WO2006006442A1

WO2006006442A1 - Welding structure and welding method for aluminum accumulator, and heat exchanger

Info

Publication number: WO2006006442A1
Application number: PCT/JP2005/012368
Authority: WO
Inventors: Kazuhiko Ito
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-07-08
Filing date: 2005-07-05
Publication date: 2006-01-19
Also published as: JP2006023018A; CN1910414A; TW200609073A

Abstract

A welding structure and a welding method for an aluminum accumulator capable of reducing weld defects and providing high productivity, and a heat exchanger. The welding structure comprises an aluminum pipe having a beading processed part, the aluminum accumulator, and a stainless steel pipe. The stainless steel pipe is inserted onto the aluminum pipe up to the beading processed part, the aluminum pipe onto which the stainless steel pipe is inserted is inserted into the aluminum accumulator up to the beading processed part, and the aluminum pipe, the aluminum accumulator, and the stainless steel pipe are welded to each other on the outer periphery of the overlapped joint part thereof.

Description

Specification

Welding structure and welding method of aluminum accumulator and heat exchanger

Technical field

The present invention relates to a welded structure and welding method for an aluminum accumulator, and a heat exchanger having a welded structure for an aluminum accumulator. Background art

[0002] Generally, in a heat exchanger used in a household refrigerator, the welded structure of an aluminum accumulator and an aluminum pipe is connected by inserting a stainless steel sleeve into the inner periphery of the joint between the aluminum accumulator and the aluminum pipe. An accumulator welding structure that welds the outer periphery of the part is known. However, recently, in household appliances such as refrigerators, flammable refrigerants are used as refrigerants. Therefore, even in heat exchangers that are internal functional parts, improvement in welding reliability against leakage of welds is required. . In addition, since further cost reduction has been achieved, there is a need for a product that is highly productive and low in cost, even though it is heat exchanged. However, aluminum welds are prone to weld defects such as leakage! / The structure is low, and because of this, the productivity becomes worse due to reworking and remanufacturing. Have difficulty.

[0003] In view of the above, there is a demand for a highly productive welded structure and welding method with almost no weld defects.

FIG. 4 is a cross-sectional view of a conventional aluminum pipe welded structure described in Japanese Patent Application Laid-Open No. 2002-188765.

[0005] As shown in FIG. 4, the aluminum accumulator welded structure also includes an aluminum pipe 4 through which refrigerant 2 flows, an aluminum accumulator 5, and a stainless steel sleeve 10 for preventing aluminum penetration during welding. ing. A recess 11 is provided in a part of the aluminum pipe 4, and the stainless sleeve 10 is inserted up to the position of the recess 11. Note that the aluminum pipe outlet 4a is the aluminum accumulator outlet because it prevents the compressor from being damaged by the liquid refrigerant returning directly to the compressor. The aluminum pipe 4 is bent so that it does not directly face 5a, and the aluminum pipe 4 has a bending force portion 4b! Next, after the aluminum pipe 4 is inserted into the aluminum accumulator 5, the outer periphery of the joint 7 where the aluminum pipe 4 and the aluminum accumulator overlap is welded. The aluminum accumulator welded structure is such an aluminum noise welded structure.

[0006] However, in the above-described conventional configuration, in the structure in which the aluminum pipe 4 is inserted into the aluminum accumulator 5, the inserted aluminum pipe 4 has a bending calorie portion 4b. Therefore, when the aluminum pipe 4 is inserted into the aluminum accumulator 5, the inner diameter of the end of the aluminum accumulator 5 is sufficiently wider than the outer diameter of the aluminum pipe 4 in consideration of the insertability of the aluminum pipe 4. I have to do it. For this reason, the clearance between the aluminum pipe 4 and the aluminum accumulator 5 becomes large during welding and a clearance suitable for welding cannot be secured, and the aluminum pipe 4 easily moves during welding and is likely to be displaced. As a result, poor welding may occur.

Furthermore, the fact that the aluminum pipe 4 is likely to be displaced and it is difficult to fix the position of the aluminum pipe 4 means that the internal dimensional accuracy of the aluminum accumulator 5 of the aluminum pipe 4 is deteriorated. If this happens, it will be difficult to maintain the bent shape of the aluminum pipe 4 provided for the purpose of preventing the liquid refrigerant from returning directly to the compressor, and the flow of the refrigerant will not be stable due to variations in the position of the aluminum pipe tip 4a. There is.

[0008] In order to determine the insertion position of the aluminum pipe 4, it is indispensable to use an insertion positioning jig. If it takes time to mount jigs and insert the aluminum pipe 4, it is necessary to install the bending force section 4b after inserting the stainless steel sleeve 10 deeply into the aluminum pipe 4! /, Etc. When a production process or production man-hour is required, it may be difficult to improve the productivity of the product.

Disclosure of the invention

[0009] The welded structure of the aluminum accumulator includes: an aluminum accumulator having a first beading force portion, an aluminum accumulator formed by drawing both ends of the aluminum tube, and a stainless steel pipe. Stainless steel pipe is made of aluminum pipe The aluminum pipe is inserted into the aluminum accumulator up to the first beading carriage, and the aluminum pipe, aluminum accumulator, and stainless steel pipe are welded at the overlapping joint.

[0010] A heat exchanger includes the welded structure of the aluminum accumulator.

[0011] An aluminum accumulator welding method includes an aluminum umno << eve having a first beading force-feed portion, an aluminum accumulator formed by drawing both ends of the aluminum pipe, and a stainless pipe, After the stainless steel knife is inserted into the aluminum pipe to the first beading force zone, the aluminum pipe is inserted into the end of the aluminum accumulator, and the aluminum pipe, aluminum accumulator, and stainless steel pipe are welded at the overlapping joint. Is done.

Brief Description of Drawings

FIG. 1 is a cross-sectional view of an aluminum accumulator welding structure according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view of an aluminum accumulator welding structure according to Embodiment 2 of the present invention.

FIG. 3 is a front view of a heat exchanger provided with an aluminum accumulator welding structure according to Embodiment 1 and Embodiment 2 of the present invention.

FIG. 4 is a sectional view of a conventional aluminum pipe welded structure.

Explanation of symbols

1 Aluminum accumulator welded structure

3a Beading section (first beading section)

3b Beading section (second beading section)

3c Dimple force section

4 Aluminum pipe

5 Aluminum accumulator

6 Stainless steel

7 Connecting part

9 Force squeeze 21 heat exchanger

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] The present invention solves the above-described conventional problems, and an aluminum accumulator welded structure that sufficiently suppresses the occurrence of welding defects in the welded portion and has high productivity, and the heat provided by the aluminum accumulator welded structure. The purpose is to provide a welding method for AC and aluminum accumulator.

[0015] In order to solve the above-described conventional problems, an aluminum accumulator welding structure according to the present invention includes an aluminum nove having a first beading force web, an aluminum accumulator, and a second bead. After the stainless steel pipe is inserted into the aluminum pipe to the second beading carriage position or the dimple carriage position, it has three parts: a stainless steel pipe with a bending force part or a dimple force part. The aluminum pipe is inserted into the aluminum accumulator and welded to the first beading carriage position.

[0016] Thereby, even if the pipe shape in the aluminum accumulator, that is, the stainless steel pipe has a bent shape, the clearance between the aluminum pipe and the aluminum accumulator can be secured with a minimum clearance suitable for welding. In addition, since the first beading part melts during welding, a sufficient amount of aluminum penetration for welding can be secured, so that welding defects can be reduced. In addition, since the insertion position is determined by the beading section, insertion workability is improved and productivity can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. About the same structure as the past, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. The present invention is not limited to the embodiments.

[0018] (Embodiment 1)

FIG. 1 is a cross-sectional view of an aluminum accumulator welded structure according to Embodiment 1 of the present invention. In FIG. 1, an aluminum accumulator welded structure 1 is composed of, for example, an aluminum pipe 4, an aluminum accumulator 5, and a stainless pipe 6. Aluminum pipe 4 is a heat transfer tube that is used at the inlet of an accumulator used in the refrigerator refrigeration system and in which refrigerant 2 flows. It has a beading processing part 3a which is a processing part. The aluminum accumulator 5 is used after the liquid refrigerant is stored and gasified so that the liquid refrigerant does not flow directly to the compressor (not shown) due to the heat load of heat exchange (described later with FIG. 3). It has a role to feed into the compressor. The stainless steel pipe 6 is inserted into the aluminum accumulator 5 and has a beading force check portion 3b which is a second beading check portion. The stainless steel pipe 6 also has a structure that also serves as a stainless steel sleeve for preventing aluminum pipe clogging by melting aluminum into the aluminum pipe 4 during welding. Further, when the stainless steel pipe outlet 6a faces the aluminum accumulator outlet 5a, the liquid refrigerant easily returns directly to the compressor. In order to prevent the failure of the compressor due to this, it is desirable to provide a bending force portion 6b on the stainless steel pipe 6 so that the stainless steel pipe outlet 6a faces the inner wall 11 of the aluminum accumulator. Note that aluminum here includes aluminum alloy in addition to pure aluminum, and for stainless steel, it is desirable to use an austenitic system from the viewpoint of corrosion.

The aluminum accumulator welded structure 1 configured as described above will be described below with respect to the structure and action.

First, the stainless steel pipe 6 is inserted into the inner periphery of the aluminum pipe 4. At this time, the beading force feeding portion 3b of the stainless pipe 6 is inserted to a position where it coincides with the end face of the aluminum pipe 4. By reducing the outer diameter of the stainless steel pipe 6 into the aluminum 4 by about 0.2 to 0.8 mm from the inner diameter of the aluminum pipe 4 to be inserted, an appropriate clearance for welding can be secured to prevent aluminum penetration. This leads to reduced welding defects. In addition, rattling and displacement of the stainless steel pipe 6 can be prevented and the insertability of the stainless steel pipe 6 can be secured, so that the working time can be reduced and the productivity can be improved. In addition, the outer surface of the aluminum knob 4 may be deformed after insertion, or a dimple such as a dimple may be provided.

[0021] Next, the aluminum pipe 4 is inserted until the beading caloe portion 3a of the aluminum pipe 4 into which the stainless steel pipe 6 is inserted coincides with the end face of the aluminum accumulator 5, and the aluminum pipe 4, the aluminum accumulator 5, and the stainless steel pipe are inserted. 6 is superimposed. Part where aluminum pipe 4 of aluminum accumulator 5 is inserted By making the inner diameter of the minute about 0.05 to 0.15 mm larger than the outer diameter of the aluminum pipe 4 to be inserted, the insertability of the aluminum pipe 4 and the reliability during welding can be improved. It is desirable that the end face of the aluminum accumulator 5 is not chamfered both inside and outside, and the corners are substantially right-angled both inside and outside in order to secure the aluminum amount during welding. Further, the outer surface of the aluminum accumulator 4 where the aluminum pipe 4 of the aluminum accumulator 5 is deformed may be deformed, or a certain! / ヽ may be fixed more firmly by providing a dimple or the like.

Next, the outer periphery of the overlapped joint portion 7 is welded. As a result, a sufficient amount of aluminum can be secured in the welded portion, so that welding defects can be reduced. In addition, the effect of reducing welding defects can be improved by reducing welding rework and remanufacturing.

[0023] (Embodiment 2)

FIG. 2 is a cross-sectional view of the aluminum accumulator welded structure according to the second embodiment of the present invention. In FIG. 2, the aluminum accumulator welded structure 1 is composed of, for example, an aluminum pipe 4, an aluminum accumulator 5, and a stainless steel pipe 6. The aluminum pipe 4 is a heat transfer tube that is used at the inlet of an accumulator used in the refrigerator refrigeration system and in which the refrigerant 2 flows, and has a beading processing portion 3a that is a first beading processing portion. ing. The aluminum accumulator 5 stores the liquid refrigerant and gasifies it so that the liquid refrigerant does not flow directly to the compressor (not shown) due to the heat load of heat exchange (described later with FIG. 3). It has a role to feed into the compressor. The stainless steel pipe 6 is inserted into the aluminum accumulator 5 and has a dimple force feeding portion 3c. Here, it is desirable to provide two or more dimple force feeding portions 3c in order to make the positioning more stable. The stainless steel pipe 6 also has a structure that also serves as a stainless steel sleeve for preventing aluminum nozzle clogging due to aluminum penetration into the aluminum pipe 4 during welding. Further, since the stainless steel pipe outlet 6a faces the aluminum accumulator outlet 5a, the liquid refrigerant can easily return directly to the compressor. In order to prevent the failure of the compressor due to this, it is desirable to provide the stainless steel pipe 6 with a bending force portion 6b so that the stainless steel pipe outlet 6a faces the inner wall 11 of the aluminum accumulator. The term “aluminum” as used herein includes aluminum alloy in addition to pure aluminum. For stainless steel, It is also desirable to use austenitic power.

[0024] The aluminum accumulator welded structure 1 configured as described above will be described below in terms of the structure and action.

First, the stainless steel pipe 6 is inserted into the inner periphery of the aluminum pipe 4. At this time, the stainless steel pipe 6 is inserted until the dimple force feeding portion 3c of the stainless steel pipe 6 coincides with the end face of the aluminum pipe 4. The outer diameter of the stainless steel pipe 6 inserted into the aluminum 4 is about 0.2 to 0.8 mm smaller than the inner diameter of the aluminum pipe 4 to be inserted. It leads to decrease. In addition, the stainless pipe 6 can be prevented from rattling and misalignment, and the stainless steel pipe 6 can be inserted, so that the working time can be reduced and the productivity can be improved. Note that the outer surface of the aluminum pipe 4 may be deformed after insertion, or a dimple or the like may be provided, that is, the force squeeze portion 9 may be provided to secure the aluminum pipe 4 more firmly.

[0026] Next, the aluminum pipe 4 is inserted until the beading caloe portion 3a of the aluminum pipe 4 into which the stainless steel pipe 6 is inserted coincides with the end face of the aluminum accumulator 5, and the aluminum pipe 4, the aluminum accumulator 5 and the stainless steel pipe are inserted. 6 are superimposed. When the aluminum pipe 4 of the aluminum accumulator 5 is inserted, the inner diameter of the aluminum pipe 4 is about 0.05 to 0.15 mm larger than the outer diameter of the inserted aluminum pipe 4 so that the aluminum pipe 4 can be inserted and welded. Can improve both reliability. The end surface of the aluminum accumulator 5 is preferably not chamfered both inside and outside, and the inside and outside corners are preferably at right angles both inside and outside in order to secure the aluminum amount during welding. Further, the outer surface of the aluminum accumulator 5 where the aluminum pipe 4 is inserted may be deformed, or a dimple or the like may be provided to fix the aluminum accumulator 5 more firmly.

Next, the outer periphery of the overlapping portion 7 is welded. As a result, a sufficient amount of aluminum can be secured in the welded portion, so that welding defects can be reduced. In addition, the effect of reducing welding defects can be improved by improving welding and remanufacturing.

[Embodiment 3]

One of the aluminum accumulators described in the first embodiment or the second embodiment Next, heat exchange with a welded structure will be described with reference to Fig. 3.

FIG. 3 is a front view of a heat exchanger provided with an aluminum accumulator welding structure according to Embodiment 1 or Embodiment 2 of the present invention. In FIG. 3, the heat exchanger 21 includes a refrigerant pipe 22 and fins 23. The refrigerant pipe 22 is formed by bending a straight pipe portion 22a and a curved pipe portion 22b into a meandering shape. The fins 23 are fixed to the outer surface of the refrigerant pipe 22. Thus, the aluminum pipe 4 of the aluminum accumulator 5 shown in FIG. 1 or 2 is connected to the tip of the refrigerant pipe 22. In this way, the heat exchanger 21 having the welded structure of the aluminum accumulator 5 is constructed. The refrigerant 2 shown in FIG. 1 or 2 passes through the refrigerant pipe 22 in FIG. In the process, refrigerant 2 exchanges heat with the outside air with the help of fins 23. The refrigerant 2 that has passed through the refrigerant pipe 22 is supplied to the aluminum accumulator ₅ through the aluminum pipe 4 inserted in the aluminum accumulator 5 shown in FIG. 1 or FIG.

[0030] As already described, the aluminum accumulator welding structure and welding method of Embodiment 1 or Embodiment 2 can sufficiently reduce welding failure and enable a smooth flow of refrigerating machine oil. Therefore, the heat exchanger having the aluminum accumulator welded structure of the present embodiment shown in FIG. 3 is a heat exchanger for aluminum refrigeration and air conditioning, automobiles, water heaters, etc. It can also be applied to applications.

[0031] As described in the first to third embodiments, the aluminum accumulator welding structure of the present invention includes an aluminum pipe having a first beading force portion, and both ends of the aluminum pipe. A stainless steel pipe is inserted into the aluminum pipe, the aluminum pipe is inserted into the aluminum accumulator up to the first beading part, and the aluminum pipe and aluminum are provided. The accumulator and stainless steel pipe are welded at the overlapping joint.

[0032] Further, in the welded structure of the aluminum accumulator of the present invention, the stainless steel knife has a second beading force zone, and the stainless steel pipe is attached to the aluminum pipe up to the second beading force zone. Inserted. This welded structure minimizes the clearance between the aluminum pipe and the aluminum accumulator, ensuring a suitable clearance for welding. Since it is possible to prevent the misalignment of the aluminum pipe, welding defects can be reduced. In addition, since a sufficient amount of aluminum can be secured in the welded portion by the beading carriage portion of the aluminum pipe, welding defects can be further reduced. In addition, since the insertion position is determined in each beading section, jigs and the like are not required, so that the insertion workability is improved and the productivity can be increased.

[0033] Further, in the welded structure of the aluminum accumulator of the present invention, the stainless steel knife has a second beading force zone, and the stainless steel pipe is attached to the aluminum pipe up to the second beading force zone. Inserted. This welded structure minimizes the clearance between the aluminum pipe and the aluminum accumulator, ensures a suitable clearance for welding, and prevents misalignment of the aluminum pipe, thus reducing welding defects. . In addition, since a sufficient amount of aluminum can be secured in the welded portion by the beading carriage portion of the aluminum pipe, welding defects can be further reduced. In addition, since the insertion position is determined by the beading caloring part and the dimple processing part, the insertion workability can be improved and the productivity can be increased by eliminating the need for tools and the like. In addition, by using dimple force for positioning the stainless steel pipe, the material for the beading portion becomes unnecessary compared to the case where beading force is used, and it is possible to reduce the cost of the expensive stainless steel.

[0034] Further, the weld structure of the aluminum accumulator of the present invention is provided with a force squeeze portion for fixing the stainless steel pipe to the outer surface of the aluminum pipe, and the stainless steel pipe can be more firmly fixed. Displacement can be prevented and welding defects can be reduced.

[0035] Further, in the welded structure of the aluminum accumulator of the present invention, the stainless steel pipe has a bent casing, and the liquid refrigerant does not flow directly to the compressor! Since the direction can be adjusted, the reliability of the compressor can be ensured.

[0036] Also, the aluminum accumulator welding structure of the present invention is such that the corners of the end face of the aluminum accumulator are substantially perpendicular to both the inside and outside, and a sufficient amount of aluminum can be secured in the welded portion, thereby further reducing welding defects. Is possible.

[0037] Further, the heat exchanger of the present invention is a heat exchanger having the above-described aluminum accumulator welding structure, and is a heat exchanger that can reduce welding defects and reduce production costs. Can be provided.

[0038] Further, the aluminum accumulator welding method of the present invention includes an aluminum pipe having a first beading caloe part, an aluminum accumulator formed by drawing both ends of the aluminum pipe, and a stainless steel pipe. After the stainless steel pipe is inserted into the aluminum pipe up to the first beading part, the aluminum pipe is inserted into the end of the aluminum accumulator, and the aluminum pipe, aluminum accumulator and stainless steel nose are joined together. Welded at the part.

[0039] Further, the stainless steel pipe has a second beading force portion, and the aluminum pipe is inserted into the end of the aluminum accumulator up to the second beading portion. This aluminum accumulator welding method minimizes the clearance between the aluminum pipe and the aluminum accumulator, making it possible to ensure a suitable clearance for welding, and also prevents misalignment of the aluminum pipe, thus reducing welding defects. Is possible. In addition, since a sufficient amount of aluminum can be secured in the welded portion by the beading carriage portion of the aluminum pipe, it is possible to further reduce welding defects. In addition, since the insertion position is determined by the beading section, jigs and the like are not necessary, so that the insertion workability can be improved and the productivity can be increased. It is inserted into the aluminum pipe up to the processed part. This aluminum accumulator welding method makes it possible to minimize the clearance between the aluminum pipe and the aluminum accumulator, to ensure a suitable clearance for welding, and to prevent misalignment of the aluminum pipe, thereby reducing welding defects. In addition, the welded part of the aluminum pipe can secure a sufficient amount of aluminum in the welded part, further reducing welding defects. In addition, since the insertion position is determined by the beading carriage part and the dimple carriage part, a tool or the like is not required, so that the insertion workability can be improved and the productivity can be increased.

[0041] As is apparent from the above description, the present invention provides an aluminum accumulator welding structure capable of sufficiently reducing defective welding and having high productivity, and a heat exchanger including the aluminum accumulator welding structure and an aluminum accumulator welding method thereof. You It can be done.

Industrial applicability

The aluminum accumulator welding structure and welding method that are effective in the present invention can sufficiently reduce welding defects and enable a smooth flow of refrigerating machine oil. Therefore, the aluminum accumulator welding structure and welding method can be used for refrigeration and air conditioning mainly for aluminum, for automobiles, and for water heaters. It can also be applied to other heat exchanger applications.

Claims

The scope of the claims

[1] an aluminum pipe having a first beading force section;

An aluminum accumulator formed by drawing both ends of the aluminum tube

With stainless pipe

With

The stainless steel pipe is inserted into the aluminum pipe,

The aluminum pipe is inserted into the aluminum accumulator up to the first beading portion,

A welded structure of an aluminum accumulator in which the aluminum pipe, the aluminum accumulator, and the stainless steel pipe are welded at overlapping joints.

[2] The stainless steel pipe has a second beading force portion,

2. The aluminum accumulator welding structure according to claim 1, wherein the stainless steel pipe is inserted into the aluminum pipe up to the second beading carriage.

[3] The stainless steel pipe has a dimple force portion.

2. The aluminum accumulator welding structure according to claim 1, wherein the stainless steel pipe is inserted into the aluminum pipe up to the dimple cover.

[4] The welded structure of an aluminum accumulator according to any one of claims 1 to 3, wherein a caulking portion for fixing the stainless steel pipe is provided on the outer surface of the aluminum pipe.

5. The weld structure for an aluminum accumulator according to any one of claims 1 to 3, wherein the stainless steel pipe has a bending force portion.

6. The weld structure for an aluminum accumulator according to any one of claims 1 to 3, wherein corners of the end surface of the aluminum accumulator are at right angles both inside and outside.

[7] A heat exchanger comprising the welded structure of the aluminum accumulator according to any one of claims 1 to 3 of claims 1 to 3.

[8] A heat exchanger comprising the aluminum accumulator welded structure according to claim 4.

[9] A heat exchanger comprising the aluminum accumulator welded structure according to claim 5.

[10] A heat exchanger comprising the aluminum accumulator welding structure according to [6].

[11] An aluminum nove having a first beading force-feed portion, an aluminum accumulator formed by drawing both ends of the aluminum tube, and a stainless steel pipe, and the stainless steel pipe comprising the first bead After being inserted into the aluminum pipe to the ding carriage part, the aluminum pipe is inserted into the end of the aluminum accumulator,

The aluminum accumulator welding method in which the aluminum pipe, the aluminum accumulator, and the stainless steel pipe are welded at overlapping joints.

[12] The stainless steel pipe has a second beading force portion,

12. The aluminum accumulator welding method according to claim 11, wherein the aluminum pipe is inserted into the end portion of the aluminum accumulator up to a second beading portion.

[13] The stainless steel pipe has a dimple force portion.

12. The aluminum accumulator welding method according to claim 11, wherein the stainless pipe is inserted into the aluminum pipe up to the dimple cover.