Automatic flame brazing device for copper components and automatic flame brazing method for copper components

Abstract

A brazing device (100) as an automatic flame brazing device for copper components comprises: a welding torch (25) for heating to which gas is supplied; a positioning mechanism (10) for positioning the welding torch (25); a first temperature measuring component (23) for measuring the temperature of a reduction portion of the copper component; a second temperature measuring component (21, 110) for measuring the temperature of an oxidation portion of the copper component; and a control component (120) for causing the brazing device (100) to perform brazing when it is determined that the temperature of the reduction portion has reached a brazing temperature and is lower than the melting temperature of the copper component, and the temperature of the oxidation portion has reached a brazing temperature.

Description

Technical Field

[0001] The present invention relates to an automatic flame brazing device for copper components and an automatic flame brazing method for copper components. Background Art

[0002] Conventional automatic soldering devices have a configuration in which the temperature of a portion heated by a heating device is obtained by a temperature measuring means, and the heating device is moved based on the temperature.

[0003] The automatic soldering device of Patent Document 1 includes a burner for heating, a positioning mechanism for the burner and a control device thereof, and a visible light vision sensor for converting brightness into temperature and an image processing unit for temperature detection.

[0004] The automatic soldering device of Patent Document 2 includes a high-frequency induction heating device, a torch heating member, a non-contact temperature measuring member, and a heating control member for controlling the high-frequency heating member, and uses a temperature detection area as an area where the surface of the soldering object is reduced.

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 6-182531

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 8-192262 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In the automatic brazing devices of Patent Documents 1 and 2, a visual sensor for detecting the temperature of the oxidized portion of the copper tube or a non-contact temperature measuring device for detecting the temperature of the reduced portion of the surface of the brazing object is used. Since the emissivity of the oxidized portion and the reduced portion of the copper tube is significantly different, the temperature of both cannot be detected by either one, and therefore the overall temperature distribution cannot be obtained. As a result, for example, both an oxidized portion and a reduced portion may be generated in the joint portion where the brazing material flows in, and thus the reliability of brazing may be reduced.

[0011] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide an automatic flame brazing device for copper members and an automatic flame brazing method for copper members that can perform brazing with high reliability.

[0012] Solutions to Solve Problems

[0013] In order to achieve the above-mentioned purpose, the automatic flame brazing device for copper components disclosed in the present invention comprises: a welding torch for heating, to which gas is supplied; a positioning mechanism for positioning the welding torch; a first temperature measuring component for measuring the temperature of a reduced portion of the copper component; a second temperature measuring component for measuring the temperature of an oxidized portion of the copper component; and a control component for causing the automatic flame brazing device for copper components to perform brazing when it is determined that the temperature of the reduced portion reaches the brazing temperature and is lower than the melting temperature of the copper component, and the temperature of the oxidized portion reaches the brazing temperature.

[0014] Effects of the Invention

[0015] According to the present disclosure, a structure capable of measuring the temperature distribution of both the oxidation part and the reduction part of the copper component can be obtained. Thus, the melting of the base material caused by overheating in the reduction part is prevented, and the appropriate temperature identification of the joint part where the brazing material flows in and the control of the gas flow rate based on the temperature distribution or the control of the position of the welding torch can be performed. Therefore, according to the present disclosure, an automatic flame brazing device for copper components and an automatic flame brazing method for copper components that can perform brazing with high reliability can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure shows a copper pipe as an object to be brazed and a brazed joint.

[0017] Figure 2 It is an overall view of the automatic flame brazing device for copper members according to the first embodiment of the present disclosure.

[0018] Figure 3 Yes means Figure 2 A partial enlarged view of the X portion.

[0019] Figure 4 This is a block diagram of the automatic flame brazing device for copper members according to the first embodiment of the present disclosure.

[0020] Figure 5 This is a flowchart showing a process of determining the temperature distribution of the automatic flame brazing device for copper members according to the first embodiment of the present disclosure.

[0021] Figure 6 This is a diagram showing an example of a temperature curve of gas flow rate control in the automatic flame brazing device for copper members according to the first embodiment of the present disclosure.

[0022] Figure 7 This is a diagram showing the relationship between the oxidation region and the reduction region of the copper pipe when the torch is oscillating.

[0023] Figure 8 This is a diagram showing an example of a temperature curve of torch swing control in the automatic flame brazing device for copper members according to the first embodiment of the present disclosure.

[0024] Fig. 9 It is a figure which shows the copper pipe brazing using the ring brazing filler metal according to the second embodiment of the present disclosure.

[0025] Fig.10 This is a diagram showing brazing of copper pipes in a case where there is a brazed pipe at a proximal location according to Embodiment 3 of the present disclosure.

[0026] Fig.11 This is a flowchart showing a process of determining the temperature distribution of the automatic flame brazing device for copper members according to the third embodiment of the present disclosure.

[0027] Fig.12 This is a block diagram of an automatic flame brazing device for copper members according to a fourth embodiment of the present disclosure.

[0028] Fig.13 It is a diagram showing a temperature measurement method of overlap brazing of copper plates according to the fifth embodiment of the present disclosure.

[0029] Fig.14 Yes means Fig.13 Arrows Y and Z in the figure represent the temperature measurement area. DETAILED DESCRIPTION

[0030] Implementation Method 1

[0031] First, refer to Figure 1 The structure of an object to be brazed 300 to be brazed in the present embodiment will be described.

[0032] The object to be brazed 300 is composed of a copper tube 30 as a copper member and a brazing joint 31. The copper tube 30 is a straight tube made of copper. The brazing joint 31 has an insertion portion 31a at one end of the straight tube made of copper for inserting the copper tube 30. The inner diameter of the insertion portion 31a is slightly larger than the outer diameter of the copper tube 30. In addition, a surface that receives the end surface of the copper tube 30 is provided on the inner side of the insertion portion 31a. The copper tube 30 is inserted into the insertion portion 31a to become the object to be brazed 300, and the brazing material is supplied to the gap of the insertion portion.

[0033] Next, refer to Figure 2 and Figure 3 Next, the structure of the brazing device 100 which is an automatic flame brazing device for copper members according to the first embodiment of the present disclosure will be described.

[0034] The soldering device 100 includes a positioning mechanism 10 and a fixing jig 20 attached to the positioning mechanism 10 .

[0035] The positioning mechanism 10 is a robot device having an articulated arm, one end of which can freely perform linear motion and rotational motion required for brazing.

[0036] The fixing jig 20 is a member formed by combining a member 20a and a member 20b extending linearly into an L shape. The vicinity of one end of the member 20a is attached to one end of a rotatable arm. The member 20b extends parallel to the axial direction of one end of the soldering device 100.

[0037] A visual sensor 21 as a temperature distribution measuring component, a non-contact temperature sensor 23, a brazing material supply device 24, and a welding torch 25 for heating are installed on the member 20b of the fixing fixture 20. These members are all facing the position where brazing is performed. A band pass filter 22 is installed at the end of the visual sensor 21.

[0038] The visual sensor 21 is a sensor for obtaining an image of the soldered portion. A bandpass filter 22 is mounted at the end of the visual sensor 21. The visual sensor 21 is configured to include an oxidation region 51 (grid portion) as a measurement region, and the oxidation region 51 is heated by the combustion flame 26. Figure 3 A portion of the insertion portion 31 a of the brazed joint 31 is formed.

[0039] The non-contact temperature sensor 23 is a temperature sensor with a detection wavelength of 3.6 to 3.95 μm. The detection wavelength of the non-contact temperature sensor 23 will be described later. The non-contact temperature sensor 23 sets the reduction area 50 (shaded area) of the copper tube 30 whose surface is cleaned by the reduction action of the combustion flame 26 as the measurement area.

[0040] The brazing material supply device 24 moves together with the welding torch 25 via the positioning mechanism 10, and supplies the brazing material at an arbitrary position and posture. Figure 2 The solder not shown in the figure is formed into a coil shape. The solder supply device 24 has a structure that can move the solder supply part 24a forward or backward relative to the soldering object by a cylinder. During soldering, after the solder supply part 24a approaches the soldering object by the cylinder, the solder supply device 24 delivers the solder from the end of the solder supply part 24a and supplies it to the soldering part.

[0041] The welding torch 25 can take any position and posture and perform swinging motion by the positioning mechanism 10. A mixed gas of combustible gas and oxygen such as acetylene, propane, natural gas or city gas is supplied to the welding torch 25 by the gas flow control device 130. The mixing ratio of the combustible gas and oxygen in the mixed gas is adjusted so that the combustion flame 26 has reducing properties.

[0042] like Figure 3As shown in FIG. 1 , the combustion flame 26 generated from the welding torch 25 is set to contact the position above the insertion portion 31a of the brazing joint 31, and the insertion portion 31a of the brazing joint 31 contacts the joint portion of the copper tube 30 of the object to be brazed 300. The reason is that the portion of the insertion portion 31a is processed to expand the end of the tube in order to fit the tubes together, and the wall is thinner than the unprocessed portion. When the combustion flame 26 directly contacts the insertion portion 31a, the copper tube 30 is more likely to melt and become defective than the case where the combustion flame 26 contacts the upper part of the insertion portion 31a.

[0043] The solder supply device 24 is adjusted to a setting where the tip of the solder contacts a portion several mm above the insertion portion 31a during soldering. The reason for this is to allow the solder to flow into the insertion portion 31a.

[0044] Next, refer to Figure 4 The structure of the brazing device 100 is further illustrated in the block diagram.

[0045] The image data acquired by the visual sensor 21 is sent to the image processing device 110. The image data is first totaled as the brightness data of each pixel in the area captured by the brightness totalization unit 111 of the image processing device 110. The brightness data is further converted into temperature data by the temperature calculation unit 112 of the image processing device 110. The temperature data is sent to the control device 120.

[0046] The image processing device 110 includes a processor for image processing such as a DSP (Digital Signal Processor) or a GPU (Graphics Processing Unit) and a buffer memory for temporarily storing processed images. The image processing device 110 controls captured images in the image processing device 110 using a well-known image processing method.

[0047] The temperature data acquired by the non-contact temperature sensor 23 is transmitted to the control device 120 in the same manner as the temperature data from the visual sensor 21 .

[0048] The brazing temperature determination unit 121 of the control device 120 determines whether the brazing temperature has been reached based on the temperature data of the visual sensor 21 and the non-contact temperature sensor 23. The brazing temperature disclosed herein refers to the temperature range in which brazing can be performed, and if it is above the lower limit of the temperature range, the brazing temperature is considered to have been reached. Based on the determination result, the control device 120 controls the positioning mechanism 10, the brazing material supply device 24, and the gas flow control device 130.

[0049] Furthermore, the control device 120 includes a control unit 122, a storage unit 123, and a communication unit 124. These units are connected via a communication bus.

[0050] The control unit 122 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU is also called a central processing unit, a central computing unit, a processor, a microprocessor, a microcomputer, a DSP, etc., and functions as a central computing unit that performs processing and computing related to the control of the soldering device 100. In the control unit 122, the CPU reads the program and data stored in the ROM, uses the RAM as a work area, and performs unified control of each part of the soldering device 100.

[0051] The storage unit 123 includes a nonvolatile semiconductor memory such as a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically Erasable Programmable ROM). The storage unit 123 functions as a so-called secondary storage device or auxiliary storage device. The storage unit 123 stores programs and data used by the control unit 122 to perform various processes. In addition, the storage unit 123 stores data generated or acquired by the control unit 122 by performing various processes.

[0052] The communication unit 124 includes a communication interface for communicating with each unit of the soldering device 100. The communication unit 124 performs wireless communication with each unit of the soldering device 100 in accordance with a well-known communication standard such as a wireless LAN (Local Area Network).

[0053] Next, the temperature distribution measurement of the brazing device 100 will be described.

[0054] In the present disclosure, in order to obtain the temperature distribution, the sensor is divided into two in the reduction region 50 and the oxidation region 51. The reason for this is that the emissivity is significantly different in the reduction region 50 and the oxidation region 51, and it is difficult to obtain the temperature of both with one sensor. As a standard of emissivity, the clean surface copper (pure copper) of the reduction region 50 is about 0.03, and the oxidized copper of the oxidation region 51 is about 0.7, which is a difference of nearly 20 times.

[0055] There are two reasons for setting the measurement area of ​​the non-contact temperature sensor 23 as the reduction area 50. The first reason is that since the surface state of the reduction area 50 is kept clean, the measurement accuracy of the non-contact temperature measuring component that detects the light radiated from the surface of the object to measure the temperature is improved. The second reason is to obtain the temperature of the highest temperature portion that the combustion flame 26 contacts.

[0056] In addition, in order to stably measure the temperature with the non-contact temperature sensor 23, a detection wavelength that is not affected by the combustion flame 26 is required. The combustion flame 26 has peaks near 2.9μm and near 4.3μm, and changes dramatically. In the vicinity of 3.6 to 3.95μm between the two peaks, an area where the radiation intensity is completely zero can be confirmed. On the other hand, the relative absorption rate of infrared rays by water vapor and carbon dioxide is the same as that of the combustion flame 26, and the absorption rate is zero in the range of 3.6 to 3.95μm. Therefore, as long as the detection wavelength of the non-contact temperature sensor 23 is 3.6 to 3.95μm, it is not affected by the infrared rays radiated from the combustion flame 26, and the proportion absorbed by the water vapor and carbon dioxide from the combustion flame 26 is small. Therefore, within the range of this detection wavelength, the temperature of the copper pipe 30 of the brazed object 300 can be accurately measured.

[0057] The reason why the visual sensor 21 is set to include the oxidation region 51 as the measurement region is to obtain the temperature of the oxidation region 51 when the insertion portion 31a into which the solder flows includes both the reduction region 50 and the oxidation region 51. In addition, the image captured by the visual sensor 21 is processed by the image processing device 110 described later to total the brightness information and convert the brightness into temperature.

[0058] In addition, a bandpass filter 22 is mounted on the visual sensor 21. The reason for this is to capture the heat radiation from the oxidation area 51 of the red-hot copper pipe 30 and reduce the influence of the heat radiation from the combustion flame 26. The visual sensor 21 has a sensitivity in the vicinity of 700nm to 900nm from the visible infrared region to the near infrared region. And, the bandpass filter 22 can detect the heat radiation from the oxidation area 51 with high accuracy as long as it cuts off the wavelengths other than 700 to 900nm.

[0059] Next, in addition to the above figure, also refer to Figure 5 The operation of the soldering device 100 according to the first embodiment will be described with reference to the flowchart of FIG.

[0060] The copper tube 30 and the brazing joint 31 are processed into respective sizes in advance, and the copper tube 30 is inserted into the insertion portion 31a. In addition, the combustible gas and oxygen are supplied in appropriate amounts from the high-pressure gas cylinder and mixed in the mixer, and then ejected from the welding torch 25 through the gas flow control device 130 to form an ignited state. In addition, the detection area and the threshold value that serves as the reference for judgment are pre-set in the non-contact temperature sensor 23 and the image processing device 110 that processes the image from the visual sensor 21. In addition, the temperature obtained from the non-contact temperature sensor 23 is set as temperature A, and the temperature obtained from the image processing device 110 that processes the image from the visual sensor 21 is set as temperature B.

[0061] By positioning the welding torch 25, Figure 2 The heating position shown (step S110). Then, the non-contact temperature sensor 23 captures the state of the reduction area 50 of the copper tube 30 gradually rising in temperature, and obtains the data of temperature A (step S120). In addition, the visual sensor 21 captures the state of the oxidation area 51 of the copper tube 30 gradually rising in temperature, and obtains the data of temperature B (step S122).

[0062] Temperature B is obtained based on the brightness information of the image obtained from the visual sensor 21. As a method for calculating temperature B, the oxidation area 51 can be set as a set area, for example, divided into several areas and the average brightness of these areas can be obtained, or the minimum brightness of these areas can be obtained and converted to temperature.

[0063] First, the temperature A of the highest temperature portion contacted by the combustion flame 26 reaches the brazing temperature (step S130).

[0064] Next, the brazing temperature determination unit 121 determines whether the temperature A reaches the pre-melting temperature of the brazing material (step S140). The pre-melting temperature of the present disclosure is a temperature close to the melting temperature of the object 300 to be brazed, and is a temperature lower than the melting temperature of the object 300 to be brazed. In the present embodiment, since the combustion flame 26 is in contact with the copper tube 30, it can be considered to be the temperature before the copper tube 30 melts. When the temperature A reaches the pre-melting temperature (step S140: yes), in order to prevent the melting of the object 300 to be brazed, the brazing temperature determination unit 121 outputs an overheating signal (step S145). When receiving the overheating signal, the control device 120 causes the gas flow rate adjustment device 130 to adjust the gas flow rate, causes the positioning mechanism 10 to swing the welding torch 25, or performs both actions. As a result, the temperature A is reduced to a temperature lower than the pre-melting temperature of the object 300 to be brazed, and the melting of the object 300 to be brazed is prevented. Then, the process returns to step S120 and step S122.

[0065] When the temperature A has not reached the pre-melting temperature (step S140: No), the brazing temperature determination unit 121 determines whether the temperature B has reached the brazing temperature (step S150). When the temperature B has not reached the brazing temperature (step S150: No), the brazing temperature determination unit 121 outputs a heating adjustment signal (step S155). When receiving the heating adjustment signal, the control device 120 causes the gas flow rate adjustment device 130 to adjust the gas flow rate, causes the positioning mechanism 10 to swing the welding torch 25, or performs both actions. Then, the process returns to step S120 and step S122.

[0066] When temperature B reaches the brazing temperature (step S150: yes), the brazing temperature determination unit 121 outputs a temperature rise completion signal (step S160). When receiving the temperature rise completion signal, the control device 120 causes the brazing material supply device 24 to start supplying the brazing material (step S170). In addition, in order to supply the amount of brazing material required for brazing, the control device 120 controls the supply amount of the brazing material and the supply speed of the coil-shaped brazing material relative to the brazing material supply device 24. After the brazing material supply device 24 supplies the necessary amount of brazing material, the control device 120 uses the positioning mechanism 10 to retreat the welding torch 25 to the standby position (step S180) to end the brazing. In addition, when there is a next brazing location, it is also possible to move to the heating position of the next brazing location instead of moving to the standby position.

[0067] When the gas flow rate adjustment device 130 adjusts the gas flow rate, the gas flow rate is suppressed to slow down the temperature rise, and the temperature B is kept on standby until the temperature B reaches the brazing temperature. After a certain period of time, when it is determined that the temperature B is above the brazing temperature, the brazing temperature determination unit 121 outputs a temperature rise completion signal. After receiving the temperature rise completion signal, the control device 120 performs the control as described above to end the brazing.

[0068] Figure 6 An example of a temperature curve for gas flow control based on an automatic flame brazing device is shown. T1 represents the lower limit of the brazing temperature, T2 represents the upper limit of the brazing temperature, T3 represents the melting temperature of the object 300 to be brazed, t1 represents the time to start gas flow control, t2 represents the time to start supply of brazing material, and t3 represents the time to end supply of brazing material. During the period from t2 to t3, the brazing material is wound around the brazing joint 31, and the copper tube 30 and the brazing joint 31 are integrated by surface contact, so the value of temperature A is close to the value of temperature B. In addition, the setting of the temperature for starting gas flow control and the temperature for starting supply of brazing material is appropriately determined according to the diameter, heat capacity or shape of the object 300 to be brazed.

[0069] When the welding torch 25 is swung, the welding torch 25 is swung upward and downward relative to the brazed joint 31 until the temperature of the oxidized region 51 reaches the brazing temperature. Figure 7 The relationship between the reduction area 50 and the oxidation area 51 of the copper pipe when the swinging action is performed is shown. The swinging action requires the position and speed of the swing to be set in advance. When a certain period of time passes and it is determined that the temperature B is above the brazing temperature, the brazing temperature determination unit 121 outputs a temperature rise completion signal. After receiving the temperature rise completion signal, the control device 120 performs the control as described above to end the brazing.

[0070] Figure 8 An example of a temperature curve for torch swing control based on an automatic flame brazing device is shown. The descriptions of T1 to T3, t2, and t3 are as described above, and t1 is the time to start swing control. The period from t1 to t2 represents the situation where the torch is swung up and down once and then returns to its original state. During the period from t1 to t2, temperature A moves to the lower temperature side and then returns to near the original temperature. In addition, as for temperature B, when the torch approaches, the temperature rises significantly, and when the torch returns, the temperature rises slowly. The period from t2 to t3 is as described above. In addition, the number of swings of the torch, the temperature at which the swing is started, and the temperature at which the supply of brazing material is started are appropriately determined according to the diameter, heat capacity or shape of the object 300 to be brazed.

[0071] In addition, when temperature A exceeds the upper limit of the brazing temperature and approaches the melting temperature of the brazing material before temperature B reaches the brazing temperature (step S140: Yes), an overheating signal is output (step S145). When receiving the overheating signal output, the control device 120 performs swing control of the welding torch 25 to reduce temperature A to the brazing temperature range to prevent melting.

[0072] According to the structure of the first embodiment, the melting of the base material caused by overheating in the reduction part can be prevented, and the temperature distribution of the joint part that allows the brazing material to flow in to generate both the oxidation part and the reduction part can be identified. Therefore, the brazing device 100 controls the gas flow rate or swings the welding torch according to the temperature distribution, so that high-reliability brazing can be performed. In addition, since the temperature distribution is identified, it is possible to respond to changes in the ambient temperature or the initial temperature of the object to be brazed 300.

[0073] In addition, in the existing structure, only one sensor is used to obtain the temperature, and only the temperature of one side of the reduction area or the oxidation area can be obtained. For example, in the case of a sensor that only obtains the temperature of the reduction area, only temperature A is obtained, and temperature A reaches the brazing temperature. At this time, if the temperature B is a temperature lower than the brazing temperature, if the brazing material is supplied, due to insufficient temperature, insufficient wetting of the brazing material or insufficient surrounding of the brazing material may occur, resulting in defects. In addition, in the case of a sensor that only obtains the temperature of the oxidation area, only temperature B is obtained, and it is judged that temperature B has reached the brazing temperature. At this time, since temperature A is higher than temperature B, the copper pipe may melt and cause defects.

[0074] Implementation Method 2

[0075] The supply of the solder to the object to be soldered 300 may be performed by using a pre-soldered solder, instead of inserting the solder as in the first embodiment. Fig. 9 Even when the supply of the brazing material is the ring brazing material 60, the method of obtaining the temperature distribution and the method of controlling the heating are the same as those in the first embodiment. Figure 5 After the temperature rise completion signal (step S160) is received, the operation is different from that in the first embodiment in that the welding torch 25 is only retracted to the standby position.

[0076] According to the structure of the second embodiment, in addition to the effects of the first embodiment, the device can be constructed at a low cost because the solder supply device 24 is not required. In addition, since there is no soldering defect caused by the solder insertion position deviation of the solder supply device 24, it is possible to achieve soldering with higher reliability.

[0077] Implementation 3

[0078] exist Fig.10 In the third embodiment shown, when the brazed portion of the object to be brazed 300 is located close to the brazed tube 32 , brazing is performed by additionally obtaining a temperature set in the oxidized region 52 of the brazed joint 34 .

[0079] The temperature acquisition of the brazing-finished pipe 32 and the brazing material 33 is performed immediately before the brazing of the copper pipe 30, and the temperature is sometimes higher than that of the copper pipe 30 at the start of brazing. Alternatively, the brazing-finished pipe 32 and the brazing material 33 may be made of materials different from those of the copper pipe 30, and the melting point of the brazing material 33 may be lower than that of the brazing material of the copper pipe 30. When brazing the copper pipe 30 under these conditions, it is necessary to make the temperature of the brazing joint 34 not exceed the melting point of the brazing material 33. If the melting point of the brazing material 33 is exceeded, the chamfer formed on the brazing material 33 may disappear, and the reliability in terms of strength may be reduced. In addition, if the melting point of the brazing material 33 is exceeded, the brazing material 33 may flow excessively into the inside of the brazing joint 34 and leak.

[0080] Next, refer to Fig.11 The operation of the soldering device 100 according to the third embodiment will be described with reference to the flowchart of FIG.

[0081] exist Fig.11 In the flowchart, the temperature obtained from the non-contact temperature sensor 23 is set to temperature A, the temperature obtained from the image processing device 110 that processes the image from the visual sensor 21 is set to temperature B, and the temperature obtained from the oxidized area 52 of the brazed portion of the brazed completed tube 32 is set to temperature C.

[0082] By positioning the welding torch 25, Figure 2 The heating position shown (step S310). Then, the non-contact temperature sensor 23 captures the state of the reduction area 50 of the copper tube 30 gradually rising in temperature, and obtains the data of temperature A (step S320). In addition, the visual sensor 21 captures the state of the oxidation area 51 of the copper tube 30 gradually rising in temperature, and obtains the data of temperature B (step S322). Furthermore, the visual sensor 21 captures the state of the oxidation area 52 of the brazed tube 32 gradually rising in temperature, and obtains the data of temperature C (step S324).

[0083] Like the temperature B, the temperature C is obtained based on the brightness information of the image obtained from the visual sensor 21. The calculation method is the same as the calculation method of the temperature B described above.

[0084] Next, the soldering temperature determination unit 121 determines whether the temperature C reaches the pre-melting temperature of the solder 33 (step S330). When the temperature C reaches the pre-melting temperature of the solder 33 (step S330: Yes), the soldering temperature determination unit 121 outputs an overheating signal (C) (step S335). When receiving the overheating signal (C), the control device 120 causes the positioning mechanism 10 to swing the welding torch 25 to reduce the temperature C to a temperature lower than the pre-melting temperature of the solder, thereby preventing the solder 33 from melting. After that, the process returns to step S320, step S322, and step S324.

[0085] When the temperature C has not reached the pre-melting temperature of the brazing material 33 (step S330: No), then the temperature A of the highest temperature portion contacted by the combustion flame 26 reaches the brazing temperature (step S340).

[0086] Next, the soldering temperature determination unit 121 determines whether the temperature A reaches the pre-melting temperature of the solder (step S350). When the temperature A reaches the pre-melting temperature (step S350: Yes), the soldering temperature determination unit 121 outputs an overheating signal (A) (step S355). When receiving the overheating signal (A), the control device 120 causes the positioning mechanism 10 to swing the welding torch 25. Thus, the temperature A is lowered to a temperature lower than the pre-melting temperature of the solder, and the solder 33 is prevented from melting. After that, the process returns to step S320, step S322, and step S324.

[0087] When temperature A has not reached the pre-melting temperature (step S350: No), the brazing temperature determination unit 121 determines whether temperature B has reached the brazing temperature (step S360). When temperature B has not reached the brazing temperature (step S360: No), the brazing temperature determination unit 121 outputs a heating adjustment signal (step S365). When receiving the heating adjustment signal, the control device 120 causes the gas flow rate adjustment device 130 to adjust the gas flow rate, causes the positioning mechanism 10 to swing the welding torch 25, or performs both actions. Thereafter, the process returns to step S320, step S322, and step S324.

[0088] When the temperature B reaches the brazing temperature (step S360: yes), the brazing temperature determination unit 121 outputs a temperature rise completion signal (step S370). When receiving the temperature rise completion signal, the control device 120 causes the brazing material supply device 24 to start supplying the brazing material (step S380). In order to supply the amount of brazing material required for brazing, the control device 120 controls the supply amount of the brazing material and the supply speed of the coil-shaped brazing material relative to the brazing material supply device 24. After the brazing material supply device 24 supplies the required amount of brazing material, the control device 120 uses the positioning mechanism 10 to retreat the welding torch 25 to the standby position (step S390) to end the brazing. In addition, if there is a next brazing part, it is also possible to move to the heating position of the next brazing part instead of the standby position. In addition, before the temperature B reaches the brazing temperature, when the temperature C approaches the melting temperature of the brazing material and reaches the pre-melting temperature (step S330: yes), an overheating signal (C) is output (step S335). When the temperature A exceeds the upper limit of the soldering temperature and approaches the melting temperature of the solder and reaches the pre-melting temperature (step S350: Yes), an overheating signal (A) is output (step S355). When receiving the overheating signal output, the control device 120 performs the control described above.

[0089] In addition, in the temperature measurement of the oxidation region 52 , it is only necessary to expand the field of view of the visual sensor 21 , and the image processing method is the same as that of the oxidation region 51 without any problem, so there is no need to add a sensor.

[0090] According to the structure of the third embodiment, in addition to the effects of the first embodiment, the reliability of the brazed pipe 32 can be ensured, so that even products to be brazed having adjacent portions can be brazed stably.

[0091] Implementation 4

[0092] The sensor for measuring the oxidation region may also be a non-contact temperature sensor. In this case, a different emissivity value is set from that of the non-contact temperature sensor (first temperature measuring member) 23 for measuring the reduction region. For example, the emissivity of the sensor for measuring the oxidation region is set to 0.7, and the emissivity of the sensor for measuring the reduction region is set to 0.03.

[0093] Fig.12 A block diagram showing a soldering device 100 according to a fourth embodiment. Fig.12 The block diagram is similar to that of FIG. 1 except that a non-contact temperature sensor 21a is provided instead of the visual sensor 21 for measuring the oxidation area. Figure 4 same.

[0094] According to the structure of the fourth embodiment, since the image processing device 110 is not required, the structure of the device is simple and the device can be configured at low cost. In addition, since the image processing program and related programs are not required, the device startup period can be shortened.

[0095] Implementation method 5

[0096] like Fig.13 As shown, the object to be brazed 301 may be a copper member, that is, copper plates 35 and 36, which are overlapped and brazed, and the visual sensor 21 is arranged at a position that is not affected by the burning flame 26 from the welding torch 25. Consider a case where the copper plates 35 and 36 are heated from the copper plate 35 side by the welding torch 25, and the brazing is performed by inserting the brazing material when the temperature of the brazing material inflow portion 37 reaches the brazing temperature.

[0097] When the objects to be brazed 301 are copper plates 35 and 36 that are overlapped and brazed, it is preferable to heat them from both sides of the copper plates 35 and 36 using the welding torch 25. In the fifth embodiment, it is considered that there is a restriction on the range of motion of the positioning mechanism, or that heating is performed only from one side because there are components around the product.

[0098] The temperature measurement area in this case is explained. Fig.14 As shown by arrow Y, the measurement area of ​​non-contact temperature sensor 23 is set in reduction area 53 which is reduced by the influence of combustion flame 26. In addition, the measurement area of ​​visual sensor 21 is set in oxidation area 54 which is not influenced by the welding torch of arrow Z.

[0099] Even in the case where the copper plates 35 and 36 are overlapped and brazed, the brazing operation is the same as that of the first embodiment. Figure 5 The heating position of the welding torch 25 is as follows: Fig.13 As shown, the copper plates 35 and 36 can be heated together, or the welding torch 25 can be swung to heat the copper plates 35 and 36 to near the brazing temperature. Figure 5 A process of swinging the welding torch 25 is added before step S110.

[0100] According to the structure of the fifth embodiment, when the objects to be brazed 301 are overlapped and brazed as copper plates 35 and 36, the melting of the base material caused by overheating in the reduction portion can be prevented. In addition, the temperature of the reduction portion on the surface side of the brazing material inflow portion and the oxidation portion on the back side can be identified. Therefore, the brazing device 100 controls the gas flow rate or swings the welding torch according to the temperature distribution, so that high-reliability brazing can be performed. In addition, since the temperature distribution is identified, it is possible to correspond to the changes in the ambient temperature or the initial temperature of the object to be brazed 301.

[0101] In addition, the present disclosure is not limited to the above-described embodiment, and various modifications and applications are possible.

[0102] In the first embodiment, the visual sensor 21, the non-contact temperature sensor 23, the brazing material supply device 24, and the welding torch 25 are all mounted on the fixing jig 20 of the positioning mechanism 10, but may be mounted on other mechanisms.

[0103] The objects to be brazed 300 have a structure in which straight pipes are butted against each other, but may also be other structures that can have both a reduced portion and an oxidized portion during brazing.

[0104] In addition, the visual sensor 21 corresponding to the temperature B and the temperature C and the non-contact temperature sensor 23 corresponding to the temperature A may also be sensors having structures other than those described above. For example, a thermal observer that can correspond to the measurement wavelength across the combustion flame may also be used. In this case, the image processing device 110 and the control device 120 have a structure for appropriately acquiring the temperature A, the temperature B, and the temperature C.

[0105] In addition, Figure 5 The overheating signal output (step S145) and Fig.11 In the overheating signal (C) output (step S335) and the overheating signal (A) output (step S355), the swinging of the welding torch 25, the adjustment of the gas flow rate, or both may be used.

[0106] The present disclosure can be implemented in various ways and variations without departing from the broad spirit and scope of the present disclosure. In addition, the above-mentioned embodiments are used to illustrate the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is not represented by the embodiments but by the claims. Moreover, various variations implemented within the meaning of the claims and their equivalents are considered to be within the scope of the present disclosure.

[0107] This application is based on Japanese Patent Application No. 2020-057825 filed on March 27, 2020. The specification, claims and drawings of Japanese Patent Application No. 2020-057825 are incorporated herein in their entirety by reference.

[0108] Industrial Applicability

[0109] The present disclosure can be applied to brazing of copper members.

[0110] Description of Reference Numerals

[0111] 10 positioning mechanism, 20 fixing fixture, 20a component, 20b component, 21 visual sensor (second temperature measuring component), 21a non-contact temperature sensor (second temperature measuring component), 22 band pass filter, 23 non-contact temperature sensor (first temperature measuring component), 24 solder supply device, 24a solder supply unit, 25 welding torch, 26 combustion flame, 30 copper tube, 31 solder joint, 31a insertion unit, 32 soldered tube (soldered copper component), 33 solder, 34 solder joint, 35 copper plate, 36 copper plate, 37 solder inflow portion, 50 reduction region, 51 oxidation region, 52 oxidation region, 53 reduction region, 54 oxidation region, 60 solder ring, 100 soldering device, 110 image processing device (second temperature measuring component, image processing device), 111 brightness totalizing portion, 112 temperature calculating portion, 120 control device (control component), 121 soldering temperature determining portion, 122 control portion, 123 storage portion, 124 communication portion, 130 gas flow adjustment device, 300 object to be soldered, 301 object to be soldered.

Claims

1. An automatic flame brazing device for copper components, characterized in that: The automatic flame brazing device for copper components has: A welding torch for heating, supplied with gas; A positioning mechanism for positioning the welding torch; a first temperature measuring component for detecting light in a first wavelength range radiated from a reduction portion of the copper member to measure a temperature of the reduction portion; a second temperature measuring means for detecting light radiated from an oxidized portion of the copper member in a second wavelength range different from the first wavelength range to measure a temperature of the oxidized portion; as well as The control means, when it is determined that the temperature of the reduction portion reaches the brazing temperature and is lower than the melting temperature of the copper member, and the temperature of the oxidation portion reaches the brazing temperature, causes the copper member to be brazed using an automatic flame brazing device, The reduced portion is a portion of the copper member whose surface is cleaned by the reducing action of the combustion flame of the welding torch. The oxidized portion is a portion of the copper member that is heated by the combustion flame of the welding torch and becomes red hot and oxidized.

2. The automatic flame brazing device for copper components according to claim 1, characterized in that: The control unit swings the welding torch when the temperature of the reduction portion reaches a pre-melting temperature.

3. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: The control means at least one of adjusts the gas flow rate and swings the welding torch when it is determined that the temperature of the reduction portion has reached the brazing temperature and is lower than the pre-melting temperature and the temperature of the oxidation portion is lower than the brazing temperature.

4. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: When the reduction part and the oxidation part reach the brazing temperature, the control unit issues a signal for judging the supply of brazing material.

5. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: Brazing is performed using a pre-applied brazing filler metal placed at the brazing site.

6. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: The second temperature measuring means measures the temperature of an oxidized portion of the brazed copper member that is close to the brazed portion and has been brazed.

7. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: The first temperature measuring device is disposed on the torch side of the overlap brazing of the copper plates to measure the temperature of the reduction portion, and the second temperature measuring device is disposed on the opposite side of the torch not affected by the combustion flame to measure the temperature of the oxidation portion.

8. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: The second temperature measuring unit includes: a visual sensor for capturing an image of the oxidation portion; an image processing unit for processing the image and converting it into a temperature; and a bandpass filter for cutting off wavelengths other than 700 nm to 900 nm.

9. The automatic flame brazing device for copper components according to claim 1 or 2, characterized in that: The first temperature measuring member and the second temperature measuring member are non-contact temperature measuring devices with set emissivity for the reduction part and the oxidation part, respectively. The first wavelength range is 3.6 μm ~ 3.95 μm, The second wavelength range is 700nm~900nm.

10. A method for automatic flame brazing of copper components, characterized in that: The automatic flame brazing method for copper components has the following features: The process of heating the copper component using a welding torch; The step of detecting light of a first wavelength range radiated from a reduced portion of the copper member by a first temperature measuring member to measure the temperature of the reduced portion, and detecting light of a second wavelength range different from the first wavelength range radiated from an oxidized portion of the copper member by a second temperature measuring member to measure the temperature of the oxidized portion; as well as When it is determined that the temperature of the reduced portion reaches the brazing temperature and is lower than the melting temperature of the copper member, and the temperature of the oxidized portion reaches the brazing temperature, a brazing step is performed. The reduced portion is a portion of the copper member whose surface is cleaned by the reducing action of the combustion flame of the welding torch. The oxidized portion is a portion of the copper member that is heated by the combustion flame of the welding torch and becomes red hot and oxidized.

11. The automatic flame brazing method for copper components according to claim 10, characterized in that: The automatic flame brazing method for copper members further includes a step of swinging the welding torch when the temperature of the reduction portion reaches a pre-melting temperature.

12. The automatic flame brazing method for copper components according to claim 10 or 11, characterized in that: The automatic flame brazing method for copper parts further includes a step of adjusting at least one of a gas flow rate and swinging the welding torch when it is determined that the temperature of the reduced portion has reached the brazing temperature and is lower than the pre-melting temperature and the temperature of the oxidized portion is lower than the brazing temperature.

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