JPS6030469Y2 - Unit injector joint part leakage gas release device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a leakage gas release device for a unit injector of an internal combustion engine in which the unit injector is inserted into a cylinder head.

An internal combustion engine in which a unit injector that integrates a fuel injection pump and an injection nozzle is inserted from the top of the cylinder head toward the combustion chamber is effective in making the engine more compact and high-performance. In order to prevent combustion gas from leaking from the combustion chamber into the gap between the injection nozzle installed at the tip of the unit injector and the cylinder head, it is necessary to insert a gas seal gas seal. .

In addition, in the upper part of the unit injector main body, when supplying fuel to such a unit injector, the fuel supplied from the fuel supply path provided in the cylinder head is introduced into the insertion part of the unit injector. If a fuel supply port is provided, the area around the fuel supply port of the unit injector and the insertion part of the cylinder head should be
It is necessary to install two upper and lower fuel cylinder O-rings to prevent fuel leakage.

However, if the gas seal gas seal becomes damaged, high-temperature combustion gas will leak to the top from the gas seal, and the 01J ring for the fuel seal will also be damaged.
The gas enters the fuel that is filled between the two O-rings, and the unit injector no longer injects fuel.Furthermore, fuel leaks from the damaged part of the O-ring. If this carbonizes between the cylinder head insertion hole and the unit injector, causing the unit injector to become stuck, or if the amount of combustion gas increases, the fuel in the O-ring section will heat up and start burning, creating a dangerous situation. Become.

Therefore, this invention was devised to prevent the above-mentioned dangerous situation in an internal combustion engine in which a unit injector is inserted into the cylinder head. The purpose of this is to prevent the fuel from being emitted to the outside and from entering the fuel sealing O-ring and damaging the O-ring.

That is, the present invention provides a unit injector that is inserted into the combustion chamber from the upper surface of the cylinder head, and a gas seal gas seal is interposed in the insertion part of the injection nozzle part of the unit injector to the cylinder head. , an O-ring for fuel sealing is interposed at the insertion part with the cylinder head around the fuel supply port of the unit injector, and the above-mentioned packing and O-ring of the insertion part of the unit injector with respect to the cylinder head are interposed. It opens between
The cylinder head is constructed by providing a slotted hole communicating with the outside in the cylinder head.

Embodiments of the present invention will be described below with reference to the drawings.

First, in a cylinder head 1 of a diesel engine according to an embodiment of the present invention shown in the drawings, a unit injector 3 is inserted at an angle θ toward a combustion chamber 4 provided on the upper surface of a piston 2, and is mounted with a presser foot. It is fixed to the cylinder head 1 in a tightened state with bolts 6 via metal fittings 5.

Next, a tapered gas sealing gas seal 8 is interposed at the insertion part of the injection nozzle 7 at the tip of the unit injector 1 to the cylinder head 1, and the gas seal 8 is inserted into the cylinder head 1 to prevent combustion gas entering from the combustion chamber 4. It is designed to perform a seal.

Further, fuel supplied from the fuel strainer side via the fuel supply path 9 as shown by arrow F is introduced into the unit injector 3 from the fuel supply port 11 of the unit injector 3, and is rotated by the fuel cam 16 provided on the camshaft 10. As a result, the fuel valve arm 14 supported by the valve arm shaft 15 swings, and as a result, the fuel F is discharged from the injection nozzle 7 of the unit injector 3.
is injected into the combustion chamber 4.

Further, two upper and lower O-rings 12 for fuel sealing are interposed at the insertion portion with the cylinder head 1 around the fuel supply port 11 to prevent leakage of the fuel F.

Therefore, in the present invention, a slotted hole 13 is opened in the gap between the gasket 8 and the O-ring 12 at the insertion part of the unit injector 3 into the cylinder head 1, and communicated with the outside of the diesel engine. cylinder head 1
It is drilled in.

By providing the above-mentioned perforation 13, even if the gas seal 8 is damaged by the combustion gas leaking from the combustion chamber 4, or if the gas sealing effect is deteriorated due to dirt in the combustion gas being trapped, the leakage combustion Gas is in this hole 1
3 It will be released to the outside of the transit agency.

Therefore, if the present invention is applied to an internal combustion engine in which a unit injector is inserted into the cylinder head, even if the gas sealing gas seal installed on the injection nozzle side is damaged by high-temperature combustion gas, the combustion gas will be transferred to the unit injector. The O-ring for the fuel seal installed around the fuel supply port of the unit was no longer penetrated, and combustion gas was mixed into the fuel, resulting in poor fuel injection from the unit injector or leakage from the unit injector. Problems such as fuel stagnation or dangerously high temperatures can be prevented.

Furthermore, with this invention, the leaked combustion gas discharged from the cut hole drilled in the cylinder head can be detected externally, making it possible to detect gas leaks at an early stage. Another advantage is that the influence on the O-ring for fuel sealing can be reduced.

Note that the present invention can be effectively applied to an internal combustion engine in which a unit injector is inserted into the cylinder head.

[Brief explanation of drawings]

The drawing is a front sectional view of a main part of a cylinder head of a diesel engine according to an embodiment of the present invention. 1... Cylinder head, 3... Unit injector, 4... Combustion chamber, 7...
・Injection nozzle, 8...Packskin, 11...
...Fuel supply port, 12...O ring, 13...
...kire hole.

Claims (1)

[Scope of utility model registration request] In a unit injector that is inserted into the combustion chamber from the top surface of the cylinder head, a gas seal gas seal is interposed at the insertion part of the injection nozzle part of the unit injector to the cylinder head, and An O-ring for fuel sealing is interposed in the insertion part with the cylinder head around the fuel supply port, and an opening is provided between the gasket and the O-ring in the insertion part of the unit injector with respect to the cylinder head. What is claimed is: 1. A unit injector insertion part leakage gas release device, characterized in that a slotted hole communicating with the outside is provided in the cylinder head.