Development of an Engine Coolant Thermostatic/Pressure Switch.

摘要

Military vehicle engine cooling systems are frequently pressurized in order to raise the operating temperature of the coolant above the ambient boiling temperature. System pressure can be lost due to a defective radiator cap or any other pressure leak. Undetected loss of pressurization renders a vehicle unusable due to loss of coolant from boiling. Such engines are often equipped with a dashboard mounted over-temperature warning light which is activated by a thermostatic switch such as is described in MIL-S-12285. This type of switch does not provide warning of loss of pressurization. This report describes the development of a thermostatic/pressure switch designed to warn of both coolant over-temperature conditions as well as loss of cooling system pressurization. The program involved the detailed design, qualification testing, and manufacture of preproduction thermostatic/pressure switches as well as preparation of a draft revision to MIL-S-12285.