JPH109791A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity of a low-cost heat exchanger by assembling a connecting tube with a header and batch brazing them without using an assembling jig. SOLUTION: A connecting tube 4 is inserted at its end into an insertion hole 7 of a header 2, and fixed to the header 2 in a temporarily fastened state via a spot welding (w) by argon welding. A sleeve 12 is disposed in the tube 4 in the state that the welded part (w) is sandwiched therebetween. The sleeve 12 is integrated with the tube 4 by radially shrinking the end of the tube 4. A jig is eliminated by the spot welding (w), and a jig removing step after the batch welding is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat exchanger made of metal such as aluminum used for a condenser for a car cooler, a heat exchanger for a room air conditioner, and the like.

[0002] In this specification, the term "aluminum" is used in a meaning including its alloy.

[0003]

2. Description of the Related Art As a condenser for a car cooler, for example, a so-called multi-flow type aluminum heat exchanger has recently been used as shown in FIG.

In this heat exchanger, a plurality of heat exchange tubes (1) are arranged in parallel at predetermined intervals, and hollow headers (2) and (2) are provided at both ends of the tubes (1). 2) are connected in a communicating state, and have a basic structure in which corrugated fins (3) are arranged between tubes (1). In this heat exchanger, a connection pipe (4) for the refrigerant inlet and a connection pipe (5) for the same outlet are connected to the headers (2) and (2) in a communicating state, and the refrigerant is connected to the refrigerant inlet. It is fed through the connecting pipe (4), flows through the inside of the tubes (1), etc., and is then sent out through the connecting pipe for outlet (5). In addition, (6) is a partition, which partitions the header (2) at a predetermined position in the length direction so that the refrigerant flows in a meandering manner through the tubes (1)... In the manufacture of this heat exchanger, components such as tubes (1), headers (2) (2), fins (3), connection tubes (4) (5), etc. are individually manufactured and temporarily It is performed in such a manner as to be assembled in a assembled state, and the whole is joined and integrated by collective brazing.

By the way, in the heat exchanger as described above, conventionally, a connection pipe (4) to the header (2) (2) is used.
As shown in FIG. 8, an attachment hole (not shown) is provided in the peripheral wall of the header (2), and the connection pipe (4) is attached to the connection pipe (4) via a ring-shaped brazing material (51) or the like as shown in FIG. Then, the header (2) is attached to the header (2) by using an assembling jig (52) such as a clip or a clamp so as to communicate with the header (2) through the insertion hole.
And, in the assembled state, joined together and integrated with the header (2) by the above-mentioned brazing.

[0006]

However, in the specification in which the connecting pipes (4) and (5) are assembled to the header (2) using the assembling jig (52), the ratio of the jig cost to the manufacturing cost is small. There is a drawback that the manufacturing cost of the heat exchanger is increased because the tool becomes considerably large and the jig cannot be used repeatedly. In addition, there is also a disadvantage that productivity is not excellent, such as a step of removing the jig (52) after batch brazing.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention makes it possible to collectively braze a connecting pipe to a header without using an assembling jig, thereby reducing manufacturing costs and improving productivity. It is an object of the present invention to provide a heat exchanger having a structure that can perform the heat treatment.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide a heat exchanger in which a heat exchange tube is provided with a hollow header having an end connected in communication with a connection pipe connected to the hollow header. The hollow header is provided with a connection pipe insertion hole for inserting a pipe end of a connection pipe, and the connection pipe has an outer peripheral shape of a pipe main body portion that is relatively larger than a connection pipe insertion hole of the header. At the same time, the pipe end is reduced in diameter so that it can be inserted into the connection pipe insertion hole of the header, and a portion between the reduced diameter pipe and the pipe main body serves as a header abutting part, and the inside of the connection pipe is formed. A sleeve is disposed so as to extend over the reduced diameter pipe portion and the pipe main body portion, and the sleeve is integrated with the connection pipe by reducing the diameter of the pipe end of the connection pipe, and
The reduced-diameter pipe portion of the connection pipe is inserted into the connection pipe insertion hole of the header so that the header abutment section is brought into contact with the header, and the connection pipe is welded to the header from the outside at their boundary. In this state, the connection pipe and the header are jointly integrated by brazing at a time.

In the above structure, the outer peripheral shape of the pipe main body of the connecting pipe is relatively larger than the connecting pipe insertion hole of the header, and the pipe end of the connecting pipe is reduced in diameter. Between the pipe section and the pipe body is the header contact section, and the reduced diameter pipe section of the connection pipe is inserted into the connection pipe insertion hole of the header so that the header contact section contacts the header. The connecting pipes are fixed to the header by temporarily fixing them by spot welding from the outside at their boundaries.
By this spot welding, the connecting pipe is assembled to the header in a firmly fixed state. Therefore, a jig for assembling the connection pipe to the header is not required, and a jig removing step after the brazing can be eliminated, so that the heat exchanger is manufactured in a cost-effective manner and with high productivity. .

In addition, a sleeve is disposed in the connecting pipe so as to extend between the reduced diameter pipe portion and the pipe main body, and the connecting pipe is arranged such that the header contact portion contacts the header. Since the connection pipe is inserted into the inside of the connection pipe insertion hole of the header, and the connection pipe is spot-fixed and fixed by welding from the outside at the boundary with the header,
The spot welding prevents the back bead from projecting into the hollow portion of the connection pipe to prevent the flow of the refrigerant from occurring.

In addition, the sleeve is disposed in the connecting pipe so as to extend between the reduced-diameter pipe portion and the pipe main body, and is integrated with the connecting pipe by reducing the diameter of the connecting pipe. With such a configuration, the sleeve is firmly held in an appropriate state in the connection pipe, and the occurrence of the above-mentioned inconvenience or the like due to the back bead of the spot welded portion is more effectively prevented. In addition, the sleeve and the connection pipe are integrated with high productivity without an increase in the number of steps involved in integrating the sleeve and the connection pipe.

[0012] In this case, the sleeve is formed of a split sleeve capable of being reduced in diameter and having a slit formed in the peripheral wall thereof over the entire length in the longitudinal direction. The sleeve can absorb the deformation, preventing damage to the sleeve and undesired deformation, etc., and properly integrating the sleeve with the connecting pipe.

In addition, the sleeve has a sleeve insertion amount regulating flange protruding outward in the radial direction at one end thereof, so that when the sleeve is inserted into the connection pipe, the flange is inserted. Is inserted to the point where it comes into contact with the pipe end face of the connecting pipe, whereby the sleeve is arranged in the connecting pipe in a proper arrangement state, and the sleeve inserting operation is properly and efficiently performed. As well,
It is also possible to prevent the sleeve from inadvertently moving into the connection pipe after the insertion and before the end of the diameter reduction processing. Further, since the flange portion is projected with a projection amount equal to or less than the wall thickness of the connection pipe, there is no trouble in reducing the diameter of the pipe end of the connection pipe.

[0014]

Next, an embodiment of the present invention will be described.

The heat exchanger of the present embodiment shown in FIG.
It is used as an aluminum condenser for car coolers.

First, each component of the heat exchanger shown in FIG. 7 will be described. As described above, (1)... Are tubes for heat exchange, (2) and (2) are hollow headers,
(3) is a fin, and (4) and (5) are connection pipes.

The heat exchange tube (1) is made of an extruded material made of aluminum and is manufactured as a flat tube having an oblong cross section. The flat tube (1) is formed into a harmonica tube whose interior is divided into a plurality of chambers in terms of pressure resistance and the like. Note that an electric resistance welded tube or the like may be used as the tube.

The hollow header (2) is composed of a header pipe (2a) and upper and lower lid members (2b) (2b) for closing both ends thereof. The header pipe (2a) is formed by bending an aluminum brazing sheet having a brazing material layer clad on one side or both sides into a tubular shape, for example, a cylindrical shape, with the side edges abutting against each other. An electric resistance welded pipe or the like may be used as the header pipe. Figure 1 shows the peripheral side of the header pipe (2a).
(A) As shown in (b), a plurality of tube insertion holes (2c) extending in a slit shape in the circumferential direction are arranged at intervals in the longitudinal direction. And the header pipe (2
As shown in the figure, a circular insertion hole (7) for inserting the connection pipes (4) and (5) is formed at a predetermined height position in the peripheral side wall of a).

The fins (3) are corrugated fins formed by bending an aluminum brazing sheet clad with a brazing material into a corrugated fin gate shape.

Then, in the connection pipes (4) and (5),
(4) is a connection pipe for a refrigerant inlet, and (5) is a connection pipe for a refrigerant outlet. Hereinafter, the connection pipe (4) will be described.
The same applies to the connection pipe (5).

The connecting pipe (4) is made of aluminum circular pipe material. The outer diameter of the pipe body (9) is designed to be larger than the connecting pipe insertion hole (7) of the header (2). I have. In addition, the connection pipe (4) may be an aluminum brazing sheet electric resistance welded pipe or the like having a brazing material clad on the surface. The pipe end of the connecting pipe (4) is reduced in diameter by swaging. The diameter-reduced pipe portion (10) is reduced in diameter to a diameter that can be inserted into the connection pipe insertion hole (7) of the header (2).
An inclined annular stepped portion (11) as a header contact portion is formed between the reduced diameter tube portion (10) and the tube main body portion (9).

Further, a sleeve (12) is provided in the connecting pipe (4) so as to extend over the reduced diameter pipe (10) and the pipe main body (9).

The sleeve (12) is made of, for example, stainless steel, and is shown in FIGS. 2 (a-1), (a-2) and (b) showing a state before being integrated with the connection pipe (4). As shown, one side in the longitudinal direction is formed into a large-diameter portion (17) and the other side is formed into a smaller-diameter portion (19) with an annular step (20) therebetween. Is formed. Large diameter part (17)
The outer diameter of the small-diameter portion (19) is designed to be equal to or substantially equal to the inner diameter of the pipe main body portion (9) of the connecting pipe (4), and the outer diameter of the small-diameter portion (19) is designed to be smaller than that. In addition, a sleeve insertion amount regulating flange (14) is formed on the periphery of the distal end of the small diameter side (19) so as to protrude radially outward with a projection amount not more than the wall thickness of the connection pipe. In the peripheral wall of (12), a slit (15) is formed over the entire length in the longitudinal direction. As described above, the outer diameter of the large-diameter portion (17) may be designed to be larger than the inner diameter of the pipe main body (9) of the connection pipe (4) on the assumption that the slit (15) is present. . In this case, the sleeve (12) is inserted into the end of the connecting pipe (4) by using the slit (15) to reduce the diameter of the sleeve (12). The outer peripheral surface is elastically abutted against the peripheral wall surface in the connection pipe (4), and the sleeve is unintentionally displaced or falls off after insertion into the connection pipe (4) until the end of the swaging process. Can be prevented.

The sleeve (12) is shown in FIGS.
As shown in FIG. 3, before swaging, it is inserted into the connecting pipe (4), and in this state, as shown in FIG. 3 (c), the pipe end of the connecting pipe (4) is swaged. By being reduced in diameter, it is integrated with the connecting pipe (4). That is, the sleeve (12) is as shown in FIG.
As shown in (b), during the process of insertion into the connection pipe (4), the flange portion (14) comes into contact with the pipe end face of the connection pipe (4), thereby setting a predetermined proper insertion state. Is done. Then, as shown in FIG. 3 (C), the diameter of the connecting pipe (4) is reduced by swaging corresponding to the small-diameter portion (19) of the sleeve (12). (12) is integrated with the connecting pipe (4).

As described above, the sleeve (12) is formed such that one side (17) in the length direction is formed to have a large diameter and the other side (19) is formed to have a smaller diameter, and an annular ring is formed therebetween. With the configuration in which the step (20) is formed, the deformation of the sleeve (12) due to the swaging of the pipe end of the connecting pipe (4) is suppressed, and in particular, the reduced diameter pipe section of the connecting pipe (4) Undesirable secondary deformation of the small diameter portion (19) existing inside the (10) can be suppressed, and after the swaging processing, the sleeve (12) is connected to the annular step portion of the connection pipe (4). The inner surface of (11) is integrated so as to conform to a more suitable state, and the inward protrusion of the back beat at the spot welding portion (W) is more effectively prevented.

The swaging process on the pipe end of the connecting pipe (4) may be performed in a mode of reducing the diameter of the small-diameter portion (19) of the sleeve (12), or may not be performed. It may be performed in an aspect.

The heat exchanger is manufactured by assembling the respective heat exchanger components in a mutually tentatively assembled state, and subjecting the heat exchanger assembly to collective brazing.

In the temporary assembling step, the ends of the tubes (1) are inserted into the tube insertion holes (2c) of the headers (2) and (2), and the fins (3) are inserted between the tubes (1). …
Insert. At the same time, the base end of the connection pipe (4) is inserted into the connection pipe insertion hole (7) of the header (2), and the header contact step (11) is brought into contact with the header (2). Then, as shown in FIGS. 1 (a) and 1 (b), the connecting pipe (4) is attached to the header (2) at their boundary portion.
From the outside, spot welding by argon welding is performed and temporarily fixed to the header (2). In FIG. 1, (w) is a spot welding portion. By this spot welding, the connecting pipe (4) is held in an appropriate assembled state without using a jig. In addition, the sleeve (12) effectively suppresses or prevents the problem that the back bead in the spot welding portion projects into the hollow portion of the connection pipe (4) and hinders the flow of the refrigerant.

[0029] In the above-described batch brazing process of the heat exchanger assembly, the header pipes (2a) and (2a) and the fins (3) ...
The entirety of the connecting pipe (4) is joined and integrated with the headers (2) and (2) using the brazing material clad on the header pipe (2a). Is done. During this batch brazing, the connecting pipe (4) is held in a state of being firmly connected to the header (2) by the above-mentioned spot welding, and is integrally joined to the header (2) in a proper mounting state by the batch brazing. Be transformed into

FIG. 4 shows a sleeve (12) according to another embodiment. This sleeve (12) shows a state before being integrated with the connection pipe (4).
As shown in (b), it is formed in a cylindrical shape of a predetermined length, and protrudes radially outward with a protruding amount equal to or less than the wall thickness of the connecting pipe at the peripheral edge at one end in the longitudinal direction. A sleeve insertion amount regulating flange portion (14) is formed, and a slit (15) is formed in the peripheral wall over the entire length in the longitudinal direction.
This sleeve (12) is inserted and arranged in the connecting pipe (4) before swaging, as shown in FIGS. 6 (a) and 6 (b), and in this state, shown in FIG. 6 (c). As a result, the pipe end of the connecting pipe (4) is reduced in diameter by swaging to be integrated with the connecting pipe (4).

That is, the sleeve (12) is as shown in FIG.
As shown in (b), in the process of insertion into the connecting pipe (4), the flange (14) is brought into contact with the peripheral edge of the pipe end opening of the connecting pipe (4), so that the connection can be easily performed. The tube (4) is inserted and arranged in an appropriate arrangement state across the reduced-diameter tube (10) and the tube main body (9).

The outer diameter of the sleeve (12) is designed to be larger than the inner diameter of the reduced-diameter pipe portion (10) of the connecting pipe (4), and the sleeve (12) is connected to the pipe of the connecting pipe (4). As shown in FIG. 6 (c), the tube end is inserted and arranged inside the end to reduce the diameter of the tube by swaging, so that the action of the diameter reduction is applied to the sleeve (12). Also, the sleeve (12) is integrated with the connecting tube (4). In this swaging process, the sleeve (12) is smoothly reduced in diameter by the slit (15) provided therein without causing undesired deformation such as distortion in the circumferential direction. At the same time, by the swaging process, the sleeve (12) is connected to the reduced-diameter tube portion (10) of the connection tube (4).
The portion protruding more inward in the length direction than this is subjected to the diameter-reducing action, and is deformed into a skirt shape that opens inward. In addition, the swaging process is performed without any trouble because the flange portion (14) is projected radially outward with a projection amount equal to or less than the wall thickness of the connection pipe.

The outer diameter of the sleeve (12) may be designed to be equal to or smaller than the inner diameter of the pipe main body (9) of the connecting pipe (4), or the outer diameter of the connecting pipe (4) may be smaller. It may be designed to be larger than the inner diameter of the part (9).
In the latter case, the sleeve (12) has its slit (15)
By inserting it into the pipe end of the connecting pipe (4) so as to reduce the diameter using a sleeve, the sleeve (1) is inserted after insertion.
The outer peripheral surface of 2) is elastically abutted against the peripheral wall surface in the connection pipe (4), and the sleeve is unintentionally displaced or falls off after insertion into the connection pipe (4) and before the swaging process is completed. Can be prevented.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications are possible. For example, although the heat exchanger of the above embodiment is to be used as a condenser for a car cooler,
The heat exchanger of the present invention can also be applied to various heat exchangers such as a radiator, an oil cooler, and a heat exchanger for a room air conditioner. Further, the connecting pipe in the present invention may be applied only to an inlet connecting pipe for feeding a heat exchange medium such as a refrigerant into the inside, or may be applied only to an outlet connecting pipe for sending a heat exchange medium to the outside. Or may be applied to both inlet and outlet connecting tubes.

[0035]

As described above, according to the heat exchanger of the present invention, the outer peripheral shape of the pipe main body of the connecting pipe is made relatively larger than the connecting pipe insertion hole of the header, and the pipe of the connecting pipe is formed. The diameter of the connecting pipe is reduced such that the end portion is reduced in diameter, a portion between the reduced diameter pipe portion and the pipe main body portion serves as a header abutting portion, and the header abutting portion abuts on the header. The connection pipe is inserted into the connection pipe insertion hole of the header, and the connection pipe is temporarily fixed to the header by welding at the boundary between the connection pipes from the outside. Is assembled to the header in a firmly fixed state,
A jig for assembling the connection pipe to the header can be made unnecessary, and the jig removal step after batch brazing can be eliminated, making it possible to manufacture the heat exchanger cost-effectively and with good productivity. it can.

In addition, a sleeve is arranged in the connecting pipe so as to extend between the reduced diameter pipe portion and the pipe main body, and the connecting pipe is arranged such that the header contact portion contacts the header. Since the connection pipe is inserted into the inside of the connection pipe insertion hole of the header, and the connection pipe is spot-fixed and fixed by welding from the outside at the boundary with the header,
The disadvantage that the back bead projects into the connection pipe and hinders the flow of the refrigerant by spot welding can be prevented from occurring, and temporary fastening by spot welding becomes possible, and the advantages in manufacturing can be enjoyed.

In addition, the sleeve is disposed in the connecting pipe so as to extend over the reduced diameter pipe portion and the pipe main body, and is integrated with the connecting pipe by reducing the diameter of the connecting pipe. As a result, the sleeve is firmly held in an appropriate state in the connection pipe, and the above-mentioned problems caused by the back bead due to the spot welding portion can be more effectively prevented. In addition, the sleeve and the connection pipe can be integrated with high productivity without increasing the number of steps involved in integrating the sleeve and the connection pipe.

[0038] Further, the sleeve is formed of a split sleeve capable of reducing the diameter and having a slit formed in the peripheral wall thereof over the entire length in the longitudinal direction. The sleeve can absorb the deformation, damage the sleeve by reducing the diameter,
The occurrence of undesired deformation or the like can be prevented, and the sleeve can be appropriately integrated with the connecting pipe.

Further, the sleeve has a sleeve insertion amount regulating flange protruding outward in the radial direction at one end in the length direction, so that the sleeve can be inserted into the connecting pipe in an operation for inserting the sleeve into the connection pipe. If the flange is inserted until it comes into contact with the pipe end surface of the connecting pipe, the sleeve is thereby placed in the connecting pipe in a proper arrangement state,
The operation of inserting the sleeve can be performed properly and efficiently. In addition, it is possible to prevent the sleeve from unintentionally moving inside the connection pipe after the insertion and before the end of the diameter reduction processing. Further, by making the flange portion project with an amount of projection not more than the wall thickness of the connecting pipe, the effect of reducing the diameter of the pipe end of the connecting pipe without any trouble is exhibited. Is done.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment, in which FIG. 1A is a cross-sectional view showing a state in which a connecting pipe is temporarily fixed to a header by spot welding and FIG. FIG. 2 is a sectional view taken along the line I.

FIG. 2 shows a sleeve, wherein FIG. 1A is a side view, FIG. 2A is a plan view, and FIG. 2B is an overall perspective view.

FIGS. 3A to 3C are cross-sectional views showing a method of attaching a sleeve to a connection pipe.

FIG. 4 shows another embodiment, in which FIG. 1A is a cross-sectional view showing a state in which a connecting pipe is temporarily fixed to a header by spot welding and FIG. 4B is an IV of FIG. FIG. 4 is a sectional view taken along the line IV.

5A and 5B show the sleeve in the embodiment of FIG. 4; FIG. 5A is a side view, FIG. 5B is a plan view, and FIG.

6 (a) to 6 (c) are cross-sectional views showing a method of attaching the sleeve shown in FIG. 5 to a connection pipe.

FIG. 7 shows the overall configuration of the heat exchanger, wherein FIG. 7A is a front view and FIG. 7B is a side view.

FIG. 8 shows a conventional example, and is a front view showing an assembled state of a connection pipe to a header.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tube 2 ... Header 4 ... Connection pipe 7 ... Connection pipe insertion hole 9 ... Pipe main body part 10 ... Reduced diameter pipe part 11 ... Step (header contact part) 12 ... Sleeve 14 ... Flange part 15 ... Slit w ... Pointing welded part

Claims (3)

[Claims] 1. A heat exchanger wherein an end of a heat exchange tube is connected in a communicating state with a hollow header, and a connecting pipe is connected to the hollow header in a communicating state. A connection pipe insertion hole for inserting a pipe end of a pipe is provided, and the connection pipe has an outer peripheral shape of a pipe main body portion that is relatively larger than a connection pipe insertion hole of a header, and has a pipe end. The header is reduced in diameter so that it can be inserted into the connection pipe insertion hole of the header, and a portion between the reduced diameter pipe section and the pipe main body is used as a header abutting section. A sleeve is disposed so as to extend over the pipe main body, and the sleeve is integrated with the connection pipe by reducing the diameter of the pipe end of the connection pipe, and the header contact portion contacts the header. And the reduced-diameter tube portion of the connection pipe is inserted into the connection pipe insertion hole of the header. And the connection pipes are temporarily fixed to the header by welding at their boundaries from outside by welding, and in this state, the connection pipe and the header are integrally joined by brazing. And heat exchanger. 2. The heat exchanger according to claim 1, wherein the sleeve is a split sleeve whose diameter is deformable and whose entire peripheral wall is slit along its entire length. 3. The sleeve has one end protruding radially outward with an amount of protrusion equal to or less than the wall thickness of the connecting pipe.
3. The heat exchanger according to claim 1, further comprising a sleeve insertion amount regulating flange portion.