JPH0886585A - Laminated heat exchanger and manufacture thereof - Google Patents

Abstract

PURPOSE: To enhance the hermetical sealability of a tube element. CONSTITUTION: The inside bent part 16a bent at one plate 11 is formed by bending the peripheral ends 16, 17 of plates 11, 12 in a superposed state, and an outside bent part 17a is formed by enclosing the part 16a with the other plate 12. An annular clamping band 6 is wound on the outer periphery of the part 17a, and band 6 is formed in a thin plate stage of a material smaller than the plates 11, 12 at the coefficient of thermal expansion, and a fixed part 10 for fixing the parts 16a and 17a by brazing or diffuse connecting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated heat exchanger and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a conventional laminated heat exchanger, for example, there is one as shown in FIG. 6 (see Japanese Utility Model Laid-Open No. 63-49189).

To explain this, a plurality of tube elements 2 are provided inside a housing of a heat exchanger (not shown).
1 are laminated via the outer fins 25.

In each tube element 21, box-shaped plates 22 and 23 are joined to each other and a first flow path 24 is defined therein.

The peripheral ends 27 of the plates 22 and 23 are fixed to each other by brazing, and the tube element 21
The airtightness of the first flow path 24 defined therein is achieved.

First channel 2 in each tube element 21
The fluid flowing through 4 through the inner fins 20 exchanges heat with the fluid flowing through the outer fins 25 on the outside of each tube element 21.

[0007]

However, in such a conventional laminated heat exchanger, when the tube element 21 is brazed, the surface pressure is uniformly applied to the joints of the peripheral end portions 27. Is difficult, and after brazing each edge 2
There is a possibility that a gap may occur at the joint portion of No. 7, and the first flow path 24
There was a problem that it was difficult to ensure sufficient airtightness.

Further, as disclosed in JP-A-53-108055, when brazing cylindrical tubes, a ring having a small coefficient of thermal expansion is fitted on the outer side of one of the cylindrical tubes, and brazing is performed due to the difference in thermal expansion from the rings. A structure for bringing the parts into close contact is disclosed.

In this case, since the ring having a high rigidity is fitted on the outer side of the cylindrical tube, the material of each member is restricted, and it is necessary to apply it to a complicated shape such as the peripheral end portion 27 of the tube element 21. There was a problem that it was difficult.

An object of the present invention is to solve the above problems and to enhance the airtightness of tube elements in a laminated heat exchanger.

[0011]

A laminated heat exchanger according to claim 1 is provided with a tube element that defines a flow path by a pair of box-shaped plates, and a peripheral end of each plate that constitutes the tube element. Bend in a state where the parts are overlapped with each other to form a bent inner bent part on one plate and an outer bent part bent on the other plate so as to wrap the inner bent part, and on the outer peripheral part of the outer bent part. The annular tightening band is wound, the annular tightening band is formed in a thin plate shape with a material having a coefficient of thermal expansion smaller than that of each plate, and the inner bent part and the outer bent part are fixed by brazing or diffusion bonding.

A laminated heat exchanger according to a second aspect of the present invention is provided with a tube element that defines a flow path by a pair of box-shaped plates, and the peripheral end portions of the respective plates constituting the tube element are overlapped with each other. And an inner bent portion is formed on one plate, and an outer bent portion is formed on the other plate so as to wrap the inner bent portion, and an annular pressing plate interposed inside the inner bent portion is formed. The annular pressing plate is made of a material having a coefficient of thermal expansion larger than that of each plate, and the inner bent portion and the outer bent portion are fixed by brazing or diffusion bonding.

According to a third aspect of the present invention, there is provided a method of manufacturing a laminated heat exchanger according to the first aspect of the present invention, wherein one plate is provided with an annular fastening band having a flat cross section when brazing or diffusion bonding the tube elements. The outer side of the plate is bent along the outer bent portion of one plate by thermal deformation caused by heating when brazing or diffusion bonding the cross section of the annular tightening band.

According to a fourth aspect of the present invention, in the laminated heat exchanger manufacturing method according to the first aspect of the present invention, when the tube element is brazed or diffusion-bonded, a recess is formed along the outer bent portion of one plate in advance. An annular band having a cross section is fitted to the outer bent portion of one plate.

[0015]

In the laminated heat exchanger according to claim 1, at the time of heating for brazing or diffusion bonding, the annular tightening band having a smaller coefficient of thermal expansion than each plate restrains the outer bent portion of one plate. , The outer bent portion is pressed with a uniform surface pressure over the entire circumference of the inner bent portion of the other plate.

In this way, the inner bent portion and the outer bent portion of each plate are fixed to each other by brazing or diffusion bonding through the annular tightening band so that a gap is formed between the both bent portions. It can be avoided.

Further, since the annular tightening band is formed in a thin plate shape, even if the annular tightening band is fixed to the outer bent portion of the plate, the outer bent portion is not deformed and the plate material is restricted. Less is.

In the laminated heat exchanger according to claim 2,
When heating by brazing or diffusion bonding, the annular pressing plate, which has a greater coefficient of thermal expansion than each plate, expands the inner bent part of one plate in the outer radial direction by expanding the inner bent part of the other plate by its thermal expansion. Press with a uniform surface pressure over the entire circumference of the part.

In this manner, the inner bent portion and the outer bent portion of each plate are fixed to each other by brazing or diffusion bonding through the annular pressing plate, so that a gap is formed between the both bent portions. It can be avoided.

In the method for manufacturing a laminated heat exchanger according to a third aspect of the present invention, the annular tightening band has a cross section curved along the outer bent portion of one plate due to thermal deformation that occurs during heating for brazing or diffusion bonding. With the structure, the annular fastening band is prevented from coming off the tube element, and the rigidity of the tube element is enhanced through the frame-shaped annular fastening band.

In the method for manufacturing a laminated heat exchanger according to claim 4, when brazing or diffusion bonding the tube elements, an annular fastening band having a cross section which is recessed along the outer bent portion of one plate is previously formed. With the configuration in which the plate is fitted to the outer bent portion of the one plate, it is possible to easily ensure the accuracy of assembly of the annular tightening band to the tube element.

[0022]

Embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 3, in the laminated heat exchanger, a plurality of tube elements 4 are laminated via outer fins 5, and the second flow path 2 through which the fluid B flows is not shown outside each tube element 4. A first flow path 1 is defined through the housing, and the fluid A flows inside each tube element 4.

In the tube element 4, a pair of box-shaped upper plates 11 and lower plates 12 are combined, and inner fins 13 are interposed between the upper plates 11 and the lower plates 12.

Upper plate 11 and lower plate 12
An inlet 14 and an outlet 15 are formed in each. A part of the fluid A flowing into the tube element 4 from the inlet 14 as shown by an arrow in the drawing is partially
To the outlet 15 and the rest flows into the interior of the other tube element 4 joined below it.

Cylindrical tubes defining inlets 14 and outlets 15 of the upper plate 11 and the lower plate 12, which are stacked on each other, are connected via a ring 18.

The fluid B flows between the tube elements 4 via the outer fins 5 as indicated by arrows in the figure, while the fluid A flows from the inlet 1a through the inner fins 13 as indicated by arrows in the figure. 4 and the heat exchange is performed between the fluid B and the fluid A.

As shown in FIG. 1, the upper plate 11
The peripheral end 16 of the lower plate 12 and the peripheral end 17 of the lower plate 12 are overlapped and bent, and both are fixed by caulking.

As a result, the inner bent portion 16a bent into two is formed on the upper plate 11, while the outer bent portion 17a bent so as to wrap the inner bent portion 16a is formed on the lower plate 12. The outer peripheral portion of the inner bent portion 16a and the inner outer peripheral portion of the outer bent portion 17a both have a cross section curved in an arc shape.

Inner bent portion 16a of the upper plate 11
Between the outer bent portion 17a and the lower bent portion 17a of the lower plate 12, there is provided a fixing portion 10 for fixing the both by brazing with a brazing material such as copper.

Each of the peripheral end portions 16 and 17 extends over the entire circumference of the tube element 4 and is formed in a substantially rectangular frame shape.

In order to prevent a gap from being left in the fixed portion 10, the outer bent portion 17a of the lower plate 12 during brazing.
An annular tightening band 6 for tightening is provided.

The annular tightening band 6 has a coefficient of thermal expansion of each plate 1
1. Each plate 11, which is made of a material smaller than 1, 12,
The outer bent portion 17a of the lower plate 12 is tightened by the difference in thermal expansion with respect to 12, and the inner peripheral portion of the outer bent portion 17a is brought into close contact with the outer peripheral portion of the inner bent portion 16a of the upper plate 11.

In the state before brazing, as shown in FIG.
The annular tightening band 6 has a flat band shape with a linear cross section.

The annular fastening band 6 is formed in a thin plate shape, and in the state after brazing, as shown in FIG. 1, the annular fastening band 6 is along the outer bent portion 17a of the lower plate 12 due to thermal deformation during brazing. Has a curved cross section. The rigidity of the tube element 4 can be enhanced by the structure in which the annular tightening band 6 is fitted in the shape of a substantially quadrangular frame over the entire circumference of each of the peripheral end portions 16 and 17.

As shown in FIG. 3, in the state before brazing,
The annular tightening band 6 has a joint portion 7 whose both ends are fixed to each other by welding or the like.

When brazing the tube element 4, the annular tightening band 6 is put in a furnace and heated to a predetermined temperature in a state where the annular tightening band 6 is temporarily fixed to the outer bent portion 17a of the lower plate 12.

When the tube element 4 is brazed, the cross section of the annular tightening band 6 is deformed by heat and the lower plate 1
While curving along the second outer bent portion 17a, the outer bent portion 17a of the lower plate 12 is tightened due to the difference in thermal expansion.

That is, the annular tightening band 6 having a smaller coefficient of thermal expansion than the plates 11 and 12 restrains the thermal expansion of the outer bent portion 17a of the lower plate 12, and the lower bent plate 16a of the inner bent portion 16a of the upper plate 11. The outer bent portion 17a of 12 is pressed with a uniform surface pressure over the entire circumference.

In this way, the fixing portion 10 is brazed in a state where the inner bent portion 16a of the upper plate 11 and the outer bent portion 17a of the lower plate 12 are in close contact with each other via the annular tightening band 6, so that a small amount of Even if a brazing material is used, it is possible to avoid the formation of gaps and ensure the airtightness of the tube element 4.

The fixed portion 10 is composed of the upper plate 1
It is also conceivable that the inner bent portion 16a of No. 1 and the outer bent portion 17a of the lower plate 12 are fixed by diffusion bonding.

Next, another embodiment shown in FIG. 4 will be described. It should be noted that the same parts as those in FIG.

In the state before brazing, the annular tightening band 8 has a band shape having a curved cross section along the outer bent portion 17a of the lower plate 12.

In the state before brazing, the annular tightening band 8 has a connecting portion whose both ends are fixed to each other by welding or the like.

At the time of brazing the tube element, the annular tightening band 8 is fitted into the furnace over the entire circumference of the outer bent portion 17a of the lower plate 12 and is heated to a predetermined temperature in the furnace.

At the time of brazing the tube element 4, the annular fastening band 6 clamps the outer bent portion 17a of the lower plate 12 due to a difference in thermal expansion and the inner bent portion 16a of the upper plate 11 and the lower plate 12 via the annular fastening band 8. By brazing the outer bent portion 17a in close contact with each other, it is possible to avoid a gap.

It is also conceivable that the inner bent portion 16a of the upper plate 11 and the outer bent portion 17a of the lower plate 12 are fixed by diffusion bonding.

With the above construction, the operation will be described.

When performing brazing or diffusion bonding of the tube element 4, an annular tightening band 8 having a cross section that is recessed along the outer bent portion 17a of the upper plate 11 in advance.
Due to the configuration in which is fitted to the outer bent portion 17a of the upper plate 11, the assembling accuracy of the annular tightening band 8 to the tube element 4 can be easily ensured.

Next, another embodiment shown in FIG. 5 will be described. It should be noted that the same parts as those in FIG.

In order to prevent a gap from being left in the fixing portion 10, the inner bent portion 1 of the upper plate 11 during brazing.
An annular pressing plate 9 for pressing and expanding 6a is provided.

The annular pressing plate 9 has a coefficient of thermal expansion of each plate 1.
1 and 12 are made of a material larger than each plate 11,
Due to the difference in thermal expansion with respect to 12, the inner bent portion 16a of the upper plate 11 is pressed and expanded, so that the outer peripheral portion of the inner bent portion 16a is brought into close contact with the inner peripheral portion of the outer bent portion 17a.

The annular pressing plate 9 is integrally or divided by a flat plate having a linear cross section.

When brazing the tube element 4, the annular pressing plate 9 having a larger coefficient of thermal expansion than the plates 11 and 12 presses and expands the inner bent portion 16a of the upper plate 11, and the inner bent portion of the upper plate 11 is expanded. 16a is pressed against the outer bent portion 17a of the lower plate 12 over the entire circumference with a uniform surface pressure.

In this way, the fixing portion 10 is brazed in a state where the inner bent portion 16a of the upper plate 11 and the outer bent portion 17a of the lower plate 12 are in close contact with each other via the annular pressing plate 9, so that a small amount of Even if a brazing material is used, it is possible to avoid the formation of gaps and ensure the airtightness of the tube element 4.

Further, the fixing portion 10 is the upper plate 1
It is also conceivable that the inner bent portion 16a of No. 1 and the outer bent portion 17a of the lower plate 12 are fixed by diffusion bonding.

[0057]

As described above, the laminated heat exchanger according to claim 1 is provided with the tube element which defines the flow path by the pair of box-shaped plates, and the circumference of each plate which constitutes the tube element. Bend in a state where the ends are overlapped to form a bent inner bent part on one plate, and an outer bent part bent on the other plate so as to wrap the inner bent part, and the outer bent part of the outer bent part. A ring-shaped tightening band is wrapped around the ring-shaped tightening band, and the ring-shaped tightening band is made of a material having a smaller coefficient of thermal expansion than each plate in a thin plate shape, and the inner bent part and the outer bent part are fixed by brazing or diffusion bonding. The inner bent part and the outer bent part of each plate are fixed in close contact with each other via the tightening band, so that the airtightness of the tube element can be sufficiently secured. .

According to a second aspect of the present invention, there is provided a laminated heat exchanger having tube elements which define a flow path by a pair of box-shaped plates, and the peripheral end portions of the plates constituting the tube element are superposed on each other. And an inner bent portion is formed on one plate, and an outer bent portion is formed on the other plate so as to wrap the inner bent portion, and an annular pressing plate interposed inside the inner bent portion is formed. Since, the annular pressing plate is formed of a material having a coefficient of thermal expansion larger than that of each plate, and an inner bent portion and an outer bent portion are fixed by brazing or diffusion bonding.
The inner bent portion and the outer bent portion of each plate are fixed in close contact with each other via the annular pressing plate, whereby the airtightness of the tube element can be sufficiently ensured.

According to a third aspect of the present invention, there is provided a method of manufacturing a laminated heat exchanger according to the first aspect of the present invention, wherein one plate is provided with an annular fastening band having a flat cross section when brazing or diffusion bonding the tube elements. The annular clamp is attached along the outer bent part of the plate and is bent along the outer bent part of one plate by the thermal deformation that occurs during heating when brazing or diffusion bonding the cross section of the annular tightening band. The disengagement is locked and the annular tie band increases the rigidity of the tube element.

According to a fourth aspect of the present invention, in the method of manufacturing the laminated heat exchanger according to the first aspect, when the tube element is brazed or diffusion-bonded, a recess is formed along the outer bent portion of one plate in advance. With the configuration in which the annular tightening band having the open cross section is fitted to the outer bent portion of the one plate, the assembling accuracy of the annular tightening band to the tube element can be easily ensured.

[Brief description of drawings]

FIG. 1 is a sectional view of a tube element showing an embodiment of the present invention.

FIG. 2 is a sectional view of the tube element similarly showing a state before brazing.

FIG. 3 is an exploded perspective view of a tube element and the like.

FIG. 4 is a sectional view of a tube element showing another embodiment of the present invention.

FIG. 5 is a sectional view of a tube element showing still another embodiment of the present invention.

FIG. 6 is a sectional view of a tube element showing a conventional example.

FIG. 7 is an exploded perspective view of a tube element and the like.

[Explanation of symbols]

 1 1st flow path 2 2nd flow path 4 Tube element 5 Outer fin 6 Annular tightening band 8 Annular tightening band 9 Annular pressing plate 10 Fixed part 11 Upper plate 12 Lower plate 16 Circumferential end part 17 Circumferential end part 16a Inner bent part 17a Outside Bent part

Claims (4)

[Claims] 1. A tube element that defines a flow path by a pair of box-shaped plates is provided, and the peripheral ends of the plates constituting the tube element are bent in a state of being overlapped with each other, and then bent into one plate. An inner bent portion is formed, and an outer bent portion is formed by bending the other plate so as to wrap the inner bent portion, and an annular fastening band is wound around the outer bent portion, and the annular fastening band has a coefficient of thermal expansion of each plate. A laminated heat exchanger characterized in that it is formed of a smaller material into a thin plate and has a fixing portion for fixing the inner bent portion and the outer bent portion by brazing or diffusion bonding. 2. A tube element that defines a flow path by a pair of box-shaped plates is provided, and the peripheral ends of the plates forming the tube element are bent in a state of being overlapped with each other, and then bent into one plate. An inner bent portion is formed, and an outer bent portion is formed by bending the other plate so as to wrap the inner bent portion.The annular pressed plate is provided inside the inner bent portion, and the annular pressed plate has a coefficient of thermal expansion. Is formed of a material larger than each plate, and is provided with a fixing portion for fixing the inner bent portion and the outer bent portion by brazing or diffusion bonding. 3. When brazing or diffusion bonding the tube element, an annular fastening band having a flat plate-shaped cross section is attached along the outer bent portion of one plate, and the cross section of the annular fastening band is brazed or diffusion bonded. The method for manufacturing a laminated heat exchanger according to claim 1, wherein the plate is bent along the outer bent portion of one plate by thermal deformation that occurs during heating. 4. When brazing or diffusion bonding a tube element, an annular fastening band having a cross section that is recessed along the outer bent portion of one plate is fitted in advance to the outer bent portion of one plate. The method for manufacturing a laminated heat exchanger according to claim 1.