JPS5943507Y2 - Diesel engine ignition system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ignition device for a diesel engine.

The deterioration of the ignitability of diesel engines is unavoidable due to the decrease in cetane number caused by the deterioration of the quality of the fuel.As a countermeasure to this problem, attempts were made to use the spark plugs used in gasoline engines in diesel engines to aid in ignition. Attempts have been made to do so, and some have been commercialized.

This spark plug prevents misfires during operation and also serves as an auxiliary device during starting.

Therefore, commercially available engines of this type are not provided with any auxiliary device for starting other than a spark plug.

However, since the thermal energy obtained by the spark is extremely small, it is not possible to lower the starting temperature limit sufficiently, and if starting fails and fuel accumulates on the plug, subsequent starting becomes difficult. There's a problem.

On the other hand, glow plugs have been widely used as an ignition source in the combustion chamber of a diesel engine.

Glow plugs use far less thermal energy than spark plugs, and have a proven track record as starting aids.

However, when considering glow plugs as a means to assist in ignitability during driving, the following problems arise.

In other words, unlike spark plugs, the timing of ignition cannot be made constant, and there are doubts about reliability and durability when electricity is applied without interrupting operation.

Furthermore, when cold air is sucked into the cylinder during operation, the temperature of the glow plug decreases, significantly reducing its function.

The present invention was devised in view of the above circumstances, and its purpose is to create a diesel engine that can take advantage of the respective advantages of spark plugs and glow plugs, and improve ignition performance and low-temperature startability. The purpose of this invention is to provide an ignition device.

Hereinafter, the present invention will be explained with reference to the drawings.

1 in the drawing is a plug body, and this plug body 1/li
It is electrically conductive and has a sparking electrode 2 protruding from its tip.

A tubular insulator 3 is provided in the center of the plug body 1, and a center electrode 4 is inserted into the insulator 3.The tip of the center electrode 4 is close to the electrode 2 and connects both electrodes. 2.4 forms the spark plug part 6.

A cylindrical insulator 5 is buried concentrically with the insulator 3 in the plug body 1, and an insulator 7 is formed between the rims 3 and 5 (D%'J). .

A glow plug coil 8 is provided in this insulating portion 7.

One end of the glow plug coil 8 is connected to the plug body 1, and the other end is led out of the plug body 1.

The glow plug coil 8 and the plug body 1 form a glow plug portion 9.

Note that a secondary voltage is applied to the center electrode 4, and 12V or 24V is applied to the glow plug coil 8.

Thus, during steady operation, the spark plug section 6 helps to ensure ignition, and when the temperature is low, the glow plug section 9 starts the engine.

Further, when ignition is caused by a spark from the spark plug portion 6, the atmosphere around the spark needs to be sufficiently conducive to ignition.

In this case, the heat from the glow plug section 9 warms the surroundings of the spark plug section 6, which is advantageous for ignition.

The present invention has been described in detail above, and includes an electrode 2 formed at the end of a conductive plug body 1, a center electrode 4 provided on the plug body 1 via an insulator 3, and sparks generated by both electrodes 2.4. A glow plug in which a plug part 6 is formed, another insulator 5 is provided on the plug body 1, an insulating part 7 is formed between the rims 3.5, and one end of the insulating part 7 is connected to the plug body 1. Since the glow plug part 9 is formed by providing the coil 8, reliable ignition can be obtained with the help of the spark plug part 6 during steady operation, reliable starting can be obtained with the help of the glow plug part 9 at low temperatures, and the spark When ignition is caused by the spark from the plug section 6, the heat from the glow plug section 9 creates an atmosphere around the spark that is sufficiently conducive to ignition, resulting in good ignitability.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view thereof, and FIG. 2 is a longitudinal sectional view thereof. 8 is a plug body, 2 is an electrode, 3 and 5 are insulators, 6 is a spark plug part, 7 is an insulating part, 8 is a glow plug coil, and 9 is a glow plug part.

Claims (1)

[Scope of utility model registration request] An electrode 2 is formed at the end of a conductive plug body 1, and a center electrode 4 is provided on the plug body 1 via an insulator 3, and both electrodes 2 and 4 form a spark plug part 6. Another insulator 5 is provided between the two wheel rims 3 and 5, and an insulating part 7 is provided.
The ignition device for a diesel engine is characterized in that a glow plug coil 8 having one end connected to the plug body 1 is provided in the insulating part 7 to form a glow plug part 9.