JPH0416707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an assembly structure of a laminated heat exchanger used as an evaporator for an automobile air conditioner.

[Conventional technology]

The structure of an evaporator for an automobile air conditioner as an example of a conventional laminated heat exchanger is shown in Figs.
This is shown in Figure 3 A and B. This figure 11~1
The one shown in Figure 3 is proposed in Japanese Utility Model Publication No. 53-32376, etc. In the figure, A indicates two core plates made of aluminum plates, which are flat tubes for the circulation of refrigerant. To give an example of each of 1, after press-forming it into a “skin-like shape in the middle of a confectionery”,
They are made by joining them together by brazing. B1 and B2 are tank parts each formed by providing two bulging parts in parallel at one end in the longitudinal direction of the two core plates 1, and are used for the inflow or outflow of refrigerant into the flat tube A. It functions as a port. 21 and 22 are piping for refrigerant in and out of these two tank parts B1 and B2, and 20 is a gap-maintaining pipe attached to the other end of the flat tube A on the side where the tank part is not formed. The spacer 20a is a slit provided at regular intervals on the plate surface of the spacer 20, and the other end of each of the flat tubes A group is inserted into the slit 20a.
By fitting into the tube a, it serves to keep the gap width in the stacking direction of the flat tube A group constant. 2
is a corrugated fin made of a thin aluminum plate inserted into the gap between adjacent flat tubes A to increase the heat transfer area. The method for assembling this type of heat exchanger is that after press forming, two core plates 1, whose front and back surfaces have been clad with brazing filler metal for assembly, are brought together to form a flat tube A. After that, the required number of units each having a corrugated fin 2 along one side thereof were stacked one on top of the other in the thickness direction of the flat tube, and the spacer 20 and the inlet/outlet pipes 21, 22 were further assembled, and the tube was temporarily assembled in this way. The assembly is held by a jig and carried into a brazing furnace, and heated to the melting temperature of the brazing material, thereby brazing the entire heat exchanger as shown in the figure.

[Problem that the invention seeks to solve]

According to the assembly structure of the heat exchanger using the above-mentioned spacer, it is possible to prevent problems such as disturbances in the even parallel arrangement of the flat tubes after assembly by brazing or collapse of the corrugated fins due to external force. However, on the other hand, the cost of manufacturing and assembling the spacer increases, and it becomes difficult to fit the spacer unless the mutual spacing between the flat tubes is maintained correctly. Therefore, there was a problem that assembly efficiency decreased.

In view of the above points, the present invention provides an assembly structure of a laminated heat exchanger that allows each flat tube to be assembled quickly and easily while maintaining a predetermined interval in the thickness direction without using additional parts such as spacers. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention provides (a) a flat tube formed by joining two press-molded core plates; (b) a flat tube extending outward from one end of the flat tube; (c) a tank portion integrally formed with the core plate in a bulging manner and having an inlet and an outlet for the heat transfer medium; a U-turn-shaped medium passage formed such that the medium flows toward the other end of the flat tube, makes a U-turn here, and flows toward the outlet of the one end; A large number of flat tubes are stacked in the thickness direction so that the outlet and inlet of each adjacent flat tube are connected, and (e) there is a bend on the other end side of the flat tube to maintain a gap between the flat tubes. A technical measure is adopted in which the part is integrally formed with the core plate.

[Effect]

According to the above technical means, the gap between the stacked flat tubes can be reliably maintained at a predetermined distance by using the core plate itself as a constituent member of the flat tube.
That is, at one end of the flat tube, the gap between the flat tubes is defined by a tank part formed integrally with the core plate, and at the other end of the flat tube, the gap is defined by a bent part integrally formed from the core plate. can be specified.

〔Effect of the invention〕

Therefore, according to the present invention, the gap between the flat tubes can be reliably defined using the core plate itself, so there is no need to add special parts such as spacers in the prior art, and the number of parts can be reduced. In addition, the complexity associated with assembling the spacer is eliminated, the number of assembly steps can be reduced, and the manufacturing cost of the heat exchanger can be significantly reduced.

Further, by eliminating the spacer, it is possible to reduce the size and weight of the heat exchanger.

〔Example〕

The heat exchanger according to the present invention will be specifically explained below based on the embodiment shown in the drawings.

FIG. 1 is a front view of an evaporator used in an automobile air conditioner as a specific example of the heat exchanger according to the present invention, in which A is a flat tube for circulating a refrigerant as a heat transfer medium, and B is a flat tube A for circulating a refrigerant as a heat transfer medium. A tank portion 1 integrally formed at one end in the longitudinal direction is a core plate, and the flat tube A is constituted by joining two of them. 2 is a corrugated fin for increasing the heat transfer area, and is formed by bending a thin strip-shaped aluminum plate or the like into pleats. 3 is core plate 1
It is a bent portion formed by bending the other end side of the longitudinal direction of the flat tube A in the right angle direction, and serves as a spacer for joining the adjacent flat tubes A while keeping the gap width at the other end side constant. 3a' and 3b' are folded portions forming part of the engaging uneven portion provided on the folded portion 3. Reference numerals 11 and 12 are pipes for discharging and supplying refrigerant to the evaporator, respectively, and the refrigerant discharge pipe 11 is connected to a gas phase refrigerant suction pipe of a refrigerant system compressor via a pipe joint 13. The refrigerant supply pipe 12 is connected via a pipe joint 14 to a pressure reducing device (for example, an expansion valve) of a refrigeration system (not shown). Reference numeral 15 denotes a side plate serving as a protection plate for the heat exchanger, which is disposed on the left and right outer surfaces of the evaporator, and a brazing material is clad in advance on only one side on the fin 2 side.

2 to 4 are a front view, an A-A sectional view of the front view, and a bottom view of one of the two symmetrical core plates 1 constituting the flat tube A, respectively, The core plate 1 is formed by pressing a metal plate such as aluminum, and a brazing material for evaporator brazing is pre-clad on both the front and back surfaces thereof by a method described later. Reference numerals 4 and 4' denote bulges formed by bulging one end of the core plate 1 outward in order to form the tank portion B;
As shown in FIG. 2, a pair of numerals 4' are provided in parallel on the left and right. 4a and 4a' are refrigerant inlet or outlet holes of the flat tube A provided at the tops 4c and 4c' of the pair of bulging parts 4 and 4', respectively;
is a flange portion provided at the periphery of one of the holes 4a, 4a' (the right side in the example of FIG. 2). Here, the other (left side in the example in Figure 2) hole 4
No flange portion is provided at the periphery of a′. The flange portions 4b of the bulging portions 4 of the adjacent core plates 1 are inserted into the holes 4a'. Similarly, the flange portion 4b of the bulge portion 4 on the right side of FIG. 2 is inserted into the hole 4a' (hole without flange portion) of the bulge portion 4' of the adjacent core plate 1. On one end side of the core plate 1, the tops 4c and 4c' of the bulging parts 4 and 4' of the core plates of adjacent flat tubes A come into contact with each other, so that the gap between the flat tubes A is kept constant. is maintained. Therefore, the gap between the flat tubes can be determined by the height H (see FIG. 3) of the tops 4c, 4c' of the bulges 4, 4'.

1a is a bonding surface for brazing on the outer peripheral edge of the core plate 1; 1b is a partition wall provided vertically in the center of the core plate 1 to form a U-turn-shaped refrigerant passage in the flat tube A; e is this partition wall 1
This is the part where the lower end of b was partially removed. The refrigerant flowing into the flat tube A from the inlet hole 4a (or 4a') at one end of the flat tube A flows toward the other end of the flat tube (the lower end in FIG. 2) through the partition wall 1b, and is It makes a U-turn and flows toward one end of flat tube A.
It is adapted to flow out from the outlet hole 4a' (or 4a). 1c and 1d are rib groups integrally formed on the core plate 1 to form a labyrinth for coolant passage inside the flat tube A, and 1e is a bonding surface 1a for brazing.
This is a reinforced part that is made by folding the outer edge part slightly outward to make it easier to obtain flatness of the bonding surface 1a for brazing.

On the other hand, the bent portion 3 serves as a spacer to connect the other end of the flat tube group A to each other while maintaining a constant gap, and serves to connect the other end of the core plate 1 to the flat tube A. It is formed by being bent at right angles in the outward direction. 3c is a bonding surface for brazing formed by bending the tip of the bent portion 3 at right angles in a direction parallel to the plane of the core plate 1. Here, the height H of the bonding surface 3c for brazing of the bent portion 3 (see Fig. 4) is designed to be the same as the height H of the top portions 4c, 4c' of the bulging portions 4, 4' mentioned above. Therefore, the bonding surfaces 3c of the bent portions 3 of adjacent core plates 1 come into contact with each other at intermediate positions between the flat tubes, so that the mutual gap on the other end side of the flat tube A is the same size as that on the one end side. It is held in place.

Further, 3a and 3b are engagement recesses and protrusions formed on the tip side of the bending part 3, and
Make a cut at an arbitrary gap on the tip side of g.
, and is formed by bending between the notches g. 3a', 3b' are the recesses 3a,
This is a folded portion of the convex portion 3b. The convex portion 3b of the bent portion 3 of the core plate 1 of the adjacent flat tube A fits into the concave portion 3a, and the convex portion 3b fits into the concave portion 3a of the bent portion 3 of the adjacent core plate 1. This prevents the other end side portion of the core plate 1 from shifting laterally in the plane direction when the core plates are stacked.

Side plates 1 located on both sides of the heat exchanger
5 also has the above-mentioned bent portion 3 on the other end side.
and engaging uneven portions 3a, 3b (see FIG. 1).

FIG. 5 is a bottom view showing a state in which the core plates 1 constituting one half of each of the adjacent flat tubes A are opposed to each other with a slight distance between them before being bonded together, and the above-mentioned recess 3a and The state before fitting with the convex part 3b is shown.

θ in the figure indicates that the notch g provided in the bent portion 3 is provided in a direction inclined by θ° from the direction orthogonal to the edge line of the bent portion 3, and thereby the recessed portion 3a,
It shows that the convex portion 3b is formed in a trapezoidal shape.

FIG. 6 shows the engagement recess 3a shown in FIG.
and shows an example in which the formation location of the convex part 3b is modified, and the concave part 3a and the convex part 3b are not provided directly adjacent to each other, but a bonding surface 3c is interposed between them. be.

FIG. 7 is a side sectional view of the other end portion of the core plates 1 constituting one half of each adjacent flat tube A, showing the state in which they are placed opposite each other before being bonded together, and FIG. An embodiment is shown in which the tip of the part 3 is simply bent at a right angle to form a bonding surface 3c for brazing, and the lower end of the bonding surface 3c for brazing is further bent at a right angle to form a reinforcing surface. An example in which a flange-shaped portion 3d is provided is shown.

FIG. 8 shows a state in which the two core plates 1 shown in FIGS. 1 to 5, which constitute one half of each of adjacent flat tubes A, are opposed to each other with a slight distance between them. , is a cutaway perspective view of the other end portion of the core plate 1. FIG.

Next, the assembly structure, which is the main point in the construction of the heat exchanger according to the present invention, will be explained with reference to the accompanying drawings. This type of heat exchanger, which is generally called a laminated type, has a shape as shown in Figures 2 to 4 to form a group of flat tubes A, and has brazing filler metal on both the front and back sides. A core plate 1 to which a solder metal is pre-clad, a corrugated fin 2 for increasing the heat transfer area (no brazing metal is clad), and a side plate 15 to which a brazing metal is pre-clad on one side of the fin are assembled. As shown in Figure 1, from one end side, the side plate 15, the corrugated fin 2, the core plate 1 constituting one half of the flat tube A, the core plate 1 constituting the other half, the corrugated fin 2, and one half part. The core plate 1 of the other half, the core plate 1 of the other half, the corrugated fin 2, etc. are overlapped, and finally the side plate 15 is applied to temporarily assemble the laminated structure part of the heat exchanger. After assembling the refrigerant pipes 11 and 12 on both sides, the temporarily assembled state is fixed using a jig, and the product is transported into a brazing furnace heated to the melting temperature of the brazing material, and maintained for a certain period of time. After each part is brazed and joined, the entire heat exchanger is integrally brazed by allowing it to cool, thereby completing the assembly. Then, at the stage of overlapping the core plates 1 to temporarily assemble the flat tube group A,
As for the gap maintaining means for the group of flat tubes A, for one end side where the tank part B is provided, a tank part B is formed at one end side of one core plate among a pair of adjacent core plates 1. The flange portion 4b provided at the periphery of the refrigerant inlet (outlet) hole 4a of the bulging portion 4 for expansion is fitted into the refrigerant outlet (inlet) hole 4a' which does not have the flange portion 4b of the other core plate. By bringing the top portions 4c, 4c' of the projecting portions 4, 4' into contact with each other, the gap between the flat tubes A can be maintained at a constant size. On the other hand, since the tank portion B is not provided on the other end side of the flat tube group A, the brazing bonding surfaces 3c of the bent portion 3 provided on the other end side of the core plate 1 are mutually connected to each other as described above. By employing the means of abutting, the mutual gap between the flat tubes A group is maintained.

Furthermore, in this embodiment, measures are taken to prevent the core plate 1 from shifting laterally as described below. That is, if the bonding surface 3c for brazing of the folded portion 3 is just a uniform flat surface,
During the temporary assembly stage before brazing, it is difficult to efficiently position the core plates 1 on top of each other while maintaining the correct positioning relationship, and the core plates 1 may shift laterally in the plane direction due to some external force. There is a high possibility that this will occur. Therefore, in the temporary assembly process of such a heat exchanger, the operator is forced to pay sufficient attention, resulting in a decrease in work ability, or in some cases requiring a jig to prevent lateral slippage. Therefore, in the heat exchanger of this embodiment, the core plate 1 to be bonded
The bent portions 3 of the group are provided with uneven portions 3a and 3b for positioning the core plates 1 when they are stacked and for engagement to prevent lateral slippage, and these two are connected to the uneven portions 3a of the adjacent core plates 1, respectively. , 3b. Furthermore, in the embodiment shown in FIGS. 5 and 6, the uneven portions 3a and 3b are formed into a trapezoidal shape, so that there are the following advantages.

That is, the above-mentioned engaging uneven portions 3a, 3b
If the recess 3a and the protrusion 3b are not in a simple U-shape or rectangular shape, unless the positions of the concave part 3a and the convex part 3b match exactly, the fitted and locked state of both cannot be realized. , 3b are the fifth
As shown in the figure, if the shape is a trapezoid with a wide base and a narrow tip with an arbitrary inclination angle θ, both core plates 1 Even if the concave portions 3a or convex portions 3b are overlapped with each other in a slightly shifted positional relationship, there is an advantage that a smooth sliding operation occurs and the fitting is extremely easy. As long as the inclination angle θ of both side edges of the uneven portions 3a and 3b does not exceed about 60°, the larger the angle is,
Although the fitting tolerance for relative positional deviation between the uneven portions 3a and 3b increases, the angle θ
If this is increased, the two core plates, which have been brought into a fitted and locked state, will tend to shift and move even with the slightest external force, resulting in a weakening of the intended locking effect of the two core plates. . In addition, if the angle θ is kept below about 10°, there will be no negative effect at all in terms of the purpose of locking, but for the purpose of improving the work efficiency of overlapping the core plates, the inclination angle θ is
The significance of its existence is diminishing. Note that the recess depth dimension of the recess 3a and the protrusion height dimension of the protrusion 3b do not necessarily have to match, and the recess dimension may be larger than the protrusion dimension at all, and the engagement uneven shape is not limited to the illustrated trapezoid, and may be formed at only one location or at several locations.

In order to achieve the object of the present invention, the location where the engagement unevenness for mutual positioning of the core plate group 1 and prevention of lateral slippage is formed is not necessarily limited to the bent portion 3 shown in the above-described embodiment. does not require In other words, this is the area where two core plates are to be bonded together, and by providing an uneven shape, there is a possibility that the assembly strength of the heat exchanger after brazing and the prevention of refrigerant leakage will be adversely affected. If there is no such location, the arrangement may be made as shown in FIG. 9, for example.

That is, FIG. 9 is a cross-sectional perspective view showing another example of the shape of the engaging uneven portions 3a, 3b provided on the core plate 1, with two core plates 1 horizontally opposed to each other. , 1h and 1 in the figure
i is a convex portion and a concave portion that are formed on the brazing bonding surface 1a of the outer peripheral edge of each core plate, and serve to position the two core plates 1 and prevent lateral slippage when bonded together; The planar shape may be circular, oval, or any other arbitrary shape. The purpose of locking is achieved by fitting the convex portion 1h into the concave portion 1i.

Further, 1j and 1k are concave and convex lines for engagement formed on the bonding surfaces for brazing of the vertical partition walls 1b of the two core plates 1, and the convex line 1k is a concave line. By fitting into the strips 1j, the purpose of positioning both core plates 1 and preventing relative lateral displacement is achieved. Furthermore, ribs 1c and 1 provided to form a labyrinth in the flat tube A
Engagement unevenness may be formed using the contact surface d.

FIGS. 10A, 10B, and 10C show still another embodiment of the present invention, in which a rib 3d is formed on the bent portion 3 formed at the end of each core plate 1, and adjacent to this rib 3d. By forming ribs 3e on the flat surface of the core plate 1 at the portion where the bending portion 3 is to be heated, the rigidity around the bent portion 3 is increased, thereby preventing the bent portion 3 from being thermally deformed due to high temperature heating during brazing. It was designed to prevent this.

As described above, the present invention can be modified in various ways and can be implemented in a wide variety of ways.

[Brief explanation of drawings]

Fig. 1 is a front view of an evaporator used in an automobile air conditioner as an embodiment of the heat exchanger according to the present invention, and Figs. 2 to 4 show cores forming flat tubes as constituent elements of the evaporator. A front view of the plate, an A-A sectional view of the front view,
FIG. 5 is a bottom view of two core plates forming one half of each adjacent flat tube placed opposite each other before bonding, and FIG. Fig. 7 is a bottom view similar to Fig. 5 and a side cross-sectional view of the lower end of a pair of core plates placed opposite each other before bonding. shows examples of different cross-sectional shapes. FIG. 8 is a perspective view of the lower end portion of the core plate, showing the state in which the two core plates shown in FIGS. 1 to 5 are placed opposite each other before being bonded together. FIG. 2 shows an example of another shape of the engagement unevenness provided in
10A, 10B, and 10C are cross-sectional perspective views of a state in which two core plates are horizontally opposed, and FIG. Figure 10B is an enlarged sectional view taken along line GG, Figure 10B is a bottom view of the core plate, and Figure 10B is a bottom view of the core plate.
Figure C is an enlarged sectional view taken along the line HH in Figure 10B, and Figures 11 and 12 are a top view and a front view, respectively, of a conventional heat exchanger. FIGS. 13A and 13B are a plan view and a side view of a spacer assembled in this conventional heat exchanger. A...Flat tube, B...tank part, 1...core plate, 1a...bonded surface of core plate, 2...corrugated fin, 3...bending part, 3a, 3b...
Engagement unevenness, 3a', 3b'...folded part of engagement unevenness, 3c...bonded surface of folded part 3, g
...notch.

Claims (1)

[Claims] 1. A flat tube formed by joining two bowl-shaped core plates at their outer peripheries, and a flat tube bulging outward at one end of the flat tube. a tank part integrally formed with the core plate and having an inlet and an outlet for a heat transfer medium; a U-turn-shaped medium passage formed such that the flow takes a U-turn here and flows toward the outlet on the one end side; and corrugated fins arranged between adjacent flat tubes; A plurality of flat tubes are stacked in the thickness direction by joining the tank portions such that the outlet and inlet of each adjacent flat tube are connected, and the other end side of the flat tube includes: The bent portion that is bent toward the adjacent flat tube and joined to the adjacent flat tube to maintain the distance between the flat tubes is integrally formed so as to extend from the joint of the core plate. Features of heat exchanger. 2. The bending portion is integrally formed from the other end side of each of the core plates of adjacent flat tubes, and abuts at an intermediate position between the flat tubes. Heat exchanger. 3. The bent portions are each formed with an engaging uneven portion, and the engagement of the uneven portions prevents the core plate from shifting laterally in the plane direction. Range 2nd
Heat exchanger as described in section. 4. The heat exchanger according to claim 3, wherein each of the engaging uneven portions has a trapezoidal shape.