JPH09112391A - Mounting structure of fuel injection pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of rust at a fuel injection pipe by providing an atmosphere release hole to communicate the internal space of a nipple with the outside in one or both of a first seal member and a nipple or a second seal member. SOLUTION: An atmosphere release hole 17 extending along an axial direction is formed in the inner peripheral surface of the cylindrical member 15a of a seal flange 15 being a seal member to cover the peripheral wall of a nipple 14. One end 17a of the hole 17 is opened and the other end 17b is extended to the lower part of a cylindrical part 15a positioned in a cylinder head cover 11 and communicated with an atmosphere release hole 14b of the nipple 14 covered in the position with the cylindrical part 15a. Further, an atmosphere release hole 18 in an inverted L-shape is formed in a seal rubber 16 being a second seal member, one end of the hole 18 is opened to the peripheral surface of the head part position of the nipple 16 and the other end is opened to the bottom of the seal rubber 16. This constitution vaporizes cooled water and prevents the occurrence of rust of a fuel injection pipe 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a fuel injection pipe, and more particularly to a nipple for introducing the fuel injection pipe into a cylinder head cover to connect the fuel injection pipe to a fuel injection nozzle holder. The present invention relates to an attachment structure for a fuel injection pipe that is open and prevents rust from occurring.

For example, as shown in FIG. 5, a fuel injection pipe 50 has one end connected to a fuel injection pump 51, and the fuel pressurized by the fuel injection pump 51 is connected to the other end. The fuel injection nozzle holder 52 is pressure-fed to the injection nozzle holder 52. However, since the fuel injection nozzle holder 52 is arranged substantially at the center of the cylinder head 53 due to its structure, the other end of the fuel injection pipe 50 is connected to the lower cylinder head cover 54. Need to extend to the inside.

Therefore, as shown in detail in FIG. 6, in the fuel injection pipe mounting hole 55 of the cylinder head cover 54,
A nipple 56 screwed to the fuel injection nozzle holder 52 is attached via a seal flange 57, and the fuel injection pipe 50 is introduced into the cylinder head cover 54 via the nipple 53 while the head of the nipple 56 is sealed. A rubber 58 is fitted to seal the gap between the nipple 56 and the fuel injection pipe 50.

According to this mounting structure, the fuel injection pipe 5
The nipple 56 is inserted into the cylinder head cover 54 through the fuel injection pipe mounting hole 55.
Of the fuel injection pipe 50, the other end of the fuel injection pipe 50 is inserted into the fuel injection nozzle holder 52, and the nipple 56 is screwed into the fuel injection nozzle holder 52. This attachment work is facilitated and the cylinder head cover 54 and the nipple 56 are inserted.
In order to perform a sufficient sealing with the nipple 56, a long nipple 56 is used, and a gap is provided between the inner wall of the nipple 56 and the outer wall of the fuel injection pipe 50.

In FIG. 5, reference numeral 60 is a cylinder block, 61 is a piston, and 62 is an upper cylinder head cover.

[0006]

According to the above-mentioned fuel injection pipe mounting structure, the space inside the nipple 56 is closed by the seal rubber 58 to form a closed space 59. For example, when the engine is stopped, the nipple 56 is closed. When the closed space 59 is cooled by the outside air, the moisture in the air in the closed space 59, which was warmed and saturated when the engine was operated, is condensed, the pressure in the closed space 59 decreases, and the outside air (water vapor) ) Is easily taken in, and once the outside air is taken into the closed space 59, it is difficult to escape because of the closed structure, and water accumulates in the closed space 59. Therefore, rust may occur in the nipple 56 and the fuel injection pipe 50 inside the nipple 56.

Therefore, an object of the present invention is to provide a mounting structure for a fuel injection pipe which is free from the risk of rusting.

[0008]

In order to achieve the above object, a fuel injection pipe mounting structure according to a first aspect of the present invention has a structure in which a cylinder head cover is attached to and detached from a fuel injection pipe holder. A nipple that is freely screwed is attached through a first seal member, the fuel injection pipe is introduced into the cylinder head cover through the nipple and connected to the fuel injection nozzle holder, and between the nipple and the fuel injection pipe. The fuel injection pipe is attached to the first seal member and the nipple and / or the second seal member, that is, the first seal member and the nipple. The second seal member, or the first seal member, the nipple and the second seal member, outside the inner space of the nipple. It is characterized by comprising providing at least one air opening hole communicating and.

Further, in the fuel injection pipe mounting structure according to the second aspect of the present invention, a ventilation space is provided in the inner wall of the fuel injection pipe mounting hole of the cylinder head cover so as to surround the nipple, and the cylinder head cover has a ventilation space. At least one atmosphere opening hole communicating with the ventilation space is provided in the peripheral wall of the nipple surrounded by the outer surface and the inner wall of the fuel injection pipe mounting hole.

In the fuel injection pipe mounting structure according to the second aspect, it is preferable that a cover member that covers the atmosphere opening hole is mounted on the cylinder head cover.

According to the fuel injection pipe mounting structure of the first aspect of the present invention, the inner space of the nipple is externally opened via the atmosphere opening hole provided in the first seal member and / or the second seal member. It does not form a closed space and does not collect water even if the nipple is cooled by the outside air when the engine is stopped. Further, even if water enters the inner space of the nipple, it easily evaporates, and there is no possibility that water will collect.

According to the fuel injection pipe mounting structure of the second aspect, the internal space of the nipple has an atmosphere opening hole provided in the peripheral wall of the nipple, a ventilation space, and an atmosphere opening hole provided on the upper surface of the cylinder head cover. It is communicated with the outside through the outside and does not form a closed space, and there is no possibility that water will collect even if the internal space of the nipple is cooled by the outside air when the engine is stopped. Further, even if water enters the inside of the nipple, it is likely to evaporate and there is no possibility of accumulation. When a cover member for covering the atmosphere opening hole is attached to the cylinder head cover, it is possible to prevent water or the like from directly entering through the atmosphere opening hole.

[0013]

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

FIG. 1 is a partially enlarged sectional view showing a first embodiment of a fuel injection pipe mounting structure of the present invention, and FIG.
2 is an enlarged sectional view taken along the line II, and FIG. 3 is an enlarged sectional view taken along the line III-III in FIG.

According to the mounting structure of the fuel injection pipe of the first embodiment, for example, a four-valve system (two on the intake side and two on the exhaust side) is used.
Fuel injection pipe mounting hole 1 on the cylinder head cover 11 on the lower side of a large diesel engine.
2 is provided, and a nipple 14 which is detachably screwed to a fuel injection nozzle holder 13 is provided in the fuel injection pipe mounting hole 12.
Is attached via a seal flange 15 which is a first seal member, and the fuel injection pipe 10 is introduced into the cylinder head cover 11 via the internal space 14a of the nipple 14 and connected to the fuel injection nozzle holder 13. A seal rubber 16 that is a second seal member that seals between the nipple 14 and the fuel injection pipe 10 is fitted on the head of the nipple 14 outside the cylinder head cover 11. The cylindrical portion 15a of the seal flange 15 that covers the peripheral wall of the nipple 14 is formed to be longer than the conventional seal flange (see FIG. 6), and the inner peripheral surface of the cylindrical portion 15a extends along the axial direction (outer circumference of the nipple 14). The surface is provided with an atmosphere opening hole 17 extending along the axial direction). An end 17a of the atmosphere opening hole 17 is open at the end of the cylindrical portion 15a located outside the cylinder head cover 11.
The other end 17b of the atmosphere opening hole 17 extends to the lower portion of the tubular portion 15a located inside the cylinder head cover 11,
At this position, it communicates with the atmosphere opening hole 14b on the outer peripheral surface of the nipple 14 covered by the tubular portion 15a. Also,
The seal rubber 16 is provided with a substantially inverted L-shaped atmosphere opening hole 18. One end of the atmosphere opening hole 18 opens at the peripheral surface located at the head of the nipple 16, and the other end opens at the bottom surface of the seal rubber 16 located inside the nipple 16.

Therefore, the internal space 16 of the nipple 16
The opening a communicates with the outside of the cylinder head cover 11 through the atmosphere opening holes 14b, 17 and 18, and has an atmosphere opening structure.

A female screw is provided on the inner peripheral surface of the lower end of the nipple 14 and is screwed with a male screw provided on the fuel injection nozzle holder 13.

According to the structure for mounting the fuel injection pipe of the first embodiment, when the internal space 14a of the nipple 14 that has been warmed during engine operation is cooled by the outside air after the engine is stopped, the internal space 14a Moisture in the saturated air is condensed (condensation). However, since the internal space 14a communicates with the outside through the atmosphere opening holes 17 and 18, the pressure in the internal space 14a does not decrease and the outside air containing water is not introduced from the outside, and therefore the amount of water does not change. Internal space 1
The condensed (condensed) water is not accumulated in 4a and is evaporated into the atmosphere, so that the inner wall surface of the nipple 14 and the nipple 1
There is no possibility that the outer wall surface of the fuel injection pipe 10 in 4 will rust.

FIG. 4 is a partially enlarged sectional view showing a second embodiment of the fuel injection pipe mounting structure of the present invention. FIG.
The same components as those shown in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted.

According to the fuel injection pipe mounting structure of the second embodiment, the atmosphere opening hole is provided on the cylinder head cover side instead of providing the atmosphere opening hole on the seal member. That is, an annular ventilation space 21 is provided in the inner wall of the cylindrical mounting hole 20 that is the fuel injection pipe mounting hole of the cylinder head cover 19 so as to surround the nipple 14, and the cylinder head cover 19 around the mounting hole 20 is provided. An air opening hole 22a communicating with the ventilation space 21 is provided on the outer surface of the nipple, and the ventilation space 21 is formed on the peripheral wall of the nipple 14 surrounded by the mounting hole portion 20.
Atmosphere opening holes 22b and 22c are provided to communicate with. Atmosphere opening hole 22 provided on the outer surface of the cylinder head cover 19
Since a is facing upward and water may enter from the outside, it is covered with the baffle plate 23 fixed to the outer peripheral surface of the mounting hole 20. The first seal member between the mounting hole 20 of the cylinder head cover 19 and the nipple 14 is an O-ring 24 that is mounted in a groove at one end and the other end in the axial direction of the inner wall of the mounting hole 20, respectively. A seal rubber 25, which is a second seal member that seals between the head of the fuel injection pipe 10 and the fuel injection pipe 10, has the same structure as that of the prior art.

Also in the fuel injection pipe mounting structure of the second embodiment, the nipple 1 was warmed when the engine was operating.
When the internal space 14a of No. 4 is cooled by the outside air after the engine is stopped, the moisture in the air saturated in the internal space 14a is condensed (condensation). However, the internal space 14a communicates with the outside through the atmosphere opening holes 22b and 22c, the ventilation space 21 and the atmosphere opening hole 22a, and the pressure in the inside space 14a decreases, and the outside air containing water is introduced from the outside. Therefore, moisture does not accumulate in the internal space 14a, and condensed (condensation) moisture evaporates into the atmosphere.
There is no risk that the inner wall surface of the nipple 14 and the outer wall surface of the fuel injection pipe 10 inside the nipple 14 will rust.

According to the mounting structure of the fuel injection pipe of the first embodiment, the seal flange 15 which is the first seal member.
The case where the atmosphere opening holes 14b, 17 and 18 are provided in the nipple 14, the seal rubber 16 which is the second seal member, respectively, but either one of the seal flange 15 and the nipple 14 and the seal rubber 16 is shown. It may be provided only in. When the atmosphere opening hole 18 is provided only in the seal rubber 16, it is not necessary to provide the atmosphere opening hole 14 b in the nipple 14. Further, the seal flange 15 and the nipple and the seal rubber 16 are provided with the atmosphere release holes 14b and 1 respectively.
Although the case where 7 and 18 are provided one by one is shown, a plurality of them may be provided.

Further, according to the fuel injection pipe mounting structure of the second embodiment, when the cylinder head cover 19 is provided with one atmosphere opening hole 22a and the nipple 14 is provided with two atmosphere opening holes 22b and 22c. However, the present invention is not limited to this, and the cylinder head cover 19 and the nipple 14 may each be provided with at least one atmosphere opening hole.

According to the first and second embodiments, 4
Although the case where the invention is applied to the mounting structure of the fuel injection pipe of the large diesel engine of the valve system is shown, the mounting structure of the fuel injection pipe of the present invention is not limited to this, and the mounting structure of the fuel injection pipe of the two-valve diesel engine or the like is shown. It can be applied to the mounting structure.

[0025]

As described above, according to the fuel injection pipe mounting structure of the first aspect of the present invention, the inner space of the nipple has the first seal member and the nipple and / or the second seal member.
Since it communicates with the outside through the atmosphere opening hole provided in the seal member, even if the nipple is cooled by the outside air when the engine is stopped, water does not collect and evaporates immediately, and the nipple and the inside of the nipple It is possible to prevent the generation of rust on the fuel injection pipe.

According to the fuel injection pipe mounting structure of the second aspect, a ventilation space is provided in the inner wall of the fuel injection pipe mounting hole of the cylinder head cover so as to surround the nipple, and the outer surface of the cylinder head cover and the fuel are covered. Since at least one atmosphere opening hole communicating with the ventilation space is provided on the peripheral wall of the nipple surrounded by the inner wall of the injection pipe mounting hole, the inner space of the nipple communicates with the outside through these atmosphere opening holes and the ventilation space. However, even if the nipple is cooled by the outside air when the engine is stopped, there is no risk of water being collected, and it is possible to prevent evaporation of the water immediately and to prevent rust from occurring in the nipple and the fuel injection pipe in the nipple.

Further, according to the fuel injection pipe mounting structure of the third aspect, it is possible to prevent water from entering through the atmosphere opening hole provided in the cylinder head cover by the baffle plate.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view showing a first embodiment of a fuel injection pipe mounting structure of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line II-II of FIG.

FIG. 3 is an enlarged cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a partially enlarged sectional view showing a second embodiment of the fuel injection pipe mounting structure of the present invention.

FIG. 5 is a sectional view showing a cylinder head portion of a V-type engine including a conventional fuel injection pipe mounting structure.

FIG. 6 is a partially enlarged cross-sectional view showing a conventional fuel injection pipe mounting structure.

[Explanation of symbols]

10 Fuel Injection Pipe 11, 19 Cylinder Head Cover 13 Fuel Injection Nozzle Holder 14 Nipple 15 First Seal Member (Seal Flange) 16 Second Seal Member (Seal Rubber) 14b, 17, 18, 22a, 22b, 22c Atmospheric Release Hole 20 Installation Hole 21 Communication space

Claims (3)

[Claims] 1. A nipple which is detachably screwed to a fuel injection nozzle holder is attached to a fuel injection pipe attachment hole of a cylinder head cover via a first seal member, and the fuel injection pipe is attached to the inside of the cylinder head cover via the nipple. To the fuel injection nozzle holder and to seal between the nipple and the fuel injection pipe with a second seal member, which has a structure for mounting the fuel injection pipe, the first seal member and the nipple. And at least one atmosphere opening hole that allows the internal space of the nipple to communicate with the outside, in either or both of the second seal members. 2. A nipple that is detachably screwed to a fuel injection nozzle holder is attached to a fuel injection pipe attachment hole of a cylinder head cover via a first seal member, and the fuel injection pipe is attached to the inside of the cylinder head cover via the nipple. The fuel injection pipe of the cylinder head cover is connected to the fuel injection nozzle holder, and the fuel injection pipe is connected to the fuel injection nozzle holder, and the nipple and the fuel injection pipe are sealed by the second seal member. A ventilation space is provided on the inner wall of the mounting hole so as to surround the nipple, and at least one atmosphere opening that communicates with the ventilation space on the outer surface of the cylinder head cover and the peripheral wall of the nipple surrounded by the inner wall of the fuel injection pipe mounting hole. A structure for mounting a fuel injection pipe, which is provided with a hole. 3. The fuel injection pipe mounting structure according to claim 2, wherein the cylinder head cover covers the atmosphere opening hole,
A structure for mounting a fuel injection pipe, characterized in that a baffle plate for preventing water or the like from entering through the atmosphere opening hole is mounted.