JP7266272B2 - brazing equipment - Google Patents

Description

The present disclosure relates to brazing equipment.

A brazing apparatus has been proposed that determines a change in the shape of an imaged placement brazing and controls a heating means in response to the determined change (see, for example, Patent Document 1). In the technique described in Patent Document 1, the shape of the contour line of the placement brazing (15) imaged by the imaging camera (30) changes as illustrated in FIG. 2 or FIG. 4 of Patent Document 1. is determined by the control unit (33), and the control unit (33) controls the heating output by the burner (19) or the heating coil (36).

JP-A-2002-263879

However, as exemplified in FIG. 1 or FIG. 5 of Patent Document 1, when the imaging camera is directed obliquely downward, even if the imaging camera captures an image of the surroundings of the placement wax, FIG. Alternatively, an image such as that illustrated in FIG. 4 cannot be obtained. 2 or 4 of Patent Document 1 is an image obtained when capturing an image of the periphery of the wax from a substantially horizontal direction, and is captured by an imaging camera directed obliquely downward. Not a possible image.

When the image pickup camera is directed obliquely downward, when the image pickup camera takes an image of the surroundings of the brazing filler metal, the outline of the brazing filler metal appears at a position overlapping the upper end surface of the member to be joined (12). In this case, if the upper end surface of the member to be joined and the color of the brazing filler metal are similar to each other, it becomes difficult to clearly identify the outline of the brazing filler metal, and there is a possibility that the melting timing of the brazing filler metal cannot be detected appropriately.

In addition, even if the contour line of the brazing filler metal can be identified, when the imaging camera is directed obliquely downward, the brazing filler metal before melting appears as a substantially elliptical ring, and the fillet formed after melting the brazing filler metal appears. also looks like an elliptical ring. In this case, there may not be a large difference in the position of the contour line before and after the melting of the brazing filler metal.

The above problems are expected when the imaging camera is directed obliquely downward. There is a possibility that it can be resolved. However, various instruments may be placed around the brazed point, as well as burners or heating coils. Therefore, if devices that cannot be placed in other positions are arranged in order, as a result, it may become difficult to dispose the image pickup camera at a position where it is possible to take an image of the surroundings of the wax from a substantially horizontal direction. .

In addition, depending on the size and shape of the base material to be brazed (joint material and material to be joined), the base material becomes an obstacle, and the camera is placed at a position where the surroundings of the brazing brazing can be imaged from a substantially horizontal direction. can be difficult to place. Alternatively, if the surroundings of the brazing filler metal are imaged from a substantially horizontal direction, the surroundings of the brazing filler metal may be hidden behind the base material. That is, due to various circumstances, there is a possibility that the surroundings of the brazing filler metal cannot be imaged from a substantially horizontal direction.

In one aspect of the present disclosure, there is provided a brazing apparatus capable of accurately recognizing changes in the shape of the brazing material and performing appropriate heating control without imaging the surroundings of the brazing material from a substantially horizontal direction. is desirable.

One aspect of the present disclosure is a brazing apparatus. A brazing apparatus includes a heating section, a detection section, and a control section. The heating unit is configured to be able to heat the brazing material placed at the brazing location. The detection unit is configured to detect a change in shape of the brazing filler metal as the brazing filler metal melts. The control unit is configured to be capable of controlling the heating output of the heating unit, and reduces or stops the heating output of the heating unit when the detection unit detects that the shape of the brazing material has changed after the heating unit starts heating. . The detection section has a light projection section and an imaging section. The light projecting unit is configured to project light to project a predetermined pattern onto the surface of the brazing material. The imaging unit is configured to be capable of imaging the pattern. The detection section is configured to be able to detect a change in the shape of the brazing material based on a change in the shape of the pattern imaged by the imaging section.

According to the brazing apparatus configured in this manner, after the heating unit starts heating, if the detection unit detects that the shape of the brazing material has changed, the heating output of the heating unit is reduced or stopped. As a result, the heating output of the heating unit can be reduced or stopped in accordance with the melting timing of the brazing filler metal, and the heating time can be optimized. Further, the detection section detects that the shape of the brazing material has changed based on the change in the shape of the pattern imaged by the imaging section. Therefore, even if the imaging unit cannot be placed at a position suitable for imaging the outline of the brazing material, or if the outline of the brazing material cannot be clearly identified in the captured image, If the projected pattern can be properly imaged by the imaging unit, it is possible to appropriately detect that the shape of the brazing material has changed.

FIG. 1 is a block diagram showing the configuration of a brazing device. FIG. 2 is an explanatory diagram showing the imaging direction and the laser line projection direction of the first sensor unit. FIG. 3A is an explanatory diagram showing a state in which the base material and the brazing filler metal forming the work are disassembled. FIG. 3B is an explanatory view showing a state in which the base material and the brazing material forming the work are assembled. FIG. 4A is an explanatory diagram showing a workpiece, a heating coil, a first sensor unit and a second sensor unit. FIG. 4B is an explanatory diagram showing a workpiece and heating coils. FIG. 5 is an explanatory diagram showing a state in which a laser line beam is irradiated onto a workpiece.

The brazing apparatus described above will now be described with reference to exemplary embodiments. As shown in FIG. 1, the brazing apparatus 1 includes a control device 3, a high-frequency induction heating device 5, a first sensor unit 7A, a second sensor unit 7B, a heating coil transportable robot 8, and a workpiece loading/unloading robot 9. . The high-frequency induction heating device 5 includes a high-frequency welding power source device 11 , a water cooling device 13 and a heating coil 15 . The first sensor unit 7A and the second sensor unit 7B each comprise a laser line generator 17 and a CCD camera 19. FIG.

The control device 3 is configured by, for example, a PLC (programmable logic controller) including a microprocessor and flash memory. The control device 3 is configured to be able to receive signals from the first sensor unit 7A and the second sensor unit 7B. Further, the control device 3 is configured to be capable of controlling the high-frequency induction heating device 5 , the heating coil portable robot 8 , and the workpiece loading/unloading robot 9 .

In the high-frequency induction heating device 5, the high-frequency welding power supply device 11 supplies alternating current to the heating coil 15 (maximum output 20 kW, frequency 30 kHz in this embodiment). When an alternating current is supplied to the heating coil 15, the heating coil 15 generates a magnetic field around a portion of the work 21 to be heated, thereby heating the work 21 by induction heating. The water cooling device 13 supplies cooling water to the heating coil 15 . Cooling water supplied from the water cooling device 13 circulates through the inside of the heating coil 15 to the water cooling device 13 . This prevents the temperature of the heating coil 15 from excessively rising due to the heat generated in the heating coil 15 and the radiant heat from the workpiece 21 .

In the first sensor unit 7A and the second sensor unit 7B, the laser line generator 17 projects a laser beam to form a line-shaped pattern (hereinafter referred to as this line-shaped pattern is also called a laser line.) can be projected. The CCD camera 19 is a measuring camera provided for measuring the molten state of the brazing material. The CCD camera 19 is arranged facing a location where the laser line generator 17 projects light.

As shown in FIG. 2, the projection direction of the laser line generator 17 and the imaging direction of the CCD camera 19 depend on the imaging positions of the first sensor unit 7A and the second sensor unit 7B (distance from the CCD camera 19 shown in FIG. 2). are arranged to intersect at a position where the imaging distance is 450 mm±10 mm). The area measured by the first sensor unit 7A and the second sensor unit 7B is within the range of height 16 mm×horizontal width 20 mm×depth ±10 mm. "Height" is the dimension in the direction perpendicular to the plane of the paper in FIG. Although illustration is omitted, the first sensor unit 7A and the second sensor unit 7B have large-field CCD cameras (70 mm in length × Width 90mm x Depth ±300mm) is also installed. Although not shown, the first sensor unit 7A and the second sensor unit 7B are also equipped with LEDs for illumination.

The heating coil transportable robot 8 is composed of a general-purpose 6-axis industrial robot (vertical articulated robot), and a heating coil 15 is attached to the tip of its movable portion. By operating the heating coil portable robot 8, the heating coil 15 can be moved to a position where brazing can be performed (hereinafter also referred to as an operating position), or a position that does not interfere with the loading and unloading of the work 21 (hereinafter referred to as The heating coil 15 can be retracted to the retracted position. The workpiece loading/unloading robot 9 is composed of a general-purpose 6-axis industrial robot, and is capable of holding the workpiece 21 with a hand portion provided at the tip of its movable portion and performing brazing of the workpiece 21 from the loading source. position (hereinafter also referred to as a brazing position), or the work 21 can be moved from the brazing position to the unloading destination.

Next, behavior of the brazing apparatus 1 will be described. In this embodiment, the work 21 as shown in FIGS. 3A and 3B is taken as an example. The workpiece 21 shown in FIGS. 3A and 3B is composed of an aluminum pipe 23 (outer diameter 16 mm, wall thickness 1.5 mm, length 200 mm) and an aluminum charge valve 25 (outer diameter 13 mm, length 30 mm). be. A recess having a depth of 2.5 mm is formed in the side surface of the aluminum pipe 23, and a hole having an inner diameter of 8 mm is formed in the bottom surface of the recess. One end of the charge valve 25 is inserted into this hole. As the brazing filler metal 27, ring brazing (outer diameter 13.5 mm, inner diameter 9.5 mm) is used. The work 21 is assembled in the state shown in FIG. 3B, fixed by a fixing jig (not shown), and integrated with the fixing jig.

The workpiece 21 integrated with the fixing jig is manually installed at the delivery source. In the control device 3 , when the user performs an operation to instruct the start of brazing, the control device 3 commands the work loading/unloading robot 9 to load the work 21 . The work loading/unloading robot 9 that receives a command from the control device 3 transports the work 21 integrated with the fixing jig from the loading source to the brazing position. Subsequently, the controller 3 commands the heating-coil transportable robot 8 to move the heating coil 15 . Upon receiving a command from the control device 3, the heating coil transportable robot 8 moves the heating coil 15 from the standby position to the operating position. As a result, the heating coil 15 and the workpiece 21 are arranged in relative positions as shown in FIGS. 4A and 4B.

As shown in FIG. 4A, the first sensor unit 7A and the second sensor unit 7B are arranged at positions capable of imaging the workpiece 21 transported to the brazing position from obliquely above the brazing filler metal 27 . A charge valve 25 and a brazing material 27 are arranged at the imaging position (see FIG. 2) of the first sensor unit 7A and the second sensor unit 7B. The first sensor unit 7A and the second sensor unit 7B project laser light from the laser line generator 17 . As a result, a laser line extending substantially vertically along the surfaces of the charge valve 25 and the brazing material 27 is projected onto the surfaces of the charge valve 25 and the brazing material 27, as shown in FIG. The first sensor unit 7A and the second sensor unit 7B capture an image of the above-described measurement area (16 mm in height×20 mm in horizontal width×±10 mm in depth) with the CCD camera 19 . In the measurement area, the range in which the laser line projected onto the brazing filler metal 27 exists can be narrowed down in advance to an arbitrary size, and that range can be designated as the brazing detection area.

Subsequently, the control device 3 commands the high-frequency induction heating device 5 to start heating. The high-frequency induction heating device 5 receives a command from the control device 3, adjusts the output of the heating coil 15 to a high output (for example, about 80% of the maximum output in the present embodiment) by the high-frequency welding power supply 11, Heating of the workpiece 21 is started. The heating coil 15 can shorten the heating time as the output is increased. However, if the output of the heating coil 15 is excessively increased (in this embodiment, for example, if it is set to about 100% of the maximum output), the base material tends to be easily distorted by heat and dented. Also, if the output of the heating coil 15 is excessively reduced (for example, about 60% of the maximum output in this embodiment), the time until the brazing filler metal 27 melts tends to increase. Therefore, in this embodiment, the output of the heating coil 15 is adjusted to about 80% of the maximum output as described above.

The first sensor unit 7A and the second sensor unit 7B detect changes in the shape of the laser line projected within the brazing detection area every 0.1 second, and monitor the melting state of the brazing filler metal 27 . When the surface shape of the brazing material 27 changes, the shape of the laser line also changes. The first sensor unit 7A and the second sensor unit 7B output a signal to that effect to the control device 3 when the shape of the laser line changes. In the case of this embodiment, the first sensor unit 7A and the second sensor unit 7B detect the three-dimensional shape of the surface of the brazing material 27 irradiated with the laser line, and when the three-dimensional shape changes, the controller 3 output a signal to

Since the arrangement position and projection direction of the laser line generator 17 and the arrangement position and imaging direction of the CCD camera 19 are known, the position of the vertical line passing through the intersection of the imaging direction and the projection direction and the laser line are known. The distance from the vertical line to the surface of the brazing filler metal 27 can be obtained by triangulation based on the amount of deviation from the position of the irradiated high-brightness region. As a result, the three-dimensional coordinate values of the surface of the brazing filler metal 27 can be calculated, and when the three-dimensional coordinate values change, it is possible to detect that the three-dimensional shape of the range irradiated with the laser line has changed. can be done. In the case of this embodiment, a change in the shape of the laser line was detected about 20 to 23 seconds after the start of heating. The change in the shape of the laser line may be detected by calculating the three-dimensional coordinates as described above and then detecting the change in the coordinate values. A change in shape of the high-brightness area may be detected.

When the first sensor unit 7A and the second sensor unit 7B detect the shape change of the laser line, the control device 3 commands the high-frequency induction heating device 5 to reduce the heating output. The high-frequency induction heating device 5 receives a command from the control device 3, and adjusts the output of the heating coil 15 to a low output (for example, about 30% of the maximum output in the present embodiment) by the high-frequency welding power supply 11, Facilitate melting of the wax. In the case of this embodiment, the state in which the output of the heating coil 15 is switched to the low output is maintained for 3 seconds, and then the output of the heating coil 15 is stopped. Since this holding time can vary depending on the shape, material, etc. of the work 21 , the optimal holding time can be determined by trial for each work 21 . Subsequently, the control device 3 commands the work loading/unloading robot 9 to carry out the work 21 . The workpiece loading/unloading robot 9 that has received a command from the control device 3 transports the workpiece 21 integrated with the fixing jig from the brazing position to the unloading destination.

[effect]
According to the brazing apparatus 1 described above, after starting heating by the heating coil 15 (corresponding to an example of the heating unit in the present disclosure), the first sensor unit 7A (corresponding to an example of the detecting unit in the present disclosure) ) and the second sensor unit 7B (corresponding to an example of the detection unit referred to in the present disclosure) detect that the shape of the brazing material 27 has changed, the heating output of the heating coil 15 is reduced. As a result, the heating output of the heating coil 15 can be reduced in accordance with the melting timing of the brazing filler metal 27, and the heating time can be optimized.

Further, the first sensor unit 7A and the second sensor unit 7B are the laser lines (corresponding to an example of the pattern in the present disclosure) imaged by the CCD camera 19 (corresponding to an example of the imaging unit in the present disclosure). Based on the change in shape, it is detected that the shape of the brazing material 27 has changed. Therefore, even if the CCD camera 19 cannot be placed at a position suitable for imaging the outline of the brazing material 27 or if the outline of the brazing material 27 cannot be clearly identified in the captured image, the laser If the CCD camera 19 can properly image the laser line projected from the line generator 17 (corresponding to an example of the light projecting section referred to in the present disclosure), it is possible to appropriately detect that the shape of the brazing material 27 has changed. .

In addition, in the case of the present embodiment, the control device 3 (corresponding to an example of the control unit referred to in the present disclosure) sets the heating coil 15 to 80% of the maximum output (the present disclosure) when starting heating by the heating coil 15. ), and after that, when the first sensor unit 7A and the second sensor unit 7B detect that the shape of the brazing material 27 has changed, the heating coil 15 is set to the maximum output. of 30% (equivalent to an example of the second heating output in the present disclosure), and then after 3 seconds (equivalent to an example of the predetermined time in the present disclosure), heating by the heating coil 15 is configured to stop Therefore, it is possible to perform proper brazing by promoting the melting of the brazing material in 3 seconds in which the heating coil 15 is operated at 30% of the maximum output.

In addition, in the case of the present disclosure, the heating coil 15 capable of heating the object to be heated by induction heating is employed, so the heating output can be easily controlled compared to the case of using other heating means.

[Other embodiments]
Although the brazing apparatus 1 has been described above with reference to exemplary embodiments, the above-described embodiments are merely examples as one aspect of the present disclosure. That is, the present disclosure is not limited to the exemplary embodiments described above, and can be embodied in various forms without departing from the technical spirit of the present disclosure.

For example, in the above embodiment, the shape change of the brazing material 27 is detected by the first sensor unit 7A and the second sensor unit 7B, but the number of such sensor units may be one or three or more. When a plurality of sensor units are provided, the output of the heating coil 15 may be reduced when any one of the sensor units detects a change in the shape of the brazing filler metal 27. The output of the heating coil 15 may be reduced when the shape change of the material 27 is detected. For these controls, an optimum one may be selected depending on the shape of the work 21, the materials of the work 21 and the brazing material 27, and the like.

Moreover, in the above-described embodiment, the heating coil 15 capable of heating the object to be heated by induction heating is used, but other heating means may be used. Examples of other heating means include, for example, gas burners. In this case, the heating output of the gas burner can be adjusted by controlling the flow rate of the gas supplied to the gas burner. Further, in the above-described embodiment, an example in which the heating coil transportable robot 8 and the workpiece loading/unloading robot 9 are provided has been shown, but it is optional whether or not to provide these robots.

Further, in the above-described embodiment, the aluminum base material (the aluminum pipe 23 and the aluminum charge valve 25) is exemplified as the base material to be brazed, but the material of the base material is also arbitrary. The material of the brazing material 27 may be selected according to the material of the base material. Also, the form of the brazing material 27 may be powder, paste, or the like. The base material to be brazed is also not limited to pipes and charge valves.

Further, in the above embodiment, an example in which one laser line is projected onto the surface of the brazing filler metal 27 was shown, but the shape and number of patterns projected onto the surface of the brazing filler metal 27 may vary depending on the surface shape of the brazing filler metal 27. The pattern is not limited to one laser line, as long as it can be detected that there has been a change. For example, a striped pattern composed of a plurality of lines may be projected, or a lattice pattern in which a plurality of lines are arranged vertically and horizontally may be projected. Alternatively, a plurality of dots may be projected, or a pattern having any other arbitrary shape may be projected. In the above embodiment, the pattern projected onto the surface of the brazing filler metal 27 is a pattern that does not move from a specific position, but a line that moves in a predetermined scanning direction may be projected.

In addition to the above, the functions realized by one component in each of the above embodiments may be configured to be realized by a plurality of components. Moreover, the function realized by a plurality of components may be realized by a single component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least part of the configuration of each of the above embodiments may be added, replaced, etc. with respect to the configuration of the other above embodiments.

[supplement]
In addition, as is clear from the exemplary embodiments described above, the brazing apparatus of the present disclosure may further include the following configurations.

In one aspect of the present disclosure, when starting heating by the heating unit, the control unit operates the heating unit with the first heating output, and after that, when the detection unit detects that the shape of the brazing material has changed, , the heating unit is operated with a second heating output that is lower than the first heating output, and after a predetermined time has elapsed since the heating unit is operated with the second heating output, heating by the heating unit may be configured to stop the

In one aspect of the present disclosure, the heating unit may be configured by a heating coil capable of heating the object to be heated by induction heating.

DESCRIPTION OF SYMBOLS 1... Brazing apparatus, 3... Control apparatus, 5... High-frequency induction heating apparatus, 7A... First sensor unit, 7B... Second sensor unit, 8... Heating coil transportable robot, 9... Work loading/unloading robot, 11... HIGH-FREQUENCY WELDING POWER SUPPLY DEVICE, 13: WATER COOLER, 15: HEATING COIL, 17: LASER LINE GENERATOR, 19: CCD CAMERA, 21: WORK, 23: ALUMINUM PIPE, 25: CHARGE VALVE, 27: BRASSING MEDIUM.

Claims (3)

a heating unit configured to heat a brazing material placed at a brazing location;
a detection unit capable of detecting a change in the shape of the brazing material as the brazing material melts;
The heating output of the heating unit can be controlled, and when the detection unit detects that the shape of the brazing material has changed after the heating unit starts heating, the heating output of the heating unit is reduced or stopped. a control unit that causes
with
The detection unit is
a light projecting unit capable of projecting a predetermined pattern on the surface of the brazing material by projecting light;
an imaging unit configured to be capable of imaging the pattern;
has
The detection unit is in a state in which the light projection unit continues to project the pattern onto the surface of the brazing material without changing the relative position between the light projection unit and the brazing material. a brazing device configured to measure a three-dimensional shape of the brazing material based on the pattern obtained by the brazing material, and detect a change in the three-dimensional shape of the brazing material based on a change in the measured value. A brazing device according to claim 1,
The brazing apparatus, wherein the light projecting unit is configured to project a laser beam and project a laser line, which is the line-shaped pattern, onto the surface of the brazing material that is the projection destination. A brazing device according to claim 2,
Based on the amount of deviation between the position of a vertical line passing through the intersection of the light projecting direction of the light projecting unit and the image capturing direction of the image capturing unit and the position of the high luminance area irradiated with the laser line, the A brazing device configured to measure the three-dimensional shape of the brazing filler metal by determining the distance from a vertical line to the surface of the brazing filler metal.

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