JP3877185B2 - Connection structure of branch connection in common rail - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to a connection structure of a branch connection body using a branch branch pipe or a branch fitting in a common rail such as a high pressure fuel manifold or a block rail in a diesel internal combustion engine.
[0002]
[Prior art]
Conventionally, as this type of common rail, for example, as shown in FIG. 3, a circular cross-sectional branch hole 11-2 communicating with an internal flow passage 11-1 provided in a peripheral wall portion on the main rail 11 side having a circular cross section is provided. By using the ring-shaped joint fitting 13 that forms the pressure receiving seat surface 11-3 that opens in the direction and surrounds the outer peripheral portion of the main rail 11 near the pressure receiving seat surface, the end portion is formed by a tapered conical buckling molding. The pressing seat surface 12-3 formed by the connection head portion 12-2 on the side of the branch connection body 12 having an enlarged diameter is brought into contact with and engaged with the screw wall 13-1 projecting from the joint fitting 13 and the branch connection body 12 in advance. There is known a system in which the connection head 12-2 is fastened and connected in accordance with the press under the neck of the connection head 12-2 by screwing a nut 14 incorporated on the side. Reference numeral 15 denotes a sleeve washer.
[0003]
[Problems to be solved by the invention]
However, in the case of the connection structure according to the prior art, the screw wall 13-1 is provided so that the ring-shaped joint fitting 13 is an integral type formed by forging, so that the manufacturing cost is high and the product weight cannot be reduced. was there.
[0004]
The present invention has been made in order to solve the above-described problems of the prior art. Instead of the conventional forged ring-shaped joint fitting, the ring portion and the screw wall portion are separated and welded. Alternatively, by providing an integrated structure by brazing, it is possible to facilitate the manufacture of ring-shaped joint fittings, to reduce the manufacturing cost, and to provide a connection structure for a branch connection in a common rail that can reduce the product weight. It is what.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a plurality of branch holes at intervals in the axial peripheral wall portion of the main rail having a flow passage inside the shaft core, and each of the peripheral surface portions of the branch holes has the above-mentioned A pressure receiving seat surface that opens outwardly connecting the branch connecting body having a flow path communicating with the flow passage is formed, and the pressing seat surface portion formed by the connection head provided at the end of the branch connecting body is brought into contact with In the common rail formed by fitting together with a ring-shaped joint fitting externally fitted to the main rail and a connection with a press at the connection head by screwing a nut assembled in advance on the branch connection body side, The ring-shaped joint fitting is joined by welding or brazing a ring body that is externally fitted to the main rail and a cylindrical screw wall portion that is screwed to the nut that is assembled in advance on the branch connection body side. Connection of branch connection in common rail characterized by comprising It is an gist of concrete.
[0006]
In the ring-shaped joint fitting according to the present invention, for example, the ring body that fits on the main rail and the cylindrical screw wall portion that is screwed with the nut incorporated on the branch connector side may be fitted to the main rail, for example. The base of the cylindrical screw wall that is screwed into the outer peripheral wall of the ring body that is pre-assembled on the side of the branch connecting body is unevenly fitted and integrated by welding or brazing the uneven fitting Or a method of directly welding or brazing the base portion of the cylindrical screw wall portion to the outer peripheral wall of the ring body externally fitted to the main rail.
[0007]
As described above, in the present invention, the ring-shaped joint fitting is easily separated from the ring portion and the screw wall portion, and has an integrated structure by welding or brazing. The manufacturing cost can be reduced and the product weight can be reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B illustrate a connection structure of a branch connection body in a common rail according to the present invention, in which FIG. 1A is a partially cutaway front view showing a branch connection body connection portion, and FIG. FIG. 2 illustrates the structure of a ring-shaped joint fitting according to the present invention. FIG. 2A shows a ring-shaped joint by a joining method of a ring body and a cylindrical screw wall portion by an uneven fitting method. The longitudinal cross-sectional view which expands and shows a part of metal fitting, (B), (C), (D) is the ring by the system which welds or brazes the base part of a cylindrical screw wall part to the outer peripheral wall of a ring body directly. 1 is a partially enlarged longitudinal sectional view of a joint fitting, 1 is a main rail as a common rail, 2 is a branch connector, 3 is a fitting, 4 is a nut, and 4-1 is a cap nut.
[0009]
The main rail 1 as a common rail is made of a thick steel pipe material such as a carbon steel pipe for pressure piping or a stainless steel pipe having a pipe diameter of about 30 m / m or less, and has a pipe diameter of 20 m / m, for example. A relatively thick metal tube of material STS 480 having a thickness of 6 m / m, and a plurality of outer pipes with the axial core as a flow passage 1-1 and with a space in the axial peripheral wall portion A branch hole 1-2 is provided in communication with the flow passage 1-1. The branch hole 1-2 is a pressure receiving seat surface 1-3.
[0010]
The branch connection body 2 is composed of a branch connection body or a branch metal fitting, and has a flow path 2-1 communicating with the flow passage 1-1 therein, and has, for example, a tapered conical buckle at its end. A pressing seat surface 2-3 formed by a connecting head 2-2 whose diameter is increased by molding is provided.
[0011]
In the present invention, a ring body 3-1 that externally fits the joint fitting of the branch connection body 2 to the main rail, and a cylindrical screw wall body 3 that is screwed into the nut 4 that is assembled in advance on the branch connection body 2 side. As shown in FIG. 1, the structure is a circular hole portion 3 having a stepped portion 3-4 in a part of the outer peripheral wall of the ring body 3-1 near the inner peripheral surface of the ring body. 3 is formed, and the root portion of the cylindrical screw wall body 3-2 having a flat outer peripheral surface to be screwed with the nut 4 previously incorporated in the branch connection body 2 side in the circular hole portion 3-3 is uneven. The joint portion between the outer opening of the circular hole portion 3-3 and the cylindrical screw wall body 3-2 is welded or brazed.
[0012]
Further, as shown in FIG. 2A, a notch 3-5 is provided at the base of the cylindrical screw wall body 3-2 so that the portion is concavo-convexly fitted into the circular hole 3-3, and the same as described above. Alternatively, the joint between the outer opening of the circular hole 3-3 and the cylindrical screw wall 3-2 may be welded or brazed.
[0013]
Fig. 1 and Fig. 2 (A) above show that the base part of a cylindrical screw wall body that is screwed into a nut that has been assembled in advance on the branch connecting body side is unevenly fitted to the outer peripheral wall of the ring body that is externally fitted to the main rail. The joint fitting is formed by welding or brazing and integrating the concave and convex fitting portions. As shown in FIGS. 2 (B), (C), and (D), the outer periphery of the ring body is illustrated. The base of the cylindrical screw wall body may be directly welded or brazed to the wall. That is, FIG. 2 (B) shows a ring body fitted around the main rail as a ring body 3-11 having substantially the same wall thickness without the circular hole portion 3-3, and the outer periphery of the ring body 3-11. Weld or braze the end of a cylindrical screw wall 3-2 having a screw surface 3-2 'screwed with a cap nut 4-1 incorporated in advance on the branch connector side at the inner position of the surface. As shown in (C), the ring body that is fitted on the main rail is a ring body 3-21 having a width substantially the same as that of the cylindrical screw wall body 3-2. A cylindrical screw wall 3-2 is welded or brazed to the outer peripheral surface of the ring body 3-21 on the outer peripheral surface of the ring body 3-21, or as shown in (D). A circular hole portion 3-13 having a flat inner peripheral surface projects from a part of the outer peripheral wall 3-31, and a cylindrical screw is inserted into the circular hole portion 3-13. It fitted in the end portion of the wall 3-2 can be configured the outer portion welded or brazed to. In addition, it can be said that the joining method shown in (D) can be applied to a ring body 3-21 having a width approximately equal to that of the cylindrical screw wall body 3-2. Not too long.
[0014]
【The invention's effect】
As described above, the connection structure of the branch connection body according to the present invention divides the ring-shaped joint fitting of the branch connection body into the ring part and the screw wall part, and the ring part and the screw wall part are welded or brazed. By adopting an integrated structure, it is possible to cut and assemble normal metal pipes regardless of the forging method, making it easier to manufacture ring-shaped fittings and reducing manufacturing costs. The effect of reducing the weight can be obtained, and it is extremely useful as a common rail.
[Brief description of the drawings]
1A and 1B illustrate a connection structure of a branch connection body in a common rail according to the present invention, in which FIG. 1A is a front view showing the branch connection body partly broken, and FIG. It is a longitudinal cross-sectional view on a line.
FIG. 2 illustrates the structure of a ring-shaped joint metal fitting according to the present invention. FIG. 2 (A) shows a part of the ring-shaped joint metal fitting produced by joining a ring body and a cylindrical screw wall by a concave-convex fitting method. (B), (C), (D) is an enlarged vertical sectional view showing a ring-shaped joint fitting by a method of directly welding or brazing the base of a cylindrical screw wall to the outer peripheral wall of the ring body. It is a longitudinal cross-sectional view which expands and shows a part.
FIGS. 3A and 3B illustrate a conventional common rail using a ring-shaped joint metal fitting, in which FIG. 3A is a front view showing a part of a branch connector connecting part, and FIG. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main rail 1-1 Flow path 1-2 Branch hole 1-3 Pressure receiving seat surface 2 Branch connection body 2-1 Flow path 2-2 Connection head 2-3 Pressing seat surface 3 Joint metal fittings 3-1, 3- 11, 3-21, 3-31 Ring body 3-2 Cylindrical screw wall body 3-2 ′ Screw surface 3-3 Circular hole portion 3-4 Stepped portion 4 Nut 4-1 Cap nut

Claims (1)

Branch connection having a plurality of branch holes in the axial peripheral wall portion of the main rail having a flow passage inside the shaft core, with a plurality of branch holes provided at intervals, and a flow passage communicating with the flow passage on the peripheral surface portion of the branch hole. A pressure-receiving seating surface that opens outwardly connecting the body is formed, and the pressing seating surface portion formed by the connection head provided at the end of the branch connection body is brought into contact with and engaged with the main rail. In a common rail formed by tightening and connecting with a ring-shaped joint fitting and a press at the connection head by a screwing of a nut incorporated in advance on the branch connector side, the ring-shaped joint fitting is connected to the main pipe. A branch in a common rail, wherein a ring body that is externally fitted to the rail and a cylindrical screw wall portion that is screwed into the nut that is assembled in advance on the branch connector side are joined by welding or brazing. Connection structure of connection body.

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