# Flame cutting machine

Walmar flame cutting machine
Inova flame cutting machine

A flame cutting machine is a machine tool for flame cutting of plates . The real tool is a flame cutter .

## Types and components

The machines are available as a portal or boom system or a combination of these. They are practically always equipped with a coordinate drive and are easy to control. The drives, mostly servomotors for the x and y directions, are basically independent of one another. Therefore they have to be coupled in the control in order to achieve a constant path speed, which is necessary for a good cut quality. Basically, the following mathematical relationship holds between the web speed in the movement direction , the velocities in x- and y-direction and and the angle between the x axis and the vector of the web speed : ${\ displaystyle v}$${\ displaystyle v_ {x}}$${\ displaystyle v_ {y}}$${\ displaystyle \ alpha}$

${\ displaystyle v = v_ {x} ^ {2} + v_ {y} ^ {2} = v ^ {2} \ cdot (\ sin ^ {2} \ alpha + \ cos ^ {2} \ alpha) = constant}$.

The machines can have up to 20 independent flame cutters. You must be able to move freely and without jolts . Speeds of up to 6000 mm / min and the smallest radii of 20 mm are possible. With smaller radii, the groove lag becomes so large that the cut edges have to be reworked. Smaller radii can be achieved through a so-called “corner delay”. Before the burner reaches a sharp curve, the path speed is then reduced to such an extent that the groove lag no longer plays a role.

Since the distance between the torch nozzle and the sheet metal influences the quality of the cut, the machine has to compensate for unevenness, warpage and waviness. The so-called burner height adjustment is mostly implemented using capacitive measuring principles. A small metal plate on the burner and the sheet metal serve as the plates of a plate capacitor. The distance between the plates then changes the capacity. This means that deviations of ± 1.5 mm in height can be maintained without any problems, and with greater effort even up to ± 0.5 mm.

Some of the work that often occurs in sheet metal processing, such as scribing, countersinking and drilling, can be integrated into the flame cutting machines. With a photoelectric control, countersinks can be used as markings for the control. Powder markers are suitable for attaching part or item numbers and marking welding positions. A zinc powder is applied to the sheet and melted with a heating flame so that lines that are around 1 mm thick are created.

## control

Photoelectric and numerical controls are used in flame cutting machines.

### Photoelectric control

Trial commissioning of a photo-optical flame cutting machine of the Sicomat type in the Mathias Thesen shipyard , December 2, 1959

In the case of photoelectric control, either the centers about 1 mm thick lines are scanned ( line center scanning ) or the edges of the component silhouette ( line edge scanning ). For the former, connecting lines must be drawn in if several components are to be cut out.

The information is usually applied to plastic films which are sensitive to temperature and moisture and should therefore not exceed a size of 2 m².

The travel paths shown on the drawing can contain markings on the component either in the form of thickenings or as countersinking.

### Numerical control

Flame cutting machines with numerical control require higher investments, which pay off with an annual output of 40,000 cutting meters. With this control, the entire processing runs automatically. This increases the service life of the machines from 35% for the photoelectrically controlled machines to over 70%. In addition, the machines are more precise and can calculate optimal nesting plans in order to cut out several components from a raw part with as little waste as possible.

## Individual evidence

1. a b Alfred Herbert Fritz, Günter Schulze (Ed.): Fertigungstechnik , Springer, 2015, 11th edition, p. 394.
2. Alfred Herbert Fritz, Günter Schulze (Ed.): Manufacturing technology , Springer, 2015, 11th edition, p. 393f.
3. ^ A b Alfred Herbert Fritz, Günter Schulze (Ed.): Fertigungstechnik , Springer, 2015, 11th edition, p. 394f.
4. Alfred Herbert Fritz, Günter Schulze (Ed.): Fertigungstechnik , Springer, 2015, 11th edition, p. 396.