JPS6025209B2 - How to punch a hole in a pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming holes in the side surface of a pipe, particularly a method suitable for forming holes in pipes made of aluminum, plastic, etc. used in pipe-on-sheet (POS) type evaporators in refrigerators, freezers, etc. It is about the method.

A POS type evaporator consists of a meandering medium pipe made of aluminum or the like fixed to one side of a sheet with adhesive or the like, and the cooling medium flows through the pipe in a two-phase gas-liquid state. It's supposed to flow.

However, in this structure, since the entire cooling medium passage is formed by one pipe, there are problems such as a decrease in cooling efficiency and an increase in flow resistance. Therefore, as an improvement, the following structure has already been proposed (Japanese Patent Application No. 56-1
33172).

In FIG. 1, which is a schematic exploded plan view, three passage units A, for example, are fixed to one side of an aluminum sheet 1 as described later. Sheet 1 is a material that is bent into a cylindrical body with a rectangular cross section as shown in Figure 2 after fixing unit A to form the wall of the cooling chamber, and unit A is attached to the side of sheet 1 opposite to cooling chamber 2. . 3 is the bottom wall of cooling chamber 2,
In FIG. 1, for example, the portion 4 within the section S forms the bottom wall 3.

The unit A includes a flat porous pipe 5 in the form of a plate and a pair of header pipes 6, 6'. The pipe 5 is made of an extruded aluminum material, for example, and can be relatively freely formed into any cross-sectional shape such as a rectangle or an ellipse. It's open. As shown in FIG. 3, the helder pipes 6, 6' used here have a notch hole 8 extending in the longitudinal direction in the pipe wall 7 thereof.

In the hole 8, pipes 5 are arranged in various positions as shown in FIGS. 4 to 8, and the cooling medium passage in the pipe 5 is closed into the pipes 6 and 6'. When the pipes 6 and 6' are made of plastic, the pipe 5 is fixed in an airtight state with adhesive, and when the pipe 5 is made of metal such as aluminum,
It is fixed in an airtight manner by brazing or pressing. In FIGS. 4 and 5, the hole 8 is provided at a position away from the sheet 1, and the center line ○-○ of the pipe 5 is aligned with the pipe 6, 6.
It passes through the center ○, of ′. In this case, in order to bring the pipe 5 into close contact with the sheet 1, either grooves are formed in the sheet 1 into which the pipes 6 and 6' partially fit, or a metal plate spacer is interposed between the pipe 5 and the sheet 1. , or it is necessary to bend the pipe 5 so that the pipes 6 and 6' come into contact with the sheet 5 as shown in FIG. Further, in FIGS. 7 and 8, the hole 8 is provided at a position shifted toward the Silito side, so that the pipe 5 fitted into the hole 8 can be brought into close contact with the sheet 1 over the entire surface. As a method for forming the notch holes 8 in the header pipes 6, 6', conventional press working has the problem that the pipes 6, 6' are crushed by the pressure during pressing, so a processing method using a milling machine is used. ing.

However, this method requires a lot of time and effort for processing, and is therefore unsuitable for mass production, and there has been a desire to develop a processing method suitable for mass production. In view of the above situation, the present invention aims to provide a method for punching holes in pipes that reduces the labor and time of processing and is suitable for mass production.
It is characterized by inserting a pipe into a core mold that has a recess on its outer surface, applying the pipe to the core mold around the recess, and thrusting the blade into the recess from the outside through the pipe.

FIG. 9 is a schematic perspective view of a punching device used in the pipe punching method according to the present invention. One end of the approximately cylindrical core mold 10 is fitted with iron into a hole 11a of the support member 11, and is fixed to the support member 11 with two bolts 11b and held horizontally. The part 10a of the core mold 10 that protrudes from the inner support member 11 has a part that passes through the center 02-Q of the core mold 10,
The longest hole (concave part on the outer surface) 12 that is long in the longitudinal direction of the core mold 10
is provided, and the elongated hole 12 passes through the core mold 10 in the vertical direction. Below the core mold 10, a lower mold 13 is disposed, in which a semicircular inner circumferential surface 13a having a radius slightly larger than the outer surface of the portion 10a is provided parallel to the core mold ID. , an upper mold 14 in which a semicircular inner peripheral surface 14a having the same radius as the inner peripheral surface 13a is provided as a center core and parallel to the mold 10;
is located. The upper die 14 is further provided with a hole 15 that penetrates vertically in the direction from the upper end of the inner peripheral surface 14a, and when the dies 10, 13, and 14 are set together, the elongated hole 12
The elongated hole 15 is arranged directly above the elongated hole 12 and along the elongated hole 12. A blade 16 that is slightly thinner than the long hole 12 and capable of passing through the holes 12 and 15 is arranged vertically above the long hole 15, and the blade 16a is slightly inclined in the longitudinal direction with respect to the horizontal direction. I do (shikar type). Next, a method for punching holes in a pipe according to the present invention will be explained using the above-mentioned apparatus.

First, the pipe 17 is inserted into the core mold 1 with the necessary play for drilling the hole, and the pipe 17 is sandwiched and fixed between the upper mold 14 and the lower mold 13 from both the upper and lower sides (FIG. 10). At this time, at least the upper end surface 10b of the core mold 10 around the closest hole 12 smoothly contacts the inner circumferential surface of the pipe 17 to support the pipe 17 from the inside. Next, the blade 16 is vertically lowered from above through the long hole 15, penetrates the pipe 17, and thrusts into the long hole 12 (FIG. 11). At this time, the removed material 18 accumulates at the lower end of the elongated hole 12. Also, the blade 1 is slightly smaller in size than the long hole 12.
6 is determined, the end of the notch 19 formed in the pipe 17 is slightly curled into the elongated hole 12 along with the blade 16 to form a burr 19a. Next, remove the blade 16 upward, remove the upper mold 14 and lower mold 13, float the pipe 17 upward from the core mold 10, and
After disengaging the burr 19a from the pipe 1
Pull out 7. The removal hole 18 is easily removed because the outermost hole 12 is a through hole. The pipe 17 having the cutout hole 19 formed in this manner is the same as the pipes 6 and 6' shown in FIG. 3, and can be used as a header pipe as shown in FIG. 1.

Moreover, as shown in FIG. 12, the notch hole 19 of the pipe 17
has a burr 19a that is curled inward, so when inserting the porous pipe 5 into the hole 19, the contact area of the notch hole 19 with the pipe 5 increases, which not only stabilizes the support of the pipe 5 but also makes it easier to insert it. They form an easy formation, making bonding work such as brazing easier. Long hole 12 penetrating in the vertical direction
Insert the pipe 17 with play in the center core type 1 extending horizontally; the center core type 10 around the long hole 12
Hold the pipe 17 from the outer circumferential side with half-split molds 13 and 14 having cylindrical inner peripheral surfaces so that the pipe 17 hits the hole 15 formed in the half-split molds 13 and 14 and the pipe 1
A cutout hole 19 having a burr 19a is formed in the pipe 17 by vertically lowering a blade 16 slightly smaller than the elongated hole 12 from above into the elongated hole 12 and thrusting it across the gap. After: Remove the blade 16 from the pipe 17 and remove the half-shaped molds 13 and 14; Next, lift the pipe 17 from the core mold 10 and remove the dovetail engagement of the burr 19a with the long hole 12, and then remove the pipe 17. It is characterized in that the core mold 10 is extracted; the scraps 18 are taken out from the lower end of the elongated hole 12; 'a- It is possible to easily and quickly transform the pipe 17 into a pipe 17 made of a soft material. Instead, a cutout hole 19 having a burr 19a can be provided.

Therefore, the pipe 1 having a cutout hole 19 with a burr 19a
7 can be mass-produced at low cost. A notch hole 19 with a burr 19a is made in the pipe 17 by inserting it slightly beyond the elongated hole 12 and lowering the blade 16 vertically into the hole 12 from above and inserting it across the gap. Since the structure of forming the notch hole 19 is adopted, the burr 19a can be formed at the same time as the notch hole 19 is formed in the pipe 17.

Therefore, a cutout hole 19 having a burr 19a in the pipe 17
The manufacturing process can be simplified. 'c} Core type 1 After inserting the pipe 17 with a gap and forming a notch hole 19 with a burr 19a in the pipe 17, lift the pipe 17 from the core type 10 and insert it into the elongated hole. The burr 19a adjacent to the burr 12 is removed and then punched out. Using a core die 10 which has a vertically extending hole 12 and extends horizontally, the scrap 18 is inserted into the lower end of the elongated hole 12. Since the pipe 17 having the burr 19a is removed using a device with an extremely simple structure,
The hole punching method has been implemented, and the long hole 1 can be drilled with an extremely simple configuration.
The scraps 18 inside 2 can be easily removed.

{d) Since the pipe 17 is inserted with some play into the core type 10 which has the largest hole 12 penetrating in the vertical direction and extends in the horizontal direction, when the pipe 17 is fitted, the elongated hole 12 is moved by gravity. The upper end peripheral portion touches the pipe 17, and the pipe 1
The location where the hole 19 of No. 7 is formed can be easily aligned with the long hole 12. Moreover, the cylindrical inner peripheral surfaces 13a and 14 are arranged so that the pipe 17 touches the center core 10 around the elongated hole 12.
Since the pipe 17 is held from the outer circumferential side by the half-split molds 13 and 14 having the shape a, even though the pipe 17 is inserted with some play in the core mold 10, the pipe 17
positioning can be performed accurately. Note that the use of the pipe 17 manufactured according to the present invention is not limited to use in an evaporator, but can be used in various other uses.

A large cutout hole 19, such as the cutout hole 8 shown in FIG.
In order to make a hole 19 in the pipe 17, after making a hole 19 in the pipe 17, rotate the pipe 17 a little, set it again, and cut off the pipe 17 again with the blade 16 so that it connects to the previously made hole 19. , insert the large notch hole 19 into the pipe 1
7 can be provided.

[Brief explanation of the drawing]

Figure 1 is a developed plan view of the evaporator, Figure 2 is a schematic perspective view of the evaporator after bending, Figure 3 is a side view of the header pipe, and Figure 4 is a side view of the header pipe.
Figures 8 through 8 are schematic longitudinal sectional front views showing how the header pipe is installed, Figure 9 is a schematic perspective view showing an example of a hole punching device for carrying out the method according to the present invention, and Figure 10 is a schematic diagram showing how the header pipe is attached to the hole punching device. Fig. 11 is a longitudinal sectional front view showing the state in which the pipe is set, Fig. 11 is a longitudinal sectional front view of the hole punching device showing the state in which a cutout hole is made in the pipe with a blade, and Fig. 12 shows the use and state of the pipe obtained by the present invention. FIG. 10...Central core type, 12...Concavity, 16...
...Blade, 17...Pipe. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. Insert the pipe 17 with some play into the core mold 10 which has a long hole 12 penetrating in the vertical direction and extends in the horizontal direction; , half-split molds 13 and 14 having a cylindrical inner circumferential surface.
Hold the pipe 17 from the outer circumferential side;
4 through the hole 15 formed in the long hole 12 and the pipe 17.
By vertically lowering a blade 16 slightly smaller than the size of the pipe 16 into the long hole 12 from above and inserting it across the gap, the pipe 1
After forming the notch hole 19 having the burr 19a at 7;
While removing the blade 16 from the pipe 17, the half-shaped mold 13,
14; Next, lift the pipe 17 from the core mold 10 and disengage the burr 19a from the elongated hole 12;
A method for punching a hole in a pipe, characterized in that the pipe 17 is pulled out from the core mold 10; and the punched waste 18 is taken out from the lower end of the elongated hole 12.