JP2001179839A - Method for welding tube and apparatus for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely weld arbitrary number of tubes and to obtain large welding strength. SOLUTION: Tubes 2 and 3 carried at the same speed are guided into a V-shape by means of guide rollers 8a, 8b, 9a and 9b and are pressed by means of the press rollers 9a and 9b from the outside to bring them into contact with each other under a condition where the facing parts are flat deformed. The contact faces of both tubes 2 and 3 are made thereby to be straight lines. These contact faces are irradiated with a laser beam 7 from a laser welding means 6. The spot shape of the laser beam 7 is controlled by means of a spot shape controlling mechanism 12 in such a way that the spot shape at a welding point is made to be a straight line coinciding with the direction of the contact faces of the both tubes 2 and 3. When both tubes 2 and 3 are welded like this, thereafter, the third tube 17 is welded by the similar method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for welding a tube made of synthetic resin using a laser, and more particularly to a method for welding a tube capable of obtaining a stable and high welding strength and a method therefor. Related to the device.

[0002]

2. Description of the Related Art In general, in a device using a fluid, it is often necessary to arrange a plurality of tubes made of synthetic resin in the device in a bundled state.

[0003] Therefore, conventionally, a method has been adopted in which tubes are tied to each other with tying tools arranged at predetermined intervals, or the tubes are connected to each other using an adhesive.

[0004]

However, in the above-mentioned conventional methods, the bundling operation or the connecting operation is not easy, and the tubes cannot be continuously bound in the axial direction.
Alternatively, there is a problem that stable connection strength cannot be obtained even if connection can be continuously performed in the axial direction.

The present invention has been made in view of the above situation, and provides a tube welding method and apparatus capable of easily welding tubes to each other and obtaining a stable welding strength over the entire axial direction. To be.

Another object of the present invention is to enable the tubes to be efficiently welded to each other to obtain a high welding strength.

It is still another object of the present invention to easily weld three or more tubes.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method in which one tube and the other tube to be welded are gradually brought closer to each other so that opposing portions are brought into contact with each other, and a contact portion between the two tubes is formed. A laser beam is irradiated in the axial direction from between the tubes, and the tubes are conveyed in the axial direction to weld the contact portions of the tubes. Since the laser beam is applied in the axial direction from between the tubes to perform welding, it is possible to easily and reliably weld the contact portions of both tubes, and to stabilize the entire axial direction. It is possible to obtain a high welding strength.

The present invention is further characterized in that the laser beam is irradiated in the form of a linear spot extending in the direction of the contact surface between the two tubes. Thus, it is possible to efficiently weld the contact portion between the two tubes, and it is possible to obtain a large welding strength.

The present invention is also characterized in that, as at least one of the one tube and the other tube, a post-weld tube to which another tube is previously welded is used. And this gives 3
More tubes can be easily welded.

[0011] The present invention also provides a guide mechanism for guiding one tube and the other tube conveyed in the axial direction so as to gradually approach each other; A contact mechanism for pressing the opposing portions into contact with each other; a laser welding means for irradiating a laser beam to a contact portion of both tubes from the entry side of the contact mechanism in a tube transport direction; A cooling mechanism for cooling the welded portion while the tube is transported for a predetermined distance in the contact state. As a result, it is possible to easily and reliably weld the contact portions of the two tubes, and it is possible to obtain stable welding strength over the entire area in the axial direction.

The present invention is also characterized in that the laser welding means is provided with a spot shape adjusting mechanism for making the spot shape of the laser beam straight in the direction of the contact surface between the two tubes. Thereby, the contact portion between the two tubes is welded in a wide range, and a large welding strength can be obtained.

The present invention further provides a guide mechanism, a contact mechanism,
A plurality of sets of the laser welding means and the cooling mechanism are arranged at intervals in the tube transport direction. This makes it possible to easily weld three or more tubes.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a tube welding device according to an embodiment of the present invention. The welding device 1 gradually brings one tube 2 and the other tube 3 conveyed at the same speed in the axial direction toward each other. Guide mechanism 4 for guiding
And a contact mechanism 5 for pressing the two tubes 2 and 3 approached from the outside and bringing the opposing portions into contact with each other. The welding is performed by a laser beam 7 emitted from the welding means 6.

The guide mechanism 4 is, as shown in FIG.
It comprises a pair of guide rollers 8a and 8b for holding one tube 2 from both sides and a pair of guide rollers 9a and 9b for holding the other tube 3 from both sides. It is guided in a V shape by the mechanism 4 and gradually approaches.

As shown in FIG. 1, a contact mechanism 5 located on the exit side of the guide mechanism 4 presses the tubes 2 and 3 from the outside to bring the opposing portions into contact with each other. As shown in FIG. 2, the two tubes 2 and 3 are brought into contact with each other in a state where the opposing portions are deformed flat as shown in FIG. 2 by pressurization by the two pressure rollers 10a and 10b. It has become.

On the other hand, as shown in FIG. 1, the laser welding means 6 comprises a laser oscillator 11 such as a CO ₂ laser.
And a spot shape adjusting mechanism 12 for adjusting the spot shape of the laser beam 7 from the laser oscillator 11.
As shown in Japanese Patent Application No. 0-138066, the laser beam 7 is formed by using a cylindrical lens or the like so that the laser beam 7 can be focused only in one direction to form a linear image.

As shown in FIG. 1, the laser welding means 6 is disposed between the two tubes 2 and 3 on the entry side of the contact mechanism 5, and the laser beam 7 is transmitted in the transport direction of the two tubes 2 and 3. The shape of the spot 13 at the welding point coincides with the direction of the contact surface of the tubes 2 and 3 at the position of the contact mechanism 5, as shown in FIG. As a result, the tubes 2 and 3 are welded to each other over a wide range, and a stable and high welding strength can be obtained.

At the exit side of the contact mechanism 5, as shown in FIG. 1, for example, two pairs of nipping rollers 14a, 14b,. A cooling mechanism 16 composed of 15a and 15b is provided, and the two tubes 2 and 3 welded by the laser welding means 6 are conveyed by the cooling mechanism 16 in a contact state for a predetermined distance. The welded portions of the tubes 2 and 3 are naturally cooled. Note that a forced cooling device such as a cooling fan may be incorporated in the cooling mechanism 16 to forcibly cool the welded portion. Thus, the welded portions of the tubes 2 and 3 can be cooled during a short transport distance.

At the outlet side of the cooling mechanism 16, as shown in FIG. 1, a second guide mechanism 18 for welding a third tube 17 to the tubes 2 and 3 after welding, A contact mechanism 19, a second laser welding means 20, and a second cooling mechanism 21 are provided, respectively, so that the three tubes 2, 3, 17 can be welded.

That is, as shown in FIG. 1, the second guide mechanism 18 has a pair of guide rollers 22a and 22b for holding the third tube 17 conveyed at the same speed as the two tubes 2 and 3 from both sides. The tubes 2, 3 and the third tube 17 after welding are connected to the guide rollers 22a, 22b and the holding roller 15 at the end on the exit side of the cooling mechanism 16.
By means of a and 15b, the guides are guided in a rectangular shape and gradually approach. That is, in the present embodiment, the holding rollers 15a, 15b at the end on the exit side of the cooling mechanism 16 are used.
Are also used as the second guide mechanism 18.

As shown in FIG. 1, the second contact mechanism 19 located on the exit side of the second guide mechanism 18 presses the welded tubes 2 and 3 and the third tube 17 from outside. It is constituted by a pair of pressure rollers 23a and 23b for bringing the opposed portions of the tube 3 and the third tube 17 into contact with each other, and the two tubes 3 and 17 are pressed by the pressure rollers 23a and 23b. As shown in FIG. 4, the contact portions come into contact with each other in a state where the facing portions are deformed flat.

On the other hand, as shown in FIG. 1, the second laser welding means 20 includes a laser oscillator 24 such as a CO ₂ laser and a spot shape adjusting mechanism for adjusting the spot shape of a laser beam 25 from the laser oscillator 24. 26, the spot shape adjusting mechanism 26 is configured using a cylindrical lens or the like, as in the case of the laser welding means 6, and condenses the laser beam 25 in only one direction to form a linear beam. You can image it.

As shown in FIG. 1, the second laser welding means 20 comprises two tubes 3, 3 on the side of the second contact mechanism 19.
17, the laser beam 25 is applied in the transport direction of the tubes 3 and 17, and the shape of the spot 27 at the welding point is shown in FIG.
As shown in the figure, the direction of the contact surface of both tubes 3 and 17 at the position of the second contact mechanism 19 coincides.
As a result, the tubes 3 and 17 are welded to each other over a wide range, so that a stable and high welding strength can be obtained.

At the exit position of the second contact mechanism 19, as shown in FIG. 1, for example, two pairs of clamping rollers 28a, 28b, 2 for clamping three tubes 2, 3, 17 from outside.
A second cooling mechanism 21 composed of 9a and 29b is provided, and the two tubes 3 and 17 welded by the second laser welding means 20 are kept in a contact state by the second cooling mechanism 21 for a predetermined distance. Conveyed, during which both tubes 3, 17
Is naturally cooled. Also in the case of the second cooling mechanism 21, a forced cooling device such as a cooling fan may be incorporated to forcibly cool the welded portion.

Next, the operation of the present embodiment will be described. When welding the tubes, first, one tube 2 and the other tube 3 conveyed in the axial direction at the same speed.
Are guided in a V-shape by the guide mechanism 4 and gradually approached, and the contact mechanism 5 presses both tubes 2 and 3 from outside to bring the opposing portions into contact with each other. As a result, the two tubes 2 and 3 come into contact with each other in a state where the facing portion is deformed flat as shown in FIG.

Then, the laser welding means 6 is started, and the contact portion between the tubes 2 and 3 is irradiated with the laser beam 7. As a result, the contact portions of the tubes 2 and 3 are welded, and the tubes 2 and 3 are conveyed and conveyed.
Are welded continuously in the axial direction.

The laser welding means 6 has a spot shape adjusting mechanism 12, and the laser beam 7 is focused only in one direction to form a linear image, and the shape of the spot 13 at the welding point is shown in FIG. As shown in the figure, the direction of the contact surface of the two tubes 2 and 3 at the position of the contact mechanism 5 matches. Therefore, the two tubes 2 and 3 are welded to each other over a wide range, and a stable and high welding strength can be obtained.

The tubes 2 and 3 welded at the position of the contact mechanism 5 are then sent to a cooling mechanism 16 where they are naturally cooled and the tubes 2 and 3 are completely welded by solidification of the welded portion.

The welded tubes 2 and 3 are fed into the second contact mechanism 19 together with the third tube 17 guided by the second guide mechanism 18, and the welded tubes 2 and 3 are fed.
3 and the third tube 17 are pressed from the outside by the second contact mechanism 19, and one of the tubes 2 and 3 after welding is pressed.
As shown in FIG. 4, the opposed portions of the three tubes 3 and the third tube 17 come into contact with each other in a state of being deformed flat.

The second laser welding means 20 is connected to this contact portion.
, And the two tubes 3 and 17 are welded as in the case of the laser welding means 6. Then, the welded portion is solidified by natural cooling in the second cooling mechanism 21, and the tubes 3 and 17 are completely welded.

Since the laser beams 7 and 25 are irradiated in the axial direction of the tubes 2, 3 and 17 to weld the contact portions, the two tubes 2, 3 and 3 are welded.
17 can be easily and reliably welded, and stable welding strength can be obtained over the entire axial direction.

The shape of the spots 13, 27 at the welding point of the laser beams 7, 25 is determined by the shape of the tubes 2, 3, and 3, 17 at the positions of the contact mechanisms 5, 19, respectively.
The contact portion can be welded over a wide range, and a large welding strength can be obtained.

In the above-described embodiment, the case where the third tube 17 is welded again after the two tubes 2 and 3 are welded has been described. However, only the two tubes 2 and 3 are welded. It may be welded, and conversely, 4
The same can be applied to welding of more than one tube.

In the above embodiment, each of the laser welding means 6 and 20 has a spot shape adjusting mechanism 12 or 2.
6 has been described so that the shapes of the spots 13 and 27 at the welding points are linear so as to coincide with the contact surface directions of the tubes 2, 3 and 3 and 17 at the positions of the contact mechanisms 5 and 19. However, even if it is a circular spot, by adjusting the spot diameter, the welding length in the contact surface direction at the contact portion can be adjusted. Therefore, the necessary welding strength may be ensured by such a method.

[0036]

As described above, according to the present invention, one tube to be welded and the other tube are gradually brought closer to each other so that the opposing portions come into contact with each other.
The laser beam is radiated in the axial direction from between the tubes, and the tubes are conveyed in the axial direction so that the contact portions of the tubes are welded. And the welding is performed, the contact portion between the two tubes can be easily and reliably welded, and a stable welding strength can be obtained over the entire area in the axial direction.

According to the present invention, the laser beam is irradiated in the form of a linear spot extending in the direction of the contact surface between the tubes, so that the contact portion between the tubes can be efficiently welded. Thus, a high welding strength can be obtained.

According to the present invention, as at least one of the one tube and the other tube, a post-weld tube in which another tube is welded in advance is used. It can be easily welded.

The present invention also provides a guide mechanism for guiding one tube and the other tube conveyed in the axial direction so as to gradually approach each other; A contact mechanism for pressing the opposing portions into contact with each other; a laser welding means for irradiating a laser beam to a contact portion of both tubes from the entry side of the contact mechanism in a tube transport direction; And a cooling mechanism for cooling the welded portion while the tube is transported for a predetermined distance in the contact state, so that the contact portion between both tubes can be easily and reliably welded, and the axial direction can be achieved. Stable welding strength can be obtained over the entire area.

According to the present invention, the laser welding means is provided with a spot shape adjusting mechanism for making the spot shape of the laser beam linear in the direction of the contact surface between the two tubes. And high welding strength can be obtained.

The present invention further provides a guide mechanism, a contact mechanism,
Since a plurality of sets of the laser welding means and the cooling mechanism are arranged at intervals in the tube transport direction,
More than one tube can be easily welded.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a tube welding device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a contact state of both tubes at a position of a contact mechanism, as viewed from a laser welding means side.

FIG. 3 is an explanatory diagram showing a relationship between a direction of a contact surface of both tubes and a spot shape of a laser beam at a welding point.

FIG. 4 is an explanatory diagram showing a contact state of two tubes at a position of a second contact mechanism as viewed from a second laser welding means side.

FIG. 5 is an explanatory diagram showing a relationship between a direction of a contact surface of two tubes and a spot shape of a laser at a welding point.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Welding apparatus 2 One tube 3 The other tube 4 Guide mechanism 5 Contact mechanism 6 Laser welding means 7, 25 Laser beam 8a, 8b, 9a, 9b, 22a, 22b Guide roller 10a, 10b, 23a, 23b Pressure roller 11 , 24 Laser oscillator 12, 26 Spot shape adjusting mechanism 13, 27 Spot 14a, 14b, 15a, 15b, 28a, 28b, 2
9a, 29b Nipping roller 16 Cooling mechanism 17 Third tube 18 Second guide mechanism 19 Second contact mechanism 20 Second laser welding means 21 Second cooling mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E068 AJ04 BG00 CB05 CD05 CE11 DA15 DB10 4F211 AD05 AD12 AD29 AG08 AG18 AK03 TA01 TC11 TD11 TH01 TH06 TJ13 TJ14 TJ16 TJ22 TN27 TQ03

Claims (6)

[Claims] 1. A tube to be welded and the other tube are gradually brought closer to each other so that opposing portions are brought into contact with each other.
A method for welding a tube, comprising: irradiating a laser beam in an axial direction from a space between both tubes to a contact portion between the tubes, and transporting the tubes in an axial direction to weld the contact portion between the tubes. 2. The method for welding a tube according to claim 1, wherein the laser beam is irradiated in the form of a linear spot in the direction of the contact surface between the two tubes. 3. The tube according to claim 1, wherein a post-weld tube to which another tube is previously welded is used as at least one of the one tube and the other tube. Welding method. 4. A guide mechanism for guiding one of the tubes and the other tube conveyed in the axial direction so as to gradually approach each other; a guide mechanism disposed on the exit side of the guide mechanism, and pressing both of the tubes from outside. A contact mechanism for bringing the opposing portions into contact with each other; a laser welding means for irradiating a laser beam in a transport direction of the tube from the entry side of the contact mechanism to a contact portion between the two tubes; A cooling mechanism for cooling the welded portion while transporting the welded portion for a predetermined distance in the contact state. 5. The tube welding apparatus according to claim 4, wherein the laser welding means has a spot shape adjusting mechanism for making the spot shape of the laser beam straight in the direction of the contact surface between the two tubes. . 6. The tube welding according to claim 4, wherein a plurality of guide mechanisms, contact mechanisms, laser welding means, and cooling mechanisms are arranged at intervals in the tube transport direction. apparatus.