JPH09145280A - Fin tube heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a heat exchanging efficiency through vibration of movable fins by a method wherein a tube and some active fins are press fitted and connected to each other and the active fins are provided with a stress shielding part for preventing a stress acting when the tube is expanded from being transmitted. SOLUTION: A coupling between a tube 1 where thermal medium such as fluorocarbon, water or the like flows and some active fins 2 is carried out such that the tube 1 is inserted into fitting holes 2a with collars formed at a central part of each of the active fins 2, thereafter an inner circumferential surface of the tube 1 is scraped by a ball (a) to expand the tube 1, thereby the tube 1 and the active fins 2 are press fitted and coupled. Then, the active fins 2 are provided with a stress shielding part 2c comprising a recess or a bead for preventing a stress acting when the tube 1 is expanded from being transmitted to the movable fins 2b. With such an arrangement as above, a bad influence from the movable fins 2b is not applied and the heat exchanging efficiency can be improved by vibration of the movable fins 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fin-tube heat exchanger formed by connecting fins to a tube through which a heat medium flows.

[0002]

2. Description of the Related Art Heretofore, various types of devices have been known in which a piezoelectric material layer is laminated on fins or blades, and an AC voltage is applied to the piezoelectric material layers to vibrate the fins or blades for cooling and blowing air ( See JP-A-3-252157 and JP-B-6-56160). Also, in fin-tube heat exchangers, attempts have been made to improve the heat exchange efficiency by incorporating active fins having movable fin portions in which piezoelectric material layers are laminated, but the piezoelectric characteristics of piezoelectric materials are constant. If the above conditions are met, the active fin cannot be joined to the tube by a method involving heat treatment such as brazing. By the way, the tube expansion method is known as one of the methods for connecting the tubes and the fins in the fin-tube heat exchanger. The tube expansion method is a method of inserting the tube into the fitting hole formed in the fin, then expanding the tube and caulking the tube and the fin, but if the active fin is connected to the tube by the tube expansion method, the fin is expanded at the time of tube expansion. Deformation of the movable fin part occurs due to the stress acting on
The movable fin part may not vibrate well.

[0003]

In view of the above points, the present invention provides a fin-tube heat exchanger in which the active fins can be connected to the tubes without adversely affecting the movable fins. A second problem is to make it possible to easily adapt a fin-tube heat exchanger having no active fin to one having an active fin.

[0004]

In order to solve the above first problem, according to the first feature of the present invention, in a fin-tube heat exchanger in which fins are connected to tubes through which a heat medium flows, The fin is composed of an active fin having a movable fin portion in which a piezoelectric material layer is laminated, a fitting hole for a tube is formed in a fin portion of the active fin that does not form the movable fin portion, and the tube is inserted into the fitting hole. The tube is expanded in this state, the tube and the active fin are caulked and coupled, and the active fin is provided with a stress blocking portion that blocks the transmission of the stress acting on the expansion of the tube to the movable fin portion. . In this case, the stress blocking portion can be formed by a notch formed between the fitting hole and the movable fin portion, or a bead formed so as to surround the fitting hole. According to this configuration, since stress does not act on the movable fin portion when the tube is expanded, the movable fin portion is not adversely affected, and the heat exchange efficiency is improved by the vibration of the movable fin portion.

According to a second aspect of the present invention, in order to solve the above-mentioned second problem, a fin-tube heat exchanger in which fins are connected to tubes for flowing a heat medium,
A strip-shaped plate portion bent in a corrugated shape that extends between the fins connected to the tube by sewing up and down between the fins, and from each vertical side portion of the strip plate portion in parallel with each fin. An active fin having an extending movable fin portion in which a piezoelectric material layer is laminated is provided, and the active fin is coupled to each fin at upper and lower horizontal side portions of the strip plate portion. According to this structure, the movable fins are inserted between the fins connected to the tubes, and the wind force can be obtained by the vibrations of the fins. Can be easily adapted into a container.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIG. 1, reference numeral 1 is a tube through which a heat medium such as CFC or water flows, and a large number of fins 2 are connected to the tube 1 to form a fin-tube heat exchanger. doing. The tube 1 and the fin 2 are connected by inserting the tube 1 into a fitting hole 2a with a collar formed in the central portion of the fin 2 and then forming the ball a on the inner peripheral surface of the tube 1 as shown in FIG. This is performed by expanding the tube 1 by rigging and caulking the tube 1 and the fins 2 together.

In the heat exchanger, a gas for heat exchange (for example, air) is made to flow from the right side to the left side in FIG.
Is a total of 8 movable fins 2b formed by stacking piezoelectric material layers, three on the right side, three on the right side, three on the left side and two in the middle.
It is composed of individually formed active fins. Each movable fin portion 2b is formed in a cantilever shape having an end portion on the upstream side in the gas flow direction, that is, a right end portion as a fixed end, and a left end portion is formed by applying an AC voltage to the piezoelectric material layer. It vibrates as a movable end and separates the gas retention layer on the fin surface to improve heat exchange efficiency. The dotted portions in the figure are the laminated portions of the piezoelectric material layers.

Here, the upper and lower right three movable fin portions 2b and the middle upper and lower two movable fin portions 2b are separated from the fins 2 by slit-shaped notches 2c formed on the left side, the upper side and the lower side. Further, a slit-shaped notch 2c is also formed between the left side movable fin portion 2b and the fitting hole 2a, and thus the stress acting on the fin 2 when the tube 1 is expanded is It is absorbed by these notches 2c and is prevented from being transmitted to the movable fin portion 2b, so that the movable fin portion 2b is not adversely affected.

The number of movable fins 2b and notches 2c
The shape of is not limited to the embodiment shown in FIG. 3, and can be appropriately set as shown in FIGS. 4 (A) to 4 (C).

FIGS. 5 (A) and 5 (B) show another embodiment. In this embodiment, a bead 2d is formed annularly on the fin 2 so as to surround the fitting hole 2a and acts when the tube 1 is expanded. The stress is confined in the inner region of the bead 2d to prevent the stress from being transmitted to the movable fin portion 2b.

FIGS. 6 (A) and 6 (B) show another embodiment, in which the tube 20 has no movable fin portion.
The active fins 30 can be retrofitted to a normal fin-tube heat exchanger formed by coupling the above.

The active fin 30 includes a plurality of fins 2.
A strip-shaped plate portion 31 that is bent in a wave shape and extends between the fins 20 in a vertically sewn manner is provided. And a pair of upper and lower movable fin portions 32, 32 which are located in parallel with each other and extend in parallel with each fin 20. Movable fin 32
Are laminated with piezoelectric material layers and function as piezoelectric fins that vibrate by applying an AC voltage to the piezoelectric material layers and blow air between the fins 20.

The active fins 30 are joined to the respective fins 20 at the upper and lower horizontal side portions 31b of the strip plate portion 31, and this will be described in detail. The notch 20a is formed at the upper and lower sides of one side of each fin 20 while forming the stop portion 31c, and the upper notch 20a of one adjacent fin 20 and the lower notch 20a of the other fin 20 are formed. The engaging portions 31c of the upper lateral side portion 31b and the engaging portions 31c of the lower lateral side portion 31b are sequentially engaged with each other to temporarily fix the active fin 30 to the heat exchanger, and then each engaging portion. 31c is crimped and each side part 3
1b is connected to each fin 20, and the active fin 30 is fixed to the heat exchanger. Thus, the existing heat exchanger that requires a blower fan can be easily adapted to a self-supporting blower type heat exchanger.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a heat exchanger of the present invention.

FIG. 2 is a view showing a method of connecting a tube with a fin.

FIG. 3 is a front view of the active fin seen from the line III-III in FIG.

FIG. 4 is a front view of a modified example of (A), (B), and (C) active fins.

5A is a front view of still another modified example of the active fin, and FIG. 5B is an enlarged cross-sectional view taken along line BB of FIG. 5A.

FIG. 6A is a perspective view showing a second embodiment of the heat exchanger of the present invention, and FIG. 6B is a perspective view showing its disassembled state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 tube 2 active fin 2a fitting hole 2b movable fin portion 2c notch 2d bead 10 tube 20 fin 30 active fin 31 strip plate portion 31a vertical side portion 31b horizontal side portion 32 movable fin portion

Claims (4)

[Claims] 1. A fin-tube heat exchanger comprising fins connected to a tube through which a heat medium flows,
It is composed of an active fin having a movable fin portion in which piezoelectric material layers are laminated, a fitting hole for a tube is formed in the fin portion of the active fin that does not form the movable fin portion, and the tube is inserted in the fitting hole. Expand the tube and crimp the tube and active fin together,
A fin-tube heat exchanger, characterized in that the active fin is provided with a stress cutoff portion for preventing the stress acting when the tube is expanded from being transmitted to the movable fin portion. 2. The fin / tube heat exchanger according to claim 1, wherein the stress cutoff portion comprises a notch formed between the fitting hole and the movable fin portion. 3. The fin-tube heat exchanger according to claim 1, wherein the stress blocking portion is formed of a bead formed so as to surround the fitting hole. 4. A fin-tube heat exchanger formed by connecting fins to a tube for flowing a heat medium, the fins extending over the plurality of fins connected to the tube so as to sew vertically between the fins. A strip plate portion that is bent in a wave shape,
Extends from each vertical side of the strip plate parallel to each fin,
A fin-tube heat exchanger, characterized in that an active fin having a movable fin portion in which piezoelectric material layers are laminated is provided, and the active fin is coupled to each fin at upper and lower lateral sides of the strip plate portion.