JP2004092510A - Fuel supply device - Google Patents

Abstract

A fuel tank is pressurized without providing a pressurizing pump or the like in a pipe passage and without connecting a pressurizing passage directly to the fuel tank.
A bypass passage (14) communicating between a purge passage (6) of a canister (4) and a transfer passage (13) for transferring fuel from a sub-chamber (8) in a fuel tank (2) to a main chamber (7) is provided. A pressure control valve V2 for opening and closing the charge passage 3 for guiding the fuel vapor in the fuel tank 2 to the canister 4; and an orifice 15 for providing resistance to the fuel flow in the transfer passage 13. During the leak check, the fuel pump 2 is pressurized by the jet pump 12 while suppressing the fuel transfer by the orifice 15.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel supply device that supplies fuel to an engine.
[0002]
[Prior art]
Conventionally, as this kind of fuel supply device, for example, a fuel supply device described in Japanese Patent Application Laid-Open No. 9-2688952 is known. This fuel supply device includes a fuel tank for storing fuel, a charge passage connected to the fuel tank and guiding the fuel vapor, and a canister connected to the charge passage. That is, the fuel evaporated in the fuel tank is adsorbed on the adsorbing member of the canister.
[0003]
The canister is connected to an air passage that guides external air into the canister, and a purge passage that guides fuel vapor in the canister to an intake passage of the engine. Thus, when the intake amount of the external air increases, the evaporated fuel is released from the adsorbing member, and the evaporated fuel is guided to the engine.
[0004]
Further, the fuel supply device is provided with a pressurizing passage that connects the purge passage and the fuel tank, and an intermediate portion of the pressurizing passage is provided with a suction passage through which external air can be sucked. A pressurizing pump is provided in the pressurizing passage, and external air can be introduced into the fuel tank by the pressurizing pump.
[0005]
According to this fuel supply device, when a leak (leakage) of the fuel system is checked, the valve of the charge passage is closed, and the external air is introduced into the fuel tank by the pressurizing pump, so that the fuel tank is opened. The inside or the like is pressurized so that fuel leakage can be detected.
[0006]
[Problems to be solved by the invention]
However, in the fuel supply device, since a pressurizing pump is provided in addition to the pressurizing passage, there is a problem that the number of parts increases and the manufacturing cost increases.
[0007]
In addition, the pressurizing passage must be directly connected to the fuel tank, which complicates the piping passage.When installing the device in a vehicle or the like, it is necessary to secure a space for disposing the pressurizing passage on the vehicle side. In addition, the layout is extremely disadvantageous.
[0008]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel pump without providing a pressurizing pump or the like in a piping passage and without connecting a pressurizing passage directly to a fuel tank. An object of the present invention is to provide a fuel supply device capable of pressurizing the inside of a tank.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a fuel tank having a main chamber and a sub-chamber for storing fuel delivered to an engine, and the fuel pumped from the fuel tank to the engine by a fuel pump And a return passage through which fuel returning from the engine to the fuel tank flows, a jet pump disposed in the return passage, and the main chamber and the sub-chamber connected to the jet pump. And a transfer passage communicating with the bypass passage communicating with the atmosphere through a control valve that can be opened and closed, and a connection portion of the transfer passage with the bypass passage. A resistance portion for providing resistance to the flow of fuel from the sub-chamber side to the main chamber side is provided on the sub-chamber side.
[0010]
According to a second aspect of the present invention, in the fuel supply device according to the first aspect, the resistance portion is an orifice disposed in the transfer passage.
[0011]
According to a third aspect of the present invention, in the fuel supply device according to the first aspect, the resistance portion is a reduced diameter portion formed by reducing the diameter of the transfer passage toward the main chamber. I do.
[0012]
According to the first, second and third aspects of the invention, the control valve communicating with the atmosphere is closed when the vehicle is in normal use. At this time, the fuel stored in the sub-chamber is transferred to the main chamber by the pressure acting on the main chamber side of the transfer passage from the jet pump.
When performing a leak check of the fuel system, the control valve communicating with the atmosphere side is opened. In this state, the bypass passage is opened to the atmosphere side, so that the fuel stored in the sub-chamber is transferred to the main chamber by the pressure acting on the main chamber side of the transfer passage from the jet pump, and the bypass passage is opened to the atmosphere side. Air is sucked into the fuel tank via the bypass passage and the transfer passage through the opened control valve. Then, by closing the switching control valve in a state where the inside of the fuel tank is pressurized to a predetermined pressure, the inside of the fuel tank is sealed in a pressurized state. In this state, a leak check of the fuel system can be performed by detecting a decrease in pressure with a pressure sensor or the like.
At this time, even if the fuel contained in the fuel tank is relatively large, the transfer of the fuel from the sub chamber to the main chamber is suppressed by the provision of the resistance portion in the transfer passage, The inside of the fuel tank is pressurized relatively quickly without reducing the efficiency of air suction from the bypass passage side.
[0013]
Therefore, when pressurizing the inside of the fuel tank at the time of the leak check, the inside of the fuel tank is pressurized using the jet pump for transferring the fuel. For example, an air pump or the like for sending air into the fuel tank is separately provided. No need. Further, since the inside of the fuel tank is pressurized by using the transfer passage, for example, it is not necessary to directly connect the pressurizing passage to the fuel tank. Therefore, the inside of the fuel tank can be pressurized with a small number of parts, and the manufacturing cost can be reduced.
Further, even when a large amount of fuel is stored in the fuel tank, the pressure in the fuel tank can be quickly increased, and a fuel leak check can be quickly performed.
[0014]
According to a fourth aspect of the present invention, in the fuel supply device of the first, second or third aspect, the bypass passage communicates with the atmosphere via a canister.
[0015]
According to the fourth aspect of the invention, in addition to the operation of the first, second or third aspect, the bypass passage communicates with the atmosphere via the canister, so that when the external air is introduced into the fuel tank, the canister is connected to the canister. The adsorbed fuel vapor can be sucked into the tank, and the fuel tank can be pressurized by the fuel vapor. Therefore, the remaining amount of fuel vapor in the canister can be reduced, and the deterioration of the adsorption performance of the canister is suppressed, which is extremely advantageous in practical use.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 3 show an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating the configuration of a fuel supply device, and FIG. 2 is a partial configuration of a fuel supply device showing a connection portion between a transfer passage and a bypass passage. FIG. 3 is a schematic block diagram showing a control system of the fuel supply device.
[0017]
As shown in FIG. 1, a fuel supply device 1 includes a fuel tank 2 in which fuel is stored, a charge passage 3 for guiding fuel vapor in the fuel tank 2, a canister 4 connected to the charge passage 3, and a canister An air passage 5 connected to the canister 4 for guiding outside air into the canister 4 and a purge passage 6 for communicating the canister 4 with an intake passage of the engine are provided. That is, the fuel evaporated in the fuel tank 2 is guided into the canister 4 through the charge passage 3 and is adsorbed by an adsorbing member such as activated carbon in the canister 4. When the outside air is guided from the air passage 5 into the canister 4, the evaporated fuel adsorbed by the adsorbing member is separated from the adsorbing member and guided to the intake passage of the engine. The air passage 5 is provided with a drain valve V1, the charge passage 3 is provided with a pressure control valve (hereinafter referred to as PCV) V2, and the purge passage 6 is provided with a canister purge control valve (hereinafter referred to as CPC) V4. Each of the valves V1, V2, and V4 is, for example, a solenoid valve, and opens and closes a passage.
[0018]
The fuel tank 2 has a ridge 2a projecting upward from a lower portion and extending in a predetermined direction. The ridge 2a is formed so that the fuel tank 2 does not interfere with other members (for example, a drive shaft) of the vehicle. The lower portion of the fuel tank 2 is partitioned into a main chamber 7 and a sub chamber 8 by a ridge 2a. The main chamber 7 is provided with a fuel pump 9 for delivering liquid fuel to the engine side. That is, fuel is supplied from the main chamber 7 side to the engine side through the delivery passage 10 by the fuel pump 9.
[0019]
In addition, a part of the delivered fuel returns from the engine side into the fuel tank 2 through the return passage 11. A jet pump 12 is provided at an end of the return passage 11 on the fuel tank 2 side. The jet pump 12 is arranged above the main chamber 7 in the fuel tank 2, and fuel returning from the return passage 11 is supplied to the main chamber 7 side.
[0020]
The jet pump 12 is connected to the main chamber 7 side of the transfer passage 13 that connects the main chamber 7 side and the sub chamber side 8. The jet pump 12 applies pressure to the transfer passage 13 using the outflow pressure of the fuel flowing out of the return passage 11 into the fuel tank 2. Thereby, the fuel stored in the sub chamber 8 is transferred to the main chamber 7 side. That is, even when the fuel level in the fuel tank 2 is lower than the upper end of the ridge 2a, the fuel in the sub chamber 8 can be transferred to the main chamber 7 and supplied to the engine.
[0021]
Further, the fuel supply device 1 is provided with a bypass passage 14 that communicates the transfer passage 13 and the purge passage 6. The bypass passage 14 is provided with a switching control valve V3 for opening and closing the passage. That is, the transfer passage 13 is connected to the bypass passage 14 that communicates with the atmosphere via the switchable control valve V3. In the present embodiment, the switching control valve V3 is a solenoid valve.
[0022]
As shown in FIG. 3, an orifice 15 is disposed in the passage on the side of the sub-chamber 8 where the transfer passage 13 is connected to the bypass passage 14. That is, in the installation section of the transfer passage 13 where the orifice 15 is installed, the passage is narrower than in other sections, and the flow resistance of the fuel is increased.
[0023]
Further, each valve V1, V2, V3, V4 is connected to the control unit 100. The control unit 100 includes a calculation unit 101, a storage unit 102, and the like. The storage unit 102 stores a normal valve control program 103, a pressurization valve control program 104, and a holding valve control program 105.
[0024]
The normal valve control program 103 is executed during normal use of the vehicle. The normal valve control program 103 controls the drain valve V1 to be open, the PCVV2 to be open, the switching control valve V3 to be closed, and the CPCV4 to operate the engine. This is a program that controls opening and closing according to.
[0025]
The pressurization valve control program 104 is executed at the time of detecting a fuel leak (leakage) in the fuel system of the vehicle, and the drain valve V1 is open, the PCVV2 is closed, the switching control valve V3 is open, and the CPCV4 is This is a program for controlling to be in a closed state.
[0026]
The holding valve control program 105 is executed subsequent to the pressurization valve control program 104 when detecting fuel leakage. The drain valve V1 is closed, the PCVV2 is open, the switching control valve V3 is closed, and the CPCV4 is This is a program for controlling to be in a closed state.
[0027]
The operation of the fuel supply device 1 configured as described above will be described.
[0028]
First, during normal use of the vehicle, the normal valve control program 103 is executed, and only the switching control valve V3 among the valves V1, V2, V3 is closed. In this state, since the drain valve V1 and the PCVV2 are open, the evaporated fuel in the fuel tank 2 flows into the canister 4 through the charge passage 3 and is adsorbed by the adsorbing member. By controlling the opening and closing of the CPCV 4 in accordance with the operation state of the engine, the fuel vapor is released from the adsorbing member of the canister 4 by utilizing the negative pressure of the intake air of the engine and guided to the intake passage of the engine through the purge passage 6 to purge the fuel. I do.
[0029]
In addition, since the switching control valve V3 is in the closed state, the transfer passage 13 is closed, and the fuel stored in the sub-chamber 8 due to the pressure acting on the main chamber 7 side of the transfer passage 13 from the jet pump 12. It is transferred to the main room 7 side.
[0030]
Here, when performing a leak check of the fuel system, the pressurization valve control program 104 is executed to close the PCVV2 and open the switching control valve V3. In this state, the charge passage 3 is closed, and the side of the charge passage 3 from the PCVV2 to the fuel tank 2 is closed. At this time, the purge of the evaporated fuel from the canister 4 is not performed to close the CPCV 4. Here, since the bypass passage 14 is opened, the transfer passage 13 and the purge passage 6 communicate with each other, and the pressure acting on the main chamber 7 side of the transfer passage 13 from the jet pump 12 causes the respective storage portions 7, 8 to communicate with each other. At the same time, fuel is transferred from the canister 4 into the fuel tank 2 through the bypass passage 14 and the transfer passage 13. In the present embodiment, since the bypass passage 14 communicates with the atmosphere through the canister 4, when external air is introduced into the fuel tank 2, the evaporated fuel adsorbed on the canister 4 is sucked into the tank 2. You.
[0031]
Here, when the fuel contained in the fuel tank 2 is relatively small, the liquid level of the fuel is low, so that a relatively large pressure is required to suck up the fuel in the sub chamber 8. That is, the pressure generated by the jet pump 12 mainly acts on the intake of air from the purge passage 6 side rather than the transfer of fuel from the sub-chamber 8 to the main chamber 7 side, and the inside of the fuel tank 2 is relatively quickly emptied. Pressurized.
[0032]
Further, even when the amount of fuel contained in the fuel tank 2 is relatively large, the orifice 15 is provided, and the transfer of fuel from the sub chamber 8 to the main chamber 7 is suppressed. The efficiency of air intake from the side does not decrease. That is, when the orifice 15 is not provided, the fuel level is high, so that the fuel in the sub-chamber 8 is sucked up with a relatively small pressure, and the air suction efficiency from the purge passage 6 decreases. I do. However, in the present embodiment, the inside of the fuel tank 2 is pressurized relatively quickly without lowering the air suction efficiency.
[0033]
When the inside of the fuel tank 2 is pressurized to a predetermined pressure, the holding valve control program 115 is executed to close the drain valve V1, the switching control valve V3, and the CPCV4, and open the PCVV2. Thereby, the fuel tank 2, the charge passage 3, the canister 4, and the transfer passage 13 are hermetically sealed in a pressurized state. In this state, a leak check of the fuel system can be performed by detecting a decrease in pressure with a pressure sensor or the like.
[0034]
As described above, according to the fuel supply device 1 of the present embodiment, when the fuel tank 2 is pressurized, the fuel pump 2 is pressurized by using the fuel transfer jet pump 12. There is no need to separately provide an air pump or the like for sending air into the fuel tank 2. Further, since the inside of the fuel tank 2 is pressurized by using the transfer passage 13, for example, it is not necessary to directly connect a pressurizing passage to the fuel tank 2. Therefore, the fuel tank 2 can be pressurized with a small number of parts, and the manufacturing cost can be reduced.
[0035]
Further, according to the fuel supply device 1 of the present embodiment, since the bypass passage 14 that connects the transfer passage 13 and the purge passage 6 is provided, the fuel supply device 1 does not require a separate passage for introducing outside air into the fuel tank 2. The inside of the tank 2 can be pressurized. Therefore, the fuel tank 2 can be pressurized with a small number of parts, and the manufacturing cost can be reduced. Further, the number of passage pipes can be reduced, and the degree of freedom of passage layout increases, which is extremely advantageous in practical use.
[0036]
Further, according to the fuel supply device 1 of the present embodiment, by providing the bypass passage 14 and the switching control valve V3 in the conventional device, a pressurizing function in the fuel tank 2 is provided, and a fuel leak check is performed. Therefore, there is no need to newly design each component of the apparatus, and this can also reduce the manufacturing cost.
[0037]
Further, according to the fuel supply device 1 of the present embodiment, when external air is introduced into the fuel tank 2, the evaporated fuel adsorbed on the canister 4 is sucked into the tank 2, so that the fuel tank 2 is evaporated. It can also be pressurized with fuel. Therefore, the remaining amount of the evaporated fuel in the canister 4 can be reduced, and the deterioration of the adsorption performance of the canister 4 is suppressed, which is extremely advantageous in practical use.
[0038]
Further, according to the fuel supply device 1 of the present embodiment, since the orifice 15 is provided, even if a large amount of fuel is stored in the fuel tank 2, the fuel tank 2 can be rapidly pressurized. Thus, a fuel leak check can be performed promptly.
[0039]
In the above-described embodiment, the fuel that is transferred from the sub chamber 8 to the main chamber 7 by the orifice 15 is suppressed. However, for example, as shown in FIG. The fuel may be suppressed by forming the reduced-diameter section 16 that decreases in diameter. Also in this case, similarly to the orifice 15 of the embodiment, the reduced diameter section 16 as the reduced diameter portion is formed closer to the sub-chamber 8 than the portion connected to the bypass passage 14. Even with this configuration, it is possible to obtain the same functions and effects as in the above embodiment.
[0040]
Although the bypass passage 14 is connected to the purge passage 6 in the above-described embodiment, the same operation and effect as in the above-described embodiment can be obtained even when the bypass passage 14 is connected to the air passage 5 instead of the purge passage 6. it can.
[0041]
Further, in the above-described embodiment, the fuel flowing through the transfer passage 13 through the orifice 15 is always applied with a constant resistance load. However, for example, a variable valve such as a variable solenoid valve, a variable throttle valve, and a variable ball valve may be used. It may be provided so that the resistance load is variable. In this case, the resistance load may be changed manually, or the resistance load may be changed based on a command from the control unit 100. Thus, the resistance load can be changed according to the liquid level of the fuel stored in the fuel tank 2 at the time of pressurization. Therefore, when the fuel in the fuel tank 2 is large, the resistance load can be increased, and when the fuel in the fuel tank 2 is small, the resistance load can be reduced, thereby further improving the air intake efficiency and the time required for the leak check. Can be further reduced.
[0042]
In the above-described embodiment, the bypass passage 14 is connected to the purge passage 6, and when the inside of the fuel tank 2 is pressurized, air is sucked from the drain valve V 1 via the canister 4 and the air passage 5. Alternatively, the switching control valve V3 may be opened to the atmosphere without connecting the bypass passage 14 to the purge passage 6, and air may be sucked in from the switching control valve V3. Of course, it can be changed as appropriate.
[0043]
【The invention's effect】
As described in detail above, according to the fuel supply device of the present invention, when pressurizing the inside of the fuel tank at the time of leak check, the inside of the fuel tank is pressurized using the jet pump for transferring fuel. For example, there is no need to separately provide an air pump or the like for sending air into the fuel tank. Therefore, the inside of the fuel tank can be pressurized with a small number of parts, and the manufacturing cost can be reduced.
Further, since the bypass passage communicating with the transfer passage is provided, the inside of the fuel tank can be pressurized without separately providing a passage for introducing external air into the fuel tank. Further, since the inside of the fuel tank is pressurized by using the transfer passage, for example, it is not necessary to directly connect the pressurizing passage to the fuel tank. Therefore, the fuel tank can be pressurized with a small number of parts, and the manufacturing cost can be reduced. In addition, the number of passage pipes can be reduced, and the degree of freedom in the layout of the apparatus increases, which is extremely advantageous in practical use.
Further, even when a large amount of fuel is stored in the fuel tank, the pressure in the fuel tank can be quickly increased, and a fuel leak check can be quickly performed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a fuel supply device according to an embodiment of the present invention.
FIG. 2 is a partial configuration explanatory view of a fuel supply device showing a connection portion between a transfer passage and a bypass passage.
FIG. 3 is a schematic block diagram showing a control system of the fuel supply device.
FIG. 4 shows another embodiment of the present invention, and is an explanatory diagram of a partial configuration of a fuel supply device.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 fuel supply device 2 fuel tank 2 a ridge 3 charge passage 4 canister 5 air passage 6 purge passage 7 main chamber 8 sub chamber 9 fuel pump 10 delivery passage 11 return passage 12 jet pump 13 transfer passage 14 bypass passage 15 orifice 16 Diameter section 100 Control unit 101 Operation unit 102 Storage unit 103 Normal valve control program 104 Pressurization valve control program 105 Holding valve control program V1 Drain valve V2 Pressure control valve V3 Switching control valve V4 Canister purge control valve

Claims (4)

A fuel tank having a main chamber and a sub-chamber for storing fuel delivered to the engine;
A delivery passage through which the fuel pumped from the fuel tank to the engine by a fuel pump flows;
A return passage through which fuel returning from the engine to the fuel tank flows;
A jet pump disposed in the return passage;
A transfer passage connected to the jet pump and communicating the main chamber and the sub-chamber,
A bypass passage communicating with the atmosphere through a control valve that can be opened and closed is connected to the transfer passage,
A fuel supply, wherein a resistance portion is provided on the sub-chamber side of the transfer passage with respect to a connection portion with the bypass passage, the resistance portion providing resistance to a flow of fuel from the sub-chamber side to the main chamber side. apparatus. The fuel supply device according to claim 1, wherein the resistance portion is an orifice disposed in the transfer passage. The fuel supply device according to claim 1, wherein the resistance portion is a reduced diameter portion formed by reducing the diameter of the transfer passage toward the main chamber. 4. The fuel supply device according to claim 1, wherein the bypass passage communicates with the atmosphere via a canister.

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