Stationary Pipe Machining with Rotating Tool

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current machining systems for large pipes in the oil and gas industry face challenges such as time-consuming centering processes, safety concerns due to rotating heavy pipes, and inefficiencies in threading operations, particularly with existing lathes and horizontal machining centers, which result in reduced accuracy and increased costs.

Innovation Solution

A machining system where the pipe remains stationary, with the cutting tool translated along a radial feed-out axis and rotated to machine the surface, using a multi-axis machine tool to automatically center the pipe and employ indexable tool inserts for efficient thread cutting, eliminating the need for manual centering and reducing cycle time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a lathe is used to rotate and machine large pipes, then threading operations can be performed, but the centering process becomes extremely time-consuming and labor-intensive

Engineering Contradiction:

Improvethreading operation efficiencyVSAvoidcentering process time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

Instead of rotating the pipe on a lathe, the patent inverts the approach by keeping the pipe stationary and rotating the cutting tool around the pipe. This eliminates the time-consuming centering process while maintaining threading capability through a horizontal machining center configuration.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the traditional lathe mechanical system with a horizontal machining center that uses computer-controlled movements. The cutting tool is positioned and moved along programmed paths to create threads, substituting manual centering and rotation with automated positioning systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If large pipes are rotated on a lathe for threading, then cutting operations can be performed, but safety concerns arise due to rotating heavy unbalanced pipes

Engineering Contradiction:

Improvethreading operation capabilityVSAvoidsafety hazards from rotation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates the safety hazards by inverting the traditional lathe operation. Instead of rotating the heavy pipe, the cutting tool rotates around the stationary pipe. This removes the rotational inertia and balance issues while maintaining the threading function through controlled tool movement.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts the rotation function from the workpiece (pipe) and transfers it to the cutting tool. By taking out the rotation requirement from the pipe, the system eliminates safety hazards associated with rotating heavy, unbalanced pipes while preserving the threading capability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Object-affected harmful factors

If a horizontal machining center is used to machine large pipes, then pipe rotation is avoided, but the movable worktable size is restricted

Engineering Contradiction:

Improvesafety issues from pipe rotationVSAvoidworktable size limitation

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent addresses the worktable size limitation by utilizing vertical movement of the cutting tool and pipe positioning. Instead of relying solely on horizontal worktable movement, the system uses vertical axes and other dimensional movements to accommodate large pipe sizes that exceed traditional worktable dimensions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Manufacturing precision

If manual centering is performed on a lathe, then pipe positioning can be achieved, but the process is extremely time-consuming

Engineering Contradiction:

Improvepipe centering accuracyVSAvoidcentering operation time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical centering with computer-controlled automated positioning. The horizontal machining center uses programmed movements and computer guidance to position and machine the pipe, eliminating the trial-and-error manual centering process while maintaining precision through digital control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs self-positioning through automated tool positioning and movement control. The computer-controlled system automatically calculates and executes the precise tool paths and positioning required, eliminating the need for operator intervention in the centering process.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8087857B2Method and apparatus for machining work pieces

Publication Date: 2012.01.03 MAZAK CORP

AI summary

A method and apparatus are provided to machine a curved surface such as an inner or outer peripheral surface of a pipe. The pipe is held stationary during machining and a rotatable spindle of a machine head moves along multiple orthogonal axes to align the rotational axis of the spindle with the longitudinal pipe axis. Preferably, the pipe axis is located by using a touch probe to engage the curved surface at multiple spots and the calculating the location of the pipe axis. The cutting tool, which is preferably a cutting tool insert, is rotated by the spindle to machine the curved surface.