JP4103583B2 - Nozzle, fuel injector and internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nozzle, a fuel injector, and an internal combustion engine.
[0002]
[Prior art]
In particular, in a diesel engine, the spray form of the fuel injected from the nozzle of the fuel injector is preferably a high penetration spray when the engine load of the internal combustion engine is medium or high from the viewpoint of reducing harmful substances in the exhaust. High diffusion spray is desirable when the engine load is low. The high penetrating spray is an injection form in which the angle of injection is narrow and the penetrating force is high, and the high diffusion spray is an injection form in which the angle of injection is wide and the fuel is dispersed and the penetrating force is low.
[0003]
As a technique for switching the fuel injection mode between high penetration spray and high diffusion spray according to the engine load of the internal combustion engine, for example, a narrow-angle spray nozzle (a nozzle) and a wide-angle spray nozzle (a nozzle) are used. There is a technique of switching the nozzle holes separately provided (see Patent Document 1).
[0004]
When such a technique is adopted, there remains a problem that fuel accumulates in unused nozzle holes and sometimes becomes clogged. Other related techniques include Patent Documents 2 and 3.
[0005]
[Patent Document 1]
JP 2000-337226 A
[Patent Document 2]
JP 2000-145586 A
[Patent Document 3]
JP-A-8-4625
[0006]
[Problems to be solved by the invention]
As described above, high penetration spray is desirable when the engine load of the internal combustion engine is medium and high, and high diffusion spray is desirable when the engine load of the internal combustion engine is low. However, there was still room for improvement.
[0007]
An object of the present invention is to provide a nozzle and a fuel injector that can be suitably switched to a high penetration spray or a high diffusion spray according to the engine load of the internal combustion engine, and an internal combustion engine with improved thermal efficiency.
[0008]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
[0009]
The present invention provides an introduction path for generating a swirling flow in the nozzle hole, and in the case of high diffusion spray, the flow from the inlet path to the nozzle hole is the main flow, and in the case of high penetration spray, the introduction is performed. The flow that flows into the nozzle hole without passing through the road was made the mainstream. This made it possible to switch between high diffusion spray and high penetration spray.
[0010]
And in this invention, in order to implement | achieve said switching operation | movement, the flow path which makes the flow which flows into an injection hole through the introduction path which generate | occur | produces a swirl flow in an injection hole main flow, and without passing through an introduction path A configuration is adopted in which a flow path variable means that can be changed to a flow path that mainly uses the flow flowing into the nozzle hole is provided.
[0011]
Further, regarding the specific configuration, a configuration in the case of a nozzle, a configuration in the case of a fuel injector, and a configuration in the case of an internal combustion engine will be described.
[0012]
First, a nozzle according to the present invention includes a nozzle body having an injection hole and an introduction path that guides fuel in a direction of forming a swirling flow in the injection hole with respect to the injection hole.
A first position having a facing surface facing the opening end surface of the nozzle hole, wherein a distance from the opening end surface to the facing surface is widened, and a flow of fuel flowing into the nozzle hole without passing through the introduction path is a main stream; A flow path variable member that is moved to a second position where a distance from the opening end surface to the facing surface is narrowed and a flow of fuel from the introduction path to the nozzle hole becomes a main flow, and the flow path variable member And a needle valve that selectively opens and closes the inner wall surface of the nozzle body at a position upstream of the flow path portion changed by the above.
[0013]
Thus, in the configuration of the present invention, the flow path is changed by the flow path variable member moved to the first position and the second position. Thereby, if the flow path variable member is in the first position, the flow of the fuel flowing into the nozzle hole without passing through the introduction path becomes the main flow, so that the fuel ejected from the nozzle hole can be made into a high penetration spray. . On the other hand, if the flow path variable member is in the second position, the flow of the fuel flowing into the nozzle hole through the introduction path becomes the main flow, so that the fuel sprayed from the nozzle hole can be made a high diffusion spray.
[0014]
Since the needle valve selectively opens and closes at a position upstream from the flow path portion changed by the flow path variable member, the needle valve is positioned at a desired position, so that the needle If the valve is opened, high penetration or high diffusion spray can be suitably performed from the beginning of injection.
[0015]
In other words, particularly when performing high penetration spray, if the flow path variable member has already injected fuel during the stage of moving from the position where the gap between the opening end face of the injection hole and the facing surface is narrow to the first position, In the beginning, the amount of fuel passing through the introduction path increases, and in the initial stage, the spray becomes highly diffuse. Then, since combustion starts near the nozzle hole, even if the flow path variable member moves to the first position, it becomes difficult for the fuel to be blown far away, and good high-throughput spraying becomes difficult. On the other hand, as described above, if the flow path variable member is moved to the first position in advance and then opened by the needle valve, the highly penetrating spray can be satisfactorily performed from the beginning of spraying.
[0016]
Moreover, the following are mentioned as a more concrete structure of a flow-path variable member.
[0017]
That is, in the flow path variable member, the opposed surface can be constituted by a single surface whose distance from the opening end surface is continuously changed by movement of the flow path variable member in the axial direction. For example, if the flow path variable member moves in the axial direction by making the tip of the flow path variable member a conical shape and the portion having the nozzle hole on the nozzle body side along the conical shape, The distance between the opening end face and the outer wall surface of the conical portion can be changed. That is, a part of the outer wall surface of the conical portion can be the above-described facing surface.
[0018]
The flow path variable member may include a plurality of surfaces each having a different interval from the opening end surface, and the surface facing the opening end surface may be switched by the axial movement of the flow path variable member. Is possible. For example, when the flow path variable member moves in the axial direction by configuring the tip of the flow path variable member to join a plurality of cylindrical members having different diameters in the axial direction, the opening end face of the nozzle hole The columnar member that faces is switched, and the interval between the opening end surface of the nozzle hole and the outer wall surface portion of the conical portion can be changed.
[0019]
In addition to the first position and the second position, the flow path variable member is preferably moved to a third position that closes the nozzle hole and the introduction path. In this way, the flow path variable member can have a valve function. Therefore, for example, when the valve is closed, the amount of fuel dripping due to the dead volume can be suppressed by closing the valve with the flow path variable member before the needle valve.
[0020]
Next, a fuel injector according to the present invention includes a nozzle body having an injection hole and an introduction path that guides fuel in a direction to form a swirling flow in the injection hole with respect to the injection hole.
A flow path variable member that includes a facing surface that faces the opening end surface of the nozzle hole, and is provided so that a distance from the opening end surface to the facing surface can be changed;
The flow path variable member is widened from the opening end surface to the facing surface, and a first position where the flow of fuel flowing into the nozzle hole without passing through the introduction path is mainstream, and from the opening end surface to the An actuator that moves the fuel flow from the introduction path to the nozzle hole to a second position that narrows the distance to the facing surface and makes it the mainstream;
A needle valve that selectively opens and closes an inner wall surface of a nozzle body at a position upstream of a flow path portion changed by the flow path variable member. .
[0021]
As described above, in the configuration of the present invention, the flow path is changed by moving the flow path variable member to the first position and the second position by the actuator. Thereby, if the flow path variable member is in the first position, the flow of the fuel flowing into the nozzle hole without passing through the introduction path becomes the main flow, so that the fuel ejected from the nozzle hole can be made into a high penetration spray. . On the other hand, if the flow path variable member is in the second position, the flow of the fuel flowing into the nozzle hole through the introduction path becomes the main flow, so that the fuel sprayed from the nozzle hole can be made a high diffusion spray.
[0022]
Since the needle valve selectively opens and closes at a position upstream from the flow path portion changed by the flow path variable member, the needle valve is positioned at a desired position, so that the needle If the valve is opened, high penetration or high diffusion spray can be suitably performed from the beginning of injection.
[0023]
In other words, particularly when performing high penetration spray, if the flow path variable member has already injected fuel during the stage of moving from the position where the gap between the opening end face of the injection hole and the facing surface is narrow to the first position, In the beginning, the amount of fuel passing through the introduction path increases, and in the initial stage, the spray becomes highly diffuse. Then, since combustion starts near the nozzle hole, even if the flow path variable member moves to the first position, it becomes difficult for the fuel to be blown far away, and good high-throughput spraying becomes difficult. On the other hand, as described above, if the flow path variable member is moved to the first position in advance and then opened by the needle valve, the highly penetrating spray can be satisfactorily performed from the beginning of spraying.
[0024]
Preferably, the actuator moves the flow path variable member to the first position when the load of the internal combustion engine is medium to high load, and moves the flow path variable member to the second position when the load is low. It is. As a result, when the load on the internal combustion engine is medium or high, high penetration spray can be performed, and when the load on the internal combustion engine is low, high diffusion spray can be performed. Therefore, harmful substances can be reduced and the output can be sufficiently increased by high penetration spray.
[0025]
Further, when the load of the internal combustion engine is a medium to high load, it is preferable that the valve opening operation by the needle valve is performed after the actuator moves the flow path variable member to the first position. Thereby, as mentioned above, highly penetrating spray can be performed from the initial stage of spraying.
[0026]
The nozzle body is provided with a valve seat that closes the nozzle hole and the introduction path when the flow path variable member is seated, and the actuator is configured to change the flow path variable member. The member may be moved to a third position where the member is seated on the valve seat. As a result, the flow path variable member can also have a valve function.
[0027]
At the end of fuel injection, the actuator may move the flow path variable member to the third position, and then the needle valve may be closed. Thereby, since the valve is closed first by the flow path variable member close to the nozzle hole, the amount of fuel dripping due to the dead volume can be suppressed.
[0028]
In the flow path variable member, the opposed surface can be constituted by a single surface whose distance from the opening end surface is continuously changed by movement of the flow path variable member in the axial direction. For example, if the flow path variable member moves in the axial direction by making the tip of the flow path variable member a conical shape and the portion having the nozzle hole on the nozzle body side along the conical shape, The distance between the opening end face and the outer wall surface of the conical portion can be changed. That is, a part of the outer wall surface of the conical portion can be the above-described facing surface.
[0029]
The flow path variable member may include a plurality of surfaces each having a different interval from the opening end surface, and the surface facing the opening end surface may be switched by the axial movement of the flow path variable member. . For example, if the flow path variable member moves in the axial direction by configuring the tip of the flow path variable member so that a plurality of cylinders having different diameters are joined in the axial direction, the front end of the flow path variable member faces the opening end surface of the nozzle hole. The cylinder is switched, and the distance between the opening end surface of the nozzle hole and the outer wall surface portion of the conical portion can be changed.
[0030]
The actuator may be configured by hydraulic control means that drives the flow path variable member in conjunction with the operation of the needle valve.
[0031]
Further, the actuator may be constituted by a solenoid that drives the flow path variable member independently of the operation of the needle valve.
[0032]
Here, a stopper for stopping the flow path variable member that moves by receiving the suction force of the coil provided in the solenoid;
First biasing means for biasing the flow path variable member in a direction opposite to the suction direction by the coil;
Second urging means for urging the stopper in a direction opposite to the suction direction by the coil;
A restricting member for restricting movement of the stopper urged by the second urging means in the urging direction,
The first urging force by the first urging means and the second urging force by the second urging means are configured to resist the first urging force when the first suction force by the coil is applied. The variable member moves, but is stopped by the stopper at a position restricted by the restricting member by the second urging force, and the flow path variable member is held at the second position,
In addition, when a second suction force larger than the first suction force by the coil is applied, the flow path variable member and the stopper together with the first biasing force against the resultant force of the first biasing force and the second biasing force are in the first position. It is preferable to satisfy the force relationship of moving up to.
[0033]
By comprising in this way, the positioning accuracy of a flow-path variable member can be made high.
[0034]
Further, in the internal combustion engine of the present invention, a fuel injector constituted by any of the above,
Detection means for detecting engine load;
When the engine load detected by the detection means is higher than the determination reference value, the flow path variable member is moved to the first position, and when the engine load is lower than the determination reference value, the flow path variable member. Control means for drivingly controlling the actuator so as to move the actuator to the second position.
[0035]
With the configuration of the present invention, the spray form of the fuel injected from the fuel injector can be spray suitable for the engine load, which contributes to the reduction of harmful substances and can improve the thermal efficiency.
[0036]
In addition, said each structure can be employ | adopted combining as much as possible.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.
[0038]
(First embodiment)
With reference to FIGS. 1-7, the nozzle which concerns on the 1st Embodiment of this invention, the fuel injector provided with the nozzle, and the internal combustion engine provided with the fuel injector are demonstrated.
[0039]
1 to 3 are schematic cross-sectional views showing the main part of the nozzle according to the first embodiment of the present invention. Here, FIG. 1 shows a state in the case of performing high penetration spray, FIG. 2 shows a state in the case of performing high diffusion spray, and FIG. 3 shows a state in the case of not performing spraying.
[0040]
4 to 6 show the nozzle holes provided in the nozzle body according to the first embodiment of the present invention. Here, FIG. 4 is a view of the vicinity of the nozzle hole from the upper surface of the nozzle, FIG. 5 is a cross-sectional view cut along the axis of the nozzle hole, and FIG. is there.
[0041]
FIG. 7 is a block diagram of the internal combustion engine provided with the fuel injector according to the first embodiment of the present invention.
[0042]
As shown in FIGS. 1 to 3, the nozzle 10 according to the present embodiment includes a nozzle body 11, a needle valve 12 provided in the nozzle body 11, and a flow path disposed coaxially with the needle valve 12. And a variable member 13.
[0043]
The nozzle body 11 has an injection hole 11a serving as a fuel injection port, an introduction passage 11b for forming a swirling flow in the injection hole with respect to the injection hole 11a, and a valve seat serving as a valve seat for the needle valve 12. 1 valve seat 11c and 2nd valve seat 11d used as the valve seat of the flow-path variable member 13 are provided.
[0044]
Here, the nozzle hole 11a and the introduction path 11b will be described in more detail with reference to FIGS.
[0045]
As shown in FIGS. 4 and 5, an introduction path 11 b is provided so as to connect to the opening end on the inner side of the injection hole 11 a. In this embodiment, the introduction path 11b is formed by a notch. As shown in FIG. 6, the introduction path 11b is formed so as to feed fuel to a position eccentric with respect to the hole axis of the injection hole 11a.
[0046]
Therefore, the fuel that has flowed through the introduction path 11b forms a swirling flow in the nozzle hole 11a as shown in FIGS. Thereby, since the fuel injected from the injection hole 11a is injected while turning, it is injected at a wide angle and becomes a high diffusion spray.
[0047]
The needle valve 12 is provided in the nozzle body 11 so as to be capable of reciprocating in the axial direction. The needle valve 12 is configured by a substantially cylindrical member, and a taper that decreases in diameter toward the distal end side is provided at the distal end. A flat surface portion 12c is provided at the forefront, and an edge portion 12a serving as a boundary between the flat surface portion 12c and the taper is closed by being seated on a first valve seat 11c provided in the nozzle body 11. It is configured. Further, the needle valve 12 is provided with a through hole 12b along the axis.
[0048]
And the flow path variable member 13 is provided with the axial part 13a inserted in the through-hole 12b provided in the needle valve 12, and the cone part 13b provided in the front-end | tip of the axial part 13a. A part of the side surface 13c of the conical portion 13b is provided so as to be disposed at a position facing the nozzle hole 11a of the nozzle body 11 and the opening end surface of the introduction path 11b. Further, the bottom surface 13 d of the conical portion 13 b is configured to abut against the flat surface portion 12 c of the needle valve 12.
[0049]
Here, the needle valve 12 and the flow path variable member 13 described above are configured to reciprocate in the axial direction by actuators not shown in FIGS.
[0050]
The fuel injection operation by the nozzle 10 configured as described above will be described. First, the case where high penetration spray is performed will be described with reference to FIG. As shown in FIG. 1, when highly penetrating spraying is performed, the edge portion 12 a of the needle valve 12 is opened from the first valve seat 11 c provided in the nozzle body 11. On the other hand, the flow path variable member 13 is moved to a position where the bottom surface 13 d of the conical portion 13 b hits the flat surface portion 12 c of the needle valve 12. Thereby, the space | interval of the opening end surface of the nozzle hole 11a of the nozzle main body 11 and the introduction path 11b, and the opposing surface (a part of side surface 13c of the cone part 13b in the flow-path variable member 13) will be in a wide state. (Hereinafter, the position of the flow path variable member 13 in this state is referred to as a first position for convenience of explanation).
[0051]
Therefore, the fuel that has flowed by opening the needle valve 12 flows mainly into the nozzle hole 11a without passing through the introduction path 11b, so that no swirl flow is formed in the nozzle hole 11a. That is, since the flow along the hole axis of the nozzle hole 11a becomes the main flow, the fuel injected from the nozzle hole 11a jumps out in the hole axis direction. Thereby, highly penetrating spraying becomes possible.
[0052]
Next, a case where high diffusion spraying is performed will be described with reference to FIG. As shown in FIG. 2, when highly diffusing spray is performed, the edge portion 12 a of the needle valve 12 is opened from the first valve seat 11 c provided in the nozzle body 11. On the other hand, the flow path variable member 13 is moved to a position where the bottom surface 13d of the conical portion 13b is separated from the flat surface portion 12c of the needle valve 12 by a certain distance. Thereby, the space | interval of the opening end surface of the nozzle hole 11a of the nozzle main body 11 and the introduction path 11b, and the opposing surface (a part of side surface 13c of the cone part 13b in the flow-path variable member 13) will be in a narrow state. (Hereinafter, the position of the flow path variable member 13 in this state is referred to as a second position for convenience of explanation).
[0053]
Accordingly, since the fuel that has flowed by opening the needle valve 12 flows mainly into the nozzle hole 11a through the introduction path 11b, a swirling flow is formed in the nozzle hole 11a. Thereby, high diffusion spraying becomes possible as already demonstrated with reference to FIGS.
[0054]
Next, a case where the injection is stopped will be described with reference to FIG. As shown in FIG. 3, when the injection is stopped, the edge portion 12 a of the needle valve 12 is seated on the first valve seat 11 c provided in the nozzle body 11 and closed. Further, the side surface 13c of the conical portion 13b in the flow path variable member 13 is also seated on the second valve seat 11d provided in the nozzle body 11, and the injection hole 11a and the introduction passage 11b are closed and closed (hereinafter referred to as the valve seat 11d). For convenience of explanation, the position of the flow path variable member 13 in this state is referred to as a third position). Accordingly, the fuel is not injected from the injection hole 11a.
[0055]
Here, not only the needle valve 12 but also the flow path variable member 13 has a function of selectively opening and closing the valve, and the needle valve 12 is selectively opened and closed. Then, since a relatively large dead volume is generated around the flow path variable member 13, even if the needle valve 12 is closed after fuel injection, fuel sagging increases. Therefore, the flow sag after fuel injection is reduced by directly closing the opening end faces of the injection hole 11a and the introduction path 11b by the flow path variable member 13.
[0056]
Next, a more specific operation when the fuel injector having the nozzle configured as described above is mounted on an internal combustion engine will be described with reference to the block diagram of FIG.
[0057]
As shown in FIG. 7, a sensor 50, which is a main component of detection means for detecting the engine load of the internal combustion engine, and data detected by the sensor 50 are input, and a command signal is transmitted based on the input data. An ECU 60 as control means and an actuator 70 for driving the needle valve 12 and the flow path variable member 13 according to a command signal from the ECU 60 are provided.
[0058]
The sensor 50 may be any sensor that can detect data capable of recognizing the engine load required in the internal combustion engine. That is, in general, it is difficult to detect the required engine load directly or indirectly, and it is sufficient that data capable of estimating the required engine load can be detected. As an example, one that detects the accelerator opening can be mentioned.
[0059]
Then, the ECU 60 determines whether the requested engine load is a medium or high load based on the input data sent from the sensor 50. Specifically, the ECU 60 determines whether the required engine load obtained based on the input data is higher or lower than a predetermined determination reference value.
[0060]
Here, since the input data sent from the sensor 50 is not usually the required engine load value itself as described above, the required engine load is estimated from the input data, and this estimated value is requested. Engine load value. In addition, the determination reference value may be a fixed value set in advance, or a value that varies according to environmental conditions or the like.
[0061]
When the ECU 60 determines that the required engine load is a medium to high load, the ECU 60 moves the needle valve 12 and the flow path variable member 13 to the positions shown in FIG. A command signal is transmitted to the actuator 70.
[0062]
Here, when performing high penetration spraying, the flow path variable member 13 is first moved to the first position from the injection stop state shown in FIG. 3 to open the nozzle holes 11a and the introduction paths 11b of the nozzle body 11. It is preferable to open the needle valve 12 after increasing the distance between the end surface and the opposing surface facing the end surface.
[0063]
This is because, when the flow path variable member 13 is driven after the needle valve 12 has been opened, the nozzle hole 11a of the nozzle body 11 and the opening end face of the introduction path 11b are opposed to each other at the initial stage. The distance from the surface is narrow. Therefore, high diffusion spraying is performed in the initial stage. And if combustion starts at this stage, it will burn only in the exit vicinity of the nozzle hole 11a. Under such circumstances, thereafter, the flow path variable member 13 further moves to the first position, and the interval between the opening end surfaces of the nozzle hole 11a and the introduction path 11b of the nozzle body 11 and the opposing surface facing this. However, even if the fuel jumps out along the hole axis of the nozzle hole 11a, combustion has already started near the outlet of the nozzle hole 11a, making it difficult to fly the fuel far.
[0064]
On the other hand, as described above, after the flow path variable member 13 is driven first, and the interval between the opening end surface of the nozzle hole 11a and the introduction path 11b of the nozzle body 11 and the facing surface facing this is secured. If the needle valve 12 is opened, high penetration spraying can be achieved from the initial stage, and fuel can be blown away.
[0065]
In this way, when the required engine load is a medium to high load, high penetration spray is performed, so that the space in the engine room can be fully utilized, the output can be sufficiently increased, and harmful substances in the exhaust gas can be obtained. Will not increase.
[0066]
When the ECU 60 determines that the required engine load is low, the ECU 60 moves the needle valve 12 and the flow path variable member 13 to the positions shown in FIG. A command signal is transmitted to the actuator 70.
[0067]
Here, when performing high diffusion spraying, the driving order of the needle valve 12 and the flow path variable member 13 is not particularly limited, and either of them may be driven first or simultaneously.
[0068]
In this way, when the required engine load is low, high diffusion spray is performed, so that the fuel is highly dispersed and evenly distributed in the combustion chamber and can be ignited simultaneously at multiple points in the combustion chamber. it can. In this case, by making the concentration of the air-fuel mixture thinner than the stoichiometric air-fuel ratio, harmful substances such as NOx and soot in the exhaust can be reduced.
[0069]
Further, when stopping the fuel injection, the ECU 60 sends a command signal to the actuator 70 so as to move the needle valve 12 and the flow path variable member 13 to the positions shown in FIG.
[0070]
Here, when stopping fuel injection, it is preferable to first close the needle valve 12 after moving the flow path variable member 13 to the third position and closing it.
[0071]
As described above, even if the needle valve 12 is closed, the dead volume is large and the fuel sag increases. Therefore, the opening end surfaces of the injection hole 11a and the introduction passage 11b are formed by the flow path variable member 13. This is because the fuel sag after the fuel injection can be reduced by directly closing it first.
[0072]
As described above, according to the present embodiment, the spray form of the fuel injected from the nozzle 10 can be suitably switched between the high penetration spray and the high diffusion spray. By switching the spray form according to the engine load, it is possible to contribute to the reduction of harmful substances in the exhaust gas, and to contribute to the improvement of the thermal efficiency of the internal combustion engine.
[0073]
(Second Embodiment)
8 to 11 show a second embodiment of the present invention. In the present embodiment, an example of an embodiment in which an actuator that drives the needle valve 12 and the flow path variable member 13 is embodied will be described.
[0074]
Since the control means (ECU) and the nozzle for transmitting a command signal to the actuator are as described in the first embodiment, the description thereof is omitted. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.
[0075]
FIGS. 8-11 is typical sectional drawing which shows the main components of the fuel injector which concerns on the 2nd Embodiment of this invention. Here, FIG. 8 shows a state when fuel injection is stopped, FIG. 9 shows a state at the time of high diffusion spray, FIG. 10 shows a state of a preparation stage when performing high penetration spray, and FIG. 11 shows high penetration spray. It shows the state of time.
[0076]
The fuel injector 100 according to the present embodiment employs a hydraulic control mechanism 20 as an actuator that drives the needle valve 12 and the flow path variable member 13.
[0077]
The hydraulic control mechanism 20 includes a first control chamber 21 that mainly controls driving of the needle valve 12, a second control chamber 22 that mainly controls driving of the flow path variable member 13, and a nozzle (not shown) side of the nozzle hole 11a. And a first passage 23 for feeding fuel toward the first control chamber 21, a second passage 24 for feeding fuel to the second control chamber 22, and a float disposed in a lift chamber 25 a upstream of the second passage 24. A valve 25, a first spring 26 that is disposed in the first control chamber 21 and pulls the needle valve 12 in the valve opening direction, and a valve 25 that is disposed in the second control chamber 22 and opens the flow path variable member 13 in the valve opening direction. A second spring 27 that pulls the first passage 23, a first orifice 28 that communicates between the first passage 23 and the first control chamber 21, and a space between the lift chamber 25 a upstream of the second passage 24 and the first control chamber 21. A second orifice 29 communicating with Obtain.
[0078]
Here, high-pressure fuel is always sent to the first passage 23 from above in the figure by a fuel pump (not shown).
[0079]
The float valve 25 is configured to reciprocate by a driving means (not shown), and is configured to be able to selectively open and close at two locations. That is, the float valve 25 can selectively block the flow of fuel that passes through the lift chamber 25 a or the flow of fuel that passes through the second orifice 29. Moreover, the float valve 25 can also open these two places simultaneously.
[0080]
With such a configuration, when stopping fuel injection, as shown in FIG. 8, the float valve 25 is moved to the upper part in the figure, the valve is closed in the lift chamber 25a, and the fuel passes through the lift chamber 25a. To block the flow.
[0081]
In this case, the first passage 23, the first control chamber 21, the second passage 24, and the second control chamber 22 are all in communication with each other through the first orifice 28 and the second orifice 29. As a result, the high-pressure fuel is accumulated in both the first control chamber 21 and the second control chamber 22 by the high-pressure fuel sent from the first passage 23. Therefore, both the needle valve 12 and the flow path variable member 13 move downward in the figure against the pulling force by the first spring 26 and the pulling force by the second spring 27, and both of them are valve seats (respectively first valve The first valve seat 11c and the second valve seat 11d) are seated and closed.
[0082]
Next, when performing high diffusion spraying, the float valve 25 is moved slightly downward in the figure from the position shown in FIG. 8, and as shown in FIG. Open the valve.
[0083]
In this case, when the lift chamber 25a is opened, the pressures in the first control chamber 21 and the second control chamber 22 are released, and these chambers are in a low pressure state. The first passage 23 and the first control chamber 21 communicate with each other through the first orifice 28. However, since the fluid flow is restricted by the first orifice 28, the fluid pressure is high on the first passage 23 side, 1 The fluid pressure is low on the control chamber 21 side.
[0084]
As described above, the fluid pressure in the first control chamber 21 and the second control chamber 22 is lowered. Accordingly, the needle valve 12 and the flow path variable member 13 are moved upward in the drawing by the first spring 26 and the second spring 27, respectively.
[0085]
At this time, the needle valve 12 and the flow path variable member 13 move in a state where a gap is provided between the flat surface portion 12 c at the tip of the needle valve 12 and the bottom surface 13 d of the conical portion 13 b of the flow path variable member 13. Thereby, since a high pressure fluid flows also into this clearance gap, both maintain a valve opening state, having this clearance gap. Accordingly, since the flow path variable member 13 is in the second position and is opened by the needle valve 12, high-diffusion spraying can be performed as described in the first embodiment.
[0086]
Further, when stopping fuel injection, as described above, the float valve 25 may be moved again upward in the drawing to close the lift chamber 25a. Here, as described in the first embodiment, in order to suppress fuel sag, it is desirable to close the flow path variable member 13 first. In order to close the flow path variable member 13 first, it is realized by adjusting the relationship between the amount of restriction by the first orifice 28 and the second orifice 29 and the tensile force by the first spring 26 and the second spring 27. Is possible.
[0087]
Next, when high penetration spraying is performed, the float valve 25 is moved downward in the drawing from the position shown in FIG. 8, and the inside of the lift chamber 25a is opened as shown in FIG. The 29 side is closed.
[0088]
In this case, although the lift chamber 25a is opened, the second orifice 29 side is closed, so the interior of the first control chamber 21 is maintained in a high pressure state. On the other hand, when the lift chamber 25a is opened, the pressure in the second control chamber 22 is released, and the interior of the second control chamber 22 is in a low pressure state.
[0089]
Accordingly, only the flow path variable member 13 is moved upward in the drawing by the second spring 27, and the needle valve 12 is maintained in the closed state. Then, the flow path variable member 13 moves to a position where the bottom surface 13d of the conical portion 13b abuts against the flat surface portion 12c at the tip of the needle valve 12 (state shown in FIG. 10).
[0090]
Thereafter, the float valve 25 is moved slightly upward in the drawing from the position shown in FIG. 10, and as shown in FIG. 11, both of the above-described two on-off valve portions are opened. Then, since the pressure in the first control chamber 21 is also released, the interior of the first control chamber 21 is also in a low pressure state. Accordingly, the needle valve 12 is moved upward in the drawing by the first spring 26.
[0091]
At this time, since there is no gap between the flat surface portion 12c at the tip of the needle valve 12 and the bottom surface 13d of the conical portion 13b in the flow path variable member 13, the gap is not present due to the pressure of the fluid. The flow path variable member 13 also moves with the needle valve 12.
[0092]
Here, the flow path variable member 13 moves in two stages, but at the first stage shown in FIG. 10, the flow path variable member 13 opens the nozzle hole 11a and the introduction path 11b of the nozzle body 11. The gap between the end face and the facing face facing this is wide, and the position has moved to a position where high penetration spraying is possible, that is, the first position. After that, the flow path variable member 13 moves to a position that further widens the above-mentioned interval, and in this case as well, the flow path variable member 13 is in the first position where high penetration spraying is possible. Absent.
[0093]
As described above, since the flow path variable member 13 is in the first position and is opened by the needle valve 12, as described in the first embodiment, highly penetrating spraying is performed. Can do.
[0094]
Further, when stopping fuel injection, as described above, the float valve 25 may be moved again upward in the drawing to close the lift chamber 25a. The drive for suppressing fuel sag is as described above.
[0095]
(Third embodiment)
12 to 15 show a third embodiment of the present invention. In the present embodiment, an example of an embodiment in which an actuator that drives the needle valve 12 and the flow path variable member 13 is embodied will be described.
[0096]
Since the control means (ECU) and the nozzle for transmitting a command signal to the actuator are as described in the first embodiment, the description thereof is omitted. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.
[0097]
12-15 is typical sectional drawing which shows the main components of the fuel injector which concerns on the 3rd Embodiment of this invention. Here, FIG. 12 shows a state when fuel injection is stopped, FIG. 13 shows a state when performing high diffusion spraying, FIG. 14 shows a state of a preparation stage when performing high penetration spraying, and FIG. It shows the situation during penetrating spray.
[0098]
The fuel injector 200 according to the present embodiment employs a solenoid drive mechanism (electromagnetic drive mechanism) 30 as an actuator that drives the needle valve 12 and the flow path variable member 13.
[0099]
In the present embodiment, a flat plate portion 13e made of a magnetic material is provided at the end of the shaft portion 13a of the flow path variable member 13 (the end opposite to the conical portion 13b).
[0100]
The solenoid drive mechanism 30 is opposed to the first coil 31 provided at a position facing the surface of the flat plate portion 13e opposite to the conical portion 13b, and the bottom surface of the needle valve 12 opposite to the conical portion 13b. A second coil 32 provided at a position to be moved, and a spring 33 that urges the flat plate portion 13e in a direction to separate the flat plate portion 13e from the first coil 31. Further, although not particularly illustrated, a member that exerts a force in a direction in which the needle valve 12 is pulled away from the second coil 32 (for example, a spring that biases the needle valve 12 as in the case of the flat plate portion 13e) is also provided. . Hereinafter, for convenience of explanation, this member is referred to as member A.
[0101]
With such a configuration, when the fuel injection is stopped, neither the first coil 31 nor the second coil 32 is energized. Accordingly, as shown in FIG. 12, the urging force of the spring 33 acts on the flat plate portion 13e, and the force of the member A acts on the needle valve 12, so that both the needle valve 12 and the flow path variable member 13 are Both move downward in the figure, and both are seated on the valve seats (the first valve seat 11c and the second valve seat 11d, respectively) and closed.
[0102]
Next, when performing high diffusion spraying, first, the second coil 32 is energized. Thereby, the needle valve 12 is attracted by the magnetic attraction force by the second coil 32 and moves upward in the figure against the acting force by the member A (the state shown in FIG. 13A).
[0103]
Thereafter, the first coil 31 is also energized. Thereby, the flat plate portion 13e is attracted by the magnetic attraction force by the first coil 31, and the flow path variable member 13 also moves upward in the figure against the urging force by the spring 33 (the state shown in FIG. 13B). ). At this time, since the high-pressure fluid flows into the gap between the flat surface portion 12c at the tip of the needle valve 12 and the bottom surface 13d of the conical portion 13b in the flow path variable member 13, both have the valve open state while having this gap. maintain. However, in the case of the present embodiment, since the suction force can be controlled by controlling the energization amount to the first coil 31 or the second coil 32, the positioning of the needle valve 12 and the flow path variable member 13 is Control is also possible by the amount of energization.
[0104]
In this way, since the flow path variable member 13 is in the second position and opened by the needle valve 12, high diffusion spraying is performed as described in the first embodiment. Can do.
[0105]
In the above description, the case where the first coil 31 is energized after the second coil 32 is energized has been described. However, the needle valve 12 and the flow path variable member 13 are driven simultaneously by energizing both at the same time. May be.
[0106]
In addition, when stopping the fuel injection, the energization to the first coil 31 and the second coil 32 may be stopped again as described above. Here, as described in the first embodiment, in order to suppress fuel sag, it is desirable to close the flow path variable member 13 first. Needless to say, in order to close the flow path variable member 13 first, it is sufficient to stop energization of the first coil 31 first.
[0107]
Next, when performing high penetration spraying, first, the first coil 31 is energized. Accordingly, the flat plate portion 13e is attracted by the magnetic attraction force by the first coil 31, and the flow path variable member 13 moves upward in the figure against the urging force by the spring 33. At this time, the flow path variable member 13 moves to a position where the bottom surface 13d of the conical portion 13b abuts against the flat surface portion 12c at the tip of the needle valve 12 (the state shown in FIG. 14).
[0108]
Thereafter, the second coil 32 is also energized. Thereby, the needle valve 12 is attracted by the magnetic attraction force by the second coil 32 and moves upward in the figure against the acting force by the member A (state shown in FIG. 15). At this time, since there is no gap between the flat surface portion 12c at the tip of the needle valve 12 and the bottom surface 13d of the conical portion 13b in the flow path variable member 13, the gap is not present due to the pressure of the fluid. The flow path variable member 13 also moves with the needle valve 12.
[0109]
Here, the flow path variable member 13 moves in two stages, but at the first stage shown in FIG. 14, the flow path variable member 13 opens the nozzle hole 11a and the introduction path 11b of the nozzle body 11. The gap between the end face and the facing face facing this is wide, and the position has moved to a position where high penetration spraying is possible, that is, the first position. After that, the flow path variable member 13 moves to a position that further widens the above-mentioned interval, and in this case as well, the flow path variable member 13 is in the first position where high penetration spraying is possible. Absent.
[0110]
However, as described above, in the case of the present embodiment, since the suction force can be controlled by controlling the energization amount to the first coil 31 or the second coil 32, the needle valve 12 and the flow path variable member. The positioning of 13 can also be controlled by the energization amount.
[0111]
In this way, since the flow path variable member 13 is in the first position and is opened by the needle valve 12, as described in the first embodiment, highly penetrating spraying can be performed. it can.
[0112]
In addition, when stopping the fuel injection, the energization to the first coil 31 and the second coil 32 may be stopped again as described above. The drive for suppressing fuel sag is as described above.
[0113]
(Fourth embodiment)
16 to 19 show a fourth embodiment of the present invention. In the present embodiment, an example of an embodiment in which an actuator that drives the needle valve 12 and the flow path variable member 13 is embodied will be described.
[0114]
Since the control means (ECU) and the nozzle for transmitting a command signal to the actuator are as described in the first embodiment, the description thereof is omitted. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.
[0115]
FIGS. 16-19 is typical sectional drawing which shows the main components of the fuel injector based on the 4th Embodiment of this invention. Here, FIG. 16 shows a state when fuel injection is stopped, FIG. 17 shows a state when performing high diffusion spraying, FIG. 18 shows a state of a preparation stage when performing high penetration spraying, and FIG. It shows the situation during penetrating spray.
[0116]
The fuel injector 300 according to the present embodiment employs a solenoid drive mechanism (electromagnetic drive mechanism) 40 as an actuator for driving the needle valve 12 and the flow path variable member 13 as in the third embodiment. Yes. The basic mechanism is the same as that of the third embodiment, but in this embodiment, the positioning accuracy of the needle valve 12 and the flow path variable member 13 is compared with that of the third embodiment. The configuration is improved to improve.
[0117]
In the present embodiment, a flat plate portion 13f made of a magnetic material is provided at the end of the shaft portion 13a of the flow path variable member 13 (the end opposite to the conical portion 13b). The flat plate portion 13f is provided with a convex portion 13g protruding toward the opposite side of the conical portion 13b.
[0118]
The solenoid drive mechanism 40 is opposed to the first coil 41 provided at a position facing the surface of the flat plate portion 13f opposite to the conical portion 13b, and the bottom surface of the needle valve 12 opposite to the conical portion 13b. The second coil 42 provided at the position to be moved, the stopper 43 for positioning the flow path variable member 13, and the direction in which the flat plate portion 13 f is separated from the first coil 41 (the direction opposite to the suction direction by the first coil 41). A first spring 44 as first urging means, a second spring 45 as second urging means for urging the stopper 43 toward the conical portion 13b (the direction opposite to the suction direction by the first coil 41), And a restricting portion 46 that restricts the movement of the stopper 43 toward the conical portion 13b at a predetermined position.
[0119]
Here, the urging force by the second spring 45 is set to be larger than the urging force by the first spring 44.
[0120]
Further, although not particularly illustrated, a member that exerts a force in a direction in which the needle valve 12 is pulled away from the second coil 42 (for example, a spring that biases the needle valve 12 as in the case of the flat plate portion 13f) is also provided. . Hereinafter, for convenience of explanation, this member is referred to as member B.
[0121]
With such a configuration, when the fuel injection is stopped, neither the first coil 41 nor the second coil 42 is energized. Accordingly, as shown in FIG. 16, the urging force of the first spring 44 acts on the flat plate portion 13f, and the force of the member B acts on the needle valve 12, so that the needle valve 12 and the flow path variable member 13 are Both of them move downward in the figure, and both are seated on the valve seats (first valve seat 11c and second valve seat 11d, respectively) and closed.
[0122]
Next, when performing high diffusion spraying, first, the first coil 41 is energized with the energization amount A. Accordingly, the flat plate portion 13f is attracted by the magnetic attraction force by the first coil 41, and the flow path variable member 13 moves upward in the figure against the urging force by the first spring 44.
[0123]
Then, the convex portion 13 g provided on the flow path variable member 13 abuts against the stopper 43. As a result, the convex portion 13g generates a pressing force against the stopper 43. However, when the energizing amount flowing through the first coil 41 is the energizing amount A, this pressing force is the urging force of the first spring 44. No magnetic attractive force (first attractive force) is generated until the resultant force of the (first urging force) and the urging force (second urging force) of the second spring 45 is resisted. Accordingly, the stopper 43 remains held at the position restricted by the restriction portion 46. In this way, the flow path variable member 13 is accurately positioned at the second position (the state shown in FIG. 17A).
[0124]
Thereafter, the second coil 42 is also energized. Thereby, the needle valve 12 is attracted by the magnetic attraction force by the second coil 42 and moves upward in the figure against the acting force by the member B (the state shown in FIG. 17B). In this way, since the flow path variable member 13 is in the second position and opened by the needle valve 12, high diffusion spraying is performed as described in the first embodiment. Can do.
[0125]
In the above description, the case where the second coil 42 is energized after the first coil 41 is energized has been described. However, the needle valve 12 and the flow path variable member 13 are driven simultaneously by energizing both of them simultaneously. May be.
[0126]
Further, when stopping the fuel injection, as described above, the energization to the first coil 41 and the second coil 42 may be stopped again. Here, as described in the first embodiment, in order to suppress fuel sag, it is desirable to close the flow path variable member 13 first. Needless to say, in order to close the flow path variable member 13 first, it is sufficient to stop energization of the first coil 41 first.
[0127]
Next, when performing high penetration spraying, first, the first coil 41 is energized with the energization amount B. Accordingly, the flat plate portion 13f is attracted by the magnetic attraction force by the first coil 41, and the flow path variable member 13 moves upward in the figure against the urging force by the first spring 44.
[0128]
Then, the convex portion 13 g provided on the flow path variable member 13 abuts against the stopper 43. As a result, the convex portion 13g generates a pressing force against the stopper 43. When the energization amount flowing through the first coil 41 is the energization amount B, the pressing force is applied to the biasing force ( A magnetic attraction force (second attraction force) that resists the resultant force of the first urging force) and the urging force of the second spring 45 (second urging force) is generated. Accordingly, the stopper 43 is pushed by the convex portion 13g and moves upward in the figure. And the flow-path variable member 13 moves to the position (1st position) where the flat plate part 13f contacts the 1st coil 41 (state shown in FIG. 18).
[0129]
Thereafter, the second coil 42 is also energized. Thereby, the needle valve 12 is attracted by the magnetic attraction force by the second coil 42 and moves upward in the figure against the acting force by the member B (state shown in FIG. 19).
[0130]
In this way, since the flow path variable member 13 is in the first position and is opened by the needle valve 12, as described in the first embodiment, highly penetrating spraying can be performed. it can.
[0131]
Further, when stopping the fuel injection, as described above, the energization to the first coil 41 and the second coil 42 may be stopped again. The drive for suppressing fuel sag is as described above.
[0132]
As described above, in the present embodiment, it is possible to increase the positioning accuracy of the flow path variable member 13 at the second position, particularly when performing high diffusion spraying.
[0133]
Here, the reason why the flow path variable member 13 can be positioned more accurately at the second position in the case of the present embodiment than in the case of the third embodiment will be described in more detail.
[0134]
In the case of the third embodiment, when the flow path variable member 13 is positioned at the second position, the position of the flow path variable member 13 is determined by the first coil 31 based on the energization amount to the first coil 31. It is determined by the balance (synthetic force) between the magnetic attractive force, the urging force of the spring 33, and the hydraulic pressure.
[0135]
If any one of these forces changes, the position of the flow path variable member 13 changes. Therefore, it is difficult to accurately position the flow path variable member 13. However, the second position means the position of the flow path variable member 13 where the high diffusion spray is performed, and the second position has a certain width. Therefore, it does not mean that it is difficult to set the flow path variable member 13 to the second position, but it means that it is difficult to accurately position the flow path variable member 13 at a specific position in the second position.
[0136]
On the other hand, in the present embodiment, when the flow path variable member 13 is positioned at the second position, the flow path variable member is in a state where the stopper 43 is at the position restricted by the restriction portion 46 as described above. What is necessary is just to make the convex part 13g provided in 13 abut against the stopper 43.
[0137]
Even if the flow path variable member 13 moves against the urging force of the first spring 44 by the magnetic attraction force of the first coil 41, the magnetic attraction force is applied to the urging force of the first spring 44 and the second spring. As long as it is weaker than the resultant force with the urging force of 45, the stopper 43 does not move from the position restricted by the restricting portion 46.
[0138]
As described above, also in the present embodiment, the flow path variable member 13 is positioned by the balance by various forces, but the magnetic attractive force by the first coil 41 is larger than the urging force of the first spring 44. In a range that is weaker than the resultant force of the urging force of the first spring 44 and the urging force of the second spring 45, the flow path variable member 13 is positioned at a position determined by the stopper 43.
[0139]
Therefore, in the present embodiment, the flow path variable member 13 can be accurately positioned at the second position (a specific position among the second positions).
[0140]
(Fifth embodiment)
20 and 21 show a fifth embodiment of the present invention. In the present embodiment, a modified example of the nozzle configuration will be described. In addition, about the actuator which drives a needle valve and a flow-path variable member, a suitable structure can be utilized, for example, the structure demonstrated in the said 2nd-4th embodiment can be utilized. Therefore, the description of the actuator is omitted in this embodiment. Further, the control means (ECU) for transmitting a command signal to the actuator is also as described in the first embodiment, and the description thereof is omitted.
[0141]
20 and 21 are schematic cross-sectional views of a nozzle according to the fifth embodiment of the present invention. Here, FIG. 20 shows a state when fuel injection is stopped, FIG. 21 (A) shows a state when performing high diffusion spraying, and FIG. 21 (B) shows a state when performing high penetration spraying. .
[0142]
In the said 1st-4th embodiment, by moving the flow-path variable member 13 to an axial direction, the nozzle hole 11a of the nozzle main body 11 and the opening end surface of the introduction path 11b, and the opposing surface facing this are made. The flow path was changed by changing the distance between the conical portion 13b and the side surface 13c in the flow path variable member 13 to be configured.
[0143]
That is, the facing surface that faces the nozzle hole 11a of the nozzle body 11 and the opening end face of the introduction path 11b is a single surface whose distance from the opening end face changes continuously as the flow path variable member 13 moves in the axial direction. It was comprised by the side surface 13c (a part) of a certain cone part 13b.
[0144]
On the other hand, in the present embodiment, the flow path variable member is provided with a plurality of surfaces having different distances from the opening end surface, and the opposed surface facing the opening end surface is switched.
[0145]
As illustrated, the nozzle 10 a according to the present embodiment includes a nozzle body 15, a needle valve 16 provided in the nozzle body 15, and a flow path variable member 17 disposed coaxially with the needle valve 16. Prepare.
[0146]
The nozzle body 15 includes an injection hole 15a serving as a fuel injection port, an introduction passage 15b for forming a swirling flow in the injection hole with respect to the injection hole 15a, a valve seat 15c of the needle valve 16, and A through hole 15d through which the flow path variable member 17 is inserted is provided.
[0147]
Here, since the nozzle hole 15a and the introduction path 15b are the same as those described with reference to FIGS. 4 to 6 in the first embodiment, description thereof will be omitted.
[0148]
The needle valve 16 is provided in the nozzle body 15 so as to reciprocate in the axial direction. The needle valve 16 is formed of a substantially cylindrical member, and a taper that decreases in diameter toward the distal end side is provided at the distal end. And the edge part 16a is provided so that the taper angle of this taper may differ on the way. The edge portion 16a is configured to be closed by being seated on a valve seat 15c provided in the nozzle body 15. Further, the needle valve 16 is provided with a through hole 16b along the axis.
[0149]
The flow path variable member 17 is coaxially provided on the first shaft portion 17a having a small diameter inserted through the through hole 16b provided in the needle valve 16 and the distal end side of the first shaft portion 17a. The second shaft portion 17b having a diameter larger than the diameter of the first shaft portion 17a and the second shaft portion 17b are provided coaxially on the distal end side of the second shaft portion 17b and have a larger diameter than the diameter of the second shaft portion 17b. A third shaft portion 17c.
[0150]
The flow path variable member 17 has a first shaft portion 17 a that slides with respect to a through hole 16 b provided in the needle valve 16, and a third shaft portion 17 c that is formed with respect to a through hole 15 d provided in the nozzle body 15. And reciprocating while sliding.
[0151]
Thus, the flow path variable member 17 is a member having the third shaft portion 17c inscribed in the through hole 15d in which the opening portion of the injection hole 15a is provided in the inner wall surface of the nozzle body 15, and is a so-called spool. It is a member similar to a spool in a valve. However, the flow path variable member 17 in the present embodiment does not have a function of selectively opening and closing the valve.
[0152]
Here, the needle valve 16 and the flow path variable member 17 described above are configured to reciprocate in the axial direction by actuators not shown in FIGS.
[0153]
The fuel injection operation by the nozzle 10a configured as described above will be described. First, in the case of performing high diffusion spraying, as shown in FIG. 21A, the second shaft portion 17b of the flow path variable member 17 faces the nozzle hole 15a of the nozzle body 15 and the opening end face of the introduction path 15b. The flow path variable member 17 is moved to the position where the movement is performed. Thereby, the space | interval of the opening end surface of the nozzle hole 15a of the nozzle main body 15 and the introduction path 15b, and the opposing surface (a part of outer wall surface of the 2nd axial part 17b) facing this will be in a narrow state.
[0154]
When the needle valve 16 is moved and opened in this state, the fuel flowing from the valve opening portion of the needle valve 16 flows into the nozzle hole 15a through the introduction passage 15b, and therefore the main hole flows. A swirl flow is formed in 15a, and the high diffusion spray is performed as described in the first embodiment.
[0155]
In addition, when performing high diffusion spraying, the driving order of the needle valve 16 and the flow path variable member 17 is not particularly limited, and either one may be driven first, or both may be driven simultaneously. Anyway.
[0156]
On the other hand, when performing high penetration spraying, as shown in FIG. 21 (B), the first shaft portion 17a of the flow path variable member 17 is the opening of the nozzle hole 15a of the nozzle body 15 and the introduction path 15b. The flow path variable member 17 is moved to a position facing the end face. Thereby, the space | interval of the opening end surface of the nozzle hole 15a of the nozzle main body 15 and the introduction path 15b, and the opposing surface (a part of outer wall surface of the 1st axial part 17a) facing this will be in a wide state.
[0157]
When the needle valve 16 is moved and opened in this state, the fuel flowing from the valve opening portion of the needle valve 16 flows into the nozzle hole 15a without passing through the introduction passage 15b, and thus the main flow. A swirl flow is not formed in the hole 15a, and high penetration spray is performed as described in the first embodiment.
[0158]
In the case of performing high penetration spraying, it is better to drive the needle valve 16 after driving the flow path variable member 17 as described in the first embodiment.
[0159]
Further, when stopping the fuel injection, the needle valve 16 is lowered downward in the drawing and the edge portion 16a of the needle valve 16 is provided in the nozzle body 15 in both cases of high diffusion spray and high penetration spray. The valve seat 15c may be seated and closed (the state shown in FIG. 20).
[0160]
Here, in the present embodiment, the configuration in the case where the flow path variable member 17 is not provided with a valve function has been described, but it is also preferable that the flow path variable member 17 be provided with a valve function. For example, the flow path variable member 17 can also have a valve function by closing the nozzle hole 15a of the nozzle body 15 and the opening end surfaces of the introduction path 15b by the third shaft portion 17c. In this case, the flow path variable member 17 can be referred to as a spool in the spool valve, and the nozzle can be referred to as a valve having the functions of both a needle valve and a spool valve.
[0161]
Thus, if the flow path variable member 17 also has a valve function, as explained in the first embodiment, when the fuel injection is stopped, the flow path variable member 17 first closes the valve. It is possible to suppress fuel sag after fuel injection.
[0162]
【The invention's effect】
As described above, according to the present invention, it is possible to suitably switch to high penetration spray or high diffusion spray according to the engine load of the internal combustion engine. Thereby, thermal efficiency can also be improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a main part of a nozzle according to a first embodiment of the present invention (when performing high penetration spraying).
FIG. 2 is a schematic cross-sectional view showing the main part of the nozzle according to the first embodiment of the present invention (when performing high diffusion spraying).
FIG. 3 is a schematic cross-sectional view showing the main part of the nozzle according to the first embodiment of the present invention (when spraying is not performed).
FIG. 4 is a view showing a nozzle hole provided in the nozzle body according to the first embodiment of the present invention (a view of the vicinity of the nozzle hole from the upper surface of the nozzle).
FIG. 5 is a diagram (a cross-sectional view cut along the axis of the nozzle hole) showing the nozzle hole provided in the nozzle body according to the first embodiment of the present invention.
FIG. 6 is a view showing a nozzle hole provided in the nozzle body according to the first embodiment of the present invention (viewed from the upper surface side of the nozzle hole).
FIG. 7 is a block diagram of the internal combustion engine provided with the fuel injector according to the first embodiment of the present invention.
FIG. 8 is a schematic cross-sectional view (state when fuel injection is stopped) showing the main components of a fuel injector according to a second embodiment of the present invention.
FIG. 9 is a schematic cross-sectional view (state during high-diffusion spraying) showing main components of a fuel injector according to a second embodiment of the present invention.
FIG. 10 is a schematic cross-sectional view (a state of a preparation stage when performing high penetration spray) showing the main components of a fuel injector according to a second embodiment of the present invention.
FIG. 11 is a schematic cross-sectional view (state at the time of high penetration spray) showing the main components of a fuel injector according to a second embodiment of the present invention.
FIG. 12 is a schematic cross-sectional view (state when fuel injection is stopped) showing main components of a fuel injector according to a third embodiment of the present invention.
FIG. 13 is a schematic cross-sectional view (state when performing high diffusion spraying) showing the main components of a fuel injector according to a third embodiment of the present invention.
FIG. 14 is a schematic cross-sectional view (a state of a preparation stage when performing high penetration spray) showing the main components of a fuel injector according to a third embodiment of the present invention.
FIG. 15 is a schematic cross-sectional view (state at the time of high penetration spraying) showing main components of a fuel injector according to a third embodiment of the present invention.
FIG. 16 is a schematic cross-sectional view (state when fuel injection is stopped) showing main components of a fuel injector according to a fourth embodiment of the present invention.
FIG. 17 is a schematic cross-sectional view (state when performing high diffusion spraying) showing the main components of a fuel injector according to a fourth embodiment of the present invention.
FIG. 18 is a schematic cross-sectional view (a state of a preparation stage when performing high penetration spraying) showing main components of a fuel injector according to a fourth embodiment of the present invention.
FIG. 19 is a schematic cross-sectional view (state at the time of high penetration spray) showing the main components of a fuel injector according to a fourth embodiment of the present invention.
FIG. 20 is a schematic cross-sectional view (state when fuel injection is stopped) of a nozzle according to a fifth embodiment of the present invention.
FIG. 21 is a schematic cross-sectional view of a nozzle according to a fifth embodiment of the present invention ((A) is a state when performing high diffusion spraying, (B) is a state when performing high penetration spraying). .
[Explanation of symbols]
10 nozzles
10a nozzle
11 Nozzle body
11a nozzle hole
11b Introduction route
11c 1st valve seat
11d Second valve seat
12 Needle valve
12a Edge part
12b Through hole
12c plane part
13 Channel variable member
13a Shaft
13b Conical part
13c side
13d bottom
13e Flat plate part
13f Flat part
13g Convex
15 Nozzle body
15a injection hole
15b Introduction route
15c Valve seat
15d through hole
16 Needle valve
16a Edge part
16b Through hole
17 Channel variable member
17a First shaft part
17b Second shaft part
17c 3rd axis part
20 Hydraulic control mechanism
21 1st control room
22 Second control room
23 1st passage
24 Second passage
25 Float valve
25a Lift room
26 First spring
27 Second spring
28 First orifice
29 Second orifice
30 Solenoid drive mechanism
31 First coil
32 Second coil
33 Spring
40 Solenoid drive mechanism
41 First coil
42 Second coil
43 Stopper
44 First spring
45 Second spring
46 Regulatory Department
50 sensors
70 Actuator
100 Fuel injector
200 Fuel injector
300 Fuel injector

Claims (15)

A nozzle body having an injection hole and an introduction path that guides fuel in a direction to form a swirling flow in the injection hole with respect to the injection hole;
A first position having a facing surface facing the opening end surface of the nozzle hole, wherein a distance from the opening end surface to the facing surface is widened, and a flow of fuel flowing into the nozzle hole without passing through the introduction path is a main stream; A flow path variable member that is moved to a second position where the distance from the opening end surface to the facing surface is narrowed and the flow of fuel from the introduction path to the nozzle hole becomes the mainstream,
A needle valve that selectively opens and closes the inner wall surface of the nozzle body at a position upstream of the flow path portion changed by the flow path variable member. nozzle. The flow path variable member is characterized in that the opposed surface is constituted by a single surface whose distance from the opening end surface is continuously changed by movement of the flow path variable member in the axial direction. The nozzle according to 1. The flow path variable member includes a plurality of surfaces each having a different interval from the opening end surface, and a surface facing the opening end surface is switched by movement of the flow path variable member in the axial direction. The nozzle according to 1. 4. The nozzle according to claim 1, wherein the flow path variable member is moved not only to the first position and the second position but also to a third position that closes the nozzle hole and the introduction path. . A nozzle body having an injection hole and an introduction path that guides fuel in a direction to form a swirling flow in the injection hole with respect to the injection hole;
A flow path variable member that includes a facing surface that faces the opening end surface of the nozzle hole, and is provided so that a distance from the opening end surface to the facing surface can be changed;
The flow path variable member is widened from the opening end surface to the facing surface, and a first position where the flow of fuel flowing into the nozzle hole without passing through the introduction path is mainstream, and from the opening end surface to the An actuator that moves the fuel flow from the introduction path to the nozzle hole to a second position that narrows the distance to the facing surface and makes it the mainstream;
A needle valve that selectively opens and closes an inner wall surface of a nozzle body at a position upstream of a flow path portion changed by the flow path variable member. Fuel injector. The actuator moves the flow path variable member to the first position when the load of the internal combustion engine is medium to high load, and moves the flow path variable member to the second position when the load is low. The fuel injector according to claim 5. 7. The valve opening operation by the needle valve is performed after the actuator moves the flow path variable member to the first position when the load of the internal combustion engine is medium to high load. The fuel injector as described in. The nozzle body is provided with a valve seat that closes the nozzle hole and the introduction path when the flow path variable member is seated,
The fuel injector according to any one of claims 5 to 7, wherein the actuator moves the flow path variable member to a third position where the flow path variable member is seated on the valve seat. . 9. The fuel injector according to claim 8, wherein at the end of fuel injection, the actuator moves the flow path variable member to a third position, and thereafter, the valve is closed by the needle valve. The flow path variable member is characterized in that the opposed surface is constituted by a single surface whose distance from the opening end surface is continuously changed by movement of the flow path variable member in the axial direction. The fuel injector as described in any one of 5-9. The flow path variable member includes a plurality of surfaces each having a different interval from the opening end surface, and a surface facing the opening end surface is switched by movement of the flow path variable member in the axial direction. The fuel injector as described in any one of 5-9. The fuel injector according to any one of claims 5 to 11, wherein the actuator is configured by hydraulic control means that drives the flow path variable member in conjunction with the operation of the needle valve. The fuel injector according to any one of claims 5 to 11, wherein the actuator is configured by a solenoid that drives the flow path variable member independently of the operation of the needle valve. A stopper for stopping the flow path variable member that is moved by receiving a suction force by a coil provided in the solenoid;
First biasing means for biasing the flow path variable member in a direction opposite to the suction direction by the coil;
Second urging means for urging the stopper in a direction opposite to the suction direction by the coil;
A restricting member for restricting movement of the stopper urged by the second urging means in the urging direction,
The first urging force by the first urging means and the second urging force by the second urging means are:
When the first suction force by the coil is applied, the flow path variable member moves against the first urging force, but the stopper is in a position restricted by the restriction member by the second urging force. Stopped, the flow path variable member is held in the second position,
In addition, when a second suction force larger than the first suction force by the coil is applied, the flow path variable member and the stopper together with the first biasing force against the resultant force of the first biasing force and the second biasing force are in the first position. The fuel injector according to claim 13, wherein a force relationship of moving to is satisfied. An internal combustion engine comprising the fuel injector according to any one of claims 5 to 14,
Detection means for detecting engine load;
When the engine load detected by the detection means is higher than the determination reference value, the flow path variable member is moved to the first position, and when the engine load is lower than the determination reference value, the flow path variable member. Control means for drivingly controlling the actuator so as to move the actuator to the second position.

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