JPS5919091A - Welding device - Google Patents

Abstract

PURPOSE:To perform automatically welding with high accuracy without the possibility of giving any adverse influence of welding on others by branching a laser beam to the same number as the number of plural blank material of quartz or the like, irradiating the same to the joining surfaces of said materials to be melt joined to each other and controlling the lasers in such a way as to weld the joining surfaces to each other. CONSTITUTION:An evacuation pipe G is set in a chuck 8b with both axial centers aligned to each other and a blank material E for a light transmission pipe is set in a chuck 8b with a small hole F and both axial centers aligned to each other, in the production of a light emitting pipe, for example, by welding the material E and the pipe G. The position of a driving member 20 and the diameter of a laser beam 26 from a device 25 are so adjusted and set that the beams 26a, 26b reflected by a mirror 19 are irradiated respectively to the periphery of the hole E and the end face of the pipe G. A control device 31 is then started to rotate both chucks in the same direction and at the same speed by a motor 11, thereby opening a shutter 27 and melting the joint surface parts. When the shutter 27 is closed and a linear moving device 22 is moved downward after a prescribed time, the mirror 19 moves downward and as movable bases 5a, 5b approach, the material E and the pipe G approach and the joining surfaces are joined by contact.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding device, and particularly to a welding device 6 suitable for melting and joining glass materials and quartz crystals together.

[Background technology of the invention]

For example, the arc tube of a high-pressure discharge lamp such as a mercury lamp or a metal halide lamp is usually a transparent tube made of quartz with a pair of electrodes placed facing each other, and a gas of a predetermined purity and a luminescent substance sealed therein. . In manufacturing such an arc tube, the following process is generally adopted. That is, as shown in FIG. 1(,), a pipe-shaped transparent tube E is prepared, and a small hole F is provided in the wall of this material E. Next, as shown in FIG. 4B, a small-diameter exhaust WG is welded to the outer surface of the moon E so as to communicate with the small hole F. Then, as shown in FIG. 3(c), with both ends of the material E softened by heating, a pair of electrodes H1 and Ib are inserted through the openings at both ends, and the ends are sealed. Hb is placed facing each other in the material E with a predetermined interval. Next, after exhausting the inside of the material E through the exhaust pipe G, a gas of a predetermined purity and the luminescent substance I are introduced into the material E through the exhaust pipe G again, and in this state, the root portion of the exhaust pipe G is sealed off. In this way, an arc tube J as shown in FIG. 2(b) is obtained.

When manufacturing the arc tube J of the discharge lamp through the steps described above, it is necessary to weld the exhaust pipe G to the transparent tube material E as described above. Conventionally, for this welding, a method has been adopted in which the joint surface of the exhaust pipe G and the joint side of the transparent tube material E are heated and melted using an oxyhydrogen flame, and the joint surfaces are welded together in this state.

[Problems with background technology]

In the method described above, in which the joint surfaces are heated and melted using an oxyhydrogen flame and then welded together, it is extremely difficult to reduce the diameter of the oxyhydrogen flame to a sufficiently small diameter. Easily softened by heating in partial shavings that do not require

As a result, the exhaust passage is significantly deformed, and the flow resistance of the exhaust passage differs for each welding operation. Therefore, a vacuum train with the same pumping performance in the pumping stage? When evacuation is performed using an arc tube, the quality of the evacuation varies from tube to tube, and as a result, it is difficult to manufacture multiple arc tubes with uniform performance.

In particular, in the case of a small arc tube, the exhaust pipe G needs to have a correspondingly small diameter, so the above-mentioned tendency is strong. Furthermore, since an oxyhydrogen flame is used as a heating source, there is a problem in that hydrogen in the flame dissolves into the quartz and diffuses into the discharge space during lighting, increasing the lighting starting voltage.

This also has a particularly large effect on small arc tubes.

Therefore, it has been difficult to manufacture arc tubes with superior performance using a welding method using an oxyhydrogen flame.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to automatically perform highly accurate welding without causing any adverse effects to others due to the welding.
For example, it is an object of the present invention to provide a welding device that is highly effective when applied to the process of manufacturing arc tubes of high-pressure discharge lamps.

[Summary of the Invention] According to the apparatus of the present invention, when a plurality of objects having joint surfaces to be joined to each other are gathered together along a plane perpendicular to the central axis and facing one central axis, they are not mutually connected to each other. A plurality of support mechanisms are provided to support each of the objects in a position that allows the joint surfaces to be brought into contact with each other. Still, a laser device is provided which sends out one Rade beam as a heating source, and the one laser beam sent out from the laser device is branched into the same number of objects as the objects, and each of the branched laser beams is split into two beams. An optical system is provided that irradiates the joint surfaces of the objects supported by the support mechanism to heat and melt each joint surface. Furthermore, there is provided a drive mechanism that collects all or part of the support mechanism along the plane and welds the joining surfaces of the objects together, and a control device that automatically controls the laser device and the drive mechanism.

〔Effect of the invention〕

As mentioned above, the apparatus of the present invention uses a laser beam as a heating source necessary for welding. It is easy to make the spot diameter of the laser beam sufficiently small using an optical method, and it is also easy to vary the diameter of the spot. Therefore, unlike when using an oxyhydrogen flame, it is possible to heat and melt only the parts of each object that truly require heating, the tabs, and each joint surface in a single and short time. It is possible to prevent shape deformation caused by heating and softening of unnecessary portions and occurrence of defects caused by this. Furthermore, since a laser beam is used as a heating source, it is possible to prevent impure gas from entering the heated object. Furthermore, one Rede beam is branched into multiple parts,
Since the branched laser beams are irradiated onto the joint surfaces of each object, each joint surface is heated and melted at the same time using a single laser device, making it possible to downsize the entire device and reduce the heating time. It is possible to prevent the occurrence of welding defects associated with. In addition, since each support mechanism is provided in the above-mentioned relationship and the drive mechanism that drives these support mechanisms and the laser device are controlled by a control device, everything from laser beam irradiation to welding completion can be completely automatically performed. can. Therefore, if this device is used in the arc tube manufacturing process, even in the case of small arc tubes, the transparent tube material and exhaust pipe can be welded automatically and with high precision without containing impurity gases. This can contribute to the mass production of high-quality, high-performance arc tubes. Of course, it can be used not only for manufacturing arc tubes but also for welding various parts.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. This embodiment is an example in which the present invention is applied to an apparatus for welding a transparent tube material and an exhaust pipe in an arc tube manufacturing process.

In FIG. 2, numeral 1 in the figure is a bed, and on the upper surface of the ped 1 in the figure, two shafts 2a and 2b (however, 2b is not shown) are parallel to the upper surface. arranged in orthogonal directions. And these Shan)
Both ends of j a + 2 b are supported by support members 3 m and 3, respectively.
Bed IK is fixed via b.

Movable tables 5m and 5b are mounted on the shafts 2a*2b via linear bearings 4* and 4b, respectively, so as to be movable in the left and right directions in the figure. Movable platform 5m
, 5b are each composed of a first pedestal 6a and a second pedestal 6b mounted thereon. A button is provided so that the relative position between the second stands 6@ and 6b in the left-right direction in the figure can be adjusted by a position adjustment mechanism 7.

Above the movable bases 5m and 5b in the figure, there is a cha, 8b, which supports the transparent tube material E and the exhaust pipe G shown in FIG.
are arranged opposite to each other and coaxially. Shanks 9m and 9b are coaxially connected to each chuck 8m and 8b, respectively, and these shanks F 9a * 9
b, which is located on the right side of the figure, is rotatably supported by bearing mechanisms 10a and 10b fixed to the second stand 6bK. The shaft 9b is connected to the rotating shaft of the motor 11. In addition, Shan)
! ? Gear 12 is fitted in each of a and 9blC,
These gears 12 mesh with each other via a rotational force transmission mechanism (not shown). Therefore, when the motor 11 rotates, the chucks 8a and 8b rotate synchronously in the same direction. Incidentally, the light-transmitting tube material E is actually supported via the auxiliary support 13 so that its axial center line is orthogonal to the axial center line of the chuck 8a.

Therefore, a force is applied between the opposing surfaces of the movable bases 5a and 5b in a direction that causes the movable bases 5a and 5b to approach each other.

For example, a coil spring 14 is tensioned. There is still a bar 15 between the opposing surfaces of each movable platform 5m and 5b.
a, 15b are protruding, and these par 15m, 1
At the tip of 5b, there is a roller 16a that is always in contact with a driving member 20, which will be described later.

16b is rotatably mounted.

On the other hand, between the transparent tube material E supported by the chucks 8a and 8b and the exhaust pipe G, there are two reflective surfaces 18* and 18b that share one ridgeline 17, as shown in an enlarged view in FIG. 90
A reflecting mirror 19 having an opening angle of 1.5 degrees connects the ridge line 17 to the chuck 8a.

The reflecting mirror 19 is arranged perpendicularly to the axis of the driving member 8b, and the reflecting mirror 19 is fixed to the upper end of the driving member 2o in the drawing. The old drive unit 20 has a movable platform of 5 m.

5b and a hole 2 provided in the ped 1, and is connected to a movable part of a linear motion device 22 such as a hydraulic piston that can be finely adjusted, and is selected by the linear motion device 22 in the direction shown by the solid line arrow 23 in the figure. movement is controlled. The thickness of the portion 24 of the driving member 20 facing the movable bases 5g and 5b in the horizontal direction in the figure is formed into a wedge shape that gradually becomes thinner as it approaches the upper direction in the figure. The rollers 16a and -16b are always in contact with both surfaces of the rollers 16a and -16b. Therefore, the linear motion device 22
When the driving member 20 is pushed upward in the figure, the movable base 5a,
The distance between the movable bases 5b becomes wider, and conversely, when the movable bases 5a and 5b are pushed down in the figure, the distance between the movable bases 5a and 5b becomes narrower.

The movable base 5h, 5 is made up of the pick, drive member 20, linear motion device 22, coil spring 14, rows 216m, 16b, etc.
b constitutes a drive mechanism that brings them closer and farther apart.

On the other hand, for example, a laser device 25 such as a carbon dioxide laser tube that selectively emits a laser beam is provided above the movable table 5a in the figure. 27, Reflector 2
8 so that the optical axis P thereof is perpendicular to and located on the ridge line 17 of the reflecting mirror 19 . Strictly speaking, in addition to the above conditions, the reflection mirror 19 is
As shown in FIG.
The beams are irradiated toward the reflection @19 in parallel with the axis 30 of b and traveling in directions 180 degrees different from each other.

The motor 11, the linear motion device 22, the laser device 25, and the shutter 27 are controlled by the control device 31 in the relationship described below.

Next, an example of use of the apparatus configured as described above will be explained.

First, the transparent tube material E is placed on the chuck 81L, and the exhaust pipe G is set on the chuck 8b. In this case, the exhaust pipe G
is automatically set so that its axial center line coincides with the axial center line of the chuck 8b, but the transparent tube material E is
The auxiliary support 1 is supported by the chuck 8a via
Adjust the supporting position of the chuck 3 so that the axial center line of the small hole F coincides with the axial center line of the chuck 8& as shown in FIG.

Next, by adjusting the position of the driving member 20 and the diameter of the laser beam 26 sent out from the laser device 25, as shown in FIG. The laser beam 2 is irradiated around the small hole F of the tube material E and is reflected at the reflective surface 18b.
6b is set so that the end face of the exhaust pipe G is irradiated.

This setting only needs to be performed once for the same type of transparent tube material and exhaust pipe.

After setting in this manner, the control device M31 is started. The control device 31 first connects the motor 11 to a power source. As a result, the motor 11 starts rotating, causing the chucks 8!L and 8b to rotate in the same direction and at the same speed. The exhaust pipe G also rotates around its axis.Then, the control device 31 then controls the laser device 2.
The shutter 27 is controlled to open.The operation of the laser device 25 causes the laser beam 826 to be
The laser beam 26 is emitted and is split into two by the reflecting surfaces 18a and 18b of the reflecting mirror 190, as shown in FIG. Then, one of the branched laser beams 26h
is applied to the periphery of the small hole F in the transparent tube material E, and the other laser beam 26b is applied to the end face of the exhaust pipe G. As mentioned above, since the transparent tube material E rotates around the axis of the small hole F, the peripheral area of the small hole F, that is, the joint surface where the exhaust pipe G is to be welded, is rapidly and uniformly welded. It is heated and melted. Similarly, since the exhaust pipe G rotates around its axis, the end face of the exhaust pipe G, that is, the joint surface where the transparent tube material E is to be welded, is rapidly and uniformly heated and melted. do.

Thus, when a predetermined period has elapsed from the point of irradiation of the laser beam 26, the control device 31 controls the shutter 27 to close 1"K and stops the operation of the busy laser device 25, and then 22 is given a command to move the driving member 20 downward in FIG. 2. When the linear motion device 22 is operated by the above command and the driving member 20 starts moving downward in FIG. The reflecting mirror 19 also escapes from the space between the transparent tube material E and the exhaust pipe G. Also, when the driving member 20 moves as described above, the portion of this member 20 that is in contact with the rollers 16a and 16b As the thickness of the tube element 24 gradually decreases, the movable bases 5a and 5b gradually approach each other, and accordingly, the transparent tube material E and the exhaust pipe G approach each other.Finally, the transparent tube material 1 'E's small hole F
The outer surface of the peripheral portion of the exhaust pipe G contacts the end surface of the exhaust pipe G. In other words,
The joint surfaces to be joined come into contact with each other. Since these bonding surfaces are melted as described above, both bonding surfaces are eventually bonded together. Then, when the drive member 2o is moved to a position where a predetermined coupling pressure can be obtained, the control device 3
1 is controlled to stop the operation of the linear motion device 22, and when the temperature of the above-mentioned joint part has sufficiently decreased, the motor 1 is stopped.
Stop 10 rotations. Therefore, at this point, the chuck 8a.

If the transparent tube material E and the exhaust pipe G are taken out integrally from 8b, the exhaust pipe G will be attached to the transparent tube material E as shown in Fig. 1(b).
This results in a strongly welded product.

In this case, depending on the thickness of the end surface of the exhaust pipe G, it is possible to uniformly heat only the above width in a short time according to the width 1 of the joining surface to be joined by twisting. , it's a size,
The solid joint surfaces can be heated and melted at the same time, and both joint surfaces can be automatically welded after heating.Moreover, in these processes, there is no element that dissolves impure gas into the heated object, so in the end , the above-mentioned effects can be obtained.

However, the present invention is not limited to the embodiments described above. That is, the above embodiment is applicable to welding a transparent tube material and an exhaust pipe, that is, to welding two objects to each other, but it can also be applied to welding three or more objects. In this case, the same number of support mechanisms such as chucks for supporting each object are required as the number of objects, and these support mechanisms are arranged as follows. In other words, when the objects supported by each support mechanism are grouped together along a plane orthogonal to the central axis, facing one central axis, the objects are in a relationship that allows the joining surfaces to be joined to each other to come into contact with each other. What is necessary is just to arrange each support mechanism.

As a reflecting mirror for branching one laser beam into a plurality of beams, a polygonal reflecting mirror that shares one vertex may be used. Further, it is not necessary to provide the entire support mechanism so that it can be moved. For example, in the embodiment shown in FIG. 2, it is sufficient that at least one of the chucks 81L and 8b is provided so that it can move forward and backward. Further, the present invention is not limited to use only for welding glass-based materials.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining an example of an arc tube manufacturing process, FIG. 2 is a diagram illustrating the configuration of a welding device according to an embodiment of the present invention,
FIG. 3 is an enlarged view of the main parts of the device. 1... Bed, 5 a, 5 b... Movable platform,
8a, 8b... Chuck, 11... Motor, 19.
...Reflecting mirror, 20...Drive unit, 22...Linear motion device, 25...Laser device, 31...Control device.

Claims (4)

[Claims] (1) When a plurality of objects having joint surfaces to be joined to each other are gathered along a plane perpendicular to the central axis and facing one central axis, the joint surfaces to be joined to each other are aligned. A plurality of support mechanisms that support each of the objects in a position where they can be brought into contact with each other, and a laser device that sends out one laser beam as a heating source. an optical system that splits the same number of laser beams into the joint surfaces of the objects supported by the support mechanisms to heat and melt the joint surfaces; or a drive mechanism that collects some of the objects along the plane and welds the joint surfaces of the respective objects together; and a control device that controls the laser device and the drive mechanism according to a predetermined program. Characteristic welding equipment. (2) The support mechanism is driven to rotate about an axis parallel to the branched laser beam at least during a period when the object is irradiated with the branched laser beam. A welding device according to claim 1, characterized in that: (3) The welding apparatus according to claim 1, wherein the optical system is a polygonal reflecting mirror that shares one apex or one ridgeline. (4) The optical system according to claim 1 or 2, wherein the optical system moves forward and backward with respect to a field where the objects gather in conjunction with the operation of the drive mechanism. Welding equipment.