JPS63123526A - Heat transfer tube - Google Patents

Abstract

PURPOSE:To prevent the trouble of an air conditioner caused by remaining burr cut off at the time of expanding a tube by rolling up a metal plate to a tube-like state and arranging a thin part at the side part of metal plate, so as to form a recessed part in the inner circumferential face of connected part of a heat transfer tube, continuously welding the connected part. CONSTITUTION:The metal plate 7, which the thickness at both end parts is thinned, is rolled up and both the end parts are brought into contact with face to face, to make it the tube-like state. Next, the connecting part 10 is continuously welded, to make the heat transfer tube 9. Then, the burr 11 is developed, but as the thickness at the constant length part from the connecting part 10 is thinned, the inner diameter only at this part is larger than that of the other part. Therefore, the end part of burr 11 is not projected to inner side from the inner face of heat transfer tube 8. And, at the time of using the heat transfer tube 9 as a heat exchanger for the air conditioner, the tube is expanded by using a jig, but the burr 11 existing in the connected part 10 is not projected to the inner face side, because of thin thickness at the inside of tube near the connected part, and the burr 11 is not cut off by the jig. As a result, the cause of trouble which the burr is remained in the heat exchanger, is not happened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to heat exchanger tubes used in heat exchangers.

Conventional technology Conventionally, this type of heat exchanger tube is manufactured by Nikkei Mechanical 1, for example.
9867-14 As shown in P54 to P57, it was as shown in Fig. 6.

That is, a single metal plate 1 shown in FIG. 4 is rolled up into a state as shown in FIG. 5, and then further rolled into a tubular shape as shown in FIG. 6. Then, the joint part 3 of the metal plate 1 is continuously welded to form a heat exchanger tube. It consists of

Problems to be Solved by the Invention However, in such a structure, burrs 4 occur at the joint portion 3.

When this heat exchanger tube is used as a heat exchanger for an air conditioner, a hole slightly thicker than the outside diameter of the heat exchanger tube is bored in the aluminum fan 5, as shown in FIG.

Stack them and insert the heat transfer tube (bent into a hairpin shape) into the hole of the fin 5 to form a bullet-shaped jig 6 as shown in Figure 8.
Expand the heat transfer tube 〇 using a holder and bring it into close contact with the fins 5. During this tube expansion process, the inner surface of the heat transfer tube is rubbed with the jig 6, so that the burr 4 at the joint portion 3 is scraped off. Therefore, the scraped burrs remain inside the heat exchanger. When an air conditioner is heated using such a heat exchanger, there is a problem that the burr 4 circulates together with the refrigerant in the refrigeration vehicle, causing the compressor to lock.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to provide a thin wall portion on the side of the metal plate so as to form a recess on the inner peripheral surface of the joint portion of the heat exchanger tube. It is something.

For production The effect of this technical means is as follows.

That is, by reducing the wall thickness of a certain portion from the joint of the heat exchanger tube, the inner diameter of that portion is larger than that of the pond portion. Therefore, there is no possibility that the tip of the burr produced during welding protrudes further inward than the inner surface of the heat exchanger tube.

As a result, even if the inner surface of the heat exchanger tube is rubbed during expansion with a bullet-shaped jig, the jig and the piers do not come into contact with each other, so there is no fear that the piers will be scraped off. Therefore, there is no worry that paris will remain in the heat exchanger and cause the air conditioner to malfunction.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. In Fig. 1, 7 is a metal plate, 9 is a heat exchanger tube body, and 10
is the joint part, and 11 is the crack that occurs when welding. Further, in FIG. 2, reference numeral 8 denotes a portion where the wall thickness is reduced at a certain portion from both ends of the metal plate 7 in the longitudinal direction.

Next, as for the mounting method, as shown in FIG. 2, a metal plate 7 with thinner walls at both ☆W edges is rolled up, and both end edges are brought together to form a tubular shape. Then, by continuously welding this joint portion 10, the heat exchanger tube is heated. At this time, Paris 11 occurs.

Next, the operation of the configuration of this embodiment will be explained. In the above manufacturing method, a paris 11 occurs during welding, but as shown in Figure 1, the wall thickness in a certain part from the joint part 10 is made thinner, so the inner diameter of that part is larger than other parts. It has become.

Therefore, the tip of the tube does not protrude further inward than the inner surface of the heat exchanger tube.

When this heat transfer tube is used as a heat exchanger for an air conditioner, the tube is expanded as described in the conventional example, but a jig 6 is inserted as shown in FIG. 3 to expand the tube. The jig 6 rubs the inner surface of the heat exchanger tube, but the jig 6 rubs the inner surface of the heat exchanger tube.
No. 1 has a thin wall around the joint, so it does not protrude toward the inner surface. Therefore, the parry 11 is not scraped by the jig 6.

As a result, there is no possibility of burrs remaining in the heat exchanger and causing damage to the air conditioner. In this embodiment, the thin wall portions are provided at both ends of the metal plate, but the thin wall portions may be provided at only one end.

Effects of the Invention As is clear from the above explanation, according to the present invention, the tip of the flare that occurs during welding does not protrude into the inner surface of the heat exchanger tube, so this heat exchanger tube can be used as a heat exchanger using an aluminum fan. When the tube is expanded during use, the piping is not scraped by the jig, and there is no need to worry about malfunction of the air conditioner due to the piping.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a heat exchanger tube according to an embodiment of the present invention, Fig. 2 is a manufacturing section 04 diagram showing a method of manufacturing a heat exchanger tube of the present invention, and Fig. 3 is a perspective view showing the state during tube expansion of the present invention. 4, 5, and 6 are perspective views of conventional heat exchanger tubes, FIG. 7 is a perspective view showing a method for manufacturing a heat exchanger, and FIG. 8 is a perspective view showing a method for expanding the tubes. 7...Metal plate, 8...Thin wall part,
... Heat exchanger tube, 10 ... Joint part. E-4 Nozuri V warehouse 10-m- with a stand p 1st Fig. 11-11 Noguso Fig. 3 n Otsu 7 Section 4 Fig. 5 Fig. 6

Claims (1)

[Claims] A heat exchanger tube made by rolling a metal plate into a tubular shape and continuously welding the joint portion thereof, the heat exchanger tube having a thin wall portion provided on the side of the metal plate so as to form a recess on the inner circumferential surface of the joint portion.