JPH024104A - Ultrasonic fuel ejection nozzle - Google Patents

Abstract

PURPOSE:To reduce the size and weight of a movable part and hence improve its response characteristics by turning into fine particles the fuel discharged by way of a valve means arranged to discharge the quantity of fuel in proportion to a passage opening time based on ultrasonic vibration in a place where the fuel is atomized. CONSTITUTION:An electromagnetic means 30 is adapted to attract a needle by a gap g by an electromagnetic suction force acting on a yoke 22b against a pushing force of a spring means 24 and hence opens a passage of a valve port between a valve seat and the needle 22. The fuel in proportion to this valve opening time is adapted to flow between a fuel supply port 5, passages 2a, 2b, 2c, 25b, and a nozzle main body 21 and the needle 22 and is discharged from a discharge port 9. By driving a ultrasonic vibration generation element 14 by way of a terminal 12c of a connector 12b installed to the end of a protection cylinder 12a, a vibrator 20 vibrates an edge section 10 based on ultrasonic vibration, using an outer periphery section 27a which is a member to fix a horn 27 to a housing 12 as a vibration node or its equivalent section so that the fuel which flows from the discharge port 9 to the edge section is turned into fine particles and is discharged in a diffused manner.

Description

[Detailed Description of the Invention] Ritsuka Shizuzu This invention is a fuel injection device for an internal combustion engine such as an automobile engine, and more specifically, a fuel injection device for an internal combustion engine, which has the function of atomizing liquid fuel injected into an internal combustion engine using ultrasonic waves. Regarding the structure of a sonic fuel injection nozzle.

In the development of internal combustion engines, fuel injection nozzles with atomized fuel particles have been proposed as well as exhaust gas control measures.

An example of this is Japanese Patent Laid-Open No. 62-70656. FIG. 2 shows an example of the fuel injection nozzle disclosed in the above-mentioned Japanese Unexamined Patent Publication No. 62-70656, which basically consists of a fixed needle 1-, which cooperates with the needle 1, A vibrator 7 that has a valve function, cuts off and jets out the fuel flowing through the needle 1, and atomizes the spouted fuel using ultrasonic waves.
It consists of The needle 1 has a flange 4 having a fuel supply port 5 connected to a fuel supply means (not shown) and supplied with fuel at the top thereof, and a fuel flow passage 2 inside which is fitted with a filter 6 for removing dust from the fuel. A turning hole 3 is bored through the outside from the tip of the flow path 2, and a valve body 11 is formed at the tip.
It is a columnar body that is integrally formed with. The vibrator 7 is loosely inserted into the needle 1, preferably with a gap of about 20 μm. A flange 7a is disposed on the upper part, and an ultrasonic vibration generating means 14 made of an annular piezoelectric element that generates ultrasonic vibration is fixed on the upper surface of the flange 7a with a nut lla. A spout 9 that opens, a plurality of edge portions 10 that expand and open from the spout 9, and a valve seat 8 that abuts the valve body 11.
is installed. Also, a screw 4 is attached to the flange 4 of the needle 1.
In a, a housing 12 containing the needle 1 and the vibrator 7 into which the needle 1 is loosely inserted is screwed together, and the shoulder 12a of the housing 12 near the spout 9 and the flange 7a of the vibrator 7 are screwed together. A spring means 13 is stretched between the lower surface and the vibrator 7, which constantly presses the vibrator 7 against the needle 1 to close the valve. Between the upper surface of the nut lla of the vibrator 7 and the lower surface of the flange 4, an attractive force generating means 15 consisting of a ring-shaped laminated piezoelectric element insulated with the needle 1 and an insulating material 15a is fitted,
By applying a voltage pulse to the attraction force generating means 15, the vibrator 7 moves downward against the pressing force of the spring means 13 and opens the valve. When the valve is opened, the fuel stored in the swirl chamber 17 from the flow passage 2 passes through the swirl hole 3 and is ejected from the ejection port 9 and flows out in layers through the edge portion 16 that opens stepwise. By applying an ultrasonic signal to the vibration generating means 14, the vibrator 7 is ultrasonically vibrated to atomize the fuel. The conventional example described above has the following problems. First, the attraction force generating means 15 uses a laminated piezoelectric element, which has superior responsiveness compared to normally used attraction methods using electromagnetic means such as coils. 7 mass and
Since it is a vibration system with the elastic force of a spring means, the basic condition for improving responsiveness is to reduce the mass of the vibrator 7. However, the vibrator 7 is a cylindrical body into which the needle 1 is loosely inserted, and The shape in which the portion 10 is disposed is a large annular shape, which produces a result that is contrary to the purpose of improving responsiveness. Secondly, similar to the first problem mentioned above, in order to improve responsiveness, the spring means 13
It is necessary to adjust the pressing force to an optimum value, but in the conventional example, the means for adjusting is the screw 48, and accurate adjustment cannot be performed. Thirdly, the suction displacement of the vibrator 7 by the suction force generating means 15 is regulated by the voltage applied to the piezoelectric element, but the piezoelectric constant is temperature dependent and an accurate opening area of the valve cannot be obtained. Therefore, there is a problem in that a flow rate characteristic that is correctly proportional to the pulse width cannot be obtained.

The present invention has been made in order to solve the problems of the conventional example described above. Firstly, the movable part is made smaller and lighter to improve responsiveness, and secondly, the spring means The purpose of this is to create a structure that allows easy adjustment of the spring force to the optimum spring force. That is,
It consists of an ultrasonic vibration generating element, a vibrator having one end fixed to the ultrasonic vibration generating element, the other end being a recess, and the inner peripheral surface of the recess being an atomizing part, and an opening in the recess is provided in the vibrator. A flow passage through which liquid fuel at a constant pressure flows is perforated, and a valve means is provided in the flow passage for normally closing the flow passage and discharging fuel in an amount corresponding to the opening time when the flow passage is opened. , characterized in that the discharged fuel is atomized by ultrasonic vibration in the atomization section.

Embodiment FIG. 1 is a block diagram for explaining the present invention in detail.
Figure A) is a side sectional view, and Figure (B) is a sectional view taken along the line X-X in Figure (A). In the figure, one component having the same function as the prior art shown in FIG. 2 and not directly related to the present invention is designated by the same reference numeral '', and its explanation will be omitted.

In FIG. 1, 14 is a cylindrical ultrasonic vibration oscillation element made of a piezoelectric element, and is fixed to the vibrator 20 at the bottom surface 14a. The vibrator 20 is disposed within a horn part 27 that is a part of an ultrasonic vibration horn, and a vibrator outer cylinder 26 that is fixed to the horn part 27 by screwing with a screw 26a, and has a horn part 27 at the end thereof. In the case of this embodiment, it is a columnar body comprising an edge portion 10 and a valve means to be described later. The horn part 27 has a circular upper surface and is joined to the ultrasonic vibration oscillation element 14, has fuel flow passages 2b and 2c bored in the radial direction and on the central axis, and is separated from the housing 12 by caulking at the outer peripheral edge 27a. (not shown) or the like. The vibrator outer cylinder 26 has a large-diameter through-hole with a circular shoulder 26b formed in the lower inner wall thereof, and inside the large-diameter through-hole is an annular stopper 23 that abuts at the circular shoulder 26b. The spout 9 is opened at the center of the recess to form a valve seat, and in the case of this embodiment, the nozzle main body 21 having an edge portion 10 with a multi-stage edge is fitted and fitted in contact with the inner peripheral surface, and the vibrator is inserted. The end portion 26c of the outer cylinder 26 is caulked and fixed. A needle 22 is loosely inserted into the axis of the nozzle body 21 and forms a valve body that comes into contact with the valve seat 8 of the nozzle body 21 . The needle 22 is provided with an annular protrusion 22a at the upper part, and the gap g between the annular protrusion 22a and the stopper 23 can be adjusted to a specified value by selecting the thickness of the stopper 23. Ru. Further, a cylindrical yoke 22b is integrally fixed to the upper part, and a spring means 24 is in contact with the upper surface of the yoke 22b. The spring means 2
4 has a recess 25c into which the spring means 24 is inserted;
A fuel flow passage 25b is provided on the shaft, and a screw is cut on the outer periphery to engage with a screw 26a threaded on the inner surface of the vibrator outer cylinder 2b.
Adjustment means 25 is provided with a driver groove 25a that is rotated by a screwdriver or the like, and the needle 22 is connected to the adjustment means 25.
The valve is closed by being pressed against the valve seat of the nozzle body 21 by the spring force of the spring means 24 whose one end is fixed. Incidentally, by rotating the adjusting means 25, the pressing force of the spring means 24 can be adjusted.

The valve means is comprised of the above-mentioned nozzle body 21, needle 22, stopper 23, spring means 24, and adjustment means 25, and is housed in the vibrator outer cylinder 26 and detachably from the horn portion 27. On the other hand, an electromagnetic means 3o is arranged near the center of the vibrator outer cylinder 26 so as to be inserted through the vibrator outer cylinder 26 with a slight gap. The electromagnetic means 30 attracts the needle 22 by the gap g by the electromagnetic attraction force acting on the yoke 22b against the pressing force of the spring means 24, and opens the valve opening between the valve seat 8 and the needle 22. It's bobbin 31
A pulse signal is applied from a drive means (not shown) to a lead wire 32, which is housed in a housing 12 and insulated by an insulating material 33, through a connector 34, for a time proportional to the pulse width. needle 2
2 is sucked in and the valve is opened, and this amount of fuel proportional to the valve time flows through the fuel supply port 5, the flow passages 2a, 2b, 2c, 25b, and between the nozzle body 21 and the needle 22, and is ejected from the jet port 9. . The ultrasonic vibration generating element 14, whose one end is fixed to the housing 12, is housed and protected by an ultrasonic power source (not shown) via the terminal 12c of the connector 12b provided at the end of the protection @ 12a. By driving the vibrator 20, the edge portion 10 is moved from the spout 9 by ultrasonic vibration with the outer peripheral portion 27a, which is the portion of the horn 27 fixed to the housing 12, as a vibration node and the edge portion 1o as the vibration antinode or its vicinity. The flowing fuel is atomized and diffused and ejected. In this embodiment, the shape of the tip of the needle 22 on the side of the atomizing section is conical, but the shape of the tip is not limited to the conical shape.
The design can be freely changed within the scope of the purpose of the present invention. Furthermore, one of the applicants has published Japanese Patent Application Laid-Open No. 60-222552.
As disclosed in the above publication, an inclined groove may be carved in the vicinity of the tip so as to swirl the liquid and guide it to the atomizing section.

FIG. 3 is a diagram showing an example of the swirl generating means disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 62-222552. As shown in the figure, a plurality of inclined grooves 41 are formed in the small diameter portion of the hollow needle valve 40.
For example, by forming two pipes diametrically opposed to each other, it is possible to generate turbulence within the fuel supply passage, give swirl to the injected fuel, and thereby eliminate uneven injection. In addition, such a structure can improve spray clarity and atomization. In addition, edge part 1o
By increasing the number of steps of the edges and selecting the length downward from the valve seat 8, the valve seat 8 can have a vibration node, and in this case, ultrasonic vibration is continuously applied to the vibrator 20. This makes it possible to reduce the load on ultrasonic drive and enable efficient operation. In addition, in the valve means, the needle 2
2 and the spring means 24 constitute a vibration system as described in the prior art, but the spring means 24 is located outside the vibrator 1?
? The valve means is removed from the horn part 27 by rotating the I adjustment means 26, and the spring force is adjusted by rotating the I adjustment means 25 with a screwdriver. After the adjustment is completed, the adjustment means 25 is fixed and the horn part 27 is removed again. After screwing and fixing the vibrator outer cylinder 26 to the housing 12, the housing 12 can be fixed by caulking or the like through a through hole (not shown) formed in the housing 12.

In addition, in this example, one of the present applicants previously applied
The present invention is not limited to the ultrasonic vibration atomizer having an edge portion on the inner surface as disclosed in Japanese Patent No. 259780, but can also be applied to atomizers having other shapes.

Effects As described above, according to the ultrasonic fuel injection nozzle of the present invention, the main valve for fuel injection is arranged so as to be housed in the vibrator, and thereby the valve means can be made compact. , Also, since a needle is used as a moving part,
Along with this, it can be made even smaller and enables fuel injection with excellent responsiveness. 6 For the same purpose, the spring force of the spring means, which is an element of the vibration system, is also screwed to the vibrator in a detachable manner. Adjustment is possible by removing the vibrator outer cylinder, and by setting the vibration node of the ultrasonic vibrating vibrator in the valve seat, efficient ultrasonic drive can be achieved. Ultrasonic fuel injection nozzle that enables efficient atomization! I! 1'JI can be provided at low cost with less man-hours.

FIG. 1 shows an outline of the ultrasonic fuel injection nozzle of the present invention, in which (A) is a side sectional view, and (B) is a cross-sectional view taken along line X-X in (A).
A sectional view taken in the direction of arrows, FIG. 2 is a diagram showing an example of the prior art, and FIG.
The figure is a diagram showing an example of a needle valve.

14... Ultrasonic vibration generating element, 20... Vibrator, 21
... Nozzle body, 22 ・Needle, 23 ... S1-
Collar 24... Spring means, 25... Adjustment means, 3o...
- Electromagnetic means.

[Brief explanation of the drawing]

No. figure No. figure

Claims (1)

[Scope of Claims] 1. A vibrator consisting of an ultrasonic vibration generating element, one end fixed to the ultrasonic vibration generating element, the other end a recess, and the inner peripheral surface of the recess an atomizing part; opening in the recess in the vibrator;
A flow path through which liquid fuel flows is bored, and a valve means is disposed in the flow path, which normally closes the flow path and discharges an amount of fuel according to the opening time when the flow path is opened, and discharges the discharged fuel. An ultrasonic fuel injection nozzle, characterized in that the atomization is atomized by ultrasonic vibration in the atomization section. 2. A nozzle body in which a valve means disposed in a vibrator is opened at the center of a recess to form a valve seat; a needle that is loosely inserted into the nozzle body and cooperates with the valve seat; a stopper that defines the amount of movement; a spring means that presses the needle against the valve seat; and an adjustment means that adjusts the pressing force of the spring means;
Efforts are being made to improve performance and efficiency based on the ability to generate suction force by suctioning the specified amount of movement of the needle against a spring means. For example, in automobile engines,
In order to optimize the air-fuel ratio, there is a trend for fuel vaporization to shift from a carburetor system to a fuel injection system, and along with this, the precision of air flow measurement has been improved, and electronically controlled carburetors have been constructed. Furthermore, ignition timing, knock control, EGR control, etc. are all centrally controlled by a computer, thereby achieving overall performance improvements while making slight improvements to each dynamic function of the engine. . The fuel injection nozzle injects liquid fuel according to the measured intake air amount, and the injection amount is proportional to the valve opening time. That is, the fuel is maintained at a constant pressure, and the fuel is flown out under ON-OFF control with a constant valve opening based on a valve opening command. Furthermore, in order to efficiently burn the injected fuel, attempts have been made to atomize the injected fuel by improving the shape of the injection port or needle to apply shearing force to the fuel. 2. The ultrasonic fuel injection nozzle according to claim 1, wherein the combustion means is an electromagnetic means and is separately arranged on the outer periphery with the vibrator as an axis. 3. The ultrasonic wave according to claim 1 or 2, characterized in that the electromagnetic means is disposed on the outer periphery of the vibrator, the valve means housed in the vibrator is detachable, and the spring means is adjustable. fuel injection nozzle. 4. The ultrasonic device according to claim 1, 2, or 3, characterized in that the vibration nodes of the ultrasonic vibrating element are defined at the fixed portion of the ultrasonic vibration generating element and the valve seat of the nozzle body. Sonic fuel injection nozzle.