Apparatus for coating a pipe surface
View Patent ↗A wear resistant coating is applied on an elbow or S-bend by weld beads applied along a pipe. A rectangular support rod is attached inside the pipe by connectors so that wheels of the carriage are guided on the corners to maintain a fixed orientation relative to the support rod. A three axis robot arm carries an electric welding head so as to be able to dynamically adjust the head both angularly and radially. A welding wire is pulled to the head by a feeding system on the carriage. The weld parameters including a predetermined wire stick out and angle of wire attack are controlled. A drive motor carried by a drive carriage propels the drive carriage longitudinally along the support rod with a series of intermediate carriages.
1. An apparatus for coating an interior surface of a pipe comprising:
the pipe having an exterior surface, an interior surface and a curved longitudinal axis extending between two ends;
the pipe having distortions from a cylindrical shape so that a radial distance of the interior surface from the longitudinal axis varies at positions along the pipe;
an elongate support member extending continuously along the interior of the pipe between the two ends and which is curved along its length to follow the longitudinal axis of the pipe;
a series of spacer straps each attached between the interior surface of the pipe and the elongate support member at spaced positions therealong for supporting the elongate support member within the pipe;
the spacer straps being arranged so that the elongate support member is supported within the pipe at a position spaced from the interior surface and parallel to and above the longitudinal axis;
an operating carriage mounted on the elongate support member for movement therealong;
the elongate support member and the operating carriage having cooperating elements which maintain the operating carriage at a fixed rotational orientation relative to said elongate support member;
the elongate support member and the operating carriage being arranged so that the operating carriage runs along the elongate support member and passes the spacer straps;
an electric welding head arranged to apply parallel beads of welding material onto the interior surface of pipe to apply a coating covering the interior surface of the pipe;
a head drive system carried by the operating carriage for moving the electric welding head relative to the operating carriage in directions both angularly around and radially of the elongate support member; and
a carriage drive system for driving the operating carriage longitudinally along said elongate support member;
wherein the head drive system comprises a multi-axis robotic arm able to dynamically adjust the electric welding head relative to the operating carriage both angularly and radially;
wherein the multi-axis robotic arm comprises a three parallel axis system including a shoulder axis connected to the carriage, an elbow axis and a wrist axis connected to the electric welding head with a pair of arms between the shoulder axis and the elbow axis and between the elbow axis and the wrist axis;
and where in the multi-axis robotic arm is arranged with the shoulder axis at the center of the pipe on the longitudinal axis of the pipe.
2. The apparatus according to claim 1 wherein the head drive system is PLC controlled.
3. The apparatus according to claim 1 wherein a pull-type wire feeder is fixed just behind the head, and therefore translates along the elongate support member with the head into the pipe thus minimizing the distance over which the wire is pushed to the head.
4. The apparatus according to claim 1 wherein the wire feeder includes roller wire guides at the angle transition between the head which extends radially and an axially extending liner.
5. The apparatus according to claim 1 wherein the electrical welding head and the head drive system maintains a preset electrical stick-out of the welding head relative to the interior surface as the radial distance of the interior surface from the longitudinal axis varies.
6. The apparatus according to claim 5 wherein the head drive system maintains the preset electrical stick-out by detecting variations in welding parameters.
7. The apparatus according to claim 1 wherein the elongate support member comprises a support rod which is rectangular in cross-section to define corners and the operating carriage includes at least four guide wheels supporting the operating carriage on the corners of the support rod and wherein each guide wheel has a V shaped groove for receiving a respective one of the corners therein.
8. The apparatus according to claim 7 wherein the guide wheels are arranged in opposed pairs with each pair being arranged respectively at a front and rear of the operating carriage.
9. An apparatus for coating an interior surface of a pipe comprising:
the pipe having an exterior surface, an interior surface and a curved longitudinal axis extending between two ends;
the pipe having distortions from a cylindrical shape so that a radial distance of the interior surface from the longitudinal axis varies at positions along the pipe;
an elongate support member extending continuously along the interior of the pipe between the two ends and which is curved along its length to follow the longitudinal axis of the pipe; a series of spacer straps each attached between the interior surface of the pipe and the elongate support member at spaced positions therealong for supporting the elongate support member within the pipe; the spacer straps being arranged so that the elongate support member is supported within the pipe at a position spaced from the interior surface and parallel to and above the longitudinal axis;
an operating carriage mounted on the elongate support member for movement therealong;
the elongate support member and the operating carriage having cooperating elements which maintain the operating carriage at a fixed rotational orientation relative to said elongate support member;
an electric welding head for coating the interior surface of the pipe from a supply of a coating material;
a head drive system carried by the operating carriage for moving the electric welding head relative to the operating carriage in directions both angularly around and radially of the elongate support member; and
a carriage drive system for driving the operating carriage longitudinally along said elongate support member;
wherein the head is an electrical welding head arranged to apply parallel beads of welding material onto the interior surface of the pipe to apply a coating covering the interior surface of the pipe;
and wherein the head drive system maintains a preset electrical stick-out relative to the pipe surface as the radial distance of the interior surface from the longitudinal axis of the pipe varies.
10. The apparatus according to claim 9 wherein the head drive system maintains a preset electrical stick-out by detecting variations in welding parameters.
11. An apparatus for coating an interior surface of a pipe comprising:
the pipe having an exterior surface, an interior surface and a curved longitudinal axis extending between two ends;
the pipe having distortions from a cylindrical shape so that a radial distance of the interior surface from the longitudinal axis varies at positions along the pipe;
an elongate support member extending continuously along the interior of the pipe between the two ends and which is curved along its length to follow the longitudinal axis of the pipe;
a series of spacer straps each attached between the interior surface of the pipe and the elongate support member at spaced positions therealong for supporting the elongate support member within the pipe;
the spacer straps being arranged so that the elongate support member is supported within the pipe at a position spaced from the interior surface and parallel to and above the longitudinal axis;
an operating carriage mounted on the elongate support member for movement therealong;
the elongate support member and the operating carriage having co-operating elements which maintain the operating carriage at a fixed rotational orientation relative to said elongate support member;
the elongate support member and the operating carriage being arranged so that the operating carriage runs along the elongate support member and passes the spacer straps;
an electric welding head for coating the interior surface of the pipe from a supply of a coating material;
a head drive system carried by the operating carriage for moving the electric welding head relative to the operating carriage in directions both angularly around and radially of the elongate support member; and
a carriage drive system for driving the operating carriage longitudinally along said elongate support member.
12. The apparatus according to claim 11 wherein the elongate support member comprises a support rod which is rectangular in cross-section to define corners and the operating carriage includes at least four guide wheels supporting the operating carriage on the corners of the support rod and wherein each guide wheel has a V shaped groove for receiving a respective one of the corners therein.
13. The apparatus according to claim 12 wherein the guide wheels are arranged in opposed pairs with each pair being arranged respectively at a front and rear of the operating carriage.
14. An apparatus for coating an interior surface of a pipe, said apparatus comprising:
an elongate support member extending along the interior of the pipe parallel to a longitudinal axis of the pipe; a series of spacer straps each attached between the interior surface of the pipe and the elongate support member at spaced positions therealong for supporting the elongate support member within the pipe; the spacer straps being arranged so that the elongate support member is supported within the pipe at a position spaced from the interior surface and parallel to and above the longitudinal axis;
an operating carriage mounted on the elongate support member for movement therealong;
the elongate support member and the operating carriage having cooperating elements which maintain the operating carriage at a fixed rotational orientation relative to said elongate support member;
an electric welding head for coating the interior surface of the pipe from a supply of a coating material;
a head drive system carried by the operating carriage for moving the electric welding head relative to the operating carriage in directions both angularly around and radially of the elongate support member; and
a carriage drive system for driving the operating carriage longitudinally along said elongate support member;
wherein electrical welding head is arranged to apply parallel beads of welding material onto the interior surface of the pipe to apply a coating covering the interior surface of the pipe;
and wherein a pull-type wire feeder is fixed just behind the electric welding head, and therefore translates along the elongate support member with the electric welding head into the pipe thus minimizing the distance over which the wire is pushed to the electric welding head.
15. The apparatus according to claim 14 wherein the wire feeder includes roller wire guides at the angle transition between the head which extends radially and an axially extending liner.
16. An apparatus for coating an interior surface of a pipe, comprising:
the pipe having an exterior surface, an interior surface and a curved longitudinal axis extending between two ends;
an elongate support member extending continuously along the interior of the pipe between the two ends and which is curved along its length to follow the longitudinal axis of the pipe;
a series of spacer straps each attached between the interior surface of the pipe and the elongate support member at spaced positions therealong for supporting the elongate support member within the pipe;
the spacer straps being arranged so that the elongate support member is supported within the pipe at a position spaced from the interior surface and parallel to and above the longitudinal axis;
an operating carriage mounted on the elongate support member for movement therealong;
the elongate support member and the operating carriage having cooperating elements which maintain the operating carriage at a fixed rotational orientation relative to said elongate support member;
the elongate support member and the operating carriage being arranged so that the operating carriage runs along the elongate support member and passes the spacer straps;
an electric welding head for coating the interior surface of the pipe from a supply of a coating material;
a head drive system carried by the operating carriage for moving the electric welding head relative to the operating carriage in directions both angularly around and radially of the elongate support member; and
a carriage drive system for driving the operating carriage longitudinally along said elongate support member;
wherein the elongate support member comprises a support rod which is rectangular in cross-section to define corners and the operating carriage includes at least four guide wheels supporting the operating carriage on the corners of the support rod;
wherein each guide wheel has a V shaped groove for receiving a respective one of the corners therein;
wherein the guide wheels are arranged in opposed pairs with each pair being arranged respectively at a front and rear of the operating carriage;
and wherein at least one of each pair of guide wheels is spring mounted so as to be pressed inwardly toward the corner of the rod.