JPH045469A - Fuel injection device - Google Patents

Abstract

PURPOSE:To provide satisfactory fuel mixed state in both low speed and high speed rotations of an engine by making the nozzle hole directing direction of a fuel injection valve variable in a fuel injection device for internal combustion engine for supplying a fuel by the fuel injection valve installed to an inlet pipe. CONSTITUTION:A nozzle hole part moving member 3 moves the directing direction of a nozzle hole 2 to, for example, a high speed rotation injection angle thetaof 60 deg. by bringing the oil pressure applied to a piston 6 into ON state at the time of engine high speed rotation. As the fuel is injected to the air main flow at a large angle, thus, the fuel is included into the air flow and satisfactorily mixed with the air. At the time of low speed rotation, the oil pressure applied to the piston 6 is brought into OFF state, the nozzle hole part moving member 3 is moved to the original position by a return spring 8 to make the directing direction of nozzle hole 2 to, for example, a low speed rotation injection angle alpha of 23 deg.. Hence, as the fuel is injected into the air main flow at a small angle, the fuel is carried on the air main flow and satisfactorily mixed with the air.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a fuel injection device.

Conventional Technology Engines equipped with a fuel injection device are known, in which a fuel injection valve is attached to the intake pipe and a predetermined amount of fuel is injected and supplied to the engine because it is suitable for controlling the combustion state. (Refer to Japanese Unexamined Patent Publication No. 1417491/1983).

Problems to be Solved by the Invention However, in such conventional fuel injection devices, the fuel injection valve is fixed to the intake pipe, and the injection hole orientation direction of the fuel injection valve is constant, and the fuel injection direction is fixed. It remains unchanged.

For this reason, there is a problem in that it is not possible to maintain a constant fuel mixture state between low speed rotation and high speed rotation of the engine.

In other words, if the fuel injection valve is installed at a small fuel injection angle relative to the main flow of air at low speed rotation of the engine, the flow velocity of the main flow of air in the intake pipe is fast at high speed rotation, so the fuel is swept away and becomes part of the main flow of air. It cannot be mixed inside.

For this reason, at high speeds, the mixing state of fuel and air deteriorates, combustion worsens, fuel efficiency worsens, and H
Harmful effects such as an increase in C emissions occur.

Therefore, if the fuel injection valve is installed at a large fuel injection angle relative to the main stream of air so that the fuel can mix into the main stream of air at high speed rotation, the fuel mixing state at high speed rotation will be improved and the combustion condition will be improved. However, since the air flow rate is small at low speeds, the fuel cannot ride the air flow and most of the injected fuel ends up in a wall flow, which worsens combustion, resulting in lower torque, worse fuel efficiency, and There have been problems in that adverse effects such as an increase in HC emissions and a deterioration in response occur.

The present invention has been made in view of these conventional problems, and an object of the present invention is to provide a fuel injection device that improves the fuel mixture state at both low speed rotation and high speed rotation of an engine. This is what I am trying to do.

Means for Solving the Problems Accordingly, the present invention provides a fuel injection device for an internal combustion engine that supplies fuel with a fuel injection valve attached to an intake pipe, in which the direction of injection hole orientation of the fuel injection valve is made variable.

In the low-speed rotation range of the engine, the injection hole orientation direction of the fuel injection valve is set at a small angle with respect to the mainstream of intake air. Since the fuel is injected approximately parallel to the mainstream of air, it mixes well with the air.

Further, in a high speed rotation range, the injection direction of the fuel injection valve is set at a large angle with respect to the mainstream of air. The fuel is injected facing the mainstream of air and mixes well with the air.

EXAMPLES Hereinafter, the present invention will be explained based on the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention.

First, the configuration will be explained. A cylindrical nozzle hole moving member 3 having a fuel nozzle hole 2 is movably attached to the tip of the fuel injection valve 1, and the nozzle hole moving member 3 is moved by hydraulic pressure via a pin 4. mouth.

5 and a piston 6. The piston 6 is provided with an O-ring 7 for oil sealing, and is also provided with a return spring 8 that returns the piston 6 when the oil is drained.

Note that 9 is a sealing member.

FIG. 2 shows a block diagram of hydraulic control for switching the orientation direction of the fuel injection valve nozzle hole 2. As shown in FIG.

The engine operating condition is detected by the engine control unit 10 based on characteristic values such as engine speed, engine load, air flow meter output, water temperature, etc., and a signal is sent to the solenoid valve 11 to send the oil sent from the oil pump 12. The oil pressure applied to the piston 6 is controlled by switching the oil passage and forming the oil passage by operating the spool valve.

Reference numeral 14 denotes an oil pressure switch that is turned on in response to oil pressure applied to the piston 6, and is used to confirm a normal operating state.

Next, the effect will be explained. When the engine rotates at high speed, the nozzle hole moving member 3 turns on the hydraulic pressure applied to the piston 6, thereby changing the orientation direction of the nozzle hole 2, for example, for a high speed rotation of 60' as shown in FIG. Move so that the injection angle is θ. As a result, the fuel is injected into the main stream of air at a large angle, so that it mixes well with the air stream.

Also, during low speed rotation, the hydraulic pressure applied to the piston 6 is turned off.
state, the nozzle hole portion moving member 3 is moved to the original position by the return spring 8, and the orientation direction of the nozzle hole 2 is set to a low-speed rotation injection angle α of, for example, 23°. As a result, the fuel is injected into the mainstream air at a small angle, so it flows along the mainstream air and mixes well with the air.

In addition, from the fuel injection angle for low speed rotation in the direction of injection hole 2,
Switching to the fuel injection angle for high-speed rotation is made at the same output point so that the driver does not feel a power shock.

Figure 4 shows the switching points. The switching point is determined using characteristic values such as engine rotation speed, vehicle speed, water temperature, and engine load, and high load is switched at a low engine rotation speed.

Additionally, in conjunction with this switching, the air-fuel ratio control and ignition timing control of the engine control device are also switched to control characteristics that match the low-speed and high-speed characteristics, respectively, and maximum control is performed.

Figure 5 shows the engine speed, output (PS), and H
The relationship with C emissions (%) is shown.

The orientation direction of the nozzle hole 2 is set at a fuel injection angle (60
It can be seen that by setting the angle (°) to be large, the output increases and the amount of HC emissions decreases, indicating that the device of the present invention is effective in improving engine performance.

In addition, at a constant high-speed engine rotation speed of 9800 rpm, the orientation direction of the injection hole 2 was set so that the fuel injection angle was 23° and 60° with respect to the mainstream air, and the fuel mixing state in the intake boat was tested. According to research, when the fuel injection angle is 23 degrees, the area where fuel is mixed is limited to a part of the upper part of the intake port, and the other area is mainly air and no fuel is mixed. On the other hand, when the fuel injection angle was 60', the fuel mixing area spread throughout the port, and it was confirmed that the mixing state was extremely good.

FIG. 6 shows a second embodiment of the invention. In this embodiment, a spherical nozzle hole moving member (variable nozzle) 15 having a through hole 16 is rotatably attached to the tip of a fuel injection valve 1, and a pin 17 is connected to the nozzle hole moving member 15. Te rod 18
and a piston 19, and is further provided with a return spring 20 that returns the piston 19 to its original position when oil pressure is not applied or when oil pressure is drained.

During high speed rotation, hydraulic pressure is applied to the piston 19 to rotate the nozzle hole moving member 15 and switch the direction of the nozzle hole (through hole) 16 to the high speed side. During low speed rotation, the oil pressure is turned off, the nozzle hole moving member 15 is returned to its original position by the return spring 20, and the orientation direction of the nozzle hole 16 is switched to the low speed side, thereby mixing the high speed and low speed partner fuel and air. improve the condition.

According to this embodiment, since the nozzle hole moving member 15 is formed into a spherical shape, there is an effect that the nozzle hole pointing direction can be switched more smoothly.

FIG. 7 shows a third embodiment of the invention. In this embodiment, a low rotation side fuel injection hole 21 and a high rotation side fuel injection hole 22 are provided at the tip of a fuel injection valve 1, a valve 23 opens and closes these injection holes 21 and 22, and hydraulic pressure is applied to a piston 24. A return spring 25 is provided to return the piston 24 to its original position when the piston 24 is not in use.
4 and 24, the low rotation side fuel injection hole 21 is closed by the valve 23, the high rotation side fuel injection hole 22 is opened, and fuel is injected from the high rotation side fuel injection hole 22. During low speed rotation, the oil pressure is drained to close the high rotation side fuel injection hole 22, open the low rotation side fuel injection hole 21, and inject fuel from the low rotation side fuel injection hole 21. This embodiment also provides the same effects as those of the embodiments described above.

Effects of the Invention Since the present invention is configured as described above, it produces the effects described below.

A good fuel mixture condition can always be obtained regardless of the engine rotation speed, and engine performance can be greatly improved.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the first embodiment of the present invention, Fig. 2 is a block diagram of hydraulic control for switching the nozzle orifice orientation direction, and Fig. 3 shows the change in fuel injection angle due to the nozzle orifice orientation direction switching. FIG. 4 is a diagram showing the switching point of the nozzle orifice direction,
FIG. 5 is a diagram showing the relationship between engine speed and output using the fuel injection angle as a parameter, and the relationship between engine speed and HC emissions, FIG. 6 is a sectional view showing the second embodiment of the present invention,
FIG. 7 is a diagram showing a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Fuel injection valve, 2... Nozzle hole, 3... Nozzle hole part moving member, 4... Pin, 5... Lot, 6... Piston, 8... Return spring, 10... ...Control Uni. 11... Solenoid valve, 12... Spool valve, 15... Nozzle hole portion moving member, 16... Through hole,
17--Pin, 18--Rot, 19--Piston, 20--Return spring, 21--Low rotation side fuel nozzle hole, 22--High rotation side fuel nozzle hole, 23--Valve, 2
4. Piston, 25. Return spring. Fig. 3 Fig. 4 Enren rotational speed 6 ejaculate 0 relation ■ J11

Claims (1)

[Claims] (1) A fuel injection device for an internal combustion engine that supplies fuel with a fuel injection valve attached to an intake pipe, characterized in that the orientation direction of the injection hole of the fuel injection valve is variable.