The three stations are: -
□ pipe length measuring,
□ chamfering and facing
□ followed by inspection.

The servo motor driven walking beam lifts the pipe out of each station and lowers it into the next station automatically. Being servo motor driven the movement is optimized to reduce cycle time.

The chamfering station machines both ends of the pipe at the same time. The chamfering heads, clamps and pipe supports are mounted on a common bed. This reduces the size of the machine foot print and reduces cycle time. One head is fixed and the other is adjustable. The movement is controlled by a servo motor which is controlled automatically to adjust to the pipe length required.

When the pipe enters the first station after cutting it is end aligned by a cylinder and the pipe length is measured. The pipe length data is recorded in the control system to be used at the time of chamfering.

The pipe is then moved by the walking beam conveyor to the chamfering station. The chamfering station has two modes of operation.
□ Fixed pipe length mode. In this mode all the pipes are machined to the same length.
□ Fixed cutting stroke mode. In this mode the same amount of material is removed from each end of the pipe resulting in the same pipe length variation as the pipe left the cutting machine.

Once the mode is selected the pipe is clamped and chamfered automatically.

The pipe clamps are of a three piece construction. The bottom clamp is fixed which provides a stable base for the pipe. The top two clamps are positioned to the left and the right of the pipe centre line. The movement of these top clamps is driven by servo motors through a toggle mechanism that is spring loaded. The spring ensures that the mechanism is not overloaded but ensures that the pipe is securely clamped. The toggle mechanism allows for rapid movement of the clamp while at the end of the stroke the force applied can be up to 8 times greater that the servo motor can deliver. This unique mechanism provides the optimum clamping conditions taking into account pipe OD and ovality variations, it is also very fast. These modern servo motor driven clamps provide considerable advantages over the old pneumatic or hydraulic clamping methods resulting in improved product quality and reduced cycle time.

The chamfering heads are driven by an inverter controlled motor through a two speed gearbox. This allows the cutting speed of the cutting tips to be optimized across the full size range. The cutting stroke and the feed rate is controlled by a servo motor driving a ball screw.

The face plate containing the cutting tools is easily changed. The face plate can contain up to 4 cutting tools. Normally only 3 cutting tools are used, external chamfer, internal chamfer and end facing. The fourth position can be used where long cutting strokes are required. For example where there is a large external chamfer two cutting tools will double the feed rate and reduce the cycle time.

The internal and external chamfering tools are of the pipe profile following type. For the external chamfer a spring load roller cam follows the outside profile of the pipe controlling the position of the external chamfering tool. For the internal chamfer a spring load roller cam follows the inside profile of the pipe controlling the position of the internal chamfering tool. The angle of the chamfer is fixed. Different tool holders are required for different chamfer angle. Using adjustable chamfer angles results in more problems and lost production. The depth of chamfer is controlled by shims which is a very positive method of adjustment and will not allow the tools to move or change position. The cutting tips are easily replaceable and the tool holders are of the quick change variety.

Optional swarf conveyors are available to be installed under the cutting heads to remove the cutting chips (swarf).

After chamfering and end facing the walking beam conveyor moves the pipe to the inspection table. The operator’s station is situated at the fixed end of the chamfering station. A video camera is located at the adjustable end of the chamfering station enabling the operator to inspect the chamfering and end facing of that end.

Optional chain hoists are available for both sides of the chamfering station to allow for quick change of the clamps and face plates. This frees up the overhead crane for other activities.

For customers that require a square pipe bypass an optional roller conveyor is available that allows these pipes to pass through the machine and onto the next process.