JPS58158493A - Heat exchanger - Google Patents

Abstract

PURPOSE:To favorably transfer heat between pipes and fins and enhance heat- exchanging efficiency, by intermediately providing thermally conductive particulates at connecting parts, in a heat exchanger wherein a plurality of fins and pipes penetrating through hole parts of the fins are integrally connected to each other by a pipe-expanding operation. CONSTITUTION:The heat exchanger comprises the pipes 1 made of Al or the like and plate fins 2 made of Al or the like, each of the fins 2 is provided with the hole parts 2a for passing the pipe 1 therethrough, and a collar part 2b is provided at the peripheral edge of each of the hole parts 2a. In assembling the heat exchanger, metallic particulates 6 having a high thermal conductivity are first applied to the inside peripheral surface of the hole part 2a of each of the fins 2. Then, after passing the pipe 1 through a predetermined number of the fins 2, the pipe 1 is enlarged in the radial direction by an pipe-expanding tool, thereby pressure-welding the pipe 1 against the inside peripheral surfaces of the hole parts 2a of the fins 2 through the particulates 6 therebetween. Accordingly, the particulates 6 are packed at the pressure-welded surfaces between the pipe 1 and the fins 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type of heat exchanger in which a plurality of fins and a tube passing through a hole in the fin are integrally joined by tube expansion.

Recently, such types of heat exchangers are used in automotive radiators,
It is used in car heater cores, hot water radiators for air conditioning, etc., but the joining of the fins and tubes is often done by expanding the tube mechanically, so microscopically each fin and The contact surface with the tube is extremely small, and the majority of the contact surface between them is a gap of several microns due to the surface roughness of the fins and tube. This has the drawback of hindering heat transfer and reducing heat exchange efficiency.

The present invention obviates the disadvantages of the conventional heat exchangers mentioned above and provides a simple and convenient form of the heat exchanger.

Next, to explain the illustrated example of the present invention, this example is an example in which the heat exchanger of the present invention is applied to an automobile radiator,
In Figures 1 and 2, 1 is a tube made of lightweight metal with good heat conductivity, for example, Alsani Dumu), 2 is a plate fin made of aluminum, and hole 2 for inserting 1 tube.
The required number of holes a are provided in advance, and the holes 2a are larger than the outer diameter of the tube 1 by about 3 to 0.4 am. Furthermore, a collar portion 2b having a double-layered structure is formed at the periphery of the hole portion 2a of the plate fin 2. 3.4 is a tank made of resin, for example, a molded product of nylon resin containing glass fiber as a reinforcing material, and the upper resin tank 3 has an inlet pizo 3a,
The water injection robot 3be (mounting bracket for mounting on the vehicle body) 3c, etc. are integrally molded. In addition, the lower resin tank 4 is integrally molded with a protruding vib 4as, a mounting plate 4b for attaching to the vehicle body, and the like.

5 is a header solate made of aluminum and fixes the tube 1. In addition, tube 1, fin 2, header plate 5
The material used is aluminum, copper or an alloy thereof, specifically A1050°A! +003 aluminum or an alloy material with a layer containing Zn such as 728 on the aluminum surface is suitable, and the plate thickness of the fin 2 is 0.
．． Approximately 1 rm is preferable. In the heat exchanger having the above structure, engine cooling water flows into the upper tank 3 from the inlet pipe 3a, and from there the engine cooling water is distributed into each pipe 1, and while flowing through the pipes 1, the engine cooling water The cooling water is cooled by exchanging heat with the cooling air blown by a blower (not shown), and returns to the engine from the lower tank 4 and out from the piston 4a.When assembling the heat exchanger, first, each plate fin 2 is Fine metal powder 6 is applied to the inner peripheral surface of the hole 2a. The metal fine powder 6 is a granular or scale-like fine powder made of copper, brass, aluminum, or an alloy thereof with good thermal conductivity, and the size of each fine powder is determined by the size of the outer peripheral surface of the tube 1 and the plate fin. 2 hole 2 &
The surface roughness value of the inner peripheral surface is also smaller. The fine powder 6 is rubbed onto the inner circumferential surface of the hole 2a, or a paste containing the fine powder mixed in oil or the like is applied to the inner circumferential surface of the hole 211.

After placing a predetermined number of plate fins 2 through the tube 1 in this way, a tube expanding tool is passed through the tube 1 and the tube 1 is expanded in the radial direction, so that the tube 1 becomes a fine powder as shown in FIG. 6, the plate fin 20 is pressed against the inner peripheral surface of the hole 2a, and this pressure contact surface is filled with fine metal powder 6 to minimize the formation of voids. It is possible to improve heat transfer between and improve heat exchange efficiency.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of an example of a heat exchanger according to the present invention, FIG. 2 is an enlarged partial cross-sectional view of a portion of the heat exchanger in FIG. 1, and FIG. 3 is a portion of the heat exchanger in FIG. FIG. 1...Pipe 2...Plate fin 3
...metal fine powder representative Asamura Kogai 4 people

Claims (2)

[Claims] (1) In a type of heat exchanger in which a plurality of fins and a tube passing through the holes in the fins are integrally connected by tube expansion, the connection between the holes in the fins and the tubes A heat exchanger characterized by having thermally conductive fine powder interposed between the parts. (2) In the heat exchanger according to claim 1,
A heat exchanger characterized in that the thermally conductive fine powder has a shape smaller than a surface roughness value of a joining surface of the fins and the tubes.