JP2003227437A - Joint structure for joining fuel pipe to fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure that secures improvement in mountability and loosening strength and joins a fuel pipe part having an inexpensive structure of a fuel injection device. <P>SOLUTION: The joint structure for joining the fuel pipe part 20 of the fuel injection device 1 comprises a seal member housing member 30 that houses a seal member 50 and prevents fuel leakage by inserting it between the fuel injection device 1 and the fuel pipe part 20, a pipe member 40 fixed to the seal member housing member, and a clip 60 for fixing the integrated pipe member 40 and seal member housing member 30 to the fuel injection device 1. A grappled part grappled by a snapping force of the clip 60 is upper end surface 30a of the seal member housing member. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for joining a fuel pipe to a fuel injection device, and more particularly to a pressure accumulation type fuel injection device for injecting high pressure fuel accumulated in a common rail to an internal combustion engine. The present invention relates to a joining structure for joining the components.

[0002]

2. Description of the Related Art As a fuel injection device, for example, in a common rail type fuel injection device as a fuel injection system for a diesel engine, high pressure fuel, which is provided in each cylinder of an internal combustion engine and accumulates pressure in the common rail, is injected into a combustion chamber of the cylinder. It is known that a fuel drain valve for supplying surplus fuel to a fuel tank or the like is attached to a fuel injection valve to be supplied.

As a structure for mounting the fuel drain pipe for a fuel injection valve of this kind, the fuel to which the fuel drain pipe is connected is selected from the relationship between the positions of the fuel tanks and the positions of the fuel injection valves mounted on the internal combustion engine. It is necessary for the direction of the opening of this pipe to be freely changeable in the circumferential direction with respect to the injection valve.

As a countermeasure against this, as shown in FIG. 5, the fuel drain pipe 520 is inserted into a connecting element 510 which is a fuel outlet end portion for leading out excess fuel in the fuel injection valve 1, and is connected to the accommodating member 530. And its fuel outlet end 51
0 and the containing member 530, the seal member 550 for ensuring the airtightness of the fuel, and the pipe 540 radially protruding from the containing member 530 are provided, and the fuel outlet end portion 510 and the containing member 530 are arranged from above. Some are fitted and fixed using a clip 560 to be sandwiched.

[0005]

In the conventional structure, the clip is attached from above when attaching and fixing the fuel outlet end portion 510 and the containing member 530. Therefore, the fitted portion K of the fuel outlet end portion 510 is attached. Was difficult to confirm, and there was a problem that the assembly work for fitting was not easy. On the contrary, if the fitting force of the clip is suppressed to facilitate the assembling work, the pipe 540 provided in the storage member 530 is easily pulled out or looses with the fuel outlet portion 510 attached to the fuel injection valve 1. There is a possibility that it will be in a fitted state.

The present invention has been made in consideration of such circumstances, and therefore an object thereof is to improve the assemblability and secure the pull-out strength, and to inject the fuel pipe portion having the inexpensive structure with the fuel injection. It is to provide a joining structure for joining to a device.

[0007]

According to a first aspect of the present invention, there is provided a joining structure for joining a fuel pipe portion of a fuel injection device, which accommodates a seal member, the fuel injection device and the fuel pipe portion. A seal member accommodating member for preventing fuel leakage by being inserted between the pipe member and the seal member accommodating member; With a clip to be fixed, the clamping part that is clamped by the elastic force of the clip,
It is an upper end surface of a seal part accommodation member.

Thus, the seal member accommodating member is clamped by the clip at its upper end surface, so that the exclusive groove can be eliminated in the seal member accommodating member, and the clip can be connected to the fuel pipe portion without any special measures. The fuel injection device can be joined.

According to the second aspect of the present invention, the fuel injection device fixed by the clip is provided with the connecting element having the groove portion into which the clip is inserted, and the connecting element accommodates the seal member accommodating member, and The seal member accommodating member is locked via a clip that engages with the groove.

Thus, the fuel pipe portion, especially the seal member accommodating member can be easily aligned in the axial direction, and an inexpensive structure for joining can be provided.

According to claim 3 of the present invention, the clip is
The seal member accommodating member integrated with the pipe member is sandwiched so as to sandwich the groove.

As a result, the clip itself can be securely prevented from coming off by the deformation of the clip itself having elastic force.

According to claim 4 of the present invention, the clip is
It penetrates through the two groove portions formed in the connection element, and is inserted and assembled in the gap between the inner circumference of the connection element and the outer circumference of the pipe member.

Thus, by inserting the elastic clip into the gap between the inner periphery of the connecting element and the outer periphery of the pipe member, the clip itself can be securely prevented from coming off due to deformation of the clip itself, and the seal member can be accommodated. The upper end surface of the member can reliably prevent the seal member accommodating member from coming off, that is, the pipe part from coming off.

According to claim 5 of the present invention, the clip is
It has both ends penetrating the groove, both ends being bent along the outer circumference of the connecting element after the insert assembly.

As a result, even if the clip has a relatively small elastic force, the clip can be securely prevented from coming off. For example, a clip as a standard component that can be obtained at a relatively low cost can be used.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A concrete embodiment of a joining structure for joining a fuel pipe portion of the present invention to a fuel injection device will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a structure of a joining structure for joining a fuel pipe portion to a fuel injection device of an embodiment of the present invention, FIG. 1 (a) is an axial cross-sectional view, and FIG. 1 (b). FIG. 2 is a transverse cross-sectional view as seen from BB in FIG. 4 is an axial sectional view showing a comparative example for comparison with the present embodiment.

As shown in FIG. 1, the joining structure for joining the fuel pipe portion to the fuel injection device is a structure for joining the fuel drain pipe portion (hereinafter referred to as the fuel pipe portion) of the fuel injection device 1. A sealing member housing member (hereinafter referred to as a housing member) 30 that houses an O-ring 50 as a sealing member and prevents fuel leakage from the fuel injection device 1 (specifically, the connection element 10), and a housing member. It is configured to include a pipe member 40 fixed to 30 and a clip 60 made of an elastic body.

The connecting element 10 is formed at a fuel outlet end of a fuel injection valve 1 (see FIG. 4 of a conventional example) as a fuel injection device, and injects fuel into a combustion chamber of an internal combustion engine. Therefore, it is a part of the fuel passage portion for collecting the surplus fuel in the fuel tank (not shown) among the high-pressure fuel supplied to the fuel injection valve 1. Also, this connecting element 10
The pipe member 4 is connected to the fuel pipe portion 20 (specifically, the pipe member 40) that guides the fuel to the fuel tank for recovery into the fuel tank, and the pipe member 4 is used because of its positional relationship with the fuel tank.
The direction of the opening 40a on the fuel tank side of 0 is freely changed in the circumferential direction, and any fuel injection device may be used as long as it needs a function of drawing surplus fuel in any direction.

The connecting element 10 described in the present embodiment.
That is, the fuel injection device 1 is provided in each cylinder of an internal combustion engine in a so-called common rail fuel injection system having a common rail for accumulating high pressure fuel, and the high pressure fuel accumulated in the common rail is injected and supplied to the combustion chamber of the cylinder. It will be described as a fuel injection valve.

As shown in FIG. 1A, the accommodating member 30 is a substantially stepped cylindrical body, and has a connecting element side flange portion 31 forming a large diameter cylindrical portion and a pipe side forming a small diameter cylindrical portion. And a flange portion 32. The connecting element side flange portion 31 and the pipe side flange portion 32
A through hole 33 is provided in the inside in the axial direction so that the surplus fuel flowing out from the fuel injection valve 1 (specifically, the connecting element 10) is led out to the fuel tank via the pipe member 40. Further, the pipe-side flange portion 32 is inserted into the inner circumference of the pipe member 40 and is liquid-tightly fixed to the pipe member 40 by welding, brazing or the like.

The accommodating member 30, in particular, the connecting element side flange portion 31 is accommodated in the inner periphery 10a of the connecting element 10 so as to be insertable therein, and the stepped portion 10a1 formed on the inner periphery 10a restricts the downward movement in the axial direction. Has been done. The pipe-side flange portion 32 is not limited to being housed in the inner periphery 10a of the connecting element 10 as shown in FIG. 1A, but is formed so as to project in the axial direction from the connecting element 10. May be

Further, an annular groove 34 is formed on the outer circumference 31a of the connecting element side flange portion 31 housed in the inner circumference 10a, and this annular groove 34 is O shown in FIG. 1 (a).
A seal member 40 such as a ring is configured to be accommodated. As a result, the connecting element side flange portion 31 is inserted between the pipe member 50 and the connecting element 10, that is, inserted between the fuel pipe portion 20 and the fuel injection valve 1, so that O
Since the ring 50 is sandwiched between the inner circumference 10a and the annular groove 34, it is possible to prevent fuel leakage from the fuel passage portion (fuel pipe portion 20) that leads the excess fuel of the fuel injection valve 1 to the fuel tank.

Further, the pipe member 40 and the containing member 30,
That is, the fuel pipe portion 20 is integrally fixed to the connecting element 10 via the clip 60. More specifically, as shown in FIG. 1B, the connecting element 10 is provided with a groove 10b, and the clip 60 sandwiches the groove 10b by the elastic force of the elastic body itself.
The pipe member 40 is sandwiched. At this time, clip 6
0 and the groove portion 10b in the axial positional relationship are shown in FIG.
As shown in (a), at the upper end surface 30b of the accommodating member 30 to which the pipe member 40 is fixed (specifically, at the upper end surface of the connection element side flange 31), the accommodating member 30 has a clip 60.
Are arranged so as to be axially locked by.
This ensures that the clip 70 is prevented from coming off due to the deformation of the clip 60 itself having elastic force. Therefore, it is possible to prevent the clip 70 from coming off while ensuring a configuration in which the direction of the opening 40a of the fuel pipe member 20 can be freely changed in the circumferential direction, and thus the strength of the fuel pipe 20 from coming out of the fuel injection valve 1 can be improved.

In the joining structure for joining the fuel pipe 20 to the fuel injection valve 1 described above, the clip 60 is used for axial alignment of the housing member 30, that is, for axial alignment of the fuel pipe portion 20. By locking the housing member 30 at the upper end surface 30b without providing the exclusive groove (second annular groove) 35 formed in the housing member 30 housing the clip 60 as shown in the comparative example of FIG. Therefore, an inexpensive joint structure can be provided.

The shape of the clip 60 is as shown in FIG.
As shown in (b), by providing the curved portion 60b having the inner diameter φ60 smaller than the outer diameter φ40 of the pipe member 40, the elastic force can be surely provided. Further, at both end portions 60a forming both curved portions 60b of the clip 60, it is desirable that the tip end side 60c thereof spreads outward. As a result, the curved portion 60b that secures a predetermined elastic force can be formed, and the clip 60 can be attached to the
When inserting and assembling as shown in (b), it is easy to assemble the clip 60 to the groove portion 10b sandwiched by the clip 60 and the outer circumference φ40 of the pipe member 40 due to the shape in which the distal end side 60c expands outward. Can be
Assembly can be improved.

(Modification) As a modification, the clip 60 described in the above embodiment is the groove portion 10 of the connecting element 10.
Instead of sandwiching b, as shown in FIG. 2, the clip 60 penetrates both groove portions 10b formed in the connection element 10 and is provided in a gap between the inner circumference 10c of the connection element 10 and the outer circumference φ40 of the pipe member 40. It may be inserted and assembled.
FIG. 2 is a cross-sectional view showing a joining structure for joining the fuel pipe portion of the modified example to the fuel injection device. Here, the inner circumference 10c of the connecting element 10 is a part of the inner circumference 10a for housing the housing member 30, and is an inner circumference formed between both groove portions 10b provided in the connecting element 10. .

As a result, the clip 60 having elastic force
The inner circumference 10c of the connecting element 10 and the outer circumference φ of the pipe member 40.
By inserting the clip 60 into the gap C, the clip 60 can be surely prevented from being deformed by the deformation of the clip 60 itself, and the upper end surface 30b of the material accommodating member 30 can be surely prevented from coming off from the connecting element 10. That is, the fuel pipe portion 20 can be prevented from coming off from the fuel injection valve 1.

As for the shape of the clip 60, both ends 60a may be arranged substantially in parallel as shown in FIG. 2 so that the clip 60 can be easily inserted into the gap C. As a result, FIG.
When inserting and assembling the clip 60 in the direction of the arrow shown in
Depending on the shapes of the inner circumference 10c of the connecting element 10 and the outer circumference φ40 of the pipe member 40 forming the gap C, the clip 60
Elastically deforms the curved portion 6 having elastic force as a result.
0b can be formed.

As another modification, the clip 60 described in the above modification is replaced with a structure in which both end portions 60a have a predetermined parallel arrangement, and as shown in FIG. It may be a pin. FIG. 3 is a cross-sectional view showing a joint structure for joining the fuel pipe portion of another modification to the fuel injection device.

When a split pin having a small elastic force is used as the clip 60, as shown in FIG.
After inserting and assembling 0 into both the groove portions 10b, both ends 60a (specifically, the tip portions 60c) of the clip 60 are connected to the connecting element 10.
It is desirable to bend along the outer circumference 10d.

As a result, even if the clip 60 has a relatively small elastic force, the clip can be securely prevented from coming off. For example, a clip 60 such as a split pin as a standard component that can be obtained at a relatively low cost can be used.

[Brief description of drawings]

1A and 1B are cross-sectional views showing a structure of a joining structure for joining a fuel pipe portion to a fuel injection device according to an embodiment of the present invention, wherein FIG. 1A is an axial cross-sectional view and FIG. Figure 1
It is the cross-sectional view seen from BB in (a).

FIG. 2 is a cross-sectional view showing a joint structure for joining a fuel pipe portion of a modified example to a fuel injection device.

FIG. 3 is a cross-sectional view showing a joining structure for joining a fuel pipe portion of another modification to a fuel injection device.

FIG. 4 is a cross-sectional view showing a joining structure for joining a fuel pipe portion of a comparative example to a fuel injection device.

FIG. 5 (a) is an explanatory view illustrating a structure for mounting a conventional fuel drain pipe for a fuel injection valve, and FIG.
Is a partial sectional view of the fuel injection valve showing the structure, FIG.
FIG. 5B is an exploded perspective view showing the structure of the fuel injection valve of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Fuel injection valve (fuel injection device) 10 Connection element 10a Inner circumference 10a1 Step portion 10b Groove portion 10c Inner circumference (formed between both groove portions 10b) Inner circumference (part of inner circumference 10a) 10d Outer circumference 20 Fuel pipe section 30 Storage Member (seal member accommodating member) 30b Upper end surface (upper end surface of connection element side flange portion 31) 31 Connection element side flange portion 31a Outer periphery 32 Pipe side flange portion 33 Through hole 34 Annular groove 40 Pipe member 40a Opening 50 O ring ( Seal member) 60 Clip 60a End portion 60b Curved portion 60c Tip side (tip portion) φ40 (pipe member) outer diameter (outer circumference) φ60 (curved portion 60b of clip 60) inner diameter C Gap

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 55/00 F02M 55/00 B F16B 7/04 302 F16B 7/04 302A F16J 15/10 F16J 15/10 C L T

Claims (5)

[Claims] 1. A joint structure for joining a fuel pipe portion of a fuel injection device, wherein a seal member is housed and is inserted between the fuel injection device and the fuel pipe portion to prevent fuel leakage. A seal member accommodating member for preventing; a pipe member fixed to the seal member accommodating member; and a clip fixed to the fuel injection device in a state where the pipe member and the seal member accommodating member are integrated, A sandwiching structure for joining the fuel pipe part to the fuel injection device, wherein the sandwiching part sandwiched by the elastic force of the clip is the upper end surface of the seal part accommodating member. 2. The fuel injection device fixed by the clip includes a connecting element having a groove portion into which the clip is inserted, the connecting element accommodating the seal member accommodating member and engaging with the groove portion. 2. The seal member accommodating member is locked via the clip to be fitted.
A joint structure for joining the fuel pipe section according to 1. to a fuel injection device. 3. The fuel injection for a fuel pipe portion according to claim 2, wherein the clip holds a seal member accommodating member integrated with the pipe member so as to sandwich the groove portion. Joining structure for joining to equipment. 4. The clip penetrates the two groove portions formed in the connecting element and is inserted and assembled in a gap between an inner circumference of the connecting element and an outer circumference of the pipe member. A joining structure for joining the fuel pipe part according to claim 2 to a fuel injection device. 5. The clip according to claim 4, wherein the clip has both end portions penetrating the groove portion, and the both end portions are bent along an outer circumference of the connecting element after insertion and assembly. Structure for joining the fuel pipe part of the above to the fuel injection device.