Abstract: In an in-cylinder injection type spark ignition internal combustion engine which uses a spark plug to ignite and burn an air-fuel mixture flow formed by fuel which is injected from a fuel injection valve and flies around inside a cylinder while mixing with air, the spark plug has a first electrode formed on its center axis and a second electrode having a substantially L-shaped cross section, a spark gap is formed between the first electrode and the second electrode, and the spark plug is arranged such that the air-fuel mixture flow passes directly through the spark gap.

Abstract: A method of controlling an operation of a copycutting apparatus including a tracer for tracing automatically a pattern and a cutting gas torch interconnected to the tracer in a given relationship. Prior to the actual working, the tracer is manually moved with respect to the pattern along a given path and stores coordinates of operational points such as a piercing point, a copy start point, a copy end point, an intermediate point, a slow down point, etc. During the actual working the stored coordinates are readout to control the movement of the tracer in such a manner that until the tracer does not reach a copy start point the copying apparatus is set in a position setting mode in which the tracer is moved under the control of the readout coordinates. After the tracer has reached the copy start point the copying apparatus is switched into a copying mode in which the movement of tracer along the pattern is controlled by detecting the pattern.

Abstract: A method of controlling an operation of a copy-cutting apparatus including a tracer for tracing automatically a pattern and a cutting gas torch interconnected to the tracer in a given relationship. Prior to the actual working, the tracer is manually moved with respect to the pattern along a given path and stores coordinates of operational points such as a piercing point, a copy start point, a copy end point, an intermediate point, a slow down point, etc. During the actual working the stored coordinates are read out to control the movement of the tracer in such a manner that until the tracer has reached a copy start point the copying apparatus is set in a position setting mode in which the tracer is moved under the control of the read out coordinates. After the tracer has reached the copy start point the copying apparatus is switched into a copying mode in which the movement of tracer along the pattern is controlled by detecting the pattern.