JPH11280593A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device by which an optimum spray shape conformed to an operating state of an internal combustion engine can be obtained. SOLUTION: A fuel injection device 1 is formed by a first coil 7 and a second coil 3 arranged on upper and lower sides within a housing 2, an air port 9a supplying air within the housing 2, an air injection nozzle 9 which is communicated with the air port 9a and is arranged on the lower side of the housing 2, a fuel injection nozzle 12 which has a formed first valve 12b which is abutted on a first valve seat 9c at a lower end of the air injection nozzle 9 and couples with a first movable iron core 10 which is movable in the vertical direction by magnetic flux when the first coil 7 is excited, a fuel port 5a which supplies fuel within the housing 2 and is communicated with the fuel injection nozzle 12 and a rod 11 which has a formed second valve which is abutted on a second valve seat at the lower end of the fuel injection nozzle 12 and couples with a second movable iron core 6 which is movable in the vertical direction by magnetic flux when the second coil 3 is exited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for directly injecting fuel into a combustion chamber of an engine, and more particularly to a fuel injection device capable of changing a fuel spray shape.

[0002]

2. Description of the Related Art Conventionally, as this type of fuel injection device,
There is one described in JP-A-2-294555. This increases the flow velocity by passing the compressed air flowing into the housing of the fuel injection device through a throttle formed near the valve of the fuel injection nozzle. Next, the fuel flows into the fuel injection device from the fuel inlet formed near the valve, and collides with the compressed air having the increased flow velocity.
The fuel is atomized and injected from a fuel injection nozzle.

[0003] Generally, in an internal combustion engine, an optimum combustion state of fuel in a combustion chamber differs depending on an operation state. When accelerating or climbing a vehicle that requires torque, the fuel and air are diffused as evenly as possible in the entire combustion chamber, such as when a vehicle that does not require a relatively large amount of torque is running at a constant speed. In such a case, it is required to change the combustion state depending on the spray shape, such as by shifting the fuel near the ignition plug in the upper layer of the combustion chamber.

[0004]

However, in the above-described fuel injection device, the fuel and the compressed air are preliminarily mixed and injected.
In order to obtain an optimal spray shape depending on the operation state of the internal combustion engine, it is necessary to change the ratio between fuel and compressed air or change the injection amount of the generated mixture of fuel and air. . This requires a separate supply device for controlling the compressed air and fuel supplied to the fuel injection device, and must be provided outside the fuel injection device. Since the distance from the fuel injection device to the supply device requires control of the supply amount of compressed air or fuel in consideration of the time difference, it has been difficult to secure an optimal spray shape suitable for the operation state of the internal combustion engine. .

Therefore, an object of the present invention is to provide a fuel injection device that can obtain an optimum spray shape suitable for the operation state of an internal combustion engine.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is directed to a housing, first and second coils arranged vertically in the housing, and air for supplying air into the housing. A port, an air injection nozzle formed at a lower end communicating with the air port and having a first valve seat formed at a lower end thereof, and a first valve and a second valve seat formed at a lower end to contact the first valve seat. A fuel injection nozzle coupled to a first movable iron core movable in the vertical direction by a magnetic flux at the time of excitation of the first coil, a fuel port for supplying fuel into the housing and communicating with the fuel injection nozzle, and a second valve seat. Since the second valve that is in contact with the second movable core is formed from a rod coupled to a second movable iron core that can move in the vertical direction by magnetic flux when the second coil is excited, fuel and air are directly injected to the outside, respectively. With fuel and air Independently it is possible to control the injection amount in the fuel injection device, it is possible to obtain a variety of spray shape, for optimal spray pattern that matches the operating state of the internal combustion engine.

According to the second aspect of the present invention, at least one of the first movable iron core and the second movable iron core according to the first aspect of the present invention is formed of a material having magnetic poles, so that various controls can be performed with simpler control. It is possible to obtain a suitable spray shape.

[0008]

Embodiments of the present invention will be described with reference to the drawings. 1 is a configuration diagram of a fuel injection device according to the present invention, FIG. 2 is an enlarged view of a lower end portion of the fuel injection device of FIG. 1, and FIG. 3 is an operation of each part of a first injection shape of the fuel injection device according to the present invention. FIG. 4 is an operation diagram of each part of the second injection shape of the fuel injection device according to the present invention, and FIG. 5 is an operation diagram of each portion of the third injection shape of the fuel injection device according to the present invention.

As shown in FIG. 1, a fuel injection device 1 mounted on an upper portion of a combustion chamber of an engine (not shown)
The housing 2, a first coil 7 and a second coil 3 arranged vertically in the housing 2, an air port 9 a for supplying air into the housing 2, and an air port 9 a communicating with the air port 9 a and arranged below the housing 2. Air injection nozzle (No. 1)
Fixed iron core) 9 and first valve seat 9 at the lower end of air injection nozzle 9
c, a first valve 12b is formed in contact with the fuel injection nozzle 12 connected to a first movable iron core 10 movable in the vertical direction by a magnetic flux when the first coil 7 is excited. A fuel port 5a communicating with the injection nozzle 12, and a second valve seat 12c at the lower end of the fuel injection nozzle 12;
The second movable iron core 6 which is formed with a second valve 11b that is in contact with the
And the rod 11 connected thereto.

The second coil 3 disposed above the housing 2 is wound around the bobbin 4 and supplied with power from the electrodes 16 in the socket 17. Inside the bobbin 4, a second fixed iron core 5 having a fuel port 5a formed at an upper end, and a second movable iron core 6 below the second fixed iron core 5 are arranged.
The fuel port 5a is supplied with fuel from a fuel supply device (not shown). A spring 14 is arranged between the second fixed iron core 5 and the second movable iron core 6 so as to constantly urge the second movable iron core 6 downward.

The second movable iron core 6 may be formed of a material having magnetic poles such as a permanent magnet or a magnetic material. For example, the S pole is arranged above and the N pole is arranged below.

A rod 11 is connected to a lower portion of the second movable core 6. The rod 11 has a circular elongated hole 1 formed inside the fuel injection nozzle 12 and extending in the longitudinal direction in FIG.
The two substantially vertically arranged guides 11a which are inserted into the second hole 2e and slide in the long hole 12e ensure linear movement in the vertical direction. A second valve 11b formed at the lower end of the rod 11 abuts a second valve seat 12c formed inside the fuel injection nozzle 12 below, and the fuel injection port 12d
Can be opened and closed.

A first coil 7 arranged below the second coil 3 in the housing 2 is wound around a bobbin 8 and supplied with power from the electrode 16 separately from the second coil 3.
Inside the bobbin 8, a first movable core 10 and an air injection nozzle 9 are arranged below the first movable core 10. A spring 15 is disposed between the first movable iron core 10 and the air injection nozzle 9 so as to constantly urge the first movable iron core 10 upward.

The first movable iron core 10 is connected to the upper end of the fuel injection nozzle 12 described above. The first movable iron core 10 fixes the inner diameter portion 13a of the diaphragm 13 with the stopper 10a. The diaphragm 13 has an outer diameter portion 1.
3b is fixed near the housing 2 and the diaphragm 13
The upper space and the lower space are completely shut off.

The air injection nozzle 9 has an air port 9a communicating with an air pump (not shown) at a portion protruding from the housing 2, and a circular elongated hole 9 extending longitudinally in FIG.
d, an air injection port 9b and a first valve seat 9c are formed at the lower end. The fuel injection nozzle 12 is inserted into the elongated hole 9d, and two vertically arranged substantially rectangular guides 12a sliding in the elongated hole 9d ensure linear movement in the vertical direction. A first nozzle formed at the lower end of the fuel injection nozzle 12
The valve 12b is in contact with the first valve seat 9c of the air injection nozzle 9 to open and close the air injection port 9b.

Next, the operation will be described.

The fuel is supplied from the fuel supply device to the fuel port 5a.
Through the fuel injection device 1. In addition, the fuel
After passing through the space defined by the inside of the second fixed iron core 5, the outer periphery of the second movable iron core 6, the outer diameter of the rod 11, and the long hole 12e of the fuel injection nozzle 12, it reaches the second valve 11b. , Second
The fuel is injected from the fuel injection nozzle 12 with the opening operation of the valve 11b.

The compressed air is supplied into the fuel injection device 1 through the air port 9a. Further, the compressed air passes through a space formed by the outer diameter of the fuel injection nozzle 12 and the long hole 9d of the air injection nozzle 9, reaches the first valve 12b, and
The air is injected from the air injection nozzle 9 with the opening operation of the valve 12b.

The fuel and the compressed air do not mix in the fuel injection device 1 because the diaphragm 13 blocks the space where each of them resides.

First, the case where fuel and compressed air are simultaneously injected into the combustion chamber of the engine will be described with reference to FIG.

As shown in FIG. 3, by using the permanent magnet as the second movable core 6, the second valve 11b and the first valve 12b can be opened and closed only by exciting only the first coil 7. When a negative current as shown in FIG. 3A is supplied from the electrode 16 to the first coil 7, the first coil 7
A magnetic flux having a pole and a south pole below the pole is generated. This magnetic flux repels the N pole below the second movable core 6 and repels the second movable core 6.
Is moved upward, and the first movable iron core 10 is moved to the air injection nozzle (first fixed iron core) 9 side. By this operation, the first valve 12b coupled to the first movable iron core 10
Is a negative displacement shown in FIG.
The second valve 1 connected to the second movable core 6 while injecting compressed air from the air injection port 9b away from the first valve seat 9c
1b makes a positive displacement shown in FIG. 3B, separates from the second valve seat 12c of the fuel injection nozzle 12, and injects fuel from the fuel injection port 12d. At the same time, the fuel and the compressed air are injected into the combustion chamber, so that a spray shape in which the fuel and the air are uniformly diffused throughout the combustion chamber can be obtained.

Next, a case where only fuel is injected into the combustion chamber of the engine will be described with reference to FIG.

As shown in FIG. 4, by exciting only the second coil 3, only the second valve 11b can be opened and closed. When a negative current is supplied to the second coil 3 from the electrode 16 as shown in FIG.
A magnetic flux having a lower portion as an S pole is generated. This magnetic flux attracts the S pole on the upper side of the second movable core 6 and moves the second movable core 6 upward. By this operation, the second valve 11b connected to the second movable iron core 6 makes a positive displacement shown in FIG. 4B, separates from the second valve seat 12c of the fuel injection nozzle 12, and moves the fuel from the fuel injection port 12d. Inject only. By injecting only the fuel into the combustion chamber, the spray can have directionality, and depending on the injection timing, a spray shape in which only the fuel is biased around the upper layer of the combustion chamber can be obtained.

Finally, a case where fuel and compressed air are simultaneously injected into the combustion chamber of the engine after only the compressed air is initially injected will be described with reference to FIG.

As shown in FIG. 5, the second movable iron core 6 is a permanent magnet, and the second coil 3 has the electric power shown in FIG. 5A and the first coil 7 has the electric power shown in FIG. And are supplied respectively.

First, when a positive current flows through both coils, the second coil 3 generates a magnetic flux having an upper N pole and a lower S pole, and the first coil 7 generates an upper S pole and a lower S pole. A magnetic flux is generated for the N pole. These magnetic fluxes repel the S pole on the upper side of the second movable core 6 and attract the N pole on the lower side to move the second movable core 6 downward.
0 is moved to the air injection nozzle (first fixed iron core) 9 side. By this operation, the first movable core 10
The valve 12b makes a negative displacement shown in FIG. 5D, separates from the first valve seat 9c of the air injection nozzle 9, and injects compressed air from the air injection port 9b. At this time, the second valve 11b connected to the second movable iron core 6 performs the negative displacement shown in FIG. No fuel is injected from the port 12d.

Next, when a negative current flows through both coils, the second coil 3 generates a magnetic flux having an upper S pole and a lower N pole, and the first coil 7 has an upper N pole and a lower N pole. Is generated as an S pole. These magnetic fluxes attract the S pole on the upper side of the second movable core 6 and repel the N pole on the lower side to move the second movable core 6 upward, and at the same time, move the first movable core 1
0 is moved to the air injection nozzle (first fixed iron core) 9 side. By this operation, the first movable core 10
The valve 12b keeps a state of being separated from the first valve seat 9c of the air injection nozzle 9 while keeping the negative displacement shown in FIG. 5D, continuously injecting compressed air from the air injection port 9b, and
The second valve 11b connected to the movable iron core 6 makes a positive displacement shown in FIG.
And the fuel is injected from the fuel injection port 12d. By injecting compressed air at the beginning, air exists in the lower layer of the combustion chamber of the engine, and then by injecting fuel and compressed air, the fuel and air are uniformly distributed in the upper layer of the combustion chamber. To obtain a spray shape diffused in

In this embodiment, only the second movable iron core 6 is formed of a material having magnetic poles such as a permanent magnet. However, it is not always necessary to form the second movable iron core 6 with a magnet. By setting a positional relationship that is affected, a similar operation can be obtained with a simple iron material. Further, the first movable core 10 may be formed of a material having a magnetic pole, or the first movable core 10 and the second movable core 6 may be formed of a material having a magnetic pole.

[0029]

As described above, the fuel injection device according to the present invention can control the injection amount of fuel and compressed air independently of each other in the fuel injection device, so that various spray shapes can be obtained. Therefore, it is possible to obtain an optimal spray shape suitable for the operation state of the internal combustion engine.

Further, by forming the second movable iron core or the first movable iron core from a material having magnetic poles such as a permanent magnet or a magnetic material, various spray shapes can be obtained with simpler control.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fuel injection device according to the present invention.

FIG. 2 is an enlarged view of a lower end portion of the fuel injection device of FIG.

FIG. 3 is an operation diagram of each part of a first injection shape of the fuel injection device according to the present invention.

FIG. 4 is an operation diagram of each part of a second injection shape of the fuel injection device according to the present invention.

FIG. 5 is an operation diagram of each part of a third injection shape of the fuel injection device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel injection device 2 Housing 3 2nd coil 5 2nd fixed iron core 5a Fuel port 6 2nd movable iron core 7 1st coil 9 Air injection nozzle (1st fixed iron core) 9a Air port 10 1st movable iron core 11 rod 12 Fuel injection nozzle

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02M 69/04 F02M 69/04 GL

Claims (2)

[Claims] 1. A housing, first and second coils disposed vertically inside the housing, an air port for supplying air into the housing, and a first valve seat at a lower end communicating with the air port. An air injection nozzle disposed below the formed housing, a first valve and a second valve seat that are in contact with the first valve seat at a lower end, and are formed in a vertical direction by a magnetic flux when the first coil is excited. A fuel injection nozzle coupled to a first movable iron core that is movable to a first position, a fuel port that supplies fuel into the housing and communicates with the fuel injection nozzle, and a second valve that contacts the second valve seat. A fuel injection device comprising: a second movable iron core movable in a vertical direction by a magnetic flux generated when two coils are excited; and a rod coupled to the second movable iron core. 2. The fuel injection device according to claim 1, wherein at least one of the first movable iron core and the second movable iron core is formed of a material having a magnetic pole.