JP5438597B2 - Evaporation feeder - Google Patents

Description

  The present invention relates to an evaporation supply device that supplies, to an intake passage, evaporation that is evaporated fuel obtained by vaporizing fuel of an internal combustion engine (hereinafter referred to as “engine”).

  When the fuel of the internal combustion engine is vaporized, it becomes an evaporative fuel. Such evaporation is supplied to the intake system, and contributes to reducing exhaust emissions at the time of starting, for example. The reduction of exhaust emission is particularly effective in starting the engine when it is cold.

  Conventionally, a fuel that evaporates by heating the fuel in the sub-tank, adsorbs the evaporated fuel to the canister, opens the purge valve when the engine starts, and supplies the evaporated fuel adsorbed to the canister to the intake passage has been proposed. (For example, see Patent Document 1)

JP 2007-239523 A

  However, in the invention described in Patent Document 1, the evaporation is generated by heating the fuel flowing through the fuel pipe or heating the fuel stored in the sub tank. Then, the generated evaporation is adsorbed to the canister. In this case, there is a delay in detachment from the canister, and there is a possibility that a sufficient amount of evaporation cannot be supplied when the engine is started.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an evaporation supply apparatus that can rapidly supply an evaporation and supply a sufficient amount of evaporation.

The evaporation supply device according to claim 1 , 2, or 3 , which has been made to achieve the above-described object, generates an evaporation by injecting fuel into an atmosphere heated by engine cooling water, and intakes the evaporation. It supplies to the passage.

  In this evaporation supply apparatus, the heat retention tank is provided in the circulation path of the engine cooling water. The storage tank is disposed in the heat retention tank. As a result, the atmosphere in the storage tank is warmed by the engine coolant. The fuel injection valve injects the fuel into the atmosphere in the storage tank, and the evaporation generated by vaporizing the fuel injected by the fuel injection valve is supplied to the intake passage by the supply pipe. The

  Here, the control unit executes a fuel injection process and an evaporation supply process. In the fuel injection process, fuel is injected into the storage tank by a fuel injection valve. Further, in the evaporation supply process, when there is a request for starting the engine, the supply piping is opened and the evaporation in the storage tank is supplied to the intake passage.

As described above, in the present invention, the evaporation tank is obtained by warming the storage tank with the engine cooling water and injecting the fuel into the high-temperature atmosphere of the storage tank. An amount of evaporation can be supplied.
In the fuel tank, it is conceivable that a part of the fuel evaporates and evaporation occurs. Therefore, as shown in claims 1 and 3, it is preferable to provide a canister that adsorbs the evaporation generated in the fuel tank. In this case, in addition to the evaporation generated in the storage tank by fuel injection, the evaporation detached from the canister is introduced into the storage tank. In this way, a sufficient amount of evaporation can be supplied.
Considering that fuel is also injected from the injector in parallel with the evaporation supply, as shown in claims 2 and 3, it is preferable to provide a pressure sensor for detecting the pressure in the storage tank. In this case, in the evaporation supply process, the concentration of the evaporation generated in the storage tank is estimated based on the information from the pressure sensor and the temperature information of the engine cooling water, and the fuel injection amount from the injector is adjusted. In this way, fuel injection from the injector can be appropriately controlled.
At this time, it is conceivable that the temperature information of the engine cooling water is obtained using, for example, a water temperature meter provided on the engine side. On the other hand, as shown in claim 4, a dedicated temperature sensor for acquiring temperature information of the engine cooling water may be provided in the heat retaining tank. In this way, since the temperature information of the engine cooling water in the heat retaining tank can be acquired, the estimation accuracy of the evaporation concentration can be increased.

The fuel injection process may be performed prior to the engine start request, as described in claim 5 . For example, when the idle stop control is performed, it is executed while the engine is stopped prior to the engine start request. In this way, it contributes to rapid evaporation supply.

By the way, when the engine cooling water in the heat retaining tank is kept at a high temperature, the controller may execute a heat retaining process as shown in claim 6 . This heat retention process circulates the engine cooling water when the temperature of the engine cooling water exceeds a predetermined temperature during engine operation, and stops the circulation of the engine cooling water when the engine is stopped.

  In this case, for example, when the engine is stopped by turning off the ignition key or the like, the circulation of the engine cooling water is also stopped. Therefore, the warmed tank is stored with the warmed engine cooling water. Thereafter, since the engine cooling water does not circulate until the temperature of the engine cooling water exceeds a predetermined temperature, the warmed engine cooling water is held in the heat retaining tank. Therefore, if it does in this way, even if it is a case where an engine is stopped, the temperature fall of the atmosphere in a storage tank can be suppressed.

Thus, from the viewpoint of suppressing the temperature drop of the atmosphere in the storage tank, as shown in claim 7 , it is preferable that the heat retaining tank has a heat insulating structure in which the internal engine cooling water is not easily cooled. In this way, the temperature drop of the atmosphere in the storage tank can be further suppressed.

Note that liquefied fuel may be stored in the storage tank. Therefore, as shown in claim 8 , it is preferable to provide a return pipe for returning the fuel liquefied in the storage tank to the fuel tank.

It is explanatory drawing which shows the evaporation supply apparatus of embodiment. It is a flowchart which shows a supply process. It is a flowchart which shows a heat retention process. It is explanatory drawing which shows the structural example in the case of adding a canister.

  FIG. 1 is an explanatory view schematically showing a gasoline engine. As shown in FIG. 1, the gasoline engine includes an engine body 10, an intake system 20, a fuel tank 30, an evaporation supply device, and the like.

  The engine body 10 has a spark plug 11, a cylinder 12, and a piston 13. The piston 13 is supported by the cylinder 12 so as to be reciprocally movable, and a combustion chamber 14 is formed above the piston 13. Although the engine body 10 has a plurality of cylinders 12, only one is shown in FIG. 1 for convenience. The engine body 10 has an intake valve 15 and an exhaust valve 16. Furthermore, the engine main body 10 has an injector 17 for injecting fuel into the combustion chamber 14. In the present embodiment, the injector 17 is configured to inject fuel into the combustion chamber 14. However, the injector 17 can be similarly applied to an internal combustion engine that is mounted on the intake system 20 and injects into the intake system 20.

  The gasoline engine shown in FIG. 1 is a water-cooled type, and a cooling water passage 18 for circulating engine cooling water is formed around the cylinder 12. The cooling water passage 18 is filled with engine cooling water.

  The intake system 20 has an intake pipe 21. The intake pipe 21 has an intake port 22 at one end and is open to the outside air. The other end is connected to the engine body 10. The intake pipe 21 forms an intake passage 23 that connects the intake port 22 and the combustion chamber 14 of the engine body 10. In the intake passage 23, an air cleaner 24, a throttle valve 25, and the like are provided in order from the upstream side. The most downstream side of the intake passage 23 is opened and closed by the intake valve 15 described above.

  An exhaust system is provided on the downstream side of the exhaust valve 16, but this embodiment does not have a feature in the exhaust system, and the description thereof is omitted.

  The fuel tank 30 is a tank that stores liquid gasoline as fuel. A fuel pump 31 is provided in the fuel tank 30, and liquid fuel is pumped up by the fuel pump 31 and supplied to the injector 17 of the engine body 10 through the fuel pipe 32. As a result, the fuel sprayed by the injector 17 is supplied to the combustion chamber 14.

  The evaporation supply device is for supplying evaporation, which is evaporated fuel, to the intake passage 23. The evaporation supply device includes a storage tank 40, a heat retaining tank 50, a supply pipe 60, a return pipe 70, and the like.

  The storage tank 40 is a tank that generates and stores an evaporation, and is disposed inside the heat retaining tank 50. The storage tank 40 is provided with a fuel injection valve 41. The fuel injection valve 41 is connected to an evaporation pipe 33 that branches from the middle of the fuel pipe 32. As a result, fuel can be injected into the storage tank 40. In addition, a pressure sensor 42 for measuring the evaporation concentration is provided inside the storage tank 40.

  The heat retaining tank 50 is connected to the cooling water channel 18 via two cooling pipes 51 and 52. A heat insulation valve 53 is provided in the middle of one cooling pipe 51. Here, the heat retaining tank 50 is incorporated in the circulation path of the engine cooling water. By opening the heat retaining valve 53, the engine cooling water is supplied from the one cooling pipe 51 to the heat retaining tank 50, and the other cooling pipe 52 is provided. As a result, the engine coolant is discharged from the heat retaining tank 50. Further, the heat retaining tank 50 has a heat insulating structure at its wall portion 54 so that the internal engine coolant is difficult to cool.

  With this configuration, high-temperature engine cooling water circulates in the heat retaining tank 50, so that the atmosphere in the storage tank 40 is warmed. Here, when the fuel is injected by the fuel injection valve 41, the fuel is vaporized in a high temperature atmosphere, and an evaporation having a high proportion of low boiling point components can be obtained in the storage tank 40.

  The supply pipe 60 connects the storage tank 40 and the intake pipe 21. A purge valve 61 is provided in the middle of the supply pipe 60, and the vapor stored in the storage tank 40 is supplied to the intake passage 23 by opening the purge valve 61.

  The return pipe 70 connects the storage tank 40 and the fuel tank 30. A return valve 71 is provided in the middle of the return pipe 70. Thereby, the fuel liquefied inside the storage tank 40 is returned to the fuel tank 30 by opening the return valve 71.

  The evaporation supply device is controlled by an ECU (not shown). Specifically, a signal from the pressure sensor 42 inside the storage tank 40 is input to the ECU, and the ECU controls the fuel injection valve 41, the heat retaining valve 53, the purge valve 61, the return valve 71, and the like. Is done.

  Next, a heat retention process executed by the ECU will be described. FIG. 2 is a flowchart showing the heat retention process. This heat retention process is repeatedly executed at a predetermined timing during operation.

  In first S100, it is determined whether or not the engine coolant temperature is higher than a predetermined temperature T. This water temperature is acquired by a water temperature gauge (not shown) attached to the engine side. If the water temperature is higher than the predetermined temperature T (S100: YES), the process proceeds to S110. On the other hand, when the water temperature is equal to or lower than the predetermined temperature T (S100: NO), the subsequent process is not executed and the heat retaining process is terminated.

  In S110, the heat retaining valve 53 of the heat retaining tank 50 is opened. In this process, the engine coolant that exceeds the predetermined temperature T is circulated and guided to the heat retaining tank 50.

  In next S120, it is determined whether or not the engine is stopped. When the engine is stopped, there is a case where idle stop control is performed. Another example is when the ignition key is turned off. If the engine is stopped (S120: YES), the heat retaining valve 53 is closed in S130, and then the heat retaining process is terminated. On the other hand, when the engine is not stopped (S120: NO), the process of S130 is not executed and the heat retaining process is terminated.

  Thus, in the heat retention process, when the temperature of the engine coolant becomes equal to or higher than the predetermined temperature T (S100 in FIG. 2: YES), the heat retention valve is opened (S110). As a result, the engine coolant circulates via the heat retaining tank 50 only when the engine coolant reaches a high temperature.

  When the engine is stopped (S120 in FIG. 2: YES). The heat retaining valve 53 is closed (S130), and high temperature engine cooling water is stored in the heat retaining tank 50. That is, when the engine is stopped, the circulation of the engine cooling water is also stopped and the temperature of the engine cooling water is lowered. The tank 40 is kept warm even when the engine is stopped.

  By executing such a heat retaining process, the engine cooling water warmed during engine operation is stored in the heat retaining tank 50 while the engine is stopped, and the storage tank 40 is warmed even when the engine is stopped. Become.

  Next, the supply process executed by the ECU will be described. FIG. 3 is a flowchart showing the supply process. In the present embodiment, the vehicle is assumed to be subjected to idle stop control, and this supply process is repeatedly executed at a predetermined timing during driving.

  In first S200, it is determined whether or not the engine is stopped. This process determines whether or not the engine is stopped by idle stop control at, for example, an intersection. If it is determined that the engine is stopped (S200: YES), the process proceeds to S210. On the other hand, when it is determined that the engine is not stopped (S200: NO), the subsequent processing is not executed and the supply processing is terminated.

  In S <b> 210, fuel is injected into the storage tank 40 by the fuel injection valve 41. As described above, the storage tank 40 is warmed even when the engine is stopped by repeatedly executing the heat retention process. Therefore, if fuel is injected into the storage tank 40, the fuel is vaporized in a high temperature atmosphere, and an evaporation with a high proportion of low boiling point components is generated in the storage tank 40.

  In subsequent S220, the concentration of the evaporation is estimated. This process is based on temperature information acquired by a water thermometer (not shown) provided on the engine body 10 side and a pressure value acquired by a pressure sensor 42 provided in the storage tank 40. The concentration is estimated.

  In next S230, it is determined whether or not an engine start request has been made. If it is determined that an engine start request has been made (S230: YES), the process proceeds to S240. On the other hand, when it is determined that there is no engine start request (S230: NO), the subsequent processing is not executed and the supply processing is terminated.

  In S240, the fuel injection amount to be injected by the injector 17 is calculated. This process calculates an appropriate fuel injection amount from the injector 17 based on the evaporation concentration estimated in S220.

  In subsequent S250, the purge valve 61 is opened and fuel is injected from the injector 17. When the purge valve 61 is opened, the evaporation is supplied to the intake passage 23 via the supply pipe 60.

  As described in detail above, in this embodiment, for example, when the engine is stopped by idle stop control at an intersection or the like (S200: YES in FIG. 3), fuel is injected into the storage tank 40 by the fuel injection valve 41. Is injected (S210). At this time, if the atmosphere in the storage tank 40 is warmed by the engine cooling water in the heat retaining tank 50, the fuel is vaporized in a high temperature atmosphere, and an evaporation with a large proportion of low boiling point components is generated in the storage tank 40. Thereafter, when there is a request for starting the engine (S230: YES), the purge valve 61 is opened, and the evaporation is supplied to the intake passage 23 via the supply pipe 60 (S250). As a result, the evaporation can be supplied quickly and a sufficient amount of the evaporation can be supplied.

  In the present embodiment, when the engine is stopped (S200 in FIG. 3: YES), that is, prior to the engine start request, fuel injection by the fuel injection valve 41 is performed (S210). This contributes to rapid evaporation supply.

  Furthermore, in this embodiment, the wall part 54 of the heat retaining tank 50 has a heat insulating structure, and when the engine is stopped (S120: YES in FIG. 2), the circulation of the engine coolant is also stopped (S130). Therefore, warmed engine cooling water is stored in the heat retaining tank 50. Thereafter, when the engine is operated and the temperature of the engine cooling water exceeds a predetermined temperature T, the engine cooling water is circulated (S100: YES, S110). That is, the engine cooling water that is cooled while the engine is stopped does not flow into the heat retaining tank 50. Thereby, even if it is a case where an engine is stopped, the temperature fall of the atmosphere in the storage tank 40 can be suppressed.

  In the present embodiment, a pressure sensor 42 for detecting the pressure in the storage tank 40 is provided. In the evaporation supply process shown in FIG. 3, the concentration of the evaporation generated in the storage tank 40 is estimated based on the information from the pressure sensor 42 and the temperature information of the engine cooling water (S220), and the fuel from the injector 17 is estimated. The injection amount is adjusted (S240). Thereby, the fuel injection from the injector 17 can be appropriately controlled. At this time, since the temperature information of the engine cooling water is obtained from a water temperature meter provided on the engine side, the number of parts can be reduced as compared with a configuration in which a temperature sensor is provided separately.

  Furthermore, in this embodiment, the return pipe 70 which returns the fuel liquefied with the storage tank 40 to the fuel tank 30 is provided. Thereby, the liquefied fuel can be quickly returned to the fuel tank 30.

  In this embodiment, the heat retention tank 50 corresponds to a “heat retention tank”, the storage tank 40 corresponds to a “storage tank”, the fuel injection valve 41 corresponds to a “fuel injection valve”, and the supply pipe 60 is “ Corresponds to “supply piping”.

  Further, an ECU (not shown) corresponds to the “control unit”, the processes of S200 and S210 in FIG. 3 are examples of “fuel injection process”, and the processes of S230 and S250 in FIG. 3 are “evaporation supply process”. It is an example. Moreover, the heat retention process shown in FIG. 2 is an example of the “heat retention process”.

  Furthermore, the pressure sensor 42 corresponds to a “pressure sensor”, the return pipe 70 corresponds to a “return pipe”, and the canister 80 corresponds to a “canister”.

As described above, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.
(A) For example, when it is set as the structure provided with a canister, it can consider configuring as shown in FIG. In this configuration, in addition to the configuration of the above embodiment, the canister 80, the suction pipe 81 that guides the evaporation generated in the fuel tank 30 to the canister 80, and the storage pipe that guides the evaporation desorbed from the canister 80 to the storage tank 40. A pipe 82 and a storage valve 83 capable of opening the pipe line of the storage pipe 82 are provided. In this way, in addition to the evaporation generated by the fuel injection by the fuel injection valve 41, the evaporation detached from the canister 80 is stored in the storage tank 40, so that a sufficient amount of evaporation can be supplied.

  (B) In the above embodiment, a water temperature meter provided on the engine side is used to estimate the evaporation concentration in the storage tank 40. In contrast, a temperature sensor that acquires temperature information of the engine coolant may be provided in the heat retaining tank 50. In this way, since the temperature information of the engine cooling water in the heat retaining tank can be acquired, the estimation accuracy of the evaporation concentration can be increased.

  (C) Furthermore, in the above embodiment, when it is determined that the engine has been stopped in the heat retention process shown in FIG. 2 (S120: YES), the heat retention valve 53 is closed (S130), and the engine cooling water is Circulation was stopped. On the other hand, the heat retaining valve 53 may be closed only when the ignition key is turned off. That is, in the case of a temporary engine stop by idle stop control, the heat retaining valve 53 may be left open.

10: Engine body 11: Spark plug 12: Cylinder 13: Piston 14: Combustion chamber 15: Intake valve 16: Exhaust valve 17: Injector 18: Cooling water channel 20: Intake system 21: Intake pipe 22: Intake port 23: Intake passage 24 : Air cleaner 25: Throttle valve 30: Fuel tank 31: Fuel pump 32: Fuel piping 33: Evaporation piping 40: Storage tank 41: Fuel injection valve 42: Pressure sensor 50: Thermal storage tank 51, 52: Cooling piping 53: Thermal insulation valve 54: Wall 60: Supply pipe 61: Purge valve 70: Return pipe 71: Return valve 80: Canister 81: Suction pipe 82: Storage pipe 83: Storage valve

Claims (8)

An evaporation supply device that generates an evaporation by injecting fuel into an atmosphere heated by engine cooling water and supplies the evaporation to an intake passage,
A heat retaining tank provided in a circulation path of the engine cooling water;
A storage tank disposed in the heat retaining tank;
A fuel injection valve capable of injecting fuel into the atmosphere in the storage tank;
A supply pipe for supplying an evaporation generated by vaporization of the fuel injected by the fuel injection valve to the intake passage;
When there is a fuel injection process for injecting fuel into the storage tank by the fuel injection valve and an engine start request, the pipeline of the supply pipe is opened, and the evaporation in the storage tank is transferred to the intake passage A control unit that executes an evaporation supply process to be supplied;
A canister that absorbs the evaporation generated in the fuel tank;
Equipped with a,
The evaporation supply apparatus, wherein the evaporation detached from the canister can be introduced into the storage tank . An evaporation supply device that generates an evaporation by injecting fuel into an atmosphere heated by engine cooling water and supplies the evaporation to an intake passage,
A heat retaining tank provided in a circulation path of the engine cooling water;
A storage tank disposed in the heat retaining tank;
A fuel injection valve capable of injecting fuel into the atmosphere in the storage tank;
A supply pipe for supplying an evaporation generated by vaporization of the fuel injected by the fuel injection valve to the intake passage;
When there is a fuel injection process for injecting fuel into the storage tank by the fuel injection valve and an engine start request, the pipeline of the supply pipe is opened, and the evaporation in the storage tank is transferred to the intake passage A control unit that executes an evaporation supply process to be supplied;
A pressure sensor for detecting the pressure in the storage tank;
Equipped with a,
In the evaporation supply process, the concentration of the evaporation generated in the storage tank is estimated based on the information from the pressure sensor and the temperature information of the engine cooling water, and the fuel injection amount from the injector is adjusted.
An evaporation supply device characterized by the above. An evaporation supply device that generates an evaporation by injecting fuel into an atmosphere heated by engine cooling water and supplies the evaporation to an intake passage,
A heat retaining tank provided in a circulation path of the engine cooling water;
A storage tank disposed in the heat retaining tank;
A fuel injection valve capable of injecting fuel into the atmosphere in the storage tank;
A supply pipe for supplying an evaporation generated by vaporization of the fuel injected by the fuel injection valve to the intake passage;
When there is a fuel injection process for injecting fuel into the storage tank by the fuel injection valve and an engine start request, the pipeline of the supply pipe is opened, and the evaporation in the storage tank is transferred to the intake passage A control unit that executes an evaporation supply process to be supplied;
A pressure sensor for detecting the pressure in the storage tank;
A canister that absorbs the evaporation generated in the fuel tank;
Equipped with a,
In the evaporation supply process, the concentration of the evaporation generated in the storage tank is estimated based on the information from the pressure sensor and the temperature information of the engine cooling water, the fuel injection amount from the injector is adjusted,
The evaporation supply apparatus, wherein the evaporation detached from the canister can be introduced into the storage tank . In the evaporation supply device according to claim 2 or 3 ,
An evaporation supply device comprising a dedicated temperature sensor for acquiring temperature information of the engine cooling water in the heat retaining tank. In the evaporation supply device according to any one of claims 1 to 4 ,
The fuel supply process is executed prior to an engine start request. In the evaporation supply device according to any one of claims 1 to 5 ,
The control unit circulates the engine cooling water when the engine cooling water exceeds a predetermined temperature during engine operation, and executes a heat retaining process for stopping circulation of the engine cooling water when the engine is stopped. Evaporation supply device. In the evaporation supply device according to any one of claims 1 to 6 ,
The evaporation supply device according to claim 1, wherein the heat retaining tank has a heat insulating structure in which internal engine coolant is difficult to cool. In the evaporation supply device according to any one of claims 1 to 7 ,
An evaporation supply apparatus comprising a return pipe for returning the fuel liquefied in the storage tank to the fuel tank.

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