Orbital welding device with improved residual oxygen measurement

Abstract

An orbital welding device (1), having a welding current source (10) in a welding current source housing (11) and an orbital welding head (20), which is separate from the welding current source housing (11) and is connected to the welding current source (10) by a cable (2), the orbital welding head (20) having a pipe mount (21) and a welding electrode holder (22) for holding a welding electrode (23). An electric motor (31) is designed to drive the welding electrode holder (22) and thus turn it with respect to the pipe mount (21). The orbital welding head (20) has a chamber (50) for shielding gas. An optical oxygen sensor (40) is designed to measure an oxygen concentration in a measuring region (51) in the chamber (50). The oxygen sensor (40) is arranged outside the chamber (50) and is optically coupled to the measuring region (51) by an optical coupling.

Claims

1. An orbital welding device, comprising: a welding current source in a welding current source housing; an orbital welding head, which is separate from the welding current source housing and is connected to the welding current source by a cable, the orbital welding head comprising an orbital welding head housing, a pipe mount, a welding electrode holder mounted rotatably with respect to the pipe mount and configured to hold a welding electrode, and a chamber for shielding gas configured to surround the welding electrode of the orbital welding head and substantially seal the welding electrode off from an environment during a welding process; an electric motor configured to drive the welding electrode holder and turn the electrode holder with respect to the pipe mount, wherein the orbital welding head comprises an optical oxygen sensor configured to measure an oxygen concentration in a measuring region in the chamber, wherein the oxygen sensor is arranged outside the chamber and inside the orbital welding head housing, and the oxygen sensor is optically coupled to the measuring region by an optical coupling.

2. The orbital welding device as claimed in claim 1, the optical coupling being at least partially formed by an opening in a wall of the chamber.

3. The orbital welding device as claimed in claim 1, the optical coupling being at least partially formed by a light guiding element.

4. The orbital welding device as claimed in claim 3, the light guiding element being at least partially formed by an optical fiber.

5. The orbital welding device as defined in claim 1, wherein the oxygen sensor is optically coupled to a further measuring region in the chamber by means of a further optical coupling.

6. The orbital welding device as defined in claim 1, wherein the orbital welding head comprises at least one further oxygen sensor, the further oxygen sensor being optically coupled to a further measuring region in the chamber by means of a further optical coupling.

7. The orbital welding device as defined in claim 1, wherein the orbital welding device comprises an electrical closed-loop control device configured to start a welding process as soon as the oxygen concentration in one or more of the measuring regions has gone below a predetermined threshold value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be illustrated further by way of example with reference to drawings, in which:

(2) FIG. 1 shows a first embodiment of a device according to the invention,

(3) FIG. 2 shows a second embodiment of a device according to the invention on the basis of the first embodiment,

(4) FIG. 3 shows a third embodiment of a device according to the invention on the basis of the second embodiment,

(5) FIG. 4 shows a fourth embodiment of a device according to the invention on the basis of the third embodiment.

DETAILED DESCRIPTION

(6) FIG. 1 will now be described in greater detail. The configuration is such that the orbital welding device 1 has a welding current source 10 in a welding current source housing 11 and an orbital welding head 20, which is separate from the welding current source housing 11 and is connected to the welding current source 10 by means of a cable 2, the orbital welding head 20 having a pipe mount 21 and a welding electrode holder 22, which is mounted rotatably with respect to the pipe mount 21 and is intended for holding the welding electrode 23, the orbital welding device 1 having an electric motor 31, which is actuated here by a motor controller 30 of the orbital welding device 1 and is designed to drive the welding electrode holder 22 and thus turn it with respect to the pipe mount 21, the orbital welding head 20 having an optical oxygen sensor 40 and a chamber 50 for shielding gas, which is designed to surround a welding electrode 23 of the orbital welding head 20 and substantially seal it off from the outside during a welding process, the optical oxygen sensor 40 being designed to measure an oxygen concentration in a measuring region 51 in the chamber 50, wherein the oxygen sensor 40 is arranged outside the chamber 50 and the oxygen sensor 40, here a light-sensitive area 41, e.g. of a photodiode, of the oxygen sensor 40, is optically coupled to the measuring region 51 by means of an optical coupling. The pipe mount 21 is closable by a hinged mechanism. Here the cable 2 has a minimum length of 1 m, here 2 m. The chamber 50 is configured here in such a way that the pipe pieces which are intended to be welded onto one another are enclosed by the chamber 50 at the ends to be connected. The chamber 50 here has an inlet 54, e.g. with a hose connection, for shielding gas, with which the chamber can thus be filled. The chamber 50 is designed here in such a way that the welding electrode 23 can be rotated around the pipe pieces to be welded in the chamber 50. The light-sensitive area 41 of the oxygen sensor 40 here is a photodiode. Here the orbital welding head 20 has a housing 90, which adjoins the chamber 50 and which forms e.g. for a user a handle and a housing for the motor 31, and the oxygen sensor 40 is arranged in the housing 90. The configuration is such that the optical coupling is at least partially formed by an opening 61 in a wall of the chamber 50. Here the oxygen sensor 40 is arranged behind the wall of the chamber 50 and the light-sensitive area 41 of the oxygen sensor 40 is directed toward the opening 61.

(7) FIG. 2 will now be described in greater detail. The configuration is such that the optical coupling is at least partially formed by a light guiding element 60, in contrast to FIG. 1. The configuration is such that the light guiding element 60 is at least partially formed by an optical fiber 62.

(8) FIG. 3 will now be described in greater detail. The configuration is such that the oxygen sensor 40, here the light-sensitive area 41 of the oxygen sensor 40, is optically coupled to a further measuring region 52 in the chamber 50 by means of a further optical coupling, in contrast to FIG. 2. Here the optical coupling is at least partially formed by a further opening 71 in a wall of the chamber 50. Here the optical coupling is at least partially formed by a further light guiding element 70. Here the further light guiding element 70 is at least partially formed by a further optical fiber 72, which is directed through the further opening 71 toward the further measuring region 52.

(9) FIG. 4 will now be described in greater detail. The configuration is such that the orbital welding head 20 has at least one further oxygen sensor 80, the further oxygen sensor 80, here a light-sensitive area 81, e.g. of a photodiode, of the oxygen sensor 80, being optically coupled to a further measuring region 53 in the chamber 50 by means of a further optical coupling, in contrast to FIG. 3. The further measuring region can have overlap regions with the first measuring region, but is different overall. Here the optical coupling is at least partially formed by a further opening 71 in a wall of the chamber 50. Here the optical coupling is at least partially formed by a further light guiding element 70. Here the further light guiding element 70 is at least partially formed by a further optical fiber 72, which is directed through the further opening 71 toward the further measuring region 53.

REFERENCE SIGNS

(10) 1 Orbital welding device 2 Cable 10 Welding current source 11 Welding current source housing 20 Connected orbital welding head 21 Pipe mount 22 Mounted welding electrode holder 23 Welding electrode 30 Motor controller 31 Electric motor 40 Optical oxygen sensor 41 Light-sensitive area 50 Sealed-off chamber 51 Measuring region 52 Further measuring region 53 Further measuring region 54 Inlet 60 Light guiding element 61 Opening 62 Optical fiber 70 Further light guiding element 71 Further opening 72 Further optical fiber 80 Further oxygen sensor 81 Light-sensitive area 90 Housing