JPH08240168A - Fuel injection device - Google Patents

Abstract

PURPOSE: To facilitate taking-around of a fuel piping and improve the easiness in the installing works by providing adjustablity for the heading of a connection part where fuel piping is connected. CONSTITUTION: A connection part 36 of a fuel suction port 1 is furnished for connecting fuel piping 63 on a housing 20 in which a fuel injection valve is installed. In the housing 20 a splicing component 37 including the connection part 36 formed separately from the housing is installed rotatably round the housing axis, and a fixing means 38 is furnished to fix the splicing component 37 in any desired rotational position. The connection of the fuel piping 63 can be executed easily by arranging the connection part 36 in an appropriate direction with respect to the fuel piping 63.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device mainly used in a vehicle internal combustion engine (also called an engine).

[0002]

2. Description of the Related Art In a conventional fuel injection device, for example, as shown in a sectional view of FIG. 4, a fuel injection valve for injecting fuel directly into a combustion chamber of an engine and an ignition integrally formed with the fuel injection valve. Some have a plug. In the fuel injection valve, the high-pressure fuel supplied under a predetermined pressure from a fuel tank (not shown) passes through the fuel passage in the housing sub-assembly 20 from the fuel intake port 1 at the upper end of the housing sub-assembly 20. It reaches the inside of the valve seat 5. However, when the valve 10 closes the injection port 5a of the valve seat 5 due to the elasticity of the valve spring 9, fuel is not injected. Here, when the coil 42 is energized, the valve 10 is opened by the suction force of the core 2 acting on the armature 3 to inject fuel. Further, in the ignition plug, the high voltage from the ignition coil is transmitted to the valve seat 5 via the high tension cord 6, the screw stopper 7, the set screw 8, the valve spring 9 and the valve 10, and the valve seat 5 is used as a central electrode. Edge 5b and GND facing it
Spark discharge is generated between the electrode 12. An example of this type of fuel injection device is disclosed in Japanese Utility Model Laid-Open No. 63-154760.

By the way, a connecting portion 36 of the fuel intake port 1 for connecting the fuel pipe 63 is integrally formed on the outer cylindrical body 35 of the housing sub-assembly (corresponding to the housing in the present invention) 20. . The fuel injection system
The tip of the cylinder head 64 of the internal combustion engine
The cap 11 is attached by screwing the male screw 11a.

[0004]

According to the fuel injection device, the connecting portion 3 is tightened to the cylinder head 64.
Since the direction of 6 cannot be adjusted, the fuel pipe 63
However, there is a problem that the handling is complicated and the assembling is poor.

The technical problem to be solved by the present invention is as follows.
An object of the present invention is to provide a fuel injection device capable of facilitating the handling of the fuel pipe and improving the assemblability by making the orientation of the connecting portion for connecting the fuel pipe adjustable.

[0006]

The invention according to claim 1 for solving the above-mentioned problems is a fuel injection device in which a housing for incorporating a fuel injection valve is provided with a connection portion of a fuel intake port for connecting a fuel pipe. The housing is provided with a joint part having the connecting portion formed separately from the housing so as to be rotatable around the housing axis, and a fixing means for fixing the joint part at an arbitrary rotational position. It is an injection device. According to a second aspect of the present invention, the fuel injection valve is a fuel injection valve that directly injects fuel into a combustion chamber of an internal combustion engine, and the fuel injection valve is integrally formed with an ignition plug. It is an injection device.

[0007]

According to the fuel injection device of the first aspect, by rotating the joint component around the housing axis, the connecting portion can be oriented in a convenient direction to the fuel pipe. After the orientation is adjusted, the joint part is fixed to the housing by the fixing means. According to the fuel injection device of the second aspect, since it is necessary to dispose the high tension cord for the spark plug in addition to the fuel pipe, the degree of freedom in manipulating the fuel pipe is limited, but in such a case, Also, the connection portion can be oriented in a convenient direction to the fuel pipe, and the fuel pipe can be easily connected.

[0008]

EXAMPLES Examples will be described with reference to the drawings. The present embodiment is implemented in a fuel injection device including a fuel injection valve that directly injects fuel into a combustion chamber of an internal combustion engine, and an ignition plug integrally configured with the fuel injection valve. Since this example is a modification of a part of the conventional example (see FIG. 4), the same or equivalent parts will be denoted by the same reference numerals. In FIG. 1, which shows a cross-sectional view of the fuel injection device, the fuel injection device is roughly classified into a housing sub-assembly 20 having a substantially hollow cylindrical shape, and a body sub-assembly 21 attached to the housing sub-assembly 20.
Valve sub-assembly 4 and cap sub-assembly 23
It consists of and. In FIG. 1, hatching showing a cross section is omitted.

The housing sub-assembly 20 has a substantially hollow cylindrical shape, and the inner cylindrical body 34 and the outer cylindrical body 3 are inserted in the inner and outer double layers.
It consists of 5. Specifically, the inner cylindrical body 34 made of SUS304 material is inserted into the outer cylindrical body 35 made of SUS magnetic material, and is attached to almost the upper half portion of the outer cylindrical body 35.
An appropriate number of grooves 34a are provided on the outer peripheral surface of the lower half of the inner cylindrical body 34 along the axial direction. Further, an appropriate number of grooves 35a are provided on the outer peripheral surface of the upper end portion of the outer tubular body 35 along the axial direction. These groove lines 34a, 35a form a fuel passage that is axially communicated with each other by being inserted into each other and is open at both axial ends (upper and lower ends in the drawing). The outer cylinder 3
5 has a flange member 60 fixed to its upper end so as to form a stepped expansion.

By the flange member 60, the inner cylindrical body 34
In the annular space portion formed around the ring-shaped joint part 37 made of SUS material so as to be rotatable around the housing axis and with a gap formed between the lower surface thereof and the bottom surface of the annular space portion. It is fitted. As shown in FIG. 1, the joint part 37 is provided in the inner cylindrical body 34 at an arbitrary rotating position.
It is fixed by tightening a fixing nut 38 made of SUS303 material. A sectional view taken along the line AA of FIG. 1 is shown in FIG. 1 or 2,
The joint part 37 includes a connecting portion 36 whose one end projects to the outer surface.
Inlet 1 with an open end on one side and an open bottom on the other end
Are formed. A strainer 39 is incorporated at the inlet of the fuel inlet 1 of the connecting portion 36. Further, a male screw 36a is formed on the outer peripheral surface of the connecting portion 36, and the fuel pipe 63 is screwed onto the male screw 36a for connection. It should be noted that O-rings 30 and 31 are provided on the inner and outer peripheral surfaces of the fitting portion of the joint component 37 to the annular space inside the flange member 60 to maintain airtightness with the respective cylinders.

As shown in FIG. 1, a body sub-assembly 2 incorporated in the housing sub-assembly 20.
Reference numeral 1 denotes a ring-shaped second block 15 made of SUS304 material and a substantially hollow cylindrical electrical insulating material such as polyphenylene sulfide resin (also referred to as PPS resin) insert-molded on the outer periphery of the central portion of the second block 15. A spring guide 41, a core 2 made of a substantially hollow cylindrical magnetic material fitted to the spring guide 41, and a bobbin 16 made of an electric insulating material such as PPS resin fitted to the outer peripheral surface of the core 2. Bobbin 1
6 is provided with a coil 42 wound in multiple layers, and a first block 14 made of a ring-shaped SUS304 material fitted on the outer peripheral surface of the lower end portion of the core 2, and is formed into a substantially hollow cylindrical shape. The yoke 17 is made of SUS magnetic material and is fitted from above. The spring guide 41 is provided with an O-ring 27 for maintaining airtightness with the core 2, and the first block 14 is provided with a yoke 17 and a core 2.
O-rings 25 and 26 for maintaining airtightness between and are provided respectively.

The connecting end of the coil 42 is drawn out to an annular space 16a formed at the upper end of the bobbin 16. On the other hand, the coil connection side end of the harness 43 is drawn into the space 16a through the upper flange portion of the core 2 from between the second block 15 and the spring guide 41, and the coil 42 is connected in the space 16a. Electrically connected to the end. A proper number of grooves 17a are provided on the outer peripheral surface of the yoke 17 along the axial direction. The groove 17a opens on the upper end surface of the yoke 17, and the lower end thereof is connected to a communication hole 44 penetrating in the yoke radial direction near the lower end of the yoke 17.

The body sub-assembly 21 is inserted in the lower half of the housing sub-assembly 20. With this insertion, the harness 43 is pulled out upward through the inner cylindrical body 34 of the housing sub-assembly 20. The lead-out end of the harness 43 is electrically connected to an electronic control unit (also referred to as an ECU) not shown, and the coil 42 receives an input from the electronic control unit to energize or deenergize the coil.

The groove 17a of the yoke 17 forms a fuel passage communicating with the axial direction by inserting the outer cylinder 35. This fuel passage communicates with the fuel passage formed by the grooves 34a, 35a in the housing sub-assembly 20 through a space surrounded by the inner cylinder 34, the outer cylinder 35, the yoke 17 and the second block 15. The upper end of the second block 15 is fitted in the inner cylindrical body 34. The second block 15 is provided with an O-ring 28 that maintains airtightness with the inner cylindrical body 34.

On the upper end of the spring guide 41, a set screw 8 made of SUS303 material and a set screw stopper (referred to as screw stopper) 7 are sequentially screwed. Specifically, the head itself of the set screw 8 having the groove 8a is screwed to the spring guide 41. A pipe 61 made of SUS303 material that comes into contact with a valve spring 9 described later is rotatably fitted into the shaft end of the set screw 8. Pipe 6
1 is the screw 8 when the set screw 8 is screwed in.
It rotates relative to the valve spring 9 to prevent the valve spring 9 from twisting due to the rotation of the valve spring 9. Set screw 8
O for maintaining airtightness with the spring guide 41.
A ring 29 is provided. The lower end of the screw stopper 7 is screwed onto the spring guide 41. The connection terminal 6a of the high tension cord 6 is electrically connected to the rectangular groove-shaped socket portion 7a formed on the upper end portion of the screw stopper 7. In addition, the high tension cord 6 and the harness 43 are provided on the upper end of the inner cylindrical body 34.
Filling material 46 such as epoxy resin for sealing the surrounding space
Is loaded.

In the sectional view of FIG. 3 in which the structure around the valve sub-assembly 4 incorporated in the lower end of the body sub-assembly 21 is shown in detail, the valve sub-assembly 4 comprises a shaft-shaped valve 10 made of SUS440C material. The valve support body 48 is made of an electrically insulating material such as PPS resin, which is insert-molded at the upper end of the valve 10, and the armature 3 is made of a magnetic material and is insert-molded on the outer periphery of the central portion of the valve support body 48. Valve support 4
In the outer peripheral portion of 8, a suitable number of pieces (for example, 4
A fuel escape passage 49 composed of a through hole is formed. The upper half of the valve support 48 is formed in a hollow cylindrical shape (see FIG. 1). Further, the valve 10 has a fuel guide portion 51 which is formed in a substantially columnar shape at the tip of the shaft portion 50 and has a swirl forming screw groove on the outer peripheral surface thereof.
And a substantially conical valve portion 52 provided at the tip of the fuel guide portion 51, and a slide portion 53 formed in a flange shape at the center of the shaft portion 50.

The valve sub-assembly 4 is fitted in the body sub-assembly 21 so as to be vertically movable, as shown in FIG. For details, see SUS3 inside the spring guide 41.
After inserting the valve spring 9 made of 04 material, the valve support 48 is fitted in the spring guide 41 with the lower end of the valve spring 9 fitted with the tubular portion of the valve support 48. The armature 3 is located inside the lower end of the yoke 17, the upper end surface of which is opposed to the lower end surface of the core 2 and receives an attractive force from the core 2 when the coil 42 is energized. Also, the yoke 1
The open end of the communication hole 44 of 7 communicates with the space portion around the valve support 48.

The cap sub-assembly 23 incorporated in the lower end of the housing sub-assembly 20 is a valve seat made of a stainless alloy material (for example, NCF 713 or 718 material) having a substantially hollow cylindrical shape and having a nozzle 5a at its lower end. 5, a ceramic cover 13 having a substantially hollow cylindrical shape and having the valve seat 5 screwed therein, and a cap made of an SUS material having a substantially hollow cylindrical shape and having the cover 13 inserted therein. 11
Consists of

The lower end of the cap 11 is provided with a GND electrode 12 made of a Ni alloy material and having its front end directed toward the lower end edge 5b of the valve seat 5. On the outer peripheral surface of the cap 11, a male screw 11a for screwing on the cylinder head 64 of the internal combustion engine is formed. The valve seat 5 is provided with an O-ring 19 for maintaining airtightness with the cover 13, and the cover 1
3 is an O-ring 2 that maintains airtightness with the cap 11.
4 are provided. The upper edge of the cap 11 is crimped to the cover 13 via an O-ring 32.
Gaskets 54 and 55 made of a copper material are interposed between the valve seat 5 and the cover 13 and between the cover 13 and the cap 11, respectively.

The cap sub-assembly 23 is incorporated in the housing sub-assembly 20 as described below. That is, the valve 10 is provided in the valve seat 5.
Is slidably inserted, and the cap 11 is fitted to the lower end of the outer cylindrical body 35 and fixed by laser welding. The valve sub-assembly 4 is normally urged downward in the figure by the elasticity of the valve spring 9, and the valve element 52 of the valve 10 is held in a state in which the injection port 5a of the valve seat 5 is closed. Also, the slide portion 5 of the valve 10
3 has a substantially circular shape that is slidably fitted in the valve seat 5 and forms a fuel passage portion that opens in the axial direction by partially cutting the outer peripheral portion. The valve 10 is opened and closed by sliding the slide portion 53 with respect to the valve seat 5, and there is a slight gap between the outer peripheral surface of the fuel guide portion 51 and the inner peripheral surface of the valve seat 5.

A cylindrical stroke adjusting ring 18A made of SUS303 material is attached to the end of the cap 11 facing the yoke 17. A ring-shaped stroke adjusting plate 22A made of SUS440C-based material is interposed between the stroke adjusting ring 18A and a portion of the yoke 17 facing the stroke adjusting ring 18A. The opening / closing stroke of the valve sub-assembly 4 is set to an appropriate amount by adjusting the plate thickness of the plate 22A. Further, the tip end portions (upper end portions in the drawing) of the stroke adjusting plate 22A and the ring 18A are fitted to the end portions of the yoke 17 facing the cap 17. The cover 13 is not in contact with the yoke 17. Further, the inner diameter of the upper end portion of the cover 13 is formed to be larger than the large diameter portion of the valve support body 48, and the fuel communicating between the cover 13 and the valve support body 48 through the communication hole 44 of the yoke 17 into the valve seat 5 is provided. A passage is formed.

The O-rings 19 and 2 used for the above respective parts
Nos. 4 to 32 are all made of a fluororubber material. Further, the material specified for each member is not limited to that, and may be any material satisfying the condition required for each member.

First, the operation of the fuel injection valve in the fuel injection device will be described. The fuel supplied under a predetermined pressure from a fuel tank (not shown) is filtered by the strainer 39 of the fuel inlet 1 and then reaches the inside of the valve seat 5 through the fuel passage. However,
Since the valve 10 is held by the elasticity of the valve spring 9 so that the injection port 5a of the valve seat 5 is closed, fuel injection from this injection port 5a does not occur.

When the coil 42 is energized by the input of an electric signal from the electronic control device, the valve sub-assembly 4 is retracted by the attraction force of the core 2 acting on the armature 3. As a result, the injection port 5a of the valve seat 5 is opened, and fuel is injected from here. At this time, the fuel is
A swirl is formed by the screw groove of the fuel guide portion 51 of the valve 10 while being given a swirling motion to form a swirl, and the swirl is injected from the injection port 5a with a wide spray angle. Then, when the electric signal to the coil 42 is turned off and the attraction force of the core 2 acting on the armature 3 is released, the elasticity of the valve spring 9 advances the valve sub-assembly 4, and the valve 10 re-opens the injection port 5a. Since it is maintained in the closed state, the fuel injection from this injection port 5a is stopped.

Next, the operation of the spark plug will be described. The high voltage from the ignition coil is transmitted to the valve seat 5 via the high tension cord 6, the screw stopper 7, the set screw 8, the pipe 61, the valve spring 9 and the valve 10, and the edge portion 5b of the valve seat 5 is used as a central electrode. And the GND electrode 12 facing it
A spark discharge is generated between and to ignite the mixture in the combustion chamber.

The fuel injection device is attached to the cylinder head 64 of the internal combustion engine by screwing the male screw 11a of the cap 11 at its tip (lower end in the figure).
Then, with the fixing nut 38 loosened, the joint part 37 is rotated around the housing axis to connect the connecting portion 36.
Can be directed to the fuel line 63 in a convenient direction. After adjusting the orientation, connect the joint part 37 to the fixing nut 3.
It is fixed to the housing sub-assembly 20 by 8. In this way, the connecting portion 36 can be adjusted to the direction convenient for the fuel pipe 63, so that the fuel pipe 63 can be easily handled and the assembling property is improved. Further, according to the fuel injection device, since the ignition plug is integrally formed with the fuel injection valve for directly injecting the fuel into the combustion chamber of the internal combustion engine, the high tension cord 6 for the ignition plug is arranged in addition to the fuel pipe 63. Since it is necessary to provide the fuel pipe 63, the degree of freedom in handling the fuel pipe 63 is limited. However, even in such a case, the connecting portion 36 can be oriented in a convenient direction to the fuel pipe 63, and the fuel pipe 63 Can be easily implemented.

[0027]

According to the fuel injection device of the first aspect, since the connecting portion can be adjusted in a direction convenient to the fuel pipe by rotating the joint component around the housing axis, the fuel pipe can be easily routed. As a result, the assemblability is improved. According to the fuel injection device of the second aspect, even when it is necessary to dispose the high tension cord for the spark plug in addition to the fuel pipe, the connection portion is adjusted in a direction convenient to the fuel pipe, Connection can be performed easily.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a fuel injection device.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged sectional view showing a tip portion of the fuel injection device.

FIG. 4 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Fuel Intake Port 20 Housing Sub-Assy (Housing) 36 Connection Part 37 Joint Parts 38 Fixing Nut (Fixing Means) 63 Fuel Pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02P 13/00 303 F02P 13/00 303A

Claims (2)

[Claims] 1. A fuel injection device in which a housing incorporating a fuel injection valve is provided with a connection portion of a fuel intake port for connecting a fuel pipe, wherein the housing is formed separately from the housing. 2. A fuel injection device, comprising: a joint part having a portion so as to be rotatable about a housing axis, and fixing means for fixing the joint part at an arbitrary rotational position. 2. The fuel injection valve is a fuel injection valve for directly injecting fuel into a combustion chamber of an internal combustion engine, and the fuel injection valve is integrally formed with an ignition plug. Fuel injector.