JPH0674110A - Method and device for raising temperature of fuel in fuel tank for vehicle - Google Patents

Abstract

PURPOSE:To rise the temperature of fuel in a fuel tank even under a practical running condition of a vehicle on a road without consuming too much time and cost so as to obtain generation condition of evaporation fuel, in the case where tests of engine and its accessories are carried out under a condition for generating evaporation fuel inside the fuel tank of the vehicle. CONSTITUTION:Excessive fuel for refluxing from the fuel injection device (J) of an engine 1into a fuel tank 5 is passed through the low temperature flow passage 15 of a heat exchanger 14, and passed through the high temperature flow passage 16 of the heat exchanger 14 for cooling water which makes its circulation between the water jacket and the radiator 12 of the engine 1, and excessive fuel heated by the heat exchanger 14 is returned into fuel tank 5 so as to rise the temperature of fuel in the tank 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to perform a predetermined evaporative fuel generation state early in order to perform a performance test of an engine and its accessory equipment in the evaporative fuel generation state in a fuel tank installed in a vehicle such as an automobile. In particular, the present invention relates to a temperature raising method and a temperature raising device for positively raising the temperature of fuel in a fuel tank.

[0002]

2. Description of the Related Art Conventionally, when performing a performance test of an engine and its accessories in a state in which fuel vapor is generated in a fuel tank of a vehicle, the vehicle is placed on a chassis dynamo in a test room and the temperature of the test room is changed. Is raised to raise the temperature of the fuel in the fuel tank of the automobile, and in this state, the test is conducted while driving the chassis dynamo with the drive wheels of the automobile.

[0003]

In such a test method, it takes a long time to raise the temperature of the test chamber to raise the temperature of the fuel in the fuel tank to a predetermined temperature, and the energy cost is increased. Since it is very difficult to reproduce a transitional traveling state such as a high cost and a congested traveling state in which the vehicle is repeatedly started and stopped, there is a drawback that the same test result as that in the actual traveling cannot be obtained.

The present invention has been made in view of such circumstances, and it is possible to raise the temperature of the inside of the fuel tank of a vehicle without much time and cost, and moreover, even when the vehicle is actually running on the road. An object of the present invention is to provide a heating method and a temperature raising device.

[0005]

In order to achieve the above-mentioned object, the method of the present invention uses the heat of cooling water which circulates excess fuel overflowing from a fuel injection device of an engine between a water jacket of an engine and a radiator. It is characterized in that it is refluxed to the fuel tank after being heated by.

Further, the device of the present invention is a vehicle equipped with a fuel return pipe for returning excess fuel overflowing from the fuel injection device of the engine to the fuel tank, and a radiator communicating with the water jacket of the engine. A heat exchanger consisting of a flow path and a low-temperature flow path is installed, and cooling water circulating between the water jacket and the radiator of the engine is circulated in the high-temperature flow path, while excess fuel passing through the fuel return pipe is supplied in the low-temperature flow path. Through a flow rate control valve, and the flow rate control valve is provided with a flow rate control valve according to a detection signal from a temperature sensor that detects the fuel temperature in the fuel tank and a pressure sensor that detects the pressure in the tank. It is characterized in that a control device that operates is connected.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

First, referring to FIG. 1 showing a first embodiment of the present invention, a multi-cylinder engine 1 of an automobile is equipped with a fuel injection nozzle 2 at the intake port of each cylinder, and a fuel distribution pipe is provided at the inlet side of these nozzles. 3 is connected.

A fuel supply pipe 4 is provided at one end of the fuel distribution pipe 3.
Is connected to the downstream end thereof, and the upstream end thereof is connected to the discharge port of the fuel pump 6 installed on the fuel tank 5. The fuel pump 6 pumps the fuel in the fuel tank 5 through a strainer 7. A fuel return pipe 8 having a downstream end opened into the fuel tank 5 is connected to the other end of the fuel distribution pipe 3 via a pressure adjusting valve 9. Thus, the fuel injection nozzle 2, the fuel distribution pipe 3, and the pressure adjusting valve 9 constitute a fuel injection device J.

The inlet and outlet of the cooling water jacket of the engine 1 are connected to the lower tank 12a and the upper tank 12b of the radiator 12 via the inlet water pipe 10 and the outlet water pipe 11, and the inlet of the water jacket is A water pump 13 for sucking cooling water from the inlet water pipe 10 and pumping it to the water jacket is mounted.

The above is the structure of the fuel system and the cooling system usually provided in the automobile, and in the present invention, the heat exchanger 14 is disposed between the both systems. This heat exchanger 14 has a low temperature passage 1
5 and a high temperature flow path 16 in contact with the low temperature flow path 15, and an inlet 15i of the low temperature flow path 15 has a flow control valve 17
Is connected to the fuel return pipe 8 via
Is connected to the fuel return pipe 8 downstream of the flow control valve 17. Further, the inlet 16i and the outlet 16o of the high temperature passage 16 are connected to the outlet water pipe 11 and the inlet water pipe 10 via a high pressure auxiliary water pipe 18 and a low pressure auxiliary water pipe 19, respectively.

Further, the fuel tank 5 is provided with a temperature sensor 20 for detecting a fuel temperature inside thereof and a pressure sensor 21 for detecting an internal pressure thereof.
The detection signals from 0 and 21 are sent to the control device 22 for calculation, and the control device 22 causes the flow control valve 1
7 is activated.

Next, the operation of this embodiment will be described.

During operation of the engine 1, the fuel in the fuel tank 5 is sucked up by the fuel pump 6, pumped to the fuel distribution pipe 3 through the fuel supply pipe 4, and then the fuel injection nozzle 2
And is supplied to each cylinder of the engine 1. At that time, the pressure in the fuel distribution pipe 3 is controlled by the pressure adjusting valve 9 in accordance with the operating conditions of the engine 1, and the surplus pressure of fuel is returned to the fuel tank 5 through the fuel return pipe 8.

During this time, between the water jacket of the engine 1 and the radiator 12, the cooling water circulates through the inlet water pipe 10 and the outlet water pipe 11 by the operation of the water pump 13, while the high-temperature, high-pressure cooling water in the outlet water pipe 11 is circulated. Is supplied to the high temperature flow path 16 of the heat exchanger 14 via the high pressure auxiliary water pipe 18, and is supplied to the low pressure inlet water pipe 1 via the low pressure auxiliary water pipe 19.
Reflux to zero. Thus, the high temperature flow path 16 of the heat exchanger 14
Are kept relatively hot.

When carrying out a performance test of the engine 1 and its accessories with the inside of the fuel tank 5 in a high temperature and high pressure state, first, the high temperature and high pressure values required in the fuel tank 5 are controlled as set values. Input to the device 22. Then, the control device 22 controls the flow rate control valve 17 while comparing the detected values of the temperature sensor 20 and the pressure sensor 21 of the fuel tank 5 with the set values. When the detected value is relatively low, the flow rate control valve 17 controls to increase the amount of the fuel flowing from the fuel return pipe 8 to the low temperature passage inlet 15i of the heat exchanger 14. If the surplus fuel heated by the high temperature passage 16 increases while passing through, and the fuel is returned to the fuel tank 5, the fuel temperature in the fuel tank 5 rises, and if the evaporation amount of the fuel increases accordingly, The tank pressure rises. Then, when the detected values of the temperature sensor 20 and the pressure sensor 21 approach the set values, the flow rate control valve 17 reduces the flow rate of the surplus fuel from the fuel return pipe 8 to the low temperature flow passage 15. Thus the fuel tank 5
The inside reaches the required high temperature and high pressure state at an early stage and a predetermined vaporized fuel generation state is obtained, so that the performance test of the engine 1 and its accessories can be quickly performed. Moreover, the test can be carried out not only in the test room but also while driving on the road.

FIG. 2 shows a second embodiment of the present invention.
The structure is the same as that of the previous embodiment except that the flow control valve 17 is installed at the connecting portion between the low temperature flow passage outlet 15o and the fuel return pipe 8. In the figure, the portions corresponding to those of the previous embodiment are the same. Is attached.

The second embodiment can also achieve the same effect as the previous embodiment.

[0019]

As described above, according to the method of the present invention, after the excess fuel overflowing from the fuel injection device of the engine is heated by the heat of the cooling water circulating between the water jacket of the engine and the radiator, Since it is returned to the tank, the heat of the cooling water of the engine can be effectively used to raise the fuel temperature in the fuel tank early, so that the fuel vapor in the fuel tank can be quickly collected without much time and cost. It is possible to create a generation state and easily and quickly test the engine and its accessories in this state, and further, this can be performed even while running on the road.

Further, according to the device of the present invention, in a vehicle provided with a fuel return pipe for returning excess fuel overflowing from a fuel injection device of an engine to a fuel tank, and a radiator communicating with a water jacket of the engine, A heat exchanger consisting of a high-temperature channel and a low-temperature channel that are in contact with each other is installed. Cooling water that circulates between the water jacket and the radiator of the engine is circulated in the high-temperature channel, while a fuel return pipe is passed in the low-temperature channel. Excess fuel is circulated through a flow rate control valve, and the flow rate control valve controls the flow rate according to a detection signal from a temperature sensor that detects the fuel temperature in the fuel tank and a pressure sensor that detects the pressure in the tank. Since the control device that operates the valve is connected, the same effect as described above can be obtained, and the predetermined high temperature and high pressure state in the fuel tank can be automatically obtained. Down and a test of its ancillary equipment can be carried out accurately.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a fuel system and a cooling system of an automobile engine equipped with a first embodiment device of the present invention.

FIG. 2 is a schematic diagram of a fuel system and a cooling system of an automobile engine equipped with a second embodiment device of the present invention.

[Explanation of symbols]

 1 Engine 2 Fuel Injection Nozzle 3 Fuel Distribution Pipe 4 Fuel Supply Pipe 5 Fuel Tank 6 Fuel Pump 8 Fuel Return Pipe 9 Pressure Adjustment Valve 12 Radiator 14 Heat Exchanger 15 Low Temperature Flow Path 15i Inlet 15o Outlet 16 High Temperature Flow Path 17 Flow Control Valve 18 High-pressure auxiliary water pipe 19 Low-pressure auxiliary water pipe 20 Temperature sensor 21 Pressure sensor 22 Control device J Fuel injection device

Claims (4)

[Claims] 1. Excess fuel overflowing from a fuel injector (J) of an engine (1) is heated with heat of cooling water circulating between a water jacket of the engine (1) and a radiator (12), and then the fuel is discharged. A method for raising the temperature of fuel in a vehicle fuel tank, characterized in that the fuel is returned to the tank (5). 2. A fuel return pipe (8) for returning excess fuel overflowing from a fuel injector (J) of the engine (1) to a fuel tank (5) and a radiator communicating with a water jacket of the engine (1). In a vehicle equipped with (12), a heat exchanger (14) consisting of a high temperature channel (16) and a low temperature channel (15) in contact with each other is installed, and the high temperature channel (1)
Cooling water that circulates between the water jacket of the engine (1) and the radiator (12) is circulated in 6), while excess fuel passing through the fuel return pipe (8) is flowed in the low temperature flow passage (15) by a flow control valve ( 17) and the flow control valve (1
7), the flow control valve (1) according to detection signals from a temperature sensor (20) for detecting the fuel temperature in the fuel tank (5) and a pressure sensor (21) for detecting the pressure in the tank.
A fuel temperature raising device in a vehicle fuel tank, characterized in that a control device (22) for operating 7) is connected. 3. The heat exchanger (14) according to claim 2, wherein an inlet (15i) and an outlet (15o) of the low temperature passage (15) of the heat exchanger (14) are provided in an upstream portion and a downstream portion of the fuel return pipe (8). A fuel temperature raising device in a fuel tank for a vehicle, characterized in that a flow control valve (17) is installed at the connection between the inlet (15i) and the fuel return pipe (8) while being connected to each other. 4. The inlet according to claim 2, wherein the inlet (15i) and the outlet (15o) of the low temperature passage (15) of the heat exchanger (14) are located upstream and downstream of the fuel return pipe (8). A fuel temperature raising device in a fuel tank for a vehicle, characterized in that a flow control valve (17) is installed at a connecting portion between the outlet (15o) and the fuel return pipe (8) while being connected to each other.