JP4680829B2 - Fuel delivery pipe - Google Patents

Description

  The present invention relates to a fuel delivery pipe used in a fuel supply device for an internal combustion engine.

  As one of the fuel supply devices for a multi-cylinder internal combustion engine, there is one in which a plurality of injectors for fuel injection are provided and fuel is injected from each injector into a corresponding cylinder. In such a fuel supply device, a fuel delivery pipe is used to store fuel pumped from a fuel pump and distribute and supply the fuel to each injector. The fuel in the fuel delivery pipe is injected and supplied to each cylinder at a predetermined pressure by controlling the opening and closing of the solenoid valve in each injector by the control unit.

  In the fuel supply device for an internal combustion engine as described above, since fuel injection is intermittently performed by opening and closing an electromagnetic valve inside the injector, pulsation (fuel pressure pulsation) may occur in the fuel pressure in the fuel delivery pipe. As a result, the pressure of the fuel supplied to the injector becomes unstable, the fuel injection amount per injection that is adjusted according to the injection time fluctuates, causing deterioration in emissions and drivability, fuel delivery pipe and fuel There is a problem that vibration or abnormal noise occurs in the supply piping.

Conventionally, a pulsation damper or the like is used to absorb and relieve fuel pressure pulsation of a fuel delivery pipe. A fuel delivery pipe that attenuates fuel pressure pulsation without using a pulsation damper has been proposed by providing a double pipe structure of an outer pipe and an inner pipe. Japanese Patent Application Laid-Open No. H10-228561 discloses that a radiated sound is reduced by disposing a damping member on the inner pipe.
JP 2005-299489 A

  By the way, in the fuel delivery pipe having a double pipe structure including the outer pipe and the inner pipe as described above, it is preferable to reduce the thickness of the inner pipe to some extent in order to improve the pulsation absorption performance of the inner pipe.

  On the other hand, the inner tube is fixed to the outer tube at both ends in the longitudinal direction, but is not fixed to the outer tube at portions other than the both ends. For this reason, resonance (string vibration) with nodes at both ends, which are fixed points, is generated in the inner tube due to engine vibration, fuel pressure pulsation, etc., and with this resonance, the strength of the inner tube decreases, There is a possibility of damage. And as the inner tube is made thinner, there is a concern that the strength of the inner tube decreases due to resonance.

  The present invention has been proposed by paying attention to such points, and in a fuel delivery pipe having a double tube structure consisting of an outer tube and an inner tube, while improving the pulsation absorption performance by thinning the inner tube, The purpose is to prevent the strength of the inner tube from decreasing due to resonance.

In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention comprises an outer tube to which a plurality of injectors are attached, and a hollow inner tube disposed inside the outer tube, the inner tube being fixed to the outer tube at both ends in the longitudinal direction, A fuel delivery pipe configured to distribute and supply fuel supplied to a fuel passage between the outer pipe and the inner pipe to the injectors and absorb fuel pressure pulsation by elastic deformation of the inner pipe, Fixing means for fixing the inner tube and the outer tube by being fixed to the inner wall of the outer tube at at least one place other than both ends in the longitudinal direction of the inner tube, and sandwiching and holding the inner tube wherein the fixing means, fixing portion of the outer tube and the inner tube is characterized that you have provided belly of the resonance that occurs in the inner tube if only both end portions of the longitudinal direction.

  According to the said structure, the fixing location of an inner tube and an outer tube is provided not only in the both ends of a longitudinal direction but in the approximate center of a longitudinal direction. For this reason, compared with the case where the fixed location of an inner tube and an outer tube is only both ends, the distance between the fixed locations of an inner tube and an outer tube becomes short. And since vibrations of the inner tube are prevented at those fixed points, resonance of the inner tube and the outer tube is compared with the resonance (string vibration) generated in the inner tube compared to the case where only the both ends are fixed. The point goes up and the amplitude becomes smaller. Thereby, the strength reduction of the inner tube due to resonance can be prevented, and the durability of the inner tube can be improved.

  In order to improve the pulsation absorption performance of the inner tube, it is preferable to make the inner tube thinner to some extent. According to the above configuration, it is possible to prevent a decrease in strength of the inner tube due to resonance while improving the pulsation absorption performance by reducing the thickness of the inner tube.

Here, the fixing means, than the fixed portion of the outer tube and the inner tube is provided on the belly of the resonance that occurs in the inner tube if only both end portions of the longitudinal inner tube due to the resonance The strength of the inner tube is prevented more effectively, and the durability of the inner tube is improved more effectively.

The fixing means for fixing the inner tube and the outer tube includes a first piece fixed to the upper wall of the outer tube and a side wall disposed on the side of the side wall of the inner tube. A fixing member and a pair of sandwiching pieces for sandwiching and holding the side wall of the inner tube from both sides, and one of the pair of sandwiching pieces is fixed to the side wall of the outer tube, and the other sandwiching piece is a second fixing member which is fixed to the side wall of the first fixing member, Tona Rukoto are preferred.

  According to the present invention, in the fuel delivery pipe having a double-pipe structure composed of an outer tube and an inner tube, the inner tube is thinned to improve the pulsation absorption performance, while preventing a decrease in the strength of the inner tube due to resonance, The durability of the inner pipe can be improved.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  The fuel delivery pipe of the present embodiment constitutes a part of a fuel supply device in a multi-cylinder engine, and distributes and supplies fuel from a fuel pump to a plurality of injectors. Hereinafter, a fuel delivery pipe provided in a fuel supply device for a four-cylinder engine will be described. Note that the present invention is not limited to a four-cylinder engine, and can be applied to a multi-cylinder engine having an arbitrary number of cylinders.

  First, a schematic configuration of the fuel delivery pipe will be described with reference to FIGS. Hereinafter, the longitudinal direction of the housing 20 of the fuel delivery pipe 10 is simply referred to as “longitudinal direction”.

  The fuel delivery pipe 10 includes a housing 20 as an outer pipe to which a plurality (four in this example) of fuel injection injectors 11 are attached, and a metal cylinder 30 as an inner pipe disposed inside the housing 20. And has a double-pipe structure.

  The housing 20 is configured such that the upper case 21 and the lower case 22 are integrally joined in a state where a sealing property is secured by brazing. Each of the upper case 21 and the lower case 22 is a member made of sheet metal processing. The open side portions of the upper case 21 and the lower case 22 face each other, and the edges on the opening side are joined to each other over almost the entire circumference.

  A fuel passage is formed between the housing 20 and the metal cylinder 30 for distributing and supplying the fuel introduced through the fuel supply pipe 12 by a fuel pump (not shown) to the plurality of injectors 11. The upper and lower cases 21 and 22 and the portions of the metal cylinder 30 that form the fuel passages are subjected to nickel plating for rust prevention.

  An inlet 23 is formed at one end in the longitudinal direction of the upper case 21. A fuel supply pipe 12 that supplies fuel pumped by a fuel pump is connected to the introduction port 23 in a state where sealing performance is secured by brazing. The fuel from the fuel pump is introduced into the housing 20, that is, into the fuel passage through the fuel supply pipe 12 and the introduction port 23.

  The lower case 22 is formed with cylindrical portions 25 for connecting the injectors 11 at predetermined intervals along the longitudinal direction. The cylindrical portion 25 is formed by recessing the bottom surface of the lower case 22 upward (toward the inside of the fuel passage). In addition, a communication hole 25 a for supplying fuel to the injector 11 is formed at the bottom of the cylindrical portion 25. And each cylinder part 25 is connected with the injector 11 in the state which ensured the sealing performance via sealing members, such as an O-ring.

  A plurality (two in this example) of mounting brackets 13 are fixed to the lower surface of the lower case 22 by projection welding or the like. In order to reduce the amount of outward projection of the mounting bracket 13, the upper and lower cases 21, 22 are respectively provided with arc-shaped depressions 26, 27 toward the inner side (the metal cylinder 30 side) in plan view. Is formed. Between the recesses 26 and 27, the portion of the upper case 21 in which the metal cylinder 30 is inserted (the left portion in FIGS. 4 and 5) is higher than the portion not inserted (the right portion in FIGS. 4 and 5). The housing 20 is formed in a substantially L shape in a sectional view.

  The metal cylinder 30 is a long and hollow member made of mild steel, and is provided as a pulsation absorbing member for absorbing and mitigating the fuel pressure pulsation of the fuel delivery pipe 10. The metal cylinder 30 extends along the longitudinal direction. The metal cylinder 30 is formed in a cylindrical shape having a rectangular cross section with rounded corners at four corners. The metal cylinder 30 has a vertically long shape in which the left and right walls 31 and 32 are formed larger than the upper and lower walls 33 and 34. The left and right walls 31 and 32 of the metal cylinder 30 are pulsation absorbing portions that absorb the fuel pressure of the fuel delivery pipe 10.

  Further, the thickness of the metal tube 30 is thinner than the thickness of the upper and lower cases 21 and 22 of the housing 20. For example, the upper and lower cases 21 and 22 have a thickness of 1.2 to 1.6 mm, whereas the metal cylinder 30 has a thickness of 0.3 to 0.4 mm.

  Both end portions in the longitudinal direction of the metal cylinder 30 protrude from the both end portions in the longitudinal direction of the housing 20 to the outside. And the both ends of the longitudinal direction of the metal cylinder 30 are inserted in the insertion ports 24 and 24 formed in the both ends of the longitudinal direction of the upper case 21, and also the sealing property was secured to the upper case 21 by brazing. It is fixed in a state.

  Thus, the metal cylinder 30 is fixed to the housing 20 at both ends in the longitudinal direction. Further, the metal cylinder 30 is fixed to the housing 20 by metal pins 41 and 42 at locations other than both ends thereof. In this example, the pins 41 and 42 are provided above and below substantially the center in the longitudinal direction of the metal cylinder 30 and approximately the center in the left-right direction, and the metal cylinder 30 is fixed to the housing 20 by the upper and lower pins 41 and 42. Yes. As described above, the upper and lower pins 41 and 42 serve as fixing means for fixing the housing 20 and the metal cylinder 30.

  The upper pin 41 is provided on the upper side of the metal cylinder 30 and is inserted from above into a pin insertion hole 28 provided at substantially the center in the longitudinal direction of the upper wall of the upper case 21 of the housing 20. The head 41a of the pin 41 is integrally joined to the upper surface of the upper case 21 by brazing. At this time, brazing is performed over the entire circumference of the pin insertion hole 28 of the upper case 21 in order to ensure sealing performance. The tip end surface of the shaft portion 41 b of the pin 41 is integrally joined to the upper wall 33 of the metal tube 30 by brazing. In this way, the metal cylinder 30 is fixed to the upper case 21 of the housing 20 via the pins 41.

  On the other hand, the lower pin 42 is provided on the lower side of the metal cylinder 30 and is inserted from above into a pin insertion hole 29 provided at substantially the center in the longitudinal direction of the lower wall of the lower case 22 of the housing 20. . The head portion 42a of the pin 42 is integrally joined to the lower surface of the lower case 22 by brazing. At this time, brazing is performed over the entire circumference of the pin insertion hole 29 of the lower case 22 in order to ensure sealing performance. The tip end surface of the shaft portion 42b of the pin 42 is integrally joined to the lower wall 34 of the metal cylinder 30 by brazing. Thus, the metal cylinder 30 is fixed to the lower case 22 of the housing 20 via the pins 42.

  In addition, at least one end in the longitudinal direction of the metal cylinder 30 may be open to the outside (atmosphere), or both ends may be sealed. In this example, both ends in the longitudinal direction of the metal cylinder 30 are open ends. The internal space of the metal cylinder 30 is cut off from the fuel passage. Thus, in the fuel delivery pipe 10, the internal space of the metal cylinder 30 is not communicated with the fuel passage inside the housing 20.

  The fuel delivery pipe 10 configured as described above stores fuel that is pumped by the fuel pump and introduced into the housing 20, and distributes and supplies the fuel to each injector 11 through the fuel passage. The fuel distributed and supplied to each injector 11 is injected and supplied to the corresponding cylinder at a predetermined pressure by opening and closing the electromagnetic valve inside each injector 11 by a control unit (not shown).

  Moreover, since the metal cylinder 30 arrange | positioned inside the housing 20 is formed thinly, the metal cylinder 30 is easy to deform | transform in the direction orthogonal to a longitudinal direction. When the fuel pressure in the fuel delivery pipe 10 increases, the metal cylinder 30 is deformed so as to be recessed inward. In this example, the metal cylinder 30 has a vertically elongated shape in which the left and right walls 31 and 32 are larger than the upper and lower walls 33 and 34. Therefore, the left and right walls 31 and 32 are more easily deformed. The left and right walls 31 and 32 are deformed (recessed) so that the deformation amount (recess amount) of the central portion in the vertical direction is maximized.

  The left and right walls 31 and 32 of the metal cylinder 30 are recessed inward according to the fuel pressure in the fuel delivery pipe 10 applied to the left and right walls 31 and 32, and the deformation amount increases as the fuel pressure increases. As the fuel pressure decreases, the amount of deformation decreases. As described above, the left and right walls 31 and 32 of the metal cylinder 30 are elastically deformed according to the fluctuation of the fuel pressure in the fuel delivery pipe 10. Then, due to the elastic deformation of the left and right walls 31 and 32 of the metal cylinder 30, fuel pressure pulsations in the fuel delivery pipe 10 caused by opening and closing of an electromagnetic valve inside the injector 11 are absorbed and alleviated. As a result, an error in the fuel injection amount due to fuel pressure pulsation is reduced, the fuel consumption rate is improved, and vibrations and abnormal noises of the fuel delivery pipe 10 and the fuel supply pipe 12 are suppressed. Here, in order to improve the pulsation absorption performance of such a metal cylinder 30, it is preferable to make the thickness of the metal cylinder 30 thin to some extent.

  The fuel delivery pipe 10 having the above-described configuration is manufactured as follows. First, the metal cylinder 30 is inserted into the insertion ports 24 and 24 at both ends of the upper case 21 in a single state, and both end portions of the metal cylinder 30 protrude from the insertion ports 24 and 24 of the upper case 21 to the outside. Let Next, the metal cylinder 30 is temporarily assembled by caulking or the like so that the outer peripheries of both ends of the metal cylinder 30 can be joined to the upper case 21 in a state where both ends of the metal cylinder 30 protrude. Then, after the fuel supply pipe 12 is inserted into the introduction port 23 of the upper case 21, the upper case 21 to which the metal cylinder 30 is temporarily assembled is put on the lower case 22, and the pin 41 is inserted into the pin insertion hole 28 and the pin 42 of the upper case 21. Are respectively inserted into the pin insertion holes 29 of the lower case 22 and brazed in the furnace. When brazing, try to place it where necessary. For brazing, for example, copper brazing can be used.

  In this way, the metal cylinder 30 is joined to the housing 20 in a state where the sealing performance is ensured, and the entire fuel delivery pipe 10 is joined and assembled in a state where the sealing performance is secured. In the fuel delivery pipe 10, the fuel passage inside the housing 20 and the internal space of the metal cylinder 30 are blocked. In addition, the metal tube 30 is fixed to the housing 20 at both ends in the longitudinal direction, and is also fixed to the housing 20 by pins 41 and 42 at substantially the center in the longitudinal direction.

  As described above, the fixing portion between the metal cylinder 30 and the housing 20 is provided not only at both ends in the longitudinal direction but also at substantially the center in the longitudinal direction. For this reason, compared with the case where the fixing location of the metal cylinder 30 and the housing 20 is only at both ends, the distance between the fixing locations of the metal cylinder 30 and the housing 20 is shortened. Since the vibration of the metal tube 30 is prevented at those fixed locations, the resonance (string vibration) generated in the metal tube 30 is compared to the case where the metal tube 30 and the housing 20 are fixed only at both ends. ) And the amplitude decreases. Thereby, the strength reduction of the metal cylinder 30 due to resonance can be prevented, and the durability of the metal cylinder 30 can be improved.

  As described above, in order to improve the pulsation absorbing performance of the metal cylinder 30, it is preferable to reduce the thickness of the metal cylinder 30 to some extent. In this example, it is possible to prevent strength reduction of the metal cylinder 30 due to resonance while improving the pulsation absorption performance by making the metal cylinder 30 thin.

  Here, substantially the center in the longitudinal direction of the metal cylinder 30 is an antinode of resonance generated in the metal cylinder 30 when the metal cylinder 30 and the housing 20 are fixed at both ends only. In this example, pins 41 and 42 are provided on the antinode where the amplitude of the resonance becomes large, and the vibration of the metal cylinder 30 on the antinode is prevented. Thereby, the strength reduction of the metal cylinder 30 due to resonance can be prevented more effectively, and the durability of the metal cylinder 30 can be improved more effectively.

  In addition, since the pins 41 and 42 are made of metal, the metal cylinder 30 and the housing 20 can be fixed at approximately the center in the longitudinal direction by brazing as described above. In this way, the metal cylinder 30 and the housing 20 can be fixed by the pins 41 and 42 by the same brazing as the other joints of the fuel delivery pipe 10, so that the manufacturing process of the fuel delivery pipe 10 is performed. Is simplified and mass production becomes possible.

  In the above, the example in which the pins as the fixing means between the metal cylinder 30 and the housing 20 are provided above and below substantially the center in the longitudinal direction of the metal cylinder 30 has been described. However, the number and location of the pins are as described above. It is not limited. For example, the metal cylinder 30 and the housing 20 may be fixed only by the upper pin 41 without providing the lower pin 42, and conversely, only by the lower pin 42 without providing the upper pin 41. The metal tube 30 and the housing 20 may be fixed.

  Moreover, you may make it provide a pin in the several location of the longitudinal direction of the metal cylinder 30. FIG. Also in this case, a pair of upper and lower pins may be provided at each fixing location, only the upper pins may be provided, or only the lower pins may be provided. In this case, if the pins are arranged so that the distances between the fixed portions of the metal cylinder 30 and the housing 20 are equal, the strength reduction of the metal cylinder 30 due to resonance can be effectively prevented.

  Further, as long as it is a metal member provided between the metal tube 30 and the housing 20, the member is not limited to the members such as the pins 41 and 42 described above. Such a metal member may be a separate member from the metal tube 30 and the housing 20, or may be a member integral with the metal tube 30 or the housing 20. In the case of an integral member, for example, it can be integrally provided on the outer surface of the metal cylinder 30 and can be a protrusion extending toward the housing 20, or can be integrally provided on the inner surfaces of the upper case 21 and the lower case 22 of the housing 20. Alternatively, the protrusion may extend toward the metal tube 30.

  In the above-described embodiment, the case where the fixing means other than both ends of the metal cylinder 30 and the housing 20 in the longitudinal direction is a metal pin, but the fixing means may be other than the pin. Next, another embodiment of a fixing means for fixing the metal cylinder 30 and the housing 20 will be described with reference to FIGS.

  In the fuel delivery pipe 10 ′ shown in FIG. 6, the fixing means other than both ends in the longitudinal direction of the metal cylinder 30 and the housing 20 are different from the fuel delivery pipe 10 of the above-described embodiment, and other configurations are almost the same. It is the same (refer FIGS. 1-4). Hereinafter, different points will be described in detail.

  In the fuel delivery pipe 10 ′, the metal cylinder 30 is fixed to the housing 20 at both ends in the longitudinal direction, and the metal cylinder 30 is fixed to a metal as shown in FIG. 7 at locations other than both ends. The members 51 and 52 are fixed to the housing 20. FIG. 7 shows only the upper fixing member 51.

  In this example, the fixing members 51 and 52 are provided above and below substantially the center in the longitudinal direction of the metal cylinder 30, and the metal cylinder 30 is fixed to the housing 20 by the upper and lower fixing members 51 and 52. The upper and lower fixing members 51 and 52 have the same shape, are formed in a substantially concave shape with sandwiching pieces formed at both ends in a side view, and are arranged in opposite directions.

  The upper fixing member 51 is provided on the upper side of the metal cylinder 30 and is integrally fixed to the upper wall of the upper case 21 of the housing 20 by brazing. At this time, the upper surface of the fixing member 51 is fixed to the wall of the upper case 21 so that the sandwiching pieces 51 a and 51 a at both ends of the fixing member 51 face downward. And the upper part of the substantially center of the longitudinal direction of the metal cylinder 30 is inserted | pinched between the clamping pieces 51a and 51a of the both ends of the fixing member 51, and is hold | maintained.

  On the other hand, the lower fixing member 52 is provided below the metal cylinder 30 and is integrally fixed to the lower wall of the lower case 22 of the housing 20 by brazing. At this time, the lower surface of the fixing member 52 is fixed to the wall of the lower case 22 so that the sandwiching pieces 52 a and 52 a at both ends of the fixing member 52 face upward. And the lower part of the substantially center of the longitudinal direction of the metal cylinder 30 is inserted | pinched between the clamping pieces 52a and 52a of the both ends of the fixing member 52, and is hold | maintained.

  Here, the fuel delivery pipe 10 'is manufactured as follows.

  First, the metal cylinder 30 is inserted into the insertion ports 24 and 24 at both ends of the upper case 21 in a single state, and both end portions of the metal cylinder 30 protrude from the insertion ports 24 and 24 of the upper case 21 to the outside. Let At this time, the fixing member 51 is disposed between the upper case 21 and the metal cylinder 30, and the upper portion of the center of the metal cylinder 30 in the longitudinal direction is sandwiched between the holding pieces 51 a and 51 a of the fixing member 51. Next, by caulking or the like so that the outer ends of both ends of the metal tube 30 can be joined to the upper case 21 in a state where both ends of the metal tube 30 are protruded and the substantially center in the longitudinal direction of the metal tube 30 is sandwiched. Temporary assembly. Then, after inserting the fuel supply pipe 12 into the introduction port 23 of the upper case 21, the upper case 21 to which the metal cylinder 30 is temporarily assembled is put on the lower case 22. At this time, the fixing member 52 is disposed between the lower case 22 and the metal tube 30, and the lower part of the center of the metal tube 30 in the longitudinal direction is sandwiched between the holding pieces 52 a and 52 a of the fixing member 52, so To do. When brazing, try to place it where necessary. For brazing, for example, copper brazing can be used. The upper fixing member 51 may fix the metal tube 30 to the upper case 21 in a single state by brazing in advance, and the lower fixing member 52 has the metal tube 30 in a single state. The lower case 22 may be fixed in advance by brazing or projection welding.

  As described above, the upper and lower fixing members 51 and 52 hold the substantially central portion of the metal cylinder 30 in the longitudinal direction so that the metal cylinder 30 is fixed to the housing 20. Therefore, the fixing part of the metal cylinder 30 and the housing 20 is provided not only at both ends in the longitudinal direction but also at the approximate center in the longitudinal direction. For this reason, compared with the case where the fixing location of the metal cylinder 30 and the housing 20 is only at both ends, the distance between the fixing locations of the metal cylinder 30 and the housing 20 is shortened. And the vibration of the metal cylinder 30 is prevented in those fixed locations. Thereby, also in fuel delivery pipe 10 ', the same operation effect as fuel delivery pipe 10 of an embodiment mentioned above is acquired.

  The number and location of the fixing members are not limited to those described above. For example, the metal tube 30 and the housing 20 are fixed by the upper fixing member 51 without providing the lower fixing member 52. On the contrary, the metal cylinder 30 and the housing 20 may be fixed only by the lower fixing member 52 without providing the upper fixing member 51.

  Moreover, you may make it provide a fixing member in the several location of the longitudinal direction of the metal cylinder 30. FIG. In this case as well, a set of upper and lower fixing members may be provided at each fixing location, only the upper fixing member may be provided, or only the lower fixing member may be provided. In this case, if the fixing member is arranged so that the distances between the fixing portions of the metal cylinder 30 and the housing 20 are equal, the strength reduction of the metal cylinder 30 due to resonance can be effectively prevented.

  Furthermore, a modified example of the above-described fixing means will be described with reference to FIGS.

  The fuel delivery pipe 10 ″ shown in FIG. 8 is different from the fuel delivery pipe 10 ′ of the other embodiments described above except for the fixing means other than the longitudinal ends of the metal cylinder 30 ″ and the housing 20 ″. (Refer to FIG. 1 to FIG. 4) The differences will be described in detail below.The cross-sectional shapes of the housing 20 ″ of the fuel delivery pipe 10 ″ and the metal cylinder 30 ″ are as follows. Although the cross-sectional shapes of the housing 20 and the metal cylinder 30 of the fuel delivery pipe 10 are slightly different, the basic configuration is the same.

  In the fuel delivery pipe 10 ″, the metal cylinder 30 ″ is fixed to the housing 20 ″ at both ends in the longitudinal direction, and the metal cylinder 30 ″ is a metal as shown in FIG. It is fixed to the housing 20 ″ by fixing members 61, 62 made of metal.

  In this example, the fixing members 61 and 62 are provided above and below substantially the center in the longitudinal direction of the metal cylinder 30 ″, and the metal cylinder 30 ″ is fixed to the housing 20 ″ by the upper and lower fixing members 61 and 62. .

  The upper fixing member 61 is provided on the upper side of the metal cylinder 30 ″, and is integrally fixed to the upper wall of the upper case 21 ″ of the housing 20 ″. At this time, the lower end portion 61a of the fixing member 61 is positioned below. The upper surface of the upper piece 61 b of the fixing member 61 is fixed to the wall of the upper case 21 ″ so as to face.

  On the other hand, the lower fixing member 62 is provided on the lower side of the metal cylinder 30 ″, and is sandwiched between the side wall of the upper case 21 ″ of the housing 20 ″ and the side wall 61c of the upper fixing member 61, and integrated by brazing. Then, a substantially central side wall portion in the longitudinal direction of the metal tube 30 ″ is sandwiched and held between the sandwiching pieces 62a and 62b of the fixing member 62.

  Here, the fuel delivery pipe 10 "is manufactured as follows.

  First, the upper piece 61b of the fixing member 61 is fixed to the upper wall of the upper case 21 "by brazing, projection welding, etc. Next, the metal cylinder 30" is inserted into the insertion ports 24 "at both ends of the upper case 21". , 24 ″, and both ends of the metal tube 30 ″ project outward from the insertion ports 24 ″, 24 ″ of the upper case 21 ″. Both ends of the metal tube 30 ″ are projected. Then, the outer periphery of both ends of the metal cylinder 30 ″ is temporarily assembled by caulking or the like so that it can be joined to the upper case 21 ″. Next, the fixing member 62 is press-fitted between the fixing member 61 and the metal cylinder 30 ″. Further, after inserting the fuel supply pipe 12 ″ into the introduction port 23 ″ of the upper case 21 ″, the metal cylinder 30 ″ is temporarily inserted. The assembled upper case 21 "is placed on the lower case 22" and brazing is performed in the furnace. When brazing, the brazing is placed at a necessary place. Can be used.

  As described above, the substantially central portion of the metal cylinder 30 ″ in the longitudinal direction is sandwiched and held by the fixing members 61 and 62, whereby the metal cylinder 30 ″ is fixed to the housing 20 ″. For this reason, also in the fuel delivery pipe 10 ″, the same operation and effect as the fuel delivery pipes 10 and 10 ′ of the above-described embodiment can be obtained. Note that the number and location of the fixing members can be arbitrarily selected in the same manner as the fuel delivery pipes 10 and 10 'of the above-described embodiment. In this case, the same function and effect can be obtained.

  Other modified examples of the fixing means include the examples shown in FIGS. 10 and 11 and the examples shown in FIGS. As shown in FIG. 10, the metal cylinder 30 ″ may be fixed to the housing 20 ″ using the metal fixing members 71 and 72 shown in FIG. 11, or as shown in FIG. The metal cylinder 30 ″ may be fixed to the housing 20 ″ using metal fixing members 81 and 82. The effects in these cases are the same as those of the fuel delivery pipes 10 and 10 'of the above-described embodiment.

It is a partially broken top view which shows one Embodiment of the fuel delivery pipe to which this invention is applied. It is the side view which fractured | ruptured similarly. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is CC sectional drawing in FIG. FIG. 6 is a view corresponding to FIG. 5 showing a modification of the fixing means for fixing the metal cylinder and the housing. It is a perspective view which shows the fixing member which fixes a metal cylinder and a housing. FIG. 6 is a view corresponding to FIG. 5 and showing another modified example of the fixing means for fixing the metal cylinder and the housing. It is a perspective view which shows the fixing member which fixes a metal cylinder and a housing. FIG. 6 is a view corresponding to FIG. 5 and showing another modification of the fixing means for fixing the metal cylinder and the housing. It is a perspective view which shows the fixing member which fixes a metal cylinder and a housing. FIG. 6 is a view corresponding to FIG. 5 and showing another modification of the fixing means for fixing the metal cylinder and the housing. It is a perspective view which shows the fixing member which fixes a metal cylinder and a housing.

Explanation of symbols

10 Fuel Delivery Pipe 11 Injector 20 Housing 21 Upper Case 22 Lower Case 30 Metal Tube 41, 42 Pin

Claims (2)

An outer tube to which a plurality of injectors are attached, and a hollow inner tube disposed inside the outer tube, the inner tube being fixed to the outer tube at both ends in the longitudinal direction, and the outer tube and the inner tube A fuel delivery pipe configured to distribute and supply the fuel supplied to the fuel passage between each of the injectors and absorb fuel pressure pulsation by elastic deformation of the inner pipe,
Fixing means for fixing the inner tube and the outer tube by being fixed to the inner wall of the outer tube at at least one place other than both ends in the longitudinal direction of the inner tube, and sandwiching and holding the inner tube equipped with a,
It said fixing means, the fuel delivery pipe, characterized that you have provided belly resonance fixing portion of the outer tube and the inner tube is generated in the inner tube if only both end portions of the longitudinal direction. The fixing means includes
A first fixing member having an upper piece fixed to the upper wall of the outer tube, and a side wall disposed on a side of the side wall of the inner tube;
It has a pair of clamping pieces that sandwich and hold the side wall of the inner tube from both sides, and one clamping piece is fixed to the side wall of the outer tube, and the other clamping piece is the first clamping piece. A second fixing member fixed to the side wall of the fixing member;
Fuel delivery pipe according to claim 1, characterized in Tona Rukoto.

Images