JP2003112222A - Method and die unit for manufacturing tube slot of header tank for heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a tube slot of a header tank for a heat exchanger, which enable press forming of the header tank for both parallel flow type and serpentine type, and also to provide the die unit for the manufacturing of the tube slot. SOLUTION: In forming the tube slot 303 of the header tank by press forming, at least two dies 51, 52 are used which hold in an surrounding manner the outer circumference of the hollow cylindrical pipe 30. One of the two dies is equipped with a slit 51b for putting through the punch 6 of the press. With the hollow cylindrical pipe held by the dies, the punch is inserted through the slit of the one die for the press forming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a tube slot, that is, a tube insertion hole of a header tank for a heat exchanger, and a mold device for manufacturing the tube slot.

[0002]

2. Description of the Related Art A radiator of an automobile and a heat exchanger such as a radiator and an evaporator in a refrigeration cycle form a core by alternately laminating a plurality of flat tubes and a plurality of corrugated fins to form a core. The end part of is inserted into the tank. The medium is taken in from the tank, exchanges heat with the heat transferred to the core, passes through the tube, and then is discharged from the tank to the outside.

In recent years, as a radiator for a refrigerating cycle, there has been known a radiator whose internal pressure exceeds a critical point of a medium (that is, a refrigerant) depending on use conditions such as temperature. For example, CO ₂ is used as a medium used in this type of heat exchanger.

A heat exchanger whose internal pressure exceeds the critical point of the medium requires extremely high pressure resistance strength as compared with an ordinary heat exchanger using a chlorofluorocarbon type medium. Therefore, it is necessary to reduce the volume of the tube and the header tank and increase their wall thickness.

When manufacturing a header tank for a heat exchanger,
Generally, a tube slot is formed in a plate-shaped material, and then the plate-shaped material is formed into a cylindrical shape by pressing or roll forming, or a pipe formed into a cylindrical shape by extrusion molding or drawing is pressed into a tube by pressing. Manufacturing methods for providing slots are known.

[0006]

By the way, the above-mentioned C
Since the header tank for the O ₂ cycle has a large wall thickness, it is necessary to devise a tube slot in the header tank.

That is, since a plate-shaped material formed into a cylindrical shape by roll forming is a thick material, the difference in length between the outer circumference and the inner circumference becomes too large, which is a problem in manufacturing.

Further, when it is attempted to form a tube slot in a hollow cylindrical pipe by pressing, the wall thickness is large as described above, and thus there has been a tendency to avoid press forming of the hollow cylindrical pipe in the past.

As a sub-optimal measure, there is a method in which the header tank is divided into two parts, and the portion to be pressed is made into a flat plate shape to facilitate the pressing. Since this method has a structure in which the respective members are overlapped with each other, there is a problem that a wasteful space and an increase in weight are caused at the mating portion.

Further, for example, Japanese Patent Laid-Open No. 11-226685.
As disclosed in Japanese Patent Laid-Open Publication No. 2000-242242, a method of forming a tube slot by cutting instead of press forming has been proposed.

However, in this method, since the processed shape is composed of straight lines and edges, the assembling property is poor, and further,
There is a problem that the cost rises as compared with press working.

Therefore, the inventors of the present invention have studied the improvement of the press forming method and apparatus based on the method of forming the tube slot by pressing.

That is, when the tube slot is formed by pressing, a die called a so-called insert type is inserted into the pipe so that the hollow cylindrical pipe is not crushed when the pressing load is increased due to its thick wall. Or
Alternatively, it is necessary to fill the inside of the pipe with a liquid and perform pressing so that the pipe is not deformed.

However, using the insert mold, CO ₂
When a thick hollow cylindrical pipe such as a header tank for a cycle is pressed, the clearance with the insert die is lost even if the pipe is slightly deformed, and the insert die cannot be removed.

In a serpentine type header tank, for example, when two long diameter tube slots are formed, when the hollow cylindrical pipe is deformed at the first hole of press forming, the second hole is formed. Even if you try to insert the insert mold into the pipe, it may not be possible.

On the other hand, the one in which the liquid is filled in the pipe is
Since it is necessary to prepare a liquid or a filling device for the liquid, there is a disadvantage that the pressing work becomes complicated.

The present invention relates to a method of manufacturing a tube slot for a header tank for a heat exchanger, which enables press forming of both parallel flow type and serpentine type header tanks without inserting an insert type into the pipe or filling the pipe with a liquid. It is an object of the present invention to provide a mold device for manufacturing the same.

[0018]

According to the present invention, in a method of forming a tube slot of a header tank by pressing, the header tank is a hollow cylindrical pipe, and at least the outer peripheral portion of the hollow cylindrical pipe is wrapped. Using two molds, one of the molds is provided with a slit through which a punch of a press is inserted, and after enclosing the hollow cylindrical pipe with the mold, one of the molds A method for manufacturing a tube slot of a header tank for a heat exchanger, wherein a tube slot is formed by inserting a punch into the slit and pressing the punch.

In the past, it was thought that hollow cylindrical pipes having a large wall thickness would not be suitable for pressing.
However, the present inventors hold or wrap a thick hollow cylindrical pipe so that the entire circumference of the outer peripheral portion of the pipe is wrapped with a plurality of molds, and the punch is driven from the slit of the mold having a slit. When well extruded, i.e. pressed, the tube slots could be accurately formed in the hollow cylindrical pipe.

As described above, at least two molds that surround the outer peripheral portion of the hollow cylindrical pipe are used, and one of the molds has a slit through which a punch of a press is inserted, After the cylindrical pipe was wrapped in the mold, a punch was inserted into the slit of the one mold and pressed, whereby a tube slot could be formed.

In this case, the die slit is provided in a direction orthogonal to the longitudinal direction of the die, and the slit is provided at a plurality of positions, that is, a tube slot of a header tank for a parallel flow type heat exchanger. Alternatively, both types can be manufactured in which the slit of the mold is provided at least at one position in the same direction as the longitudinal direction of the mold, that is, the tube slot of the header tank for the heat exchanger of the serpentine type.

Further, when actually manufactured, when the outer diameter L and the wall thickness t of the hollow cylindrical pipe are set, there is a relationship of 0.15 <(t / L) <0.3, It has been found that this is a tube slot manufacturing method with good molding quality and easy to manufacture.

When the header tank is for parallel flow, the lower limit is whether or not the pipe is deformed, and the upper limit is whether or not the scraps removed by the press are clogged in the pipe. It was confirmed that
The actual numerical value will be described in detail in a specific example described later.

On the other hand, in the case where the header tank is for serpentine and for high pressure, for example, a thick hollow cylindrical pipe for CO ₂ cycle, the flat tube is inserted into the tube slot, which is the tube slot of the insertion portion. It has been found that the above-mentioned relationship is required in terms of pressure resistance when the attachment point is used on the low pressure side and the high pressure side of the cycle.

Further, according to the present invention, in a mold device used for press-forming a tube slot of a header tank composed of a hollow cylindrical pipe, at least two molds for enclosing the outer peripheral portion of the hollow cylindrical pipe. And a punch forming the tube slot, one of the molds has a slit for inserting a punch of a press, and the hollow cylindrical pipe is wrapped with the mold,
A die device for manufacturing a tube slot of a header tank for a heat exchanger, which has a configuration of forming a tube slot by inserting a punch into the slit of the one die and pressing the punch.

In particular, the slit is provided at one location in the same direction as the longitudinal direction of the die, the punch is provided at a plurality of locations in the same direction as the longitudinal direction of the die, and the hollow cylindrical pipe is Enclosed with the mold, while pressing the punch through the slit of the one mold,
By further pressing at a position different from this pressing position to form one tube slot, the tube formation of the serpentine type header pipe can be easily formed by pressing.

The above-described method and apparatus of the present invention is suitable for a heat exchanger in which the pressure inside the heat exchanger exceeds the critical point of the medium.

Here, the critical point is the high temperature side limit (that is, the high pressure side limit) of the state in which the gas layer and the liquid layer coexist,
It is the end point on one side of the vapor pressure curve. The pressure, temperature, and density at the critical point are critical pressure, critical temperature, and critical density, respectively. It is known that when the pressure exceeds the critical point of the refrigerant inside the heat exchanger, the refrigerant is not condensed.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be described below in detail with reference to the drawings.

The heat exchanger 1 of this example shown in FIGS. 1 and 2 is
This is a radiator used in a refrigeration cycle for cooling the interior of an automobile. CO ₂ is used as the medium (that is, the refrigerant), and the pressure inside the heat exchanger 1 exceeds the critical point of the medium depending on the usage conditions such as the temperature.

The heat exchanger of this example has a flat tube 21.
0 and a corrugated fin 220 provided with a louver are alternately laminated, and a tank 300 into which the end of the tube 210 is inserted is provided. It is configured to perform heat exchange.

Side plates 400, which are reinforcing members, are provided on the upper and lower sides of the core 200, and both ends of each side plate 400 are supported by the tank 300.

Further, one tank 300 is provided with an inlet portion 310 for introducing the medium, and the other tank 300 is provided with an outlet portion 320 for discharging the medium. Each of the inlet portion 310 and the outlet portion 320 is configured by providing a hole portion at a main part of the tank 300 and providing a joint for connecting an external pipe in the hole portion.

The medium flows from the inlet 310 to one tank 3
00 is introduced into the inside of the tank 00, and after passing through the tube 210 while exchanging heat with the heat transmitted to the core 200, it is discharged to the outside from the outlet portion 320 of the other tank 300.
White arrows in FIG. 1 indicate the flow of the medium.

Each tank 300 is a tubular member whose both ends are closed, and each tube 210 has a flat shape having a plurality of small flow paths.

Each tube 210 has one end inserted in one tank 300 and the other end inserted in the other tank 300. As shown in FIG. 2, each tank 300 is provided with tube slots (insertion holes) 301 for inserting the ends of the tubes 210 at a predetermined pitch over the longitudinal direction.

Then, the tube 210, the fins 220,
The tank 300, the inlet portion 310, the outlet portion 320, and the side plate 400 are members made of aluminum or aluminum alloy, and are assembled together using a jig, and the assembly is heat treated in a furnace to be brazed. is doing. In addition, regarding such brazing, a brazing material and a flux are provided in advance at important points of each member.

FIGS. 3 and 4 show a mold device used for press forming the tube slot of the header tank.

The mold device 2 includes at least two molds 21 and 22 for enclosing the outer peripheral portion of the hollow cylindrical pipe 3.
Punches 4 and 4 forming the tube slot.

These molds 21 and 22 are combined to form a trapezoidal shape, and the pipe 3
Arc-shaped recesses 21a and 22a for accommodating the are formed. That is, when the pipe 3 is housed in the arcuate recesses 21a and 22a of the molds 21 and 22, the outer peripheral portion of the pipe 3 is wrapped by the arcuate recesses 21a and 22a and the pipe 3 is fixed.

One of the molds 21 is provided with slits 21b, 21b for inserting punches 4, 4 of the press.

In order to form the tube slot 301 with the molds 21 and 22 and the punches 4 and 4, the hollow cylindrical pipe 3 is wrapped with the molds 21 and 22, and one mold 21 is used. It is carried out by inserting the punch 4 into the slit 21b and pressing.

In this way, the hollow cylindrical pipe 3 is attached to the mold 2.
By enclosing with 1 and 22 and inserting the punch 4 into the slit 21b of the one mold 21 and pressing, the tube slot could be accurately formed in the hollow cylindrical pipe. For example, as shown in FIG. 5, when the pipe 4 is pressed by the punch 4 in the initial stage of the press (see FIG. 5 (1)), the tube slot is formed by this press. However, it is considered that the mold is enclosed by the molds 21 and 22 to prevent its deformation, and as a result, the tube slot is accurately formed (see FIG. 5 (2)).

When the header tank is for parallel flow and the outer diameter of the empty cylindrical pipe is 10 mm and the wall thickness is less than 1.5 mm, the tube slot is not formed well by the press and the pipe is not formed. It has been confirmed that there is a tendency for deformation to occur, and that if the wall thickness exceeds 3 mm, the scraps punched out by the press tend to become clogged in the pipe, which is not preferable.

That is, the outer diameter L of the hollow cylindrical pipe 3,
When the wall thickness is t, the relationship of 0.15 <(t / L) <0.3 was found to be good in molding quality and easy to manufacture when manufacturing the tube slot.

FIG. 6 shows a heat exchanger using a thick hollow cylindrical pipe as a header pipe for a serpentine. In this heat exchanger 10, an external pipe (not shown) is connected to an inlet side connector 11. Connected, this connector 11
Communicate with the header pipe 12, and further, tubes 13 and 14 are arranged in two directions from the header pipe 12, and each of the tubes 13 and 14 includes a header pipe 15 and a header pipe 16, respectively.
The header pipes 15 and 16 communicate with the connector 19 on the output side via the pipes 17 and 18. The medium flows out from the connector 19 on the output side to an external pipe (not shown).

Since the bidirectional tubes 13 and 14 are connected to the header pipe 12 connected to the inlet side connector 11, two tube slots are formed in one header pipe in the longitudinal direction.

FIG. 7 shows a thick hollow cylindrical pipe used as a header pipe of the internal heat exchanger 7 for exchanging heat between the high pressure side and the low pressure side of the refrigerant in the refrigeration cycle. The pipe of FIG. 7 has one tube slot.

The refrigerating cycle of the internal heat exchanger 7 will be described. As shown in FIG. 8, the refrigerating cycle 31 is for cooling the inside of a vehicle mounted on a vehicle and is a compressor for compressing a refrigerant. 32, a radiator 33 for cooling the refrigerant compressed by the compressor 32, a decompressor 34 for decompressing and expanding the refrigerant cooled by the radiator 33, and a decompressor 34.
An evaporator 35 for evaporating the refrigerant decompressed by
An accumulator 36 that separates the refrigerant flowing out from the gas layer into a gas layer and a liquid layer and sends the refrigerant in the gas layer to the compressor 32 is provided.

CO ₂ is used as the refrigerant, and the pressure inside the radiator 33 exceeds the critical point of the refrigerant depending on the operating conditions such as the temperature.

Regarding the present refrigeration cycle 31, the space between the radiator 33 and the pressure reducer 34 and the accumulator 3 are also provided.
A heat exchanger for exchanging heat between the high pressure side and the low pressure side of the refrigerant is provided between the compressor 6 and the compressor 32. This heat exchanger is the internal heat exchanger 7, which improves the efficiency of the refrigeration cycle 31 by exchanging heat between the high-pressure side refrigerant and the low-pressure side refrigerant.

The white arrow in the figure indicates the direction in which the high-pressure side refrigerant flows, and the black arrow indicates the direction in which the low-pressure side refrigerant flows.

Further, in FIG. 7, the internal heat exchanger 7 of this example is a tube body 71 in which an extruded tube is polymerized.
0 and each header pipe 723, 7 to which the tube is connected
33, 743, 753 and the pipe parts 722, 732, 742, 752 connected to these header pipes are assembled, and this assembly is heat-treated and brazed in a furnace.

The header pipes shown in FIGS. 6 and 7 will be described below by taking as an example a pipe having one tube slot formed in the pipe.

FIG. 9 shows a mold device used for press forming the tube slot of the header tank.

This mold device 5 comprises a hollow cylindrical pipe 30.
At least two molds 51, 52 for enclosing the outer peripheral portion of the
And punches 6, 6 forming the tube slot,
Equipped with.

The individual punches 6 and 6 are integrally formed on the lower end of the punch base 60 in a row direction.
However, a pressing device (not shown) performs a pressing operation in the vertical direction. Further, in this example, the punch table 60 is provided so as to be movable at a predetermined interval in the direction of the arrow. That is, after the punch table 60 has been pressed and moved up, the punch table 60 is moved in the longitudinal direction by a predetermined distance, and the next pressing operation can be performed at the moved position.

The molds 51 and 52 are combined to have a trapezoidal shape, and arc-shaped recesses 51a and 52a for accommodating the pipe 33 are formed at opposing portions. That is, the arc-shaped recess 5 of the molds 51 and 52.
When the pipe 30 is housed in the pipes 1a and 52a, the outer peripheral portion of the pipe 30 is held by the arcuate recesses 51a and 52a so that the pipe 30 is fixed.

One of the molds 51 has a slit 51b through which the punches 6 and 6 of the press are inserted.

In order to form the tube slot 303 with the molds 51 and 52 and the punches 6 and 6, the hollow cylindrical pipe 30 is wrapped by the molds 51 and 52, and one mold 51 is formed. The punch 6 is inserted into the slit 51b and pressed.

In this example, the slit 51b of the die 51 is provided at one location in the same direction as the longitudinal direction of the die. As described above, the punches 6 and 6 are provided at a plurality of positions in the same direction as the longitudinal direction of the mold. Then, the press wraps the hollow cylindrical pipe 30 in the molds 51 and 52, and
The punches 6 and 6 are inserted into the slit 51b of No. 1 and pressed. At this time, small slits 302, 302 are formed in the pipe 30, as shown in FIG.

Further, pressing is performed at a position different from this pressing position. That is, after the punch table 60 is pressed and lifted, the punch table 60 is moved in the longitudinal direction by a predetermined distance,
The next press operation is performed at the moved position. When the punch table 60 is moved by a predetermined distance and the next pressing is performed, the portion between the small slits 302 formed in the pipe 30 is pressed, and as a result, one tube slot 303 is formed as a whole. .

It is extremely difficult to press-form the tube slot of the long hole of the serpentine-type header pipe because it is usually performed by one-time press, but when it is pressed by the die apparatus of this example, the press-forming is performed a plurality of times. It can be easily formed.

Further, when the above-mentioned inequality, that is, the outer diameter L of the hollow cylindrical pipe and the wall thickness t are satisfied, the relationship of 0.15 <(t / L) <0.3 is also valid in this example. It is known to do.

That is, in the case where the header tank is for the serpentine and for the high pressure, for example, a thick hollow cylindrical pipe for the CO ₂ cycle in the internal heat exchanger (FIG. 7) shown in FIG. 7, the header on the high pressure side is used. The maximum tank pressure is 15MPa and the low pressure side header tank is maximum 10MPa. Considering these values, the brazing point of the tube slot, which is the insertion part where the flat tube is inserted into the tube slot, is It has been found that the above relationship is required in terms of pressure resistance strength when used on the low voltage side and when used on the high voltage side.

[0066]

As described above, according to the present invention, in the method of forming the tube slot of the header tank by pressing, the header tank is a hollow cylindrical pipe, and the outer peripheral portion of the hollow cylindrical pipe is wrapped. Using at least two molds, one of the molds,
A heat that forms a tube slot by providing a slit through which a punch of a press is inserted, enclosing the hollow cylindrical pipe with the mold, and then inserting the punch into the slit of the one mold and pressing the tube. It is a method for manufacturing a tube slot of a header tank for a exchanger.

According to such a manufacturing method, when the thick hollow cylindrical pipe is pressed, the tube slot can be accurately formed in the hollow cylindrical pipe.

When the outer diameter L and the wall thickness t of the hollow cylindrical pipe are set to 0.15 <(t / L) <0.3, good molding quality and easy manufacture can be obtained. A tube slot manufacturing method can be obtained.

Further, the present invention relates to a mold device used for press-forming a tube slot of a header tank composed of a hollow cylindrical pipe, wherein at least two molds for enclosing the outer peripheral portion of the hollow cylindrical pipe. And a punch forming the tube slot, one of the molds has a slit for inserting a punch of a press, and the hollow cylindrical pipe is wrapped with the mold,
A die device for manufacturing a tube slot of a header tank for a heat exchanger, which has a configuration of forming a tube slot by inserting a punch into the slit of the one die and pressing the punch.

In particular, the slit is provided at one location in the same direction as the longitudinal direction of the die, the punch is provided at a plurality of locations in the same direction as the longitudinal direction of the die, and the hollow cylindrical pipe is Enclosed with the mold, while pressing the punch through the slit of the one mold,
By further pressing at a position different from this pressing position to form one tube slot, the tube formation of the serpentine type header pipe can be easily formed by pressing.

As described above, the method and apparatus of the present invention are
The pressure inside the heat exchanger is suitable for heat exchangers above the critical point of the medium.

[Brief description of drawings]

FIG. 1 is a front view showing a heat exchanger according to a specific example of the present invention.

FIG. 2 is an exploded perspective view showing a main part of a heat exchanger according to a specific example of the present invention.

FIG. 3 is a perspective view showing a mold device according to a specific example of the present invention.

FIG. 4 is an exploded perspective view of a mold device according to a specific example of the present invention.

FIG. 5 is a cross-sectional view showing a pressed state of a pipe using a mold device according to a specific example of the present invention, wherein (1) is an initial stage of pressing and (2) is a state after pressing.

FIG. 6 is a front view showing a serpentine type heat exchanger according to a specific example of the present invention.

FIG. 7 is a perspective view showing an internal heat exchanger according to a specific example of the present invention.

FIG. 8 is a schematic diagram showing a refrigeration cycle according to a specific example of the present invention.

FIG. 9 is a perspective view showing a mold device according to a specific example of the present invention.

FIG. 10 is a perspective view showing a process of forming a tube slot in a header pipe for a serpentine according to an embodiment of the present invention.

[Explanation of symbols]

1 heat exchanger 2 Mold equipment 3 pipes 4 punch 5 Mold equipment 6 punches 7 Internal heat exchanger 10 heat exchanger 11 Input side connector 12 header pipe 13 tubes 14 tubes 15 header pipe 16 header pipe 17 Piping 18 piping 19 Output connector 19 21 mold 21a depression 21b slit 22 mold 22a depression 30 pipes 31 Refrigeration cycle 32 compressor 33 radiator 34 Pressure reducer 35 Evaporator 36 Accumulator 51 mold 51a depression 51b slit 52 mold 52a depression 60 punch table 200 cores 210 tubes 220 fins 300 tanks 301 tube slots 302 small slots 303 tube slot 310 Entrance 320 Exit 400 side plate t pipe wall thickness Outer diameter of L pipe

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hatsuko Kobayashi             39, Higashihara, Chiyo-ji, Konan-cho, Osato-gun, Saitama Prefecture               Zexel Valeo Climate Co., Ltd.             In control (72) Inventor Hideki Makino             39, Higashihara, Chiyo-ji, Konan-cho, Osato-gun, Saitama Prefecture               Zexel Valeo Climate Co., Ltd.             In control (72) Inventor Takafumi Umehara             39, Higashihara, Chiyo-ji, Konan-cho, Osato-gun, Saitama Prefecture               Zexel Valeo Climate Co., Ltd.             In control F-term (reference) 4E048 AB03 KA02 KA04

Claims (6)

[Claims] 1. A method for forming a tube slot of a header tank by a press, wherein the header tank is a hollow cylindrical pipe, and at least two molds for enclosing an outer peripheral portion of the hollow cylindrical pipe are used. Among the molds, one mold is provided with a slit for inserting a punch of a press, after enclosing the hollow cylindrical pipe with the mold, the punch is inserted into the slit of the one mold. A method for manufacturing a tube slot for a header tank for a heat exchanger, characterized in that the tube slot is formed by pressing. 2. The header tank for a heat exchanger according to claim 1, wherein the slit of the mold is provided in a direction orthogonal to the longitudinal direction of the mold, and the slit is provided at a plurality of positions. Tube slot manufacturing method. 3. The method for manufacturing a tube slot for a header tank for a heat exchanger according to claim 1, wherein the slit of the mold is provided at at least one location in the same direction as the longitudinal direction of the mold. 4. The outer diameter L and the wall thickness t of the hollow cylindrical pipe.
When it is set, it is 0.15 <(t / L) <0.3. The tube slot manufacturing method of the header tank for heat exchangers of Claim 2 or 3 characterized by the above-mentioned. 5. A mold device used for press-forming a tube slot of a header tank made of a hollow cylindrical pipe, comprising at least two molds for enclosing an outer peripheral portion of the hollow cylindrical pipe, and the tube. A punch forming a slot, and one of the molds has a slit through which a punch of a press is inserted, the hollow cylindrical pipe is wrapped in the mold, and one of the molds is formed. A die apparatus for producing a tube slot of a header tank for a heat exchanger, wherein a tube slot is formed by inserting a punch into the slit of the die and pressing the punch. 6. The slit is provided at one location in the same direction as the longitudinal direction of the die, and the punch is provided at a plurality of locations in the same direction as the longitudinal direction of the die, wherein the hollow cylindrical pipe is It is wrapped with the mold, and a punch is inserted into the slit of the one mold and pressed, and further pressed at a position different from this pressing position to form one tube slot. A mold apparatus for manufacturing a tube slot of a header tank for a heat exchanger according to claim 5.