JPS58122359A - Porous type intermittent fuel supply device - Google Patents

Abstract

PURPOSE:To supply the fuel which is adapted to the operating conditions pulverized, by equipping a fuel supply device for the suction pipe of the engine, in which the fuel is supplied through a number of nozzle holes excavated in a nozzle plate contacting the suction pipe by the action of a metal film excited in accordance with the operating conditions. CONSTITUTION:The upper members of a fuel chamber 13, into which the fuel shall flow in, are made of metal films 4, over which a movable coil 3 receiving exciting signals from a signal transmitter 24 and a magnet 2, whose center piece is set in this movable coil 3, are arranged. The lower members of the fuel chamber 13 are made from a nozzle plate 12 provided with a number of nozzle holes 7. According to the operating conditions of engine, an intermittent exciting signal, for ex. with varying frequency, is given to the moving coil 3 from the signal transmitter 24, to oscillate the metal film 4, and thus the fuel pulverized is fed into the suction pipe 33 from the nozzle holes 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automobile fuel supply system, and more particularly to an intermittent solvent injection system using a porous metal membrane.

Solvent supply devices used in conventional automobiles are roughly divided into two types: a vaporizer type and an intermittent solenoid valve type.

The former carburetor method continuously measures fuel using the engine's intake negative pressure, but it is superior in forming an air-fuel mixture because the sucked air and fuel are mixed almost homogeneously. However, during transient operations or operations where it is necessary to increase the amount of fuel such as during startup, the responsiveness of fuel supply is poor, and there are drawbacks in that it is difficult to achieve both drivability and exhaust purification.

On the other hand, the scope of use of the intermittent solenoid valve method has increased significantly with the spread of microcomputers in recent years. It is determined by the fuel pressurizing force per fuel injection amount and the opening time width of the solenoid valve, and the higher the pressurizing force, the shorter the valve opening time width. Therefore, the injected fuel has a high initial velocity layer and actively #! ! l
Although it atomizes the particles, it has the disadvantage that it has a strong tendency to spread on the surface, colliding with the opposite wall of the intake pipe and increasing the amount of particles deposited.Currently, drivability and exhaust purification are not compatible. There is.

A number of countermeasures have been attempted to improve the shortcomings of the intermittent solenoid valve system. Examples include fuel atomization using auxiliary air, and atomization methods using ultrasonic waves, electrostrictive phenomena, etc. Microscopically, the fine specific pressure of Fi fuel is considered to be an effective means, but it is insufficient to satisfy a wide range of operating conditions. This caused problems such as a lack of supply capacity.

The object of the present invention is to provide a multi-hole intermittent fuel injection device that can supply an appropriate amount of atomized fuel in the entire operating range including the full load operating range. a metal film that forms the upper side of the fuel chamber, a moving coil whose lower end is fixed to the upper surface of this metal film and whose free end is connected to the conductor from the signal generator, and a center piece that surrounds this moving coil and has a center piece. It has a solvent injection device consisting of a magnet inserted into the winding, and a nozzle plate that forms the lower side of the nozzle chamber facing the metal film and has a large number of nozzle holes. The determined signals are detected and processed, and intermittent excitation signals from the signal generator are output to the moving coil to vibrate the metal membrane, and the fuel is pulverized from the nozzle hole and is injected into the operating state. The reason is that it is configured so that it is supplied into the pipe.

FIG. 1 is a system diagram of a solvent supply device which is an embodiment of the present invention. This type of fuel injection device has a nozzle plate 12t at the bottom of the fuel chamber 13 which has 1fl fuel population 5 and smoke outlet 6.
A metal membrane 4 is installed above the fuel chamber 13. A movable coil 3 is connected to the upper surface of this metal film 4, and a magnet 20 centerpiece is inserted into the center of the movable coil 3.

The moving coil 3 receives an engine rotational speed signal 26, an intake pipe negative pressure signal 27, a throttle valve opening signal 28, an oxygen sensor signal 29 that detects the exhaust gas composition, etc., and generates an output pipe signal from a microcomputer 23. 24 and an amplifier 25.

Therefore, the metal membrane 4 attached to the moving coil 3tl vibrates up and down, causing the pressure inside the fuel chamber 13 to change rapidly. As a result, atomized fuel is drawn into the intake pipe 33 through the many nozzle holes 7 of the nozzle plate 12 .

A fuel supply 5 of the fuel injection device 1 is connected to a check valve 15 . There is a ball valve 18 pushed by a return spring 17, which seals the valve seat 19, thereby increasing the pressure within the fuel injection device 1 and promoting atomization of the injected fuel. A filter 30 is provided between the check valve 15 and the pump 31 for pumping fuel, and removes dust and the like from the fuel trapped in the tank 32.

In the fuel supply system configured in this manner, the output signal of the microcomputer 23 is changed to change the excitation frequency depending on the operating state. That is, during high-speed driving that requires a large amount of curvature, the purpose can be achieved by increasing the vibration frequency. In addition, during low-speed operation, the excitation frequency is lowered to reduce the amount of fuel supplied, etc.
It is now possible to supply atomized fuel suitable for a wide range of operating conditions.

FIG. 2 is a sectional view of the fuel injection device of FIG. 1.

This fuel injection device 1 is roughly divided into three parts. The first is the movable coil 3 connected to the metal film 4 and the metal film 41 - excited! The second part is the part that forms the fuel inlet 5 and the fuel outlet 6 and forms the fuel chamber 13t between them, and the third part is the part of the nozzle plate 12 in which a large number of nozzle holes 7 are formed. . These three parts are airtightly assembled with O-rings 11j1 and 1lbf: a plurality of intervening screws lO.

Figure 3 is an enlarged view of the main parts of the nozzle plate in Figure 2, with nozzle holes 7
A portion of the nozzle near the fuel chamber 13 forms a nozzle inlet 8 which is tapered and expanded through the nozzle's narrowest part 9. Although the fuel is metered when passing through the narrowest part 9, the amount of fuel to be supplied can be adjusted by the diameter and axial length of the nozzle narrowest part 9 and the number thereof. That is, when reducing the amount of supplied fuel,
For example, if the car model used is different and the engine displacement is reduced,
By adding a hatched capillary tube 14 to the nozzle hole 7 and changing its length, it is possible to supply a suitable amount of fuel.

Note that the narrowest part 9 of the nozzle has a diameter of 0.05 to 0.2 m,
The appropriate length in the axial direction is about 0.5 to 3w, and the processing method may be a mechanical method or a method such as etching. Further, when a capillary tube 14 is added to the nozzle hole 7, it is desirable that the inner diameter of the capillary tube 14 is equal to that of the narrowest part 9 of the nozzle.

FIG. 4 is a plan view of the nozzle plate, and FIG. 5 is a sectional view taken along the line ^-B in FIG. 4. In this case, a large number of nozzle holes 7 are distributed at approximately equal intervals, and in the case where the nozzle holes 7 are arranged like the eyes of the board, the shape of the downstream intake pipe 33 is structured so that the air flow is not biased. This is suitable when .

FIG. 6 is a plan view of another nozzle plate. In this case, the nozzle hole 7 in the center part is moved upward, and as shown in FIG. 11, a throttle valve 34 is present in the intake pipe 33 downstream of the trap. This is effective for configurations where That is, the distribution of the nozzle holes 7 is adjusted so that the fuel particles are evenly mixed into the intake air flow.

FIG. 7 is a plan view of yet another nozzle plate, in which the number of nozzle holes 7 increases toward the outside.

This arrangement is effective when the throttle valve 34 is half open.

Generally, K, which atomizes the fuel, is better as the diameter of the nozzle's narrowest part 90 is made smaller, but clogging of the nozzle hole 7 becomes a problem. Therefore, as mentioned above, the nozzle narrowest part 9
The pore diameter is preferably in the range of 0.05 to 0.2 .

Figure 8 shows the excitation frequency f that vibrates the moving coil in Figure 2.
This is a diagram showing the relationship between the amplitude and the amplitude of the metal film, where the horizontal axis is approximately logarithm 0 and the frequency tH! of the oscillating current. , and the vertical axis indicates the amplitude with ■. The metal film 4 is made of a flexible and corrosion-resistant material such as a phosphor blue steel plate or a thin spring steel plate. The solid line shows the case when a material with a low spring constant is used, and the dashed line shows the case when a material with a high spring constant is used. This is the result of using nine times. In other words, when using a material with a low spring constant, the frequency is relatively low, 100H! It resonates in the rest, and when it is a material with a high spring constant, it is about 800H.
2 is the resonant frequency. If this resonant frequency tube is avoided and a portion with a constant amplitude value is used, the excitation frequency and fuel amount will be proportional.

Figure 9 is a diagram showing the relationship between excitation frequency and fuel flow rate.
The number of nozzle holes 7 in the nozzle plate 12 is shown as a parameter, and the diameter of the nozzle holes 7 in this case is 0.1-. In this case, the fuel injection device 1 uses a metal film 4 with a low spring constant shown by the solid line in FIG. 8, so the spring constant is approximately 100H!
1, the fuel flow rate proportional to the frequency (mcc/@trok
e) is shown.

Note that the greater the number of nozzle holes 7, the greater the amount of fuel supplied.

If we further consider the atomization status of the fuel ejected from the fuel injection device 1, we can see that the particle size of the fuel particles is the narrowest part of the nozzle 90, the casing diameter d, and the fuel injection speed is U%. The following formula holds.

D=(34"u/2f)~...Song...(υ, that is, the frequency is large, the ejection speed is small, and the nozzle narrowest part 9
The smaller the diameter of the fuel particles, the smaller the fuel particle diameter. However, as the excitation frequency f1ft increases, the amplitude gradually decreases to 10000H, as shown in FIG. In the above case, the amplitude is 100μ or less, but since the fuel flow rate is determined by the product of the frequency ft amplitude, it can be seen from FIG. 9 that even if the amplitude decreases, the fuel flow rate does not decrease.

Next, the frequency instruction # where the amplitude is constant! Two methods can be used: one uses HI't, and the other uses variable HI't at 10,000 HI't depending on the operating conditions. The former, constant amplitude, is for stationary engines whose operating range is not very wide.
The latter is suitable for engines that require high response.

The problem of clogging of the nozzle hole 7 can be solved by outputting a command from the microcomputer 23 to excite the metal M4° and remove the fuel from the narrowest part 9 of the nozzle for a period of time after the engine is stopped. In order to make this work more effective, the fuel chamber 13t can be made as small as possible to reduce the amount of accumulated fuel.

FIG. 1O is a sectional view of the check valve of FIG. 1. The check valve 15 has an outlet 21 connected to the fuel inlet 5 of the fuel injection device 1, and an inlet 20 connected to the filter 30. A ball valve 18 is in contact with a valve seat 19 inside the valve seat 19, and the ball valve 18 is held down by a return spring 17 and a valve guide 16.
is surrounded by. The spring force of the return spring 17 can be increased by screwing in the adjustment stopper 22, and can be decreased by retracting it to adjust the set value.

This check valve 15 closes the fuel passage as shown in FIG. 10 when the pressure inside the fuel chamber 13 of the fuel injection device 1 increases, and opens when the pressure decreases due to the pressure of the fuel. , allowing fuel to pass through. In this way, the pressure inside the fish stock chamber 13 is increased and the excitation efficiency of the metal film 4 is increased.

As described above, the fuel supply device of this embodiment supplies the fuel pressure-fed from the fuel pump to the fuel injection device via the filter and the check valve, and excites the metal membrane inside this device in accordance with the operational crop rotation. Fuel suitable for the operating conditions can be atomized and supplied through a large number of nozzle holes in the nozzle plate in contact with the pipe. Further, by greatly changing the excitation frequency, it is possible to supply a wide range of fuel amounts to obtain suitable drivability, and also to prevent deterioration of the exhaust gas composition and save fuel.

The eleventh factor is a sectional view of a main part of a fuel supply device according to another embodiment of the present invention. In the case of Fig. 1, there was no throttle valve provided in the intake pipe 33, and the mixture was directly supplied to the engine/engine, but in this case, the mixture was supplied to the engine/engine/gin through the throttle valve 34. are doing.

The fuel injection device 1 and the seven flange 36 of the intake pipe 33 are screwed together via a backing 37 that is both heat insulating and airtight, and the nozzle plate 12b shown in FIG. 6 is suitable as the nozzle plate 12 in this case. This is as stated above.

FIG. 12 is a sectional view of a main part of a fuel supply device according to another embodiment of the present invention, in which case the fuel injection device 1t is accommodated in the intake pipe 33. At this time, the nozzle plate 12C shown in FIG. 7 is suitable as the nozzle plate 12, which is symmetrical as shown in FIG. 7, and the number of nozzle holes 7 increases toward the periphery.

The porous intermittent fuel supply device of the present invention can supply an appropriate amount of atomized fuel over the entire operating range, achieve suitable drivability and purify the exhaust gas composition, and also reduce the quality and pressure of the fuel. It has the effect of being able to respond to

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a fuel supply device according to an embodiment of the present invention, FIG. 2 is a sectional view of the fuel injection device of FIG. 1, and FIG. 3 is an enlarged view of main parts of the nozzle plate of FIG. 2. 4 is a plan view of the nozzle plate in FIG. 2, FIG. 5 is a sectional view taken along line A-B of the nozzle plate in FIG. 4, FIGS. 6 and 7 are plan views of other nozzle plates, and FIG. 9 is a diagram showing the relationship between the excitation frequency and amplitude of the metal film of the fuel injection device, FIG. 9 is a diagram showing the relationship between the excitation frequency of the metal film of the fuel injection device and fuel flow rate, and FIG. 11 and 12 are cross-sectional views showing how the fuel injection device of another fuel supply device is installed. 1...Fuel injection device, 2...Magnet, 3...
Moving coil, 4... Metal film, 5... Fuel population, 6.
... Fuel outlet, 7... Nozzle hole, 8... Nozzle inlet, 9... Nozzle narrowest part, 10... Screw, 11...
0 ring% 12... Nozzle plate, 13... Fuel chamber, 1
4... Capillary tube, 15... Check valve, 23...
Microcomputer, 24... Signal generator, 25.
...Amplifier, 26...Engine speed signal, 27...
・Intake pipe negative pressure signal, 28... Throttle valve opening signal, 29.
...Oxygen sensor, 30...Filter, 31...Pump, 32...Tank, 33...Intake pipe, 34...
- Throttle valve, 35...engine, 36...flange,
Y 1 Figure broom Zf2] Figure 3 Figure 4 Figure 5 Figure 7 Figure $ 7 (¥) Figure 8 f (t-tz) Figure 1 OE g tt Figure 2

Claims (1)

[Claims] 1. A metal film forming the upper side of a fuel chamber into which fuel flows, and a movable coil whose lower end is fixed to the upper surface of this metal film and whose free end is connected to a conductor from a signal generator. , which surrounds this moving coil and whose center piece is connected to the winding internal pressure.
It has a fuel injection device consisting of an inserted magnet and a nozzle plate that forms the lower side of the fuel chamber facing the metal film and is provided with a large number of nozzle holes, and detects various signals determined by the operating conditions of the engine. The signal generator outputs an intermittent excitation signal to the movable coil to vibrate the metal film, and supplies atomized fuel from the nozzle hole into the intake pipe according to the operating condition. A porous intermittent fuel supply device characterized by being configured as follows. 2. The porous intermittent fuel supply according to claim 1, wherein the fuel injection device has a check valve attached to the upstream side of the fuel inlet for increasing the pressure in the fuel chamber. Device.