JPH06330824A - Hydrocarbon exhaust gas reducing device for vehicle - Google Patents

Abstract

PURPOSE:To provide a hydrocarbon exhaust gas reducing device for vehicle which drastically reduces exhaust gas in hydrocarbon series much discharged just after starting an engine. CONSTITUTION:This hydrocarbon exhaust gas reducing device is provided with a fuel separation device separating fuel much containing a combustible light component from the gasoline in a fuel tank 1, a storage tank 3 which is provided separately from the fuel tank and stores fuel much containing the separated light component, and a fuel feed device which feeds fuel much containing the light component in the storage tank to an engine at starting the engine and at cold operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for reducing hydrocarbon-based exhaust gas when starting an engine.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 63-68713 discloses an apparatus for reducing exhaust gas by using a hydrocarbon adsorbent. This device is composed of a main passage and a bypass passage that are parallel to each other. The adsorbent is disposed in the bypass passage, and the passage through which the exhaust gas flows is switched according to the temperature of the gas to purify the exhaust gas. is there. Also,
JP-A-48-54312 discloses a catalytic converter having an electrically resistive catalyst support. The apparatus utilizes a catalyst support structure to rapidly and effectively heat at least a portion of the catalyst to an operating temperature. further,
Japanese Unexamined Patent Publication No. 53-95417 discloses a catalyst heating device for a catalytic converter. This device is provided with an engine temperature detector and a catalyst temperature detector, and the output of each temperature detector is sent to a heating device control circuit. The heating device is operated when the catalyst temperature is input and the catalyst temperature is below a predetermined value and the engine temperature is below a predetermined value. As described above, the conventional exhaust gas reduction device uses the adsorbent or the catalyst and can effectively utilize the adsorbent or the catalyst to purify the exhaust gas more efficiently.

[0003]

However, the aforementioned Japanese Patent Laid-Open No. 63-63
The device described in the -68713 publication is not suitable for large vehicles because the adsorption amount of the adsorbent is limited. In addition, the above-mentioned Japanese Patent
When using the oxidation catalyst, the devices described in JP-A-48-54312 and JP-A-53-95417 need to incorporate an electric heater into the catalyst and heat it to increase the catalyst activity because the catalyst activity is insufficient at low temperature. There is. Moreover, they have a drawback that the weight is greatly increased and the system is complicated. In addition, there is a problem that the adsorbent and the catalyst deteriorate due to long-term use and the initial performance cannot be maintained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned conventional problems and provide a hydrocarbon exhaust gas reducing apparatus for a vehicle, which greatly reduces hydrocarbon-based exhaust gas that is often exhausted immediately after the engine is started. To do.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve this object, and as a result, have developed a device for separating a light combustible component from gasoline and supplying it at the time of engine start, and use it. As a result, they have found that the hydrocarbon-based exhaust gas can be reduced, and have completed the present invention.

That is, according to the present invention, a fuel separation device for separating a fuel containing a large amount of light components easily combusted from gasoline in a fuel tank, and a large amount of the separated light components separately provided from the fuel tank. A hydrocarbon exhaust gas reduction device for a vehicle, comprising: a storage tank for storing fuel; and a fuel supply device for supplying a fuel containing a large amount of light components of the storage tank to the engine during engine startup and cold operation. is there.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the drawings with reference to the drawings. A device according to a first embodiment of the present invention is shown in FIG. In the device shown in the figure, the main part of the fuel separation device is a condenser 2, which collects the gasoline vapor generated in the fuel tank 1 and liquefies it as a cooling liquid to separate the fuel containing a large amount of light components. A pipe for guiding saturated gasoline vapor is attached to the upper part of the fuel tank 1, and this pipe is connected to the condenser 2. A storage tank 3 is provided below the condenser 2 to collect and extract the liquefied components. The controller 20 controls the condenser 2, the two-way solenoid valve 5, and the three-way solenoid valve 4 based on the signals detected by the water temperature sensor and the liquid amount sensor of the storage tank 3 to adjust the liquid flow. Further, a fuel supply device provided with a three-way solenoid valve 4 connected to the fuel tank 1 and the engine 19 is provided in the lower portion of the storage tank 3, and the storage of the storage tank 3 at the time of starting the engine 19 and during cold operation by switching the valve 4. Fuel containing a large amount of light components in the tank 3 is supplied to the engine 19 via the pump 15, the filter 16 and the injection valve 17. The pressure regulator 18 regulates the pressure of the supplied fuel.

The operation of this apparatus will be further described. A condenser 2 connected to the fuel tank 1 through a pipe is filled with saturated gasoline vapor. At this time, if cooled with a condenser, saturated vapor is liquefied and gradually stored in the storage tank 3.
The liquefied component is collected in the [Step 5 (S5)]. The condenser 2 is preferably cooled by the refrigerant (Freon) of the air conditioner, but may be air-cooled when the outside air temperature is low. Table 1 shows the composition of regular gasoline and the composition of the components accumulated in the storage tank 3. If C5 or less is a light component, the light component contained in regular gasoline is about 22%, whereas about 75% of the components accumulated in the storage tank 3 are light components. The stronger the cooling of the condenser 2, the faster the speed of accumulating in the storage tank 3. It is necessary to cool at least 10 ° C or higher than the temperature of saturated steam, but preferably 15 ° C or higher. The light components thus accumulated in the storage tank 3 are used at the next engine start.

[0009]

[Table 1]

FIG. 2 shows the change over time in the concentration of hydrocarbon-based exhaust gas immediately after the engine 19 is started. If regular gasoline is used within 5 seconds immediately after starting the engine 19, the maximum is 4
Although it increased to 5,000ppm, when the separated light component was used, hydrocarbon-based exhaust gas was significantly reduced at a maximum of about 10,000ppm immediately after the engine 19 was started. The light component is supplied for at least 10 seconds (S3, 4), preferably about 30 seconds immediately after the engine 19 is started, and thereafter, the three-way solenoid valve 4 is opened to the fuel tank 1 side. However, since the supply of the light component is effective only when the engine 19 is cold, when the water temperature sensor is 30 ° C. or higher, it is opened to the fuel tank 1 side and started (S2). At least 10 g, preferably 20 g of light components are required to start the engine 19. Separate 10 to 20g of light components so that they can be stored in the storage tank 3 while traveling. When the light components are less volatilized in cold weather, the blower 6 may be operated to accelerate the volatilization.

FIG. 3 shows a method of operating the solenoid valve and the condenser. This flow sheet is executed when the ignition switch is activated. In S1, the cooling water temperature (T
_W ) is detected. Next, compare T _W with 30 ° C in S2. This is because under conditions below 30 ° C, a large amount of HC is generated, so it is necessary to supply light components, but above 30 ° C, the amount of HC generation is small even in gasoline before separation, so there is no need to supply light components. .

Next, if Y in S2, the process proceeds to S3 in order to supply the light component to the engine 19, the three-way solenoid valve 4 is opened to the storage tank 3 side, and the supply from the fuel tank 1 is stopped. Next, at S4, count 10 seconds from the start. If it is N, the process returns to S4 and the light component is supplied until 10 seconds have elapsed. If Y, move to S5 to operate the condenser 2 and the blower 6 to cool the gasoline vapor and return it to the fuel tank 1 via the canister 14. This operation separates the light components. If S2 is N, the process proceeds to S6, the three-way solenoid valve 4 is opened to the fuel tank 1 side, and fuel is supplied. Furthermore, it moves to S5 and separates light components. Next to S5 is S7
If it is determined that the engine 19 is stopped, the process proceeds to S9 to stop the condenser 2 and the blower 6, and the two-way solenoid valve 5 is closed to stop the separation. If it is N, it is judged in S8 that the storage tank 3 is full,
If N, return to S7. If Y, move to S9.

The apparatus of the second embodiment of the present invention is shown in FIG. In the device shown in the figure, the main part of the fuel separation device is composed of a distillation column 8 and a condenser 2, and heats and distills gasoline to separate light components. The fuel tank 1 is provided with a pipe communicating with the distillation column 8 via the fuel supply pump 7. A pipe is connected to the upper part of the distillation column to guide the vapor passing through the column to a condenser. A storage tank 3 for collecting and extracting the liquefied component is mounted below the condenser 2. The controller 20 is based on the signals detected by the water temperature sensor and the liquid quantity sensors of the storage tank 3 and the distillation column tank 13, the condenser 2, the two-way solenoid valves 10 and 12, the three-way solenoid valves 4 and 11, the pump 7, and the heater 9. To control the flow of liquid. The fuel supply device is similar to that shown in FIG.

Next, the function of the apparatus shown in FIG. 4 will be described. This apparatus sends gasoline from the fuel tank 1 to the distillation column 8 (S5), and then heats the gasoline using the heater 9 provided at the bottom of the distillation column (S7). When heating with the heater 9, the boiling point of the intended light component of C5 or less is 40 ° C. or less, so the temperature of the distillation column 8 is controlled so as not to exceed 40 ° C.
As the entire distillation column 8 approaches 40 ° C, gasoline vapor passes through the pipe connected to the top of the column. The passed vapor is cooled and liquefied by the condenser 2, and the liquefied component is accumulated in the storage tank 3. Also in this embodiment, for cooling the condenser,
It is preferable to use the refrigerant of the air conditioner, but it may be air cooled when the outside temperature is low. The temperature of the condenser 2 is kept at least 25 ° C. or lower, preferably 20 ° C. or lower. Further, the distillation column 8 has, for example, a diameter of 50 mm and a length of 200 to 300 mm.
Install about 500 mL and supply about 500 mL of gasoline.

Table 2 shows the composition of the components passed through the distillation column 8 and stored in the storage tank 3. About 90% of light components below C5
Is.

[0016]

[Table 2]

FIG. 5 shows the change over time in the concentration of hydrocarbon-based exhaust gas when the engine 19 is started using the light component obtained by distillation. When starting with regular gasoline, a maximum of 45,000 ppm hydrocarbon-based exhaust gas was detected, but when the separated light component was used, it was stable at around 7,000 ppm, and the exhaust gas was significantly reduced.

The supply time and supply method (operation of the solenoid valve 4) of the light component when the engine 19 is started are the same as in the previous embodiment.

FIG. 6 shows a solenoid valve and a condenser according to this embodiment.
Shows how to operate the heater, heater, and pump. This flocy
Also when the ignition switch is activated as in the previous embodiment
To be executed. In S1, the cooling water temperature (T
_W) Is detected. Then S2 to T _WIs compared to 30 ° C. In S2
If Y, move to S3 and move the three-way solenoid valves 4 and 11 to the storage tank 3 side.
Opens and cuts off gasoline supply. Then in S4, count 10 seconds
Get If N, return to S4 and supply light components until 10 seconds have elapsed.
It If Y, start cooling of condenser 2 at S5, distilling column 8
Open the two-way solenoid valve 10 to supply fuel to the
Close 12 and run pump 15. Distillation tower tank 13 is full in S7
When it becomes tongue, stop the pump 15 with S8 and turn on the two-way solenoid valve 10.
Close and operate heater 9 to start distillation,
To separate. If S2 is N, move to S5 and prepare for distillation.
Get ready. After starting distillation at S8, it was decided at S9 that engine 19 was stopped.
If YES, move to S11 to end separation if Y. If N, S10
It is judged that the storage tank 3 is full, and if N, the process returns to S9 and Y
To S11.

[0020]

As described above, according to the present invention, by providing the fuel separation device, the storage tank, and the fuel supply device, the light components that are easily combusted from gasoline are separated on-board and separated at the time of engine start. The fuel supply device that supplies the light component can significantly reduce the amount of hydrocarbon-based exhaust gas that is often discharged immediately after the engine is started.

Further, in each of the embodiments, the load on the hydrocarbon adsorption catalyst is reduced and the light component is supplied, so that the engine startability at low temperature can be improved.

[Brief description of drawings]

FIG. 1 is a layout view of an example of a device for reducing hydrocarbon exhaust gas for vehicles according to the present invention.

FIG. 2 is a curve diagram showing the effect of reducing hydrocarbon-based exhaust gas in the device shown in FIG.

FIG. 3 is a diagram showing an operation procedure of the apparatus shown in FIG.

FIG. 4 is a layout view of another example of the apparatus for reducing vehicle hydrocarbon exhaust gas according to the present invention.

5 is a curve diagram showing a reduction effect of hydrocarbon-based exhaust gas in the apparatus shown in FIG.

FIG. 6 is a diagram showing an operation procedure of the apparatus shown in FIG.

[Explanation of symbols]

 1 Fuel Tank 2 Condenser 3 Storage Tank 4 Three Way Solenoid Valve 5 Two Way Solenoid Valve 6 Blower 7 Pump 8 Distillation Tower 9 Heater 10 Two Way Solenoid Valve 11 Three Way Solenoid Valve 12 Two Way Solenoid Valve 13 Distillation Tower Tank 14 Canister 15 Pump 16 Filter 17 Injection Valve 18 Pressure Regulator 19 Engine 20 Controller

Claims (3)

[Claims] 1. A fuel separation device for separating a fuel containing a large amount of a light component that easily burns from gasoline in a fuel tank; and a fuel separated from the fuel tank, which stores the separated fuel containing a large amount of the light component. And a fuel supply device for supplying a fuel containing a large amount of light components of the storage tank to the engine at the time of engine startup and cold operation. 2. The fuel separation device is a device whose main part is a condenser for collecting gasoline vapor generated in a fuel tank and liquefying it to separate fuel containing a large amount of light components. The device according to claim 1. 3. The device according to claim 1, wherein the fuel separation device is a device mainly comprising a distillation column and a condenser for separating a fuel containing a large amount of light components by distillation.