JP4148861B2 - Fuel delivery pipe - Google Patents

Description

  The present invention relates to a fuel delivery pipe for supplying fuel supplied from a fuel pressurizing pump of an electronic fuel injection type automobile engine to each intake passage of the engine via an injection nozzle. The purpose is to reduce radiated sound.

JP 2000-329030 A JP 2000-320422 A JP 2000-329031 A Japanese Patent Laid-Open No. 11-37380 JP-A-11-2164 JP-A-60-240867

  2. Description of the Related Art Conventionally, there is known a fuel delivery pipe that is provided with a plurality of injection nozzles and supplies fuel such as gasoline to a plurality of cylinders of an engine. This fuel delivery pipe injects fuel introduced from a fuel tank via an underfloor pipe into a plurality of intake pipes or cylinders of an engine sequentially from a plurality of injection nozzles, and mixes this fuel with air. The engine output is generated by burning the fuel.

  This fuel delivery pipe has a return type that has a circuit that returns the extra fuel to the fuel tank by a pressure regulator when extra fuel is supplied from the fuel tank, and a circuit that returns the extra fuel to the fuel tank. There is no returnless type. Recently, returnless fuel delivery pipes are often used for the purpose of reducing costs and preventing an increase in gasoline temperature in a fuel tank.

  This returnless type fuel delivery pipe does not have piping to return excess fuel to the fuel tank, so if the pressure inside the fuel delivery pipe is reduced by fuel injection from the engine intake pipe or the injection nozzle to the cylinder, Pressure waves generated by sudden pressure reduction and stop of fuel injection cause pressure pulsation inside the fuel delivery pipe. This pressure pulsation is propagated from the fuel delivery pipe and the connecting pipe connected to the fuel delivery pipe to the fuel tank side, then reversed and returned from the pressure regulating valve in the fuel tank, and then the fuel delivery pipe is connected via the connecting pipe. Is propagated to. The fuel delivery pipe is provided with a plurality of injection nozzles, and the plurality of injection nozzles sequentially inject fuel to generate pressure pulsation. As a result, the underfloor piping is propagated as noise into the vehicle through the clip that holds the underfloor pipe under the floor, and this noise causes discomfort to the driver and the rider.

  Conventionally, as a method of suppressing such harmful effects caused by pressure pulsation, a pulsation damper containing a rubber diaphragm is placed in a returnless type fuel delivery pipe, and the generated pressure pulsation energy is absorbed by this pulsation damper. If the underfloor pipe located under the floor from the fuel delivery pipe to the fuel tank side is fixed to the underfloor via a vibration absorbing clip, it will occur in the fuel delivery pipe or underfloor pipe to the tank. Absorbing vibration is done. These methods are relatively effective and have the effect of suppressing the adverse effects caused by the occurrence of pressure pulsation.

  In addition, as in the inventions shown in Patent Documents 1 to 6, a fuel delivery pipe having a pulsation absorbing function capable of absorbing pressure pulsations has been proposed for the purpose of reducing pressure pulsations. Fuel delivery pipes with these pressure pulsation absorbing functions form a flexible absorber surface on the outer wall of the fuel delivery pipe, and the pressure generated by fuel injection causes the absorber surface to bend and deform. Absorbs and reduces pulsation, making it possible to prevent the generation of noise due to the vibration of fuel delivery pipes and other parts.

  However, pulsation dampers and vibration-absorbing clips are expensive, increasing the number of parts and increasing costs, and creating new problems in securing installation space. On the other hand, in the prior arts shown in Patent Document 1 to Patent Document 6, there is an effect of absorbing pressure pulsation, but when the injection nozzle is seated on the spool as the injection nozzle opens and closes during fuel injection, etc. There is a possibility that the sound on the high frequency side of several kHz or more is amplified by the absorber surface and radiated to the outside.

The first shot light of the present application to solve the such problem described above, and connect the fuel inlet pipe to the return-less type fuel delivery pipe body return circuit to a fuel tank provided with a jet nozzle is not provided, the fuel In the fuel delivery pipe connected to the fuel tank via the underfloor pipe, at least one wall surface of the fuel delivery pipe body is a flexible absorber wall surface, and faces any one of the absorber wall surfaces. An elastic member with one end connected to the absorber wall surface and the other end connected to the wall surface facing the absorber wall surface is inserted into the fuel delivery pipe main body between the wall surface and the wall surface to be bent. Correspondingly, a damper member that can be elastically deformed and restored is formed.

In the second invention of the present application, a fuel introduction pipe is connected to a return-less type fuel delivery pipe main body provided with an injection nozzle and not provided with a return circuit to the fuel tank, and the fuel introduction pipe is connected to the under floor pipe. In the fuel delivery pipe connected to the fuel tank, at least one wall surface of the fuel delivery pipe body is a flexible absorber wall surface, and the fuel between any one of the absorber wall surfaces and the opposite wall surface. In the delivery pipe body, it is composed of a piston connected to one of the wall surface opposite to the absorber wall surface and a cylinder connected to the other of the wall surface opposite to the absorber wall surface and inserted in such a manner that the piston can be moved forward and backward. A damper member is provided, and the piston can be moved back and forth in this cylinder according to the bending of the wall surface of the absorber. It is obtained by the.

The damper member has a fluid flow interval between the inner periphery of the cylinder and the outer periphery of the piston, and enables communication between the cylinder and the fuel delivery pipe body through the flow interval. Also good.

  Further, the cylinder may open an orifice on the side opposite to the piston, which enables a small amount of fuel to flow between the cylinder and the fuel delivery pipe body.

Further , the damper member allows the piston to be moved forward and backward by inserting the piston into the cylinder in a liquid-tight manner through an insertion port and interposing a fluid flow interval between the inner periphery of the cylinder and the outer periphery of the piston. In addition, the inside of the cylinder and the fuel delivery pipe main body may be formed so as not to communicate with each other.

The first and second rounds light of the present application which was constructed as described above, not only the good absorption effect of the pressure pulsation is obtained by deforming deflection Absorb wall, damper with the bending deformation of the Absorb wall The elastic expansion and contraction of the member suppresses the bending deformation of the absorber wall surface due to the high frequency pulsation. As a result, it is possible to suppress radiation of high-frequency sound such as a ticking sound when the injection nozzle is seated on the spool to the outside. Moreover, compared to the case where a pulsation damper or a vibration absorbing clip is used outside the fuel delivery pipe, the manufacturing cost can be reduced, and the fuel delivery pipe and the underfloor piping are not bulky. The pipe can be installed even in a limited space, and the layout is highly flexible.

  In the first invention of the present application, an elastic member having one end connected to the absorber wall surface and the other end connected to the wall surface opposite to the absorber wall surface is inserted, and the damper member is formed by this elastic member. The member can be formed at a low cost, and the cost of the fuel delivery pipe can be reduced. Further, the second invention of the present application, in the fuel delivery pipe body, is connected to either one of the absorber wall surface and the opposite wall surface, connected to the other of the absorber wall surface and the opposite wall surface, the piston Since a damper member composed of a cylinder inserted so as to be able to move forward and backward is provided, a desired high-frequency sound radiation preventing effect can be obtained as the piston of the damper member moves forward and backward.

Example 1 which is the first invention of the present application will be described in detail with reference to FIG. 1. (1) is a fuel delivery pipe main body, which is composed of a pair of straight wall surfaces (2) and a pair of straight wall surfaces (2). It is comprised with a pair of circular arc-shaped wall surface (3) which connects both ends. In addition, although the cross-sectional shape of the circumferential direction of the fuel delivery pipe main body (1) of Example 1 is not shown in figure, it is the circumferential direction similarly to the fuel delivery pipe main body (1) shown in FIG. This is a flat tube having an oval cross-sectional shape. In addition, a plurality of sockets (4) that can connect the injection nozzle (9) to one straight wall surface (2) are provided. For example, in the case of a three-cylinder engine, as shown in FIG. (4) is provided at a desired interval and angle.

  The fuel delivery pipe body (1) is connected to a fuel introduction pipe (5) at one end, and the fuel introduction pipe (5) is connected to a fuel tank (not shown) via an underfloor pipe (not shown). It is connected. The fuel in the fuel tank is transferred to the fuel introduction pipe (5) through the underfloor pipe, flows from the fuel introduction pipe (5) to the fuel delivery pipe body (1), and is connected to the socket (4). The fuel is directly injected into the intake passage or the cylinder of the engine through the nozzle (9). The fuel delivery pipe main body (1) is provided with a bracket (not shown) for connecting and fixing the fuel delivery pipe main body (1) to the engine main body on the mounting side of the socket (4).

  The other straight wall surface (2) not provided with the socket (4) is formed so as to be able to bend and deform by the pulsation of the fluid, thereby forming an elastic wall surface (6) having flexibility. Further, two damper members (7) are disposed between the absorber wall surface (6) in the fuel delivery pipe main body (1) and the one straight wall surface (2) opposed to the absorber wall surface (6). The damper member (7) is an elastic member formed of a rubber piece (8), one end of which is connected and fixed to the absorber wall surface (6) by connecting means such as an oil-resistant adhesive, and the other end is connected to one straight wall surface ( Connected to 2). Since the rubber piece (8) is used in this way, the damper member (7) can be formed at a low cost, and the cost of the fuel delivery pipe can be reduced.

  In the fuel delivery pipe as described above, the inside of the fuel delivery pipe body (1) is suddenly depressurized by the fuel injection from the injection nozzle (9) to the intake pipe or cylinder of the engine, or the pressure wave is generated by stopping the fuel injection. When pressure pulsation occurs inside the fuel delivery pipe body (1), the pressure pulsation is absorbed by the deformation of the absorber wall (6) to change its internal volume. Propagation is suppressed.

  On the other hand, when a high frequency pulsation of several kHz or more, such as a ticking sound generated when the injection nozzle (9) is seated on the spool after fuel injection, the absorber wall (6) tries to bend in resonance with the high frequency pulsation. Then, the damper member (7) having a frequency different from the high-frequency pulsation frequency absorbs the pulsation energy while elastically repeating contraction deformation and restoration, and supports the vibration absorption of the absorber wall surface (6). The bending deformation of the absorber wall surface (6) at the frequency is suppressed. For this reason, it is possible to suppress radiation (speaker phenomenon) of high-frequency sound to the outside.

As the first embodiment the damper member (7), although disposed rubber piece (8) is an elastic member, FIG. 2, the actual施例2 is the second invention in FIG. 3 shows the be present, Two damper members (7) comprising a cylinder (10) and a piston (11) inserted into the cylinder (10) so as to be able to advance and retract are disposed. The cylinder (10) and the piston (11) are both made of a resin material, a corrosion-resistant metal, etc., and formed into a cylindrical shape and a cylindrical shape, respectively, and the cylinder (10 ) Is connected and fixed to one straight wall surface (2) provided with the socket (4), and one end of the piston (11) is connected and fixed to the absorber wall surface (6).

  The other end of the piston (11) is inserted and disposed in the cylinder (10) through the insertion port (14) on the other end of the cylinder (10) so as to be able to move forward and backward. A small flow interval (12) in which the inner diameter is slightly larger than the outer diameter of the piston (11), and the fuel flows between the inner peripheral surface of the cylinder (10) and the outer peripheral surface of the piston (11). Is provided. Furthermore, the inside of the cylinder (10) communicates with the inside of the fuel delivery pipe main body (1) through this flow interval (12), allowing fuel to enter and exit from the cylinder (10), and by the hydraulic pressure. The resistance to the piston (11) is increased to greatly suppress the forward / backward movement of the piston (11).

  Further, as shown in FIG. 3, if a tubular orifice (13) that allows a small amount of fuel to flow is provided on the wall surface at one end of the cylinder (10), the piston (11) moves forward and backward. The fuel enters and exits the cylinder (10) also through the orifice (13). By adjusting the flow resistance of the fuel in the cylinder (10) by adjusting the flow interval (12) and the orifice (13), the vibration frequency of the damper member (7) due to the forward and backward movement of the piston (11) can be adjusted. Thus, the fuel delivery pipe body (1) having the desired high frequency sound radiation preventing effect can be formed.

  In the second embodiment, the circular tubular orifice (13) is provided on the wall surface of the cylinder (10). However, in the third embodiment shown in FIG. 4, the edge on one end side of the cylinder (10) is cut into a V shape. The opening and the straight wall surface (2) form a triangular orifice (13). The cylinder (10) and the piston (11) are respectively formed in a cylindrical shape and a columnar shape as in the second embodiment, and between the inner peripheral surface of the cylinder (10) and the outer peripheral surface of the piston (11). In addition, a minute flow interval (12) through which fuel flows is provided. Even with the orifice (13) as in the third embodiment, it is possible to control the flow resistance of the fuel into the cylinder (10). Furthermore, the orifice (13) can be formed only by cutting out the edge on one end side of the cylinder (10) into a V shape, and a fine tubular orifice (13) is formed on the wall surface of the cylinder (10) as in the second embodiment. ) Can be easily formed with simple manufacturing technology, and the size of the orifice (13) can be easily adjusted, thereby reducing the manufacturing cost of the damper member (7). Can be lowered.

  In the second and third embodiments, the inside of the cylinder (10) and the fuel delivery pipe body (1) can be communicated with each other via the flow interval (12). In the fourth embodiment shown in FIG. The inside of the cylinder (10) is not in communication with the inside of the fuel delivery pipe body (1). First, the outer diameter of the cylindrical piston (11) mounted in the cylinder (10) is made slightly smaller than the inner diameter of the cylinder (10), and the inner peripheral surface of the cylinder (10) and the piston (11 ) Is formed between the outer peripheral surface and the outer peripheral surface of the). Further, the piston rod (15) is liquid-tightly protruded from the insertion port (14) provided on the wall surface (16) on one end side of the cylinder (10) via the O-ring (17), and the protruding piston rod (15 ) Is connected and fixed to the absorber wall surface (6) of the fuel delivery pipe body (1). The bottom (18) on the other end side of the cylinder (10) is connected and fixed to one straight wall surface (2) of the fuel delivery pipe main body (1).

  A fluid such as silicon oil is sealed in the cylinder (10). The silicon oil passes through a minute flow interval (12) formed between the cylinder (10) and the piston (11), and then the one end side and the other end side of the cylinder (10) through the piston (11). Therefore, the forward / backward movement of the piston (11) in the cylinder (10) can be suppressed. In addition, by changing the viscosity of the fluid sealed in the cylinder (10) and the surface area of the piston (11), the hydraulic pressure to the piston (11) is changed and the elastic force of the damper member (7) is arbitrarily controlled. Thus, it is possible to obtain the desired high-frequency sound silencing effect.

In Example 1, power spring elastic member used as a damper member (7), had a rubber piece (8), the actual施例5 of the first aspect of the shown to present 6, as the elastic member, preferably Uses the activated firing (20). One end of the energized strip (20) is connected and fixed to the absorber wall (6) by adhesive, brazing, welding or the like, and the other end of the strip (20) is connected and fixed to one straight wall (2). ing. Even in the case of such a damper member (7), the bending of the absorber wall surface (6) with respect to the high-frequency sound can be suppressed, the sound radiation to the outside can be reduced, and inexpensive implementation is possible.

  In each of the above embodiments, the fuel delivery pipe body (1) is formed by a flat tube having an oval cross-sectional shape. However, as another different embodiment, the cross-sectional shape is an oval, a rectangular tube or the like. The fuel delivery pipe body (1) may be formed. In Examples 2 to 4, the piston (11) is connected and fixed to the absorber wall surface (6), and the cylinder (10) is connected and fixed to one straight wall surface (2). ) And the cylinder (10) may be connected and fixed, and the piston (11) may be connected and fixed to one straight wall surface (2). In the second and third embodiments, the cylinder (10) and the piston (11) are formed in a cylindrical shape and a cylindrical shape, but may be formed in a polygonal cylindrical shape and a prism shape. In the fourth embodiment, the piston (11) is a cylinder, but may be a prism. Further, by appropriately adjusting the elastic force of the damper member (7), it is possible to suppress the bending of the absorber wall surface (6) with respect to a desired high-frequency pulsation, and to reduce the radiation of noise accompanying the high-frequency pulsation to the outside. it can.

Sectional view of the fuel delivery pipe of the actual Example 1 showing the first invention of the present application. Sectional view of the fuel delivery pipe of the real施例2 showing a second aspect of the present invention. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. Sectional view of the fuel delivery pipe of the real施例3 showing a second aspect of the present invention. Partially enlarged sectional view of the fuel delivery pipe of the real施例4 showing a second aspect of the present invention. Partially enlarged sectional view of the fuel delivery pipe of the real施例5 showing a first invention of the present application.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel delivery pipe main body 5 Fuel introduction pipe 6 Absorber wall surface 7 Damper member 8 Rubber piece (elastic member of this invention)
9 Injection nozzle 10 Cylinder 11 Piston 12 Flow interval 13 Orifice
14 Insertion Port 20 Energized Strip (Elastic Member of the Present Invention)

Claims (5)

A fuel delivery pipe connected to a fuel tank via an underfloor pipe and a fuel introduction pipe connected to a returnless type fuel delivery pipe main body provided with an injection nozzle and not provided with a return circuit to the fuel tank In this case, at least one wall surface of the fuel delivery pipe body is a flexible absorber wall surface, and one end of the fuel delivery pipe body is disposed between the one of the absorber wall surfaces and the opposite wall surface in the fuel delivery pipe body. An elastic member connected to the wall surface and having the other end connected to the wall surface facing the absorber wall surface is inserted, and this elastic member forms a damper member that can be elastically deformed and restored in response to the bending of the absorber wall surface. A fuel delivery pipe characterized by A fuel delivery pipe connected to a fuel tank via an underfloor pipe and a fuel introduction pipe connected to the body of a returnless type fuel delivery pipe with an injection nozzle and no return circuit to the fuel tank In this case, at least one wall surface of the fuel delivery pipe body is a flexible absorber wall surface, and there is an absorber wall surface in the fuel delivery pipe body between any one of the absorber wall surfaces and the opposite wall surface. A damper member comprising a piston connected to one of the opposite wall surfaces, and an absorber wall surface and a cylinder connected to the other of the opposite wall surfaces and inserted in such a manner that the piston can be moved back and forth is provided. The piston is capable of advancing and retracting in response to the bending of the absorber wall surface. Over El delivery pipe. The damper member is characterized in that a fluid flow interval is interposed between the inner periphery of the cylinder and the outer periphery of the piston, and the cylinder and the fuel delivery pipe main body can be communicated with each other through the flow interval. Item 2. Fuel delivery pipe. 4. The fuel delivery pipe according to claim 3, wherein the cylinder has an orifice that allows a small amount of fuel to flow between the cylinder and the fuel delivery pipe main body on the side opposite to the piston. The damper member inserts the piston into the cylinder in a liquid-tight manner through the insertion port, and allows the piston to move forward and backward by interposing a fluid flow interval between the inner periphery of the cylinder and the outer periphery of the piston. 3. The fuel delivery pipe according to claim 2, wherein the cylinder and the fuel delivery pipe main body are formed in a non-communication manner.

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