JPS6245421A - Production of header for heat exchanger and the like - Google Patents

Abstract

PURPOSE:To increase the production efficiency of a header by placing the header material on which a prepared hole is pierced on a concave metal die and by interfacing the prepared hole with the concave hole thereof as well, then by subjecting the peripheral edge part of the prepared hole to plastic formation with the projecting part of a projecting metal die. CONSTITUTION:The convex metal die 3 providing the convex part 3a for forming a short pipe is prepared together with the concave metal die 2 having the concave hole 2a for forming a short pipe. A prepared hole 1a is pierced by machining on a header material 1 and interfaced with the concave hole 2a by placing it on the concave metal die 2. The short pipe 10 for tube connection is subjected to a plastic formation on the peripheral edge part of the prepared hole 1a via a press machine by inserting the convex metal die 3 providing the plural convex parts for forming into the header material 1. A heat exchanging tube (b) is connected with a fillet welding by forming the short pipe 10 thereof with its cutting. With this method the production efficiency of the header is increased and the fitting accuracy, etc. of the short pipe (b) are improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing headers used in heat exchangers and the like.

(Prior art) The header (1) of a heat exchanger connects a large number of heat exchange tubes (6) as shown in Fig. 3.4, and the heat exchange tube (b) is Since it is a low pressure specification and the plate thickness is thin, it is difficult to weld directly to the header (,). Fillet weld (d) the heat exchange tube (b) to the tube (6).
z) is connected.

(Problems with the Prior Art) The conventional header requires a beveling process for attaching the short pipe to the header, a welding process for attaching the short pipe to the header, and a welding process as described above, in order to connect the heat exchange tube. In the process of welding to prevent and eliminate distortion in pipe headers, and in the case of stainless steel materials, it is necessary to backshield with Ar gas to prevent oxidation during welding, making the manufacturing process extremely complicated and requiring a lot of work. There are problems such as the process is labor intensive, takes a long time, is expensive, and also causes variations in product accuracy and lacks reliability.

(Objective of the Invention, Means for Solving Problems) The present invention was developed to solve the above-mentioned problems. After aligning the pilot hole with the recessed hole, the circumferential edge of the pilot hole is placed on a concave mold with a recessed hole, and then the short tube forming convex part of the convex mold inserted into the header material is used to form a short tube. It is characterized by a structure in which a short pipe for tube connection is formed by plastic forming into the recessed hole by pressing, and the peripheral edge of the pilot hole drilled in the header material is formed into a recessed hole for forming the short pipe. By using a concave mold and a convex mold with a convex part for forming short tubes, the short tube for tube connection can be used as a header material easily, easily, and at high cost by plastically forming the short tube for tube connection using a press. It is an object of the present invention to provide a method for manufacturing a header for a heat exchanger, which can be efficiently attached in one piece, improves the accuracy and reliability of attaching short tubes for tube connection, and solves the above-mentioned problems.

(Example) Figure 1 (A) (Bl tc+) shows an example of the method of the present invention, in which (1) shows cutting to required dimensions and drilling a plurality of pilot holes (15) at desired positions. (2) is a concave mold having a plurality of concave holes (2a) for forming short tubes, (3)
is a convex mold having a plurality of convex parts (3 cL) for forming short tubes, and the concave mold (2) is for tube contact, short tube forming θ0
) with a cross-sectional shape corresponding to the outer diameter of the short tube forming hole (2
The support surface (2h
), and the convex mold (3) has a plurality of short tube forming convex portions (3 are arranged as shown in the figure) with a cross-sectional shape corresponding to the inner diameter of the short tube for tube connection. It has a presser surface (3b) having an arc-shaped cross section and a flat upper surface (3c)f corresponding to the inner surface of the header material (1), and is large enough to be freely inserted into the header material (1). The header member (1) is formed to have an appropriate length that protrudes from both sides of the header material (1), and is configured to be able to apply pressing force.

Next, we will explain the manufacturing method of protruding and molding the short pipes 0Q for tube connection onto the header material (1). IcL) is drilled, and the header material (1) is placed on a concave mold (2) with a plurality of short tube forming concave holes (2α), and the pilot hole (1cL) is inserted into the concave hole (1cL). 2a), insert a convex mold (3) with a plurality of short tube forming convex parts (3a) into the header material (11), and
Apply pressing force (p) to both protruding ends of 3) using an appropriate press machine.
Add l tp+ to each convex part (3a) of the convex mold (3)
Then insert the peripheral edge of each pilot hole (1) of the header material (1) into each recessed hole (2
a) Plastically mold the pipes by pressing into the tube to protrude each tube connection short pipe (1).

(Function) According to the conventional method, (a) beveling process for header, (
(b) Welding process for attaching the short pipe to the header, and (c) Strain prevention and strain relief process for the header. (c) In the case of stainless steel materials, pack shielding with Ar gas to prevent oxidation during bath welding. In contrast, the method of the present invention requires a step of drilling a pilot hole (1α) in the header material (1), a concave mold (2) with a concave hole (2 cL) for forming a short tube, and a short tube forming process. A pilot hole (short pipe α0 for tube connection) of the header material (1) is formed using a convex mold (3) for tube forming (by a plastic forming process by pressing the periphery of 11) into the header material. It is possible to protrude integrally from a large number of tube connection short tubes, and to simultaneously extrude and mold a large number of tube connection short tubes, and to perform molding in an extremely simple process and with high efficiency.
) are integrally protruded from the header material (1), and are successively formed thinner from the header material (1) as shown in the figure, and have an appropriate wall thickness relative to the heat exchange tube (6). In addition, there is no thermal stress caused by conventional welding (DL), and the attachment accuracy of each tube connection short tube 00) is improved, resulting in an excellent tube connection short tube with significantly improved reliability.

Each tube connection short tube formed by the above manufacturing method 0■
is used by shaping the tips by cutting or the like, and connecting each heat exchange tube (b) with fillet welding (d2) as shown in FIG.

(Effects of the Invention) As described above, the present invention provides a header material (1) in which a pilot hole (1a) is formed on a concave mold (2) with a concave hole (25) for forming a short tube. After aligning the pilot hole (1a) with the concave hole (2-resistant), insert the pilot hole (3a) into the short tube forming convex part (3a) of the convex mold (3) inserted into the header material (1). Since the peripheral edge of Ia) is plastically formed into the recessed hole (2G) and the short tube for tube connection 00) is provided protrudingly, the short tube for tube connection can be used as a header material easily and efficiently. This is an excellent header manufacturing method, as it can be attached in one piece, and the attachment accuracy and reliability of the short tube for tube connection are significantly improved.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

FIG. 1 [A] is a longitudinal sectional view showing the method of the present invention;
Bl is a cross-sectional view of Figure 1 (N), Figure 1 (C) is also an enlarged cross-sectional view, and Figure 2 is a partial cross-sectional view of the connection between the header and the heat exchange tube manufactured by the method of the present invention. The side view shown, FIG. 3 is a connection layout diagram of the header and heat exchange tube showing a conventional example, and FIG. 4 is an enlarged view of the main part of FIG. 3. 1: Header material 1 + z: Pilot hole 2 : Concave mold 2a: Concave hole for short pipe forming 3: Convex mold 3α: Convex part for short pipe forming Sub-agents 2 patent attorneys and non-Kaihon important scholars (B) ＼侃(C)

Claims (1)

[Claims] A header material with a pilot hole drilled therein is placed on a concave mold with a recessed hole for short tube forming, and the pilot hole is aligned with the recessed hole, and then a convex metal is inserted into the header material. A method for manufacturing a header for a heat exchanger, etc., characterized in that the peripheral edge of the prepared hole is plastically formed into the recessed hole by pressing with a short tube forming convex portion of a mold to protrude a short tube for connecting the tube. .