JP3834574B2 - Fuel delivery assembly - Google Patents

Description

  The present invention relates to a fuel delivery assembly for use in an electronically controlled fuel injection engine or the like.

  In this type of fuel delivery assembly, as disclosed in, for example, Patent Document 1 below, a thin-walled body whose both ends are liquid-tightly closed inside a fuel delivery pipe composed of a sheet metal lower case and an upper case joined together. In some cases, a fuel delivery pipe is integrally connected to one end of the fuel delivery pipe by brazing.

The above-described fuel delivery assembly is used by connecting a plurality of fuel injection valves attached to a multi-cylinder engine in a liquid-tight manner through each O. The fuel of a predetermined pressure supplied via the control unit is supplied to the engine by controlling the opening and closing of each fuel injection valve by the control unit so that the optimum condition is obtained. In this type of fuel delivery assembly, when the fuel injection valve is opened and fuel is supplied to the engine, the fuel pressure inside the fuel delivery pipe pulsates, causing an error in the fuel injection amount and reducing the fuel consumption rate. There is a problem that the fuel delivery pipe generates vibrations and abnormal noise. In the technique of Patent Document 1, a thin metal cylinder is liquid-tightly provided inside a fuel delivery pipe, and the volume thereof changes according to the pulsation of the fuel pressure, thereby reducing such pulsation of the fuel pressure. .
JP 2002-339835 A.

  In the technique of Patent Document 1, a thin metal tube sealed at both ends by brazing in advance is put into a lower case, temporarily fixed with a pipe rivet, and the upper case is covered and brazed in a furnace to be liquid-tightly coupled. It is assembled. However, since the brazing of both ends of the thin metal cylinder is located inside the assembled fuel delivery assembly, it is not possible to visually check whether the brazing is properly maintained, and quality control is easy. There was a problem that could not be done. In addition, the metal cylinder requires a process such as liquid-tight closing both ends in advance and a pipe rivet for temporarily fixing the metal cylinder to the lower case, which increases the number of parts and processes. It was. The object of the present invention is to solve each of these problems.

  In order to solve the above problems, a fuel delivery assembly according to claim 1 of the present invention is connected to a plurality of fuel injection valves that are supplied with fuel of a predetermined pressure from a fuel pump and controlled by a control unit to be opened and closed. In a fuel delivery assembly comprising a metal fuel delivery pipe and a thin metal cylinder that is liquid-tight inside the fuel delivery pipe and whose volume changes according to the pulsation of the fuel pressure inside the fuel delivery pipe, both ends of the metal cylinder Is open to the outside of the fuel delivery pipe, and its outer periphery is liquid-tightly fixed to the fuel delivery pipe.

  As for invention of Claim 1, as shown in Claim 2, it is preferable to form a metal cylinder flat.

  In the invention according to claim 1 or claim 2, as shown in claim 3, the fuel delivery pipe is made of sheet metal, and the lower case and the upper case having a U-shaped cross section are faced to each other, and joined around the entire circumference. It is preferable to couple together with the metal cylinder in a liquid-tight manner by brazing.

  According to the first to third aspects of the present invention, as shown in the fourth aspect, both ends of the metal tube are squeezed toward the tip, and the squeezed portion is liquid-tightly fixed to the fuel delivery pipe. Preferably it is.

  Moreover, as for the invention of Claims 1-4, as shown in Claim 5, it is preferable that the cross-sectional shape of a metal cylinder is a rectangular shape.

  According to the fuel delivery assembly of the present invention, the pulsation of the fuel pressure in the fuel delivery pipe due to the opening and closing of the fuel injection valve is such that the volume of the metal cylinder provided in the fuel delivery pipe changes according to the pulsation of the fuel pressure. Therefore, the fuel injection rate error due to the pulsation of the fuel pressure is reduced, the fuel consumption rate is improved, and no vibration or noise is generated in the fuel delivery pipe. In addition, the metal cylinder that relieves the pulsation of the fuel pressure does not allow the fuel to permeate or deteriorate, so that there is no possibility that the fuel will diverge into the atmosphere or its function will deteriorate over time. In addition, the outer periphery of both ends of the metal cylinder is liquid-tightly fixed to the fuel delivery pipe, so that when the metal cylinder and the fuel delivery pipe are brazed, the brazed portion can be visually confirmed, and quality control is easy. Yes. In addition, since both ends of the metal cylinder are open to the outside, the metal cylinder is not deformed by heating during brazing, and a fuel delivery assembly with no variation in pressure pulsation mitigation performance can be obtained. Note that the fuel delivery assembly according to the present invention does not require a step of liquid-tightly closing both ends of the metal cylinder in advance as compared with the case where the metal cylinder is located inside the fuel delivery pipe. Since the pipe rivet for stopping is unnecessary, the number of parts and the process can be reduced.

  According to the fuel delivery assembly in which the metal cylinder is flattened, the change in the volume of the metal cylinder with respect to the pulsation of the fuel pressure increases, so the degree of relaxation of the pulsation of the fuel pressure increases, and therefore the error in the fuel injection amount also increases. It is greatly reduced.

  According to the fuel delivery assembly, each of the fuel delivery pipes is made of sheet metal, and the lower case and the upper case having a U-shaped cross section are faced to each other and joined together around the circumference, and together with the metal cylinder, it is joined together in a liquid-tight manner by brazing. A fuel delivery assembly that is lightweight and suitable for mass production is obtained.

  According to the fuel delivery assembly in which both ends of the metal cylinder are narrowed toward the tip, when the fuel delivery pipe is composed of the upper case and the lower case, both ends of the metal cylinder are connected to the fuel delivery pipe. Since it can be inserted into an opening provided in one of the lower case and the upper case, the alignment work when brazing the metal cylinder and the fuel delivery pipe is facilitated.

  According to the fuel delivery assembly in which the cross-sectional shape of the metal cylinder is rectangular, the volume of the metal cylinder increases because the area of the side surface plane portion is larger than that of a metal cylinder having the same cross-sectional shape and vertical and horizontal lengths. The amount of fluctuation increases. Accordingly, the absorption of pressure fluctuation is increased and the pressure pulsation mitigating performance is improved.

  1 to 4 show a fuel delivery assembly according to a first embodiment of the present invention. The fuel delivery assembly according to the first embodiment is provided with a metal tube 16 whose volume changes according to the fuel pressure pulsation of the fuel delivery pipe 10 to relieve the fuel pressure pulsation.

  As shown in FIGS. 1 to 4, the fuel delivery pipe 10 is made of sheet metal and has a U-shaped lower case 11 and an upper case 13 facing each other and fitted and joined on the entire circumference of the opening side. , Which are integrally joined in a liquid-tight manner by brazing. The lower case 11 is formed with four cylindrical portions 12 for connecting fuel injection valves (not shown) so as to be recessed in the fuel delivery pipe 10 at a predetermined interval. Is provided with a hole 12a. A fuel supply pipe 14 to which pressurized fuel from a fuel pump (not shown) is supplied is connected to one end of the upper case 13 by brazing, and two mounting brackets 15 are connected to the lower case 11. It is fixed to the middle of the cylindrical portion 12 by projection welding or the like. In addition, in order to reduce the protrusion amount of the attachment part of the attachment bracket 15, the fuel delivery pipe 10 is provided with the circular-arc-shaped dent in the attachment part. The dimensions of the fuel delivery pipe 10 are, for example, a total length of 300 mm, a width and a height of 28 mm and 27 mm, respectively, and the thicknesses of the lower case 11 and the upper case 13 are 1.2 mm and 1.6 mm, respectively. Both cases 11 and 13 are subjected to nickel plating or the like for rust prevention.

  The metal cylinder 16 has a flat shape with a rectangular cross section of the intermediate portion 16c, and both ends are narrowed toward the tip in the major axis direction, and the tip portions 16a and 16b have a cylindrical shape with a constant cross section. It is a thin metal tube (thickness is 0.3 mm, for example), and the width and length of the metal tube 16 and the height of the intermediate portion 16c and the tip portions 16a and 16b are, for example, 5.5 mm and 305 mm, respectively. 17.9 mm and 9.0 mm. As shown in FIG. 2, the one end portion 16a of the metal tube 16 is sufficiently inserted obliquely from the inside into an opening portion 13a provided on one end surface of the upper case 13 in a single state, so that the entire metal tube 16 is Is placed in the upper case 13, the other end 16b of the metal tube 16 is aligned with the opening 13b provided on the other end surface of the opening 13a of the upper case 13, and the metal tube 16 is moved in the opposite direction. The distal end portion 16b is also inserted into the opening 13b, the distal end portions 16a and 16b on both sides are slightly extended from both end surfaces of the upper case 13 to the outside, and the outer periphery of the metal tube 16 is fixed to the thick portion of the upper case 13 Temporarily assembled by caulking or the like. The upper case 13 temporarily attached with the metal cylinder 16 is placed on the lower case 11 and brazed in the furnace with the fuel supply pipe 14 inserted into the upper case 13, so that the thick part of the upper case 13 is metallized. The outer periphery of the cylinder 16 is fixed in a liquid-tight manner, and the entire fuel delivery assembly is assembled in a liquid-tight manner. As a result, the interior of the fuel delivery pipe 10 is blocked from the atmosphere and the internal space of the metal cylinder 16. In addition, the solder used is, for example, a copper solder, and it is assumed that the solder is placed at a necessary place when brazing. The metal cylinder 16 is also plated with nickel for rust prevention.

  In this fuel delivery assembly, for example, four fuel injection valves (not shown) attached to a four-cylinder engine are used by connecting each cylindrical portion 12 formed in the lower case 11 in a liquid-tight manner via an O-ring or the like. The fuel at a predetermined pressure supplied from the fuel pump to the fuel delivery pipe 10 via the fuel supply pipe 14 is controlled by a control unit (not shown) so that each fuel injection valve is controlled to be opened and closed so as to be in an optimum condition. To be supplied to the engine.

  According to the fuel delivery assembly of the first embodiment described above, the pulsation of the fuel pressure in the fuel delivery pipe 10 caused by opening and closing of the fuel injection valve is caused by the volume of the metal cylinder 16 provided in the fuel delivery pipe 10 being the fuel pressure. Therefore, the fuel injection amount error due to the pulsation of the fuel pressure is reduced, the fuel consumption rate is improved, and vibration and noise are generated in the fuel delivery pipe 10. It will not be. Further, since the metal cylinder 16 that relieves the pulsation of the fuel pressure does not allow the fuel to permeate or deteriorate, there is no possibility that the fuel diverges into the atmosphere or the function deteriorates with time. Further, since the outer circumferences of the tip portions 16a and 16b on both sides of the metal cylinder 16 are liquid-tightly fixed to the openings 13a and 13b of the upper case 13 of the fuel delivery pipe 10, the metal cylinder 16 and the fuel delivery pipe 10 are brazed. After that, the brazed portion can be visually confirmed, and quality control can be easily performed. Further, since the metal tube 16 is a flat thin wall tube having flat both side surfaces, the flat side surface of the metal tube 16 is likely to be dented by the pulsation of the fuel pressure, and the amount of change in volume compared to the volume of the metal tube 16 is increased. growing. Therefore, the degree of relaxation of the pulsation of the fuel pressure is increased, the error of the fuel injection amount is greatly reduced, the fuel consumption rate is improved, and no vibration or noise is generated in the fuel delivery pipe. The metal cylinder 16 that relieves the pulsation of the fuel pressure does not allow gasoline to permeate or deteriorate due to gasoline or the like, so there is no possibility that gasoline or the like will diverge into the atmosphere or the function will deteriorate over time.

  Further, in the above-described embodiment, the lower case 11 and the upper case 13 of the fuel delivery pipe 10 are made of sheet metal having a U-shaped cross section, and the metal cylinder 16 is provided inside and integrally joined liquid-tightly by brazing. A fuel delivery assembly that is lightweight and suitable for mass production is obtained.

  In the first embodiment, the tip portions 16a and 16b on both sides of the metal tube 16 are narrowed toward the tip and have a cylindrical shape with a constant cross-sectional shape. Therefore, the tip portions 16a and 16b on both sides are formed. Can be inserted only into the openings 13a and 13b provided in the upper case 13 of the fuel delivery pipe 10, so that the metal tube 16 and the fuel delivery pipe 10 can be easily aligned, and the gaps in the brazed portion are not uniform. This also reduces brazing defects.

  Since the tip portions 16a and 16b at both ends of the metal tube 16 are open to the outside, the metal tube 16 is not deformed by heating during brazing, and a fuel delivery assembly with no variation in pressure pulsation mitigation performance is obtained. Obtainable.

  In addition, although the intermediate part 16c of the metal cylinder 16 is a flat thin tube, the cross-sectional shape has a rectangular shape and an oval shape. In the case of an oval-shaped metal cylinder, the volume fluctuation amount of the metal cylinder is small because the area of the side plane part excluding the curved part is smaller than that of the rectangular metal cylinder. On the other hand, in the first embodiment, the cross-sectional shape of the intermediate portion 16c of the metal tube 16 is rectangular, and in this way, the side plane portion of the rectangular metal tube 16 is larger than the oval shape. The volume fluctuation amount of the metal cylinder 16 increases. Therefore, the rectangular metal cylinder 16 has higher pressure fluctuation absorption than the oval metal cylinder, and the pressure pulsation mitigating performance is improved. However, the present invention is not limited to this, and the cross-sectional shape of the intermediate portion 16c of the metal tube 16 may be implemented as an oval shape.

  In the above embodiment, the case of a four-cylinder engine has been described. However, the present invention is not limited to this and can be applied to an engine having an arbitrary number of cylinders including a single-cylinder engine.

  Next, the second embodiment shown in FIGS. 4 and 5 will be described. In the second embodiment, the metal tube 16 is a thin metal tube having a constant cross-sectional shape over the entire length, and the tip end portions 16 a are provided at both ends of the upper case 13 and the lower case 11 of the fuel delivery pipe 10. It is brazed and fixed according to each notch part 13a, 11a, and the point which the other side tip part is also brazed and fixed according to the notch part provided in upper case 13 and lower case 11 similarly. Only the embodiment described above is different.

  In the second embodiment, when brazing the tip 16a of the metal tube 16 and the fuel delivery pipe 10, notches 13a provided in the tip 16a, the upper case 13, and the lower case 11, respectively. 11a has to be brazed and fixed, and the metal tube 16 is difficult to match as compared with the first embodiment, which only needs to be matched to the upper case 13, but this difficulty is in both cases 11 and 13. It can be overcome by increasing the accuracy. In addition, since the same effect as 1st Embodiment is acquired except that it is difficult to match | combine the front-end | tip part 16a and the notch parts 13a and 11a, detailed description is abbreviate | omitted.

1 is a partially cutaway plan view showing the structure of a first embodiment of a fuel delivery assembly according to the present invention. 1 is a partially cutaway side view showing the structure of a first embodiment of a fuel delivery assembly according to the present invention. It is an expanded sectional view along the AA line of FIG. It is an expanded sectional view along the BB line of FIG. It is a fragmentary sectional view which shows the principal part of 2nd Embodiment of the fuel delivery assembly by this invention. FIG. 6 is an end view of a second embodiment of a fuel delivery assembly according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel delivery pipe, 11 ... Lower case, 13 Upper case, 16 ... Metal cylinder, 16a ... Tip part, 16b ... Tip part.

Claims (5)

A metal fuel delivery pipe to which a fuel pump is supplied with a predetermined pressure and a plurality of fuel injection valves that are controlled by a control unit to be opened and closed is connected, and the fuel delivery pipe is liquid-tightly provided inside the fuel delivery pipe. In a fuel delivery assembly consisting of a thin metal cylinder whose volume changes according to the pulsation of the internal fuel pressure,
A fuel delivery assembly characterized in that both ends of the metal cylinder are open to the outside of the fuel delivery pipe, and the outer periphery thereof is liquid-tightly fixed to the fuel delivery pipe.   2. The fuel delivery assembly according to claim 1, wherein the metal cylinder is formed flat.   3. The fuel delivery assembly according to claim 1 or 2, wherein each of the fuel delivery pipes is made of sheet metal and has a U-shaped cross-section of a lower case and an upper case facing each other and joined around the entire circumference. A fuel delivery assembly characterized by being integrally joined in a liquid-tight manner by brazing.   4. The fuel delivery assembly according to claim 1, wherein both ends of the metal cylinder are squeezed toward the tip, and the squeezed part is fixed in a liquid-tight manner to the fuel delivery pipe. Fuel delivery assembly. 5. The fuel delivery assembly according to claim 1, wherein a cross-sectional shape of the metal cylinder is a rectangular shape.

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