JP5760935B2 - Fuel filling method and fuel filling system for fuel tank of DME fuel - Google Patents

Description

  According to the present invention, when a vehicle equipped with a DME fuel-using engine and a plurality of fuel tanks for DME fuel is simultaneously filled with fuel, a shock wave is generated when the fuel supply to the fuel tank is stopped. The present invention relates to a fuel filling method and a fuel filling system of DME fuel that can be prevented from occurring and can be filled in a short time.

  The fuel supply system for automobiles using DME (dimethyl ether) fuel is manufactured in conformity with the structure handling standards for LP gas automobiles under the current regulations. DME fuel is supplied from a fuel supply stand, but currently, the supply method is very similar to the LP gas supply stand.

  For example, the fuel in the storage tank provided in the fuel supply stand is pumped by a pump (fuel pump) to a meter (dispenser: liquid metering device), and the hose for supply attached to this meter The fuel tank is supplied. A nozzle that can be connected to the filling port of the fuel tank on the automobile side is attached to the tip of the supply hose so that it can be attached to and detached from the fuel tank.

  The fuel is filled by attaching a nozzle on the meter side to the filling port of the fuel tank and supplying the fuel stored in the storage tank to the fuel tank by a pressure pump. The fuel is supplied or stopped by opening and closing a valve attached to the nozzle.

  In the prior art of this filling apparatus, the fuel supply is stopped at the nozzle side (fuel supply side) and the fuel tank 10 on the automobile side (receiving side) as in the fuel filling system 1X shown in FIG. An overfilling prevention device 12 is provided, and fuel fed from a fuel storage tank 30 by a pressure pump 40 is supplied from a filling nozzle 21 of a meter (dispenser) 20 to a filling port 13. When the fuel tank is fully supplied and the tank is full (approximately 85% of the fuel tank capacity), the overfill prevention device 12 provided in the fuel tank 10 functions to shut off the supply port 13 and supply it. There is a method of stopping filling by relieving the fuel on the system side and stopping the supply-side pressure pump 40 from stopping. Thereafter, the pumping pump 40 is stopped, for example, by stopping the switch on the supply side.

  Since the filling device of the prior art is based on an LPG fuel stand premised on a passenger car or a small truck, the fuel supply flow rate is approximately 20 to 30 (1 / min), which is widely used in large trucks. Considering the fuel supply flow rate is not enough. DME has a lower calorific value than light oil, and an amount of 1.86 times the volume ratio is required to obtain the same calorific value. That is, in order to obtain a cruising distance equivalent to that of a light oil vehicle, it is necessary to load 1.86 times as much fuel. For this reason, high-speed filling is also required for the filling speed, and when it is supplied in the same time as the current oil supply, a filling speed of 80 to 100 (1 / min) is required.

  On the other hand, if the filling speed is increased, when the overfill prevention device is activated, a shock wave is generated in the piping due to the operation of the valve, and excessive pressure is applied to the supply system line, hose, nozzle, and measuring instrument. . When the shock wave becomes large and the supply system side exceeds the allowable withstand voltage, each component is adversely affected and may be damaged in some cases.

  As a countermeasure, there is an example in which a method of reducing the shock wave by reducing the filling flow rate on the supply side before the fuel in the fuel tank is full, that is, before the overfilling prevention device is activated, is employed. As an example of this, for example, liquid level information is acquired, and when the decelerating liquid level is high, filling is performed at a high filling speed, and when the decelerating liquid level is reached, the speed is decelerated from the high filling speed to the threshold liquid level. However, a DME fuel filling system has been proposed that can sufficiently reduce the filling speed before reaching the maximum filling amount and sufficiently suppresses the water hammer effect caused by the filling stop (see, for example, Patent Document 1).

  Such a fuel filling system is, for example, a fuel filling system 1Y as shown in FIG. 11 or a fuel filling system 1Z as shown in FIG. 12, and the fuel tank 10 on the automobile side (receiving side) is prevented from being overfilled. In addition to the device 12, the liquid level gauge 11 is provided, and the fuel sent from the fuel storage tank 30 by the pressure feed pump 40 is controlled from the filling nozzle 21 while controlling the flow control valve 22 of the meter (dispenser) 20. Supply to the filling port 13.

  This control is performed according to the control flow illustrated in FIG. 13, and the measured value of the liquid level gauge (liquid level sensor) 11 indicating the liquid level (fuel level) of the fuel tank 10 in step S11 is measured on the measuring instrument 20 side. It is determined whether it can be used, that is, whether or not the liquid level level can be measured on the measuring instrument 20 side. If not (NO), the process goes to step S13, and the second filling speed (low speed) Filling speed) Fuel is filled at a low flow rate of V2. On the other hand, when the liquid level can be measured (YES), the process goes to step S12, and the time set in advance at the high flow rate filling at the first filling speed (high speed filling speed) V1 (the liquid at S15). For a period of time related to the surface level check interval), then the liquid level is measured in step S14, and the fuel level set in advance in step S15 (decelerated liquid level height). Until the liquid level is reached (NO), the flow rate control valve 22 is adjusted and filled at the first filling speed V1, and when this liquid level is reached (YES), step S16. Then, the flow control valve 22 is adjusted to reduce the filling to a low flow rate filling at the second filling speed V2 at which the water hammer does not become a problem, and when the tank becomes full, the overfilling prevention device 12 automatically stops. If the automatic stop is performed, the filling operation is terminated in step S17 by stopping the pumping pump 40 or the like. The level gauge 11 and the measuring instrument 20 are connected by the signal cable 50 in FIG. 11, but in FIG. 12, the transmitter 51 and the receiver 52 are connected between the level gauge 11 and the measuring instrument 20. Connected by wireless communication.

  A liquid level gauge such as a float type liquid level gauge or an ultrasonic level sensor is attached as a liquid level gauge 11 for detecting the position of the liquid level in the fuel tank. The liquid level is detected by transferring to a fuel supply-side meter (dispenser) 20 via an optical cable or radio and inputting fuel level information.

  In other words, in these fuel fillings, when the filling nozzle is set in the fuel tank, the liquid level information is transmitted to the measuring instrument by the liquid level gauge and cable (or wireless transmission / reception). Start the fuel supply by operating the pump. At the start of fuel filling, high-speed filling is used, and the flow rate is, for example, 80 to 100 (1 / min). At this time, the liquid level information detected by the liquid level gauge is continuously transmitted to the measuring instrument. When the measuring device determines that the liquid level has reached a predetermined level (for example, about 90% to 95% of the full tank state), the flow rate level at which the shock wave at the time of stopping the supply does not cause a problem To slow down. After reducing the flow rate to this flow level, stop filling with the overfill prevention device, or determine whether the tank is full based on the liquid level information and stop the supply-side pump to stop the fuel supply. Stop.

  However, in the case of an automobile such as a large truck that travels for a long distance, a plurality of fuel tanks may be mounted in order to secure the loaded fuel. In adopting this method, there is a problem that it is difficult to control each fuel tank in consideration of low cost and simplified control.

JP 2009-138755 A

  The present invention has been made in view of the above situation, and its object is to provide a vehicle using a DME fuel equipped with a plurality of fuel tanks in order to secure the amount of fuel to be loaded for long-distance driving or the like. However, it is possible to easily fill the fuel tank with DME fuel that can easily avoid the generation of shock waves when the fuel supply is stopped while simultaneously filling the fuel tanks at the time of fuel filling with simple control and low cost. It is to provide a method and a fuel filling system.

  In order to achieve the above object, a fuel filling method of a DME fuel in a fuel tank according to the present invention includes a DME fuel-using engine and a fuel in a DME fuel tank for a vehicle equipped with a plurality of fuel tanks for DME fuel. In the filling method, when a plurality of fuel tanks are filled with fuel at the same time, the control of the fuel filling speed to the fuel tank is performed not to the filling speed of each of the fuel tanks but to the entire fuel tank. At the start of filling, the filling speed of the entire fuel tank is set as the first filling speed, and then one fuel filling amount of the fuel tank is preset in the fuel tank. When the reduced deceleration filling amount is reached, the filling speed of the entire fuel tank is reduced to a second filling speed at which shock waves at the time of supply stop are not a problem. When the fuel filling quantity of the fuel tank reaches the stop loading a preset of the fuel tank, a method characterized by stopping only the filling of the first one of the fuel tank.

  According to this method, in order to ensure the amount of fuel to be loaded for long-distance driving, etc., fuel is filled into a plurality of fuel tanks at the same time when fuel is filled in an automobile using DME fuel equipped with a plurality of fuel tanks. However, the generation of a shock wave when filling is stopped can be easily avoided at a low cost with simple control.

  Further, in the fuel filling method of the DME fuel into the fuel tank, after the fuel filling is stopped in one of the fuel tanks, the filling speed of the whole fuel tank is increased to the third filling speed, When the second fuel filling amount of the fuel tank reaches the deceleration filling amount of the fuel tank, the filling speed of the entire fuel tank is reduced to the fourth filling speed, When the fuel filling amount of the fuel tank reaches this fuel tank stop filling amount, only the filling of the second fuel tank is stopped. According to this method, since the filling speed of the second fuel tank is increased, the entire filling time can be shortened.

  In order to achieve the above object, a fuel filling system for DME fuel in a fuel tank according to the present invention provides a DME fuel use engine and a vehicle equipped with a plurality of fuel tanks for DME fuel. In the fuel filling system for the fuel tank, a liquid level gauge for detecting a fuel filling amount is provided on each of the fuel tanks on the vehicle side, and a fuel supply line for connecting the storage tank and the fuel tank is provided on the fuel stand side. A filling control device for controlling the pressure feeding pump and the flow rate adjusting valve in response to the output of the liquid level gauge, and providing a pressure feeding pump and a flow rate adjusting valve in the middle of the fuel supply line; When the filling control device fills fuel into a plurality of the fuel tanks at the same time, the fuel filling speed is controlled in the fuel tank. In addition to the filling speed of each tank, the filling speed of the entire fuel tank is collectively changed, and at the start of filling, the filling speed of the entire fuel tank is set as the first filling speed. In addition, when one fuel filling amount of the fuel tank reaches a preset filling amount for deceleration of the fuel tank, the second filling that does not cause a shock wave at the time of stopping the supply of the filling speed to the whole fuel tank. Deceleration to a speed, and when the fuel filling amount of the first fuel tank reaches a preset stopping filling amount of the fuel tank, control is performed to stop only filling of the first fuel tank. Configured as follows.

  According to this configuration, in order to ensure the amount of fuel to be loaded for long-distance driving, etc., for a vehicle using DME fuel equipped with a plurality of fuel tanks, the fuel tanks are filled with fuel simultaneously when fuel is filled. However, the generation of a shock wave when filling is stopped can be easily avoided at a low cost with simple control.

  Further, in the fuel filling system for DME fuel into the fuel tank, after the fuel filling is stopped in one of the fuel tanks, the filling speed of the whole fuel tank is increased to the third filling speed. When the second fuel filling amount of the fuel tank reaches the deceleration filling amount of the fuel tank, the filling speed of the entire fuel tank is reduced to the fourth filling speed, When the fuel filling amount of the fuel tank reaches the fuel tank stopping filling amount, control is performed to stop only filling of the second fuel tank. According to this configuration, since the filling speed of the second fuel tank is increased, the entire filling time can be shortened.

  In the fuel filling system of the DME fuel into the fuel tank, a contact switch that turns on and off when the liquid level gauge detects that the liquid level has reached the specified liquid level, and the contact switch are connected in parallel. With the electrical resistance provided, the contact switch is ON until the liquid level reaches the specified liquid level, the electric resistance value is substantially zero, and the liquid level reaches the specified liquid level. When this is detected, the contact switch is turned off, and the electric resistance value is changed from a substantially zero state, and the liquid level gauge is connected in series to detect the liquid level of the entire fuel tank. And an electric circuit for detecting that the fuel filling amount of the fuel tank has reached the deceleration filling amount from a change in electric resistance in the electric circuit. According to this configuration, it is possible to collectively control the filling speeds of the plurality of fuel tanks with a very simple circuit configuration.

  According to the fuel filling method and the fuel filling system of the DME fuel of the present invention, in order to secure the amount of fuel to be loaded for long-distance driving or the like, the vehicle using DME fuel equipped with a plurality of fuel tanks is used. On the other hand, it is possible to easily avoid the generation of a shock wave at the time of filling stop at a low cost while simultaneously filling fuel into a plurality of fuel tanks at the time of fuel filling.

It is a figure which shows the structure of the fuel filling system in case the number of the fuel tank of 1st and 2nd embodiment which concerns on invention is two. It is a figure which shows the structure of the connection relation of the liquid level indicator in the case of two fuel tanks. It is a figure which shows the electric circuit of the signal of the liquid level meter of 1st and 2nd embodiment which concerns on invention, and shows the case where both two liquid level meters have not reached the preset liquid level. It is a figure which shows the electric circuit of the signal of the liquid level gauge of 1st and 2nd embodiment which concerns on invention, and shows the case where one liquid level gauge has reached the preset liquid level. It is a figure which shows the control flow of the fuel filling method of 1st Embodiment which concerns on this invention. It is a figure which shows the temporal change of the resistance value of a liquid level meter, and fuel supply amount in the fuel filling method of 1st Embodiment which concerns on this invention. It is a figure which shows the control flow of the fuel filling method of 2nd Embodiment which concerns on this invention. It is a figure which shows the detailed control flow of step S20 of the control flow of FIG. It is a figure which shows the temporal change of the resistance value of a liquid level meter, and fuel supply amount in the fuel filling method of 2nd Embodiment which concerns on this invention. It is a figure which shows the structure of the fuel filling system in case the vehicle side fuel tank is one. It is a figure which shows the structure of a fuel filling system in case the fuel tank by the side of a vehicle is used, and a level gauge and a signal cable are used. It is a figure which shows the structure of a fuel filling system in case the fuel tank of the vehicle side is one and uses a liquid level gauge and a radio signal. It is a figure which shows the control flow of the fuel filling method of a prior art.

  Hereinafter, a fuel filling method and a fuel filling system for DME fuel in a fuel tank according to an embodiment of the present invention will be described. Hereinafter, the number of fuel tanks will be described as two. However, the present invention is not limited to the number of fuel tanks, but two or more, in other words, fuel filling for filling a plurality of fuel tanks with DME fuel. Applicable to systems and fuel filling methods.

  As shown in FIG. 1, the fuel filling system 1 for a DME fuel tank according to the first embodiment of the present invention is provided with two fuel tanks 10A and 10B on the vehicle side (receiving side: automobile side). In addition, the liquid level gauges 11A and 11B are respectively arranged, and an overfill prevention device 12 is provided. The fuel sent from the DME fuel storage tank 30 by the pressure feed pump 40 is supplied from the filling nozzle 21 of the meter (dispenser: filling control device) 20 to the filling port 13 on the vehicle side via the flow rate control valve 22. When the fuel is full, the overfilling prevention device 12 automatically stops. The detection signals of the liquid level gauges 11A and 11B are input to the measuring instrument (dispenser) 20 side by the electric circuit 14 and the signal cable 50.

  Also, as shown in FIGS. 2 to 4, the level gauges 11A and 11B are configured such that the contact switch 11a is turned off when the fuel exceeds a preset liquid level, and an electric switch is connected in parallel with the contact switch 11a. The electric circuit 14 to which the resistor 11b is connected is configured. In other words, when the fuel reaches the specified liquid level, the contact switch 11a becomes non-contact as shown in FIG. 4, and the resistance value is changed by the electric resistor 11b attached in parallel. Then, the level gauges 11A and 11B are attached to the respective fuel tanks 10A and 10B, and further connected in series. In addition, energization is allowed until the specified liquid level is reached. The electric circuit 14 and the signal cable 50 are indicated by a one-dot chain line in FIGS. 1 and 2 and a solid line in FIGS. 3 and 4.

  By using such an electric circuit 14, when one of the fuel tanks 10A, 10B reaches a specified liquid level, the contact switch 11a becomes non-contact, and the current passes through the electric resistance 11b side, Since the resistance value changes, it can be determined whether one of the fuel tanks 10A, 10B has reached the first liquid level before full tank (full filling) on the measuring instrument 20 side. It becomes possible to perform the control to decelerate.

  Next, a method for filling the fuel tank with the DME fuel according to the first embodiment of the present invention will be described with reference to FIGS. In this fuel filling method, a filling nozzle (dispenser nozzle) 21 is set in the fuel filling port 13 of the fuel tank 10A, 10B on the vehicle side. When the control is performed using the communication cable 50 on the measuring instrument 20 side, the communication cable 50 is connected to the electric circuit 14 of the liquid level gauges 11A and 11B on the vehicle side simultaneously or in advance. This operation is not necessary when using wireless.

  When the fuel in the fuel tanks 10A and 10B is small before the filling is started, the contact switches 11a of the liquid level gauges 11A and 11B are closed and the electric circuit 14 is closed. When the filling control is started, the control flow of FIG. 5 is started, and the measured value of the liquid level meter (liquid level sensor) 11 indicating the liquid level (fuel level) of the fuel tank 10 in the first step S11 is measured. In other words, it is determined whether or not the liquid level can be measured on the measuring instrument 20 side. If this determination is not possible (NO), the process goes to step S13, and the fuel is filled with low flow rate filling at the second filling speed (low speed filling speed) V2 in order to avoid the occurrence of a shock wave. On the other hand, when the liquid level can be measured (YES), the process goes to step S12, and the time set in advance at the high flow rate filling at the first filling speed (high speed filling speed) V1 (the liquid at S15). For a period of time related to the surface level check interval).

  The first filling speed V1 is a flow rate that passes through the flow rate control valve 22, and is set to 160 to 200 (l / min), for example. That is, it is set to 80-100 (l / min) per fuel tank. The second filling speed V2 is a flow rate that passes through the flow rate control valve 22, and is set to, for example, 20 to 60 (l / min). That is, it is set to 10 to 30 (l / min) per fuel tank.

  Next, in step S14, the liquid level is measured, and in the next step S15, it is determined whether any one of the fuel tanks 10A, 10B has reached a predetermined liquid level (deceleration liquid level). Until one of the fuel tanks 10A (or 10B) reaches this liquid level (NO), the flow rate control valve 22 is adjusted and filled at the first filling speed V1, until one of the fuel tanks 10A (or 10B) reaches this liquid level. When 10A (or 10B) reaches this liquid level (YES), as shown in FIG. 4, the contact switch 11a on the right side of the drawing is turned OFF, and the electric circuit 14 operates so that one electric resistor 11b acts as a resistance. Therefore, it can be determined whether or not this state is present. If it is determined in step S15 that this state has been reached (YES), the process goes to step S16A, and the flow rate control valve 22 is adjusted to perform filling at the second filling speed V2 at which the water hammer does not cause a problem.

  When one fuel tank 10A (or 10B) becomes full at the second filling speed V2 in step S16A, the overfilling prevention device 12 automatically stops in step S17A. Thereafter, filling is performed at a fourth filling speed V4 that is half of the second filling speed V2, and the other fuel tank 10B (or 10A) is filled at the second filling speed V2 in step S16A in step S16B. In the same manner as described above, when filling with low flow rate is continued and the other fuel tank 10B (or 10A) becomes full, the overfilling prevention device 12 automatically stops at step S17B. When the fuel supply lines of both the fuel tanks 10A and 10B are automatically stopped by the overfilling prevention device 12, the filling pump is terminated in step S18 by stopping the pressure feed pump 40 or the like.

  That is, when fuel filling is started, fuel filling is started from the filling nozzle 21 on the meter 20 side, and at this time, high flow rate filling at the first filling speed V1 is performed. When one of the two fuel tanks 10A, 10B has a predetermined liquid level of a specified value, for example, from 5% before full tank to 10% or less, Since the contact switch 11a of the level gauge 11 of the fuel tank 10A (or 10B) is opened, the resistance value changes as a circuit only on the side of the electric resistor 11b provided in parallel as shown in FIGS. To do. As a result, the meter 20 side determines that the tank will be full soon, and switches the fuel filling to the low flow rate filling at the second filling speed V2. Thereafter, the overfill prevention device 12 is operated, and the filling of the fuel tank 10A (or 10B) is completed.

  However, the other fuel tank 10B (or 10A) continues to be filled with low flow rate filling, and filling is continued until the overfilling prevention device 12 is activated. When the other fuel tank 10B (or 10A) is full, the overfill prevention device 12 is activated and filling is stopped.

  In the fuel filling system and the fuel filling method in the DME fuel-using engine according to the first embodiment, the fuel tank 10A (or 10B) that reaches the full tank first is controlled so as to be filled at a low flow rate, and the shock wave Prevent damage caused by. Looking at this in FIG. 6, the fuel in one of the fuel tanks 10A (or 10B) reaches a preset liquid level from the time ta when the filling of the fuel is started, and the electric resistance is “R0”. From time tb until one fuel tank 10A (or 10B) becomes full and automatically stops by the overfill prevention device 12 from time tc The fuel tank 10B (or 10A) of the other fuel tank 10B (or 10A) reaches the liquid level set in advance and the other fuel tank 10B (or 10A) passes through a time te when the electric resistance changes from “R1” to “R1 + R2”. ) Until the point of time tf when the tank is fully filled and automatically stops by the overfilling prevention device 12.

  Therefore, since the flow rate to be filled is reduced to the low flow rate filling at the end of the filling of one fuel tank 10A (or 10B) and the filling of the other fuel tank 10B (or 10A), the fuel supply The water hammer effect when stopping can be avoided.

  Note that when multiple fuel tanks are installed as described above, the time until the tank is full when fuel is filled by controlling the fuel supply on the vehicle side so that it is consumed approximately evenly. Since the difference between the fuel tanks can be reduced, the effect can be further increased.

  Next, a fuel filling system and a fuel filling method in a DME fuel-using engine according to a second embodiment will be described with reference to FIGS. 7, 8 and 9. FIG. The fuel filling system and the fuel filling method in the second embodiment are different from the fuel filling system and the fuel filling method in the first embodiment after one of the fuel tanks 10A and 10B becomes full. The difference is that the flow rate to be filled is increased again.

  The fuel filling method of the second embodiment is the same as that of the first embodiment shown in the control flow of FIG. 5 from step S11 to S17A in FIG. 7, and the other fuel tank 10B ( Or the control of the continuation of filling to 10A) is only different as shown in FIG.

  In the control flow of the first embodiment of FIG. 5, when the filling of one fuel tank 10 </ b> A (or 10 </ b> B) ends the filling by the overfill prevention device 12, the flow rate to the two fuel tanks 10 </ b> A and 10 </ b> B. On the other hand, since the flow rate to one fuel tank 10A (or 10B) decreases, the overall flow rate decreases.

  In the second embodiment of FIG. 7 and FIG. 8, in step S21, this decrease is determined on the measuring instrument 20 side, the filling stop of one fuel tank 10A (or 10B) is confirmed, and in step S22, The filling of the other fuel tank 10B (or 10A) is switched to the high flow rate filling at the third filling speed V3. By setting the third filling speed V3 after passing through the flow control valve 22 to be half of the first filling speed V1, the other fuel tank 10B is filled in the same manner as when filling at the first filling speed V1 in step S12. (Or 10A) can be filled at a high flow rate. In this case, for example, the first filling speed V1 is set to 160 to 200 (l / min) and the third filling speed V3 is set to 80 to 100 (l / min) at the flow rate when passing through the flow control valve 22.

  Subsequent filling is performed in the same manner as the filling control until one of the fuel tanks 10A (or 10B) is in a full tank state. In step S22, the time set in advance at the high flow rate filling at the third filling speed V3 (step The fuel is charged for a time period related to the liquid level check interval in S24).

  Next, in step S23, the liquid level is measured, and in the next step S24, whether or not the other fuel tank 10B (or 10A) has reached a predetermined liquid level (deceleration liquid level height). Until this liquid level is reached (NO), the flow rate control valve 22 is adjusted to increase the third filling speed V3 for filling, and when this liquid level is reached (YES), it is shown in FIG. As described above, since one of the contact switches 11a is turned OFF and one electric resistor 11b becomes the resistance of the electric circuit 14, the flow rate control valve 22 is adjusted in step S25, and the water filling effect does not become a problem. (Low speed filling speed) The speed is reduced to low flow rate filling of V4. The fourth filling speed V4 as a whole after passing through the flow rate control valve 22 is set to half of the second filling speed V2 as a whole, so that it is the same as the case of filling at the second filling speed V2 in step S16A. In addition, the other fuel tank 10B (or 10A) can be filled with low flow rate filling. In this case, for example, the second filling speed V2 is set to 20 to 60 (l / min) and the fourth filling speed V4 is set to 10 to 30 (l / min) at the flow rate when passing through the flow control valve 22.

  In the fuel filling system and the fuel filling method in the DME fuel-using engine according to the second embodiment, the fuel tank 10A (or 10B) that fills first is preferentially controlled to low flow rate filling, and damage due to shock waves is prevented. After the fuel filling to the fuel tank 10A (or 10B) that has reached the full tank is stopped, the filling time of the other fuel tank 10B (or 10A) is shortened again as a high flow rate filling. .

  As seen from FIG. 9, the fuel in one of the fuel tanks 10 </ b> A (or 10 </ b> B) reaches a preset liquid level from the time ta when filling of the fuel is started, and the electric resistance is “R0”. From time tb, when one fuel tank 10A (or 10B) is in a full tank state and is automatically stopped by the overfill prevention device 12, time tc is reached. The low flow rate filling is performed until the time point td when the filling stop of one fuel tank 10A (or 10B) can be confirmed.

  Furthermore, from the time td at which the filling stop of the one fuel tank 10A (or 10B) can be confirmed, the fuel in the other fuel tank 10B (or 10A) reaches a preset liquid level, and the electric resistance becomes “ The high flow rate filling can be performed up to the time point te when “R1” changes to “R1 + R2”. In addition, it fills with low flow volume until the time tf when the other fuel tank 10B (or 10A) is in a full tank state and automatically stops by the overfill prevention device 12.

  According to the fuel filling method and the fuel filling system of the DME fuel described above, in order to secure the amount of fuel to be loaded for long-distance traveling or the like, the use of the DME fuel in which a plurality of fuel tanks 10A and 10B are mounted is used. While a vehicle is being filled with fuel, a plurality of fuel tanks 10A and 10B are simultaneously filled with fuel, and the generation of shock waves when filling is stopped can be easily avoided at a low cost.

  According to the fuel filling method and the fuel filling system of the DME fuel of the present invention, in order to secure the amount of loaded fuel for a long-distance driving or the like, the vehicle using DME fuel equipped with a plurality of fuel tanks is used. On the other hand, with simple control and low cost, it is possible to easily avoid the generation of shock waves when stopping fuel supply while simultaneously filling fuel into multiple fuel tanks at the time of fuel filling. It can be used for automobiles using DME fuel.

DESCRIPTION OF SYMBOLS 1 Fuel filling system 10A, 10B Fuel tank 11A, 11B Liquid level gauge 11a Contact switch 11b Electric resistance 12 Overfill prevention apparatus 13 Filling port 14 Electric circuit 20 Meter (dispenser)
21 Filling nozzle 22 Flow control valve 30 Storage tank 40 Pressure pump 50 Signal cable

Claims (5)

In a method of filling a fuel tank with DME fuel for a vehicle equipped with a DME fuel-using engine and a plurality of fuel tanks for DME fuel,
When simultaneously filling a plurality of fuel tanks, control of the fuel filling speed to the fuel tank is not performed to the filling speed of each of the fuel tanks, but to the filling speed of the entire fuel tank. For all at once,
At the start of filling, the filling speed of the entire fuel tank is set as the first filling speed,
Next, when one fuel filling amount of the fuel tank reaches a preset filling amount for deceleration of the fuel tank, a shock wave at the time of stopping the supply of the filling speed to the whole fuel tank is not a second problem. Decelerate to filling speed,
When the fuel filling amount of the first fuel tank reaches a preset stopping filling amount of the fuel tank, only filling of the first fuel tank is stopped. How to fill the fuel tank. After filling of fuel in one of the fuel tanks is stopped, the filling speed of the whole fuel tank is increased to a third filling speed,
Next, when the second fuel filling amount of the fuel tank reaches the deceleration filling amount of the fuel tank, the filling speed of the entire fuel tank is reduced to the fourth filling speed,
2. The filling of the second fuel tank is stopped only when the fuel filling amount of the second fuel tank reaches a filling amount for stopping the fuel tank. A method of filling a fuel tank with DME fuel. In a fuel filling system for a DME fuel tank for a vehicle equipped with a DME fuel engine and a plurality of fuel tanks for DME fuel,
On the vehicle side, a liquid level gauge for detecting the fuel filling amount is provided in each of the fuel tanks,
A fuel supply line connecting the storage tank and the fuel tank is provided on the fuel stand side, a pressure feed pump and a flow rate adjusting valve are provided in the middle of the fuel supply line, a filling nozzle is provided at the tip, and the output of the liquid level gauge is further provided. And a filling control device for controlling the pressure-feed pump and the flow rate adjustment valve.
The filling control device comprises:
When simultaneously filling a plurality of fuel tanks, control of the fuel filling speed to the fuel tank is not performed to the filling speed of each of the fuel tanks, but to the filling speed of the entire fuel tank. For all at once,
At the start of filling, the filling speed of the entire fuel tank is set as the first filling speed,
Next, when one fuel filling amount of the fuel tank reaches a preset filling amount for deceleration of the fuel tank, a shock wave at the time of stopping the supply of the filling speed to the whole fuel tank is not a second problem. Decelerate to filling speed,
When the fuel filling amount of the first fuel tank reaches a preset filling amount for stoppage of the fuel tank, control for stopping only filling of the first fuel tank is performed. A fuel filling system for a fuel tank of DME fuel. The filling control device comprises:
After filling of fuel in one of the fuel tanks is stopped, the filling speed of the whole fuel tank is increased to a third filling speed,
Next, when the second fuel filling amount of the fuel tank reaches the deceleration filling amount of the fuel tank, the filling speed of the entire fuel tank is reduced to the fourth filling speed,
4. The control for stopping only the filling of the second fuel tank when the fuel filling amount of the second fuel tank reaches the filling amount for stopping the fuel tank is performed. The fuel filling system to the fuel tank of DME fuel described in 1. The liquid level gauge includes a contact switch that is turned on and off when it detects that the liquid level has reached a specified liquid level, and an electric resistance provided in parallel with the contact switch, and the liquid level is the specified liquid level Until the level is reached, the contact switch is ON and the electric resistance value is substantially zero, and when the liquid level reaches the specified liquid level, the contact switch is turned OFF and the electric resistance value While forming the value to change from a substantially zero state,
The liquid level gauge is connected in series to form an electric circuit for detecting the liquid level of the entire fuel tank, and the fuel filling amount of the fuel tank reaches the deceleration filling amount from a change in electric resistance in the electric circuit. The fuel filling system for a fuel tank of DME fuel according to claim 3 or 4, wherein the fuel is detected.

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