JP4533298B2 - Fuel delivery pipe - Google Patents

Description

  The present invention relates to a distribution pipe for distributing and supplying fuel to each cylinder in an internal combustion engine such as an automobile.

In a fuel delivery pipe for a returnless injection system that has a flexible absorber wall surface on the wall surface of the communication pipe and absorbs fuel pressure pulsation, it is arranged on the absorber wall surface as in the invention described in Patent Document 1 for convenience of layout. A fuel delivery pipe in which a fuel supply pipe is directly connected or a fuel delivery pipe in which a joint member (41) for connecting a fuel supply pipe is arranged on an absorber wall surface (40) as shown in FIG. Yes.
Japanese Patent No. 3518577

  However, when the fuel supply pipe is directly connected to the absorber wall surface as in the invention described in Patent Document 1, or as in the conventional example shown in FIGS. 15 and 16, the joint member (41) is arranged on the absorber wall surface (40). When the fuel supply pipe is connected to the joint member (41), the relatively thin wall surface (40) is deformed when the fuel pressure pulsation occurs, so that the fuel supply pipe or the joint member (41) and the absorber are connected. There is a concern that stress may be generated in the connection portion (44) with the wall surface (40) to cause damage in the connection portion (44).

  Accordingly, the present invention provides a fuel delivery pipe having a relatively thin and flexible absorber wall surface on the wall surface of the communication pipe, and connecting the fuel supply pipe to the absorber wall surface directly or via a joint member. While maintaining the absorption function of fuel pressure pulsation due to deformation of the fuel, it is possible to reduce the stress generated at the connection between the fuel supply pipe or joint member and the wall surface of the absorber, and to reduce the risk of damage at this connection It is.

  In order to solve the above-mentioned problems, the present invention includes a flexible absorber wall surface that penetrates a fuel supply hole in a wall surface of a communication tube, and the fuel supply tube is directly or jointed to the fuel supply hole of the absorber wall surface. In the fuel delivery pipe connected through the fixed pipe, the absorber wall of the communicating pipe has a frustum-shaped tapered peripheral wall tapering outward and a fuel supply hole at the tip. And a fuel supply pipe is connected and fixed to the fuel supply hole of the fixed projection directly or via a joint member.

  Further, the fixed protrusion may have a tip formed flat.

  Further, the fixed protrusion may be formed such that the cross-sectional contours in the axial direction and the direction perpendicular to the axis of the communication pipe on the peripheral wall are linearly inclined.

  The fixed protrusion may be formed such that the cross-sectional contour in the axial direction and the direction perpendicular to the axial direction of the communication pipe on the peripheral wall is curved and inclined.

  Further, the fixed protrusion may be one in which the inclination angle of the peripheral wall is 10 ° to 35 °.

  Further, the fixed protrusion may have a substantially truncated pyramid shape.

  Further, the fixed protrusion may have a substantially truncated cone shape.

  Further, the fixed protrusion may be provided as a continuous protrusion in the axial direction over substantially the entire length of the communication pipe.

  The present invention is configured as described above. The fuel delivery pipe is provided with a relatively thin flexible absorber wall surface on the wall surface of the communication pipe, and the fuel supply pipe is connected to the absorber wall surface directly or via a joint member. In the pipe, a fixed protrusion with a tapered peripheral wall is formed on the absorber wall surface of the communication pipe, and a fuel supply pulsation absorbing function due to deformation of the absorber wall surface is achieved by connecting and fixing the fuel supply pipe to this fixed protrusion. It is possible to reduce the stress generated at the connecting portion between the fuel supply pipe or joint member and the wall surface of the absorber while maintaining the above, and to prevent the risk of breakage at the connecting portion.

  1 to 4, the first embodiment of the present invention will be described. (1) is a communication pipe, and as shown in FIG. 1, a pipe-type element pipe having an integral structure provided with a fuel passage (2) therein. Is formed into a flat rectangular shape. Moreover, the wall surface of this communication pipe (1) has a flexible absorber wall surface (3), and this absorber wall surface (3) can absorb fuel pressure pulsation generated in the communication pipe (1). It is supposed to be. In the first embodiment, the communication pipe (1) is formed using a pipe-type element pipe having an integral structure. However, in other different embodiments, two cross-sectionally U-shaped or L-shaped cross-sections are used. The communicating pipe (1) may be formed into an integral structure by press forming a member, butting the end faces, and laser welding, brazing, or the like.

  Further, on the absorber wall surface (3) of the communication pipe (1), as shown in FIGS. 1 and 2, a substantially quadrangular frustum-shaped fixed protrusion (4) is formed. The fixed protrusion (4) has a tapered peripheral wall (5) with a base on the base end side having a large size and a small size on the top side on the front end side, and a fuel supply hole ( 7) and a tip end portion (8) having an opening, and the tip end portion (8) is formed flat.

  Further, an approximately cubic joint member (10) is disposed above the tip (8) as shown in FIG. An L-shaped through hole (11) is formed through the joint member (10), and one end of the through hole (11) faces the fuel supply hole (7) of the communication pipe (1). In this state, the joint member (10) is disposed at the tip end portion (8) of the fixed protrusion (4). The fuel supply pipe (6) can be connected to the other end of the through hole (11). In the first embodiment and the following embodiments, the inclination angle of the peripheral wall (5) of the fixed protrusion (4) is set to 35 ° as shown in FIG. In the present invention, the inclination angle of the peripheral wall (5) is preferably 10 ° to 35 °. If the inclination angle is less than 10 °, the layout property is poor. The effect of reducing the stress generated in the connecting portion (12) with the fuel supply pipe (6) or the joint member (10) is reduced.

  In this embodiment, the stress value of the stress generated in the connecting portions (12) and (44) between the absorber wall surfaces (3) and (40) and the joint members (10) and (41) when fuel pressure pulsation occurs is A comparison was made between Example 1 and a conventional fuel delivery pipe as shown in FIGS. This comparison is performed by FEM (Finit Element Method), and the stress value is obtained by analyzing the result of internal pressure deformation when fuel pressure pulsation occurs. In addition, in order to perform the FEM analysis, the shape of a predetermined portion of the communication pipe (1) (43) excluding the cross-sectional shape near the fuel supply hole (7) is common to the first embodiment and the comparative example, The conditions are as follows.

  First, as shown in FIG. 15 (cut and displayed in half in the longitudinal direction only), the total length of the communication pipes (1) and (43) is 300 mm, the formation width is 34 mm, the height is 12 mm, and the plate thickness is It is made of 1.2mm steel plate. Further, four sockets (45) into which injectors (not shown) having a diameter of 16 mm are inserted are fixed in the length direction of the communication pipes (1) and (43), and the distance between these sockets (45) is fixed. Is 80 mm. Further, fuel supply holes (7) for connecting the fuel supply pipe (6) directly or via the joint members (10) (41) are provided in the center in the length direction and the width direction of the communication pipe (1) (43). ) (46).

  Further, in addition to the above, various parameters were set to Young's modulus of 200,000 MPa, Poisson's ratio: 0.29, and internal pressure of 0.5 MPa, and the inside of the communication pipes (1) and (43) of Example 1 and Comparative Example was pressurized in FEM analysis. However, the cross-sectional shape of Example 1 was partially deformed as shown in FIG. In the comparative example, the same deformation was observed as shown in FIG. From this, it was confirmed that the pressure pulsation generated inside the communication pipes (1) and (43) can be absorbed by the absorber wall surfaces (3) and (40) provided in the communication pipes (1) and (43). Further, the stress value in the connection portion (44) of the comparative example was 256 MPa as shown in FIG. 15, whereas in Example 1, it was 181 MPa as shown in FIG.

  From the above results, the fixed protrusion (4) having the flexible wall surface (3) on the wall surface of the communication pipe (1) and the tapered wall surface (5) formed on the wall surface (3). By providing the joint member (10) on the fixed protrusion (4), the connecting portion between the joint member (10) and the absorber wall surface (3) while maintaining the pulsation absorbing function by the absorber wall surface (3) It was revealed that the stress generated in (12) can be reduced. Accordingly, it is possible to prevent the connection portion (12) from being damaged due to the pressure deformation of the absorber wall surface (3). In use, as shown in FIG. 4, a fuel supply pipe (6) is connected to the other end of the through hole (11) of the joint member (10), and this fuel supply pipe (6) is connected to the shaft of the communication pipe (1). It is arranged in the direction.

  Further, in the first embodiment, the substantially quadrangular frustum-shaped fixed protrusion (4) is formed on the absorber wall surface (3) of the communication pipe (1). However, in the second embodiment of the present invention, FIGS. As shown in FIG. 3, a substantially frustoconical fixed protrusion (4) is formed on the absorber wall surface (3). As in the first embodiment, the fixed projection (4) includes a truncated cone-shaped peripheral wall (5) that tapers outward, and a fuel supply hole of the fuel supply pipe (6). It consists of a flat tip portion (8) having an opening (7). A cylindrical joint member (10) is disposed at the tip. Thus, even when the fixed protrusion (4) provided on the absorber wall surface (3) is formed in a substantially truncated cone shape, the pulsation absorbing function by the absorber wall surface (3) is maintained as in the first embodiment. However, the stress generated in the connection part (12) between the joint member (10) and the absorber wall surface (3) can be reduced.

In the first and second embodiments, the fixed projections (4) having a substantially quadrangular frustum shape and a substantially frustoconical shape are respectively formed in the center in the length direction and the width direction of the communication pipe (1). In Example 3, as shown in FIG. 7 and FIG. 8, in the center in the width direction of the absorber wall surface (3) of the communication pipe (1), it faces the entire length continuously from one end to the other end in parallel to the axial direction. The tapered peripheral wall (5) and the tip (8) formed flat from one end of the absorber wall (3) to the other end form a fixed protrusion (4) with a trapezoidal cross-sectional profile. is doing. Thus, even when the fixed protrusion (4) is continuously formed in the axial direction from one end to the other end of the absorber wall surface (3), the rigidity of the absorber wall surface (3) is slightly increased, but the absorber wall surface (3) While maintaining the pulsation absorbing function according to (3), it is possible to reduce the stress generated in the connecting portion (12) between the joint member (10) and the absorber wall surface (3).

  Moreover, in the said Examples 1-3, although the communicating pipe (1) is formed in the flat rectangular shape of the pipe-type element pipe of an integral structure, in Example 4 of this invention, it divides | segments into the up-down direction. The formed communication pipe (1) is used. That is, as shown in FIG. 9, the communication pipe (1) of the fourth embodiment has a U-shaped cross section consisting of an upper wall (13) and a pair of upper side walls (14) and a thin upper body (15) and a bottom. A wall (16) and a lower body (18) comprising a pair of lower side walls (17) are assembled and formed. The upper body (15) has an upper wall (13) provided with a substantially quadrangular pyramid-shaped fixed projection (4) similar to that of the first embodiment, and the tip of the fixed projection (4). A joint member (10) is disposed in the portion (8).

  Then, the upper body (15) and the lower body (18) formed as described above are assembled, and the contact portion between the upper body (15) and the lower body (18) is fixed in the circumferential direction by brazing, beam welding or the like. As a result, a communication pipe (1) having a fuel passage (2) therein is formed. Further, in this communication pipe (1), an absorber wall surface (3) is formed on the upper wall (13) of the upper body (15) and the bottom wall (16) of the lower body (18). Therefore, the stress generated in the connection portion (12) between the joint member (10) and the absorber wall surface (3) can be reduced while maintaining the pulsation absorbing function by the absorber wall surface (3).

  In the fourth embodiment, the cross-sectional shape of the communication pipe (1) formed by assembling the upper body (15) and the lower body (18) is substantially rectangular. However, in the fifth embodiment of the present invention, the upper body ( The cross-sectional shape of the communication pipe (1) formed by assembling 15) and the lower body (18) is substantially goggle type as shown in FIG. That is, as shown in FIGS. 10 and 11, a groove (20) is provided in the axial direction of the center of the upper wall (13) of the upper body (15) in the width direction, and the length direction in the groove (20) is provided. A substantially quadrangular pyramid-shaped fixed projection (4) is provided in the center. Thus, even when the cross-sectional shape of the communication pipe (1) is a substantially goggle type, the joint member (10) and the absorber wall surface (3) are maintained while maintaining the pulsation absorbing function by the absorber wall surface (3). The stress generated in the connecting portion (12) can be reduced.

  In the first to fifth embodiments, the fuel supply pipe (6) is connected to the fuel supply hole (7) of the fixed protrusion (4) via the joint member (10). 6, as shown in FIGS. 12 and 13, by inserting and fixing one end (21) of the fuel supply pipe (6) into the fuel supply hole (7) of the fixed protrusion (4) formed in a substantially square frustum shape. The fuel supply pipe (6) is directly connected to the fuel supply hole (7) of the fixed protrusion (4). Thus, even when the fuel supply pipe (6) is directly connected to the fuel supply hole (7) of the fixed protrusion (4) without the joint member (10) or the like, the absorber wall surface (3) Thus, the stress generated in the connecting portion (12) between the fuel supply pipe (6) and the absorber wall surface (3) can be reduced while maintaining the pulsation absorbing function.

  In the first to sixth embodiments, the peripheral wall (5) of the fixed protrusion (4) is linearly inclined. However, in the seventh embodiment of the present invention, as shown in FIG. The peripheral wall (5) of the fixed protrusion (4) is curved and inclined. In this way, even when the peripheral wall (5) of the fixed protrusion (4) is curved and inclined, the joint member (10) and the absorber wall surface are maintained while maintaining the pulsation absorbing function by the absorber wall surface (3). The stress generated in the connection part (12) with (3) can be reduced.

Sectional drawing of the fuel delivery pipe which shows Example 1 of this invention. FIG. 3 is a partial plan view of the first embodiment when the fuel supply pipe is not connected. Sectional drawing at the time of pressurization of the fuel delivery pipe of Example 1. FIG. FIG. 3 is a partial plan view of the fuel delivery pipe according to the first embodiment. The fragmentary top view of the fuel delivery pipe which shows Example 2 of this invention. AA line sectional view of Drawing 5. The partial top view of the fuel delivery pipe which shows Example 3 of this invention. BB sectional drawing of FIG. Sectional drawing of the fuel delivery pipe which shows Example 4 of this invention. The partial top view of the fuel delivery pipe which shows Example 5 of this invention. The CC sectional view taken on the line of FIG. The fragmentary top view of the fuel delivery pipe which shows Example 6 of this invention. The DD sectional view taken on the line of FIG. Sectional drawing of the fuel delivery pipe which shows Example 7 of this invention. The partial top view and sectional drawing which show the conventional fuel delivery pipe. Sectional drawing at the time of pressurization of the conventional fuel delivery pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication pipe 3 Absorber wall surface 4 Fixed protrusion 5 Perimeter wall 6 Fuel supply pipe 7 Fuel supply hole 10 Joint member

Claims (8)

  In a fuel delivery pipe having a flexible absorber wall surface penetrating a fuel supply hole on the wall surface of the communication tube, and connecting the fuel supply tube to the fuel supply hole of the absorber wall surface directly or via a joint member, A fixed projection with a tapered frustum-shaped peripheral wall tapering outward and formed with a fuel supply hole at the tip is formed on the absorber wall surface of the communication pipe, and fuel is supplied to the fixed projection A fuel delivery pipe, wherein a fuel supply pipe is connected and fixed to the hole directly or via a joint member.   The fuel delivery pipe according to claim 1, wherein the fixed protrusion has a flat tip.   The fuel delivery pipe according to claim 1 or 2, wherein the fixed protrusion is formed such that an axial direction and a cross-sectional outline in a direction perpendicular to the axial direction of the communication pipe on the peripheral wall are linearly inclined.   The fuel delivery pipe according to claim 1 or 2, wherein the fixed protrusion is formed so that a cross-sectional contour in an axial direction and a direction perpendicular to the axial direction of the communication pipe on the peripheral wall is curved and inclined.   The fuel delivery pipe according to claim 1, 2, 3, or 4, wherein the fixed protrusion has an inclination angle of a peripheral wall of 10 ° to 35 °.   The fuel delivery pipe according to claim 1, 2, 3, 4, or 5, wherein the fixed protrusion has a substantially truncated pyramid shape.   The fuel delivery pipe according to claim 1, 2, 3, 4, or 5, wherein the fixed protrusion has a substantially truncated cone shape. Fixing protrusion portions are over substantially the entire length of the communicating pipe, according to claim 1, or the second fuel delivery pipe, characterized in that provided as a continuous ridges in the axial direction.

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