JP7238637B2 - induction heating device - Google Patents

Description

The disclosure herein relates to an induction heating device and method of manufacturing a heat exchanger.

Patent Literature 1, Patent Literature 2, and Patent Literature 3 disclose a brazing method for joining metal pipes using an induction heating device.

Japanese Patent No. 5842183 Japanese Patent No. 6065743 Japanese Patent No. 6268653

The brazing joining methods disclosed in Patent Literature 1, Patent Literature 2, and Patent Literature 3, respectively, have room for improvement in terms of improving productivity.

One object of the disclosure is to provide an induction heating device capable of increasing the productivity of brazing joints.

The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. In addition, the symbols in parentheses described in the claims and this section are an example showing the correspondence relationship with the specific means described in the embodiment described later as one aspect, and limit the technical scope isn't it.

One of the disclosed induction heating devices is a heat exchanger (1) in which members formed of a material containing aluminum are connected to each other by applying a high-frequency current to a brazed joint to generate a magnetic flux to generate an induced current. A plurality of coils (3; 10 3; 503) heated by and a current output unit (4) that outputs a high frequency current to energize the coils,
The coil extends along the object to be heated, in which a plurality of brazed joints are arranged in a line, and heats the object to be heated by an induced current (31a, 32a, 33a, 34a, 35a). and the second heating that extends along the object to be heated and the first heating unit, the high-frequency current flows in the direction opposite to the direction of the current flowing in the first heating unit, and heats the object to be heated by the induced current parts (31b, 32b, 33b, 34b, 35b), and folded parts (31c, 32c, 31c, 32c, 33c, 34c, 35c).
The plurality of coils are arranged in a plurality of rows orthogonal to the direction in which the plurality of brazed joints are arranged,
The coils are installed on both one side and the other side of the object to be heated in the direction of the plurality of rows with respect to each of the objects to be heated that are arranged in the direction of the plurality of rows and at least two pieces of the object to be heated are arranged. cage,
The coil on one side and the coil on the other side are installed so that the first heating section and the second heating section face each other and the direction of the current is opposite,
The first heating unit and the second heating unit are installed such that the object to be heated as viewed from the side is positioned between the first heating unit and the second heating unit,
At least two objects to be heated arranged in a plurality of rows include a first object to be heated and a second object to be heated,
A first coil portion located on one side and a second coil portion located on the other side with respect to the first object to be heated are the second heating portion in the first coil portion and the first heating portion in the second coil portion. and are connected by a connecting portion located on the opposite side of the folded portion with respect to the direction in which the plurality of objects to be heated are arranged,
A second coil portion located on one side and a third coil portion located on the other side with respect to the second object to be heated are the second heating portion in the second coil portion and the first heating in the third coil portion. and are connected by a connecting portion located on the opposite side of the folded portion with respect to the direction in which the plurality of objects to be heated are arranged.
One of the disclosed induction heating devices is a heat exchanger (1) in which members formed of a material containing aluminum are connected to each other by applying a high-frequency current to a brazed joint to generate a magnetic flux to generate an induced current. A coil (203; 303; 403; 503) heated by and a current output unit (4) for outputting a high frequency current to energize the coil,
The coil extends along the object to be heated, in which a plurality of brazed joints are arranged in a line, and heats the object to be heated by an induced current (31a, 32a, 33a, 34a, 35a). and the second heating that extends along the object to be heated and the first heating unit, the high-frequency current flows in the direction opposite to the direction of the current flowing in the first heating unit, and heats the object to be heated by the induced current parts (31b, 32b, 33b, 34b, 35b), and folded parts (31c, 32c, 31c, 32c, 33c, 34c, 35c), and the coils are installed such that the first heating section and the second heating section are located on both sides of the object to be heated.

According to this induction heating device, the first heating section and the second heating section extending along the object to be heated can simultaneously generate an induced current for a plurality of brazed joints. This induction heating device can collectively induction-heat a plurality of brazing joints, so that the productivity of brazing joints can be improved. Further, by moving the coil in the direction in which the plurality of brazed joints are arranged, the coil can be installed in the vicinity of the plurality of brazed joints. As a result, the installation workability of the coil capable of collectively induction-heating a plurality of brazed joints can be enhanced, and the productivity of brazed joints can be improved.

It is an external view of a heat exchanger. FIG. 4 is a plan view showing a coil and a brazed joint; FIG. 3 is a view in the direction of arrow III in FIG. 2; FIG. 3 is a sectional view taken along line IV-IV in FIG. 2; It is a block diagram concerning an induction heating apparatus. FIG. 4 is a plan view showing the positional relationship between a coil and a brazing material; FIG. 4 is a diagram showing the positional relationship between a brazing joint and a brazing material; It is the figure which showed the state after brazing. It is the front view which showed the magnetic flux and the induced current about 1st Embodiment. FIG. 4 is a side view showing the coil and the brazed joint of the first embodiment; It is the front view which showed the magnetic flux about a comparative example. FIG. 11 is a side view showing induced current for a comparative example; It is the front view which showed the magnetic flux and the induced current about 2nd Embodiment. It is the front view which showed the magnetic flux and the induced current about 3rd Embodiment. It is the front view which showed the magnetic flux and the induced current about 4th Embodiment. It is the front view which showed the magnetic flux and the induced current about 5th Embodiment. It is a plane sectional view of the device concerning a 6th embodiment. FIG. 11 is a side view of the device of the sixth embodiment; 19 is a cross-sectional view taken along line XIX-XIX in FIG. 18; FIG. FIG. 19 is a cross-sectional view taken along line XX-XX in FIG. 18; FIG. 11 is a side cross-sectional view of the device of the sixth embodiment;

A plurality of modes for carrying out the present disclosure will be described below with reference to the drawings. In each form, the same reference numerals may be given to the parts corresponding to the matters described in the preceding form, and overlapping explanations may be omitted. When only a part of the configuration is described in each form, the previously described other forms can be applied to other parts of the configuration. Not only combinations of parts that are explicitly stated that combinations are possible in each embodiment, but also partial combinations of embodiments even if they are not explicitly stated unless there is a particular problem with the combination. is also possible.

(First embodiment)
A first embodiment will be described with reference to FIGS. 1 to 12. FIG. Brazed joints between aluminum members can be applied to heat exchangers. Brazed joints are applied to pipe-to-tube joints, pipe-to-vessel joints, and the like. The brazed joints herein can be produced using induction heating equipment. The brazed joint is placed in a magnetic flux generated by applying a high-frequency current, thereby generating an induced current and self-heating due to Joule heat. The heat generated melts the brazing filler metal in the brazed joint, and when the brazing filler metal solidifies, the joining is completed.

The heat exchanger 1 comprises brazed joints joined using an induction heating device 10 to provide heat exchange between the fluid flowing inside the tubes 12 and the fluid flowing outside the tubes. As shown in FIG. 1 , heat exchanger 1 has a plurality of tubes 12 , a plurality of fins 18 , side plates 11 , and tubes 12 inserted through fins 18 and side plates 11 . The tube 12 is made of a material containing aluminum as its main component. The heat exchanger 1 has fins 18 and side plates 11 arranged in one direction, pipes 12 passing through a plurality of openings passing through the side plates 11 and the fins 18, and pipes 12 and other pipes outside the side plate 11. It can be manufactured by brazing and joining. The pipes 12 are connected to an inlet pipe for introducing a fluid, a U-shaped pipe connecting two adjacent pipes 12, and an outlet pipe through which the pipes 12 are circulated to form flow paths through which the fluid circulates.

The side plate 11 is a plate-like member made of a non-magnetic material. The side plate 11 is preferably made of an aluminum alloy. The side plate 11 is a plate-like member having a plate thickness thicker than that of the fins 18 . The side plate 11 is installed outside the fins 18 positioned at the ends in the arrangement direction among the plurality of fins 18 . The side plates 11 are installed parallel to the adjacent fins 18 . Side plate 11 has a plurality of openings through which tubes 12 pass. The opening is a through hole that penetrates the side plate 11 in the plate thickness direction. The side plate 11 is a support member that supports the tube 12 by closely contacting the opening with the tube 12 .

An induction heating device 10 for heating brazed joints will be described. FIG. 2 is a plan view of the side plate 11 and shows the positional relationship between the coils and the brazed joints. FIG. 3 shows the coil and the brazed joint viewed in the longitudinal direction of the coil in which the coil extends. FIG. 4 shows a state in which the coil and the brazed joint are viewed in the direction in which the objects to be heated are arranged in multiple rows. FIG. 5 shows the configuration of the induction heating device 10. As shown in FIG. FIG. 6 is a plan view of the side plate 11 and shows the positional relationship between the coil and the brazing material. FIG. 7 shows the positional relationship between the brazing joint and the brazing material. FIG. 8 shows the brazing material after the brazing joint has been completed and solidified.

The induction heating device 10 includes a power source section 8 , a high frequency inverter 4 and a coil 3 . The high-frequency inverter 4 is an example of a current output section that outputs a high-frequency current that energizes the coil 3 . The high-frequency inverter 4 is a high-frequency oscillation device that converts electricity supplied from the power supply unit 8 into high-frequency energy. The output of the high frequency inverter 4 is controlled by an ECU 7, which is an electronic control unit. The ECU 7 may be installed inside the device of the high-frequency inverter 4, or may be installed outside the device. The high-frequency inverter 4 can control the magnetic flux by changing the frequency of the output alternating current, control the temperature of the brazed joint, and set the melting state of the brazing material. Further, the high-frequency inverter 4 can set the heating range in the brazed joint by changing the frequency of the alternating current to be output. The ECU 7 may be configured not only to control the high-frequency inverter 4 but also to function as a control device that controls the brazing process.

The induction heating device 10 has a current transformer 5 . The current transformer 5 is a device that converts the magnitude of alternating current. The current transformer 5 can increase the current output when the impedance of the coil 3 is small. The induction heating device 10 may be configured without the current transformer 5 if the output capability of the high-frequency inverter 4 is sufficient for the current value input to the coil 3 .

The induction heating device 10 comprises a cooling device 6 for cooling the coil 3 . The cooling device 6 has a cooling passage through which a cooling fluid for cooling the coil 3 flows. The cooling device 6 has, for example, a fluid circulation circuit in which cooling fluid such as cooling water circulates. The ECU 7 may be configured to function as a control device that controls the operation and stop of the cooling device 6 . The cooling device 6 may be configured to be used as a device for cooling the power supply unit 8 , substrates, and the high-frequency inverter 4 .

As shown in FIGS. 2 to 4 and 6, the induction heating device 10 is a device capable of simultaneously heating and brazing a plurality of brazing joints coated with a brazing material. The plurality of brazed joints are arranged side by side in a row and are objects to be heated by the induction heating device 10 . The direction in which the plurality of brazed joints are arranged corresponds to the direction in which the plurality of brazed joints are arranged in a row in each drawing, and is the direction in which the object to be heated extends, and is also the direction along the object to be heated. In this specification, the direction in which the brazed joints are aligned in a row is also simply referred to as the direction of alignment.

The heat exchanger 1 comprises rows of brazed joints. The heat exchanger 1 has a plurality of rows of objects to be heated. The direction in which the plurality of objects to be heated are arranged corresponds to the direction of multiple rows. The multiple-row direction is a direction perpendicular to the direction in which the brazed joints are arranged in a row and along the side plate 11 . It is preferable that the plurality of rows of the target portions to be heated are arranged in the direction of the plurality of rows at regular intervals.

The heat exchanger 1 of this embodiment has four rows of objects to be heated, as shown in FIGS. Here, the tubes 12 included in the first row of objects to be heated are referred to as first row tubes 12a, and the tubes 12 included in the second row of objects to be heated are referred to as second row tubes 12b. Furthermore, the pipes 12 included in the third row of objects to be heated are referred to as third row pipes 12c, and the pipes 12 included in the fourth row of objects to be heated are referred to as fourth row pipes 12d. Tube 12 a , tube 12 b , tube 12 c and tube 12 d form a series of fluid passages in heat exchanger 1 .

The heat exchanger 1 includes connection pipes of various shapes as shown in FIG. 4 objects to be heated 12d and collector 14 are provided.

The first object to be heated is a connecting portion where the plurality of pipes 12a and the plurality of first connecting pipes 16 are in contact with each other on the most one side of the four rows of objects to be heated. Each of the plurality of pipes 12a and the end portion 16a of the first connecting pipe 16 form a brazed joint. The first connecting pipe 16 is a pipe that connects the pipe 12 a and the distributor 17 . The distributor 17 is, for example, a container that distributes the fluid that has flowed in from the outside to the plurality of pipes 12a. For example, the tube 12 a forms an upstream flow path in the internal passage of the heat exchanger 1 . All brazed joints forming the first heated object are preferably provided so as to be positioned at substantially equally spaced distances relative to the side plate 11 .

The second object to be heated is formed by contacting the plurality of pipes 12b forming a row on the other side of the first object to be heated among the four rows of objects to be heated and the plurality of second connecting pipes 15. It is a joint where Each of the plurality of pipes 12b and one end portion 15a of the second connecting pipe 15 constitute a brazed joint. All brazed joints forming the second object to be heated are preferably provided so as to be positioned at substantially equally spaced distances relative to the side plate 11 .

The third object to be heated is formed by contacting the plurality of pipes 12c forming a row on the other side of the second object to be heated among the four rows of objects to be heated and the plurality of second connecting pipes 15. It is a joint where Each of the plurality of tubes 12c and the other end 15b of the second connecting tube 15 constitute a brazed joint. The second connecting pipe 15 is a U-shaped pipe that connects the plurality of pipes 12b forming the second object to be heated and the plurality of pipes 12c forming the third object to be heated. All brazed joints constituting the third heated object are preferably provided so as to be positioned at substantially equally spaced distances with respect to the side plate 11 .

The fourth object to be heated is a connecting portion where the plurality of pipes 12d forming a row on the othermost side of the four rows of objects to be heated and the plurality of third connecting pipes 13 are in contact. Each of the plurality of pipes 12d and the end portion 13a of the third connecting pipe 13 form a brazed joint. The third connecting pipe 13 is a pipe that connects the pipe 12 d and the collector 14 . The collector 14 is, for example, a container that collects the fluid flowing out from the plurality of tubes 12d. For example, the pipe 12d forms a downstream flow path in the internal passage of the heat exchanger 1. All brazed joints forming the fourth object to be heated are preferably provided so as to be positioned at substantially equally spaced distances relative to the side plate 11 . Preferably, all the brazed joints that make up the rows of heated objects are positioned at substantially equally spaced distances with respect to the side plate 11 .

An example of a coil included in the induction heating device 10 will be described. The coil 3 has a plurality of coil portions. A plurality of coil parts are located in a line with a plurality of row directions like a plurality of to-be-heated objects. The coil part has a shape extending along the object to be heated. The plurality of coil portions are arranged in parallel in the multiple row direction. A plurality of coil portions forming the coil 3 are connected in series so that high-frequency currents flow in order.

Each coil unit connects a first heating unit that heats an object to be heated, a second heating unit that is separated from the first heating unit and heats the object to be heated, and the first heating unit and the second heating unit. and a folded portion. The first heating section extends along the object to be heated. The second heating section extends along the first heating section and the object to be heated. In the coil section, the current flows through the first heating section, the folded section, and the second heating section in this order. Therefore, the direction of current in the second heating portion is opposite to the direction of current in the first heating portion. For example, as shown in FIG. 4, the coil section has a configuration in which a first heating section and a second heating section forming parallel lines and a hairpin-shaped folded section form a U shape.

The coil 3 has a coil portion located between adjacent objects to be heated in the direction of a plurality of rows. The coil 3 of this embodiment has five coil portions, as shown in FIGS. The coil 3 includes a first coil portion 31, a second coil portion 32, a third coil portion 33, a fourth coil portion 34, and a fifth coil portion 35, which are arranged in multiple rows. The first coil portion 31 is connected to the cable on the side of the current output portion via the current lead-in portion 36 . The fifth coil portion 35 is connected to the current lead-out portion 38 . A high-frequency current flows down from the current introducing portion 36 to the first coil portion 31 . The five coil portions are connected in series so that a high-frequency current flows in order from the first coil portion 31 to the fifth coil portion 35 . A high-frequency current flows down from the fifth coil portion 35 to the current lead-out portion 38 .

The coil 3 includes a set of coil portions installed on both sides in the direction of multiple rows with respect to one object to be heated. The coil 3 includes a first coil portion 31 located on one side of the first object to be heated and a second coil portion 32 located on the other side. The first coil portion 31 and the second coil portion 32 are provided at positions facing each other in the direction of multiple rows. The coil 3 includes a second coil portion 32 located on one side of the second object to be heated and a third coil portion 33 located on the other side. The second coil portion 32 and the third coil portion 33 are provided at positions facing each other in the direction of multiple rows. The coil 3 includes a third coil portion 33 positioned on one side of the third object to be heated and a fourth coil portion 34 positioned on the other side. The third coil portion 33 and the fourth coil portion 34 are provided at positions facing each other in the direction of multiple rows. The coil 3 includes a fourth coil portion 34 positioned on one side of the fourth object to be heated and a fifth coil portion 35 positioned on the other side. The fourth coil portion 34 and the fifth coil portion 35 are provided at positions facing each other in the direction of multiple rows.

Coil portions adjacent to each other in the direction of multiple rows are connected by connecting portions 37 extending in the direction of multiple rows. The first coil portion 31 and the second coil portion 32 are connected by a connecting portion 37a. The connecting portion 37a is provided at a position outside the object to be heated in the alignment direction and not facing the object to be heated. The second coil portion 32 and the third coil portion 33 are connected by a connecting portion 37b. The connecting portion 37b is provided outside the object to be heated in the alignment direction and at a position not facing the object to be heated. The third coil portion 33 and the fourth coil portion 34 are connected by a connecting portion 37c. The connecting part 37c is provided at a position outside the object to be heated in the alignment direction and not facing the object to be heated. The fourth coil portion 34 and the fifth coil portion 35 are connected by a connecting portion 37d. The connecting portion 37d is provided outside the object to be heated in the alignment direction and at a position not facing the object to be heated.

The first coil portion 31 includes a first heating portion 31a, a second heating portion 31b positioned closer to the side plate 11 than the first heating portion 31a, and a folded portion 31c. The folded portion 31c is provided outside the object to be heated on the side opposite to the connecting portion 37a in the alignment direction and at a position not facing the object to be heated. The first heating part 31a is located on the opposite side of the side plate 11 from the object to be heated. The second heating part 31b is located closer to the side plate 11 than the object to be heated. The first heating section 31a and the second heating section 31b are installed so that the object to be heated as viewed from the side is positioned between the first heating section 31a and the second heating section 31b. In the first coil portion 31, the high-frequency current flows through the first heating portion 31a, the folded portion 31c, and the second heating portion 31b in this order, and then flows down to the second coil portion 32 via the connecting portion 37a.

The second coil portion 32 includes a first heating portion 32a, a second heating portion 32b located on the opposite side of the side plate 11 from the first heating portion 32a, and a folded portion 32c. The folded portion 32c is provided outside the object to be heated on the opposite side of the connecting portion 37 in the alignment direction and at a position not facing the object to be heated. The first heating unit 32a is installed closer to the side plate 11 than the object to be heated. The second heating unit 32b is installed on the opposite side of the side plate 11 from the object to be heated. The first heating section 32a and the second heating section 32b are installed so that the object to be heated as viewed from the side is positioned between the first heating section 32a and the second heating section 32b. The first heating section 31a and the second heating section 32b are provided at positions facing each other in the direction of multiple rows. The second heating section 31b and the first heating section 32a are provided at positions facing each other in the direction of multiple rows. The folded portion 31c and the folded portion 32c are provided at positions facing each other in the direction of multiple rows. In the second coil portion 32, the high-frequency current flows through the first heating portion 32a, the folded portion 32c, and the second heating portion 32b in that order, and then flows down to the third coil portion 33 via the connecting portion 37b.

The third coil portion 33 includes a first heating portion 33a, a second heating portion 33b located closer to the side plate 11 than the first heating portion 33a, and a folded portion 33c. The folded portion 33c is provided outside the object to be heated on the side opposite to the connecting portion 37 in the alignment direction and at a position not facing the object to be heated. The first heating unit 33a is installed on the opposite side of the side plate 11 from the object to be heated. The second heating unit 33b is installed closer to the side plate 11 than the object to be heated. The first heating section 33a and the second heating section 33b are installed so that the object to be heated as viewed from the side is positioned between the first heating section 33a and the second heating section 33b. The first heating section 32a and the second heating section 33b are provided at positions facing each other in the direction of multiple rows. The second heating section 32b and the first heating section 33a are provided at positions facing each other in the direction of multiple columns. The folded portion 32c and the folded portion 33c are provided at positions facing each other in the direction of multiple rows. In the third coil portion 33, the high-frequency current flows through the first heating portion 33a, the folded portion 33c, and the second heating portion 33b in that order, and then flows down to the fourth coil portion 34 via the connecting portion 37c.

The fourth coil portion 34 includes a first heating portion 34a, a second heating portion 34b located on the opposite side of the side plate 11 from the first heating portion 34a, and a folded portion 34c. The folded portion 34c is provided outside the object to be heated on the side opposite to the connecting portion 37 in the alignment direction and at a position not facing the object to be heated. The first heating unit 34a is installed closer to the side plate 11 than the object to be heated. The second heating unit 34b is installed on the opposite side of the side plate 11 from the object to be heated. The first heating section 34a and the second heating section 34b are installed such that the object to be heated as viewed from the side is positioned between the first heating section 34a and the second heating section 34b. The first heating section 33a and the second heating section 34b are provided at positions facing each other in the direction of multiple rows. The second heating section 33b and the first heating section 34a are provided at positions facing each other in the direction of multiple rows. The folded portion 33c and the folded portion 34c are provided at positions facing each other in the direction of multiple rows. In the fourth coil portion 34, the high-frequency current flows through the first heating portion 34a, the folded portion 34c, and the second heating portion 34b in that order, and then flows down to the fifth coil portion 35 via the connecting portion 37d.

The fifth coil portion 35 includes a first heating portion 35a, a second heating portion 35b positioned closer to the side plate 11 than the first heating portion 35a, and a folded portion 35c. The folded portion 35c is provided outside the object to be heated on the side opposite to the connecting portion 37 in the alignment direction and at a position not facing the object to be heated. The first heating unit 35a is installed on the opposite side of the side plate 11 from the object to be heated. The second heating unit 35b is installed closer to the side plate 11 than the object to be heated. The first heating section 35a and the second heating section 35b are installed such that the object to be heated as viewed from the side is located between the first heating section 35a and the second heating section 35b. The first heating section 34a and the second heating section 35b are provided at positions facing each other in the direction of multiple rows. The second heating section 34b and the first heating section 35a are provided at positions facing each other in the direction of multiple rows. The folded portion 34c and the folded portion 35c are provided at positions facing each other in the direction of multiple rows. In the fifth coil portion 35, the high-frequency current flows through the first heating portion 35a, the folded portion 35c, and the second heating portion 35b in that order, and flows down to the current lead-out portion 38. As shown in FIG.

The first coil portion 31 or the second heating portion 31b is installed at a distance of 30 mm or less from the side plate 11 . The second coil portion 32 or the first heating portion 32a is installed at a distance of 30 mm or less from the side plate 11 . The third coil portion 33 or the second heating portion 33b is installed at a distance of 30 mm or less from the side plate 11 . The fourth coil portion 34 or the first heating portion 34a is installed at a distance of 30 mm or less from the side plate 11 . The fifth coil portion 35 or the second heating portion 35b is installed at a distance of 30 mm or less from the side plate 11 . If the side plate 11 is made of non-magnetic metal such as aluminum, each of the above distances may be set within the range of 3 to 8 mm. The side plate 11 made of a non-magnetic material is less likely to be heated by an induced current than iron, which is a magnetic material, when the brazing joint portion is brazed by energizing the coil 3 . As a result, it is possible to prevent melting of the base material of the side plate 11 due to overheating of the side plate 11, melting of the base material caused by overheating of the brazed joint, and melting of the heat exchanger member. Such a distance relationship between the coil and the side plate 11 is applied to all embodiments in the specification.

A method of manufacturing a heat exchanger having a brazed joint member includes a brazed joint installation step, a brazing material installation step, a coil installation step, a heat melting step, and a brazing material solidification step. The step of installing a brazed joint is a step of connecting members to be brazed and placing them in a predetermined position. This step is a step of preparing the object to be heated described above with reference to FIGS.

The brazing filler metal placement step is a step of placing the brazing filler metal to be melted in the subsequent heating and melting step at a predetermined position. In this step, it is preferable to apply the brazing material 19 to the positions shown in FIGS. FIG. 6 shows the positional relationship between the brazing material 19 and each coil when there are multiple rows of objects to be heated. FIG. 7 shows the state of the connecting portion between the pipe 12d and the third connecting pipe 13 as a representative example of the installation location of the brazing material 19. As shown in FIG. In this step, a paste-like brazing material 19 is applied to the side surface of the pipe, which is a member constituting the brazed joint, not facing each coil portion. The side surfaces that do not face each coil portion are the side surfaces located at both ends in the line-up direction or the coil insertion direction on the pipe surface. The paste-like brazing material 19 is a mixture of brazing alloy, flux, binder, solvent, and the like. The brazing filler metal 19 applied to this position can prevent the distance between the coil portion and the brazing filler metal 19 placed on the side of the object to be heated from becoming smaller than the distance between the coil portion and the pipe. Therefore, it is possible to prevent the brazing filler metal 19 from interfering with the coil portion in the later step of placing the coil near the plurality of brazed joints or in the heating and melting step.

The coil installation process is a process of installing the coil at the predetermined position described with reference to FIGS. 2 to 4 with respect to the object to be heated. In the coil installation step, the coil is moved along the object to be heated and installed at a predetermined position near the object to be heated. In the coil installation step, the coils are installed so that the coils are aligned parallel to the object to be heated. When joining a plurality of objects to be heated by brazing, the plurality of coil portions are simultaneously moved along the objects to be heated and installed at predetermined positions in the coil installation step. Each coil part is installed between adjacent objects to be heated.

As described above, the heating and melting process is a process of controlling the output of the high frequency inverter 4 to heat the brazing joint and melting the brazing filler metal 19 . In the heating and melting process, the heating temperature and heating range of the brazing joint are set so that the brazing filler metal 19 is melted appropriately.

The brazing filler metal solidification step is a step of solidifying the brazing filler metal that has been melted in the heating and melting step to properly join the joints. In this step, the brazed joint is placed in an environment of room temperature or a predetermined temperature until a predetermined period of time has elapsed. When the solidification process is completed, it can be assumed that traces of solidification of the brazing material 19 remain in the product as shown in FIG. FIG. 8 shows the solidified brazing material 19 at the joint between the pipe 12d and the third connecting pipe 13 as a representative example after brazing. As shown in FIG. 8, the brazing filler metal 19 is solidified so that the brazing filler metal 19 is present in a smaller amount on the side surfaces of the members constituting the brazed joint facing the coil than on the other side surfaces. The reason why the amount of the brazing filler metal 19 flowing into the side surface of the member facing the coil is small is due to the placement position of the brazing filler metal 19 shown in FIG. As a result, it is possible to prevent the brazing filler metal 19 from coming too close to the coil in the process of placing the coil in the vicinity of a plurality of brazed joints. In addition, it is possible to prevent the melted brazing material 19 from coming too close to the coil in the heating and melting process. According to the manufacturing process described above, it is possible to provide a manufacturing method capable of collectively brazing a plurality of brazed joints in a row. Furthermore, according to the manufacturing process described above, it is possible to provide a manufacturing method capable of collectively brazing and joining a plurality of objects to be heated having a plurality of rows of brazed joint portions.

In the step of installing the brazing material, the brazing material may be, for example, a ring brazing material with one or more turns so as not to be too close to the coil so as to obtain an appropriate amount of brazing material. Alternatively, the step of installing the braze material may be performed by supplying the braze material to the braze joint. With this configuration as well, it is possible to prevent the brazing filler metal 19 from coming too close to the coil in the process of placing the coil in the vicinity of a plurality of brazed joints or in the heating and melting process.

Next, the induced current acting on the brazed joint manufactured using the induction heating apparatus 10 will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 shows induced currents acting on the first object to be heated, the second object to be heated, and the third object to be heated, and the magnetic flux generated by energizing the coil 3 . In FIG. 9, the solid arrow indicates the direction of the magnetic flux, the direction of the high frequency current in the coil portion, and the thick white arrow indicates the induced current acting on the brazed joint. In FIG. 10, the direction of the high-frequency current is indicated in the second coil portion 32, and the bold white arrow indicates the induced current acting on the brazed joint.

An induced current acting on a plurality of brazed joints existing between the first coil portion 31 and the second coil portion 32 will be described. A magnetic flux is generated in the direction away from the side plate 11 at the brazing joint and its vicinity on the side opposite to the plate due to the current flowing through the first heating portion 31a and the second heating portion 32b. At the portion between the first heating portion 31a and the second heating portion 32b, an eddy current as indicated by the bold white arrow in FIG. . Furthermore, in the brazing joint and its vicinity on the plate side, a magnetic flux is generated in a direction approaching the side plate 11 due to the current flowing through the second heating portion 31b and the first heating portion 32a. At the portion between the second heating portion 31b and the first heating portion 32a, an eddy current as indicated by the white bold arrow in FIG. . The eddy current near the opposite plate side and the eddy current near the plate side contribute to uniformly heating the plurality of brazed joints of the first object to be heated. In the first object to be heated, the eddy current near the opposite plate side and the eddy current near the plate side are in opposite directions.

The induced current acting on the plurality of brazed joints existing between the second coil portion 32 and the third coil portion 33 will be described. A magnetic flux is generated in the direction approaching the side plate 11 at the brazed joint and its vicinity on the opposite side of the plate due to the current flowing through the second heating portion 32b and the first heating portion 33a. At the portion between the second heating portion 32b and the first heating portion 33a, an eddy current as indicated by the white bold arrow in FIG. . Furthermore, magnetic flux is generated in the direction away from the side plate 11 by the current flowing through the first heating portion 32a and the second heating portion 33b at the brazed joint and its vicinity on the plate side. At the portion between the first heating portion 32a and the second heating portion 33b, an eddy current as indicated by the white bold arrow in FIG. . The eddy current near the opposite plate side and the eddy current near the plate side contribute to uniform heating of the plurality of brazed joints on the second object to be heated. In the second object to be heated, the eddy current in the vicinity of the anti-plate side and the eddy current in the vicinity of the plate side have opposite eddy directions.

An induced current acting on a plurality of brazed joints existing between the third coil portion 33 and the fourth coil portion 34 will be described. A magnetic flux is generated in the direction away from the side plate 11 at the brazing joint and its vicinity on the side opposite to the plate due to the current flowing through the first heating portion 33a and the second heating portion 34b. At the portion between the first heating portion 33a and the second heating portion 34b, an eddy current as indicated by the bold white arrow in FIG. . Furthermore, in the brazing joint and its vicinity on the plate side, a magnetic flux is generated in a direction approaching the side plate 11 due to the current flowing through the second heating portion 33b and the first heating portion 34a. At the portion between the second heating portion 33b and the first heating portion 34a, an eddy current is intensively generated as indicated by the outline thick arrow in FIG. . The eddy current near the opposite plate side and the eddy current near the plate side contribute to uniform heating of the plurality of brazed joints in the third object to be heated. In the third object to be heated, the eddy current in the vicinity of the anti-plate side and the eddy current in the vicinity of the plate side have opposite eddy directions. Any eddy currents will flow in a circle around the pipes that make up the brazed joint.

On the other hand, as a comparative example, a case where currents flow in the same direction in the first coil portion 100 and the second coil portion 101 provided on both sides of the brazed joint and facing each other will be described. FIG. 11 shows, from the front, the magnetic flux generated by energizing the coil in the comparative example. FIG. 12 shows loop-shaped induced currents that are not eddy currents for a similar comparative example. 11 and 12 show the brazed joint between the pipe 12d and the third connecting pipe 13 as a representative example.

As shown in FIG. 11, the first heating section 100a of the first coil section 100 and the first heating section 101a of the second coil section 101 face each other with the object to be heated in between. The second heating section 100b of the first coil section 100 and the second heating section 101b of the second coil section 101 are opposed to each other with the object to be heated in between. Since current flows in the same direction in the first heating portion 100a and the first heating portion 101a, a magnetic flux is generated in the vicinity of the brazed joint on the side opposite to the plate as shown in FIG. Since the current flows in the same direction in the second heating portion 100b and the second heating portion 101b, a magnetic flux is generated in the vicinity of the plate side of the brazed joint as shown in FIG. These magnetic fluxes provide flux in the same direction transverse to the brazed joint.

An induced current is generated in the brazed joint as indicated by the dashed line in FIG. This induced current passes through the brazed joint and flows in a loop through adjacent brazed joint tubes in the row direction. In FIG. 12, the induced currents indicated by the dashed lines that are adjacent to each other cancel each other out, and the density of the induced currents becomes non-uniform depending on the location. Therefore, it is difficult to uniformly heat the plurality of brazed joints by themselves, and it is difficult to bring the temperatures of the plurality of brazed joints closer to uniformity. The induced currents acting with the induction heating device 10 can form concentrated eddy currents in the vicinity of each braze joint, as previously described. Therefore, compared to the comparative example, even in the heat exchanger as shown in FIG. 3, it is possible to provide an induced current density that makes the temperatures of a plurality of brazed joints nearly uniform without forming a loop.

Next, the effects of the induction heating device 10 of the first embodiment will be described. The induction heating device 10 includes a coil 3 and a current output section that outputs a high-frequency current to energize the coil 3 . The coil 3 heats the brazed joint between members made of a material containing aluminum in the heat exchanger 1 by induced current by generating a magnetic flux by applying a high-frequency current. The coil 3 includes a first heating section, a second heating section, and a folded section connecting the first heating section and the second heating section such that a high frequency current flows from the first heating section to the second heating section. . The first heating section and the second heating section extend along the object to be heated, and heat the object to be heated by induced current. The second heating part extends along the first heating part, and the high-frequency current flows in the direction opposite to the direction of the current flowing through the first heating part.

According to the induction heating device 10, the first heating section and the second heating section extending along the object to be heated can simultaneously generate an induced current to heat the plurality of brazed joints. Since the induction heating device 10 can collectively induction-heat a plurality of brazed joints, productivity of the brazed joints can be improved. Since the coil 3 can be moved in the direction in which the plurality of brazed joints are arranged in the manufacturing process, the coil 3 can be installed in the vicinity of the plurality of brazed joints with a small number of man-hours. As a result, the installation workability of the coil 3 for collectively induction-heating a plurality of brazing joints is improved, and the productivity of brazing joints can be enhanced. According to the induction heating device 10, it is possible to provide the coil 3 with a simple shape, which can simultaneously braze-join a plurality of brazing joints by an induced current.

In this way, the induction heating device 10 can collectively induction-heat a plurality of brazed joints, so that it is possible to improve the productivity of a wide variety of heat exchangers and reduce the size of the equipment.

The coil 3 is positioned on one side of both sides of the object to be heated. The first heating unit and the second heating unit are installed with respect to the object to be heated so that the object to be heated when viewed from the side is positioned between the first heating unit and the second heating unit. According to this configuration, the magnetic flux applied by the first heating unit and the magnetic flux applied by the second heating unit are opposite to each other with respect to the object to be heated. These magnetic fluxes generate eddy currents on both the plate side and the anti-plate side of the plurality of brazed joints that make up the object to be heated. Eddy currents acting on both sides of a braze joint can cause multiple braze joints to self-heat in the same manner, heating all braze joints contained in the object to be heated to a similar temperature.

The coil 3 includes a first coil portion 31 positioned on one side of the object to be heated and a second coil portion 32 positioned on the other side and extending along the first coil portion 31 . including. The first heating portion 31a of the first coil portion 31 and the second heating portion 32b of the second coil portion 32 face each other and the directions of the electric currents are opposite to each other. The second heating portion 31b of the first coil portion 31 and the first heating portion 32a of the second coil portion 32 face each other and the direction of current flow is opposite to each other.

According to this configuration, the first heating unit and the second heating unit facing each other with respect to the object to be heated between the first coil unit 31 and the second coil unit 32 are oriented in the same direction as shown in FIG. gives a magnetic flux of In addition, this magnetic flux generates eddy currents on the plate side and the anti-plate side, respectively, with respect to the brazed joint. Due to the generation of such eddy currents, a plurality of brazed joints can similarly self-heat and heat all brazed joints contained in the object to be heated to a similar temperature. It is possible to provide an induction heating apparatus 10 that can stabilize the quality of brazing with little variation in the joint state after brazing for a plurality of brazed joints included in the object to be heated.

The coils are installed on both one side and the other side of at least two objects to be heated arranged side by side. The coil on one side and the coil on the other side are installed so that the first heating section and the second heating section are opposed to each other and the directions of the currents are opposite to each other.

According to this, coils exist on both sides of each of a plurality of objects to be heated, and the first heating unit and the second heating unit facing each other give magnetic fluxes in the same direction as shown in FIG. This magnetic flux generates eddy currents on both the plate side and the anti-plate side of all the brazed joints that make up the plurality of objects to be heated. Due to the generation of such eddy currents, each brazed joint similarly self-heats, and all brazed joints constituting a plurality of objects to be heated can be heated to a similar temperature. It is possible to provide an induction heating apparatus 10 that can stabilize the quality of brazing with little variation in the joint state after brazing for brazed joints included in a plurality of objects to be heated.

The brazed joints brazed by the induction heating device 10 are joints between pipes that are connected to each other. The coil 3 is placed close to the side plate 11 of the heat exchanger 1 which supports one tube. The material of the side plate 11 is, for example, an aluminum alloy. According to this configuration, during brazing by the induction heating device 10, the base material of the side plate 11 melts due to overheating of the side plate 11, the base material melts due to overheating of the brazed joint, and the heat exchanger member melts. etc. can be prevented.

The shortest distance between the side plate 11 and the coil 3 is 30 mm or less. According to this configuration, it is possible to provide the induction heating device 10 in which the temperature of the side plate 11 at the time of brazing can be suppressed within an allowable range where it can function as a product.

The method of manufacturing the heat exchanger is to heat and braze the brazed joints of the heat exchanger 1, in which the members formed of a material containing aluminum are connected to each other, using a coil that passes a high-frequency current. The method. This manufacturing method includes a step of setting a brazed joint in which a plurality of brazed joints are arranged in a row to form an object to be heated, a step of setting a brazing material, and a step of setting a coil. , a heating and melting step, and a brazing filler metal solidification step. The brazing material placement step places a brazing material that forms a brazed joint. In the coil installation step, a coil having a first heating section, a second heating section, and a folded section connecting the first heating section and the second heating section is provided so that the first heating section and the second heating section are heated. It is installed along the object to be heated in the vicinity of the object. In the heating and melting step, a high-frequency current is applied to the coil, and a magnetic flux is generated by the current flowing through the first heating portion and the current flowing through the second heating portion in a direction opposite to the direction of the current flowing through the first heating portion. , the induced current heats the object to be heated and melts the brazing material. In the step of solidifying the brazing material, the brazing material melted in the heating and melting step to join the brazed joint is solidified.

According to this manufacturing method, the first heating part and the second heating part extending along the object to be heated can simultaneously generate an induced current to heat the plurality of brazed joints. Since a plurality of brazed joints can be collectively induction-heated in this manner, the productivity of the brazed joints can be improved. Since this manufacturing method can move the coil 3 in the direction in which the plurality of brazed joints are arranged, the coil 3 can be installed in the vicinity of the plurality of brazed joints with a small number of man-hours. Therefore, the installation workability of the coil 3 for collectively induction-heating a plurality of brazing joints is improved, and the productivity of brazing joints can be improved.

In the step of installing the brazing material, the brazing material is installed on the side surface of the member at a position not facing the coil. According to this manufacturing method, the brazing material 19 approaches the coil 3 in the subsequent step of placing the coils in the vicinity of a plurality of brazing joints or in the heating and melting step, impairing the progress of the process and the quality of the brazing joint. Contribute to contain the situation.

Further, in the coil installation step, a first coil located on one side of the object to be heated and a second coil located on the other side are installed as the coils. Specifically, the first heating portion of the first coil and the second heating portion of the second coil are opposed to each other, and the second heating portion of the first coil and the first heating portion of the second coil are Oppose. In the heating and melting step, the first heating portion of the first coil and the second heating portion of the second coil are energized so that the directions of the high-frequency currents are opposite to each other. Further, the second heating portion of the first coil and the first heating portion of the second coil are energized so that the directions of the high-frequency currents are opposite to each other.

According to this manufacturing method, the first heating unit and the second heating unit facing the object to be heated between the first coil and the second coil are oriented in the same direction as shown in FIG. Give magnetic flux. In addition, this magnetic flux generates eddy currents on the plate side and the opposite plate side, respectively, so that multiple brazed joints likewise self-heat. This action allows all brazed joints included in the object to be heated to be heated to a similar temperature. It is possible to provide a manufacturing method in which variations in the state of joints after brazing are small for a plurality of brazed joints included in an object to be heated, and in which the quality of brazing can be stabilized.

In the coil installation step, a plurality of coils adjacent to the sides of the plurality of objects to be heated are installed to the objects to be heated. In the heating and melting step, a high-frequency current is applied to at least one arbitrarily selected coil among the plurality of coils. According to this, it is possible to provide a manufacturing method capable of brazing a plurality of objects to be heated in a plurality of times as required.

(Second embodiment)
In the second embodiment, the coil 103 included in the induction heating device will be described with reference to FIG. 13 . In FIG. 13, constituent elements denoted by the same reference numerals as in the drawing of the first embodiment are similar constituent elements and have similar effects.

The coil 103 of the second embodiment differs from that of the first embodiment in the number of coil portions. The coil 103 includes a first coil portion 31 and a second coil portion 32 . The coil 103 can be applied to an induction heating device for brazing one object to be heated.

In the coil 103 of the second embodiment, a plurality of coil portions are connected in series, and current flows in series. Also, the coil 103 may have a configuration in which a plurality of coil portions are connected in parallel, and current flows through each coil portion in parallel.

(Third embodiment)
In the third embodiment, a coil 203 included in an induction heating device will be described with reference to FIG. In FIG. 14, constituent elements denoted by the same reference numerals as in the drawing of the first embodiment are similar constituent elements and have similar effects.

The coil 203 of the third embodiment differs from that of the first embodiment in the positional relationship between the object to be heated and the coil portion. The coil 203 includes a first coil portion 131 and a second coil portion 132 facing each other in the extending direction of the pipe 12 and the first connecting pipe 16 with a plurality of brazed joints interposed therebetween. The second coil portion 132 is located closer to the side plate 11 than the first coil portion 131 is.

The first coil portion 131 includes a first heating portion 131a, a second heating portion 131b, and a folded portion 131c. Both the first heating part 131a and the second heating part 131b are installed so that the distance to the side plate 11 and the distance to the brazed joint are the same. A first connecting pipe 16 is present between the first heating section 131a and the second heating section 131b. The first heating part 131 a is positioned on one of the two sides of the first connecting pipe 16 . The second heating part 131 b is positioned on the other side of the first connecting pipe 16 . The folded portion 131c extends across the first connecting pipe 16 and connects the first heating portion 131a and the second heating portion 131b.

The second coil portion 132 includes a first heating portion 132a, a second heating portion 132b, and a folded portion 132c . Both the first heating part 132a and the second heating part 132b are installed so that the distance to the side plate 11 and the distance to the brazed joint are the same. A pipe 12a exists between the first heating section 132a and the second heating section 132b. The second heating section 132b is positioned on one side of the tube 12a. The first heating section 132a is positioned on the other side of the tube 12a. The folded portion 132c extends across the pipe 12a and connects the first heating portion 132a and the second heating portion 132b.

The first coil portion 131 and the second coil portion 132 are installed such that the object to be heated as viewed from the side is positioned between the first coil portion 131 and the second coil portion 132 . The first heating section 131a and the second heating section 132b are provided at positions facing each other in the direction in which the pipe 12 and the first connecting pipe 16 extend. The second heating part 131b and the first heating part 132a are provided at positions facing each other in the direction in which the pipe 12 and the first connecting pipe 16 extend. The folded portion 131c and the folded portion 132c are provided at positions facing each other in the direction in which the pipe 12 and the first connecting pipe 16 extend.

A plurality of coil portions are connected in series in the coil 203, and current flows in series. In the first coil portion 131, the high-frequency current flows through the first heating portion 131a, the folded portion 131c, and the second heating portion 131b in that order, and then flows down to the second coil portion 132 via the connecting portion. In the second coil portion 132, the high-frequency current flows down through the first heating portion 132a, the folded portion 132c, and the second heating portion 132b in this order. Also, the coil 203 may have a configuration in which a plurality of coil portions are connected in parallel, and current flows through each coil portion in parallel.

FIG. 14 shows the induced current acting on the object to be heated and the magnetic flux generated by energizing the coil 203 . In FIG. 14, the solid arrow indicates the direction of the magnetic flux, the direction of the high frequency current in the coil portion, and the thick white arrow indicates the induced current acting on the brazed joint.

The induced current acting on a plurality of brazed joints existing inside both the first coil portion 131 and the second coil portion 132 will be described. A magnetic flux is generated in the direction approaching the side plate 11 at the brazed joint and its vicinity on the side opposite to the plate due to the current flowing through the first heating portion 131a and the second heating portion 131b. Between the first heating portion 131a and the second heating portion 131b, an eddy current as indicated by a bold white arrow in FIG. 14 is intensively generated by an induced current that generates a magnetic flux that cancels this magnetic flux. Furthermore, magnetic flux is generated in the direction away from the side plate 11 by the current flowing through the first heating portion 132a and the second heating portion 132b at the brazed joint and its vicinity on the plate side. Between the first heating portion 132a and the second heating portion 132b, an eddy current as indicated by the bold white arrow in FIG. 14 is intensively generated by an induced current that generates a magnetic flux in a direction to cancel the magnetic flux. These eddy currents promote concentrated self-heating from both the anti-plate side and the plate side for multiple braze joints. These eddy currents contribute to uniform heating of multiple braze joints in the object to be heated. The direction of the eddy current near the anti-plate side and the eddy current near the plate side are opposite to each other.

The coil 203 of the third embodiment is installed such that the first heating section and the second heating section are located on both sides of the object to be heated. According to this configuration, the magnetic flux applied by the first heating unit and the magnetic flux applied by the second heating unit are in the same direction with respect to the object to be heated. These magnetic fluxes generate eddy currents in the brazed joints that make up the object to be heated. The eddy currents can similarly self-heat multiple braze joints and heat all braze joints contained in the object to be heated to a similar temperature.

Furthermore, the coil 203 includes a first coil portion 131 and a second coil portion 132 extending along the first coil portion 131 . The 1st coil part 131 and the 2nd coil part 132 are installed so that a to-be-heated target object may be interposed between these coil parts. The first heating portion 131a of the first coil portion 131 and the second heating portion 132b of the second coil portion 132 face each other and the directions of the electric currents are opposite to each other. The second heating portion 131b of the first coil portion 131 and the first heating portion 132a of the second coil portion 132 face each other and the directions of the electric currents are opposite to each other.

According to this, the first heating unit and the second heating unit facing the object to be heated between the first coil unit 131 and the second coil unit 132 are oriented in the same direction as shown in FIG. Give magnetic flux. In addition, this magnetic flux generates eddy currents on the plate side and the opposite side of the brazed joint, so that the brazed joints also self-heat. Therefore, the coil 203 can heat all braze joints contained in the object to be heated to a similar temperature. The induction heating apparatus of the third embodiment can stabilize the quality of brazing with little variation in the state of brazing of a plurality of brazed joints included in the object to be heated.

(Fourth embodiment)
In the fourth embodiment, a coil 303 included in an induction heating device will be described with reference to FIG. In FIG. 15, the components denoted by the same reference numerals as in the drawings of the above-described embodiment are the same components and have the same effects.

The coil 303 of the fourth embodiment differs from that of the third embodiment in the positional relationship between the object to be heated and the coil. The coil 303 includes a first coil portion 231 having a first heating portion 231a and a second heating portion 231b on both sides of a plurality of brazed joints. The first coil portion 231 includes a first heating portion 231a, a second heating portion 231b, and a folded portion 231c. The first heating part 231a is positioned on one of the two sides of the object to be heated. The second heating part 231b is positioned on the other side of the object to be heated. Both the first heating part 231a and the second heating part 231b are installed so that the distance from the side plate 11 is the same as the brazing joint. The folded portion 231c extends across a plurality of brazed joints and connects the first heating portion 231a and the second heating portion 231b. The first coil part 231 is installed so that the object to be heated when viewed from the side overlaps with the first coil part 231 .

In the coil 303, the high-frequency current flows down through the first heating portion 231a, the folded portion 231c, and the second heating portion 231b in this order. FIG. 15 shows the induced current acting on the object to be heated and the magnetic flux generated by energizing the coil 303 . In FIG. 15, the solid arrow indicates the direction of the magnetic flux, the direction of the high frequency current in the coil portion, and the thick white arrow indicates the induced current acting on the brazed joint.

A magnetic flux is generated in a direction toward the side plate 11 at and near the brazed joint by the current flowing through the first heating portion 231a and the second heating portion 231b. Between the first heating portion 231a and the second heating portion 231b, an eddy current as indicated by a thick white arrow in FIG. 15 is intensively generated by an induced current that generates magnetic flux in a direction that cancels this magnetic flux. This eddy current promotes self-heating of the plurality of brazed joints and contributes to uniform heating of the plurality of brazed joints in the object to be heated.

The coil 303 of the fourth embodiment is installed so that the object to be heated is interposed between the first heating section and the second heating section. According to this configuration, the magnetic flux applied to the object to be heated by the first heating unit and the magnetic flux applied by the second heating unit are directed in the same direction as in the case of the coil 203 . Since this magnetic flux exerts a high magnetic flux density on a plurality of brazed joints forming the object to be heated, eddy currents can be efficiently generated. The induction heating device of the fourth embodiment contributes to stabilizing the brazing quality of a plurality of brazed joints included in the object to be heated.

(Fifth embodiment)
In the fifth embodiment, a coil 403 included in an induction heating device will be described with reference to FIG. In FIG. 16, the components denoted by the same reference numerals as in the drawings of the above-described embodiment are the same components and have the same effects.

The coil 403 of the fifth embodiment differs from that of the third embodiment in that the objects to be heated are arranged in multiple rows. In the fifth embodiment, an example in which the coil 403 heats three rows of objects to be heated will be described. The coil 403 heats the first heated object, the second heated object and the third heated object. The second heated object is positioned between the first heated object and the third heated object. The coil 403 includes a third coil portion 331 and a fourth coil portion 332 in addition to the first coil portion 131 and the second coil portion 132 that heat the first object to be heated.

The third coil portion 331 and the fourth coil portion 332 face each other in the direction in which the pipe 12 and the second connecting pipe 15 extend, with the plurality of brazed joints forming the third object to be heated interposed therebetween. The fourth coil portion 332 is located closer to the side plate 11 than the third coil portion 331 is.

The third coil portion 331 includes a first heating portion 331a, a second heating portion 331b, and a folded portion 331c. Both the first heating part 331a and the second heating part 331b are installed so that the distance to the side plate 11 and the distance to the brazed joint are the same. A part of the second connecting pipe 15 on the side of the other end 15b exists between the first heating part 331a and the second heating part 331b. The first heating part 331 a is positioned on one side of the two sides of the second connecting pipe 15 . The second heating part 331 b is positioned on the other side of the two sides of the second connecting pipe 15 . The folded portion 331c extends across the portion of the second connecting pipe 15 on the other end portion 15b side, and connects the first heating portion 331a and the second heating portion 331b.

The fourth coil portion 332 includes a first heating portion 332a, a second heating portion 332b, and a folded portion 331c. Both the first heating part 332a and the second heating part 332b are installed so that the distance to the side plate 11 and the distance to the brazed joint are the same. A pipe 12c exists between the first heating section 332a and the second heating section 332b. The second heating section 332b is located on one side of the tube 12c. The first heating portion 332a is positioned on the other side of the tube 12c. The folded portion 332c extends across the pipe 12c and connects the first heating portion 332a and the second heating portion 332b.

The third coil portion 331 and the fourth coil portion 332 are installed such that the third object to be heated as viewed from the side is positioned between the third coil portion 331 and the fourth coil portion 332 . The first heating portion 331a and the second heating portion 332b are provided at positions facing each other in the direction in which the pipe 12 and the second connecting pipe 15 extend. The second heating portion 331b and the first heating portion 332a are provided at positions facing each other in the direction in which the pipe 12 and the second connecting pipe 15 extend. The folded portion 331c and the folded portion 332c are provided at positions facing each other in the direction in which the pipe 12 and the second connecting pipe 15 extend.

The first heating unit 131a and the second heating unit 331b are installed on both sides of the second object to be heated so as to face each other in the multiple row direction. Both the first heating part 131a and the second heating part 331b are installed so that the distance to the side plate 11 and the distance to the brazed joint are the same. A part of the second connecting pipe 15 on the one end 15a side is present between the first heating part 131a and the second heating part 331b. The second heating part 331 b is positioned on one side of the two sides of the second connecting pipe 15 . The first heating portion 131 a is positioned on the other side of the two sides of the second connecting pipe 15 .

The second heating unit 132b and the first heating unit 332a are installed on both sides of the second object to be heated so as to face each other in the multiple row direction. Both the second heating part 132b and the first heating part 332a are installed so that the distance to the side plate 11 and the distance to the brazed joint are the same. A pipe 12b exists between the second heating section 132b and the first heating section 332a. The first heating section 332a is positioned on one side of the two sides of the tube 12b. The second heating section 132b is positioned on the other side of the tube 12b.

A plurality of coil portions are connected in series in the coil 403, and current flows in series. In the first coil portion 131, the high-frequency current flows through the first heating portion 131a, the folded portion 131c, and the second heating portion 131b in that order, and flows down to the second coil portion 132 via the connecting portion. In the second coil portion 132, the high-frequency current flows through the first heating portion 132a, the folded portion 132c, and the second heating portion 132b in that order, and then flows down to the fourth coil portion 332 via the connecting portion. In the fourth coil portion 332, the high-frequency current flows through the first heating portion 332a, the folded portion 332c, and the second heating portion 332b in that order, and then flows down to the third coil portion 331 via the connecting portion. In the third coil portion 331, the high-frequency current flows down through the first heating portion 331a, the folded portion 331c, and the second heating portion 331b in this order. Also, the coil 403 may have a configuration in which a plurality of coil portions are connected in parallel, and current flows through each coil portion in parallel.

FIG. 16 shows the induced current acting on the object to be heated and the magnetic flux generated by energizing the coil 403 . In FIG. 16, the solid arrow indicates the direction of the magnetic flux, the direction of the high frequency current in the coil portion, and the thick white arrow indicates the induced current acting on the brazed joint.

The induced current that acts on the first object to be heated that exists inside both the first coil portion 131 and the second coil portion 132 is the same as in the third embodiment.

The induced current acting on the second object to be heated will be described. A magnetic flux is generated in the direction away from the side plate 11 in the vicinity of the second object to be heated and its side opposite to the plate by the current flowing through the first heating portion 131a and the second heating portion 331b. Between the first heating portion 131a and the second heating portion 331b, an eddy current as indicated by a thick outline arrow in FIG. 16 is intensively generated by an induced current that generates a magnetic flux in a direction to cancel the magnetic flux. A magnetic flux is generated in the direction approaching the side plate 11 by the current flowing through the second heating unit 131b and the first heating unit 332a in the second object to be heated and its plate side vicinity. Between the second heating portion 131b and the first heating portion 332a, an eddy current is intensively generated as indicated by the outline thick arrow in FIG. These eddy currents promote intensive self-heating of the second object to be heated from both the anti-plate side and the plate side. These eddy currents contribute to uniform heating of multiple braze joints in the second heated object. The eddy currents on the side opposite to the plate and the eddy currents on the plate side with respect to the second object to be heated have opposite eddy directions.

The induced current acting on the third object to be heated will be described. A magnetic flux is generated in the direction approaching the side plate 11 in the vicinity of the third object to be heated and its side opposite to the plate due to the current flowing through the first heating portion 331a and the second heating portion 331b. Between the first heating portion 331a and the second heating portion 331b, an eddy current as indicated by a bold white arrow in FIG. 16 is intensively generated by an induced current that generates a magnetic flux in a direction to cancel the magnetic flux. A magnetic flux is generated in the direction away from the side plate 11 by the current flowing through the second heating part 332b and the first heating part 332a in the third object to be heated and its plate side vicinity. Between the second heating portion 332b and the first heating portion 332a, an eddy current is intensively generated as indicated by the outline thick arrow in FIG. These eddy currents promote intensive self-heating of the third object to be heated from both the anti-plate side and the plate side. These eddy currents contribute to uniform heating of multiple braze joints in the third heated object. The direction of the eddy current in the vicinity of the non-plate side and the eddy current in the vicinity of the plate side with respect to the third object to be heated are opposite in direction.

(Sixth embodiment)
In the sixth embodiment, the coil 503 included in the induction heating device will be described with reference to FIGS. 17 to 21. FIG. In each figure, the components denoted by the same reference numerals as in the drawings of the above-described embodiment are the same components and have the same effects.

The coil 503 has cooling passages applicable to the induction heating apparatus according to the above-described embodiments. As shown in FIGS. 17 and 18, the coil 503 includes coil portions located between objects to be heated adjacent to each other in a plurality of rows. The coil 503 includes, for example, a first coil portion 531, a second coil portion 532, and a third coil portion 533 arranged in multiple rows. The coils are connected in parallel so that high-frequency currents flow simultaneously.

The first coil part 531 is positioned on one of the two sides of the first object to be heated. The second coil part 532 is positioned on the other side of the first object to be heated. The first coil portion 531 and the second coil portion 532 are provided at positions facing each other in the direction of multiple rows. The second coil part 532 is positioned on one of the two sides of the second object to be heated. The third coil part 533 is positioned on the other side of the two sides of the second object to be heated. The second coil portion 532 and the third coil portion 533 are provided at positions facing each other in the direction of multiple rows.

The first coil portion 531 includes a first heating portion 31a, a second heating portion 31b located closer to the side plate 11 than the first heating portion 31a, and a folded portion 531c. The first coil portion 531 includes a first conducting portion 531d electrically connected to the first heating portion 31a and a second conducting portion 531e electrically connected to the second heating portion 31b. The inside of the first conducting portion 531d communicates with the inside of the first heating portion 31a. The inside of the second conducting portion 531e communicates with the inside of the second heating portion 31b. The inside of the second conducting portion 531e communicates with the inside of the first conducting portion 531d through the inside of the second heating portion 31b, the inside of the folded portion 531c, and the inside of the first heating portion 31a. An internal passage extending from the second conduction portion 531e to the first conduction portion 531d constitutes a cooling passage. The folded portion 531c is provided at a position outside the object to be heated in the alignment direction and not facing the object to be heated. In the first coil portion 531, the high-frequency current flows through the first conducting portion 531d, the first heating portion 31a, the folded portion 531c, the second heating portion 31b, and the second conducting portion 531e in this order.

The second coil portion 532 includes a first heating portion 32a, a second heating portion 32b located on the opposite side of the side plate 11 from the first heating portion 32a, and a folded portion 532c. The second coil portion 532 includes a first conducting portion 532d electrically connected to the first heating portion 32a and a second conducting portion 532e electrically connected to the second heating portion 32b. The inside of the first conducting portion 532d communicates with the inside of the first heating portion 32a. The inside of the second conducting portion 532e communicates with the inside of the second heating portion 32b. The inside of the second conducting portion 532e communicates with the inside of the first conducting portion 532d through the inside of the second heating portion 32b, the inside of the folded portion 532c, and the inside of the first heating portion 32a. An internal passage extending from the second conduction portion 532e to the first conduction portion 532d constitutes a cooling passage. The folded portion 532c is provided at a position outside the object to be heated in the alignment direction and not facing the object to be heated. The folded portion 531c and the folded portion 532c are provided at positions facing each other in the direction of multiple rows. In the second coil portion 532, the high-frequency current flows through the first conducting portion 532d, the first heating portion 32a, the folded portion 532c, the second heating portion 32b, and the second conducting portion 532e in this order.

The third coil portion 533 includes a first heating portion 33a, a second heating portion 33b positioned closer to the side plate 11 than the first heating portion 33a, and a folded portion 533c. The third coil portion 533 includes a first conducting portion 533d electrically connected to the first heating portion 33a and a second conducting portion 533e electrically connected to the second heating portion 33b. The inside of the first conducting portion 533d communicates with the inside of the first heating portion 33a. The inside of the second conducting portion 533e communicates with the inside of the second heating portion 33b. The inside of the second conducting portion 533e communicates with the inside of the first conducting portion 533d through the inside of the second heating portion 33b, the inside of the folded portion 533c, and the inside of the first heating portion 33a. An internal passage extending from the second conduction portion 533e to the first conduction portion 533d constitutes a cooling passage. The folded portion 533c is provided at a position outside the object to be heated in the alignment direction and not facing the object to be heated. The folded portion 532c and the folded portion 533c are provided at positions facing each other in the direction of multiple rows. In the third coil portion 533, the high-frequency current flows through the first conducting portion 533d, the first heating portion 33a, the folded portion 533c, the second heating portion 33b, and the second conducting portion 533e in this order.

FIG. 19 shows the configuration of the first heating section and the second heating section in the coil 503, taking the first heating section 33a as a representative example. Therefore, the configuration related to the first heating unit 33a described below can be applied to other first heating units and second heating units. As shown in FIG. 19, the first heating portion 33a has a configuration in which two copper pipes 33a1 and 33a2 are integrally joined via a brazing material portion 33f. The brazing material portion 33f is preferably made of phosphor copper brazing material. The copper tube 33a1 and the copper tube 33a2 are preferably made of a heat-resistant copper alloy such as C1862 and C5010 of the JIS standard, for example. In addition, the first heating section and the second heating section in the coil 503 may be composed of a copper member having an internal passage or a copper member having no internal passage other than the copper pipe. If a copper member without internal passages is employed, the copper member can be cooled by air cooling, for example.

As shown in FIG. 20, the first conducting portion 531d, the second conducting portion 531e, the first conducting portion 532d, the second conducting portion 532e, the first conducting portion 533d, and the second conducting portion 533e are electrically connected to each other by the insulating portion 503a. effectively insulated. The folded portion 531c, the folded portion 532c, and the folded portion 533c are electrically insulated from each other. FIG. 21 shows the configuration of a third coil portion 533 as a representative example among the plurality of coil portions included in the coil 503. As shown in FIG.

The path of the fluid that flows down the cooling passage in the coil 503 will be described with reference to FIG. In the first coil portion 531, the cooling fluid flows from the inflow portion 531e1 into the second conduction portion 531e, passes through the insides of the two copper pipes 31b1 and 31b2 of the second heating portion 31b, and flows down into the folded portion 531c. do. Further, the cooling fluid passes through the inside of the two copper pipes 31a1 and 31a2 of the first heating portion 31a from the folded portion 531c, flows into the first conducting portion 531d, and flows out of the outflow portion 531d1. In the second coil portion 532, the cooling fluid flows from the inflow portion 532d1 into the first conduction portion 532d, passes through the insides of the two copper pipes 32a1 and 32a2 of the first heating portion 32a, and flows down into the folded portion 532c. do. Further, the cooling fluid passes through the inside of the two copper pipes 32b1 and 32b2 of the second heating portion 32b from the folded portion 532c, flows into the second conducting portion 532e, and flows out of the outflow portion 532e1. In the third coil portion 533, the cooling fluid flows from the inflow portion 533e1 into the second conduction portion 533e, passes through the insides of the two copper pipes 33b1 and 33b2 of the second heating portion 33b, and flows down into the folded portion 533c. do. Furthermore, the cooling fluid passes through the inside of the two copper pipes 33a1 and 33a2 of the first heating portion 33a from the folded portion 533c, flows into the first conducting portion 533d, and flows out of the outflow portion 533d1.

A coil 503 of the sixth embodiment is formed of a plurality of copper tubes or copper members. A plurality of copper tubes or copper members are integrally formed by phosphor-copper brazing. According to this configuration, it is possible to provide a coil with high strength after brazing.

The copper pipe or copper member is preferably made of a heat-resistant copper alloy. According to this configuration, a coil with high straightness can be provided. A coil with high straightness and strength allows the distance between the coil and the braze joint to be maintained even for heat exchangers with a small pitch between adjacent tubes. Therefore, it is possible to provide an induction heating device capable of heating a plurality of brazed joints to a similar temperature.

Further, when a plurality of rows of coil portions are energized, magnetic fields in opposite directions are generated between the adjacent coil portions, so forces act on the coil portions at both ends in mutually repulsive directions. A coil having high rigidity can be obtained by a configuration in which a plurality of copper tubes or copper members are integrally formed by phosphor-copper brazing and a configuration in which the coil is made of a heat-resistant copper alloy.

The induction heating device of the sixth embodiment includes a cooling device 6 through which a cooling fluid for cooling the coil 503 can flow. Cooling device 6 has cooling passages through which cooling fluid flows parallel to coil 503 . The high-frequency current is configured to flow in series with the coil 503 . According to this configuration, since the coil 503 is configured such that the cooling fluid flows in parallel, even if the diameter of the tube forming the coil 503 is made small, it is easy to secure the flow rate of the fluid in the tube. In this induction heating device, the coil 503 can be installed on the side of a plurality of brazed joints with small pipe diameters and narrow pipe pitches, and cooling performance can be ensured to suppress abnormal heat generation of the coils in the heating and melting process.

(Other embodiments)
The disclosure in this specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiments, and various modifications can be made. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses abbreviations of parts and elements of the embodiments. The disclosure encompasses the permutations, or combinations of parts, elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is indicated by the description of the claims, and should be understood to include all modifications within the meaning and range of equivalents to the description of the claims.

The induction heating device capable of achieving the objects disclosed in the specification is not limited to the configurations described in the above embodiments. An induction heating device capable of achieving the purpose also includes, for example, a device that is a coil configuration without the second coil portion 32 in the second embodiment. That is, the induction heating device may be configured to have one coil portion. In this case as well, the first coil portion 31 can heat a plurality of brazing joints at once by generating a magnetic flux by applying a high-frequency current, and by an induced current, and perform a plurality of brazing joints.

In the coil 3 of the first embodiment, a plurality of coil portions are connected in series, and current flows in series. Alternatively, a plurality of coil portions may be connected in parallel, and current may flow in parallel.

The induction heating apparatus and the manufacturing method according to the above-described embodiments may be configured to perform brazing in multiple stages by changing the coil circuit that is energized in series when there are many objects to be heated.

3, 103, 203, 303, 403... Coil 4... High frequency inverter (current output section) 11... Side plate 31, 131... First coil section 31a, 32a, 33a, 34a, 35a... First heating section 31b, 32b , 33b, 34b, 35b... Second heating part 31c, 32c, 33c, 34c, 35c... Folding part 32, 132... Second coil part

Claims (6)

In the heat exchanger (1), a plurality of coils (3; 10 3 ) for heating the brazed joints of members formed of a material containing aluminum by induced current by generating magnetic flux by applying high-frequency current. ; 503) and
a current output unit (4) for outputting a high-frequency current to energize the coil;
with
The coil is
a first heating unit (31a, 32a, 33a, 34a, 35a) that extends along an object to be heated in which the plurality of brazed joints are arranged in a line and heats the object to be heated by an induced current; ,
Extending along the object to be heated and the first heating unit, a high-frequency current flows in a direction opposite to the direction of the current flowing in the first heating unit, and heats the object to be heated by an induced current. 2 heating units (31b, 32b, 33b, 34b, 35b);
a folded portion (31c, 32c, 33c, 34c, 35c) connecting the first heating portion and the second heating portion so that high-frequency current flows from the first heating portion to the second heating portion;
including
The plurality of coils are arranged in a plurality of rows perpendicular to the direction in which the plurality of brazed joints are arranged,
For each of the objects to be heated which are arranged in the direction of the plurality of rows, the coils are arranged on one side and the other side of the objects to be heated in the direction of the plurality of rows. installed on both
The coil on the one side and the coil on the other side are installed so that the first heating section and the second heating section face each other and the directions of the currents are opposite to each other,
The first heating unit and the second heating unit are installed such that the object to be heated as viewed from the side is positioned between the first heating unit and the second heating unit,
at least two of the objects to be heated arranged in the multiple row direction include a first object to be heated and a second object to be heated;
A first coil portion located on one side and a second coil portion located on the other side with respect to the first object to be heated are the second heating portion and the second coil portion of the first coil portion. The first heating unit in is connected by a connecting portion located on the opposite side of the folded portion in the direction in which a plurality of objects to be heated are arranged,
The second coil portion located on one side and the third coil portion located on the other side with respect to the second object to be heated are the second heating portion and the third coil in the second coil portion. The induction heating device, wherein the first heating part of the part is connected to the first heating part by a connecting part located on the opposite side of the folded part with respect to the direction in which the plurality of objects to be heated are arranged. The folded portion and the connecting portion are provided outside the object to be heated in the direction in which the plurality of brazed joints are arranged, and at a position not facing the object to be heated in the direction of the plurality of rows. The induction heating device according to claim 1, wherein Coils (203; 303; 403; 403; 503) and
a current output unit (4) for outputting a high-frequency current to energize the coil;
with
The coil is
a first heating unit (31a, 32a, 33a, 34a, 35a) that extends along an object to be heated in which the plurality of brazed joints are arranged in a line and heats the object to be heated by an induced current; ,
Extending along the object to be heated and the first heating unit, a high-frequency current flows in a direction opposite to the direction of the current flowing in the first heating unit, and heats the object to be heated by an induced current. 2 heating units (31b, 32b, 33b, 34b, 35b);
a folded portion (31c, 32c, 33c, 34c, 35c) connecting the first heating portion and the second heating portion so that high-frequency current flows from the first heating portion to the second heating portion;
including
The induction heating device, wherein the coil is installed such that the first heating section and the second heating section are positioned on both sides of the object to be heated. The coil (203) includes a first coil portion (131) and a second coil portion (132) extending along the first coil portion,
The first coil portion and the second coil portion are installed such that the object to be heated is interposed between the coil portions,
The first heating portion in the first coil portion and the second heating portion in the second coil portion are opposed to each other and the directions of the currents are in opposite directions,
4. The induction heating device according to claim 3 , wherein the second heating portion of the first coil portion and the first heating portion of the second coil portion are opposed to each other and the directions of the electric currents are opposite to each other. . The induction heating device according to claim 3 , wherein the coil (303) is installed so that the object to be heated is interposed between the first heating section and the second heating section. A cooling device (6) through which a cooling fluid for cooling the coil can flow,
the cooling device has a cooling passage through which the cooling fluid flows in parallel with the coil;
The induction heating device according to any one of claims 1 to 5, wherein the high-frequency current flows in series with the coil .

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