Hironori Osamura

Development of new iridium alloy for spark plug electrodes

From the view of suppressing the global warming and environmental pollution, responding to the regulation of fuel consumption and exhaust gases along with lengthening the maintenance interval, are becoming more demanded. The development of a high-performance, long life spark plug has become essential in response to these demands. While improve performance (high ignitability and low required voltage), the discharge part of the spark plug needs to be reduced in size. But, in the past this has been difficult because of the limitations of platinum alloys in terms of wear. It has been difficult to achieve both smaller discharge parts and longer life. To dramatically improve wear resistance, we researched materials that are both resistant to oxidation and have a high melting point. This research resulted in our development of a new iridium alloy. Through this development we have been able to produce an iridium spark plug that surpasses the conventional platinum technology. The new iridium spark plug is now being used in high volume vehicle production. This paper is divided into the following three parts and describes the development of the new generation of iridium spark plugs. Chapter 1: Introduction The need for smaller electrode diameter and longer life spark plugs and related issues Chapter 2: Development of Electrode Materials History of the development of the new iridium alloy Chapter 3: Application in Spark Plugs 1. High-performance and maintenance free spark plugs 2. Super high-performance spark plugs CHAPTER