JPH10169528A - High-pressure fuel supply member and its connecting method, and gasket used for the connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb a tilt at the time of fitting to the mating member to retain a high-close sealing property, and make most members reusable even after dismounted from the mating member. SOLUTION: In this connecting method, a hatlike gasket 10 which is composed of soft metal having an annular flange 10a extending in a diameter direction from the outer peripheral edge of a pressing seat surface 2a, is mounted on the pressure receiving seat surface of the mating member 6 with a high- pressure fuel supply member 1 which is sealedly connected to the partner member 6 and supplying high-pressure fuel, or on the pressing seat surface 2a for pressing the pressure receiving seat surface. In this case, the hatlike gasket 10 can be simply replaced, and the other member can be used intact for a long time, by selecting a soft metallic member in accordance with the pressure of sealed connection to increase sealing effect, absorbing a tilt, etc., when the high-pressure fuel supply member 1 and the mating member 6 are fitted together to keep a sure sealing property, and locking the annular flange 10a to move it outward from the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a common rail used for a fuel supply passage for high-pressure fuel, a high-pressure fuel injection pipe having a pipe diameter of about 20 mm or less for a diesel internal combustion engine, an injection nozzle,
The present invention relates to a high-pressure fuel supply member such as an injector pipe, a connection method thereof, and a gasket used therefor.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional fuel injection pipe as a high-pressure fuel supply member of this type is provided at an end of an injection pipe 1 having a through hole 1a formed at a shaft center position from the outside of the shaft center. A frusto-conical connection head 2 was formed by press working with a punch tool, and a pressing seat surface 2a was formed on the distal end peripheral surface of the connection head 2. Then, the pressing seat surface 2a of the connection head 2 comes into contact with the conical or arc-shaped pressure receiving seat surface of the mating member such as the nozzle holder, and is fixed and connected with the fastening nut.

However, in this high-pressure fuel injection pipe,
Since cavitation, erosion, corrosion, or chemical corrosion occurs on the pressing seat surface 2a, the present applicant disclosed in Japanese Unexamined Patent Application Publication No. Hei 6-42428 that a connecting head 2 of the injection pipe 1 is provided with a shaft as shown in FIG. It has been proposed that a cap-shaped collar 3 made of a high-strength, high-corrosion-resistant metal material such as stainless steel, inconel, hastelloy, or titanium having a through-hole 3a communicating with the through-hole 1a is formed at the core position.

[0004]

In the conventional high-pressure fuel injection pipe shown in FIG. 5, the connecting head 2 is brought into direct contact with the pressure receiving seat surface of the other party, and is pressed and contacted so as to obtain a sufficient sealing property. Therefore, the pressing seat surface of the connection head 2 is deformed, and once removed, it is difficult to reuse the injection pipe 1. Also, as recently, when the supply fuel pressure is increased to reduce particulates and NOx and the injection pressure exceeds 1300 bar, such a work-hardened connection head maintains sufficient sealing performance. I can't.

Further, in the conventional high-pressure fuel injection pipe shown in FIG. 6, a cap-shaped collar 3 made of a high-strength, high-corrosion-resistant metal material is attached to the connection head 2 of the injection pipe 1, so that it is pressed. Although cavitation erosion and corrosion generated on the seating surface 2a or chemical corrosion can be prevented, since the cap-shaped collar 3 is made of a high-hardness metal material, compatibility with the pressing seating surface or the pressure receiving seating surface is reduced. Since the sealing performance deteriorated and the bearing surface of the mating member was damaged, the mating member could not be reused once removed. In addition, hat-shaped collar 3
There is a high possibility that the seat surface will be damaged by the tool used in removing the cap, and the cap-shaped collar 3 will be deformed at the time of attachment, so once removed, the entire fuel injection pipe cannot be reused, and Unless the posture at the time of attachment is set with high precision, there is also a problem that it is impossible to assemble with good sealing properties.

The present invention has been made in view of the current situation of the conventional high-pressure fuel injection pipe as described above, and an object of the present invention is to absorb the inclination of the high-pressure fuel supply member at the time of attachment to a counterpart member, While maintaining high sealing performance,
It is an object of the present invention to provide a high-pressure fuel supply member that can be reused even after detachment, a method of connecting the high-pressure fuel supply member, and a gasket used therefor.

[0007]

In order to achieve the above object, a first embodiment of the present invention is a high-pressure fuel supply member which is connected to a counterpart member and supplies high-pressure fuel,
A cap-shaped gasket made of a soft metal having an annular flange extending radially from an outer peripheral edge thereof is covered on a pressure receiving seat surface of the counterpart member of the high-pressure fuel supply member or a pressing seat surface pressing the pressure receiving seat surface. It is characterized by the high-pressure fuel supply member being worn.

[0008] Similarly, in order to achieve the above object, a second embodiment of the present invention provides a pressing seat surface of a high-pressure fuel supply member,
In a connection method of a high-pressure fuel supply member that presses against a pressure-receiving seat surface of a mating member and hermetically connects the high-pressure fuel supply member and the mating member, the pressure-receiving seat surface or the pressing seat surface is radially extended from an outer peripheral edge thereof. An applying step of applying a cap-shaped gasket made of a soft metal having an annular flange extending, and pressing the pressure seating surface of the high-pressure fuel supply member with the cap-shaped gasket applied thereto, the pressure-receiving seating surface. And a method of connecting the high-pressure fuel supply member, comprising a pressing step of pressing the high-pressure fuel supply member.

Further, a third embodiment of the present invention is characterized by a cap-shaped gasket for a high-pressure fuel supply member having an annular flange extending radially from an outer peripheral edge thereof.

In the first embodiment and the third embodiment, it is preferable that the annular flange has at least a pair of arms extending axially from an outer peripheral edge thereof.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in more detail with reference to FIGS. FIG. 1 is a partially cutaway longitudinal sectional view showing a first embodiment of the present invention, FIG. 2 is an explanatory view of removing a cap-like gasket shown in FIG. 1, and FIG. 3 is a part of a second embodiment of the present invention. FIG. 4 is an enlarged sectional view showing a part of the third embodiment of the present invention.

1 to 4, a common rail will be described as an example of a high-pressure fuel supply member. As shown in FIG. 1, the pressing seat surface 2a formed on the distal end peripheral surface of the frusto-conical connecting head 2 of the branch branch pipe 1 has the pressing seat surface 2a and a boss 6 of a common rail as a mating member. A cap-shaped gasket 10 made of copper, aluminum, annealed mild steel, or the like, which is softer than the material of the pressure receiving seat surface 6a having a substantially frustoconical shape, is attached. The cap-shaped gasket 10 is formed with a through-hole 3a communicating with the through-hole 1a at the position of the axis, and the outer edge of the cap-shaped gasket 10 is radially outward from the outer edge, that is, with respect to the axis. And an annular flange 10a projecting outward at a substantially right angle. On the other hand, a sleeve washer 4 is fitted to the rear of the connection head 2 as necessary, and the branch branch pipe 1 is fastened to the boss 6 of the common rail by a fastening nut 5 via the sleeve washer 4. I have.

In the present invention, in order to assemble the branch pipe 1 with the boss 6 of the common rail, as shown in FIGS. 1 and 4, the pressing seat surface 2a of the truncated conical connection head 2 of the branch branch pipe 1 is used.
The cap-shaped gasket 10 is attached to the
As shown in FIG. 3A and FIG. 3, the cap-shaped gasket 10 is attached to the pressure receiving seat surface 6a of the boss 6 of the common rail in a state where the gasket 10 is in contact with the boss portion 6. In this case, the annular flange 10a of the cap-shaped gasket 10 is attached so that a predetermined distance d is provided between the end face of the boss portion 6 of the common rail and the pressing seat surface 2a in contact with the pressure receiving seat surface 6a. Need to be done. On the other hand, a sleeve washer 4 is provided behind the connection head of the branch pipe 1.
And a tightening nut 5, and a cap-shaped gasket 10 disposed on a pressure receiving surface 6 a of a boss 6 of the common rail.
To the through-hole 3 of the cap-shaped gasket 10 of the branch pipe 1
a and the center of the through-hole 1a so that the cap-shaped gasket 1
The branch branch pipe 1 is disposed at 0, and the branch branch pipe 1 is assembled and fixed to the boss portion 6 of the common rail by the fastening nut 5.

When the cap-shaped gasket 10 is detached and the cap-shaped gasket 10 comes into close contact with the pressing seat surface 2a of the connecting head as shown in FIG. 1, a normal tool is engaged with the annular flange 10a. It can be easily removed by moving it axially outward. On the other hand, the boss 6 of the common rail
Even if the cap-shaped gasket 10 is fitted closely to the pressure receiving seat surface 6a, the removal jig 12 having a substantially U-shaped end shown in FIG. 2C is inserted into the space d. The cap-shaped gasket 10 can be easily removed from the pressure receiving seat surface 6a by engaging the annular flange 10a and moving it outward in the axial direction.

As described above, according to the present invention, the connection head 2 of the branch branch pipe 1 or the pressure bearing surface 6a of the boss 6 of the common rail is provided with the material of the pressure bearing surface 2a and the pressure bearing surface 6a. Since the cap-shaped gasket 10 made of copper, aluminum, annealed mild steel, or the like, which is softer than the above, is attached, the axis of the branch pipe 1 does not match the axis of the boss portion 6 of the common rail, and the pressure seat surface 2a and the pressure receiving surface Even if there are inconsistencies in the inclination angles of the conical surfaces forming the seat surface 6a, and minute scratches and the like on the seat surfaces 2a and 6a that occur during disassembly and removal, these are absorbed, and the branch branch pipe 1 is connected to the boss of the common rail. It becomes possible to assemble and fix to the part 6 while maintaining high sealing properties. After a predetermined operation time has elapsed, the assembly is removed for maintenance and inspection, and the cap-shaped gasket 10 deformed more than specified is easily removed with a normal tool or a jig 12 shown in FIG. By exchanging, another member can be reused as it is, and a high-pressure fuel supply member having long durability characteristics at low manufacturing cost is provided.

A second embodiment of the high-pressure fuel supply member of the present invention will be described with reference to FIG. FIG. 3 is a partially enlarged cross-sectional view showing the configuration of the second embodiment, and FIG.
(B) is a figure which shows another example.

In these embodiments, as shown in FIG. 3A, a distance d is set between the end face of the boss 6 of the common rail and
A plurality of arms 10b (a pair in FIG. 3) extending axially integrally from the outer peripheral surface are provided on the outer peripheral edge of the annular flange 10a of the cap-shaped gasket 10 extending outward in the radial direction.
Are provided at equal intervals.

In this embodiment, the cap-shaped gasket 10 is fitted on the pressure-receiving seat surface 6a of the boss 6 of the common rail in advance so that the axial centers thereof are aligned with each other.
The arm 10b clamps the cap-like gasket 10 to the boss 6 of the common rail, which holds the connection end of the boss 6 of the common rail by holding the cap-like gasket 10 at a fixed position, through the sleeve washer 4 as necessary. Nut 5
The connection head 2 is assembled and fixed, and the pressing seat surface 2a is pressed against the pressure receiving seat surface 6a.

According to this embodiment, the material of the pressure bearing surface 6a of the boss 6 of the common rail is made of the same material as that of the above embodiment, which is softer than the material of the pressure bearing surface 6a of the boss 6 of the common rail. The formed cap-shaped gasket 10
The branch branch pipe 1 can be attached to the common rail boss 6 in advance so as to be concentric with the axis of the boss 6 of the common rail.
It is possible to assemble and fix without dropping out of zero. After a predetermined operation time has elapsed, the jig 12 shown in FIG. 2C is inserted into the gap d as shown in FIG. By moving outward, the soft metal arm 10b is deformed and the cap-shaped gasket 10 can be easily removed, and by replacing this cap-shaped gasket 10, other members can be reused as they are. A high-pressure fuel supply member having long durability and low manufacturing cost is provided.

Further, as shown in FIG. 3B, if the outer end of the arm 10b of the cap-shaped gasket 10 is fitted into a notch 6b provided on the outer peripheral portion of the connection end of the boss 6 of the common rail. Since the holding force of the cap-shaped gasket 10 is further improved in addition to the operation and effect of the embodiment shown in FIG. 3A, the gasket 10 can be more effectively prevented from falling off during assembly.

FIG. 4 shows still another embodiment of the present invention. In this embodiment, the outer end of an arm 10b extending in the axial direction from the outer peripheral edge of the annular flange 10a is connected to the connection head of the branch pipe 1. The cap-shaped gasket 10 is held at a fixed position on the pressing seat surface 2a by fitting into a notch 1b provided on the outer peripheral surface of the pressing seat surface 2a at an interval from the pressing seat surface 2a in the axial direction. Also in this embodiment, the cap-shaped gasket 10 does not fall off during assembly, and the cap-shaped gasket 10 can be easily removed.

[0022]

As described above, according to the present invention, according to the present invention, a pressure-receiving seat surface of a counterpart member of a high-pressure fuel supply member for supplying high-pressure fuel which is hermetically connected to the counterpart member or a pressing seat surface for pressing the pressure-receiving seat surface. Is covered with a cap-shaped gasket made of a soft metal having an annular flange extending radially from the outer peripheral edge thereof, so that a soft metal material corresponding to the pressure of the sealed connection is selected to enhance the sealing effect. The misalignment of the axes of the branch branch pipe and the boss of the common rail due to the inclination of the high-pressure fuel supply member and the mating member when the member is mounted, and the inconsistency of the inclination angle of the conical surface forming the pressing seat surface and the pressure receiving seat surface. Absorbs minute scratches on each seat surface that occur during disassembly / removal, etc., and can maintain a reliable seal. Simply replace only the cap-shaped gasket and reuse other members for a long time. Becomes possible Further, according to the present invention, the plurality of arms extending in the axial direction from the outer peripheral edge of the annular flange makes it possible to accurately position the cap-shaped gasket and prevent the cap-shaped gasket from falling off at the time of attachment.

[Brief description of the drawings]

FIG. 1 is a partially cutaway longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is an explanatory view of removing the cap-shaped gasket of FIG. 1,
(A) is a view showing an attached state, (b) is a view showing a removed state, (c) is a plan view of a removing jig, and (d) is a state in which the removing jig is engaged with an annular flange. It is a top view showing a state.

FIGS. 3A and 3B are partially enlarged cross-sectional views showing the configuration of a second embodiment of the present invention, wherein FIG. 3A is a diagram showing an example, and FIG. 3B is a diagram showing another example.

FIG. 4 is a partially enlarged sectional view showing the configuration of a third embodiment of the present invention.

FIG. 5 is a partially cutaway longitudinal sectional view of a conventional high-pressure fuel supply member.

FIG. 6 is a partially cutaway longitudinal sectional view of another conventional high-pressure fuel supply member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 branch branch pipe 1 a through hole 1 b notch 2 connection head 2 a pressing seat surface 3 a through hole 4 sleeve washer 5 tightening nut 6 mating member 6 a pressure receiving seat surface 6 b notch 10 cap-shaped gasket 10 a flange 10 b arm

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[Procedure amendment]

[Submission date] January 20, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (4)

[Claims] 1. A high-pressure fuel supply member hermetically connected to a counterpart member for supplying high-pressure fuel, wherein the high-pressure fuel supply member has a pressure-receiving seat surface of the counterpart member or a pressing seat surface for pressing the pressure-receiving seat surface. A high-pressure fuel supply member, wherein a cap-shaped gasket made of soft metal having an annular flange extending radially from an outer peripheral edge thereof is attached to the gasket. 2. The high-pressure fuel supply member according to claim 1, wherein the annular flange has at least a pair of arms extending axially from an outer peripheral edge thereof. 3. A method for connecting a high-pressure fuel supply member, wherein a pressing seat surface of a high-pressure fuel supply member is pressed against a pressure-receiving seat surface of a counterpart member to hermetically connect the high-pressure fuel supply member and the counterpart member. A step of applying a cap-shaped gasket made of a soft metal having an annular flange extending radially from an outer peripheral edge of the pressure-receiving seat or the pressing seat, and in a state where the cap-shaped gasket is applied. A pressing step of pressing a pressing seat surface of the high-pressure fuel supply member against the pressure-receiving seat surface. 4. A cap-shaped gasket for a high-pressure fuel supply member, comprising an annular flange extending radially from an outer peripheral edge thereof.