JP2003148240A - Fuel injection valve cooling structure for cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve cooling structure in which a nozzle is disposed in a cooling water passage to flow cooling water toward the combus tion chamber side of a sleeve. SOLUTION: In an internal combustion engine, an annular water chamber is formed between a cylinder head and the sleeve supporting the fuel injection valve, and the cooling water passage suppling the cooling water to the water chamber is disposed to the cylinder. The nozzle, which makes the cooling water diagonally flow so that the cooling water flows toward the high temperature side of the sleeve, is disposed to an outlet of the cooling water passage. The nozzle is set to make the cooling water flowing into the annular water chamber flow toward the combustion chamber side of the sleeve. The nozzle is set to make the cooling water flowing into the annular water chamber circulate in the annular water chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure which enables cooling water flowing through a cooling water passage provided in a cylinder head to cool a fuel injection valve satisfactorily.

[0002]

2. Description of the Related Art FIG. 4 is a vertical sectional front view of a fuel injection valve 94 of a conventional internal combustion engine 200. The internal combustion engine 200 is
A fuel injection valve 94 is supported by a sleeve 93 fixed to the cylinder head 90. A cooling water passage 91 is provided in the cylinder head 90, and the cooling water supplied from the cooling water passage 91 enters an annular water chamber 92. The cooling water that has flowed into the water chamber 92 is discharged from the drainage channel 94.

The fuel injection valve 94 is exposed to the combustion chamber 97 and becomes extremely hot. The cooling water passage 91 is adapted to supply the cooling water into the water chamber 92. The cooling water collides with the sleeve 93 at a right angle, and the collision portion is cooled well, but the other portion, for example, combustion. It is difficult to flow to a portion having a relatively high temperature near the chamber 97.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a cooling structure for a fuel injection valve having a nozzle portion in a cooling water passage so that the cooling water flows toward the combustion chamber of the sleeve.

[0005]

In order to solve the above problems, in the invention of claim 1, an annular water chamber is formed between a cylinder head and a sleeve supporting a fuel injection valve, and cooling water is provided in the water chamber. In the internal combustion engine in which the cooling water passage for supplying the cooling water is provided in the cylinder head, the outlet of the cooling water passage is provided with a nozzle portion for obliquely flowing the cooling water so that the traveling direction of the cooling water is toward the high temperature side of the sleeve. In the invention of claim 2, in the invention of claim 1, the nozzle portion is set so that the cooling water flowing into the annular water chamber faces the combustion chamber side of the sleeve. In the invention of claim 3, in the invention of claim 1,
The nozzle part was set so that the cooling water flowing into the annular water chamber circulated in the annular water chamber.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical sectional front view of the vicinity of a fuel injection valve 4 of an internal combustion engine 100 according to the first and second aspects of the invention. Further, FIG. 2 is an enlarged view of a portion A in FIG.

As shown in FIG. 1, a cylinder head 1 of an internal combustion engine 100 is provided with a fuel injection valve 4 via a sleeve 2. The cylinder head 1 extends below the sleeve 2 to support the fuel injection valve 4, and the sleeve 2 is not exposed to the combustion chamber 6.

A heat-resistant packing 13 is provided between the lower end of the sleeve 2 and the cylinder head 1. An annular water chamber 3 is formed between the outer peripheral side surface of the sleeve 2 and the cylinder head 1.

As shown in FIG. 1, the cylinder head 1 is provided with a cooling water passage 7 for supplying cooling water into the water chamber 3.
The cooling water passage 7 is perforated, and a cylindrical nozzle member 8 is mounted in the cooling water passage 7. The nozzle member 8 penetrates the right end side in FIG. 2, and the wall 11 is provided on the left end side (the water chamber 3 side). The wall 11 is provided with an inclined hole 9, and the cooling water flows from the cooling water passage 7 through the inside of the nozzle member 8 and flows into the water chamber 3 from the inclined hole 9.

The fuel injection valve 4 is exposed in the combustion chamber 6,
Since it directly contacts the hot gas generated by combustion, it tends to become hot. In particular, the valve seat 14 controls the injection of the fuel supplied from the fuel supply path 12 by seating the valve body 5, but when the valve seat 14 becomes a high temperature (200 ° C. or higher), combustion residue adheres to the valve body 5 and May not seat completely and may leak fuel.
In addition, as the temperature rises, the fatigue strength of the material decreases, and the seat impact of the valve element 5 may cause the valve seat 14 to settle. As a result, the valve element 5 may not be completely seated on the valve seat 14 and fuel may leak.

The high-temperature fuel injection valve 4 is cooled to 150 ° C. or lower by cooling water through the sleeve 2. The cooling water, after flowing into the water chamber 3 through the inclined hole 9, moves to the combustion chamber 6 side (high temperature side) of the sleeve 2 to remove heat from the sleeve 2 (fuel injection valve 4) and discharge from the drainage channel 10. To be done.

The nozzle member 8 is composed of a rigid member having an outer diameter E (about 6 to 15 mm) slightly smaller than the inner diameter B of the cooling water passage 7 and having a wall thickness t of about 1.5 to 3 mm. . As described above, when the nozzle member 8 is made of a rigid member (for example, steel material), the nozzle member 8 can play a role of reinforcing the cooling water passage 7. Therefore, the deformation and distortion of the cylinder head 1 (the portion between the intake valve and the exhaust valve, which are not shown, adjacent to each other) can be reduced, and the strength of the cylinder head 1 can be improved.

FIG. 3 is a schematic vertical sectional view showing a state in which the position of the inclined hole 9 is set so that the cooling water swirls in the annular water chamber 3. When the orientation of the inclined hole 9 is set so that the cooling water swirls in the annular water chamber 3 and approaches the combustion chamber side (high temperature side), the cooling water that has been heated by heat transfer and has just entered the water chamber 3. The low temperature cooling water is easily mixed, and the high temperature sleeve 2 (fuel injection valve 4) is cooled well.

Although the sleeve 2 is not exposed to the combustion chamber 6 in the structure of FIG. 1, it may be exposed to the combustion chamber 6. However, as long as the sleeve 2 as shown in FIG. 1 is not exposed to the combustion chamber 6, the sleeve 2
Since it is not directly exposed to the flame, it is easy to maintain a relatively low temperature, the high temperature fuel injection valve 4 can be cooled well, and the performance deterioration of the fuel injection valve 4 due to the high temperature can be avoided.

[0015]

According to the invention of claim 1, the flow direction of the cooling water flowing along the cooling water passage 7 is limited to the direction perpendicular to the sleeve 2 (fuel injection valve 4). By providing the nozzle member 8 in the cooling water passage 7, the water chamber 3
The cooling water flowing into the inside can be directed to the high temperature side (combustion chamber 6 side) of the sleeve 2 (fuel injection valve 4), and the sleeve 2
The high temperature part of the (fuel injection valve 4) can be cooled well.

According to the second aspect of the invention, since the nozzle portion 8 is set so that the flow direction of the cooling water faces the combustion chamber side of the sleeve, the cooling water can be supplied to the high temperature portion of the sleeve in the shortest distance, The cooling effect can be improved.

According to the third aspect of the present invention, by directing the inclined hole 9 of the nozzle portion 8 in the circumferential direction of the sleeve 2, the cooling water can be swirled in the annular water chamber 3 and the heat can be recovered well. It can be performed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view of the vicinity of a fuel injection valve of an internal combustion engine that implements the first and second aspects of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a vertical plan view of a nozzle member.

FIG. 4 is a vertical sectional front view of the vicinity of a fuel injection valve of a conventional internal combustion engine.

[Explanation of symbols]

1 cylinder head 2 sleeve 3 water chamber 4 Fuel injection valve 5 valve body 6 Combustion chamber 7 Cooling water passage 8 nozzle members 9 inclined holes 10 drainage channels 11 walls 12 Fuel supply path 13 packing 14 seat 100 internal combustion engine

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Claims (3)

[Claims] 1. An internal combustion engine in which an annular water chamber is formed between a cylinder head and a sleeve supporting a fuel injection valve, and a cooling water passage for supplying cooling water to the water chamber is provided in the cylinder head. A fuel injection valve cooling structure for a cylinder head, characterized in that a nozzle portion for obliquely flowing the cooling water is provided at an outlet of the cooling water passage so that a traveling direction of the cooling water is directed to a high temperature side of the sleeve. 2. The fuel injection valve cooling structure for a cylinder head according to claim 1, wherein the nozzle portion is set so that the cooling water flowing into the annular water chamber faces the combustion chamber side of the sleeve. 3. The fuel injection valve cooling structure for a cylinder head according to claim 1, wherein the nozzle portion is set so that the cooling water flowing into the annular water chamber circulates in the annular water chamber.