JPH0738694Y2 - Fuel injector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fuel injection device suitably used for injecting fuel in a fuel tank into an engine of, for example, an automobile, and particularly to a vapor in a fuel filter. The present invention relates to a fuel injection device capable of automatically discharging to the fuel tank side when the fuel pump is stopped.

[Conventional technology]

Generally, a fuel pump for discharging the fuel in the fuel tank,
A pressure regulator that regulates the pressure of the fuel discharged from the fuel pump into the fuel pipe, an injection valve that injects the fuel regulated by the pressure regulator into the engine, and a position between the injection valve and the fuel pump. There is known a fuel injection device including a fuel filter which is provided in the middle of the fuel pipe and removes dust from the fuel in the fuel pipe.

Therefore, FIGS. 3 and 4 show a fuel injection device according to this type of prior art.

In the figure, 1 is a fuel tank for containing a fuel F, 2 is a fuel pump immersed in the fuel F of the fuel tank 1, and the fuel pump 2 is provided with a fuel tank 1 through a main bracket 3 and a sub-bracket 4. The fuel F sucked in from the filter 2A side is discharged into the fuel pipe 5 through the discharge port 2B.

Reference numeral 6 denotes a pressure regulator provided on the tip side of the fuel pipe 5. The pressure regulator 6 is divided into a fuel chamber and a control pressure chamber (both not shown) by a diaphragm, and the pressure regulator 6 is provided on the inlet side of the fuel chamber. Is connected to the fuel pipe 5, and the outlet side is connected to the fuel tank 1 via the return pipe 7.
Further, the control pressure chamber of the pressure regulator 6 is provided with an intake manifold (not shown) of the engine via an air conduit 8.
The pressure of the control pressure chamber is changed within a range of, for example, about ² to 3 kg / cm ² according to the air suction pressure of the intake manifold.

Further, the diaphragm is provided with a valve body (not shown) which is seated on and off the valve seat on the outlet side of the fuel chamber, and the valve body separates from the valve seat when the fuel chamber becomes higher in pressure than the control pressure chamber. Then, the excess pressure in the fuel pipe 5 is returned from the outlet side of the fuel chamber to the inside of the fuel tank 1 through the return pipe 7, and the fuel pressure (fuel pressure) in the fuel pipe 5 is adjusted. That is,
The pressure regulator 6 controls the fuel pipe 5 when the air intake pressure of the intake manifold becomes positive when the accelerator is depressed.
Is adjusted to about 3.0 kg / cm ² , and when the air suction pressure becomes negative pressure at idle, etc., it is adjusted to about 2.0 kg / cm ^2, and when the engine is stopped, the valve body is closed to close the fuel pipe 5. For example 2.55
It is designed to be maintained at about kg / cm ² .

Reference numeral 9 denotes an injection valve provided in the middle of the fuel pipe 5. The injection valve 9 injects the fuel F in the fuel pipe 5 to the engine and explodes the mixture of the injected fuel F and air. , It is designed to give the desired output to the engine. Here, since the fuel pressure supplied to the injection valve 9 is regulated by the pressure regulator 6, when the intake air amount increases when the accelerator is depressed, the injection amount of the fuel F injected from the injection valve 9 is increased. Is increased, and the injection amount is decreased at the time of idling when the intake air amount is decreased, so that the mixture ratio of the fuel F and the air is kept constant.

Reference numeral 10 denotes a fuel filter provided between the fuel pump 2 and the injection valve 9 and provided in the middle of the fuel pipe 5. The fuel filter 10 is a filter case 11 and a filter member described later as shown in FIG. It is composed of 14 and. Here, the filter case 11 is formed in a cylindrical shape with a bottom, a casing 12 provided with an inflow port 12A for the fuel F immediately at the bottom portion, and an upper end side of the casing 12 is covered so that the flow in the fuel F flows. The cover 13 is provided with an outlet 13A, and a cylindrical filter chamber A is defined between the cover 13 and the casing 12 by a defining member 15 described later.

14 is a filter member disposed in the casing 12, the filter member 14 is a plurality of small holes 15A on the lower surface side and the peripheral surface side,
15A, ... Are provided in the defining member 15 and the filter chamber A defined by the defining member 15 to remove dust in the fuel F flowing from the inlet 12A side, The filter element 16 is mainly configured to flow clean fuel F from the outlet 13A side toward the injection valve 9 through the chamber B inside the defining member 15.

Further, 17 denotes a resin tube which is press-fitted into the outlet 13A and whose lower end side protrudes into the chamber B. The tube 17 is formed of a resin material such as vinyl or nylon into a cylindrical shape, and is provided in the chamber B at a fourth position. As shown in the figure, the vapor is allowed to remain, so that the abnormal noise generated when the vapor flows out to the outlet 13A is suppressed. The fuel filter 10 and the injection valve 9 are arranged in the engine room on the front wheel side of the vehicle, and the fuel tank 1 and the fuel pump 2 are arranged on the rear wheel side of the vehicle. 1
0, the fuel pipe 5 between the fuel pumps 2 is long.

In the fuel injection device configured as described above, the discharge port of the fuel pump 2 is connected to the fuel filter 10, the injection valve 9 and the inlet side of the pressure regulator 6 via the fuel pipe 5, and the outlet side of the pressure regulator 6 is connected. Is connected to the fuel tank 1 via a return pipe 7 or the like, and the excess pressure in the fuel pipe is returned from the outlet side of the pressure regulator 6 to the fuel tank 1 side, thereby reducing the fuel pressure in the fuel pipe 5. For example 2-3 kg / cm ²
Within a certain range, it is adjusted according to the air intake pressure of the intake manifold, whereby the pressure of the fuel injected from the injection valve 9 is changed according to the air intake pressure, and the mixture ratio of air and fuel is kept constant. I try to keep it.

[Problems to be solved by the device]

By the way, in the above-described conventional technique, the fuel temperature of the fuel F in the fuel tank 1 and the fuel pipe 5 changes according to the temperature in the engine room, and is cooled by a cooling fan such as a radiator when the engine is driven. When stopped, cooling by the cooling fan is also stopped, and the fuel temperature temporarily rises to about 80 degrees with the temperature in the engine room. Then, when the fuel temperature rises, vapor is likely to be generated in the fuel F, and this vapor stays in the fuel pipe 5,
When the fuel is injected from the injection valve 9 when the engine is restarted, the mixture ratio of air and fuel changes significantly, and the fuel becomes lean,
The engine cannot be restarted.

For this reason, in the prior art, a hot restart valve (not shown) is provided in the fuel pump 2 to discharge the vapor generated in the fuel pump 2 into the fuel tank 1, and the vapor in the fuel pump 2 is replaced by the fuel. The discharge is prevented in the pipe 5. However, in reality, vapor is also generated from the fuel F in the fuel pipe 5, and the vapor also enters the fuel filter 10. Therefore, this vapor is injected together with the fuel F from the injection valve 9 when the engine is restarted. As a result, the fuel becomes lean and it becomes difficult to restart the engine.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can automatically discharge the vapor in the fuel filter to the fuel tank side when the fuel pump is stopped, etc., and reliably restart the engine. The fuel injection device is provided.

[Means for Solving the Problems]

The features of the configuration adopted by the present invention to solve the above-described problems are that the fuel filter has an inlet port that is closed at both axial ends, an upwardly projecting inlet port at the upper end side, and a downwardly projecting flow port at the lower end side. It is composed of a tubular filter case having an outlet and a filter member arranged in the filter case, and the vapor in the filter case is discharged to the fuel tank side at the upper end side of the filter case. A vapor discharge valve is provided, and a check valve is provided on the upper side of the filter member to allow vapor in the filter member to flow upward and to prevent reverse flow.

[Action]

With the above configuration, even if vapor is generated in the fuel filter or the like when the fuel pump is stopped, this can be automatically discharged to the fuel tank side by the vapor discharge valve and the check valve provided in the fuel filter. Then, when the engine is restarted, the fuel not containing vapor can be injected from the injection valve.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the embodiments, the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 21 is located between the fuel pump 21 and the injection valve 9,
A fuel filter provided in the middle of the fuel pipe 5 is shown. The fuel filter 21 has a filter case 22 as shown in FIG.
And a filter member 25, which will be described later, and the like.
Here, the filter case 22 is formed in a cylindrical shape with a lid, and has a casing 23 provided with an inflow port 23A of the fuel F protruding upward on the lid portion side (upper end side) and a lower end side of the casing 23. The cover 24 is provided with an outlet 24A in the fuel F projecting downward, and a cylindrical filter chamber A is defined between the cover 24 and the casing 23 by a defining member 26 described later. It is supposed to be done.

Further, the filter member 25 is the filter member described in the related art.
Almost the same as 14, but comprises a defining member 26 having a plurality of small holes 26A, 26A ... And a filter element 27,
A plurality of flow holes 26C, 26C ... Are formed in the upper lid portion 26B of the partition member 26, which is located above the chamber B communicating with the outlet 24A. The respective circulation holes 26C are annularly arranged in the vicinity of the central portion of the upper lid portion 26B and are opened and closed by a check valve 30 described later.

On the other hand, the filter element 27 is housed in the filter chamber A defined by the defining member 26, removes dust in the fuel F flowing in from the inlet 23A side, and defines a clean fuel F. It is designed to flow out from the outlet 24A side toward the injection valve 9 through the chamber B inside the member 26. The fuel filter 21 is vertically arranged so that the inflow port 23A is located on the upper side and the outflow port 24A is located on the lower side (see FIG. 1).

Reference numeral 28 denotes a hot restart valve as a vapor discharge valve provided on the upper end side of the casing 23. The hot restart valve 28 includes a valve case 28C having a vapor intake port 28A and a discharge port 28B, and the valve. Provided inside the case 28C, valve spring
28D and a valve body 28E which is normally urged in the valve opening direction with a spring load of about 0.2 kg / cm ² , and the valve body 28E is driven by the fuel pressure in the fuel pipe 5 when the fuel pump 2 is operating.
It is designed to be closed against D. Then, when the fuel pressure in the fuel pipe 5 becomes 0.2 kg / cm ² or less when the fuel pump 2 is stopped, the hot restart valve 28 opens the valve body 28E by the valve spring 28D, and The vapor or the like is discharged from the outlet 28B of the valve case 28C to the fuel tank 1 side via a hose 29 or the like described later. Reference numeral 29 denotes a vapor discharging hose whose one end side is connected to the discharge port 28B and the other end side is connected in the middle of the return pipe 7 (see FIG. 1).

Reference numeral 30 denotes a check valve provided in the center of the upper lid portion 26B of the defining member 26, and the check valve 30 is formed in an umbrella type by a soft resin material such as chlorosilicon rubber, and has a valve body 30A and a defining member. 26 includes a support portion 30B that passes through the center of the upper lid portion 26B and is attached to the upper lid portion 26B and supports the valve body 30A. An annular lip portion 30C is formed thin on the outer peripheral side of the valve body 30A. Has been done. When the fuel pump 2 is in operation, the fuel F flows downward from the inlet 23A in FIG. 2, so that the flow of the fuel F pushes the valve body 30A from the upper portion of the check valve 30. The annular lip portion 30C comes to sit closely on the portion 26B. As a result, the fuel F cannot pass through each flow hole 26C, which is the fuel passage of the check valve 30,
The gas flows in toward the cylindrical filter chamber A side. Further, since the valve body 30A is made of a soft material when the fuel pump 2 is stopped, etc., if the flow of the fuel F from the upper portion is stopped, the annular lip portion 30C is formed from the upper surface of the upper lid portion 26B.
Are separated by a small force, and the vapor staying in the chamber B inside the partition member 26 passes through each circulation hole 26C by the buoyancy of the vapor and floats above the casing 23. It is designed to allow Then, the vapor that has surfaced is connected to the hose by the hot restart valve 28.
29, Returning to the inside of the fuel tank 1 via the return pipe 7.

The fuel injection device according to the present embodiment has the above-described structure, and the basic operation thereof is not different from that of the prior art.

Therefore, in this embodiment, the fuel filter 21 is arranged so that the inflow port 23A is on the upper side and the outflow port 24A is on the lower side, and the fuel filter 21 is provided with the hot restart valve 28. It is generated in the fuel filter 21 because the outflow port 28B of is connected to the return pipe 7 via the hose 29 and the check valve 30 is provided in the center of the upper lid portion 26C of the partition member 26 provided in the fuel filter 21. Fuel pump 2
Hot stop valve 28 when the
It can be automatically discharged to the fuel tank 1 through B, the hose 29, and the return pipe 7. Further, the vapor accumulated in the chamber B inside the partition member 26 can be automatically discharged upward through the check valve 30 and can be discharged to the fuel tank 1 side by the hot restart valve 28. As a result, it is possible to effectively prevent the fuel containing the vapor from being injected from the injection valve 9 when the engine is restarted, and to improve the restart of the engine.

[Effect of device]

As described in detail above, according to the present invention, the fuel filter is provided with the hot restart valve for discharging the vapor in the fuel pipe to the fuel tank side, and the check valve is provided in the fuel filter. Since the inlet is on the upper side and the outlet is on the lower side, the vapor in the fuel filter can be automatically discharged to the fuel tank side when the fuel pump is stopped, and restarted. At times, it is possible to effectively prevent the fuel containing the vapor from being injected from the injection valve, and it is possible to improve the restartability of the engine.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is an overall view of a fuel injection device, FIG. 2 is a longitudinal sectional view of a fuel filter shown in FIG. 1, FIG. 3 and FIG. FIG. 3 shows a prior art, FIG. 3 is an overall view of a fuel injection device, and FIG. 4 is a vertical sectional view of a fuel filter. 1 ... Fuel tank, 2 ... Fuel pump, 5 ... Fuel piping, 6 ...
Pressure regulator, 7 ... Return piping, 8 ... Air conduit, 9 ...
Injection valve, 21 ... Fuel filter, 22 ... Filter case, 23 ...
Casing, 23A ... inlet, 24 ... cover, 24A ... outlet,
25 ... Filter member, 26 ... Definition member, 27 ... Filter element, 28 ... Hot restart valve, 29 ... Hose, 30 ...
Check valve.

Claims (1)

[Scope of utility model registration request] 1. A fuel pump for discharging fuel in a fuel tank, a pressure regulator for regulating the pressure of fuel discharged from the fuel pump into a fuel pipe, and fuel regulated by the pressure regulator for an engine. In a fuel injection device comprising an injection valve for injecting and a fuel filter which is provided between the injection valve and a fuel pump and is provided in the middle of the fuel pipe, and which removes dust from the fuel in the fuel pipe,
The fuel filter has a cylindrical filter case with both ends in the axial direction closed, an upwardly projecting inlet port at the upper end side, and a downwardly projecting outlet port at the lower end side, and a fuel filter disposed in the filter case. It is composed of the installed filter member,
A vapor discharge valve for discharging the vapor in the filter case to the fuel tank side is provided on the upper end side of the filter case, and the vapor in the filter member flows upward on the upper side of the filter member. A fuel injection device, which is provided with a check valve that allows the above-mentioned flow and prevents the flow in the opposite direction.