JPS6087921A - Welding method of spiral fin - Google Patents

Abstract

PURPOSE:To wind a spiral fin to a working allowance of a tube of a heat exchanger by working the tube in a state that a winding allowance is left on the tube and a welded spiral fin is pushed and contracted, and thereafter, expanding said fin end part to the working allowance, and welding it to the tube. CONSTITUTION:As shown in a figure (b), a solder cylinder-shaped fixed pinching jig 10 whose one end is closed up with semiannular plate 9 is pressed against a non-winding part 2b end of a spiral fin 2, and fixed in a state that the non- winding part 2b is pushed and contracted to a welded weld zone 2a side along a tube 1. Subsequently, in this state, various workings of the tube 1 end part side are executed. Thereafter, the jig 10 is removed, the pushed and contracted non-winding part 2b is returned to its original state, and it is welded to the tube 1, respectively, as shown in a figure C. In this way, the fin 2 is welded extending over the almost full length of a straight pipe part of the tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method capable of bath welding up to the machining allowance for a 7-piece tube.

As a manufacturing method for heat exchange passages that use all spiral fin tubes, such as those shown in Figures 1 (a), (b), and (c), the conventional method is known. ing.

The one shown in Fig. 1 (a) is called the stick pend method, in which a straight tube 1 is welded with a thread or an inlufin 2, and one end of the tube is bent into an iU shape (cane-like). The heat exchanger is made by welding together all of the heat exchangers.

In the figure, W is a welded part.

The one shown in Figure 1(b) is called the U-shaped tube system, in which spiral fins 2 are completely wrapped around a straight tube 1. ]l- A plurality of pipes are arranged in parallel and adjacent pipes are welded together using iU-shaped tubes 3.

The one shown in Fig. 1(c) is called a header system, in which spiral fins 2 are attached to a straight tube 1.
Both ends of the fully wound tube are welded to the nozzle 5 of the header 4.

By the way, in the above method, the bending allowance B at one end of the tube,
Processing allowances such as the processing allowance T required for spiral welding, chucking during groove processing, joint welding, etc., and the length K of the nozzle stub 5 are required, so snogible fins 2 are required for these parts.
It is not possible to wrap it completely. Therefore, in contrast to the straight pipe section on which the spiral fins 2 can be wound, the length of the part where the spiral fins 2 can be wound is actually shorter, and there are many bare pipe parts with poor heat transfer effects. It's gone.

If there are a lot of bare tube parts like this, is it a given ability? In order to obtain this, the heat exchanger must be made larger, which also increases the cost.

The present invention has been made in view of the two previous circumstances, and in heat exchangers that use spline fin tubes, spline fins can be used to reduce the machining cost of tubes, which previously could not be done with spiral fins. The purpose is to be able to wrap it.

The uninvented structure for achieving all of the above objects is that the length of the spiral fin including the machining allowance at the end of the tube can be wrapped around the tube, and at least the machining allowance can be secured when the end of the spiral fin is compressed. Weld the spiral fin to the tube, leaving some length, then completely shorten the end of the spiral fin, and then process the end of the tube in that state.Then, extend the shortened end of the spiral fin to the processing allowance and weld it to the tube. It is characterized by the following.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for connecting spiral fins according to the present invention will be explained in detail based on an embodiment shown in the drawings.

In the past, as mentioned earlier, processing allowance was left at the end of the tube, and spiral fins were added to the other parts. I was welding. Cane bend method? For example, as shown in FIG. 2(a), the processing allowance T required for welding and beveling at both ends of the tube 1, the radius chucking allowance t, and the bending allowance B.
? -The remaining parts were welded to the other parts. Of course, the spiral fin 2 is not welded to the part to be bent (the bend part b, its welding, and the processing allowance T required for groove processing).

On the other hand, in the present invention, as shown in FIG. 2(b), machining allowance (including machining allowance for the connected tube ends of Z- and h)? The straight pipe portion 11 of the tube 1 including the total length (Lmax)
Two spiral fins are welded over a period of time.

As mentioned above, is the spiral fin 2 the bent part of the tube 1? The straight pipe parts of the connected tubes are wrapped around the entire length and welded to the tube IK, as shown in Fig. 2 (a) when the end t of the spiral fin 2 is compressed. ) as shown in the processing allowance (T+
t) or the fin length that can secure B! ! :υ, machining allowance (T+t) or length equivalent to B and these machining allowances ('
T+t) or B can be done. Thickness P or Q' of spiral fin 2 reduced to c5 (r plus length 7, remaining part L' (
=L-(P+Q)) (hereinafter referred to as the welded portion 2a), and the other portions are not in contact and are left unwound (hereinafter referred to as the unwound portion 2b). To create the above state, start by winding two spiral fins in a spiral shape from the end of tube 1, and then welding (for example, resistance welding, arc welding) after about ('r+t+i') from the end of tube 1. etc.) Welding is performed over the entire length L', and then welding the spiral fin 2 completely over the distance (B + Q) to the end of the straight pipe section, or welding the spiral fin 2 over the entire length of the straight pipe section. After wrapping completely, attach (T + P ) or (
A possible method is to leave the entire empty winding part of length B+Q') and weld the other length L'. FIG. 3(a) shows an external appearance 7 of a part of the welded portion 2a and the empty wound portion 2b.

Next, as shown in FIG. 3(b), a semi-cylindrical solid leg clamping jig 10 whose one end is closed with a half-ring plate 9 is applied to the end of the free winding part 2b of the spiral fin 2, It is compressed along the tube 1 toward the empty winding portion 2b and the gold welding portion 2a, and is fixed in that state. In addition, there is a machining allowance (T) at one end of the tube.
+t) or B is ensured.10 Furthermore, when the empty winding part 2b is extended from the tube 1 to the other tube end connected to this tube 1, it cannot be wound at the same pitch as the welding part 2a, so Is the winding between the time and the pitch?
Narrow it and wrap it, then use a fixed clamping jig in the same way as above] o
Use everything to shrink it.

In this state, the machining of the tube 11': 2i section side is performed. In this embodiment, ZiA is welded to the pendant portion of another tube, and the other tube 41.1 is bent and welded to the other tube. After welding, the excess buildup at the bath contact portion is removed so that it is flush with the surface of the tube 1.

After this, the fixed clamping jig 107. The unrolled portions 2b' (5) which had been pressed and compressed are removed and returned to their original state, and each welded to the tube 1 as shown in FIG. 3(c).

As described above, the straight tube portion 1 of the tube 1 is welded with the pipe 4 inner fin 2 over almost the entire length. In addition, FIG. 4 shows a cross section of the boundary between the welded part 2a which is welded to the tube 1 from the beginning and the empty wound part 2b which is in bath contact after processing the end of the tube 1.

Although the above embodiment is applied to the method of manufacturing a stick head type heat exchanger according to the present invention, it is of course applicable to other U-shaped tube force type or header type heat exchangers. When applied to the U-shaped tube force type shown in Fig. 1(b), the spiral fin 2
is wound around the tube 1 for a length of L+2 (B0T) and compressed so that a machining allowance (B0T) is secured at both ends. Moreover, when applying the header method shown in FIG. 1(c), the spiral fin 2 is L+2(K+T
) and is compressed to ensure a machining allowance (K+T) at both ends. In other words, the machining allowance for extra winding of the extra viral fin 2 changes depending on the manufacturing method.

As explained above in detail based on the examples, according to the uninvented spiral fin welding method, it becomes possible to wrap the spiral fin up to the machining allowance of the tube of the heat converter. Miniaturization of exchangers,
A reduction in manufacturing costs can be achieved.

[Brief explanation of drawings]

Figures 1(a), (b), and (c) are explanatory diagrams showing the entire manufacturing method of the heat exchanger, Figure 2(a) is a schematic diagram showing the mounting state of conventional tubes and spiral fins, and Figure 2(b) ) is a schematic diagram showing the mounting state of the tube and spiral fin according to an embodiment of the present invention, Figures 3 (a), (b), and (c) are process explanatory diagrams of an embodiment of the present invention, and Figure 4 is a FIG. 3 is a cross-sectional view of a bath welding portion and a welded portion of a tube. In the drawings, 1 is a tube, 2 is a serpentine fin, 2a is a welded portion of the spiral fin, 2b is an empty winding portion of the spiral fin, and 10 is a fixed clamping jig. Patent applicant Sankazume Kokuri Co., Ltd. Sub-agent patent attorney Shibu Mitsuishi (and 1 other person)

Claims (1)

[Claims] Spiral fillet on the tube/Including machining allowance on the end of the tube? :, Weld the end of the spiral fin to the snowboard or radial finke tube, leaving enough length to ensure at least a machining allowance when the end of the spiral fin is completely retracted. This method of welding snow and round fins is characterized in that the end side of the tube is shortened and processed in that state, and then the shortened end of the straight round fin is extended to the processing allowance and welded to the tube.