JP3021956B2 - Fuel injection device - Google Patents

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.

[0002]

2. Description of the Related Art In Japanese Utility Model Laid-Open No. 4-16665, a flange portion is formed on an outer peripheral portion of an injector, and a bolt hole is formed in the flange portion. There has been disclosed a fuel injection device in which a bolt is inserted into a bolt hole and a flange portion is fastened to a cylinder head so that an injector is fixed to the cylinder head.

[0003]

However, in this fuel injection device, there is a problem that the mounting space is increased because the injector is fixed by the bolt by forming the flange portion in which the bolt hole is formed. Therefore, an annular small expanding step concentric with the injector is formed on the outer periphery of the cylindrical injector, and after inserting the injector into the injector insertion hole, the expanding step is pressed with a cylindrical tightening collar surrounding the injector. To fix the injector. This eliminates the need for a bolt mounting space, thereby reducing the injector mounting space.

However, in this case, in the injector in which the center direction of the injected fuel is inclined with respect to the axis of the injector, the injector can be fixed regardless of the direction of the center direction of the injected fuel. ,
There is a problem that the fuel injection direction cannot be easily directed to a desired direction.

[0005]

A fuel injection device according to the present invention comprises a substantially cylindrical injector in which a center direction of fuel injection is inclined with respect to an injector axis, and a fuel injection device for supporting the injector on a support member. A pressing means for pressing an enlarged step provided on an outer peripheral portion of the injector against the support member; and a fuel pipe extending non-rotatably about the injector axis, wherein the expanding step is provided by the pressing means. By fixing the fuel pipe to the injector before the portion is pressed, the injector is positioned around the injector axis such that the center direction of the injected fuel is oriented in a predetermined direction. Features.

[0006]

According to this fuel injection device, the injector is
Since the enlarged step portion is supported by the support member by being pressed by the pressing means, no mounting bolt is required, and the mounting space for the injector is reduced. Also, before the expansion step is pressed by the pressing means, by fixing the fuel pipe, which extends non-rotatably around the injector axis, to the injector, the injector can move in the direction in which the center direction of the injected fuel is predetermined. Is positioned around the injector axis so as to face the injector.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIGS. Referring to FIG. 2, 1 is an injector for directly injecting fuel into the combustion chamber of each cylinder, 2 is a cylinder head to which the injector 1 is fixed, and 3 is each injector 1
And 4 are fuel supply pipes that connect the rear end of each injector 1 and the delivery pipe 3.

FIG. 3 is a sectional view taken along the line III-III of FIG. Referring to FIG. 3, the lower half of the cylindrical positioning pin 5 is press-fitted into the cylinder head 2. A bolt hole 6 penetrates through the delivery pipe 3, and the lower end of the bolt hole 6 is enlarged to form a pin fitting hole 6 a into which the positioning pin 5 is fitted. The delivery pipe 3 is fixed to the cylinder head 2 by bolts 7 by fitting the positioning pins 5 into the pin fitting holes 6a. Thus, the delivery pipe 3 is accurately positioned with respect to the cylinder head 2.

FIG. 1 is a partial sectional view taken along the line II of FIG. Referring to FIG. 1, an injector insertion hole 8 is formed through the combustion chamber 9 in the cylinder head 2, and the injector 1 is inserted into the injector insertion hole 8. An annular step 1b having a diameter slightly larger than that of the injector body 1a is formed on the outer periphery of the lower portion of the substantially cylindrical injector 1. The inner diameter of the upper portion 8a of the injector insertion hole 8 is larger than the outer diameter of the injector body 1a and substantially the same as the step 1b of the injector 1. A gap is formed. A female screw is formed on an inner peripheral surface of the upper portion 8a of the injector insertion hole, and a step 1b of the injector 1 is provided at a lower end of the upper portion 8a of the injector insertion hole.
Receiving step 8b is formed.

After the annular gasket 10 is disposed on the reduction step 8b, the injector 1 is inserted into the injector insertion hole 8, and the step 1b of the injector 1 engages with the gasket 10 to lock the injector 1. Is done. Then
The outer diameter is substantially equal to the inner diameter of the upper portion 8a of the injector insertion hole, the inner diameter is substantially equal to the outer diameter of the injector body 1a,
And a cylindrical tightening collar 1 having an external thread formed on the outer peripheral surface.
1 is screwed into the female screw of the upper portion 8a of the injector insertion hole and inserted into the gap between the upper portion 8a of the injector insertion hole and the injector body 1a. By tightening the tightening collar 11, the lower end of the tightening collar 11 presses the step 1b of the injector 1 toward the step 8b of the injector insertion hole 8, thereby fixing the injector 1 to the cylinder head 2.

As described above, in the injector 1, the flange formed on the injector 1 is not fixed by the bolts as in the prior art, but is fixed by the tightening collar 11, so that the mounting space for the injector 1 is reduced. I can do it. When the injector 1 is fixed, the tip of the injector 1 projects into the combustion chamber 9, whereby fuel can be directly injected into the combustion chamber 9.

The fuel F injected from the injector 1 has a predetermined spread angle, and the center direction X of the injected fuel F is inclined at a predetermined angle with respect to the axis Y of the injector 1. Incidentally, in particular, in an engine that directly injects fuel into the combustion chamber 9, the fuel must be accurately injected in a predetermined injection direction.

However, when the injector is fixed by the tightening collar 11 as shown in FIG.
Can be fixed at any position around its axis Y,
It is difficult to easily direct the fuel injection direction to a desired direction to fix the injector 1. Therefore, in the first embodiment, when one end of the fuel supply pipe 4 is fixed to the rear end of the injector 1 in advance and the other end of the fuel supply pipe 4 is connected to the delivery pipe 3, the fuel injection direction becomes the desired direction. I am trying to become.

Referring to FIG. 1, one end of the fuel supply pipe 4 is fixed to the rear end of the injector 1 and is formed integrally in advance. After the fuel supply pipe 4 extends from the rear end of the injector 1 along the axis Y of the injector 1, approximately 9
It is bent by 0 ° and the other end is fixed to the delivery pipe 3 by a nut 13. The bending direction and length of the fuel supply pipe 4 are such that when the other end of the fuel supply pipe 4 is fixed to the delivery pipe 3 accurately positioned as described above, the fuel injection direction of the injector 1 is in a desired direction. It is decided to point.

As described above, in this embodiment, the injector 1 is inserted into the injector insertion hole 8 and the other end of the fuel supply pipe 4 is fixed to the delivery pipe 3.
The fuel injection direction of the injector 1 can be easily directed to a desired direction. In this embodiment, after fixing the fuel supply pipe 4 to the delivery pipe 3, the injector 1 is fixed by the fastening collar 11.

Next, a second embodiment will be described with reference to FIGS. 4 and 5, the same components as those of the first embodiment are denoted by the same reference numerals. Referring to FIG. 4, an annular sliding gasket 15 is disposed on the upper surface of the step portion 1b of the injector body 1a. Therefore, even if the tightening collar 11 is rotated and tightened, the rotational force is almost absorbed by the sliding gasket 15 and the injector 1
, The torque of the fastening collar 11 is hardly transmitted.
For this reason, it is possible to prevent the fuel injection direction of the injector 1 from shifting due to the tightening of the tightening collar 11.

The fuel supply pipe 4 extends from the rear end of the injector 1 along the axis Y of the injector 1 and then bends greatly. The other end of the fuel supply pipe 4 extends along the axis Z perpendicular to the axis Y of the injector 1. Extend. Referring to FIGS. 4 and 5, the other end of the fuel supply pipe 4 is connected to a side peripheral surface of a substantially cylindrical joint 16, which is fixed to the delivery pipe 3 by a union bolt 17. A detent 18 extends from the side peripheral surface of the joint 16 on the side opposite to the connection with the fuel supply pipe 4.
Is locked to the delivery pipe 3. As a result, even if the union bolt 17 is tightened, the joint 16 does not rotate, and the torque of the union bolt 17 is not transmitted to the fuel supply pipe 4. Therefore, it is possible to prevent the rotational force of the union bolt 17 from being transmitted to the fuel supply pipe, thereby preventing the fuel injection direction of the injector 1 from shifting.

Next, a third embodiment will be described with reference to FIG. Referring to FIG. 6, in the third embodiment, the fuel supply pipe 4 formed integrally with the injector 1 is attached to a fuel supply pump 20 that is accurately positioned with respect to the cylinder head 2 so that the fuel of the injector 1 can be improved. The injection direction is directed to a desired direction.

[0019]

The mounting space for the injector can be reduced, and the fuel injection direction of the injector can be easily directed to a desired direction.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of the fuel injection device shown in FIG. 2 taken along line II.

FIG. 2 is a front view showing a first embodiment of the fuel injection device of the present invention.

FIG. 3 is a sectional view of the delivery pipe shown in FIG. 2 taken along line III-III.

FIG. 4 is a partial sectional view showing a second embodiment of the fuel injection device of the present invention.

FIG. 5 is a plan view of the joint in FIG. 4;

FIG. 6 is a front view showing a third embodiment of the fuel injection device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Injector 3 ... Delivery pipe 4 ... Fuel supply pipe 8 ... Injector insertion hole 11 ... Tightening collar

Continuation of front page (56) References JP-A-62-117266 (JP, A) JP-A-61-12971 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02M 61 / 14-61/16 F02M 55/02 350

Claims (1)

(57) [Claims] 1. A substantially cylindrical injector in which a center direction of fuel injection is inclined with respect to an injector axis,
Pressing means for pressing an enlarged step provided on an outer peripheral portion of the injector against the support member to support the injector on a support member, and a fuel pipe extending non-rotatably about the injector axis. Before the expanding step is pressed by the pressing means, the fuel pipe is fixed to the injector so that the injector is oriented so that the center direction of the injected fuel is in a predetermined direction. The fuel injection device is positioned around the injector axis.