JPH06330828A - Fuel feed device - Google Patents

Abstract

PURPOSE:To prevent deterioration of performance of a fuel pump due to non- operation for a long time, and shorten a starting time. CONSTITUTION:A first and a second fuel pumps 2, 4 forcedly feeding fuel in a fuel tank 1 to a fuel injection valve 8 are provided in parallel, at a small fuel injection quantity the first fuel pump 2 is only driven, and at a large quantity the first and the second fuel pumps 2, 4 are driven. A rotation detecting sensor 36 detecting rotation of an internal combustion engine 10 is provided. When the rotation is not detected by means of the rotation detecting sensor 36, and from making an ignition switch 38 ON, until the rotation of the internal combustion engine 10 is detected, or until a decided time is passed away, or until a starter is made ON, the second fuel pump 4 is only driven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system in which fuel in a fuel tank is pressure-fed to a fuel injection valve by a fuel pump and is injected / supplied from the fuel injection valve into an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Utility Model Laid-Open No. 59-7263, a plurality of fuel pumps are provided in parallel in a supply pipe, and a suction negative pressure is a predetermined value or more or a rotation speed is a predetermined value. There has been proposed a device for stopping the operation of some of the plurality of fuel pumps when the internal combustion engine has a low speed and a low load that is less than or equal to a value.

Further, as disclosed in Japanese Patent Laid-Open No. 62-288359, a plurality of fuel pumps arranged in parallel for pumping the fuel in a fuel tank to a fuel injection valve and a unit of a fuel injection type internal combustion engine. There has been proposed an apparatus provided with a selection drive means for selecting and driving a fuel pump to be driven from a plurality of fuel pumps according to a fuel injection amount per unit time.

Further, as disclosed in JP-A-56-27064, a fuel pressure sensor for adjusting the fuel pressure fed by a fuel pump by a fuel pressure adjusting valve and detecting the fuel pressure in the fuel pressure adjusting valve is provided at the time of starting. Drives the fuel pump as soon as the power is turned on. After that, when the rotation of the internal combustion engine is not detected for a certain period of time, the driving of the fuel pump is stopped. Further, when the fuel pressure detected by the fuel pressure sensor at the time of starting is below a predetermined value, the fuel injection is stopped, and the fuel injection is not performed until the fuel pressure rises at the time of starting. There is also a proposal to reduce the amount of exhaust gas containing unburned components on the exhaust gas.

[0005]

However, such conventional Japanese Utility Model Laid-Open No. 59-7263 and Japanese Patent Laid-Open No. 62-2 have been proposed.
As disclosed in Japanese Patent No. 88359, in the case where a plurality of fuel pumps are provided, when a low load operation is continued, a state occurs in which some fuel pumps are not operated for a long time,
The performance of the fuel pump is deteriorated, for example, the contact of the rotor of the motor of the fuel pump is oxidized by the fuel and a conduction failure is caused.

On the other hand, in the one disclosed in Japanese Patent Laid-Open No. 56-27064, it takes a certain period of time for the fuel pressure to reach a predetermined value or more, and fuel injection into the internal combustion engine is not performed during that time, so the ignition switch is turned on. Even if it is turned to the starter position, the operation is not started, and there is a problem that the starting time becomes long.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fuel supply device capable of preventing the deterioration of the performance of the fuel pump due to the fact that it is not operated for a long time and shortening the starting time. .

[0008]

In order to achieve such an object, the present invention has the following constitution as means for solving the problem. That is, as illustrated in FIG. 1, the fuel tank M1
First and second fuel pumps M3 and M4 for pumping the internal fuel to the fuel injection valve M2 are provided in parallel, the fuel injection amount is calculated according to the operating state of the internal combustion engine M5, and the fuel injection valve M2 is switched on. Only the fuel injection control means M6 for controlling and injecting fuel into the internal combustion engine M5 and the first fuel pump M3 are driven when the fuel injection amount is small, and the first and second fuel pumps M3 are driven when the fuel injection amount is large. Second fuel pump M
In a fuel supply device including drive control means M7 for driving M3 and M4, a rotation detection sensor M8 that detects the rotation of the internal combustion engine M5 and a rotation detection sensor M8 that does not detect rotation, and , From the time the ignition switch M9 is turned on until the rotation of the internal combustion engine M5 is detected, or until a fixed time elapses, or until the starter M11 is turned on, the second fuel pump M4 is turned on. Auxiliary drive control means M for driving
That is, the configuration of the fuel supply device is characterized in that

[0009]

In the fuel supply device having the above-described structure, the rotation detection sensor M8 detects the rotation of the internal combustion engine M5, and the auxiliary drive control means M10 does not detect the rotation by the rotation detection sensor M8. Ignition switch M
The second fuel pump M4 is driven from the time when 9 is turned on until the rotation of the internal combustion engine M5 is detected, or until a fixed time elapses, or until the starter M11 is turned on.

After the internal combustion engine M5 is rotated,
The fuel injection control unit M6 calculates the fuel injection amount according to the operating state of the internal combustion engine M5, and the drive control unit M7 drives only the first fuel pump M3 when the fuel injection amount is small, and the fuel injection amount is When the number is large, the first and second fuel pumps M3 and M4 are driven. The driven first and second fuel pumps M3, M4 pressure-feed the fuel in the fuel tank M1 to the fuel injection valve M2 and control the fuel injection valve M2 to control the internal combustion engine M2.
Fuel is injected into 5.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 is a schematic configuration diagram of a fuel supply device according to an embodiment of the present invention. 1 is a fuel tank, fuel tank 1
The first and second fuel pumps 2 and 4 are housed therein and immersed in the fuel. In the first and second fuel pumps 2 and 4, the pump main body and the DC motor are integrally configured, and when the DC motor is rotationally driven, the fuel in the fuel tank 1 is transferred to the inside of the pump main body through a filter (not shown). Suction, pressurize and discharge.

One end of a fuel supply pipe 6 is connected to each of the first and second fuel pumps 2 and 4, and the other end of the fuel supply pipe 6 is connected to a fuel injection valve 8 so that the first and second fuel pumps 8 are connected. Fuel pumps 2 and 4 are provided in parallel. When one of the first and second fuel pumps 2 and 4 is driven, fuel corresponding to the supply amount of one of them is supplied to the fuel injection valve 8, and when both are driven simultaneously, The fuel injection valve 8 is configured to supply an amount of fuel that is the sum of both supply amounts.

Internal combustion engine 10 provided with a fuel injection valve 8
Includes a piston 14 slidably supported in the cylinder block 12, the cylinder block 12, the piston 1
4. A combustion chamber 18 is formed by the cylinder head 16, and an ignition plug 20 is arranged in the combustion chamber 18.

The intake system of the internal combustion engine 10 includes an intake valve 2
2, the combustion chamber 18 and the intake pipe 24 are connected to each other, and the intake pipe 24 is provided with a throttle valve 26. Further, on the upstream side thereof, an air flow meter 28 that detects the intake air amount according to the swing of the measuring plate 27 that swings in proportion to the intake air amount is provided.
The outside air can be sucked into the intake pipe 24 via the filter 30. The exhaust system is configured such that the combustion chamber 18 and the exhaust pipe 34 are connected via the exhaust valve 32, and exhaust gas can be released.

Further, a rotation detecting sensor 36 for detecting the rotation of the crankshaft of the internal combustion engine 10 is provided, and an ignition switch 38 having an OFF, accessory, ON, start switching position is also provided. When the ignition switch 38 is in the off position, the connection between the battery power supply 40 and another device is cut off, and when it is in the accessory position, the battery power supply 40 is connected to the radio or the like. When in the ON position, the battery power source 40 and the electronic control circuit 50, which will be described later, are connected to enable operation of the internal combustion engine 10. When in the start position, a starter (not shown) is rotationally driven to drive the internal combustion engine 10 Is started.

The fuel injection valve 8, the air flow meter 28, the rotation detecting sensor 36, and the ignition switch 3 described above.
8 is connected to an electronic control circuit 50, and the electronic control circuit 50 includes a well-known CPU 52, ROM 54, RAM 56.
Is the center of the logical operation circuit and performs input / output with the outside, here, the input circuit 58 and the output circuit 6
0s are connected to each other via a common bus 61.

The CPU 52 inputs signals from the air flow meter 28, the rotation detecting sensor 36 and the ignition switch 38 via the input circuit 58. On the other hand, the CPU 52 calculates the fuel injection amount, the ignition timing, etc. according to the operating state of the internal combustion engine 1 based on these signals, the data in the ROM 54 and the RAM 56, and the control program stored in advance, and based on the calculated values. A drive signal is output to the fuel injection valve 8 and an igniter (not shown) via the output circuit 60 to control the fuel injection and ignition timing of the internal combustion engine 1.

The CPU 52 also outputs a control signal to the first relay 62 and the second relay 64 via the output circuit 60, and the first relay 62 outputs the control signal to the battery power source 40 and the first relay 62 according to the control signal. The first fuel pump 2 is connected / disconnected, and the second relay 64 connects / disconnects the battery power source 40 and the second fuel pump 4 according to the control signal,
The driving of the first and second fuel pumps 2, 4 can be controlled separately.

Next, the fuel supply control process performed in the electronic control circuit 50 will be described with reference to the flowchart of FIG. In the present embodiment, this fuel injection control process is interrupted every 16 ms or 32 ms by turning on the ignition switch 38.

First, it is determined whether or not the internal combustion engine 10 is rotating based on whether or not the rotation detection sensor 36 detects the rotation of the internal combustion engine 10 (step 100). If it is not rotating, it is determined whether the ignition switch 38 is at the start position and the starter is on (step 180). When the internal combustion engine 10 is rotating, or when the starter is turned on even when the internal combustion engine 10 is not rotating, depending on the operating state of the internal combustion engine 10 such as the intake air amount detected by the air flow meter 28, the fuel injection valve 8 From this, the fuel injection amount injected and supplied to the combustion chamber 18 is calculated (step 110).

Next, the calculated fuel injection amount and the supply amount of the first fuel pump 2 are compared in the same unit time (step 120), and the fuel injection amount is smaller than that of the first fuel pump 2. When the amount of supply supplied to the fuel injection valve 8 via the fuel supply pipe 6 is sufficient for driving, for example, when operating at low speed and low load with low fuel consumption, the first relay 62 Is connected to drive only the first fuel pump 2, the second relay 64 is cut off, and the second fuel pump 4 is not driven (step 130).

The fuel injection amount is larger (step 12
0), when the fuel supply amount for driving the first fuel pump 2 is insufficient, for example, when operating at high speed and high load with large fuel consumption, the first and second relays 62 , 6
4 is connected to drive both the first and second fuel pumps 2 and 4 to supply the amount of fuel added to the supply amount of both (step 140). When the processing of steps 130 and 140 is executed, the present fuel supply control processing is once terminated, and other processing (not shown), for example, fuel injection control processing is executed.
Based on the calculated fuel injection amount, the valve opening time of the fuel injection valve 8 is controlled to inject and supply fuel to the combustion chamber 18.

On the other hand, as in the state before starting, the internal combustion engine 1
When the rotation of 0 is not detected, the internal combustion engine 10 is not rotating (step 100), and the ignition switch 38 is not at the start position (step 180), a key is inserted into the ignition switch 38,
It is judged whether or not it is within a certain time after switching to the ON position, that is, within 5 seconds in this embodiment (step 150).

Within the fixed time, the CPU 52 outputs a control signal for disconnecting the first relay 62 and connecting the second relay 64, and the second relay 64 outputs the second control signal without driving the first fuel pump 2. Only the fuel pump 4 is driven (step 16)
0). The fuel in the fuel tank 1 is pressurized by driving the second fuel pump 4, and the fuel is pressure-fed to the fuel injection valve 8 via the fuel supply pipe 6. As a result, the fuel pressure in the fuel supply pipe 6 is increased.

Further, by driving the second fuel pump 4,
The rotor of the DC motor of the second fuel pump 4 rotates, and the oxide film on the contact is removed by the brush that is in contact with the contact of the rotor. For example, the second fuel pump 4 does not operate for a long time. Performance degradation is prevented.

When the internal combustion engine 10 is not rotated (step 100) and a certain time has elapsed (step 15)
0), the first and second relays 62 and 65 are cut off to bring the first and second pumps 2 and 4 into a non-driving state (step 170). The fixed time is set to 5 seconds in the present embodiment, but this is the time during which the fuel pressure in the fuel supply pipe 6 reaches an appropriate fuel injection pressure by driving the second fuel pump 4.

In the above process, even when a key (not shown) is inserted into the ignition switch 38 and continuously turned from the off position to the start position, some time is required while being turned from the on position to the start position. Therefore, the fuel supply control process is executed, that is, the fuel supply control process is executed in a short time every 16 ms or 32 ms, so that the fuel supply is executed during the turning from the ON position to the start position. The control process is executed several times, and the DC motor of the second fuel pump 4 is driven by several revolutions by executing the processes of steps 100, 150, and 160. As a result, it is possible to prevent performance deterioration due to the second fuel pump 4 not operating for a long time, such as removal of the oxide film on the contact point of the rotor.

When the starter motor is turned to the start position, the starter motor (not shown) is rotated, and the fuel consumption is small at the start, so steps 100, 110, 120, 1
The process of 30 is executed, only the first fuel pump 2 is driven, and the fuel is supplied. Further, at the time of starting, the first fuel pump 2 alone is driven without driving the second fuel pump 4 because of the load on the battery power source 40 driven by the starter motor.

The processing of step 110 and the execution of fuel injection control processing (not shown) function as fuel injection control means M6, the execution of the processing of steps 120-140 function as drive control means M7, and steps 100, 150-.
The execution of the processing of 170 functions as the auxiliary drive control means M10.

As described above, when the internal combustion engine 10 is not rotating, and when a certain period of time elapses after the ignition switch 38 is turned on until the internal combustion engine 10 is rotated, the second period is maintained during the certain period of time. By driving the fuel pump 4 to prevent performance deterioration due to not being operated for a long time, by driving the second fuel pump 4 for a certain period of time,
The fuel pressure can be increased before starting, improving startability.

Further, when the ignition switch 38 is switched to the start position and the internal combustion engine 10 is rotated before the elapse of a predetermined time, the ignition switch 38 is turned on without waiting for the elapse of the predetermined time. The second fuel pump 4 is driven by the time it is rotated to prevent performance deterioration due to non-operation for a long time.

The present invention is not limited to such embodiments as described above, and can be carried out in various modes without departing from the scope of the present invention. For example, step 180 in FIG. 3 is omitted. Alternatively, instead of determining whether the internal combustion engine is rotating in step 100, it is determined whether or not the starter is turned on and the internal combustion engine is started, and step 180 is omitted. Alternatively, instead of determining whether or not the internal combustion engine is rotating in step 100, it is determined whether or not a predetermined time (for example, 5 seconds) has elapsed since the ignition switch 38 was turned on, and steps 180 and 150 are performed. , 170 are omitted.

[0033]

As described in detail above, the fuel supply system of the present invention is used when the internal combustion engine is not rotating and when the ignition switch is turned on until the rotation is detected or for a fixed time. Since the second fuel pump is driven for a shorter period until the time elapses, it is possible to prevent deterioration of the performance of the fuel pump due to the fact that the fuel pump is not operated for a long time and to shorten the starting time.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of a fuel supply device of the present invention.

FIG. 2 is a schematic configuration diagram as an embodiment of a fuel supply device of the present invention.

FIG. 3 is a flowchart showing an example of a fuel supply control process performed by the electronic control circuit of this embodiment.

[Explanation of symbols]

M1,1 ... Fuel tank M2, 8 ... Fuel injection valve M3, 2 ... First fuel pump M4, 4 ... Second fuel pump M5, 10 ... Internal combustion engine M6 ... Fuel injection control means M7 ... Drive control means M8, 36 ...
Rotation detection sensor M9, 38 ... Ignition switch M10 ... Auxiliary drive control means M11 ... Starter 28 ... Air flow meter 40 ... Battery power supply 50 ... Electronic control circuit

Claims (1)

[Claims] 1. A first fuel pump and a second fuel pump for pumping the fuel in a fuel tank to a fuel injection valve are provided in parallel, the fuel injection amount is calculated according to the operating state of the internal combustion engine, and the fuel injection valve is used. Fuel injection control means for injecting fuel into the internal combustion engine and driving only the first fuel pump when the fuel injection amount is small, and the first fuel pump when the fuel injection amount is large.
And a drive control means for driving the second fuel pump, wherein a rotation detection sensor for detecting rotation of the internal combustion engine, and when rotation is not detected by the rotation detection sensor, and Auxiliary drive control for driving the second fuel pump from the time when the ignition switch is turned on until the rotation of the internal combustion engine is detected, or until a fixed time elapses or until the starter is turned on. And a fuel supply device.