JPH0742406U - Double tube heat exchanger - Google Patents

Abstract

(57) [Summary] [Purpose] As the shape of the inner fin is simple,
A double-tube heat exchanger that can be easily and inexpensively manufactured. A double-tube heat exchanger includes an aluminum inner tube 1 and an outer tube 2 which are coaxially arranged, and an aluminum inner fin 3 interposed between the tubes 1 and 2, A heat exchange medium circulation space 4 is formed between the tubes 1 and 2. The inner fin 3 is a disk-shaped fin, and a notch 3a for circulating the heat exchange medium is formed in a part of the disk surface. A predetermined number of inner fins 3 are arranged in parallel at a required interval, and the notches 3a of the inner fins 3 adjacent to each other are arranged 180 ° apart from each other in the circumferential direction of the inner pipe 1. It is easy to manufacture and has high heat exchange performance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a double-tube heat exchanger which is incorporated in a radiator of an automobile and is used as, for example, a cooler for cooling oil for an automatic transmission (auto transmission).

In this specification, aluminum means not only pure aluminum but also aluminum alloy.

[0003]

[Prior art]

 In recent years, due to the increase in mission load accompanying the higher output of automobile engines, there is a tendency that higher cooling performance is required even for coolers that cool the oil for automatic transmission. In addition, the so-called slant nose type, which increases the inclination of the front part of the vehicle, has been adopted as a recent trend of vehicle body design, and it is desired that the space in the engine room, especially the radiator space, be as small as possible. ing. For this reason, it is desired to maintain compactness and improve the performance of the automatic transmission as well.

In order to meet such a demand, a double-tube heat exchanger that has been conventionally incorporated in a tank portion of a radiator of an automobile to cool oil for an automatic transmission is shown in, for example, FIG. 6 (B). Thus, it is known that a so-called multi-entry fin (33) is interposed as an inner fin between the inner pipe (31) and the outer pipe (32).

[0005]

[Problems to be solved by the device]

 However, it is not easy to manufacture a double-tube heat exchanger having such multi-entry fins (33). That is, the double-tube heat exchanger is usually manufactured by pressing an aluminum brazing sheet into a predetermined shape, and then using a plate-shaped fin (34) having a large number of protrusions as shown in FIG. 6 (A). ) Is obtained, pre-bend processed, and wound on the outer surface of the inner pipe (31) to form a multi-entry fin (33). However, such work is not only labor-intensive, but the pre-bending process largely depends on experience, and only a skilled worker can perform the desired process. In addition, since the die for pressing has a complicated shape, it is expensive.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a double-tube heat exchanger that can be manufactured easily and inexpensively by using a simple inner fin shape.

[0007]

[Means for Solving the Problems]

 The double-tube heat exchanger according to the present invention has an aluminum inner tube and an outer tube coaxially arranged, and has an aluminum inner fin interposed between the two tubes, so that heat between the tubes can be reduced. In the double-tube heat exchanger used as the exchange medium circulation space, the inner fin is a disc-shaped fin, and a cutout for heat exchange medium circulation is formed on at least a part of the disc surface. The predetermined number of inner fins are arranged in parallel at a required interval, and the notches of adjacent inner fins are arranged so as to be offset from each other in the circumferential direction of the inner pipe.

In the present invention, a plurality of notches of the inner fin may be provided on the disc surface. Further, the disk surface of the inner fin may be provided with a required number of circulation holes for reducing the circulation resistance of the heat exchange medium. In the present invention, the notches of the inner fins adjacent to each other are arranged so as to be displaced from each other in the circumferential direction of the inner pipe, but are displaced from each other in the circumferential direction of the inner pipe by, for example, 180 ° or 90 °. It may be any one, such as those shifted by 45 °.

[0009]

[Action]

 According to the double-tube heat exchanger of the present invention, the inner fins are disk-shaped fins, and at least a part of the disk surface is formed with a cutout for heat exchange medium circulation. The inner fin itself is very easy to fabricate, and the work to place the inner fin on the inner pipe is also easy. Further, according to the double-tube heat exchanger of the present invention, a predetermined number of inner fins are arranged in parallel at a required interval, and the notches of the inner fins adjacent to each other are arranged in the inner pipe circumferential direction. Since the heat exchange medium is arranged so that the heat exchange medium is turbulent, the heat exchange performance is good.

[0010]

【Example】

 Next, an embodiment of the present invention will be specifically described with reference to FIGS.

In the following description, the upper and lower sides and the left and right sides are respectively referred to as the upper and lower sides in FIG. 1 and the left and right sides are respectively referred to as the left and right sides.

As shown in FIG. 1, a double-tube heat exchanger (10) according to the present invention comprises an aluminum inner tube (1), an outer tube (2), and both inner and outer tubes (1) ( It is equipped with aluminum disc-shaped inner fins (3) interposed between 2) and aluminum oil inlet / outlet pipes (5a) (5b), and heat exchange between both pipes (1) (2) It is used as a medium distribution space (4).

The inner pipe (1) is coaxially arranged inside the outer pipe (2), and aluminum brazing material is allowed to exist on the outer peripheral surfaces of the left and right ends of the inner pipe (1). Both ends are expanded respectively to form expanded parts (1a) (1a), and these expanded parts (1a) (1a) are joined to the inner surface of both ends of the outer pipe (2) through aluminum brazing material. ing.

The disc-shaped inner fin (3) has a shape as shown in FIG. That is, the diameter of the disc is equal to the inner diameter of the outer pipe (2), and a circular hole through which the inner pipe (1) is inserted is formed at the center of the disc surface. Then, a notch (3a) for circulating the heat exchange medium is formed in a part of the disc surface.

As shown in FIGS. 1 and 3, the predetermined number of disc-shaped inner fins (3) are arranged in parallel between the inner pipe (1) and the outer pipe (2) with a required space in the left-right direction. In addition, the notches (3a) of the inner fins (3) which are adjacent to each other are arranged 180 ° apart from each other in the circumferential direction of the inner pipe (1). That is, the cutouts (3a) are arranged so as to intersect with the upper, lower, upper, and lower of the inner pipe (1).

The double tube heat exchanger (10) can be easily manufactured. That is, for example, when the inner pipe (1) and the outer pipe (2) are each formed by processing a double-sided brazing sheet into a cylindrical shape, the disc-shaped inner fin (3) is used as described above for the inner pipe (1). After setting on the outer surface, both ends of the inner pipe (1) are expanded, the outer pipe (2) is attached to this, and brazing can be performed.

FIG. 4 shows a vehicle radiator (20) equipped with the double-tube heat exchanger (10) according to the present invention. The car radiator (20) is made of aluminum, which consists of the upper and lower headers (21) and (22) and a large number of water pipes (23) arranged in parallel between the headers (21) and (22). Consists of corrugated fins (24) interposed between water pipes (23).

In the lower header (22) of the radiator (20), the double-tube heat exchanger (10) according to the present invention is arranged. The oil inlet pipe (5a) and the oil outlet pipe (5b) of the double pipe heat exchanger (10) extend to the outside of the lower header (22).

The working oil for the automatic transmission enters the heat exchange medium distribution space (4) through the inlet pipe (5a) and, while passing through the distribution space (4), the lower part of the radiator (20). It is cooled by the cooling water in the header (22) and exits from the outlet pipe (5b).

According to the double-tube heat exchanger (10) having the above-mentioned configuration, the inner fin (3) is a disc-shaped fin, and the notch for circulating the heat exchange medium is formed in a part of the disc surface. Since the inner fins (3a) are formed, the inner fins (3) themselves are much easier to fabricate than the conventional inner fins having a complicated shape, and the inner fins (3) are arranged on the inner pipe. The work to do is also easy. Further, according to the double-tube heat exchanger (10), the inner fins (3) having a predetermined number of inner fins (3) adjacent to each other are arranged in parallel at predetermined intervals, and the notches ( Since 3a) is arranged so as to alternate between the upper pipe, the lower pipe, the upper pipe, and the lower pipe of the inner pipe (1), turbulent flow occurs in the flow of the heat exchange medium, and the heat exchange performance is good.

Next, a preferred modified example of the disc-shaped inner fin is shown in FIG. The inner fin (6) in FIG. 5 has a required number of heat exchange medium flow holes (7) in addition to the notch (6a) on the disc surface, and the inner pipe ( The circular hole into which 1) is to be inserted is formed by burring and has an annular convex portion (8) on the periphery of the hole on one side of the disc.

According to the double-tube heat exchanger in which the inner fin (6) having the above-mentioned structure is used instead of the inner fin (3), the fin (6) pitch can be changed depending on the height of the annular convex portion (8). Since the contact area between the inner fin (6) and the outer surface of the inner pipe (1) is increased, the fin (6) and the inner pipe (1) can be brazed more reliably. Furthermore, since the required number of circulation holes (7) for the heat exchange medium are provided, the circulation resistance of the heat exchange medium can be reduced even if the fins (6) are made fine.

[0023]

[Effect of device]

 According to the double-tube heat exchanger of the present invention, the inner fin itself is very simple to fabricate, and the work of arranging the inner fin on the inner tube is also easy, so that the double-tube heat exchanger is manufactured. Manufacturing cost is low. Further, according to the double-tube heat exchanger of the present invention, a turbulent flow occurs in the flow of the heat exchange medium, so that the heat exchange performance is excellent. Further, the heat radiation performance and the oil-side pressure loss can be finely set by the shape and area of the notch of the inner fin, the number of inner fins, and the like.

[Brief description of drawings]

FIG. 1 is a partially omitted vertical sectional view of a double-tube heat exchanger of the present invention.

FIG. 2 is a plan view of inner fins of the double-tube heat exchanger of the present invention.

FIG. 3 is a perspective view showing how the inner fins are arranged in the double-tube heat exchanger of the present invention.

FIG. 4 is a front view of a radiator including a double-tube heat exchanger of the present invention.

FIG. 5 is a perspective view showing a preferable modified example of the disc-shaped inner fin.

FIG. 6 shows an inner fin of a conventional double-tube heat exchanger, and (A) is a perspective view of a multi-entry fin before being set in an inner tube. (B) is a perspective view of the multi-entry fin set in the inner tube.

[Explanation of symbols]

 (1) ... Inner tube (2) ... Outer tube (3) ... Inner fin (3a) ... Notch (4) ... Heat exchange medium distribution space (6) ... Inner fin (6a) ... Notch (7) ... Heat Exchange medium flow hole (8) ... Annular protrusion

Claims (1)

[Scope of utility model registration request] 1. An inner pipe (1) and an outer pipe (2) made of aluminum
And (2) are coaxially arranged, and an aluminum inner fin (3) interposed between these two pipes (1) and (2) is provided.
In the double-tube heat exchanger in which the heat exchange medium circulation space (4) is provided between (2), the inner fins (3) are disc-shaped fins, and heat exchange is performed on at least a part of the disc surface. A cutout portion (3a) for medium distribution is formed, and a predetermined number of inner fins (3) are arranged in parallel at a required interval and adjacent to each other. (3a)
Are the inner tubes (1), which are arranged circumferentially offset from each other, 2
Heavy pipe heat exchanger.