JPH0157965B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a petal-shaped finned tube suitable for use in heat exchangers and the like.

As shown in FIGS. 1 and 2, the applicant previously proposed a mold rotating body 12 having a plurality of pins 26 annularly implanted on its side end surface, and at least two press molds 20a, 20b on its outer periphery. A molding device consisting of a pressing mold rotating body 11 equipped with
The material is formed into a wave shape by the pushing operation of a and 20b, and then the forming material is formed into the core tube P by intermittent rotation of the forming device and the core tube P and relative intermittent movement of the forming device in the core tube axial direction. We proposed a method for manufacturing petal-shaped finned tubes in which the tubes are wrapped and then heated and soldered.

However, there are other problems to be solved when putting the invention into practice. When the molded material is wound around the core tube P, the contact between the molded material and the core tube P is poor due to the springback phenomenon of the molded material, and subsequent soldering cannot be performed reliably.

This invention was made to solve these problems, and as shown in Figures 3 and 4,
The supporting position of the core tube P with respect to the mold rotating body 12 is
The axial center O ₁ of the hollow shaft 16 is adjusted so that it is slightly shifted from the axial center O of the hollow shaft 16 in the pushing direction of the pressing mold, and the amount of extrusion of both the pressing molds 20a and 20b is adjusted to the extent that it roughly contacts the outer periphery of the core tube P with the shifted amount. and adjust to the same amount.

Next, the tape material 1 unwound from the reel is wound around the pin 26, and its tip is clamped to the core tube P. In this state, the cylinder 19a presses the mold 20.
a downward, and align the tape-shaped material 1 on the pin 26 with the shaft center O.
Press and bend towards. Subsequently, the press die 20b is moved down by the cylinder 19b to release the tape-shaped material 1 as described above.
(See Figure 3).

When this operation is finished, the forming device and the core tube P are moved at the same angle (in the embodiment, 30°゜) in the same direction. At this time, even if the molding device is arranged with a misalignment with respect to the core tube P, the amount of rotation is small (30 degrees) and the core tube P is bent due to the pushing force of the press die. It can be rotated. Subsequently, the cylinders 19a and 19b are simultaneously moved upward to release the double press die 20.
a, 20b are pulled outward from the pin 26, returned to their original positions by the tensile force of the tension spring 22, and at this return position, the cylinder 19 is opened by the same operation as described above.
a, the press die 20a is pressed into the press die 2 in the previous process.
Hold the molded material by pushing it into the molded part formed by 0b. Subsequently, the cylinder 19b is operated to press down the unformed tape-like material with the press die 20b to form it. Thereafter, the molding operation is continued by repeating the above operations.

The inner end of the molded material formed in this way connects the axis O of the hollow shaft 16 and the molded inner end P'.
It is formed so that it lies on the inner end imaginary diameter a whose radius is P'. This inner end imaginary diameter a is smaller than the outer diameter D of the core tube P, as can be seen in FIG. are the outer diameter D of the core tube and the imaginary diameter a of the inner end of the molded material
It is expanded by the difference in radius, that is, D-d/2, and the contact with the core tube P is improved accordingly.

In addition, in the above explanation, misalignment of the core tube with respect to the axis of the hollow shaft is adjusted by adjusting the support device for the core tube, and the inner end virtual diameter of the molded material is made smaller than the outer diameter of the core tube. As mentioned above, this is possible without displacing the axis between the hollow shaft and the core tube.
During molding of the tape-like material, the core tube may be bent by the pressing force of the press die so that the inner end imaginary diameter of the molded material is smaller than the outer diameter of the core tube.

By employing the means described in detail above, it is possible to reliably perform soldering subsequent to the winding operation of the molding material, and the intended purpose of the invention can be reliably achieved.

[Brief explanation of drawings]

The drawings show an embodiment suitable for carrying out the present invention, in which Fig. 1 is a side sectional view of the molding device, Fig. 2 is a front view, and Figs. 3 and 4 are front views of main parts to explain the operation. Show the diagram. In the figure: 1... Tape-shaped material, 11... Push die rotating body, 12... Die rotating body, 19a, 19b
...Cylinder, 20a, 20b...Press die, 22
...Tension spring, 26...Pin, P...Core tube.

Claims (1)

[Claims] 1. A molding device consisting of a mold rotor having a plurality of pins annularly implanted on the side end surface and a press rotor having at least two press molds on its outer periphery is disposed around the core tube, Tape-like material wrapped around a pin,
Molding is performed by a pressing operation of a press mold, and then the molding material is wound around the core tube by intermittent rotation of the molding device and the core tube and intermittent movement of the molding device in the axial direction of the core tube, and then heated. A method for manufacturing a petal-shaped finned tube in which the tube is soldered to the core tube, characterized in that the imaginary diameter of the inner end of the molding material wound around the core tube is smaller than the outer diameter of the core tube. A method for manufacturing a petal-shaped finned tube.