JPH08158975A - Fuel feed device - Google Patents

Abstract

PURPOSE: To make a fuel feed device compact and reduce the cost. CONSTITUTION: This fuel feed device is provided with a pressure regulator 22 regulating the pressure of fuel in a fuel tank 25 pressurized by means of a fuel pump 21, a fuel introducing passage 27 leading the pressure-regulated fuel by the pressure regulator to an engine, a fuel return passage 34 returning surplus fuel from the pressure regulator to the fuel tank, and a fuel filter 28 provided on the fuel introducing passage, and it is constituted so that the fuel pump and the pressure regulator are provided integratedly with a fuel tank fitting member 24.

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 for supplying fuel from a fuel tank to an engine.

[0002]

2. Description of the Related Art As a fuel supply device for supplying fuel from a fuel tank to an engine, for example, Japanese Utility Model Laid-Open No. 5-12643.
Some are disclosed in Japanese Patent Publication. This device is shown in FIG.
A fuel pump 2 installed in the fuel tank 1 as shown in FIG.
Fuel is pressure-fed to the fuel filter 5 through the fuel introduction passage 3 and the fuel pressure control valve 4, is filtered by the fuel filter 5, and is then filtered through the fuel introduction passage 6 to the fuel injection device 7
Fuel pressure control valve 4 returns excess fuel from the fuel pressure control valve 4 to the fuel tank 1 through a fuel return passage (bypass passage) 8, and a fuel pressure for detecting the fuel pressure supplied to the fuel injection device 7 by the electronic control device 10 is detected. The fuel pressure control valve 4 is controlled according to the operating state of the engine on the basis of the signals from the sensor 11, the engine intake negative pressure sensor 12, the engine rotation sensor 13, the cooling water temperature sensor 14, the temperature sensor 15, and the like. It was done.

[0003]

The fuel supply device having the above-mentioned structure requires many sensors to control the fuel pressure control valve 4, and the device becomes complicated, resulting in an increase in cost. Further, since the fuel pressure control valve 4 is arranged outside the fuel tank 1, the fuel return passage 8 for returning excess fuel from the fuel pressure control valve 4 to the fuel tank 1 becomes long,
Moreover, there is a problem in that a high-pressure hose and a pipe 3 are required, and a high sealing property (zero seal) is required in the mounting portion, resulting in high cost.

The present invention has been made in view of the above points, and shortens the fuel return passage for returning the surplus fuel from the pressure regulator to the fuel tank and lowers the sealing property to reduce the cost, and further the fuel filter. It is an object of the present invention to provide a fuel supply device adapted to check the state of.

[0005]

To achieve the above object, according to the present invention, a pressure regulator for regulating the pressure of fuel in a fuel tank pressurized by a fuel pump, and fuel regulated by the pressure regulator are provided. A fuel introduction passage that guides the fuel to the engine, a fuel return passage that returns excess fuel from the pressure regulator to the fuel tank, and a fuel filter that is provided in the fuel introduction passage. The pressure regulator and the pressure regulator are integrally provided.

According to a second aspect of the present invention, the fuel pump and the pressure regulator are arranged in the fuel tank. According to a third aspect of the present invention, a check valve is arranged downstream of the fuel pump and the pressure regulator. According to a fourth aspect of the present invention, the fuel filter is arranged downstream of the fuel pump and the pressure regulator, and pressure sensors are arranged upstream and downstream of the fuel filter.

According to a fifth aspect of the present invention, the alarm is turned on according to the differential pressure of the pressure sensor.

[0008]

The fuel in the fuel tank pressurized by the fuel pump is pressure-regulated by the pressure regulator and then pressure-fed to the fuel filter through the fuel introduction passage. The high-pressure fuel supplied to the fuel filter is filtered and supplied to the fuel injection device of the engine. The low-pressure surplus fuel after the pressure is adjusted by the pressure regulator is returned to the fuel tank through the fuel return passage.

In the present invention, the fuel pump and the pressure regulator are arranged in the fuel tank, and the excess fuel of the pressure regulator is returned to the fuel tank through the short fuel return passage in the fuel tank. According to the third aspect of the present invention, the fuel introduction passage is closed when the engine is stopped by the check valve provided on the downstream side of the fuel pump and the pressure regulator, and the fuel pressure in the fuel introduction passage is maintained at a high pressure.

In the present invention, the fuel pressure is detected by the pressure gauges arranged on the upstream side and the downstream side of the fuel filter, and the pressure loss due to the clogging of the fuel filter is checked by the pressure difference. According to the fifth aspect, when the pressure loss of the fuel filter becomes high, an alarm is turned on to notify the driver to prompt replacement of the fuel filter.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 2, the fuel supply device 20 includes a fuel pump 21, a pressure regulator 22, and a check valve 23, which are integrally formed.
It is fixed to No. 4 and is housed in the fuel tank 25. The fuel pump 21 is connected to a fuel introduction passage 27 via a pressure regulator 22 and a check valve 23, and the fuel introduction passage 27 is connected to a delivery pipe 29 of a fuel injection device of an engine via a fuel filter 28. ing.

FIG. 3 is an enlarged sectional view of FIG. 2, in which the pressure regulator 2 is provided at the discharge port 21b of the fuel pump 21.
The second inlet 22a is mounted and fixed liquid-tightly, and the outlet 22b of the pressure regulator 22 is mounted and fixed liquid-tightly to the inlet 23a of the check valve 23. The return port 22c of the pressure regulator 22 is closed by the valve body 31 fixed to the diaphragm 30 being pressed by a spring 32 housed in the air chamber 22d to close the pressure of fuel introduced from the fuel pump 21. Is opened when the spring force of the spring 32 is exceeded. The air chamber 2
An air hole 22e is provided above 2d. The check valve 23 is connected from the pressure regulator 22 side so as to allow the fuel flow only in the fuel introduction passage 27 (FIG. 2) direction, and maintains the fuel pressure in the fuel introduction passage 27 at a high pressure when the engine is stopped. To do.

The fuel pump 21 is fixed to a bracket 24, and the upper end of the bracket 24 is fixed to a lid 26 of the fuel tank 25. The upper end of the check valve 23 penetrates the hole provided in the lid 26 in a liquid-tight manner and projects to the outside of the fuel tank. A filter 33 is connected to the suction port 21a of the fuel pump 21, and a return passage 34 is connected to the return port 22c of the pressure regulator 22. The fuel pump 21, the pressure regulator 22, and the check valve 23 are provided with a bracket 24 and a hole 25 a formed in the upper surface of the fuel tank 25.
From the above, the hole 25a is liquid-tightly closed by the lid 26. The outlet 23b of the check valve 23 is connected to the fuel filter 28 (FIG. 2) via the fuel introduction passage 27.

From the check valve 23 to the fuel filter 28
The fuel introduction passage 27 leading to the delivery pipe 29 via
A high pressure hose or pipe is used to supply the high pressure fuel, and the mounting portion is a zero seal. On the other hand, the fuel return passage 34 of the pressure regulator 22 in the fuel tank 25 is a passage for surplus fuel after pressure adjustment,
A low pressure hose or pipe is used and can be shortened. Further, the seal of the caulking portion 22f of the container of the pressure regulator 22 does not need to be a strict zero seal.

Pressure gauges 35 and 36 are connected to the fuel introduction passage 27 on the upstream side and the downstream side of the fuel filter 28, for example, on the upstream side of the inlet and on the delivery pipe 29 to detect the fuel pressure. These pressure gauges 35 and 36 are connected to an electronic control unit (ECU) 37. Electronic control unit 3
7 detects the pressure difference between these pressure gauges 35 and 36, and lights the alarm 38 when the pressure difference exceeds a predetermined value.

The operation will be described below. Fuel pump 21
Operates when the engine is operating and pressurizes and discharges the fuel in the fuel tank 25. Pressure regulator 22
When the pressure of the fuel pumped from the fuel pump 21 exceeds a predetermined pressure set by the spring 32, the diaphragm 30 is displaced to open the valve, and excess fuel is returned to the return port 23c.
Is returned to the fuel tank 25 through the fuel return passage 35. The surplus fuel has a low pressure, and since the fuel return passage 34 is in the fuel tank 25, the surplus fuel is reliably returned to the fuel tank 25 even if the sealing property of the mounting portion is low.

The high-pressure fuel regulated to a predetermined pressure by the pressure regulator 22 opens the check valve 23, is pressure-fed to the fuel filter 28 through the fuel introduction passage 27, is filtered and is then pressure-fed to the delivery pipe 29 for fuel injection. It is injected and supplied from the valve into the engine. When the engine stops and the fuel pump 21 stops, the check valve 2
3 immediately closes and prevents the fuel in the fuel introduction passage 27 from returning to the fuel tank 25. As a result, the fuel pressure in the fuel introduction passage 27 is maintained at a high pressure, high-pressure fuel can be immediately supplied to the engine at the next start, and the start becomes easy.

The pressure gauges 35 and 36 detect fuel pressures on the upstream and downstream sides of the fuel filter 28 and output corresponding signals. When the pressure difference between the pressure gauges 35 and 36 exceeds a predetermined pressure, the electronic control unit 37 turns on an alarm 38 to notify the driver that the fuel filter 28 is clogged and the pressure loss is high. That is, the electronic control unit 37
Informs when to replace the fuel filter 28. When the pressure loss of the fuel filter 28 increases, the required amount of fuel is not supplied to the delivery pipe 29 side, and the output of the engine decreases. Therefore, the driver replaces the fuel filter early when the alarm 38 is turned on.

[0019]

As described above, according to the present invention, the fuel supply device can be made compact by integrally providing the fuel tank mounting member with the fuel pump and the pressure regulator. In addition, by returning excess fuel with low pressure from the pressure regulator to the fuel tank, a low-pressure hose or pipe can be used for the fuel return passage. Therefore, the sealing property is facilitated and the cost can be reduced.

According to the present invention, the fuel pump and the pressure regulator are arranged in the fuel tank to further downsize the device, and the fuel return passage for returning the surplus fuel from the pressure regulator to the fuel tank is shortened. Therefore, the cost can be reduced. According to the third aspect, by providing the check valve on the downstream side of the fuel pump and the pressure regulator, the fuel pressure in the fuel introduction passage after the engine is stopped can be maintained at a high pressure, and the high pressure fuel is immediately supplied at the next engine start. Can be supplied and the starting is easy.

According to the present invention, the pressure loss of the fuel filter can be detected by arranging the pressure sensor on the upstream side and the downstream side of the fuel filter to detect the fuel pressure. The pressure loss can cause clogging of the fuel filter. Can be detected and the replacement time can be checked. According to the fifth aspect, when the pressure loss of the fuel filter becomes high, the alarm can be turned on to notify the driver of the replacement time of the fuel filter, and the fuel supply device can be kept in a good state.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a conventional fuel supply device.

FIG. 2 is a configuration diagram showing an embodiment of a fuel supply device according to the present invention.

FIG. 3 is an enlarged cross-sectional view of the fuel pump, pressure regulator, and check valve of FIG.

[Explanation of symbols]

 20 Fuel Supply Device 21 Fuel Pump 22 Pressure Regulator 23 Check Valve 24 Bracket 25 Fuel Tank 26 Lid 27 Fuel Introduction Passage 28 Fuel Filter 29 Delivery Pipe 30 Diaphragm 31 Valve Body 32 Spring 33 Filter 34 Fuel Return Passage 35, 36 Pressure Gauge 37 Electronic Control device 38 alarm

Claims (5)

[Claims] 1. A pressure regulator for regulating the pressure of fuel in a fuel tank pressurized by a fuel pump, a fuel introduction passage for guiding the fuel regulated by the pressure regulator to an engine, and the pressure regulator to the fuel tank. A fuel supply device comprising: a fuel return passage for returning excess fuel; and a fuel filter provided in the fuel introduction passage, wherein the fuel pump and the pressure regulator are integrally provided in a fuel tank mounting member. 2. The fuel supply device according to claim 1, wherein the fuel pump and the pressure regulator are arranged in the fuel tank. 3. The fuel supply device according to claim 1, further comprising a check valve disposed downstream of the fuel pump and the pressure regulator. 4. The fuel filter is arranged downstream of the fuel pump and the pressure regulator, and pressure sensors are arranged upstream and downstream of the fuel filter. The fuel supply device described. 5. The fuel supply device according to claim 4, wherein an alarm is turned on according to the output of the pressure sensor.