JPH0741314B2 - Method for manufacturing cooling fins - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to cooling fins, and more particularly to a method of manufacturing cooling fins for attachment to the outer peripheral surface of a circular cross-section tube through which a fluid flows.

BACKGROUND OF THE INVENTION In order to cool the fluid flowing in a tube of circular cross section,
A cooling fin having a constant pitch is fixed to the outer peripheral surface of the tube. The fixing is usually performed by brazing a cooling fin to the outer peripheral surface of the pipe. In order to improve the cooling efficiency, it is desirable that there is no gap between the portion where the cooling fin is attached to the outer peripheral surface of the pipe and the outer peripheral surface of the pipe.

The simplest method for manufacturing cooling fins is to wind the strip around the mandrel so that the thickness direction of the strip forms a constant angle with the axial direction of the mandrel, and then wind the coil into a fixed length. This is a method of removing the shaped cooling fin from the mandrel.

Conventionally, as shown in FIG. 5, for winding the strip around the outer peripheral surface of the mandrel, one end of the strip is fixed to the mandrel by using a molding jig 230 that can freely rotate and slide with respect to the mandrel 220. This is done by rotating 220 to wind the strip around mandrel 220. The molding jig 230 has a spiral guide surface 232 with a fixed pitch of 2 to 3 turns to form a coil shape.
The strip is guided along the guide surface 232 of the molding jig 230. There is also a method of winding the strip around the mandrel using a so-called coiling machine.

Problems to be Solved by the Invention In the above conventional method, when a thick and narrow strip is used, the formed cooling fins for cooling do not have wrinkles or breaks as shown in FIG. Although it does not occur, the cooling efficiency of the cooling fin is reduced. When using a thin and wide strip to increase the cooling efficiency of the cooling fins, when winding the strip around the mandrel, the widthwise part of the strip close to the mandrel is compressed and the widthwise part far from the mandrel. Is stretched, and wrinkles and breaks as shown in FIG. 6 occur in the widthwise portion of the strip material wound around the mandrel, close to the mandrel.

In the wrinkled cooling fin, the inside diameter of the part to be attached to the pipe is not constant, and a gap is created between the part where the cooling fin is attached to the pipe and the outer peripheral surface of the pipe, which reduces the cooling efficiency of the cooling fin. Will be invited.

It is an object of the present invention to provide a method for manufacturing a cooling fin using a thin and wide strip material without generating wrinkles.

It is a further object of the present invention to provide a method for manufacturing a cooling fin that has high cooling efficiency and can be easily fixed to a pipe.

Means for solving the problem The purpose as described above is to form a continuous coil shape by winding the strip material on the outer peripheral surface of the round mandrel so that the thickness direction of the strip material is substantially parallel to the axial direction of the mandrel. In the method for manufacturing the cooling fins of 1., when the strip is wound around the outer peripheral surface of the mandrel, the inner side in the width direction of the strip is pressed by the adjoining strip and the pressing member already wound on the mandrel. It is achieved by providing a method characterized by applying an axial compressive force.

In order to wind the strip around the outer peripheral surface of the mandrel so that the thickness direction of the strip is substantially parallel to the axial direction of the mandrel, the thickness of the strip is passed through a guide hole having a cross-sectional shape approximately equal to that of the strip. The mandrel may be rotated while supplying the strip material onto the outer peripheral surface of the mandrel so that one of the two surfaces parallel to the vertical direction contacts the outer peripheral surface of the mandrel.

When winding the strip around the outer peripheral surface of the mandrel, in the widthwise inner portion of the strip, by the adjoining strip and the pressing member already wound around the mandrel, in order to apply a compressive force in the axial direction of the mandrel, A force may be applied to the pressure member in the direction of the adjacent strip already wound on the mandrel, for example by a suitable elastic means such as a spring or rubber.

This pressing member can be constituted by an annular ridge having a constant height formed in a portion of the guide surface near the outer peripheral surface of the mandrel, or from the portion of the guide surface farther than the outer peripheral surface of the mandrel. It can be constituted by a ridge that gradually rises to a portion close to the surface.

The cooling fin is obtained by winding a strip of a certain length around the mandrel, stopping the rotation of the mandrel, and removing the strip wound around the mandrel from the mandrel. The cooling fin has a continuous coil shape, and the fin is in contact with an adjacent fin. Insert the cooling fin into the tube,
The cooling fin is fixed to the pipe in a state where a force is applied to both ends of the cooling fin to give a constant pitch between the fins. The fixing can be done by conventional methods, for example by brazing.

A metal material such as steel, iron, aluminum or copper is suitable for the material of the band material used. The width and thickness of the strip depend on the required cooling efficiency of the cooling fins. The cross section of the strip can be any quadrilateral cross section such as rectangular or trapezoidal. The edges of the strip may be chamfered.

Effect According to the present invention, when the strip is wound around the outer peripheral surface of the mandrel, the axial compression of the mandrel is performed on the widthwise inner portion of the mandrel by the adjacent strip and the pressing member already wound on the mandrel. Apply force. Therefore, when wrinkles are likely to occur, the widthwise inner portion of the strip, which is the location where wrinkles are likely to occur, is pressed from both sides, and wrinkles are prevented from occurring.

Example Hereinafter, an example of a method for manufacturing a cooling fin of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a plan view of a cooling fin manufacturing apparatus 1 suitable for carrying out the method for manufacturing a cooling fin using the strip according to the present invention. The cooling fin manufacturing apparatus 1 includes a mandrel 20 around which the strip 10 is wound, a strip end fixing portion 24 provided on the outer peripheral surface of the strip 20 for fixing an end 10D of the strip, and a spring 22. And a guide jig assembly 30. Guide jig assembly 30
Is composed of a first guide jig 32 and a second guide jig 34. First
The guide jig 32 and the second guide jig 34 are bolts (not shown).
Are connected by. The mandrel 20 is the arrow 2 shown in FIG.
It can rotate in the 0'direction. The guide jig assembly 30 is fixed to a guide jig slide device (not shown) that can slide parallel to the axial direction of the mandrel 20. One end of the spring 22 is detachably attached to the guide jig slide device. The other end of the spring 22 is engaged with the first guide jig 32, and the spring 22 biases the guide jig assembly 30 toward the wound strip material 10. In FIG. 1, 10A is a mandrel 20.
10B is a strip that is being wound around the outer peripheral surface of the mandrel 20, 10C is a strip that is already wound around the mandrel 20 and is adjacent to the strip 10B, and 10D is a strip Represents the end of.

2 shows a guide jig assembly 30 along the line II-II in FIG.
FIG. 3 is a view of the belt member 10 and the belt member 10. First guide jig 32 and second
The engaging surface of the guide jig 34 of the strip 10 is supplied to the mandrel 20.
A guide hole 40 for guiding A is provided, and guide hole 4
The cross-sectional shape of 0 is almost equal to the cross-sectional shape of the strip 10A. As can be seen from FIG. 2, 2 parallel to the thickness direction of the strip 10A
The strip 10A is supplied to the outer peripheral surface of the mandrel 20 through the guide hole 40 so that one of the surfaces of the two strips contacts the outer peripheral surface of the mandrel 20. FIG. 3 shows the first guide jig 32 along the line of FIG.
FIG. 3 is a view taken along line III-III and with the strip 10 removed. The first guide jig 32 has a center hole 36 for passing the mandrel 20.
Is provided. On the surface 32A of the first guide jig 32,
A linear recess 42 forming the guide hole 40, a guide surface 44 following the recess 42, which is an annular recess concentric with the mandrel 20 and having a radius slightly larger than the sum of the width of the strip 10 and the radius of the mandrel, and Guide
An annular ridge 46 adjacent to the central hole 36 is provided in the inner portion of 44. The raised portion 46 constitutes a pressing member. The depth of the recess 42 and the guide surface 44 with respect to the surface other than the linear recess 42, the guide surface 44 and the raised portion 46 on the surface 32A of the first guide jig 32 is about half the thickness of the strip 10. . Guide surface 44
The height of the ridge 46 with respect to is preferably about 0.05-0.3 mm.

On the surface of the second guide jig 34 that engages with the first guide jig 32, a recess is provided at a portion facing the recess 42, and the guide hole 40 is formed together with the recess 42.

An example of a method for manufacturing fins using the strip material of the present invention using the cooling fin manufacturing apparatus 1 will be described with reference to FIGS.

With the mandrel 20 stationary, the end portion 10D of the strip that passes through the guide hole 40 is sandwiched between the strip end fixing portions 24 and fixed to the mandrel 20. The spring 22 is attached between the first guide jig 32 and the guide jig slide device, and the raised portion 46, which is the pressing member of the guide jig assembly 30, is urged toward the strip. Then move the mandrel 20 to the arrow 20 '
When the strip material 10A is supplied to the outer peripheral surface of the mandrel 20 through the guide hole 40 while rotating in the direction of, the strip material is wound around the outer peripheral surface of the mandrel 20. The urging force of the spring does not cause wrinkles on the strip 10 wound around the mandrel 20 and guides the surface of the strip 10 on the guide surface.
The urging force is adjusted so that scratches due to contact with the 44 and the raised portion 46 do not occur. This adjustment can be performed, for example, by changing the position of one end of the spring 22 attached to the guide jig slide device. The guide jig sliding device is moved in a direction away from the already wound band material 10C according to the number of wound band materials. Upon movement, the spring 22 keeps the ridge 46, which is a pressing member, forced in the direction of the adjacent strip already wound on the mandrel, whereby the widthwise inner portion of the strip 10B is already Adjacent strip 10C wrapped around a mandrel
A compressive force in the axial direction of the mandrel 20 is applied by and the raised portion 46 which is a pressing member. When the mandrel 20 is rotated to wind the strip 10 around the mandrel 20, in effect, the strip only contacts the guide holes 40 formed by the linear recesses 42 and the ridges 46 which are the pressing members. Guided, the strip 10 is wrapped around the mandrel 20. Once a band of a specified length is wrapped around the outer peripheral surface of the mandrel 20, stop the rotation of the mandrel 20, cut the band, and remove the band 10 from the mandrel 20 to complete the manufacture of the cooling fins. To do.

The end portion 10D of the strip is fixed to the mandrel 20, and the guide jig assembly 30 and the spring 22 are slid with respect to the mandrel 22 to provide a cooling fin manufacturing method using the strip of the present invention. Although described, it goes without saying that the guide fin assembly 30 and the spring 22 may be stationary, and the mandrel 20 may be slid to manufacture the cooling fin.

FIG. 4 shows a tube 52 fitted with a cooling fin 50. Insert cooling fin 50 into pipe 52 and then
Braze to 52.

Using the device shown in Figs. 1-3, width 8.0mm, thickness 0.4mm
A coil-shaped cooling fin having an inner diameter of 14.0 mm was manufactured using the SPCC strip material. The cross-sectional shape of the guide hole 40 is 8.5 mm × 0.45 m
It was m. The height of the raised portion 46 with respect to the guide surface 44 was 0.1 mm. Mandrel 20 diameter 13.95 mm, mandrel 20 rotation speed 300 rpm
And No wrinkles were found in the cooling fin strips produced as described above. The cooling fins had a uniform inner diameter.

Effect With the method for manufacturing a cooling fin of the present invention, a cooling fin having a uniform inner diameter can be manufactured and can be easily fixed to the outer peripheral surface of a pipe through which a fluid flows without any gap. or,
The materials used can be kept to a minimum.

When the cooling fins are manufactured using the strip material, wrinkles do not occur in the strip material, and the cooling efficiency of the cooling fins can be improved.

[Brief description of drawings]

FIG. 1 is a plan view of a cooling fin manufacturing apparatus suitable for manufacturing a cooling fin using the strip material of the present invention. 2 is a view of the apparatus of FIG. 1 taken along line II-II of FIG. FIG. 3 is a view of the first guide jig taken along the line III-III in FIG. 1 and with the strip material removed. FIG. 4 is a view in which a cooling fin manufactured from a strip material is attached to a pipe. FIG. 5 is a schematic view showing a conventional manufacturing apparatus for cooling fins using a strip material. FIG. 6 is a view showing wrinkles and breakage occurring in a cooling fin manufactured by a conventional cooling fin manufacturing apparatus using a strip material. 1 …… Cooling fin manufacturing equipment 10 …… Strip 20 …… Mandrel 22 …… Spring 30 …… Guide jig assembly 32 …… First guide jig 34 …… Second guide jig 40 …… Guide hole 44 …… Guide surface 46 …… Raised part 50 …… Cooling fin 52 …… Tube

Claims (1)

[Claims] 1. A strip (10) is continuously wound around the outer circumference of a round mandrel (20) so that the thickness direction of the strip (10) is substantially parallel to the axial direction of the mandrel (20). In the method for manufacturing the coil-shaped cooling fin (50), when the strip (10) is wound around the outer peripheral surface of the mandrel (20), it is already wrapped around the mandrel around the widthwise inner part of the strip (10B). A method of applying a compressive force in the axial direction of the mandrel (20) by the adjacent strip (10C) and the pressing member (46).