Vehicular high-pressure fuel piping device

Abstract

To prevent corrosion of high-pressure fuel piping while exhibiting sound absorption performance by using an insulator.SOLUTION: A vehicular high-pressure fuel piping device 33 includes a vehicular high-pressure fuel piping structure 24 and a connection wire system 34. The vehicular high-pressure fuel piping structure 24 includes high-pressure fuel piping 30, an insulator 31 and an electrode 32. The connection wire system 34 includes a connection wire 35 and a DC power source 36. A circuit formed by the connection wire system 34 becomes an open circuit while the insulator 31 does not retain moisture and becomes a closed circuit while the insulator 31 retains moisture. The vehicular high-pressure fuel piping device 33 absorbs pulsation noise of the high-pressure fuel piping 30 by using the insulator 31, and enables electrolytic protection of the high-pressure fuel piping 30 by using the electrode 32 together with the connection wire system 34.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a high-pressure fuel piping device for a vehicle. [Background technology]

[0002] Known examples of conventional engine covers and soundproofing structures for engines include the structure described in Patent Document 1. The engine cover is made of a laminated structure in which an outer sound-insulating layer having sound-insulating properties and an inner sound-absorbing layer made of a foam molded body are laminated together, and is attached to cover at least a portion of the engine on which noise-generating equipment protrudes.

[0003] Another known conventional anticorrosion system is the system described in Patent Document 2. Guy rods and anchors buried underground are supplied with anticorrosion current generated by solar cells or commercial power over a long period of time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-207593 [Patent Document 2] International Publication No. 2022 / 180731 Summary of the Invention [Problem to be solved by the invention]

[0005] High-pressure fuel pipes are also required to have a soundproof structure and are sometimes wrapped in insulators. Insulators wrapped around high-pressure fuel pipes tend to absorb moisture in wet surrounding environments and retain it for long periods of time. Moisture retained by the insulators over long periods of time may come into contact with the high-pressure fuel pipe and cause corrosion.

[0006] The present invention has been made in view of the above circumstances, and relates to a high-pressure fuel piping device for a vehicle that prevents corrosion of the high-pressure fuel piping while providing sound absorption performance through an insulator. [Means for solving the problem]

[0007] The high-pressure fuel piping device for a vehicle of the present invention is a high-pressure fuel piping device for a vehicle that is installed in a vehicle, and is characterized by comprising: an insulator made of an open-cell molded product; a high-pressure fuel piping covered by the insulator; an electrode provided within the insulator with a predetermined gap between it and the high-pressure fuel piping; and a connecting wire that electrically connects the high-pressure fuel piping and the electrode. [Effects of the Invention]

[0008] A high-pressure fuel piping device for a vehicle according to one embodiment of the present invention prevents corrosion of the high-pressure fuel piping while providing sound absorption performance due to the insulator. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view illustrating a vehicle equipped with a fuel piping system including a high-pressure fuel piping for a vehicle according to an embodiment of the present invention; [Figure 2] 1 is a plan view illustrating an overview of an engine room in which a high-pressure fuel pipe for a vehicle according to an embodiment of the present invention is arranged; [Figure 3] 3 is a schematic diagram illustrating a high-pressure fuel piping device for a vehicle according to one embodiment of the present invention, using a cross section taken along line AA of the high-pressure fuel piping for a vehicle in FIG. 2. FIG. [Figure 4] 1 is a schematic diagram illustrating a high-pressure fuel pipe device for a vehicle according to an embodiment of the present invention, using a cross section in the longitudinal direction of the high-pressure fuel pipe for a vehicle; [Figure 5] FIG. 2 is a cross-sectional view illustrating the cell structure of an open-cell molded article according to one embodiment of the present invention. [Figure 6] 1 is a cross-sectional view illustrating the sound absorbing and corrosion preventing effects of a high-pressure fuel piping device for a vehicle according to an embodiment of the present invention. [Figure 7]FIG. 3 is a schematic view illustrating a high-pressure fuel piping device for a vehicle according to an embodiment of the present invention, which is a first modified example, using a cross section taken along line AA in FIG. 2. [Figure 8] FIG. 3 is a schematic view illustrating a high-pressure fuel piping device for a vehicle according to an embodiment of the present invention, which is a second modified example, using a cross section taken along line AA in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a high-pressure fuel piping system 33, 38, 42 for a vehicle according to one embodiment of the present invention will be described in detail with reference to the drawings. In the description of this embodiment, the same components will generally be designated by the same reference numerals, and repeated description will be omitted. In the following description, the up-down direction will be referred to as the height direction of the vehicle, the left-right direction will be referred to as the width direction of the vehicle, and the front-rear direction will be referred to as the length direction of the vehicle.

[0011] First, a vehicle 10 equipped with a vehicle high-pressure fuel piping device 33, 38, 42 will be described with reference to Figure 1. The vehicle high-pressure fuel piping device 33, 38, 42 prevents corrosion of the high-pressure fuel piping while exhibiting the sound-absorbing performance of the vehicle high-pressure fuel piping structure 24, 25 included in the fuel piping system 20. Figure 1 is a diagram showing an example of a vehicle 10 equipped with a fuel piping system 20 including the vehicle high-pressure fuel piping structure 24, 25 of the embodiment.

[0012] The vehicle 10 is equipped with an engine 11 and includes a fuel tank 12 and a fuel piping system 20 that supplies fuel from the fuel tank 12 to the engine 11. The vehicle 10 also includes a radiator 13 for cooling the engine 11. The vehicle 10 also has a grill opening 14 for drawing airflow into the radiator 13. The area around the engine 11 may be subject to water that enters from the grill opening 14 or from below the vehicle 10 due to rainfall, car washing, water splashes, etc., and may also be subject to condensation depending on the environment. A portion of the fuel piping system 20 is disposed around the engine 11 and is therefore in an environment exposed to water, and therefore the fuel piping is made of steel and is subjected to anti-rust treatment such as galvanization.

[0013] The vehicle 10 is an all-wheel drive vehicle, but may be a front-wheel drive vehicle or a rear-wheel drive vehicle. The engine 11 is a horizontally opposed engine, but may be an in-line engine, a V-engine, a rotary engine, or the like. The fuel piping system 20 supplies gasoline as fuel from the fuel tank 12 to the engine 11, but may also supply other fuels such as diesel.

[0014] Next, an overview of the inside of the engine room 15 in which the high-pressure fuel piping structures 24, 25 for a vehicle are arranged will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of an overview of the inside of the engine room 15 in which the high-pressure fuel piping structures 24, 25 for a vehicle according to the embodiment are arranged.

[0015] 2 shows a bird's-eye view of the engine compartment 15 from above the vehicle 10. The engine compartment 15 accommodates the engine 11, the radiator 13, and the fuel piping system 20, as well as a battery 16. The battery 16 is charged by an alternator (not shown), and is capable of supplying power to various electrical components.

[0016] The fuel piping system 20 includes a fuel hose 21 , a fuel pump 22 , high-pressure fuel piping structures 24 and 25 for a vehicle, delivery pipes 26 and 27 , a relief valve 28 , and a return pipe 29 .

[0017] Fuel hose 21 supplies fuel supplied from a feed pump (low-pressure fuel pump) in fuel tank 12 to fuel pump 22. Fuel hose 21 is connected to the intake port of fuel pump 22. Fuel hose 21 is one of the components constituting a low-pressure fuel system that sends fuel discharged from the feed pump to fuel pump 22.

[0018] Fuel pump 22 draws fuel through fuel hose 21 and creates high pressure in vehicle high-pressure fuel piping structures 24, 25 and delivery pipes 26, 27. Vehicle high-pressure fuel piping structure 24 connects the discharge port of fuel pump 22 to delivery pipe 26 provided on an upper part of a cylinder head on the left side in the vehicle width direction of engine 11, and sends fuel discharged from fuel pump 22 to delivery pipe 26. Vehicle high-pressure fuel piping structure 25 connects delivery pipe 26 to delivery pipe 27 provided on an upper part of a cylinder head on the right side in the vehicle width direction of engine 11.

[0019] Delivery pipe 26 supplies fuel to injectors that inject fuel into combustion chambers of engine 11. Delivery pipe 27 supplies fuel to injectors that inject fuel into combustion chambers of engine 11. Delivery pipe 27 is connected to return pipe 29 via relief valve 28. Return pipe 29 returns fuel to fuel tank 12 when excessive pressure is released by relief valve 28. High-pressure fuel piping structures 24, 25 for a vehicle and delivery pipes 26, 27 are components that make up a high-pressure fuel system that sends fuel discharged by fuel pump 22 to the injectors.

[0020] The high-pressure fuel piping structures 24, 25 for a vehicle may generate pulsating noise when delivering high-pressure fuel. The pulsating noise may be caused by the fuel pump 22, the injector, or both. Because the high-pressure fuel piping structures 24, 25 for a vehicle are located near the engine 11, they are exposed to a water-damaged environment where there is a risk of perforation due to corrosion. The high-pressure fuel piping structures 24, 25 for a vehicle have a soundproofing structure that covers the piping with an insulator 31 (described later), as well as the corrosion-preventing properties of the electrodes 32, 44 embedded in the insulator 31, which reduce the risk of perforation due to corrosion even in a water-damaged environment, thereby making it possible to suppress the pulsating noise.

[0021] Next, the configuration of the high-pressure fuel piping device 33 for a vehicle will be described with reference to Figures 3 and 4. The open-cell urethane foam 31A constituting the insulator 31 will be described with reference to Figure 5. Figure 3 is a schematic diagram of the high-pressure fuel piping structure 24 for a vehicle in Figure 2, taken along the line AA, showing an example of the configuration of the high-pressure fuel piping device 33 for a vehicle according to an embodiment. Figure 4 is a schematic diagram of the high-pressure fuel piping structure 24 in the longitudinal direction, showing an example of the configuration of the high-pressure fuel piping device 33 for a vehicle according to an embodiment. Figure 5 is a diagram showing an example of the cell structure of the open-cell urethane foam 31A for an embodiment. Note that the high-pressure fuel piping structure 25 for a vehicle can also be used as a component of the high-pressure fuel piping device 33 for a vehicle in the same manner as the high-pressure fuel piping structure 24 for a vehicle.

[0022] 3, the high-pressure fuel piping device 33 for a vehicle includes the high-pressure fuel piping structure 24 for a vehicle and a connecting line system 34. The high-pressure fuel piping structure 24 for a vehicle includes a high-pressure fuel pipe 30, an insulator 31, and an electrode 32. The connecting line system 34 includes a connection line 35 and a DC power supply 36. The high-pressure fuel piping device 33 for a vehicle uses the insulator 31 to absorb pulsating noise from the high-pressure fuel pipe 30, and the electrode 32, together with the connecting line system 34, enables cathodic protection of the high-pressure fuel pipe 30.

[0023] The high-pressure fuel pipe 30 is a pipe with a circular cross section, as shown by the cross-hatched area, that has been treated with a metal coating for rust prevention. For example, the high-pressure fuel pipe 30 is a steel pipe that has been treated with a rust prevention treatment such as zinc plating. The insulator 31 is an open-cell molded body made of an insulating material, and has a U-shaped cross section, as shown by the cross-hatched area. The electrode 32 is a refractory electrode used for cathodic protection, and is cylindrical, as shown by the dark hatched area.

[0024] The insulator 31 has a recess with a U-shaped cross section, into which the high-pressure fuel pipe 30 is inserted. In other words, the high-pressure fuel pipe 30 is covered in the longitudinal direction by the insulator 31 with a U-shaped cross section. The electrode 32 is provided in the longitudinal direction of the high-pressure fuel pipe 30, similar to the insulator 31. The electrode 32 may be embedded in the insulator 31 during molding, or may be inserted into the insulator 31 after molding.

[0025] The insulator 31 is an open-cell molded body made of an insulating material. The insulator 31 is made of, for example, an open-cell urethane foam 31A as an open-cell molded body. When the vehicle high-pressure fuel piping structure 24 is placed on the vehicle 10, the insulator 31 is disposed so that the open end of the U-shaped cross section faces downward.

[0026] The open-cell urethane foam 31A is an example of an open-cell molded article made from urethane or polyurethane, but may be made from styrene or polystyrene instead of urethane, or may be made from other raw materials such as resin or rubber. Note that the term "open cell" may also be referred to as "open foam."

[0027] The open-cell urethane foam 31A has an open-cell structure 31B in which multiple cells are interconnected. The open-cell structure 31B allows fluids such as air and water to easily enter and exit the open-cell urethane foam 31A. The open-cell urethane foam 31A has excellent sound-absorbing properties because sound waves have many opportunities to be attenuated as they propagate through the open-cell structure 31B. The excellent sound-absorbing properties of the open-cell urethane foam 31A absorb pulsating noise originating from the high-pressure fuel pipe 30, contributing to improved quietness of the vehicle 10.

[0028] As a result, the high-pressure fuel piping structure 24 for a vehicle can improve the quietness of the vehicle 10 by absorbing the pulsating noise of the high-pressure fuel piping 30 with the open-cell urethane foam 31A.

[0029] The connection line system 34 electrically connects the high-pressure fuel pipe 30 and the electrode 32 via a connection line 35, and enables a constant voltage to be applied between the high-pressure fuel pipe 30 and the electrode 32 by a DC power supply 36. The connection line 35 connects the high-pressure fuel pipe 30 and the electrode 32 at one longitudinal end of the insulator 31. The connection line 35 is an electric wire in which a conductor is covered with an insulator, and is, for example, a single-core wiring wire.

[0030] The electrode 32 is located above the high-pressure fuel pipe 30 and is provided within the insulator 31 with a predetermined gap between it and the high-pressure fuel pipe 30. The electrode 32 is a refractory electrode used for corrosion protection using an external power source. The electrode 32 acts as an auxiliary electrode for passing a current that cancels out the corrosion protection current. The electrode 32 is made of a metal having a higher potential than the metal coating of the high-pressure fuel pipe 30. For example, the electrode 32 can be a refractory electrode such as a metal oxide-coated electrode, a high-silicon cast iron electrode, or a platinum-plated gold electrode.

[0031] The DC power supply 36 is a power source for the circuit formed by the connection line system 34. The DC power supply 36 outputs a constant voltage with the electrode 32 as the anode and the high-pressure fuel pipe 30 as the cathode, and can apply a voltage so that the equilibrium potential of the metal coating or base metal of the high-pressure fuel pipe 30 is lower than the corrosion protection potential. For example, the DC power supply 36 can use the battery 16 as the power source supplied by the vehicle 10. The DC power supply 36 may directly input the voltage of the battery 16, or may include a circuit for stepping down the voltage, or may input a voltage that is increased or decreased by a certain amount. The DC power supply 36 may always input the voltage of the battery 16, or may input the voltage as needed while the vehicle 10 is in operation or under predetermined control. The DC power supply 36 may also use a primary battery or a secondary battery as its power source.

[0032] As described above, the circuit formed by the connecting wire system 34 is an open circuit because the insulator 31 is made of an insulating material. However, the open-cell structure 31B of the insulator 31 has excellent water retention properties, and therefore can form a conductive path in the open-cell urethane foam 31A that has been exposed to a wet environment and has absorbed moisture. In other words, the circuit formed by the connecting wire system 34 is an open circuit when the insulator 31 does not retain moisture, and is a closed circuit when the insulator 31 retains moisture.

[0033] The high-pressure fuel piping device 33 for a vehicle can insulate noise from the high-pressure fuel piping 30, which is a noise source, by the excellent sound-absorbing performance of the insulator 31. The open-cell structure 31B that realizes the excellent sound-absorbing performance of the insulator 31 also has water-retaining properties, so there is a risk that the high-pressure fuel piping 30 will be exposed to a water-soaked environment for a long period of time. The high-pressure fuel piping device 33 for a vehicle prevents corrosion of the high-pressure fuel piping 30 by cathodic protection made possible by the water-retaining properties of the open-cell structure 31B.

[0034] In this way, the high-pressure fuel piping device 33 for a vehicle can prevent corrosion of the high-pressure fuel piping 30 while exhibiting the sound absorbing performance of the insulator 31. Furthermore, by using a hardly soluble electrode as the electrode 32, the high-pressure fuel piping device 33 for a vehicle can prevent electrode wear and contamination of the insulator 31 due to electrode wear, thereby reducing long-term maintenance costs.

[0035] Next, the sound absorbing and anti-corrosion effects of the vehicle high-pressure fuel piping device 33 will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of a sound absorbing mechanism and an anti-corrosion mechanism of the vehicle high-pressure fuel piping structure 24 according to the embodiment. Note that solid arrows in Fig. 6 indicate sound propagation or air vibration, and dashed arrows indicate water flow.

[0036] The vehicle high-pressure fuel piping structure 24 achieves high sound absorption performance by covering the high-pressure fuel piping 30 with the insulator 31, thereby enabling the reduction of noise emitted by the high-pressure fuel piping 30. The insulator 31 allows water to flow down along its surface, but also allows some of the water to penetrate into the insulator 31. Water that penetrates from above the insulator 31 flows down through the open-cell urethane foam 31A due to gravity and is retained on the periphery of the high-pressure fuel piping 30. The water retained on the periphery of the high-pressure fuel piping 30 can form a conductive path between the electrode 32 located above the high-pressure fuel piping 30 and the electrode 32.

[0037] As a result, in the vehicle high-pressure fuel piping device 33, when the insulator 31 is in a moisture-retaining state, a closed circuit including the DC power supply 36, the high-pressure fuel piping 30, and the electrode 32 is formed, thereby providing corrosion protection for the high-pressure fuel piping 30. As a result, the vehicle high-pressure fuel piping device 33 can prevent corrosion of the high-pressure fuel piping 30 while providing sound absorption performance through the insulator 31.

[0038] Since the insulator 31 allows water to flow down along its surface, more water permeates from the top than from the sides. The water that permeates from the top is easily retained between the high-pressure fuel pipe 30 and the electrode 32 above the high-pressure fuel pipe 30. The electrode 32 above the high-pressure fuel pipe 30 facilitates the formation of a conductive path between the high-pressure fuel pipe 30 and the electrode 32 in a water-soaked environment.

[0039] The cylindrical shape of electrode 32 allows water that has permeated from above to flow downward from the sides, thereby contributing to the formation of a conductive path in a water-exposed environment. Although one electrode 32 is provided, two or more electrodes may be provided. While electrode 32 has been described as cylindrical, it may also be flat, arc-shaped, or the like.

[0040] Although the high-pressure fuel piping structure 24 for a vehicle allows water that has fallen on the insulator 31 to flow down along the surface, there is a risk that some of the water may seep in laterally. Water seeping in from the side does not contribute to the formation of a conductive path between the electrode 32 and the high-pressure fuel piping 30. Water that seeps in from the side of the insulator 31 flows down inside the open-cell urethane foam 31A due to gravity and flows down from the lower end. Therefore, this high-pressure fuel piping structure 24 for a vehicle quickly removes water that does not contribute to the corrosion prevention function of the high-pressure fuel piping 30, making it possible to prevent corrosion of the high-pressure fuel piping 30.

[0041] Furthermore, the lower end of open-cell urethane foam 31A extends downward below the lower surface of high-pressure fuel pipe 30. This prevents water flowing down from the end of open-cell urethane foam 31A from contacting high-pressure fuel pipe 30 in vehicle high-pressure fuel pipe structure 24.

[0042] Next, a high-pressure fuel piping device 38 for a vehicle, which is a first modified example of the high-pressure fuel piping device 33 for a vehicle, will be described with reference to Fig. 7. Fig. 7 is a schematic diagram using the AA cross section of the high-pressure fuel piping structure 24 for a vehicle in Fig. 2, and shows an example of the configuration of the high-pressure fuel piping device 38 for a vehicle.

[0043] The vehicle high-pressure fuel piping device 38 shares the vehicle high-pressure fuel piping structure 24 with the vehicle high-pressure fuel piping device 33. The vehicle high-pressure fuel piping device 38 has a connection line system 39 instead of the connection line system 34 of the vehicle high-pressure fuel piping device 33. Therefore, a description of the vehicle high-pressure fuel piping structure 24 in the vehicle high-pressure fuel piping device 38 will be omitted.

[0044] The connection line system 39 electrically connects the high-pressure fuel pipe 30 and the electrode 32 via a connection line 40, and enables a voltage to be applied between the high-pressure fuel pipe 30 and the electrode 32 using a DC power supply 41. The connection line 40 connects the high-pressure fuel pipe 30 and the electrode 32 at one end in the longitudinal direction of the insulator 31. The connection line 40 is an electric wire in which a conductor is covered with an insulator, and is, for example, a single-core wiring wire.

[0045] DC power supply 41 is a power source for the circuit formed by connection line system 39. DC power supply 41 outputs a constant voltage with electrode 32 as the anode and high-pressure fuel pipe 30 as the cathode. DC power supply 41 transforms the voltage output by piezoelectric element P1 using transformer T1, full-wave rectifies the voltage using bridge diode BD1 consisting of diodes D1, D2, D3, and D4, and outputs a voltage that is smoothed by capacitor C1.

[0046] The piezoelectric element P1 enables power to be supplied from vibrations generated inside the vehicle. The piezoelectric element P1 converts sounds and vibrations in the engine compartment 15 into voltage. The sounds and vibrations in the engine compartment 15 may be sounds and vibrations based on pulsation in the high-pressure fuel pipe 30, operating sounds and vibrations of the engine 11, or running sounds and vibrations of the vehicle 10. The sounds and vibrations in the engine compartment 15 may also be sounds and vibrations based on wind drawn in through the grill opening 14.

[0047] Such a high-pressure fuel piping system 38 for a vehicle does not rely on an external power source. Furthermore, the high-pressure fuel piping system 38 for a vehicle can omit wiring to the battery 16 and contributes to reducing the load on the battery 16.

[0048] As described above, the circuit formed by the connection line system 39 is an open circuit when the insulator 31 does not retain moisture, and is a closed circuit when the insulator 31 retains moisture.

[0049] The high-pressure fuel piping device 38 for a vehicle can insulate noise from the high-pressure fuel piping 30, which is a noise source, by the excellent sound absorption performance of the insulator 31. The high-pressure fuel piping device 38 for a vehicle prevents corrosion of the high-pressure fuel piping 30 by cathodic protection made possible by the water retention performance of the open-cell structure 31B.

[0050] In this way, the high-pressure fuel piping device 38 for a vehicle can prevent corrosion of the high-pressure fuel piping 30 while exhibiting the sound absorbing performance of the insulator 31. Furthermore, by using a hardly soluble electrode as the electrode 32, the high-pressure fuel piping device 38 for a vehicle can prevent electrode wear and contamination of the insulator 31 due to electrode wear, thereby reducing long-term maintenance costs.

[0051] Next, a high-pressure fuel piping device 42 for a vehicle, which is a second modified example of the high-pressure fuel piping device 33 for a vehicle, will be described with reference to Fig. 8. Fig. 8 is a schematic diagram using the AA cross section of the high-pressure fuel piping structure 24 for a vehicle in Fig. 2, and shows an example of the configuration of the high-pressure fuel piping device 42 for a vehicle.

[0052] The high-pressure fuel piping device 42 for a vehicle includes a high-pressure fuel piping structure 43 for a vehicle and a connecting line system 45. The high-pressure fuel piping structure 43 for a vehicle includes a high-pressure fuel piping 30, an insulator 31, and an electrode 44. The high-pressure fuel piping 30 and the insulator 31 are similar to those in the high-pressure fuel piping structure 24 for a vehicle, and therefore a description thereof will be omitted. Note that the high-pressure fuel piping device 42 for a vehicle has the high-pressure fuel piping structure 43 for a vehicle instead of the high-pressure fuel piping structures 24 and 25 in the high-pressure fuel piping device 33 for a vehicle.

[0053] The electrode 44 is located above the high-pressure fuel pipe 30 and is provided within the insulator 31 with a predetermined gap between it and the high-pressure fuel pipe 30. The electrode 44 is a sacrificial anode used in general cathodic protection. The electrode 44 corrodes before the high-pressure fuel pipe 30, protecting the high-pressure fuel pipe 30 from corrosion. The electrode 44 is made of a metal having a lower equilibrium potential than the metal coating or base metal of the high-pressure fuel pipe 30. For example, when the metal coating of the high-pressure fuel pipe 30 is made of zinc, the electrode 44 can be made of aluminum or the like, which is made of a metal having a lower equilibrium potential than zinc.

[0054] The connection line system 45 electrically connects the high-pressure fuel pipe 30 and the electrode 44 via a connection wire 46. The connection wire 46 connects the high-pressure fuel pipe 30 and the electrode 44 at one longitudinal end of the insulator 31. The connection wire 46 is an electric wire in which a conductor is covered with an insulator, and is, for example, a single-core wiring wire.

[0055] Such a high-pressure fuel piping device 42 for a vehicle does not require an external power source, and therefore can have a simpler configuration than the high-pressure fuel piping devices 33 and 38. Although the high-pressure fuel piping device 42 for a vehicle requires replacement costs when the electrode 44 is lost and care must be taken to prevent contamination of the insulator 31, because it does not require the DC power sources 36 and 41, it is possible to reduce initial costs and maintenance costs until the electrode 44 is lost.

[0056] The high-pressure fuel piping device 42 for a vehicle can insulate noise from the high-pressure fuel piping 30, which is a noise source, by the excellent sound-absorbing performance of the insulator 31. The high-pressure fuel piping device 42 for a vehicle prevents corrosion of the high-pressure fuel piping 30 by cathodic protection made possible by the water retention performance of the open-cell structure 31B. In this way, the high-pressure fuel piping device 42 for a vehicle can prevent corrosion of the high-pressure fuel piping 30 while utilizing the sound-absorbing performance of the insulator 31.

[0057] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Furthermore, the configurations of the above-described embodiments and modifications may be combined and applied. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0058] 10 vehicles 11 Engine 12 Fuel tank 13 Radiator 14 Grill opening 15 Engine Room 16 Battery 20 Fuel piping system 21 Fuel hose 22 Fuel pump 24, 25, 43 High-pressure fuel piping structure for vehicles 26,27 Delivery pipe 28 Relief valve 29 Return pipe 30 High-pressure fuel pipe 31 Insulator 31A Open-cell urethane foam 31B open cell structure 32,44 electrode 33, 38, 42 High-pressure fuel piping system for vehicles 34, 39, 45 Connection line system 35, 40, 46 connecting wires 36,41 DC power supply P1 Piezoelectric element T1 transformer BD1 Bridge diode D1, D2, D3, D4 diodes C1 capacitor

Claims

1. A high-pressure fuel piping device for a vehicle, an insulator made of an open-cell molded body; a high-pressure fuel pipe covered with the insulator; and an electrode provided within the insulator with a predetermined gap between the electrode and the high-pressure fuel pipe; a connection wire electrically connecting the high-pressure fuel pipe and the electrode; A high-pressure fuel piping device for a vehicle, comprising:

2. The electrode is a poorly soluble electrode, 2. The high-pressure fuel piping system for a vehicle according to claim 1, wherein the connecting wire electrically connects the high-pressure fuel piping and the hardly soluble electrode via a DC power source.

3. 3. The high-pressure fuel piping system for a vehicle according to claim 2, wherein the DC power source is a power source supplied by the vehicle.

4. 3. The high-pressure fuel piping system for a vehicle according to claim 2, wherein the DC power source is a power source supplied from vibrations generated inside the vehicle using a piezoelectric element.

5. the high-pressure fuel pipe is a metal pipe that has been treated with a metal coating for rust prevention, 2. The high-pressure fuel pipe system for a vehicle according to claim 1, wherein the electrode is a sacrificial anode made of a metal having an equilibrium potential lower than that of the metal coating.

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