JP4138709B2 - Fuel supply system for liquefied gas engine - Google Patents

Description

  The present invention relates to a fuel supply device for a liquefied gas engine including a vaporizer that vaporizes liquid phase fuel.

In a liquefied gas engine using liquefied gas fuel (liquefied petroleum gas, compressed natural gas, etc.), liquid phase fuel is vaporized through a vaporizer and then supplied to a combustion chamber.
In the above engine, when the carburetor is excessively cooled by the latent heat of vaporization of the fuel, the fuel is not sufficiently vaporized, so that it is difficult to supply an appropriate amount of fuel according to the operating state to the combustion chamber. Become.

Therefore, conventionally, a fuel supply device for a liquefied gas engine having a mechanism for preventing excessive cooling of the carburetor has been proposed (for example, Patent Document 1). In the fuel supply apparatus, the carburetor is heated through the heat of the cooling water by supplying the cooling water of the engine to the carburetor.
JP-A-7-293345

However, there are concerns about the following in the fuel supply apparatus.
That is, when the temperature of the cooling water is low, such as when the engine is cold started, the carburetor is not sufficiently heated by the cooling water, so that the fuel cannot be vaporized properly in the carburetor.

  The present invention has been made in view of these circumstances, and an object of the present invention is to provide a fuel supply apparatus for a liquefied gas engine that can sufficiently vaporize fuel through a carburetor even when the engine is started. .

In the following, means for achieving the above object and its effects are described.
<Claim 1>
The invention according to claim 1 is a liquefaction comprising a vaporizer for vaporizing liquefied gas fuel, a circulation circuit for circulating a heat medium between the vaporizer and the engine, and a heat insulating container for storing the heat medium. A fuel supply apparatus for a gas engine, wherein a high-temperature heat medium stored in the heat insulating container is enclosed in the carburetor before the engine is started, and is vaporized by the carburetor after the engine is started. The gist of the invention is that a control means for releasing the containment of the heat medium based on the accumulated amount of fuel is provided.

  In the above configuration, since the high-temperature heat medium in the heat insulating container is enclosed in the carburetor before the engine is started, fuel vaporization is promoted by the heat medium when the engine is started. In the heat insulating container, a high-temperature heat medium supplied during the previous operation of the engine is stored in a heat-retained state.

  In addition, since the heat medium is released from the containment based on the accumulated amount of the vaporized fuel, it is difficult to sufficiently vaporize the fuel with the heat medium contained in the vaporizer. By supplying the heated heat medium to the vaporizer, a state where the fuel is sufficiently vaporized is suitably maintained.

  Incidentally, the magnitude of the thermal energy of the cooling water in the vaporizer decreases as the amount of fuel vaporized through the vaporizer increases. Therefore, it is possible to grasp whether or not the cooling water in the carburetor has thermal energy that can sufficiently vaporize the fuel through the accumulated amount of vaporized fuel.

Thus, according to the above configuration, fuel can be appropriately vaporized by the carburetor even when the engine is started.
<Claim 2>
According to a second aspect of the present invention, in the fuel supply apparatus for a liquefied gas engine according to the first aspect, the control means controls the fuel injection amount after the heat medium in the heat insulating container is sealed in the vaporizer. The present invention adopts a cumulative amount as an index value of the cumulative amount of vaporized fuel, and releases the containment of the heat medium based on the fact that the cumulative amount of the fuel injection amount is equal to or greater than a determination value for the injection amount. It is said.

  The injection amount determination value is set in advance as a value for determining whether or not the cooling water in the carburetor is in a state where the fuel can be sufficiently vaporized. The control means determines that the thermal energy of the cooling water in the carburetor is not large enough to vaporize the fuel when the cumulative fuel injection amount is equal to or greater than the injection amount determination value. On the contrary, when the cumulative amount of fuel injection is less than the value for determining the injection amount, it is determined that the thermal energy of the cooling water in the carburetor is large enough to vaporize the fuel.

  In the above configuration, since the containment is released based on the comparison result between the determination value for the injection amount set in this manner and the cumulative amount of fuel injection, fuel vaporization is promoted in the cooling water contained in the carburetor. When it becomes difficult to achieve this, the heat medium heated by the engine is quickly supplied to the vaporizer. Thereby, it is possible to suitably maintain a state in which the fuel is sufficiently vaporized through the vaporizer.

<Claim 3>
According to a third aspect of the present invention, in the fuel supply apparatus for a liquefied gas engine according to the second aspect, the control means is configured to control the injection amount based on the temperature of the heat medium immediately after being contained in the carburetor. The gist is to set a judgment value.

  Immediately after the heat medium is enclosed in the vaporizer, the heat energy of the heat medium is not consumed due to the latent heat of vaporization of the fuel. Therefore, the temperature of the heat medium at this time is used as an index value of the heat energy of the heat medium. Can be adopted.

  Therefore, by setting the anti-injection amount determination value in the above manner, it is possible to more accurately release the heat medium confinement based on the comparison result between the cumulative amount of fuel injection amount and the anti-injection amount determination value. Become.

<Claim 4>
The gist of a fourth aspect of the present invention is the fuel supply apparatus for a liquefied gas engine according to the third aspect, wherein the control means further sets the determination value for the injection amount in consideration of the temperature of the outside air. Yes.

The heat medium enclosed in the carburetor is cooled not only by the latent heat of vaporization of the fuel but also by the outside air.
Therefore, by setting the anti-injection amount determination value in the above-described manner, it becomes possible to more accurately release the heat medium containment.

<Claim 5>
According to a fifth aspect of the present invention, in the fuel supply apparatus for a liquefied gas engine according to the first aspect, the control means controls the amount of intake air after the heat medium in the heat insulating container is sealed in the vaporizer. The present invention adopts a cumulative amount as an index value of the cumulative amount of vaporized fuel and releases the containment of the heat medium based on the fact that the cumulative amount of the intake air amount is equal to or greater than a determination value for the intake air amount. It is said.

  The intake air amount determination value is set in advance as a value for determining whether or not the cooling water in the carburetor is in a state where the fuel can be sufficiently vaporized. The control means determines that the thermal energy of the cooling water in the carburetor is not large enough to vaporize the fuel when the cumulative amount of intake air is greater than or equal to the intake air amount determination value. On the other hand, when the cumulative amount of intake air is less than the intake air amount determination value, it is determined that the thermal energy of the cooling water in the carburetor is large enough to vaporize the fuel.

  Since there is a correlation between the fuel injection amount and the intake air amount, as shown in the above configuration, by releasing the containment of the heat medium based on the comparison result between the cumulative intake air amount and the intake air amount determination value In addition, an operational effect equivalent to the operational effect of the invention described in claim 2 can be obtained.

<Claim 6>
According to a sixth aspect of the present invention, in the fuel supply apparatus for a liquefied gas engine according to the fifth aspect, the control means is configured to control the intake air amount based on the temperature of the heat medium immediately after being contained in the carburetor. The gist is to set a judgment value.

By adopting such a configuration, the function and effect similar to the function and effect of the invention described in claim 3 can be achieved.
<Claim 7>
The gist of a seventh aspect of the present invention is that, in the fuel supply device for a liquefied gas engine according to the sixth aspect, the control means further sets the air intake amount determination value in consideration of the temperature of the outside air. Yes.

By adopting such a configuration, the function and effect similar to the function and effect of the invention of claim 4 can be achieved.
<Claim 8>
The invention according to claim 8 is the fuel supply device for a liquefied gas engine according to any one of claims 1 to 7, wherein the circulation circuit is not connected to the engine, and the carburetor, the heat insulating container, and the like. A first circulation circuit that circulates the heat medium between, a second circulation circuit that circulates the heat medium through the engine and without the carburetor, and between the engine and the carburetor And a third circulation circuit that circulates the heat medium, and the control means circulates the heat medium through the first circulation circuit and then moves the circulation circuit from the first circulation circuit. Switching the second circulation circuit to contain the heat medium in the vaporizer, and switching the circulation circuit from the second circulation circuit to the third circulation circuit releases the heat medium containment. Is summarized in that the at it.

  In the above configuration, the heat medium is circulated through the first circulation circuit before starting the engine, whereby the high-temperature heat medium in the heat insulating container is supplied into the vaporizer. Then, by switching the circulation circuit from the first circulation circuit to the second circulation circuit, a high-temperature heat medium is contained in the vaporizer. In addition, when it becomes difficult to sufficiently vaporize the fuel with the heat medium contained in the carburetor after the engine is started, the circulation circuit is switched from the second circulation circuit to the third circulation circuit. The containment of the heat medium is released.

<Claim 9>
The invention according to claim 9 is a fuel supply device for a liquefied gas engine that supplies fuel through an injector, wherein the carburetor vaporizes the liquefied gas fuel and supplies the fuel to the injector, and a heat medium heated by the engine A heat insulating container that stores the heat medium, a first circulation circuit that circulates the heat medium between the heat insulating container and the vaporizer without going through the engine, and the engine and the vaporizer without going through the vaporizer A second circulation circuit that circulates the heat medium; and a third circulation circuit that circulates the heat medium between the engine and the carburetor. The circulation of the heat medium through the first circulation circuit is started, and based on the fact that the high-temperature heat medium stored in the heat insulating container is supplied into the vaporizer, The medium circulation circuit is switched from the first circulation circuit to the second circulation circuit, and the engine is allowed to start. After the engine is started, the fuel injected through the injector from the start of the engine to the present The gist is to calculate a cumulative amount, and to switch the circulation circuit of the heat medium from the second circulation circuit to the third circulation circuit based on the cumulative amount of fuel being equal to or greater than the injection amount determination value. Yes.

<Claim 10>
The invention according to claim 10 is a fuel supply device for a liquefied gas engine that supplies fuel through a carburetor, a vaporizer that vaporizes the liquefied gas fuel and supplies the fuel to the carburetor, and a heat medium heated by the engine A heat insulating container that stores the heat medium, a first circulation circuit that circulates the heat medium between the heat insulating container and the vaporizer without going through the engine, and the engine and the vaporizer without going through the vaporizer A second circulation circuit that circulates the heat medium; and a third circulation circuit that circulates the heat medium between the engine and the carburetor. The circulation of the heat medium through the first circulation circuit is started, and based on the fact that the high-temperature heat medium stored in the heat insulating container is supplied into the vaporizer, The circulation circuit of the heat medium is switched from the first circulation circuit to the second circulation circuit, and the engine is allowed to start. After the engine is started, the engine has been sucked into the engine from the start to the present. Calculating a cumulative amount of air, and switching the circulation circuit of the heat medium from the second circulation circuit to the third circulation circuit based on the fact that the cumulative amount of air is greater than or equal to the intake air amount determination value. It is a summary.

  According to the ninth and tenth aspects of the present invention, since the high-temperature heat medium in the heat insulation container is enclosed in the carburetor prior to starting the engine, fuel vaporization is promoted by the heat medium when the engine is started. Be able to. In the heat insulating container, a high-temperature heat medium supplied during the previous operation of the engine is stored in a heat-retained state.

  Further, since the heat medium is not contained based on the cumulative amount of fuel injection (intake air quantity) of the engine, it is difficult to sufficiently promote fuel vaporization with the contained heat medium. By supplying the heat medium heated in step 1 to the carburetor, the state in which the fuel is sufficiently vaporized is suitably maintained.

  Thus, according to the above configuration, fuel can be appropriately vaporized by the carburetor even when the engine is started.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the present invention is embodied as a fuel supply device for a liquefied gas engine using liquefied petroleum gas (LPG).

<Configuration of the entire device>
FIG. 1 shows the configuration of a fuel supply device for a liquefied gas engine.
The liquefied gas fuel supply device 1 includes a fuel injection mechanism 3 for supplying fuel to the engine 9 and a cooling water circulation mechanism 5 for circulating cooling water (heat medium) of the engine 9. The engine 9 and the liquefied gas fuel supply device 1 are controlled through the electronic control device E. The control means includes an electronic control device E.

<Configuration of fuel injection mechanism>
The fuel injection mechanism 3 includes the following elements.
The fuel tank 31 stores fuel in a sealed state. In the fuel tank 31, there are liquid phase fuel and gas phase fuel.

The fuel pump 32 pumps up the liquid phase fuel in the fuel tank 31 and discharges it to the regulator 33 (vaporizer) side.
The first fuel passage P <b> 1 connects the fuel pump 32 and the regulator 33.

The fuel passage opening / closing valve 34 switches between opening and closing of the first fuel passage P1.
The regulator 33 regulates and vaporizes the liquid phase fuel supplied through the fuel pump 32. The regulator 33 is provided with a fuel chamber 33A for vaporizing fuel and a cooling water chamber 33B for storing cooling water.

The second fuel passage P <b> 2 connects the regulator 33 and the delivery pipe 35.
The delivery pipe 35 distributes fuel to the injectors 36.
The injector 36 supplies gas-phase fuel to the combustion chamber of the engine 9.

<Configuration of cooling water circulation mechanism>
The cooling water circulation mechanism 5 opens and closes a heat insulating container 51 that keeps the cooling water stored therein, an electric pump 52 that circulates the cooling water, a three-way valve 53 that switches a circulation path of the cooling water, and a part of the circulation path of the cooling water. A cooling water passage opening / closing valve 54 is provided.

In the cooling water circulation mechanism 5, a cooling water circulation circuit is formed through the following cooling water passages.
The first cooling water passage R <b> 1 connects the discharge port of the electric pump 52 and the heat insulating container 51.

The second cooling water passage R <b> 2 connects the heat insulating container 51 and the first port 53 </ b> A of the three-way valve 53.
The third cooling water passage R3 connects the second port 53B of the three-way valve 53 and the inlet of the cooling water chamber 33B of the regulator 33.

The fourth cooling water passage R4 connects the outlet of the cooling water chamber 33B of the regulator 33 with the fifth cooling water passage R5 and the sixth cooling water passage R6.
The fifth cooling water passage R5 connects the fourth cooling water passage R4 and the sixth cooling water passage R6 to the suction port of the electric pump 52.

The sixth cooling water passage R6 connects the suction port of the water pump 91 of the engine 9 to the fourth cooling water passage R4 and the fifth cooling water passage R5.
The seventh coolant passage R7 connects the third port 53C of the three-way valve 53 and the coolant passage formed inside the engine 9. The cooling water passage formed inside the engine 9 includes a water jacket that communicates with the radiator.

The function of each element provided in the cooling water circulation circuit will be described.
The electric pump 52 discharges cooling water on the engine 9 side toward the heat insulating container 51 during driving. On the other hand, the cooling water is not discharged during the stop, but the cooling water is allowed to flow between the first cooling water passage R1 and the fifth cooling water passage R5.

The three-way valve 53 can be switched to any of the following “first open / close state”, “second open / close state”, “third open / close state”, and “fourth open / close state”.
[A] In the first open / close state, the cooling water is circulated between the second cooling water passage R2 and the third cooling water passage R3, while each of the cooling water passages R2, R3 and the seventh cooling water passage R7. Do not circulate cooling water between the two.
[B] In the second open / close state, while circulating the cooling water between the second cooling water passage R2 and the seventh cooling water passage R7, each of these cooling water passages R2, R7 and the third cooling water passage R3 Do not circulate cooling water between the two.
[C] In the third open / close state, the coolant is circulated between the seventh coolant passage R7 and the third coolant passage R3, while the coolant passages R7, R3 and the second coolant passage R2 Do not circulate cooling water between the two.
[D] In the fourth open / close state, the cooling water is circulated among the second cooling water passage R2, the third cooling water passage R3, and the seventh cooling water passage R7.

The cooling water passage opening / closing valve 54 opens the fourth cooling water passage R4 when the valve is open. On the other hand, when the valve is closed, the fourth coolant passage R4 is closed.
The water pump 91 of the engine 9 circulates cooling water between the engine 9 and the radiator. The cooling water is also circulated in the cooling water circulation mechanism 5. The water pump 91 can circulate the cooling water only while the engine 9 is operating.

The electronic control unit E controls the driving state of the electric pump 52 and the opening / closing states of the three-way valve 53 and the cooling water passage opening / closing valve 54 based on the operating state of the engine 9 and the like.
The electronic control unit E includes a CPU that executes arithmetic processing for engine control, a memory for storing programs and information necessary for engine control, and an input port and an output port for inputting / outputting signals to / from the outside. Configured.

The following various sensors for detecting the operation status of the engine 9 are connected to the input port of the electronic control unit E.
The engine water temperature sensor E1 is provided in the cooling water passage inside the engine 9 and detects the temperature of the cooling water flowing through the cooling water passage (engine cooling water temperature TWE).

The regulator water temperature sensor E2 is provided in the cooling water chamber 33B of the regulator 33, and detects the temperature of the cooling water in the cooling water chamber 33B (regulator cooling water temperature TWR).
To the output port of the electronic control unit E, an electric pump 52, a three-way valve 53, a cooling water passage opening / closing valve 54, an injector 36, and the like are connected. The electronic control unit E adjusts the fuel injection amount from the injector 36 by controlling the valve opening time of the injector 36 based on the operating state of the engine 9.

<Circulation form of cooling water circulation mechanism>
In the cooling water circulation mechanism 5, the cooling water circulation mode is switched as shown in FIGS. 2 to 5 in accordance with the open / closed state of the three-way valve 53. In each figure, the path | route where the flow of the cooling water has arisen is shown as the continuous line, and the path | route where the flow of the cooling water has not arisen is shown with the broken line, respectively. Moreover, the arrow on each path | route has shown the circulation direction of cooling water.

Hereinafter, the circulation form shown in each figure is referred to as follows.
-Let the circulation form of FIG. 2 be a 1st circulation form.
-Let the circulation form of FIG. 3 be a 2nd circulation form.
-Let the circulation form of FIG. 4 be a 3rd circulation form.
-Let the circulation form of FIG. 5 be a 4th circulation form.

[1] "First circulation form"
As shown in FIG. 2, in the first circulation mode, the cooling water circulates between the regulator 33 and the heat insulating container 51 without passing through the inside of the engine 9. In this circulation mode, the electric pump 52, the first cooling water passage R1, the heat insulating container 51, the second cooling water passage R2, the three-way valve 53, the third cooling water passage R3, the regulator 33, the fourth cooling water passage R4, and the first A cooling water circulation circuit is configured by the five cooling water passages R5. Hereinafter, this circulation circuit is referred to as a first circulation circuit.

In the first circulation mode, the three-way valve 53 and the coolant passage opening / closing valve 54 are maintained in the following open / closed state.
The three-way valve 53 is maintained in the first open / close state.
The cooling water passage opening / closing valve 54 is maintained in the opened state.

Further, the electric pump 52 and the water pump 91 are maintained in the following driving state.
The electric pump 52 is maintained in a driven state.
-The water pump 91 is maintained in the stopped state.

That is, in the first circulation mode, a flow of cooling water is formed through the electric pump 52. Accordingly, the cooling water circulates in the direction indicated by the arrow in FIG.
[2] "Second circulation form"
As shown in FIG. 3, in the second circulation mode, the cooling water circulates between the heat insulating container 51 and the inside of the engine 9 without passing through the regulator 33. In this circulation mode, the water pump 91, the cooling water passage inside the engine 9, the seventh cooling water passage R7, the three-way valve 53, the second cooling water passage R2, the heat insulating container 51, the first cooling water passage R1, the electric pump 52, A cooling water circulation circuit is formed by the fifth cooling water passage R5 and the sixth cooling water passage R6. Hereinafter, this circulation circuit is referred to as a second circulation circuit.

In the second circulation mode, the three-way valve 53 and the coolant passage opening / closing valve 54 are maintained in the following open / closed state.
The three-way valve 53 is maintained in the second open / close state.
The cooling water passage opening / closing valve 54 is maintained in a closed state.

Further, the electric pump 52 and the water pump 91 are maintained in the following driving state.
The electric pump 52 is maintained in a stopped state.
-The water pump 91 is maintained in the driven state.

That is, in the second circulation mode, a flow of cooling water is formed through the water pump 91. Accordingly, the cooling water circulates in the direction indicated by the arrow in FIG.
[3] “Third circulation mode”
As shown in FIG. 4, in the third circulation mode, the cooling water circulates between the inside of the engine 9 and the regulator 33 without passing through the heat insulating container 51. In this circulation mode, the water pump 91, the cooling water passage inside the engine 9, the seventh cooling water passage R7, the three-way valve 53, the third cooling water passage R3, the regulator 33, the fourth cooling water passage R4, and the sixth cooling water. A cooling water circulation circuit is formed by the passage R6. Hereinafter, this circulation circuit is referred to as a third circulation circuit.

In the third circulation mode, the three-way valve 53 and the coolant passage opening / closing valve 54 are maintained in the following open / closed state.
The three-way valve 53 is maintained in the third open / close state.
The cooling water passage opening / closing valve 54 is maintained in the opened state.

Further, the electric pump 52 and the water pump 91 are maintained in the following driving state.
The electric pump 52 is maintained in a stopped state.
-The water pump 91 is maintained in the driven state.

That is, in the third circulation mode, a flow of cooling water is formed through the water pump 91. Accordingly, the cooling water circulates in the direction indicated by the arrow in FIG.
[4] "4th circulation form"
As shown in FIG. 5, in the fourth circulation mode, the cooling water circulates between the inside of the engine 9, the regulator 33, and the heat insulating container 51. That is, this corresponds to a state in which the circulation of the cooling water in the second circulation form and the circulation of the cooling water in the third circulation form are simultaneously formed.

  In this circulation mode, the third circulation circuit is constituted by the water pump 91, the seventh cooling water passage R7, the three-way valve 53, the third cooling water passage R3, the regulator 33, the fourth cooling water passage R4, and the sixth cooling water passage R6. Is formed. Further, the water pump 91, the seventh cooling water passage R7, the three-way valve 53, the second cooling water passage R2, the heat insulating container 51, the first cooling water passage R1, the electric pump 52, the fifth cooling water passage R5, and the sixth cooling. A second circulation circuit is formed by the water passage R6. Hereinafter, the circulation circuit in which the second circulation circuit and the third circulation circuit are simultaneously formed is referred to as a fourth circulation circuit.

In the fourth circulation mode, the three-way valve 53 and the coolant passage opening / closing valve 54 are maintained in the following open / closed state.
The three-way valve 53 is maintained in the fourth open / close state.
The cooling water passage opening / closing valve 54 is maintained in the fourth opening / closing state.

Further, the electric pump 52 and the water pump 91 are maintained in the following driving state.
The electric pump 52 is maintained in a stopped state.
-The water pump 91 is maintained in the driven state.

That is, in the fourth circulation form, a flow of cooling water is formed through the water pump 91. Accordingly, the cooling water circulates in the direction indicated by the arrow in FIG.
<Changing mode of cooling water circulation mode>
The electronic control unit E switches the circulation form of the cooling water circulation mechanism 5 based on the following conditions.

[1] “Switching to the first circulation mode”
The electronic control unit E switches the circulation form of the cooling water circulation mechanism 5 to the first circulation form based on the detection of the start preparation operation of the engine 9. That is, based on the detection of the start preparation operation of the engine 9, the cooling water circulation circuit is switched from the circulation circuit selected in advance to the first circulation circuit. The start preparation operation of the engine 9 indicates an operation performed on the vehicle through the driver until the engine 9 is started.

  Thereby, the high-temperature cooling water stored in the heat insulation container 51 during the previous operation of the engine 9 is supplied from the heat insulation container 51 to the regulator 33, and the low-temperature cooling water staying in the regulator 33 is also removed from the regulator 33. It will be pushed out from.

  Further, when the electronic control unit E detects that the ignition switch has been switched to “START” by the driver's operation while driving the cooling water circulation mechanism 5 in the first circulation mode, the electronic control unit E starts the engine 9. Hold on. Then, the engine 9 is allowed to start based on the fact that the high-temperature cooling water stored in the heat insulating container 51 is sufficiently supplied into the cooling water chamber 33B of the regulator 33.

  As a result, a situation in which the engine 9 is started before the high-temperature cooling water is supplied to the regulator 33 is avoided. While the engine 9 is suspended from starting, for example, the driver is informed that the engine 9 is in a normal state by guiding the driver that the engine 9 is on standby through an indicator lamp or the like. be able to.

[2] “Switching to the second circulation mode”
In the first circulation mode, the electronic control unit E is sufficiently supplied with the high-temperature cooling water stored in the heat insulating container 51 into the cooling water chamber 33B of the regulator 33, and then starts ( Alternatively, immediately after starting, the circulation form of the cooling water circulation mechanism 5 is switched from the first circulation form to the second circulation form. Note that the cooling water circulation circuit starts from the first circulation circuit to the second circulation based on the fact that the high-temperature cooling water stored in the heat insulating container 51 is sufficiently supplied into the cooling water chamber 33B of the regulator 33. Switch to circuit.

  Accordingly, since the high-temperature cooling water stored in the heat insulating container 51 is enclosed in the regulator 33 prior to the start of the engine 9, fuel vaporization is promoted through the heat of the cooling water when the engine 9 is started. Be able to. Further, since the situation in which the high-temperature cooling water passes through the regulator 33 through the containment of the cooling water in the regulator 33 is avoided, the high-temperature cooling water is efficiently supplied to the regulator 33. It becomes like this.

[3] “Switching to the third circulation mode”
The electronic control unit E changes the circulation form of the cooling water circulation mechanism 5 to the third circulation based on the fact that in the second circulation form, the cooling water contained in the regulator 33 cannot sufficiently vaporize the fuel. Switch to form. That is, the cooling water circulation circuit is switched from the second circulation circuit to the third circulation circuit based on the fact that the cooling water contained in the regulator 33 cannot sufficiently evaporate the fuel.

  As a result, the containment of the cooling water in the regulator 33 is released, and the cooling water heated in the engine 9 is supplied to the regulator 33, so that a state in which the fuel can be sufficiently vaporized is suitably maintained. Will come to be.

[4] “Switch to the fourth circulation mode”
In the third circulation mode (or the second circulation mode), the electronic control unit E performs the cooling water circulation mechanism 5 based on the fact that the cooling water can be promoted to vaporize the fuel when the engine 9 is started next time. Is switched to the fourth circulation mode. That is, the cooling water circulation circuit is switched from the third circulation circuit to the fourth circulation circuit based on the fact that the cooling water is in a state in which fuel vaporization can be promoted at the next start of the engine 9.

  Thereby, since the cooling water heated by the engine 9 is supplied to the regulator 33 and the heat insulation container 51, the state which can promote vaporization of fuel at the time of the next engine 9 starting will be ensured.

<Release of cooling water containment>
In the liquefied gas fuel supply apparatus 1, when the release of the cooling water containment is not properly performed by switching the circulation mode from the second circulation mode to the third circulation mode, the vaporization performance of the regulator 33 reduces the fuel performance. Vaporization is not performed sufficiently.

  Therefore, in the present embodiment, the above problem is solved by releasing the containment of the cooling water based on the accumulated amount of fuel vaporized through the regulator 33 after containing the cooling water into the regulator 33. .

  Incidentally, when the fuel is vaporized in the regulator 33, the thermal energy of the cooling water in the regulator 33 is consumed by the latent heat of vaporization of the fuel, so the thermal energy of the cooling water in the regulator 33 is vaporized through the regulator 33. The smaller the cumulative amount of fuel, the smaller it becomes. Therefore, it is possible to estimate whether or not the coolant contained in the regulator 33 has sufficient heat energy to vaporize the fuel through the cumulative amount of fuel vaporized in the regulator 33.

  Regarding the release of the cooling water containment, specifically, the cumulative amount of the fuel injection amount is used as an index value of the cumulative amount of fuel vaporized through the regulator 33, and the cumulative amount is compared with the determination value for the injection amount. Based on the result, switching from the second circulation mode to the third circulation mode is performed. That is, the cumulative amount of fuel injected through the injector 36 after the engine 9 is started (fuel injection amount integrated value Fsum) is calculated, and this fuel injection amount integrated value Fsum is determined injection amount integrated value FsumX (vs. injection amount determination value). Based on the above, the containment of the cooling water is released.

  The determination injection amount integrated value FsumX is set as a value for determining whether or not the cooling water contained in the regulator 33 has heat energy that can sufficiently vaporize the fuel. When the fuel injection amount integrated value Fsum is less than the determination injection amount integrated value FsumX, the fuel is sufficiently vaporized by the thermal energy of the cooling water in the regulator 33. On the contrary, when the fuel injection amount integrated value Fsum is equal to or larger than the determination injection amount integrated value FsumX, the fuel cannot be sufficiently vaporized by the thermal energy of the cooling water in the regulator 33.

  As a result, when the cooling water sealed in the regulator 33 can no longer promote the vaporization of the fuel, the cooling water heated by the engine 9 is quickly supplied to the regulator 33. The state of being vaporized can be suitably maintained.

<Circulation mechanism control processing>
In the present embodiment, the driving mode of the cooling water circulation mechanism 5 is controlled through “circulation mechanism control processing”. This process is executed through the electronic control unit E.

The “circulation mechanism control process” includes the following processes.
・ "Switching process before starting" (Fig. 6)
・ "Judgment value setting process" (Fig. 7)
・ "Switching during operation [1]" (Fig. 9)
・ "Switching process during operation [2]" (Fig. 10)
Hereinafter, each of these processes will be described. In the present embodiment, each of the above processes is executed in the order of “switching process before start” → “determination value setting process” → “switching process during operation [1]” → “switching process during operation [2]”.

<Switching process before starting>
FIG. 6 shows a processing procedure of the “pre-startup switching process”. The electronic control unit E starts this process before the engine 9 is started.

[Step S110] It is determined whether a start preparation operation of the engine 9 has been performed.
In this embodiment, the start preparation operation of the engine 9 is detected when the ignition switch is switched from “OFF” to “ON” through the operation of the driver.
When the start preparation operation of the engine 9 is detected (when the ignition switch is switched from “OFF” to “ON”), the process proceeds to step S120.
When the start preparation operation of the engine 9 is not detected, the process of step S110 is executed again.

[Step S120] The cooling water circulation mechanism 5 is driven in the first circulation mode (FIG. 2).
[Step S <b> 130] It is determined whether or not the high-temperature cooling water stored in the heat insulating container 51 has been sufficiently supplied into the cooling water chamber 33 </ b> B of the regulator 33.

In the present embodiment, the period in which the cooling water circulation mechanism 5 is driven through the first circulation form (first form driving period TD), that is, the circulation period of the cooling water through the first circulation circuit is equal to or longer than the determination period TDX. It is detected that the high-temperature cooling water is sufficiently supplied into the regulator 33.
When the high-temperature cooling water is sufficiently supplied into the regulator 33 (when the first form driving period TD is equal to or longer than the determination period TDX), the process proceeds to step S140.
When the high-temperature cooling water is not sufficiently supplied into the regulator 33, the process of step S130 is executed again.

[Step S140] The circulation mode of the cooling water circulation mechanism 5 is switched from the first circulation mode (FIG. 2) to the second circulation mode (FIG. 3).
[Step S150] The “determination value setting process” (FIG. 7) is started and the process is terminated.

  Thus, in the “pre-startup switching process”, the high-temperature cooling water stored in the heat insulating container 51 is supplied into the cooling water chamber 33B of the regulator 33 based on the start preparation operation of the engine 9. Then, based on the fact that the high-temperature cooling water is sufficiently supplied into the regulator 33, the high-temperature cooling in the regulator 33 is performed by switching the circulation form of the cooling water circulation mechanism 5 from the first circulation form to the second circulation form. Contain water.

<Determination value setting process>
FIG. 7 shows the procedure of the “determination value setting process”.
[Step S210] Immediately after the cooling water is contained in the regulator 33 (immediately after switching from the first circulation mode to the second circulation mode), the temperature of the regulator cooling water temperature TWR detected through the regulator water temperature sensor E2. Is read. Hereinafter, the regulator cooling water temperature TWR at this time is referred to as the initial cooling water temperature TWRIN.

  [Step S220] The initial coolant temperature TWRIN is applied to the determined injection amount integrated value map (FIG. 8) to set the determined injection amount integrated value FsumX. The relationship between the initial cooling water temperature TWRIN and the determined injection amount integrated value FsumX is set in advance through a test or the like.

[Step S230] The “switching process during operation [1]” (FIG. 9) is started and this process is terminated.
Thus, in the “determination value setting process”, the determination injection amount integrated value FsumX is set based on the initial coolant temperature TWRIN.

<Operation switching process [1]>
FIG. 9 shows a processing procedure of “switching process during operation [1]”.
[Step S310] A cumulative amount of fuel injected through the injector 36 from the start of the engine 9 to the present (fuel injection amount integrated value Fsum) is calculated. The fuel injection amount integrated value Fsum is calculated by adding the current fuel injection amount to the fuel injection amount integrated value Fsum calculated so far. In this embodiment, the fuel injection amount integrated value Fsum is updated every time fuel is injected through the injector 36.

[Step S320] It is determined whether the fuel injection amount integrated value Fsum is equal to or greater than the determination injection amount integrated value FsumX.
When the fuel injection amount integrated value Fsum is less than the determination injection amount integrated value FsumX, the process of step S310 is executed again.
When the fuel injection amount integrated value Fsum is equal to or greater than the determination injection amount integrated value FsumX, the process proceeds to step S330.

  When the fuel injection amount integrated value Fsum is equal to or greater than the determination injection amount integrated value FsumX, the electronic control unit E determines that the fuel cannot be sufficiently vaporized with the thermal energy of the cooling water in the regulator 33. Conversely, when the fuel injection amount integrated value Fsum is less than the determination injection amount integrated value FsumX, it is determined that the fuel can be sufficiently vaporized by the thermal energy of the cooling water in the regulator 33.

[Step S330] The circulation mode of the cooling water circulation mechanism 5 is switched from the second circulation mode (FIG. 3) to the third circulation mode (FIG. 4).
[Step S340] The “switching process during operation [2]” (FIG. 10) is started and this process is terminated.

  As described above, in the “switching process during operation [1]”, the circulation form of the cooling water circulation mechanism 5 is changed from the second circulation form to the third based on the fact that the fuel injection amount integrated value Fsum is equal to or greater than the determination injection amount integrated value FsumX. By switching to the circulation mode, the containment of the cooling water is released and the cooling water heated inside the engine 9 is supplied to the regulator 33.

<Operation switching process [2]>
FIG. 10 shows a processing procedure of “switching process during operation [2]”.
[Step S410] It is determined whether or not the cooling water in the engine 9 is in a state (vs. starting high temperature state) in which fuel vaporization can be promoted when the engine 9 is started next time.

In the present embodiment, when the engine coolant temperature TWE detected through the engine coolant temperature sensor E1 is equal to or higher than the determination coolant temperature TWEX, it is detected that the coolant is in the high temperature state for starting.
When the cooling water inside the engine 9 is in the high temperature state for starting (when the engine cooling water temperature TWE is equal to or higher than the determination cooling water temperature TWEX), the process proceeds to step S420.
When the cooling water inside the engine 9 is not in the high temperature state for starting, the process of step S410 is executed again.

[Step S420] The circulation mode of the cooling water circulation mechanism 5 is switched from the third circulation mode (FIG. 4) to the fourth circulation mode (FIG. 5).
As described above, in the “switching process during operation [2]”, the cooling mode of the cooling water circulation mechanism 5 is changed from the third circulation mode to the fourth circulation based on the fact that the cooling water inside the engine 9 is in the high-temperature state for starting. By switching to the form, high-temperature cooling water is supplied to the heat insulating container 51.

<Example of control mode of cooling water circulation mechanism>
With reference to FIG. 11, the control aspect of the cooling water circulation mechanism 5 is demonstrated. FIG. 11 shows an example of the control mode of the cooling water circulation mechanism 5.

In FIG. 11, each time t111-t114 shows the next timing, respectively.
Time t111 indicates the time when the ignition switch is switched from “OFF” to “ON” by the driver's operation.
Time t112 indicates the time when the cooling water is completely contained in the regulator 33.
Time t113 indicates the time when the fuel injection amount integrated value Fsum is equal to or greater than the determination injection amount integrated value FsumX.
-Time t114 shows the time when engine cooling water temperature TWE became more than judgment cooling water temperature TWEX.

  When the electronic control unit E detects that the ignition switch has been switched from “OFF” to “ON” (time t111), the electronic control unit E starts to drive the cooling water circulation mechanism 5 through the first circulation mode.

  At this time, the high-temperature cooling water stored in the heat insulating container 51 is supplied into the cooling water chamber 33 </ b> B of the regulator 33. Further, the cooling water in the regulator 33 having a temperature lower than that of the supplied cooling water is pushed out of the regulator 33.

  When the electronic control unit E detects that the cooling water has been contained in the regulator 33 (when the first form driving period TD is equal to or greater than the determination period TDX (time t112)), the electronic control unit E The circulation mode is switched from the first circulation mode to the second circulation mode, and the engine 9 is allowed to start. Also, calculation of the fuel injection amount integrated value Fsum is started.

At this time, the high-temperature cooling water supplied to the regulator 33 is enclosed in the regulator 33. Thereby, vaporization of fuel can be promoted through high-temperature cooling water.
When the fuel injection amount integrated value Fsum becomes equal to or greater than the determination injection amount integrated value FsumX (time t113), the electronic control unit E switches the circulation form of the coolant circulation mechanism 5 from the second circulation form to the third circulation form. Further, the calculation of the fuel injection amount integrated value Fsum is finished.

  At this time, the cooling water in the engine 9 that is higher in temperature than the cooling water in the regulator 33 is supplied to the regulator 33. Thereby, the state in which the fuel is sufficiently vaporized in the regulator 33 is maintained.

  When the engine coolant temperature TWE becomes equal to or higher than the determined coolant temperature TWEX (time t114), the electronic control unit E switches the circulation form of the coolant circulation mechanism 5 from the third circulation form to the fourth circulation form.

  At this time, high-temperature cooling water inside the engine 9 is supplied to the heat insulating container 51. Thereby, the vaporization performance of the regulator 33 can be ensured through the high-temperature cooling water stored in the heat insulating container 51 at the next start of the engine 9.

<Effect of embodiment>
As described above in detail, according to the fuel supply apparatus for a liquefied gas engine according to the first embodiment, the effects listed below can be obtained.

  (1) In the liquefied gas fuel supply device 1 of the present embodiment, prior to the start of the engine 9 (when the start preparation operation is detected), the high-temperature cooling water stored in the heat insulating container 51 is fed into the regulator 33. It is trying to contain. As a result, when the engine 9 is started (particularly during a cold start), the fuel can be sufficiently vaporized through the contained cooling water.

  (2) In the liquefied gas fuel supply device 1 of the present embodiment, switching from the second circulation mode to the third circulation mode is performed based on the comparison result between the fuel injection amount integrated value Fsum and the determination injection amount integrated value FsumX. I have to. Thereby, when it becomes impossible to promote the vaporization of the fuel through the cooling water sealed in the regulator 33, the cooling water heated by the engine 9 is promptly supplied to the regulator 33. The state of being vaporized can be suitably maintained.

  (3) In the liquefied gas fuel supply apparatus 1 of the present embodiment, determination injection is performed based on the regulator coolant temperature TWR (initial coolant temperature TWRIN) immediately after the circulation mode is switched from the first circulation mode to the second circulation mode. The amount integrated value FsumX is set.

  Incidentally, immediately after the cooling water is contained in the regulator 33, the consumption of the cooling water due to the latent heat of vaporization of fuel does not occur, so the initial cooling water temperature TWRIN is equal to the thermal energy of the cooling water in the regulator 33. It can be adopted as an index value.

Therefore, by setting the determined injection amount integrated value FsumX in the above manner, the switching from the second circulation mode to the third circulation mode can be performed more accurately.
(4) Further, since it is possible to promote the vaporization of the fuel by using the thermal energy of the cooling water contained in the regulator 33 to the limit, the deterioration of the vaporization performance of the regulator 33 is avoided through a small amount of cooling water. Will be able to. Furthermore, by adopting the heat insulating container 51 having a smaller capacity, it is possible to contribute to downsizing of the apparatus.

  (5) As a method for releasing the containment of the cooling water (switching method from the second circulation mode to the third circulation mode), the following method can be considered in addition to the method according to the present invention. That is, it is possible to switch from the second circulation mode to the third circulation mode based on the fact that the detection value of the regulator water temperature sensor E2 (regulator cooling water temperature TWR) has fallen below a preset determination value.

  The determination value is set in advance as a value for determining whether or not the cooling water in the regulator 33 can sufficiently vaporize the fuel. When the regulator coolant temperature TWR is equal to or higher than the determination value, it is determined that the coolant in the regulator 33 has thermal energy that can sufficiently vaporize the fuel. On the other hand, when the regulator cooling water temperature TWR is less than the determination value, it is determined that the cooling water in the regulator 33 does not have heat energy that can sufficiently vaporize the fuel.

  By the way, when the fuel is vaporized in the regulator 33, the cooling water closer to the fuel chamber 33A is deprived of more thermal energy, so the temperature distribution in the cooling water chamber 33B becomes non-uniform. Therefore, when fuel is vaporized through the regulator 33, the degree of correlation between the regulator cooling water temperature TWR by the regulator water temperature sensor E2 and the magnitude of the thermal energy of the cooling water in the regulator 33 is small. Incidentally, the regulator cooling water temperature TWR indicated through the regulator water temperature sensor E2 when the fuel is vaporized is different depending on the mounting position of the regulator water temperature sensor E2.

For this reason, when switching the circulation form of the cooling water circulation mechanism 5 based on the detection value of the regulator water temperature sensor E2 as described above, the following problem arises.
That is, based on the fact that the regulator cooling water temperature TWR is equal to or higher than the determination value even though the cooling water in the regulator 33 does not actually have the thermal energy for sufficiently vaporizing the fuel, Switching from the 2-circulation mode to the third circulation mode may not be performed. In this case, the state in which the cooling water not having sufficient heat energy is confined in the regulator 33 is continued, leading to a decrease in the vaporization capability of the regulator 33.

  On the other hand, the regulator coolant temperature TWR is less than the criterion value even though the coolant in the regulator 33 actually has thermal energy sufficient to vaporize the fuel. Based on a certain thing, switching from the 2nd circulation form to the 3rd circulation form may be performed. In this case, cooling water that has not been sufficiently heated inside the engine 9 is supplied into the regulator 33, and high-temperature cooling water is pushed out of the regulator 33, thereby causing a lack of vaporization capability of the regulator 33. It is done.

  In this regard, in the liquefied gas fuel supply device 1 of the present embodiment, the fuel injection amount integrated value Fsum is used as an index value of the cumulative amount of fuel vaporized by the regulator 33, and the fuel injection amount integrated value Fsum and the determined injection amount are used. Based on the comparison result with the integrated value FsumX, it is determined whether or not the cooling water in the regulator 33 has thermal energy that can sufficiently vaporize the fuel. To the third circulation mode (cancel cooling water containment) can be appropriately performed.

  (6) As a method for releasing the containment of cooling water (switching method from the second circulation mode to the third circulation mode), in addition to the method based on the regulator cooling water temperature TWR described above, the following method is also available. Conceivable. That is, it is possible to switch to the third circulation mode (cancel the cooling water containment) based on the fact that the elapsed time after switching to the second circulation mode becomes a certain time or more.

Since the amount of fuel vaporized through the regulator 33 varies depending on the operating state of the engine 9, the following problem arises when the above method is employed.
In other words, when the predetermined time is set to correspond to the high load operation of the engine 9, if the low load operation is performed when the engine 9 is started, the cooling water in the regulator 33 has sufficient thermal energy. In spite of this, the containment of the cooling water may be released based on the fact that the elapsed time after switching to the second circulation mode has become equal to or longer than the predetermined time.

  At this time, because the engine 9 is operated at a low load, cooling water inside the engine 9 that is not sufficiently heated (cooling water having a temperature lower than that in the regulator 33) is supplied to the regulator 33. As a result, the vaporization performance of the regulator 33 is lowered.

  Further, when the predetermined time is set to correspond to the low load operation of the engine 9, if the high load operation is performed when the engine 9 is started, the heat energy of the cooling water in the regulator 33 is insufficient. In spite of this, the cooling water containment may be continued based on the fact that the elapsed time after switching to the second circulation mode is less than the predetermined time.

  At this time, the cooling water that does not have sufficient thermal energy to vaporize the fuel continues to stay in the regulator 33, leading to a decrease in the vaporization performance of the regulator 33.

  In the liquefied gas fuel supply device 1 of the present embodiment, as described above, the second circulation mode is changed to the third circulation mode based on the comparison result between the fuel injection amount integrated value Fsum and the determined injection amount integrated value FsumX. Since switching (canceling of cooling water containment) is performed, the concern in the switching method can be solved.

<Example of change>
In addition, the said 1st Embodiment can also be implemented as the following forms which changed this suitably, for example.

  In the first embodiment, the determination injection amount integrated value FsumX is calculated through the determination injection amount integrated value calculation map of FIG. 8, but the initial coolant temperature TWRIN and the determination injection amount in the determination injection amount integrated value calculation map are described. The relationship with the integrated value FsumX is not limited to the illustrated relationship. In short, an appropriate calculation map is adopted as long as it is a determination injection amount integrated value calculation map that is set based on test results and has a relationship that the determination injection amount integrated value FsumX increases as the initial cooling water temperature TWRIN increases. be able to.

  In the first embodiment, the determination injection amount integrated value FsumX is set based on the initial cooling water temperature TWRIN. However, it can be changed as follows. That is, the determination injection amount integrated value FsumX can be set based on the initial cooling water temperature TWRIN and the temperature of the outside air. Incidentally, the cooling water enclosed in the regulator 33 is cooled not only by the vaporization latent heat of the fuel but also by the outside air. Therefore, by setting the determination injection amount integrated value FsumX in the above manner, it becomes possible to more accurately release the cooling water containment.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, it is assumed that the present invention is applied to a fuel supply device (mixer-type fuel supply device) that supplies fuel to the combustion chamber of the engine 9 through a carburetor. That is, the fuel supply device of the present embodiment has a configuration in which the carburetor is provided instead of the injector in the fuel supply device of the first embodiment.

And the control concerning cancellation | release of containment of cooling water is changed according to the change of such a fuel supply system.
In the present embodiment, the cumulative amount of the intake air amount is used as an index value of the cumulative amount of fuel vaporized through the regulator 33, and from the second circulation mode based on the comparison result between the cumulative amount and the intake air amount determination value. Switch to the third circulation mode. That is, the cumulative amount of air sucked into the engine 9 after the engine 9 is started (intake air amount integrated value Qsum) is calculated, and this intake air amount integrated value Qsum is determined as the determined intake air amount integrated value QsumX (vs. intake air amount determination value). ) Based on the above, release the cooling water containment.

  The determination intake air amount integrated value QsumX is set as a value for determining whether or not the cooling water contained in the regulator 33 has thermal energy that can sufficiently vaporize the fuel. When the intake air amount integrated value Qsum is less than the determined intake air amount integrated value QsumX, the fuel can be sufficiently vaporized by the thermal energy of the cooling water in the regulator 33. On the other hand, when the intake air amount integrated value Qsum is equal to or greater than the determined intake amount integrated value QsumX, the heat energy of the cooling water in the regulator 33 cannot sufficiently vaporize the fuel.

  In the fuel supply device of this embodiment, since there is a correlation between the amount of fuel supplied to the engine 9 through the carburetor and the amount of intake air, the first embodiment can also be performed by releasing the containment of cooling water in the above manner. The effect according to the effect of a form comes to be show | played.

  Hereinafter, a process changed from the first embodiment in the “injection mechanism control process” will be described. In addition, except the structure demonstrated below, the structure similar to the said 1st Embodiment is employ | adopted.

<Determination value setting process>
FIG. 12 shows a processing procedure of the “judgment value setting process [2]”.
[Step T210] The regulator cooling water temperature TWR (initial cooling water temperature TWRIN) immediately after the containment of the cooling water into the regulator 33 is read.

  [Step T220] The initial cooling water temperature TWRIN is applied to the determined intake air amount integrated value map (FIG. 13) to set the determined intake air amount integrated value QsumX. The relationship between the initial coolant temperature TWRIN and the determined intake air amount integrated value QsumX is set in advance through a test or the like.

[Step T230] The “switching process during operation [3]” (FIG. 14) is started and this process is terminated.
Thus, in the “determination value setting process”, the determination intake air amount integrated value QsumX is set based on the initial cooling water temperature TWRIN.

<Operation switching process [3]>
FIG. 14 shows a processing procedure of “switching process during operation [3]”.
[Step T310] The cumulative amount of air sucked into the engine 9 from the start of the engine 9 to the present (intake air amount integrated value Qsum) is calculated. In the present embodiment, the intake air amount integrated value Qsum is calculated based on the intake air amount detected through the air flow meter.

[Step T320] It is determined whether the intake air amount integrated value Qsum is greater than or equal to the determined intake air amount integrated value QsumX.
When the intake air amount integrated value Qsum is less than the determined intake air amount integrated value QsumX, the process of step T310 is executed again.
When the intake air amount integrated value Qsum is greater than or equal to the determined intake air amount integrated value QsumX, the process proceeds to step T330.

  When the intake air amount integrated value Qsum is equal to or greater than the determined intake amount integrated value QsumX, the electronic control unit E determines that the fuel cannot be sufficiently vaporized with the thermal energy of the cooling water in the regulator 33. Conversely, when the intake air amount integrated value Qsum is less than the determined intake amount integrated value QsumX, it is determined that the fuel can be sufficiently vaporized by the thermal energy of the cooling water in the regulator 33.

[Step T330] The circulation mode of the cooling water circulation mechanism 5 is switched from the second circulation mode (FIG. 3) to the third circulation mode (FIG. 4).
[Step T340] The “switching process during operation [2]” (FIG. 10) is started and this process is terminated.

  As described above, in the “switching process during operation [3]”, the circulation form of the cooling water circulation mechanism 5 is changed from the second circulation form to the third circulation form based on the intake air amount integrated value Qsum being equal to or greater than the determined intake amount integrated value QsumX. By switching to the circulation mode, the containment of the cooling water is released and the cooling water heated inside the engine 9 is supplied to the regulator 33.

<Effect of embodiment>
As described above in detail, according to the fuel supply apparatus for a liquefied gas engine according to the second embodiment, effects similar to the effects (1) to (6) according to the first embodiment can be obtained. become.

<Example of change>
In addition, the said 2nd Embodiment can also be implemented as the following forms which changed this suitably, for example.

  In the second embodiment, the determined intake air amount integrated value QsumX is calculated through the determined intake air amount integrated value calculation map of FIG. 13, but the initial cooling water temperature TWRIN and the determined intake air amount in the determined intake air amount integrated value calculation map are described. The relationship with the integrated value QsumX is not limited to the illustrated relationship. In short, an appropriate calculation map is adopted as long as it is a determined intake air amount integrated value calculation map that is set based on test results and has a relationship that the determined intake air amount integrated value QsumX increases as the initial coolant temperature TWRIN increases. be able to.

  In the second embodiment, the determination intake air amount integrated value QsumX is set based on the initial cooling water temperature TWRIN. However, it can be changed as follows. That is, the determination intake air amount integrated value QsumX can be set based on the initial cooling water temperature TWRIN and the temperature of the outside air. Incidentally, the cooling water enclosed in the regulator 33 is cooled not only by the vaporization latent heat of the fuel but also by the outside air. Therefore, by setting the determined intake air amount integrated value QsumX in the above manner, the cooling water containment can be released more accurately.

(Other embodiments)
In addition, elements that can be changed in common with each of the above embodiments are listed below.
In each of the above embodiments, the engine 9 is prepared to detect the start preparation operation when the ignition switch is switched from “OFF” to “ON” through the driver's operation. However, the conditions for detecting such a state are described. Is not limited to the conditions exemplified in each embodiment. For example, the start preparation operation of the engine 9 can be detected when the door of the vehicle is opened.

  In each of the above-described embodiments, the high-temperature cooling water is sufficiently supplied into the regulator 33 because the period during which the cooling water circulates through the first circulation circuit (the first form driving period TD) is equal to or longer than the determination period TDX. However, the conditions for detecting such a state are not limited to the conditions exemplified in each embodiment.

For example, any of the following detection methods [a] and [b] may be employed.
[A] Based on the fact that the temperature of the cooling water in the regulator 33 is equal to or higher than a predetermined determination value, it is detected that the high-temperature cooling water is sufficiently supplied into the regulator 33.
[B] Based on the fact that the temperature rise degree of the cooling water in the regulator 33 is equal to or higher than a predetermined determination value, it is detected that the high-temperature cooling water is sufficiently supplied into the regulator 33.

  In each of the above embodiments, the regulator water temperature sensor E2 is provided in the cooling water chamber 33B of the regulator 33. However, the regulator water temperature sensor E2 can be changed as follows. That is, the regulator water temperature sensor E2 can be provided at the inlet or outlet of the cooling water chamber 33B.

  In each of the above embodiments, the liquefied gas fuel supply device 1 having the configuration shown in FIG. 1 is assumed, but the configuration of the fuel injection mechanism 3 in the device 1 is not limited to the configuration illustrated in each embodiment. . In short, the configuration of the fuel injection mechanism 3 can be appropriately changed as long as the configuration includes the regulator 33 that regulates and vaporizes the liquid phase fuel.

  In each of the above embodiments, the liquefied gas fuel supply device 1 having the configuration shown in FIG. 1 is assumed, but the configuration of the cooling water circulation mechanism 5 in the device 1 is not limited to the configuration illustrated in each embodiment. . In short, a first circulation circuit that circulates the cooling water between the heat insulating container 51 and the regulator 33 without going through the engine 9, and a second circulation circuit that circulates the cooling water through the engine 9 and without going through the regulator 33. If it is the structure provided with the 3rd circulation circuit which circulates cooling water between the engine 9 and the regulator 33, the structure of the cooling water circulation mechanism 5 can be changed suitably.

  In each of the above embodiments, the present invention is applied to a fuel supply device for a liquefied petroleum gas engine using liquefied petroleum gas as a fuel. However, a liquefied gas such as compressed natural gas (CNG) or dimethyl ether (DME) is used as a fuel. The present invention can be applied to any fuel supply device as long as it is a fuel supply device for a liquefied gas engine. Even in such a case, the operational effects according to the operational effects of the above-described embodiments can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the whole structure about 1st Embodiment which actualized the fuel supply apparatus of the liquefied gas engine concerning this invention. The operation | movement figure which shows one of the circulation forms about the fuel supply apparatus of the liquefied gas engine of the embodiment. The operation | movement figure which shows one of the circulation forms about the fuel supply apparatus of the liquefied gas engine of the embodiment. The operation | movement figure which shows one of the circulation forms about the fuel supply apparatus of the liquefied gas engine of the embodiment. The operation | movement figure which shows one of the circulation forms about the fuel supply apparatus of the liquefied gas engine of the embodiment. 9 is a flowchart showing a processing procedure of a “pre-startup switching process” executed as part of the “circulation mechanism control process” in the embodiment. 9 is a flowchart showing a processing procedure of “determination value setting processing” executed as part of “circulation mechanism control processing” in the embodiment. The graph which shows an example of the determination injection amount integrated value calculation map used for the "determination value setting process" of the embodiment. The flowchart which shows the process sequence of "switching process at the time of operation [1]" performed as a part of "circulation mechanism control process" in the embodiment. The flowchart which shows the process sequence of "switching process at the time of operation [2]" performed as a part of "circulation mechanism control process" in the embodiment. The time chart which shows an example of the control aspect of the cooling water circulation mechanism by the "circulation mechanism control process" of the embodiment. Processing procedure of “determination value setting process [2]” executed as part of “circulation mechanism control process” in the second embodiment that embodies the fuel supply device for a liquefied gas engine according to the present invention. The flowchart which shows. The graph which shows an example of the determination injection amount integrated value calculation map used for "determination value setting process [2]" of the embodiment. The flowchart which shows the process sequence of "switching process at the time of operation [3]" performed as a part of "circulation mechanism control process" in the embodiment.

Explanation of symbols

1 ... liquefied gas fuel supply device.
DESCRIPTION OF SYMBOLS 3 ... Fuel injection mechanism, 31 ... Fuel tank, 32 ... Fuel pump, 33 ... Regulator, 33A ... Fuel chamber, 33B ... Cooling water chamber, 34 ... Fuel passage opening / closing valve, 35 ... Delivery pipe, 36 ... Injector, P1 ... No. 1 fuel passage, P2... Second fuel passage.

  DESCRIPTION OF SYMBOLS 5 ... Cooling water circulation mechanism, 51 ... Thermal insulation container, 52 ... Electric pump, 53 ... Three-way valve, 53A ... First port, 53B ... Second port, 53C ... Third port, 54 ... Cooling water passage opening / closing valve, R1 ... First 1 cooling water passage, R2 ... 2nd cooling water passage, R3 ... 3rd cooling water passage, R4 ... 4th cooling water passage, R5 ... 5th cooling water passage, R6 ... 6th cooling water passage, R7 ... 7th cooling Water passage.

9 ... Engine, 91 ... Water pump.
E: Electronic control device, E1: Engine water temperature sensor, E2: Regulator water temperature sensor.
TWE: engine coolant temperature, TWR: regulator coolant temperature, TWRIN: initial coolant temperature, Fsum: fuel injection amount integrated value, FsumX: determined injection amount integrated value, Qsum: intake air amount integrated value, QsumX: determined intake air amount Integrated value.

Claims (10)

A fuel supply apparatus for a liquefied gas engine, comprising: a vaporizer that vaporizes liquefied gas fuel; a circulation circuit that circulates a heat medium between the vaporizer and the engine; and a heat insulating container that stores the heat medium. ,
Prior to starting the engine, a high-temperature heat medium stored in the heat insulating container is enclosed in the carburetor, and after the engine is started, the heat based on the accumulated amount of fuel vaporized by the carburetor. A fuel supply device for a liquefied gas engine, characterized by comprising control means for releasing containment of the medium. The fuel supply apparatus for a liquefied gas engine according to claim 1,
The control means adopts a cumulative amount of fuel injection amount after enclosing the heat medium in the heat insulating container in the carburetor as an index value of the cumulative amount of vaporized fuel, and accumulates the fuel injection amount. The fuel supply device for a liquefied gas engine, wherein the heat medium is released from being sealed when the amount becomes equal to or greater than an injection amount determination value. The fuel supply apparatus for a liquefied gas engine according to claim 2,
The fuel supply device for a liquefied gas engine, wherein the control means sets the determination value for the injection amount based on the temperature of the heat medium immediately after being contained in the vaporizer. The fuel supply apparatus for a liquefied gas engine according to claim 3,
The control means further sets the anti-injection amount determination value in consideration of the temperature of the outside air. A fuel supply apparatus for a liquefied gas engine, wherein: The fuel supply apparatus for a liquefied gas engine according to claim 1,
The control means adopts a cumulative amount of intake air after enclosing the heat medium in the heat insulating container in the vaporizer as an index value of the cumulative amount of vaporized fuel, and accumulates the intake air amount. A fuel supply apparatus for a liquefied gas engine, wherein the heat medium is released from being sealed when the amount becomes equal to or greater than an intake air amount determination value. The fuel supply apparatus for a liquefied gas engine according to claim 5,
The fuel supply device for a liquefied gas engine, wherein the control means sets the air intake amount determination value based on a temperature of the heat medium immediately after being enclosed in the carburetor. The fuel supply apparatus for a liquefied gas engine according to claim 6,
The control means further sets the air intake amount determination value in consideration of the temperature of the outside air. A fuel supply apparatus for a liquefied gas engine, wherein: In the fuel supply apparatus of the liquefied gas engine as described in any one of Claims 1-7,
The circulation circuit includes a first circulation circuit that circulates the heat medium between the vaporizer and the heat insulating container without passing through the engine, and the heat medium that passes through the engine and not through the vaporizer. Including a second circulation circuit that circulates and a third circulation circuit that circulates the heat medium between the engine and the carburetor,
The control means encloses the heat medium in the vaporizer by switching the circulation circuit from the first circulation circuit to the second circulation circuit after circulating the heat medium through the first circulation circuit, A fuel supply device for a liquefied gas engine, wherein the heat medium is released by switching the circulation circuit from the second circulation circuit to the third circulation circuit. A fuel supply apparatus for a liquefied gas engine that supplies fuel through an injector,
A vaporizer for vaporizing liquefied gas fuel and supplying the fuel to the injector;
An insulated container for storing a heat medium heated by the engine;
A first circulation circuit for circulating the heat medium between the heat insulating container and the vaporizer without going through the engine;
A second circulation circuit for circulating the heat medium through the engine and without going through the vaporizer;
A third circulation circuit for circulating the heat medium between the engine and the vaporizer,
Based on the detection of the start preparation operation of the engine, the circulation of the heat medium through the first circulation circuit is started,
Based on the fact that the high-temperature heat medium stored in the heat insulating container is supplied into the vaporizer, the circulation circuit of the heat medium is switched from the first circulation circuit to the second circulation circuit, and the engine Allow starting,
After starting the engine, calculate the cumulative amount of fuel injected through the injector from the start of the engine to the present,
A fuel for a liquefied gas engine, wherein the circulation circuit of the heat medium is switched from the second circulation circuit to the third circulation circuit on the basis that the accumulated amount of the fuel becomes equal to or greater than an injection amount determination value. Feeding device. A fuel supply system for a liquefied gas engine that supplies fuel through a carburetor,
A vaporizer for vaporizing liquefied gas fuel and supplying the carburetor;
An insulated container for storing a heat medium heated by the engine;
A first circulation circuit for circulating the heat medium between the heat insulating container and the vaporizer without going through the engine;
A second circulation circuit for circulating the heat medium through the engine and without going through the vaporizer;
A third circulation circuit for circulating the heat medium between the engine and the vaporizer,
Based on the detection of the start preparation operation of the engine, the circulation of the heat medium through the first circulation circuit is started,
Based on the fact that the high-temperature heat medium stored in the heat insulating container is supplied into the vaporizer, the circulation circuit of the heat medium is switched from the first circulation circuit to the second circulation circuit, and the engine Allow starting,
After the engine is started, the cumulative amount of air taken into the engine from the start of the engine to the present is calculated,
A fuel for a liquefied gas engine, wherein the circulation circuit of the heat medium is switched from the second circulation circuit to the third circulation circuit based on the fact that the accumulated amount of air is equal to or greater than an intake air amount determination value. Feeding device.

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