CN1164270A - fuel nozzle - Google Patents

Abstract

The present invention relates to a fuel injection nozzle including a nozzle body having nozzle holes, a needle valve opening and closing the nozzle holes, a rotor mechanically coupled to the needle valve, and a stator facing the rotor, whereby a lift amount of the needle valve can be adjusted by moving the stator using a micro motor. Further, a cover member is provided to be slidably rotatable around the circumference of the nozzle body, and by rotating the cover member by a micro motor, the opening area of the nozzle hole for ejection can be changed. By means of these structural features, the desired injection pattern can be achieved in a targeted manner.

Description

fuel nozzle

field of invention

The present invention relates to a nozzle for supplying fuel to an internal combustion engine, such as a diesel engine. More specifically, it relates to fuel nozzles capable of obtaining various injection patterns by changing the lift amount of the needle valve and the total opening area of the nozzle holes functioning as injection.

Description of related technologies

Fuel nozzles used in internal combustion engines include, for example, a nozzle disclosed in Japanese Unexamined Patent Publication No. S59-200063, which ejects fuel through a nozzle hole formed at the front end of the nozzle body, in a A wedge-shaped pressure-receiving surface is provided at the needle valve which is slidably packaged in the nozzle body, and the needle valve is opened by applying fuel pressure to the pressure-receiving surface.

Also, more recent examples include the fuel nozzle disclosed in Japanese Unexamined Patent Publication No. H4-76266, which features a technology that achieves enhanced combustion, improved power and fuel efficiency, reduced combustion noise, and reduced NOx emissions , which is formed by forming a passage leading pressurized fuel to the front end portion of the nozzle body 1, forming a plurality of nozzle holes 2 communicating with this passage, passing through a needle valve controlling the intermittent inflow of fuel to the passage Insert a rotary valve (rotary shaft) 17, and change the rotary position of the rotary valve (rotary shaft) 17 to increase/decrease the opening area of the nozzle hole that plays a role in fuel injection, so that the injection pressure, injection time and Injection volume.

However, in the first fuel nozzle, it adopts such a structure that the injection pressure, injection quantity, injection time and similar parameters are determined by the injection pump delivering fuel to the fuel nozzle, the number of nozzle holes is fixed, and accordingly It follows that it is structurally impossible to increase/decrease the total area of the spray nozzle openings. This presents a problem that it is difficult to maintain a good combustion state because the injection pressure will be lowered when the engine rotates at a low speed, and the injection time will be shortened under a low load state of the engine.

In addition, in the second fuel nozzle, it adopts such a system that the nozzle hole in the nozzle body is blocked from the inside by the rotating shaft (as shown in Fig. 26), since the nozzle hole is only restricted from the inside, so in the nozzle The open area of the nozzle holes on the surface of the body is practically unchanged. Thus, there is a problem that the injected fuel is not really finely atomized. Furthermore, as shown in Figure 1, in Japanese Unexamined Patent Publication No.S4-76266, for the nozzle hole in the nozzle body is blocked from the inside, multiple guide grooves 18 are required, which cannot reduce the suction volume, And then there is the possibility of residual fuel overflow after injection, which will increase the emission of HC. Still further, in such a structure, it is necessary to improve the accuracy of axial alignment of the needle valve 3 and the rotating shaft 17 .

In addition, there is another problem in the structure of the prior art, that is, since the structure does not allow the lift amount of the needle valve to be purposefully changed, by adjusting the lift amount to change the pressure loss and to increase or decrease the injection amount, it is necessary to change the lift amount. It is not possible to purposefully change the injection state by changing the injection pressure and injection speed or similar parameters.

In view of the above problems, an object of the present invention is to provide a fuel nozzle that can obtain the desired injection pattern by purposefully changing the lift of the needle valve or by changing the total area of the nozzle hole that is used for injection, so that the injection Pressure, injection time, injection quantity and other similar parameters adapted to the engine load and speed can be finally obtained, so as to achieve the purpose of reducing NOx and improving fuel efficiency.

Another object of the present invention is to provide a fuel nozzle that takes into consideration the needs of a fine atomization of the injected fuel, prevention of an increase in the amount of suction, a rotary member that allows the effective area of the nozzle hole to be changed, and an axial alignment of the needle valve. Accuracy is not very strict.

Summary of the invention

Accordingly, a fuel nozzle according to the present invention includes a nozzle body having a nozzle hole for spraying pressurized fuel formed at its front end, a nozzle body slidably inserted into the nozzle body for opening/closing the nozzle hole. Needle valve, a spring that applies a force to the needle valve in the direction of closing the nozzle hole, a rotor set on the extension of the axis of the needle valve that can move with the needle valve, and a rotor set on the extension of the axis of the needle valve The stator facing the rotor on the line, when the current passes, it counteracts the spring force to attract the rotor electromagnetically, a first micro-motor driven and controlled by an external signal and a lifting amount changing mechanism, which utilizes the first micro-motor to realize The displacement of the stator on the extension line of the axis of the needle valve finally makes it possible to change the maximum lift of the needle valve.

The lifting amount changing mechanism can be constructed as follows: the stator is fastened in the axial direction of the needle valve in such a manner that it can advance or retreat in a spiral shape, so that the stator moves along with the outer circumference of the stator in the axial direction of the needle valve. The teeth formed on the surface are meshed and its rotation is derived from the gear displacement of the first micro-motor; by providing a stator that can slide in the axial direction of the needle valve, and making the stator follow a contact with the outer circumferential surface of the stator A rack part formed on a part meshes and its rotation originates from the displacement of the cylindrical worm gear of the first micro-motor in the axial direction of the needle valve; A cantilever portion with a female thread is formed, and the stator is displaced in the axial direction of the needle valve through a male thread portion, which is rotated by the first micro-motor, thereby spirally advancing or retreating on the female thread of the cantilever portion.

As a result, since the maximum lift amount of the needle valve can be controlled by the lift amount changing mechanism, it can be facilitated by increasing the lift amount to increase the injection pressure and prolong the injection time under low-load, low-speed operation such as when the engine is started. Jet fine atomization. In addition, in high-load, high-speed rotation operation, stable combustion is achieved by reducing the boost amount to lower the injection pressure and shorten the injection time. Furthermore, the flow rate through the cross-section can be changed by changing the flow resistance by changing the lift amount, so in the case of an accumulator fuel injection pump, for example, it is possible to change the injection amount by changing the lift amount, while in the pulse type fuel injection pump Under certain circumstances, it is possible to change the injection pressure and injection speed by changing the lift amount.

In addition, the fuel nozzle according to the present invention includes a nozzle body having a nozzle hole for injecting pressurized fuel formed at its front end, a needle valve slidably inserted in the nozzle body to open/close the nozzle hole , a housing member with a blocking portion that can rotate around the nozzle body in a sliding manner, the blocking portion is integral with the housing member, changes the degree of clogging of the nozzle hole in proportion to the rotation angle of the housing member, and includes an external signal Drive and control the second micromotor. In this fuel nozzle, the second micro-motor enables the rotation of the cover part, so that the opening area of the nozzle hole for injection can be changed.

This structure can be realized in such a way that, for example, a plurality of nozzle holes are formed at specific intervals in the circumferential direction of the nozzle body, and the number of nozzle holes blocked by the blocking member is changed by rotating the cover member, thereby finally changing the nozzle that performs the spraying function. The opening area of the hole, or forming a slit-shaped nozzle hole within a certain angle range on the circumference of the front end of the nozzle body, instead of forming a plurality of nozzle holes, and blocking these slit-shaped nozzle holes with a blocking portion part to change the open area. In the case of the nozzle hole of the former example, such a structure can be adopted that the diameter of the nozzle hole is gradually reduced in the order in which the nozzle hole is blocked by the blocking member, while in the case of the nozzle hole of the latter example, A wedge-shaped structure may be employed in which the slit width is gradually reduced in the direction in which the ejection area is reduced by the blocking portion.

In addition, a plurality of nozzle holes that can communicate with the nozzle holes formed at the front end of the nozzle body can be formed at specific intervals in the circumferential direction on the blocking part of the cover part, so that the blocking part can be changed as the cover part rotates. The number of nozzle holes on the component that communicates with the nozzle holes on the nozzle body, thereby changing the opening area of the nozzle holes that play a role in spraying. Also in this example, the diameters of the plurality of nozzle holes formed in the circumferential direction of the blocking portion are gradually reduced in the order in which their communication with the nozzle holes on the nozzle body is blocked.

As a result, according to the present invention, because the rotational position of the cover member is regulated by the second micro-motor, it is possible to change the opening area of the nozzle hole that plays a role in spraying. The spraying pressure and spraying time can be increased and the spraying time can be increased by reducing the total area of the spraying nozzle hole by rotating the cover part. In this way, it is expected to promote the fine atomization of the spray and increase the excess air factor in the spray to reduce NOx.

In addition, since the total area of the nozzle hole that plays a role in spraying can be changed from the outside, it is possible to reduce the amount of suction formed in the nozzle body. At the same time, the outer cover member that changes the effective area of the nozzle hole and the needle valve in the nozzle body The axial alignment is not required anymore. Furthermore, since changing the opening area of the nozzle hole can be carried out on the surface of the nozzle body through the outer cover member, the fine atomization of the injected fuel can be improved compared with the nozzle whose opening area of the nozzle hole is changed from inside the nozzle body. more realistically.

Still further, if the total area of nozzle holes for injection is increased by rotating the cover member under high-load, high-speed rotational operation, the injection pressure is lowered and the injection time is shortened. This will ensure that the injection is at the flow rates required for high load operation and is more evenly dispersed for stable combustion and high power output.

Brief description of the drawings

1 is a cross-sectional view showing a schematic structure of a fuel nozzle according to the present invention;

2 is an enlarged cross-sectional view showing an example of a drive mechanism and a front end portion of a nozzle body in the fuel nozzle shown in FIG. 1;

3 is an enlarged cross-sectional view showing another example of the driving mechanism of the fuel nozzle shown in FIG. 1 and the front end portion of the nozzle body;

Fig. 4-7 shows the example of a first structure of the front end portion of the nozzle, representing the positional relationship between a plurality of nozzle holes formed on the nozzle body and the outer cover member;

Fig. 8 is the flow chart of an example of the control operation of the nozzle that is accomplished by the control device;

9 is an enlarged cross-sectional view of another example of the drive mechanism in the fuel nozzle shown in FIG. 1;

Fig. 10 is a partially enlarged cross-sectional view of another example of the lifting amount changing mechanism;

Fig. 11 is a partially enlarged cross-sectional view of yet another example of the lifting amount changing mechanism;

Fig. 12 is a cross-sectional view taken from line XII-XII in Fig. 11;

13-16 show an example of a second structure of the front end of the fuel nozzle, showing the communication relationship between the nozzle hole formed on the nozzle body and the plurality of nozzle holes formed on the cover member;

17-20 show an example of a third structure of the front end of the fuel nozzle, showing the positional relationship between the slit-shaped nozzle hole formed on the nozzle body and the cover member;

21-24 show an example of a fourth structure of the front end of the fuel nozzle, showing the positional relationship between the slit-shaped nozzle hole formed on the nozzle body and the cover member;

Figure 25 is a cross-sectional view showing the vicinity of the nozzle hole of the present invention; and

Fig. 26 is a cross-sectional view showing the vicinity of a conventional nozzle hole.

Detailed description of the embodiment of the invention

The following is a detailed description of the present invention with reference to the accompanying drawings.

FIG. 1 shows an example of a first configuration of a nozzle 1 . In Fig. 1, the nozzle 1 is constructed in such a way that a nozzle body 3 is provided at the front end of a nozzle housing 2, and a stop nut 4 is used to fasten the nozzle housing 2 and the nozzle body 3 together as a whole , The stop nut 4 is screwed on the nozzle housing 2.

On the upper side surface of the nozzle housing 2, a fuel inlet 5 is formed. A nozzle chamber 8 communicates. A pressure receiving portion 11 of a needle valve (needle valve) 10 slidably inserted into a fitting hole 9 of the nozzle body 3 faces the nozzle chamber 8, and high-pressure fuel flowing in through the fuel inlet 5 is guided to the needle valve 10 The pressure receiving part 11.

The high-pressure fuel directed to the fuel inlet 5 is supplied from a fuel injection pump 12, which is connected through a line, in the range of 10MPa-150MPa. Although we are not going to go into detail about it here, the fuel injection pump 12 can be, for example, a pulsating fuel injection pump that forces fuel in a desired amount and required amount consistent with the engine's operating environment and the like. The fuel tank 13 is supplied to the nozzle 1 at the moment.

A through hole 14 is formed along the axis of the nozzle housing 2 in line with the assembly hole 9 of the nozzle body 3, and a movable spring socket 15 in contact with the needle valve 10 is provided in the through hole 14, A plugging member 16 fitted in the through hole 14 so as to block its upper portion and fixed to the nozzle housing 2 and a coil spring 17 interposed between the movable spring insertion hole 15 and the plugging member 16 . The movable spring socket 15, the hollow part of the spring 17 and a rod 18 for moving the needle valve are engaged together at the needle valve 10, wherein the rod 18 passes through the plug 16 and is bonded to a rotor 19 which will be described in detail later. Knotted.

A drive mechanism 20 is provided at the upper portion of the nozzle housing 2 . As shown in Figure 2, more specifically, a stator 21 is rotatably fixed on a threaded portion of the upper end of the plugging member 16, and along with the rotation of the stator 21, the stator 21 can be screwed relative to the plugging member 16. Forward or backward, so that the distance L1 between the rotor 19 stored in a space 22 formed between the stator 21 and the blocking member 16 and the surface of the stator 21 facing the rotor 19 can be changed.

A solenoid 47 is wound on the stator 21, and the power supply to the solenoid 47 is controlled by a control device 25 (shown in FIG. 1). Note that reference numeral 72 designates a helical wire which connects the cable connected to the control device 25 to the solenoid 47 and which absorbs the rotation of the stator 21.

In addition, in order to control the degree of rotation of the stator 21, a gear 23 is provided on one side of the stator 21, which meshes with teeth 24 formed on the outer peripheral surface of the stator 21, and the gear 23 is controlled by a first micro-rotation as required. The motor 26 rotates, the latter being driven by a control signal from the control unit 25 (shown in FIG. 1 ). It should be noted that the first micro-motor 26 is mounted on a first reduction gear 65 and inserted into a mounting hole 28 of a head 27 fixed on the upper part of the nozzle housing 2 . The first micro-motor 26 utilizes a first cover plate 29 to be fixed at the first motor installation position 30, and the cover plate 29 seals the mounting hole 28, and the gear 23 is fixed on the rotating shaft of the first reduction gear 65.

Furthermore, a mounting hole 48 for installing a second micro-motor 31 is also formed at the head 27, and the second micro-motor 31 is inserted in the mounting hole 48, and its state is installed at a second reduction gear 66 place, and It is fixed at the second micromotor installation position 32 through a second cover plate 49 that closes the installation hole 48 . The gear 33 is fixed to the rotation shaft of the second reduction gear 66 and meshes with a gear 35 fixed at one end of a flexible rod 34 .

In this structure, the first and second micromotors 26 and 31 adopt, for example, commercially available two-pole drive, two-phase stepping motors with an outer diameter of Ф10mm, a voltage of 5V, and an output torque of 1mN·m; while the first and second The reduction gears 65 and 66 are, for example, commercially available reduction gears with a reduction ratio of 1:15, with an outer diameter of Ф12 mm and a rated allowable torque of about 10 mN·m, so the torque of the micromotor is improved through the reduction gears.

According to another mode of the first and second micromotors 26 and 31, an ultrasonic motor disclosed in Japanese Unexamined Patent Application NoH6-189569 may be used. And, if adopted high-torque motor, so gear 23 and 33 can be directly installed on the rotating shaft of first and second micromotor 26 and 31, as shown in Figure 3, do not install reduction gearbox. In such a structure, the space required for mounting the reduction gear box is saved, contributing to miniaturization of the nozzle.

The other end of the flexible rod 34 passes through the rod insertion holes 36, 37 and 38 formed on the head 27, the nozzle housing 2 and the nozzle body 3 respectively, and extends into the space 39 formed between the nozzle body 3 and the stop nut 4 Inside, on this other end of flexible rod 34 is fixed with gear 40, and its diameter is smaller, is placed in the space 39.

At the portion where the nozzle body 3 protrudes from the stop nut 4, a housing member 41 is provided in such a manner that its rotation is only a sliding on the peripheral surface of the nozzle body. One end of the cover member 41 protrudes into the space 39 through the area between the nozzle body 3 and the stop nut 4 , and a gear 42 which meshes with the gear 40 is formed on the outer peripheral edge of this protruding portion. As a result, when the second micromotor 31 is rotated, the flexible rod 34 rotates, and finally causes the housing part 41 to also rotate.

In the front end portion of the nozzle body 3 is formed a nozzle hole 43 which opens and closes with the rotation of the cover member 41 so that, as shown in FIG. 1, fuel can be injected into the combustion chamber 44 of the engine. As shown in FIGS. 4 to 7, the nozzle hole 43 includes a large-diameter nozzle hole 43a, a medium-diameter nozzle hole 43b, and a small-diameter nozzle hole 43c, which are sequentially formed at a specific offset angle, and each diameter is formed with a mutual Two nozzle holes with a phase difference of 180°. Depending on the required engine specifications, the size of the nozzle holes will vary. In this example, the dimensions of the holes are Ф0.24 mm, Ф0.19 mm and Ф0.14 mm for the large, medium and small diameter holes, respectively. In addition, the phase angle from the large-diameter nozzle hole 43a to the small-diameter nozzle hole 43c is set to be less than 90°.

Along the circumferential edge of the front end portion of the cover member 41 , two cutout portions 45 and two blocking portions 46 that can cover the nozzle hole 43 are alternately formed, each phase shifted by 180° from each other. Both the blocking portion 46 and the notch portion 45 are larger than the phase angle from the large-diameter nozzle hole 43a to the small-diameter nozzle hole 43c.

Referring again to Fig. 1, reference sign A indicates a flow rate sensor, which is located near the fuel inlet to detect the flow rate of fuel supplied from the injection pump, and reference sign B indicates a pressure sensor, which is located near the fuel inlet to detect the flow rate of fuel supplied from the injection pump. Fuel pressure, reference sign C denotes an accelerator opening sensor using engine load to detect the opening angle of the accelerator relative to the engine load, reference sign D denotes a combustion chamber temperature sensor which detects the temperature of the combustion chamber in the engine, reference Reference numeral E denotes a combustion chamber pressure sensor which detects the pressure of the combustion chamber in the engine, reference numeral F denotes a needle lift sensor which detects the lift amount of the needle valve, and reference numeral G denotes a rotational speed sensor which detects the rotational speed of the engine. Signals from these sensors are input to the control device 25 .

Control device 25 is a kind of control device in the known technology, and it comprises a control micromotor 26 and 31 and the output circuit of solenoid 47, a microcomputer that controls this output circuit, a input from each sensor to this microcomputer and the like. signal input circuit. This microcomputer is equipped with a central processing unit (CPU), a memory and similar components, and according to the signal from the sensor, completes the calculation process according to a specific program, to control the nozzle hole that plays a role in spraying by the first micromotor 26 The opening area; the maximum lift of the needle valve 10 regulated by the second micro-motor 31; the timing of fuel injection controlled by supplying power to the solenoid 47, the time of injection and similar variables.

In other words, there are many variables for controlling the nozzle 1, including the rotation angle of the cover member 41, the lifting amount of the needle valve 10, the timing of supplying power to the solenoid 47, the duration of power supply and the like, and by changing these variables, the The total area of the nozzle holes that are used for spraying, the spraying pressure, the spraying timing, the spraying time and the like are adjusted to change the spraying pattern. Fig. 8 shows a specific example of the control operation in the form of a flow chart, and some explanations will be made with reference to this flow chart. It should be noted that the engine load (accelerator opening angle), the rotational speed of the engine, the combustion chamber pressure, the combustion chamber temperature, the lift amount of the needle valve, the fuel pressure and the fuel flow rate, and a control map for the optimal combination of the above-mentioned control variables are stored in the control device 25, and the control chart is created using data previously obtained through basic tests and the like.

When the ignition switch is turned on, the control device 25 starts the signal input process of step 50 . In step 50, the measurement data from the combustion chamber pressure sensor and similar measuring elements measured at a predetermined specific crankshaft angle (the appropriate crankshaft angle for the expansion stroke or exhaust stroke), and the previous time of the engine The engine speed that has been detected by the speed sensor during rotation.

Then, in subsequent step 52, a fuel injection mode is determined based on the input signal. In other words, the optimal value of the rotation angle of the cover member 41 and the lift of the needle valve 10 is determined according to the control map stored in the internal memory of the control device 25, and then, according to the lift of the needle valve and the nozzle lift during the previous operation, The opening area of the hole is calculated by calculating the rotation angle of the first micro-motor 26 and the rotation angle of the second micro-motor 31. The former will change the lift of the needle valve to a predetermined value, while the latter will change the total amount of the nozzle hole 43 that is used for spraying. The area is adjusted to a predetermined value. In addition, here, the duration of power supply to the solenoid 47 is also calculated.

After that, in step 54, a driving pulse is supplied to the first micro-motor 26, so that the lifting displacement amount of the needle valve 10 determined in step 52 can be completed. By doing so, the first micromotor 26 is turned, which in turn turns the stator 21 , thereby adjusting the distance L1 between the rotor 19 and the stator 21 facing the rotor 19 . In addition, at step 56 , a driving pulse is provided to operate the second micro-motor 31 to adjust the opening state of the nozzle hole 43 .

In this state, determine the valve opening time and valve opening moment consistent with the control chart, and compare it with the data obtained at a specific crankshaft angle. When a specific moment (crankshaft angle) is reached, a pulse is generated A rectangular wave whose width coincides with the opening time of the valve. Then, power is supplied to the solenoid 47, so that the needle valve 10 is lifted during the rising portion of the rectangular wave (step 58). This moment coincides with the time when the piston is lifted to start fuel supply in a pulsating injection pump, whereupon, as the needle valve 10 lifts, a fuel flow path is obtained and fuel injection begins.

When starting to energize the solenoid 47 for a certain length of time, that is, when the lifting of the needle valve 10 is completed and the needle valve 10 is in contact with the stator 21, the driving current is switched from the starting current to the holding current (step 60). This holding current need only be at the level at which the spring force of the balance spring 17 keeps the rotor 19 in contact with the stator 21, and can be less than that required for starting when rapid acceleration is required. Then, the position of the needle valve 10 at the time point at which the displacement of the needle valve 10 measured by the needle lift sensor F reaches a constant state is stored in the memory of the control device 25 .

Then, in the falling section of the rectangular wave, the power supply to the solenoid 47 is stopped (step 62). Along with this, the needle valve 10 moves in a direction to be closed by the spring force applied by the spring 17, and the nozzle hole 43 is closed.

The feature of this series of processes is that the maximum lift of the needle valve 10 is regulated by the first micro-motor 26 in step 54 . In other words, by turning the first micro-motor 26 in the direction of increasing the distance between the stator 21 and the rotor 19 in step 54 , the maximum lift of the needle valve 10 is increased, thereby increasing the amount of fuel supplied to the nozzle hole 43 . Conversely, by turning the first micro-motor 26 in a direction that makes the stator 21 and the rotor 19 approach each other, the lifting amount of the needle valve 10 is reduced, thereby reducing the amount of fuel supplied to the nozzle hole 43 finally.

For example, during low-load, low-rpm operation at engine start, by increasing the amount of lift (by increasing the distance L1 between the stator 21 and rotor 19), the injection pressure is increased and ultimately the power to the solenoid is increased , can promote the fine atomization of the injected fuel, and in the process of large load and high speed operation, by reducing the lift amount to reduce the injection pressure, and finally shorten the power supply time to the solenoid, stable combustion can be achieved. In this way, various spray patterns can be obtained.

In addition, the operation of changing the lifting amount of the needle valve is also an operation of changing the resistance of the flow passage by changing the area of the flow passage, and in the case of using a pulse type fuel injection pump as in this embodiment, since the amount of fuel flowing out of the pump is constant Yes, so changes in pressure loss in the fuel flow passage also constitute changes in injection pressure and injection velocity. In other words, when the lift amount is small, since the flow passage area is small, the pressure loss increases to increase the peak value of the injection pressure and also increase the variation of the injection velocity. On the contrary, when the lifting amount is large, the pressure loss is relatively reduced due to the increase of the flow channel area, so as to reduce the peak value of the injection pressure and also reduce the change of the injection velocity. On the other hand, if an accumulator jet pump is used, since the pressure of the fuel flowing out of the pump is constant, when the pressure loss in the fuel flow path changes due to a change in lift, the output flow rate also changes. In other words, with an accumulator fuel injection pump, the injection quantity can be changed by changing the lift quantity. As a result, by driving and controlling the first micro-motor to change the lifting amount, the injection amount or injection pressure and injection speed can be purposefully changed to obtain the desired injection pattern.

The characteristics of the present invention also include that the processing completed in step 54 is combined with the control of the opening area of the nozzle hole completed by the second micro-motor 31 in step 56 . That is, in the process of step 56, by positioning the blocking portion 46 of the cover member 41 on the area where the nozzle hole 43 is not formed, as shown in FIG. All of the nozzle holes 43c with a small diameter are opened to the combustion chamber 44 through the notch portion 45 .

If as shown in Figure 5, the rotation of the second micro-motor 31 makes the blocking portion 46 only block the nozzle hole 43a of the large diameter, so the nozzle hole 43b of the middle diameter and the nozzle hole 43c of the small diameter are still open to the combustion chamber 44; , if as shown in Figure 6, the rotation of the second micro-motor 31 makes the nozzle hole 43a of the large diameter and the nozzle hole 43b of the middle diameter all blocked by the blocking portion 46, only the nozzle hole 43c of the small diameter is opened to the combustion chamber 44 . With the needle valve lifted in this state, fuel will only be ejected through the open nozzle hole. As shown in FIG. 7, by continuing to rotate the cover member 41, all the nozzle holes 43 can be completely blocked, so even if the needle valve 10 is lifted, the injection cannot be performed.

For example, if the state shown in Figure 6 is reached during low-load, low-rpm operation at engine start, the injection pressure will increase due to the decrease in the number of opened nozzle holes and the total area of the opened nozzle holes , to prolong the injection time.

The size of the spray particles is mainly determined by the opening area of the nozzle holes 43 (43a, 43b and 43c) and the injection pressure, and since the fuel mist becomes more dense with the decrease of the opening area of the nozzle holes and the increase of the injection pressure Fine, so the state shown in Figure 6 can promote fine atomization, which is expected to increase the excess air coefficient in the spray to reduce NOx. Conversely, in the process of high load and high speed operation, if the state shown in Figure 4 or Figure 5 is reached, the injection pressure will decrease due to the increase in the number of opened nozzle holes and the total area of the opened nozzle holes, so as to shorten the injection time. time. In this state, the spray is always dispersed while being supplied to the combustion chamber 44 to obtain stable combustion and high power output.

As a result, changing the opening state of the nozzle hole that plays a role in spraying constitutes an operation of changing the spraying pressure, spraying time, and degree of atomization, and by combining it with the operation completed in the aforementioned step 54, the degree of freedom in changing the spraying pattern can be more big. In addition, as shown in Figure 25, in the structure of the present invention, because the area of the nozzle hole 43 that plays a role in spraying is regulated by the cover member 41 that covers the outside of the nozzle body 3, it is the actual nozzle hole that changes. The opening area of the front end of 43, compared with the structure in which the nozzle hole is blocked from the inside as shown in FIG. 26, has the advantage of facilitating the fine atomization of the injected fuel.

It should be noted that for the mechanism for changing the distance L1 between the rotor 19 and the stator 21, in addition to the above-mentioned mode, the stator 21 can be mounted by means of a threaded portion that can rotate relative to the inner peripheral surface 67 of the head 27, as shown in FIG. 9 As shown, teeth are formed on the outer peripheral surface of the stator, and the gear 23 meshing with these teeth is rotated by the first micromotor, thereby moving the stator 21 in the axial direction of the needle valve, as in the previous mode.

Furthermore, as shown in FIG. 10, the stator 21 can be in such a form that it faces the rotor 19, and it is arranged to cover the end of the plugging member 16, and it can move in the axial direction of the needle valve 10, while On the side of the stator 21, there is a cantilever portion 69 extending in the direction of motion of the stator, with a female thread portion 68, so that a male thread portion 71 rotated by the first micromotor 26 (this thread can be engraved into the micromotor The rotating shaft) spirally advances or retreats on the female thread portion 68 of the cantilever portion 69, so that the stator 21 moves in the axial direction of the needle valve.

In yet another mode, as shown in FIGS. 11 and 12 , the stator 21 is similarly arranged to cover the end of the plugging member 16 , and a groove along the plugging member 16 is formed on the inner surface of the stator 21 . A keyway 73 extending in the axial direction, so that a fixed keylock 74 fixed on the plug 16 engages with the keyway 73 to prevent the stator 21 from rotating, thus only allowing the stator 21 to move in the axial direction of the needle valve. In addition, a rack portion 75 on which teeth are formed along the radial direction of the stator 21 is formed by carving an arc-shaped groove on a part of the outer surface of the stator 21 . A cylindrical worm gear 76 meshing with the teeth of the rack portion 75 is fixedly mounted on the rotating shaft of the first micromotor 26, so that by rotating the first micromotor 26, the stator 21 can move in the axial direction of the needle valve. .

An example of a second structure employed to realize the adjustment of the opening state of the nozzle hole 43 is given in FIGS. 13 to 16. FIG. In this embodiment, different from the previous embodiments, a blocking portion 46 of a cover member 41 covers the entire circumference, and on the blocking portion 46, there are nozzle holes 70a of large diameter, nozzle holes 70b of medium diameter and nozzle holes of small diameter. 70c are sequentially formed at a specific offset angle. Each diameter consists of two nozzle holes that are 180° out of phase with each other. In this embodiment, the phase angle from the large-diameter nozzle hole 70a to the small-diameter nozzle hole 70c is also set to be smaller than 90°.

On the other hand, two large-angle nozzle holes 43 are formed at the front end of the nozzle body 3, and they are mutually phase-shifted by 180°, and the circumferential angles of the nozzle holes 43 and the angles of the circumference of the area without nozzle holes are larger than those in the housing. The angle between the large-diameter nozzle hole 43a and the small-diameter nozzle hole 43c formed on the member 41 is set.

It should be noted that other structural features of this embodiment are the same as those of the first embodiment, so the description thereof is omitted, and the reference numerals attached to the elements in FIGS. 13 to 16 are the same as those in FIGS. 4 to 7.

In this structure, the spraying mode can also be changed by adjusting the communication state between the nozzle hole 43 on the nozzle body 3 and the nozzle holes 70a, 70b and 70c on the cover member 41 by using the second micromotor 31 . In other words, as shown in FIG. 13, by making the nozzle hole 43 on the nozzle body 3 communicate with the nozzle holes 70a, 70b, and 70c formed on the plugging part 46 of the housing part 41, the fuel passes through all the nozzle holes, that is, the nozzle with a large diameter. Hole 70a, the nozzle hole 70b of medium diameter and the nozzle hole 70c of small diameter, spray into combustion chamber 44; However, as shown in Figure 14, cut off the nozzle hole 43a on the nozzle body 3 of large diameter and nozzle The fuel is injected into the combustion chamber through the middle-diameter nozzle hole 43b and the small-diameter nozzle hole 43c. As shown in Figure 15, by turning the outer cover member 41, the nozzle hole 43a of the large diameter and the nozzle hole 43b of the middle diameter are disconnected from the nozzle hole 43 of the nozzle body 3, and the fuel is injected into the combustion chamber only through the nozzle hole 43c of the small diameter. 44. When the cover member 41 is further rotated, the nozzle holes of the cover member 41 can all be disconnected from the nozzle holes 43 of the nozzle body 3, so that fuel is not injected even if the needle valve 10 is lifted. As a result, by controlling the second micro-motor 31, the injection pressure, injection time and atomization degree can also be changed as in the first embodiment to obtain various injection modes.

An example of a third structure adopted in order to realize the adjustment of the opening state of the nozzle hole is given in FIGS. There is provided a nozzle hole 43 in the shape of a slit having a specific circumferential angle. The circumferential angle of this nozzle hole 43 is set to be smaller than 90°. It should be noted that the slit width of the slit-shaped nozzle hole 43 is set approximately equal to the diameter of the aforementioned large-diameter nozzle hole (0.24 mm at most), and if the nozzle hole 43 is formed at four positions at the front end of the nozzle body 3, its The circumferential angle only needs to be set to be less than 45°.

On the other hand, at the front end portion of the cover member 41, notch portions 45 and blocking portions 46 capable of covering the nozzle holes 43 are formed alternately at two positions whose phases are shifted by 180° on the circumference of the front end, as in the first embodiment. The case of the example (Figs. 4-7) is the same. The blocking portion 46 and the notch portion 45 form a circumferential angle each larger than the nozzle hole 43 forming the slit shape.

The structure in which the nozzle hole 43 is provided in the above-mentioned form is equivalent to a structure in which nozzle holes of equal diameter are continuously formed in a specific range. The relative position of the spray pattern can be changed. In other words, by making the nozzle hole 43 of the nozzle body 3 face the combustion chamber 44 without being completely blocked by the blocking member 46 of the cover member 41, as shown in FIG. 17, a large amount of fuel can be injected into the combustion chamber at a wide angle. 44; however, by turning the cover member 41 to block part of the nozzle hole 43 on the nozzle body 3 with the blocking member 46, as shown in FIG. 18 or 19, the range of spraying becomes narrow. Furthermore, by further turning the cover member 41, the nozzle hole 43 on the nozzle body 3 becomes completely blocked by the blocking member, as shown in FIG. 20, and no fuel is injected even if the needle valve 10 is lifted. As a result, by controlling the second micro-motor 31, the degree of dispersion of the sprayed spray and the opening area of the nozzle hole can be changed, so as in the aforementioned first embodiment, the injection pressure, injection time and atomization degree can be changed to obtain various sprays model.

As shown in FIGS. 21 to 24, in order to realize the adjustment of the opening state of the nozzle hole 43, there is another example of structure, that is, an example of a fourth structure. In this embodiment, similar to the example of the third structure, slit-shaped nozzle holes are formed at two positions whose phases are shifted 180° from each other, but the nozzle holes 43 are wedge-shaped, and the nozzle holes 43 are wedge-shaped. They are gradually reduced in the direction in which the open area is reduced by the cover member 41 . Since the other aspects of this embodiment are identical to those of the third embodiment, components identical to those shown in Figs. 17 to 20 are assigned the same reference numerals and their descriptions are omitted. In this structure, advantages similar to those obtained in the third embodiment are also obtained.

As has been explained, according to the embodiment of the present invention, since the maximum lift of the needle valve opening and closing the nozzle hole is adjusted by the lift changing mechanism, it is possible to promote fine atomization of spray and maintain stable combustion. In addition, it can be adapted to various environments by purposefully changing the spray pattern, that is, by changing the spray quantity in the case of an accumulation type nozzle, and by changing the spray pressure and spray speed in the case of a pulse type nozzle.

In addition, since the total area of the nozzle holes that are used for injection can be adjusted by rotating the outer cover part, an injection pressure, injection time and injection amount that are consistent with a given load and engine speed are obtained, thereby reducing NOx and improving Fuel efficiency is possible. Furthermore, since the total area of the nozzle hole for spraying can be adjusted from the outside by using the cover member, there is no need for a part for changing the area of the nozzle hole inside the nozzle body, thereby successfully reducing the area of the nozzle hole in the nozzle hole. The amount of inhalation formed before. In such a structure, the axis of the housing member which changes the effective area of the nozzle hole and the valve in the nozzle body need not be in a straight line. Furthermore, since the opening area of the front end of the nozzle hole is changed, fine atomization of the injected fuel is facilitated.

Furthermore, by adjusting the lift amount of the needle valve in combination with the adjustment of the total area of the nozzle holes that perform the injection function, the injection mode can be changed with greater freedom to adapt to various environmental conditions.

Claims (14)

1. A fuel nozzle comprising; a nozzle body having a nozzle hole formed at a front end thereof from which pressurized fuel is ejected; a needle valve slidably inserted into said nozzle body for opening and closing said nozzle hole; a spring that applies a force to said needle valve in a direction to close said nozzle hole; a rotor disposed on an extension of the axis of the above-mentioned needle valve to move together with the above-mentioned needle valve; a stator, which faces the above-mentioned rotor and is arranged on the extension line of the above-mentioned axis of the above-mentioned needle valve, and when power is supplied to the above-mentioned stator, it electromagnetically attracts the above-mentioned rotor to counteract the above-mentioned force exerted by the above-mentioned spring; a first micromotor driven and controlled by an external signal; and A lift amount changing mechanism, which can move the stator on the extension line of the above-mentioned axis of the above-mentioned needle valve by using the above-mentioned first micro-motor, so as to ensure that the maximum lift amount of the above-mentioned needle valve can be changed. 2. A fuel nozzle comprising; a nozzle body having a nozzle hole formed at a front end thereof from which pressurized fuel is ejected; - a needle valve slidably inserted into said nozzle body for opening and closing said nozzle hole; a housing member slidably rotatable about the circumference of said nozzle body and having a blocking portion integral therewith for varying the clogging condition of said nozzle corresponding to the angle of rotation thereof; and A second micromotor, which is driven and controlled by an external signal, wherein: The above-mentioned second micro-motor enables the above-mentioned rotation of the above-mentioned outer cover member to change the opening area of the above-mentioned nozzle hole that plays a role in spraying. 3. A fuel nozzle comprising; a nozzle body having a nozzle hole formed at a front end thereof through which pressurized fuel is ejected; a needle valve slidably inserted into said nozzle body for opening and closing said nozzle hole; a spring that applies a force to said needle valve in a direction to close said nozzle hole; a rotor disposed on an extension of the axis of the above-mentioned needle valve to move together with the above-mentioned needle valve; a stator, which faces the above-mentioned rotor and is arranged on the extension line of the above-mentioned axis of the above-mentioned needle valve, and when power is supplied to the above-mentioned stator, it electromagnetically attracts the above-mentioned rotor to counteract the above-mentioned force exerted by the above-mentioned spring; a first micromotor driven and controlled by an external signal; and A lifting amount changing mechanism, which can move the stator on the extension line of the above-mentioned axis of the above-mentioned needle valve by using the above-mentioned first micro-motor, so as to ensure that the maximum lifting amount of the above-mentioned needle valve can be changed; a housing member slidably rotatable about the circumference of said nozzle body and having a blocking portion integral therewith for varying the clogging condition of said nozzle corresponding to the angle of rotation thereof; and A second micromotor, which is driven and controlled by an external signal, wherein: The above-mentioned second micro-motor enables the above-mentioned rotation of the above-mentioned outer cover member to change the opening area of the above-mentioned nozzle hole that plays a role in spraying. 4. A fuel nozzle as claimed in claim 1 or 3, wherein: The aforementioned lifting amount changing mechanism is achieved by fixing the aforementioned stator in such a manner that the aforementioned stator can be spirally advanced or retreated in the direction of the aforementioned axis of the aforementioned needle valve with respect to a stationary member provided near the aforementioned rotor, in the aforementioned The outer peripheral surface of the stator is formed with teeth and a gear engaged with the teeth is rotated by the first micro-motor to cause the stator to move in the direction of the axis of the needle valve. 5. A fuel nozzle as claimed in claim 1 or 3, wherein: The aforementioned lifting amount changing mechanism is realized by providing a stator slidable in the aforementioned axial direction of the aforementioned needle valve relative to a fixed member provided near the aforementioned rotor, the tooth edges of which are formed on a part of the outer peripheral surface of the aforementioned stator. The rack portion of the stator extends in the axial direction, and the cylindrical worm gear meshed with the rack portion is rotated by the first micro-motor to cause the stator to move in the direction of the axis of the needle valve. 6. A fuel nozzle as claimed in claim 1 or 3, wherein: The aforementioned lifting amount changing mechanism is achieved by providing a stator that can slide relative to a fixed member near the above-mentioned rotor in the aforementioned axial direction of the aforementioned needle valve, and on one side of the aforementioned stator is provided a Extending the cantilever part with a female thread part, and making a male thread part rotated by the above-mentioned first micro-motor spirally advance or retreat on the above-mentioned female thread part of the above-mentioned cantilever part, so that the above-mentioned stator is in the above-mentioned position of the above-mentioned needle valve The axis moves in the above direction. 7. A fuel nozzle as claimed in claim 1 or 3, wherein: said nozzle body having formed at a front end thereof said nozzle hole through which pressurized fuel is injected, fastened to a front end of a nozzle body by a stop nut; said needle valve slidably inserted into said nozzle body for opening and closing said nozzle hole is connected to said rotor through a rod passing through a through hole formed at said nozzle body; and The above-mentioned spring, which applies a force to the above-mentioned needle valve in the direction of closing the above-mentioned nozzle hole, is arranged in the above-mentioned through hole in such a manner that the above-mentioned rod passes through the above-mentioned spring and the above-mentioned spring is also located in a moving contact with the above-mentioned needle valve. Between the type spring insertion hole and a plugging member fixed on the above-mentioned nozzle body for blocking the above-mentioned through hole. 8. A fuel nozzle as claimed in claim 2 or 3, wherein: A plurality of nozzle holes are formed at specific intervals in the circumferential direction of the nozzle body, and with the rotation of the above-mentioned cover member, the number of the above-mentioned nozzle holes blocked by the above-mentioned blocking part is changed, that is, the above-mentioned nozzle holes that play a role in spraying are changed. The open area of the nozzle hole. 9. A fuel nozzle as claimed in claim 8, wherein: The diameters of the plurality of nozzle holes formed at certain intervals in the circumferential direction of the nozzle body are gradually reduced in the order in which the nozzle holes are blocked by the blocking portion. 10. A fuel nozzle as claimed in claim 2 or 3, wherein: A plurality of nozzle holes that can communicate with the nozzle holes on the nozzle body are formed at specific intervals in the circumferential direction of the blocking portion of the cover member, and are changed with the rotation of the cover member. The number of the above-mentioned nozzle holes connected with the above-mentioned nozzle holes of the nozzle body changes the opening area of the above-mentioned nozzle holes for spraying. 11. A fuel nozzle as claimed in claim 10, wherein: The diameters of the plurality of injection holes formed at specific intervals in the circumferential direction of the blocking portion are gradually reduced in the order in which communication with the nozzle holes on the nozzle body is cut off. 12. A fuel nozzle as claimed in claim 2 or 3 wherein: The nozzle body is provided with a slit-shaped nozzle hole at a specific circumferential angle, and the blocking state of the nozzle hole is changed by the blocking part through the rotation of the above-mentioned cover member, that is, the opening of the nozzle hole that plays a role in spraying is changed. open area. 13. A fuel nozzle as claimed in claim 12, wherein: The nozzle hole provided in the nozzle body in a slit shape has a wedge shape, and the wedge shape is narrowed in a direction in which the area of the nozzle hole is reduced by the blocking portion. 14. A fuel nozzle as claimed in claim 2 or 3, further provided with: A flexible rod near the above-mentioned second micromotor to the vicinity of the above-mentioned cover part is provided with gears at its two ends; wherein The above-mentioned one gear provided at one end of the above-mentioned flexible rod meshes with a gear rotated by the above-mentioned second micro-motor, and the above-mentioned another gear, that is, the gear provided at the other end of the above-mentioned flexible rod, is provided with the outer circumference of the above-mentioned cover member. A gear on the surface is engaged, and a motion force is transmitted from the second micro-motor to the cover part through the flexible rod.

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