JPH08128797A - Stacked type heat exchanger - Google Patents

Abstract

PURPOSE: To improve airtightness of a tube element by a method wherein raised parts fitting to each other are brought into close contact with each other due to a thermal expansion difference between an inner ring having a flange part and an outer ring at the time of heating when soldering of fixing parts and others are executed. CONSTITUTION: At the time of soldering a tube element 4, an inner ring 19, upper and lower plates 11 and 12 and an outer ring 18 are put in a furnace, in a state of being assembled with a soldering material interposed, and heated to a prescribed temperature. Since the inner ring 19 has a flange part 19a formed in the direction of the outside diameter, it does not slip off from a raised part 12a of the lower plate 12 on the occasion, and a jig for supporting the inner ring 19, and others, can be dispensed with. At the time of the soldering, the respective raised parts 11a and 12a of the upper and lower plates 11 and 12 are held between the outer ring 18 and the inner ring 19 and brought into closed contact with each other due to a thermal expansion difference between the two rings. By the flange part 19a, accordingly, rigidity can be ensured and also reduction of the weight can be attained.

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 in which a plurality of tube elements are laminated.

[0002]

2. Description of the Related Art As a conventional laminated heat exchanger, for example, there is one as shown in FIGS.
9189, gazette).

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.

A rising portion 28 and a hole 29 which are fitted to each other are formed at an inlet 30 and an outlet (not shown) for communicating the adjacent tube elements 21, respectively. The fitting portions of the rising portion 28 and the hole 29 are also fixed to each other by brazing, so that the inlet and outlet of the first flow path 24 are airtight.

First flow path 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.

[0008]

However, in such a conventional laminated heat exchanger, when the tube element 21 is brazed, a uniform surface pressure is applied to the joint between the rising portion 28 and the hole 29. It is difficult to add, and there is a possibility that a gap will be created at the joint between the two after brazing.
There was a problem that it was difficult to secure the airtightness.

Further, in order to address this, Japanese Patent Laid-Open No. 53-10
In Japanese Patent No. 8055, as shown in FIG.
When 32 and 32 are diffusion-bonded, a ring 33 having a small coefficient of thermal expansion is fitted on the outer side of one cylindrical tube 32, and the other cylindrical tube 31
Fit a ring 34 with a large coefficient of thermal expansion inside the
There is disclosed a structure in which the fixing portion 35 is brought into close contact with each other by the difference in thermal expansion between 3 and 34.

In this case, however, each ring 33, 3
When removing 4 after diffusion-bonding the cylindrical pipes 32 and 31, it is necessary to limit the ring 33 and the cylindrical pipe 32 or the ring 34 and the cylindrical pipe 31 to materials that do not diffuse-bond to each other, and it is troublesome to remove the rings 33 and 34. There is a problem that it costs.

In order to omit the step of removing the rings 33 and 34, when the ring 34 is diffusion-bonded to the cylindrical tube 31 and left inside the cylindrical tube 31, in order to secure the rigidity during the diffusion bonding. There is a problem that the disk-shaped ring 34 greatly narrows the flow path flowing in the cylindrical tube 31 and the flow path resistance increases.

Further, the rings 33 and 34 are connected to the respective cylindrical tubes 3.
When the structure is formed by diffusion-bonding to 2, 31 and leaving it in the tube element, the weight of the rings 33, 34 having a large thickness occupies a large proportion in the tube element formed by the thin plate, and the weight of the tube element is significantly increased. There is a problem that it invites.

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

[0014]

A laminated heat exchanger according to claim 1, wherein a plurality of tube elements defining a flow path are laminated by a pair of box-shaped plates, and adjacent tube elements are communicated with each other. Equipped with inlets and outlets, each plate of adjacent tube elements defines an inlet and outlet and integrally forms a rising portion that protrudes in a cylindrical shape, and the rising portions of adjacent tube elements are fitted together and brazed together. Or it has a fixed part that is fixed by diffusion bonding, an inner ring and an outer ring that sandwich the fixed part through each rising part, and the inner ring is made of a material whose coefficient of thermal expansion is larger than that of the outer ring. The inner ring arranged at is formed in a thin-walled cylinder shape having a flange portion at least one end of which extends in the outer diameter direction.

According to a second aspect of the present invention, in the laminated heat exchanger according to the first aspect of the present invention, at least one of the rising portions of the adjacent tube elements is formed with an annular protrusion portion that annularly protrudes toward the other. .

In the laminated heat exchanger according to a third aspect of the present invention, in the invention according to the first or second aspect, the outer ring is formed in a thin arc shape having a circular arc-shaped cross section.

According to another aspect of the laminated heat exchanger of the present invention, a plurality of tube elements defining a flow path are laminated by a pair of box-shaped plates, and the adjacent tube elements are provided with an inlet / outlet communicating with each other. Each plate of the tube element is integrally formed with a rising part that defines the entrance and exit and protrudes in a tubular shape, and is equipped with an inner ring and an outer ring that sandwich the rising parts of adjacent tube elements. The inner ring is formed of a material having a coefficient of thermal expansion larger than that of the outer ring, and the inner ring is provided at the inlet / outlet of the tube element. Is formed into a thin-walled cylinder having at least one end having a flange portion that expands in the outer diameter direction.

According to a fifth aspect of the present invention, in the laminated heat exchanger, a plurality of tube elements defining a flow path are laminated by a pair of box-shaped plates, and an inlet / outlet for communicating adjacent tube elements is provided. The inner ring is provided with an outer ring interposed between the plates of the tube elements adjacent to each other on the outer periphery, and the inner ring is formed into a thin-walled tubular shape with both end portions having flanges that expand in the outer diameter direction. Between each flange of the ring and the outer ring, sandwich each plate of the adjacent tube element, and at least one of the flange of the inner ring and at least one of the outer ring has a fixing part that fixes each plate by brazing or diffusion bonding. The inner ring is made of a material having a coefficient of thermal expansion smaller than that of the outer ring.

[0019]

In the laminated heat exchanger according to claim 1, during heating for brazing or diffusion bonding of the fixed portion, the inner ring and the outer ring have their rising portions that are fitted to each other due to a difference in thermal expansion between them. Make them adhere closely. Since the fixing portions are fixed by brazing or diffusion bonding in a state where the rising portions that are fitted to each other are in close contact with each other with a sufficient surface pressure, it is possible to prevent a gap from being formed in the fixing portion.

Since the thin-walled inner ring has a flange portion that expands in the outer diameter direction, sufficient rigidity is ensured against the reaction force acting from the rising portion during heating.

Since the inner ring arranged at the inlet / outlet of the tube element is formed in a thin-walled cylindrical shape, it is possible to suppress the reduction of the flow passage area at the inlet / outlet, and
The weight can be reduced, and the increase in weight of the tube element due to the inner ring can be suppressed to a small level.

Since it is not necessary to remove the inner ring from the tube element, the rigidity of the tube element can be increased and there are few restrictions on the material of the inner ring.

In the laminated heat exchanger according to claim 2,
The annular protrusion that annularly protrudes from one rising portion of the adjacent tube elements toward the other rising portion causes the surface pressure acting on the joint portion of each rising portion due to the difference in thermal expansion between the inner ring and the outer ring. It is possible to concentrate and prevent a gap from being left in the fixed portion, and the airtightness of the tube element can be improved.

In the laminated heat exchanger according to claim 3,
The outer ring, which is formed in a thin arc shape that curves with an arc-shaped cross section, bulges annularly toward the rising parts of the adjacent tube elements and joins the rising parts due to the difference in thermal expansion between the inner ring and the outer ring. It is possible to concentrate the surface pressure acting on the portion, prevent a gap from forming in the fixed portion, and improve the airtightness of the tube element.

In the laminated heat exchanger according to claim 4,
During heating for brazing or diffusion bonding, the inner ring and the outer ring come into close contact with the respective rising portions of the adjacent tube elements due to the difference in thermal expansion between the inner ring and the outer ring. By fixing the fixing portion by brazing or diffusion bonding in a state where the inner ring and the outer ring are in close contact with each rising portion with sufficient surface pressure, it is possible to prevent a gap from being left in the fixing portion.

Further, it is also possible to set the difference in thermal expansion between the inner ring and the outer ring so as to apply surface pressure to each rising portion even when the heat exchanger is in use at a rising temperature, so as to be in close contact with each other. Even if peeling occurs in the fixed part,
The airtightness of the tube element can be secured.

Since the thin-walled inner ring has a flange portion that expands in the outer diameter direction, sufficient rigidity is ensured against the reaction force acting from the rising portion during heating.

Since the inner ring arranged at the inlet / outlet of the tube element is formed in a thin-walled tubular shape, it is possible to suppress reduction of the flow passage area at the inlet / outlet, and
The weight can be reduced, and the increase in weight of the tube element due to the inner ring can be suppressed to a small level.

Since it is not necessary to remove the inner ring from the tube element, the rigidity of the tube element can be increased and there are few restrictions on the material of the inner ring.

In the laminated heat exchanger according to claim 5,
During heating for brazing or diffusion bonding, the inner ring and the outer ring bring the flange portions of the inner ring and the outer ring into close contact with the plates of the adjacent tube elements due to the difference in thermal expansion between them.

The fixing portion is fixed by brazing or diffusion bonding in a state where each flange portion of the inner ring and the outer ring are in close contact with each plate with sufficient surface pressure, thereby preventing a gap from being formed in the fixing portion. .

Since the thin-walled inner ring has a flange portion that expands in the outer diameter direction from both ends thereof, sufficient rigidity is secured against the reaction force exerted by each plate during heating.

Since the inner ring arranged at the inlet / outlet of the tube element is formed in a thin-walled tubular shape, it is possible to suppress reduction of the flow passage area at the inlet / outlet, and
The weight can be reduced, and the increase in weight of the tube element due to the inner ring can be suppressed to a small level.

Since it is not necessary to remove the inner ring from the tube element, the rigidity of the tube element can be increased and there are few restrictions on the material of the inner ring.

[0035]

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 passage 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.

The tube element 4 is a combination of a pair of box-shaped upper plate 11 and lower plate 12, and an inner fin 13 is interposed between the upper plate 11 and the lower plate 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.

The cylindrical tubes defining the inlets 14 and the outlets 15 of the upper plate 11 and the lower plate 12, which are laminated 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 14 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.

The peripheral end 16 of the upper plate 11 and the peripheral end 17 of the lower plate 12 are overlapped and bent,
Fix both by caulking. Between the joint between the peripheral end 16 of the upper plate 11 and the peripheral end 17 of the lower plate 12,
They are fixed to each other by brazing through a brazing material such as copper,
The airtightness inside the tube element 4 is released.

As shown in FIG. 1 and FIG. 2, the rising portion 12 which projects cylindrically from the lower plate 12 at the portion where the outlets 15 are defined by the adjacent tube elements 4.
a and a rising portion 11a protruding in a cylindrical shape on the upper plate 11 are fitted to each other.

Cylindrical rising part 12a and rising part 11a
Are fitted with each other with a predetermined overlap margin L, and a joint portion between the two is provided with a fixing portion 10 that is fixed to each other by brazing, so that the tube element 4 is hermetically sealed.

In order to prevent a gap from being left in the fixing portion 10, the inner ring 19 and the outer ring 1 that press the rising portion 12a and the rising portion 11a against each other during brazing.
8 are provided.

The outer ring 18 is made of a material having a coefficient of thermal expansion smaller than that of each of the plates 11 and 12, and is formed in an annular shape.
It serves to tighten the outer peripheral portion of a to bring the inner peripheral portion of the rising portion 11a into close contact with the outer peripheral portion of the rising portion 12a.

The inner ring 19 is made of a material having a coefficient of thermal expansion larger than that of the plates 11 and 12, and is formed in an annular shape.
The diameter of the inner peripheral portion of a is increased so that the outer peripheral portion of the rising portion 12a is brought into close contact with the inner peripheral portion of the rising portion 11a.

1 to 3 show a state before the rising portion 12a and the rising portion 11a are brazed. There are gaps between the inner ring 19, the rising portion 11a, the rising portion 12a, and the outer ring 18, respectively. By setting the dimensions and the coefficient of thermal expansion of each part so that the difference in thermal expansion between the inner ring 19 and the outer ring 18 becomes large with respect to the sum of these gaps, the inner peripheral part of the rising part 11a is set at the time of brazing. It is adapted to be in close contact with the outer peripheral portion of the rising portion 12a.

That is, as shown in FIG. 3, the outer diameter of the inner ring 19 is Db, the gap between the inner ring 19 and the rising portion 12a is d _1, and the gap between the rising portion 12a and the rising portion 11a. and d _2, the gap rising portion 11a and the outer ring 18 and d _3, .alpha.b with the inner diameter of the outer ring 18 and Da, the thermal expansion coefficient of the inner ring 19 and .alpha.a, the coefficient of thermal expansion of the outer ring 18
If the temperature rise during brazing is ΔT ₁ , each value is set so as to satisfy (αb · Db−αa · Da) × ΔT ₁ > d ₁ + d ₂ + d ₃ (1).

The cross section of the outer ring 18 is formed into a substantially rectangular shape, and its four corners are curved.

The inner ring 19 is formed in a thin cylindrical shape, and has a right cylindrical portion 19b having a right cylindrical shape extending in parallel with the rising portions 12a and 11a, and the right cylindrical portion 19b.
It has a collar portion 19a continuously expanding from the upper end of b in the shape of a trumpet. The cross-section of the collar portion 19a is formed by curving in an arc shape so that the outer peripheral end portion thereof is substantially orthogonal to the straight cylindrical portion 19b.

Cylindrical rising part 12a and rising part 11a
The fixed portion 10, which is fitted with a predetermined overlap margin L, faces the right cylindrical portion 19 of the inner ring 19 and is formed close to the flange portion 19a.

The structure of the inlet 14 of the tube element 4 is similar to the structure of the outlet 15 and is fixed by brazing via an inner ring and an outer ring 18 not shown.

With the above construction, the operation will be described below.

When brazing the tube element 4, as shown in FIG.
As shown in FIG. 3, the inner ring 19, the plates 11 and 12, and the outer ring 18 assembled in the brazing material are placed in a furnace and heated to a predetermined temperature.

Since the inner ring 19 has the flange portion 19a which expands in the outer diameter direction thereof, the rising portion 1a is assembled with the tube element 4 assembled before brazing.
It does not fall off from 2a, and a jig for supporting the inner ring 19 is unnecessary.

When the tube element 4 is brazed, the rising portion 12a and the rising portion 11a are sandwiched between the outer ring 18 and the inner ring 19 due to the difference in thermal expansion between them, and are in close contact with each other.

That is, the outer ring 18 has the rising portion 11a due to the difference in thermal expansion between the plates 11 and 12.
While tightening the outer peripheral portion of the inner ring 19, the inner ring 19 has a rising portion 1 due to a difference in thermal expansion between the plates 11 and 12.
The inner peripheral portion of 2a is expanded in diameter, and the inner peripheral portion of the rising portion 11a and the outer peripheral portion of the rising portion 12a are pressed with a uniform surface pressure over the entire circumference.

In this way, the rising portion 11a and the rising portion 12a are pressed by the difference in thermal expansion between the outer ring 18 and the inner ring 19, so that the rising portion 11a and the rising portion 12a are in a state before brazing. A gap can be provided between the rising portion 11a and the rising portion 1
2a is not required to have a high precision, and the processing precision can be reduced to improve the productivity.

Since the inner ring 19 has the flange portion 19a that expands in the outer diameter direction, sufficient rigidity is secured against the reaction force exerted from the rising portion 12a during brazing.

Cylindrical rising part 12a and rising part 11a
The fixed portion 10, which is fitted with a predetermined overlap margin L, faces the highly rigid portion in the vicinity of the flange portion 19a of the inner ring 19, so that the inner peripheral portion of the rising portion 11a and the rising portion 12a. The outer peripheral portion of is pressed against the entire circumference with a large surface pressure.

As described above, the inner ring 19 has the collar portion 19
By having a, it becomes possible to form a thin-walled cylindrical shape, the weight is reduced, and the weight increase of the tube element 4 by the inner ring 19 can be suppressed to be small.

On the other hand, when the inner ring 19 is formed in a right cylindrical shape without the collar portion 19a, the inner ring 19 is thermally expanded during brazing as shown in FIGS. As a result, a deformed portion 19c that locally expands in the inner diameter direction is generated by the reaction force that acts from the rising portion 12a as the rising portion 12a is pressed and expanded, and the desired pressure is applied from the inner ring 19 to the rising portion 12a. May not be granted.

In this manner, the fixing portion 10 has the rising portion 12a via the outer ring 18 and the inner ring 19.
Since brazing is performed in a state in which the rising portion 11a and the rising portion 11a are in close contact with each other, it is possible to avoid a gap even if a small amount of brazing material is used, and it is possible to ensure the airtightness of the outlet 15 in the tube element 4.

FIG. 5 shows a state after the tube element 4 is brazed. Inner ring 19, rising portion 12a, rising portion 11a, and outer ring 1
8 are fixed to each other by brazing.

Outer ring 18 and inner ring 19
Is fixed to the upper plate 11 and the lower plate 12 by brazing, so that the outlet 15 can be airtight and the rigidity of the tube element 4 can be increased by these fixing portions.

Further, since it is not necessary to remove the outer ring 18 and the inner ring 19 from the tube element 4 after brazing, the productivity can be improved and the degree of freedom in selecting the materials of the outer ring 18 and the inner ring 19 can be increased.

After brazing, the inner ring 19 is left inside the tube element 4, but the inner ring 19
Is formed in a thin-walled cylindrical shape along the rising portion 12a and the rising portion 11a, it is possible to minimize the reduction of the passage cross-sectional area of the outlet 15.

The fixed portion 10 is formed by the upper plate 1
1 riser 11a and lower plate 12 riser 12
It is also conceivable that a is fixed by diffusion bonding.

Next, another embodiment shown in FIGS. 8 and 9 will be described. It should be noted that the same parts as those in FIG.

The rising portion 11a of the upper plate 11 is integrally formed with an annular protrusion 11d which projects toward the rising portion 12a of the lower plate 12.

In this case, when the tube element 4 is brazed, the fixing portion 10 is the annular protrusion 11 of the rising portion 11a.
Due to the difference in thermal expansion between the outer ring 48 and the inner ring 19, d and the rising portion 12a are sandwiched between the two and closely contact each other.

Since the annular protrusion 11d of the rising portion 11a is pressed with a large surface pressure over the entire circumference of the outer peripheral portion of the rising portion 12a, it is possible to avoid a gap even if a small amount of brazing material is used. In the tube element 4, the outlet 15 can be surely airtight.

The rising portion 12a of the lower plate 12
Alternatively, an annular protrusion that protrudes toward the rising portion 11a of the upper plate 11 may be formed.

Next, still another embodiment shown in FIGS. 10 and 11 will be described. It should be noted that the same parts as those in FIG.

The outer ring 4 which serves to tighten the outer peripheral portion of the rising portion 12a of the lower plate 12 when brazing.
8 are provided. The outer ring 48 is formed in a thin arc shape having a cross-sectional shape curved in an arc shape.

FIG. 10 shows the start-up section 12a and the start-up section 11.
The state before a is brazed is shown. There are gaps between the inner ring 19, the rising portion 11a, the rising portion 12a, and the outer ring 48, respectively. By setting the dimensions and the coefficient of thermal expansion of each part so that the difference in thermal expansion between the inner ring 19 and the outer ring 48 becomes large with respect to the sum of these gaps, the inner peripheral part of the rising part 11a is set at the time of brazing. It is adapted to be in close contact with the outer peripheral portion of the rising portion 12a.

The outer diameter of the inner ring 19 is Db, the gap between the outer ring 48 and the rising portion 12a is d ₁ , the gap between the rising portion 12a and the rising portion 11a is d ₂ , and the rising portion 11a is Set the gap of the outer ring 48 to d ₃
If the inner diameter of the outer ring 48 is Dc, the coefficient of thermal expansion of the inner ring 19 is αa, the coefficient of thermal expansion of the outer ring 48 is αb, and the temperature rise during brazing is ΔT ₁ , then (αb · Each value is set so as to satisfy Dc−αa · Da) × ΔT ₁ > d ₁ + d ₂ + d ₃ (2).

The sectional shape of the outer ring 48 is the rising portion 1
Since it bulges in an arc shape toward 1a, the rising portion 11a is pressed with a large surface pressure over the entire circumference of the rising portion 12a via the outer ring 48 during brazing. As a result, even if a small amount of brazing material is used, it is possible to avoid the formation of a gap, and the tube element 4 has an outlet 15
The airtightness of can be reliably measured.

Next, still another embodiment shown in FIGS. 12 and 13 will be described. It should be noted that the same parts as those in FIG.

The rising portion 12a of the lower plate 12 and the rising portion 11a of the upper plate 11 do not overlap with each other and have a width of a predetermined value L ₃ or more on each of the outer ring 18 and the inner ring 19 by brazing. The fixing portions 6 to 9 for fixing are provided, and the airtightness inside the tube element 4 is ensured.

The outer ring 18 is made of a material having a coefficient of thermal expansion smaller than that of each of the plates 11 and 12, and is formed in an annular shape.
It adheres to the outer peripheral portion of a.

The inner ring 19 is made of a material having a coefficient of thermal expansion larger than that of the plates 11 and 12, and is formed in an annular shape.
It adheres to the inner peripheral part of a.

FIG. 12 shows a state before brazing. There are gaps between the inner ring 19, the rising portion 11a, the rising portion 12a, and the outer ring 18, respectively. By setting the dimensions and the coefficient of thermal expansion of each part so that the difference in thermal expansion between the inner ring 19 and the outer ring 18 becomes large with respect to the sum of these gaps, the inner ring 19 and the outer ring 18 are respectively separated during brazing. The riser 11a and the riser 12a are brought into close contact with each other.

That is, as shown in FIG. 12, the outer diameter of the inner ring 19 is Db, and the gap between the inner ring 19 and the outer periphery of the rising portion 12a and the rising portion 11a is d ₁ , and the rising portion 12a is Also, the clearance between the inner peripheral portion of the rising portion 11a and the outer ring 18 is d ₃ , the inner diameter of the outer ring 18 is Da, the thermal expansion coefficient of the inner ring 19 is αa, and the thermal expansion coefficient of the outer ring 18 is αb and the temperature rise during brazing is ΔT ₁
Then, each value is set so as to satisfy (αb · Db−αa · Da) × ΔT ₁ > d ₁ + d ₃ (3).

As compared with the embodiment shown in FIG. 1, the rising portion 11
Since a and rising portion 12a does not fit together, a gap d ₂ to be spaced therebetween by brazing previous state is not provided, the difference in thermal expansion between the inner ring 19 and outer ring 18 (αb · Db- It suffices to manage the gap d ₁ + d ₃ with respect to αa · Da) × ΔT ₁ , and the processing accuracy required for each component can be reduced.

The cross section of the outer ring 18 is formed into a substantially rectangular shape, and its four corners are curved.

The inner ring 19 is formed in a thin cylindrical shape, and has a right cylindrical portion 19b having a right cylindrical shape extending in parallel with the rising portions 12a and 11a, and the right cylindrical portion 19b.
It has a collar portion 19a continuously expanding from the upper end of b in the shape of a trumpet. The cross-section of the collar portion 19a is formed by curving in an arc shape so that the outer peripheral end portion thereof is substantially orthogonal to the straight cylindrical portion 19b.

With the above construction, the operation will be described below.

When brazing the tube element 4, as shown in FIG.
As shown in 2, inner ring 19 and each plate 1
1 and 12 and the outer ring 18 are put in a furnace and heated to a predetermined temperature in a state where they are assembled via a brazing material.

Since the inner ring 19 has the brim portion 19a that expands in the outer diameter direction, the rising portion 1a is assembled with the tube element 4 assembled before brazing.
It does not fall off from 2a, and a jig for supporting the inner ring 19 is unnecessary.

At the time of brazing the tube element 4, the rising portion 12a and the rising portion 11a are sandwiched between the outer ring 18 and the inner ring 19 due to the difference in thermal expansion between the outer ring 18 and the inner ring 19 and are in close contact with each other. At the time of brazing, since the inner ring 19 has the flange portion 19a that expands in the outer diameter direction thereof, sufficient rigidity is secured against the reaction force acting from the rising portion 12a at the time of brazing.

In this way, the fixing portions 6 to 9 are connected to the rising portion 12 via the outer ring 18 and the inner ring 19.
By brazing the a and the rising portion 11a in close contact with each other, it is possible to avoid a gap even if a small amount of brazing material is used, and it is possible to reliably ensure the airtightness of the outlet 15 in the tube element 4.

Further, the difference in thermal expansion between the inner ring 19 and the outer ring 18 is set so as to apply surface pressure to the rising portions 11a and 12a to join them even at a rising temperature when the heat exchanger is used. Even if peeling occurs in the brazed portions of the fixing portions 6 to 9, the airtightness of the tube element 4 can be ensured.

It is also possible to adopt a structure in which the fixing portions 6 to 9 are fixed by diffusion bonding.

Next, still another embodiment shown in FIGS. 14 and 15 will be described. It should be noted that the same parts as those in FIG.

Lower plate 12 and upper plate 11
Is fixed to each of the outer ring 58 and the inner ring 59 by brazing, so that the tube element 4 is hermetically sealed.

The inner ring 59 is formed in a thin cylindrical shape, and has a straight cylindrical portion 59b having a straight cylindrical shape extending parallel to the rising portions 12a and 11a, and a trumpet shape continuous from the upper end of the straight cylindrical portion 59b. It has a collar portion 59a that expands in diameter and a collar portion 59c that continuously expands in a trumpet shape from the lower end of the straight cylindrical portion 59b. The cross-sections of the collar portions 59a and 59c are curved in an arc shape so that the outer peripheral ends thereof are substantially orthogonal to the right cylindrical portion 59b.

The inner ring 59 is the upper plate 1
One or both of the flange portions 59a and 59c are formed by press working in a state of being assembled to the 1 and the lower plate 12.

FIG. 14 shows a state before brazing. The inner ring 59, the plates 11 and 12, and the outer ring 58 are joined to each other without leaving a gap.

As a result, it is not necessary to manage the gaps between the inner ring 59 and the plates 11 and 12 and the outer ring 58, as compared with the above-mentioned respective embodiments, and the machining accuracy required for each component can be reduced. it can.

The inner ring 59 is made of a material having a coefficient of thermal expansion smaller than that of the plates 11 and 12, and is formed in an annular shape.
It adheres to 1 and 12.

The outer ring 58 has a substantially rectangular cross-section, and annular projections 58a and 58b are formed on the upper and lower surfaces thereof.

The outer ring 58 is made of a material having a coefficient of thermal expansion larger than that of the plates 11 and 12, and is formed in an annular shape.
It adheres to 1 and 12.

With the above arrangement, the operation will be described.

When brazing the tube element 4, as shown in FIG.
Inner ring 59 and empty plate 1 as shown in FIG.
1, 12 and the outer ring 58 are put in a furnace in a state where they are assembled via a brazing material and heated to a predetermined temperature.

Since the inner ring 59 has the brim portions 59a and 59c extending in the outer diameter direction, the inner ring 59 does not fall off from the rising portion 12a in the state where the tube element 4 is assembled before brazing. A jig or the like for supporting the inner ring 59 is unnecessary.

At the time of brazing the tube element 4, the plates 11 and 12 are sandwiched between the outer ring 58 and the inner ring 59 due to the difference in thermal expansion between them, so that they closely contact each other. At the time of brazing, the inner ring 59 has the brim portions 59a and 59c that spread in a U-shaped cross section, so that sufficient rigidity is secured against the reaction force that has been exerted after brazing.

When brazing the tube element 4, the outer ring 58 annular projections 58a and 58b are continuously pressed against the plates 11 and 12 within a predetermined width L ₄ with a large surface pressure, so that a small amount of brazing material can be obtained. Even if you use the tube element 4
The outlet 15 can be surely airtight.

[0109]

As described above, in the laminated heat exchanger according to the first aspect of the present invention, a plurality of tube elements that define a flow path are laminated by a pair of box-shaped plates, and adjacent tube elements communicate with each other. Each of the plates of the adjacent tube elements is integrally formed with a rising portion that defines the entrance and exit and protrudes in a tubular shape, and the rising portions of the adjacent tube elements are fitted to each other to form a row. An inner ring and an outer ring that sandwich the fixing part through each rising part are provided with a fixing part that is fixed by attachment or diffusion bonding, and the inner ring is formed of a material having a coefficient of thermal expansion larger than that of the outer ring. Since the inner ring arranged at the inlet / outlet is formed into a thin-walled cylinder having at least one end having a flange portion that expands in the outer diameter direction, By being fixed in a standing state up portion is in close contact with a sufficient surface pressure, it is possible to sufficiently secure the airtightness of the tube element. In addition, the inner ring does not need to be removed from the tube element, increasing the rigidity of the tube element and
There are less restrictions on the material of the inner ring, and the cost of the product can be reduced.

In the laminated heat exchanger according to claim 2, in the invention according to claim 1, at least one of the rising portions of the adjacent tube elements is formed with an annular projection portion that annularly projects toward the other. The annular projection portion concentrates the surface pressure acting on the joint portion of each rising portion due to the difference in thermal expansion between the inner ring and the outer ring, can prevent a gap from being formed in the fixed portion, and can enhance the airtightness of the tube element.

In the laminated heat exchanger according to claim 3, in the invention according to claim 1 or 2, the outer ring is formed in a thin arc shape which is curved with an arc cross section.
The outer ring concentrates the surface pressure acting on the joints of the respective rising portions, can prevent a gap from being formed in the fixed portion, and can enhance the airtightness of the tube element.

According to a fourth aspect of the present invention, in the laminated heat exchanger, a plurality of tube elements defining a flow path are laminated by a pair of box-shaped plates, and adjacent tube elements are provided with an inlet / outlet communicating with each other. Each plate of the tube element is integrally formed with a rising part that defines the entrance and exit and protrudes in a tubular shape, and is equipped with an inner ring and an outer ring that sandwich the rising parts of adjacent tube elements. To the at least one of the rising portions is provided with a fixing portion for fixing both surfaces by brazing or diffusion bonding, the inner ring is formed of a material having a coefficient of thermal expansion larger than that of the outer ring, and is arranged at the inlet and outlet of the tube element. The inner ring is formed in a thin-walled cylinder shape having a flange portion at least one end of which extends in the outer diameter direction. Each rising portion by the both surfaces is fixed in close contact with a sufficient surface pressure to the inner ring and the outer ring, it is possible to sufficiently secure the airtightness of the tube element. In addition, the inner ring does not have to be removed from the tube element, the rigidity of the tube element can be increased, restrictions on the material of the inner ring are reduced, and the processing accuracy required for each plate etc. is reduced, reducing the cost of the product. Be peeled off.

According to a fifth aspect of the laminated heat exchanger, a plurality of tube elements defining a flow path are laminated by a pair of box-shaped plates, and an inlet / outlet for communicating adjacent tube elements is provided. The inner ring is provided with an outer ring that is interposed between the plates of the tube elements that are located on the outer periphery and that are adjacent to each other, and the inner ring is formed into a thin-walled tubular shape with flanges that expand in the outer radial direction. Between each flange of the ring and the outer ring, sandwich each plate of the adjacent tube element, and at least one of the flange of the inner ring and at least one of the outer ring has a fixing part that secures each plate by brazing or diffusion bonding. Since the inner ring is made of a material whose coefficient of thermal expansion is smaller than that of the outer ring, each plate is By being fixed in close contact with a sufficient surface pressure to Utaringu, you are possible to sufficiently secure the airtightness of the tube element. In addition, the inner ring does not have to be removed from the tube element, the rigidity of the tube element can be increased, restrictions on the material of the inner ring are reduced, and the processing accuracy required for each plate etc. is reduced, resulting in product cost reduction. Be peeled off.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of the tube element similarly showing a state before brazing.

FIG. 4 is an exploded perspective view of a tube element and the like.

FIG. 5 is a sectional view of the tube element similarly showing a state after brazing.

FIG. 6 is a sectional view of a tube element showing a comparative example different from the present embodiment.

FIG. 7 is a perspective view of the inner ring.

FIG. 8 is a sectional view of a tube element showing a state before brazing in another embodiment of the present invention.

FIG. 9 is a sectional view of the tube element similarly showing a state after brazing.

FIG. 10 is a cross-sectional view of a tube element showing a state before brazing in still another embodiment of the present invention.

FIG. 11 is a sectional view of the tube element similarly showing a state after brazing.

FIG. 12 is a sectional view of a tube element showing a state before brazing in yet another embodiment of the present invention.

FIG. 13 is a sectional view of the tube element similarly showing a state after brazing.

FIG. 14 is a sectional view of a tube element showing a state before brazing in still another embodiment of the present invention.

FIG. 15 is a sectional view of the tube element similarly showing a state after brazing.

FIG. 16 is a sectional view of a tube element showing a conventional example.

FIG. 17 is an exploded perspective view of a tube element and the like.

FIG. 18 is a sectional view of the tube element similarly showing a state before brazing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st flow path 2 2nd flow path 4 Tube element 5 Outer fin 10 Fixed part 11 Upper plate 11a Rise part 11d Annular protrusion 12 Lower plate 12a Rise part 14 Inlet 15 Outlet 18 Outer ring 19 Inner ring 19a Collar part 19b Straight cylindrical portion 48 Outer ring 58 Outer ring 58a Annular projection portion 59 Inner ring 59a Collar portion 59c Collar portion

Claims (5)

[Claims] 1. A plurality of tube elements defining a flow path are laminated by a pair of box-shaped plates, and an inlet / outlet for communicating adjacent tube elements is provided, and an inlet / outlet is defined in each plate of adjacent tube elements. Then, each of the rising portions is formed integrally with each other, and the rising portions of adjacent tube elements are fitted to each other and fixed by brazing or diffusion bonding. The inner ring is made of a material having a coefficient of thermal expansion higher than that of the outer ring, and the inner ring is placed at the inlet / outlet of the tube element. A laminated heat exchanger, characterized in that it is formed in a thin-walled tubular shape having a flange portion that spreads over. 2. The laminated heat exchanger according to claim 1, wherein at least one of the rising portions of the adjacent tube elements is formed with an annular protrusion protruding annularly toward the other. 3. The laminated heat exchanger according to claim 1, wherein the outer ring is formed in a thin arc shape which is curved with an arc-shaped cross section. 4. A plurality of tube elements that define a flow path are stacked by a pair of box-shaped plates, and an inlet / outlet for communicating adjacent tube elements is provided, and an inlet / outlet is defined in each plate of the adjacent tube elements. And the inner ring and the outer ring that sandwich the respective rising portions of the adjacent tube elements are formed integrally with each other, and the rising portions are formed for at least one of the inner ring and the outer ring. The inner ring is made of a material having a coefficient of thermal expansion larger than that of the outer ring, and at least one end of the inner ring is arranged at the inlet and outlet of the tube element in the outer radial direction. A laminated heat exchanger, characterized in that it is formed in a thin-walled tubular shape having a flange portion that spreads over. 5. A plurality of tube elements that define a flow path are laminated by a pair of box-shaped plates, and an inlet / outlet for communicating adjacent tube elements is provided. An outer ring is provided between each plate, and both ends of the inner ring are formed in a thin-walled tubular shape with a flange portion that expands in the outer diameter direction.The inner ring is provided between each flange portion and the outer ring. Each plate of the adjacent tube element is sandwiched between the inner ring and each flange of the inner ring and at least one of the outer ring and each plate is fixed by brazing or diffusion bonding. A laminated heat exchanger characterized by being formed of a material smaller than a ring.