JP2001263204A - Common rail type fuel injector of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for taking out an electric connecting part and a high pressure fuel connecting part from a fuel injection valve in a rocker chamber in a common rail type fuel injector. SOLUTION: A base end part of the fuel injection valve 1 is arranged in the rocker chamber 8, and an electric connector part 11 and a high pressure fuel supply port 9 are mutually extended in the direction for penetrating through a rocker cover 7 in parallel from the base end part. An oil seal member 16 for sealing a taking-out part of a high pressure fuel pipe 10 and the electric connector part 11 is fixed to the rocker cover 7, and the electric connector part 11 is exposed outside via the oil seal member 16. While the high pressure fuel pipe 10 is connected to the high pressure fuel supply port 9 by a cylindrical nut 2 inserted from the outside via the oil seal member 16 to seal the outer periphery of the cylindrical nut 24 by the oil seal member 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a common rail fuel injection device for an engine, and more particularly to a structure for taking out a fuel connection (high-pressure fuel pipe) and an electrical connection (electric connector) from a fuel injection valve.

[0002]

2. Description of the Related Art Conventionally, a so-called four-valve engine having two intake valves and two exhaust valves has been provided with a common rail type fuel injection device in which a fuel injection valve is mounted on a cylinder head so as to be located substantially at the center of a cylinder bore. Was.

[0003] Japanese Patent Application Laid-Open No. 11-230004 discloses a common rail type fuel injection device in which a connector for supplying high-pressure fuel to a fuel injection valve is mounted through a rocker cover.

[0004]

By the way, the base end of the fuel injection valve which is mounted substantially at the center of the cylinder bore is exposed by penetrating the rocker cover. When trying to connect the harness, it is necessary to avoid the thickness of the rocker cover and the cams from touching, so the high-pressure fuel supply position becomes high, and as a result, the position of the injection valve fixture becomes high. Become. For this reason, the movable needle valve of the fuel injection valve becomes longer, and it becomes difficult to perform precision machining of the deep hole into which the movable needle valve is inserted. There was a possibility.

In a configuration in which an electromagnetic coil portion of an injection valve, an injection control portion (control hydraulic chamber), and an electrical connector are arranged outside the rocker cover, the characteristics of fuel injection change due to a change in environmental temperature. There is a possibility that the exhaust performance of the engine may be deteriorated.

Therefore, high-pressure fuel is supplied to the fuel injection valve in the rocker chamber in the rocker cover, and
The adoption of a structure in which the electromagnetic coil section of the injection valve, the injection control section (control hydraulic chamber), and the electrical connector are arranged in the rocker chamber was studied.

However, in this case, it is necessary to take out the supply path of the high-pressure fuel and the electric connector by penetrating the rocker cover, and it is necessary to ensure the sealing property at the take-out portion. No. 230004 discloses a structure in which both the supply path of the high-pressure fuel and the electric connector are taken out by penetrating the rocker cover, and the supply path of the high-pressure fuel and the electric connector are taken out of the rocker chamber. It has been desired to provide a structure capable of easily sealing the take-out portion while having a configuration.

[0008] The present invention has been made in view of the above circumstances, and a high-pressure fuel supply path (fuel connection portion) from the rocker chamber.
It is another object of the present invention to provide a common rail type fuel injection device for an engine, in which an electric connector (electric connection portion) is taken out and an oil seal at a portion penetrating a rocker cover can be easily performed.

[0009]

According to the present invention, a common rail type fuel injection valve is mounted on a cylinder head, and a high pressure fuel connection and an electric connection are arranged in a rocker chamber. The part and the electrical connection part are configured to pass through the rocker cover substantially parallel to each other and to be taken out to the outside.

According to this configuration, the high-pressure fuel is supplied to the fuel injection valve in the rocker chamber in the rocker cover, and the electromagnetic coil section of the fuel injection valve and the injection control section (control hydraulic chamber) are provided in the rocker chamber. , An electrical connector is arranged. Furthermore, the penetration directions of the fuel connection portion and the electric connection portion in the rocker cover are set substantially parallel to each other.

According to the second aspect of the present invention, the oil seal sealing the portion where the fuel connection portion penetrates the rocker cover and the oil seal sealing the portion where the electric connection portion penetrates the rocker cover are integrally formed on the rocker cover. It was configured to be attached.

According to this structure, an oil seal for preventing fuel and oil from leaking from a portion penetrating the rocker cover is provided, but the oil seal on the fuel connection portion side and the oil seal on the electric connection portion side are integrated. And attach it to the rocker cover.

According to the third aspect of the present invention, the main body is formed with two cylindrical portions which are fixed to the rocker cover and through which the fuel connection portion and the electric connection portion are respectively inserted, and one end is provided at each of the two cylindrical portions. Are fixed to each other and extend substantially parallel to each other toward the rocker chamber, and the other end is fitted into a groove formed on the outer periphery of the other end of the cylindrical seal member. And a ring-shaped elastic member for urging in a direction to reduce the diameter of the oil seal.

[0014] According to this configuration, the rocker cover 2
The two cylindrical seal members extend substantially parallel to each other toward the rocker chamber, and the fuel connection portion and the electric connection portion are respectively inserted through the seal members. The ring-shaped elastic member to be fitted presses the inner peripheral wall of the cylindrical seal member against the outer peripheral walls of the fuel connection portion and the electric connection portion to make close contact with each other, thereby performing sealing.

According to the fourth aspect of the present invention, the cylindrical nut for connecting and fixing the high-pressure fuel pipe to the high-pressure fuel supply port of the fuel injection valve is substantially connected to the electrical connection portion while the high-pressure fuel pipe is provided inside. It is configured so as to penetrate the rocker cover in parallel and be exposed to the outside, and to perform sealing by bringing a cylindrical sealing member into close contact with the outer peripheral wall of the nut.

According to this configuration, the high-pressure fuel pipe is connected and fixed to the high-pressure fuel supply port by tightening the nut to the high-pressure fuel supply port of the fuel injection valve that opens into the rocker chamber. Since the base end portion of the high-pressure fuel pipe is exposed to the outside through the rocker cover, by tightening a portion exposed to the outside of the rocker cover, the connection of the high-pressure fuel pipe to the high-pressure fuel supply port is fixed, and Sealing is performed on the outer periphery of the nut.

According to the fifth aspect of the present invention, a dustproof cover made of a flexible material through which an electric harness connected to the electric connection portion penetrates is attached by engaging with a peripheral edge of the main body of the oil seal. It was configured to cover the connection part.

According to this configuration, the dust cover that covers the electrical connection portion is attached by being engaged with the peripheral edge of the oil seal main body, and the electric harness that extends through the dust cover is covered with the dust cover. It is connected to an electrical connection (electrical connector) in the space.

According to the sixth aspect of the present invention, there is provided an insertion hole for inserting the fuel connection portion into the dustproof cover, and a notch for opening the insertion hole to the periphery of the dustproof cover. The electrical connection part and the fuel connection part were covered with a dustproof cover so that the part was positioned in the insertion hole.

According to this configuration, the electric harness is integrally provided so as to penetrate the dustproof cover.
The fuel connecting portion is positioned in the fuel connecting portion insertion hole through the cut formed in the dustproof cover, so that the fuel connecting portion penetrates the dustproof cover. In this state, the electric connection portion and the fuel connecting portion are formed by the dustproof cover. Covered.

According to a seventh aspect of the present invention, in the V-type engine, the oil seal mounting surface of the rocker cover is configured to be an inclined surface descending between the banks. According to this configuration, the oil seal mounting surface of the rocker cover forms an inclined surface that generally descends between the banks where the intake system is disposed, and fuel and oil leaking from the oil seal portion flow toward the intake side. Will be.

According to the present invention, a high-pressure fuel pipe for supplying high-pressure fuel from the common rail to the fuel injection valve, and an electric connector of the fuel injection valve for taking out from the rocker chamber to the outside are provided. A penetrating portion provided with two oil seals is formed in the rocker cover, and an electric harness is connected to an electric connector exposed to the outside through one of the two penetrating portions, while a high pressure fuel supply port of the fuel injection valve is connected to the electric harness. The high-pressure fuel pipe to be connected is provided inside, and a cylindrical nut for connecting and fixing the high-pressure fuel pipe to the high-pressure fuel supply port by fastening the tip to the high-pressure fuel supply port is used to connect the other of the two through-holes. The high-pressure fuel pipe is connected to the high-pressure fuel supply port of the fuel injection valve by tightening a base end of the nut exposed to the outside of the rocker cover.

According to this configuration, the rocker cover is fixed to the cylinder head to which the fuel injection valve is fixed so that the electric connector of the fuel injection valve is exposed from the penetration portion of the rocker cover, and then the other end of the rocker cover is opened. By inserting a cylindrical nut together with the high-pressure fuel pipe and tightening a portion of the nut exposed to the outside of the rocker cover, the nut is fastened and fixed to the high-pressure fuel supply port of the fuel injection valve. The high-pressure fuel pipe is connected and fixed.

[0024]

According to the first aspect of the present invention, it is possible to easily take out the fuel connection portion and the electric connection portion from the rocker chamber while securing the oil sealing function, and to lower the position of the fixture of the injection valve. As a result, the movable needle valve of the fuel injection valve can be shortened, and the injection characteristics can be stabilized without being affected by changes in the environmental temperature.

According to the second aspect of the invention, there is an effect that the mounting structure of the oil seal to the rocker cover can be simplified. According to the third aspect of the present invention, there is an effect that high oil sealing performance can be exhibited while realizing easy assemblability.

According to the fourth aspect of the present invention, there is an effect that the oil seal function can be secured while enabling connection and fixing of the high-pressure fuel pipe after the rocker cover is attached. According to the fifth aspect of the invention, there is an effect that it is possible to cover the periphery of the electric connection portion while fixing the electric harness to the rocker cover.

According to the sixth aspect of the invention, there is an effect that the electric connection portion and the fuel connection portion can be covered by one cover. According to the seventh aspect of the present invention, even if fuel or the like leaks from the oil seal portion of the rocker cover, the leaked fuel can be prevented from touching the high-temperature portion.

According to the invention, the electric connector is taken out from the rocker chamber while the oil sealing function is secured, and the connection of the high-pressure fuel pipe to the high-pressure fuel supply port of the fuel injection valve in the rocker chamber is fixed. There is an effect that can be done.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a longitudinal sectional view showing a cylinder head portion of an automobile diesel engine, and FIG. 1B is a view in the direction of arrow B in FIG. 1A.

The engine shown in FIGS. 1 (A) and 1 (B) is a four-valve engine having two intake valves and two exhaust valves for each cylinder. The fuel injection valve 1 is provided substantially along the center of the cylinder bore. A deep hole 2 for attachment is opened in the cylinder head 3.

An outer peripheral wall of the fuel injection valve 1 inserted into the deep hole 2 is recessed to form a stepped portion 4, and a cylinder head 3 is formed.
The tip of the bracket 5 having the pin 40 fixed to the fulcrum as a fulcrum presses the step portion 4 downward, and the intermediate portion of the bracket 5 is bolted to the cylinder head 3.
, The fuel injection valve 1 is pressed downward and fixed.

A rocker cover 7 is provided on the cylinder head 3.
Is fixed, and an outer peripheral wall of a base end portion of the fuel injection valve 1 disposed in a rocker chamber 8 surrounded by the rocker cover 7 includes:
A high-pressure fuel supply port 9 (fuel connection portion) is screwed to the fuel injection valve body obliquely upward and is formed integrally with the valve. On the outer periphery of the high-pressure fuel supply port 9 opening into the rocker chamber 8, an external thread 9a for connecting and fixing the high-pressure fuel pipe 10 is formed.

From the outer peripheral wall of the fuel injection valve 1 above the high-pressure fuel supply port 9, the tip is exposed to the outside through the rocker cover 7 in parallel with the high-pressure fuel supply port 9. Electrical connector 11 (electrical connection)
Are integrally extended. A cylindrical portion 11a is formed in a portion of the electrical connector portion 11 which is disposed in the rocker chamber 8 so as to be in close contact with an oil seal described later. Female connector (or male connector) provided at the end of the electric harness
A male connector (or female connector) 12 that fits with the connector is provided.

The other end of the high-pressure fuel pipe 10 having one end connected to the high-pressure fuel supply port 9 is connected to the cylinder head 3 with a bolt 1
3 is connected to a common rail 14 fixed. Specifically, while forming an external thread on the outer periphery of the distribution port 13a of the common rail 13, an enlarged-diameter portion is provided at the other end of the high-pressure fuel pipe 10, and the reference diameter section of the high-pressure fuel pipe 10 is inserted. The other end of the high-pressure fuel pipe 10 is connected and fixed to the common rail 14 by fastening the nut 15 to the external thread on the outer periphery of the distribution port 13a.

An elliptical opening 7a is opened at a portion of the rocker cover 7 from which the electric connector section 11 and the high-pressure fuel pipe 10 are taken out, and an oil seal member 16 is fixed to the opening 7a.

As shown in the partially enlarged view of FIG. 2, the oil seal member 16 has two cylindrical through portions 1 for taking out the electric connector portion 11 and the high-pressure fuel pipe 10.
A sheet metal fitting 19 (main body) whose flanges 7 and 18 are subjected to flange processing or burring processing;
8, two cylindrical rubbers (seal members) 20, 21 extending parallel to each other toward the inside of the rocker chamber 8;
Grooves 22 formed on the outer periphery of the distal ends of the cylindrical rubbers 20, 21
And a garter spring 23 (ring-shaped elastic member) that urges the distal end portion in the direction of reducing the diameter.

The garter spring 23 is formed by connecting both ends of a coil spring to form a ring. The penetrating portion 17 is provided at a position where the electric connector portion 11 penetrates the rocker cover 7 and in a penetrating direction, and is provided with a cylindrical rubber 20 fixed to the penetrating portion 17.
The cylindrical portion 11a is fitted to the inner periphery of the portion where the garter spring 23 at the end of the cylindrical portion is fitted, so that sealing is performed.

The penetrating portion 18 is provided at a position where an extension of the high-pressure fuel supply port 9 penetrates the rocker cover 7 and in a penetrating direction, and is provided with a cylindrical rubber fixed to the penetrating portion 18. The length of the cylindrical rubber 21 is set so that the portion of the tip 21 into which the garter spring 23 is fitted surrounds the periphery of the high-pressure fuel supply port 9.

When the rocker cover 7 to which the oil seal member 16 is fixed is attached in a state where the fuel injection valve 1 is attached to the cylinder head 3, the electric connector portion 11 is fitted into the cylindrical rubber 20. The male connector 12 is made to protrude from the penetrating portion 17 with the rocker cover 7 attached. In this state, the high-pressure fuel supply port 9 is loosely fitted to the distal end side of the cylindrical rubber 21, and the high-pressure fuel pipe 10 is connected to the high-pressure fuel supply port 9.

More specifically, similarly to the connection to the common rail 14, a large-diameter portion is provided at the end of the high-pressure fuel pipe 10, and the cylindrical nut 24 through which the reference diameter section of the high-pressure fuel pipe 10 is inserted.
Is inserted into the cylindrical rubber 21 through the penetrating portion 18 so as to be pushed into the cylindrical rubber 21, and the portion of the cylindrical rubber 21 at which the garter spring 23 is fitted is pushed open to hit the high-pressure fuel supply port 9. To do.

The cylindrical nut 24 is formed in such a length as to protrude outside from the rocker cover 7 in a state where the cylindrical nut 24 is fastened to the male screw 9a on the outer periphery of the high-pressure fuel supply port 9. Hex head 24 formed at the base end protruding to the outside after pushing until it hits 9
By tightening a with a spanner, the cylindrical nut 24 is fastened to the external thread 9 a on the outer periphery of the high-pressure fuel supply port 9, and the high-pressure fuel pipe 10 is connected and fixed to the high-pressure fuel supply port 9. At this time, the portion of the cylindrical rubber 21 at which the garter spring 23 is fitted is in close contact with the outer peripheral portion of the distal end of the cylindrical nut 24, and sealing is performed.

According to the above configuration, since the base end of the fuel injection valve 1 where the high-pressure fuel supply port 9 and the electric connector 11 are provided is provided in the rocker chamber 8, they are affected by changes in the environmental temperature. In addition, the change in the injection characteristics due to the temperature change can be suppressed, and the fixed position of the fuel injection valve 1 can be made as low as possible. As a result, the movable needle valve can be made as short as possible, so that the occurrence of the movable needle valve can be avoided.

Further, as described above, the electric connector and the high-pressure fuel pipe are taken out from the base end of the fuel injection valve 1 provided in the rocker chamber 8 because the electric connector and the high-pressure fuel pipe are parallel to each other. 7 so that the electric connector 11 and the high-pressure fuel supply port 9 can be easily inserted into the cylindrical rubbers 20 and 21 simultaneously while the rocker cover 7 is attached. Therefore, it can be easily taken out from the rocker cover 7 while ensuring the sealing property.

Incidentally, when connecting the electric harness to the electric connector section 11, it is preferable to cover the connection section with a dustproof cover 31 as shown in FIG. In FIG. 3, a rubber dustproof cover 3 as a flexible material is used.
1 is formed in an elliptical shape in accordance with the sheet metal fitting 19, has a groove 32 formed inside its outer peripheral edge, and is formed in a flange shape with a clearance secured to the rocker cover 7. The dustproof cover 31 is fixed to the rocker cover 7 by covering the periphery of the sheet metal fitting 19 so that the groove 32 fits.

Further, the connector portion 33a at the tip of the electric harness 33 is arranged in a space surrounded by the dust cover 31 so as to penetrate the dust cover 31 at a position corresponding to the electric connector portion 11. That is, the dustproof cover 31 is provided at the tip of the electric harness 33 in a collar shape before being attached to the rocker cover 7.

An insertion hole 34 for inserting the high-pressure fuel pipe 10 is formed at a position corresponding to the high-pressure fuel pipe 10 on the dustproof cover 31 so as to extend from the insertion hole 34 to the periphery. And a notch 3 that opens the insertion hole 34 to a lower end position of the peripheral edge of the dustproof cover 31.
5 is provided so that the high-pressure fuel pipe 10 can be positioned in the insertion hole 34 by passing through the cut 35 while crossing the high-pressure fuel pipe 10 with the dustproof cover 31.

Thus, after or before the electric harness 33 is connected to the electric connector section 11, the high-pressure fuel pipe 10 is positioned in the insertion hole 34 of the dustproof cover 31 through the cut 35, The high-pressure fuel pipe 10 is extended to penetrate through the dustproof cover 31.
If the cover 1 is attached to the rocker cover 7 so as to cover the periphery of the sheet metal fitting 19, the dustproof cover 31 covers the electric connector portion 11 of the rocker cover 7 and the take-out portion of the high-pressure fuel pipe 10, and furthermore, the dustproof cover The electric harness 33 is fixed to the rocker cover 7 via the base 31.

The common rail type fuel injection device shown in FIGS. 1 to 3 can be applied not only to an in-line engine but also to a V-type engine. In particular, FIG. Shown in

The engine shown in FIG. 4 is a V-type diesel engine. An intake manifold 41 for distributing and supplying air to each cylinder is arranged between banks, and common rails 14a and 14b of each bank are arranged between banks. Be placed.

The surface of the rocker cover 7 from which the electric connector portion 11 and the high-pressure fuel pipe 10 are taken out from the fuel injection valve 1 of each bank is formed as an inclined surface descending between the banks.

According to the above structure, even if fuel or oil leaks from the oil seal member 16, the fuel does not flow to the high-temperature exhaust side.
Since it flows to the low-temperature intake side, safety can be ensured.

In the configuration shown in FIG.
Is omitted, but it is obvious that the V-type engine may be configured to cover the take-out portion with the dustproof cover 31.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder head according to a first embodiment.

FIG. 2 is a partially enlarged view of FIG. 1 showing the first embodiment.

FIG. 3 is a partially enlarged view showing a second embodiment.

FIG. 4 is a partial sectional view of a V-type engine showing a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve 3 ... Cylinder head 7 ... Rocker cover 8 ... Rocker chamber 9 ... High-pressure fuel supply port 10 ... High-pressure fuel pipe 11 ... Electric connector part 14 ... Common rail 17, 18 ... Penetration part 19 ... Sheet metal fittings 20, 21 ... Cylindrical rubber 22 Groove 23 Garter spring 24 Cylindrical nut 31 Dust-proof cover 33 Electric harness 34 Insert hole 35 Cut

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 55/02 350 F02M 55/02 350H 61/16 61/16 K (72) Inventor Yasuyuki Iwade Kanagawa 2F, Takaracho, Kanagawa-ku, Yokohama-shi Nissan Motor Co., Ltd. F term (reference) 3G066 AA07 AB02 AC09 AD12 BA41 BA51 BA56 BA65 CB05 CC05U CD04 CD10 CE22

Claims (8)

[Claims] 1. A fuel injection valve for mounting a common rail type fuel injection valve to a cylinder head, and a fuel connection for supplying high-pressure fuel to the fuel injection valve and an electric connection of the fuel injection valve are arranged in a rocker chamber. A common rail fuel injection device for an engine, wherein the fuel connection portion and the electrical connection portion are configured to pass through the rocker cover substantially parallel to each other and to be taken out to the outside. 2. An oil seal for sealing a portion where the fuel connection portion penetrates the rocker cover and an oil seal for sealing a portion where the electric connection portion penetrates the rocker cover are integrally attached to the rocker cover. The engine common rail fuel injection system according to claim 1, wherein: 3. A main body in which the oil seal is fixed to the rocker cover and formed with two cylindrical portions through which the fuel connection portion and the electrical connection portion are respectively inserted.
Two cylindrical seal members having one end fixed to each of the two cylindrical portions and extending substantially parallel to each other into the rocker chamber, and formed on the outer periphery of the other end of the cylindrical seal members. 3. A common rail fuel injection system for an engine according to claim 2, further comprising: a ring-shaped elastic member fitted into the groove and biasing the other end in a direction to reduce the diameter. 4. A cylinder nut for connecting and fixing a high-pressure fuel pipe as the fuel connection portion connecting the common rail and a high-pressure fuel supply port of the fuel injection valve to the high-pressure fuel supply port, A high-pressure fuel pipe is provided inside and is configured to penetrate through the rocker cover and be exposed to the outside substantially in parallel to the electrical connection portion, and the cylindrical seal member is brought into close contact with the outer peripheral wall of the nut. 4. The common rail fuel injection device for an engine according to claim 3, wherein the sealing is performed. 5. A dustproof cover made of a flexible material through which an electric harness connected to the electric connection portion penetrates, and is attached by being engaged with a peripheral edge of a main body of the oil seal, and at least the electric connection is made by the dustproof cover. The common rail fuel injection device for an engine according to claim 3, wherein the fuel injection device covers the portion. 6. The dustproof cover is provided with an insertion hole through which the fuel connection portion is inserted, and a notch for opening the insertion hole to the periphery of the dustproof cover. 6. The common rail fuel injection device for an engine according to claim 5, wherein the dustproof cover covers the electrical connection portion and the fuel connection portion so as to be positioned in the insertion hole. 7. The engine according to claim 2, wherein the engine is a V-type engine, and an oil seal mounting surface of the rocker cover is an inclined surface descending between banks.
The common rail fuel injection device for an engine according to any one of the above-mentioned items. 8. An oil seal for taking out a high-pressure fuel pipe for supplying high-pressure fuel from a common rail to the fuel injection valve and an electric connector of the fuel injection valve from the rocker chamber to the outside. The high-pressure fuel pipe having two through-portions formed in the rocker cover and connecting an electric harness to the electric connector exposed to the outside through the one through-portion, and connecting the electric harness to a high-pressure fuel supply port of the fuel injection valve. A cylindrical nut for connecting and fixing the high-pressure fuel pipe to the high-pressure fuel supply port by fastening the tip to the high-pressure fuel supply port is inserted through the other penetrating portion, and the nut is inserted. A high-pressure fuel pipe connected to a high-pressure fuel supply port of the fuel injection valve by tightening a base end exposed to the outside of the rocker cover. -Rail fuel injection system.