JPH07280482A - Joining method of base plate of stacked type heat exchanger - Google Patents

Abstract

PURPOSE:To obtain a method for joining a base plate to a closing plate positioned at the lowermost end of a stacked type heat exchanger, with ease and with components in reduced numbers. CONSTITUTION:An opening 1a is provided in a closing plate 2 and a plurality of pawl parts 7 are provided in projection at the peripheral edge of the opening so that they are separate in the peripheral direction from each other. On the other hand, a circular protuberance 8 is formed on the inner side of a base plate 6 and this circular protuberance 8 is matched with the fore ends of the pawl parts 7, positioned thereby and engaged therewith. Prior to joining of the inner surface of the closing plate 2 with inner fin 3, moreover, a solder fin 9 for joining is interposed between them and this solder fin 9 is disposed in extension from the edge of the opening 1a onto the center side thereof. According to this constitution, the solder fin 9 provided on the inner surface of the closing plate 2 is melted, reaches the base plate 6 through between the peripheral edge of the circular protuberance 8 and a communication hole 1 and penetrates into the part of contact of the base plate 6 with the closing plate from a gap between them and the base plate 6 is joined therewith in a liquidtight manner on the outer surface side of the plate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for joining a bottom plate located at the lowermost end of a laminated plate in a laminated heat exchanger (also referred to as a multi-plate heat exchanger) mainly used as an oil cooler. Regarding

[0002]

2. Description of the Related Art This type of laminated oil cooler has been shown in FIG.
The parts were assembled as shown in Fig. 1 and each part was integrally brazed and fixed in a high temperature furnace with a brazing foil. That is, each of the plates 2a and 2b formed in the shape of a slender plate has a communication hole 1 at both ends thereof, and both plates are stacked in opposite directions.
The inner fin 3 and the lean hosement 13 are arranged inside, and a pair of brazing foils 9 are arranged between the inner fin 3 and the lean hosement 13 and the inner surface of the plate to form the element 4. Then, such elements 4 are laminated in a plurality of stages with the ring spacers 10 interposed therebetween. At this time, the ring-shaped brazing foil 9c is also arranged on both surfaces of the ring spacer 10.

Further, a boss portion 5 is attached to a hole edge portion of the communication hole 1 of the plate 2a located at the uppermost stage via a brazing foil 9b. The bolt 11 is inserted into the bolt hole formed in the boss portion 5 through the brazing foil 9a. Further, a closing plate having no communication holes is used as the lower surface side plate of the element 4 located at the lowermost end, and the bottom plate 6 is arranged on the lower surface of the closing plate via the brazing foil 9d. In this embodiment, the elements 4 are shown only in two stages for the sake of simplification of the drawing. However, in many cases, a multi-stage element 4 is laminated. Each part assembled in this way is held from above and below by a suitable jig, inserted into a high temperature furnace, and melts the brazing foil interposed between each part,
Then, by solidifying it, each component was integrally brazed and fixed.

[0004]

In the conventional method of manufacturing a heat exchanger as described above, in order to join the bottom plate 6 to the bottom closing plate, the relatively small bottom plate 6 and the brazing foil 9d are accurately attached to the closing plate. It is necessary to position and assemble it at the same time, which is a troublesome assembling work.

[0005]

Therefore, according to the present invention, the bottom plate 6 is provided.
It is an object of the present invention to provide a bottom plate joining method for a laminated heat exchanger that does not require a disc-shaped brazing foil for brazing and fixing the bottom plate to the closing plate and facilitates positioning of the bottom plate 6. The following structure is used to achieve the purpose. That is, in the bottom plate joining method for a laminated heat exchanger according to the present invention, a pair of elongated dish-shaped plates 2a and 2b each having a communication hole 1 formed at both ends thereof are superposed in opposite directions, and the inner fin 3 The pair of plates 2a on both sides in the thickness direction,
The elements 4 are configured by being joined to the inner surfaces of 2b, respectively.
Then, a plurality of elements 4, 4 are laminated, and a boss portion 5 for entrance and exit is provided in the communication hole 1 of the outermost plate 2a on one side in the laminating direction.

Further, the object is one in which the bottom plate 6 is joined to the outer surface of the other outermost closed plate 2 having no communication hole. The closing plate 2 is provided with an opening 1a, and a plurality of narrow claw portions 7 spaced apart from each other in the circumferential direction are provided on the edge of the closing plate 2 so as to project in the center direction of the opening 1a. At the same time, a circular convex portion 8 is formed on the inner surface of the bottom plate 6, and the peripheral edge of the circular convex portion 8 is aligned and locked with the tips of the plurality of claw portions 7. Before the inner surface of the plate 2 and the inner fin 3 are joined, a brazing foil 9 for joining is interposed between the inner fin 3 and the inner fin 3, and the brazing foil 9 extends from the edge of the opening 1a to the center side in the opening 1a. It is placed there.
The brazing foil 9 is melted and then solidified to liquid-tightly close the opening 1a with the bottom plate 6 from the outer surface side of the closing plate.

[0007]

The operation and effect of the bottom plate joining method of the present invention is the same as the bottom plate 6
The circular protrusion 8 for engagement, which is provided on the inner surface of the above, is aligned with the tip of the claw portion 7 of the opening 1a of the closing plate 2 and positioned.
Then, a brazing foil 9 is interposed between the inner surface of the plate 2 and the inner fin 3, and the brazing foil 9 is arranged so as to extend from the edge of the opening 1a toward the center side in the opening 1a. Therefore, when the wax foil 9 is melted, the edge of the opening 1a and the circular convex portion 8 are
Flows into the three arc-shaped gaps between the bottom plate 6 and
And reaches the outer edge of the bottom plate 6 and the outer surface of the opening 1a. Then, by solidifying it, the opening 1a can be liquid-tightly closed by the bottom plate 6, and the bottom plate 6 can be joined to the outer surface of the closing plate 2. Therefore, a separate brazing foil for joining the bottom plate 6 is not required. That is, according to this method, it is possible to reduce the number of parts for manufacturing the laminated heat exchanger, dramatically simplify the assembly, and improve the mass productivity.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic perspective view showing an assembling method of the laminated heat exchanger of the present invention, and FIG. 2 is a longitudinal sectional view of an essential part showing the assembled state. The laminated heat exchanger of this embodiment is mainly used as an oil cooler of an internal combustion engine, and its element 4 has a pair of plates 2a and 2b.
And the inner fin 3, the lean hosement 13 interposed between them, and the pair of brazing foils 9 interposed between them and the inner surface of each plate. Plate 2
Each of a and 2b is formed in an elongated dish shape, and communication holes 1 are formed at both ends in the longitudinal direction. At the hole edge of each communication hole 1, three claws 7 are provided 120 ° apart from each other and project toward the center side, and the claws 7 are bent to the outer surface side in an L shape. Then, the edge of the ring spacer 10 and the opening edge of the boss 5 are locked to the tip of the claw 7 bent outward. The diameters of the openings of the ring spacer 10 and the boss portion 5 are formed to be smaller than that of the communication hole 1, and their rims extend inside the hole edge of the communication hole 1.

In addition, the brazing foil 9 having a thickness of 0.01 or less (which is shown as being thicker than the actual one in FIG. 2 for the sake of convenience of illustration in FIG. 2) has its outer circumference substantially aligned with the inner circumference of each plate. At the same time, openings 12 are formed at both ends in the longitudinal direction. The inner diameter of the opening 12 is smaller than the inner diameter of the communication hole 1. Therefore, when the element 4 is assembled, the edge portion of the opening 12 of the brazing foil 9 extends from the hole edge portion of the communication hole 1 toward the center side. Due to such mutual relationship, when the wax foil at the edge of the opening 12 is melted, the communication hole 1
To the outer surface side of each plate, and the infiltrated brazing foil integrally joins each plate with the boss portion 5, the ring spacer 10 and the bottom plate 6 without any special brazing foil. A plurality of stages of elements 4 are stacked via a ring spacer 10, a bottom plate 6 is arranged at the lowermost end, and a boss portion 5 is arranged at the uppermost stage. The boss portion 5 has a pair of bolt holes into which the bolts
11 is inserted. A small recess 15 is provided on the lower surface of the boss 5 around the pair of openings. (Only one is shown) The small concave portion 15 and the small circular convex portion 14 projectingly provided on the uppermost surface of the uppermost stage are aligned to position the boss portion 5 on the plate 2a. The tip of the claw portion 7 is locked to the inner circumference of the center hole of the boss portion 5.

Further, the bottom plate 6 is formed in a disk shape, and a circular convex portion 8 is provided at the center thereof so as to project. The circular convex portion 8 is formed by press molding, and the outer peripheral edge of the circular convex portion 8 is aligned with the tip portion of the claw portion 7 provided in the opening 1a of the lowermost closing plate 2. Note that this embodiment is different from the conventional example in FIG. 3 in that all the brazing foils arranged on the outer surface side of each plate are eliminated. At the same time, a circular convex portion 8 is provided on the upper surface of the bottom plate 6 so as to project. Then, in the present invention, as shown in FIG. 2, each element 4 is laminated (the element 4 having only two stages is shown for simplification of the drawing), and the whole is held by an appropriate jig from above and below, and the high temperature Insert in the furnace. Then, the brazing foil 9 provided on the inner surface side of each plate is melted. Then, the molten brazing foil is applied to each plate, the inner fin 3 and the lean hosement 13
The part of the brazing foil 9 protruding from the hole edge part of the communication hole 1 is melted as it penetrates into the contact part with the bottom plate 6 due to the capillary action.
Into the contact area between the plate and the outer surface of the plate 2. At the same time, it also penetrates between the outer surfaces of the plates 2a and 2b and the ring spacer 10 and each contact portion of the boss portion 5. Then, by cooling the whole, the melted brazing foil is solidified and the contact portions are integrally brazed to complete the heat exchanger.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a bottom plate joining method of a laminated heat exchanger of the present invention.

FIG. 2 is an explanatory longitudinal sectional view of a main part of the laminated heat exchanger according to the same method.

FIG. 3 is a perspective view showing an assembly sequence of a conventional heat exchanger.

[Explanation of symbols]

 1 Communication Hole 1a Opening 2 Closure Plate 2a, 2b Plate 3 Inner Fin 4 Element 5 Boss 6 Bottom Plate 7 Claw 8 Circular Convexity 9, 9a-9d Wax Foil 10 Ring Spacer 11 Bolt 12 Opening 13 Lean Horsement 14 Small Circular Convex 15 Small recess

Claims (1)

[Claims] 1. A pair of elongated plate-like plates 2a, 2b each having a communication hole 1 formed at both ends thereof are superposed in opposite directions, and both sides of the inner fin 3 in the thickness direction are provided with the pair of plates 2a, 2b. An element 4 is formed by being joined to the inner surface of each of them, and a plurality of the elements 4 and 4 are laminated, and a boss portion 5 for entrance and exit is provided in the communication hole 1 of the outermost plate 2a in the laminating direction. In the bottom plate joining method of the laminated heat exchanger in which the bottom plate 6 is joined to the outer surface of the closing plate 2 having no communication hole located on the other outermost side, in the closing plate 2, an opening 1a is provided, and at the rim thereof,
A plurality of narrow claws 7 spaced apart from each other in the circumferential direction are provided so as to protrude toward the center of the opening 1a, and an engaging circular convex portion 8 is formed on the inner surface of the bottom plate 6, and the peripheral edge of the circular convex portion 8 is formed. Are aligned and locked to the tips of the plurality of claws 7, and prior to joining the inner surface of the closing plate 2 and the inner fins 3, a brazing foil 9 for joining is interposed between them and the opening is formed. 1a, the brazing foil 9 is arranged so as to extend from the edge of the opening 1a to the center side, and the brazing foil 9 is melted and then solidified so that the opening 1a is closed by the bottom plate 6 of the closing plate 2. A bottom plate joining method for a laminated heat exchanger, characterized in that it is liquid-tightly closed from the outer surface side.