JPH0352787A - Manufacture of grating - Google Patents

Abstract

PURPOSE:To manufacture the grating in which no welding strain is generated by irradiating only an abutting part of an end plate and a main bar with a laser beam and welding both of them. CONSTITUTION:In a state that an end plate E is allowed to abut on a partially fabricated item (a) and held, and simultaneously, positioned, a laser welding part 4 is driven, and a laser beam from a irradiating part 41 irradiates the abutting part of a main bar M and the end plate E. Simultaneously, by driving a irradiating part moving device, a movement of the irradiating part 41 is started at a prescribed speed. Also, this irradiating part 41 emits a laser beam only when it reaches right above the abutting part of the main bar M and the end plate E. Accordingly, the main bar M irradiated with the laser beam is welded to the end plate E since its end part is melted. On the other hand, in the part on which the main bar M is not allowed to abut, the laser beam does not irradiate the end plate E nor the main bar M, and a welding strain and a flaw are not generated.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention relates to a method of manufacturing a steel grating, such as a lattice-like grating that covers, for example, road side ditches or cross ditches. The present invention relates to a method of manufacturing a grating in which end plates are fixed to both sides by welding.

Conventional technology> The above grating is generally made by arranging 20 to 30 or even several dozen long flat bars, etc., which serve as the main nodes, in parallel at even intervals, and on top of these, straight or twisted rods, etc. The grating material is manufactured by placing the crossbar in the orthogonal direction, connecting the electrodes and applying electricity to weld them together.Furthermore, a cutter placed in the direction orthogonal to the flat bar is used to cut the grating material to a length commensurate with the gutter width. The flat steel is cut to produce a semi-finished product (commonly called a centipede) consisting of a main bar (cut to a predetermined length) and a cross bar.

Then, end plates made of flat steel or angle bars are fixed to both ends of this semi-finished main bar by welding, thereby producing a grating as shown in FIG. 3.

This grating is painted or galvanized as necessary to become a product.

Among such grating formation processes, the conventional method of welding end plates to both ends of a semi-finished main bar is to hold the end plate in contact with the end of the main bar,
After temporarily fixing the four corners, spot welding is performed along the end plates at the abutting portions of the main bar and the end plates to weld them together.

Problems to be Solved by the Invention However, in the above method, electric welding is performed at the abutting portions of the two end plates 3, which has the disadvantage of increasing heat accumulation due to the high temperatures used for welding. . Therefore, there is a problem in that welding distortion occurs in the end plates and the main bar, and the manufactured grating is deformed and has low commercial value.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a method for manufacturing a grating in which an end plate and a main bar are fixedly welded together without causing welding distortion.

Means for Solving the Problems> In order to achieve the above object, the grating manufacturing method of the present invention provides a grating manufacturing method of the present invention, in which a laser beam irradiation port is moved along an end plate and a contact portion between the end plate and the main bar is moved. The grating is manufactured by irradiating only the laser beam with a laser beam to weld the two together.

In addition, in the grating manufacturing method of the present invention, the end plate is continuously irradiated with a laser beam at a portion slightly away from the inside of the end plate, and the end plate is moved along the main bar and the end plate, which intersect with the laser beam. The grating may be manufactured by welding the end plate and the main bar by applying a laser beam only to the portion that contacts the plate.

According to the above method, by applying a laser beam to the abutting portion of the end plate and the main bar, the two can be welded, and the end plate can be fixed to a predetermined part of the grating semi-finished product. .

In addition, according to the method of moving the laser beam along the end plate, which irradiates a part slightly away from the end plate, even if the laser beam is continuously irradiated and moves, the end plate that needs welding can be moved. This laser beam hits only the part that contacts the main bar, making it possible to fix the end plate to the semi-finished grating.

Example Next, embodiments of the invention will be described with reference to the drawings.

FIG. 1 is a schematic perspective view of an apparatus for manufacturing a grating as an embodiment of the present invention.

This manufacturing apparatus 1 includes a transport section 2 for transporting a semi-finished grating a, a positioning section 3 for positioning the semi-finished grating a at a predetermined position during welding, and a main bar in the semi-finished product a positioned by the positioning section 3. It is provided with a laser welding section 4 for welding the contact portion between M and the end plate E.

The conveyance unit 2 includes a plurality of roller conveyors 21 arranged in a direction intersecting the conveyance direction, and can convey the semi-finished product a at a predetermined timing.

As shown in FIG. 2, the positioning section 3 is provided on a reference plate 31 provided along one side of the roller conveyor 21 and on the advancing direction side of the semi-finished product a conveyed by the roller conveyor 21. a positioning stopper 32 disposed in a direction intersecting the reference plate 31; a pusher 33 that approaches and moves away from the reference plate 31 while maintaining a parallel state; a pneumatic cylinder 34 that reciprocates the pusher 33; It is provided with an auxiliary suppressing plate 35 that approaches and moves away from the positioning stopper 32 while maintaining a parallel state. The positioning stopper 32 can be projected from below the roller conveyor 21 to the upper surface side of the roller conveyor 21 at a predetermined timing, and the auxiliary suppressing plate 35 is
Like the positioning stopper 32, it is configured to be able to freely protrude toward the surface of the roller conveyor 21 and to be able to reciprocate in the conveyance direction of the roller conveyor 21.

The laser welding section 4 is equipped with an irradiation section 41 that emits a laser beam of approximately 0.2φ, and by irradiating the abutment area between the end plate E and the main bar M from directly above, welds them together. be able to. Furthermore, this laser welding part 4 is provided with an irradiation part moving device (not shown), which moves the irradiation part 41 to the end plate E.
The laser beam can be irradiated onto all of the above-mentioned abutting portions. Note that the irradiation section 41 is connected to a laser beam generator 42 through an optical fiber, and can send out a laser beam with a predetermined intensity.

Next, the operation of this manufacturing apparatus 1 and the manufacturing method will be explained.

First, the supplied semi-finished product a is moved to the positioning section 3 by the conveyance section 2. The semi-finished product a that has moved to the positioning section 3 stops moving when its tip side contacts the positioning stopper 32, and end plates E are supplied to both sides of the semi-finished product a, and then the pusher 33 and the auxiliary pressing plate 35 are activated. do. As a result, the end plate E is held in contact with the semi-finished product a and is positioned at the same time.

In this state, the laser welding section 4 is driven, and the irradiation section 41
A laser beam from the main bar M and the end plate E are irradiated toward the abutting portion. At the same time, the irradiation section moving device is driven to start moving the irradiation section 41 at a predetermined speed. This moving speed is set, for example, to such a speed that the entire length of the end plate E can be moved in about 40 seconds.

In addition, in the case of a type that irradiates a laser beam intermittently, this irradiation unit 41 is configured to include a main bar M and an end plate E.
It can be irradiated only when it reaches directly above the contact area with the object.

On the other hand, in the case of the irradiation section 41 that continuously irradiates the laser beam, the irradiation position is set slightly away from the inner edge of the end plate E, and the irradiation section 41 continuously irradiates the laser beam. Even if it moves, the laser beam will not hit anything other than the contact area. That is, as in the embodiment shown in FIG.
The laser beam is set so that it can irradiate an area approximately 0.4 mm away from the inner edge of the end plate E (indicated by the symbol y). It can be applied only to the end of the main bar M at the abutting part. The main bar M irradiated with the laser beam is welded to the end plate E by melting its end. On the other hand, in the portions where the main bar M is not in contact, the laser beam will not irradiate either the end plate E or the main bar M, and there is no risk of damaging them due to the laser beam irradiation.

In this way, in the above-mentioned manufacturing apparatus, since the abutting portion of the main bar M and the end plate E can be welded using a laser beam, the amount of heat generated during welding is considerably smaller than that of conventional electric welding, and the main bar M The amount of heat stored in the contact portion between the end plate E and the end plate E is small. Therefore, even when welding is performed by moving in one direction from one end of the end plate E to the other end, no welding distortion occurs, and a good-looking grating can be manufactured. Furthermore, since the amount of heat storage is small as described above, main welding can be performed immediately without temporary attachment while the end plate E is held in contact with the end of the semi-finished product a. Therefore, the manufacturing efficiency of the grating can be dramatically improved, contributing to a reduction in the cost of the grating.

In addition, if the laser beam can be continuously irradiated, even if the end plate E is moved while continuously irradiating the laser beam, the end plate E and the main bar M will not come into contact with each other. These parts can be welded by applying a laser beam to only the parts, improving work efficiency.

Furthermore, when welding the contact area with a laser beam, although there are almost no welding traces on the surface side, the welding range reaches quite deep from the surface, and not only does it look better, It also has the advantage of being much stronger than before.

As described above, according to the grating manufacturing method of the present invention, since a laser beam is used, the amount of heat generated during welding is considerably lower than that of conventional electric welding, and the end plate can be welded. It is possible to reduce the amount of heat stored when Therefore, even when welding is performed by moving the end plate in one direction from one end to the other, welding distortion does not occur, and a high-quality grating can be provided.

In addition, as mentioned above, the amount of heat stored in the grating is small, so the final welding can be carried out immediately with the end plate held in contact with the end of the semi-finished product without the need for temporary attachment. Dramatically improve manufacturing efficiency,
Contributes to cost reduction.

Furthermore, by welding the abutment area with a laser beam, the welding range reaches quite deep from the surface, even though there are almost no welding traces on the surface side, which not only improves the appearance, but also It also has the advantage of being much stronger than before.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an apparatus for manufacturing a grating as an embodiment of the present invention, FIG. 2 is a plan view of a positioning section, and FIG. 3 is a partial perspective view showing an example of a grating. 1 2 M... Main bar C... Cross bar a... Gretching semi-finished product, 4... Laser welding part.

Claims (1)

[Claims] 1. In a manufacturing method of manufacturing a grating by welding an end plate to a semi-finished grating consisting of a metal main bar and a cross bar, the laser beam irradiation port is moved along the end plate. 1. A method for manufacturing a grating, which comprises manufacturing the grating by irradiating a laser beam only on the abutting portion of the end plate and the main bar to weld them together. 2. In the manufacturing method of manufacturing a grating by welding an end plate to a semi-finished grating consisting of a metal main bar and cross bar, a laser beam is continuously irradiated onto a part slightly outside the inside of the end plate. By moving the laser beam along the end plate, the laser beam acts only on the contact area between the main bar and the end plate, which intersects with the laser beam, welding the end plate and the main bar, thereby manufacturing the grating. Characteristic grating manufacturing method.