JP4601517B2 - Sealing method for common rail - Google Patents

Description

  The present invention generally relates to a sealing method for performing auto-fragment processing on a common rail such as a high-pressure fuel manifold or a block rail in a diesel internal combustion engine.

  Conventionally, as this type of common rail, for example, as shown in FIG. 15, a plurality of cylindrical boss portions 101-4 provided at intervals on an axial peripheral wall portion on the side of a circular pipe-shaped main rail 101. A branch hole 101-2 having a pressure-receiving seat surface 101-3 that communicates with the flow passage 101-1 of the main rail 101 and opens outward is formed in the inner bottom portion, and branch connections such as branch pipes and branch joint fittings are made. The pressing seat surface 102-3 formed by the connecting head portion 102-2 on the body 102 side is brought into contact with and engaged with the pressure receiving seat surface 101-3 on the main rail 101 side, and is tightened in advance on the branch connecting body 102 side. A system (boss type) in which an external screw nut 103 is screwed into the tubular boss 101-4 to be connected with a press under the neck of the connecting head 102-2 (patent type) Reference 1), as shown in FIG. Branch hole having a pressure receiving seat surface 111-3 that communicates with the flow passage 111-1 of the main rail 111 and opens outwardly in a plurality of boss portions 111-6 provided at intervals on the peripheral wall portion of the rail 111. 11-2 is drilled, and the pressing seat surface 112-3 formed by the connecting head portion 112-2 on the branch connector 112 side is brought into contact with and engaged with the pressure receiving seat surface 111-3 on the main rail 111 side, and the cylinder The boss portion 111-6 and the branch connecting body 112 are preliminarily fastened together with the press under the neck of the connecting head 112-2 by screwing the fastening nut 114 which is assembled in advance through the sleeve 115. As shown in FIG. 17, a connection configuration method (boss type), as shown in FIG. 17, a branch hole 121-leading to an internal flow passage 121-1 provided in an outer peripheral wall portion on the main rail 121 side. No pressure receiving seat surface 121-3 that opens two parts outward A cylindrical joint fitting 123 is attached to a flat surface formed around the pressure-receiving seat surface by welding or brazing, and the pressing seat surface 122-3 formed by the connection head 122-2 on the branch connector 122 side is connected to the main rail. The connecting head 122 is engaged with the pressure-receiving seat surface 121-3 on the 121 side, and is screwed with a fastening cap nut 124 that is assembled in advance via the sleeve 125 to the joint fitting 123 side through the sleeve 125. -In the system of fastening and connecting with the press under the neck (see Patent Document 3), as shown in FIG. 18, the internal circulation provided on the outer peripheral wall on the main rail 131 side Use of an annular joint fitting 133 that forms a branching hole 131-2 communicating with the path 131-1 as a pressure receiving seat surface 131-3 that opens outward, and surrounds the outer periphery of the main rail 131 near the pressure receiving seat surface. By connecting the branch connector 132 side The pressing seating surface 132-3 formed by the connecting head 132-2 is abutted and engaged, and the screw wall 133-1 projecting from the joint metal fitting 133 and the external screw for fastening incorporated in advance on the branch connector 132 side As shown in FIG. 19, the flow path 141-is internally connected as shown in FIG. 19, which is fastened and connected in accordance with the press under the neck of the connection head 132-2 by screwing the nut 134. The flow path of the main rail 141 is provided at the bottom of a plurality of connection holes 141-4 provided at intervals on the axial peripheral wall portion on the side of the block main rail 141 having various cross-sectional shapes having 1. A branch hole 141-2 having a pressure receiving seat surface 141-3 that communicates with 141-1 and opens outwardly is formed, and a pressing seat surface 142-3 formed by the connection head 14-2 on the branch connector 142 side. Is brought into contact with and engaged with the pressure-receiving seat surface 141-3 on the main rail 141 side. The external screw nut 143 for tightening which is assembled in advance on the branch connection body 142 side is screwed into the connection hole 141-4 to be tightened and connected with the pressure under the neck of the connection head 142-2. A block rail type common rail and the like that are configured are known (see Patent Document 5). In the figure, 102-1, 112-1, 122-1, 132-1, 142-1 are flow paths of the branch connectors 102, 112, 122, 132, 142, respectively.

JP 10-246168 Japanese Patent Laid-Open No. 10-213045 Japanese Patent Laid-Open No. 9-236064 JP-A-10-159679 JP-A-10-318086

  As shown in FIGS. 15 to 19, the autofrettage process performed to alleviate the stress concentration in the vicinity of the peripheral edge of the branch hole opening of this type of common rail including the common rail having the above connection structure and improve the internal pressure fatigue strength is as shown in FIGS. 15 to 19. In general, the main rails 101, 111, 121, 131, 141 are connected to the branch connectors 102, 112, 122, 132, 142. However, in a system in which the common rail auto-frettage process is performed with the branch connection body or the branch connection body plug connected to the main rail, the connection structure of the branch connection body has the branch connection bodies 102, 112, 122, 132. , 142 side connection heads 102-2, 112-2, 122-2, 132-2, 142-2, pressing seat surfaces 102-3, 112-3, 122-3, 132-3, 142- 3 and the pressure-receiving seat surfaces 101-3, 111-3, 121-3, 131-3, 141-3 provided on the main rails 101, 111, 121, 131, 141 side, The connection heads 102-2, 112-2, 122-by screwing nuts 103, 114, 124, 134, 143 incorporated on the branch connection bodies 102, 112, 122, 132, 142 side , 132-2, 142-2, the pressure receiving seat surface on the main rail side is compressed with the pressure under the neck, and the pressure receiving seat surface is plastically deformed particularly when the tightening force of the nut is excessive. There is a problem that normal functions cannot be exhibited in subsequent use.

  The present invention has been made to solve the above-described problems, and prevents plastic deformation of the seat surface in the sealing operation during auto-frettage processing, and the stability of the seal of the branch connector connection portion during subsequent use. In order to ensure this, an attempt is made to propose a method for sealing a common rail that can be sealed at a portion other than the original pressure-receiving seat surface and subjected to common rail auto-frettage processing.

In the method for sealing a common rail according to the present invention, a plurality of branch holes are provided at intervals in the axial peripheral wall portion of the main rail having a flow passage inside the shaft core, and the peripheral surface portions of the branch holes are respectively Forming a pressure receiving seat surface that opens outwardly connecting the branch connection body having a flow path that communicates with the flow passage, and abuts the pressing seat surface formed by the connection head provided at the end of the branch connection body The common rail auto-freight is formed by tightening and connecting together with the joint head that is integral with the main rail or separate from the joint head, and by pressing the connecting head by means of a nut that has been assembled in advance on the branch connector side. A sealing method at the time of cottage processing, characterized in that sealing is performed such that an auto-fretting processing pressure is applied to the pressure-receiving seating surface, and as the sealing method, a nut-shaped seal that is screwed into the joint portion Of the pressure-receiving seat surface From forming a large-diameter annular projection diameter, in which is pressed against the annular projection in the portion other than the pressure receiving seat surface, characterized in that seal.

  As this sealing method, an external screw type member is used as the nut-shaped sealing member, and the annular protrusion is formed integrally or separately on the flange portion of the member so as to surround the external screw portion. A method can be used in which the protrusion is sealed by being brought into pressure contact with the opening end face of the joint portion. The separate annular protrusion in this sealing method can be constituted by an annular ring having an annular protrusion on the surface facing the opening end face of the joint portion. At that time, a thrust washer may be interposed between the sealing member and the separate annular ring for sealing.

  Further, as a sealing method using the nut-shaped sealing member, an external screw type member is used as the nut-type sealing member, and the pressure-receiving seat surface facing surface of the external screw type nut-type sealing member is used. Alternatively, a method may be used in which the annular protrusion is formed integrally or separately so as to surround the pressure-receiving seat surface, and the annular protrusion is pressed against the opening end surface of the pressure-receiving seat surface and sealed. Also in this sealing method, the separate annular protrusion is formed of an annular ring having an annular protrusion on the surface facing the opening end surface of the joint portion, and between the sealing member and the separate annular ring. It may be sealed with a thrust washer.

On the other hand, in the case where a cap nut-shaped member is used as the nut-shaped sealing member, the integral or separate annular protrusion formed so as to surround the pressure-receiving seat surface on the pressure-receiving seat surface facing surface of the member. The pressure-receiving seat surface can be sealed by being brought into pressure contact with the opening end surface.
Also in this sealing method, the separate annular protrusion is formed of an annular ring having an annular protrusion on the surface facing the opening end surface of the joint portion, and between the sealing member and the separate annular ring. It may be sealed with a thrust washer.

  Further, as a sealing method using a cap nut-shaped member as the nut-shaped sealing member, the annular or integrally formed separate member is formed on the member so as to surround the pressure-receiving seat surface. It is possible to use a method in which a gasket having a protrusion is fitted, and the annular protrusion of the gasket is pressed against the opening end surface of the pressure-receiving seat surface and sealed. Also in this sealing method, the separate annular protrusion is constituted by an annular ring having an annular protrusion on the surface facing the opening end surface of the pressure receiving seat surface, and the sealing member and the separate annular ring You may seal by interposing a thrust washer in between.

  Further, as another sealing method at the time of auto-fragement processing of the common rail according to the present invention, the maximum diameter of the pressure-receiving seat surface is between the nut-shaped sealing member screwed into the joint portion and the pressure-receiving seat surface. A spherical gasket having a larger diameter or a gasket having a spherical surface or curved surface having a diameter larger than the maximum diameter of the pressure receiving seat surface is fitted in part, and the spherical surface of the spherical gasket or the spherical surface or curved surface of the gasket is fitted to the pressure receiving seat surface. It is possible to use a method of sealing by press-contacting to a portion other than the opening or the pressure-receiving seat surface.

  All of the common rails that have been subjected to the autofrettage treatment by the above-described sealing methods of the present invention have a compressive residual stress in the circumferential direction on the pressure-receiving seat surface.

  In addition, as a sealing member in the present invention, a cap or plug can be used.

  The common rail sealing method according to the present invention employs a method of sealing without using the pressure-receiving seat surface which is the original seat surface used in the assembly of the branch connector, so that the pressure-receiving seat surface is unused. It is possible to perform auto-frettage processing, and there is no plastic deformation or the like due to the pressure contact surface such as the branch connection body or the branch connection body plug to the pressure-receiving seat surface, and the auto-fraget processing. Due to the presence of circumferential compressive residual stress on the conical pressure-receiving seat surface, the deformation of the pressure-receiving seat surface due to pressing of the branch connector pressing seat surface when using an internal combustion engine is suppressed as much as possible. It has an excellent effect of ensuring the stability and reliability of the seal of the part.

  1 to 14 exemplify a common rail sealing method according to the present invention, and FIGS. 1 to 7 are longitudinal sectional views showing first to seventh embodiments of the common rail sealing method using annular projections. FIG. 11 is a longitudinal sectional view showing the eighth to eleventh embodiments of the common rail sealing method using a spherical gasket, and FIGS. 12 to 14 are the twelfth to fourteenth embodiments of the common rail sealing method using a gasket having a spherical surface. 10 to 80 are main rails, 11A to 11N are nut-shaped sealing members, 12 is a gasket, 13 to 16 are spherical gaskets, 17 to 19 are gaskets having a spherical surface in part, 31 Reference numerals 34 denote joint fittings.

That is, the common rail sealing method (first embodiment) shown in FIG. 1 is provided in a plurality of intervals in the axial peripheral wall portion on the side of the circular pipe-shaped main rail 10 similar to that shown in FIG. A branch hole having a pressure-receiving seat surface (sheet surface) 10-3 that communicates with the flow passage 10-1 of the main rail 10 and opens outward at the inner bottom of each cylindrical boss portion (joint portion) 10-4. 10-2 is drilled, and the pressing seat surface formed by the connecting head on the side of the branch connector similar to that shown in FIG. 15 (not shown) is brought into contact with and engaged with the pressure receiving seat surface 10-3 on the main rail 10 side. Then, by tightening an external screw nut (not shown) for tightening which is preliminarily assembled on the branch connection body side with the cylindrical boss portion 10-4, it is fastened together with the press under the neck of the connection head. In the common rail of the connection configuration method (boss type), the cylindrical boss 10- An annular protrusion 11A-3 is formed so as to surround the outer screw portion 11A-2 on the outer screw portion 11A-2 side of the flange portion 11A-1 of the nut-shaped sealing member (plug shape) 11A that is screwed to The nut-shaped sealing member 11A is screwed into the cylindrical boss portion 10-4 so that the annular protrusion 11A-3 is brought into pressure contact with the opening end surface of the cylindrical boss portion 10-4 for sealing.
The annular protrusion 11A-3 in this sealing method is shown in FIG. 1 (a) in the case where it is provided integrally with the nut-shaped sealing member 11A. However, as shown in FIG. . That is, an annular ring SR-1 having an annular protrusion SR-2 on the surface facing the opening end face of the cylindrical boss portion 10-4 is used, and this annular ring SR-1 alone is used as the flange portion 11A-1 of the sealing member 11A. Between the annular ring SR-1 and the flange portion 11A-1 as shown in FIG. 1 (b). Further, a method of sealing with the thrust washer SW-1 interposed may be adopted.

The common rail sealing method (second embodiment) shown in FIG. 2 is the same boss type common rail as shown in FIG. 1, and the pressure receiving seat of the nut-type sealing member (plug shape) 11B with the flange portion 11B-1 is used. An annular protrusion 11B-2 is formed on the surface facing the surface (seat surface) 10-3 so as to surround the pressure-receiving seat surface, and the nut-shaped sealing member 11B is screwed into the cylindrical boss portion 10-4. Thus, the annular protrusion 11B-2 is pressed against the opening end surface of the pressure receiving seat surface 10-3 for sealing.
2A, the annular protrusion 11B-2 in this sealing method is provided integrally with the nut-shaped sealing member 11A in the same manner as described above, but as shown in FIGS. 2B and 2C. It is good also as another body shape. That is, as shown in FIG. 2B, an annular ring SR-1 having an annular protrusion SR-2 on the surface facing the pressure receiving seat surface (seat surface) 10-3 is used, and the annular ring SR-1 is sealed. The thrust washer SW-1 is interposed between the lower end surface of the member 11B and the open end surface of the pressure receiving seat surface 10-3, and the bolt 42 is attached to the lower end surface of the sealing member 11B via the pressing plate 41. The ring ring SR-1 is prevented from being dropped and sealed, or the ring ring SR-1 having the ring protrusion SR-2 and the thrust washer SW-1 are overlapped as shown in FIG. Alternatively, a method of attaching and sealing to the sealing member 11 </ b> B with a bolt 43 through a spacer may be employed. Of course, it goes without saying that the annular ring SR-1 alone may be sealed without using the thrust washer SW-1.

The common rail sealing method (third embodiment) shown in FIG. 3 is similar to that shown in FIG. 16 in that a plurality of boss portions 20- provided at intervals on the peripheral wall portion of a circular pipe-shaped main rail 20 is provided. 4 is provided with a branch hole 20-2 having a pressure receiving seat surface 20-3 that communicates with the flow passage 20-1 of the main rail 20 and opens outward, and forms a connection head on the side of the branch connector (not shown). The pressing seating surface is brought into contact with and engaged with the pressure-receiving seating surface 20-3 on the main rail 20 side, and a tightening cap nut (not shown) is assembled to the boss portion 20-4 in advance via a sleeve on the branch connector side. ) Of the nut-type sealing member (cap shape) 11C screwed to the boss portion 20-4 in the common rail of the configuration in which the connection is configured by fastening with the press under the neck of the connection head by screwing The pressure receiving surface on the surface facing the pressure receiving seat surface (sheet surface) 20-3 An annular protrusion 11C-1 is formed so as to surround the surface 20-3, and the nut-shaped sealing member 11C is screwed into the boss portion 20-4 to thereby connect the annular protrusion 11C-1 to the pressure receiving seat surface 20-3. This is a method of sealing by being brought into pressure contact with the opening end face of the.
The annular protrusion 11C-2 in this sealing system is also an annular ring SR-1 having an annular protrusion SR-2 on the surface facing the pressure receiving seat surface (sheet surface) 20-3, for example, as in FIG. A method may be employed in which the annular ring SR-1 is attached and sealed to the nut-shaped sealing member 11C so that the bolt 42 does not fall through the presser plate 41 with the thrust washer SW-1 overlaid.

The common rail sealing method (fourth embodiment) shown in FIG. 4 is a pressure receiving seat that opens to the outside a branch hole 30-2 communicating with an internal flow passage 30-1 provided in a peripheral wall portion on the main rail 30 side. A connection head on the side of a branch connector similar to that shown in FIG. 17 (not shown) is attached to a flat surface formed around the pressure-receiving seat surface by welding or brazing. The pressing seat surface formed by the contact portion is brought into contact with and engaged with the pressure receiving seat surface 30-3 on the main rail 30 side, and is fastened to the joint fitting 31 and the branch connector side in advance via a sleeve (not shown). A nut-type sealing member (cap) that is screwed into the joint fitting 31 in a common rail that is fastened and connected in connection with pressing under the neck of the connecting head by screwing a cap nut (not shown). Shape) on the main rail 30 in the 11D. A gasket 12 having an annular protrusion 12-1 formed so as to surround the pressure receiving seat surface 30-3 is fitted, and the annular protrusion 12-1 of the gasket 12 is brought into pressure contact with the opening end surface of the pressure receiving seat surface 30-3. This is a sealing method. Also in this system, although not shown, the annular protrusion 12-1 of the gasket 12 can be sealed instead of the system shown in FIGS. 2 (b) and 2 (c).

The common rail sealing method (fifth embodiment) shown in FIG. 5 is formed on a flat surface on the side of the branch hole 40-2 that communicates with the internal flow passage 40-1 provided in the peripheral wall portion of the main rail 40 made of a circular pipe. A joint fitting 32 formed by drilling a flow path 32-1 having a pressure receiving seat surface (sheet surface) 32-2 that communicates with the flow passage 40-1 of the main rail 40 and opens outward is welded or brazed. The pressing seat surface formed by the connecting head on the side of the branch connector similar to that shown in FIG. 16 (not shown) is abutted and engaged with the pressure receiving seat surface 32-2 on the side of the joint metal fitting 32, and the joint metal fitting 32 is connected in advance. In the common rail of the type in which the connection is configured by fastening with the press under the neck of the connection head by screwing of a tightening cap nut (not shown) incorporated on the branch connection body side through the sleeve, FIG. Similar to the one shown in FIG. An annular protrusion 11E-1 is formed so as to surround the pressure-receiving seat surface on a surface of the nut-type sealing member (cap-shaped) 11E to be screwed to face the pressure-receiving seat surface (sheet surface) 32-2. This is a system in which the annular protrusion 11E-1 is brought into pressure contact with the opening end surface of the pressure receiving seat surface 32-2 and sealed by screwing the sealing member 11E into the joint fitting 32.
In this method, although not shown, the annular protrusion 11E-1 of the nut-shaped sealing member 11E can be sealed instead of the method shown in FIG.

The common rail sealing method (sixth embodiment) shown in FIG. 6 is a pressure receiving seat that opens outwardly a branch hole 50-2 portion communicating with an internal flow passage 50-1 provided in a peripheral wall portion on the main rail 50 side. By using an annular joint fitting 52 that forms a surface (seat surface) 50-3 and surrounds the outer periphery of the main rail 50 in the vicinity of the pressure-receiving seat surface, the side of the branch connector similar to that shown in FIG. The pressure seating surface formed by the connecting head of the joint is abutted and engaged, and a screw wall 52-1 projecting from the joint fitting 52 and a tightening external screw nut (not shown) previously assembled on the branch connector side are provided. In the common rail that is connected and configured in accordance with the press under the neck of the connection head by screwing, the pressure-receiving seat surface 50 of the nut-shaped sealing member (plug shape) 11F with the flange portion 11F-1 -3 so as to surround the pressure-receiving seat surface on the surface facing -3 A protrusion 11F-2 is formed, and the nut-shaped sealing member 11F is screwed into the screw wall 52-1 of the joint fitting 52, whereby the annular protrusion 11F-2 is pressed against the opening end surface of the pressure receiving seat surface 50-3. This is a method of sealing.
Also in this system, although not shown, the annular protrusion 11F-2 of the nut-shaped sealing member 11F may be sealed instead of the system shown in FIGS. 1 (b), 2 (b) and 2 (c). Is possible.

The block rail type common rail sealing method (seventh embodiment) shown in FIG. 7 is a method of sealing using a nut-type sealing member (plug shape) 11G similar to that shown in FIG. 19, a plurality of connection hole portions 60 provided at intervals in an axial peripheral wall portion on the block-shaped main rail 60 side having various cross-sectional shapes having flow passages 60-1 therein. -4 is provided with a branch hole 60-2 having a pressure receiving seat surface (seat surface) 60-3 that communicates with the flow passage 60-1 of the main rail 60 and opens outwardly. A pressing seat surface formed by a connection head of a branch connection body similar to that shown in FIG. 19 is brought into contact with and engaged with the pressure receiving seat surface 60-3, and is assembled in advance with the connection hole 60-4 on the branch connection body side. Pressing under the neck of the connecting head by screwing a nut (not shown) In the block-rail type common rail that has been fastened and connected together, the pressure-receiving seat surface 60-3 of the nut-type sealing member 11G with the flange portion 11G-1 similar to that shown in FIG. An annular protrusion 11G-2 is formed on the opposite surface of the pressure-receiving seat surface so as to surround the pressure-receiving seat surface, and the nut-shaped sealing member 11G is screwed into the connection hole 60-4 to thereby receive the annular protrusion 11G-2. In this method, the seating surface 60-3 is sealed by being brought into pressure contact with the opening end surface.
In this system, although not shown, the annular projection 11G-2 of the nut-shaped sealing member 11G can be sealed instead of the system shown in FIGS. 2 (b) and 2 (c).

Next, the common rail sealing method using the spherical gasket shown in FIG. 8 (eighth embodiment) is the same as the boss type common rail shown in FIGS. 1 and 2 for nut-type sealing with a flange portion 11H-1. Between the main rail 10 side pressure receiving seat surface (seat surface) 10-3 of the member (plug shape) 11H, a spherical gasket 13 having a diameter larger than the maximum diameter of the pressure receiving seat surface 10-3 is internally fitted, The nut-type sealing member 11H is screwed into the cylindrical boss portion 10-4 so that the spherical surface of the spherical gasket 13 is brought into pressure contact with the opening edge portion of the pressure-receiving seat surface 10-3 for sealing. In the case of this method, a spherical surface is formed so that the contact surface of the nut-shaped sealing member 11H with the spherical gasket 13 is along the spherical surface of the spherical gasket 13 in order to position the spherical gasket 13 at the center of the pressure receiving seat surface 10-3. Or conical concave surface 11H-2.
In the case of this sealing method, instead of the method of directly pressing the spherical gasket 13 by the nut-shaped sealing member 11H, the sealing is performed by the method of pressing the spherical gasket 13 through the thrust washer SW-2 and the V-shaped block VB-1. May be.

The common rail sealing method using the spherical gasket shown in FIG. 9 (the ninth embodiment) is the same as the boss type common rail shown in FIG. 3 in the nut-type sealing member 11I screwed into the boss portion 20-4. Between the main rail 20 side pressure receiving seat surface (seat surface) 20-3, a spherical gasket 14 having a diameter larger than the maximum diameter of the pressure receiving seat surface 20-3 is fitted, and the nut-type sealing member (cap) This is a system in which the spherical surface of the spherical gasket 14 is brought into pressure contact with the opening edge portion of the pressure receiving seat surface 20-3 by screwing the 11I into the boss portion 20-4. Also in this method, the contact surface of the nut-shaped sealing member 11I with the spherical gasket 14 is along the spherical surface of the spherical gasket 14 in order to position the spherical gasket 14 at the center of the pressure receiving seat surface 20-3. The concave surface 11I-1 is preferably spherical or conical.
In the case of this sealing method, similarly to FIG. 8B, instead of the method of directly pressing the spherical gasket 14 with the nut-shaped sealing member 11I, the thrust washer SW-2 and the V-shaped block VB-2 are used. The spherical gasket 14 may be sealed by a method of pressing.

The common rail sealing method (tenth embodiment) shown in FIG. 10 is a sealing method using a spherical gasket similar to the sealing method (ninth embodiment) shown in FIG. 9, and is the same as that shown in FIG. A two-stage opening on the flat surface on the branch hole 40-2 side that communicates with the internal flow passage 40-1 provided in the peripheral wall portion of the main rail 40 and that opens to the outside through the flow passage 40-1 of the main rail 40. A joint fitting 33 formed by drilling a flow path 33-1 having a pressure-receiving seat surface (sheet surface) 33-2 made of a taper is attached by welding or brazing, and is not connected to the branch connection similar to that shown in FIG. The pressing seating surface formed by the body-side connecting head is brought into contact with and engaged with the pressure-receiving seating surface 33-2 on the joint fitting 33 side, and the fastening cap nut is assembled to the joint fitting 33 and the branch connection body side in advance via a sleeve. Said connection by screwing (not shown) In a common rail that is connected and configured in accordance with pressing under the radical, between the nut-type sealing member (cap-shaped) 11J that is screwed into the joint fitting 33 and the pressure-receiving seat surface 33-2. A spherical gasket 15 having a diameter larger than the maximum diameter of the pressure-receiving seat surface 33-2 is fitted inside, and the nut-shaped sealing member 11J is screwed into the boss portion 20-4 to thereby form a spherical surface of the spherical gasket 15. Is pressed against the opening edge of the pressure-receiving seat surface 33-2 for sealing. In this case, even if the opening edge is slightly deformed by the pressure contact of the spherical gasket 15, there is no fear of causing a problem in the subsequent assembly of the branch connector.
Also in this method, although not shown, a method of pressing the spherical gasket 15 through a V-shaped block and a thrust washer as shown in FIG. 9B can be adopted.

The common rail sealing method (11th embodiment) shown in FIG. 11 is a seal using a spherical gasket similar to the above, instead of the nut-shaped sealing member 11F with the annular protrusion 11F-2 in the sealing method shown in FIG. A pressure receiving seat surface (seat surface) 50-3 that opens outwardly to a branch hole 50-2 portion that communicates with an internal flow passage 50-1 provided in a peripheral wall portion on the main rail 50 side, By using an annular joint bracket 52 that surrounds the outer periphery of the main rail 50 near the pressure-receiving seat surface, the pressing seat surface formed by the connection head on the side of the branch connector similar to that shown in FIG. Pressing below the neck of the connecting head by engaging and screwing a screw wall 52-1 projecting from the joint fitting 52 and an external screw nut (not shown) for tightening which has been previously assembled on the branch connector side. The connection configuration is tightened along with In the common rail, a spherical gasket 16 having a diameter larger than the maximum diameter of the pressure-receiving seat surface 50-3 is fitted between the nut-type sealing member (plug-shaped) 11K and the pressure-receiving seat surface 50-3, and the nut This is a system in which the spherical member 16 is pressed against the opening edge of the pressure-receiving seat surface 50-3 and sealed by screwing the shape sealing member 11K into the screw wall 52-1 of the joint fitting 52.
Also in this method, although not shown, a method of pressing the spherical gasket 16 through a V-shaped block and a thrust washer as shown in FIG.

  The common rail sealing method shown in FIG. 12 (a twelfth embodiment) is a sealing method in which a gasket having a spherical surface or curved surface larger in diameter than the maximum diameter of the pressure-receiving seat surface is used in place of the spherical gasket. 4 and the pressure receiving seat surface 70-3 that opens outwardly from the branch hole 70-2 communicating with the internal flow passage 70-1 provided in the peripheral wall portion on the main rail 70 side similar to that shown in FIG. A cylindrical joint fitting 34 is attached to a flat surface formed around the pressure-receiving seat surface by welding or brazing, and a pressure seat surface formed by a connection head on the side of a branch connector (not shown) is used as a pressure-receiving seat on the main rail 70 side. The connecting head by screwing a fastening nut (not shown) which is brought into contact with and engaged with the surface 70-3 and is previously assembled to the joint fitting 34 and the branch connecting body via a sleeve (not shown). Fasten with the press under the neck and configure the connection In the common rail of the system, a part of the outer opening end diameter of the joint fitting 34 is between the nut-shaped sealing member (cap shape) 11L screwed into the joint fitting 34 and the outer opening of the joint fitting 34. A gasket 17 having a large-diameter spherical or curved seal surface 11L-1 is fitted therein, and the nut-type sealing member 11L is screwed into the joint fitting 34, whereby the spherical or curved seal surface 17 of the gasket 17 is obtained. -1 is pressed against the opening end face of the joint fitting 34 and sealed.

The common rail sealing method (13th embodiment) shown in FIG. 13 is partially larger than the maximum diameter of the pressure-receiving seat surface, instead of the spherical gasket 16 of the common rail sealing method (11th embodiment) shown in FIG. This is a sealing method using a gasket 18 having a spherical spherical surface or a curved sealing surface, and in a common rail having the same connection configuration as shown in FIG. 11, a nut-shaped sealing member (cap-shaped) 11M and a pressure receiving seat surface 50-3 The gasket 18 having a spherical or curved sealing surface 18-1 larger than the maximum diameter of the pressure-receiving seat surface 50-3 is fitted between the nut-type sealing member 11M and the joint fitting 52. In this method, the sealing surface of the gasket 18-1 is pressed against the opening of the pressure-receiving seat surface 50-3 by being screwed to the screw wall 52-1.
Also in this method, although not shown, a method of pressing the gasket 18 via a V-shaped block and a thrust washer can be adopted as shown in FIG.

The common rail sealing method (fourteenth embodiment) shown in FIG. 14 is the same block rail type common rail sealing method as shown in FIG. 7, and has various cross-sectional shapes having flow passages 80-1 therein. At the bottom of a plurality of connection holes 80-4 provided at intervals in the axial peripheral wall portion on the block-shaped main rail 80 side, communicate with the flow passage 80-1 of the main rail 80 and outward A branch hole 80-2 having a pressure receiving seat surface (seat surface) 80-3 opening in the bottom of a step portion having a diameter larger than the diameter of the pressure receiving seat surface is formed, and is similar to that shown in FIG. The pressure seat surface formed by the connection head of the branch connection body is abutted and engaged with the pressure receiving seat surface 80-3, and a connection hole 80-4 and a nut (not shown) previously assembled on the branch connection body side are provided. Fastening and connecting with the press under the neck of the connecting head by screwing In the block rail type common rail, a spherical or curved surface having a diameter larger than the maximum diameter of the pressure receiving seat surface 80-3 is provided between the nut-shaped sealing member (plug shape) 11N and the pressure receiving seat surface 80-3. A gasket 19 having a seal surface 19-1 is fitted therein, and the nut-type sealing member 11N is screwed into the connection hole 80-4, thereby making the spherical surface 19-1 of the gasket 19 the pressure-receiving seat surface 80-3. This is a method of sealing by being brought into pressure contact with the opening edge of the. In this case as well, there is no risk of causing problems in the assembly of the branch connecting body later even if the gasket 15 is brought into contact with the gasket 15 and the opening edge of the step portion is slightly deformed. Needless to say, a spherical gasket may be used instead of the gasket 19.
In the case of the sealing method shown in FIG. 14, a method of pressing the gasket 19 via a V-shaped block and a thrust washer as shown in FIG.

In addition, the main rails 10 to 80 as the common rail in each of the above embodiments are, for example, pipe materials or forged products such as materials S45C, SCM435, SNCM439, etc. having a relatively thick tubular portion having a diameter of 28 mm and a thickness of 9 mm. In addition, a plurality of integral bosses or separate bosses, block rails are formed by machining the boring, gun drill, or the like so that the inside of the shaft core becomes a flow passage, and a space is maintained in the peripheral wall portion in the axial direction. In the case of a mold, connection holes are provided.
In addition, the annular protrusion in each of the first to seventh embodiments shown in FIGS. 1 to 7 may be not only a single line but also two or more lines, and the cross-sectional contour shape of the tip of the annular protrusion may be a pointed shape. Not limited to this, it may be arcuate or curved with a small curvature radius.

  The common rail sealing method according to the present invention is not limited to a high pressure fuel manifold in a diesel internal combustion engine or a seal method when performing auto-fragment processing on a common rail such as a block rail, but also a high pressure manifold other than a diesel internal combustion engine. It can also be applied to the auto-fragment processing.

The 1st Example of the sealing method of the common rail based on this invention is shown, (a) is a longitudinal cross-sectional view of the whole sealing part, (b) is a principal part expanded vertical cross-sectional view which shows the modification of an Example same as the above. The 2nd Example of the sealing method of the common rail based on this invention is shown, (a) is a longitudinal cross-sectional view of the whole sealing part, (b) (c) is a principal part expanded longitudinal cross-sectional view which shows the modification of an Example same as the above. is there. The 3rd Example of the sealing method of the common rail which concerns on this invention is shown, (a) is a longitudinal cross-sectional view of the whole sealing part, (b) is a principal part expanded longitudinal cross-sectional view which shows the modification of an Example same as the above. It is a longitudinal cross-sectional view of the whole sealing part which shows 4th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole sealing part which shows 5th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole sealing part which shows 6th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole sealing part which shows the 7th Example of the sealing method of the block rail type common rail which concerns on this invention. 8th Example of the sealing method of the common rail which concerns on this invention is shown, (a) is a longitudinal cross-sectional view of the whole sealing part, (b) is a principal part expanded longitudinal cross-sectional view which shows the modification of an Example same as the above. The 9th Example of the sealing method of the common rail which concerns on this invention is shown, (a) is a longitudinal cross-sectional view of the whole seal part, (b) is a principal part expanded longitudinal cross-sectional view which shows the modification of an Example same as the above. It is a longitudinal cross-sectional view of the whole sealing part which shows 10th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole seal part which shows 11th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole sealing part which shows 12th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole sealing part which shows 13th Example of the sealing method of the common rail which concerns on this invention. It is a longitudinal cross-sectional view of the whole sealing part which shows the 14th Example of the sealing method of the block rail type common rail which concerns on this invention. It is a longitudinal cross-sectional view which shows an example of the common rail which has the integrated boss | hub part made into the object of this invention. It is a longitudinal cross-sectional view which shows the other example of the common rail which has the integrated boss | hub part made into the object of this invention. It is a longitudinal cross-sectional view which shows an example of the common rail which has the separate body boss | hub part made into the object of this invention. It is a longitudinal cross-sectional view which shows an example of the common rail which has the separate type | mold boss | hub part (annular joint metal fitting) made into the object of this invention. It is a longitudinal cross-sectional view which shows an example of the block rail type | mold common rail made into the object of this invention.

Explanation of symbols

10 to 80 Main rails 11A to 11N Nut-type sealing members 11A-3, 11B-2, 11C-1, 12-1, 11E-1, 11F-2,
11G-2, SR-2 Annular projection 12 Gaskets 13-16 Spherical gaskets 17-19 Gaskets 31-34 having a spherical surface in part Joint fitting SR-1 Annular ring SW-1, SW-2 Thrust washer VB-1 V-shaped block

Claims (15)

  A branch connection having a plurality of branch holes provided at intervals in the axial peripheral wall portion of the main rail having a flow passage inside the shaft core, and a flow passage communicating with the flow passage on the peripheral surface portion of the branch hole. Form a pressure-receiving seating surface that opens to the outside where the body is connected, and press and engage the pressing seating surface formed by the connection head provided at the end of the branch connection body. It is a sealing method at the time of auto-frettage processing of a common rail formed by fastening and connecting with a press at the connection head by screwing of a nut assembled in advance on a joint body part of a body, An annular protrusion having a diameter larger than the maximum diameter of the pressure-receiving seat surface is formed on a nut-shaped sealing member that is screwed into the joint portion so that an autofrage processing pressure is applied to the pressure-receiving seat surface. The protrusion is sealed by being brought into pressure contact with a portion other than the pressure receiving seat surface. Sealing method of the common rail, wherein the door. An external screw type member is used for the nut-shaped sealing member, and the annular protrusion is formed integrally or separately on the flange portion of the member so as to surround the external screw portion, and the annular protrusion is attached to the joint portion. 2. The method for sealing a common rail according to claim 1 , wherein the sealing is performed by pressing against the end face of the opening. 3. The method of sealing a common rail according to claim 2 , wherein the separate annular protrusion includes an annular ring having an annular protrusion on a surface facing the opening end surface of the joint portion. The common rail sealing method according to claim 3 , wherein a thrust washer is interposed between the sealing member and the separate annular ring. The nut-shaped sealing member uses an external thread type member, and the annular threading that is integral or separate so as to surround the pressure-receiving seat surface on the pressure-receiving seat surface facing surface of the nut-type sealing member of the external screw type 2. The method for sealing a common rail according to claim 1 , wherein the annular protrusion is pressed against the opening end face of the pressure-receiving seating surface and sealed. 6. The method for sealing a common rail according to claim 5 , wherein the separate annular protrusion is formed of an annular ring having an annular protrusion on a surface facing the opening end surface of the joint portion. The common rail sealing method according to claim 6 , wherein a thrust washer is interposed between the sealing member and the separate annular ring. A cap nut-shaped member is used as the nut-shaped sealing member, and the integral or separate annular projection formed so as to surround the pressure-receiving seat surface on the pressure-receiving seat surface-facing surface of the member is formed on the pressure-receiving seat surface. 2. The method for sealing a common rail according to claim 1 , wherein the sealing is performed by pressing against the end face of the opening. 9. The method for sealing a common rail according to claim 8 , wherein the separate annular protrusion is formed of an annular ring having an annular protrusion on a surface facing the opening end surface of the joint portion. The method for sealing a common rail according to claim 9 , wherein a thrust washer is interposed between the sealing member and the separate annular ring. A cap nut-shaped member is used as the nut-shaped sealing member, and a gasket having the annular protrusion, which is formed integrally or separately, is formed on the member so as to surround the pressure-receiving seat surface. and, sealing method of the common rail of claim 1, the annular projection of the gasket, characterized in that seal is pressed against the opening end face of the pressure receiving seat surface. 12. The method for sealing a common rail according to claim 11 , wherein the separate annular protrusion is configured by an annular ring having an annular protrusion on a surface facing the opening end surface of the pressure receiving seat surface. 13. The common rail sealing method according to claim 12 , wherein a thrust washer is interposed between the sealing member and the separate annular ring for sealing.   A branch connection having a plurality of branch holes provided at intervals in the axial peripheral wall portion of the main rail having a flow passage inside the shaft core, and a flow passage communicating with the flow passage on the peripheral surface portion of the branch hole. Form a pressure-receiving seating surface that opens to the outside where the body is connected, and press and engage the pressing seating surface formed by the connection head provided at the end of the branch connection body. It is a sealing method at the time of auto-frettage processing of a common rail formed by fastening and connecting with a press at the connection head by screwing of a nut assembled in advance on a joint body part of a body, A spherical gasket having a diameter larger than the maximum diameter of the pressure-receiving seat surface, or a part larger than the maximum diameter of the pressure-receiving seat surface, between the nut-shaped sealing member screwed into the joint portion and the pressure-receiving seat surface. The spherical gas is fitted with a gasket having a spherical or curved surface. Sealing method of the common rail, characterized in that Tsu and bets spherical or gasket spherical or curved surface is pressed against a part other than the opening or the pressure receiving seat surface of the pressure receiving seat surface to seal. A common rail in which a compressive residual stress in the circumferential direction is present on the pressure-receiving seating surface by the auto-frettage process.

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