JPH0196462A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To increase the degree of freedom of mounting a fuel injection valve on an engine and improve combustion by connecting a holder formed with a fuel path and jet to a nozzle body while providing in the holder a controlling valve for opening and closing the jet. CONSTITUTION:A throttle hole 112 provided in a nozzle body 111 is opened and closed by a needle valve 113 to jet fuel from the throttle hole 112. A holder 151 is formed with a fuel path 152 and a jet 101 communicating thereto and opening to the outside. The holder 151 is connected to the nozzle body 111 so that the fuel path 152 communicates to the throttle hole 112. A controlling valve 161 for opening and closing the jet 101 according to fuel pressure in the fuel path 152 is provided in said holder 151. The degree of freedom of mounting a fuel injection valve 100 on an engine is thus increased to improve combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection valve that injects fuel directly into, for example, a combustion chamber of an internal combustion engine.

[Conventional technology and problems]

Traditionally, the mixture near the spark plug in the combustion chamber is made richer than in other parts of the combustion chamber, so-called mixture stratification, which improves combustion and improves fuel efficiency, engine transient characteristics, and exhaust emissions. In order to obtain such stratification of the air-fuel mixture, a fuel injection valve that injects fuel directly into the combustion chamber has been proposed (Utility Model Application Publication No. 58-2363, S To E Pa
per 780767).

However, such fuel injection valves are fixed to the cylinder block or cylinder head with the nozzle hole for injecting fuel facing into the combustion chamber, and most of the part protrudes from the cylinder block, etc. There were restrictions on its position in relation to other equipment. For this reason,
There are restrictions on the fuel injection position, and there is a risk that the stratification of the air-fuel mixture may become insufficient.

The present invention has been made with the object of obtaining a fuel injection valve that has a large degree of freedom in attachment to an engine and has no restrictions on the injection position.

[Means for solving problems]

The present invention relates to a fuel injection valve that discharges fuel from the throttle hole by opening and closing a throttle hole bored in a nozzle body using a needle valve, the fuel injection valve having a fuel passage and a nozzle hole communicating with the fuel passage and opening to the outside. A holder formed with a holder is connected to the nozzle body so that a fuel passage communicates with the throttle hole, and a control valve is disposed within the holder to open and close the nozzle hole according to the fuel pressure in the fuel passage. It is characterized by having the following.

〔Example〕

The present invention will be explained below based on illustrated embodiments.

FIG. 1 shows an internal combustion engine equipped with a fuel injection valve 100 according to a first embodiment of the present invention. In this figure, a piston 13 is slidably provided in a cylinder bore 12 formed in a cylinder block 11, a cylinder head 14 placed on the cylinder block 11, and a cylinder bore 12 formed in a cylinder block 11.
and the top surface 15 of the piston 13 form a combustion chamber 16.

The ignition plug 21 is fitted into a hole 22 formed in the cylinder head 14, and its electrode 23 projects into the combustion chamber 16. The fuel injection valve 100 is fitted and supported in a support hole 17 formed in the cylinder head 14 and the cylinder block 11 and extending in the vertical direction. Nozzle hole 1 formed in this fuel injection valve 100
01 communicates with the combustion chamber 16 through a hole 18 formed in the cylinder block 11.

Fuel stored in a tank 31 is supplied to the fuel injection valve 100 . The pump 32 is driven by a motor 33 to rotate, and pumps the fuel in the tank 31 to the fuel injection valve 100 via the filter 34 and the supply line 36.

The pressure of the fuel supplied to the fuel injection valve 100 is controlled by the pressure regulating valve 35.
The pressure is regulated to a constant value, and the excess fuel is returned to the tank 31 via the reflux line 37.

The fuel injection valve 100 includes a fuel metering section 110 and a fuel injection section 1.
50, which are interconnected.

The fuel metering section 110 has a structure similar to that of a normal fuel injection valve. That is, a throttle hole 112 is formed in the lower end of the nozzle body 111, and a needle valve 113 for opening and closing the throttle hole 112 is housed inside the nozzle body 111 so as to be able to move up and down. An annular plate 114 is provided above the nozzle body 111.
4 is fitted into the lower end opening 116 of the casing 115. Meanwhile, the inlet member 121 connected to the supply line 36 is fitted into the upper end opening 117 of the casing 115. A fuel passage 123 is formed in a pipe member 122 fixed to the axial center of the inlet member 121, and a filter 123 is formed in a connecting portion of the inlet member 121 with the supply line 36.
24 are provided. The fuel passage 123 and the throttle hole 112 are connected by a passage formed inside the casing 115 and the nozzle body 111, and the fuel passing through the filter 124 and the fuel passage 123 and flowing into the fuel metering section 110 is When the valve is opened, the fuel is discharged from the throttle hole 112 and supplied to the fuel injection section 150.

An annular member 125 is fitted into the head of the needle valve 113, and a spring 126 is inserted between the annular member 125 and the pipe member 122.
is provided. This spring 126 always urges the needle valve 113 downward via the annular member 125, so that when the needle valve 113 is not in operation, the nozzle body 111
seated on the seat portion 127 formed at the bottom of the aperture hole 1.
12 is occluded. The needle valve 113 is opened by energizing the solenoid coil 131. That is, the annular member 125 is formed from a magnetic material, and is attracted upward by energizing the solenoid coil 131, whereby the needle valve 113 is moved from the seat portion 127 to the throttle hole 1.
Open 12.

When the power supply to the solenoid coil 131 is cut off, the needle valve 113 is lowered by the elastic force of the spring 126 and closes the throttle hole 112. Power supply control to the solenoid coil 131 is performed by an electronic control unit (ECU) 132.
The CU 132 supplies a voltage pulse signal to the solenoid coil 131 depending on the operating state of the engine. That is, for example, when the engine is operated under a high load condition, in order to increase the injection amount, a signal with a longer pulse width is supplied to the solenoid coil 131 than in the case of a low load condition, and the needle valve 113 is opened. It takes longer.

The boulder 151 of the fuel injection section 150 is connected to the fuel metering section 110.
The nozzle body 111 is fitted in an oil-tight manner. A fuel passage 152 communicating with the throttle hole 112 of the fuel metering section 110 is formed in the holder 151 . The fuel passage 152 extends linearly along the axial center of the holder 151, and a nozzle hole 101 that extends perpendicularly to the fuel passage 152 and opens on the side surface of the holder 151 is provided at the lower end of the fuel passage 152. It is formed. Inside the nozzle hole 101, in order to open and close it,
A control valve 161, which is an automatic valve that opens outward, is provided.

The control valve 161 includes an annular seat member 162 fitted into the opening of the nozzle hole 101 and a valve body 164 that opens and closes a hole 163 formed in the center of the seat member 162.

The valve body 164 protrudes outward from the hole 163 of the seat member 162 to open the hole 163, and retreats inward to open the hole 163.
occlude. A pin 165 is fixed to the back surface of the valve body 164, and a beam retainer 166 is provided at the tip of the pin 165. A spring 167 is provided between the retainer 166 and the seat member 162, and urges the valve body 164 to close the hole 163.

Therefore, when the fuel pressure in the fuel passage 152 exceeds the elastic force of the spring 167, that is, the valve opening pressure, the control valve 161
The valve opens against the force of the spring 167, and when the fuel pressure becomes lower than the valve opening pressure, the valve closes due to the elastic force of the spring 167.

While the control valve 161 is open, fuel is horizontally injected into the combustion chamber 16 through the injection hole 101 and the hole 18. The fuel injected in this manner flows toward the electrode 23 of the spark plug 21 due to the upward airflow generated by the upward movement of the piston 13, and a rich air-fuel mixture is formed near the electrode 23. In other words, stratification of the air-fuel mixture is obtained.

When the screw I/N 13 further rises, the hole 18 is closed, the spark plug 21 is ignited, and the air-fuel mixture explodes. At this time, since the air-fuel mixture is stratified, the average air-fuel ratio in the combustion chamber 16 may be in a lean state, thus improving fuel efficiency and reducing HC and CO in the exhaust gas. In addition, the fuel metering unit 110 is provided with a fuel injection unit 150 between it and the combustion chamber 16, and is separated from the combustion chamber 16, so that high-temperature, high-pressure gas and fine particles are generated in the combustion chamber 16 during an explosion. are not directly affected by Furthermore, control valve 1
61 is an outward opening type, so the inside of the fuel passage 152 is the combustion chamber 16.
Less susceptible to internal influences. Therefore, the fuel metering section 110 hardly undergoes thermal deformation or contamination with exhaust particulates, and can maintain stable fuel metering performance over a long period of time.

In the first embodiment, the nozzle hole 101 is connected to the fuel passage 152.
Although it extends in a direction perpendicular to that, it is not limited thereto, and may be inclined at any angle. That is, the nozzle hole 101 may face diagonally upward or diagonally downward.

Further, the height position of the nozzle hole 101, that is, the length of the fuel passage 152 can also be freely selected. However, combustion chamber 1
The direction and position of fuel injection with respect to 6 can be freely determined.
It becomes easier to generate a rich mixture near 1.

FIG. 2 shows a fuel injection valve 100 according to a second embodiment.

This second embodiment is based on the fuel injection valve 100 of the first embodiment.
In contrast, the atomization of the injected fuel has been improved. For this reason, the second embodiment is provided with a mechanism for mixing air with the fuel injected from the nozzle hole 101, and the other configurations are the same as those of the first embodiment.

The cylindrical body 201 of the air supply mechanism is fitted into the holder 151, thereby forming an annular passage 202 between the body 201 and the holder 151. A cap 203 is fitted to the lower ends of the cylindrical body 201 and the holder 151,
An air chamber 2 is provided between the side wall of the cap 203 and the holder 151.
04 is formed. The cap 203 has an opening 205 in a portion facing the nozzle hole 101, and this opening 205 is a hole formed in the cylinder block (in FIG.
8J) to the combustion chamber. Air chamber 204 communicates with passageway 202 via hole 206 . A pipe 210 is connected to the upper part of the cylindrical body 201.

The pipe 210 extends obliquely upward from the body 201 and is connected to a pressurized air source 211 .

Therefore, the air pumped from the pressurized air source 211 flows into the passage 202 through the pipe 210 and into the hole 206.
The air flows into the air chamber 204 from there. The fuel discharged from the nozzle hole 101 is mixed with the air in the air chamber 204, and the fuel is discharged from the opening 205.
is sprayed from. Thus, fuel atomization is promoted and combustion is improved.

Note that instead of the pressurized air source 211, the pipe 210 may be communicated with the atmosphere.

FIG. 3 shows an engine in which two fuel injection valves 100 shown in FIG. 1 are provided in the cylinder block 11. Each fuel injection valve 1
No. 00 has the same configuration, and each nozzle hole 101 is set at the same height position and is provided facing each other.

Therefore, the fuel injected from each nozzle hole 101 collides in the center of the combustion chamber 16, and this collision atomizes the fuel. As a result, the penetration force of the injected fuel is significantly reduced, and a rich air-fuel mixture is formed in the center of the combustion chamber 16, that is, in the vicinity of the spark plug 21, resulting in good combustion.

FIG. 4 shows that the fuel injection valve 100 of FIG.
An example in which 01 is opened is shown. The air port 301 is connected to the check valve 3
02 to a source of pressurized air 304. The pressurized air source 304 has a valve (not shown), which is controlled by the ECU 132 and opens and closes in synchronization with fuel injection.

That is, when fuel is injected from the nozzle hole 101, pressurized air is injected from the air port 301, and the fuel and air collide at the center of the combustion chamber 16. As a result, the fuel becomes atomized, and at the same time, the penetration power of the fuel is significantly reduced.

As a result, a rich air-fuel mixture is formed near the ignition plug 21,
Good combustion can be obtained.

Although the above embodiment is an example in which the fuel injection valve 100 is provided in a reciprocating engine, instead of this, it is provided in a side housing of a rotary engine, and a hole that is opened and closed by the rotor is formed in the side housing. Fuel injection may also be performed. In addition, fuel injection valve 1
It goes without saying that 00 may be provided in the intake manifold.

〔Effect of the invention〕

As described above, according to the present invention, the degree of freedom in attaching the fuel injection valve to the engine is increased, thereby eliminating restrictions on the fuel injection position, and making it possible to improve combustion.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a first embodiment of the present invention, Fig. 2 is a sectional view showing a second embodiment, and Fig. 3 is a sectional view showing an engine provided with two fuel injection valves according to the first embodiment. FIG. 4 is a sectional view showing an engine having an air port facing the fuel injection valve of the first embodiment. 100...Fuel injection valve, 101...Nozzle hole, 11
1... Nozzle body, 112... Aperture hole, 113
...Needle valve, 151...Holder, 152.
...Fuel passage, 161...Control valve.

Claims (3)

[Claims] 1. A fuel injection valve that opens and closes a throttle hole drilled in a nozzle body using a needle valve to discharge fuel from the throttle hole, the fuel injection valve having a fuel passage and a nozzle hole that communicates with the fuel passage and opens to the outside. The holder is connected to the nozzle body so that the fuel passage communicates with the throttle hole, and a control valve is provided in the holder to open and close the nozzle hole according to the fuel pressure in the fuel passage. A fuel injection valve characterized by: 2. 2. The fuel injection valve according to claim 1, wherein the fuel passage extends in a straight line, and the injection holes extend in different directions with respect to the fuel passage. 3. 2. The fuel injection valve according to claim 1, further comprising an air supply mechanism for mixing air with the fuel injected from the nozzle hole.