MXPA99006894A - Multiple beam laser welding apparatus - Google Patents

Abstract

A laser welding apparatus for use in industrial processing, which is operable to emit laser energy to weld blanks and the like together along a seamline. The emitted laser energy comprises a multiple beam of two or more coherent light sources. The apparatus is adapted to selectively reposition the orientation of the multiple beam relative to the seamline to compensate for gaps between the abutting portions of the workpieces to be joined.

Description

MULTI-RAY LASER WELDING MACHINE. DESCRIPTION OF THE INVENTION: The present invention relates to a method and apparatus for laser welding * two or more fibers of sheet or sheet along a seam line, and more particularly, to an apparatus that adjusts the Intensity seal the laser beam energy on the seam line and / or welding time to compensate for variations in diatnce between the edges of the shapes to be joined. The manufacturing requirements of the present iracusp * -; emen "Ga r] ac * ee? T, an omation of several composi ons. A low-level welding by welding two or more forms of metal. More often, the laser has have been used to weld butt-edge portions of the sheet shapes to the length of seam lines in the formation of the workpiece components, and the laser has suffered the disadvantage that -J- -. -,? "U3C of lase forms requires that the edges of the sheet form be pre-finishedE:, ** tspgEn a smooth acs.bs.dc is ado. The requirements for the preparation of the edge of form have been on a large scale responsible for the reluctance of the induatria? to adapt the use of the laser welding apparatus in the continuous welding process used to form sheets.

Conventional laser apparatuses have suffered from the disadvantage that in order to ensure the formation of a complete weld and to prevent welding seams at the top having concavity, it is necessary to ensure the precise contact between the leading edges of the sheet forms. Metals along the entire length of the weld srur. The need to maintain the sheet shapes in a precise contact during the welding reacts disadvantageously in an increase of the production time of the work piece as a result of the need to ensure that the strands are in an exact position of the front cup. l welding. The ínver.tcr has prepared improved apparatus for the butt welding of metallic eye shapes that incorpor ur. yttrium aluminum garnet laser (YAC). and has presented the operation of that paragraph in the Canadian patent application series 2, 167. lil filed on January 14, 1936. The use of a YAG laser to weld the sheets has been found advantageous to produce seams of soldadur without a concave welding profile where there is space of up to 0.1 ¡pm between the leaf shapes. However, the applicant has appreciated that providing an apparatus that can efficiently weld to top sheet shapes that are separated by larger spaces would facilitate the production of work pieces by requiring a less demanding placement and not a finish of the edge of the sheet. sheet shapes before welding. This, in turn, would decrease the production time and reduce the manufacturing cost of the sheet form. To at least partially disregard the disadvantages of the prior art, the present invention provides a welding apparatus for use in industrial processing, an apparatus that operates by emitting a beam of energy or an ion beam (hereinafter referred to collectively as energy beam), to weld similar shapes along a seam line. The beam of energy used to weld the shapes preferably consists of a multiple beam of two or more coherent light sources. The apparatus includes a mechanism for selectively adjusting the orientation of the multiple beam with respect to the seam line. Another object of the invention is to provide an apparatus for the top and bottom of portions close to two or more blade shapes that are separated by a blade. or more. The purpose of the invention is to produce two or more sheet shapes, without requiring the edge portions of the forms to be pre-finished. Still another object of the invention is to provide an apparatus for joining together forms of work to form a composite work piece., - and that does not require an alignment and precise placement of the forms before the union .. Another object of the invention is to provide an apparatus for welding adjacent edge portions of the sheet forms having relatively different thicknesses. Still another object of the invention is to provide an apparatus for a butt laser ballast of two or more sheet shapes along a seam line, and to automatically sense the distance between the proximal edges of the sheets and to compensate. be the speed and / or the placement and / or the power of the energy to ensure the formation of an effective welding seam through the next portion. Another object of the invention is to provide a laser welding apparatus adapted to weld portions of bord proximate to the metal foil shapes along d-seams. welding that are straight, non-linear curves. To achieve at least one of the above objects, the present invention includes a welding apparatus for welding adjacent edge portions of two more blade shapes. The welding apparatus is configured to emit a multiple energy beam or composite qu c-onsits of two, three or more energy beams. Preferentially the energy rays are laser beams or coherent sources, used to weld the sheet shapes together along a seam line, however the use of the invention with other energy rays such as electron ion beams is also It is possible and will work in a similar manner. The coherent light sources or laser rays forming the composite beam are focused towards a portion of the shapes to be welded in a respective focal area. The f: norcaai! Pe-Fs. rcíee poop one ie? ae rayes íiaflepeyi t enen centro • .ptiro where centers ¡PiiC S de menoão GGS of ios rayes .ase2 this is i * v ~ ± v i mer * ray and the second laser beam) that form the composite beam, moves together from the other. The optic centers displaced from the first beam or beam will be struck by lightning or light with a power of intensity of intensity a? orientation of the centers - optical. These optical centers can be said to define each end of the focal line of elongation of the composite beam. The beam composed of laser energy is emitted from a laser head that is movable on the shapes of the workpiece. The apparatus also includes mechanisms for varying the intensity per unit area of the composite beam. For example, the laser head is rotatably mounted to meer the focal line of the comtored beam with respect to the near edge portions of the shapes that have been welded. The beam can move between a position where the focal line is placed normal to the but-ions of bords with the shapes and position where the focal line is oriented in an aligned position csn the adjacent edge portions of the pieces of work to be welded. Other suitable mechanisms to alter the intensity of the beam per unit area would also include a drive mechanism to vary the speed at which the laser head moves over the seam line, a power-regulator to vary the power of the laser beams. . The sources of coherent lus that make up the composite beam can, for example, comprise almost any type of beam, including laser COc. More preferably, however, high energy lasers, such as yttrium aluminum garnet laser (YAG.) Are used to weld the shapes. The laser head is preferably movable so that the apparatus moves the beam with respect to the sheet or blade shapes along a predetermined and / or sensed linear and / or curved path. The laser can thus activate and move the laser head along said sensed and / or predetermined path to weld the proximal edges of the sheet forms together along a line of stitching. More preferably, the apparatus includes a sensor mechanism of the space between the edge portions of the shapes to be welded. A microprocessor control is provided, to rotate the head of the beam or the fiber optic connectors with respect to the seam line in response to the sensed spacing. In this way the composite beam can be rotated selectively to move the focal line. The focal line can be rotated to a pre-established orientation with respect to the portion of the seam line to be formed, such as in an orientation at or between a position normal to the edge-to-edge portions of the shapes and a position substantially there aligned. Where there is a space or lus between the butt edge portions of the shapes to be joined, the composite beam is positioned so that the optical centers of the first beam and the second laser beam are each located on a respective edge portion. of each shape, with the focal line of the composite ray riding in the light or space. This position provides maximum amplitude of the laser energy through the light producing the maximum of molten metal filling in the light from the edge portions of the shapes. Where there is no light between the edge portions at 3 tops of the shapes, the laser head can be rotated so that the composite beam is aligned with its focal line "moving towards or in alignment with the seam line. position, the laser energy is focused along the seam line to be trimmed.This advantageously concentrates the intensity of the laser energy along the seam line and decreases the time required to form a complete weld seam, allowing a finished shape produced with high welding speeds.Most preferably, the speed of movement of the laser head above the shape is controlled in relation to the degree of distance between the proximal portions of the shapes and / or orientation of the focal line of the composite ray in relation to the seam line that has to be formed., if desired, the power output of the energy beam could also be varied with even sensed distance between the edge portions of the shapes. In this way, greater energy can be provided when the focal beam of lightning energy is mounted or formed into a chair to cast light and lower beam energy when the focal line is aligned with the seam of the weld. Therefore, one aspect of the present invention is based on an apparatus for joining the proximal edge portions of two forms of workpiece along a seam line, comprising: laser means for emitting a composite beam for welding the shapes with each other along the seam line the compound beam includes a first laser beam and a second laser beam, each of which is focused towards a portion of the shapes to be welded in respective focal areas having An optical center, where the optical centers of the first and second laser beams are displaced from each other and each defines one end of the focal line of the composite beam.; rotation means for selectively rotating e. laser means to move the focal line with r-speci fi ed to the portion? e the forms between a position in which the focal line is oriented normal to the portion of the seam line. and a position wherein the focal line is aligned with the aforementioned portion of the seam line. In another aspect, the present invention is based on a laser apparatus for welding together edge-to-edge portions of two forms of sheet sheet along a seam line, the apparatus comprising: a laser head operable to emit laser energy to weld the shapes between them along the line of costur; rotating means for rotating the laser head and changing the orientation of the laser energy with respect to the line of curvature; where the laser energy generates multiple ray of at least two laser-displaced rays. In another aspect, the present invention is based on a method as claimed in claim 15, wherein the apparatus includes sensing means for sensing and distancing between the shocking portions of the shapes and wherein the method includes the extra step sensing the space between the adjacent portions of the shape in the portion of the shapes to be welded before moving the focal line to the long, and where the pre-established position of the focal line is determined by the d = iar.ciaairr . or sapated between the adjacent portions of the forms. In another aspect, the present invention is based on an apparatus for joining the portions of proximal borae of two working pieces along a seam line comprising: medies for emitting a beam of enrgia composite for welding. forms along the mentioned stitch line; The beam composed of energy includes a first ray of energy and a second ray of energy, each one of them is focused towards a portion of the shapes to be welded in respective focal areas having an optical center, wherein the centers The optical rays of the first and second energy rays are displaced from each other and each defines one end of the focal line of the composite energy beam. sensing means for sensing any distance between the edge portions of the shapes and means for changing the intensity of the beam per unit area selected from the group consisting of; rotational means for positively rotating the means for emitting the beam of composite energy to move the focal line relative to the portion of the shapes between a position where the focal line is oriented normal to the portion of the seam line, and a position where the focal length is oriented to be aligned with the portion of the seam line; driving means for moving the means for emitting the beam of composite energy along the seam line, the driving means s: n activates trees to vary the speed of movement of the laser beam depending on the distance sensed between the adjacent edge portions of the shapes, and means of power regulation to vary the energy of the composite beam depending on the spacing between the neighboring edge portions of the shapes.

DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will appear in the following description, given with reference to the accompanying drawings, where: Figure 1 shows a schematic top view of a production assembly line for forming work pieces composed of according to the present invention; Figure 2 shows a schematic side view of a welding laser head used in the production assembly line of Figure 1; Figure 3 shows the welding apparatus shown in the assembly line of Figure 1 taken along line 3-3 'showing the use of a laser to weld sheet sheet shapes; Figure 4 graphically shows a profile d intensity of a laser beam composed according to a first embodiment of the invention; Figure 5 schematically shows a plan view of the focal areas of the composite laser beam profile shown in Figure 4; Figure 6 shows a plan view of the focal areas of beam l be composite shown in Figure 4, e where the composite beam is oriented with its seal line placed normally to the shock portions of the shape to be welded; Figure 7 shows a plan view of the laser beam areas of the composite laser beam shown in Fig. 4, wherein the composite laser beam is oriented with the focal line placed in alignment with the portions of shock of the shapes that have been of welding; and FIGS. 1 shows schematically and schematically shows laser beam focal areas of a coherent lu beam source for use with the laser of FIG. 1, in accordance with another embodiment of the invention. Reference is made to Figure 1, which shows a trial line 10 used in the simultaneous manufacture of two composite workpieces 12a. 12b. With line d assembly 10 showed a. vaoic robot lifters l.s., l? b s use to move pairs of sheet shapes 14 to 16a, 14b, 16 from respective supply stacks. Each robot 18a IBb is adapted to move the pair of shapes 14a, loa, 14b 16b to a tranport arrangement 20 used to transport the forms 14a, 16a, 14b, 16b and the finished workpieces 12a, 12b along the assembly line 10. The transport arrangement 20 consists of three sets of elongated magnetic stepped conveyors 22, 24, 26 that are operable to move the pairs of shapes 14, a, 16a, 14b, 16b and the work pieces 12a, 12b in the longitudinal direction of the arrow 28. The staggered magnetic conveyors 22. 24 26 are shown in Figure 1 arranged with a parallel orientation both between the conveyors and the remaining conveyors. It has to be appreciated that sor-configurations of tranportadores. As will be described hereafter, the first conveyor set 22 is used in the initial postion of the forms 14a, 16a, 14b, 16b in the production line 10, and transportation of the placed forms I4aa, 16a; 14b, 16b e the second set of conveyors 24. The conveyors are provided as part of a laser welding station 32 in which the adjacent edge portions of the forms 14a, 16a, and 14b 16b are welded together along of a seam line by a 36 lane (YAG). The conveyors 24 are thus used to move the unwelded shapes 14a, 16a; 14b, 16b to a welding position, and then to transport the finished work pieces 12a, 12b to a third set of conveyors 26.

The third set of conveyors 24 is used to transport finished composite workpieces 12a 12b to the vacuum lifters robots 38a, 38b that lift the work pieces 12a, 12b from them and put them in stacks. The production line 10 of Figure 1 is configured for the concurrent manufacture of two terminated workpieces 12a, 12b by a single laser 36. As shown best in Figures 1 to 3, the YAG 36 laser included a source generator. of coherent light 40 used to generate two sources of coherent light or laser beams, a movable laser head 42 (Figure 2) and a fiber optic coupling 44 (Figures 1 and 3) that optically connect the generator 40 and the laser head 42. The fiber optic coupling 44 consists of a bundle of two fiber cables optics (not shown). The energy of the two coherent light sources generated in the generator 40 travels through a respective fiber optic cable to the laser head assembly. Figure 2 shows better the laser head assembly 42 which includes a laser light emitting head 46 from which the laser energy is emitted. As shown, the laser energy comprises a composite beam consisting of two coherent light sources. The assembly 42 includes via support 48 which rotatably assembles the laser head 46, and a motor 52 for rotating the head 46 on the support 4-3. The laser head assembly 42 can be pre-programmed in motion. However, it is preferably provided with a sensor 49 Figure 20) that follows the sewing controlled by the microprocessor. The sensor 49 senses the spacing between the neighboring edge portions of each pair of sheet shapes 14a, 16a; 14b, 16b to be united. The sensor 49 may, for example, include a separate source of coherent light that directs a coherent beam of light downward over the proximal portions of the sheet shapes and a vision or optical sensor to sense the light reflected therefrom. In the absence of reflected light, the optical sensor can be used to provide data that indicate the space between the shock edges of the foil shapes. More preferably, the sensor 49 is used to trace the seam line 34 and to provide control signals to the motors 52 and 64 and the stand robot 54 to automatically place the laser head 42 so that the composite beam 30 is direct to weld seam. Figure 1 better shows the laser 36 as being completely housed within a housing 50. The housing 50 is provided with a buzzer type entrance and exit doors 51,53. The entrance and exit doors 51,53 are open to allow the movement of the forms 14a, 16a: 14b, 16b and the work pieces 12a, 12b into and out of the housing 50. The entry and exit doors 51 , 53 are closed during the welding operations to optically isolate the laser 5 and contain any harmful YAG laser energy for sight. The gripping units 60 are provided within housing 50 to maintain the sheet or blade shapes 14a, 16a and 14b, 16b in a fixed shock position during the weld. Although many types of gripping arrangements are possible, gripping units 60 preferably consist of a magnetic gripping unit of the type presented in the applicant's application for a Canadian patent No. 2,167, 111 exposed on July 12, 1997. The entire assembly The laser head 42 is configured to move horizontally on two axes. The assembly 42 is movable in a first horizontal direction on the conveyors 24 and the shapes 14a. 16a; 14b. 16 via a trestle or gantry robot 54, along a support in pair, above and a slave support 56a, 56b. The laser head assembly 42 is moved in the first direction by the robot 54, along a path 58 (Figur 3) provided in the support above 56a. Each of the brackets 56a, 56b are also slidable in a second horizontal direction that is perpendicular to the first end brackets 62a, 62b spaced apart in parallel. Each of the end supports 62a, 62b movably supports the ends of the parallel supports 56a, 56b. A servo motor 64 (Fig. 1) is provided at the end of the support 56a and engages a track 66 extending s along one end of the support 62a. The movement of the laser assembly 42 along the supports 56a, 56b and the movement of the supports 56a, 56b on the end supports 62a, 62b allow the laser head 46 to move on the forms 14a, 16a; 14b, 16b and any horizontal direction. Furthermore, it is preferable that the laser head 42 be vertically movable, such as, for example, by a rack-and-pinion lifting mechanism or a pneumatic slider 68 (FIG 2), thereby allowing a movement of the laser head 42 along the the trems to provide an increased adaptability to the assembly line 10. It should be appreciated that with this construction, the laser 36 can be used not only to join the work pieces 14a, 14b; 16a, 16b, along linear pre-programmed welding seams, but also along curved weld seams, for a variety of different work pieces, without a previous job placement of the sheet forms. During welding operations, two coherent light sources are produced in the generator. coherent lu source 40. Coherent light sources travel by respective fiber optic cable in coupling 44 to laser head 42 and are there emitted to the portion of seam line 34 to be welded. Two laser beams thus emit from the laser head 42 to weld the adjacent edges of the shapes 14a, 14b.; 16a, 16b, as a laser composite ray 30. Figure 4 graphically shows the energy profile of the composite beam 30 formed of two Bi-Bs beams that essentially do not overlap. Figure 5 shows better the divergence or focal area Fa ?, Fe.2 of the two laser beams on the surface of the work pieces 14, 16 to be joined. Each of the beams l has an optical center Cl and C2 respectively, and a radius of divergence in the work pieces selected between 0.2 mm and 1 mm, and more preferably of approximation 0 or mm. The optical centers Cl, C2 are displaced from each other by a distance D (FIG.4) of between 0. Imm and 3.0 mm and preferably greater than about 1.2 mm. The optical centers Cl, C2 each define one end of a focal line Ll (FIG 5) of the composite laser beam 30 which extends in the direction along which the energy leaving the beam l is .30 extends . When the assembler 10 operates, pairs of component sheets 14a, 16a; 14b, 16b are moved in sequence by the vacuum robot lifters 18a, 18b from the respective supply stacks. The pairs of shapes 14a, 16a; 14b; 16b are placed on the magnetic and parallel feed conveyors 22. The robotic vacuum lifters 18a, 18b are used to move each component blade 14a, 16a; 14b, 16b through an initial qualification procedure. The qualification procedure ensures correct positioning of the sheets on the feed conveyors 22, and includes the sliding of the sheet shapes 14,16 against sets of retractable locating pins 72 (FIG 1) to ensure that the shapes are in the desired starting position.

Vacuum lifters 18a, 18b operate with suction cups having varying suction pressures. Initially, robot lifters 18 are operated under a high vacuum pressure to initially take the 'sheet form 14a, 116a, 14b, 16b to retain in a fixed manner each way as it rises from its stacking d supply. As the blade moves in the qualification procedure, the suction pressure is reduced. The reduced pressure is chosen in such a way that the shapes 14a, 16a and 14b 16b are retained by the vacuum force of the respective lifters 18a, 18b, while allowing the shapes to slide laterally with respect to the suction cups. The edges of the shapes 14a, 16a, 14b, 16b move against the locating pins 72 to position the sheets 14, 15 on the conveyors 22 in the desired initial position. Following the initial qualification position of the leaves or sheets 14a, 16a, a4b, 16b the vacuum lifters 13a, 18b are deactivated to completely release the leaves, and the locating pins 72 back off from the surface of the conveyors 22, allowing the sheets 22 are transported to the housing 50 if impediment. Following the initial qualification, the leaf shape stops * 14a, 16a, 14b, 16b move away 50 for laser welding. The shapes 14a, 16a, 14b, 16b move from the conveyors 22 to the conveyors 24 via the housing box or sliding door 51. The housing 50 functions as a space for laser operations and provides an extra safety feature, with which The workers are protected by the housing of the laser energy, which is emitted during the laser welding of the forms. The transporotators 24 in turn move the forms 14a, 16a, 14b, 16b to the magnetic clamping assemblies 6 which are magnetically activated to tighten the pairs d of sheet shapes 14a, 16a and 14b, 16b. The pairs of shapes s place in respective tightening units 60 so that their proximal edge portions to be welded are in a substitial abutment relationship. Although it is preferred that the forms of work 14a, 16a, 14b, 16b estJ > n positioned so that their proximal edge portions are precisely abutted along the entire length of the seam 34, the laser 36 can advantageously be used for welding operations where lights of up to 0.3mm exist between the next edge portion, without producing a final seam that has a concave profile. After tightening, the laser 36 is activated to emit the composite laser beam 30 from the head 42.? The laser head 42 is composed of laser beams B 1, or 32, or the adjacent light sources are stuck in a respective focal area FAl, FA2 on the surfaces of one of the form walls 14a, 16a, 14b, 16b. The focus of the adjoining light sources is such that the divergence or focal area FAl, FA of beam Bl, B2 has an average diameter of 1.2 mm. The laser beams Bl, 32 are oriented so that the optical center C, C2 of each beam B X B2 are spaced from each other by a distance of 1.2 mm. To weld the shapes, the coherent light source generator 40 is activated to emit the composite beam 3 from the laser head 46 while moving first along the seam 34 of the shapes 14a, 16a and then along the length of the stitching 34 of the shapes 14b, 16b. If the laser head 46 is moved by the movement of the laser head assembly 42 on the supports 56a, 56b and 62a, 52b for the gantry robot 54 and the servo motor 64; as well as by its rotation on the support 48 by the motor 52. The operation of the laser 36 for welding stops them individually of shapes 14, so at 1: - length of the seam 34 is shown better with reference to the figures o and 7. which illustrate an enlarged view of the proximal portion of the shapes 14, 16 to be welded. When the laser head 46 moves along the length of each seam 34 in the direction of arrow 79, the sensor 49 continuously senses the space between the butt edge portions of the shapes 14a, 16a, 14b, 16b and provides signals to the microprocessor control. Where larger lights or spaces are sensed between the proximal edges of the workpiece shapes 14, 16, as shown for example in Figure 6, the control of the microprocessor activates the motor 52 to rotate the laser head 46. so that the focal line Ll of the composite beam 3 extends transverse to the direction of the seam line 34 and movement of the head, and usually to the portion of the neighboring edge portions of the shapes 14, 16 that are being welded. Simultaneously, the control signals of the microprocessor cause the gantry robot 54 the servo motor 64 to decrease the horizontal movement of the head 46 on the sewing portion 34. The slower movement of the laser head 46 increases the dwell time of the laser energy on the corresponding portions of the blade forms 14, 16 to ensure that a complete weld seam is formed. If desired, simultaneously with the head movement 46, the power output of the generator 40 can be varied by increasing the power of the composite beam 30 when the focal line Ll is placed transverse to the seam line 34. The increased power of the beam 30 will compensate Thus the fact that the focal area of only one laser beam Bl, B2 hits each workpiece 16, 1 respectively.

The energy of each laser beam Bl, B2 on the sheet or blade form 16, 14 respectively, penetrates the edge portions of the sheet metal forms or sheet 16, 14. the vapor pressure created by the metal vaporized from the shapes 14, 16 stops the liquid metal suspended in the edges of the beam until the laser head 46 moves along the joint. The metal in liquefaction from the edge portions of each form flows in the light that separates the shapes 14, 16 and solidifies to form a full-face weld of full autogenous penetration. When the laser head 46 moves along the seam 34, and the sensor 49 senses that there is no light or quite small between the butt edge portions of the shapes 14, 16, as shown in Figure 7, the microprocessor control activates the motor 52 to rotate the laser head 46, so that the focal line Ll of the composite ray 30 is aligned above and in the direction of the seam 34, in the position shown in. Figure 7. In this orientation, the energy of the two laser beams Bl is connected along the seam 34. Less dwell time is needed for the composite beam to reach the vaporization of the metal. As such, the control of the microprocessor d active preference to the gantry robot 54 and the servo motorcycle 64 to increase the speed at which the laser head 46 moves horizontally on the seam line 34, accelerating the production of workpieces, and / or decreasing the power intensity of the composite beam 30. It should be appreciated that where the lights or spaces are of a size between the maximum tolerable and the non-existence of light, the control of the microprocessor activates the motor (or other actuator such as an air cylinder) 52 for rotating the laser head 46 and moving the focal line Ll of the composite beam 30 to a position that extends obliquely with respect to the neighboring edge portions of the shapes 14,16. Following the rotation of the pairs of shapes 14a, 16a and 14b, 16b to form the workpieces 12a, 12b the workpieces are moved on conveyors 24. through the exit door 53 and placed on the conveyors. 26- The conveyors 26 move the finished work pieces 12a, 12b of a discharge station from the unloading robots 38a, 33b place the work pieces 12a, 12b in discharge containers 74a. 74b (Figure The inventive method features the use of a rotatable laser head 46 to replenish the focal line Li of the composite beam C. The invention is not limited as well. If desired, the laser head 46 can be provided with 2, 3, 4 or more fiber optic cables selectively activatable to form a beam, each providing a contiguous energy source. In this manner by selectively emitting two or more sources of contiguous lu from the fiber optic bundle, the orientation of the focal line Ll of the composite beam 30 could be varied instantaneously. Similarly, although Figures 4 to 7 describe a composite laser beam consisting of two contiguous lu sources that do not overlap, the invention is not limited by that. The composite beam 30 could, for example, consist of two, three or more lasers as long as they have an energy profile with an overlapping or n overlap configuration. Figures 8 and 9 show one more mode, where equal reference figures are used to specify equal components. In the mode shown, you can emit up to seven contiguous light sources Bl, B, B3, B4. B5, B6 B7 from a fiber bundle, seven-wire optics i, to shown) to form the beam 30, the switching between the fiber optic cables in the beam can, for example, be accomplished by the selective activation and deactivation in the beam. generator 40, or by the selective positioning of the position d lenses or other focusing devices. When used, where there are large lights between the neighboring edge portions of the shapes, 16 as shown in Figure 8, the light sources Bl, B3, B5 and B are activated simultaneously. This effectively provides a laser composite ray 30 which is elongated in two directions along the focal lines Ll and L2. As shown in FIG. 8, the focal lines Ll, L2 of the laser beam 30, thus extend obliquely to the direction of the seam line 34 and to the direction of movement of the laser head 42. The transverse orientation of the energy of the ray is focused on the edge portions of the blade shapes 14, 16. Again, the microprocessor control can be used to signal the gantry robot 54 and the servo motor 64 to slow down the movement of the laser head 46. on stitching 34 and / or increase the output power of the emitted laser beam. Where the adjacent edge portions of the shapes 14, 16 are in contact with the tight stop as shown in FIG. 9, the light sources B2, B4, B6 are emitted as a composite beam 30. The composite beam 30 shown in FIG. Figure 9, therefore, has a single focal line Ll which is aligned with the seam .34. As with the composite beam shown in Figure 7, the energy is now focussed along the seam 34 and a shorter stay of the laser beam is required to form the butt weld. The control of the microprocessor can be used to increase the speed with which the laser head 42 moves on the seam line 34 in the direction of the arrow 79 in the manner already described.

Furthermore, if desired, the optical fibers can be activated selectively so that one or more of the laser beams is provided either aligned with or off-center of the focal line Ll of the composite beam 30. In this aspect the laser ray B2, shown in Figure 8 partial torque can be used to pre-vaporize the edge portions of the separate sheet shapes 14, 16 to be welded. The preferred embodiment of the invention features the use of a YAG laser for use in butt welding operations, the invention is not limited thereto. If desired, other lasers can be used, including COa lasers. Although the invention is suitable for use in top welding of sheet shapes, other welding applications are also possible and are now apparent. Figure 1 shows the simultaneous production of work pieces 12a, 12b each having a linear seam line 34. If desired, the present invention can be used to weld one, two or more work pieces along straight seam stitches , curves or angled. Although Figures 1 to 3 show a production assembly line 10 incorporating a single laser 3 used to weld pairs of shapes 14a, 16a, 14b, 16 together, the invention is not limited thereto. If two or more lasers are desired, each with its own movable laser head can be used to simultaneously weld a pair of shapes 14, 16 along the seam line. Although the preferred modality of ia ipvenoic. presents the apparatus as including a sensor 49 for continuously sensing the space between the blade forms 14, the invention is not limited thereto. In a more cost effective mode, the sensor 46 can be omitted. With such a configuration, the position of the laser head 42 can be manually operated by the operator as the welding operations are performed. Alternatively, the laser head 42 can be moved to a fixed initial position which is held constant during welding, as for example when forms 14 of different thickness have to be joined together. Although the preferred embodiment of the invention presents the coherent light source generator 40 as generating separate laser beams, if desired, the energy source can be used to generate a single source of coherent light that is separated into doe or more kings. be in the laser head 42 or on its way. Although the detailed description described and illustrate preferred embodiments of the invention, for the technic there are many variations and modifications without departing from the scope and spirit of the present invention.

Claims (20)

1. CLAIMS 1. An apparatus for joining portions of edges close to two forms of workpieces along the seam line, which comprises; laser means for emitting a composite beam to weld the shapes together along the seam; The composite beam includes a first laser beam and a second laser beam, each of the first and second laser beams is focused towards a portion of the shapes to be welded in respective focal areas having an optical center, wherein the optical centers of the first and second laser beams are displaced by each other and each defines one end of a focal line of the composite beam; rotational means for selectively rotating the laser means to move the focal line relative to the portion of the shapes between a position where the focal line is oriented substantially normally to the seam portion, and a position where the line The focal portion is substantially aligned with the portion of the seam, sensing means for sensing the spacing between the abutting or abutting portions of the shapes in the portion of the shapes, and control means for controlling the rotation means in response to the sensing distance to rotate the laser means and move the focal line to a pre-set orientation with respect to the portion of the shapes to be welded.
2. 2. An apparatus according to claim 1, wherein the optical centers are displaced from each other by a distance between approximately 0.1 mm and 3 mm.
3. 3. An apparatus according to claim 2, wherein the focal area of each of the first and second laser beams in the seam line has a divergence radius selected between approximately 0.2mm and Im.
4. 4. An apparatus according to claim 1, wherein the sensor means comprises a coherent light source, and a sensor for sensing the light of the coherent light source.
5. 5. An apparatus according to claim 1, wherein the laser means includes a laser head that is movable along a trajectory substantially aligned with the seam line, and the apparatus further includes activatable drive means for moving the laser head along the path, and wherein the speed of movement of the laser head along the path is related to operating factors selected from the group consisting of the sensed distance and the position of the focal line with with respect to the portion of the shapes to be welded.
6. A laser apparatus for welding between the edge-to-tape portions of the sheet-to-sheet forms along a seam line, the apparatus comprising: a laser head operable to emit laser energy to weld the shapes together along the stitching; rotation means for rotating the laser head to change the orientation of the laser energy with respect to the seam line; sensing the spacing or space between the butt edge portions of the shapes in the portion of the shapes, and control means for controlling the rotational means in response to sensing spacing; wherein the laser energy comprises a multiple beam of at least two displaced laser beams.
7. 7. An apparatus according to claim 6, wherein the sensor means comprises a coherent light source, 'a sensor to sense the light of the coherent light source.
8. 8. An apparatus according to claim 7, wherein the focal area of each of the laser beams has a divergence radius selected between about 0.2 and 1.0 mm in the seam line.
9. 9. An apparatus according to claim 1, wherein the composite laser beam also includes a third laser beam, which is focused towards the shapes in a focal area having an optical center, * wherein the optical center of the third laser beam It is intersected by the focal line.
10. 10. An apparatus according to claim 1, wherein the composite laser beam further includes a third laser beam, which is focused towards the shapes in a focal area having an optical center, wherein the optical center of the third laser beam is spaced from the focal line.
11. 11. An apparatus according to claim, wherein the optical centers are displaced an approximate distance of 0.1 to 3 mm.
12. 12. An apparatus according to claim 5, wherein the focal area of each of the first and second rayers has a radius of divergence selected between approximately 0.2 mm and 1 mm in the seam line.
13. 13. An apparatus according to claim 5, wherein the sensor means comprises a source of coherent lu, and a sensor for sensing light from the source of coherent lu.
14. 14. - A method for using an apparatus for joining together butt portions of two forms of workpiece, along the seam line, the composite laser beam comprises a first laser beam and a second laser beam, each of The first and second laser beams are focused towards a portion of the shapes to be welded in respective focal areas having an optical center, wherein the optical centers of the first and second laser beams are displaced between each other and one defines an extreme of a composite ray focal line; rotational means for selectively rotating the laser means to move the focal line relative to the portion of the shapes between a position where the focal line is oriented substantially normal to the seam portion, and a position where the seal line is substantially aligned with the seam portion; wherein the stop portions of the workpiece shapes are joined by the steps of: activating the laser means to direct the composite ray toward the seam line; move the laser beam and the shapes of the laser with respect to each other to move the focal line along the portion of the shapes to be welded.
15. 15. A method according to claim 14, wherein during the step of moving the laser beam, the laser beam and the blade forms move relative to each other at a speed determined by at least the position of the focal line. with respect to the portion of the shapes to be welded or the spacing between the workpiece shapes in that portion.
16. 16. A method according to claim 15, wherein the apparatus further includes sensing means for sensing the spacing between the abutting portions of the shapes, wherein the method includes the step of sensing and distancing between the adjacent portions of the shapes. form in the portion of the shapes to be welded before moving the focal line to its length, and where the pre-established position of the focal line is determined by the sensed distance between the adjacent portions of the shapes.
17. 17. An apparatus according to claim 1, wherein the laser means comprises a liter of yttrium aluminum granat.
18. 18. - A method according to claim 14, wherein the apparatus includes sensing means for sensing and distancing between the abutting portions of the shapes, and wherein the method includes the step of sensing and distancing between the adjacent portions of the form in the portion of the shapes to be welded before the focal line is moved along its length, and wherein the pre-established position of the focal line 38 is determined by the asigned response enters the adjacent portions of the shapes.
19. 19. An apparatus for joining together adjacent edge portions of two forms of workpiece along the seam line, comprising means for emitting a beam of composite energy to weld the shapes together along the line d) the composite energy beam includes a first ray of energy and a second beam of energy, each of the first and second laser beams is focused towards a portion of the shapes to be welded in respective focal areas which have a center optical, wherein the optical centers of the first and second laser beams are displaced within if one defines one end of a focal line of the composite ray; sensor means for sensing any space between the neighboring edge portions of the shapes and means for changing the intensity of the ray per unit ere selected from the group consisting of rotation means for selectively rotating the laser means to move the relative focal line to the portion of the shapes between a position wherein the focal line is subtantially oriented in a normal manner to the portion of the seam, and a position wherein the seal line is substantially aligned with the seam portion; driving means for moving the means for emitting the composite energy beam along the seam line, the driving means are activatable to vary the speed of movement of the ray of lager depending on sensed space between the neighboring edge portions of The shapes, and means of power regulation for varying the energy output of the composite beam depending on the sensed space between the neighboring edge portions of the shapes.
20. 20. The apparatus according to claim 19 wherein the first and second energy beams each comprise a coherent light source.