WO1992013189A1

WO1992013189A1 - Fuel injection valve for diesel engine

Info

Publication number: WO1992013189A1
Application number: PCT/JP1992/000008
Authority: WO
Inventors: Toshio Yoshimitsu
Original assignee: Kabushiki Kaisha Komatsu Seisakusho
Priority date: 1991-01-19
Filing date: 1992-01-09
Publication date: 1992-08-06
Also published as: JPH04237869A; JP2919983B2

Abstract

A fuel injection valve for a diesel engine capable of raising injection pressure without the dimensional change of a nozzle currently used, thereby being high in combustion efficiency. For attaining the purpose, the body of a fuel injection nozzle (2) is divide into an upper and lower halves, in which the upper half body (3) is provided with an oil feeding hole (7) with a proper wall thickness between it and the sliding part (6) of a needle valve, the upper part of the lower half (4) is provided with a recess (8) as an oil reservoir communicating with said oil feeding hole (7), and either the upper part of the upper body (3) or the lower part of the nozzle proper (1) in contact with the upper body is provided with an annular groove (10) so that the oil feeding hole (9) on the side of the nozzle proper may communicate with said oil feeding hole (7) of the lower body.

Description

Technical description Fuel injection valve technology for diesel engines

The present invention relates to an improvement in a fuel injection valve of a diesel engine that loses high injection pressure.

Background technology

Conventionally, 2 5 0~ 8 0 0 kg / cm 2 have been used as a * morphism pressure fuel «event of de ^ one Zeruenjin, Roh nozzle portion of the« case of fuel瘦射valve structure As shown in FIG. 2, a single oil feed hole 24 is provided near the sliding portion 23 of the needle valve 22 fitted to the nozzle 21. In addition, the fuel sent to the oil feed hole 2 is injected through the «feed passage 26» of the needle valve 22 and the body 25 below the sliding portion 23 via the sheet 27. It is injected into the combustion chamber from hole 28. At this time, the needle valve 22 is pressed against the nozzle 21 by the spring 30 provided on the fuel * firing valve main body 29, and the _β that seals the fuel at the seat portion 27 described above and the fuel is When the specified pressure (spring force) is reached by pulling out from oil feed hole 24, needle valve 22 is pushed up.

Conventionally, various measures have been taken against the pollution of Si noise and gas generated from automobiles and factories, but in recent years pollution regulations have become increasingly strict. Demand for low pollution (low emission) is also increasing. Therefore, one of the measures to reduce soot (carbon) in exhaust gas is to increase the fuel injection pressure to atomize the fuel injection box and improve the combustion efficiency. However, at present, as shown in FIG. 2, the oil sump chamber 31 of the nozzle 21 is formed by electric discharge machining, electrolytic processing, machining, or the like, so that the diameter cannot be further increased. Therefore, in the vicinity of the oil sump chamber 31, the thickness between the one oil feed hole 2, which is provided at an angle, and the sliding portion 23 is reduced. For example, with this structure, the fuel injection pressure When used at a pressure of more than 100 kg Z cm ² or more, it was impossible to use it continuously because it caused damage. In the figure, reference numeral 32 denotes a spill that returns internal fuel leakage to a pump or the like, and reference numeral 33 denotes a fuel supply passage. Disclosure of the invention

The present invention is seen trowel thereto, without changing the magnitude of the current nozzle, moreover 1 0 0 0 kg / cm ² or more injection pressure prior to provide a fuel injection valve is also available diesel engine with respect to It aims to eliminate the shortcomings of the technology.

For this purpose, Honki Akira divides the body of the fuel injection nozzle into upper and lower parts and drills an oil feed hole in the upper body while maintaining the sliding thickness of the needle valve and the thickness. And a concave portion for oil pan communicating with the oil feed hole is provided on one of the upper surface of the upper body or the lower surface of the nozzle body in contact with the oil feed hole. A vertical groove communicating with the hole is provided.

With such a configuration, a large amount of oil can be obtained, so that the thickness of the oil feed hole and the driving portion can be increased. Therefore, it can be used even under low injection pressure, and the combustion efficiency is improved. Brief description of drawings

FIG. 1 is a front sectional view of a fuel injection valve of a diesel engine according to the present invention, and FIG. 2 is a front sectional view of a conventional fuel injection valve of a diesel engine. BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of a fuel injection valve for diesel engines according to the present invention will be described in a detailed box based on FIG.

The body of the fuel injection nozzle 2 is divided into upper and lower bodies 3 and 4, and the upper body 3 holds the sliding part 6 of the needle valve 5 and has a suitable thickness and has a plurality of parallel oil feed holes. 7 is provided, and an upper portion 8 of an oil reservoir communicating with the oil feed hole Ί is provided at an upper portion of the lower body 4. Further, the lower fiber of the nozzle body 1 which is in contact with the upper surface of the upper body 3 is provided with a portion ttla formed with a 璟 -shaped groove 10 through which the main body side oil feed hole 9 communicates with the oil feed hole 7. .

The nozzle body 1, which is attached to a cylinder head (not shown), is formed in an appropriately long rod shape, and a fuel supply port 11 is provided at an upper end thereof. A nozzle body-side oil supply hole 9 is provided from the supply port 11 to the injection nozzle 2 so as to pass therethrough avoiding the shaft core. This core is provided with a spring chamber 1 2, and a svil 13 whose 1 鵰 communicates with the spring chamber 12 and which is open in proximity to the supply port 11. The svil 13 is for returning an internal leak of the fuel supplied to the fuel injection nozzle 2 to a pump or a tank (not shown) via the svil vibe 14. A spring 15 for pressing the needle valve 5 is provided in the spring chamber 12.

It should be noted that the cross-sectional area of the number II oil feed hole 7 provided in the upper body 3 is formed to have a small diameter so as to be substantially the same as the surface ridge of the conventional oil feed hole. Therefore, these oil feed holes 7 are thicker than the conventional case and the gap between the oil feed hole 7 and the sliding portion 6 and are provided on a large circumference. The recess 8 for the oil ST, which is provided on the upper surface of the lower body 4, has a large diameter so as to pass through the front 8B oil feed hole 7. The gap between the needle valve 5 and the needle valve 5 is the fuel passage 16. A seat surface 17 and a hole 18 are formed below the lower body 4. Further, the fuel in the nozzle body side oil feed hole 9 is simultaneously sent to the plurality of oil feed holes 7 of the upper body 3 by the groove 10 provided in the member 1 a.

As shown in FIG. 1, the upper body 3 and the lower body 4 are joined together by press-fitting with a part of the inner space, or integrated by electron beam welding or the like at the joint, and then the sliding part 6 and the sheet are joined together. The surface 17 is completed by simultaneous finishing.

Next, the operation will be described.

First, the fuel supplied to the supply port 11 passes through the nozzle body side oil feed hole 9, passes through the annular groove 10 of the lower member 1 a, and passes through the plurality of oil feed holes 7, 7 of the upper body 3. The oil is collected in the lower part 8 of the lower body 4 for oil sump. Part of it reaches the fuel passage 16 and is sealed at the seat surface 17. When the fuel reaches the specified pressure, the needle valve 5 pushes the spring 15 When raised, the seal on the sheet surface 17 is released, and the fuel is injected from the injection hole 18 into a combustion chamber (not shown) as fog.

As for the oil feed holes 7, for example, 2 × 2 holes may be changed to 1.6 5 × 6 holes, in which case the thickness of the sliding portion 6 and the hole can be further increased. FIG. 1 shows a case where the annular groove 10 is provided in the member 1 a attached to the lower end of the nozzle body 1, but the member 1 a may be attached to the upper body 3.

As described above, according to the present invention, the thickness of the plurality of oil feed holes の of the upper body 3 and the sliding portion 6 can be increased, and the recess 8 for the oil skirt can be enlarged. The problem of strength is eliminated. Therefore, the fuel injection nozzle 2 can be used at a high pressure, and the fuel consumption is improved. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention is useful as a fuel efficient fuel injection valve for a diesel engine that can be used without changing the size of the current nozzle and at an injection pressure of 100 kg / cm * or more.

Claims

-δ-Scope of billing

1. The body of the fuel injection nozzle is divided into upper and lower parts, and an oil feed hole is drilled in the upper body while keeping the sliding part of the needle valve and the wall thickness as appropriate, and the oil feed hole is formed in the upper part of the lower body. In addition to providing an oil hole recess communicating with the hole, the nozzle body side oil feed hole and the oil feed hole communicate with either the upper part of the upper body or the lower part of the nozzle body in contact with the upper body. A fuel injection valve in diesel engine characterized by having a 溝 -shaped groove.

2. The oil hole drilled in the upper body is parallel to the sliding part of the needle valve, and it is specially provided that a few ffls are provided. Fuel * Valve.