JPH03217653A - Fuel injection device of internal combustion engine - Google Patents

Abstract

PURPOSE:To make a fuel injection device compact for a simple pipe by operating two valves with a single movable iron core and a single solenoid coil which drives it. CONSTITUTION:When one-way current is applied to a solenoid coil 36 which has a single driving circuit, a movable iron core made of a permanent magnet moves in one direction to open a fuel measuring valve 54 so as to inject the fuel into an intermixing chamber 46 by the amount in proportion to the time when current is being applied. Compressed air is led in the intermixing chamber 46, so fuel is diffused and mixed in compressed air existing in passages and spaces from the intermixing chamber 46 to a nozzle orifice 20. When the direction of the current applied to the solenoid coil 36 is reversed, the nozzle pore 20 opens and air-fuel mixture is thrust out by the pressure of compressed air and is injected from the nozzle port 20 to be supplied to the internal combustion engine, however, air-fuel mixture is injected, so it is thus possible to provide good fuel mist and easy atomization for a good combustion condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection device for injecting fuel together with compressed air into an intake port or directly into a combustion chamber of an internal combustion engine.

[Conventional technology]

The typical configuration of this type of conventional fuel injection device is
It is described in Japanese Patent No. 3-248965. This fuel injection device is an integral combination of a solenoid valve for fuel metering and a solenoid valve for air injection, but the solenoid actuator that drives these two solenoid valves is mechanically They are completely independent and each is controlled separately.

The fuel is injected into the compressed air passage upstream of the nozzle nozzle, where it mixes with compressed air, and then when the solenoid valve for air injection provided in the nozzle nozzle protrudes outward and opens, the mixture is mixed. It is ejected into the intake port of the internal combustion engine or directly into the combustion chamber, where it mixes with the main combustion air there.

In this way, since the fuel once injected into the internal combustion engine through the air blast valve is mixed with compressed air beforehand and then injected from the nozzle, there is an advantage that the atomization of the fuel progresses and a good combustion state can be obtained.

[Problem to be solved by the invention]

In conventional fuel injection systems, it is necessary to centrally place both the solenoid valve for fuel metering and the solenoid valve for air injection, and one is lightweight and the other uses compressed air to blow out the entire amount of injected fuel. Because of the need for linked operations, 2.
Since the relative positions of the two solenoid valves are limited, the degree of clarity in design is reduced. And it becomes bulky as a whole.
When installed on an engine, it required a considerable amount of space, and the routing of fuel piping and compressed air piping became complicated, causing problems when installing the engine.

An object of the present invention is to solve these problems of the conventional fuel injection device.

[Means to solve the problem]

The fuel injection device for an internal combustion engine according to the present invention includes a single solenoid coil, a single permanent magnet movable core that can move within the solenoid coil, and a valve that opens by moving the single movable core in one direction. a fuel metering valve that injects fuel into the internal mixing chamber; a nozzle valve that opens when the single movable iron core moves in the other direction to inject the compressed air passing through the internal mixing chamber to the outside; and the solenoid coil. The device is characterized in that it is provided with a drive circuit that supplies current so that the direction of the current flow is repeatedly reversed.

[For production]

When the drive circuit supplies a unidirectional current to a single solenoid coil, the permanent magnet movable core moves in one direction to open the fuel metering valve, causing the current to flow in an amount proportional to the amount of time the current continues to flow. of fuel is injected into the internal mixing chamber. Since compressed air is introduced into the internal mixing chamber, the fuel spreads and mixes into the compressed air in the passage and space from the internal mixing chamber to the nozzle.

Next, when the direction of the current supplied to the solenoid coil is reversed, the nozzle nozzle opens and the air-fuel mixture is pushed out by the pressure of the compressed air, which is ejected from the nozzle nozzle and supplied to the internal combustion engine. Since the air mixture is injected, the fuel is atomized well, easily atomized, and good combustion conditions can be obtained.

〔Example〕

In FIG. 1 showing the structure of an embodiment of the present invention, a fuel injection device 10 includes a lower body 12 made of a magnetic material, a nozzle portion 14 hermetically crimped below the lower body 12, and a lower body 12.
An upper main body 16 is attached to the upper part with a lever, and a delivery pipe 1 is fitted airtightly over the upper main body 16.
8, the outer shell is generally formed.

Inserted into the nozzle part 14 is an elongated twenty-one dollar 24 equipped with an outer ring-shaped valve part 22 that closes the nozzle throat 20 at the tip, and a ring 26 fitted to the neck of the dollar is inserted into the nozzle part 14 .
By urging the needle 24 upwardly, the valve portion 22 of the needle 24 is pressed against the nozzle rod 20, thereby closing the fuel injection device 10. In addition, 30 is a spring seat, 32
indicates a shim for adjusting the valve lift β1.

An annular fixed iron core 34 is attached to the inner cavity of the lower body 12, and a solenoid coil 36 is wound on the annular fixed iron core 34. 38 is a terminal for energizing the solenoid coil 36. 4D is a yoke made of a magnetic material, which is magnetically connected to the fixed iron core 34, and whose cylindrical portion extending upward has a plurality of radial or tangential air inflow holes 42, and which has a fuel nozzle (described later). 44 is sandwiched between the upper body 16 and the upper body 16 via a shim 46, thereby forming an internal mixing chamber 48.

The fuel nozzle 44 has a fuel nozzle 50 that forms a conical valve seat in the downward direction inside thereof, and a conical valve portion formed in a fuel valve 52 passing through it is provided so as to be seatable. It constitutes a fuel metering valve 54.

A relatively weak compression spring 56 is provided between the upper end of the needle 52 and the upper body 16 to bias the fuel needle 52 in the direction in which the fuel metering valve 54 closes. 5 in Figure 1
8 is a fuel strainer, 60 is, for example, 5.5 kg/cu
62 indicates a rubber seal ring.

1. The fuel barrel 52 also includes a plurality of rectangular flanges 66 and a disc-shaped stopper 6 that are slidably guided and supported by the inner wall surface of the fuel chamber 64, which is a cylindrical inner cavity of the fuel nozzle 44.
By contacting the shim 46, the stopper 68 regulates the lift β2 of the fuel metering valve 54, and by providing a slit or the like on the top surface, the stopper 68 prevents the fuel passing through the strainer 58 from entering the fuel chamber 64. It is now allowed to enter.

Reference numeral 70 denotes a movable iron core manufactured as a permanent magnet, the upper and lower ends of which are respectively N-pole or S-pole. A rod 74 provided at the bottom abuts the lower end of the second fuel barrel 52. A bearing material 7 is provided at the lower end of the movable iron core 70.
6 is attached, and the upper end of the aforementioned 21 dollar 24 abuts against the recessed portion. The cross-sectional shape of the movable core 70 taken along the line A-A' is shown in FIG. It is designed to lead to the central passage of the main body 12 and the nozzle portion 14.

The hole 80 on the side surface of the upper body 16 communicates with the air inlet hole 42 provided in the cylindrical portion of the yoke 40 and the air chamber 82 formed on the outside thereof, and the air is supplied to the air passage 84, for example, 3. Accepts 0 kg/cut of compressed air,
The air is sent to an air chamber 82. In this way, the compressed air enters the internal mixing chamber 48 from the air inlet 42, passes through the vertical groove 78 of the movable core 70 and around the ring 26, and enters the nozzle portion 14 through the hole 86 drilled in the spring seat 30, etc. The space around 21 dollars 24 is filled.

When a current in a certain direction is supplied from a control device (not shown) to the solenoid coil 36 via the terminal 38, the fixed iron core 3
4 (represented by the broken line m in FIG. 1). ) and the direction of N of the permanent magnet that constitutes the movable iron core 70.
Depending on the relationship with the (constant) direction of the south pole, the movable core 70 moves either upward or downward in FIG. 1. Therefore, if the direction of the current supplied to the solenoid coil 36 is repeatedly changed from one direction to the other, the movable iron core 7
0 means repeating up and down movements.

When the movable iron core 70 moves upward, the fuel 21 dollar 52 is pushed up against the compression spring 56 via the rod 74,
Since the fuel metering valve 54 is opened by ref}A2, an amount of fuel proportional to the energization time is ejected into the compressed air in the internal mixing chamber 48, forming a mixture of air and fuel, and the fuel is Of course, inside the internal mixing chamber 48, at this time, the nozzle roller 2
The nozzle part 14 reaches the valve part 22 which is seated at 0 and closed.
It spreads to the space around the 21 dollar 24 inside.

Next, when a current in the opposite direction is supplied to the solenoid coil 36, the movable iron core 70 moves downward in FIG. The valve is opened by protruding only the helix l+. Therefore, the mixture of the compressed air in an amount proportional to the energization time and the fuel metered and injected into the internal mixing chamber 48 as described above is generated in the intake boat of the internal combustion engine (not shown) or directly in the combustion chamber. The fuel is injected into the combustion air, and since it is mixed with the air before it is ejected from the nozzle tube 20, it is easy to atomize and diffuse into a larger amount of air, and it quickly vaporizes completely. Can be burned.

In order to alternately supply currents in different directions to the solenoid coil 36, a pulse signal as shown in FIG. 3(a) is applied from a control device (not shown) to a driving circuit as shown in FIG. 4. . As shown in FIG. 3(a), the pulse Tt of the fuel injection signal and the pulse T1 of the air injection or mixture injection signal are alternately and repeatedly generated and applied to the gate circuit shown in FIG. When the fuel injection signal Tf is generated, the circuit shown by the solid line becomes conductive, and the positive current shown in FIG. 3(b), that is, the current flowing from the left to the right in the solenoid coil 36 in the solenoid coil 36, is conducted. flows, the movable iron core 70 moves upward in FIG. Inject to 48. Next, the air injection signal T. is applied, the circuit shown by the broken line in FIG. 4 becomes conductive, and the negative current shown in FIG. 3(b), that is, the solenoid coil 36
A current flows from right to left in FIG. 4 through the T. The valve part 22 of the 21 dollar 24 opens the nozzle 20 only for a period of time during which the air-fuel mixture is injected by the pressure of the compressed air.

In addition, in the case of the embodiment shown in FIG. 1, the delivery pipe 18
is a fuel passage 60 defined by a seal ring 62
and an air passage 84, which has the advantage that the fuel and air supply systems can be arranged in a compact manner.

〔Effect of the invention〕

The fuel injection system developed by Honshahu is capable of operating two valve parts using a single movable iron core and a single solenoid coil that drives it, so unlike conventional solenoid valves, the fuel injection system is Compared to a system that incorporates two units, it is more compact, has easier piping, and is easier to install in an engine.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing the structure of an embodiment of the present invention, and FIG.
3 is a diagram showing a drive signal and a current waveform generated thereby, and FIG. 4 is a circuit diagram showing an embodiment of the drive circuit. DESCRIPTION OF SYMBOLS 10... Fuel injection device, 12... Lower body, 14.
... Nozzle part, 16... Upper body, 18... Delivery pipe, 20... Nozzle bottom, 22... Valve part, 24
... needle, 26 ... ring, 28 ... compression spring, 30 ... spring seat, 32 ... shim, 34 ... fixed iron core, 36 ... solenoid coil, 38 ...・Terminal, 40... Yoke, 42... Air inflow hole, 44...
・Fuel nozzle 46...Shim, 48...Internal mixing chamber, 50...Fuel nozzle, 52...Fuel needle, 54
... Fuel metering valve, 56 ... Spring, 58 ... Fuel strainer, 60 ... Fuel passage, 62 ... Seal ring, 64 ... Fuel chamber, 6th ... Square collar, 68...
・Stopper, 70...Movable iron core, 72...Inner cavity, 7
4...Rod, 76...Bearing material, 78...Vertical groove,
80...hole, 82...air chamber, 84...air passage, 86...hole.

Claims (1)

[Claims] a single solenoid coil, a single permanent magnet movable core movable within the solenoid coil, and a valve opened by movement of the single movable core in one direction to inject fuel into an internal mixing chamber. A fuel metering valve, a nozzle port that opens when the single movable iron core moves in the other direction and injects compressed air passing through the internal mixing chamber to the outside, and a current flowing direction to the solenoid coil. A fuel injection device for an internal combustion engine, characterized in that it is provided with a drive circuit that repeatedly inverts the supply.