JP4218676B2 - Fuel storage system - Google Patents

Description

  The present invention relates to a fuel storage system provided with a plurality of storage units for storing fuel.

In a vertical fuel tank having a tank primary side for storing fuel supplied to the engine and a tank secondary side capable of storing fuel independently of the tank primary side, a transfer pump disposed on the tank primary side is operated. Then, a technique is known in which fuel on the secondary side of the tank is transferred to the primary side of the tank by causing the fuel to flow through the jet pump (see, for example, Non-Patent Document 1).
Toyota Technical Disclosure Issue No. 15635 (issued April 28, 2004) Japan Society of Invention Disclosure Technical Bulletin No. 2004-504464 (issued July 1, 2004) Japan Society of Invention Disclosure Technical Bulletin No. 2004-504336 (issued July 1, 2004) JP-A-9-324716 JP-A-5-87005 JP 2000-356174 A Japanese Patent Laid-Open No. 4-292567 JP 2000-257524 A JP-A-11-117821 JP-A-6-55944

  However, in the conventional technology as described above, the transfer pump is always operated when the remaining fuel level reaches a predetermined condition. In other words, since the control parameter is only the fuel level, the transfer pump is wasted. In some cases, it was activated.

  In view of the above fact, an object of the present invention is to obtain a fuel storage system capable of operating the fuel transfer means efficiently.

  In order to achieve the above object, a fuel storage system according to a first aspect of the present invention includes a first fuel storage section for storing fuel supplied to an engine, and the first fuel storage section. A second fuel storage section capable of storing fuel, a fuel transfer means for transferring fuel from the second fuel storage section to the first fuel storage section, and a signal corresponding to the temperature of the fuel is output A temperature detector that operates, and operates the fuel transfer means in a predetermined case, and operates the fuel transfer means when it is determined that the temperature of the fuel is lower than a predetermined temperature based on an output signal of the temperature detector. And a control device that prohibits the control.

  In the fuel storage system according to claim 1, for example, in a predetermined case such as when the fuel in the first storage part decreases, the control device operates the fuel transfer means, so that the fuel in the second storage part is the first. It is transferred to the reservoir. When the control device determines that the temperature of the fuel is lower than (or below) a predetermined temperature based on the output signal of the temperature detector, the control device prohibits the operation of the fuel transfer means. Thus, for example, it is possible to prevent the fuel transfer means from operating when the viscosity of the fuel is high and the transfer efficiency is poor, or when the fuel is waxed and cannot be transferred. In this case, it is possible to prevent wasteful operation energy associated with the operation of the fuel transfer means.

  Thus, in the fuel storage system according to the first aspect, the fuel transfer means can be operated efficiently.

  A fuel storage system according to a second aspect of the present invention is the fuel storage system according to the first aspect, wherein the control device is set to a temperature equal to or higher than a temperature at which wax in the fuel is deposited as the predetermined temperature.

  In the fuel storage system according to the second aspect, the control means prohibits the operation of the fuel transfer means when the fuel temperature becomes lower than the temperature at which the wax in the harmful fuel is deposited (the fuel is waxed). This reliably prevents the operating energy from being wasted when the fuel transfer means attempts to transfer the fuel that has become waxed and cannot be transferred.

  As described above, the fuel storage system according to the present invention has an excellent effect that the fuel transfer means can be operated efficiently.

  A dual fuel tank system 10 as a fuel storage system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the following description, when the vertical direction is used, the vertical direction in the vehicle body is indicated.

  FIG. 1 is a system configuration diagram showing a schematic overall configuration of a dual fuel tank system 10 as a fuel storage system. As shown in this figure, the dual fuel tank system 10 includes a main tank 12 as a first reservoir and a sub tank 14 as a second reservoir.

  A main suction 16A provided at the upstream end of the fuel supply line 16 is disposed in the main tank 12, and the main suction 16A is close to the bottom surface 12A of the main tank 12 and faces the bottom surface 12A. . A downstream end located outside the main tank 12 in the fuel supply line 16 is connected to a diesel engine 18 that is an internal combustion engine so that fuel can be supplied.

  The diesel engine 18 is provided with a suction pump (not shown) driven by the diesel engine 18 so that diesel (light oil) as fuel is supplied from the main tank 12 to the diesel engine 18 by the operation of the suction pump. It has become.

  In the main tank 12, an electric pump 20 provided with a suction 20A downward is disposed. The suction 20A is close to the bottom surface 12A of the main tank 12 and faces the bottom surface 12A. The discharge 20 </ b> B of the electric pump 20 is connected to the fuel inlet 24 </ b> A of the jet pump 24 via the communication pipe 22.

  The jet pump 24 is configured such that a fuel inlet 24A is provided at the upper end and a fuel outlet 24B is provided at the lower end, and the downstream end of the fuel transfer line 26 is joined to a merging portion 24C provided at an intermediate portion in the vertical direction. is doing. The upstream end side of the fuel transfer line 26 is located in the sub tank 14, and a sub suction 26A is provided at the upstream end thereof. The sub suction 26A is close to the bottom surface 14A of the sub tank 14 and faces the bottom surface 14A.

  As described above, in the dual fuel tank system 10, when the electric pump 20 is operated and the fuel flow from the fuel inlet 24 </ b> A to the fuel outlet 24 </ b> B is generated in the jet pump 24, the negative pressure generated in the jet pump 24 is caused by this flow. The fuel in the sub tank 14 is sucked into the jet pump 24 from the junction 24C via the fuel transfer line 26. The fuel in the sub-tank 14 merged with the main flow of the jet pump 24 is discharged from the fuel outlet 24 </ b> B, transferred to the main tank 12, and stored in the main tank 12.

  The electric pump 20, the communication pipe 22, the jet pump 24, and the fuel transfer line 26 described above constitute the “fuel transfer means” in the present invention.

  A main fuel level gauge 28 is disposed in the main tank 12, and a sub fuel level gauge 30 is disposed in the sub tank 14. The main-side fuel level gauge 28 and the sub-side fuel level gauge 30 output signals corresponding to the fuel level in the corresponding tank. In this embodiment, the main-side fuel level gauge 28 and the sub-side fuel level gauge 30 both change their electrical resistance values according to the angles of the arms 28B, 30B with respect to the main bodies 28C, 30C according to the liquid levels of the floats 28A, 30A. This is a so-called sender gauge.

  Further, the dual fuel tank system 10 includes a temperature sensor 32 as a temperature detector that outputs a signal corresponding to the temperature of the fuel. In this embodiment, the temperature sensor 32 is disposed in the vicinity of the fuel inlet of the diesel engine 18. The temperature sensor 32 may be provided in other parts, for example, in the main tank 12, the sub tank 14, the fuel transfer line 26, and the like. Further, the diesel engine 18 is provided with a fuel consumption meter 34 that outputs a signal corresponding to the fuel consumption. Or, even without the fuel consumption meter 34, the EFI / ECU can calculate the fuel consumption based on the injected fuel amount. For example, instead of the signal from the fuel consumption meter 34, the calculation result of the EFI / ECU will be described later. May be output to the tank ECU 36.

  The dual fuel tank system 10 operates the electric pump 20 based on the output signals of the main fuel level gauge 28, the sub fuel level gauge 30, the temperature sensor 32, and the fuel consumption meter 34, that is, from the sub tank 14 to the main tank 12. A tank ECU 36 is provided as a control device for controlling the fuel transfer amount and the transfer timing.

  The tank ECU 36 outputs a signal corresponding to the voltage of a battery (not shown) mounted on the automobile, in addition to the main-side fuel level gauge 28, the sub-side fuel level gauge 30, the temperature sensor 32, the fuel consumption meter 34, and the electric pump 20. The battery voltage sensor 38 is also electrically connected. The electric pump 20 operates by consuming the electric power of the battery.

  The tank ECU 36 is configured so that the amount of fuel in the main tank 12 is maintained at a set amount (for example, 20 liters) or more, and an amount of fuel commensurate with the amount consumed by the diesel engine 18 is transferred from the sub tank 14 to the main tank 12. The electric pump 20 is configured to operate so as to be replenished. The tank ECU 36 is electrically operated when the fuel level in the main tank 12 falls below a specified value based on the output signal of the main fuel level gauge 28 in order to maintain the amount of fuel in the main tank 12 at or above the set amount. The pump 20 is configured to be driven.

  Further, the tank ECU 36 supplies a specified amount of fuel based on the output signal of the fuel consumption meter 34 in order to replenish the main tank 12 with fuel corresponding to the amount consumed by the diesel engine 18 from the sub tank 14. The electric pump 20 is configured to operate when consumed. That is, the electric pump 20 does not always operate during operation of the diesel engine 18 but operates intermittently.

  Here, in order to secure the fuel replenishment amount from the sub tank 14 by the operation of the electric pump 20, the tank ECU 36 operates the electric pump for a predetermined time t0 commensurate with the replenishment amount (the prescribed amount described above). . In this embodiment, the predetermined time (hereinafter referred to as a reference time) t0 is corrected based on the output signal of the temperature sensor 32 and the output signal of the battery voltage sensor 38.

  Specifically, the tank ECU 36 stores a correction coefficient Kt based on the fuel temperature and a correction coefficient Kb based on the battery voltage in a built-in ROM or the like as a one-dimensional map, and each of the temperature sensor 32 and the battery voltage sensor 38 is stored. The operation time t (= Kt × Kb × t0) of the electric pump 20 is determined by multiplying the reference time t0 by the correction coefficients Kt and Kb read from the map according to the output signal. The correction coefficient Kt is set to be smaller as the fuel temperature is higher (kinematic viscosity is lower), and the correction coefficient Kb is set to be smaller as the battery voltage is higher (the current of the electric pump 20 is higher). ing.

  Further, the tank ECU 36 receives the fuel corresponding to the detection lower limit from the sub-side fuel level gauge 30 and the fuel in the sub-tank 14 when the operating condition of the electric pump 20 is satisfied (the operation timing is reached). The electric pump 20 is operated only for a predetermined time according to the remaining amount. As a result, in the dual fuel tank system 10, the sub fuel level gauge 30 outputs a detection lower limit signal before entering the entire amount of fuel in the sub tank 14 (enters the structural dead zone), but the remaining fuel in the sub tank 14. Is collected in the main tank 12. The predetermined time may be multiplied by each correction coefficient described above. When the sub-side fuel level gauge 30 outputs a detection lower limit signal, the electric pump 20 may be operated for a predetermined time regardless of whether the electric pump 20 is operating.

  When the temperature of the fuel is less than a predetermined threshold based on the output signal of the temperature sensor 32, the tank ECU 36 determines whether or not the electric pump 20 operates at the timing described above. It is comprised so that the operation | movement of may be prohibited. This predetermined value is set as a temperature at which wax in diesel as fuel is deposited, or a temperature slightly higher than the deposition temperature.

  Hereinafter, the operation of the present embodiment will be described with reference to a flowchart shown in FIG. 2 as an example of a control flow of the tank ECU 36.

  In the dual fuel tank system 10 configured as described above, when the ignition key is turned on and the diesel engine 18 is started, the tank ECU 36 reads the output signal of the temperature sensor 32 in step S10, and in step S12, the fuel temperature exceeds the above threshold value. Judge whether there is. If the tank ECU 36 determines that the fuel temperature is lower than the threshold value, the tank ECU 36 proceeds to step S14, stops the electric pump 20 (inhibits operation), and returns to step S10. Therefore, the above routine is repeated until the fuel temperature becomes equal to or higher than the threshold value.

  On the other hand, if the tank ECU 36 determines in step S12 that the fuel temperature is equal to or higher than the threshold value, the tank ECU 36 proceeds to step S16 to read the output signal of the main fuel level gauge 28, and in step S18 the fuel level of the main tank 12 is determined. It is determined whether or not the value is equal to or greater than a specified value. When the tank ECU 36 determines that the fuel level in the main tank 12 is less than the specified value, the tank ECU 36 proceeds to step S20 to operate the electric pump 20 and returns to step S10. Therefore, the above routine is repeated until the fuel level (storage amount) of the main tank 12 becomes equal to or greater than the threshold value. If the tank ECU 36 determines in step S18 that the fuel level in the main tank 12 is greater than or equal to the specified value, the tank ECU 36 proceeds to step S22 and stops the electric pump 20.

  Further, the tank ECU 36 proceeds to step S24, integrates the output signals of the fuel consumption meter 34, integrates the fuel consumption by the diesel engine 18, and proceeds to step S26. In step S26, it is determined whether or not the amount of fuel consumed by the diesel engine 18 is greater than or equal to a specified value. When the tank ECU 36 determines that the fuel consumption of the diesel engine 18 is less than the specified value, the tank ECU 36 returns to step S26 and repeats this until the fuel consumption reaches the specified value.

  If the tank ECU 36 determines in step S26 that the fuel consumption is greater than or equal to the specified value, the tank ECU 36 proceeds to step S28, reads the output signal of the battery voltage sensor 38, and proceeds to step S30. In step S30, correction coefficients Kt and Kb are extracted based on the output signal of the temperature sensor 32 input in step S10 and the output signal of the battery voltage sensor 38 input in step S28, and these correction coefficients are set to the reference time t0. The operating time of the electric pump 20 is determined by multiplication.

  Next, the tank ECU 36 proceeds to step S32 and operates the electric pump 20 for the operating time determined in step S30. The tank ECU 36 stops the electric pump 20 after the operation time has elapsed, and returns to step S10.

  Thus, in the dual fuel tank system 10, the fuel in the main tank 12 is maintained at a set amount or more, and an amount of fuel corresponding to the specified amount consumed by the diesel engine 18 is replenished from the sub tank 14 to the main tank 12. Is done. Since the dual fuel tank system 10 intermittently operates the electric pump 20 to supplement the fuel consumed by the diesel engine 18, for example, the dual fuel tank system 10 is compared with a dual fuel tank system configured to always operate the electric pump 20 (continuously). Thus, energy consumption for operating the electric pump 20 is suppressed.

  Here, in the dual fuel tank system 10, when the fuel temperature is determined to be lower than the threshold value based on the output signal of the temperature sensor 32, the operation of the electric pump 20 is prohibited, so that it is waxed and transferred to the main tank 12. It is prevented that the electric pump 20 is operated to transfer the impossible fuel. For this reason, although the fuel cannot be transferred, the battery power is not consumed.

  Thus, in the dual fuel tank system 10 according to the present embodiment, the electric pump 20 for transferring fuel from the sub tank 14 to the main tank 12 can be operated efficiently.

  Further, in the dual fuel tank system 10, since the waxed fuel is not transferred, it is possible to prevent the wax (wax) from entering the jet pump 24 to become a pump lock, thereby improving the reliability.

  In the above embodiment, the fuel in the main tank 12 is maintained at a set amount or more, and an amount of fuel corresponding to the specified amount consumed by the diesel engine 18 is replenished from the sub tank 14 to the main tank 12. Although the example in which the tank ECU 36 functions is shown in FIG. 1, the present invention is not limited to this. For example, the electric pump 20 may be always operated while the diesel engine 18 is operating. In a configuration in which the replenishment amount is operated, a configuration in which the operation time is not corrected may be employed, or a replenishment amount may be secured by a control parameter other than the time.

  In the above embodiment, the dual fuel tank system 10 includes the main tank 12 and the sub tank 14 separated from each other. However, the present invention is not limited to this, and the mutual fuel tank system 10 such as a vertical tank is used. It is good also as a structure which has two fuel storage parts by which the upper part was connected and connected, and good also as a structure which has three or more independent tanks or fuel storage parts.

1 is a system configuration diagram of a dual fuel tank system according to an embodiment of the present invention. It is a flowchart which shows the control flow of tank ECU which comprises the dual fuel tank system which concerns on embodiment of this invention.

Explanation of symbols

10 Dual fuel tank system (fuel storage system)
12 Main tank (first reservoir)
14 Subtank (second reservoir)
18 Diesel engine
20 Electric pump (fuel transfer means)
22 Communication pipe (fuel transfer means)
24 Jet pump (fuel transfer means)
26 Fuel transfer line (fuel transfer means)
32 Temperature sensor (temperature detector)
36 Tank ECU (control device)

Claims (2)

A first fuel storage section for storing fuel supplied to the engine;
A second fuel storage section capable of storing fuel independently of the first fuel storage section;
Fuel transfer means for transferring fuel from the second fuel reservoir to the first fuel reservoir;
A temperature detector that outputs a signal corresponding to the temperature of the fuel;
A control device that operates the fuel transfer means in a predetermined case and prohibits the operation of the fuel transfer means when it is determined that the temperature of the fuel is lower than a predetermined temperature based on an output signal of the temperature detector; ,
A fuel storage system.   The fuel storage system according to claim 1, wherein the control device is set to a temperature equal to or higher than a temperature at which wax in the fuel is deposited as the predetermined temperature.

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