JPH04198692A - Tube for conducting heat medium of heat exchanger and manufacture thereof - Google Patents

Abstract

PURPOSE:To retain brazing alloy and flux on a waveform configured top to braze the top surely by a method wherein an insert plate, abutted against the inner surface of at least one wall body between two flat wall bodies of a flat tube, is provided with a recessed stripe on the top of the projected stripes along the lengthwise direction of them. CONSTITUTION:A flat tube 1 is formed of two pieces of flat wall bodies 11, 12, arranged in parallel, and cylindrical wall bodies 13, connecting the flat wall bodies 11, 12 smoothly while an interval between the wall bodies 11, 12 is smaller than a width of the wall bodies 11, 12. An insert plate 2 is provided with lengthwisely continuous first projected stripes 23 and second projected stripes 24 while recessed stripes 28 are formed continuously on the top of the first projected stripes 23 along the lengthwise direction of the first stripes 23. The plating of a brazing alloy is applied on the outer peripheral surface of the insert plate 2 and the mixture of fine granular brazing alloy and solution of flux is applied on the whole surface of the insert plate 2 to reserve it in the recessed stripes 28 to dry it, then, the insert plate 2 is inserted into the flat tube 1 and, thereafter, the flat tube 1 is pushed into a direction wherein both wall surfaces 11, 12 approach to each other so that the same surfaces 11, 12 are abutted against the top of the projected stripes 23, 24 to braze them through heating.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention constitutes a heat exchanger together with fins, and heats air in contact with the fins by transmitting the temperature of a heat medium flowing inside the fins. Or cool.

This invention relates to a heat medium distribution tube for a heat exchanger.

[Conventional technology]

A heat exchanger is constructed by arranging a plurality of flat tubes in parallel, connecting them in series, and brazing corrugated roll-formed fins between the flat tubes. Ru.

In addition, in order to improve heat transfer from the flat tube to the fins, an insert plate called an inner fin, which is a metal plate shaped into a corrugated shape, is inserted into the flat tube, and the top of the corrugated shape on the insert plate is inserted into the flat tube. There is also a known heat medium distribution tube which is brazed to the inner wall of the flat tube so that more of the temperature of the heat medium flowing inside the flat tube is transferred to the fins via the insert plate.

In order to join the insert plate and fins to the inner and outer surfaces of the flat tube in a state with good heat transfer, it is necessary to apply a flux mixed with a brazing alloy in advance to the joint, let it dry, and then insert the insert plate into the flat tube. After the plates and fins are assembled, the whole is heated to melt the brazing alloy and flow the molten alloy into the joint to braze the joint.

[Problem to be solved by the invention]

When inserting a corrugated insert plate into a flat pipe formed into a flat shape and brazing it, the corrugated insert plate and the flat tube are usually placed in a flux liquid containing fine particles of a brazing alloy. After soaking the tube and adhering it to the entire surface, it is taken out and dried, and then the insert plate is inserted into the flat tube and heated to melt the brazing alloy, giving the insert plate a corrugated shape. The abutting portion between the top of the section and the inner surface of the flat tube is brazed.

The insert plate itself has low strength and tends to bend in the direction of continuous corrugations, so when inserting the insert plate into a flat pipe, the top of the shaped wave will come into contact with the inlet edge of the flat pipe and slide against it. There is a risk that the brazing alloy attached to the corrugated top may fall off along with the dry flux, and if sufficient brazing alloy is not attached to the contact area between the corrugated top of the insert plate and the inner surface of the flat tube during brazing. Unusual problems may occur. In order to avoid this, we installed a feeding roll device in which two rolls whose rotational axes are arranged parallel to each other are each formed with a protrusion in the circumferential direction that contacts the slope of the corrugated portion of the insert plate. Japanese Patent Application Laid-Open No. 62-207572 discloses a device for inserting the corrugated top portion of a flat tube without sliding it into contact with the inlet edge of the flat tube.

The present invention provides a heat source that can maintain sufficient brazing alloy and flux for brazing at the top of the corrugated portion of the insert plate to reliably braze without using such a feeding roll. An object of the present invention is to provide a heat medium distribution tube for an exchanger and a method for manufacturing the same.

[Means to solve the problem]

The heat medium distribution tube of the heat exchanger according to the present invention is formed from a metal plate and includes two substantially flat wall bodies facing each other in parallel in a cross section perpendicular to the length direction. a flat tube with an inter-body spacing smaller than the width of the wall, and a metal plate formed from a metal plate and inserted into the flat tube;
an insert plate formed by forming a plurality of protrusions exhibiting a waveform in the cross section so that the longitudinal direction of the protrusions is parallel to the longitudinal direction of the flat tube, and the tops of the protrusions protrude from both sides of the insert plate; The flat tube is brazed to the inner surfaces of the two walls of the flat tube, and a plurality of spaces along the longitudinal direction of the flat tube defined by the corrugated ridges are used as flow paths for the heat medium, At least one recess formed concavely relative to the inner surface of the wall on the top of the protrusion of the insert plate that abuts the inner surface of at least one of the two walls of the flat tube. The ridge is provided along the longitudinal direction of the ridge.

Further, the method of manufacturing the heat medium distribution tube of the heat exchanger according to the present invention includes two substantially flat wall bodies made of metal plates facing each other in parallel in a cross section perpendicular to the longitudinal direction; A process of forming a flat tube in which the interval between the walls is smaller than the width of the walls, and roll forming of the metal plate, whereby a plurality of protrusions are continuous in a wavy shape in a cross section perpendicular to the forming direction, and At least one recess opening at the top of the protrusion protruding from at least one surface of the metal plate,
a step of forming an insert plate having such cross-sectional shape continuous in the longitudinal direction of the metal plate and having a plurality of protrusions having grooves at the top parallel to each other, and placing the insert plate inside the flat tube. The longitudinal direction of the protrusion is aligned with the longitudinal direction of the flat tube, and the flat tube is pressed in a direction in which the two opposing walls approach each other to protrude from both sides of the insert plate. The tops of the protrusions are brought into contact with the inner surface of the wall of the flat tube and heated to heat and melt the mixture of brazing alloy and flux applied to the insert plate, and the insert plate is attached to the protrusion. This method includes the step of brazing and fixing the top of the strip to the inner surface of the wall of the flat tube.

〔Example〕

FIG. 1 is a sectional view taken in a plane perpendicular to the longitudinal direction of the heat medium distribution tube of the present invention, and FIG. 2 is a sectional view of an insert plate thereof.

Reference numeral 1 in the figure is a flat tube formed of a metal plate,
In the cross section, two flat walls 11 and 12 are formed facing each other in parallel, and these walls 11 and 12 are smoothly connected by cylindrical walls 13 and 13. The distance between the flat wall bodies 11 and 12 is made smaller than the width of the wall bodies 11 and 12 in the cross section. Code 2 in the diagram
is an insert plate roll-formed from a metal plate, and includes a first protrusion 21 that is convex on one side of the metal plate and a second protrusion 22 that is convex on the other side of the metal plate in the cross section. First protrusions 23 and second protrusions 24 are formed alternately in a wave shape in the width direction of the metal plate and are continuous in the longitudinal direction of the metal plate by these protrusions 21 and 22.
was formed. The top 25 of the first protrusion 23 and the top 26 of the second protrusion 24 are both flat surfaces that come into contact with the inner surfaces of the flat walls 11 and 12 of the flat tube 1, and the top of the first protrusion 21 A recess 27 is formed in the wall 11 of the flat tube 1, and the recess 27 continues in the longitudinal direction of the first protrusion 23 to form a recess 28. Third
The figure shows a partially enlarged cross-sectional view.

The above-mentioned flat tube 1 is produced by drawing out a continuous flat metal plate while bending it in the width direction using a forming roller, and when the cross section in the width direction is formed into a circular shape, the side edges of the plates are butted together. Welding is performed, and then the cross section is flattened by pressing in the diametrical direction with upper and lower parallel rolls, and the shape shown in FIG. 1 is cut to a predetermined dimension in the length direction.

The insert plate 2 is formed by a pair of forming rollers 3 and 4 shown in cross section in FIG. The first roller 3 has a top mold surface 31 for molding the top of the first protrusion 21 of the insert plate 2 and a recess mold surface 32 for molding the recess 27 inside the rolling center surface 3o of both rollers. A top mold surface 33 for molding the top of the second protrusion 22 is provided on the outside of the transfer center surface 30, and a slope 34 connecting the ends of the top mold surfaces 31 and 33 is provided continuously in the circumferential direction, The second roller 4 is a forming roller rotated around a rotation center axis 35, and the second roller 4 has a first protrusion 21 of the insert plate 2 on the outside of the transfer center plane 3o.
A top mold surface 41 for molding the top of the recess 27, a recess mold surface 42 for molding the recess 27, a top mold surface 43 for molding the top of the second protrusion 22 inside the transfer center surface 30, This forming roller is provided with a slope 44 continuous in the circumferential direction, connecting the ends of mold surfaces 41 and 43, and is rotated around a central axis of rotation 45. When the first roller 3 and the second roller 4 are rotated in opposite directions about their respective central rotation axes 35.45 and the metal plate is roll-formed, the insert plate 2 shown in FIGS. 2 and 3 is formed. is formed.

The insert plate 2 is inserted into the flat tube 1 and fixed to each other by brazing. Flat tube 1 of insert plate 2
Prior to insertion into the interior, the outer peripheral surface is plated with a brazing alloy in order to join the flat tube 1 to the heat exchanger fins 5 (see Figure 5), and the insert plate 2 is plated with a brazing alloy. A mixture of fine particles of the alloy and a flux solution is applied to the entire surface by dipping or other means, and is collected in the grooves 28 and dried.

After the insert plate 2 is inserted into the flat tube 1 so that the longitudinal direction of the protrusions 23, 24 is parallel to the longitudinal direction of the flat tube 1, the flat wall surface 11, 12 of the flat tube 1 is inserted into the flat tube 1. so as to come into contact with the tops of the protrusions 23 and 24 of the insert plate 2,
They are pressed in a direction closer to each other and heated. Top portion 2 of the first protrusion 23 and second protrusion 24 of the insert plate 2
The brazing alloy applied to 5, 26 is melted and the tops 25, 26 and the flat walls 11, 12 of the flat tube 1 are melted.
Braze between the inside surface and the inside surface. Top 2 of first protrusion 23
The brazing alloy held in the groove 28 formed in the first projection 23 prevents the fixation between the top 25 of the first projection 23 and the wall 11 of the flat tube 1 with which the top 25 comes into contact. The brazing alloy that had been strengthened and adhered to the oblique side of the second protrusion 24 of the insert plate 2 melts and forms a wedge at the abutment area between the insert plate 2 and the wall 12 of the flat tube 1 located at the lower position. Fill in the corners. As a result, the insert plate 2 is fixed to the inside of the flat tube 1, and a heat medium distribution tube 6 is formed in which the inside of the flat tube 1 is partitioned with a plurality of flow passages partitioned by the insert plate 2.

When manufacturing a heat exchanger, in the assembled state before heating and melting the brazing alloy of the heat medium distribution tube 6,
As shown in Figure 5, multiple pieces are arranged horizontally in a square shape,
A fin 5 made of a corrugated metal plate is sandwiched between the flat wall surfaces 11 and 12 of the tube 6 to form a heat exchanger core, and is assembled with side plates 7 and 7 disposed above and below the fin 5. Fit both ends into the connection openings of the side tank 8°8, apply flux mixed with fine particles of brazing alloy to each joint, and heat the entire assembly in a heating furnace to melt the brazing alloy. temperature, remove it from the furnace and cool it to room temperature to obtain a heat exchanger.

It has been explained that in manufacturing the heat medium distribution tube, a flux liquid mixed with fine particles of a brazing alloy is applied to the insert plate 2 before inserting the insert plate 2 into the flat tube 1. After inserting the insert plate 2 into the flat tube 1, the inserted insert plate 2 and the flat tube 1 are immersed in the flux liquid, so that the entire surface of the assembled body is coated with the flux liquid. It's okay.

In the above embodiment, the two flat walls 1 of the flat tube 1
Although the grooved line 28 was formed only on the top of the first protruding line 23 of the insert plate 2 that comes into contact with the inner surface of one of the two walls 11 and 12, When a groove similar to the groove 28 is formed on the top 26 of the second protrusion 24 that comes into contact with the inner surface of the other wall 12, the second protrusion 2
4 to the flat tube 1 is further strengthened.

[Operation and effects of the invention]

The heat medium distribution tube of the heat exchanger of the present invention is formed from a metal plate and includes two substantially flat wall bodies facing each other in parallel in a cross section perpendicular to the length direction. A flat tube with an interval smaller than the width of the wall, and a plurality of ridges formed from a metal plate and inserted into the flat tube and exhibiting a wavy shape in the cross section in the longitudinal direction of the ridges. an insert plate shaped parallel to the longitudinal direction of the flat tube, the tops of protrusions protruding from both sides of the insert plate being brazed to the inner surfaces of the two walls of the flat tube, A plurality of spaces along the longitudinal direction of the flat tube defined by the corrugated ridges are used as flow paths for a heat medium, and at least one of the two walls of the flat tube is At least one concave strip formed concavely with respect to the inner surface of the wall body is provided on the top of the protrusion of the insert plate that comes into contact with the inner surface along the longitudinal direction of the protrusion. Therefore, a sufficient amount of brazing alloy is held in at least one concave strip on the top of the protruding strip of the insert plate that contacts the inner surface of the wall of the flat tube, and a sufficient amount of brazing alloy is held in the groove between the two. and ensure that the inside of the flat tube is divided into a plurality of spaces by the insert plate, and the heat of the heat medium flowing through the space as a flow path is transmitted to the flat tube via the insert plate, Furthermore, the air in contact with the flat tubes and the fins that are brazed onto the flat tubes and constitute the heat exchanger are ensured, thereby improving the heat exchange efficiency of the heat exchanger.

Further, the method for manufacturing a heat medium distribution tube for a heat exchanger according to the present invention includes two substantially flat wall bodies made of metal plates facing each other in parallel in a cross section perpendicular to the longitudinal direction; A process of forming a flat tube with an interval between the bodies smaller than the width of the wall body, and roll forming a metal plate, so that a plurality of protrusions are continuous in a wave shape in a cross section perpendicular to the forming direction,
and at least one recess opening at the top of the projection protruding on at least one surface side of the metal plate, the protrusion having such a cross-sectional shape continuous in the longitudinal direction of the metal plate and having a recess at the top. inserting the insert plate into the flat tube with the longitudinal direction of the ridges aligned with the longitudinal direction of the flat tube; 2 flat tubes facing each other
The walls are pressed in a direction in which they approach each other, and the tops of the protrusions protruding from the inner surface of the insert plate are brought into contact with the inner surface of the wall of the flat tube, respectively, and heated, so that the insert plate is heated. The method comprises the steps of melting the applied mixture of brazing alloy and flux and brazing the insert plate to the inner surface of the wall of the flat tube at the top of the protrusion. The forming process is similar to the process of forming tubes for conventional heat exchangers, and can be easily formed.In addition, in the process of forming insert plates, protrusions are added to the rolls used to form conventional corrugated insert plates. It can be easily formed by simply attaching a mold surface for forming grooves opening at the top.Furthermore, in the step of brazing and fixing the insert plate to the flat tube, the insert plate is preliminarily coated with a mixture of brazing alloy and flux. When inserting the insert plate into a flat tube after coating and drying, even if the top of the protrusion on the insert plate comes into contact with and slides against the inlet edge of the flat tube, at least one of the protrusions formed on the top of the protrusion Since the mixture of brazing alloy and flux retained in the grooves of the strips is not separated, the mixture between the top of the protrusions of the insert plate and the inner surface of the wall of the flat tube during heat-fixing. Sufficient brazing alloy is retained for brazing to ensure brazing fixation, and when the insert plate is inserted into the flat tube and then immersed in a mixture of brazing alloy and flux liquid. Also, the groove formed on the top of the protrusion of the insert plate has a sufficient amount of brazing to the inner surface of the wall of the flat tube compared to the rest of the top of the protrusion. Since a sufficient amount of the brazing alloy is applied and maintained, it is possible to reliably braze the top of the protrusion and the inner surface of the wall.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a section perpendicular to the longitudinal direction of an embodiment of the heat medium distribution tube of the present invention, and FIG.
FIG. 3 is a partially cutaway perspective view showing a part of the insert plate, FIG. 4 is a cross-sectional view of the main part of the forming roll for forming the insert plate, and FIG. 5 is a cross-sectional view of the insert plate shown in the figure. FIG. 2 is a front view showing an example of a heat exchanger using the heat medium distribution tube of the present invention. The numbers in the figure indicate the following parts. 1...Flat tube, 11,12...
The wall, 2...insert board. 23...First protrusion, 24...Second protrusion, 25.26...Top part, 28...
Concave line.

Claims (2)

[Claims] (1) It is formed from a metal plate and has two substantially flat walls that face each other in parallel in a cross section perpendicular to the length direction, and the distance between these two walls is smaller than the width of the walls. A flat tube formed from a metal plate and inserted into the flat tube, and a plurality of protrusions having a waveform in the cross section are formed by making the longitudinal direction of the protrusions parallel to the longitudinal direction of the flat tube. The flat tube consists of a shaped insert plate, and is brazed to the inner surface of the two walls of the flat tube at the top of the protrusion protruding on both sides of the insert plate, and is partitioned by the wavy protrusion. In a heat medium tube of a heat exchanger in which a space along the longitudinal direction is used as a heat medium flow path, a protrusion of the insert plate that comes into contact with an inner surface of at least one of the flat walls of the flat tube; for heat medium distribution of a heat exchanger, characterized in that at least one concave strip formed concavely on the inner surface of the wall body along the longitudinal direction of the protrusion is provided on the top of the wall body. Tube. (2) Two substantially flat walls made of metal plates that face each other in parallel in a cross section perpendicular to the length direction, and the distance between these two walls is smaller than the width of the walls. A process of forming a flat tube, and roll forming a metal plate, so that a plurality of protrusions are continuous in a waveform in a cross section perpendicular to the forming direction, and the protrusions protrude from at least one side of the metal plate at the top. a step of molding an insert plate having at least one open recess, a plurality of protrusions parallel to each other, the cross-sectional shape of which is continuous in the longitudinal direction of the metal plate, and having grooves at the top; The insert plate is inserted into a flat tube with the longitudinal direction of its protrusion aligned with the longitudinal direction of the flat tube, and the flat tube is oriented in a direction in which the two opposing walls approach each other. The mixture of brazing alloy and flux applied to the insert plate is heated while pressing the tops of the protrusions protruding from both sides of the insert plate into contact with the inner surface of the wall of the flat tube, respectively. melt,
A method of manufacturing a heat medium circulation tube for a heat exchanger, comprising the step of brazing and fixing the insert plate to the inner surface of the wall of the flat tube at the top of the protrusion.