furnace is significantly reduced. In view of such problems, it is an object of the present invention to provide a brazing heating furnace capable of preventing the generation of defective products and the reduction of the operating rate when the discharging means fails. In addition, Japanese Patent Publication No. 3-3541 discloses that
Disclosed is a continuous furnace for soldering an electronic component assembly, which comprises a first heating section, a second heating section and a cooling section coupled to each other.
It does not directly cool the heating section, and the purpose of cooling is different from that of the present invention. The present invention has achieved the above objects.
To achieve this, the following technical means will be adopted. In the present invention
Is a heating furnace for brazing which heats and melts a brazing material placed on a brazed portion of a welding base material, and a first heating provided with a heater for preheating the brazing material to a predetermined temperature not exceeding the melting point. Chamber, a second heating chamber provided with an infrared lamp heater for heating the brazing filler metal preheated in the first heating chamber to a melting point or higher, and the melt in the first heating chamber and the second heating chamber.
Unloading means for loading and unloading the base material , a cooling water passage provided in the furnace walls of the first heating chamber and the second heating chamber, and a valve for controlling the flow of cooling water in the cooling water passage And the red
An external line lamp heater and a controller for controlling the bulb;
And the controller controls the infrared lamp heater.
When turning on electricity, open the valve to open the cooling water passage.
Cooling water is flowed to the infrared lamp heater to shut off electricity.
When shutting off, close the valve and close the cooling water passage.
Will be configured to block the flow of cooling water to
It features a contact heating furnace. According to the above heating furnace for brazing,
An infrared ray with a small heat capacity is used as the heat source of the second heating chamber.
Is provided with the Puhita, if stopping the power supply to the heater, a second heating chamber is cooled rapidly. Therefore, when the unloading means for unloading the welding member from the furnace fails, the infrared lamp heater elapses after the time required for melting the brazing material placed in the brazed portion of the welding member in the second heating chamber has elapsed. By stopping the energization to, it is possible to prevent defective products due to overheating or insufficient heating. Further, when the discharging means fails, the heat of the first heating chamber is
Be continued energization of the chromatography data, since the heater is not heated brazing material higher than the melting point, the welding base material of the first heating chamber there is no risk that a defective due to excessive heating. Therefore, the welding base metal can be kept warm by continuing to energize the heater in the first heating chamber during the repair of the failure of the carry-out means. Therefore, if the power supply to the infrared lamp heater is restarted after the failure is repaired, the temperature of the welding member is rapidly raised to the temperature required for melting the brazing filler metal, so that the reduction of the heating furnace operating rate can be suppressed to the minimum . Further, the infrared lamp heater of the second heating chamber is so constructed that water is passed through a cooling water passage provided inside the furnace wall when electricity is supplied to the infrared lamp heater and is stopped when electricity is not supplied. Energizing
Controls the intermittent operation and the opening and closing of the cooling water passage valve
Since the infrared lamp heater is turned on and off,
A sudden rise and fall in wall temperature can be controlled by passing water through the cooling water passage.
It can be suppressed by intermittently and the furnace wall temperature can be maintained so as to be almost constant at all times. Therefore, not only the pressure <br/> heat by an infrared lamp heater, a change in the heating maximum temperature in the welding base material is also heated by radiation heat from the furnace wall can be minimized. In addition, an infrared lamp can be
Even if the power to the heater is cut off, the water passage to the cooling water passage is stopped.
Since the temperature of the furnace wall can be prevented from lowering by stopping the
The rise in the melting temperature of the brazing material of the welding base metal in
It can be promoted and can contribute to the improvement of the heating furnace operating rate. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a brazing heating furnace according to an embodiment of the present invention. The heating furnace includes a tubular furnace body 10 made of a heat resistant material and having a rectangular cross-sectional shape. The inside of the furnace body 10 is partitioned into a first heating chamber 11 and a second heating chamber 12 which is adjacent to and communicates with the first heating chamber 11.
A first guide groove 11a is provided at the center of the bottom of the.
A conduction heat type heater 13 is embedded in the first guide groove 11a,
It is fixed. The conductive heat type heater 13 has a built-in metal wire such as a nichrome wire as a heating element, and a welding base material 1 described later.
The heating temperature is set so that the solder placed on the soldered portion of No. 5 can be heated to a predetermined temperature not exceeding its melting point. By the way, when the solder having a melting point of about 240 degrees Celsius is used as the brazing material, it is preferable that the preset heating temperature of the conduction heater 13 is about 200 degrees Celsius. At the bottom of the second heating chamber 12, there is provided a second guide groove 12a having a bottom surface flush with the top surface of the conductive heat type heater 13. The second guide groove 12a and the first
The first guide groove 11a provided in the heating chamber 11 is for slidably fitting a quadrangular prism-shaped welding base material carrying jig (hereinafter simply referred to as carrying jig) 14 and is in communication with each other. However, it extends linearly from the inlet 10a of the furnace body 10 to the outlet 10b. A plurality of recesses 14a are formed on the upper surface of the transfer jig 14 fitted in the guide grooves 11a, 12a, and solder is placed in advance in the recesses 14a outside the furnace body 10 on the soldered portion. The welded base material 15 is fitted. Further, the carrying jig 14 is pushed by an actuator (not shown) so as to be guided from the inlet 10a to both the guide grooves 11a, 12a.
It is carried into the furnace main body 10 along a, and carried out from the outlet 10b. An opening 12b is formed in the upper wall of the second heating chamber 12 and is covered with a heat resistant glass 16. An infrared radiation type heater 17 capable of heating the solder placed on the brazed portion of the welding base material 15 in the second heating chamber 12 to a temperature equal to or higher than the melting point is fixedly provided outside the upper portion of the heat resistant glass 16. ing. The infrared radiant heater 17 is provided with a reflecting mirror 17a having a concave surface with gold plating, and an infrared lamp 17b attached at the focal position of the reflecting mirror 17a. Next, the welding base material 1 is provided at the center of the furnace body 10.
5 and a nozzle 10c for supplying hydrogen gas into the furnace main body 10 in order to reduce the oxidation of the surface of the solder and improve the wettability of the molten solder. Further, nozzles 10d and 10e are provided at the inlet 10a and the outlet 10b of the furnace main body 10 to prevent hydrogen gas from leaking to the outside of the furnace main body 10 and to eject nitrogen gas to form a gas curtain. Further, a heat insulating groove 21 for insulating the upper side and the lower side of the furnace wall is provided on the outer periphery of the furnace body 10, and upper and lower cooling water passages 22, 22 are provided in the upper furnace wall. Has been. The cooling water passages 22 and 22 and the cooling water tank 2
3 is connected by a cooling water supply pipe 24. A valve 25 is installed in the cooling water supply pipe 24, and the controller 2
6, the opening and closing of the infrared radiant heater 17 is controlled in association with whether the infrared heater 17 is energized or de-energized. This embodiment is constructed as described above, and the welding base material 15 is fitted into the concave portion 14a of the carrying jig 14 in advance, solder is placed on the soldered portion of the same base material 15, and then the carrying material 15 is carried. The jig 14 is pushed by an actuator (not shown) and is carried into the first heating chamber 11 from the inlet 10a along the first guide groove 11a. Then, the carrying jig 14 is stopped in the first heating chamber 11, and the conductive heat transmitted from the conductive heat type heater 13 through the carrying jig 14 and the welding base material 15 brings the solder to a predetermined temperature that does not exceed the melting point. Heat up to. After heating for a certain period of time, while carrying the carrying jig 14 into the second heating chamber 12 while sliding the carrying jig 14 along the first guide groove 11a and the second guide groove 12a by the actuator, Carry it into the first heating chamber. Then, the solder preheated in the first heating chamber 11 is heated in the second heating chamber 12 by the infrared radiation type heater 17 for a certain period of time to be melted. Then, the transport jig 14 is slid along the second guide groove 12a by the actuator to be carried out of the second heating chamber 12 to the outside of the furnace body 10. Through the series of steps, the transfer jig 14
The brazed portions of the welding base material 15 placed on the are sequentially brazed by solder. As described above, according to this embodiment, since the infrared radiant heater 17 is provided as the heat source of the second heating chamber 12, the second heating chamber 12 can be quickly operated by stopping the power supply to the heater 17. To lower the temperature. Therefore, when the carrying jig 14 cannot be carried out of the furnace body 10 due to a failure of the actuator, it is necessary for the brazing material placed in the brazed portion of the welding base material 15 in the second heating chamber 12 to melt. If the power supply to the infrared radiation heater 17 is stopped after a lapse of time, it is possible to prevent defective products due to overheating or insufficient heating. Further, since the heating temperature of the conductive heat type heater 13 is set to a temperature at which the brazing filler metal is not heated above the melting point, even if the heater 13 is energized continuously when the actuator or the like fails, the first heating chamber 11 is not heated. There is no possibility that the welding base material 15 in the above will become defective due to overheating. Therefore, the welding base material 15 can be kept warm by energizing the conductive heat type heater 13 during the repair of the failure of the actuator or the like. Therefore, when the power supply to the infrared radiation heater 17 is restarted after the failure is repaired, the welding base material 15 is quickly heated to the temperature required for melting the solder, and thus the reduction of the operating rate can be prevented. However, since the welding base metal 15 in the second heating chamber 12 is heated not only by the infrared radiation type heater 17 but also by the radiant heat from the furnace wall, the maximum heating temperature for the welding base metal 15 is caused by the furnace wall temperature. Changes. For example, the temperature of the outer wall of the furnace decreases by about 90 ° C. in 30 minutes from the failure of the unloading means etc. to the repair of the failure, and the maximum heating temperature of the welding base material 15 immediately after the restart of energization of the infrared radiation heater 17 decreases by about 55 ° C. To do. Therefore, the furnace body 1 is attached to the outer periphery of the furnace wall of the furnace body 10.
0 is provided with a heat insulating groove 21 for partitioning the upper part and the lower part, and a lower part in which the conductive heat type heater 13 which continues to generate heat when energized is embedded and an infrared radiation type heater 17 which stops energization when the carry-out means 14 fails. Insulate the upper part and the upper part. Then, the infrared radiation heater 1 of the second heating chamber 12 is provided in the cooling water passages 22 and 22 provided in the furnace wall above the heat insulating groove 21.
During energization to 7, the valve 25 is opened by the signal of the controller 26 to allow water to flow. As a result, the temperature of the furnace wall of the second heating chamber 12 is suppressed by water cooling while the infrared radiant heater 17 is energized, and supercooling is prevented by stopping water when the heater 17 is not energized. It can be maintained at a substantially constant temperature (about 15 ° C. difference). Further, the difference in the maximum heating temperature before the failure of the welding base material 15 and immediately after the failure repair can be made as small as about 10 ° C., and the temperature can be rapidly raised with good temperature reproduction accuracy. Further, in this embodiment, as a means for loading the welding base material 15 into the furnace body 10, a quadrangular prism-shaped transportation jig 14 which is pushed by an actuator and slides along the guide grooves 11a and 12a is used. Since it is provided, compared with the conventional heating furnace provided with a chain conveyor or a heat-resistant belt conveyor as the carry-out means, the structure of the heating furnace can be simplified and downsized to save the installation space, and the maintenance and inspection of the furnace body 10 can be performed. It will be easy. Although the heating furnace for melting the solder has been described in the present embodiment, the present invention is not limited to this, and a brazing material having a melting point higher than that of the solder, such as an aluminum alloy brazing material, a phosphor copper brazing silver brazing material, etc., is melted. It can also be applied to a heating furnace.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of a brazing heating furnace. FIG. 2 is a cross-sectional view taken along the line AA of FIG. [Explanation of reference numerals] 10 ... Furnace body, 11 ... First heating chamber, 11a ... First
Guide groove, 12 ... Second heating chamber, 12a ... Second guide groove, 13 ... Conductive heat type heater, 14 ... Transfer jig,
15 ... Welding base material, 17 ... Infrared radiation type heater, 2
2, 22 ... Water passage, 25 ... Valve.

Claims (1)

Claim: What is claimed is: 1. In a brazing heating furnace for heating and melting a brazing material placed on a brazed portion of a welding base material, the brazing material is preheated to a predetermined temperature not exceeding its melting point.
A first heating chamber provided with a heater, a second heating chamber provided with an infrared lamp heater for heating the brazing filler metal preheated in the first heating chamber to a melting point or higher, the first heating chamber and the second heating chamber. The welding base metal in the heating chamber
A carry-out means for carrying in and out , a cooling water passage provided on the furnace walls of the first heating chamber and the second heating chamber, a valve for controlling the flow of cooling water in the cooling water passage, and the infrared rays. Control for controlling the lamp heater and the bulb
And a controller for energizing the infrared lamp heater by the controller.
When the valve is opened, the cooling water is put in the cooling water passage.
And disconnecting the power to the infrared lamp heater
First, close the valve to cool into the cooling water passage.
A heating furnace for brazing, which is configured to block the flow of water .