JP2001182614A - Internal combustion engine head cover - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To avoid connection of an electric system or joint of a fuel system in an oil atmosphere. A head cover (4) of an internal combustion engine (1) according to the present invention includes an upper cover (5) and a lower cover (6) that can be divided into upper and lower parts, and a pair of partition walls that divides the inside of the head cover into three parts in a horizontal direction when both covers are combined. 24 and 25 are provided. In each of the three divided chambers, the center is an oil chamber 28, one side is a connection room 29 of an electric system, and the other side is a joint room 30 of a fuel system. According to this, the connection part of the electric system and the joint part of the fuel system can be isolated from the oil atmosphere, malfunction of the electric system due to carbon components in the oil, delay in finding out when fuel leaks from the joint part, etc. Can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head cover for an internal combustion engine such as a diesel engine.

[0002]

2. Description of the Related Art Normally, in an engine, a cylinder head integrally provided with an intake / exhaust port on a cylinder block is fixed by bolts, and a fuel injection nozzle and a valve operating mechanism are attached to the cylinder head. A head cover is attached so as to cover the opening.

On the other hand, in the field of diesel engines, an electronically controlled fuel injection system, such as a common rail type or an electro-hydraulic operation type (a so-called HEUI), in which a fuel injection amount is controlled by an injector, is frequently used.

[0004] In this system, in a valve operating chamber in an oil atmosphere surrounded by a cylinder head and a head cover,
In many cases, the solenoid valve of the injector is connected to the electric wiring, and the fuel inlet of the injector and the fuel pipe are jointed.

[0005]

However, when such an electric system is connected in an oil atmosphere, malfunction of the electric system (for example, short circuit) due to carbon components and the like contained in the engine oil, and high-temperature lubricating oil In such a case, problems such as a decrease in the durability of the connection parts occur. Further, there is also a problem that oil penetrates from the terminal caulking portion of the connection portion into the gap between the cover of the lead wire and the core wire, and the oil leaks out from the connection portion at the other end of the lead wire outside.

[0006] On the other hand, if the joint of the fuel system as described above is performed, if a fuel leaks from the joint portion, the discovery is delayed, and the fuel is mixed with the oil, the oil is diluted, and the problem of poor lubrication is caused. Reach.

Accordingly, an object of the present invention is to provide a head cover of an internal combustion engine which can avoid connection of an electric system or joint of a fuel system in an oil atmosphere.

[0008]

A head cover for an internal combustion engine according to the present invention comprises an upper cover and a lower cover which can be divided into upper and lower parts, and a pair of partitions which divide the inside of the head cover into three parts in a horizontal direction when the two covers are joined. A wall is provided, and in each of the three divided chambers, the center is an oil chamber, one side is a connection room for an electric system, and the other side is a joint room for a fuel system.

According to this, the connection portion of the electric system and the joint portion of the fuel system can be isolated from the oil atmosphere, and the above-mentioned problem can be solved.

[0010] The pair of partition walls may be erected on the lower cover, and when the two covers are connected, the partition walls may be in close contact with the upper cover.

It is preferable that the upper cover has a U-shaped cross section that opens downward, and that both sides of the upper cover are provided with a hanging wall that is spaced apart from the partition wall by a predetermined distance and overlapped.

It is preferable that the lower cover integrally has a connecting portion extending in both side directions and connecting both partition walls.

[0013] The oil chamber is for disposing a T-type injector, and the pair of partition walls have notches for projecting both branches of the T-type injector into the connection chamber or the joint chamber, respectively. It is preferable that a sealing member is attached to the outer side surfaces of both partition walls to seal the gap of the notch.

[0014]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, the engine 1 is an in-line multi-cylinder common rail direct injection diesel engine.
A head cover 4 is mounted on the cylinder head 2. The head cover 4 is made of resin and includes an upper cover 5 and a lower cover 6 that can be divided into upper and lower parts. The lower cover 6 is mounted on the cylinder head 2 with a plurality of bolts 7, the upper cover 5 is mounted on the lower cover 6 in a fitting manner, and is fixed with a plurality of mounting screws (tapping screws) 8. A packing groove 9 is formed in the joint surface of the lower cover 6 with the cylinder head 2.
Are provided, and a packing 10 for sealing a joint portion is attached to the packing groove 9.

The cylinder head 2 is of a type that can be divided into upper and lower parts, and only the upper side is shown in the figure. A camshaft 11 for intake and exhaust is provided on the upper cylinder head 2.
The suction / exhaust port is formed integrally with the lower cylinder head, and the intake / exhaust valve is attached. Then, the injector 13 is fixed to the lower cylinder head using the bracket 14. That is,
The injectors 13 are arranged for each cylinder, and are collectively pressed downward and fixed by a plate-like bracket 14 extending in the front-rear direction of the engine. A post is erected from the lower cylinder head at a position between the cylinders, and a post hole 16 of the bracket 14 is inserted into a screw portion at the tip of the post, and a washer 17 and a nut 18 are attached. In this way, the injector 13 is fixed at the center position of the left and right sides of the engine.

The injector 13 is a T-type injector.
At the upper end of the nozzle portion 19 extending vertically and serving as a reference axis, a branch portion extending left and right, that is, an electromagnetic valve portion 20 and a fuel inlet portion 21 are provided.

The lower cover 6 is formed in a frame shape as a whole, and has a front wall 22, a rear wall 23, and a left wall 24 erected from the bottom.
And the right wall 25 integrally. The front wall 22 also serves as a cover for an accessory drive mechanism (a chain mechanism, a belt mechanism, etc.) in front of the engine. The left wall 24 and the right wall 25 are located slightly inside the positions of the left and right outer ends of the cylinder head 2 and form a pair of partition walls according to the present invention, each of which forms one and the other one of the partition walls. That is, “left” and “right” in the present embodiment correspond to “one side” and “the other side” in the present invention.

The upper cover 5 has a U-shaped cross section cut in the left-right direction and opens downward. The upper cover 5 is fitted between the front wall 22 and the rear wall 23 of the lower cover 6 in a fitting manner. The upper cover 5 integrally has a substantially flat upper wall 26 and a hanging wall 27 hanging from both left and right sides thereof.

As shown in FIG. 1, when the two covers 5 and 6 are combined, the inside of the head cover 4 is divided into three parts by a left wall 24 and a right wall 25 in the horizontal direction along the left and right or in the width direction of the cover. In each of the three divided chambers, the center is an oil chamber 28, the left side is a connection room 29 of an electric system, and the right side is a joint room 30 of a fuel system. The oil chamber 28 communicates with the inside of the cylinder head 2 at a lower portion and is in an oil atmosphere, but the connection chamber 29 and the joint chamber 30 are
Completely separated from the so-called dry atmosphere.

When the covers 5 and 6 are combined, the left and right hanging walls 2
7 is superimposed on the left wall 24 and the right wall 25 with a predetermined distance outward from the left wall 24 and the right wall 25. Hanging wall 27
Is separated from the connection chamber 29 and the joint chamber 30 from the outside, and is substantially flush with the left and right outer surfaces of the cylinder head 2.

Although the injector 13 has the nozzle portion 19 disposed in the oil chamber 28, the electromagnetic valve portion 20 projects into the connection chamber 29, and the fuel inlet portion 21 projects into the joint chamber 30. Therefore, in order to enable such protrusion, the left wall 24 and the right wall 25 are provided with U-shaped notches 31 for penetration. Then, a sealing member 32 is attached to the left wall 24 and the right wall 25 with bolts 45 in order to seal the gap between the notches 31.

The sealing member 32 is provided on the left wall 24 or the right wall 25.
A cylindrical portion having a plate portion 33 that is superimposed on and adhered to the outer surface of the fuel cell, and a lip-shaped seal that protrudes inward from the plate portion 33 and is closely fitted to the solenoid valve portion 20 or the fuel inlet portion 21 of the injector 13. 34 and become one. After the attachment of the seal member 32, the upper end surface 35 of the plate portion 33 is flush with the upper end surface 36 of the lower cover 6. When the two covers 5 and 6 are joined, these upper end surfaces 35 and 36
Is adhered to the back surface of the upper wall 26 of the upper cover 5. Lower cover 6
A rubber packing 37 is attached to the upper end surface 36 along the upper end surface 36 in a housed state, and a liquid packing 46 is further applied to the entire upper end surfaces 35 and 36 to attach the upper cover 5. This ensures that the joints are completely sealed. Thus, the oil chamber 28 is completely isolated from the connection chamber 29 and the joint chamber 30.

The oil chamber 28, the connection chamber 29, and the joint chamber 30 extend over the entire length of the head cover 4. In the connection room 29, the lead wires 3 are connected to two terminals 38 provided at the tip of the solenoid valve portion 20 of each injector 13.
9 are respectively connected. One bundle of wire harness is in connection room 2
9 extend in the longitudinal direction, and a pair of lead wires 39 are sequentially connected to the terminal 38 of each electromagnetic valve section 20. This connection is performed by caulking a terminal (not shown) on the lead wire 39 side to the terminal 38. In the joint chamber 30, fuel pipes 40 independently extending from a common rail (not shown) for each cylinder are jointed (connected) to the fuel inlet 21 of the injector 13.

On the right hanging wall 27 of the upper cover 5, a U which is opened downward to avoid a joint portion of the fuel pipe 40 is provided.
The letter-shaped notches 41 are provided for the number of cylinders. As a result, the upper cover 5 can be attached and detached after the joint, and the attachment and detachment of the upper cover 5 becomes easy.

The lower cover 6 extends in the left-right direction and
And a connecting portion 42 connecting the right wall 25 and the right wall 25. The connecting portion 42 is provided at a position between the cylinders in the oil chamber 28. The rigidity of the lower cover 6, particularly the rigidity in the left and right opening and closing directions, is improved by these connecting portions 42.

As described above, according to this configuration, the connection between the injector 13 and the lead wire 39 and the connection of the injector 13
And the joint of the fuel pipe 40 need not be performed in an oil atmosphere. Therefore, it is possible to avoid problems such as malfunction of the electric system (for example, short circuit) due to the carbon component or the like in the oil and reduction in the durability of the connection parts. Further, the oil does not permeate into the gap between the coating of the lead wire and the core wire, and does not seep out from the other end of the external lead wire. On the other hand, even if the fuel leaks from the joint portion, the fuel leaks out of the gap between the upper cover 5 and the lower cover 6 so that the fuel can be quickly found, and the fuel cannot enter the oil chamber 28. There is no mixing of fuel into oil.

This head cover 4 is most suitable for a T-type injector. That is, the T-type injector is effective when the height of the engine room cannot be made large because the height dimension is small. However, for such a T-type injector, the head cover 4 can isolate the connection portion and the joint portion from the oil. Therefore, there is an advantage that the total height of the engine can be reduced and the height of the engine room can be reduced in combination with the T-type injector.

Further, since the hanging wall 27 covers the connection portion and the joint portion from the outside, these are protected from the outside,
When fuel leaks from the joint portion, the scattering of fuel can also be prevented.

As described above, the embodiments of the present invention are not limited to those described above. For example, the joint between the left wall 24, the right wall 25, the seal member 32, and the upper cover 5 may be provided with a convex butting surface on the back surface of the upper cover 5, or may be joined in a fitting manner. The partition wall of the present invention can be provided on the upper cover, or can be provided on both the upper and lower covers. The left and right configurations of the present embodiment may be reversed. What is connected and joined in the connection room and the joint room is not limited to the injector, the electric wiring, and the fuel pipe. The engine may be a gasoline engine or the like.

[0031]

The present invention exhibits the following excellent effects.

(1) The connection of the electric system and the joint of the fuel system in the oil atmosphere can be avoided.

(2) It is possible to prevent malfunction of the electric system due to carbon components in oil and the like.

(3) Even if there is a fuel leak from the joint portion, this can be quickly detected and the fuel can be prevented from being mixed into the oil.

[Brief description of the drawings]

FIG. 1 conceptually shows the periphery of an engine head cover,
FIG. 3 is a longitudinal sectional view when the engine is viewed from the rear.

FIG. 2 is an exploded perspective view more specifically showing a periphery of a head cover of an engine, and mainly shows a method of mounting an injector.

FIG. 3 is an exploded perspective view more specifically showing the periphery of a head cover of an engine, and mainly shows a method of attaching an upper cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 4 Head cover 5 Upper cover 6 Lower cover 13 Injector 20 Solenoid valve part 21 Fuel inlet part 24 Left wall 25 Right wall 27 Hanging wall 28 Oil chamber 29 Electrical connection room 30 Fuel system joint room 31 Notch 32 Sealing member 42 Connection

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[Procedure amendment]

[Submission date] January 13, 2000 (2000.1.1)
3)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (5)

[Claims] An upper cover and a lower cover which can be divided into upper and lower parts are provided. A pair of partition walls are provided to divide the inside of the head cover into three parts in a horizontal direction when the two covers are joined. , An oil chamber, one side of which is a connection room of an electric system, and the other side is a joint room of a fuel system, wherein the head cover of the internal combustion engine is provided. 2. The head cover for an internal combustion engine according to claim 1, wherein said pair of partition walls are erected on said lower cover, and said partition walls are brought into close contact with said upper cover when said two covers are joined. 3. The head cover for an internal combustion engine according to claim 2, wherein the upper cover has a U-shaped cross section that opens downward, and a hanging wall is provided on both sides of the upper cover at a predetermined distance from the partition wall and overlapped. . 4. The head cover for an internal combustion engine according to claim 2, wherein the lower cover has a connecting portion extending in both sides and connecting the partition walls. 5. The oil chamber has a T-shaped injector disposed therein, and the pair of partition walls have notches for projecting both branches of the T-shaped injector into the connection chamber or the joint chamber, respectively. The head cover for an internal combustion engine according to any one of claims 1 to 4, wherein a sealing member is attached to an outer surface of each of the partition walls so as to seal a gap of the notch.